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Sample records for bidimensional abrangente gcxgc

  1. Partially oxidised organic components in urban aerosol using GCXGC-TOF/MS

    NASA Astrophysics Data System (ADS)

    Hamilton, J. F.; Webb, P. J.; Lewis, A. C.; Hopkins, J. R.; Smith, S.; Davy, P.

    2004-08-01

    Partially oxidised organic compounds associated with PM2.5 aerosol collected in London, England, have been analysed using direct thermal desorption coupled to comprehensive gas chromatography-time of flight mass spectrometry (GCXGC-TOF/MS). Over 10000 individual organic components were isolated from around 10µg of aerosol material in a single procedure and with no sample pre-treatment. Chemical functionalities observed using this analytical technique ranged from alkanes to poly-oxygenated species. The chemical band structures commonly used in GCXGC for group type identifications overlap for this sample type, and have required mass spectrometry as an additional level of instrument dimensionality. An investigation of oxygenated volatile organic compounds (o-VOC) contained within urban aerosol has been performed and in a typical sample around 130 o-VOCs were identified based on retention behaviour and spectral match. In excess of 100 other oxygenated species were also observed but lack of mass spectral library or pure components prevents positive identification. Many of the carbonyl species observed could be mechanistically linked to gas phase aromatic hydrocarbon oxidation and there is good agreement in terms of speciation between the urban samples analysed here and those degradation products observed in smog chamber experiments of aromatic oxidation. The presence of partially oxidised species such as linear chain aldehydes and ketones and cyclic products such as furanones suggests that species generated early in the oxidative process may undergo gas to particle partitioning despite their relatively high volatility.

  2. Kawasaki Dynamics on Bidimensional Spin Systems

    NASA Astrophysics Data System (ADS)

    Resende, Denilson C.; Cacüador, Felipe C.; Dantas, Sócrates O.

    Under the influence of an external field many systems exhibit slow relaxations processes. In that sense, we study the Physics of this behavior/process in the early stages of its evolution on bidimensional Ising systems using Monte Carlo simulations at a broad range of temperature and spins up concentration. The Monte Carlo simulations were done up to second neighbors interactions shown a more stable dynamic regime than first neighbors interactions, when the systems energy is considered. The behavior of relative energy/spin and the relative perimeter (the line between spin up and spin down regions) are monitored against Monte Carlo steps. Also, our findings show that the stretching index (a2) exhibit values below the borderline (1) in a broad range of concentration below 50% and temperature from 0.5 ≤T ≤ 4.5 (in units of J/kB , where J is the ferromagnetic constant and kB is the Boltzmann constant).

  3. Using Comprehensive Two-dimensional Gas Chromatography (GCxGC) for the Analysis of Volatile Organic Compounds (VOCs)

    NASA Astrophysics Data System (ADS)

    Lidster, R. T.; Hamilton, J. F.; Lewis, A. C.; Lee, J. D.; Hopkins, J. R.; Punjabi, S.

    2012-04-01

    Volatile organic compounds (VOC) play an important role in atmospheric chemistry through their contribution to the formation of ozone and secondary organic aerosol, both of which may lead to human health impacts. VOC monitoring and quantification has traditionally used techniques like gas chromatography and mass spectrometry, with methods developed to target specific groups of compounds. However studies have shown that in some locations the VOC loading in the atmosphere is not fully accounted for. Comprehensive two-dimensional Gas chromatography (GC-GC) utilises two columns coupled via a modulator and can give rise to significant increases in resolution and peak capacity. Used in combination with mass spectrometry it makes a powerful tool for complex sample analysis. Unfortunately GC-GC has found only limited application in atmospheric chemistry due to the instrument size, expense, power consumption and cryogen requirement. GC-GC-TOF/MS has been used to analyse Whole Air Samples (WAS) collected onboard the FAAM research aircraft as part of the "ROle of Nighttime chemistry in controlling the Oxidising Capacity of the AtmOsphere" (RONOCO) campaign. RONOCO studied the transformation of pollutants during nightime over the UK and North Sea. GCxGC results have shown good agreement with an established GC-FID instrument and the comprehensive analysis has allowed for the identification and quantification of additional species not covered by the GC-FID system. The higher molecular weight aromatic compounds detected showed a strong correlation with toluene and this has enabled the calculation of proportionally factors. The additional reactive carbon identified using GC-GC is calculated to provide a large OH sink and may account for some of the missing reactivity seen in previous studies. A number of additional NO3 sink compounds were also identified, although their impact is likely to be small due to their reactivity. Further work has also been carried out on the development

  4. Micropolar continuum modelling of bi-dimensional tetrachiral lattices

    PubMed Central

    Chen, Y.; Liu, X. N.; Hu, G. K.; Sun, Q. P.; Zheng, Q. S.

    2014-01-01

    The in-plane behaviour of tetrachiral lattices should be characterized by bi-dimensional orthotropic material owing to the existence of two orthogonal axes of rotational symmetry. Moreover, the constitutive model must also represent the chirality inherent in the lattices. To this end, a bi-dimensional orthotropic chiral micropolar model is developed based on the theory of irreducible orthogonal tensor decomposition. The obtained constitutive tensors display a hierarchy structure depending on the symmetry of the underlying microstructure. Eight additional material constants, in addition to five for the hemitropic case, are introduced to characterize the anisotropy under Z2 invariance. The developed continuum model is then applied to a tetrachiral lattice, and the material constants of the continuum model are analytically derived by a homogenization process. By comparing with numerical simulations for the discrete lattice, it is found that the proposed continuum model can correctly characterize the static and wave properties of the tetrachiral lattice. PMID:24808754

  5. Percolation and coarsening in the bidimensional voter model

    NASA Astrophysics Data System (ADS)

    Tartaglia, Alessandro; Cugliandolo, Leticia F.; Picco, Marco

    2015-10-01

    We study the bidimensional voter model on a square lattice with numerical simulations. We demonstrate that the evolution takes place in two distinct dynamic regimes; a first approach towards critical site percolation and a further approach towards full consensus. We calculate the time dependence of the two growing lengths, finding that they are both algebraic but with different exponents (apart from possible logarithmic corrections). We analyze the morphology and statistics of clusters of voters with the same opinion. We compare these results to the ones for curvature driven two-dimensional coarsening.

  6. Affective biases in English are bi-dimensional.

    PubMed

    Warriner, Amy Beth; Kuperman, Victor

    2015-01-01

    A long-standing observation about the interface between emotion and language is that positive words are used more frequently than negative ones, leading to the Pollyanna hypothesis which alleges a predominantly optimistic outlook in humans. This paper uses the largest available collection of affective ratings as well as insights from linguistics to revisit the Pollyanna hypothesis as it relates to two dimensions of emotion: valence (pleasantness) and arousal (intensity). We identified systematic patterns in the distribution of words over a bi-dimensional affective space, which (1) run counter to and supersede most prior accounts, and (2) differ drastically between word types (unique, distinct words in the lexicon) and word tokens (number of occurrences of available words in the lexicon). We argue for two factors that shape affect in language and society: a pro-social benevolent communication strategy with its emphasis on useful and dangerous phenomena, and the structure of human subjective perception of affect. PMID:25313685

  7. Heat string model of bi-dimensional dc Glidarc

    NASA Astrophysics Data System (ADS)

    Pellerin, S.; Richard, F.; Chapelle, J.; Cormier, J.-M.; Musiol, K.

    2000-10-01

    The gliding arc discharge (`Glidarc') is the subject of renewed interest in application to a variety of chemical reactions. The gliding arc creates a weakly ionized gas `string' between two horn-shaped electrodes. In this paper, we present a simple model for a bi-dimensional dc Glidarc working in air, in which the conducting zone of the discharge that is heated by the Joule effect is considered as a hot wire cooled by an air flow. Inside this wire, the heat transfer results from thermal conduction. The exchange of heat between the hot wire and the air flow is assured by convection and depends on the wire radius and the relative velocity of the arc with respect to the gas flow. The model correctly describes experimental results and allows us to predict the working parameters of the Glidarc in different experimental situations.

  8. Single Photon Avalanche Diodes: Towards the Large Bidimensional Arrays

    PubMed Central

    Privitera, Simona; Tudisco, Salvatore; Lanzanò, Luca; Musumeci, Francesco; Pluchino, Alessandro; Scordino, Agata; Campisi, Angelo; Cosentino, Luigi; Finocchiaro, Paolo; Condorelli, Giovanni; Mazzillo, Massimo; Lombardo, Salvo; Sciacca, Emilio

    2008-01-01

    Single photon detection is one of the most challenging goals of photonics. In recent years, the study of ultra-fast and/or low-intensity phenomena has received renewed attention from the academic and industrial communities. Intense research activity has been focused on bio-imaging applications, bio-luminescence, bio-scattering methods, and, more in general, on several applications requiring high speed operation and high timing resolution. In this paper we present design and characterization of bi-dimensional arrays of a next generation of single photon avalanche diodes (SPADs). Single photon sensitivity, dark noise, afterpulsing and timing resolution of the single SPAD have been examined in several experimental conditions. Moreover, the effects arising from their integration and the readout mode have also been deeply investigated.

  9. Bidimensional spectroscopy of double galaxies. I. Markarian 463.

    NASA Astrophysics Data System (ADS)

    Chatzichristou, E. T.; Vanderriest, C.

    1995-06-01

    We report on photometry and bidimensional spectroscopy of the double-nucleus galaxy Mkn 463 (E and W). The high spatial resolution and large wavelength coverage of the integral field spectrograph SILFID under sub-arcsec resolution conditions allow us to map the kinematics and ionization structure of the extended emitting gas and subsequently to identify the individual components of this complex system. Detailed spectroscopy of the nuclear regions confirms the Seyfert 2 characteristics of the E (east) component (known to be a "hidden" Seyfert 1) while placing the W (west) component on the Veilleux-Osterbrock diagrams in the region between Seyfert 2s and LINERs. The highest ionization occurs in and around the east nucleus. 3-4" to the north the line widths seem to correlate with the strength of the low ionization lines, this being suggestive of an additional ionizing mechanism operating in these regions. The N-S collimated emission originating from the E nucleus is a striking feature on the [OIII]_5007_ and Hα reconstructed images and on the V-R colour map. The relatively high ionization of the emitting gas ~14" south of the E nucleus may be due either to beamed ionizing radiation from the nucleus or to ionization by "in situ" generated continuum. The velocity maps constructed for the [OIII]_5007_, Hα and Hβ lines at the peak 80% and 50% intensity levels reveal a SE-NW velocity gradient of ~450km/s with a sharply blue-shifted region within 2" NE of the E nucleus. This velocity gradient, previously undetected, is discussed in relation with the presence of a radio component in the same region. The optical jet of the E nucleus and a very blue region westwards of the W nucleus, discovered on HST images, are detected on our direct images and the B-V colour map. We discuss some further correlations between the kinematical and physical conditions and discuss the implications of these new results for the understanding of this complex system.

  10. Effect of pressure and hydrogen flow in nucleation density and morphology of graphene bidimensional crystals

    NASA Astrophysics Data System (ADS)

    Chaitoglou, S.; Bertran, E.

    2016-07-01

    In this paper we present new results concerning the growth of graphene by low pressure chemical vapor deposition on polycrystalline copper foils and using methane as carbon precursor. We have studied the role of hydrogen and pressure in graphene growth on substrates of polycrystalline copper foil and we have examined how they affect the nucleation density and the size of graphene bidimensional crystals. For that, small ranges of pressure (between 10 and 30 Pa) and hydrogen flow (between 10 and 20 sccm) were explored. In addition, the antagonism between two of the main effects of hydrogen was studied. Hydrogen promotes the growth but, at the same time, applies an intense dry etching during the growth process of graphene. The challenge of the present study is to find the equilibrium between these two effects so that, the growth of highly ordered crystals on copper becomes possible. The results reveal that the total pressure during the growth process of graphene affects the size as well as the nucleation density of the graphene bidimensional crystals on polycrystalline copper. Besides, the hydrogen flow affects the morphology and quality of the graphene layer. An important parameter for a correct interpretation of the results is the change of the partial pressure ratio, < {P}{{{H}}2}> /< {P}{{{C}{{H}}}4}> , during the growth process under a constant flow of H2 and CH4. Dendritic graphene crystals with lobe lengths around 30 μm along with a nucleation density of 25 nuclei/10 000 μm2 were obtained in the studied technological conditions, which corroborates that a low nucleation of graphene is required to obtain large graphene islands and a low number of crystal boundaries. Raman spectroscopy and scanning electron microscopy evidenced the effects of hydrogen on the characteristics of growth and morphology of the graphene dendritic bidimensional crystals.

  11. On the illumination compensation of retinal images by means of the bidimensional empirical mode decomposition

    NASA Astrophysics Data System (ADS)

    Marrugo, Andrés. G.; Vargas, Raúl; Chirino, Melet; Millán, María. S.

    2015-12-01

    Retinal images are used for diagnostic purposes by ophthalmologists. However, despite controlled conditions in acquisition retinal images often suffer from non-uniform illumination which hinder their clinical use. In this work we propose the compensation of the illumination by modeling the intensity as a sum of non-stationary signals using bidimensional empirical mode decomposition (BEMD). We compare the estimation and compensation of the background illumination with a widely used technique based retinal image pixel classification. The proposed method has shown to provide a better estimation of the background illumination, particularly in complicated areas such as the optic disk (usually bright) and the periphery of fundus images (usually dim).

  12. Bidimensional Lens Systems : A Rational Approach To Group Displacements During Focusing And/Or Zooming

    NASA Astrophysics Data System (ADS)

    Angénieux, J. P. L.

    1987-06-01

    Modern objective lenses for cinematography, television or photography, and particularly zoom lenses, are composed of several groups of lenses which are axially displaced during zooming and/or focusing. The number of these groups has increased recently as well as the complexity of their relative movements and functions. In this paper, we give a short history of zooming and focusing techniques ; we discuss the inconvenience of traditional solutions. We then introduce the concept of bidimensional law. We propose a systematic classification of possible lens-types according to the 4 possible types of group. We finally present a few types of lenses in the form of truth tables and parametered diagrams explaining which groups move and how during focusing and/or zooming.

  13. The Bidimensional Impression Management Index (BIMI): measuring agentic and communal forms of impression management.

    PubMed

    Blasberg, Sabrina A; Rogers, Katherine H; Paulhus, Delroy L

    2014-01-01

    Measures of impression management have yet to incorporate two-factor models of person perception. The 2 primary factors are often labeled agency and communion. In Study 1, we assembled a new measure of impression management—the Bidimensional Impression Management Index (BIMI): It comprises 2 subscales designed specifically to tap agentic and communal content. Both subscales showed adequate alpha reliabilities under both honest and faking conditions. In Study 2, the BIMI was cross-validated in a new sample: The subscales remained relatively independent, and their reliabilities remained solid. A coherent pattern of personality correlates also supported the validities of both subscales. In Study 3, the differential sensitivity of the 2 subscales was demonstrated by manipulating the job type in simulated job applications. Implications and applications of the BIMI are discussed. PMID:24328818

  14. Bidimensional assemblies of nonspherical gold nanoparticles for SERS analysis of biomolecules

    NASA Astrophysics Data System (ADS)

    Matteini, Paolo; de Angelis, Marella; Ulivi, Lorenzo; Centi, Sonia; Pini, Roberto

    2015-03-01

    Direct SERS analysis of proteins has been mainly devoted to the characterization of short peptide fragments or to the prosthetic group of metallo-proteins due to their strong SERS response. Nonetheless, this perspective restricts the investigation to very limited peptide sequences and appears of scarce interest for a thorough characterization of the protein. We tried to overcome the above limitations by setting-up an effective platform for the structural SERS detection of proteins. Our proposal escapes the needs of a preliminary modification of the biomolecule and confers rapidity and reproducibility to the analysis. Optimal results are achieved by the use of nonspherical tipped metallic nanostructures with controlled architectural parameters and their assembly into organized bidimensional arrays including a regular distribution of hot spots for protein entrapment and detection. The investigation evidenced that both the contact points between nanoparticle corners and the holes at the interface between nanoparticles are responsible for substantial SERS activity.

  15. Bidimensional simulation of oil and gas generation and entrapment across Northern Viking graben (Norway), with emphasis on hydraulic regime

    SciTech Connect

    Burrus, J.; Ungerer, P.; Doligez, B.; Rabiller, P.

    1988-01-01

    A bidimensional forward numerical model was used to reconstruct the history of sedimentation, compaction, heat transfer, hydrocarbon generation, and migration along a 150-km southeast-northwest cross section in the Northern Viking graben. The model is based on the heat equation and on the diphasic Darcy's law. An empirical relationship between porosity and effective stress was used to study the pressure regime. The model takes into account hydraulic fracturing and subsequent relaxation of pressures. A kinetic model describes the generation of hydrocarbon.

  16. Controlling the dynamics of a bidimensional gel above and below its percolation transition

    NASA Astrophysics Data System (ADS)

    Orsi, D.; Ruta, B.; Chushkin, Y.; Pucci, A.; Ruggeri, G.; Baldi, G.; Rimoldi, T.; Cristofolini, L.

    2014-04-01

    The morphology and the microscopic internal dynamics of a bidimensional gel formed by spontaneous aggregation of gold nanoparticles confined at the water surface are investigated by a suite of techniques, including grazing-incidence x-ray photon correlation spectroscopy (GI-XPCS). The range of concentrations studied spans across the percolation transition for the formation of the gel. The dynamical features observed by GI-XPCS are interpreted in view of the results of microscopic imaging; an intrinsic link between the mechanical modulus and internal dynamics is demonstrated for all the concentrations. Our work presents an example of a transition from a stretched to a compressed correlation function actively controlled by quasistatically varying the relevant thermodynamic variable. Moreover, by applying a model proposed some time ago by Duri and Cipelletti [Europhys. Lett. 76, 972 (2006), 10.1209/epl/i2006-10357-4] we are able to build a master curve for the shape parameter, whose scaling factor allows us to quantify a "long-time displacement length." This characteristic length is shown to converge, as the concentration is increased, to the "short-time localization length" determined by pseudo-Debye-Waller analysis of the initial contrast. Finally, the intrinsic dynamics of the system is then compared with that induced by means of a delicate mechanical perturbation applied to the interface.

  17. Image denoising in bidimensional empirical mode decomposition domain: the role of Student's probability distribution function.

    PubMed

    Lahmiri, Salim

    2016-03-01

    Hybridisation of the bi-dimensional empirical mode decomposition (BEMD) with denoising techniques has been proposed in the literature as an effective approach for image denoising. In this Letter, the Student's probability density function is introduced in the computation of the mean envelope of the data during the BEMD sifting process to make it robust to values that are far from the mean. The resulting BEMD is denoted tBEMD. In order to show the effectiveness of the tBEMD, several image denoising techniques in tBEMD domain are employed; namely, fourth order partial differential equation (PDE), linear complex diffusion process (LCDP), non-linear complex diffusion process (NLCDP), and the discrete wavelet transform (DWT). Two biomedical images and a standard digital image were considered for experiments. The original images were corrupted with additive Gaussian noise with three different levels. Based on peak-signal-to-noise ratio, the experimental results show that PDE, LCDP, NLCDP, and DWT all perform better in the tBEMD than in the classical BEMD domain. It is also found that tBEMD is faster than classical BEMD when the noise level is low. When it is high, the computational cost in terms of processing time is similar. The effectiveness of the presented approach makes it promising for clinical applications. PMID:27222723

  18. Testing the bi-dimensional effects of attitudes on behavioural intentions and subsequent behaviour.

    PubMed

    Elliott, Mark A; Brewster, Sarah E; Thomson, James A; Malcolm, Carly; Rasmussen, Susan

    2015-11-01

    Attitudes are typically treated as unidimensional predictors of both behavioural intentions and subsequent behaviour. On the basis of previous research showing that attitudes comprise two independent, positive and negative dimensions, we hypothesized that attitudes would be bi-dimensional predictors of both behavioural intentions and subsequent behaviour. We focused on health-risk behaviours. We therefore also hypothesized that the positive dimension of attitude (evaluations of positive behavioural outcomes) would better predict both behavioural intentions and subsequent behaviour than would the negative dimension, consistent with the positivity bias/offset principle. In Study 1 (cross sectional design), N = 109 university students completed questionnaire measures of their intentions to binge-drink and the positive and negative dimensions of attitude. Consistent with the hypotheses, both attitude dimensions independently predicted behavioural intentions and the positive dimension was a significantly better predictor than was the negative dimension. The same pattern of findings emerged in Study 2 (cross sectional design; N = 186 university students) when we predicted intentions to binge-drink, smoke and consume a high-fat diet. Similarly, in Study 3 (prospective design; N = 1,232 speed limit offenders), both the positive and negative dimensions of attitude predicted subsequent (6-month post-baseline) speeding behaviour on two different road types and the positive dimension was the better predictor. The implications for understanding the motivation of behaviour and the development of behaviour-change interventions are discussed. PMID:25440892

  19. Bidimensional intercalation of Ge between SiC(0001) and a heteroepitaxial graphite top layer

    SciTech Connect

    Kubler, L.; Dentel, D.; Bischoff, J.-L.; Derivaz, M.; Aiet-Mansour, K.; Diani, M.

    2005-09-15

    High temperature annealing of 4H- or 6H-SiC(0001) crystals is well known to desorb Si from the surface and to generate a C-rich (6{radical}3x6{radical}3)R30 deg. (6{radical}3) reconstruction explained as a graphite monolayer in heteroepitaxial registry with the substrate. Ge deposition at room temperature and in the monolayer range on this graphitized reconstruction results in Ge islands. Using a number of surface techniques, we follow subsequent Ge morphology evolutions as a function of isochronal post-annealing treatments at increasing temperatures. In a particular temperature window Ge reacts with the substrate by diffusion under the graphite planes and wets the Si-terminated SiC surface. In spite of this bidimensional insertion of a Ge layer, the epitaxial relationship between the SiC substrate and the graphite is maintained as shown by very clear graphite-(1x1) LEED or RHEED patterns. They denote extended and well-ordered graphite planes at the surface of a graphite/Ge/SiC heterostructure. XPS analyses reveal a complete passivation of the intercalated Ge layer against oxidation by the overlying graphite sheets. Moreover, drastic spectroscopic changes on the bulk-SiC Si 2p and C 1s core levels are observed, depending on whether graphite(6{radical}3)/SiC or graphite(1x1)/Ge/SiC terminations are analyzed. In the latter case, the observed core level splitting of the bulk components is interpreted by a significant upward band bending ({approx}1.2 eV) of the n-doped SiC, making this second interface to act as a Schottky barrier. Above 1300 deg. C, a delayed Ge desorption takes place that allows the graphite sheets to re-form in their initial 6{radical}3 form, i.e., without Ge and with flatter bands.

  20. Automated screening system for retinal health using bi-dimensional empirical mode decomposition and integrated index.

    PubMed

    Acharya, U Rajendra; Mookiah, Muthu Rama Krishnan; Koh, Joel E W; Tan, Jen Hong; Bhandary, Sulatha V; Rao, A Krishna; Fujita, Hamido; Hagiwara, Yuki; Chua, Chua Kuang; Laude, Augustinus

    2016-08-01

    Posterior Segment Eye Diseases (PSED) namely Diabetic Retinopathy (DR), glaucoma and Age-related Macular Degeneration (AMD) are the prime causes of vision loss globally. Vision loss can be prevented, if these diseases are detected at an early stage. Structural abnormalities such as changes in cup-to-disc ratio, Hard Exudates (HE), drusen, Microaneurysms (MA), Cotton Wool Spots (CWS), Haemorrhages (HA), Geographic Atrophy (GA) and Choroidal Neovascularization (CNV) in PSED can be identified by manual examination of fundus images by clinicians. However, manual screening is labour-intensive, tiresome and time consuming. Hence, there is a need to automate the eye screening. In this work Bi-dimensional Empirical Mode Decomposition (BEMD) technique is used to decompose fundus images into 2D Intrinsic Mode Functions (IMFs) to capture variations in the pixels due to morphological changes. Further, various entropy namely Renyi, Fuzzy, Shannon, Vajda, Kapur and Yager and energy features are extracted from IMFs. These extracted features are ranked using Chernoff Bound and Bhattacharyya Distance (CBBD), Kullback-Leibler Divergence (KLD), Fuzzy-minimum Redundancy Maximum Relevance (FmRMR), Wilcoxon, Receiver Operating Characteristics Curve (ROC) and t-test methods. Further, these ranked features are fed to Support Vector Machine (SVM) classifier to classify normal and abnormal (DR, AMD and glaucoma) classes. The performance of the proposed eye screening system is evaluated using 800 (Normal=400 and Abnormal=400) digital fundus images and 10-fold cross validation method. Our proposed system automatically identifies normal and abnormal classes with an average accuracy of 88.63%, sensitivity of 86.25% and specificity of 91% using 17 optimal features ranked using CBBD and SVM-Radial Basis Function (RBF) classifier. Moreover, a novel Retinal Risk Index (RRI) is developed using two significant features to distinguish two classes using single number. Such a system helps to reduce eye

  1. A bi-dimensional genome scan for prolificacy traits in pigs shows the existence of multiple epistatic QTL

    PubMed Central

    2009-01-01

    Background Prolificacy is the most important trait influencing the reproductive efficiency of pig production systems. The low heritability and sex-limited expression of prolificacy have hindered to some extent the improvement of this trait through artificial selection. Moreover, the relative contributions of additive, dominant and epistatic QTL to the genetic variance of pig prolificacy remain to be defined. In this work, we have undertaken this issue by performing one-dimensional and bi-dimensional genome scans for number of piglets born alive (NBA) and total number of piglets born (TNB) in a three generation Iberian by Meishan F2 intercross. Results The one-dimensional genome scan for NBA and TNB revealed the existence of two genome-wide highly significant QTL located on SSC13 (P < 0.001) and SSC17 (P < 0.01) with effects on both traits. This relative paucity of significant results contrasted very strongly with the wide array of highly significant epistatic QTL that emerged in the bi-dimensional genome-wide scan analysis. As much as 18 epistatic QTL were found for NBA (four at P < 0.01 and five at P < 0.05) and TNB (three at P < 0.01 and six at P < 0.05), respectively. These epistatic QTL were distributed in multiple genomic regions, which covered 13 of the 18 pig autosomes, and they had small individual effects that ranged between 3 to 4% of the phenotypic variance. Different patterns of interactions (a × a, a × d, d × a and d × d) were found amongst the epistatic QTL pairs identified in the current work. Conclusions The complex inheritance of prolificacy traits in pigs has been evidenced by identifying multiple additive (SSC13 and SSC17), dominant and epistatic QTL in an Iberian × Meishan F2 intercross. Our results demonstrate that a significant fraction of the phenotypic variance of swine prolificacy traits can be attributed to first-order gene-by-gene interactions emphasizing that the phenotypic effects of alleles might be strongly modulated by the

  2. Initial adaptation testing of the bidimensionally self-adapting wall of the French T2 wind tunnel, around a three-dimensional object

    NASA Technical Reports Server (NTRS)

    Archambaud, J. P.; Dor, J. B.; Mignosi, A.; Lamarche, L.

    1986-01-01

    The test series was carried out at ONERA/CERT at the T2 wind tunnel in September 1984. The objective of this series was to minimize wall interference through a bidimensional adaptation around the models, inducing tridimensional flows. For this, three different models were used, measuring either the pressures or the forces and moment of pitch (balance). The adaptation was derived from a correction computation in the compressible axisymmetric tridimensional.

  3. On the bi-dimensional variational decomposition applied to nonstationary vibration signals for rolling bearing crack detection in coal cutters

    NASA Astrophysics Data System (ADS)

    Jiang, Yu; Li, Zhixiong; Zhang, Chao; Hu, Chao; Peng, Z.

    2016-06-01

    This work aims to detect rolling bearing cracks using a variational approach. An original method that appropriately incorporates bi-dimensional variational mode decomposition (BVMD) into discriminant diffusion maps (DDM) is proposed to analyze the nonstationary vibration signals recorded from the cracked rolling bearings in coal cutters. The advantage of this variational decomposition based diffusion map (VDDM) method in comparison to the current DDM is that the intrinsic vibration mode of the crack can be filtered into a limited bandwidth in the frequency domain with an estimated central frequency, thus discarding the interference signal components in the vibration signals and significantly improving the crack detection performance. In addition, the VDDM is able to simultaneously process two-channel sensor signals to reduce information leakage. Experimental validation using rolling bearing crack vibration signals demonstrates that the VDDM separated the raw signals into four intrinsic modes, including one roller vibration mode, one roller cage vibration mode, one inner race vibration mode, and one outer race vibration mode. Hence, reliable fault features were extracted from the outer race vibration mode, and satisfactory crack identification performance was achieved. The comparison between the proposed VDDM and existing approaches indicated that the VDDM method was more efficient and reliable for crack detection in coal cutter rolling bearings. As an effective catalyst for rolling bearing crack detection, this newly proposed method is useful for practical applications.

  4. Nonpreemptive run-time scheduling issues on a multitasked, multiprogrammed multiprocessor with dependencies, bidimensional tasks, folding and dynamic graphs

    SciTech Connect

    Miller, Allan Ray

    1987-05-01

    Increases in high speed hardware have mandated studies in software techniques to exploit the parallel capabilities. This thesis examines the effects a run-time scheduler has on a multiprocessor. The model consists of directed, acyclic graphs, generated from serial FORTRAN benchmark programs by the parallel compiler Parafrase. A multitasked, multiprogrammed environment is created. Dependencies are generated by the compiler. Tasks are bidimensional, i.e., they may specify both time and processor requests. Processor requests may be folded into execution time by the scheduler. The graphs may arrive at arbitrary time intervals. The general case is NP-hard, thus, a variety of heuristics are examined by a simulator. Multiprogramming demonstrates a greater need for a run-time scheduler than does monoprogramming for a variety of reasons, e.g., greater stress on the processors, a larger number of independent control paths, more variety in the task parameters, etc. The dynamic critical path series of algorithms perform well. Dynamic critical volume did not add much. Unfortunately, dynamic critical path maximizes turnaround time as well as throughput. Two schedulers are presented which balance throughput and turnaround time. The first requires classification of jobs by type; the second requires selection of a ratio value which is dependent upon system parameters. 45 refs., 19 figs., 20 tabs.

  5. A bi-dimensional index for the selective assessment of myoelectric manifestations of peripheral and central muscle fatigue.

    PubMed

    Mesin, Luca; Cescon, Corrado; Gazzoni, Marco; Merletti, Roberto; Rainoldi, Alberto

    2009-10-01

    Two physiological factors are assumed in this paper to mainly determine the myoelectric manifestations of fatigue: (1) the decrease of the conduction velocity (CV) of motor unit action potentials (MUAP) (peripheral fatigue), and (2) the increase of MU synchronization by the central nervous system (central fatigue). To describe separately the peripheral and central components of the myoelectric manifestations of fatigue, we investigated the following indexes: (1) mean spectral frequency - MNF, (2) median spectral frequency - MDF, (3) root mean square - RMS, (4) average rectified value - ARV, (5) estimation of muscle fiber conduction velocity - ECV, (6) percentage of determinism - %DET, (7) spectral indexes defined as the ratio between signal spectral moments - FI(k), (8) MNF estimated by autoregressive analysis - MNF(AR), (9) MNF estimated by Choi-Williams time-frequency representation - MNF(CWD), (10) MNF estimated by continuous wavelet transform - MNF(CWT), (11) signal entropy - S, (12) fractal dimension - FD. The indexes were tested with a set of synthetic EMG signals, with different CV distribution and level of MU synchronization. The indexes were calculated on epochs of 0.5s. It was observed that ECV is uncorrelated with the level of simulated synchronization (promising index of peripheral fatigue). On the other hand FD was the index least affected by CV changes and most related to the level of synchronism (promising index of central fatigue). A representative application to some experimental signals from vastus lateralis muscle during an isometric endurance test supported the results of the simulations. The vector (ECV, FD) is suggested to provide selective indications of peripheral and central fatigue. The description of EMG fatigue by a bi-dimensional vector opens new perspectives in the assessment of muscle properties, with potential application in both clinical and sport sciences. PMID:18824375

  6. Simulating the interaction of the heliosphere with the local interstellar medium: MHD results from a finite volume approach, first bidimensional results

    NASA Technical Reports Server (NTRS)

    Chanteur, G.; Khanfir, R.

    1995-01-01

    We have designed a full compressible MHD code working on unstructured meshes in order to be able to compute accurately sharp structures embedded in large scale simulations. The code is based on a finite volume method making use of a kinetic flux splitting. A bidimensional version of the code has been used to simulate the interaction of a moving interstellar medium, magnetized or unmagnetized with a rotating and magnetized heliopspheric plasma source. Being aware that these computations are not realistic due to the restriction to two dimensions, we present it to demonstrate the ability of this new code to handle this problem. An axisymetric version, now under development, will be operational in a few months. Ultimately we plan to run a full 3d version.

  7. Thermal image enhancement using bi-dimensional empirical mode decomposition in combination with relevance vector machine for rotating machinery fault diagnosis

    NASA Astrophysics Data System (ADS)

    Tran, Van Tung; Yang, Bo-Suk; Gu, Fengshou; Ball, Andrew

    2013-07-01

    In this study, a novel fault diagnosis system for rotating machinery using thermal imaging is proposed. This system consists of bi-dimensional empirical mode decomposition (BEMD) for image enhancement, a generalized discriminant analysis (GDA) for feature reduction, and a relevance vector machine (RVM) for fault classification. Firstly, the thermal image obtained from machine conditions is decomposed into intrinsic mode functions (IMFs) by using BEMD. At each decomposed level, the IMF is expanded and fused with the residue by gray-scale transformation and principal component analysis fusion technique, respectively. The enhanced image is then formed by the improved IMFs in reconstruction process. Subsequently, feature extraction is applied for the enhanced images to obtain histogram features which characterize the thermal image and contain useful information for diagnosis. The high dimensionality of the achieved feature set can be reduced by GDA implementation. Moreover, GDA also assists in the increase of the feature cluster separation. Finally, the diagnostic results are performed by RVM. The proposed system is applied and validated with the thermal images of a fault simulator. A comparative study of the classification results obtained from RVM, support vector machines, and adaptive neuro-fuzzy inference system is also performed to appraise the accuracy of these models. The results show that the proposed diagnosis system is capable of improving the classification accuracy and efficiently assisting in rotating machinery fault diagnosis.

  8. Lie algebraic approach to the time-dependent quantum general harmonic oscillator and the bi-dimensional charged particle in time-dependent electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Ibarra-Sierra, V. G.; Sandoval-Santana, J. C.; Cardoso, J. L.; Kunold, A.

    2015-11-01

    We discuss the one-dimensional, time-dependent general quadratic Hamiltonian and the bi-dimensional charged particle in time-dependent electromagnetic fields through the Lie algebraic approach. Such method consists in finding a set of generators that form a closed Lie algebra in terms of which it is possible to express a quantum Hamiltonian and therefore the evolution operator. The evolution operator is then the starting point to obtain the propagator as well as the explicit form of the Heisenberg picture position and momentum operators. First, the set of generators forming a closed Lie algebra is identified for the general quadratic Hamiltonian. This algebra is later extended to study the Hamiltonian of a charged particle in electromagnetic fields exploiting the similarities between the terms of these two Hamiltonians. These results are applied to the solution of five different examples: the linear potential which is used to introduce the Lie algebraic method, a radio frequency ion trap, a Kanai-Caldirola-like forced harmonic oscillator, a charged particle in a time dependent magnetic field, and a charged particle in constant magnetic field and oscillating electric field. In particular we present exact analytical expressions that are fitting for the study of a rotating quadrupole field ion trap and magneto-transport in two-dimensional semiconductor heterostructures illuminated by microwave radiation. In these examples we show that this powerful method is suitable to treat quadratic Hamiltonians with time dependent coefficients quite efficiently yielding closed analytical expressions for the propagator and the Heisenberg picture position and momentum operators.

  9. Bidimensional Particle-In-Cell simulations for laser-driven proton acceleration using ultra-short, ultra-high contrast laser

    SciTech Connect

    Scisciò, M.; Palumbo, L.; D'Humières, E.; Fourmaux, S.; Kieffer, J. C.; Antici, P.

    2014-12-15

    In this paper, we report on bi-dimensional Particle-In-Cell simulations performed in order to reproduce the laser-driven proton acceleration obtained when a commercial 200 TW Ti:Sa Laser hits a solid target. The laser-to prepulse contrast was enhanced using plasma mirrors yielding to a main-to-prepulse contrast of ∼10{sup 12}. We varied the pulse duration from 30 fs to 500 fs and the target thickness from 30 nm to several tens of μm. The on-target laser energy was up to 1.8 J leading to an intensity in excess of 10{sup 20 }W cm{sup −2}. A comparison between numerical and existing experimental data [S. Fourmaux et al., Phys. Plasmas 20, 013110 (2013)] is performed, showing a good agreement between experimental results and simulations which confirms that for ultra-thin targets there is an optimum expansion regime. This regime depends on the target thickness and on the laser intensity: if the target is too expanded, the laser travels through the target without being able to deposit its energy within the target. If the target is not sufficiently expanded, the laser energy is reflected by the target. It is important to note that maximum proton energies are reached at longer pulse durations (in the 100 fs regime) than what is currently the best compression pulse length for this type of lasers (typically 20–30 fs). This duration, around 50–100 fs, can be considered a minimum energy transfer time between hot electrons to ions during the considered acceleration process.

  10. Blood flow volume of uterine arteries in human pregnancies determined using 3D and bi-dimensional imaging, angio-Doppler, and fluid-dynamic modeling.

    PubMed

    Rigano, S; Ferrazzi, E; Boito, S; Pennati, G; Padoan, A; Galan, H

    2010-01-01

    The primary aim of this pilot study was to study uterine artery (UtA) blood flow volume in uneventful human pregnancies delivered at term, at mid and late gestation by means of 3D and bi-dimensional ultrasound imaging with angio-Doppler combined with fluid-dynamic modeling. Secondary aims were to correlate flow volume to placental site and to UtA Pulsatility Index (PI). Women with singleton, low-risk pregnancies were examined at mid and late gestation. The structure and course of the uterine artery (UtA) was studied in each patient by means of 3D-angio-Doppler and included vessel diameter D, blood flow velocity and PI (measured along the UtA). Fetal weight estimation and placental insertion site were assessed by ultrasound. A robust fluid-dynamic modeling was applied to calculate absolute flow and flow per unit fetal weight. Mean UtA diameter and blood flow velocity increased significantly (p < 0.0001) from mid-gestation to late gestation from 2.6 mm and 67.5 cm/s, to 3.0 mm and 85.3 cm/s, respectively, yielding an increasing absolute flow troughout gestation. h coefficient, derived by fluid-dynamic modeling to calculate mean velocity, increased significantly from 0.52 at mid-gestation to 0.57 at late gestation. UtA blood flow volume ml/min/kg-fetal weight was significantly higher at mid-gestation than at late gestation (535 ml/min/kg vs 193 ml/min/kg; p < 0.0001). In cases with strictly lateral placentas the ipsilateral UtA accommodates at mid and late gestation 63% and 67% of the total UtA flow. In central placentas UtA flow was evenly distributed between the two vessels. An inverse correlation was observed between PI and blood flow volume ml/min/kg (Pearson's coefficient r = -0.54). Our work confirms the technological and methodological limitations in the measurement of uterine artery blood flow. However, Doppler measurements supported by three-dimensional angio imaging of the uterine vessel, high resolution imaging and diameter measurement, and a robust

  11. Combined effect of tobacco smoking and alcohol drinking in the risk of head and neck cancers: a re-analysis of case-control studies using bi-dimensional spline models.

    PubMed

    Dal Maso, Luigino; Torelli, Nicola; Biancotto, Elisa; Di Maso, Matteo; Gini, Andrea; Franchin, Gianni; Levi, Fabio; La Vecchia, Carlo; Serraino, Diego; Polesel, Jerry

    2016-04-01

    The synergistic effect of tobacco smoking and alcohol consumption on the risk of head and neck cancers has been mainly investigated as a cross-product of categorical exposure, thus leading to loss of information. We propose a bi-dimensional logistic spline model to investigate the interacting dose-response relationship of two continuous exposures (i.e., ethanol intake and tobacco smoking) on the risk of head and neck cancers, representing results through three-dimensional graphs. This model was applied to a pool of hospital-based case-control studies on head and neck cancers conducted in Italy and in the Vaud Swiss Canton between 1982 and 2000, including 1569 cases and 3147 controls. Among never drinkers and for all levels of ethanol intake, the risk of head and neck cancers steeply increased with increasing smoking intensity, starting from 1 cigarette/day. The risk associated to ethanol intake increased with incrementing exposure among smokers, and a threshold effect at approximately 50 g/day emerged among never smokers. Compared to abstainers from both tobacco and alcohol consumption, the combined exposure to ethanol and/or cigarettes led to a steep increase of cancer risk up to a 35-fold higher risk (95 % confidence interval 27.30-43.61) among people consuming 84 g/day of ethanol and 10 cigarettes/day. The highest risk was observed at the highest levels of alcohol and tobacco consumption. Our findings confirmed a combined effect of tobacco smoking and alcohol drinking on head and neck cancers risk, providing evidence that bi-dimensional spline models could be a feasible and flexible method to explore the pattern of risks associated to two interacting continuous-exposure variables. PMID:25855002

  12. A simple controller for bidimensional image detectors

    NASA Astrophysics Data System (ADS)

    Angeles, F.; Martínez, L. A.

    2012-07-01

    The increasing use of many and different kind of light detectors to acquire, monitor and control various aspects of the observation imposes the need to standardize the acquisition and processing of images and data. While scientific image acquisition systems usually include a complex controller, some less demanding subsystems require the development of electronics and software to read the image. Most of the times these image detectors are rather small and high speed is of no concern, so controllers need not to be fast; take for instance a telescope guider. With these directives in mind, in this work we present a very simple image acquisition system based on a Texas Instruments microcontroller of the family MSP430 and a serial static memory as a standard instrumentation starting for small image acquisition controllers.

  13. Bidimensional silicon dosimeter: Development and characterization

    NASA Astrophysics Data System (ADS)

    Talamonti, C.; Bruzzi, M.; Marrazzo, L.; Menichelli, D.; Scaringella, M.; Bucciolini, M.

    2011-12-01

    Clinical dosimetry in radiotherapy is a well known matter but high conformal radiotherapy modalities (Intensity Modulated Radiation Therapy (IMRT), stereotactic treatments with photons and protons, Intensity Modulated Proton Therapy (IMPT)) possess problems due to small radiation fields with high dose gradients, variation in space and time of the dose rate and variation in space and time of the beam energy spectrum. A modular dosimetric detector, adequate for 2D pre-treatment dose verifications, has been developed in the framework of the European Integrated project MAESTRO. The detector is a monolithic segmented sensor obtained by n-type implantation on a 50 μthick epitaxial silicon p-type layer; this is later used to guarantee improved radiation hardness of the device against the accumulated dose. The detector is composed of a matrix of 21×21 pixels with a size of 2×2 mm 2 each and a 3 mm center-to-center distance. A full dosimetric characterization of the detector was performed with photon and proton beams and with gammas from a 60Co unit. Results have been compared with those obtained with a Farmer and a CC13 Scanditronix/Welhoffer ion chamber as well as with the silicon matrix MapCHECK™. The first application of the MAESTRO prototype in the dosimetric verification of a clinical IMRT field is also reported. Results show that our modular detector represents a valuable tool for quality assurance in IMRT dose delivery and for high precision radiotherapy techniques.

  14. Ab initio simulations of pseudomorphic silicene and germanene bidimensional heterostructures

    NASA Astrophysics Data System (ADS)

    Debernardi, Alberto; Marchetti, Luigi

    2016-06-01

    Among the novel two-dimensional (2D) materials, silicene and germanene, which are two honeycomb crystal structures composed of a monolayer of Si and Ge, respectively, have attracted the attention of material scientists because they combine the advantages of the new 2D ultimate-scaled electronics with their compatibility with industrial processes presently based on Si and Ge. We envisage pseudomorphic lateral heterostructures based on ribbons of silicene and germanene, which are the 2D analogs of conventional 3D Si/Ge superlattices and quantum wells. In spite of the considerable lattice mismatch (˜4 % ) between free-standing silicene and germanene, our ab initio simulations predict that, considering striped 2D lateral heterostructures made by alternating silicene and germanene ribbons of constant width, the silicene/germanene junction remains pseudomorphic—i.e., it maintains lattice-matched edges—up to critical ribbon widths that can reach some tens of nanometers. Such critical widths are one order of magnitude larger than the critical thickness measured in 3D pseudomorphic Si/Ge heterostructures and the resolution of state-of-the-art lithography, thus enabling the possibility of lithography patterned silicene/germanene junctions. We computed how the strain produced by the pseudomorphic growth modifies the crystal structure and electronic bands of the ribbons, providing a mechanism for band-structure engineering. Our results pave the way for lithography patterned lateral heterostructures that can serve as the building blocks of novel 2D electronics.

  15. Wideband image demodulation via bi-dimensional multirate frequency transformations.

    PubMed

    Liu, Wenjing; Santhanam, Balu

    2016-09-01

    Existing image demodulation approaches based on the two-dimensional (2D) multicomponent AM-FM model assume narrowband components that can be demodulated using energy operators, Hilbert transforms, or the monogenic image approaches. However, if the FM components are wideband, then these demodulation approaches incur significant errors. Recent work by the authors extended wideband FM demodulation in one dimension to accommodate large conversion factors using multirate frequency transformations. In this paper, we extend the multirate frequency transformations technique developed for one-dimensional signals to 2D and images in conjunction with a recently proposed 2D higher-order energy demodulation approach. This extension is applied to both synthetic and real images to demonstrate the efficacy of the approach. PMID:27607487

  16. Nonlinear bidimensional evolution of ion beam driven electrostatic instabilities in the auroral region

    NASA Astrophysics Data System (ADS)

    Mottez, Fabrice; Chanteur, Gerard

    1991-12-01

    A 2D (in configuration space), 3D (in velocity space) electrostatic explicit particle code is used to investigate the interaction between an ion beam flowing along the magnetic field and a highly magnetized plasma. The beam drift velocity Vdi is larger than Vte, the electron thermal velocity, and much larger than the thermal velocities of the core and beam ions. Two instabilities are found to develop. First, the interaction between the ion beam and electrons leads to the rapid growth of parallel modes and to the fast diffusion of electrons along the magnetic field, predominantly in the ion beam direction. This ion-electron instability is rapidly quenched by electron heating. Second, and ion-ion instability develops, which involves oblique modes leading to a selective heating of ions in a direction oblique to B. It is shown that the heating via the electron-ion instability is a necessary step for the development of the ion-ion instability. Finally, it is shown that the nonlinear development of the ion-ion instability gives rise to purely perpendicular modes that are not linearly unstable.

  17. Applying fuzzy bi-dimensional scenario-based model to the assessment of Mars mission architecture scenarios

    NASA Astrophysics Data System (ADS)

    Tavana, Madjid; Zandi, Faramak

    2012-02-01

    Sending man to Mars has been a long-held dream of humankind. NASA plans human planetary explorations using approaches that are technically feasible, have reasonable risks and have relatively low costs. This study presents a novel Multi-Attribute Decision Making (MADM) model for evaluating a range of potential mission scenarios for the human exploration of Mars. The three alternatives identified by the Mission Operations Directorate (MOD) at the Johnson Space Center (JSC) include split mission, combo lander and dual scenarios. The proposed framework subsumes the following key methods: first, the conjunction method is used to minimize the number of alternative mission scenarios; second, the Fuzzy Risk Failure Mode and Effects Analysis (RFMEA) is used to analyze the potential failure of the alternative scenarios; third, the fuzzy group Real Option Analysis (ROA) is used to estimate the expected costs and benefits of the alternative scenarios; and fourth, the fuzzy group permutation approach is used to select the optimal mission scenario. We present the results of a case study at NASA's Johnson Space center to demonstrate: (1) the complexity of mission scenario selection involving subjective and objective judgments provided by multiple space exploration experts; and (2) a systematic and structured method for aggregating quantitative and qualitative data concerning a large number of competing and conflicting mission events.

  18. In situ growth and coalescence of He-filled bi-dimensional defects in Si by H supply

    SciTech Connect

    Vallet, M.; Barbot, J. F. Beaufort, M. F.; Oliviero, E.; Donnelly, S. E.; Hinks, J. A.

    2014-06-14

    In this work, ion implantations with in situ transmission electron microscopy observations followed by different rates of temperature ramp were performed in (001)-Si to follow the evolution of He-plates under the influence of hydrogen. The JANNUS and MIAMI facilities were used to study the first stages of growth as well as the interactions between co-planar plates. Results showed that under a limited amount of H, the growth of He-plates resulting from a subcritical stress-corrosion mechanism can be fully described by the kinetic model of Johnson-Mehl-Avrami-Kolmogorov with effective activation energy of 0.9 eV. Elastic calculations showed that the sudden and non-isotropic coalescence of close He-plates occurs when the out-of-plane tensile stress between them is close to the yield strength of silicon. After hydrogen absorption, surface minimization of final structure occurs.

  19. In situ growth and coalescence of He-filled bi-dimensional defects in Si by H supply

    NASA Astrophysics Data System (ADS)

    Vallet, M.; Barbot, J. F.; Oliviero, E.; Donnelly, S. E.; Hinks, J. A.; Beaufort, M. F.

    2014-06-01

    In this work, ion implantations with in situ transmission electron microscopy observations followed by different rates of temperature ramp were performed in (001)-Si to follow the evolution of He-plates under the influence of hydrogen. The JANNUS and MIAMI facilities were used to study the first stages of growth as well as the interactions between co-planar plates. Results showed that under a limited amount of H, the growth of He-plates resulting from a subcritical stress-corrosion mechanism can be fully described by the kinetic model of Johnson-Mehl-Avrami-Kolmogorov with effective activation energy of 0.9 eV. Elastic calculations showed that the sudden and non-isotropic coalescence of close He-plates occurs when the out-of-plane tensile stress between them is close to the yield strength of silicon. After hydrogen absorption, surface minimization of final structure occurs.

  20. Development of an offline bidimensional high-performance liquid chromatography method for analysis of stereospecific triacylglycerols in cocoa butter equivalents.

    PubMed

    Kadivar, Sheida; De Clercq, Nathalie; Nusantoro, Bangun Prajanto; Le, Thien Trung; Dewettinck, Koen

    2013-08-21

    Acyl migration is a serious problem in enzymatic modification of fats and oils, particularly in production of cocoa butter equivalent (CBE) through enzymatic acidolysis reaction, which leads to the formation of non-symmetrical triacylglycerols (TAGs) from symmetrical TAGs. Non-symmetrical TAGs may affect the physical properties of final products and are therefore often undesired. Consequently, an accurate method is needed to determine positional isomer TAGs during the production of CBE. A bidimentional high-performance liquid chromatography (HPLC) method with combination of non-aqueous reversed-phase HPLC and silver ion HPLC joining with an evaporative light scattering detector was successfully developed for the analysis of stereospecific TAGs. The best separation of positional isomer standards was obtained with a heptane/acetone mobile-phase gradient at 25 °C and 1 mL/min. The developed method was then used in multidimensional determination of the TAG positional isomers in fat and oil blends and successfully identified the TAGs and possible isomers in enzymatically acidolyzed CBE. PMID:23931630

  1. A Basic Positron Emission Tomography System Constructed to Locate a Radioactive Source in a Bi-dimensional Space.

    PubMed

    Montaño-Zetina, Luis Manuel; Villalobos-Mora, Omar

    2016-01-01

    A simple Positron Emission Tomography (PET) prototype has been constructed to fully characterize its basic working principles. The PET prototype was created by coupling plastic scintillator crystals to photomultipliers or PMT's which are placed at opposing positions to detect two gamma rays emitted from a radioactive source, of which is placed in the geometric center of the PET set-up. The prototype consists of four detectors placed geometrically in a 20 cm diameter circle, and a radioactive source in the center. By moving the radioactive source centimeters from the center the system one is able to detect the displacement by measuring the time of flight difference between any two PMT's and, with this information, the system can calculate the virtual position in a graphical interface. In this way, the prototype reproduces the main principles of a PET system. It is capable to determine the real position of the source with intervals of 4 cm in 2 lines of detection taking less than 2 min. PMID:26863081

  2. A comprehensive two-dimensional gas chromatography method for analyzing extractable petroleum hydrocarbons in water and soil.

    PubMed

    Seeley, Stacy K; Bandurski, Steven V; Brown, Robert G; McCurry, James D; Seeley, John V

    2007-01-01

    A flow-switching two-dimensional gas chromatography (GCxGC) apparatus has been constructed that can operate at temperatures as high as 340 degrees C. This system is employed to analyze complex hydrocarbon mixtures such as diesel fuel, gas-oil, motor oil, and petroleum contaminated environmental samples. The GCxGC system generates two-dimensional chromatograms with minimal overlap between the aliphatic and aromatic regions This allows these compound classes to be independently quantitated without prior fractionation. The GCxGC system is used to analyze extracts of spiked water samples, wastewater, and soil. The accuracy of the method is compared to that of the Massachusetts Extractable Petroleum Hydrocarbons (MA EPH) method. The GCxGC system generates a quantitative accuracy similar to the MA EPH method for the analysis of spiked water samples. The GCxGC method and the MA EPH method generate comparable levels of total hydrocarbons when wastewater is analyzed, but the GCxGC method detects a significantly higher aromatic content and lower aliphatic content. Both the GCxGC method and MA EPH method measure comparable levels of aromatics in the soil samples. PMID:18078573

  3. Chemical warfare agent detection in complex environments with comprehensive two-dimensional gas chromatography

    NASA Astrophysics Data System (ADS)

    Reichenbach, Stephen E.; Ni, Mingtian; Kottapalli, Visweswara; Visvanathan, Arvind; Ledford, Edward B., Jr.; Oostdijk, John; Trap, Henk C.

    2003-08-01

    Comprehensive two-dimensional gas chromatography (GCxGC) is an emerging technology for chemical separation that provides an order-of-magnitude increase in separation capacity over traditional gas chromatography. GCxGC separates chemical species with two capillary columns interfaced by two-stage thermal desorption. Because GCxGC is comprehensive and has high separation capacity, it can perform multiple traditional analytical methods with a single analysis. GCxGC has great potential for a wide variety of environmental sensing applications, including detection of chemical warfare agents (CWA) and other harmful chemicals. This paper demonstrates separation of nerve agents sarin and soman from a matrix of gasoline and diesel fuel. Using a combination of an initial column separating on the basis of boiling point and a second column separating on the basis of polarity, GCxGC clearly separates the nerve agents from the thousands of other chemicals in the sample. The GCxGC data is visualized, processed, and analyzed as a two-dimensional digital image using a software system for GCxGC image processing developed at the University of Nebraska - Lincoln.

  4. Exploring the effects of high-velocity flows in abundance determinations in H II regions: bidimensional spectroscopy of HH 204 in the Orion nebula

    NASA Astrophysics Data System (ADS)

    Núñez-Díaz, M.; Mesa-Delgado, A.; Esteban, C.; López-Martín, L.; García-Rojas, J.; Luridiana, V.

    2012-04-01

    We present results from integral field optical spectroscopy with the Potsdam Multi-Aperture Spectrograph of the Herbig-Haro (HH) object HH 204, with a spatial sampling of 1 × 1 arcsec2. We have obtained maps of different emission lines, physical conditions and ionic abundances from collisionally excited lines. The ionization structure of the object indicates that the head of the bow shock is optically thick and has developed a trapped ionization front. The density at the head is at least five times larger than in the background ionized gas. We discover a narrow arc of high Te([N II]) values delineating the southeast edge of the head. The temperature in this zone is about 1000 K higher than in the rest of the field and should correspond to a shock-heated zone at the leading working surface of the gas flow. This is the first time this kind of feature is observed in a photoionized HH object. We find that the O+ and O abundance maps show anomalous values at separate areas of the bow shock probably due to: (a) overestimation of the collisional de-excitation effects of the [O II] lines in the compressed gas at the head of the bow shock, and (b) the use of a too high Te([N II]) at the area of the leading working surface of the flow.

  5. Filamentation of plasma in the auroral region by an ion-ion instability - A process for the formation of bidimensional potential structures

    NASA Astrophysics Data System (ADS)

    Mottez, F.; Chanteur, G.; Roux, A.

    1992-07-01

    The nonlinear behavior of electrostatic ion waves generated by an ion beam flowing through a thermal ion and electron background in a strongly magnetized plasma is investigated by means of a 2D, explicit, electrostatic particle code. To follow the nonlinear evolution of these ion waves, a long-lasting simulation is run with a large simulation grid: 128 x 512 lambda(d). Beam ions are shown to generate oblique waves. The nonlinear beatings between these oblique waves produce purely transverse waves, which leads to a strong modulation of the density and of the electric potential in a direction transverse to the magnetic field. The transverse scale of these essentially field-aligned filaments is 10 rho(i), where rho(i) is the ion Larmor radius of beam ions. Within these filaments, relatively stable field-aligned density and potential structures develop. Unlike the potential structures that develop in a two-component plasma with downgoing electrons, these structures move upward.

  6. Evaluation of a Kalman-based block matching method to assess the bi-dimensional motion of the carotid artery wall in B-mode ultrasound sequences.

    PubMed

    Zahnd, Guillaume; Orkisz, Maciej; Sérusclat, André; Moulin, Philippe; Vray, Didier

    2013-07-01

    We aim at investigating arterial diseases at early stage, by assessing the longitudinal (i.e. in the same direction as the blood flow) motion of the intima-media complex. This recently evidenced phenomenon has been shown to provide relevant and complementary information about vascular health. Our method assesses the longitudinal and radial motion from clinical in vivo B-mode ultrasound sequences. To estimate the trajectory of a selected point during the cardiac cycle, we introduce a block matching method that involves a temporal update of the reference block using a pixel-wise Kalman filter. The filter uses the initial gray-level of the pixel as control signal to avoid divergence due to cumulating errors. The block and search-window sizes are adapted to the tissue of interest. The method was evaluated on image sequences of the common carotid artery, acquired in 57 healthy volunteers and in 25 patients at high cardiovascular risk. Reference trajectories were generated for each sequence by averaging the tracings performed by three observers. Six different computerized techniques were also compared to our method. With a pixel size of 30 μm, the average absolute motion estimation errors were 84 ± 107 μm and 20 ± 19 μm for the longitudinal and radial directions, respectively. This accuracy was of the same order of magnitude as the inter- and intra-observers variability, and smaller than for the other methods. The estimated longitudinal motion amplitude was significantly reduced in at-risk patients compared with healthy volunteers (408 ± 281 μm vs. 643 ± 274 μm, p<0.0001). Our method can constitute a reliable and time-saving technique to investigate the arterial stiffness in clinical studies, in the objective to detect early-stage atherosclerosis. PMID:23612497

  7. Descripción de la zona de alta difusión en un modelo bidimensional para hojas de corriente

    NASA Astrophysics Data System (ADS)

    Montero, M. F.; Paola, C. A.; Platzeck, A. M.

    Los modelos bidimensionales para describir hojas de corriente de alta simetría no suministran una descripción detallada de las regiones donde la difusión es considerablemente importante. Tal es el caso de los modelos desarrollados en la década del '60 por Sweet, Parker, Petschek y Sonnerup. En esta comunicación presentamos una solución de las ecuaciones MHD en el entorno del origen, construyendo series bidimensionales para todas las magnitudes físicas involucradas. Valiéndonos de la alta simetría y de las características del problema, logramos reducir el número de coeficientes a calcular. Utilizamos un programa autoconsistente para extender el cálculo a regiones vecinas con difusión moderada o despreciable.

  8. Application of comprehensive two-dimensional gas chromatography for the assessment of oil contaminated soils.

    PubMed

    Van De Weghe, Hendrik; Vanermen, Guido; Gemoets, Johan; Lookman, Richard; Bertels, Diane

    2006-12-22

    A crucial step in the remediation of oil contaminated soils is the characterization of the pollution. Information on the chemical composition is used to assess the toxicity (and thus the need for remediation) and to determine the most appropriate technology for treatment. Mostly these analyses are carried out in routine environmental laboratories using gas chromatography with flame ionization detection (GC/FID) based on a protocol developed by the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG). In the present study, an alternative method was developed using comprehensive two-dimensional gas chromatography (GCXGC) with FID. Sample preparation was limited to pressurized liquid extraction (PLE), and the analysis was carried out on a commercially available instrument with a conventional column combination (RTX-1/BPX50) and with standard chromatographic software. Compared to the TPH method, the group-types in the GCXGC analysis are chemically better defined and more specific information is obtained especially for the (toxicologically important) aromatic hydrocarbon fraction. Preliminary results indicate that higher recoveries and lower RSDs are obtained with GCXGC, probably because of the less complex sample preparation. Furthermore a data processing method was developed to generate TPH results from GCXGC data; the volatility distribution profiles compared very well with conventional TPH data. The possibility of extracting physicochemical properties directly from the GCXGC chromatogram was briefly explored, but software limitations hindered this promising application. PMID:17055525

  9. Biomark/Organic Analysis with Time-of-Flight Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Waite, J. Hunter, Jr.

    2004-01-01

    The concept of a Comprehensive 2-Dimensional Gas Chromatography coupled with Time-of-Flight Mass Spectrometry (GCxGC-TOWS) for the analysis of organic compounds has been proven with commercially available instrumentation (LECO Corp). The performance of a GCxGC instrument has been characterized in various stages using two independent breadboard systems. The GCxGC separation systems, including the thermal modulator, have been miniaturized to the size of a benchtop configuration. One breadboard system employs a Flame Ionization Detector (FID), whereas the second breadboard system employs a Time-of-Fight mass spectrometer (TOFWS) as a detection system.

  10. "Heart-cut" bidimensional achiral-chiral liquid chromatography applied to the evaluation of stereoselective metabolism, in vivo biological activity and brain response to chiral drug candidates targeting the central nervous system.

    PubMed

    Battisti, Umberto M; Citti, Cinzia; Larini, Martina; Ciccarella, Giuseppe; Stasiak, Natalia; Troisi, Luigino; Braghiroli, Daniela; Parenti, Carlo; Zoli, Michele; Cannazza, Giuseppe

    2016-04-22

    A "heart-cut" two-dimensional achiral-chiral liquid chromatography triple-quadrupole mass spectrometry method (LC-LC-MS/MS) was developed and coupled to in vivo cerebral microdialysis to evaluate the brain response to the chiral compound (±)-7-chloro-5-(3-furanyl)-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine-1,1-dioxide ((±)-1), a potent positive allosteric modulator (PAM) of AMPA receptor. The method was successfully employed to evaluate also its stereoselective metabolism and in vitro biological activity. In particular, the LC achiral method developed, employs a pentafluorinated silica based column (Discovery HS-F5) to separate dopamine, acetylcholine, serotonin, (±)-1 and its two hepatic metabolites. In the "heart-cut" two-dimension achiral-chiral configuration, (±)-1 and (±)-1-d4 eluted from the achiral column (1st dimension), were transferred to a polysaccharide-based chiral column (2nd dimension, Chiralcel OD-RH) by using an automatic six-port valve. Single enantiomers of (±)-1 were separated and detected using electrospray positive ionization mode and quantified in selected reaction monitoring mode. The method was validated and showed good performance in terms of linearity, accuracy and precision. The new method employed showed several possible applications in the evaluation of: (a) brain response to neuroactive compounds by measuring variations in the brain extracellular levels of selected neurotransmitters and other biomarkers; (b) blood brain barrier penetration of drug candidates by measuring the free concentration of the drug in selected brain areas; (c) the presence of drug metabolites in the brain extracellular fluid that could prove very useful during drug discovery; (d) a possible stereoselective metabolization or blood brain barrier stereoselective crossing of chiral drugs. Finally, compared to the methods reported in the literature, this technique avoids the necessity of euthanizing an animal at each time point to measure drug concentration in whole brain tissue and provides continuous monitoring of extracellular concentrations of single chiral drug enantiomers along with its metabolites in specific brain regions at each selected time point for a desired period by using a single animal. PMID:27020886

  11. Iterative adaption of the bidimensional wall of the French T2 wind tunnel around a C5 axisymmetrical model: Infinite variation of the Mach number at zero incidence and a test at increased incidence

    NASA Technical Reports Server (NTRS)

    Archambaud, J. P.; Dor, J. B.; Payry, M. J.; Lamarche, L.

    1986-01-01

    The top and bottom two-dimensional walls of the T2 wind tunnel are adapted through an iterative process. The adaptation calculation takes into account the flow three-dimensionally. This method makes it possible to start with any shape of walls. The tests were performed with a C5 axisymmetric model at ambient temperature. Comparisons are made with the results of a true three-dimensional adaptation.

  12. Programmed automation of modulator cold jet flow for comprehensive two-dimensional gas chromatographic analysis of vacuum gas oils.

    PubMed

    Rathbun, Wayne

    2007-01-01

    A method is described for automating the regulation of cold jet flow of a comprehensive two-dimensional gas chromatograph (GCxGC) configured with flame ionization detection. This new capability enables the routine automated separation, identification, and quantitation of hydrocarbon types in petroleum fractions extending into the vacuum gas oil (VGO) range (IBP-540 degrees C). Chromatographic data acquisition software is programmed to precisely change the rate of flow from the cold jet of a nitrogen cooled loop modulator of a GCxGC instrument during sample analysis. This provides for the proper modulation of sample compounds across a wider boiling range. The boiling point distribution of the GCxGC separation is shown to be consistent with high temperature simulated distillation results indicating recovery of higher boiling semi-volatile VGO sample components. GCxGC configured with time-of-flight mass spectrometry is used to determine the molecular identity of individual sample components and boundaries of different molecular types. PMID:18078570

  13. A procedure for comprehensive two-dimensional gas chromatography retention time locked dual detection.

    PubMed

    Mommers, John; Ritzen, Erik; Dutriez, Thomas; van der Wal, Sjoerd

    2016-08-26

    In this paper, a novel, and easy to perform, retention time locking procedure for locking primary and secondary retention times of detector signals in comprehensive two-dimensional gas chromatography (GCxGC) dual-detection is proposed and its advantages are demonstrated and discussed. The dual detection retention time locking procedure is a 2-step process for a GCxGC system in which the effluent of the primary column is split, by using a pressure regulated splitter, towards the GCxGC modulator using two identical secondary GC columns of which one is installed in the main GC oven and the other is installed in a secondary GC oven. The first step of the locking procedure is to minimize the secondary retention time difference between both detectors of a compound, which has a retention factor (k) close to 0. This is done by stepwise altering the effective secondary column length, simply by sliding the secondary column, which is installed in the main oven, forwards or backwards through the modulator. The second step is to minimize the secondary retention time difference of a compound which has a significant retention in both dimensions. This is done by stepwise altering the secondary oven temperature rate. This locking procedure was successfully demonstrated for the analysis of a diesel sample by GCxGC coupled to a time of flight mass spectrometer (TOFMS) and a nitrogen chemiluminescence detector (NCD) and by GCxGC coupled to a TOFMS and a flame ionization detector (FID). For all compounds the average absolute secondary retention time differences between the NCD or the FID and the TOFMS detectors were 0.03, and 0.07s, respectively, which are significantly less than the average peak widths at half heights, which was 0.2s. PMID:27466154

  14. Optimization of separation and detection conditions for the multiresidue analysis of pesticides in grapes by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

    PubMed

    Banerjee, Kaushik; Patil, Sangram H; Dasgupta, Soma; Oulkar, Dasharath P; Patil, Shubhangi B; Savant, Rahul; Adsule, Pandurang G

    2008-05-01

    A comprehensive GCxGC-TOFMS method was optimized for multiresidue analysis of pesticides using a combination of a non-polar (RTX-5MS, 10 m x 0.18 mm x 0.2 microm) and a polar capillary column (TR-50MS, 1 m x 0.1 mm x 0.1 microm), connected in series through a dual stage thermal modulator. The method resolved the co-elution problems as observed in full scan one-dimensional GC-MS analysis and allowed chromatographic separation of 51 pesticides within 24 min run time with library-searchable mass spectrometric confirmation. Four pesticides, viz. chlorpyrifos-methyl, vinclozoline, parathion-methyl and heptachlor could be baseline separated on GCxGC, which were otherwise closely eluting and interfering each other's detection in 1D GC-MS run. Similarly, it could be possible to separate myclobutanil, buprofezin, flusilazole and oxyfluorfen on GCxGC. Although in 1D GC-MS, these closely eluting compounds could be identified through deconvolution algorithm and 'peak-find' option of the Chromatof software but the spectral purity significantly improved on GCxGC analysis. Thorough optimization was accomplished for the oven temperature programming, ion source temperature and GCxGC parameters like modulation period, duration of hot pulses, modulation-offset temperature, acquisition rate, etc. to achieve best possible separation of the test compounds. The limit of detection significantly improved by 2-12 times on GCxGC-TOFMS against GC-TOFMS because of sharper and narrower peak shapes. The method was tested for grape matrix after preparing the samples using previously described method and recoveries of the entire test pesticides were within 70-110% at 10 ng/g level of fortification. GCxGC-TOFMS was found to be an excellent technique for library-based screening of pesticides with high accuracy and sensitivity. PMID:18371973

  15. Characterisation of dense non-aqueous phase liquids of coal tar using comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry.

    NASA Astrophysics Data System (ADS)

    Gauchotte-Lindsay, Caroline; McGregor, Laura; Richards, Phil; Kerr, Stephanie; Glenn, Aliyssa; Thomas, Russell; Kalin, Robert

    2013-04-01

    Comprehensive two-dimensional gas chromatography (GCxGC) is a recently developed analytical technique in which two capillary columns with different stationary phases are placed in series enabling planar resolution of the analytes. The resolution power of GCxGC is one order of magnitude higher than that of one dimension gas chromatography. Because of its high resolution capacity, the use of GCxGC for complex environmental samples such as crude oils, petroleum derivatives and polychlorinated biphenyls mixtures has rapidly grown in recent years. We developed a one-step method for the forensic analysis of coal tar dense non-aqueous phase liquids (DNAPLs) from former manufactured gas plant (FMGP) sites. Coal tar is the by-product of the gasification of coal for heating and lighting and it is composed of thousands of organic and inorganic compounds. Before the boom of natural gases and oils, most towns and cities had one or several manufactured gas plants that have, in many cases, left a devastating environmental print due to coal tar contamination. The fate of coal tar DNAPLs, which can persist in the environment for more than a hundred years, is therefore of crucial interest. The presented analytical method consists of a unique clean-up/ extraction stage by pressurized liquid extraction and a single analysis of its organic chemical composition using GCxGC coupled with time of flight mass spectrometry (TOFMS). The chemical fingerprinting is further improved by derivatisation by N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) of the tar compounds containing -OH functions such as alcohols and carboxylic acids. We present here how, using the logical order of elution in GCxGC-TOFMS system, 1) the identification of never before observed -OH containing compounds is possible and 2) the isomeric selectivity of an oxidation reaction on a DNAPL sample can be revealed. Using samples collected at various FMGP sites, we demonstrate how this GCxGC method enables the simultaneous

  16. Assessing Acquiescence in Binary Responses: IRT-Related Item-Factor-Analytic Procedures

    ERIC Educational Resources Information Center

    Ferrando, Pere J.; Condon, Lorena

    2006-01-01

    This article proposes procedures for assessing acquiescence in a balanced set of binary personality items. These procedures are based on the bidimensional item-factor analysis model, which is an alternative parameterization of the bidimensional 2-parameter normal-ogive item response theory model. First the rationale and general approach are…

  17. A Framework for Describing Interlanguages in Multilingual Settings.

    ERIC Educational Resources Information Center

    Tenjoh-Okwen, Thomas

    1989-01-01

    Outlines a contrastive analysis model and a non-contrastive analysis model for studying interlanguage in strictly bilingual settings, and suggests a bidimensional framework, including both linguistic and curricular components, for studying interlanguage in multilingual settings. (21 references) (CB)

  18. Characterisation of biodegradation capacities of environmental microflorae for diesel oil by comprehensive two-dimensional gas chromatography.

    PubMed

    Penet, Sophie; Vendeuvre, Colombe; Bertoncini, Fabrice; Marchal, Rémy; Monot, Frédéric

    2006-12-01

    In contaminated soils, efficiency of natural attenuation or engineered bioremediation largely depends on biodegradation capacities of the local microflorae. In the present study, the biodegradation capacities of various microflorae towards diesel oil were determined in laboratory conditions. Microflorae were collected from 9 contaminated and 10 uncontaminated soil samples and were compared to urban wastewater activated sludge. The recalcitrance of hydrocarbons in tests was characterised using both gas chromatography (GC) and comprehensive two-dimensional gas chromatography (GCxGC). The microflorae from contaminated soils were found to exhibit higher degradation capacities than those from uncontaminated soil and activated sludge. In cultures inoculated by contaminated-soil microflorae, 80% of diesel oil on an average was consumed over 4-week incubation compared to only 64% in uncontaminated soil and 60% in activated sludge cultures. As shown by GC, n-alkanes of diesel oil were totally utilised by each microflora but differentiated degradation extents were observed for cyclic and branched hydrocarbons. The enhanced degradation capacities of impacted-soil microflorae resulted probably from an adaptation to the hydrocarbon contaminants but a similar adaptation was noted in uncontaminated soils when conifer trees might have released natural hydrocarbons. GCxGC showed that a contaminated-soil microflora removed all aromatics and all branched alkanes containing less than C(15). The most recalcitrant compounds were the branched and cyclic alkanes with 15-23 atoms of carbon. PMID:16477350

  19. Electrically heated, air-cooled thermal modulator and at-column heating for comprehensive two-dimensional gas chromatography.

    PubMed

    Libardoni, Mark; Waite, J Hunter; Sacks, Richard

    2005-05-01

    An instrument for comprehensive two-dimensional gas chromatography (GCxGC) is described using an electrically heated and air-cooled thermal modulator requiring no cryogenic materials or compressed gas for modulator operation. In addition, at-column heating is used to eliminate the need for a convection oven and to greatly reduce the power requirements for column heating. The single-stage modulator is heated by current pulses from a dc power supply and cooled by a conventional two-stage refrigeration unit. The refrigeration unit, together with a heat exchanger and a recirculating pump, cools the modulator to about -30 degrees C. The modulator tube is silica-lined stainless steel with an internal film of dimethylpolysiloxane. The modulator tube is 0.18 mm i.d. x 8 cm in length. The modulator produces an injection plug width as small as 15 ms. PMID:15859594

  20. What Are the Proteolytic Enzymes of Honey and What They Do Tell Us? A Fingerprint Analysis by 2-D Zymography of Unifloral Honeys

    PubMed Central

    Rossano, Rocco; Larocca, Marilena; Polito, Teresa; Perna, Anna Maria; Padula, Maria Carmela; Martelli, Giuseppe; Riccio, Paolo

    2012-01-01

    Honey is a sweet and healthy food produced by honeybees (Apis mellifera L.) from flower nectars. Using bidimensional zymography, we have detected the, until now unrevealed, proteolytic activities present in row honey samples. The resulting zymograms were specific for each type of the four unifloral honey under study, and enzymes were identified as serine proteases by the use of specific inhibitors. Further, using bidimensional electrophoresis, we have shown that honey proteases are able to degrade the major Royal Jelly proteins and in particular MRPJ-1, the protein that promotes queen differentiation in honeybees. Our findings open new perspectives for the better understanding of honeybee development, social behaviour and role in honey production. The now discovered honey proteases may influence honey properties and quality, and bidimensional zymograms might be useful to distinguish between different honey types, establish their age and floral origin, and allow honey certification. PMID:23145107

  1. Numerical Algorithms Based on Biorthogonal Wavelets

    NASA Technical Reports Server (NTRS)

    Ponenti, Pj.; Liandrat, J.

    1996-01-01

    Wavelet bases are used to generate spaces of approximation for the resolution of bidimensional elliptic and parabolic problems. Under some specific hypotheses relating the properties of the wavelets to the order of the involved operators, it is shown that an approximate solution can be built. This approximation is then stable and converges towards the exact solution. It is designed such that fast algorithms involving biorthogonal multi resolution analyses can be used to resolve the corresponding numerical problems. Detailed algorithms are provided as well as the results of numerical tests on partial differential equations defined on the bidimensional torus.

  2. Two-dimensional DOSY experiment with Excitation Sculpting water suppression for the analysis of natural and biological media

    NASA Astrophysics Data System (ADS)

    Balayssac, Stéphane; Delsuc, Marc-André; Gilard, Véronique; Prigent, Yann; Malet-Martino, Myriam

    2009-01-01

    The Bipolar Pulse Pair Stimulated Echo NMR pulse sequence was modified to blend the original Excitation Sculpting water signal suppression. The sequence is a powerful tool to generate rapidly, with a good spectrum quality, bidimensional DOSY experiments without solvent signal, thus allowing the analysis of complex mixtures such as plant extracts or biofluids. The sequence has also been successfully implemented for a protein at very-low concentration in interaction with a small ligand, namely the salivary IB5 protein binding the polyphenol epigallocatechine gallate. The artifacts created by this sequence can be observed, checked and removed thanks to NPK and NMRnotebook softwares to give a perfect bidimensional DOSY spectrum.

  3. Dosimetric Verification and Validation of Conformal and IMRT Treatments Fields with an Ionization Chamber 2D-Array

    NASA Astrophysics Data System (ADS)

    Evangelina, Figueroa M.; Gabriel, Reséndiz G.; Miguel, Pérez P.

    2008-08-01

    A three-dimensional treatment planning system requires comparisons of calculated and measured dose distributions. It is necessary to confirm by means of patient specific QA that the dose distributions are correctly calculated, and that the patient data is correctly transferred to and delivered by the treatment machine. We used an analysis software for bi-dimensional dosimetric verification of conformal treatment and IMRT fields using as objective criterion the gamma index. An ionization chamber bi-dimensional array was used for absolute dose measurement in the complete field area.

  4. Modular detector for deep underwater registration of muons and muon groups

    NASA Technical Reports Server (NTRS)

    Demianov, A. I.; Sarycheva, L. I.; Sinyov, N. B.; Varadanyan, I. N.; Yershov, A. A.

    1985-01-01

    Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences.

  5. A molecular chemical approach to the magnetic multilayers

    NASA Astrophysics Data System (ADS)

    Coronado, E.; Galán-Mascarós, J. R.; Gómez-García, C. J.; Burriel, R.

    1999-05-01

    Using the bi-dimensional bimetallic networks based upon oxalate complexes, it is possible to prepare new multilayered materials by insertion of 'electroactive' molecules in between these layers. According to this approach a new family of compounds presenting alternating ferromagnetic—paramagnetic layers have been successfully prepared. Here we present the magnetic and specific heat characterization.

  6. Tridimensional Acculturation and Adaptation among Jamaican Adolescent-Mother Dyads in the United States

    ERIC Educational Resources Information Center

    Ferguson, Gail M.; Bornstein, Marc H.; Pottinger, Audrey M.

    2012-01-01

    A bidimensional acculturation framework cannot account for multiple destination cultures within contemporary settlement societies. A "tridimensional model" is proposed and tested among Jamaican adolescent-mother dyads in the United States compared to Jamaican Islander, European American, African American, and other Black and non-Black U.S.…

  7. Dirac operator on a disk with global boundary conditions

    SciTech Connect

    Falomir, H.; Gamboa Saravi, R.E.; Santangelo, E.M.

    1998-01-01

    We compute the functional determinant for a Dirac operator in the presence of an Abelian gauge field on a bidimensional disk, under global boundary conditions of the type introduced by Atiyah{endash}Patodi{endash}Singer. We also discuss the connection between our result and the index theorem. {copyright} {ital 1998 American Institute of Physics.}

  8. Multidimensional Properties of LOT-R: Effects of Optimism and Pessimism on Career and Well-Being Related Variables in Adolescents.

    ERIC Educational Resources Information Center

    Creed, Peter A.; Patton, Wendy; Bartrum, Dee

    2002-01-01

    Exploratory and confirmatory factor analyses of data from the Life Orientation Test Revised for 504 adolescents demonstrated its bidimensionality. High optimism was associated with high levels of career planning, exploration, decision-making confidence, and career-related goals. High pessimism was associated with career indecision, low…

  9. Promoting Hope: Suggestions for School Counselors

    ERIC Educational Resources Information Center

    Pedrotti, Jennifer Teramoto; Edwards, Lisa M.; Lopez, Shane J.

    2008-01-01

    School counselors need multiple resources to assist today's students in developing to their fullest potential. This development might often be measured outwardly by academic success; however, psychological and emotional well-being of students is a large part of this success. The construct of hope is defined as a bidimensional characteristic…

  10. The Assessment of Present-Moment Awareness and Acceptance: The Philadelphia Mindfulness Scale

    ERIC Educational Resources Information Center

    Cardaciotto, LeeAnn; Herbert, James D.; Forman, Evan M.; Moitra, Ethan; Farrow, Victoria

    2008-01-01

    The purpose of this project was to develop a bidimensional measure of mindfulness to assess its two key components: present-moment awareness and acceptance. The development and psychometric validation of the Philadelphia Mindfulness Scale is described, and data are reported from expert raters, two nonclinical samples (n = 204 and 559), and three…

  11. Acculturation and Adjustment among Immigrant Chinese Parents: Mediating Role of Parenting Efficacy

    ERIC Educational Resources Information Center

    Costigan, Catherine L.; Koryzma, Celine M.

    2011-01-01

    This study examined parenting efficacy beliefs as a mediator of the association between acculturation and adjustment. The sample consisted of 177 immigrant Chinese mothers and fathers with early adolescent children in Canada. Acculturation was assessed bidimensionally as Canadian and Chinese orientations. A latent psychological adjustment variable…

  12. Cycloartane triterpenoids from Guarea macrophylla.

    PubMed

    Lago, João Henrique G; Roque, Nídia F

    2002-06-01

    Nine cycloartane triterpenoids, including two new derivatives 22,25-dihydroxy-cycloart-23E-en-3-one and 24-methylenecycloartane-3 beta,22-diol have been isolated from leaves of Guarea macrophylla. The structures were elucidated by interpretation of spectral data, mainly 1H and 13C NMR, including bidimensional analysis (HOMOCOSY, HMQC and HMBC). PMID:12031420

  13. Acculturation and Eating Disorders in a Mexican American Community Sample

    ERIC Educational Resources Information Center

    Cachelin, Fary M.; Phinney, Jean S.; Schug, Robert A.; Striegel-Moore, Ruth H.

    2006-01-01

    Our purpose was to investigate acculturation and eating disorders by examining the role of ethnic identity and by utilizing a bidimensional perspective toward two cultures. We predicted that orientation toward European American culture and lower ethnic identity would be positively associated with eating disorders. Participants were 188 Mexican…

  14. Exploratory Procedures of Tactile Images in Visually Impaired and Blindfolded Sighted Children: How They Relate to Their Consequent Performance in Drawing

    ERIC Educational Resources Information Center

    Vinter, Annie; Fernandes, Viviane; Orlandi, Oriana; Morgan, Pascal

    2012-01-01

    The aim of the present study was to compare the types of exploratory procedures employed by children when exploring bidimensional tactile patterns and correlate the use of these procedures with the children's shape drawing performance. 18 early blind children, 20 children with low vision and 24 age-matched blindfolded sighted children aged…

  15. Complete characterization of a spatiotemporal pulse shaper with two-dimensional Fourier transform spectral interferometry

    NASA Astrophysics Data System (ADS)

    Amir, W.; Planchon, T. A.; Durfee, C. G.; Squier, J. A.

    2007-04-01

    Spatiotemporal pulse shaping is characterized with two-dimensional Fourier transform spectral interferometry. A deformable-mirror-based bidimensional pulse shaper is used to create simple spatiotemporal structures on a femtosecond pulse, structures that are directly calculated from the measured spatiospectral phases and intensities.

  16. From Newton's Second Law to Huygens's Principle: Visualizing Waves in a Large Array of Masses Joined by Springs

    ERIC Educational Resources Information Center

    Dolinko, A. E.

    2009-01-01

    By simulating the dynamics of a bidimensional array of springs and masses, the propagation of conveniently generated waves is visualized. The simulation is exclusively based on Newton's second law and was made to provide insight into the physics of wave propagation. By controlling parameters such as the magnitude of the mass and the elastic…

  17. Separating Optimism and Pessimism: A Robust Psychometric Analysis of the Revised Life Orientation Test (LOT-R)

    ERIC Educational Resources Information Center

    Herzberg, Philipp Yorck; Glaesmer, Heide; Hoyer, Jurgen

    2006-01-01

    The internal structure of the revised Life Orientation Test (LOT-R, German version; M. F. Scheier, C. S. Carver, & M. W. Bridges, 1994) was analyzed in a sample of 46,133 participants who ranged in age from 18 years to 103 years. Confirmatory factor analysis showed that dispositional optimism, as measured by the LOT-R, is bidimensional, …

  18. Dimensions of Acculturation: Associations with Health Risk Behaviors among College Students from Immigrant Families

    ERIC Educational Resources Information Center

    Schwartz, Seth J.; Weisskirch, Robert S.; Zamboanga, Byron L.; Castillo, Linda G.; Ham, Lindsay S.; Huynh, Que-Lam; Park, Irene J. K.; Donovan, Roxanne; Kim, Su Yeong; Vernon, Michael; Davis, Matthew J.; Cano, Miguel A.

    2011-01-01

    In the present study, we examined a bidimensional model of acculturation (which includes both heritage and U.S. practices, values, and identifications) in relation to hazardous alcohol use, illicit drug use, unsafe sexual behavior, and impaired driving. A sample of 3,251 first- and second-generation immigrant students from 30 U.S. colleges and…

  19. Petroleum Weathering Associated with Hydrocarbon Migration and Seepage, a Case Study From the Santa Barbara Channel, CA.

    NASA Astrophysics Data System (ADS)

    Wardlaw, G. D.; Nelson, R. K.; Reddy, C. M.; Valentine, D. L.

    2005-12-01

    A 2003 report by the National Research Council estimates that 50 to 70 percent of oil that is released into the sea is from natural seeps (National Research Council, 2003), indicating that catastrophic oil spills or the runoff from roads and highways are not the major sources of oil in the marine environment. For example, approximately 37 tons of petroleum is emitted daily from seeps off the coast of Santa Barbara, California (Quigley et al. 1996). The Santa Barbara seeps are some of the most active in the world and have been releasing petroleum for thousands of years. Sheens of oil on the water surface and tar patches on the beaches are ubiquitous along the coastline of Santa Barbara and are continuing reminders of this natural process. Although the geochemistry of these seeps have been studied in the past, it has been hindered by the complexity of the petroleum hydrocarbons and the inability of traditional gas chromatography to separate, identify, and quantify each component of the oil. To expand on these previous efforts, we have begun to use comprehensive two-dimensional gas chromatography (GCxGC). This new technology provides at least an order of magnitude increase in the resolution and detection of petroleum hydrocarbons compared to traditional methods. Preliminary work using GCxGC has focused on examining the chemical composition of unrefined petroleum as it migrates up from depth through natural faults to the seafloor, from the seafloor to the sea surface, and from the sea surface to local beaches. Petroleum collected from a subsurface reservoir (Platform Holly Well 2342-15) is composed of a wide range of resolved petroleum hydrocarbons including n-alkanes, branched alkanes, cycloalkanes, linear alkane benzenes, polycyclic aromatic hydrocarbons, steranes, hopanes, cyclic isoprenoids, and very large branched biomarkers with 38 to 40 carbons. This product is significantly different than oil emerging from the seafloor at the Jackpot seep, which we believe is

  20. [Development of the Japanese Optimism and Pessimism Scale: reliability and validity].

    PubMed

    Toyama, Miki

    2013-08-01

    This study reports about the construction of a bidimensional measure of optimism and pessimism (defined as positive and negative outcome expectancies), called the Japanese Optimism and Pessimism Scale (J-OPS), and examines its reliability and validity. The participants were college students. The results revealed the following: (a) the J-OPS had sufficient reliability and validity, (b) optimism and pessimism were bidimensional in structure, (c) the general pattern of correlations with external criteria of psychological well-being (positive and negative affectivity). After controlling for optimism and pessimism respectively, it indicated that these two constructs were partially independent of each other. Namely, optimism, but not pessimism, was found to be a consistent predictor of positive affectivity (psychological well-being), whereas pessimism, but not optimism, was found to be a predictor of negative affectivity (psychological distress). PMID:24063152

  1. Construction and validation of the Measurement of Acculturation Strategies for People of African Descent (MASPAD).

    PubMed

    Obasi, Ezemenari M; Leong, Frederick T L

    2010-10-01

    This paper describes the development of the Measurement of Acculturation Strategies for People of African Descent (MASPAD), a bidimensional instrument designed to assess acculturation strategies (i.e., Traditionalist, Integrationist, Assimilationist, and Marginalist). Two studies were conducted to describe the development of the MASPAD and to assess its psychometric properties. Data were collected from 367 African American participants in Atlanta, GA; Columbus, OH; Los Angeles; and New York City, NY. The MASPAD consistently produced scores with adequate reliability and independent raters provided initial evidence for face and content validity. Pearson correlation coefficients supported the purported orthogonality of the MASPAD subscales. The MASPAD was found to be a significant predictor of cultural worldview and values. The bidimensional model of acculturation theorized to exist in the MASPAD was supported with a confirmatory factor analysis on data collected from 831 participants. Future directions for this body of research are discussed. PMID:21058816

  2. Avoiding sensor blindness in Geiger mode avalanche photodiode arrays fabricated in a conventional CMOS process

    NASA Astrophysics Data System (ADS)

    Vilella, E.; Diéguez, A.

    2011-12-01

    The need to move forward in the knowledge of the subatomic world has stimulated the development of new particle colliders. However, the objectives of the next generation of colliders sets unprecedented challenges to the detector performance. The purpose of this contribution is to present a bidimensional array based on avalanche photodiodes operated in the Geiger mode to track high energy particles in future linear colliders. The bidimensional array can function in a gated mode to reduce the probability to detect noise counts interfering with real events. Low reverse overvoltages are used to lessen the dark count rate. Experimental results demonstrate that the prototype fabricated with a standard HV-CMOS process presents an increased efficiency and avoids sensor blindness by applying the proposed techniques.

  3. Use of digital wave front reconstruction for vibration analysis

    NASA Astrophysics Data System (ADS)

    Picart, Pascal; Leval, Julien; Boileau, Jean-Pierre; Pascal, Jean-Claude; Dalmont, Jean-Pierre

    2006-09-01

    This paper aims to present the different opportunities using digital wave front reconstruction in vibration analysis. The paper deals with off axis digital holography for which the wave front reconstruction is performed by fast Fourier transform methods. According to this way for the object plane reconstruction, we discuss about image formation by considering the exposure time of the detector. For the case of a long exposure time compared to the vibration period, that is the time-averaging regime, applications are presented, examples of which include vibrations of a clarinet reed and detection of defaults in a dome mode. For the case of a short exposure time compared to the vibration period, algorithm for the full field bidimensional amplitude and phase retrieving is presented. Applications of the method are presented, example of which include modal characterization of loudspeakers and bidimensional vibrometry of elastomer components.

  4. Assessment of opacimeter calibration on kraft pulp mills

    NASA Astrophysics Data System (ADS)

    Gomes, Joa˜o. F. P.

    This paper describes the methodology and specific techniques for calibrating automatic on-line industrial emission analysers, specifically equipments that measure total suspended dust installed in pulp mills within the scope of Portuguese Regulation No. 286/93 on air quality. The calibration of opacimeters is a multi-parameter relationship instead of the bidimensional calibration which is used in industrial practice. For a stationary source from a pulp mill such as the recovery boiler stack, which is subjected to significant variations, the effects of parameters such as the humidity and gas temperature, deviations of isokinetism, size range of particles and characteristic transmittance of equipment are analysed. The multivariable analysis of a considerable set of data leads to an estimate of about 98% of equipment transmittance over the other parameters with a level of significance greater than 0.99 which is a validation of the bidimensional practical calibrations.

  5. Aromatic chemicals by iron-catalyzed hydrotreatment of lignin pyrolysis vapor.

    PubMed

    Olcese, Roberto Nicolas; Lardier, George; Bettahar, Mohammed; Ghanbaja, Jaafar; Fontana, Sébastien; Carré, Vincent; Aubriet, Frédéric; Petitjean, Dominique; Dufour, Anthony

    2013-08-01

    Lignin is a potential renewable material for the production of bio-sourced aromatic chemicals. We present the first hydrotreatment of lignin pyrolysis vapors, before any condensation, using inexpensive and sustainable iron-silica (Fe/SiO2 ) and iron-activated carbon (Fe/AC) catalysts. Lignin pyrolysis was conducted in a tubular reactor and vapors were injected in a fixed bed of catalysts (673 K, 1 bar) with stacks to investigate the profile of coke deposit. More than 170 GC-analyzable compounds were identified by GCxGC (heart cutting)/flame ionization detector mass spectrometry. Lignin oligomers were analyzed by very high resolution mass spectrometry, called the "petroleomic" method. They are trapped by the catalytic fixed bed and, in particular, by the AC. The catalysts showed a good selectivity for the hydrodeoxygenation of real lignin vapors to benzene, toluene, xylenes, phenol, cresols, and alkyl phenols. The spent catalysts were characterized by temperature-programmed oxidation, transmission electron microscopy (TEM), and N2 sorption. Micropores in the Fe/AC catalyst are completely plugged by coke deposits, whereas the mesoporous structure of Fe/SiO2 is unaffected. TEM images reveal two different types of coke deposit: 1) catalytic coke deposited in the vicinity of iron particles and 2) thermal coke (carbonaceous particles ≈1 μm in diameter) formed from the gas-phase growth of lignin oligomers. PMID:23784799

  6. Molecular Characterization of Organic Indicators of Petroleum Biosouring

    NASA Astrophysics Data System (ADS)

    Nowak, J.; Weber, R.; Loutey, D.; Coates, J. D.; Goldstein, A. H.

    2015-12-01

    The production of sulfide in a petroleum reservoir by anaerobic sulfate reducing microorganisms (SRM) is environmentally, industrially, and epidemiologically hazardous. More knowledge is needed about the anaerobic respiration pathway of SRM in petroleum, and whether the activity of SRM could be effectively inhibited using nitrate or perchlorate treatments. In order to understand the molecular transformations and metabolic fingerprints of SRM in petroleum reservoirs, and how they are altered by nitrate or perchlorate treatments, the Coates and Goldstein Laboratories at UC-Berkeley have run controlled column incubation studies of petroleum from an oil reservoir. By using two dimensional gas chromatography (GCxGC) with high resolution time-of-flight mass spectrometry coupled to vacuum ultraviolet radiation at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL), detailed chemical characterizations of hydrocarbons from approximately C9-C30 have been completed, separating the complete oil sample by number of carbon atoms and chemical classes (including normal alkanes, branched alkanes, number of alkyl rings, and number of aromatic rings) corresponding to petroleum transformations in sulfate, nitrate, and perchlorate reducing environments. Results demonstrate that the anaerobic pathway of SRM preferentially involves the transformation of heavier polycyclic aromatic hydrocarbons (PAHs), and that a large number of products are created that contain either two or four oxygen atoms, suggesting fumarate additions initialize the anaerobic process.

  7. Catalytic Hydrotreatment of Humins in Mixtures of Formic Acid/2-Propanol with Supported Ruthenium Catalysts.

    PubMed

    Wang, Yuehu; Agarwal, Shilpa; Kloekhorst, Arjan; Heeres, Hero Jan

    2016-05-10

    The catalytic hydrotreatment of humins, which are the solid byproducts from the conversion of C6 sugars (glucose, fructose) into 5-hydroxymethylfurfural (HMF) and levulinic acid (LA), by using supported ruthenium catalysts has been investigated. Reactions were carried out in a batch setup at elevated temperatures (400 °C) by using a hydrogen donor (formic acid (FA) in isopropanol (IPA) or hydrogen gas), with humins obtained from d-glucose. Humin conversions of up to 69 % were achieved with Ru/C and FA, whereas the performance for Ru on alumina was slightly poorer (59 % humin conversion). Humin oils were characterized by using a range of analytical techniques (GC, GC-MS, GCxGC, gel permeation chromatography) and were shown to consist of monomers, mainly alkyl phenolics (>45 % based on compounds detectable by GC) and higher oligomers. A reaction network for the reaction is proposed based on structural proposals for humins and the main reaction products. PMID:26836970

  8. Qualitative drug analysis of hair extracts by comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry.

    PubMed

    Guthery, Bill; Bassindale, Tom; Bassindale, Alan; Pillinger, Colin T; Morgan, Geraint H

    2010-06-25

    A technique using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GCxGC/TOFMS) is applied to a qualitative analysis of three sample extracts from hair suspected of containing various drug compounds. The samples were also subjected to a quantitative target analysis for codeine, morphine, 6-monoacetylmorphine (6-MAM), amphetamine, methamphetamine, methylenedioxyamphetamine (MDA), methylenedioxymethylamphetamine (MDMA), methadone, and benzylpiperazine (BZP) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). GCxGC/TOFMS provided a non-specific procedure that identified various drugs, metabolites, and impurities not included in the target analysis. They included cocaine, diazepam, and methaqualone (quaalude). Comprehensive GCxGC separation was achieved using twin-stage cryo-modulation to focus eluant from a DB-5 ms (5% phenyl) to a BPX50 (50% phenyl) GC column. The TOF mass spectrometer provided unit mass resolution in the mass range m/z 5-1000 and rapid spectral acquisition (< or = 500spectra/s). Clean mass spectra of the individual components were obtained using mass spectral deconvolution software. The 'unknown' components were identified by comparison with mass spectra stored in a library database. PMID:20471020

  9. The discriminant pixel approach: a new tool for the rational interpretation of GCxGC-MS chromatograms.

    PubMed

    Vial, Jérôme; Pezous, Benoît; Thiébaut, Didier; Sassiat, Patrick; Teillet, Béatrice; Cahours, Xavier; Rivals, Isabelle

    2011-01-30

    GCxGC is now recognized as the most suited analytical technique for the characterization of complex mixtures of volatile compounds; it is implemented worldwide in academic and industrial laboratories. However, in the frame of comprehensive analysis of non-target analytes, going beyond the visual examination of the color plots remains challenging for most users. We propose a strategy that aims at classifying chromatograms according to the chemical composition of the samples while determining the origin of the discrimination between different classes of samples: the discriminant pixel approach. After data pre-processing and time-alignment, the discriminatory power of each chromatogram pixel for a given class was defined as its correlation with the membership to this class. Using a peak finding algorithm, the most discriminant pixels were then linked to chromatographic peaks. Finally, crosschecking with mass spectrometry data enabled to establish relationships with compounds that could consequently be considered as candidate class markers. This strategy was applied to a large experimental data set of 145 GCxGC-MS chromatograms of tobacco extracts corresponding to three distinct classes of tobacco. PMID:21215866

  10. Towards the identification of cassava root protein genes.

    PubMed

    De Souza, C R B; Carvalho, L J C B; De Almeida, E R P; Gander, E S

    2002-01-01

    The protein population of cassava root layers was characterized by SDS-PAGE and bidimensional polyacrylamide gel electrophoresis. SDS-Page revealed the presence of a protein population in the molecular weight range between 94 and 20 kDa. The expression pattern of these proteins was well-defined within the different layers. Partial protein sequence analyses and preliminary results on the layer-specific expression pattern obtained with Northern analyses are presented. PMID:12602941

  11. Geometry of Prismatic Tensegrity Constructions Composed of Three and Four-strut Cells

    NASA Astrophysics Data System (ADS)

    Olejníková, Tatiana

    2014-11-01

    In the paper there is described geometry of double layer tensegrity constructions composed of prismatic cells with rhombic configuration of three or four strut bases so-called prismatic Tensegrity constructions. There are described bi-dimensional assemblies creating double layer grids of three or four-strut cells with a node-on-node junction. The grids can be planar, of one or two curvature constructions.

  12. Cloud modeling of a quiet solar region in Halpha .

    NASA Astrophysics Data System (ADS)

    Bostanci, Z. F.; Al Erdoğan, N.

    We present chromospheric cloud modeling on the basis of Halpha profile-sampling images taken with the Interferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope (DST). We choose the required reference background profile by using theoretical NLTE profile synthesis. The resulting cloud parameters are converted into estimates of physical parameters (temperature and various densities). Their mean values compare well with the VAL-C model.

  13. Automatic classification of clouds on Meteosat imagery - Application to high-level clouds

    NASA Technical Reports Server (NTRS)

    Desbois, M.; Seze, G.; Szejwach, G.

    1982-01-01

    A statistical classification method based on clustering on three-dimensional histograms is applied to the three channels of the Meteosat imagery. The results of this classification are studied for different cloud cover cases over tropical regions. For high-level cloud classes, it is shown that the bidimensional IR-water vapor histogram allows one to deduce the cloud top temperature even for semi-transparent clouds.

  14. Traumatic tricuspid insufficiency in a kitten.

    PubMed

    Closa, J M; Font, A

    1999-01-01

    A four-month-old, male, common European kitten developed pleural effusion and ascites after falling from a fourth-floor flat. Radiographic, bidimensional echocardiography and color-flow Doppler findings were compatible with right-sided atrioventricular valve insufficiency. Necropsy confirmed the diagnosis that tricuspid insufficiency resulted from the rupture of the chordae tendineae of the nonseptal cusp of the valve at the level of the cranial papillary muscle insertion in the right ventricle. PMID:9934923

  15. Mechanichal Behavior of a Noncohesive Packing at Small Deformations: Deviation From Continuum Elasticity

    NASA Astrophysics Data System (ADS)

    Amar, El Hadji Bouya; Clamond, Didier; Fraysse, Nathalie; Rajchenbach, Jean

    2009-06-01

    In order to specify the mechanical behavior of grain piles, we investigate the response of a non-cohesive bidimensional packing of cylinders submitted to a point load. By means of image processing, we have an accurate access to the individual grain displacements in the reversible regime. The measured displacement field deviates unambiguously from the predictions of Continuum Elasticity. The data reveal a partial agreement with the diffusive models of Harr (1966) or of Coppersmith et al. (1996).

  16. Ag{sub 2}CuMnO{sub 4}: A new silver copper oxide with delafossite structure

    SciTech Connect

    Munoz-Rojas, David; Subias, Gloria; Fraxedas, Jordi; Martinez, Benjamin; Casas-Cabanas, Montse; Canales-Vazquez, Jesus; Gonzalez-Calbet, Jose; Garcia-Gonzalez, Ester; Walton, Richard I.; Casan-Pastor, Nieves . E-mail: nieves@icmab.es

    2006-12-15

    The use of hydrothermal methods has allowed the synthesis of a new silver copper mixed oxide, Ag{sub 2}CuMnO{sub 4}, the first example of a quaternary oxide containing both elements. It crystallizes with the delafossite 3R structure, thus being the first delafossite to contain both Ag and Cu. Synthesis conditions affect the final particle size (30-500nm). Powder X-ray diffraction Rietveld refinement indicates a trigonal structure (R3-bar m) and cell parameters a=2.99991A and c=18.428A, where Cu and Mn are disordered within the octahedral B positions in the plane and linearly coordinated Ag occupies de A position between layers. X-ray absorption near edge spectroscopy (XANES) for copper and manganese, and XPS for silver evidence +2, +4, and +1 oxidation states. The microstructure consists of layered parts that may form large twins showing 5nm nanodomains. Finally, magnetic measurements reveal the existence of ferromagnetic coupling yielding in-plane moments that align antiferromagnetically at lower temperatures. The singularity of the new phase resides on the fact that is an example of a bidimensional arrangement of silver and copper in an oxide that also shows clear bidimensionality in its physical properties. That is of special relevance to the field of high T{sub c} superconducting oxides, while the ferromagnetic coupling in a bidimensional system deserves itself special attention.

  17. Protein microdeposition using a conventional ink-jet printer.

    PubMed

    Roda, A; Guardigli, M; Russo, C; Pasini, P; Baraldini, M

    2000-03-01

    Many recent bioanalytical systems based on immunologic and hybridization reactions in a mono- or bidimensional microarray format require technology that can produce arrays of spots containing biospecific molecules. Some microarray deposition instruments are commercially available, and other devices have been described in recent papers. We describe a system obtained by adapting a commercial ink-jet printer and used to produce mono- and bidimensional arrays of spots containing horseradish peroxidase on cellulose paper. In a few minutes, it was possible to obtain bidimensional arrays containing several thousands of spots with a diameter as low as 0.2 mm, with each of which requiring only a few nanoliters of the enzyme deposition solution. The quantity of enzyme in each spot was evaluated with a chemiluminescent reaction and a charge-coupled device-based, low-light imaging luminograph. The chemiluminescence measurements revealed that the reproducibility of the enzyme deposition was satisfactory for analytical purposes, with the variation coefficients being lower than 10% in almost all cases. PMID:10723562

  18. Ag 2CuMnO 4: A new silver copper oxide with delafossite structure

    NASA Astrophysics Data System (ADS)

    Muñoz-Rojas, David; Subías, Gloria; Oró-Solé, Judith; Fraxedas, Jordi; Martínez, Benjamín; Casas-Cabanas, Montse; Canales-Vázquez, Jesús; Gonzalez-Calbet, Jose; García-González, Ester; Walton, Richard I.; Casañ-Pastor, Nieves

    2006-12-01

    The use of hydrothermal methods has allowed the synthesis of a new silver copper mixed oxide, Ag 2CuMnO 4, the first example of a quaternary oxide containing both elements. It crystallizes with the delafossite 3 R structure, thus being the first delafossite to contain both Ag and Cu. Synthesis conditions affect the final particle size (30-500 nm). Powder X-ray diffraction Rietveld refinement indicates a trigonal structure (R3¯m) and cell parameters a=2.99991 Å and c=18.428 Å, where Cu and Mn are disordered within the octahedral B positions in the plane and linearly coordinated Ag occupies de A position between layers. X-ray absorption near edge spectroscopy (XANES) for copper and manganese, and XPS for silver evidence +2, +4, and +1 oxidation states. The microstructure consists of layered particles that may form large twins showing 5 nm nanodomains. Finally, magnetic measurements reveal the existence of ferromagnetic coupling yielding in-plane moments that align antiferromagnetically at lower temperatures. The singularity of the new phase resides on the fact that is an example of a bidimensional arrangement of silver and copper in an oxide that also shows clear bidimensionality in its physical properties. That is of special relevance to the field of high Tc superconducting oxides, while the ferromagnetic coupling in a bidimensional system deserves itself special attention.

  19. Toward the Complete Characterization of Atmospheric Organic Particulate Matter: Derivatization and Two-Dimensional Comprehensive Gas Chromatography/Time of Flight Mass Spectrometry as a Method for the Determination of Carboxylic Acids

    NASA Astrophysics Data System (ADS)

    Boris, Alexandra Jeanne

    Understanding the composition of atmospheric organic particulate matter (OPM) is essential for predicting its effects on climate, air quality, and health. However, the polar oxygenated fraction (PO-OPM), which includes a significant mass contribution from carboxylic acids, is difficult to speciate and quantitatively determine by current analytical methods such as gas chromatography-mass spectrometry (GC-MS). The method of chemical derivatization and two-dimensional GC with time of flight MS (GCxGC/TOF-MS) was examined in this study for its efficacy in: 1) quantifying a high percentage of the total organic carbon (TOC) mass of a sample containing PO-OPM; 2) quantitatively determining PO-OPM components including carboxylic acids at atmospherically relevant concentrations; and 3) tentatively identifying PO-OPM components. Two derivatization reagent systems were used in this study: BF3/butanol for the butylation of carboxylic acids, aldehydes, and acidic ketones, and BSTFA for the trimethylsilylation (TMS) of carboxylic acids and alcohols. Three alpha-pinene ozonolysis OPM filter samples and a set of background filter samples were collected by collaborators in a University of California, Riverside environmental chamber. Derivatization/GCxGC TOF-MS was used to tentatively identify some previously unidentified α-pinene ozonolysis products, and also to show the characteristics of all oxidation products determined. Derivatization efficiencies as measured were 40-70% for most butyl derivatives, and 50-58% for most trimethylsilyl derivatives. A thermal optical method was used to measure the TOC on each filter, and a value of the quantifiable TOC mass using a gas chromatograph was calculated for each sample using GCxGC separation and the mass-sensitive response of a flame ionization detector (FID). The TOC quantified using TMS and GCxGC-FID (TMS/TOCGCxGC FID) accounted for 15-23% of the TOC measured by the thermal-optical method. Using TMS and GCxGC/TOF-MS, 8.85% of the

  20. Identification and quantification of individual chemical compounds in biogenic secondary organic aerosols using GCxGC-VUV/EI-HRTOFMS

    NASA Astrophysics Data System (ADS)

    Decker, M.; Worton, D. R.; Isaacman, G. A.; Chan, A. W.; Ruehl, C.; Zhao, Y.; Wilson, K. R.; Goldstein, A. H.

    2012-12-01

    Atmospheric aerosols have adverse effects on human health and air quality and affect radiative forcing and thus climate. While the organic fraction of aerosols is substantial, the sources and chemistry leading to the formation of secondary organic aerosols are very poorly understood. Characterizing individual compounds present in organic aerosol provides insights into the sources, formation mechanisms and oxidative transformations that have taken place. Fifteen aerosol samples collected over a 5 day period at the Blodgett Forest Research Station in the Sierra Nevada Mountains, part of the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX) in July 2009, were analyzed using comprehensive two dimensional gas chromatography with high resolution time of flight mass spectrometry (GCxGC-HRTOFMS). Approximately 600 compounds were observed in each sample as significant peaks in the chromatogram. Of these, around a third were identified by matching the unique electron ionization (EI) mass spectrum of each compound to the NIST library of characteristic fragmentation patterns. One filter sample was also analyzed using vacuum ultraviolet ionization (VUV) instead of EI. This 'soft' ionization technique results in much less fragmentation yielding the molecular ion of each compound, from which the exact mass was determined. If the formula of the EI library matched compound equaled the high mass resolution VUV molecular weight within a certain tolerance (< 30 ppm), then the library match was considered confirmed; 226 compounds were identified in this way. Using the VUV technique 234 additional compounds that were not in the EI mass spectral database were assigned chemical formulas based on the observed molecular weights. The chemical formulas in conjunction with the location of the compound in the GCxGC chromatogram were used to provide further classification of these compounds based on their likely functionalization. The broad array of observed oxygenated

  1. Fatty acids as biomarkers for food web structure in the eastern North Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Behrens, J.; Aluwihare, L.; Stephens, B. M.

    2015-12-01

    Resulting from a NSF funded REU program at Scripps Institution of Oceanography in 2015, this research utilized gas chromatography-mass spectrometry (GC-MS) to analyze the fatty acid composition of suspended particulate organic matter (POM) and zooplankton (ZP; primarily copepods). Samples analyzed for this study were collected simultaneously from surface waters approximately 9 miles off the coast of San Diego in June 2015. I was testing the hypothesis that essential fatty acids in ZP should reflect their diet, in particular, distinguishing contributions from a microbial versus traditional food web. Food web structure in this region of the ocean has been shown to be sensitive to climate change on inter-annual and longer timescales. Thus, a proxy that identifies restructuring of food webs would be useful for examining the response of ocean ecosystems to future climate change. Lipids were extracted from ZP and POM using a modified Bligh and Dyer method with sonication. Following saponification free fatty acids and other lipids were further purified using column chromatography. Polar functional groups in lipids were then methylated prior to GC-MS analysis. In addition, 2-dimensional GCxGC with time of flight MS was used to distinguish polyunsaturated fatty acid isomers. My poster will present initial findings of shared fatty acids of zooplankton and POM suspended material from the Northern Pacific collection site. Further research will be focused on analyzing the hydrogen isotope composition of fatty acids in zooplankton and suspended DOM obtained at the collection site to further characterize and increase certainty on the role of microbes and phytoplankton in the region's food-web to distinguish prokaryotic and eukaryotic sources.

  2. Heterogeneous OH oxidation of motor oil particles causes selective depletion of branched and less cyclic hydrocarbons

    NASA Astrophysics Data System (ADS)

    Isaacman, G.; Chan, A. W.; Nah, T.; Worton, D. R.; Ruehl, C.; Kolesar, K. R.; Cappa, C. D.; Wilson, K. R.; Goldstein, A. H.

    2012-12-01

    Motor oil serves as a useful model system for atmospheric oxidation of hydrocarbon mixtures typical of anthropogenic atmospheric particulate matter, but its complexity often prevents comprehensive chemical speciation. In this work we fully characterize this formerly "unresolved complex mixture" at the molecular level using two-dimensional gas chromatography with vacuum-ultraviolet ionization and high resolution time-of-flight mass spectrometry (GCxGC/VUV-HRTOFMS). This "soft" ionization technique allows us to classify compounds by carbon number, cyclization, and branching, resolving 80-90% of hydrocarbon mass in petroleum fuels. Nucleated motor oil (15W-40) particles were oxidized by OH radicals in a flow tube reactor and the oxidative decay and transformations of straight, branched, cyclic, and polycyclic alkanes were measured using high resolution analysis. Oxidation of hydrocarbons in a complex aerosol is found to be efficient and steady, with approximately three-quarters (0.72 ± 0.06) of OH collisions yielding a reaction. Reaction rates of individual hydrocarbons are structurally dependent: compared to normal alkanes, reaction rates increased by 20-50% with branching, while rates decreased ~20% per non-aromatic ring present. These differences in rates will alter particle composition as a function of oxidation, with depletion of branched and enrichment of cyclic hydrocarbons. Compositional changes in turn influence oxidation pathways, since functionalization reactions are more prevalent with cyclic compounds. The GCxGC plane provides separation by parameters typically used in current models (volatility and polarity) so is used to explore changes in oxidation mechanisms of motor oil. Estimates of fragmentation and functionalization of this complex hydrocarbon mixture are compared to simple model compounds based on movement in the chromatographic plane.

  3. Advances in the gas chromatographic determination of persistent organic pollutants in the aquatic environment.

    PubMed

    van Leeuwen, S P J; de Boer, J

    2008-04-01

    Environmental chemists have been challenged for over 30 years to analyse complex mixtures of halogenated organic pollutants like polychlorinated biphenyls (PCBs), polychlorinated alkanes (PCAs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and polychlorinated furans (PCDD/Fs). Gas chromatography (GC) often proved to be the method of choice because of its high resolution. The recent developments in the field of comprehensive two-dimensional GC (GCxGC) show that this technique can provide much more information than conventional (single-column) GC. Large volume injection (e.g. by programmed temperature vaporiser, or on-column injection) can be employed for the injection of tens of microliters of sample extract, in that way substantially improving the detection limits. Electron-capture detection (ECD) is a sensitive detection method but unambiguous identification is not possible and misidentification easily occurs. Mass spectrometric (MS) detection substantially improves the identification and the better the resolution (as with MS/MS, time-of-flight (TOF) MS and high-resolution (HR)MS), the lower the chances of misidentification are. Unfortunately, this comes only with substantially higher investments and maintenance costs. Co-extracted lipids, sulphur and other interferences can disturb the GC separation and detection leading to unreliable results. Extraction, and more so, sample clean-up and fractionation, are crucial steps prior to the GC analysis of these pollutants. Recent developments in sample extraction and clean-up show that selective pressurised liquid extraction (PLE) is an effective and efficient extraction and clean-up technique that enables processing of multiple samples in less than 1h. Quality assurance tools such as interlaboratory studies and reference materials are very well established for PCDD/Fs and PCBs but the improvement of that infrastructure is needed for brominated flame retardants, PCAs and toxaphene. PMID

  4. Investigation of the detailed chemical composition of organic aerosol in a South East Asian Rainforest

    NASA Astrophysics Data System (ADS)

    Hamilton, Jacqueline; Ward, Martyn; Rami Alfarra, M.; Lewis, Alastair; McFiggans, Gordon; Robinson, Niall

    2010-05-01

    The formation of secondary organic aerosol (SOA) in tropical regions is a key uncertainty in quantifying the effect of man made emissions on the climate. Large quantities of volatile organic compounds are emitted from natural biogenic sources in the tropics, including isoprene, monoterpenes and sequiterpenes. There are very few studies of the detailed chemical composition of organic aerosols in tropical rainforest regions, but these would provide information on the importance of primary versus secondary organic aerosols, the key VOC precursors, oxidation state and volatility. Particle samples were collected in a tropical rainforest at Danum Valley in Borneo as part of the OP3 field campaign in 2008. Twenty four hour filter samples were collected at the Global Atmospheric Watch station at a height of around 10 m and shipped back to the laboratory (below -4 °C) for offline analysis. The OA composition was studied using multiple high resolution chromatographic techniques including comprehensive two dimensional gas chromatography coupled to time of flight mass spectrometry (GCXGC-TOFMS) and liquid chromatography coupled to ion trap mass spectrometry (LC-MSn). The composition was directly compared to chamber generated SOA (as part of the Aerosol Coupling in the Earths System , ACES, experiment) to determine SOA tracers. A biogenic SOA tracer MS fragmentation library was constructed and a number of SOA components from limonene, linalool and -pinene were identified in the rainforest OA. Very high resolution mass spectrometry (Fourier Transform Ion Cyclotron Resonance FTICR-MS) allowed the O:C and H:C ratios to be determined and these will be compared to those obtained by aerosol mass spectrometry (AMS). In addition, the OA composition from the rainforest will be compared to other locations.

  5. Performance analysis of parallel supernodal sparse LU factorization

    SciTech Connect

    Grigori, Laura; Li, Xiaoye S.

    2004-02-05

    We investigate performance characteristics for the LU factorization of large matrices with various sparsity patterns. We consider supernodal right-looking parallel factorization on a bi-dimensional grid of processors, making use of static pivoting. We develop a performance model and we validate it using the implementation in SuperLU-DIST, the real matrices and the IBM Power3 machine at NERSC. We use this model to obtain performance bounds on parallel computers, to perform scalability analysis and to identify performance bottlenecks. We also discuss the role of load balance and data distribution in this approach.

  6. Note: Background Oriented Schlieren as a diagnostics for airflow control by plasma actuators.

    PubMed

    Biganzoli, I; Capone, C; Barni, R; Riccardi, C

    2015-02-01

    Background Oriented Schlieren (BOS) is an optical technique sensitive to the first spatial derivative of the refractive index inside a light-transmitting medium. Compared to other Schlieren-like techniques, BOS is more versatile and allows to capture bi-dimensional gradients rather than just one spatial component. We propose to adopt BOS for studying the capabilities of surface dielectric barrier discharges to work like plasma actuators in flow control applications. The characteristics of the BOS we implemented at this purpose are discussed, together with few results concerning the ionic wind produced by the discharge in absence of an external airflow. PMID:25725896

  7. A far infrared/terahertz micromechanical sensor based on surface plasmons resonance

    NASA Astrophysics Data System (ADS)

    Hastanin, J.; Renotte, Y.; Fleury-Frenette, K.; Defise, J. M.; Habraken, S.

    2008-10-01

    This paper describes a new concept related to the bolometric micromechanical sensors for detecting far IR and THz radiation. We believe that this concept permits a low cost and ease of fabrication of large bi-dimensional array of sensors with an enhanced signal-to-noise ratio. The micromechanical sensor comprises a thermo-sensitive bi-material (multi-material) micro-cantilever beam with a selective absorber dedicated to far IR and THz radiation energy, and optical readout system based on surface plasmon resonance for detecting the bending of the micro-cantilever element. To increase the radiation detector sensitivity, the SPR phenomenon is used for cantilever deflection monitoring.

  8. Conditions for achieving ideal and Lambertian symmetrical solar concentrators.

    PubMed

    Luque, A; Lorenzo, E

    1982-10-15

    In this paper we are concerned with symmetrical bidimensional concentrators, and we prove that for a given source's angular extension a curve exists that divides the plane into two regions. No ideal concentrator can be found with its edges on the outer region and no Lambertian concentrator can be found with its edges on the inner region. A consequence of this theorem is that a concentrator is forced to cast some of the incident energy outside the collector to ensure its obtaining the maximum power. PMID:20396308

  9. Seed layer technique for high quality epitaxial manganite films

    NASA Astrophysics Data System (ADS)

    Graziosi, P.; Gambardella, A.; Calbucci, M.; O'Shea, K.; MacLaren, D. A.; Riminucci, A.; Bergenti, I.; Fugattini, S.; Prezioso, M.; Homonnay, N.; Schmidt, G.; Pullini, D.; Busquets-Mataix, D.; Dediu, V.

    2016-08-01

    We introduce an innovative approach to the simultaneous control of growth mode and magnetotransport properties of manganite thin films, based on an easy-to-implement film/substrate interface engineering. The deposition of a manganite seed layer and the optimization of the substrate temperature allows a persistent bi-dimensional epitaxy and robust ferromagnetic properties at the same time. Structural measurements confirm that in such interface-engineered films, the optimal properties are related to improved epitaxy. A new growth scenario is envisaged, compatible with a shift from heteroepitaxy towards pseudo-homoepitaxy. Relevant growth parameters such as formation energy, roughening temperature, strain profile and chemical states are derived.

  10. Pyroelectric Applications of the VDF-TrFE Copolymer

    NASA Technical Reports Server (NTRS)

    Simonne, J. J.; Bauer, Ph.; Audaire, L.; Bauer, F.

    1995-01-01

    VDF/TrFe pyroelectric sensors have now definitely reached the level of a product. Based on a bidimensional staring array, it can be considered as a whole system with a monolithic technology processed on a silicon substrate provided with the integrated read out circuit. The paper will describe the main procedure dealing with the elaboration of a 32 x 32 focal plane array developed, in the context of the PROMETHEUS PROCHIP European Program (EUREKA), as a passive infrared obstacle detection applied to automotive. Additional experimental data suggest that this microsystem could operate in space environment.

  11. Emerging properties of financial time series in the "Game of Life".

    PubMed

    Hernández-Montoya, A R; Coronel-Brizio, H F; Stevens-Ramírez, G A; Rodríguez-Achach, M; Politi, M; Scalas, E

    2011-12-01

    We explore the spatial complexity of Conway's "Game of Life," a prototypical cellular automaton by means of a geometrical procedure generating a two-dimensional random walk from a bidimensional lattice with periodical boundaries. The one-dimensional projection of this process is analyzed and it turns out that some of its statistical properties resemble the so-called stylized facts observed in financial time series. The scope and meaning of this result are discussed from the viewpoint of complex systems. In particular, we stress how the supposed peculiarities of financial time series are, often, overrated in their importance. PMID:22304152

  12. The double superficiality of the frontal image of the Turin Shroud

    NASA Astrophysics Data System (ADS)

    Fanti, Giulio; Maggiolo, Roberto

    2004-06-01

    Photographs of the back surface of the Turin Shroud were analysed to verify the existence of a double body image of a man. The body image is very faint and the background not uniform; i.e., the signal-to-noise ratio is lower than one. Therefore, image processing, developed ad hoc, was necessary to highlight body features. This was based on convolution with Gaussian filters, summation of images, and filtering in spatial frequency by direct and inverse bidimensional Fourier transformations. Body features were identified by template matching. The face and probably also the hands are visible on the back of the Turin Shroud, but not features related to the dorsal image.

  13. Third order nonlinear optical response exhibited by mono- and few-layers of WS2

    NASA Astrophysics Data System (ADS)

    Torres-Torres, Carlos; Perea-López, Néstor; Elías, Ana Laura; Gutiérrez, Humberto R.; Cullen, David A.; Berkdemir, Ayse; López-Urías, Florentino; Terrones, Humberto; Terrones, Mauricio

    2016-06-01

    In this work, strong third order nonlinear optical properties exhibited by WS2 layers are presented. Optical Kerr effect was identified as the dominant physical mechanism responsible for these third order optical nonlinearities. An extraordinary nonlinear refractive index together with an important contribution of a saturated absorptive response was observed to depend on the atomic layer stacking. Comparative experiments performed in mono- and few-layer samples of WS2 revealed that this material is potentially capable of modulating nonlinear optical processes by selective near resonant induced birefringence. We envision applications for developing all-optical bidimensional nonlinear optical devices.

  14. Motion of a two-degree-of-freedom structure in the presence of a fluidelastic force

    SciTech Connect

    Turbelin, G.; Porcher, G.; Gibert, R.J.

    1996-12-01

    The fluidelastic force induced by a confined flow in a bidimensional flow channel, has been determined by using a method which takes into account the dissipative effects by a linearizing of the pressure losses considered as boundary conditions. This force has been used to study the stability of a two-degree-of-freedom structure for several boundary conditions. The motion equation of the system can be solved with an iterative method, and a parametric study has been carried out. The results obtained show the appearance of a flutter instability which has been largely influenced by the position and the value of the pressure losses.

  15. Effective photoconductivity of exfoliated black phosphorus for optoelectronic switching under 1.55 μm optical excitation

    NASA Astrophysics Data System (ADS)

    Penillard, A.; Tripon-Canseliet, C.; Rosticher, M.; Maksimovic, I.; Liu, Z.; Géron, E.

    2016-01-01

    We present a microwave photoconductive switch based on exfoliated black phosphorus and strongly responding to a 1.55 μm optical excitation. According to its number of atomic layers, exfoliated black phosphorus presents unique properties for optoelectronic applications, like a tunable direct bandgap from 0.3 eV to 2 eV, strong mobilities, and strong conductivities. The switch shows a maximum ON/OFF ratio of 17 dB at 1 GHz, and 2.2 dB at 20 GHz under 1.55-μm laser excitation at 50 mW, never achieved with bidimensional materials.

  16. Evidence of cortical reorganization in hemiparetic patients

    SciTech Connect

    Brion, J.P.; Demeurisse, G.; Capon, A. )

    1989-08-01

    We studied the mechanisms underlying the recovery of motor function of the hand using a bidimensional xenon-133 inhalation technique to measure regional cerebral blood flow at rest and during the performance of a motor task (test condition). The regional cerebral blood flow patterns under rest and test conditions were compared in normal control and in stroke patients with either a cortico-subcortical or a deep-seated lesion. Functional recovery appears to depend upon cortical reorganization involving both hemispheres, particularly in both parietal regions in the subgroup of patients with cortico-subcortical lesions.

  17. Anti-inertial lift in foams: a signature of the elasticity of complex fluids.

    PubMed

    Dollet, Benjamin; Aubouy, Miguel; Graner, François

    2005-10-14

    To understand the mechanics of a complex fluid such as a foam we propose a model experiment (a bidimensional flow around an obstacle) for which an external sollicitation is applied, and a local response is measured, simultaneously. We observe that an asymmetric obstacle (cambered airfoil profile) experiences a downwards lift, opposite to the lift usually known (in a different context) in aerodynamics. Correlations of velocity, deformations, and pressure fields yield a clear explanation of this inverse lift, involving the elasticity of the foam. We argue that such an inverse lift is likely common to complex fluids with elasticity. PMID:16241847

  18. Emerging properties of financial time series in the ``Game of Life''

    NASA Astrophysics Data System (ADS)

    Hernández-Montoya, A. R.; Coronel-Brizio, H. F.; Stevens-Ramírez, G. A.; Rodríguez-Achach, M.; Politi, M.; Scalas, E.

    2011-12-01

    We explore the spatial complexity of Conway’s “Game of Life,” a prototypical cellular automaton by means of a geometrical procedure generating a two-dimensional random walk from a bidimensional lattice with periodical boundaries. The one-dimensional projection of this process is analyzed and it turns out that some of its statistical properties resemble the so-called stylized facts observed in financial time series. The scope and meaning of this result are discussed from the viewpoint of complex systems. In particular, we stress how the supposed peculiarities of financial time series are, often, overrated in their importance.

  19. A 3-D Generalization of the Budyko Framework Captures the Mutual Interdependence Between Long-Term Mean Annual Precipitation, Actual and Potential Evapotranspiration

    NASA Astrophysics Data System (ADS)

    Carmona, A. M.; Poveda, G.

    2012-12-01

    We study the behavior of the 3-D parameter space defined by Φ =PET/P (so-called Aridity Index), Ψ =AET/P, and Ω =AET/PET, where P denotes mean annual precipitation, and PET and AET denote mean annual potential and actual evapotranspiration, respectively. Using information from the CLIMWAT 2.0 database (www.fao.org/nr/water/infores_databases_climwat.html) for P and PET, we estimate AET using both Budyko's and Turc's equations. Our results indicate that the well-known Budyko function that relates Φ vs.Ψ corresponds to a particular bi-dimensional cross-section of a broader coupling existing between Φ, Ψ and Ω (Figure 1a), and in turn of the mutual interdependence between P, PET and AET. The behavior of the three bi-dimensional projections are clearly parameterized by the remaining ortogonal parameter, such that: (i) the relation Φ vs. Ψ is defined by physically consistent varying values of Ω (Figure 1b); (ii) the relation Ω vs. Ψ is defined by physically consistent varying values of the Aridity Index,Φ (Figure 1c), and (iii) the relation Ω vs. Φ is defined by physically consistent varying values of Ψ (Figure 1d). Interestingly, we show that Φ and Ω are related by a power law, Φ~Ω-θ, with scaling exponent θ=1.15 (R2=0.91, n=3420) for the whole world (Figure 1d). Mathematical functions that model the three bi-dimensional projections and the surface defining the interdependence between Φ, Ψ and Ω will be presented. Our results provide a new framework to understand the coupling between the long-term mean annual water and energy balances in river basins, and the hydrological effects brought about by climate change, while taking into account the mutual interdependence between the three non-dimensional parameters Φ, Ψ and Ω, and in turn between P, PET and AET. Figure 1. (a) Three-dimensional rendering of sample values of Φ =PET/P (so-called Aridity Index), Ψ =AET/P, and Ω=AET/PET. Bi-dimensional projections of: (b) relation Φ vs.

  20. A hardware and software overview of the Delphi contiguity trigger

    SciTech Connect

    Darbo, G. ); Heck, B.W.; Wildman, J.M. )

    1991-04-01

    The contiguity processor of the Delphi detector, which is composed of 12 Fastbus modules (one for each TPC sector), is the main second-level track trigger component in the experiment. More than 3000 Mips of processing power are achieved by 4608 processing elements (PE) packed in specially designed ASIC IC's. High interconnectivity among PE's (bidimensional lattice) and a highly parallel algorithm (contiguity mask) allow a three-dimensional vertex reconstruction in less than 5{mu}s. In this paper an overview of the single instruction multiple data (SIMD) architecture, together with the programming language and the interactive debugging tools for the processor, are given.

  1. Digital Model of Fourier and Fresnel Quantized Holograms

    NASA Astrophysics Data System (ADS)

    Boriskevich, Anatoly A.; Erokhovets, Valery K.; Tkachenko, Vadim V.

    Some models schemes of Fourier and Fresnel quantized protective holograms with visual effects are suggested. The condition to arrive at optimum relationship between the quality of reconstructed images, and the coefficient of data reduction about a hologram, and quantity of iterations in the reconstructing hologram process has been estimated through computer model. Higher protection level is achieved by means of greater number both bi-dimensional secret keys (more than 2128) in form of pseudorandom amplitude and phase encoding matrixes, and one-dimensional encoding key parameters for every image of single-layer or superimposed holograms.

  2. Hysteretic mode exchange in the wake of two circular cylinders in tandem

    NASA Astrophysics Data System (ADS)

    Tasaka, Yuji; Kon, Seiji; Schouveiler, Lionel; Le Gal, Patrice

    2006-08-01

    Our experimental study is devoted to the analysis of the flow past two tandem circular cylinders near the vortex shedding threshold. A recent bidimensional numerical analysis of this flow [Mizushima and Suehiro, Phys. Fluids 17, 104107 (2005)] has predicted that the bifurcation diagram should become complex in the vicinity of the instability threshold. Subcritical and saddle node bifurcations that lead to hysteretic exchanges between two different modes of vortex shedding were detected for particular distances of separation of the cylinders. We present here visualizations and velocity measurements of this flow in a water channel that prove the robustness of the complexity of the bifurcation diagram in real flows.

  3. Nonsynchronous updating in the multiverse of cellular automata.

    PubMed

    Reia, Sandro M; Kinouchi, Osame

    2015-04-01

    In this paper we study updating effects on cellular automata rule space. We consider a subset of 6144 order-3 automata from the space of 262144 bidimensional outer-totalistic rules. We compare synchronous to asynchronous and sequential updatings. Focusing on two automata, we discuss how update changes destroy typical structures of these rules. Besides, we show that the first-order phase transition in the multiverse of synchronous cellular automata, revealed with the use of a recently introduced control parameter, seems to be robust not only to changes in update schema but also to different initial densities. PMID:25974442

  4. Nonsynchronous updating in the multiverse of cellular automata

    NASA Astrophysics Data System (ADS)

    Reia, Sandro M.; Kinouchi, Osame

    2015-04-01

    In this paper we study updating effects on cellular automata rule space. We consider a subset of 6144 order-3 automata from the space of 262144 bidimensional outer-totalistic rules. We compare synchronous to asynchronous and sequential updatings. Focusing on two automata, we discuss how update changes destroy typical structures of these rules. Besides, we show that the first-order phase transition in the multiverse of synchronous cellular automata, revealed with the use of a recently introduced control parameter, seems to be robust not only to changes in update schema but also to different initial densities.

  5. A comparison of locally adaptive multigrid methods: LDC, FAC and FIC

    NASA Technical Reports Server (NTRS)

    Khadra, Khodor; Angot, Philippe; Caltagirone, Jean-Paul

    1993-01-01

    This study is devoted to a comparative analysis of three 'Adaptive ZOOM' (ZOom Overlapping Multi-level) methods based on similar concepts of hierarchical multigrid local refinement: LDC (Local Defect Correction), FAC (Fast Adaptive Composite), and FIC (Flux Interface Correction)--which we proposed recently. These methods are tested on two examples of a bidimensional elliptic problem. We compare, for V-cycle procedures, the asymptotic evolution of the global error evaluated by discrete norms, the corresponding local errors, and the convergence rates of these algorithms.

  6. Faithful test of nonlocal realism with entangled coherent states

    SciTech Connect

    Lee, Chang-Woo; Jeong, Hyunseok; Paternostro, Mauro

    2011-02-15

    We investigate the violation of Leggett's inequality for nonlocal realism using entangled coherent states and various types of local measurements. We prove mathematically the relation between the violation of the Clauser-Horne-Shimony-Holt form of Bell's inequality and Leggett's one when tested by the same resources. For Leggett inequalities, we generalize the nonlocal realistic bound to systems in Hilbert spaces larger than bidimensional ones and introduce an optimization technique that allows one to achieve larger degrees of violation by adjusting the local measurement settings. Our work describes the steps that should be performed to produce a self-consistent generalization of Leggett's original arguments to continuous-variable states.

  7. Width of the level at E sub x congruent 18 MeV in sup 5 Li

    SciTech Connect

    Arena, N.; Cavallaro, S. Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Catania, Italy); D'Arrigo, A.; Fazio, G.; Giardina, G.; Italiano, A.; Herman, M.; Lombardi, M.

    1989-09-01

    The {alpha}{alpha} bidimensional spectra for the {sup 6}Li({sup 3}He, {alpha}{ital p}){sup 4}He reaction at 11, 13, and 14 MeV incident energy have been measured. The {sup 5}Li state at {ital E}{sub {ital x}}=(17.9{plus minus}0.4) MeV has been observed and its width has been determined as (3.5{plus minus}0.8) MeV. The excitation energy is in line with the shell-model calculations while the {Gamma} value is the first quantitative estimate of the width of the above state.

  8. Contribution to the numerical study of turbulence in high intensity discharge lamps

    SciTech Connect

    Kaziz, S.; Ben Ahmed, R.; Helali, H.; Gazzah, H.; Charrada, K.

    2011-07-15

    We present in this paper a comparison between results obtained with a laminar and turbulent models for high-pressure mercury arc. The two models are based on the resolution of bidimensional time-dependent equations by a semi-implicit finite-element code. The numerical computation of turbulent model is solved with large eddy simulation model; this approach takes into account the various scales of turbulence by a filtering method on each scale. The results show the quantitative influence of turbulence on the flow fields and also the difference between laminar and turbulent effects on the dynamic thermal behaviour and on the characteristics of the discharge.

  9. Unsteady flow characteristics in the near-wake of a two-dimensional obstacle

    NASA Technical Reports Server (NTRS)

    Dyment, A.; Gryson, P.

    1984-01-01

    The influence of the characteristics of the boundary layer separation on the formation of vortices and alternate paths in the wake of a bidimensional obstacle at high Reynolds numbers was studied by ultra fast visualization system. It is shown that there are alternate paths for laminar and turbulent flows, with similar flow characteristics. It is found that emission of vortices does not change substantially when the flow passes from laminar to turbulent. A film with a time scale change of 10,000 times illustrates some of the discussed phenomena.

  10. A full 3D plane-wave-expansion model for 1-3 piezoelectric composite structures.

    PubMed

    Wilm, Mikaël; Ballandras, Sylvain; Laude, Vincent; Pastureaud, Thomas

    2002-09-01

    The plane-wave-expansion (PWE) approach dedicated to the simulation of periodic devices has been extended to 1-3 connectivity piezoelectric composite structures. The case of simple but actual piezoelectric composite structures is addressed, taking piezoelectricity, acoustic losses, and electrical excitation conditions rigorously into account. The material distribution is represented by using a bidimensional Fourier series and the electromechanical response is simulated using a Bloch-Floquet expansion together with the Fahmy-Adler formulation of the Christoffel problem. Application of the model to 1-3 connectivity piezoelectric composites is reported and compared to previously published analyses of this problem. PMID:12243182

  11. Optical beam steering using a 2D MEMS scanner

    NASA Astrophysics Data System (ADS)

    Pétremand, Yves; Clerc, Pierre-André; Epitaux, Marc; Hauffe, Ralf; Noell, Wilfried; de Rooij, N. F.

    2007-10-01

    This paper presents the design, fabrication and operation principle of an optical beam steerer for laser fiber coupling based on a MEMS device. The MEMS chip consists on a bi-dimensional movable platform based on uni-dimensional comb drive actuation. An optical lens is assembled onto the mobile platform to focus and steer the light comping from a laser diode and couple it into an optical fiber. Assembly of a complete system and measurements were performed and compared to simulation results. Both the trajectory of the MEMS and resonance frewquency measurements agree with the simulated ones.

  12. Anti-Inertial Lift in Foams: A Signature of the Elasticity of Complex Fluids

    NASA Astrophysics Data System (ADS)

    Dollet, Benjamin; Aubouy, Miguel; Graner, François

    2005-10-01

    To understand the mechanics of a complex fluid such as a foam we propose a model experiment (a bidimensional flow around an obstacle) for which an external sollicitation is applied, and a local response is measured, simultaneously. We observe that an asymmetric obstacle (cambered airfoil profile) experiences a downwards lift, opposite to the lift usually known (in a different context) in aerodynamics. Correlations of velocity, deformations, and pressure fields yield a clear explanation of this inverse lift, involving the elasticity of the foam. We argue that such an inverse lift is likely common to complex fluids with elasticity.

  13. Optical correlators: systems and domains of applications

    NASA Astrophysics Data System (ADS)

    Dragulinescu, Andrei; Cojoc, Dan

    2005-08-01

    The paper presents the basic concepts of the optical correlators. In our knowledge, it is the first systematic presentation of the applications of optical correlators. The main three types of optical correlators: the optical correlator in incoherent light, the optical correlator in coherent light (VanderLugt) and the joint transform correlator are presented. The optical correlators are very powerll systems used for image recognition, that perform a correlation between a bidimensional function which represents a Scene that must be analyzed and another bidimensional function that contains information about the reference function. This correlation is optically realized by a Fourier transform between the two functions. The optical Correlators have found a lot of applications for image recognition and target detection in various fields, such as the military field, robotics, medical field, industry a.s.o. Among the various applications of the optical correlators we can mention: digital fingerprints identification, credit card security, antique scripts recognition, determination of the cosmic ships and satellites behavior, amelioration of cancer tests precision, quality control etc.

  14. Iterative fragmentation of cognitive maps in a visual imagery task.

    PubMed

    Fourtassi, Maryam; Hajjioui, Abderrazak; Urquizar, Christian; Rossetti, Yves; Rode, Gilles; Pisella, Laure

    2013-01-01

    It remains unclear whether spontaneous eye movements during visual imagery reflect the mental generation of a visual image (i.e. the arrangement of the component parts of a mental representation). To address this specificity, we recorded eye movements in an imagery task and in a phonological fluency (non-imagery) task, both consisting in naming French towns from long-term memory. Only in the condition of visual imagery the spontaneous eye positions reflected the geographic position of the towns evoked by the subjects. This demonstrates that eye positions closely reflect the mapping of mental images. Advanced analysis of gaze positions using the bi-dimensional regression model confirmed the spatial correlation of gaze and towns' locations in every single individual in the visual imagery task and in none of the individuals when no imagery accompanied memory retrieval. In addition, the evolution of the bi-dimensional regression's coefficient of determination revealed, in each individual, a process of generating several iterative series of a limited number of towns mapped with the same spatial distortion, despite different individual order of towns' evocation and different individual mappings. Such consistency across subjects revealed by gaze (the mind's eye) gives empirical support to theories postulating that visual imagery, like visual sampling, is an iterative fragmented processing. PMID:23874672

  15. Measuring science or religion? A measurement analysis of the National Science Foundation sponsored science literacy scale 2006-2010.

    PubMed

    Roos, J Micah

    2014-10-01

    High scientific literacy is widely considered a public good. Methods of assessing public scientific knowledge or literacy are equally important. In an effort to measure lay scientific literacy in the United States, the National Science Foundation (NSF) science literacy scale has been a part of the last three waves of the General Social Survey. However, there has been debate over the validity of some survey items as indicators of science knowledge. While many researchers treat the NSF science scale as measuring a single dimension, previous work (Bann and Schwerin, 2004; Miller, 1998, 2004) suggests a bidimensional structure. This paper hypothesizes and tests a new measurement model for the NSF science knowledge scale and finds that two items about evolution and the big bang are more measures of a religious belief dimension termed "Young Earth Worldview" than they are measures of scientific knowledge. Results are replicated in seven samples. PMID:23825273

  16. Effect of adiabatic square ribs on natural convection in an asymmetrically heated channel

    NASA Astrophysics Data System (ADS)

    Abidi-Saad, Aissa; Kadja, Mahfoud; Popa, Catalin; Polidori, Guillaume

    2016-06-01

    A 2-D numerical simulation is carried out to investigate the effect of two adiabatic square ribs on laminar flow and heat transfer in an asymmetrically heated channel. The two ribs are symmetrically located on each wall, exactly above the heating zone. The computational procedure is made by solving the unsteady bi-dimensional continuity, momentum and energy equations with the finite volume method. The investigations focused more specifically on the influence of ribs sizes on the flow structure and heat transfer enhancement. The results showed that the variation of ribs sizes significantly alters the heat transfer and fluid flow distribution along the channel, especially in the vicinity of protrusions. Also, the results show that streamlines, isotherms, and the number, sizes and formation of vortex structures inside the channel strongly depend on the size of protrusions. The changes in heat transfer parameters have also been presented.

  17. Scanning in biomedical imaging: from classical devices to handheld heads and micro-systems

    NASA Astrophysics Data System (ADS)

    Duma, Virgil-Florin

    2014-01-01

    We review some of the most important scanning systems that are competitive in high-end biomedical imaging applications such as Optical Coherence Tomography (OCT), but also Confocal Microscopy (CM) or multiphoton microscopy. Both 1-D (uni-dimensional) and 2-D (bi-dimensional) scanning systems are considered. The paper discusses different scanners, including polygon mirror, galvanometer-based and Risley prisms. Their configurations and characteristics, as well some of our contributions in the domain are presented. The tendency of applying them into special designs such as handheld scanning probes and endoscopes - the latter with MEMS (Micro-Electro-Mechanical Systems) and micro-systems is pointed out. A discussion on further advancements of scanning technology in biomedical applications in general and in OCT in particular concludes the study.

  18. Acoustic behavior of ordered droplets in a liquid: A phase space approach

    SciTech Connect

    Rivera, A.L.; Lozada-Cassou, M.; Palomino, M.R.; Icaza, M. de; Castano, V.M.

    2005-03-01

    The transmission of an acoustical signal through a spatial arrangement consisting of a bidimensional crystal of droplets (liquid spheres) immersed into another liquid is analyzed. As a first approximation, the paraxial case is solved by considering a set of acoustical lenses which allow us to model the effect of each droplet on the signal. An expression for the Wigner distribution function that lets us evaluate the corresponding image, diffraction pattern, and even the output signal of any given paraxial input signal to that crystalline substrate is obtained, with particular emphasis on the case of an incoming plane wave. To solve the nonparaxial situation, a generalization of the concept of focal distance interpreting every sphere as a superposition of concentric rings of different radius, which permits us to find a general expression for the Wigner distribution function is proposed.

  19. Dispersion analysis and measurement of circular cylindrical wedge-like acoustic waveguides.

    PubMed

    Yu, Tai-Ho

    2015-09-01

    This study investigated the propagation of flexural waves along the outer edge of a circular cylindrical wedge, the phase velocities, and the corresponding mode displacements. Thus far, only approximate solutions have been derived because the corresponding boundary-value problems are complex. In this study, dispersion curves were determined using the bi-dimensional finite element method and derived through the separation of variables and the Hamilton principle. Modal displacement calculations clarified that the maximal deformations appeared at the outer edge of the wedge tip. Numerical examples indicated how distinct thin-film materials deposited on the outer surface of the circular cylindrical wedge influenced the dispersion curves. Additionally, dispersion curves were measured using a laser-induced guided wave, a knife-edge measurement scheme, and a two-dimensional fast Fourier transform method. Both the numerical and experimental results correlated closely, thus validating the numerical solution. PMID:26074457

  20. Neuromorphic silicon neuron circuits.

    PubMed

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin-Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  1. Analysis of brain activity and response during monoscopic and stereoscopic visualization

    NASA Astrophysics Data System (ADS)

    Calore, Enrico; Folgieri, Raffaella; Gadia, Davide; Marini, Daniele

    2012-03-01

    Stereoscopic visualization in cinematography and Virtual Reality (VR) creates an illusion of depth by means of two bidimensional images corresponding to different views of a scene. This perceptual trick is used to enhance the emotional response and the sense of presence and immersivity of the observers. An interesting question is if and how it is possible to measure and analyze the level of emotional involvement and attention of the observers during a stereoscopic visualization of a movie or of a virtual environment. The research aims represent a challenge, due to the large number of sensorial, physiological and cognitive stimuli involved. In this paper we begin this research by analyzing possible differences in the brain activity of subjects during the viewing of monoscopic or stereoscopic contents. To this aim, we have performed some preliminary experiments collecting electroencephalographic (EEG) data of a group of users using a Brain- Computer Interface (BCI) during the viewing of stereoscopic and monoscopic short movies in a VR immersive installation.

  2. 1024 pixels single photon imaging array for 3D ranging

    NASA Astrophysics Data System (ADS)

    Bellisai, S.; Guerrieri, F.; Tisa, S.; Zappa, F.; Tosi, A.; Giudice, A.

    2011-01-01

    Three dimensions (3D) acquisition systems are driving applications in many research field. Nowadays 3D acquiring systems are used in a lot of applications, such as cinema industry or in automotive (for active security systems). Depending on the application, systems present different features, for example color sensitivity, bi-dimensional image resolution, distance measurement accuracy and acquisition frame rate. The system we developed acquires 3D movie using indirect Time of Flight (iTOF), starting from phase delay measurement of a sinusoidally modulated light. The system acquires live movie with a frame rate up to 50frame/s in a range distance between 10 cm up to 7.5 m.

  3. In vitro imaging of remaining dentin and pulp chamber by optical coherence tomography: comparison between 850 and 1280 nm

    NASA Astrophysics Data System (ADS)

    Fonsêca, Déborah D. D.; Kyotoku, Bernardo B. C.; Maia, Ana M. A.; Gomes, Anderson S. L.

    2009-03-01

    We report the application of optical coherence tomography (OCT) to generate images of the remaining dentin and pulp chamber of in vitro human teeth. Bidimensional images of remaining dentin and of the pulp chamber were obtained parallel to the long axis of the teeth, by two OCT systems operating around 1280 and 850 nm, and compared to tomography images using the i-CAT® Cone Beam Volumetric Tomography system as the gold standard. The results demonstrated the efficacy of the OCT technique; furthermore, the wavelength close to 1280 nm presented greater penetration depth in the dentine than 850 nm, as expected from scattering and absorption coefficients. The OCT technique has great potential to be used on clinical practice, preventing accidental exposure of the pulp and promoting preventive restoration treatment.

  4. Non-Gaussian behavior in jamming / unjamming transition in dense granular materials

    NASA Astrophysics Data System (ADS)

    Atman, A. P. F.; Kolb, E.; Combe, G.; Paiva, H. A.; Martins, G. H. B.

    2013-06-01

    Experiments of penetration of a cylindrical intruder inside a bidimensional dense and disordered granular media were reported recently showing the jamming / unjamming transition. In the present work, we perform molecular dynamics simulations with the same geometry in order to assess both kinematic and static features of jamming / unjamming transition. We study the statistics of the particles velocities at the neighborhood of the intruder to evince that both experiments and simulations present the same qualitative behavior. We observe that the probability density functions (PDF) of velocities deviate from Gaussian depending on the packing fraction of the granular assembly. In order to quantify these deviations we consider a q-Gaussian (Tsallis) function to fit the PDF's. The q-value can be an indication of the presence of long range correlations along the system. We compare the fitted PDF's obtained with those obtained using the stretched exponential, and sketch some conclusions concerning the nature of the correlations along a granular confined flow.

  5. High-quality molecular-beam epitaxial regrowth of (Al,Ga)As on Se-modified (100) GaAs surfaces

    NASA Astrophysics Data System (ADS)

    Turco, F. S.; Sandroff, C. J.; Hwang, D. M.; Ravi, T. S.; Tamargo, M. C.

    1990-08-01

    It is shown that high-quality molecular-beam epitaxial (MBE) regrowth of (Al,Ga)As on GaAs can be achieved by chemically passivating the GaAs surface ex situ prior to regrowth with aqueous selenium reagents. Reflection high-energy electron diffraction intensity oscillations show the bidimensional character of the regrowth and high-resolution transmission electron microscopy reveals defect-free regrown interfaces. Photoluminescence intensity from the Se-treated GaAs surfaces on which Al0.5Ga0.5 As is regrown rivals that from an all in situ grown AlGaAs/GaAs interface. The high quality of these regrown interfaces could be attributed to the thermally and chemically stable selenium and oxygen phases that remain bound to GaAs under MBE conditions.

  6. Tunable superconductivity in decorated graphene

    NASA Astrophysics Data System (ADS)

    Han, Zheng; Allain, Adrien; Marty, Laetitia; Bendiab, Nedjma; Toulemonde, Pierre; Strobel, Pierre; Coraux, Johann; Bouchiat, Vincent

    2013-03-01

    Graphene offers an exposed bidimensional gas of high mobility charge carriers with gate tunable density. Its chemical inertness offers an outstanding platform to explore exotic 2D superconductivity. Superconductivity can be induced in graphene by means of proximity effect (by depositing a set of superconducting metal clusters such as lead or tin nanoparticles). The influence of decoration material, density or particles and disorder of graphene will be discussed. In the case of disordered graphene, Tin decoration leads to a gate-tunable superconducting-to-insulator quantum phase transition. Superconductivity in graphene is also expected to occur under strong charge doping (induced either by gating or under chemical decoration, in analogy with graphite intercalated compounds). I will also show preliminary results showing the influence of Calcium intercalation of few layer graphene and progress toward the demonstration of intrinsic superconductivity in such systems. Work supported by EU GRANT FP7-NMP GRENADA.

  7. Observation of a phononic Mollow triplet in a multimode hybrid spin-nanomechanical system

    PubMed Central

    Pigeau, B.; Rohr, S.; Mercier de Lépinay, L.; Gloppe, A.; Jacques, V.; Arcizet, O.

    2015-01-01

    Reminiscent of the bound character of a qubit's dynamics confined on the Bloch sphere, the observation of a Mollow triplet in the resonantly driven qubit fluorescence spectrum represents one of the founding signatures of quantum electrodynamics. Here we report on its observation in a hybrid spin-nanomechanical system, where a nitrogen-vacancy spin qubit is magnetically coupled to the vibrations of a silicon carbide nanowire. A resonant microwave field turns the originally parametric hybrid interaction into a resonant process, where acoustic phonons are now able to induce transitions between the dressed qubit states, leading to synchronized spin-oscillator dynamics. We further explore the vectorial character of the hybrid coupling to the bidimensional deformations of the nanowire. The demonstrated microwave assisted synchronization of the spin-oscillator dynamics opens novel perspectives for the exploration of spin-dependent forces, the key ingredient for quantum state transfer. PMID:26477639

  8. Self-construal, mental distress, and family relations: a mediated moderation analysis with Asian American adolescents.

    PubMed

    Liu, Freda F; Goto, Sharon G

    2007-04-01

    The interactive effects between interdependent and independent self-construal on family cohesion and mental distress were examined. Survey responses from 153 Asian American high school students supported the hypothesized moderation of interdependence by independence on family cohesion, which was found to further mediate the relationship between self-construal and mental distress. Specifically, interdependence was positively associated with family cohesion when independence was high and negatively associated with family cohesion when independence was low. Accounting for the mediator effects of family cohesion, mental distress was positively associated with interdependence and more so for those low on independence than those high on independence. The benefits of biculturalism and research implications for the bidimensional conceptualization of self-construal for ethnic minority populations are discussed. PMID:17500602

  9. Left Atrium by Echocardiography in Clinical Practice: From Conventional Methods to New Echocardiographic Techniques

    PubMed Central

    Caso, Pio; D'Andrea, Antonello; Di Salvo, Giovanni; Arenga, Fortunato; Coppola, Maria Gabriella; Sellitto, Vincenzo; Macrino, Maria; Calabrò, Raffaele

    2014-01-01

    Although often referred to as “the forgotten chamber”, compared with left ventricle (LV), especially in the past years, the left atrium (LA) plays a critical role in the clinical expression and prognosis of patients with heart and cerebrovascular disease, as demonstrated by several studies. Echocardiographers initially focused on early detection of atrial geometrical abnormalities through monodimensional atrial diameter quantification and then bidimensional (2D) areas and volume estimation. Now, together with conventional echocardiographic parameters, new echocardiographic techniques, such as strain Doppler, 2D speckle tracking and three-dimensional (3D) echocardiography, allow assessing early LA dysfunction and they all play a fundamental role to detect early functional remodelling before anatomical alterations occur. LA dysfunction and its important prognostic implications may be detected sooner by LA strain than by volumetric measurements. PMID:25009828

  10. Code System to Simulate 3D Tracer Dispersion in Atmosphere.

    Energy Science and Technology Software Center (ESTSC)

    2002-01-25

    Version 00 SHREDI is a shielding code system which executes removal-diffusion computations for bi-dimensional shields in r-z or x-y geometries. It may also deal with monodimensional problems (infinitely high cylinders or slabs). MESYST can simulate 3D tracer dispersion in the atmosphere. Three programs are part of this system: CRE_TOPO prepares the terrain data for MESYST. NOABL calculates three-dimensional free divergence windfields over complex terrain. PAS computes tracer concentrations and depositions on a given domain. Themore » purpose of this work is to develop a reliable simulation tool for pollutant atmospheric dispersion, which gives a realistic approach and allows one to compute the pollutant concentrations over complex terrains with good accuracy. The factional brownian model, which furnishes more accurate concentration values, is introduced to calculate pollutant atmospheric dispersion. The model was validated on SIESTA international experiments.« less

  11. Heterogeneity of compulsive buyers based on impulsivity and compulsivity dimensions: a latent profile analytic approach.

    PubMed

    Yi, Sunghwan

    2013-07-30

    Despite the recognition that compulsive buyers are not one homogenous group, there is a dearth of theory-guided empirical investigation. Furthermore, although compulsivity and impulsivity are used as major psychiatric criteria for diagnosing compulsive buyers, these dimensions have rarely been considered in assessing the heterogeneity issue. We fill this gap by applying the motivation shift model of addiction to compulsive buying and empirically assessing the heterogeneity issue in the bi-dimensional space represented by the buying impulsivity and compulsivity dimensions. These hypotheses were tested with latent profile analysis based on survey data (N=445). Consistent with the hypothesis, we identified the cluster of buyers with high buying compulsivity and impulsivity ("compulsive-impulsive buyers"), the cluster of buyers with low buying compulsivity and high impulsivity ("impulsive excessive buyers"), and the cluster of ordinary buyers. Furthermore, it was found that disparate clusters of buyers exhibit unique dispositional tendencies. Theoretical contributions and policy implications of the findings are discussed as well. PMID:23083915

  12. Environmental effect on essential oil composition of Aloysia citriodora from Corrientes (Argentina).

    PubMed

    Ricciardi, Gabriela; Torres, Ana Maria; Bubenik, Ana Laura; Ricciardi, Armando; Lorenzo, Daniel; Dellacassa, Eduardo

    2011-11-01

    Lemon verbena (Aloysia citriodora Palau) is indigenous to South America and was introduced into Europe. It is cultivated mainly due to the lemon-like aroma emitted from its leaves, which are utilized for the preparation of herbal tea reputed to have antispasmodic, antipyretic, sedative and digestive properties. In this work we introduce the enantiomeric distribution of sabinene and limonene by bidimensional gas chromatography (chiral GC-GC) as a genuine quantitative parameter in order to improve the knowledge so far available on A. citriodora oil. Multivariate analysis afforded information on the similarities and differences of wild and cultivated A. citriodora populations during different seasons in the same environmental conditions. The results indicated that it was possible to discard the environmental and seasonal effect on the chemical composition of A. citriodora for wild and cultivated materials belonging to the same genetic origin. PMID:22224294

  13. Hybrid methods for witnessing entanglement in a microscopic-macroscopic system

    SciTech Connect

    Spagnolo, Nicolo; Vitelli, Chiara; Paternostro, Mauro; De Martini, Francesco; Sciarrino, Fabio

    2011-09-15

    We propose a hybrid approach to the experimental assessment of the genuine quantum features of a general system consisting of microscopic and macroscopic parts. We infer entanglement by combining dichotomic measurements on a bidimensional system and phase-space inference through the Wigner distribution associated with the macroscopic component of the state. As a benchmark, we investigate the feasibility of our proposal in a bipartite-entangled state composed of a single-photon and a multiphoton field. Our analysis shows that, under ideal conditions, maximal violation of a Clauser-Horne-Shimony-Holt-based inequality is achievable regardless of the number of photons in the macroscopic part of the state. The difficulty in observing entanglement when losses and detection inefficiency are included can be overcome by using a hybrid entanglement witness that allows efficient correction for losses in the few-photon regime.

  14. Stereotyping by Omission: Eliminate the Negative, Accentuate the Positive

    PubMed Central

    Bergsieker, Hilary B.; Leslie, Lisa M.; Constantine, Vanessa S.; Fiske, Susan T.

    2014-01-01

    Communicators, motivated by strategic self-presentation, selectively underreport negative content in describing their impressions of individuals and stereotypes of groups, particularly for targets whom they view ambivalently with respect to warmth and competence. Communicators avoid overtly inaccurate descriptions, preferring to omit negative information and emphasize positive information about mixed individual targets (Study 1). With more public audiences, communicators increasingly prefer negativity omission to complete accuracy (Study 2), a process driven by self-presentation concerns (Study 3), and moderated by bidimensional ambivalence. Similarly, in an extension of the Princeton Trilogy studies, reported stereotypes of ethnic and national outgroups systematically omitted negative dimensions over 75 years—as anti-prejudice norms intensified—while neutral and positive stereotype dimensions remained constant (Study 4). Multiple assessment methods confirm this stereotyping-by-omission phenomenon (Study 5). Implications of negativity omission for innuendo and stereotype stagnation are discussed. PMID:22448889

  15. MAGELLAN: High resolution spectroscopy at FUV and EUV wavelengths

    NASA Technical Reports Server (NTRS)

    Grewing, M.; Alighieri, S. D.; Burton, W.; Coleman, C. I.; Hoekstra, R.; Jamar, C.; Labeque, A.; Laurent, C.; Vidal-Madjar, A.; Rafanelli, P.

    1982-01-01

    The aim of ESA's MAGELLAN mission is to provide high resolution spectra of celestial sources down to sixteenth magnitude over the extreme ultraviolet wavelength range (between 50 and 140 nm). This range extends from studies of interstellar matter in the disc and halo of this and other galaxies, to stellar envelopes, hot and evolved stars, clusters, intergalactic matter, nuclei of galaxies, quasars, and, finally, planets and satellites. The instrument has a nonconventional optical design using only one reflecting surface; a high groove density concave grating collects the star light, diffracts it and focuses its spectrum into a bidimensional windowless detector operated in a photon counting mode. The slitless configuration provides the spectra of all the sources (point like and extended) in the field of view of the grating. This field of view is limited by a grid collimator to reduce the diffuse background, the stray light and the probability of overlapping spectra in crowded fields.

  16. Hydrolysis of GTP associated with the formation of tubulin oligomers is involved in microtubule nucleation.

    PubMed Central

    Carlier, M F; Didry, D; Pantaloni, D

    1997-01-01

    Hydrolysis of GTP is known to accompany microtubule assembly. Here we show that hydrolysis of GTP is also associated with the formation of linear oligomers of tubulin, which are precursors (prenuclei) in microtubule assembly. The hydrolysis of GTP on these linear oligomers inhibits the lateral association of GTP-tubulin that leads to the formation of a bidimensional lattice. Therefore GTP hydrolysis interferes with the nucleation of microtubules. Linear oligomers are also formed in mixtures of GTP-tubulin and GDP-tubulin. The hydrolysis of GTP associated with heterologous interactions between GTP-tubulin and GDP-tubulin in the cooligomer takes place at a threefold faster rate than upon homologous interactions between GTP-tubulins. The implication of these results in a model of vectorial GTP hydrolysis in microtubule assembly is discussed. Images FIGURE 7 PMID:9199805

  17. Sunitinib in relapsed or refractory diffuse large B-cell lymphoma: a clinical and pharmacodynamic phase II multicenter study of the NCIC Clinical Trials Group

    PubMed Central

    Buckstein, Rena; Kuruvilla, John; Chua, Neil; Lee, Christina; Macdonald, David A; Al-Tourah, Abdulwahab J; Foo, Alison H; Walsh, Wendy; Ivy, S Percy; Crump, Michael; Eisenhauer, Elizabeth A

    2011-01-01

    There are limited effective therapies for most patients with relapsed diffuse large B-cell lymphoma (DLBCL). We conducted a phase II trial of the multi-targeted vascular endothelial growth factor receptor (VEGFR) kinase inhibitor, sunitinib, 37.5 mg given orally once daily in adult patients with relapsed or refractory DLBCL. Of 19 enrolled patients, 17 eligible patients were evaluable for toxicity and 15 for response. No objective responses were seen and nine patients achieved stable disease (median duration 3.4 months). As a result, the study was closed at the end of the first stage. Grades 3—4 neutropenia and thrombocytopenia were observed in 29% and 35%, respectively. There was no relationship between change in circulating endothelial cell numbers (CECs) and bidimensional tumor burden over time. Despite some activity in solid tumors, sunitinib showed no evidence of response in relapsed/refractory DLBCL and had greater than expected hematologic toxicity. PMID:21463120

  18. Application of computed tomography for supernumerary teeth location in pediatric dentistry.

    PubMed

    Raupp, Suziane; Kramer, Paulo Floriani; de Oliveira, Helena Willhelm; da Rosa, Francinne Miranda; Faraco, Italo Medeiros

    2008-01-01

    Conventional radiographs provide bi-dimensional images of three-dimensional structures limiting optimal treatment planning. To overcome this deficiency, Computed Tomography (CT) has been used as a diagnostic method in Medicine and Dentistry. CT allows for supernumerary teeth location, the establishment of positional relations with other teeth, and the assessment of surrounding bone thickness; thus, facilitating surgical access and technique choice while reducing the procedure time, of great importance in pediatric dental care. The aim of this study was to present the possibility of applying CT for supernumerary teeth location, through the case report of a five-year-old female patient presenting two supernumerary teeth in the anterior palatal area. In conclusion, CT appears to be an excellent image diagnostic method for locating unerupted supernumerary teeth, providing precise information for planning and performing the surgical approach, while reducing operatory time and post-operatory complications; factors of extreme importance when treating young children. PMID:18767456

  19. Developing and improving a scanning system for dosimetric applications

    SciTech Connect

    Perez, P.; Galvan, V.; Castellanoa, G.; Valente, M.

    2010-08-04

    Radiotherapy is nowadays one of the most used techniques for the treatment of different pathologies, particularly cancer diseases. The accuracy regarding the application of these treatments, which are planned according to patient information, depends mainly on the dosimetric measurements of absorbed dose within irradiated tissues. The present work is devoted to the study, design and construction of an original device capable of performing visible light transmission measurements in order to analyze Fricke gel dosimeters. Furthermore, a suitable bi-dimensional positioning system along with a dedicated control system and image processing software has been adapted to the dosimetric device in order to perform 2D dose mapping. The obtained results confirm the feasibility of the proposed method, therefore suggesting its potentiality for clinical applications.

  20. NONPOTENTIALITY OF CHROMOSPHERIC FIBRILS IN NOAA ACTIVE REGIONS 11092 AND 9661

    SciTech Connect

    Jing Ju; Yuan Yuan; Xu Yan; Wang Haimin; Reardon, Kevin; Wiegelmann, Thomas E-mail: yy46@njit.edu E-mail: haimin@flare.njit.edu E-mail: wiegelmann@linmpi.mpg.de

    2011-10-01

    In this paper, we present a method to automatically segment chromospheric fibrils from H{alpha} observations and further identify their orientation. We assume that chromospheric fibrils are aligned with the magnetic field. By comparing the orientation of the fibrils with the azimuth of the embedding chromospheric magnetic field extrapolated from a potential field model, the shear angle, a measure of nonpotentiality, along the fibrils is readily deduced. Following this approach, we make a quantitative assessment of the nonpotentiality of fibrils in two NOAA active regions (ARs): (1) the relatively simple AR 11092, observed with very high resolution by Interferometric Bidimensional Spectrometer, and (2) a {beta}-{gamma}-{delta} AR 9661, observed with median resolution by Big Bear Solar Observatory before and after an X1.6 flare.

  1. How large grains increase bulk friction in bi-disperse granular chute flows

    NASA Astrophysics Data System (ADS)

    Staron, Lydie; Phillips, Jeremy C.

    2016-07-01

    In this contribution, we apply contact dynamics discrete simulations to explore how the mechanical properties of simple bi-dimensional granular chute flows are affected by the existence of two grain sizes. Computing partial stress tensors for the phases of small and large grains, we show that the phase of large grain exhibits a much larger shear strength than the phase of small grains. This difference translates in terms of the flow internal friction: adopting the μ (I) dependence to describe the flow frictional properties, we establish that the flow mean friction coefficient increases with the volume fraction of large grains. Hence, while the presence of large grains may induce lubrication in 3D unconfined flows due to the self-channelisation and levées formation, the effect of large grains on the bulk properties is to decrease the flow mobility.

  2. Stereotyping by omission: eliminate the negative, accentuate the positive.

    PubMed

    Bergsieker, Hilary B; Leslie, Lisa M; Constantine, Vanessa S; Fiske, Susan T

    2012-06-01

    Communicators, motivated by strategic self-presentation, selectively underreport negative content in describing their impressions of individuals and stereotypes of groups, particularly for targets whom they view ambivalently with respect to warmth and competence. Communicators avoid overtly inaccurate descriptions, preferring to omit negative information and emphasize positive information about mixed individual targets (Study 1). With more public audiences, communicators increasingly prefer negativity omission to complete accuracy (Study 2), a process driven by self-presentation concerns (Study 3) and moderated by bidimensional ambivalence. Similarly, in an extension of the Princeton Trilogy studies, reported stereotypes of ethnic and national outgroups systematically omitted negative dimensions over 75 years--as anti-prejudice norms intensified--while neutral and positive stereotype dimensions remained constant (Study 4). Multiple assessment methods confirm this stereotyping-by-omission phenomenon (Study 5). Implications of negativity omission for innuendo and stereotype stagnation are discussed. PMID:22448889

  3. Re-examining the role of attitude in information system acceptance: a model from the satisfaction-dissatisfaction perspective

    NASA Astrophysics Data System (ADS)

    Guo, Bin; Zhou, Shasha

    2016-05-01

    This study attempts to re-examine the role of attitude in voluntary information system (IS) acceptance and usage, which has often been discounted in the previous technology acceptance research. We extend the unidimensional view of attitude into a bidimensional one, because of the simultaneous existence of both positive and negative evaluation towards IS in technology acceptance behaviour. In doing so, attitude construct is divided into two components: satisfaction as the positive attitudinal component and dissatisfaction as the negative attitudinal component. We argue that satisfaction and dissatisfaction will interactively affect technology usage intention. Besides, we explore the predictors of satisfaction and dissatisfaction based on the disconfirmation theory. Empirical results from a longitudinal study on bulletin board system (BBS) usage confirm the interaction effect of satisfaction and dissatisfaction on usage intention. Moreover, perceived task-related value has a significant effect on satisfaction, while perceived personal value has a significant effect on dissatisfaction. We also discuss the theoretical and managerial implications of our findings.

  4. Hope and General Self-efficacy: Two Measures of the Same Construct?

    PubMed

    Zhou, Mingming; Kam, Chester Chun Seng

    2016-07-01

    The aim of this study was to test the extent to which hope measure is equivalent to general self-efficacy measure. Questionnaire data on these two constructs and other external variables were collected from 199 Chinese college students. The factor analytic results suggested that hope and self-efficacy items measured the same construct. The unidimensional model combining hope items and GSE items fit the data as well as the bidimensional model, indicating that their corresponding items measured the same underlying construct. Further analyses showed that hope and GSE did not correlate with external variables differently in a systematic manner. Most of these correlational differences were non-significant and negligible. These findings suggested that the literatures studying GSE and hope could be considered to be integrated and that researchers need to recognize and acknowledge the conceptual and operational similarities among these constructs in the literature. PMID:26761605

  5. Multi-focus parallel detection of fluorescent molecules at picomolar concentration with photonic nanojets arrays

    SciTech Connect

    Ghenuche, Petru; Torres, Juan de; Ferrand, Patrick; Wenger, Jérôme

    2014-09-29

    Fluorescence sensing and fluorescence correlation spectroscopy (FCS) are powerful methods to detect and characterize single molecules; yet, their use has been restricted by expensive and complex optical apparatus. Here, we present a simple integrated design using a self-assembled bi-dimensional array of microspheres to realize multi-focus parallel detection scheme for FCS. We simultaneously illuminate and collect the fluorescence from several tens of microspheres, which all generate their own photonic nanojet to efficiently excite the molecules and collect the fluorescence emission. Each photonic nanojet contributes to the global detection volume, reaching FCS detection volumes of several tens of femtoliters while preserving the fluorescence excitation and collection efficiencies. The microspheres photonic nanojets array enables FCS experiments at low picomolar concentrations with a drastic reduction in apparatus cost and alignment constraints, ideal for microfluidic chip integration.

  6. Chaotic dynamics of dilute thermal atom clouds on stationary optical Bessel beams

    NASA Astrophysics Data System (ADS)

    Castañeda, J. A.; Pérez-Pascual, R.; Jáuregui, R.

    2013-07-01

    We characterize the semiclassical dynamics of dilute thermal atom clouds located in three-dimensional optical lattices generated by stationary optical Bessel beams. The dynamics of the cold atoms is explored in the quasi-Hamiltonian regime that arises using laser beams with far-off resonance detuning. Although the transverse structure of Bessel beams exhibits a complex topological structure, it is found that the longitudinal motion along the main propagation axis of the beam is the detonator of a high sensitivity of the atoms' motion to the initial conditions. This effect would not be properly described by bidimensional models. We show that an experimental implementation can be highly simplified by an analysis of the behaviour of the dynamical system under scale transformations. Experimentally feasible signatures of the chaotic dynamics of the atom clouds are also identified.

  7. Nonextraction treatment of severe crowding with the aid of corticotomy-assisted orthodontics.

    PubMed

    Aljhani, Ali S; Zawawi, Khalid H

    2012-01-01

    THIS PAPER ILLUSTRATES THE COMBINED NONEXTRACTION ORTHODONTIC TREATMENT WITH THE CORTICOTOMY TECHNIQUE IN AN ADULT PATIENT (AGE: 25 years and 3 months) with severely crowded arches to accelerate tooth movement and shorten the treatment time. Both her upper lateral incisors were congenitally absent and both upper central incisors' roots were short. Initial fixed orthodontic appliances (bidimensional) were bonded and one week later buccal and lingual corticotomy with alveolar augmentation procedure in the maxilla and mandible was performed. Orthodontic activation to level and align and unravel the crowding was performed every two weeks. The total treatment time was 8 months with no adverse effects observed at the end of active treatment. The addition of the decortication procedure to the conventional orthodontic therapy decreased the duration of treatment significantly. Successful alignment of both arches with ideal overbite and overjet as well as adequate occlusion was achieved. PMID:22848854

  8. Nonextraction Treatment of Severe Crowding with the Aid of Corticotomy-Assisted Orthodontics

    PubMed Central

    Aljhani, Ali S.; Zawawi, Khalid H.

    2012-01-01

    This paper illustrates the combined nonextraction orthodontic treatment with the corticotomy technique in an adult patient (age: 25 years and 3 months) with severely crowded arches to accelerate tooth movement and shorten the treatment time. Both her upper lateral incisors were congenitally absent and both upper central incisors' roots were short. Initial fixed orthodontic appliances (bidimensional) were bonded and one week later buccal and lingual corticotomy with alveolar augmentation procedure in the maxilla and mandible was performed. Orthodontic activation to level and align and unravel the crowding was performed every two weeks. The total treatment time was 8 months with no adverse effects observed at the end of active treatment. The addition of the decortication procedure to the conventional orthodontic therapy decreased the duration of treatment significantly. Successful alignment of both arches with ideal overbite and overjet as well as adequate occlusion was achieved. PMID:22848854

  9. From scientific discovery to health outcomes: A synergistic model of doctoral nursing education.

    PubMed

    Michael, Melanie J; Clochesy, John M

    2016-05-01

    Across the globe, health system leaders and stakeholder are calling for system-level reforms in education, research, and practice to accelerate the uptake and application of new knowledge in practice and to improve health care delivery and health outcomes. An evolving bi-dimensional research-practice focused model of doctoral nursing education in the U.S. is creating unprecedented opportunities for collaborative translational and investigative efforts for nurse researchers and practitioners. The nursing academy must commit to a shared goal of preparing future generations of nurse scientists and practitioners with the capacity and motivation to work together to accelerate the translation of evidence into practice in order to place nursing at the forefront of health system improvement efforts and advance the profession. PMID:27125154

  10. Rise of a Brazil nut: A transition line

    NASA Astrophysics Data System (ADS)

    Godoy, Sergio; Risso, Dino; Soto, Rodrigo; Cordero, Patricio

    2008-09-01

    Using molecular dynamics we study the behavior of a large particle immersed in a bed of smaller ones. The system is bidimensional, consisting of many rough inelastic hard disks of equal size plus a larger one: the intruder. All possible parameters of the system are kept fixed except for two dimensionless parameters determining the frequency and amplitude of the vibrating base. A systematic exploration of this parameter space leads to determining a transition line separating a zone in which the Brazil nut effect is observed and one in which it is not. The results strongly suggest that, in the region of the parameter space in which the study is made, there is a minimum amplitude and a maximum frequency for the Brazil nut effect to take place. These results compare well with isolated results from other authors.

  11. Observation of a phononic Mollow triplet in a multimode hybrid spin-nanomechanical system

    NASA Astrophysics Data System (ADS)

    Pigeau, B.; Rohr, S.; Mercier de Lépinay, L.; Gloppe, A.; Jacques, V.; Arcizet, O.

    2015-10-01

    Reminiscent of the bound character of a qubit's dynamics confined on the Bloch sphere, the observation of a Mollow triplet in the resonantly driven qubit fluorescence spectrum represents one of the founding signatures of quantum electrodynamics. Here we report on its observation in a hybrid spin-nanomechanical system, where a nitrogen-vacancy spin qubit is magnetically coupled to the vibrations of a silicon carbide nanowire. A resonant microwave field turns the originally parametric hybrid interaction into a resonant process, where acoustic phonons are now able to induce transitions between the dressed qubit states, leading to synchronized spin-oscillator dynamics. We further explore the vectorial character of the hybrid coupling to the bidimensional deformations of the nanowire. The demonstrated microwave assisted synchronization of the spin-oscillator dynamics opens novel perspectives for the exploration of spin-dependent forces, the key ingredient for quantum state transfer.

  12. First dose-map measured with a polycrystalline diamond 2D dosimeter under an intensity modulated radiotherapy beam

    NASA Astrophysics Data System (ADS)

    Scaringella, M.; Zani, M.; Baldi, A.; Bucciolini, M.; Pace, E.; de Sio, A.; Talamonti, C.; Bruzzi, M.

    2015-10-01

    A prototype of bidimensional dosimeter made on a 2.5×2.5 cm2 active area polycrystalline Chemical Vapour Deposited (pCVD) diamond film, equipped with a matrix of 12×12 contacts connected to the read-out electronics, has been used to evaluate a map of dose under Intensity Modulated Radiation Therapy (IMRT) fields for a possible application in pre-treatment verifications of cancer treatments. Tests have been performed under a 6-10 MVRX beams with IMRT fields for prostate and breast cancer. Measurements have been taken by measuring the 144 pixels in different positions, obtained by shifting the device along the x/y axes to span a total map of 14.4×10 cm2. Results show that absorbed doses measured by our pCVD diamond device are consistent with those calculated by the Treatment Planning System (TPS).

  13. Dynamical analysis of fluid lines coupled to mechanical systems taking into account fluid frequency-dependent damping and non-conventional constitutive models: part 1 - Modeling fluid lines

    NASA Astrophysics Data System (ADS)

    Catania, Giuseppe; Sorrentino, Silvio

    2015-01-01

    The design of hydraulic transmission systems for control and actuation requires accurate knowledge of their dynamic response: some standard techniques are known to obtain a consistent dynamic model of a fluid line, including the contribution of inertia, compressibility and friction. In this paper an efficient procedure is developed for simulating the dynamic response of a fluid line in both the frequency and time domains, focusing the attention on the modal analysis of a discretized model, in view of coupling with mechanical systems. A bi-dimensional approach is adopted, and the laminar flow frequency-dependent friction is modeled using non-integer order differential laws, which may improve the accuracy of the simulated responses in comparison with more traditional Newtonian models.

  14. Dynamical analysis of fluid lines coupled to mechanical systems taking into account fluid frequency-dependent damping and non-conventional constitutive models: Part 2 - Coupling with mechanical systems

    NASA Astrophysics Data System (ADS)

    Catania, Giuseppe; Sorrentino, Silvio

    2015-01-01

    The design of hydraulic transmission systems for control and actuation requires accurate knowledge of their dynamic response: some standard techniques are known to obtain a consistent dynamic model of a fluid line, including the contribution of inertia, compressibility and friction. In this study an efficient procedure is developed for simulating the dynamic response of a fluid line coupled with mechanical systems, in both the frequency and time domains. A bi-dimensional approach is adopted for the fluid line, and the laminar flow frequency-dependent friction is modeled using non-integer order differential laws, which may improve the accuracy in comparison with more traditional Newtonian models. The coupling problem with mechanical systems is studied by means of both continuous models of the fluid line (yielding frequency response functions in exact analytical form), and discretized models of the fluid line (to express time response functions in approximate analytical form), focusing on the damping properties of the resulting vibrating systems.

  15. Spontaneous chiral resolution in two-dimensional systems of patchy particles.

    PubMed

    Martínez-González, J A; Chapela, G A; Quintana-H, J

    2014-05-21

    Short ranged potentials and their anisotropy produce spontaneous chiral resolution in a two dimensional model of patchy particles introduced in this paper. This model could represent an equimolar binary mixture (racemic mixture) of two kinds of chiral molecules (enantiomers) adsorbed to a bi-dimensional domain where only lateral short ranged interactions are present. Most racemic mixtures undergo chiral resolution due to their spatial anisotropy, the combined effect of long range forces and the thermodynamic conditions. The patchy particles are modeled as a hard disk and four different bonding sites located to produce chirality. Phase behavior and structural properties are analysed using Discontinuous Molecular Dynamics in the canonical ensemble. When the four patchy particles are separated by the angles {60°, 120°, 60°, 120°}, spontaneous chiral resolution is produced, given by the formation of homochiral clusters, if started from the corresponding racemic mixture. Gel behavior is also obtained in all the systems for low temperatures and low densities. PMID:24852548

  16. Spontaneous chiral resolution in two-dimensional systems of patchy particles

    SciTech Connect

    Martínez-González, J. A.; Chapela, G. A.; Quintana-H, J.

    2014-05-21

    Short ranged potentials and their anisotropy produce spontaneous chiral resolution in a two dimensional model of patchy particles introduced in this paper. This model could represent an equimolar binary mixture (racemic mixture) of two kinds of chiral molecules (enantiomers) adsorbed to a bi-dimensional domain where only lateral short ranged interactions are present. Most racemic mixtures undergo chiral resolution due to their spatial anisotropy, the combined effect of long range forces and the thermodynamic conditions. The patchy particles are modeled as a hard disk and four different bonding sites located to produce chirality. Phase behavior and structural properties are analysed using Discontinuous Molecular Dynamics in the canonical ensemble. When the four patchy particles are separated by the angles (60°, 120°, 60°, 120°), spontaneous chiral resolution is produced, given by the formation of homochiral clusters, if started from the corresponding racemic mixture. Gel behavior is also obtained in all the systems for low temperatures and low densities.

  17. Testing quantum contextuality of continuous-variable states

    SciTech Connect

    McKeown, Gerard; Paternostro, Mauro; Paris, Matteo G. A.

    2011-06-15

    We investigate the violation of noncontextuality by a class of continuous-variable states, including variations of entangled coherent states and a two-mode continuous superposition of coherent states. We generalize the Kochen-Specker (KS) inequality discussed by Cabello [A. Cabello, Phys. Rev. Lett. 101, 210401 (2008)] by using effective bidimensional observables implemented through physical operations acting on continuous-variable states, in a way similar to an approach to the falsification of Bell-Clauser-Horne-Shimony-Holt inequalities put forward recently. We test for state-independent violation of KS inequalities under variable degrees of state entanglement and mixedness. We then demonstrate theoretically the violation of a KS inequality for any two-mode state by using pseudospin observables and a generalized quasiprobability function.

  18. Pangolin v1.0, a conservative 2-D advection model towards large-scale parallel calculation

    NASA Astrophysics Data System (ADS)

    Praga, A.; Cariolle, D.; Giraud, L.

    2015-02-01

    To exploit the possibilities of parallel computers, we designed a large-scale bidimensional atmospheric advection model named Pangolin. As the basis for a future chemistry-transport model, a finite-volume approach for advection was chosen to ensure mass preservation and to ease parallelization. To overcome the pole restriction on time steps for a regular latitude-longitude grid, Pangolin uses a quasi-area-preserving reduced latitude-longitude grid. The features of the regular grid are exploited to reduce the memory footprint and enable effective parallel performances. In addition, a custom domain decomposition algorithm is presented. To assess the validity of the advection scheme, its results are compared with state-of-the-art models on algebraic test cases. Finally, parallel performances are shown in terms of strong scaling and confirm the efficient scalability up to a few hundred cores.

  19. Pangolin v1.0, a conservative 2-D transport model for large scale parallel calculation

    NASA Astrophysics Data System (ADS)

    Praga, A.; Cariolle, D.; Giraud, L.

    2014-07-01

    To exploit the possibilities of parallel computers, we designed a large-scale bidimensional atmospheric transport model named Pangolin. As the basis for a future chemistry-transport model, a finite-volume approach was chosen both for mass preservation and to ease parallelization. To overcome the pole restriction on time-steps for a regular latitude-longitude grid, Pangolin uses a quasi-area-preserving reduced latitude-longitude grid. The features of the regular grid are exploited to improve parallel performances and a custom domain decomposition algorithm is presented. To assess the validity of the transport scheme, its results are compared with state-of-the-art models on analytical test cases. Finally, parallel performances are shown in terms of strong scaling and confirm the efficient scalability up to a few hundred of cores.

  20. Generation and transfer of polarized radiation in the solar atmosphere: Physical mechanisms and magnetic-field diagnostics

    NASA Technical Reports Server (NTRS)

    Deglinnocenti, E. L.

    1985-01-01

    The main physical mechanisms responsible for the generation and transfer of polarized radiation in the solar atmosphere can be classified in a suitable bidimensional diagram with an indicator of the magnetic field strength on its vertical axis and an indicator of the radiation field anisotropy on its horizontal axis. The various polarimetric observations performed on solar spectral lines are interpreted with different theoretical schemes according to their classification in the diagram and to the optical depths involved. These theoretical schemes, and the associated diagnostic tools for inferring the magnetic field vector from observations are reviewed. In particular, the role of magneto-optical effects in determining the direction of the observed linear polarization in active regions is discussed in some detail.

  1. Time-cumulated visible and infrared radiance histograms used as descriptors of surface and cloud variations

    NASA Technical Reports Server (NTRS)

    Seze, Genevieve; Rossow, William B.

    1991-01-01

    The spatial and temporal stability of the distributions of satellite-measured visible and infrared radiances, caused by variations in clouds and surfaces, are investigated using bidimensional and monodimensional histograms and time-composite images. Similar analysis of the histograms of the original and time-composite images provides separation of the contributions of the space and time variations to the total variations. The variability of both the surfaces and clouds is found to be larger at scales much larger than the minimum resolved by satellite imagery. This study shows that the shapes of these histograms are distinctive characteristics of the different climate regimes and that particular attributes of these histograms can be related to several general, though not universal, properties of clouds and surface variations at regional and synoptic scales. There are also significant exceptions to these relationships in particular climate regimes. The characteristics of these radiance histograms provide a stable well defined descriptor of the cloud and surface properties.

  2. Growth Laws and Self-Similar Growth Regimes of Coarsening Two-Dimensional Foams: Transition from Dry to Wet Limits

    NASA Astrophysics Data System (ADS)

    Fortuna, Ismael; Thomas, Gilberto L.; de Almeida, Rita M. C.; Graner, François

    2012-06-01

    We study the topology and geometry of two-dimensional coarsening foam with an arbitrary liquid fraction. To interpolate between the dry limit described by von Neumann’s law and the wet limit described by Marqusee’s equation, the relevant bubble characteristics are the Plateau border radius and a new variable: the effective number of sides. We propose an equation for the individual bubble growth rate as the weighted sum of the growth through bubble-bubble interfaces and through bubble-Plateau border interfaces. The resulting prediction is successfully tested, without an adjustable parameter, using extensive bidimensional Potts model simulations. The simulations also show that a self-similar growth regime is observed at any liquid fraction, and they also determine how the average size growth exponent, side number distribution, and relative size distribution interpolate between the extreme limits. Applications include concentrated emulsions, grains in polycrystals, and other domains with coarsening that is driven by curvature.

  3. 915 MHz microwave interstitial hyperthermia. Part II: Array of phase-monitored antennas.

    PubMed

    Camart, J C; Dubois, L; Fabre, J J; Vanloot, D; Chive, M

    1993-01-01

    In order to heat the whole volume of a tumour by microwave interstitial hyperthermia it is necessary to use an antenna array. The antenna modelization and the numerical solution of the bidimensional bioheat transfer equation allow determination of temperature evolution during a heating session. The calculations are taken for four antennas fed in phase and the theory is then proven by experiments on gel and on patients. Results are presented on cross-section heating patterns and their time evolution. Temperature distribution is calculated when feeding one antenna by a feeding current out of phase with the other currents. The phase difference value is optimized and it is then demonstrated that the heated volume is increased by successively feeding each antenna with an out-of-phase current. The time taken to feed each antenna one after the other is optimized. PMID:8515146

  4. MORPHOLOGY AND DYNAMICS OF THE LOW SOLAR CHROMOSPHERE

    SciTech Connect

    Woeger, F.; Uitenbroek, H.; Rimmele, T. R.; Wedemeyer-Boehm, S.

    2009-11-20

    The Interferometric Bidimensional Spectrometer (IBIS) installed at the Dunn Solar Telescope of the NSO/SP is used to investigate the morphology and dynamics of the lower chromosphere and the virtually non-magnetic fluctosphere below. The study addresses in particular the structure of magnetic elements that extend into these layers. We choose different quiet-Sun regions inside and outside the coronal holes. In inter-network regions with no significant magnetic flux contributions above the detection limit of IBIS, we find intensity structures with the characteristics of a shock wave pattern. The magnetic flux elements in the network are long lived and seem to resemble the spatially extended counterparts to the underlying photospheric magnetic elements. We suggest a modification to common methods to derive the line-of-sight magnetic field strength and explain some of the difficulties in deriving the magnetic field vector from observations of the fluctosphere.

  5. Context-specific attentional sampling: Intentional control as a pre-requisite for contextual control.

    PubMed

    Brosowsky, Nicholaus P; Crump, Matthew J C

    2016-08-01

    Recent work suggests that environmental cues associated with previous attentional control settings can rapidly and involuntarily adjust attentional priorities. The current study tests predictions from adaptive-learning and memory-based theories of contextual control about the role of intentions for setting attentional priorities. To extend the empirical boundaries of contextual control phenomena, and to determine whether theoretical principles of contextual control are generalizable we used a novel bi-dimensional stimulus sampling task. Subjects viewed briefly presented arrays of letters and colors presented above or below fixation, and identified specific stimuli according to a dimensional (letter or color) and positional cue. Location was predictive of the cued dimension, but not the position or identity. In contrast to previous findings, contextual control failed to develop through automatic, adaptive-learning processes. Instead, previous experience with intentionally changing attentional sampling priorities between different contexts was required for contextual control to develop. PMID:27500654

  6. Acoustic behavior of ordered droplets in a liquid: a phase space approach.

    PubMed

    Rivera, A L; Palomino, M R; de Icaza, M; Lozada-Cassou, M; Castaño, V M

    2005-03-01

    The transmission of an acoustical signal through a spatial arrangement consisting of a bidimensional crystal of droplets (liquid spheres) immersed into another liquid is analyzed. As a first approximation, the paraxial case is solved by considering a set of acoustical lenses which allow us to model the effect of each droplet on the signal. An expression for the Wigner distribution function that lets us evaluate the corresponding image, diffraction pattern, and even the output signal of any given paraxial input signal to that crystalline substrate is obtained, with particular emphasis on the case of an incoming plane wave. To solve the nonparaxial situation, a generalization of the concept of focal distance interpreting every sphere as a superposition of concentric rings of different radius, which permits us to find a general expression for the Wigner distribution function is proposed. PMID:15903601

  7. PHAROS: a spectrometer-on-a-chip for digital radiology systems with spectral detection

    NASA Astrophysics Data System (ADS)

    Cadeddu, S.; Caredda, D.; Caria, M.; Lai, A.; Randaccio, P.

    2002-02-01

    When a beam of X-rays crosses an object, its spectrum is modified depending on both the density and effective atomic number of the material. We describe an integrated (VLSI) spectrometer used in a digital radiology system for performing spectral analysis of the detected X-rays. It integrates 16 independent channels and gives seven bits of energy resolution. This permits the distinction between tissues featuring small differences in effective atomic number, e.g. micro-calcifications and fat cysts, which have the same contrast in a normal radiography. The integrated circuit services a row of solid-state detectors that can travel along the specimen in the radiology system in perpendicular directions, so that bi-dimensional images can be recorded. The circuit performs pulse height analysis and stores the spectral distribution of the detected photons. The circuit is described and its performance analyzed.

  8. Reduced ablative Rayleigh-Taylor growth measurements in indirectly driven laminated foils

    SciTech Connect

    Huser, G.; Casner, A.; Masse, L.; Liberatore, S.; Galmiche, D.; Jacquet, L.; Theobald, M.

    2011-01-15

    Indirectly driven, ablative Rayleigh-Taylor instability growth measurements in Ge-doped plastic foils were studied using face-on and side-on x-ray radiography. Laminated samples consisting of alternating layers of Ge-doped and undoped plastic and homogeneous Ge-doped foils were considered. We show for the first time that hydrodynamics do not depend upon structuration of the samples and that stabilization occurs in the case of laminated samples. All data were found to be in good agreement with bi-dimensional hydrosimulations based on theoretical and numerical predictions published earlier [L. Masse, Phys. Rev. Lett. 98, 245001 (2007)], encouraging new designs using laminated structures for ignition capsules.

  9. Analysis of transit time spread on FBK silicon photomultipliers

    NASA Astrophysics Data System (ADS)

    Acerbi, F.; Gola, A.; Ferri, A.; Zorzi, N.; Paternoster, G.; Piemonte, C.

    2015-07-01

    In this paper we studied one of the aspects potentially limiting the single-photon time-resolution (SPTR) of the silicon photomultiplier (SiPM): the transit time spread (TTS). We illuminated the SiPM in different positions with a fast-pulsed laser collimated to a circular spot of 0.2 mm-diameter and acquired bi-dimensional maps of the avalanche-signal arrival time of RGB and RGB-HD SiPMs, produced at FBK. We studied the effect of both the number of bonding wires connecting the device to the package and the layout of the top-metal connection (on the device). We found that the TTS does not simply depend on the trace length between the cell and the bonding pad and it could vary in the range between tens of picoseconds (with 3 bonding connections) to more than one hundred of picoseconds (with one connection).

  10. Revealing the Structure of a Granular Medium through Ballistic Sound Propagation

    NASA Astrophysics Data System (ADS)

    Lherminier, S.; Planet, R.; Simon, G.; Vanel, L.; Ramos, O.

    2014-08-01

    We study the propagation of sound through a bidimensional granular medium consisting of photoelastic disks, which are packed into different crystalline and disordered structures. Acoustic sensors placed at the boundaries of the system capture the acoustic signal produced by a local and well-controlled mechanical excitation. By compressing the system, we find that the speed of the ballistic part of the acoustic wave behaves as a power law of the applied force with both exponent and prefactor sensitive to the internal geometry of the contact network. This information, which we are able to link to the force-deformation relation of single grains under different contact geometries, provides enough information to reveal the structure of the granular medium.

  11. Estimation of Thickness and Cadmium Composition Distributions in HgCdTe Focal Plane Arrays

    NASA Astrophysics Data System (ADS)

    Mouzali, S.; Lefebvre, S.; Rommeluère, S.; Ferrec, Y.; Primot, J.

    2016-09-01

    Mercury cadmium telluride (HgCdTe) is one of the most commonly used material systems for infrared detection. The performance of infrared focal-plane arrays (IRFPAs) based on this material is limited by several noise sources. In this paper, we focus on the fixed pattern noise, which is related to disparities between the spectral responses of pixels. In our previous work, we showed that spectral nonuniformities in a HgCdTe IRFPA were caused by inhomogeneities of thickness and cadmium composition in the HgCdTe layer, using an optical description of the pixel structure. We propose to use this bidimensional dependence combined with experimental spectral responses to estimate disparities of thickness and cadmium composition in a specific HgCdTe-based IRFPA. The estimation methods and the resulting maps are presented, highlighting the accuracy of this nondestructive method.

  12. Impact of molecular diffusion on the CO2 distribution and the temperature in the mesosphere

    NASA Astrophysics Data System (ADS)

    Chabrillat, Simon; Kockarts, Gaston; Fonteyn, Dominique; Brasseur, Guy

    2002-08-01

    Modelling the energy budget in the mesosphere and lower thermosphere requires a precise evaluation of CO2 distribution in this region. This distribution is primarily determined by competition between vertical eddy diffusion and molecular diffusion. A simple algorithm is proposed to take into account both processes, at all altitudes. Using the SOCRATES bi-dimensional model of the middle atmosphere, we show that molecular diffusion has a direct impact on CO2 vertical distribution down to approximately 80 km altitude, i.e. well into the mesosphere and below the turbopause altitude. A sensitivity study with regard to different aeronomical processes shows that molecular diffusion has the deepest influence in the mesospheric polar night region. Our model shows that molecular diffusion of CO2 is responsible for a polar night mesopause 12 K warmer than if this process was neglected. Hence, dynamical models should take this process in account across the whole mesospheric altitude range.

  13. Analysis of off-state leakage mechanisms in GaN-based MIS-HEMTs: Experimental data and numerical simulation

    NASA Astrophysics Data System (ADS)

    Marino, F. A.; Bisi, D.; Meneghini, M.; Verzellesi, G.; Zanoni, E.; Van Hove, M.; You, S.; Decoutere, S.; Marcon, D.; Stoffels, S.; Ronchi, N.; Meneghesso, G.

    2015-11-01

    This paper presents an extensive analysis of the off-state conduction mechanisms in AlGaN/GaN Meta-Insulator-Semiconductor (MIS) transistors. Based on combined bi-dimensional numerical simulation and experimental measurements, we demonstrate the following relevant results: (i) under off-state bias conditions, the drain current can show a significant increase when the drain bias is swept up to 600 V; (ii) several mechanisms can be responsible for off-state current conduction, including band-to-band tunneling and impact ionization; (iii) two-dimensional numerical simulations indicate that band-to-band tunneling plays a major role, while impact ionization does not significantly contribute to the overall leakage. Temperature-dependent I-V measurements were also carried out to identify the origin of the vertical drain-bulk leakage.

  14. Surface treatment for the atomic layer deposition of HfO{sub 2} on silicon

    SciTech Connect

    Damlencourt, J-F.; Renault, O.; Martin, F.; Semeria, M-N.; Billon, T; Bedu, F.

    2005-04-04

    The atomic layer deposition (ALD) of HfO{sub 2} on silicon with a Cl{sub 2} surface treatment is investigated by physicochemical and electrical techniques. The specificity of this treatment is to create, on a HF-dipped silicon surface, the nucleation sites necessary for the ALD growth. The growth rates obtained by spectroscopic ellipsometry and total x-ray fluorescence spectroscopy indicate that the nucleation sites (i.e., the -OH groups), which are necessary to perform some bidimensional ALD growth, are generated during this surface treatment. After deposition of thin HfO{sub 2} layers (from a few monolayers up to 8.7 nm), a very thin parasitic SiO{sub x} layer, underneath 1 monolayer of Hf silicate, is observed by x-ray photoelectron spectroscopy. Nevertheless, an equivalent oxide thickness of 1.1 nm is obtained with an as-deposited 3.7 nm thick HfO{sub 2} layer.

  15. Neuromorphic Silicon Neuron Circuits

    PubMed Central

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  16. An experimental study of the "faster-is-slower" effect using mice under panic

    NASA Astrophysics Data System (ADS)

    Lin, Peng; Ma, Jian; Liu, Tianyang; Ran, Tong; Si, Youliang; Li, Tao

    2016-06-01

    A number of crowd accidents in last decades have attracted the interests of scientists in the study of self-organized behavior of crowd under extreme conditions. The faster-is-slower effect is one of the most referenced behaviors in pedestrian dynamics. However, this behavior has not been experimentally verified yet. A series of experiments with mice under panic were conducted in a bi-dimensional space. The mice were trained to be familiar with the way of escape. A varying number of joss sticks were used to produce different levels of stimulus to drive the mice to escape. The evacuation process was video-recorded for further analysis. The experiment found that the escape times significantly increased with the levels of stimulus due to the stronger competition of selfish mice in panic condition. The faster-is-slower effect was experimentally verified. The probability distributions of time intervals showed a power law and the burst sizes exhibited an exponential behavior.

  17. Westernization, intuitive eating, and BMI: an exploration of Jordanian adolescents.

    PubMed

    Wirtz, Amanda L; Madanat, Hala N

    The purpose of this study was to validate the Arabic-version of the adapted Marin Bidimensional Acculturation Scale and investigate the relationship between Westernization, intuitive eating, and body mass index (BMI) in a sample of Jordanian female adolescents. A total of 199 subjects between the ages of 11-18 were surveyed. Participants who scored higher on the Arabic domain exhibited higher Intuitive Eating Scale (IES) intrinsic subscale scores (r = 0.147, P = 0.048) suggesting that those who are more orientated toward Arabic culture may respond more naturally to physical hunger cues than their more Westernized counterparts. Reinforcing intuitive eating attitudes and behaviors and emphasizing body ideals resonant with the Arabic culture may propagate the continuation of intuitive eating in this population, potentially reducing the risk of obesity and other nutrition-related non-communicable diseases. PMID:23896036

  18. A numerical study of the supply mode effects on high-pressure mercury discharge lamp dynamic thermal behavior

    SciTech Connect

    Kaziz, S.; Ahmed, R. Ben; Araoud, Z.; Gazzah, M.H.; Charrada, K.; Said, R.

    2005-06-15

    This paper presents a numerical study of the dynamic behavior of high-pressure mercury discharge lamp as a function of supply mode. Bidimensional time-dependent equations have been solved by using a semi-implicit finite-element code. The model has been developed in the frame of the local thermodynamic equilibrium hypothesis. After validation by using experimental data from the literature, this model was applied to analyze the effects of some key parameters such as frequency for an ac arc current and the ratio cycle parameter for square arc-current wave form on the convective process. The results obtained have been used to analyze the dynamic thermal behavior of high-pressure mercury plasma (pressure equal to 0.3 MPa) working under currents widely different in frequency and wave form.

  19. Observation of a phononic Mollow triplet in a multimode hybrid spin-nanomechanical system.

    PubMed

    Pigeau, B; Rohr, S; Mercier de Lépinay, L; Gloppe, A; Jacques, V; Arcizet, O

    2015-01-01

    Reminiscent of the bound character of a qubit's dynamics confined on the Bloch sphere, the observation of a Mollow triplet in the resonantly driven qubit fluorescence spectrum represents one of the founding signatures of quantum electrodynamics. Here we report on its observation in a hybrid spin-nanomechanical system, where a nitrogen-vacancy spin qubit is magnetically coupled to the vibrations of a silicon carbide nanowire. A resonant microwave field turns the originally parametric hybrid interaction into a resonant process, where acoustic phonons are now able to induce transitions between the dressed qubit states, leading to synchronized spin-oscillator dynamics. We further explore the vectorial character of the hybrid coupling to the bidimensional deformations of the nanowire. The demonstrated microwave assisted synchronization of the spin-oscillator dynamics opens novel perspectives for the exploration of spin-dependent forces, the key ingredient for quantum state transfer. PMID:26477639

  20. Antifungal and cytotoxic activity of withanolides from Acnistus arborescens.

    PubMed

    Roumy, Vincent; Biabiany, Murielle; Hennebelle, Thierry; Aliouat, El Moukhtar; Pottier, Muriel; Joseph, Henry; Joha, Sami; Quesnel, Bruno; Alkhatib, Racha; Sahpaz, Sevser; Bailleul, François

    2010-07-23

    Three compounds were isolated from Acnistus arborescens, a tree commonly used in South and Central America in traditional medicine against several infectious diseases, some of which are caused by fungi. Bioassay-guided fractionation of a MeOH extract of leaves, based on its anti-Pneumocystis carinii activity, led to the isolation of compounds 1-3. Mono- and bidimensional NMR analyses enabled identification of two new withanolides, (20R,22R)-5beta,6beta-epoxy-4beta,12beta,20-trihydroxy-1-oxowith-2-en-24-enolide (1) and (20R,22R)-16beta-acetoxy-3beta,4beta;5beta,6beta-diepoxy-12beta,20-dihydroxy-1-oxowith-24-enolide (2), and withanolide D (3). Antifungal activity on 13 fungi responsible for human infections (five dermatophytes, one nondermatophyte mold, six yeasts, and Pneumocystis carinii) was examined. Cytotoxicity of these compounds was also evaluated in vitro. PMID:20590148

  1. Consciousness: a neurological perspective.

    PubMed

    Cavanna, Andrea E; Shah, Sachin; Eddy, Clare M; Williams, Adrian; Rickards, Hugh

    2011-01-01

    Consciousness is a state so essentially entwined with human experience, yet so difficult to conceptually define and measure. In this article, we explore how a bidimensional model of consciousness involving both level of arousal and subjective awareness of the contents of consciousness can be used to differentiate a range of healthy and altered conscious states. These include the different sleep stages of healthy individuals and the altered states of consciousness associated with neurological conditions such as epilepsy, vegetative state and coma. In particular, we discuss how arousal and awareness are positively correlated in normal physiological states with the exception of REM sleep, while a disturbance in this relationship is characteristic of vegetative state, minimally conscious state, complex partial seizures and sleepwalking. PMID:21447904

  2. [Isolation of Mycobacterium avium-intracellulare from a hepatic biopsy].

    PubMed

    Ruiz, Aroldo; Mederos, Lilian; Capó, Virginia

    2002-01-01

    A 64 years-old patient, who was a farmer suffering from chronic fever for two years, loss of weight and acute asthenia, was studied. He was admitted to "Pedro Kourí" Tropical Medicine Institute where the studies were conducted and revealed a globular sedimentation rate of 116 mm in 2 hours, and anemia of 9,8g% hemoglobin. The laparoscopic study indicated hepatic granulomatosis that was confirmed by hepatic biopsy in which a sample was taken from the liver to be microbiologically and cytologically examined. By microbiological methods, a non-pigmented slowly-growing strain was isolated, which was classified by conventional diagnostic techniques for the non-tuberculous mycobacteria classification and the alternative diagnosing technique known as bidimensional thin layer chromatography to confirm the previous classification and set the mycolic acid patterns. The isolated strain belonged to group III of Rynyon and was identified as Mycobacterium avium-intracellulare. PMID:15849945

  3. Estimation of Thickness and Cadmium Composition Distributions in HgCdTe Focal Plane Arrays

    NASA Astrophysics Data System (ADS)

    Mouzali, S.; Lefebvre, S.; Rommeluère, S.; Ferrec, Y.; Primot, J.

    2016-05-01

    Mercury cadmium telluride (HgCdTe) is one of the most commonly used material systems for infrared detection. The performance of infrared focal-plane arrays (IRFPAs) based on this material is limited by several noise sources. In this paper, we focus on the fixed pattern noise, which is related to disparities between the spectral responses of pixels. In our previous work, we showed that spectral nonuniformities in a HgCdTe IRFPA were caused by inhomogeneities of thickness and cadmium composition in the HgCdTe layer, using an optical description of the pixel structure. We propose to use this bidimensional dependence combined with experimental spectral responses to estimate disparities of thickness and cadmium composition in a specific HgCdTe-based IRFPA. The estimation methods and the resulting maps are presented, highlighting the accuracy of this nondestructive method.

  4. A Lattice Boltzmann Model for Oscillating Reaction-Diffusion

    NASA Astrophysics Data System (ADS)

    Rodríguez-Romo, Suemi; Ibañez-Orozco, Oscar; Sosa-Herrera, Antonio

    2016-07-01

    A computational algorithm based on the lattice Boltzmann method (LBM) is proposed to model reaction-diffusion systems. In this paper, we focus on how nonlinear chemical oscillators like Belousov-Zhabotinsky (BZ) and the chlorite-iodide-malonic acid (CIMA) reactions can be modeled by LBM and provide with new insight into the nature and applications of oscillating reactions. We use Gaussian pulse initial concentrations of sulfuric acid in different places of a bidimensional reactor and nondiffusive boundary walls. We clearly show how these systems evolve to a chaotic attractor and produce specific pattern images that are portrayed in the reactions trajectory to the corresponding chaotic attractor and can be used in robotic control.

  5. A New Oxyborate in the Ternary Phase Diagrams Li 2O- Ln2O 3-B 2O 3: Li 2Ln5O 4(BO 3) 3 ( Ln=Yb, Lu): Crystal Structure of the Ytterbium Phase

    NASA Astrophysics Data System (ADS)

    Jubera, Veronique; Gravereau, Pierre; Chaminade, Jean-Pierre; Fouassier, Claude

    2001-01-01

    A new type of lithium rare earth oxyborate of formula Li2Ln5O4(BO3)3 (Ln=Yb, Lu) has been discovered in the ternary phase diagrams Li2O-Ln2O3-B2O3. Single crystals of Li2Yb5O4(BO3)3 were grown by the flux method. The structure of this oxyborate was solved from a data collection with a four circle automatic diffractometer and with MoKα radiation. The cell is monoclinic (space group P21/m, Z=2) with a=10.095(2) Å, b=3.519(2) Å, c=15.647(11) Å, β=105.45(3)°, V=535.7(5) Å-3. Refinement of 86 parameters using 3298 independent reflections having intensity I>2σ(I) led to R=0.037 (wR=0.091). The structure of Li2Yb5O4(BO3)3 is made up of a bidimensional framework of edge or corner-sharing YbO7 polyhedra parallel to the (10overline1) plane and connected by three-coordinated boron atoms and lithium ions. It can also be described as a bidimensional assembly of OYb4 tetrahedra, ((Yb10O8)14+)n, separated by borate groups and lithium coordination polyhedra forming ribbons, ((Li4B6O18)14-)n, along the b direction. The presence of oxygen atoms sharing only Yb polyhedra justifies the oxyborate label.

  6. Nonlinear absorption tuning by composition control in bimetallic plasmonic nanoprism arrays

    NASA Astrophysics Data System (ADS)

    Cesca, Tiziana; Michieli, Niccolò; Kalinic, Boris; Sánchez-Espinoza, Ana; Rattin, Marco; Russo, Valentina; Mattarello, Valentina; Scian, Carlo; Mazzoldi, Paolo; Mattei, Giovanni

    2015-07-01

    The nonlinear absorption properties of bidimensional arrays of Au-Ag bilayered nanoprisms have been investigated by z-scan measurements as a function of the bimetallic nanoprism composition. A tunable ps laser system was used to excite the ultrafast, electronic nonlinear response matching the laser wavelength with the quadrupolar surface plasmon resonances, in the visible range, of each nanoprism array. Due to the strong electromagnetic field confinement effects at the nanoprism tips, demonstrated by finite element method simulations, these nanosystems proved to have enhanced nonlinear optical properties. Moreover, a tunable changeover from reverse saturable absorption (RSA) to saturable absorption (SA) can be obtained by properly controlling the bimetallic composition of the nanoprisms, without modifying the overall morphology of the nanosystems. This capability makes these nanosystems extremely interesting for the realization of solid-state nanophotonic devices with enhanced ultrafast nonlinear optical properties.The nonlinear absorption properties of bidimensional arrays of Au-Ag bilayered nanoprisms have been investigated by z-scan measurements as a function of the bimetallic nanoprism composition. A tunable ps laser system was used to excite the ultrafast, electronic nonlinear response matching the laser wavelength with the quadrupolar surface plasmon resonances, in the visible range, of each nanoprism array. Due to the strong electromagnetic field confinement effects at the nanoprism tips, demonstrated by finite element method simulations, these nanosystems proved to have enhanced nonlinear optical properties. Moreover, a tunable changeover from reverse saturable absorption (RSA) to saturable absorption (SA) can be obtained by properly controlling the bimetallic composition of the nanoprisms, without modifying the overall morphology of the nanosystems. This capability makes these nanosystems extremely interesting for the realization of solid

  7. Equilibrium and stability properties of detonation waves in the hydrodynamic limit of a kinetic model

    NASA Astrophysics Data System (ADS)

    Marques, Wilson, Jr.; Jacinta Soares, Ana; Pandolfi Bianchi, Miriam; Kremer, Gilberto M.

    2015-06-01

    A shock wave structure problem, like the one which can be formulated for the planar detonation wave, is analyzed here for a binary mixture of ideal gases undergoing the symmetric reaction {{A}1}+{{A}1}\\rightleftharpoons {{A}2}+{{A}2}. The problem is studied at the hydrodynamic Euler limit of a kinetic model of the reactive Boltzmann equation. The chemical rate law is deduced in this frame with a second-order reaction rate, in a chemical regime such that the gas flow is not far away from the chemical equilibrium. The caloric and the thermal equations of state for the specific internal energy and temperature are employed to close the system of balance laws. With respect to other approaches known in the kinetic literature for detonation problems with a reversible reaction, this paper aims to improve some aspects of the wave solution. Within the mathematical analysis of the detonation model, the equation of the equilibrium Hugoniot curve of the final states is explicitly derived for the first time and used to define the correct location of the equilibrium Chapman-Jouguet point in the Hugoniot diagram. The parametric space is widened to investigate the response of the detonation solution to the activation energy of the chemical reaction. Finally, the mathematical formulation of the linear stability problem is given for the wave detonation structure via a normal-mode approach, when bidimensional disturbances perturb the steady solution. The stability equations with their boundary conditions and the radiation condition of the considered model are explicitly derived for small transversal deviations of the shock wave location. The paper shows how a second-order chemical kinetics description, derived at the microscopic level, and an analytic deduction of the equilibrium Hugoniot curve, lead to an accurate picture of the steady detonation with reversible reaction, as well as to a proper bidimensional linear stability analysis.

  8. LIDAR Data Resolution Versus Hydro-Morphological Models for Flood Risk Assessment

    NASA Astrophysics Data System (ADS)

    Avanzi, A.; Frank, E.; Righetto, M.; Fattorelli, S.

    2013-01-01

    Uncertainties in topographic data have a significant influence on hydro-morphological and hydraulic predictions and therefore on flood risk assessment. In this work, the effects of topographic data resolution on the results of hydro-morphologic and hydraulic simulations are analysed using respectively the morphological bi-dimensional curvilinear model MIKE 21C and mono-bidimensional SOBEK. The studies have been carried out in the Torre river, located in Northern Italy. The evaluations on hydro-morphological and hydraulic risk require accurate spatial information for the area of interest. In order to characterize the river morphology, mainly for large areas, the availability of high resolution topography derived by airborne laser scanner represents an effective tool. Nowadays LiDAR (Light Detection And Ranging) DTM covering large areas are readily available for public authorities, and there is a greater and more widespread interest in the application of such information for the development of automated methods aimed at solving geomorphological and hydrological problems. For the models analysed, high-resolution LiDAR data were used to create the basic topographic information. An additional source for the topography of the Torre river has been provided by river cross-section data. Digital elevation models at different resolution have been created to test the effects of different grid cell sizes on the simulations. The impact of topographic information on hydraulic and morphological model results was evaluated for the area through a comparison of results. Additionally, morphologic variations and position of erosional and depositional zones along the watercourse and variations in flood extent and dynamics have been investigated. The obtained results emphasise the importance of quality of input information for reliable results of hydraulic and sediment transport models. Criteria for selecting the optimal DTM resolution are suggested, based on the quality of available

  9. Hierarchical structures of correlations networks among Turkey’s exports and imports by currencies

    NASA Astrophysics Data System (ADS)

    Kocakaplan, Yusuf; Deviren, Bayram; Keskin, Mustafa

    2012-12-01

    We have examined the hierarchical structures of correlations networks among Turkey’s exports and imports by currencies for the 1996-2010 periods, using the concept of a minimal spanning tree (MST) and hierarchical tree (HT) which depend on the concept of ultrametricity. These trees are useful tools for understanding and detecting the global structure, taxonomy and hierarchy in financial markets. We derived a hierarchical organization and build the MSTs and HTs during the 1996-2001 and 2002-2010 periods. The reason for studying two different sub-periods, namely 1996-2001 and 2002-2010, is that the Euro (EUR) came into use in 2001, and some countries have made their exports and imports with Turkey via the EUR since 2002, and in order to test various time-windows and observe temporal evolution. We have carried out bootstrap analysis to associate a value of the statistical reliability to the links of the MSTs and HTs. We have also used the average linkage cluster analysis (ALCA) to observe the cluster structure more clearly. Moreover, we have obtained the bidimensional minimal spanning tree (BMST) due to economic trade being a bidimensional problem. From the structural topologies of these trees, we have identified different clusters of currencies according to their proximity and economic ties. Our results show that some currencies are more important within the network, due to a tighter connection with other currencies. We have also found that the obtained currencies play a key role for Turkey’s exports and imports and have important implications for the design of portfolio and investment strategies.

  10. Integral field spectroscopy and multi-wavelength imaging of the nearby spiral galaxy NGC 5668: a case for MEGARA

    NASA Astrophysics Data System (ADS)

    Marino, R. A.; Gil de Paz, A.; Castillo-Morales, A.; Muñoz-Mateos, J. C.; Sánchez, S. F.; Pérez-González, P. G.; Gallego, J.; Zamorano, J.; Alonso-Herrero, A.; Boissier, S.

    2013-05-01

    In order to improve our understanding of the mechanisms that drive the evolution of disk galaxies we analyze the full bi-dimensional spectral cube of the nearby spiral galaxy NGC 5668, which was obtained as a mosaic of 6 pointings, covering a total area of 2 × 3 arcmin^{2}, obtained with the PPAK Integral Field Unit at the Calar Alto (CAHA) observatory 3.5 m telescope. From these data we obtain the bidimensional spatial distribution maps of the attenuation of the ionized gas, and chemical abundances of oxygen. We find a mean ionized-gas attenuation of A_V˜1 mag, with the gas attenuation appearing larger than the continuum attenuation by a factor of 3. With respect to the oxygen abundance, we find that, while inwards of r ˜36''˜ 4.4kpc ˜ 0.36 ({D_{25}}/{2}) the derived O/H ratio follows the radial gradient typical of the disks of spiral galaxies, the abundance gradient beyond r˜36'' flattens out. The multi-wavelength surface brightness profiles of NGC 5668 are compared with those predicted by chemo-spectrophotometric evolutionary models of galaxy disks in the context of the inside-out scenario of disk formation. Both the deviations of the color profiles and the shape of the metallicity radial distribution indicate that a secondary mechanism, possibly gas transfer induced by the presence of a young bar, must have played a role in shaping the recent chemical and star formation histories of NGC5668 beyond what is predicted by the inside-out scenario. This study demonstrates the strength of the combination of IFU and multi-wavelength imaging data. With MEGARA, the future optical IFU & MOS for 10.4-m GTC we will fill the gap currently existing in astronomical instrumentation with high spectral resolution and large area coverage simultaneously addressing such fundamental issues in galactic structure and evolution.

  11. Separation and characterization of mares' milk alpha(s1)-, beta-, kappa-caseins, gamma-casein-like, and proteose peptone component 5-like peptides.

    PubMed

    Egito, A S; Miclo, L; López, C; Adam, A; Girardet, J M; Gaillard, J L

    2002-04-01

    The equine alpha(s1)- and beta-caseins (CN) were purified by chromatography on DEAE-cellulose and by reversed-phase HPLC. The alpha(s1)-, beta-, and kappa-CN were characterized either by monodimensional urea-PAGE or sodium dodecylsulfate (SDS)-PAGE or by bidimensional electrophoresis. Kappa-casein was characterized after electrophoresis by glycoprotein-specific staining. To identify alpha(s1)-CN without ambiguity, internal sequences were determined after trypsin or chymosin digestion of purified alpha(s1)-CN. These sequences, that could be estimated to correspond to 62% of the full protein, presented strong identities with regions of alpha(s1)-CN primary structures of other species. In particular, 51, 48, 43, and 40% identities were obtained with corresponding regions of sow, dromedary, cow, and human alpha(s1)-CN, respectively. On the other hand, trace amounts of equine gamma-CN-like and proteose peptone component 5-like peptides were found in the whole CN. They were identified by microsequencing and corresponded to beta-CN peptides generated by plasmin action on the whole CN. The equine alpha(s1), beta-, and kappa-CN were separated by bidimensional electrophoresis in numerous isoelectric variants with apparent isoelectric points distributed between pH 4.4 to 6.3, 4.4 to 5.9, and 3.5 to 5.5, respectively. The beta- and kappa-CN displayed a more acidic character in the mare than in the cow. PMID:12018413

  12. An extended real-time flood impact forecasting system for the Chapare watershed in Bolivia

    NASA Astrophysics Data System (ADS)

    Rossi, Lauro; Gabellani, Simone; Masoero, Alessandro; Dolia, Daniele; Rudari, Roberto

    2016-04-01

    All over the world a lot of cities are located in flood-prone areas and million of people are exposed to inundation risk. To cope with that the social safety demands efficient civil protection structures able to reduce flood risk by issuing warnings. This task requires civil protection organisms to adopt systems able to support their activities in predicting floods and rainfall impacts. For this reason flood early warning systems, based on rainfall observations and predictions, has become very useful because they are able to provide in advance a quantitative evaluation of possible effects in term of discharge and peak flow. Traditionally those forecasting systems use hydrologic models coupled with meteorological models to forecast discharge in relevant river sections and are called hydro-meteorological chains. In order to have a better representation of the flood dynamics, these hydro-meteorological chains can be expanded to include bi-dimensional hydraulic models where the level exposure is high or flow singularities (e.g. junctions, deltas, etc.) require more accurate investigation. That information allows the generation of real-time inundation scenarios that can be used by civil protection and authorities to estimate impact on population and take counter-measures. The new real-time flood impact forecasting chain consists of a suite of hydrometeorological tools that combines meteorological models, a disaggregation tool and a fully distributed hydrological model and a bidimensional hydraulic model that produces inundation scenarios in the most exposed river segments of the flood plain and a scenario tool that allows the assessment of assets involved. The complete modelling chain has been implemented in the Chapare watershed in Bolivia and it is managed by the Dewetra platform, which since 2013 is used by the Civil Defense and National Meteorological service as the main national Early Warning supporting tool.

  13. Élements d'introduction à l'invariance conforme

    NASA Astrophysics Data System (ADS)

    Grandati, Y.

    These notes constitute an elementary introduction to the concept of conformal invariance and its applications to the study of bidimensional critical phenomena. The aim is to give an access as pedestrian as possible to this vast subject. After a brief account of the general properties of conformal transformations in D dimensions, we study more specifically the case D = 2. The center of the discussion is then the consequences of the action of this symmetry group on bidimensional field theories, and in particular the links between the representations of the Virasoro algebra and the structure of the correlation functions of conformal field theories. Finally after showing how the Ising model reduces to a Majorana fermionic field theory, we see how the general formalism previously discussed can be applied to the Ising case at the critical point. Ce texte constitue une introduction élémentaire au concept d'invariance conforme et à ses applications dans l'étude des phénomènes critiques bidimensionnels. L'objectif est de fournir un accès aussi linéaire et pédagogique que possible aux idées de base de ce vaste sujet. Après une présentation sommaire des propriétés générales des transformations conformes en dimension quelconque, nous nous intéressons plus spécifiquement au cas de la dimension 2. Le coeur de la discussion porte alors sur les conséquences de l'action de ce groupe de symétrie sur les théories de champs bidimensionnelles et en particulier, sur les liens entre la théorie des représentations de l'algèbre de Virasoro et la structure des fonctions de corrélation des théories de champs invariantes conformes. Enfin, après avoir montré de quelle manière l'étude du modèle d'Ising peut être ramenée à celle d'une théorie de champs de fermions de Majorana, nous voyons comment le formalisme général discuté précédemment s'applique au cas de ce modèle au point critique.

  14. Concave gold nanocube assemblies as nanotraps for surface-enhanced Raman scattering-based detection of proteins

    NASA Astrophysics Data System (ADS)

    Matteini, Paolo; de Angelis, Marella; Ulivi, Lorenzo; Centi, Sonia; Pini, Roberto

    2015-02-01

    SERS detection of proteins is typically performed by using labeling agents with stable and high Raman scattering cross sections. This is a valuable approach for trace detection and quantification of a target protein but is unsuitable for inspecting its inherent structural and functional properties. On the other hand, direct SERS of proteins has been mainly devoted to the study of short peptides and aminoacid sequences or of prosthetic groups with intense Raman signals, which is of scarce interest for a thorough characterization of most proteins. Here we try to overcome these limitations by setting-up an effective platform for the structural SERS analysis of proteins. The platform consists of an extended bidimensional array of gold concave nanocubes (CNCs) supported on a PDMS film. CNCs are closely-packed through face-face and face-corner interactions generating a monolayered arrangement featuring well distributed nanoholes. Here the protein homogeneously experiences an E-field enhancement outward from the metal surfaces surrounding it, which causes a large number of vibrations to be contemporarily amplified. The proposed platform provides stable and detailed SERS spectra and confers rapidity and reproducibility to the analysis.SERS detection of proteins is typically performed by using labeling agents with stable and high Raman scattering cross sections. This is a valuable approach for trace detection and quantification of a target protein but is unsuitable for inspecting its inherent structural and functional properties. On the other hand, direct SERS of proteins has been mainly devoted to the study of short peptides and aminoacid sequences or of prosthetic groups with intense Raman signals, which is of scarce interest for a thorough characterization of most proteins. Here we try to overcome these limitations by setting-up an effective platform for the structural SERS analysis of proteins. The platform consists of an extended bidimensional array of gold concave

  15. Comparison of Existing Response Criteria in Patients with Hepatocellular Carcinoma Treated with Transarterial Chemoembolization Using a 3D Quantitative Approach

    PubMed Central

    Tacher, Vania; Lin, MingDe; Duran, Rafael; Yarmohammadi, Hooman; Lee, Howard; Chapiro, Julius; Chao, Michael; Wang, Zhijun; Frangakis, Constantine; Sohn, Jae Ho; Maltenfort, Mitchell Gil; Pawlik, Timothy; Geschwind, Jean-François

    2015-01-01

    Purpose To compare currently available non-three-dimensional methods (Response Evaluation Criteria in Solid Tumors [RECIST], European Association for Study of the Liver [EASL], modified RECIST [mRECIST[) with three-dimensional (3D) quantitative methods of the index tumor as early response markers in predicting patient survival after initial transcatheter arterial chemoembolization (TACE). Materials and Methods This was a retrospective single-institution HIPAA-compliant and institutional review board–approved study. From November 2001 to November 2008, 491 consecutive patients underwent intraarterial therapy for liver cancer with either conventional TACE or TACE with drug-eluting beads. A diagnosis of hepatocellular carcinoma (HCC) was made in 290 of these patients. The response of the index tumor on pre- and post-TACE magnetic resonance images was assessed retrospectively in 78 treatment-naïve patients with HCC (63 male; mean age, 63 years ± 11 [standard deviation]). Each response assessment method (RECIST, mRECIST, EASL, and 3D methods of volumetric RECIST [vRECIST] and quantitative EASL [qEASL]) was used to classify patients as responders or nonresponders by following standard guidelines for the uni- and bidimensional measurements and by using the formula for a sphere for the 3D measurements. The Kaplan-Meier method with the log-rank test was performed for each method to evaluate its ability to help predict survival of responders and nonresponders. Uni- and multivariate Cox proportional hazard ratio models were used to identify covariates that had significant association with survival. Results The uni- and bidimensional measurements of RECIST (hazard ratio, 0.6; 95% confidence interval [CI]: 0.3, 1.0; P = .09), mRECIST (hazard ratio, 0.6; 95% CI: 0.6, 1.0; P = .05), and EASL (hazard ratio, 1.1; 95% CI: 0.6, 2.2; P = .75) did not show a significant difference in survival between responders and nonresponders, whereas vRECIST (hazard ratio, 0.6; 95% CI: 0.3, 1

  16. Outbreaks source: A new mathematical approach to identify their possible location

    NASA Astrophysics Data System (ADS)

    Buscema, Massimo; Grossi, Enzo; Breda, Marco; Jefferson, Tom

    2009-11-01

    Classical epidemiology has generally relied on the description and explanation of the occurrence of infectious diseases in relation to time occurrence of events rather than to place of occurrence. In recent times, computer generated dot maps have facilitated the modeling of the spread of infectious epidemic diseases either with classical statistics approaches or with artificial “intelligent systems”. Few attempts, however, have been made so far to identify the origin of the epidemic spread rather than its evolution by mathematical topology methods. We report on the use of a new artificial intelligence method (the H-PST Algorithm) and we compare this new technique with other well known algorithms to identify the source of three examples of infectious disease outbreaks derived from literature. The H-PST algorithm is a new system able to project a distances matrix of points (events) into a bi-dimensional space, with the generation of a new point, named hidden unit. This new hidden unit deforms the original Euclidean space and transforms it into a new space (cognitive space). The cost function of this transformation is the minimization of the differences between the original distance matrix among the assigned points and the distance matrix of the same points projected into the bi-dimensional map (or any different set of constraints). For many reasons we will discuss, the position of the hidden unit shows to target the outbreak source in many epidemics much better than the other classic algorithms specifically targeted for this task. Compared with main algorithms known in the location theory, the hidden unit was within yards of the outbreak source in the first example (the 2007 epidemic of Chikungunya fever in Italy). The hidden unit was located in the river between the two village epicentres of the spread exactly where the index case was living. Equally in the second (the 1967 foot and mouth disease epidemic in England), and the third (1854 London Cholera epidemic

  17. Sorafenib in advanced melanoma: a Phase II randomised discontinuation trial analysis.

    PubMed

    Eisen, T; Ahmad, T; Flaherty, K T; Gore, M; Kaye, S; Marais, R; Gibbens, I; Hackett, S; James, M; Schuchter, L M; Nathanson, K L; Xia, C; Simantov, R; Schwartz, B; Poulin-Costello, M; O'Dwyer, P J; Ratain, M J

    2006-09-01

    The effects of sorafenib--an oral multikinase inhibitor targeting the tumour and tumour vasculature--were evaluated in patients with advanced melanoma enrolled in a large multidisease Phase II randomised discontinuation trial (RDT). Enrolled patients received a 12-week run-in of sorafenib 400 mg twice daily (b.i.d.). Patients with changes in bi-dimensional tumour measurements <25% from baseline were then randomised to sorafenib or placebo for a further 12 weeks (ie to week 24). Patients with > or =25% tumour shrinkage after the run-in continued on open-label sorafenib, whereas those with > or =25% tumour growth discontinued treatment. This analysis focussed on secondary RDT end points: changes in bi-dimensional tumour measurements from baseline after 12 weeks and overall tumour responses (WHO criteria) at week 24, progression-free survival (PFS), safety and biomarkers (BRAF, KRAS and NRAS mutational status). Of 37 melanoma patients treated during the run-in phase, 34 were evaluable for response: one had > or =25% tumour shrinkage and remained on open-label sorafenib; six (16%) had <25% tumour growth and were randomised (placebo, n=3; sorafenib, n=3); and 27 had > or =25% tumour growth and discontinued. All three randomised sorafenib patients progressed by week 24; one remained on sorafenib for symptomatic relief. All three placebo patients progressed by week-24 and were re-started on sorafenib; one experienced disease re-stabilisation. Overall, the confirmed best responses for each of the 37 melanoma patients who received sorafenib were 19% stable disease (SD) (ie n=1 open-label; n=6 randomised), 62% (n=23) progressive disease (PD) and 19% (n=7) unevaluable. The overall median PFS was 11 weeks. The six randomised patients with SD had overall PFS values ranging from 16 to 34 weeks. The most common drug-related adverse events were dermatological (eg rash/desquamation, 51%; hand-foot skin reaction, 35%). There was no relationship between V600E BRAF status and disease

  18. Exploring the promising properties of 2D exfoliated black phosphorus for optoelectronic applications under 1.55 μm optical excitation

    NASA Astrophysics Data System (ADS)

    Penillard, A.; Tripon-Canseliet, C.; Maksimovic, I.; Rosticher, M.; Servet, B.; Liu, Z.; Géron, E.

    2016-04-01

    A great interest has been lately initiated in the optoelectronics field for 2D materials with a tunable bandgap. Being able to choose the bandgap of a material is a huge progress in optoelectronics, since it would permit to overcome the limitation imposed by the graphene lack of energy bandgap, but also the restriction imposed by already used semiconductor whose bandgap are fixed and cannot apply for IR-NIR applications. From DFT simulations predictions, Black Phosphorus (bP) becomes a bidimensional semiconducting material with a direct tunable energy bandgap from 0.3 eV to 2 eV by controlling number of layers. This material also has a picosecond carrier response and exceptional mobilities under external excitation. Hence black phosphorus is a promising 2D material candidate for photoconductive switching under a NIR optical excitation as in telecommunication wavelength range of 1.55 μm. In this paper, material electromagnetic properties analysis is described in a large frequency band from optical to microwave measurements executed on different samples allowing energy bandgap and work function dependency to fabrication techniques, anisotropy and multiscale optoelectronic device realization by switch contact engineering and material passivation or encapsulation. Material implementation in microwave devices opens the route to new broadband electronic functionalities triggered by optics, thanks to light/matter extreme confinement degree. In this paper we present fabrication method of bP based microwave photoconductive switch, with a focus on black phosphorus Raman characterization, and obtained performances.

  19. Dual-energy x-ray absorptiometry using 2D digital radiography detector: application to bone densitometry

    NASA Astrophysics Data System (ADS)

    Dinten, Jean-Marc; Robert-Coutant, Christine; Darboux, Michel

    2001-06-01

    Dual Energy X-Rays Absorptiometry (DXA) is commonly used to separate soft tissues and bone contributions in radiographs. This decomposition leads to bone mineral density (BMD) measurement. Most clinical systems use pencil or fan collimated X-Rays beam with mono detectors or linear arrays. On these systems BMD is computed from bi-dimensional (2D) images obtained by scanning. Our objective is to take advantage of the newly available flat panels detectors and to propose a DXA approach without scanning, based on the use of cone beam X-Rays associated with a 2D detector. This approach yields bone densitometry systems with an equal X and Y resolution, a fast acquisition and a reduced risk of patient motion.Scatter in this case becomes an important issue. While scattering is insignificant on collimated systems, its level and geometrical structure may severely alter BMD measurement on cone beam systems. In our presentation an original DXA method taking into account scattering is proposed. This new approach leads to accurate BMD values.In order to evaluate the accuracy of our new approach, a phantom representative of the spine regions tissue composition (bone, fat , muscle) has been designed. The comparison between the expected theoretical and the reconstructed BMD values validates the accuracy of our method. Results on anthropomorphic spine and hip regions are also presented.

  20. A three dimensional integral equation approach for fluids under confinement: Argon in zeolites.

    PubMed

    Lomba, Enrique; Bores, Cecilia; Sánchez-Gil, Vicente; Noya, Eva G

    2015-10-28

    In this work, we explore the ability of an inhomogeneous integral equation approach to provide a full three dimensional description of simple fluids under conditions of confinement in porous media. Explicitly, we will consider the case of argon adsorbed into silicalite-1, silicalite-2, and an all-silica analogue of faujasite, with a porous structure composed of linear (and zig-zag in the case of silicalite-1) channels of 5-8 Å diameter. The equation is based on the three dimensional Ornstein-Zernike approximation proposed by Beglov and Roux [J. Chem. Phys. 103, 360 (1995)] in combination with the use of an approximate fluid-fluid direct correlation function furnished by the replica Ornstein-Zernike equation with a hypernetted chain closure. Comparison with the results of grand canonical Monte Carlo/molecular dynamics simulations evidences that the theory provides an accurate description for the three dimensional density distribution of the adsorbed fluid, both at the level of density profiles and bidimensional density maps across representative sections of the porous material. In the case of very tight confinement (silicalite-1 and silicalite-2), solutions at low temperatures could not be found due to convergence difficulties, but for faujasite, which presents substantially larger channels, temperatures as low as 77 K are accessible to the integral equation. The overall results indicate that the theoretical approximation can be an excellent tool to characterize the microscopic adsorption behavior of porous materials. PMID:26520539

  1. The structure and properties of 5,6-dinitro-1H-benzotriazole

    NASA Astrophysics Data System (ADS)

    Santa María, Dolores; Claramunt, Rosa M.; Torralba, M. Carmen; Torres, M. Rosario; Alkorta, Ibon; Elguero, José

    2016-06-01

    5,6-Dinitro-1H-benzotriazole crystallizes in the monoclinic system, space group P21/c. The asymmetric unit contains the planar 1H-tautomer together with a water molecule of crystallization. Each water molecule is hydrogen bonded to three adjacent 5,6-dinitrobenzotriazoles forming a tape along the b-axis of the crystal. These tapes stack along the c-axis through hydrogen bonds involving the water molecules and one of the nitro groups leading to a bidimensional structure. Solid-state 13C and 15N CPMAS NMR allow to confirm that the tautomer present is the 1H one. In DMSO-d6 solution the results are quite different and, based on GIAO/B3LYP/6-311++G(d,p) calculations, lead us to conclude that the major tautomer is the 5,6-dinitro-2H-benzotriazole, a surprising result that contradicts the rule that the major tautomer in solution coincides with the one present in the crystal. An anhydrous pseudopolymorph of 5,6-dinitro-1H-benzotriazole has been obtained as a non-crystalline form and from solid-state NMR and theoretical calculations, we conclude that it is an 1H-tautomer.

  2. Reprint of: self-assembly of nanoparticles employing polymerization-induced phase separation.

    PubMed

    Williams, Roberto J J; Hoppe, Cristina E; Zucchi, Ileana A; Romeo, Hernán E; dell'Erba, Ignacio E; Gómez, María L; Puig, Julieta; Leonardi, Agustina B

    2015-06-01

    Nanoparticles (NPs) may be homogeneously dispersed in the precursors of a polymer (reactive solvent) by an adequate selection of their stabilizing ligands. However, the dispersion can become metastable or unstable in the course of polymerization. If this happens, NP-rich domains can be segregated by a process called polymerization-induced phase separation (PIPS). This occurs mainly due to the decrease in the entropic contribution of the reactive solvent to the free energy of mixing (increase in its average size) and, for a reactive solvent generating a cross-linked polymer, the additional contribution of the elastic energy in the post-gel stage. The extent of PIPS will depend on the competition between phase separation and polymerization rates. It can be completely avoided, limited to a local scale or conveyed to generate different types of NPs' aggregates such as crystalline platelets, self-assembled structures with a hierarchical order and partitioning at the interface, and bidimensional patterns of NPs at the film surface. The use of a third component in the initial formulation such as a linear polymer or a block copolymer, provides the possibility of generating an internal template for the preferential location and self-assembly of phase-separated NPs. Some illustrative examples of morphologies generated by PIPS in solutions of NPs in reactive solvents, are analyzed in this feature article. PMID:25736431

  3. Self-assembly of nanoparticles employing polymerization-induced phase separation.

    PubMed

    Williams, Roberto J J; Hoppe, Cristina E; Zucchi, Ileana A; Romeo, Hernán E; dell'Erba, Ignacio E; Gómez, María L; Puig, Julieta; Leonardi, Agustina B

    2014-10-01

    Nanoparticles (NPs) may be homogeneously dispersed in the precursors of a polymer (reactive solvent) by an adequate selection of their stabilizing ligands. However, the dispersion can become metastable or unstable in the course of polymerization. If this happens, NP-rich domains can be segregated by a process called polymerization-induced phase separation (PIPS). This occurs mainly due to the decrease in the entropic contribution of the reactive solvent to the free energy of mixing (increase in its average size) and, for a reactive solvent generating a cross-linked polymer, the additional contribution of the elastic energy in the post-gel stage. The extent of PIPS will depend on the competition between phase separation and polymerization rates. It can be completely avoided, limited to a local scale or conveyed to generate different types of NPs' aggregates such as crystalline platelets, self-assembled structures with a hierarchical order and partitioning at the interface, and bidimensional patterns of NPs at the film surface. The use of a third component in the initial formulation such as a linear polymer or a block copolymer, provides the possibility of generating an internal template for the preferential location and self-assembly of phase-separated NPs. Some illustrative examples of morphologies generated by PIPS in solutions of NPs in reactive solvents, are analyzed in this feature article. PMID:25014172

  4. Purification and characterization of macrodontain I, a cysteine peptidase from unripe fruits of Pseudananas macrodontes (Morr.) harms (Bromeliaceae).

    PubMed

    López, L M; Sequeiros, C; Natalucci, C L; Brullo, A; Maras, B; Barra, D; Caffini, N O

    2000-03-01

    A new papain-like cysteine peptidase isolated from fruits of Pseudananas macrodontes (Morr.) Harms, a species closely related to pineapple (Ananas comosus L.), has been purified and characterized. The enzyme, named macrodontain I, is the main proteolytic component present in fruit extracts and was purified by acetone fractionation followed by anion-exchange chromatography. Separation was improved by selecting both an adequate pH value and a narrow saline gradient. Optimum pH range (more than 90% of maximum activity with casein) was achieved at pH 6.1-8.5. Homogeneity of the enzyme was confirmed by bidimensional electrophoresis and mass spectroscopy (MS). Molecular mass of the enzyme was 23,459 (MS) and its isoelectric point was 6.1. The alanine, glutamine, and tyrosine derivatives were strongly preferred when the enzyme was assayed on N-alpha-CBZ-l-amino acid p-nitrophenyl esters. The N-terminal sequence of macrodontain (by comparison with the N-terminus of 30 plant proteases with more than 50% homology) showed a great deal of sequence similarity to the other pineapple-stem-derived cysteine endopeptidases, being 85.7, 85. 2, and 77.8% identical to comosain, stem bromelain, and ananain, respectively. It seems clear that the Bromeliaceae endopeptidases are more closely related to each other than to other members of the papain family, suggesting relatively recent divergence. PMID:10686143

  5. Changes in language usage of Puerto Rican mothers and their children: Do gender and timing of exposure to English matter?

    PubMed Central

    HAMMER, CAROL SCHEFFNER; LAWRENCE, FRANK; RODRIGUEZ, BARBARA; DAVISON, MEGAN DUNN; MICCIO, ADELE W.

    2012-01-01

    This longitudinal study investigated changes in reported language usage between Puerto Rican mothers and their preschoolers over a 4-year period. It also examined whether differences in language usage occurred depending on the timing of children’s exposure to English and children’s gender. Seventy-six mothers reported the languages they and their children used when talking to each other during 2 years in Head Start, kindergarten, and first grade. Mothers of children who were exposed to Spanish and English prior to preschool entry reported using more English to their children than mothers of children who were not exposed to English until after preschool entry. The language usage of the children followed the same patterns as their mothers. The difference between the groups was maintained over the 4 years, although both groups increased their English usage. A gender effect was observed. Mothers of girls were five times more likely to use “More or All Spanish” than mothers of sons. In addition, girls who were exposed to Spanish only prior to preschool entry were six times more likely to speak to their mothers in “More or All Spanish” than other participating children. The bidimensional model of acculturation is used to present and interpret the findings. PMID:23258946

  6. Further evidences for the mode of action of the larvicidal m-pentadecadienyl-phenol isolated from Myracrodruon urundeuva seeds against Aedes aegypti.

    PubMed

    Souza, Terezinha M; Menezes, Erika S Bezerra; Oliveira, Rodrigo V; Almeida Filho, Luiz Carlos P; Martins, Jorge M; Moreno, Frederico B; Monteiro-Moreira, Ana Cristina O; Moura, Arlindo A Araripe; Carvalho, Ana F Urano

    2015-12-01

    Nowadays, dengue fever is considered the most important arbovirosis worldwide and its control is still based upon combating the vector Aedes aegypti. Besides monitoring of mosquito populations resistant to conventional insecticides, the search for new environmentally safe insecticides and conduction of molecular studies focusing on the elucidation of mode of action and possible resistance mechanisms are considered the key for a sustainable management of the mosquito vector. Thus, the present work aimed to assess changes in protein expression of 3rd-instar larvae of Ae. aegypti after exposure to the natural insecticide m-pentadecadienyl-phenol. Bidimensional electrophoresis followed by mass spectrometry resulted in identification of 12 proteins differentially expressed between control and treated groups. Larvae exposed to the toxic compound for 24h showed elevated detoxification response (glutathione-S-transferase), increased levels of stress-related proteins (HSP70) as well as evidence of lysosome stabilization to enable survival. Furthermore, expression of proteins involved in protection of peritrophic membrane and metabolism of lipids indicated systemic effect of toxic effects in treated larvae. PMID:26299195

  7. Massive Exploration of Perturbed Conditions of the Blood Coagulation Cascade through GPU Parallelization

    PubMed Central

    Cazzaniga, Paolo; Nobile, Marco S.; Besozzi, Daniela; Bellini, Matteo; Mauri, Giancarlo

    2014-01-01

    The introduction of general-purpose Graphics Processing Units (GPUs) is boosting scientific applications in Bioinformatics, Systems Biology, and Computational Biology. In these fields, the use of high-performance computing solutions is motivated by the need of performing large numbers of in silico analysis to study the behavior of biological systems in different conditions, which necessitate a computing power that usually overtakes the capability of standard desktop computers. In this work we present coagSODA, a CUDA-powered computational tool that was purposely developed for the analysis of a large mechanistic model of the blood coagulation cascade (BCC), defined according to both mass-action kinetics and Hill functions. coagSODA allows the execution of parallel simulations of the dynamics of the BCC by automatically deriving the system of ordinary differential equations and then exploiting the numerical integration algorithm LSODA. We present the biological results achieved with a massive exploration of perturbed conditions of the BCC, carried out with one-dimensional and bi-dimensional parameter sweep analysis, and show that GPU-accelerated parallel simulations of this model can increase the computational performances up to a 181× speedup compared to the corresponding sequential simulations. PMID:25025072

  8. Morpho-elasticity of intestinal villi

    PubMed Central

    Balbi, V.; Ciarletta, P.

    2013-01-01

    Villi are ubiquitous structures in the intestine of all vertebrates, originating from the embryonic development of the epithelial mucosa. Their morphogenesis has similar stages in living organisms but different forming mechanisms. In this work, we model the emergence of the bi-dimensional undulated patterns in the intestinal mucosa from which villi start to elongate. The embryonic mucosa is modelled as a growing thick-walled cylinder, and its mechanical behaviour is described using an hyperelastic constitutive model, which also accounts for the anisotropic characteristics of the reinforcing fibres at the microstructural level. The occurrence of surface undulations is investigated using a linear stability analysis based on the theory of incremental deformations superimposed on a finite deformation. The Stroh formulation of the incremental boundary value problem is derived, and a numerical solution procedure is implemented for calculating the growth thresholds of instability. The numerical results are finally discussed with respect to different growth and materials properties. In conclusion, we demonstrate that the emergence of intestinal villi in embryos is triggered by a differential growth between the mucosa and the mesenchymal tissues. The proposed model quantifies how both the geometrical and the mechanical properties of the mucosa drive the formation of previllous structures in embryos. PMID:23486174

  9. Calculation of a double reactive azeotrope using stochastic optimization approaches

    NASA Astrophysics Data System (ADS)

    Mendes Platt, Gustavo; Pinheiro Domingos, Roberto; Oliveira de Andrade, Matheus

    2013-02-01

    An homogeneous reactive azeotrope is a thermodynamic coexistence condition of two phases under chemical and phase equilibrium, where compositions of both phases (in the Ung-Doherty sense) are equal. This kind of nonlinear phenomenon arises from real world situations and has applications in chemical and petrochemical industries. The modeling of reactive azeotrope calculation is represented by a nonlinear algebraic system with phase equilibrium, chemical equilibrium and azeotropy equations. This nonlinear system can exhibit more than one solution, corresponding to a double reactive azeotrope. The robust calculation of reactive azeotropes can be conducted by several approaches, such as interval-Newton/generalized bisection algorithms and hybrid stochastic-deterministic frameworks. In this paper, we investigate the numerical aspects of the calculation of reactive azeotropes using two metaheuristics: the Luus-Jaakola adaptive random search and the Firefly algorithm. Moreover, we present results for a system (with industrial interest) with more than one azeotrope, the system isobutene/methanol/methyl-tert-butyl-ether (MTBE). We present convergence patterns for both algorithms, illustrating - in a bidimensional subdomain - the identification of reactive azeotropes. A strategy for calculation of multiple roots in nonlinear systems is also applied. The results indicate that both algorithms are suitable and robust when applied to reactive azeotrope calculations for this "challenging" nonlinear system.

  10. A Deep Look Into Erionite Fibres: an Electron Microscopy Investigation of their Self-Assembly

    NASA Astrophysics Data System (ADS)

    Matassa, Roberto; Familiari, Giuseppe; Relucenti, Michela; Battaglione, Ezio; Downing, Clive; Pacella, Alessandro; Cametti, Georgia; Ballirano, Paolo

    2015-11-01

    The exposure of humans to erionite fibres of appropriate morphology and dimension has been unambiguously linked to the occurrence of Malignant Mesothelioma. For this reason, a detailed morpho-structural investigation through Electron Microscopy techniques has been performed on erionite samples collected at two different localities, Durkee (ED) and Rome (ER), Oregon, USA. The sample from Rome has been also investigated after a prolonged leaching with Gamble’s solution (ER4G) in order to evaluate the possible occurrence of morpho-structural modifications induced by this Simulated-Lung-Fluid (SLF). Here we report how the micrometric erionite fibres evolve in irregular ribbon- or rod-like bundles as a function of different nano-structural features. The reasons for the observed morphological variability have been explained by considering the structural defects located at ED surface fibrils (bi-dimensional ribbons) and the presence of nontronite, an iron-bearing clay mineral embedding the ER fibrils (mono-dimensional rods). ER4G shows a decrease in width of the rod-like fibres due to their partial digestion by SLF leaching, which synchronously dissolves nontronite. The reported results represent a valuable background toward the full comprehension of the morphological mechanisms responsible for potentially damage of lung tissue through the potential relocation of fibers to extrapulmonary sites, increasing the carcinogenic risk to humans.

  11. Automated segmentation of mesothelioma volume on CT scan

    NASA Astrophysics Data System (ADS)

    Zhao, Binsheng; Schwartz, Lawrence; Flores, Raja; Liu, Fan; Kijewski, Peter; Krug, Lee; Rusch, Valerie

    2005-04-01

    In mesothelioma, response is usually assessed by computed tomography (CT). In current clinical practice the Response Evaluation Criteria in Solid Tumors (RECIST) or WHO, i.e., the uni-dimensional or the bi-dimensional measurements, is applied to the assessment of therapy response. However, the shape of the mesothelioma volume is very irregular and its longest dimension is almost never in the axial plane. Furthermore, the sections and the sites where radiologists measure the tumor are rather subjective, resulting in poor reproducibility of tumor size measurements. We are developing an objective three-dimensional (3D) computer algorithm to automatically identify and quantify tumor volumes that are associated with malignant pleural mesothelioma to assess therapy response. The algorithm first extracts the lung pleural surface from the volumetric CT images by interpolating the chest ribs over a number of adjacent slices and then forming a volume that includes the thorax. This volume allows a separation of mesothelioma from the chest wall. Subsequently, the structures inside the extracted pleural lung surface, including the mediastinal area, lung parenchyma, and pleural mesothelioma, can be identified using a multiple thresholding technique and morphological operations. Preliminary results have shown the potential of utilizing this algorithm to automatically detect and quantify tumor volumes on CT scans and thus to assess therapy response for malignant pleural mesothelioma.

  12. A multipurpose ultra-high vacuum-compatible chamber for in situ X-ray surface scattering studies over a wide range of temperature and pressure environment conditions

    NASA Astrophysics Data System (ADS)

    Ferrer, P.; Rubio-Zuazo, J.; Heyman, C.; Esteban-Betegón, F.; Castro, G. R.

    2013-03-01

    A low/high temperature (60-1000K) and pressure (10-10-3x103 mbar) "baby chamber", specially adapted to the grazing-incidence X-ray scattering station, has been designed, developed and installed at the Spanish CRG BM25 SpLine beamline at European Synchrotron Radiation Facility. The chamber has a cylindrical form with 100 mm of diameter, built on a 360° beryllium nipple of 150 mm height. The UHV equipment and a turbo pump are located on the upper part of the chamber to leave a wide solid angle for exploring reciprocal space. The chamber features 4 CF16 and 5 CF40 ports for electrical feed through and leak valves, ion gun, etc. The heat exchanger is a customized compact LN2 (or LHe) continuous flow cryostat. The sample is mounted on a Mo support on the heat exchanger, which has in the back side a BORALECTRIC® Heater Elements. Experiments of surfaces/interfaces/ multilayer materials, thin films or single crystals in a huge variety of environments can be performed, also in situ studies of growth or evolution of the samples. Data measurement can be collected with a punctual and a bi-dimensional detector, being possible to simultaneously use them.

  13. The influence of pitch dimensions on performance during small-sided and conditioned soccer games.

    PubMed

    Vilar, Luís; Duarte, Ricardo; Silva, Pedro; Chow, Jia Yi; Davids, Keith

    2014-01-01

    This study examined the influence of pitch dimensions in small-sided soccer games in shaping opportunities for performers to maintain ball possession, pass to teammates and shoot at goal. Fifteen amateur standard male participants (M = 21.87, σ = 1.96 years) played 5 v 5 small-sided soccer games in three varying pitch conditions (28 m × 14 m, 40 m × 20 m and 52 m × 26 m). Thirty sequences of play in each condition were selected for digitisation using TACTO software, allowing the capture of bi-dimensional displacement coordinate data of all players and the ball. The values of interpersonal distance between all attackers and immediate defenders and the relative distances of defenders to intercept a shot and a pass were computed as dependent variables. Results showed existence of fewer opportunities to maintain ball possession on smaller pitches, compared to medium and larger pitches. Conversely, the different dimensions set to the pitch did not influence opportunities for players to shoot at goal, or to perform passes to other teammates. By examining the specific spatial-temporal relationships of players and key-task constraints, the data from this study explain how effects of manipulating pitch dimensions of small-sided games might enhance opportunities for acquiring specific movement and decision-making skills. PMID:24915106

  14. 3D tracking of single nanoparticles and quantum dots in living cells by out-of-focus imaging with diffraction pattern recognition

    NASA Astrophysics Data System (ADS)

    Gardini, Lucia; Capitanio, Marco; Pavone, Francesco S.

    2015-11-01

    Live cells are three-dimensional environments where biological molecules move to find their targets and accomplish their functions. However, up to now, most single molecule investigations have been limited to bi-dimensional studies owing to the complexity of 3d-tracking techniques. Here, we present a novel method for three-dimensional localization of single nano-emitters based on automatic recognition of out-of-focus diffraction patterns. Our technique can be applied to track the movements of single molecules in living cells using a conventional epifluorescence microscope. We first demonstrate three-dimensional localization of fluorescent nanobeads over 4 microns depth with accuracy below 2 nm in vitro. Remarkably, we also establish three-dimensional tracking of Quantum Dots, overcoming their anisotropic emission, by adopting a ligation strategy that allows rotational freedom of the emitter combined with proper pattern recognition. We localize commercially available Quantum Dots in living cells with accuracy better than 7 nm over 2 microns depth. We validate our technique by tracking the three-dimensional movements of single protein-conjugated Quantum Dots in living cell. Moreover, we find that important localization errors can occur in off-focus imaging when improperly calibrated and we give indications to avoid them. Finally, we share a Matlab script that allows readily application of our technique by other laboratories.

  15. Cognitive control and language across the life span: does labeling improve reactive control?

    PubMed

    Lucenet, Joanna; Blaye, Agnès; Chevalier, Nicolas; Kray, Jutta

    2014-05-01

    How does cognitive control change with age, and what are the processes underlying these changes? This question has been extensively studied using versions of the task-switching paradigm, which allow participants to actively prepare for the upcoming task (Kray, Eber, & Karbach, 2008). Little is known, however, about age-related changes in this ability across the life span when there is no opportunity to anticipate task goals. We examined the effect of 2 kinds of verbal self-instruction-labeling either the task goal or the relevant feature of the stimulus-on 2 components of cognitive control, goal setting and switching, in children, young adults, and older adults. All participants performed single-task blocks and mixed-task blocks (involving unpredictable switching between 2 tasks) in silent and labeling conditions. Participants categorized bidimensional stimuli either by picture or by color, depending on their spatial position in a 2-cell vertical grid. Response times revealed an inverted U shape in performance with age. These age differences were more pronounced for goal setting than for switching, thus generalizing results obtained in situations taping proactive control to this new context forcing reactive control. Further, differential age-related effects of verbalization were also obtained. Verbalizations were detrimental for young adults, beneficial for older adults, and had mixed effects in children. These differences are interpreted in terms of qualitative developmental changes in reactive goal-setting strategies. PMID:24491213

  16. Mass Spectrometry-Based Identification Of The Tumor Antigen UN1 as the Transmembrane CD43 Sialoglycoprotein*

    PubMed Central

    de Laurentiis, Annamaria; Gaspari, Marco; Palmieri, Camillo; Falcone, Cristina; Iaccino, Enrico; Fiume, Giuseppe; Massa, Ornella; Masullo, Mariorosario; Tuccillo, Franca Maria; Roveda, Laura; Prati, Ubaldo; Fierro, Olga; Cozzolino, Immacolata; Troncone, Giancarlo; Tassone, Pierfrancesco; Scala, Giuseppe; Quinto, Ileana

    2011-01-01

    The UN1 monoclonal antibody recognized the UN1 antigen as a heavily sialylated and O-glycosylated protein with the apparent molecular weight of 100–120 kDa; this antigen was peculiarly expressed in fetal tissues and several cancer tissues, including leukemic T cells, breast, and colon carcinomas. However, the lack of primary structure information has limited further investigation on the role of the UN1 antigen in neoplastic transformation. In this study, we have identified the UN1 antigen as CD43, a transmembrane sialoglycoprotein involved in cell adhesion, differentiation, and apoptosis. Indeed, mass spectrometry detected two tryptic peptides of the membrane-purified UN1 antigen that matched the amino acidic sequence of the CD43 intracellular domain. Immunological cross-reactivity, migration pattern in mono- and bi-dimensional electrophoresis, and CD43 gene-dependent expression proved the CD43 identity of the UN1 antigen. Moreover, the monosaccharide GalNAc-O-linked to the CD43 peptide core was identified as an essential component of the UN1 epitope by glycosidase digestion of specific glycan branches. UN1-type CD43 glycoforms were detected in colon, sigmoid colon, and breast carcinomas, whereas undetected in normal tissues from the same patients, confirming the cancer-association of the UN1 epitope. Our results highlight UN1 monoclonal antibody as a suitable tool for cancer immunophenotyping and analysis of CD43 glycosylation in tumorigenesis. PMID:21372249

  17. Architecture and migration of an epithelium on a cylindrical wire.

    PubMed

    Yevick, Hannah G; Duclos, Guillaume; Bonnet, Isabelle; Silberzan, Pascal

    2015-05-12

    In a wide range of epithelial tissues such as kidney tubules or breast acini, cells organize into bidimensional monolayers experiencing an out-of-plane curvature. Cancer cells can also migrate collectively from epithelial tumors by wrapping around vessels or muscle fibers. However, in vitro experiments dealing with epithelia are mostly performed on flat substrates, neglecting this out-of-plane component. In this paper, we study the development and migration of epithelial tissues on glass wires of well-defined radii varying from less than 1 µm up to 85 µm. To uncouple the effect of out-of-plane curvature from the lateral confinement experienced by the cells in these geometries, we compare our results to experiments performed on narrow adhesive tracks. Because of lateral confinement, the velocity of collective migration increases for radii smaller than typically 20 µm. The monolayer dynamics is then controlled by front-edge protrusions. Conversely, high curvature is identified as the inducer of frequent cell detachments at the front edge, a phenotype reminiscent of the Epithelial-Mesenchymal Transition. High curvature also induces a circumferential alignment of the actin cytoskeleton, stabilized by multiple focal adhesions. This organization of the cytoskeleton is reminiscent of in vivo situations such as the development of the trachea of the Drosophila embryo. Finally, submicron radii halt the monolayer, which then reconfigures into hollow cysts. PMID:25922533

  18. Observation of Neutral Sodium Above Mercury During the Transit of November 8, 2006

    NASA Technical Reports Server (NTRS)

    Potter, A. E.; Killen, R. M.; Reardon, Kevin P.; Bida, T. A.

    2013-01-01

    We mapped the absorption of sunlight by sodium vapor in the exosphere of Mercury during the transit of Mercury on November 8, 2006, using the IBIS Interferometric BIdimensional Spectrometer at the Dunn Solar Telescope operated by the National Solar Observatory at Sunspot, New Mexico. The measurements were reduced to line-of-sight equivalent widths for absorption at the sodium D2 line around the shadow of Mercury. The sodium absorption fell off exponentially with altitude up to about 600 km. However there were regions around north and south polar-regions where relatively uniform sodium absorptions extended above 1000 km. We corrected the 0-600 km altitude profiles for seeing blur using the measured point spread function. Analysis of the corrected altitude distributions yielded surface densities, zenith column densities, temperatures and scale heights for sodium all around the planet. Sodium absorption on the dawn side equatorial terminator was less than on the dusk side, different from previous observations of the relative absorption levels. We also determined Earthward velocities for sodium atoms, and line widths for the absorptions. Earthward velocities resulting from radiation pressure on sodium averaged 0.8 km/s, smaller than a prediction of 1.5 km/s. Most line widths were in the range of 20 mA after correction for instrumental broadening, corresponding to temperatures in the range of 1000 K.

  19. An Improved Quantitative Analysis Method for Plant Cortical Microtubules

    PubMed Central

    Lu, Yi; Huang, Chenyang; Wang, Jia; Shang, Peng

    2014-01-01

    The arrangement of plant cortical microtubules can reflect the physiological state of cells. However, little attention has been paid to the image quantitative analysis of plant cortical microtubules so far. In this paper, Bidimensional Empirical Mode Decomposition (BEMD) algorithm was applied in the image preprocessing of the original microtubule image. And then Intrinsic Mode Function 1 (IMF1) image obtained by decomposition was selected to do the texture analysis based on Grey-Level Cooccurrence Matrix (GLCM) algorithm. Meanwhile, in order to further verify its reliability, the proposed texture analysis method was utilized to distinguish different images of Arabidopsis microtubules. The results showed that the effect of BEMD algorithm on edge preserving accompanied with noise reduction was positive, and the geometrical characteristic of the texture was obvious. Four texture parameters extracted by GLCM perfectly reflected the different arrangements between the two images of cortical microtubules. In summary, the results indicate that this method is feasible and effective for the image quantitative analysis of plant cortical microtubules. It not only provides a new quantitative approach for the comprehensive study of the role played by microtubules in cell life activities but also supplies references for other similar studies. PMID:24744684

  20. Interactions between the surface gravity waves and the Von Karman streets: a numerical study

    NASA Astrophysics Data System (ADS)

    Gunnoo, Hans; Bennis, Anne-Claire; Rivier, Aurélie; Abcha, NIzar; Ezersky, Alexander

    2015-04-01

    The growth of renewable energy over the past decade is impressive. Offshore wind farms are planned to construct along the site of Courseulles s/mer (Normandy, France) in 2018. The ofelia project leads to study the environmental impacts of the offshore wind farms in the Channel. In parallel with the regional modeling of the changes in hydrodynamic and in sediment transport due to monopiles (Rivier et al., 2014), studies at local scales are also carried out. Laboratory experiments show that the resonance between the surface gravity waves and the Von Karman streets leads to modify the synchronisation of the vortex (Gunnoo et al., 2014). Numerical simulations are performed to reproduce this mechanism. The CFD code, IHFOAM, based on an OpenFoam Kernel, allows to simulate the wave-current interactions at local scales. First, bi-dimensional and three-dimensional simulations without waves are set-up to validate our modeling plateform. The well-known Von Karman streets are obtained. Results are in agreement with the experimental data. Second, waves are included in the simulations. The free-surface is explicitely solved by the Volume Of Fluid method. Regular and irregular wave spectrums are tested. Changes in Von Karman Streets due to waves are observed. In the future, some comparisons with the experimental results will be done.

  1. MuSICa: the Multi-Slit Image Slicer for the est Spectrograph

    NASA Astrophysics Data System (ADS)

    Calcines, A.; López, R. L.; Collados, M.

    2013-09-01

    Integral field spectroscopy (IFS) is a technique that allows one to obtain the spectra of all the points of a bidimensional field of view simultaneously. It is being applied to the new generation of the largest night-time telescopes but it is also an innovative technique for solar physics. This paper presents the design of a new image slicer, MuSICa (Multi-Slit Image slicer based on collimator-Camera), for the integral field spectrograph of the 4-m aperture European Solar Telescope (EST). MuSICa is a multi-slit image slicer that decomposes an 80 arcsec2 field of view into slices of 50 μm and reorganizes it into eight slits of 0.05 arcsec width × 200 arcsec length. It is a telecentric system with an optical quality at diffraction limit compatible with the two modes of operation of the spectrograph: spectroscopic and spectro-polarimetric. This paper shows the requirements, technical characteristics and layout of MuSICa, as well as other studied design options.

  2. MuSICa image slicer prototype at 1.5-m GREGOR solar telescope

    NASA Astrophysics Data System (ADS)

    Calcines, A.; López, R. L.; Collados, M.; Vega Reyes, N.

    2014-07-01

    Integral Field Spectroscopy is an innovative technique that is being implemented in the state-of-the-art instruments of the largest night-time telescopes, however, it is still a novelty for solar instrumentation. A new concept of image slicer, called MuSICa (Multi-Slit Image slicer based on collimator-Camera), has been designed for the integral field spectrograph of the 4-m European Solar Telescope. This communication presents an image slicer prototype of MuSICa for GRIS, the spectrograph of the 1.5-m GREGOR solar telescope located at the Observatory of El Teide. MuSICa at GRIS reorganizes a 2-D field of view of 24.5 arcsec into a slit of 0.367 arcsec width by 66.76 arcsec length distributed horizontally. It will operate together with the TIP-II polarimeter to offer high resolution integral field spectropolarimetry. It will also have a bidimensional field of view scanning system to cover a field of view up to 1 by 1 arcmin.

  3. [A new concept in surgery of the digestive tract: surgical procedure assisted by computer, from virtual reality to telemanipulation].

    PubMed

    Marescaux, J; Clément, J M; Vix, M; Russier, Y; Tassetti, V; Mutter, D; Cotin, S; Ayache, N

    1998-02-01

    Surgical simulation increasingly appears to be an essential aspect of tomorrow's surgery. The development of a hepatic surgery simulator is an advanced concept calling for a new writing system which will transform the medical world: virtual reality. Virtual reality extends the perception of our five senses by representing more than the real state of things by the means of computer sciences and robotics. It consists of three concepts: immersion, navigation and interaction. Three reasons have led us to develop this simulator: the first is to provide the surgeon with a comprehensive visualisation of the organ. The second reasons is to allow for planning and surgical simulation that could be compared with the detailed flight-plan for a commercial jet pilot. The third lies in the fact that virtual reality is an integrated part of the concept of computer assisted surgical procedure. The project consists of a sophisticated simulator which must include five requirements: a) visual fidelity, b) interactivity, c) physical properties, d) physiological properties, e) sensory input and output. In this report we describe how to obtain a realistic 3D model of the liver from bi-dimensional 2D medical images for anatomical and surgical training. The introduction of a tumor and the consequent planning and virtual resection is also described, as are force feedback and real-time interaction. PMID:9752550

  4. [A new concept in digestive surgery: the computer assisted surgical procedure, from virtual reality to telemanipulation].

    PubMed

    Marescaux, J; Clément, J M; Nord, M; Russier, Y; Tassetti, V; Mutter, D; Cotin, S; Ayache, N

    1997-11-01

    Surgical simulation increasingly appears to be an essential aspect of tomorrow's surgery. The development of a hepatic surgery simulator is an advanced concept calling for a new writing system which will transform the medical world: virtual reality. Virtual reality extends the perception of our five senses by representing more than the real state of things by the means of computer sciences and robotics. It consists of three concepts: immersion, navigation and interaction. Three reasons have led us to develop this simulator: the first is to provide the surgeon with a comprehensive visualisation of the organ. The second reason is to allow for planning and surgical simulation that could be compared with the detailed flight-plan for a commercial jet pilot. The third lies in the fact that virtual reality is an integrated part of the concept of computer assisted surgical procedure. The project consists of a sophisticated simulator which has to include five requirements: visual fidelity, interactivity, physical properties, physiological properties, sensory input and output. In this report we will describe how to get a realistic 3D model of the liver from bi-dimensional 2D medical images for anatomical and surgical training. The introduction of a tumor and the consequent planning and virtual resection is also described, as are force feedback and real-time interaction. PMID:9554121

  5. Computation of the dynamic thermal properties of a three-dimensional unit cell of porous media by Brownian motion simulation

    NASA Astrophysics Data System (ADS)

    Perrot, Camille; Olny, Xavier; Panneton, Raymond; Bouchard, Richard

    2001-05-01

    Acoustic dissipation in porous media is mainly due to viscous and thermal mechanisms that occur in the pores of the microstructure. The purpose of this study is the determination of the macroscopic dynamic acoustic bulk modulus and thermal permeability of real foams from a local scale approach. To achieve this goal, two distinct steps are followed. First, the local geometry of a real foam is obtained using computed microtomography (μCT), then a periodic and regularly paving space tetrakaidecahedron cell is identified from the microstructure. Second, the heat equation is solved for the geometrical model. The paper provides a three-dimensional application of the efficient simulation technique of Brownian motion proposed by Torquato et al. for steady state diffusion-controlled problems [Appl. Phys. Lett. 55, 1847-1849 (1989)] and adapted by Lafarge [Poromechanics II, 708 (2002)] in a bi-dimensional case. The influence of the model's microstructural details (anisotropy, and struts junction and cross-section) on the macroscopic properties are studied. The predictions of the macroscopic properties using this local scale approach are then compared to experimental measurements.

  6. Microstructure and acoustical macro-behavior: Approach by reconstruction of a representative elementary cell

    NASA Astrophysics Data System (ADS)

    Perrot, Camille

    The fundamental issue of determining acoustic properties of porous media from their local geometry is examined in this PhD dissertation thesis, thanks to a sample of open-cell aluminum foam analyzed by axial computed microtomography. Various geometric properties are measured to characterize the experimental sample at the cell size level. This is done in order to reconstruct a porous medium by means of idealized three- and two-dimensional unit-cells. The frequency dependant thermal and velocity fields governing the propagation and dissipation of acoustic waves through rigid porous media are computed by Brownian motion simulation and the finite element method, respectively. Macroscopic behavior is derived by spatial averaging of the local fields. Our results are compared to experimental data obtained from impedance tube measurements. Firstly, this approach leads to the identification of the macroscopic parameters involved in Pride and Lafarge semiphenomenological models. Secondly, it yields a direct access to thermal and viscous dynamic permeabilities. However, the bi-dimensional model underestimates the static viscous permeability as well as the viscous characteristic length; what thus require a three-dimensional implementation. Key-words: microstructure - acoustics - porous media - open-cell foams - reconstruction method - microtomography - Brownian motion - dynamic thermal and viscous permeabilities.

  7. Skin Parameter Map Retrieval from a Dedicated Multispectral Imaging System Applied to Dermatology/Cosmetology

    PubMed Central

    2013-01-01

    In vivo quantitative assessment of skin lesions is an important step in the evaluation of skin condition. An objective measurement device can help as a valuable tool for skin analysis. We propose an explorative new multispectral camera specifically developed for dermatology/cosmetology applications. The multispectral imaging system provides images of skin reflectance at different wavebands covering visible and near-infrared domain. It is coupled with a neural network-based algorithm for the reconstruction of reflectance cube of cutaneous data. This cube contains only skin optical reflectance spectrum in each pixel of the bidimensional spatial information. The reflectance cube is analyzed by an algorithm based on a Kubelka-Munk model combined with evolutionary algorithm. The technique allows quantitative measure of cutaneous tissue and retrieves five skin parameter maps: melanin concentration, epidermis/dermis thickness, haemoglobin concentration, and the oxygenated hemoglobin. The results retrieved on healthy participants by the algorithm are in good accordance with the data from the literature. The usefulness of the developed technique was proved during two experiments: a clinical study based on vitiligo and melasma skin lesions and a skin oxygenation experiment (induced ischemia) with healthy participant where normal tissues are recorded at normal state and when temporary ischemia is induced. PMID:24159326

  8. Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa.

    PubMed

    Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

    2015-01-01

    The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation. PMID:25978319

  9. 2D Flood Modelling Using Advanced Terrain Analysis Techniques And A Fully Continuous DEM-Based Rainfall-Runoff Algorithm

    NASA Astrophysics Data System (ADS)

    Nardi, F.; Grimaldi, S.; Petroselli, A.

    2012-12-01

    Remotely sensed Digital Elevation Models (DEMs), largely available at high resolution, and advanced terrain analysis techniques built in Geographic Information Systems (GIS), provide unique opportunities for DEM-based hydrologic and hydraulic modelling in data-scarce river basins paving the way for flood mapping at the global scale. This research is based on the implementation of a fully continuous hydrologic-hydraulic modelling optimized for ungauged basins with limited river flow measurements. The proposed procedure is characterized by a rainfall generator that feeds a continuous rainfall-runoff model producing flow time series that are routed along the channel using a bidimensional hydraulic model for the detailed representation of the inundation process. The main advantage of the proposed approach is the characterization of the entire physical process during hydrologic extreme events of channel runoff generation, propagation, and overland flow within the floodplain domain. This physically-based model neglects the need for synthetic design hyetograph and hydrograph estimation that constitute the main source of subjective analysis and uncertainty of standard methods for flood mapping. Selected case studies show results and performances of the proposed procedure as respect to standard event-based approaches.

  10. The Simulation of AN Imaging Gamma-Ray Compton Backscattering Device Using GEANT4

    NASA Astrophysics Data System (ADS)

    Flechas, D.; Sarmiento, L. G.; Cristancho, F.; Fajardo, E.

    2014-02-01

    A gamma-backscattering imaging device dubbed Compton Camera, developed at GSI (Darmstadt, Germany) and modified and studied at the Nuclear Physics Group of the National University of Colombia in Bogotá, uses the back-to-back emission of two gamma rays in the positron annihilation to construct a bidimensional image that represents the distribution of matter in the field-of-view of the camera. This imaging capability can be used in a host of different situations, for example, to identify and study deposition and structural defects, and to help locating concealed objects, to name just two cases. In order to increase the understanding of the response of the Compton Camera and, in particular, its image formation process, and to assist in the data analysis, a simulation of the camera was developed using the GEANT4 simulation toolkit. In this work, the images resulting from different experimental conditions are shown. The simulated images and their comparison with the experimental ones already suggest methods to improve the present experimental device

  11. A simulation method for the study of laser transillumination of biological tissues.

    PubMed

    Maarek, J M; Jarry, G; de Cosnac, B; Lansiart, A; Bui-Mong-Hung

    1984-01-01

    The Monte-Carlo method is employed to simulate the illumination of a blood slab by a continuous laser. It is assumed that the geometry of the medium is bidimensional and that scattering or absorption takes place only when a photon strikes a red blood cell. The parameters involved in the calculations concern the photons free path lengths between two collisions, the scattering angles and the absorption probability at collision. These parameters are assessed according to experimental or literature data. Fortran programs allow the computation of diffuse and collimated transmittances (Td and Tc, respectively), of transmittance measured with an optic fiber Tf and of reflectance R. The variations of Tc and Tf with blood thickness are in accordance with established laws. Moreover, measured and computed reflectances change with hematocrit ratio in a similar way. This work demonstrates that the Monte-Carlo method is a simple reliable tool which can be used to provide a realistic model of laser penetration in complex biological structures. Moreover, this method will permit investigations in laser tomo-spectrometry by providing a useful simulation of the interaction of ultrashort light pulses with biological media. PMID:6517406

  12. A Deep Look Into Erionite Fibres: an Electron Microscopy Investigation of their Self-Assembly.

    PubMed

    Matassa, Roberto; Familiari, Giuseppe; Relucenti, Michela; Battaglione, Ezio; Downing, Clive; Pacella, Alessandro; Cametti, Georgia; Ballirano, Paolo

    2015-01-01

    The exposure of humans to erionite fibres of appropriate morphology and dimension has been unambiguously linked to the occurrence of Malignant Mesothelioma. For this reason, a detailed morpho-structural investigation through Electron Microscopy techniques has been performed on erionite samples collected at two different localities, Durkee (ED) and Rome (ER), Oregon, USA. The sample from Rome has been also investigated after a prolonged leaching with Gamble's solution (ER4G) in order to evaluate the possible occurrence of morpho-structural modifications induced by this Simulated-Lung-Fluid (SLF). Here we report how the micrometric erionite fibres evolve in irregular ribbon- or rod-like bundles as a function of different nano-structural features. The reasons for the observed morphological variability have been explained by considering the structural defects located at ED surface fibrils (bi-dimensional ribbons) and the presence of nontronite, an iron-bearing clay mineral embedding the ER fibrils (mono-dimensional rods). ER4G shows a decrease in width of the rod-like fibres due to their partial digestion by SLF leaching, which synchronously dissolves nontronite. The reported results represent a valuable background toward the full comprehension of the morphological mechanisms responsible for potentially damage of lung tissue through the potential relocation of fibers to extrapulmonary sites, increasing the carcinogenic risk to humans. PMID:26567530

  13. A Deep Look Into Erionite Fibres: an Electron Microscopy Investigation of their Self-Assembly

    PubMed Central

    Matassa, Roberto; Familiari, Giuseppe; Relucenti, Michela; Battaglione, Ezio; Downing, Clive; Pacella, Alessandro; Cametti, Georgia; Ballirano, Paolo

    2015-01-01

    The exposure of humans to erionite fibres of appropriate morphology and dimension has been unambiguously linked to the occurrence of Malignant Mesothelioma. For this reason, a detailed morpho-structural investigation through Electron Microscopy techniques has been performed on erionite samples collected at two different localities, Durkee (ED) and Rome (ER), Oregon, USA. The sample from Rome has been also investigated after a prolonged leaching with Gamble’s solution (ER4G) in order to evaluate the possible occurrence of morpho-structural modifications induced by this Simulated-Lung-Fluid (SLF). Here we report how the micrometric erionite fibres evolve in irregular ribbon- or rod-like bundles as a function of different nano-structural features. The reasons for the observed morphological variability have been explained by considering the structural defects located at ED surface fibrils (bi-dimensional ribbons) and the presence of nontronite, an iron-bearing clay mineral embedding the ER fibrils (mono-dimensional rods). ER4G shows a decrease in width of the rod-like fibres due to their partial digestion by SLF leaching, which synchronously dissolves nontronite. The reported results represent a valuable background toward the full comprehension of the morphological mechanisms responsible for potentially damage of lung tissue through the potential relocation of fibers to extrapulmonary sites, increasing the carcinogenic risk to humans. PMID:26567530

  14. Architecture and migration of an epithelium on a cylindrical wire

    PubMed Central

    Yevick, Hannah G.; Duclos, Guillaume; Bonnet, Isabelle; Silberzan, Pascal

    2015-01-01

    In a wide range of epithelial tissues such as kidney tubules or breast acini, cells organize into bidimensional monolayers experiencing an out-of-plane curvature. Cancer cells can also migrate collectively from epithelial tumors by wrapping around vessels or muscle fibers. However, in vitro experiments dealing with epithelia are mostly performed on flat substrates, neglecting this out-of-plane component. In this paper, we study the development and migration of epithelial tissues on glass wires of well-defined radii varying from less than 1 µm up to 85 µm. To uncouple the effect of out-of-plane curvature from the lateral confinement experienced by the cells in these geometries, we compare our results to experiments performed on narrow adhesive tracks. Because of lateral confinement, the velocity of collective migration increases for radii smaller than typically 20 µm. The monolayer dynamics is then controlled by front-edge protrusions. Conversely, high curvature is identified as the inducer of frequent cell detachments at the front edge, a phenotype reminiscent of the Epithelial−Mesenchymal Transition. High curvature also induces a circumferential alignment of the actin cytoskeleton, stabilized by multiple focal adhesions. This organization of the cytoskeleton is reminiscent of in vivo situations such as the development of the trachea of the Drosophila embryo. Finally, submicron radii halt the monolayer, which then reconfigures into hollow cysts. PMID:25922533

  15. Hydrophobic Silica Nanoparticles Induce Gel Phases in Phospholipid Monolayers.

    PubMed

    Orsi, Davide; Rimoldi, Tiziano; Guzmán, Eduardo; Liggieri, Libero; Ravera, Francesca; Ruta, Beatrice; Cristofolini, Luigi

    2016-05-17

    Silica nanoparticles (SiNP) can be incorporated in phospholipid layers to form hybrid organic-inorganic bidimensional mesostructures. Controlling the dynamics in these mesostructures paves the way to high-performance drug-delivery systems. Depending on the different hydrophobicity/hydrophilicity of SiNP, recent X-ray reflectivity experiments have demonstrated opposite structural effects. While these are reasonably well understood, less is known about the effects on the dynamics, which in turn determine molecular diffusivity and the possibility of drug release. In this work we characterize the dynamics of a mixed Langmuir layer made of phospholipid and hydrophobic SiNP. We combine X-ray photon correlation spectroscopy and epifluorescence discrete Fourier microscopy to cover more than 2 decades of Q-range (0.3-80 μm(-1)). We obtain evidence for the onset of an arrested state characterized by intermittent stress-relaxation rearrangement events, corresponding to a gel dominated by attractive interactions. We compare this with our previous results from phospholipid/hydrophilic SiNP films, which show an arrested glassy phase of repulsive disks. PMID:27133453

  16. Anisotropic effective medium properties from interacting Ag nanoparticles in silicon dioxide.

    PubMed

    Menegotto, Thiago; Horowitz, Flavio

    2014-05-01

    Films containing a layer of Ag nanoparticles embedded in silicon dioxide were produced by RF magnetron sputtering. Optical transmittance measurements at several angles of incidence (from normal to 75°) revealed two surface plasmon resonance (SPR) peaks, which depend on electric field direction: one in the ultraviolet and another red-shifted from the dilute Ag/SiO₂ system resonance at 410 nm. In order to investigate the origin of this anisotropic behavior, the structural properties were determined by transmission electron microscopy, revealing the bidimensional plane distribution of Ag nanoparticles with nearly spherical shape as well as the filling factor of metal in the composite. A simple model linked to these experimental parameters allowed description of the most relevant features of the SPR positions, which, depending on the field direction, were distinctly affected by the coupling of oscillations between close nanoparticles, as described by a modified Drude-Lorentz dielectric function introduced into the Maxwell-Garnett relation. This approach allowed prediction of the resonance for light at 75° incidence from the SPR position for light at normal incidence, in good agreement with experimental observation. PMID:24921871

  17. Simulation of space charge compensation in a multibeamlet negative ion beam.

    PubMed

    Sartori, E; Maceina, T J; Veltri, P; Cavenago, M; Serianni, G

    2016-02-01

    Ion beam space charge compensation occurs by cumulating in the beam potential well charges having opposite polarity, usually generated by collisional processes. In this paper we investigate the case of a H(-) ion beam drift, in a bi-dimensional approximation of the NIO1 (Negative Ion Optimization phase 1) negative ion source. H(-) beam ion transport and plasma formation are studied via particle-in-cell simulations. Differential cross sections are sampled to determine the velocity distribution of secondary particles generated by ionization of the residual gas (electrons and slow H2 (+) ions) or by stripping of the beam ions (electrons, H, and H(+)). The simulations include three beamlets of a horizontal section, so that multibeamlet space charge and secondary particle diffusion between separate generation regions are considered, and include a repeller grid biased at various potentials. Results show that after the beam space charge is effectively screened by the secondary plasma in about 3 μs (in agreement with theoretical expectations), a plasma grows across the beamlets with a characteristic time three times longer, and a slight overcompensation of the electric potential is verified as expected in the case of negative ions. PMID:26932089

  18. 3D tracking of single nanoparticles and quantum dots in living cells by out-of-focus imaging with diffraction pattern recognition

    PubMed Central

    Gardini, Lucia; Capitanio, Marco; Pavone, Francesco S.

    2015-01-01

    Live cells are three-dimensional environments where biological molecules move to find their targets and accomplish their functions. However, up to now, most single molecule investigations have been limited to bi-dimensional studies owing to the complexity of 3d-tracking techniques. Here, we present a novel method for three-dimensional localization of single nano-emitters based on automatic recognition of out-of-focus diffraction patterns. Our technique can be applied to track the movements of single molecules in living cells using a conventional epifluorescence microscope. We first demonstrate three-dimensional localization of fluorescent nanobeads over 4 microns depth with accuracy below 2 nm in vitro. Remarkably, we also establish three-dimensional tracking of Quantum Dots, overcoming their anisotropic emission, by adopting a ligation strategy that allows rotational freedom of the emitter combined with proper pattern recognition. We localize commercially available Quantum Dots in living cells with accuracy better than 7 nm over 2 microns depth. We validate our technique by tracking the three-dimensional movements of single protein-conjugated Quantum Dots in living cell. Moreover, we find that important localization errors can occur in off-focus imaging when improperly calibrated and we give indications to avoid them. Finally, we share a Matlab script that allows readily application of our technique by other laboratories. PMID:26526410

  19. Use of organo-clays in the removal of toxic organics from industrial wastewaters

    SciTech Connect

    Srinivasan, K.R.; Fogler, H.S.

    1987-01-01

    This study describes the development of organo-clays as cost-effective adsorbents for the removal of nonionic, toxic organics from wastewaters. Cetyl pyridinium montmorillonite (CPC-CLAY; an interlayer organo-clay) and Cetyl pyridinium hydroxy aluminum montmorillonite (CPC(HYDAL-CLAY; a predominantly external layer organo-clay) were prepared as model sorbents. Using pentachlorophenol (PCP) as the target organic molecule, our studies show that CPC-HYDAL-CLAY containing 12.0% by weight surface organic carbon is significantly more effective (about 10 times) than CPC-CLAY with 19.2% by weight surface organic carbon. Similar results were obtained with La-CPC-CLAY (12% organic carbon) and CPC-kaolinite (3.0% organic carbon), both of which exhibit surface orientation of organic carbon similar to that of CPC-HYDAL-CLAY. Specifically, the effectiveness of CPC-kaolinite establishes the idea that orientation of surface organic carbon may be as significant as the actual amount. All the three external surface oriented organo-clays studied here are comparable to activated carbon in their sorption potential for PCP. Electrokinetic and adsorption/desorption measurements reveal that in the cases of CPC-HYDAL-CLAY and La-CPC-CLAY, binding of CPC ion to the respective surfaces is of the high affinity and irreversible type and that the endpoint of adsorption may be in the form of a bidimensional aggregate or a ''hemimicelle''.

  20. Two-dimensional Spectropolarimetry At The Dunn Solar Tower

    NASA Astrophysics Data System (ADS)

    Uitenbroek, Han; Tritshler, A.; Reardon, K.; Kleint, L.

    2007-07-01

    Measurement of the solar magnetic field within individual atmospheric structures is a desirable, but persistently challenging goal, in particular in chromospheric layers. Successful measurements over different heights would provide an important contribution to our understanding of the solar atmosphere and would provide valuable input for theoretical modeling. We provide a short description of the capabilities of the Interferometric BIdimensional Spectrometer (IBIS), which has recently been upgraded to full Stokes capabilities. IBIS is installed at the Dunn Solar Tower (DST) at the Sacramento Peak observatory operated by NSO. Using IBIS we achieve high spatial resolution over a large field of view in both the photosphere and the chromosphere, which allows us to connect the observed profiles to the overall topology of the target region. After performing suitable calibrations for the telescope and instrument polarization properties, we can extract Stokes profiles for each point in the field of view. Stokes V profiles observed in the Ca II 854.2 nm line show a large variety of forms, indicating widely varying vertical behavior of the field strength, velocity, and temperature. We examine the center-of-gravity method for determining a representative field strength from the observed profiles looking at observations and comparing with simulated profiles.

  1. Perturbation Enstrophy Decay in Poiseuille and Couette Flows according to Synge's Method

    NASA Astrophysics Data System (ADS)

    Domenicale, Loris; Fraternale, Federico; Staffilani, Gigliola; Tordella, Daniela

    2015-11-01

    In this work we derive the conditions for no enstrophy growth for bidimensional perturbations in the plane Couette and Poiseuille flows. We follow the method of vorticity proposed by Synge in 1938 (see the Semi-Centennial Puplication of the Amer. Math. Soc., equation 12.13, and the more detailed version in the Proc. of the Fifth Inter. Congress of Applied Mechanics, pages 326-332), which is actually based on the analysis of the spatially averaged enstrophy. We find that the limit curve in the perturbation wavenumber-Reynolds number map differs from the limit for no energy growth (see e.g. Reddy 1993). In particular, the absolute stability region for the enstrophy is wider than that of the kinetic energy, and the maximum Reynolds number giving the monotonic enstrophy decay, at all wavenumbers, is 155 and 80 for the Poiseuille and Couette flows, respectively. It should be noted that in past literature the energy-based analysis was preferred to Synge's enstrophy analysis. This, possibly, for two reasons: the low diffusivity of the 1938 Vth ICAM proceedings and the objectively very complicated analytical treatment required. Nevertheless, the potentiality of this method seems high and therefore it is interesting nowadays to exploit it by means of the symbolic calculus. MITOR-MISTI SEEDS GRANT http://web.mit.edu/mitor/recipients/faculty.html

  2. Redox stress proteins are involved in adaptation response of the hyperthermoacidophilic archaeon Sulfolobus solfataricus to nickel challenge

    PubMed Central

    Salzano, Anna M; Febbraio, Ferdinando; Farias, Tiziana; Cetrangolo, Giovanni P; Nucci, Roberto; Scaloni, Andrea; Manco, Giuseppe

    2007-01-01

    Background Exposure to nickel (Ni) and its chemical derivatives has been associated with severe health effects in human. On the contrary, poor knowledge has been acquired on target physiological processes or molecular mechanisms of this metal in model organisms, including Bacteria and Archaea. In this study, we describe an analysis focused at identifying proteins involved in the recovery of the archaeon Sulfolobus solfataricus strain MT4 from Ni-induced stress. Results To this purpose, Sulfolobus solfataricus was grown in the presence of the highest nickel sulphate concentration still allowing cells to survive; crude extracts from treated and untreated cells were compared at the proteome level by using a bi-dimensional chromatography approach. We identified several proteins specifically repressed or induced as result of Ni treatment. Observed up-regulated proteins were largely endowed with the ability to trigger recovery from oxidative and osmotic stress in other biological systems. It is noteworthy that most of the proteins induced following Ni treatment perform similar functions and a few have eukaryal homologue counterparts. Conclusion These findings suggest a series of preferential gene expression pathways activated in adaptation response to metal challenge. PMID:17692131

  3. Kohn-Sham approach to Fermi gas superfluidity: The bilayer of fermionic polar molecules

    NASA Astrophysics Data System (ADS)

    Ancilotto, Francesco

    2016-05-01

    By using a well-established "ab initio" theoretical approach developed in the past to quantitatively study the superconductivity of condensed matter systems, based on the Kohn-Sham density functional theory, I study the superfluid properties and the BCS-BEC crossover of two parallel bi-dimensional layers of fermionic dipolar molecules, where the pairing mechanism leading to superfluidity is provided by the interlayer coupling between dipoles. The finite temperature superfluid properties of both the homogeneous system and one where the fermions in each layer are confined by a square optical lattice are studied at half filling conditions, and for different values of the strength of the confining optical potential. The T = 0 results for the homogeneous system are found to be in excellent agreement with diffusion Monte Carlo results. The superfluid transition temperature in the BCS region is found to increase, for a given interlayer coupling, with the strength of the confining optical potential. A transition occurs at sufficiently small interlayer distances, where the fermions becomes localized within the optical lattice sites in a square geometry with an increased effective lattice constant, forming a system of localized composite bosons. This transition should be signaled by a sudden drop in the superfluid fraction of the system.

  4. Polar discontinuities and 1D interfaces in monolayered materials

    NASA Astrophysics Data System (ADS)

    Martinez-Gordillo, Rafael; Pruneda, Miguel

    2015-12-01

    Interfaces are the birthplace of a multitude of fascinating discoveries in fundamental science, and have enabled modern electronic devices, from transistors, to lasers, capacitors or solar cells. These interfaces between bulk materials are always bi-dimensional (2D) 'surfaces'. However the advent of graphene and other 2D crystals opened up a world of possibilities, as in this case the interfaces become one-dimensional (1D) lines. Although the properties of 1D nanoribbons have been extensively discussed in the last few years, 1D interfaces within infinite 2D systems had remained mostly unexplored until very recently. These include grain boundaries in polycrystalline samples, or interfaces in hybrid 2D sheets composed by segregated domains of different materials (as for example graphene/BN hybrids, or chemically different transition metal dichalcogenides). As for their 2D counterparts, some of these 1D interfaces exhibit polar characteristics, and can give rise to fascinating new physical properties. Here, recent experimental discoveries and theoretical predictions on the polar discontinuities that arise at these 1D interfaces will be reviewed, and the perspectives of this new research topic, discussed.

  5. Preparation and properties of antigen 60 from Mycobacterium bovis BCG.

    PubMed Central

    Cocito, C; Vanlinden, F

    1986-01-01

    Antigen 60 (A60) is the main thermostable immunogen of both 'old tuberculin' (OT) and 'purified protein derivative' (PPD), known reagents for cutaneous tests in tuberculosis. It is recognized by bidimensional immunoelectrophoresis with anti-BCG antiserum, where it appears as the less mobile component. A60 was prepared from the cytoplasm of Mycobacterium bovis BCG, and purified by exclusion gel chromatography and lectin affinity chromatography. Labelled A60 was obtained by radioiodination and used for a radioimmunoassay. Composition of A60 was explored by use of organic solvents, chemicals and enzymes. It contained two fractions of free and bound lipids, as well as protein and polysaccharide moieties. After removal of both free and bound lipid fractions, the core still retained the ability to form immunoprecipitinogen lines with anti-BCG antiserum. The lipopolysaccharide and lipo-protein moieties of A60, as well as the free lipid fraction, were also complexed by antibodies. It is concluded that A60 is a lipopolysaccharide-protein complex of 10(6) to 10(7) daltons, which is a major immunogenic component of mycobacterial cytoplasm. The detailed structure of this antigen, its immunological properties, and its use for an ELISA type immunoassay for tuberculosis are described in two other publications. Images Fig. 1 Fig. 3 Fig. 6 PMID:3545572

  6. Imaging the Hot Stellar Content of Early Type Galaxies

    NASA Astrophysics Data System (ADS)

    Bertola, Francesco

    1991-07-01

    WE PROPOSE TO IMAGE WITH THE FOC IN THE F/96 CONFIGURATION FIVE EARLY TYPE GALAXIES IN FOUR PASSBANDS CENTERED AT 1500 A, 2200 A, 2800 A AND 3400 A. WHEN COUPLED WITH PHOTOMETRY OBTAINED FROM THE GROUND OUR OBSERVATIONS WILL ALLOW US TO DERIVE COMPLETE SED OF THESE GALAXIES AS A FUNCTION OF THE DISTANCE FROM THE CENTER. THIS IS A KEY STEP TOWARDS THE UNDERSTANDING OF STELLAR POPULATIONS - IN PARTICULAR THE ONE RESPONSIBLE FOR THE UV EMISSION - IN EARLY TYPE GALAXIES AND WILL PROVIDE IMPORTANT INSIGHT IN THEIR FORMATION AND EVOLUTION. WE PLAN TO OBSERVE NGC 1399, NGC 2681, NGC 4552, NGC 5018 AND NGC 4627 WHICH SAMPLE A WIDE RANGE OF INTRINSIC PROPERTIES AS INDICATED BY PREVIOUS IUE OBSERVATIONS. FOR NGC 4627 THERE IS EVIDENCE OF ONGOING STAR FORMATION AND THE HST WILL BE ABLE TO SHOW THE CHARACTERISTIC CLUMPINESS. NGC 2681 HAD A STARBUST OF AGE GREATER THAN 1 GYR. NGC 4552 IS ONE OF THE MOST METAL RICH GALAXY KNOWN. NGC 1399 HAS THE SAME METALLICITY AND LUMINOSITY OF THE PREVIOUS GALAXY BUT IS A MUCH STRONGER X-RAY EMITTER. NGC 5018 IS A VERY GOOD CANDIDATE FOR ONGOING STAR FORMATION. WE BELIEVE IN THIS WAY WE CAN OBTAIN SED FOR THE TWO-DIMENSIONAL IMAGES OF EARLY TYPE GALAXIES FROM BROAD BAND IMAGING ALONE. THE CALIBRATION OF OUR FILTER SYSTEM WILL ALLOW US TO APPLY IT TO THE BIDIMENSIONAL ANALYSIS OF THE GENERAL SAMPLE OF EARLY TYPE GALAXIES.

  7. Circuit-level input integration in bacterial gene regulation.

    PubMed

    Espinar, Lorena; Dies, Marta; Cagatay, Tolga; Süel, Gürol M; Garcia-Ojalvo, Jordi

    2013-04-23

    Gene regulatory circuits can receive multiple simultaneous inputs, which can enter the system through different locations. It is thus necessary to establish how these genetic circuits integrate multiple inputs as a function of their relative entry points. Here, we use the dynamic circuit regulating competence for DNA uptake in Bacillus subtilis as a model system to investigate this issue. Specifically, we map the response of single cells in vivo to a combination of (i) a chemical signal controlling the constitutive expression of key competence genes, and (ii) a genetic perturbation in the form of copy number variation of one of these genes, which mimics the level of stress signals sensed by the bacteria. Quantitative time-lapse fluorescence microscopy shows that a variety of dynamical behaviors can be reached by the combination of the two inputs. Additionally, the integration depends strongly on the relative locations where the two perturbations enter the circuit. Specifically, when the two inputs act upon different circuit elements, their integration generates novel dynamical behavior, whereas inputs affecting the same element do not. An in silico bidimensional bifurcation analysis of a mathematical model of the circuit offers good quantitative agreement with the experimental observations, and sheds light on the dynamical mechanisms leading to the different integrated responses exhibited by the gene regulatory circuit. PMID:23572583

  8. [A century of research on masculinity and femininity: a critical review].

    PubMed

    Fernández Sánchez, Juan

    2011-04-01

    The psychological study of masculinity (M) and femininity (F) throughout the twentieth century shows two very different approaches. In the first half of last century, authors try to test the bipolar continuum hypothesis, whereas during the second half, the hypothesis of two orthogonal dimensions predominates. Empirical studies carried out in various countries with the classic M and F scales show that the data do not support: a) the bipolar continuum hypothesis; b) the close relationship between masculinity/men and femininity/women as the single pattern of functional development; and c) the convergence validity of the different assessment instruments. In turn, the empirical results obtained with the new M and F scales show: a) the multidimensionality instead of bi-dimensionality of the different scales; b) that the different M and F scales are not equivalent; and c) that there is no theory capable of guiding the development of new scales to assess these constructs. At the beginning of the 21st century, after the critical evaluation of the studies carried out during about 100 years, we face a critical question: is it worthwhile to continue talking about M and F within the field of science and, more specifically, within the field of psychology? PMID:21504665

  9. Infiltrating a thin or single-layer opal with an atomic vapour: Sub-Doppler signals and crystal optics

    NASA Astrophysics Data System (ADS)

    Moufarej, Elias; Maurin, Isabelle; Zabkov, Ilya; Laliotis, Athanasios; Ballin, Philippe; Klimov, Vasily; Bloch, Daniel

    2014-10-01

    Artificial thin glass opals can be infiltrated with a resonant alkali-metal vapour, providing novel types of hybrid systems. The reflection at the interface between the substrate and the opal yields a resonant signal, which exhibits sub-Doppler structures in linear spectroscopy for a range of oblique incidences. This result is suspected to originate in an effect of the three-dimensional confinement of the vapour in the opal interstices. It is here extended to a situation where the opal is limited to a few- or even a single-layer opal film, which is a kind of bidimensional grating. We have developed a flexible one-dimensional layered optical model, well suited for a Langmuir-Blodgett opal. Once extended to the case of a resonant infiltration, the model reproduces quick variations of the lineshape with incidence angle or polarization. Alternately, for an opal limited to a single layer of identical spheres, a three-dimensional numerical calculation was developed. It predicts crystalline anisotropy, which is demonstrated through diffraction on an empty opal made of a single layer of polystyrene spheres.

  10. Mango butter emulsion gels as cocoa butter equivalents: physical, thermal, and mechanical analyses.

    PubMed

    Sagiri, Sai S; Sharma, Vijeta; Basak, Piyali; Pal, Kunal

    2014-11-26

    The search for cocoa butter equivalents in food and pharmaceutical industries has been gaining importance. In the present study, mango butter was explored as cocoa butter equivalent. Aqueous gelatin solution (20% w/w) containing cocoa butter and mango butter water-in-oil (fat) type emulsion gels were prepared by hot emulsification method. XRD and DSC melting profiles suggested the presence of unstable polymorphic forms (α and β') of fats in the emulsion gels. The crystal size and solid fat content analyses suggested that the presence of aqueous phase might have hindered the transformation of unstable polymorphic forms to stable polymorphic form (β) in the emulsion gels. Fat crystals in the emulsion gels were formed by instantaneous nucleation via either uni- or bidimensional growth (Avrami analysis). The viscoelastic nature of the emulsion gels was evaluated by modified Peleg's analysis (stress relaxation study). Results inferred that the physical, thermal, and mechanical properties of mango butter emulsion gels are comparable to those of cocoa butter emulsion gels. On the basis of preliminary studies, it was suggested that the mango butter emulsion gels may have potential to be used as cocoa butter equivalents. PMID:25363450

  11. Italian panoramic monochromator for the THEMIS telescope: the first results and instrument evaluation

    NASA Astrophysics Data System (ADS)

    Cavallini, Fabio; Berrilli, Francesco; Caccin, Bruno; Cantarano, Sergio; Ceppatelli, Guido; Egidi, Alberto; Righini, Alberto

    1998-07-01

    We briefly describe the design and the characteristics of the Italian Panoramic Monochromator installed at the focal plane of the THEMIS telescope built in Izana by a joint venture of the French and Italian National Research Councils. The Panoramic Monochromator substantially is a narrow band filter (approximately equals 22 mAngstrom bandwidth) tunable on the visible spectrum for quasi simultaneous bidimensional spectrometry of the solar atmosphere. The narrow bandwidth is obtained by using a non standard birefringent filter and a Fabry Perot interferometer mounted in series. This assembly has the advantage of the spectral purity of one channel of the Fabry Perot interferometer and a very large free spectral range. Moreover the spectral stability depends on the interferometer, the environment of which may be carefully controlled. The design of this instrument is not really new, but, only now it has been possible to build it thanks to the development of servo controlled Fabry Perot interferometers, which are stable in time and may easily be tuned. The system seems to perform well. It is stable in wavelength and the spectral pass band and stray light are within the expected values, as it may be deduced by very preliminary tests performed at the THEMIS Telescope and in Arcetri (Firenze) at the 'G. B. Donati' solar tower.

  12. Ellerman Bombs—Evidence for Magnetic Reconnection in the Lower Solar Atmosphere

    NASA Astrophysics Data System (ADS)

    Nelson, C. J.; Shelyag, S.; Mathioudakis, M.; Doyle, J. G.; Madjarska, M. S.; Uitenbroek, H.; Erdélyi, R.

    2013-12-01

    The presence of photospheric magnetic reconnection has long been thought to give rise to short and impulsive events, such as Ellerman bombs (EBs) and Type II spicules. In this article, we combine high-resolution, high-cadence observations from the Interferometric BIdimensional Spectrometer and Rapid Oscillations in the Solar Atmosphere instruments at the Dunn Solar Telescope, National Solar Observatory, New Mexico, with co-aligned Solar Dynamics Observatory Atmospheric Imaging Assembly and Hinode Solar Optical Telescope (SOT) data to observe small-scale events situated within an active region. These data are then compared with state-of-the-art numerical simulations of the lower atmosphere made using the MURaM code. It is found that brightenings, in both the observations and the simulations, of the wings of the Hα line profile, interpreted as EBs, are often spatially correlated with increases in the intensity of the Fe I λ6302.5 line core. Bipolar regions inferred from Hinode/SOT magnetic field data show evidence of flux cancellation associated, co-spatially, with these EBs, suggesting that magnetic reconnection could be a driver of these high-energy events. Through the analysis of similar events in the simulated lower atmosphere, we are able to infer that line profiles analogous to the observations occur co-spatially with regions of strong opposite-polarity magnetic flux. These observed events and their simulated counterparts are interpreted as evidence of photospheric magnetic reconnection at scales observable using current observational instrumentation.

  13. Statistical Analysis of Small Ellerman Bomb Events

    NASA Astrophysics Data System (ADS)

    Nelson, C. J.; Doyle, J. G.; Erdélyi, R.; Huang, Z.; Madjarska, M. S.; Mathioudakis, M.; Mumford, S. J.; Reardon, K.

    2013-04-01

    The properties of Ellerman bombs (EBs), small-scale brightenings in the Hα line wings, have proved difficult to establish because their size is close to the spatial resolution of even the most advanced telescopes. Here, we aim to infer the size and lifetime of EBs using high-resolution data of an emerging active region collected using the Interferometric BIdimensional Spectrometer (IBIS) and Rapid Oscillations of the Solar Atmosphere (ROSA) instruments as well as the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). We develop an algorithm to track EBs through their evolution, finding that EBs can often be much smaller (around 0.3″) and shorter-lived (less than one minute) than previous estimates. A correlation between G-band magnetic bright points and EBs is also found. Combining SDO/HMI and G-band data gives a good proxy of the polarity for the vertical magnetic field. It is found that EBs often occur both over regions of opposite polarity flux and strong unipolar fields, possibly hinting at magnetic reconnection as a driver of these events.The energetics of EB events is found to follow a power-law distribution in the range of a nanoflare (1022-25 ergs).

  14. Evidence of viscoplastic behavior of exfoliated graphite nanofluids.

    PubMed

    Hermida-Merino, Carolina; Pérez-Rodríguez, Martín; Piñeiro, Manuel M; Pastoriza-Gallego, María José

    2016-02-17

    The rheological behavior of ethylene glycol-based nanofluids containing exfoliated graphite nanoplatelets has been carried out using a cone-plate Physica MCR rheometer. Initial experiments based on flow curves were carried out, the flow curves were based on the controlled shear stress model, these tests show that the studied nanofluids present non-Newtonian shear thinning behavior with yield stress. Furthermore, linear viscoelastic experiments were conducted in order to determine the viscoelastic behavior: using strain sweep and frequency sweep tests the storage and loss modulus were determined. The fractal dimension (Df) was estimated from the suspension static yield-stress and volume fraction (ϕ) dependence, and was determined to be Df = 2.36, a value consistent with a process of aggregation of RLCA type (reaction limited cluster aggregation). This value is unusual if compared with other nanofluids, and can be regarded as a result of the bidimensionality of the suspended nanoplatelets. Finally, creep-recovery tests and mechanical models confirm the viscoplastic nature of our nanofluids, a feature never shown so far for this type of systems, increasing the solid-like character in the range of concentrations studied if compared with other nanofluids reported in the literature. This is a result of the combination of a remarkable internal structure and strong interactions, which evidence an unexpected behaviour sharing many solid-like features. PMID:26822724

  15. Axon terminals from the nucleus isthmi pars parvocellularis control the ascending retinotectofugal output through direct synaptic contact with tectal ganglion cell dendrites.

    PubMed

    González-Cabrera, Cristian; Garrido-Charad, Florencia; Mpodozis, Jorge; Bolam, J Paul; Marín, Gonzalo J

    2016-02-01

    The optic tectum in birds and its homologue the superior colliculus in mammals both send major bilateral, nontopographic projections to the nucleus rotundus and caudal pulvinar, respectively. These projections originate from widefield tectal ganglion cells (TGCs) located in layer 13 in the avian tectum and in the lower superficial layers in the mammalian colliculus. The TGCs characteristically have monostratified arrays of brush-like dendritic terminations and respond mostly to bidimensional motion or looming features. In birds, this TGC-mediated tectofugal output is controlled by feedback signals from the nucleus isthmi pars parvocellularis (Ipc). The Ipc neurons display topographically organized axons that densely ramify in restricted columnar terminal fields overlapping various neural elements that could mediate this tectofugal control, including the retinal terminals and the TGC dendrites themselves. Whether the Ipc axons make synaptic contact with these or other tectal neural elements remains undetermined. We double labeled Ipc axons and their presumptive postsynaptic targets in the tectum of chickens (Gallus gallus) with neural tracers and performed an ultrastructural analysis. We found that the Ipc terminal boutons form glomerulus-like structures in the superficial and intermediate tectal layers, establishing asymmetric synapses with several dendritic profiles. In these glomeruli, at least two of the postsynaptic dendrites originated from TGCs. We also found synaptic contacts between retinal terminals and TGC dendrites. These findings suggest that, in birds, Ipc axons control the ascending tectal outflow of retinal signals through direct synaptic contacts with the TGCs. PMID:26224333

  16. Mother-Youth Acculturation Gaps and Health-Risking/Emotional Problems among Latin-American Adolescents.

    PubMed

    Wiesner, Margit; Arbona, Consuelo; Capaldi, Deborah M; Kim, Hyoun K; Kaplan, Charles D

    2015-01-01

    Second-generation Latin-American adolescents tend to show higher levels of various health-risking behaviors and emotional problems than first-generation Latin-American adolescents. This cross-sectional study of 40 mother-adolescent dyads examined the association of mother-youth acculturation gaps to youth adjustment problems. Intergenerational acculturation gaps were assessed as a bidimensional self-report component and a novel observational measurement component. The Latin-American adolescents were predominantly second-generation of Mexican descent (M age = 13.42 years, SD = 0.55). Most of the mothers were born in Mexico (M age = 39.18 years, SD = 5.17). Data were collected from mothers, adolescents, and coders, using questionnaires, structured interviews, and videotaped mother-youth interaction tasks. Findings revealed generally weak support for the acculturation gap-distress hypothesis. In addition, stronger relative adherence to their heritage culture by the adolescents was significantly (p < .05, ES = 0.15) related to less engagement in early health-risking sexual behaviors, possibly reflecting selective acculturation processes. Mother-youth acculturation gaps in orientation to the heritage culture were the most salient dimension, changing the focus on the original formulation of the acculturation gap-distress hypothesis. PMID:26190068

  17. Observation of neutral sodium above Mercury during the transit of November 8, 2006

    NASA Astrophysics Data System (ADS)

    Potter, A. E.; Killen, R. M.; Reardon, Kevin P.; Bida, T. A.

    2013-09-01

    We mapped the absorption of sunlight by sodium vapor in the exosphere of Mercury during the transit of Mercury on November 8, 2006, using the IBIS Interferometric BIdimensional Spectrometer at the Dunn Solar Telescope operated by the National Solar Observatory at Sunspot, New Mexico. The measurements were reduced to line-of-sight equivalent widths for absorption at the sodium D2 line around the shadow of Mercury. The sodium absorption fell off exponentially with altitude up to about 600 km. However there were regions around north and south polar-regions where relatively uniform sodium absorptions extended above 1000 km. We corrected the 0-600 km altitude profiles for seeing blur using the measured point spread function. Analysis of the corrected altitude distributions yielded surface densities, zenith column densities, temperatures and scale heights for sodium all around the planet. Sodium absorption on the dawn side equatorial terminator was less than on the dusk side, different from previous observations of the relative absorption levels. We also determined Earthward velocities for sodium atoms, and line widths for the absorptions. Earthward velocities resulting from radiation pressure on sodium averaged 0.8 km/s, smaller than a prediction of 1.5 km/s. Most line widths were in the range of 20 mA after correction for instrumental broadening, corresponding to temperatures in the range of 1000 K.

  18. Optimisation methods for bathymetry and open boundary conditions in finite element model of ocean tides

    SciTech Connect

    Lyard, F.; Genco, M.L.

    1994-10-01

    A bidimensional, spectral in time, quasi-linearised hydrodynamic ocean tide model has been developed at the Institut de Mecanique de Grenoble. This model is derived from the classical shallow water equations by removing the velocity unknowns in the continuity equation, that leads to an elliptic, second-order differential equation where tide denivellation remains the only unknown quantity. The problem is solved in its variational formulation and the finite elements method is used to discretise the equations in the spatial domain with a Lagrange-P2 approximation. Bottom topography has to be known at the integration points of the elements. In the case of the large oceanic basins, a specific method, called the bathymetry optimisation method, is needed to correctly take into account the bottom topography inside the model. The accuracy of the model`s solutions is also strongly dependent on the quality of the open boundary conditions because of the elliptic characteristics of the problem. The optimisation method for open boundary conditions relies on the use of the in situ data available in the modelled domain. The aim of this paper is to present the basis of these optimisations of bathymetry and open boundary conditions. An illustration of the related improvements is presented on the North Atlantic Basin. 36 refs., 10 figs., 5 tabs.

  19. Finite elements study of the Flexi Post and Flexi Flange post systems in a maxillary central incisor.

    PubMed

    Lewgoy, Hugo Roberto; Youssef, Michel Nicolau; Matson, Maurício Rufaiel; Bocangel, Jorge Antônio Javier Saldivar; Netto, Camillo Anauate; Amore, Ricardo

    2003-01-01

    The use of post and core systems has become an excellent alternative for restoring endodontically treated teeth. The aim of this study was to evaluate the von Mises, maximal compressive and tensile stresses distribution using the Finite Element Method (FEM) on human teeth restored with different post and core systems. The analysis was made on endodontically treated maxillary central incisors. The post systems used in this investigation were the stainless steel or titanium Flexi Post/Flexi Flange. Composite resin was used as core material and resin cement was the cement material of choice to seat a full porcelain crown. The bi-dimensional mathematical model was created from pictures taken from an intact human maxillary central incisor and prefabricated posts. This image was transferred to a personal computer in the MSC/Nastran 4.5 software. A static and linear analysis treatment was performed when a 45 load of 100 N was applied on the lingual surface of the tooth. Based on the results obtained, it can be concluded that the post design and its material can alter the stress pattern distribution. PMID:14569354

  20. Numerical studies of fibrous composites from the view point of fiber-matrix interface and fiber-matrix bonding

    NASA Astrophysics Data System (ADS)

    Yilmaz, Yahya Ilyas

    In the present research, the micromechanics of fibrous composites was studied numerically. The effects of the fiber/matrix interphase region and fiber/matrix bonding were the main goals of this research. Throughout the research NASTRAN finite element analyses were used. First we investigated the effect of the interphase region on the stress field by varying the thickness of the interphase region and the material properties in the interphase region. Second, we numerically simulated the bonding qualities between the fiber and the matrix by the implementation of the fiber/matrix interphase region. The change for bonding between the fiber and the matrix were simulated through a periodic material property change in the interphase region. Third, we developed a bi-dimensional concentric cylindrical model for stress transfer between the fiber and the matrix model in case of a broken fiber or short fiber composites. This model is unique in accounting for the real non-linear stress-strain relationship for the matrix material. The stress transfer between the fiber and the matrix was also analyzed by finite element models. Toward this end finite element analysis proved a useful tool to help us evaluate key model parameters, most importantly the radius of fiber influence. This parameter is also a key parameter of simple models upon which the new model is based. Finally we applied our stress transfer model to analyze single fiber fragmentation test data obtained at Kansas State University.

  1. Oxidative damage of 14-3-3 zeta and gamma isoforms in Alzheimer's disease and cerebral amyloid angiopathy.

    PubMed

    Santpere, G; Puig, B; Ferrer, I

    2007-06-01

    Previous studies have shown oxidative damage resulting from amyloid Abeta exposure to cultured cells and in murine models. A target of oxidation is 14-3-3 which comprises a group of proteins involved in kinase activation and chaperone activity. The present study shows glycoxidative damage, as revealed with mono and bi-dimensional gel electrophoresis and Western blotting, followed by in-gel digestion and mass spectrometry, in the frontal cortex in Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA), a neurodegenerative disease with deposition of Abeta in cerebral blood vessels and in diffuse plaques unaccompanied by intraneuronal hyper-phosphorylated tau deposition. malondialdehyde-lysine (MDA-Lys)-, but not 4-hydroxy-2-nonenal (HNE)-immunoreactive adducts, and N-carboxyethyl-lysine (CEL), but not N-carboxymethyl-lysine (CML)-products, were present in 14-3-3 involving zeta and gamma isoforms in both AD and CAA. These findings demonstrate that 14-3-3 glyco- and lipoxidation occurs in AD and CAA, probably as a direct consequence of Abeta deposition. PMID:17445990

  2. On boredom: a close encounter with encapsulated parts of the psyche.

    PubMed

    Bergstein, Avner

    2009-06-01

    The psychoanalytical literature has numerous scattered references to the analyst's experience of boredom, especially amongst writers working with primitive mental states. In the present paper, the author tries to gather some of these references in an attempt to integrate the various facets of this widespread phenomenon, and reflect on some clinical issues and dilemmas it raises. It is suggested that the experience of boredom in analysis may be a reaction to an encounter with a hidden, encapsulated part of the psyche, a bidimensional area of experience in which mental activity has been suspended, and experience remains meaningless. This is a barren area of lack, an encounter with the autistic core of the psyche. However, boredom may also be an experiential expression of despair, a re-living of primitive object relations with an emotionally non-existent primary object. Through bringing the emptiness and desolation into analysis, the individual makes room for the empty, blunt, dead inner object which resides within him, and that needs to be integrated into the psyche. This inner object is a vital part of the patient's inner world, part of his history, and can neither be erased nor filled in order to eradicate the emptiness. This is illustrated by clinical material from patients along the spectrum of autism, autistic reaction following trauma and autistic barriers in neurotic patients. PMID:19580600

  3. Multifractal Surfaces: Lucena and Stanley Approaches

    NASA Astrophysics Data System (ADS)

    Corso, G.; Moreira, D. A.

    2013-12-01

    We review multifractal surfaces focusing on a comparison between Lucena and Stanley approaches. The multifractal model as presented by Stanley is basically a multinomial measure over a standard partition of a square. The Lucena approach is geometric oriented, the multifractality is not imposed over a regular lattice, but the lattice itself follows a partition where area tiles obey a multifractal distribution. The non-trivial tilling has a distribution of neighbors of lattice elements that shows a fat tail. Despite the strong differences in the two bidimensional models, both Liacir and Stanley multifractals can be reduced to the same object in one dimension. The message of this article is that there is no unique multifractal object in two dimensions and, as a consequence, we should caution about algorithms that estimate multifractal spectrum in two dimensions because it is not clear what kind of multifractality is being measured. Finally we propose a mixed Lucena-Stanley bimultifractal, an object that combines a multifractal measure over a geometric multifractal tilling.

  4. Multifractal surfaces: Lucena and Stanley approaches

    NASA Astrophysics Data System (ADS)

    Corso, G.; Moreira, D. A.

    2014-03-01

    We review multifractal surfaces focusing on a comparison between Lucena and Stanley approaches. The multifractal model as presented by Stanley is basically a multinomial measure over a standard partition of a square. The Lucena approach is geometric oriented, the multifractality is not imposed over a regular lattice, but the lattice itself follows a partition where area tiles obey a multifractal distribution. The non-trivial tilling has a distribution of neighbors of lattice elements that shows a fat tail. Despite the strong differences in the two bidimensional models, both Liacir and Stanley multifractals can be reduced to the same object in one dimension. The message of this article is that there is no unique multifractal object in two dimensions and, as a consequence, we should caution about algorithms that estimate multifractal spectrum in two dimensions because it is not clear what kind of multifractality is being measured. Finally we propose a mixed Lucena-Stanley bimultifractal, an object that combines a multifractal measure over a geometric multifractal tilling.

  5. Metabolomics of meat exudate: Its potential to evaluate beef meat conservation and aging.

    PubMed

    Castejón, David; García-Segura, Juan Manuel; Escudero, Rosa; Herrera, Antonio; Cambero, María Isabel

    2015-12-11

    In this study we analyzed the exudate of beef to evaluate its potential as non invasive sampling for nuclear magnetic resonance (NMR) based metabolomic analysis of meat samples. Exudate, as the natural juice from raw meat, is an easy to obtain matrix that it is usually collected in small amounts in commercial meat packages. Although meat exudate could provide complete and homogeneous metabolic information about the whole meat piece, this sample has been poorly studied. Exudates from 48 beef samples of different breeds, cattle and storage times have been studied by (1)H NMR spectroscopy. The liquid exudate spectra were compared with those obtained by High Resolution Magic Angle Spinning (HRMAS) of the original meat pieces. The close correlation found between both spectra (>95% of coincident peaks in both registers; Spearman correlation coefficient = 0.945) lead us to propose the exudate as an excellent alternative analytical matrix with a view to apply meat metabolomics. 60 metabolites could be identified through the analysis of mono and bidimensional exudate spectra, 23 of them for the first time in NMR meat studies. The application of chemometric tools to analyze exudate dataset has revealed significant metabolite variations associated with meat aging. Hence, NMR based metabolomics have made it possible both to classify meat samples according to their storage time through Principal Component Analysis (PCA), and to predict that storage time through Partial Least Squares (PLS) regression. PMID:26614053

  6. [Current possibilities of echography in pneumological diagnosis (preliminary note)].

    PubMed

    Anastasatu, C; Burnea, D; Pop, T; Petcu, E

    1982-01-01

    Various types of echographies are presented, and it is concluded that the bi-dimensional echography, also called type B or echo-tomography is the most useful for the study of pulmonary affections, and of compact formations in contact with the pulmonary tissues. With the aid of Model E.D.B. Unirad sonograph (Technicare, USA), and of the Scintron 5 computer (Scintag, Berthold, Switzerland) 6 patients with pleurisy of various extension, one patient with fibrothorax, and 2 patients with pulmonary tumours have been examined. Five of the cases are presented. Echotomography has demonstrated its usefulness in measuring the thickness of the thoracic wall, in establishing by means of a non-invasive technique the solid or fluid character of pleural affections, in assessing the structure of pachypleuritis and in detecting changes induced by tumours, or atelectasia in the vicinity of the pleura. However, the method does not provide information on round peripheral tumours which do not come into contact with the pleura. Also this method cannot replace other methods already used in the pneumological practice, but can provide supplementary informations without any risks for the patient. PMID:6294805

  7. Interaction of Cu(II) and Ni(II) with Ypk9 Protein Fragment via NMR Studies

    PubMed Central

    Peana, Massimiliano Francesco; Medici, Serenella; Ledda, Alessia; Nurchi, Valeria Marina; Zoroddu, Maria Antonietta

    2014-01-01

    P1D2E3K4H5E6L7 (PK9-H), a fragment of Ypk9, the yeast homologue of the human Park9 protein, was studied for its coordination abilities towards Ni(II) and Cu(II) ions through mono- and bi-dimensional NMR techniques. Both proteins are involved in the transportation of metal ions, including manganese and nickel, from the cytosol to the lysosomal lumen. Ypk9 showed manganese detoxification role, preventing a Mn-induced Parkinsonism (PD) besides mutations in Park9, linked to a juvenile form of the disease. Here, we tested PK9-H with Cu(II) and Ni(II) ions, the former because it is an essential element ubiquitous in the human body, so its trafficking should be strictly regulated and one cannot exclude that Ypk9 may play a role in it, and the latter because, besides being a toxic element for many organisms and involved in different pathologies and inflammation states, it seems that the protein confers protection against it. NMR experiments showed that both cations can bind PK9-H in an effective way, leading to complexes whose coordination mode depends on the pH of the solution. NMR data have been used to build a model for the structure of the major Cu(II) and Ni(II) complexes. Structural changes in the conformation of the peptide with organized side chain orientation promoted by nickel coordination were detected. PMID:24790577

  8. Fast readout architectures for large arrays of digital pixels: examples and applications.

    PubMed

    Gabrielli, A

    2014-01-01

    Modern pixel detectors, particularly those designed and constructed for applications and experiments for high-energy physics, are commonly built implementing general readout architectures, not specifically optimized in terms of speed. High-energy physics experiments use bidimensional matrices of sensitive elements located on a silicon die. Sensors are read out via other integrated circuits bump bonded over the sensor dies. The speed of the readout electronics can significantly increase the overall performance of the system, and so here novel forms of readout architectures are studied and described. These circuits have been investigated in terms of speed and are particularly suited for large monolithic, low-pitch pixel detectors. The idea is to have a small simple structure that may be expanded to fit large matrices without affecting the layout complexity of the chip, while maintaining a reasonably high readout speed. The solutions might be applied to devices for applications not only in physics but also to general-purpose pixel detectors whenever online fast data sparsification is required. The paper presents also simulations on the efficiencies of the systems as proof of concept for the proposed ideas. PMID:24778588

  9. A study on large coherent structures and noise emission in a turbulent round jet

    NASA Astrophysics Data System (ADS)

    Wan, ZhenHua; Zhou, Lin; Sun, DeJun

    2014-08-01

    A moderate Reynolds number, and high subsonic turbulent round jet is investigated by large eddy simulation. The detailed results (e.g. mean flow properties, turbulence intensities, etc.) are validated against the experimental data, and special attention is paid to study motions of coherent structures and their contributions to far-field noise. Eulerian methods (e.g. Q-criteria and λ2 criteria) are utilized for visualizing coherent structures directly for instantaneous flow fields, and Lagrangian coherent structures accounting for integral effect are shown via calculating fields of finite time Lyapunov exponents based on bidimensional velocity fields. All visualizations demonstrate that intrusion of three-dimensional vortical structures into jet core occurs intermittently at the end of the potential core, resulting from the breakdown of helical vortex rings in the shear layer. Intermittencies in the shear layer and on the centerline are studied quantitatively, and distinctively different distributions of probability density function are observed. Moreover, the physical sound sources are obtained through a filtering operation of defined sources in Lighthill's analogy, and their distributions verify that intrusion of vortical structures into the core region serves as important sound sources, in particular for noise at aft angles. The facts that intermittent behaviors are caused by motions of coherent structures and correlated with noise generation imply that to establish reasonable sound sources in active noise production region based on intermittent coherent structures is one of the key issues for far-field noise prediction.

  10. Human osteoarthritic chondrocytes exposed to extremely low-frequency electromagnetic fields (ELF) and therapeutic application of musically modulated electromagnetic fields (TAMMEF) systems: a comparative study.

    PubMed

    Corallo, Claudio; Volpi, Nila; Franci, Daniela; Vannoni, Daniela; Leoncini, Roberto; Landi, Giacomo; Guarna, Massimo; Montella, Antonio; Albanese, Antonietta; Battisti, Emilio; Fioravanti, Antonella; Nuti, Ranuccio; Giordano, Nicola

    2013-06-01

    Osteoarthritis (OA) is the most common joint disease, characterized by matrix degradation and changes in chondrocyte morphology and metabolism. Literature reported that electromagnetic fields (EMFs) can produce benefits in OA patients, even if EMFs mechanism of action is debated. Human osteoarthritic chondrocytes isolated from femoral heads were cultured in vitro in bidimensional (2-D) flasks and in three-dimensional (3-D) alginate beads to mimic closely cartilage environment in vivo. Cells were exposed 30 min/day for 2 weeks to extremely low-frequency electromagnetic field (ELF) with fixed frequency (100 Hz) and to therapeutic application of musically modulated electromagnetic field (TAMMEF) with variable frequencies, intensities, and waveforms. Cell viability was measured at days 7 and 14, while healthy-cell density, heavily vacuolized (hv) cell density, and cluster density were measured by light microscopy only for 3-D cultures after treatments. Cell morphology was observed for 2-D and 3-D cultures by transmission electron microscopy (TEM). Chondrocyte exposure to TAMMEF enhances cell viability at days 7 and 14 compared to ELF. Light microscopy analysis showed that TAMMEF enhances healthy-cell density, reduces hv-cell density and clustering, compared to ELF. Furthermore, TEM analysis showed different morphology for 2-D (fibroblast-like) and 3-D (rounded shape) cultures, confirming light microscopy results. In conclusion, EMFs are effective and safe for OA chondrocytes. TAMMEF can positively interfere with OA chondrocytes representing an innovative non-pharmacological approach to treat OA. PMID:23263545

  11. Effectiveness and efficiency in clinical orthodontic practice.

    PubMed

    Rinchuse, Daniel J; Cozzani, Mauro

    2015-12-01

    Proffitt et al. have described "effectiveness and efficiency" (E&E) as achieving desired results without wasting the orthodontist's and patients' time. In 1972, Archibald Cochrane published a monograph entitled "Effectiveness and Efficiency," which challenged the medical community to use medical protocols that were evidence-based. As a possible starting point for E&E, the orthodontist could consider an "Evidence-based clinical practice" (EBCP) model, which integrates the best research evidence with clinical expertise and patient values. This model considers scientific or evidence-based orthodontics (EBO) together with patient preferences and patient autonomy, clinical or patient circumstances, and clinical experience and judgment. In this paper, therefore, E&E will be discussed from an EBCP perspective which, for our purposes, includes relevant evidence but also our clinical experience and rationale. We will discuss: wire sequence; NiTi Wire types; space closure by sliding; canine retraction versus en masse retraction, 18" slot versus 22" slot, the Bidimensional System; self-ligating brackets (SL); vertical slot; economic aspects. PMID:26527490

  12. Ex-vivo multi-modal microscopy of healthy skin

    NASA Astrophysics Data System (ADS)

    Guevara, Edgar; Gutiérrez-Hernández, José Manuel; Castonguay, Alexandre; Lesage, Frédéric; González, Francisco Javier

    2014-09-01

    The thorough characterization of skin samples is a critical step in investigating dermatological diseases. The combination of depth-sensitive anatomical imaging with molecular imaging has the potential to provide vast information about the skin. In this proof-of-concept work we present high-resolution mosaic images of skin biopsies using Optical Coherence Tomography (OCT) manually co-registered with standard microscopy, bi-dimensional Raman spectral mapping and fluorescence imaging. A human breast skin sample, embedded in paraffin, was imaged with a swept-source OCT system at 1310 nm. Individual OCT volumes were acquired in fully automated fashion in order to obtain a large field-of-view at high resolution (~10μm). Based on anatomical features, the other three modalities were manually co-registered to the projected OCT volume, using an affine transformation. A drawback is the manual co-registration, which may limit the utility of this method. However, the results indicate that multiple imaging modalities provide complementary information about the sample. This pilot study suggests that multi-modal microscopy may be a valuable tool in the characterization of skin biopsies.

  13. Multidimensional Human Dynamics in Mobile Phone Communications

    PubMed Central

    Quadri, Christian; Zignani, Matteo; Capra, Lorenzo; Gaito, Sabrina; Rossi, Gian Paolo

    2014-01-01

    In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process. PMID:25068479

  14. Evaluation of Central and Peripheral Fatigue in the Quadriceps Using Fractal Dimension and Conduction Velocity in Young Females

    PubMed Central

    Beretta-Piccoli, Matteo; D’Antona, Giuseppe; Barbero, Marco; Fisher, Beth; Dieli-Conwright, Christina M.; Clijsen, Ron; Cescon, Corrado

    2015-01-01

    Purpose Over the past decade, linear and non-linear surface electromyography descriptors for central and peripheral components of fatigue have been developed. In the current study, we tested fractal dimension (FD) and conduction velocity (CV) as myoelectric descriptors of central and peripheral fatigue, respectively. To this aim, we analyzed FD and CV slopes during sustained fatiguing contractions of the quadriceps femoris in healthy humans. Methods A total of 29 recreationally active women (mean age±standard deviation: 24±4 years) and two female elite athletes (one power athlete, age 24 and one endurance athlete, age 30 years) performed two knee extensions: (1) at 20% maximal voluntary contraction (MVC) for 30 s, and (2) at 60% MVC held until exhaustion. Surface EMG signals were detected from the vastus lateralis and vastus medialis using bidimensional arrays. Results Central and peripheral fatigue were described as decreases in FD and CV, respectively. A positive correlation between FD and CV (R=0.51, p<0.01) was found during the sustained 60% MVC, probably as a result of simultaneous motor unit synchronization and a decrease in muscle fiber CV during the fatiguing task. Conclusions Central and peripheral fatigue can be described as changes in FD and CV, at least in young, healthy women. The significant correlation between FD and CV observed at 60% MVC suggests that a mutual interaction between central and peripheral fatigue can arise during submaximal isometric contractions. PMID:25880369

  15. Compact interferometer transducer based on surface plasmon phase resonance.

    PubMed

    Hadjar, Yassine; Renault, Mikael; Blaize, Sylvain; Bruyant, Aurélien; Vincent, Rémi; Hmima, Abdelhamid

    2015-05-01

    We propose a new monolithic interferometric configuration and implement a novel method for spectroscopic phase shift detection of surface plasmon resonance (SPR) sensors. The interference pattern is obtained using a nonpolarizing beam splitter cube with two attached right angle prisms in such a way that each interference field undergoes two total internal reflections (TIR) at prisms/air interface and one attenuated total reflection (ATR) through surface plasmon interaction. The evanescent part of the interferogram around the Zero optical path difference (ZOPD) is sampled and detected in the far field, thanks to a bidimensional array of scattering optical near-field probes deposited on the corresponding prism surface. A Fourier transform of the sampled interferogram is performed to measure the input light wavelength, while a direct comparison of the interferogram in TM and TE polarization modes allows us to determine the differential phase shift induced by the SPR layer. The phase shift measurement is made possible thanks to a remarkable time stability of the interferogram in the glass bulk. By tuning the input laser wavelength around the resonance, we show a good agreement between experimental and theoretical calculations for both amplitude and phase spectral responses. PMID:26366899

  16. Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies.

    PubMed

    Raffaini, Giuseppina; Ganazzoli, Fabio; Mazzaglia, Antonino

    2016-01-01

    Chemically modified cyclodextrins carrying both hydrophobic and hydrophilic substituents may form supramolecular aggregates or nanostructures of great interest. These systems have been usually investigated and characterized in water for their potential use as nanocarriers for drug delivery, but they can also aggregate in apolar solvents, as shown in the present paper through atomistic molecular dynamics simulations and dynamic light scattering measurements. The simulations, carried out with a large number of molecules in vacuo adopting an unbiased bottom-up approach, suggest the formation of bidimensional structures with characteristic length scales of the order of 10 nm, although some of these sizes are possibly affected by the assumed periodicity of the simulation cell, in particular at longer lengths. In any case, these nanostructures are stable at least from the kinetic viewpoint for relatively long times thanks to the large number of intermolecular interactions of dipolar and dispersive nature. The dynamic light scattering experiments indicate the presence of aggregates with a hydrodynamic radius of the order of 80 nm and a relatively modest polydispersity, even though smaller nanometer-sized aggregates cannot be fully ruled out. Taken together, these simulation and experimental results indicate that amphiphilically modified cyclodextrins do also form large-scale nanoaggregates even in apolar solvents. PMID:26877809

  17. Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies

    PubMed Central

    Ganazzoli, Fabio; Mazzaglia, Antonino

    2016-01-01

    Summary Chemically modified cyclodextrins carrying both hydrophobic and hydrophilic substituents may form supramolecular aggregates or nanostructures of great interest. These systems have been usually investigated and characterized in water for their potential use as nanocarriers for drug delivery, but they can also aggregate in apolar solvents, as shown in the present paper through atomistic molecular dynamics simulations and dynamic light scattering measurements. The simulations, carried out with a large number of molecules in vacuo adopting an unbiased bottom-up approach, suggest the formation of bidimensional structures with characteristic length scales of the order of 10 nm, although some of these sizes are possibly affected by the assumed periodicity of the simulation cell, in particular at longer lengths. In any case, these nanostructures are stable at least from the kinetic viewpoint for relatively long times thanks to the large number of intermolecular interactions of dipolar and dispersive nature. The dynamic light scattering experiments indicate the presence of aggregates with a hydrodynamic radius of the order of 80 nm and a relatively modest polydispersity, even though smaller nanometer-sized aggregates cannot be fully ruled out. Taken together, these simulation and experimental results indicate that amphiphilically modified cyclodextrins do also form large-scale nanoaggregates even in apolar solvents. PMID:26877809

  18. Modeling and simulation of a grand piano.

    PubMed

    Chabassier, Juliette; Chaigne, Antoine; Joly, Patrick

    2013-07-01

    A time-domain global modeling of a grand piano is presented. The string model includes internal losses, stiffness, and geometrical nonlinearity. The hammer-string interaction is governed by a nonlinear dissipative compression force. The soundboard is modeled as a dissipative bidimensional orthotropic Reissner-Mindlin plate where the presence of ribs and bridges is treated as local heterogeneities. The coupling between strings and soundboard at the bridge allows the transmission of both transverse and longitudinal waves to the soundboard. The soundboard is coupled to the acoustic field, whereas all other parts of the structure are supposed to be perfectly rigid. The acoustic field is bounded artificially using perfectly matched layers. The discrete form of the equations is based on original energy preserving schemes. Artificial decoupling is achieved, through the use of Schur complements and Lagrange multipliers, so that each variable of the problem can be updated separately at each time step. The capability of the model is highlighted by series of simulations in the low, medium, and high register, and through comparisons with waveforms recorded on a Steinway D piano. Its ability to account for phantom partials and precursors, consecutive to string nonlinearity and inharmonicity, is particularly emphasized. PMID:23862839

  19. A three dimensional integral equation approach for fluids under confinement: Argon in zeolites

    NASA Astrophysics Data System (ADS)

    Lomba, Enrique; Bores, Cecilia; Sánchez-Gil, Vicente; Noya, Eva G.

    2015-10-01

    In this work, we explore the ability of an inhomogeneous integral equation approach to provide a full three dimensional description of simple fluids under conditions of confinement in porous media. Explicitly, we will consider the case of argon adsorbed into silicalite-1, silicalite-2, and an all-silica analogue of faujasite, with a porous structure composed of linear (and zig-zag in the case of silicalite-1) channels of 5-8 Å diameter. The equation is based on the three dimensional Ornstein-Zernike approximation proposed by Beglov and Roux [J. Chem. Phys. 103, 360 (1995)] in combination with the use of an approximate fluid-fluid direct correlation function furnished by the replica Ornstein-Zernike equation with a hypernetted chain closure. Comparison with the results of grand canonical Monte Carlo/molecular dynamics simulations evidences that the theory provides an accurate description for the three dimensional density distribution of the adsorbed fluid, both at the level of density profiles and bidimensional density maps across representative sections of the porous material. In the case of very tight confinement (silicalite-1 and silicalite-2), solutions at low temperatures could not be found due to convergence difficulties, but for faujasite, which presents substantially larger channels, temperatures as low as 77 K are accessible to the integral equation. The overall results indicate that the theoretical approximation can be an excellent tool to characterize the microscopic adsorption behavior of porous materials.

  20. Characterisation, immunolocalisation and antifungal activity of a lipid transfer protein from chili pepper (Capsicum annuum) seeds with novel α-amylase inhibitory properties.

    PubMed

    Diz, Mariângela S; Carvalho, Andre O; Ribeiro, Suzanna F F; Da Cunha, Maura; Beltramini, Leila; Rodrigues, Rosana; Nascimento, Viviane V; Machado, Olga L T; Gomes, Valdirene M

    2011-07-01

    Lipid transfer proteins (LTPs) were thus named because they facilitate the transfer of lipids between membranes in vitro. This study was triggered by the characterization of a 9-kDa LTP from Capsicum annuum seeds that we call Ca-LTP(1) . Ca-LTP(1) was repurified, and in the last chromatographic purification step, propanol was used as the solvent in place of acetonitrile to maintain the protein's biological activity. Bidimensional electrophoresis of the 9-kDa band, which corresponds to the purified Ca-LTP(1) , showed the presence of three isoforms with isoelectric points (pIs) of 6.0, 8.5 and 9.5. Circular dichroism (CD) analysis suggested a predominance of α-helices, as expected for the structure of an LTP family member. LTPs immunorelated to Ca-LTP(1) from C. annuum were also detected by western blotting in exudates released from C. annuum seeds and also in other Capsicum species. The tissue and subcellular localization of Ca-LTP(1) indicated that it was mainly localized within dense vesicles. In addition, isolated Ca-LTP(1) exhibited antifungal activity against Colletotrichum lindemunthianum, and especially against Candida tropicalis, causing several morphological changes to the cells including the formation of pseudohyphae. Ca-LTP(1) also caused the yeast plasma membrane to be permeable to the dye SYTOX green, as verified by fluorescence microscopy. We also found that Ca-LTP(1) is able to inhibit mammalian α-amylase activity in vitro. PMID:21382036

  1. Assessment of self-organizing maps to analyze sole-carbon source utilization profiles.

    PubMed

    Leflaive, Joséphine; Céréghino, Régis; Danger, Michaël; Lacroix, Gérard; Ten-Hage, Loïc

    2005-07-01

    The use of community-level physiological profiles obtained with Biolog microplates is widely employed to consider the functional diversity of bacterial communities. Biolog produces a great amount of data which analysis has been the subject of many studies. In most cases, after some transformations, these data were investigated with classical multivariate analyses. Here we provided an alternative to this method, that is the use of an artificial intelligence technique, the Self-Organizing Maps (SOM, unsupervised neural network). We used data from a microcosm study of algae-associated bacterial communities placed in various nutritive conditions. Analyses were carried out on the net absorbances at two incubation times for each substrates and on the chemical guild categorization of the total bacterial activity. Compared to Principal Components Analysis and cluster analysis, SOM appeared as a valuable tool for community classification, and to establish clear relationships between clusters of bacterial communities and sole-carbon sources utilization. Specifically, SOM offered a clear bidimensional projection of a relatively large volume of data and were easier to interpret than plots commonly obtained with multivariate analyses. They would be recommended to pattern the temporal evolution of communities' functional diversity. PMID:15823397

  2. Protein phosphorylation during Plasmodium berghei gametogenesis.

    PubMed

    Alonso-Morales, Alberto; González-López, Lorena; Cázares-Raga, Febe Elena; Cortés-Martínez, Leticia; Torres-Monzón, Jorge Aurelio; Gallegos-Pérez, José Luis; Rodríguez, Mario Henry; James, Anthony A; Hernández-Hernández, Fidel de la Cruz

    2015-09-01

    Plasmodium gametogenesis within the mosquito midgut is a complex differentiation process involving signaling mediated by phosphorylation, which modulate metabolic routes and protein synthesis required to complete this development. However, the mechanisms leading to gametogenesis activation are poorly understood. We analyzed protein phosphorylation during Plasmodium berghei gametogenesis in vitro in serum-free medium using bidimensional electrophoresis (2-DE) combined with immunoblotting (IB) and antibodies specific to phosphorylated serine, threonine and tyrosine. Approximately 75 protein exhibited phosphorylation changes, of which 23 were identified by mass spectrometry. These included components of the cytoskeleton, heat shock proteins, and proteins involved in DNA synthesis and signaling pathways among others. Novel phosphorylation events support a role for these proteins during gametogenesis. The phosphorylation sites of six of the identified proteins, HSP70, WD40 repeat protein msi1, enolase, actin-1 and two isoforms of large subunit of ribonucleoside reductase were investigated using TiO2 phosphopeptides enrichment and tandem mass spectrometry. In addition, transient exposure to hydroxyurea, an inhibitor of ribonucleoside reductase, impaired male gametocytes exflagellation in a dose-dependent manner, and provides a resource for functional studies. PMID:26008612

  3. Circumnuclear Keplerian Disks in Galaxies

    NASA Astrophysics Data System (ADS)

    Bertola, Francesco; Cappellari, Michele; Funes, S. J., José G.; Corsini, Enrico M.; Pizzella, Alessandro; Beltrán, Juan C. Vega

    1998-12-01

    In this Letter, we demonstrate the possibility of inferring the presence of Keplerian gaseous disks using properly equipped optical ground-based telescopes. We have modeled the peculiar bidimensional shape of the emission lines in a sample of five early-type disk galaxies as due to the motion of a gaseous disk rotating in the combined potential of a central pointlike mass and of an extended stellar disk. The value of the central mass concentration estimated for four galaxies of the sample (NGC 2179, NGC 4343, NGC 4435, and NGC 4459) is ~109 Msolar. This value, according to the assumptions made in our model, is overestimated. However, we have calculated that the effect is well within the errors. For the remaining galaxy, NGC 5064, an upper limit of 5×107 Msolar is estimated. Based on observations carried out at ESO, La Silla, (Chile) (ESO N. 58, A-0564) and at the Mount Graham International Observatory (AZ) with the VATT: the Alice P. Lennon Telescope and the Thomas J. Bannan Astrophysics Facility.

  4. Tris buffer modulates polydopamine growth, aggregation, and paramagnetic properties.

    PubMed

    Della Vecchia, Nicola Fyodor; Luchini, Alessandra; Napolitano, Alessandra; D'Errico, Gerardino; Vitiello, Giuseppe; Szekely, Noemi; d'Ischia, Marco; Paduano, Luigi

    2014-08-19

    Despite the growing technological interest of polydopamine (dopamine melanin)-based coatings for a broad variety of applications, the factors governing particle size, shape, and electronic properties of this bioinspired multifunctional material have remained little understood. Herein, we report a detailed characterization of polydopamine growth, particle morphology, and paramagnetic properties as a function of dopamine concentration and nature of the buffer (pH 8.5). Dynamic Light Scattering data revealed an increase in the hydrodynamic radii (Rh) of melanin particles with increasing dopamine concentration in all buffers examined, especially in phosphate buffer. Conversely, a marked inhibition of particle growth was apparent in Tris buffer, with Rh remaining as low as <100 nm during polymerization of 0.5 mM dopamine. Small angle neutron scattering data suggested formation of bidimensional structures in phosphate or bicarbonate buffers, while apparently three-dimensional fractal objects prevailed in Tris buffer. Finally, electron paramagnetic resonance spectra revealed a broader signal amplitude with a peculiar power saturation decay profile for polydopamine samples prepared in Tris buffer, denoting more homogeneous paramagnetic centers with respect to similar samples obtained in phosphate and bicarbonate buffers. Overall, these results disclose Tris buffer as an efficient modulator of polydopamine buildup and properties for the rational control and fine-tuning of melanin aggregate size, morphology, and free radical behavior. PMID:25066905

  5. Fast Readout Architectures for Large Arrays of Digital Pixels: Examples and Applications

    PubMed Central

    Gabrielli, A.

    2014-01-01

    Modern pixel detectors, particularly those designed and constructed for applications and experiments for high-energy physics, are commonly built implementing general readout architectures, not specifically optimized in terms of speed. High-energy physics experiments use bidimensional matrices of sensitive elements located on a silicon die. Sensors are read out via other integrated circuits bump bonded over the sensor dies. The speed of the readout electronics can significantly increase the overall performance of the system, and so here novel forms of readout architectures are studied and described. These circuits have been investigated in terms of speed and are particularly suited for large monolithic, low-pitch pixel detectors. The idea is to have a small simple structure that may be expanded to fit large matrices without affecting the layout complexity of the chip, while maintaining a reasonably high readout speed. The solutions might be applied to devices for applications not only in physics but also to general-purpose pixel detectors whenever online fast data sparsification is required. The paper presents also simulations on the efficiencies of the systems as proof of concept for the proposed ideas. PMID:24778588

  6. Development of a hybrid dextrin hydrogel encapsulating dextrin nanogel as protein delivery system.

    PubMed

    Molinos, Maria; Carvalho, Vera; Silva, Dina M; Gama, Francisco M

    2012-02-13

    Dextrin, a glucose polymer with low molecular weight, was used to develop a fully resorbable hydrogel, without using chemical initiators. Dextrin was first oxidized (oDex) with sodium periodate and then cross-linked with adipic acid dihidrazide, a nontoxic cross-linking molecule. Furthermore, a new bidimensional composite hydrogel, made of oxidized dextrin incorporating dextrin nanogels (oDex-nanogel), was also developed. The oDex hydrogels showed good mechanical properties and biocompatibility, allowing the proliferation of mouse embryo fibroblasts 3T3 cultured on top of the gel. The gelation time may be controlled selecting the concentrations of the polymer and reticulating agent. Both the oDex and oDex-nanogel hydrogels are biodegradable and present a 3-D network with a continuous porous structure. The obtained hybrid hydrogel enables the release of the dextrin nanogel over an extended period of time, paralleling the mass loss curve due to the degradation of the material. The dextrin nanogel allowed the efficient incorporation of interleukin-10 and insulin in the oDex hydrogel, providing a sophisticated system of controlled release. The new hydrogels present promising properties as an injectable carrier of bioactive molecules. Both proteins and poorly water-soluble low-molecular-weight drugs are efficiently encapsulated in the nanogel, which performs as a controlled release system entrapped in the hydrogel matrix. PMID:22288730

  7. Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa

    PubMed Central

    Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

    2015-01-01

    The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation. PMID:25978319

  8. Reactivity of Au nanoparticles supported over SiO2 and TiO2 studiedby ambient pressure photoelectron spectroscopy

    SciTech Connect

    Herranz, Tirma; Deng, Xingyi; Cabot, Andreu; Alivisatos, Paul; Liu, Zhi; Soler-Illia, Galo; Salmeron, Miquel

    2009-04-15

    The influence of the metal cluster size and the identity of the support on the reactivity of gold based catalysts have been studied in the CO oxidation reaction. To overcome the structural complexity of the supported catalysts, gold nanoparticles synthesized from colloidal chemistry with precisely controlled size have been used. Those particles were supported over SiO{sub 2} and TiO{sub 2} and their catalytic activity was measured in a flow reactor. The reaction rate was dependent on the particle size and the support, suggesting two reaction pathways in the CO oxidation reaction. In parallel, ambient pressure photoelectron spectroscopy (APPS) has been performed under reaction conditions using bidimensional model catalysts prepared upon supporting the Au nanoparticles over planar polycrystalline SiO{sub 2} and TiO{sub 2} thin films by means of the Langmuir-Blodgett (LB) technique to mimic the characteristic of the powder samples. In this way, the catalytically active surface was characterized under true reaction conditions, revealing that during CO oxidation gold remains in the metallic state.

  9. Orthodontic treatment of an anterior openbite with the aid of corticotomy procedure: Case report

    PubMed Central

    Aljhani, Ali S.; Aldrees, Abdullah M.

    2010-01-01

    This case report illustrates the orthodontic treatment combined with the corticotomy technique in an adult patient to accelerate tooth movement and shorten the treatment time. The patient was a 22-year-old woman with an anterior open bite and flared and spaced upper and lower incisors. First, fixed orthodontic appliances (bidimensional edgewise brackets) were bonded, and a week later buccal and lingual corticotomy with alveolar augmentation procedure in the maxillary arch from the first molar to the contralateral first molar, and from canine to canine in the mandibular arch was performed. Orthodontic therapy proceeded with frequent activation of the appliances to retract the incisors every 2 weeks. The total treatment time was 5 months and no adverse effects were observed at the end of active treatment. The addition of the decortication procedure to the conventional orthodontic therapy decreased the duration of treatment significantly. Successful closure of the anterior open bite with adequate overbite and interdigitation of the teeth were achieved. PMID:24151417

  10. Orthodontic treatment of an anterior openbite with the aid of corticotomy procedure: Case report.

    PubMed

    Aljhani, Ali S; Aldrees, Abdullah M

    2011-04-01

    This case report illustrates the orthodontic treatment combined with the corticotomy technique in an adult patient to accelerate tooth movement and shorten the treatment time. The patient was a 22-year-old woman with an anterior open bite and flared and spaced upper and lower incisors. First, fixed orthodontic appliances (bidimensional edgewise brackets) were bonded, and a week later buccal and lingual corticotomy with alveolar augmentation procedure in the maxillary arch from the first molar to the contralateral first molar, and from canine to canine in the mandibular arch was performed. Orthodontic therapy proceeded with frequent activation of the appliances to retract the incisors every 2 weeks. The total treatment time was 5 months and no adverse effects were observed at the end of active treatment. The addition of the decortication procedure to the conventional orthodontic therapy decreased the duration of treatment significantly. Successful closure of the anterior open bite with adequate overbite and interdigitation of the teeth were achieved. PMID:24151417

  11. Internal wave attractors examined using laboratory experiments and 3D numerical simulations

    NASA Astrophysics Data System (ADS)

    Brouzet, C.; Sibgatullin, I. N.; Scolan, H.; Ermanyuk, E. V.; Dauxois, T.

    2016-04-01

    In the present paper, we combine numerical and experimental approaches to study the dynamics of stable and unstable internal wave attractors. The problem is considered in a classic trapezoidal setup filled with a uniformly stratified fluid. Energy is injected into the system at global scale by the small-amplitude motion of a vertical wall. Wave motion in the test tank is measured with the help of conventional synthetic schlieren and PIV techniques. The numerical setup closely reproduces the experimental one in terms of geometry and the operational range of the Reynolds and Schmidt numbers. The spectral element method is used as a numerical tool to simulate the nonlinear dynamics of a viscous salt-stratified fluid. We show that the results of three-dimensional calculations are in excellent qualitative and quantitative agreement with the experimental data, including the spatial and temporal parameters of the secondary waves produced by triadic resonance instability. Further, we explore experimentally and numerically the effect of lateral walls on secondary currents and spanwise distribution of velocity amplitudes in the wave beams. Finally, we test the assumption of a bidimensional flow and estimate the error made in synthetic schlieren measurements due to this assumption.

  12. Multidimensional human dynamics in mobile phone communications.

    PubMed

    Quadri, Christian; Zignani, Matteo; Capra, Lorenzo; Gaito, Sabrina; Rossi, Gian Paolo

    2014-01-01

    In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process. PMID:25068479

  13. Early stages of epitaxial CoSi 2 formation on Si(111) surface as investigated by ARUPS, XPS, LEED and work function variation

    NASA Astrophysics Data System (ADS)

    Pirri, C.; Peruchetti, J. C.; Gewinner, G.; Derrien, J.

    1985-04-01

    We performed the CoSi 2 formation on a clean (7 × 7) Si(111) surface under UHV conditions. The used techniques were angle resolved UV photoemission, X-ray photoemission, work function change and low energy electron diffraction in order to study the electronic and structural properties of the interface during its formation. At room temperature, a small amount of Co reacts strongly with Si to form an interfacial and very thin cobalt suicide. The ultraviolet photoelectron spectrum displays already two features corresponding respectively to the Co 3d and Si 3p electron bonding states and the Co 3d non-bonding states. With increasing coverage ( θ ≳ 4 ML) it seems that the interfacial suicide prevents further Co-Si interdiffusion to achieve the suicide reaction and a metal rich film is found. At high temperature (˜ 600°C) and in the first monolayer range, several superstructures are found (√7 × √7, and 2 × 2). They are induced by a Co-Si bidimensional compound where the Co atoms are not yet completely surrounded by Si atoms as in their bulk CoSi 2 structure. With increasing coverage, a CoSi 2-like photoemission spectrum is observed reflecting the formation of the disilicide. The LEED pattern testifies an epitaxial growth displaying a (1 × 1) CoSi 2 diagram. The work function change technique also reflects faithfully this growth.

  14. Recent results on fast intermediate velocity electron production induced by 19 + 45 A MeV 58Ni highly charged ions on thin solid targets

    NASA Astrophysics Data System (ADS)

    Lanzanò, G.; De Filippo, E.; Anzalone, A.; Arena, N.; Geraci, M.; Giustolisi, F.; Pagano, A.; Rothard, H.; Volant, C.

    2003-05-01

    In order to study the emission of energetic electrons induced by the impact of swift heavy ions on thin solid targets, we carried out a series of experiments at the superconducting cyclotron of the Catania Laboratori Nazionali del Sud. We report results on a recent experiment where electron-electron coincidences were measured in a forward ring by bombarding a thin carbon target of 7.4 μg/cm 2 with 19 + 45 A MeV 58Ni beam. The velocity1-velocity2 bidimensional plot is dominated by events in which the two detected electrons have a velocity close to the beam velocity 9.03 cm/ns (convoy electrons). The remaining small fraction of coincidences has still a convoy electron and a second electron having either a velocity almost twice the beam velocity 16.5 cm/ns (binary encounter, BE electrons) or a velocity of about 12.7 cm/ns intermediate between BE and convoy velocities (IV electrons). We interprete this last intermediate component as due to in-flight de-excitation of highly excited n +58Ni ions by Auger electrons. Although less distinct, we observe also an intense peak close to the convoy velocity peak, centered at ≈9.7 cm/ns, corresponding to electrons emitted with an energy of only about ≈170 eV in the projectile rest frame of reference.

  15. Post-acquisition data processing for the screening of transformation products of different organic contaminants. Two-year monitoring of river water using LC-ESI-QTOF-MS and GCxGC-EI-TOF-MS.

    PubMed

    López, S Herrera; Ulaszewska, M M; Hernando, M D; Martínez Bueno, M J; Gómez, M J; Fernández-Alba, A R

    2014-11-01

    This study describes a comprehensive strategy for detecting and elucidating the chemical structures of expected and unexpected transformation products (TPs) from chemicals found in river water and effluent wastewater samples, using liquid chromatography coupled to electrospray ionization quadrupole-time-of-flight mass spectrometer (LC-ESI-QTOF-MS), with post-acquisition data processing and an automated search using an in-house database. The efficacy of the mass defect filtering (MDF) approach to screen metabolites from common biotransformation pathways was tested, and it was shown to be sufficiently sensitive and applicable for detecting metabolites in environmental samples. Four omeprazole metabolites and two venlafaxine metabolites were identified in river water samples. This paper reports the analytical results obtained during 2 years of monitoring, carried out at eight sampling points along the Henares River (Spain). Multiresidue monitoring, for targeted analysis, includes a group of 122 chemicals, amongst which are pharmaceuticals, personal care products, pesticides and PAHs. For this purpose, two analytical methods were used based on direct injection with a LC-ESI-QTOF-MS system and stir bar sorptive extraction (SBSE) with bi-dimensional gas chromatography coupled with a time-of-flight spectrometer (GCxGC-EI-TOF-MS). PMID:24952251

  16. 3D tracking of single nanoparticles and quantum dots in living cells by out-of-focus imaging with diffraction pattern recognition.

    PubMed

    Gardini, Lucia; Capitanio, Marco; Pavone, Francesco S

    2015-01-01

    Live cells are three-dimensional environments where biological molecules move to find their targets and accomplish their functions. However, up to now, most single molecule investigations have been limited to bi-dimensional studies owing to the complexity of 3d-tracking techniques. Here, we present a novel method for three-dimensional localization of single nano-emitters based on automatic recognition of out-of-focus diffraction patterns. Our technique can be applied to track the movements of single molecules in living cells using a conventional epifluorescence microscope. We first demonstrate three-dimensional localization of fluorescent nanobeads over 4 microns depth with accuracy below 2 nm in vitro. Remarkably, we also establish three-dimensional tracking of Quantum Dots, overcoming their anisotropic emission, by adopting a ligation strategy that allows rotational freedom of the emitter combined with proper pattern recognition. We localize commercially available Quantum Dots in living cells with accuracy better than 7 nm over 2 microns depth. We validate our technique by tracking the three-dimensional movements of single protein-conjugated Quantum Dots in living cell. Moreover, we find that important localization errors can occur in off-focus imaging when improperly calibrated and we give indications to avoid them. Finally, we share a Matlab script that allows readily application of our technique by other laboratories. PMID:26526410

  17. Hydrothermal changes in wheat starch monitored by two-dimensional NMR.

    PubMed

    Kovrlija, R; Rondeau-Mouro, C

    2017-01-01

    The temperature-dependent changes in wheat starch powder and wheat starch-water mixtures were monitored in real-time throughout the heating/cooling program using a classical one-dimensional T1 method and a novel bi-dimensional approach to correlate spin-lattice and spin-spin relaxation times (T1-T2) including acquisition of the FID signal. The influence of two controlling factors (i.e. water content (11%, 35-50%, wet basis) and temperature (20-90°C and back to 20°C)) on water distribution and starch transformation was investigated. Quantitative analysis of 2D T1-T2 maps greatly facilitated the interpretation of T1 relaxation times, which have been interpreted rather narrowly in the literature when classically measured in one-dimension. Application of the new IR-FID-CPMG sequence allowed distinction between different proton pools with different T1 relaxation times, particularly when the starch gelatinization occurred. The quantification of each T1 component permitted to assign the short T1 to slow cross relaxation phenomena, highlighting proton chemical and/or diffusional exchanges between water and starch. PMID:27507493

  18. Reference values for echocardiographic parameters and indexes of left ventricular function in healthy, young adult sheep used in translational research: comparison with standardized values in humans

    PubMed Central

    Locatelli, Paola; Olea, Fernanda D; Lorenzi, Andrea De; Salmo, Fabián; Janavel, Gustavo L Vera; Hnatiuk, Anna P; Guevara, Eduardo; Crottogini, Alberto J

    2011-01-01

    Ovine models of ischemic heart disease and cardiac failure are increasingly used in translational research. However, reliable extrapolation of the results to the clinical setting requires knowing if ovine normal left ventricular (LV) function is comparable to that of humans. We thus assessed for echocardiographic LV dimensions and indexes in a large normal adult sheep population and compared them with standardized values in normal human adults. Bidimensional and tissue Doppler echocardiograms were performed in 69 young adult Corriedale sheep under light sedation. LV dimensions and indexes of systolic and diastolic function were measured. Absolute and body surface areanormalized values were compared to those for normal adult humans and their statistical distribution was assessed. Normalized dimensions (except for end diastolic diameter) as well as ejection fraction and fractional shortening fell within the ranges established by the American Society of Echocardiography and European Association of Echocardiography for normal adult humans. Normalized end diastolic diameter exceeded the upper normal limit but got close to it when correcting for the higher heart mass/body surface area ratio of sheep with respect to humans. Diastolic parameters also fell within normal human ranges except for a slightly lower mitral deceleration time. All values exhibited a Gaussian distribution. We conclude that echocardiographic parameters of systolic and diastolic LV performance in young adult sheep can be reliably extrapolated to the adult human, thus supporting the use of ovine models of human heart disease in translational research. PMID:22140597

  19. Replicational organization of three weakly expressed loci in Physarum polycephalum.

    PubMed

    Maric, Chrystelle; Swanston, Emma; Bailey, Juliet; Pierron, Gérard

    2002-06-01

    We previously mapped early-activated replication origins in the promoter regions of five abundantly transcribed genes in the slime mold Physarum polycephalum. This physical linkage between origins and genes is congruent with the preferential early replication of the active genes in mammalian cells. To determine how general this replicational organization is in the synchronous plasmodium of Physarum, we analyzed the replication of three weakly expressed genes. Bromodeoxyuridine (BrdUrd) density-shift and gene dosage experiments indicated that the redB (regulated in development) and redE genes replicate early, whereas redA replicates in mid-S phase. Bi-dimensional gel electrophoresis revealed that redA coincides with an origin that appears to be activated within a large temporal window in S phase so that the replication of the gene is not well defined temporally. The early replication of the redB and redE genes is due to the simultaneous activation of flanking origins at the onset of S phase. As a result, these two genes correspond to termination sites of DNA replication. Our data demonstrate that not all the Physarum promoters are preferred sites of initiation but, so far, all the expressed genes analyzed in detail either coincide with a replication origin or are embedded into a cluster of early firing replicons. PMID:12034812

  20. Hydration in Lipid Monolayers: Correlation of Water Activity and Surface Pressure.

    PubMed

    Disalvo, E Anibal; Hollmann, Axel; Martini, M Florencia

    2015-01-01

    In order to give a physical meaning to each region of the membrane we define the interphase as the region in a lipid membrane corresponding to the polar head groups imbibed in water with net different properties than the hydrocarbon region and the water phase. The interphase region is analyzed under the scope of thermodynamics of surface and solutions based on the definition of Defay-Prigogine of an interphase and the derivation that it has in the understanding of membrane processeses in the context of biological response. In the view of this approach, the complete monolayer is considered as the lipid layer one molecule thick plus the bidimensional solution of the polar head groups inherent to it (the interphase region). Surface water activity appears as a common factor for the interaction of several aqueous soluble and surface active proteins with lipid membranes of different composition. Protein perturbation can be measured by changes in the surface pressure of lipid monolayers at different initial water surface activities. As predicted by solution chemistry, the increase of surface pressure is independent of the particle nature that dissolves. Therefore, membranes give a similar response in terms of the determined surface states given by water activity independent of the protein or peptide. PMID:26438267

  1. Selective growth and ordering of SiGe nanowires for band gap engineering

    NASA Astrophysics Data System (ADS)

    Benkouider, A.; Ronda, A.; Gouyé, A.; Herrier, C.; Favre, L.; Lockwood, D. J.; Rowell, N. L.; Delobbe, A.; Sudraud, P.; Berbezier, I.

    2014-08-01

    Selective growth and self-organization of silicon-germanium (SiGe) nanowires (NWs) on focused ion beam (FIB) patterned Si(111) substrates is reported. In its first step, the process involves the selective synthesis of Au catalysts in Si{{O}_{2}}-free areas; its second step involves the preferential nucleation and growth of SiGe NWs on the catalysts. The selective synthesis process is based on a simple, room-temperature reduction of gold salts (A{{u}^{3+}}Cl_{4}^{-}) in aqueous solution, which provides well-organized Au catalysts. By optimizing the reduction process, we are able to generate a bidimensional regular array of Au catalysts with self-limited sizes positioned in Si{{O}_{2}}-free windows opened in a Si{{O}_{2}}/Si(111) substrate by FIB patterning. Such Au catalysts subsequently serve as preferential nucleation and growth sites of well-organized NWs. Furthermore, these NWs with tunable position and size exhibit the relevant features and bright luminescence that would find several applications in optoelectronic nanodevices.

  2. Fatty acid transfer in the food web of a coastal Mediterranean lagoon: Evidence for high arachidonic acid retention in fish

    NASA Astrophysics Data System (ADS)

    Koussoroplis, Apostolos-Manuel; Bec, Alexandre; Perga, Marie-Elodie; Koutrakis, Emmanuil; Bourdier, Gilles; Desvilettes, Christian

    2011-02-01

    The transfer of fatty acids (FAs) in the food web of a Mediterranean lagoon was studied using FA compositional patterns across several trophic levels. The structure of the food web was inferred from C and N stable isotopes values and an isotope mixing model was used in order to estimate the relative contribution of the different potential food sources to the biomass of consumers. Bidimensional plots of FA composition of food web components against their δ 15N values indicated a general trend of increasing proportions of highly unsaturated fatty acids (HUFAs) with increasing trophic levels while the proportions of saturated fatty acids (SAFAs) and 18-carbon polyunsaturated fatty acids (PUFAs) decreased. Using the relative contributions of food sources to consumers and their FA compositions, a model was built in order to estimate the PUFA composition of consumer mixed diets which was compared to consumer PUFA profiles. The latter allowed the identification of the PUFAs which were mostly enriched/retained in consumer lipids. There was a surprisingly high retention of arachidonic acid (ARA), a trend which challenges the idea of low ARA needs in marine fish and suggests the important physiological role of this essential FA for fish in estuarine environments.

  3. Intra-cavity upconversion to 631 nm of images illuminated by an eye-safe ASE source at 1550 nm.

    PubMed

    Torregrosa, A J; Maestre, H; Capmany, J

    2015-11-15

    We report an image wavelength upconversion system. The system mixes an incoming image at around 1550 nm (eye-safe region) illuminated by an amplified spontaneous emission (ASE) fiber source with a Gaussian beam at 1064 nm generated in a continuous-wave diode-pumped Nd(3+):GdVO(4) laser. Mixing takes place in a periodically poled lithium niobate (PPLN) crystal placed intra-cavity. The upconverted image obtained by sum-frequency mixing falls around the 631 nm red spectral region, well within the spectral response of standard silicon focal plane array bi-dimensional sensors, commonly used in charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) video cameras, and of most image intensifiers. The use of ASE illumination benefits from a noticeable increase in the field of view (FOV) that can be upconverted with regard to using coherent laser illumination. The upconverted power allows us to capture real-time video in a standard nonintensified CCD camera. PMID:26565863

  4. Handheld scanning probes for optical coherence tomography: developments, applications, and perspectives

    NASA Astrophysics Data System (ADS)

    Duma, V.-F.; Demian, D.; Sinescu, C.; Cernat, R.; Dobre, G.; Negrutiu, M. L.; Topala, F. I.; Hutiu, Gh.; Bradu, A.; Podoleanu, A. G.

    2016-03-01

    We present the handheld scanning probes that we have recently developed in our current project for biomedical imaging in general and for Optical Coherence Tomography (OCT) in particular. OCT is an established, but dynamic imagistic technique based on laser interferometry, which offers micrometer resolutions and millimeters penetration depths. With regard to existing devices, the newly developed handheld probes are simple, light and relatively low cost. Their design is described in detail to allow for the reproduction in any lab, including for educational purposes. Two probes are constructed almost entirely from off-the-shelf components, while a third, final variant is constructed with dedicated components, in an ergonomic design. The handheld probes have uni-dimensional (1D) galvanometer scanners therefore they achieve transversal sections through the biological sample investigated - in contrast to handheld probes equipped with bi-dimensional (2D) scanners that can also achieve volumetric (3D) reconstructions of the samples. These latter handheld probes are therefore also discussed, as well as the possibility to equip them with galvanometer 2D scanners or with Risley prisms. For galvanometer scanners the optimal scanning functions studied in a series of previous works are pointed out; these functions offer a higher temporal efficiency/duty cycle of the scanning process, as well as artifact-free OCT images. The testing of the handheld scanning probes in dental applications is presented, for metal ceramic prosthesis and for teeth.

  5. Three-Dimensional BEM and FEM Submodelling in a Cracked FML Full Scale Aeronautic Panel

    NASA Astrophysics Data System (ADS)

    Citarella, R.; Cricrì, G.

    2014-06-01

    This paper concerns the numerical characterization of the fatigue strength of a flat stiffened panel, designed as a fiber metal laminate (FML) and made of Aluminum alloy and Fiber Glass FRP. The panel is full scale and was tested (in a previous work) under fatigue biaxial loads, applied by means of a multi-axial fatigue machine: an initial through the thickness notch was created in the panel and the aforementioned biaxial fatigue load applied, causing a crack initiation and propagation in the Aluminum layers. Moreover, (still in a previous work), the fatigue test was simulated by the Dual Boundary Element Method (DBEM) in a bidimensional approach. Now, in order to validate the assumptions made in the aforementioned DBEM approach and concerning the delamination area size and the fiber integrity during crack propagation, three-dimensional BEM and FEM submodelling analyses are realized. Due to the lack of experimental data on the delamination area size (normally increasing as the crack propagates), such area is calculated by iterative three-dimensional BEM or FEM analyses, considering the inter-laminar stresses and a delamination criterion. Such three-dimensional analyses, but in particular the FEM proposed model, can also provide insights into the fiber rupture problem. These DBEM-BEM or DBEM-FEM approaches aims at providing a general purpose evaluation tool for a better understanding of the fatigue resistance of FML panels, providing a deeper insight into the role of fiber stiffness and of delamination extension on the stress intensity factors.

  6. Syndecan-2 downregulation impairs angiogenesis in human microvascular endothelial cells

    SciTech Connect

    Noguer, Oriol Villena, Joan; Lorita, Jordi; Vilaro, Senen; Reina, Manuel

    2009-03-10

    The formation of new blood vessels, or angiogenesis, is a necessary process during development but also for tumour growth and other pathologies. It is promoted by different growth factors that stimulate endothelial cells to proliferate, migrate, and generate new tubular structures. Syndecans, transmembrane heparan sulphate proteoglycans, bind such growth factors through their glycosaminoglycan chains and could transduce the signal to the cytoskeleton, thus regulating cell behaviour. We demonstrated that syndecan-2, the major syndecan expressed by human microvascular endothelial cells, is regulated by growth factors and extracellular matrix proteins, in both bidimensional and tridimensional culture conditions. The role of syndecan-2 in 'in vitro' tumour angiogenesis was also examined by inhibiting its core protein expression with antisense phosphorothioate oligonucleotides. Downregulation of syndecan-2 reduces spreading and adhesion of endothelial cells, enhances their migration, but also impairs the formation of capillary-like structures. These results suggest that syndecan-2 has an important function in some of the necessary steps that make up the angiogenic process. We therefore propose a pivotal role of this heparan sulphate proteoglycan in the formation of new blood vessels.

  7. Exploring the Shift in Structure and Function of Microbial Communities Performing Biological Phosphorus Removal.

    PubMed

    Mao, Yanping; Wang, Zhiping; Li, Liguan; Jiang, Xiaotao; Zhang, Xuxiang; Ren, Hongqiang; Zhang, Tong

    2016-01-01

    A sequencing batch reactor fed mainly by acetate was operated to perform enhanced biological phosphorus removal (EBPR). A short-term pH shock from 7.0 to 6.0 led to a complete loss of phosphate-removing capability and a drastic change of microbial communities. 16S rRNA gene pyrosequencing showed that large proportions of glycogen accumulating organisms (GAOs) (accounted for 16% of bacteria) bloomed, including Candidatus Competibacter phosphatis and Defluviicoccus-related tetrad-forming organism, causing deteriorated EBPR performance. The EBPR performance recovered with time and the dominant Candidatus Accumulibacter (Accumulibacter) clades shifted from Clade IIC to IIA while GAOs populations shrank significantly. The Accumulibacter population variation provided a good opportunity for genome binning using a bi-dimensional coverage method, and a genome of Accumulibacter Clade IIC was well retrieved with over 90% completeness. Comparative genomic analysis demonstrated that Accumulibacter clades had different abilities in nitrogen metabolism and carbon fixation, which shed light on enriching different Accumulibacter populations selectively. PMID:27547976

  8. Crystallization of sputtered-deposited and ion implanted amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} thin films

    SciTech Connect

    Rimini, E.; De Bastiani, R.; Carria, E.; Grimaldi, M. G.; Nicotra, G.; Bongiorno, C.; Spinella, C.

    2009-06-15

    X-ray diffraction and transmission electron microscopy have been utilized to measure the ion irradiation-induced modification in amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} thin films. The isothermal crystallization of sputtered-deposited and Sb{sup +} ion irradiated amorphous samples has been studied, focusing on the evolution of the microstructure during the initial stage of the transformation. In both samples, the amorphous to crystal transition occurs through the nucleation of face centered cubic (fcc) crystal domains at the film surface. A fast bidimensional growth of the crystalline nuclei in the sputtered-deposited films occurs by the generation of transrotational grains. The lattice parameter decreases as the crystalline fraction increases above 80%, and it approaches the fcc bulk value at the end of the transformation. Ion irradiation produces a densification of the deposited amorphous film (approx4% vertical shrinkage measured by atomic force microscopy) and an enhancement of the crystallization rate. Even in the irradiated amorphous, the nucleation occurs at the film surface and proceeds by the growth of the grains through the thickness of the layer although the density of the transrotational grains is strongly reduced with respect to the unirradiated amorphous. A link between the ion beam induced densification and the reduction of transrotational grains is proposed.

  9. Surface metrology with a stitching Shack-Hartmann profilometric head

    NASA Astrophysics Data System (ADS)

    Floriot, J.; Levecq, X.; Bucourt, S.; Thomasset, M.; Polack, F.; Idir, M.; Mercère, P.; Brochet, S.; Moreno, T.

    2007-06-01

    In this article, a stitching Shack-Hartmann profilometric head is presented. This instrument has been developed to answer improved needs for surface metrology in the domain of short-wavelength optics (X/EUV). It is composed of a highaccuracy Shack-Hartmann wavefront sensor and an illumination platform. This profilometric head is mounted on a translation stage to perform bidimensional mappings by stitching together successive sub-aperture acquisitions. This method ensures the submicroradian accuracy of the system and allows the user to measure large surfaces with a submillimetric spatial resolution. We particularly emphasize on the calibration method of the head; this method is validated by characterizing a super-flat reference mirror. Cross-checked tests with the Soleil's long-trace profiler are also performed. The high precision of profilometric head has been validated with the characterization of a spherical mirror. We also emphasize on the large curvature dynamic range of the instrument with the measurement of an X-ray toric mirror. The instrument, which performs a complete diagnostic of the surface or wavefront under test, finds its main applications in metrology (measurement of large optics/wafers, post-polishing control and local surface finishing for the industry, spatial quality control of laser beam).

  10. Concave gold nanocube assemblies as nanotraps for surface-enhanced Raman scattering-based detection of proteins.

    PubMed

    Matteini, Paolo; de Angelis, Marella; Ulivi, Lorenzo; Centi, Sonia; Pini, Roberto

    2015-02-28

    SERS detection of proteins is typically performed by using labeling agents with stable and high Raman scattering cross sections. This is a valuable approach for trace detection and quantification of a target protein but is unsuitable for inspecting its inherent structural and functional properties. On the other hand, direct SERS of proteins has been mainly devoted to the study of short peptides and aminoacid sequences or of prosthetic groups with intense Raman signals, which is of scarce interest for a thorough characterization of most proteins. Here we try to overcome these limitations by setting-up an effective platform for the structural SERS analysis of proteins. The platform consists of an extended bidimensional array of gold concave nanocubes (CNCs) supported on a PDMS film. CNCs are closely-packed through face-face and face-corner interactions generating a monolayered arrangement featuring well distributed nanoholes. Here the protein homogeneously experiences an E-field enhancement outward from the metal surfaces surrounding it, which causes a large number of vibrations to be contemporarily amplified. The proposed platform provides stable and detailed SERS spectra and confers rapidity and reproducibility to the analysis. PMID:25563172

  11. He I Spectropolarimetry with FIRS: Towards Vector Magnetometry of Chromospheric Fibrils Plus New Diagnostics of Coronal Rain

    NASA Astrophysics Data System (ADS)

    Schad, T. A.; Penn, M. J.; Lin, H.; Tritschler, A.

    2012-12-01

    At the Dunn Solar Telescope, the Interferometric Bidimensional Spectrometer (IBIS) can measure the full Stokes vector of the Ca II 854.2 nm spectral line while the Facility Infrared Spectropolarimeter (FIRS) measures the Stokes vector of the He I triplet at 1083 nm. We analyze the He I triplet observed in two widely different features above NOAA AR 11295 on 19 September 2011 - thin (< 1″) chromospheric fibrils and a large-scale loop hosting a high-velocity coronal rain event. These two features are shown to first demonstrate the diagnostic potential of the He I triplet for magnetic fields in the chromosphere/transition region and second to stress the need to pair large-aperture facilities with flexible instrumentation. Inversions of the He I triplet near the penumbral boundary return azimuthal directions of the magnetic field aligned with fine-scale fibrils observed in the line core of Ca II. The coronal rain event shows Doppler velocities up to 195 km s-1, among the largest reported. We observe measurable polarization within the raining material, which may be a good magnetic diagnostic of chromospheric-like material higher in the corona within condensating loops.

  12. Burst propagation in Texas Helimak

    NASA Astrophysics Data System (ADS)

    Pereira, F. A. C.; Toufen, D. L.; Guimarães-Filho, Z. O.; Caldas, I. L.; Gentle, K. W.

    2016-05-01

    We present investigations of extreme events (bursts) propagating in the Texas Helimak, a toroidal plasma device in which the radial electric field can be changed by application of bias. In the experiments analyzed, a large grid of Langmuir probes measuring ion saturation current fluctuations is used to study the burst propagation and its dependence on the applied bias voltage. We confirm previous results reported on the turbulence intermittency in the Texas Helimak, extending them to a larger radial interval with a density ranging from a uniform decay to an almost uniform value. For our analysis, we introduce an improved procedure, based on a multiprobe bidimensional conditional averaging method, to assure precise determination of burst statistical properties and their spatial profiles. We verify that intermittent bursts have properties that vary in the radial direction. The number of bursts depends on the radial position and on the applied bias voltage. On the other hand, the burst characteristic time and size do not depend on the applied bias voltage. The bias voltage modifies the vertical and radial burst velocity profiles differently. The burst velocity is smaller than the turbulence phase velocity in almost all the analyzed region.

  13. Design, realization and test of a rad-hard 2D-compressor and packing chip for high energy physics experiments

    NASA Astrophysics Data System (ADS)

    Antinori, Samuele; Falchieri, Davide; Gabrielli, Alessandro; Gandolfi, Enzo

    2004-09-01

    CARLOSv3 is a third version of a chip that plays a significant role in the data acquisition chain of the A Large Ion Collider Experiment Inner Tracking System experiment. It has been designed and realized with a 0.25 μm CMOS 3-metal rad-hard digital library. The chip elaborates and compresses, by means of a bi-dimensional compressor, data belonging to a so-called event. The compressor looks for cross-shaped clusters within the whole data set coming from the silicon detector. To test the chip a specific PCB has been designed; it contains the connectors for probing the ASIC with a pattern generator and a logic state analyzer. The chip is inserted on the PCB using a ZIF socket. This allows to test the 35 packaged samples out of the total amount of bare chips we have from the foundry. The test phase has shown that 32 out of 35 chips under test work well. It is planned to redesign a new version of the chip by adding extra features and to submit the final version of CARLOS upon the final DAQ chain will be totally tested both in Bologna and at CERN.

  14. Proteomic analysis of the urine of Dirofilaria immitis infected dogs.

    PubMed

    Hormaeche, Marta; Carretón, Elena; González-Miguel, Javier; Gussoni, Stefania; Montoya-Alonso, José Alberto; Simón, Fernando; Morchón, Rodrigo

    2014-06-16

    Canine cardiopulmonary dirofilariosis caused by Dirofilaria immitis habitually develops as a chronic disease affecting pulmonary arteries, lung parenchyma and heart. Other organs like kidneys can also be involved. Renal pathology is a consequence of glomerulonephritis whose main sign is proteinuria. The aim of the present work is to identify proteins excreted in the urine of D. immitis infected dogs showing proteinuria, and the possible contribution of their loss to heartworm disease. Proteinuria is higher in microfilaremic (mf+) than in amicrofilaremic (mf-) dogs. Using bidimensional electrophoresis and mass spectrometry 9 different proteins from Canis lupus familiaris in the urine of both mf- and mf+ dogs were identified (serotransferrin isoform 6, serum albumin precursor, albumin, immunoglobulin gamma heavy chain D, apolipoprotein A-I, immunoglobulin lambda-like polypeptide 5-like, arginine esterase precursor, inmunoglobulin gamma heavy chain B and hemoglobin subunit alpha). Furthermore, 3 additional proteins were identified only in the urine of mf+ dogs, corresponding to dog fibrinogen alpha chain and immunoglobulin gamma heavy chain A and actin 2 homologous to a protein of Brugia malayi. The loss of these proteins and other in the urine of D. immitis infected dogs could affect the general condition of parasitized dogs through the interference in the cholesterol metabolism and O₂ transport, among other mechanisms. PMID:24566125

  15. Evaluation of a biomarker of Cd(II) exposure on Limnoperna fortunei.

    PubMed

    Mariano, Belaich; Cristian, Oliver; Marcela, Pilloff; Porta, Andrés

    2006-11-01

    The use of organisms to monitor contamination allows the access to information that cannot be acquired by chemical methods. Limnoperna fortunei, mussel frequently found in Río de la Plata estuary, fulfils the requirements to be used as a biomonitoring organism. In this work we report that a polypeptide of 22 kDa of molecular weight (LF22) is induced when L. fortunei is exposed to Cd (II), Cu(II) and Hg(II) sublethal levels. To characterize LF22, mussels were sampled from a non-polluted region and whole soft tissue was homogenized, with and without previous exposure to 100 microg/L of Cd(II). The cytosolic proteins were evaluated by mono and bidimensional SDS-PAGE, and size exclusion chromatography. All the methods showed that LF22 triples its concentration in presence of Cd(II). Purification of LF22 was achieved by fractioned precipitation, salting-out, ionic exchange and size exclusion chromatography. We conclude that LF22 is a useful biomarker of heavy metal exposure. PMID:16603290

  16. NATIVITY AND YEARS IN THE RECEIVING CULTURE AS MARKERS OF ACCULTURATION IN ETHNIC ENCLAVES

    PubMed Central

    SCHWARTZ, SETH J.; PANTIN, HILDA; SULLIVAN, SUMMER; PRADO, GUILLERMO; SZAPOCZNIK, JOSÉ

    2006-01-01

    The current study was conducted to ascertain the validity of two commonly used markers of acculturation (nativity and years in the receiving culture) in an enclave context. Relationships between these markers and a bidimensional measure of acculturation were examined in a convenience sample of Hispanic immigrant adolescents and their caregivers in Miami. Nativity was examined using adolescent-reported data; approximately half of the youth were U.S.-born and half foreign-born, but all of the caregivers were foreign-born. Years in the receiving culture was examined using both adolescent and caregiver data. Results indicated that nativity was significantly associated with adoption of receiving-culture practices, with a small to moderate effect size. Years in the receiving culture was significantly associated with adoption of receiving-culture practices only for adolescent girls and for female caregivers who immigrated as youth. Neither nativity nor years in the receiving culture explained even moderate amounts of variance in retention or loss of culture-of-origin practices. PMID:16799700

  17. Simulation of space charge compensation in a multibeamlet negative ion beam

    NASA Astrophysics Data System (ADS)

    Sartori, E.; Maceina, T. J.; Veltri, P.; Cavenago, M.; Serianni, G.

    2016-02-01

    Ion beam space charge compensation occurs by cumulating in the beam potential well charges having opposite polarity, usually generated by collisional processes. In this paper we investigate the case of a H- ion beam drift, in a bi-dimensional approximation of the NIO1 (Negative Ion Optimization phase 1) negative ion source. H- beam ion transport and plasma formation are studied via particle-in-cell simulations. Differential cross sections are sampled to determine the velocity distribution of secondary particles generated by ionization of the residual gas (electrons and slow H2+ ions) or by stripping of the beam ions (electrons, H, and H+). The simulations include three beamlets of a horizontal section, so that multibeamlet space charge and secondary particle diffusion between separate generation regions are considered, and include a repeller grid biased at various potentials. Results show that after the beam space charge is effectively screened by the secondary plasma in about 3 μs (in agreement with theoretical expectations), a plasma grows across the beamlets with a characteristic time three times longer, and a slight overcompensation of the electric potential is verified as expected in the case of negative ions.

  18. FEM modeling and histological analyses on thermal damage induced in facial skin resurfacing procedure with different CO2 laser pulse duration

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Zingoni, Tiziano; Di Cicco, Emiliano; Manetti, Leonardo; Pini, Roberto; Fortuna, Damiano

    2011-07-01

    Laser light is nowadays routinely used in the aesthetic treatments of facial skin, such as in laser rejuvenation, scar removal etc. The induced thermal damage may be varied by setting different laser parameters, in order to obtain a particular aesthetic result. In this work, it is proposed a theoretical study on the induced thermal damage in the deep tissue, by considering different laser pulse duration. The study is based on the Finite Element Method (FEM): a bidimensional model of the facial skin is depicted in axial symmetry, considering the different skin structures and their different optical and thermal parameters; the conversion of laser light into thermal energy is modeled by the bio-heat equation. The light source is a CO2 laser, with different pulse durations. The model enabled to study the thermal damage induced into the skin, by calculating the Arrhenius integral. The post-processing results enabled to study in space and time the temperature dynamics induced in the facial skin, to study the eventual cumulative effects of subsequent laser pulses and to optimize the procedure for applications in dermatological surgery. The calculated data where then validated in an experimental measurement session, performed in a sheep animal model. Histological analyses were performed on the treated tissues, evidencing the spatial distribution and the entity of the thermal damage in the collageneous tissue. Modeling and experimental results were in good agreement, and they were used to design a new optimized laser based skin resurfacing procedure.

  19. Evaluation of human hand thermal images using wavelet transform based local spatial features - biomed 2013.

    PubMed

    Suganthi, S S; Ramakrishnan, S

    2013-01-01

    Transform-based spatial analyses of medical Infrared (IR) images are found to be useful to extract local information, which can be used to identify the abnormalities associated with in region of interest. In this work, human hand infrared images are analyzed by extracting local spatial features using wavelet transform method. The images for this study were acquired using uncooled micro bolometer with focal plane array technology based medical IR camera with dedicated software having high array resolution and spectral response under controlled protocol. The acquired images were decomposed into Intrinsic Mode Functions (IMFs) using bidimensional empirical mode decomposition. Extrema points were detected using eight connected neighbor window method and interpolated using thin plate spline interpolation technique to generate IMFs. The edge information were extracted from local phase of the first IMF. Edges were detected using phase congruency measure by applying Gabor function based wavelet transform. The results showed that it was possible to detect edges from only the first IMF without being influenced by other IMFs. It was further observed that the edge intermittence that arises due to noise component was reduced by treating images with local phase distributions. Hence, it appears that the edge information extraction could enhance the diagnostic relevance of thermal image analysis. PMID:23686173

  20. Hydroconversion reactions catalyzed by highly stable pillared clays

    SciTech Connect

    Gomez, S.A.; Mosqueira, L.; Espinosa, J.; Fuentes, G.A.

    1993-12-31

    Al-pillared clays (Al-PILC) and Al-X-PILC (X = Ga, Ni), structurally stable at high temperature - in the case of Ga above 800{degrees}C-have been synthesized by controlling intercalation steps and stabilization procedures. New bidimensional materials with an interlaminar distance about 10-12{angstrom} and with different chemical reactivities in the pillars have thus been produced. The analytical techniques employed to characterize the materials and the processes involved during stabilization include N{sub 2} adsorption, AA, XRD, NH{sub 3}-TPD, TGA-DTA, HR- and MAS-NMR (Al, Si, and Ga) and in-situ IR and DRIFTS. Chemical characterization using high pressure reactions with probe molecules such as diphenylmethane and tert-butylbenzene shows selectivity patterns than can be clearly associated with the microstructure of the PILC used, as well as an effect due to the composition of the pillars. Similar studies with zeolites give patterns that differ from those of PILC, probably because of the change in dimensionality of the internal structure. Poisoning studies with metal porphyrins prove that PLIC have improved resistance compared to standard catalysts. Hydrotreatment of Maya crude results a significant reduction in total sulfur under conditions suitable for commercial operation.

  1. A robust large area x-ray imaging system based on 100 μ m thick Gas Electron Multiplier

    NASA Astrophysics Data System (ADS)

    Amaro, F. D.; Mir, J. A.; Carvalho, X.; Azevedo, C. D. R.; dos Santos, J. M. F.; Natal da Luz, H.

    2015-12-01

    We have developed an imaging detector based on a non-standard GEM, made from a 100 μ m thick kapton foil (2-fold thicker than standard GEM's). The 100 micron thick GEM is produced using the same wet etching technique as the standard GEM and is less prone to the damage caused by discharges, creating a robust detector that can safely operate at high gain. In this work we present the results obtained with a cascaded gaseous electron multiplier composed by two 100 micron thick GEM and a 10× 10 cm2 bi-dimensional readout electrode with resistive charge division. We have recorded energy resolution of 21% and charge gains above 104 when the detector was irradiated with 5.9 keV X-rays emitted by a 55Fe radioactive source. We also present 10× 10 cm2 images acquired with the detector when irradiated with X-rays. The minimum position resolution recorded was 1.7 mm.

  2. Design and Development of a Framework Based on Ogc Web Services for the Visualization of Three Dimensional Large-Scale Geospatial Data Over the Web

    NASA Astrophysics Data System (ADS)

    Roccatello, E.; Nozzi, A.; Rumor, M.

    2013-05-01

    This paper illustrates the key concepts behind the design and the development of a framework, based on OGC services, capable to visualize 3D large scale geospatial data streamed over the web. WebGISes are traditionally bounded to a bi-dimensional simplified representation of the reality and though they are successfully addressing the lack of flexibility and simplicity of traditional desktop clients, a lot of effort is still needed to reach desktop GIS features, like 3D visualization. The motivations behind this work lay in the widespread availability of OGC Web Services inside government organizations and in the technology support to HTML 5 and WebGL standard of the web browsers. This delivers an improved user experience, similar to desktop applications, therefore allowing to augment traditional WebGIS features with a 3D visualization framework. This work could be seen as an extension of the Cityvu project, started in 2008 with the aim of a plug-in free OGC CityGML viewer. The resulting framework has also been integrated in existing 3DGIS software products and will be made available in the next months.

  3. Synthesis and characterization of a new organic sulphate, [2,3-(CH{sub 3}){sub 2}C{sub 6}H{sub 3}NH{sub 3}]HSO{sub 4}·H{sub 2}O

    SciTech Connect

    Sahbani, T.; Smirani, W.; Al-Deyab, Salem S.; Rzaigui, M.

    2012-06-15

    Highlights: ► The packing of this hybrid compound shows strong and moderate non-centrosymmetrical structure. ► In all the studied temperature range, this conductivity increases with the temperature showing that this material has semi-conductor behaviour. ► The reported crystal could be an optically non-linear material. A study of this activity could open to it opportunities on applied plan. -- Abstract: Crystals of a new hybrid compound C{sub 8}H{sub 12}N{sup +}, HSO{sub 4}{sup −}·H{sub 2}O were synthesized in aqueous solution and characterized by X-ray diffraction and IR absorption spectroscopy. This compound crystallizes in the orthorhombic non-centrosymmetrical space group P2{sub 1}2{sub 1}2{sub 1} and an unit cell with a = 5.74(2) Å, b = 9.17(2) Å, c = 21.34(4) Å, V = 1124(6) Å{sup 3}, and Z = 4. Its crystal structure is a packing of alternated inorganic and organic layers parallel to (a,b) planes. The different components are connected by a bi-dimensional network of strong O-H…O and N-H…O hydrogen bonds. Then, in order to detect phase transitions and watch changes in the conductivity behaviour, investigations by DTA–TG and differential scanning calorimetry (DSC) and electrical conductivity measurements were carried out.

  4. Ellerman bombs—evidence for magnetic reconnection in the lower solar atmosphere

    SciTech Connect

    Nelson, C. J.; Doyle, J. G.; Madjarska, M. S.; Shelyag, S.; Mathioudakis, M.; Uitenbroek, H.; Erdélyi, R.

    2013-12-20

    The presence of photospheric magnetic reconnection has long been thought to give rise to short and impulsive events, such as Ellerman bombs (EBs) and Type II spicules. In this article, we combine high-resolution, high-cadence observations from the Interferometric BIdimensional Spectrometer and Rapid Oscillations in the Solar Atmosphere instruments at the Dunn Solar Telescope, National Solar Observatory, New Mexico, with co-aligned Solar Dynamics Observatory Atmospheric Imaging Assembly and Hinode Solar Optical Telescope (SOT) data to observe small-scale events situated within an active region. These data are then compared with state-of-the-art numerical simulations of the lower atmosphere made using the MURaM code. It is found that brightenings, in both the observations and the simulations, of the wings of the Hα line profile, interpreted as EBs, are often spatially correlated with increases in the intensity of the Fe I λ6302.5 line core. Bipolar regions inferred from Hinode/SOT magnetic field data show evidence of flux cancellation associated, co-spatially, with these EBs, suggesting that magnetic reconnection could be a driver of these high-energy events. Through the analysis of similar events in the simulated lower atmosphere, we are able to infer that line profiles analogous to the observations occur co-spatially with regions of strong opposite-polarity magnetic flux. These observed events and their simulated counterparts are interpreted as evidence of photospheric magnetic reconnection at scales observable using current observational instrumentation.

  5. A scintillating fiber dosimeter for radiotherapy

    NASA Astrophysics Data System (ADS)

    Bartesaghi, G.; Conti, V.; Bolognini, D.; Grigioni, S.; Mascagna, V.; Prest, M.; Scazzi, S.; Mozzanica, A.; Cappelletti, P.; Frigerio, M.; Gelosa, S.; Monti, A.; Ostinelli, A.; Giannini, G.; Vallazza, E.

    2007-10-01

    Radiotherapy, together with chemotherapy and surgery, is one of the main methods applied in the fight against cancer; in order to increase the chances of a successful radiotherapy treatment the dose delivery to the tumor and the surrounding normal tissues has to be computed with high accuracy. Traditional dosimeters are accurate but single channel (ionization chambers and diodes) or non real-time (radiographic films) devices. At present there is no device water equivalent that can perform real-time and bidimensional measurements of a dose distribution. This article describes the development of a real-time dosimeter based on scintillating fibers for photon and electron beams; the fibers are made of polystyrene, that is water equivalent and thus tissue equivalent, allowing a direct dose calculation. Three prototypes (single and multichannel) have been assembled, consisting in small scintillators coupled to white fibers that carry the light to photomultiplier tubes. In this article the prototypes and the readout electronics are described, together with the results of the measurements with electron and photon beams with energy up to 20 MeV (produced by linear accelerators Varian Clinac 1800 and 2100CD).

  6. Emotion expression in body action and posture.

    PubMed

    Dael, Nele; Mortillaro, Marcello; Scherer, Klaus R

    2012-10-01

    Emotion communication research strongly focuses on the face and voice as expressive modalities, leaving the rest of the body relatively understudied. Contrary to the early assumption that body movement only indicates emotional intensity, recent studies have shown that body movement and posture also conveys emotion specific information. However, a deeper understanding of the underlying mechanisms is hampered by a lack of production studies informed by a theoretical framework. In this research we adopted the Body Action and Posture (BAP) coding system to examine the types and patterns of body movement that are employed by 10 professional actors to portray a set of 12 emotions. We investigated to what extent these expression patterns support explicit or implicit predictions from basic emotion theory, bidimensional theory, and componential appraisal theory. The overall results showed partial support for the different theoretical approaches. They revealed that several patterns of body movement systematically occur in portrayals of specific emotions, allowing emotion differentiation. Although a few emotions were prototypically expressed by one particular pattern, most emotions were variably expressed by multiple patterns, many of which can be explained as reflecting functional components of emotion such as modes of appraisal and action readiness. It is concluded that further work in this largely underdeveloped area should be guided by an appropriate theoretical framework to allow a more systematic design of experiments and clear hypothesis testing. PMID:22059517

  7. Antifungal Metabolites from the Roots of Diospyros virginiana by Overpressure Layer Chromatography

    PubMed Central

    Wang, Xiaoning; Habib, Eman; León, Francisco; Radwan, Mohamed M.; Tabanca, Nurhayat; Gao, Jiangtao

    2011-01-01

    A preparative overpressure layer chromatography (OPLC) method was successfully used for the separation of two new natural compounds, 4-hydroxy-5,6-dimethoxy-2-naphthaldehyde (1) and Δ12,13-20,29-dihydrobetulin (2) together with nine known compounds including 7-methyl-juglone (3), diospyrin (4), isodiospyrin (5), shinanolone (6), lupeol (7), betulin (8), betulinic acid (9), betulinaldehyde (10), and ursolic acid (11) from the acetone extract of the roots of Diospyros virginiana. Their identification was performed with mono and bidimensional NMR spectroscopy and HR-ESI-MS methods. All the isolated compounds were evaluated for their antifungal activity against Colletotrichum fragariae, C. gloeosporioides, C. acutatum, Botrytis cinerea, Fusarium oxysporum, Phomopsis obscurans, and P. viticola using in vitro micro-dilution broth assay. The results indicated that compounds 3 and 5 showed high antifungal activity against P. obscurans at 30 μM with 97.0 % and 81.4 % growth inhibition and moderate activity against P. viticola (54.3 % and 36.6 %). It appears that an optimized OPLC system offers a rapid and efficient method of exploiting bioactive natural products. PMID:22162171

  8. A New MAP Kinase Protein Involved in Estradiol-Stimulated Reproduction of the Helminth Parasite Taenia crassiceps

    PubMed Central

    Escobedo, Galileo; Soldevila, Gloria; Ortega-Pierres, Guadalupe; Chávez-Ríos, Jesús Ramsés; Nava, Karen; Fonseca-Liñán, Rocío; López-Griego, Lorena; Hallal-Calleros, Claudia; Ostoa-Saloma, Pedro; Morales-Montor, Jorge

    2010-01-01

    MAP kinases (MAPK) are involved in the regulation of cellular processes such as reproduction and growth. In parasites, the role of MAPK has been scarcely studied. Here, we describe the participation of an ERK-like protein in estrogen-dependent reproduction of the helminth parasite Taenia crassiceps. Our results show that 17β-estradiol induces a concentration-dependent increase in the bud number of in vitro cultured cysticerci. If parasites are also incubated in presence of an ERK-inhibitor, the stimulatory effect of estrogen is blocked. The expression of ERK-like mRNA and its corresponding protein was detected in the parasite. The ERK-like protein was over-expressed by all treatments. Nevertheless, a strong induction of phosphorylation of this protein was observed only in response to 17β-estradiol. Cross-contamination by host cells was discarded by flow cytometry analysis. Parasite cells expressing the ERK-like protein were exclusively located at the subtegument tissue by confocal microscopy. Finally, the ERK-like protein was separated by bidimensional electrophoresis and then sequenced, showing the conserved TEY activation motif, typical of all known ERK 1/2 proteins. Our results show that an ERK-like protein is involved in the molecular signalling during the interaction between the host and T. crassiceps, and may be considered as target for anti-helminth drugs design. PMID:20145710

  9. Separation of Highly Complex Mixtures by Two-Dimension Liquid Chromatography

    SciTech Connect

    Georges Guiochon

    2009-12-11

    This report summarizes the progress made on the title project during the grant period. We developed a new classification of two-dimensional separations based on the observation that separations can be made in time or in space. Thus, two-dimensional separations can be made in time×time, space×space, space×time, or time×space. The two successive separations must use two different modes of chromatography that afford uncorrelated or weakly correlated patterns of retention factors for the components of the samples analyzed. Our attention was mainly focused on the separation of protein digests, particularly, on those of the digests of myoglobin and bovine serum albumin as model systems and extremely efficient temporal separations were developed. We also designed and constructed new instruments to carry out space×space separations (True Bidimensional Chromatography, HPLC2 or spacial separations) and time×space separations (a new hybrid combination of a temporal and a spacial separation that we designed).

  10. The University of Bern Atmospheric Ion Model: Time-dependent modeling of the ions in the mesosphere and lower thermosphere

    NASA Astrophysics Data System (ADS)

    Kazil, Jan; Kopp, Ernest; Chabrillat, Simon; Bishop, James

    2003-07-01

    In this paper the first time-dependent model of ion chemistry in the mesosphere/lower thermosphere (MLT) region acting within a global, time-dependent, two-dimensional neutral atmosphere model is described. Selected diurnal results are presented for undisturbed solar minimum conditions. The University of Bern Atmospheric Ion Model (UBAIM) is a time-dependent, pseudo-two-dimensional model of the ion chemistry in the Earth atmosphere. It covers latitudes from 85°S to 85°N and (log-pressure) altitudes from 20 to 120 km. On this grid a system of differential equations describing the ion chemistry is integrated numerically until a periodical solution, governed by the diurnal changes in the incident radiation, is reached; this solution constitutes a model for quiet or undisturbed conditions. The basic ion chemistry of the UBAIM contains 311 reactions for 71 charged species. Ionization sources are solar X-ray and EUV radiation, resonantly scattered Lyman α and β photons, and galactic cosmic rays. Densities of main and trace neutral atmospheric constituents are taken from a new version of the bidimensional NCAR model SOCRATES, which has been specifically optimized for mesospheric and lower thermospheric processes with upper boundary conditions set using the empirical MSIS thermosphere model. Direct solar flux inputs are computed by the SOLAR2000 model; scattered Lyman α and β fluxes are calculated using geocoronal hydrogen density profiles consistent with the adopted MSIS density distributions.

  11. [Aortic intramural hematoma. An atypical pattern equivalent to aortic dissection].

    PubMed

    López-Mínguez, J R; Merchán, A; Arrobas, J; Fernández, G; González-Egüaras, M; García-Andoaín, J M; Alonso, M; Gamero, C; Poblador, M A; Alonso, F

    1995-09-01

    A case is presented of a hypertensive woman who had suffered a stabbing back pain for some three hours, with mild irradiation to precordium and accompanied by vegetative signs. A sinusal rhythm and negative T waves of little depth were seen on the ECG. A transthoracic bidimensional echocardiogram (TTE) showed a normal left ventricle with a somewhat dilated aortic root and the existence of a double echo running parallel to the anterior wall of the aorta but non-ondulating and without a visible intimal flap. Because of suspected aortic dissection an urgent contrasted CAT and a transesophageal echocardiogram were performed. These were informed as an aneurysm of the aortic root with mural thrombus from the ascending to descending aorta, but with no existing intimal flap suggesting dissection. A cardiac catheterization showed a mildly some dilated aortic root without dissection signs and normal left ventricle and coronary arteries. The patient was presented for surgical evaluation but, since no dissection was present, was not considered urgent surgery; she was admitted to the coronary unit and died 48 hours later in a situation of acute pericardial tamponade, documented by TTE, surely due to rupture of the aortic root to pericardial sack. This way of presenting threatened aorta rupture that has been only recently recognized is discussed, as well as some misconceptions which must be avoided. PMID:7569267

  12. Clustering and flow around a sphere moving into a grain cloud.

    PubMed

    Seguin, A; Lefebvre-Lepot, A; Faure, S; Gondret, P

    2016-06-01

    A bidimensional simulation of a sphere moving at constant velocity into a cloud of smaller spherical grains far from any boundaries and without gravity is presented with a non-smooth contact dynamics method. A dense granular "cluster" zone builds progressively around the moving sphere until a stationary regime appears with a constant upstream cluster size. The key point is that the upstream cluster size increases with the initial solid fraction [Formula: see text] but the cluster packing fraction takes an about constant value independent of [Formula: see text]. Although the upstream cluster size around the moving sphere diverges when [Formula: see text] approaches a critical value, the drag force exerted by the grains on the sphere does not. The detailed analysis of the local strain rate and local stress fields made in the non-parallel granular flow inside the cluster allows us to extract the local invariants of the two tensors: dilation rate, shear rate, pressure and shear stress. Despite different spatial variations of these invariants, the local friction coefficient μ appears to depend only on the local inertial number I as well as the local solid fraction, which means that a local rheology does exist in the present non-parallel flow. The key point is that the spatial variations of I inside the cluster do not depend on the sphere velocity and explore only a small range around the value one. PMID:27339702

  13. Nonequilibrium Equation of State in Suspensions of Active Colloids

    NASA Astrophysics Data System (ADS)

    Ginot, Félix; Theurkauff, Isaac; Levis, Demian; Ybert, Christophe; Bocquet, Lydéric; Berthier, Ludovic; Cottin-Bizonne, Cécile

    2015-01-01

    Active colloids constitute a novel class of materials composed of colloidal-scale particles locally converting chemical energy into motility, mimicking micro-organisms. Evolving far from equilibrium, these systems display structural organizations and dynamical properties distinct from thermalized colloidal assemblies. Harvesting the potential of this new class of systems requires the development of a conceptual framework to describe these intrinsically nonequilibrium systems. We use sedimentation experiments to probe the nonequilibrium equation of state of a bidimensional assembly of active Janus microspheres and conduct computer simulations of a model of self-propelled hard disks. Self-propulsion profoundly affects the equation of state, but these changes can be rationalized using equilibrium concepts. We show that active colloids behave, in the dilute limit, as an ideal gas with an activity-dependent effective temperature. At finite density, increasing the activity is similar to increasing adhesion between equilibrium particles. We quantify this effective adhesion and obtain a unique scaling law relating activity and effective adhesion in both experiments and simulations. Our results provide a new and efficient way to understand the emergence of novel phases of matter in active colloidal suspensions.

  14. Optical Coherence Tomography Angiography in Healthy Subjects.

    PubMed

    Coscas, Gabriel; Lupidi, Marco; Coscas, Florence

    2016-01-01

    Fluorescein angiography and indocyanine green angiography provide information about normal retinal and choroidal anatomy that is nearly comparable to histological findings. These results are absolutely fundamental for the evaluation of retinal and choroidal vascular diseases and allow the clinician to define and diagnose several pathological conditions. Fluorescein angiography has become the 'gold standard' in retinal imaging due to its capacity to allow visualization of the retinal capillary bed and its changes, particularly in the macular area. Although the fluorescence of the injected dye enables improved visualization of retinal capillaries, not all of the different layers of the retinal capillary network can be visualized using this bi-dimensional examination technique, possibly because of a light scattering phenomenon. Optical coherence tomography angiography allows depth-resolved visualization of the retinal and choroidal microvasculature by calculating the difference between static and nonstatic tissue. Given that the main moving elements in the eye fundus are contained within vessels, determining a vascular decorrelation signal enables three-dimensional visualization of the retinal and choroidal vascular network without the administration of intravenous dye and therefore reduces the risk of potential adverse events. PMID:27023473

  15. Zeroing In on Mindfulness Facets: Similarities, Validity, and Dimensionality across Three Independent Measures

    PubMed Central

    Siegling, Alex B.; Petrides, K. V.

    2016-01-01

    The field of mindfulness has seen a proliferation of psychometric measures, characterised by differences in operationalisation and conceptualisation. To illuminate the scope of, and offer insights into, the diversity apparent in the burgeoning literature, two distinct samples were used to examine the similarities, validity, and dimensionality of mindfulness facets and subscales across three independent measures: the Five Facet Mindfulness Questionnaire (FFMQ), Philadelphia Mindfulness Scale (PHLMS), and Toronto Mindfulness Scale (TMS). Results revealed problematic associations of FFMQ Observe with the other FFMQ facets and supported a four-factor structure (omitting this facet), while disputing the originally envisaged five-factor model; thus, solidifying a pattern in the literature. Results also confirmed the bidimensional nature of the PHLMS and TMS subscales, respectively. A joint Confirmatory Factor Analysis showed that PHLMS Acceptance could be assimilated within the FFMQ’s four-factor model (as a distinct factor). The study offers a way of understanding interrelationships between the available mindfulness scales, so as to help practitioners and researchers make a more informed choice when conceptualising and operationalising mindfulness. PMID:27055017

  16. Core Self-Evaluations Mediate the Associations of Dispositional Optimism and Life Satisfaction

    PubMed Central

    Jiang, Haipeng; Yu, Lili; Liu, Wenbo; Li, Qiang; Zuo, Luning

    2014-01-01

    Background Positive traits, such as life satisfaction, optimism, and core self-evaluation (CSE), have garnered increasing attention from researchers and professionals. However, the trilateral relationship among them remains unclear. Objective This study examines the effect of dispositional optimism on life satisfaction and primarily verified the mediator role of CSEs. Methods Six hundred thirty college students from two general universities completed a questionnaire packet containing life orientation test–revised (LOT–R), core self-evaluations, and satisfaction with life scale. Confirmatory factor analysis (CFA) was conducted to assess the dimension of LOT–R. Bootstrap was used in structural equation modeling to analyze mediation effect. Results Results revealed that dispositional optimism and core self-evaluations were significantly correlated with life satisfaction. CFA identified the bidimensional structure of dispositional optimism. SEM indicated that core self-evaluations partially mediated the effect of dispositional optimism on life satisfaction. The final model also revealed significant paths from optimism and pessimism to life satisfaction through core-self evaluations. Conclusion The findings extended prior studies and shed light on how dispositional optimism influences life satisfaction. This study provides valuable evidence on how to promote the life satisfaction of human beings in positive psychology. A further study can fully explore the relationship among them in multi-cultural follow-up studies. PMID:24911367

  17. ASIC-based architecture for the real-time computation of 2D convolution with large kernel size

    NASA Astrophysics Data System (ADS)

    Shao, Rui; Zhong, Sheng; Yan, Luxin

    2015-12-01

    Bidimensional convolution is a low-level processing algorithm of interest in many areas, but its high computational cost constrains the size of the kernels, especially in real-time embedded systems. This paper presents a hardware architecture for the ASIC-based implementation of 2-D convolution with medium-large kernels. Aiming to improve the efficiency of storage resources on-chip, reducing off-chip bandwidth of these two issues, proposed construction of a data cache reuse. Multi-block SPRAM to cross cached images and the on-chip ping-pong operation takes full advantage of the data convolution calculation reuse, design a new ASIC data scheduling scheme and overall architecture. Experimental results show that the structure can achieve 40× 32 size of template real-time convolution operations, and improve the utilization of on-chip memory bandwidth and on-chip memory resources, the experimental results show that the structure satisfies the conditions to maximize data throughput output , reducing the need for off-chip memory bandwidth.

  18. Room-Temperature AlGaN/GaN Terahertz Plasmonic Detectors with a Zero-Bias Grating

    NASA Astrophysics Data System (ADS)

    Spisser, H.; Grimault-Jacquin, A.-S.; Zerounian, N.; Aassime, A.; Cao, L.; Boone, F.; Maher, H.; Cordier, Y.; Aniel, F.

    2016-03-01

    In this paper, we present sensitivity measurement as well as measured and calculated absorption spectra for AlGaN/GaN THz plasmonic detector made of a metallic grating in-between two ohmic contacts. Detectors with different grating patterns have been fabricated and their sensitivity, reaching 1.9 μA/W at 77 K and 0.7 μA/W at 300 K, measured with a voltage applied between the ohmic contacts. It is the first time that such a detector shows THz detection with no voltage applied on the grating, namely with a bidimensional electron gas (2DEG) having a homogeneous electron density. These results are consistent with detection by drag-effect rectification. Measurements held between 0.648 and 0.690 THz show that the dependence of the sensitivity on the frequency follows the absorption spectrum, indicating that absorption is a crucial step in the detection process. Further simulations of absorption spectra show the tunability offered by such detector and allow us to predict frequency behavior for grating-biased detectors as well, in which the rectification is mainly governed by ratchet effect.

  19. He I VECTOR MAGNETOMETRY OF FIELD-ALIGNED SUPERPENUMBRAL FIBRILS

    SciTech Connect

    Schad, T. A.; Penn, M. J.; Lin, H.

    2013-05-10

    Atomic-level polarization and Zeeman effect diagnostics in the neutral helium triplet at 10830 A in principle allow full vector magnetometry of fine-scaled chromospheric fibrils. We present high-resolution spectropolarimetric observations of superpenumbral fibrils in the He I triplet with sufficient polarimetric sensitivity to infer their full magnetic field geometry. He I observations from the Facility Infrared Spectropolarimeter are paired with high-resolution observations of the H{alpha} 6563 A and Ca II 8542 A spectral lines from the Interferometric Bidimensional Spectrometer from the Dunn Solar Telescope in New Mexico. Linear and circular polarization signatures in the He I triplet are measured and described, as well as analyzed with the advanced inversion capability of the ''Hanle and Zeeman Light'' modeling code. Our analysis provides direct evidence for the often assumed field alignment of fibril structures. The projected angle of the fibrils and the inferred magnetic field geometry align within an error of {+-}10 Degree-Sign . We describe changes in the inclination angle of these features that reflect their connectivity with the photospheric magnetic field. Evidence for an accelerated flow ({approx}40 m s{sup -2}) along an individual fibril anchored at its endpoints in the strong sunspot and weaker plage in part supports the magnetic siphon flow mechanism's role in the inverse Evershed effect. However, the connectivity of the outer endpoint of many of the fibrils cannot be established.

  20. Biomechanics of front and back squat exercises

    NASA Astrophysics Data System (ADS)

    Braidot, A. A.; Brusa, M. H.; Lestussi, F. E.; Parera, G. P.

    2007-11-01

    Squat constitutes one of the most popular exercises to strengthen the muscles of the lower limbs. It is considered one of the most widely spread exercises for muscle sport training and is part of the competition movements comprised within olympic weight-lifting. In physical rehabilitation, squats are used for muscular recovery after different injuries of the lower limbs, especially the knee. In previous anterior cruciate ligament injuries, the mini-squats are generally used, in a knee flexion motion range from 0° to 50° because in this range the shear forces, the tibiofemoral and patellofemoral compression forces decrease related to greater flexion angles. The aim of this work is to make a comparative bidimensional study of the kinematic and dynamic variables of the excecution of the parallel squat exercise with the front and back bar. It is observed in the knee a better development of energy with the front bar, allowing a better muscular exercise with the same load. The mean power absorbed by the hip with the back bar is considerably greater, associated to the speed of the gesture.

  1. Effects of satellite data resolution on measuring the space/time variations of surfaces and clouds

    NASA Technical Reports Server (NTRS)

    Seze, Genevieve; Rossow, William B.

    1991-01-01

    The correlated distributions of satellite-measured visible and infrared radiances, caused by spatial and temporal variations in clouds and surfaces, have been found to be characteristic of the major climate regimes and can be described by the attributes of bidimensional and monodimensional histograms and time-composite images. Most of the variability of both the surfaces and clouds is found to occur at scales larger than the minimum resolved by satellite imagery. Since satellite imaging data sets are difficult to analyze because of their large volumes, many studies reduce the volume by various sampling or averaging schemes. The effects of data resolution and sampling on the radiance histogram statistics and on the time-composite image characteristics are examined. In particular, the sampling strategy used by the International Satellite Cloud Climatology Project is tested. This sampling strategy is found to preserve the statistics of smaller cloud variations for most regions, with the exception of very rare events, if they are accumulated over large enough areas (at least 500 km in dimension) and long enough time periods (at least one month).

  2. Production and Transfer of Energy and Information in Hamiltonian Systems

    PubMed Central

    Antonopoulos, Chris G.; Bianco-Martinez, Ezequiel; Baptista, Murilo S.

    2014-01-01

    We present novel results that relate energy and information transfer with sensitivity to initial conditions in chaotic multi-dimensional Hamiltonian systems. We show the relation among Kolmogorov-Sinai entropy, Lyapunov exponents, and upper bounds for the Mutual Information Rate calculated in the Hamiltonian phase space and on bi-dimensional subspaces. Our main result is that the net amount of transfer from kinetic to potential energy per unit of time is a power-law of the upper bound for the Mutual Information Rate between kinetic and potential energies, and also a power-law of the Kolmogorov-Sinai entropy. Therefore, transfer of energy is related with both transfer and production of information. However, the power-law nature of this relation means that a small increment of energy transferred leads to a relatively much larger increase of the information exchanged. Then, we propose an “experimental” implementation of a 1-dimensional communication channel based on a Hamiltonian system, and calculate the actual rate with which information is exchanged between the first and last particle of the channel. Finally, a relation between our results and important quantities of thermodynamics is presented. PMID:24586891

  3. Ab initio study of the buckling on silicene and germanene

    NASA Astrophysics Data System (ADS)

    Martinez-Guerra, Edgar; Hernández, Karla; Cifuentes-Quintal, Eduardo; de Coss, Romeo

    2013-03-01

    Recently, a new graphene-like silicon structure was discovered: silicene. Since its discovery, silicene has been more exciting than graphene because this is a semiconductor and it should be compatible with silicon-based electronic. Silicon and germanium atoms have similar electronic configurations as those of carbon and this the reason that the bandstructure of silicene and germacene exhibits the Dirac cones at K point, with a very similar linear dispersion around it, like in graphene. The disvintage is that sp2 bonded Si is much less stable than for carbon resulting that to be stable in the planar layer their atoms must buckle. In this work, we calculated the sp character on silicene and germacene to correlate its hibridization with the velocity of electrons and holes at Dirac cones. The calculations were performed using the pseudopotential LCAO method with GGA for the exchange-correlation energy functional. The buckling of silicene and germacene layer was 0.50 and 0.69 Å, respectively. In addition, the sp- character of silicene and germacene buckled was 2.33 and 2.64, respectively. Thus, a detailed analysis on the electronic band structure of these system show that as sp character goes from sp2 to sp3 it is correlated with a decrease of velocity of electrons and holes at Dirac cones. This study is primarly important and it could address a new future to modulate carrier velocities on bidimensional systems. This research was supported by Conacyt under Grant No. 133022.

  4. Two qutrits universal quantum gates from the nine-dimensional unitary solutions of the Yang-Baxter equation

    NASA Astrophysics Data System (ADS)

    Vélez, Mario; Ospina, Juan

    2007-04-01

    Using the Kauffman-Lomonaco method, some two-qutrits universal quantum gates are derived from the nine-dimensional unitary solutions of the Yang-Baxter equations associated with algebraic structures like the partial transpose operator and the dihedral group, which admit three dimensional representations. The Yang-Baxterization method given by Zhang-Kauffman-Ge is continuously used to obtain two-qutrits quantum gates and certain Hamiltonians for the evolution of the quantum gates are obtained, being such Hamiltonians interpreted as physical Hamiltonians of chain of particles of spin 1. Finally, the generalization for systems of two qudits is presented in the case of Yang-Baxterization of representations of braided monoidal algebra like the BH algebra and the bicolored Birman-Wenzl-Muraki algebra. For these algebras the corresponding two-qudits quantum gates are constructed jointly with the associated Hamiltonians interpreted like physical chains of particles with spin d. It is conjectured that the derived two-qdits quantum gates and the Hamiltonians may be implemented over bi-dimensional lattice systems like anyons systems or more generally over any physical systems ruled by the Yang-Baxter equations.

  5. Modeling the temperature rise during diode laser welding of the cornea

    NASA Astrophysics Data System (ADS)

    Rossi, F. E.; Pini, Roberto

    2005-04-01

    We present the results of a model describing the temperature rise in the cornea during low power diode laser welding of the stroma to induce the repair of corneal wounds. A bi-dimensional model of the anterior segment of the porcine eye was developed. A full thickness corneal cut was considered to be filled by a solution of Indocyanine Green (ICG) in distilled water, which is used to topically enhance the optical absorption of the corneal stroma at the diode laser emission wavelength (810 nm). The typical irradiation conditions used for laser-induced suturing in the transplant of the cornea were considered. The Finite Element Method was used to solve the bio-heat equation inside the cornea wound by using the proper thermal parameters of porcine ocular tissues, providing the thermal response during and shortly after laser treatment. Results indicated a relatively modest temperature increase (of about 20°C), that was spatially confined within the region stained by the chromophore. Calculation of the Arrhenius integral showed no significant thermal damage in the region of the laser-treated wound, thus supporting our previous experimental observations and histological examinations performed on animal models.

  6. Image-Based Analysis to Predict the Activity of Tariquidar Analogs as P-Glycoprotein Inhibitors: The Importance of External Validation.

    PubMed

    Shayanfar, Shadi; Shayanfar, Ali; Ghandadi, Morteza

    2016-02-01

    Permeability glycoprotein (P-gp) is involved in the pathology of various diseases including cancer and epilepsy, mainly through the translocation of some medicines across the cell membrane. Here, we employed image-based quantitative structure-activity relationship (QSAR) models to predict the P-gp inhibitory activity of some Tariquidar derivatives. The structures of 65 Tariquidar derivatives and their P-gp inhibition activities were collected from the literature. For each compound, the pixels of bidimensional images and their principal components (PCs) were calculated using MATLAB software. Various statistical methods including principal component regression, artificial neural networks, and support vector machines were employed to investigate the correlation between the PCs and the activity of the compounds. The predictability of the models was investigated using external validation and applicability domain analysis. An artificial neural network-based model demonstrated the best prediction results for the test set. Moreover, external validation analysis of the developed models supports the idea that R(2) cannot assure the validity of QSAR models and another criterion, i.e., the concordance correlation coefficient (CCC) parameter, should be involved to evaluate the validity of the QSAR models. The results of this study indicate that image analysis could be as suitable as descriptors calculated by commercial software to predict the activity of drug-like molecules. PMID:26708190

  7. Epileptic qualia and self-awareness: a third dimension for consciousness.

    PubMed

    Hanoğlu, Lütfü; Özkara, Çiğdem; Yalçiner, Betül; Nani, Andrea; Cavanna, Andrea E

    2014-01-01

    Over the last few decades, there has been increasing awareness among epileptologists about the need to refine our understanding and assessment of ictal consciousness, focusing on both subjective and behavioral aspects of seizures. Specifically, there have been suggestions that both the internal and external milieux - the former related to the phenomenal qualia of experience, the latter related to behavior - must be taken into account for a better understanding of altered states of consciousness in epilepsy. It has been proposed that clinical and experimental data from patients experiencing alterations of consciousness during epileptic seizures could be better understood within a bidimensional model, in which any manifestation of conscious experience can be plotted according to the level and contents of consciousness. The 'level' axis measures the degree of alertness/arousal, whereas the 'contents' axis measures the vividness of specific experiential phenomena reported by the patient. We argue that certain seizure types might require more rigorous conceptual models for their characterization, and we highlight the potential usefulness of a more refined framework which includes a further dimension related to the 'self', in addition to those of 'level' and 'contents'. This model could be visualized in a three-dimensional space to allow fine-grained distinctions between epileptic seizures. PMID:24100248

  8. Computational study of the mechanism of half-reactions in class 1A dihydroorotate dehydrogenase from Trypanosoma cruzi.

    PubMed

    Silva, Natália de Farias; Lameira, Jerônimo; Alves, Cláudio Nahum; Martí, Sergio

    2013-11-21

    Chagas' disease is considered to be a health problem affecting millions of people in Latin America. This disease is caused by the parasite Trypanosoma cruzi. Recently dihydroorotate dehydrogenase class 1A from Trypanosoma cruzi (TcDHODA) was shown to be essential for the survival and growth of T. cruzi and proposed as a drug target against Chagas' disease. This enzyme catalyzes the oxidation of (S)-dihydroorotate to orotate, with a proposed catalytic cycle consisting of two half-reactions. In the first half-reaction dihydroorotate is oxidized to orotate, with the consequent reduction of the flavin mononucleotide cofactor. In the second half-reaction fumarate is reduced to succinate. The first oxidation half-reaction may occur via a concerted or a stepwise mechanism. Herein, the catalytic mechanism of TcDHODA has been studied using hybrid Quantum Mechanical/Molecular Mechanical (QM/MM) Molecular Dynamics (MD) simulations. The free energy profiles derived from the bidimensional potential of mean force reveal more details for two half-reaction processes. PMID:24084894

  9. [Immune complex glomerulonephritis associated with pulmonary tuberculosis].

    PubMed

    Villar, I; Hernández, E; Cozzi, J; Paletta, C; Mathurín, S

    1994-01-01

    A 32 year old man was admitted for dyspnea, hemoptysis, macroscopic hematuria, hypertension (140/100), peripheral edema and hemodynamic decompensation. Lung Xrays revealed pulmonary edema and a cavity in the left apex. Laboratory determinations revealed an altered renal function with increased creatinine and urea levels and nephrotic syndrome. There was leucocyturia, hematuria and cylindruria. The sputum showed a large number of acid-fast bacilli. The patient began anti-tuberculosis treatment with three drugs (isoniacid, rifampicin, pirazinamide). On ultrasonography, both kidneys revealed ecogenic lesions with size, shape and cortico-medular relationship preserved. The patient persisted with altered renal function, steady levels of urea nitrogen, creatinine and potassium, preserved diuresis and hypertension. Bidimensional echocardiogram: LVDD 55 mm, hypoquinetic septum, pericardic effusion, thickened pericardium, pleural effusion, shortening fraction decreased. He received treatment for this congestive cardiac failure and hypertension with enalapril, nifedipine and fursemide. A percutaneous renal biopsy was performed with anatomopathologic diagnosis of diffuse encocapillar proliferative glomerulonephritis with crescents (15%) and total glomerular sclerosis (33%). Immunofluorescence: positive, immune-complexes with IgM and C3. The patient gradually recovered his normal renal function, improved his pleural effusions and normalized his cardiac function. He was discharged in good clinical condition on the 69th day of anti-tuberculosis treatment. An association between pulmonary tuberculosis and glomerulonephritis is discussed. It is proposed that renal lesions might be the consequence of the tuberculosis due to the sedimentation of circulating immune-complexes. PMID:7854090

  10. Exploring the Shift in Structure and Function of Microbial Communities Performing Biological Phosphorus Removal

    PubMed Central

    Mao, Yanping; Wang, Zhiping; Li, Liguan; Jiang, Xiaotao; Zhang, Xuxiang; Ren, Hongqiang; Zhang, Tong

    2016-01-01

    A sequencing batch reactor fed mainly by acetate was operated to perform enhanced biological phosphorus removal (EBPR). A short-term pH shock from 7.0 to 6.0 led to a complete loss of phosphate-removing capability and a drastic change of microbial communities. 16S rRNA gene pyrosequencing showed that large proportions of glycogen accumulating organisms (GAOs) (accounted for 16% of bacteria) bloomed, including Candidatus Competibacter phosphatis and Defluviicoccus-related tetrad-forming organism, causing deteriorated EBPR performance. The EBPR performance recovered with time and the dominant Candidatus Accumulibacter (Accumulibacter) clades shifted from Clade IIC to IIA while GAOs populations shrank significantly. The Accumulibacter population variation provided a good opportunity for genome binning using a bi-dimensional coverage method, and a genome of Accumulibacter Clade IIC was well retrieved with over 90% completeness. Comparative genomic analysis demonstrated that Accumulibacter clades had different abilities in nitrogen metabolism and carbon fixation, which shed light on enriching different Accumulibacter populations selectively. PMID:27547976

  11. Anisotropy on the collective dynamics of water confined in swelling clay minerals.

    PubMed

    Jiménez-Ruiz, M; Ferrage, E; Delville, A; Michot, L J

    2012-03-15

    Collective excitations of water confined in the interlayer space of swelling clay minerals were studied by means of inelastic neutron scattering. The effect of bidimensional confinement on the dynamics of the interlayer water was investigated by using a synthetic Na-saponite sample with a general formula of Si(7.3)Al(0.7)Mg(6)O(20)(OH)(4)Na(0.7) in a bilayer hydration state. Experimental results reveal two inelastic signals, different from those described for bulk water with a clear anisotropy on the low-energy excitation of the collective dynamics of interlayer water, this difference being stronger in the perpendicular direction. Results obtained for the parallel direction follow the same trend as bulk water, and the effect of the confinement is mainly manifested from the fact that clay interlayer water is more structured than bulk water. Data obtained in the perpendicular direction display a nondispersive behavior below a cutoff wavenumber value, Q(c), indicating a nonpropagative excitation below that value. Molecular dynamics simulations results agree qualitatively with the experimental results. PMID:22324768

  12. Self-Monitoring and the Metatraits.

    PubMed

    Wilmot, Michael P; DeYoung, Colin G; Stillwell, David; Kosinski, Michal

    2016-06-01

    Prior attempts at locating self-monitoring within general taxonomies of personality traits have largely proved unsuccessful. However, past research has typically neglected (a) the bidimensionality of the Self-Monitoring Scale and (b) the hierarchical nature of personality. The objective of this study was to test hypotheses that the two self-monitoring factors are located at the level of the metatraits. Using data from two large multi-informant samples, one community (Sample 1: N = 552, Mage  = 51.26, 61% female; NPeers  = 1,551, Mage  = 48.61, 37% female) and one online (Sample 2: N = 3,726, Mage  = 24.89, 59% female; NPeers  = 17,868, Mage  = 26.23, 64% female), confirmatory factor analysis was used to test the hypotheses. Results confirmed hypotheses that acquisitive self-monitoring would have a strong positive relation to metatrait Plasticity, whereas protective self-monitoring would have a moderate negative relation to metatrait Stability. In both samples, constraining the correlation between acquisitive self-monitoring and Plasticity to unity did not alter model fit indices, indicating that the two putatively distinct constructs are identical. Findings have wide-ranging implications, including integration of the construct of self-monitoring into the mainstream of personality research, as the latter moves toward the development of broad explanatory theories. PMID:25565551

  13. Formation of the Penumbra and Start of the Evershed Flow

    NASA Astrophysics Data System (ADS)

    Murabito, M.; Romano, P.; Guglielmino, S. L.; Zuccarello, F.; Solanki, S. K.

    2016-07-01

    We studied the variations of line of sight photospheric plasma flows during the formation phase of the penumbra around a pore in active region NOAA 11490. We used a high spatial, spectral, and temporal resolution data set acquired by the Interferometric BIdimensional Spectrometer operating at the NSO/Dunn Solar Telescope as well as data taken by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory satellite (SDO/HMI). Before the penumbra formed we observed a redshift of the spectral line in the inner part of the annular zone surrounding the pore as well as a blueshift of material associated with opposite magnetic polarity farther away from the pore. We found that the onset of the classical Evershed flow occurs on a very short timescale (1 to 3 hr) while the penumbra is forming. During the same time interval we found changes in the magnetic field inclination in the penumbra, with the vertical field actually changing sign near the penumbral edge, while the total magnetic field showed a significant increase, about 400 G. To explain these and other observations related to the formation of the penumbra and the onset of the Evershed flow we propose a scenario in which the penumbra is formed by magnetic flux dragged down from the canopy surrounding the initial pore. The Evershed flow starts when the sinking magnetic field dips below the solar surface and magnetoconvection sets in.

  14. VELOCITY AND MAGNETIC FIELD DISTRIBUTION IN A FORMING PENUMBRA

    SciTech Connect

    Romano, P.; Guglielmino, S. L.; Frasca, D.; Zuccarello, F.; Ermolli, I.; Tritschler, A.; Reardon, K. P.

    2013-07-01

    We present results from the analysis of high-resolution spectropolarimetric and spectroscopic observations of the solar photosphere and chromosphere, obtained shortly before the formation of a penumbra in one of the leading polarity sunspots of NOAA active region 11490. The observations were performed at the Dunn Solar Telescope of the National Solar Observatory on 2012 May 28, using the Interferometric Bidimensional Spectrometer. The data set is comprised of a 1 hr time sequence of measurements in the Fe I 617.3 nm and Fe I 630.25 nm lines (full Stokes polarimetry) and in the Ca II 854.2 nm line (Stokes I only). We perform an inversion of the Fe I 630.25 nm Stokes profiles to derive magnetic field parameters and the line-of-sight (LOS) velocity at the photospheric level. We characterize chromospheric LOS velocities by the Doppler shift of the centroid of the Ca II 854.2 nm line. We find that, before the formation of the penumbra, an annular zone of 3''-5'' width is visible around the sunspot. In the photosphere, we find that this zone is characterized by an uncombed structure of the magnetic field although no visible penumbra has formed yet. We also find that the chromospheric LOS velocity field shows several elongated structures characterized by downflow and upflow motions in the inner and outer parts of the annular zone, respectively.

  15. Automatic detection of motor unit innervation zones of the external anal sphincter by multichannel surface EMG.

    PubMed

    Ullah, Khalil; Cescon, Corrado; Afsharipour, Babak; Merletti, Roberto

    2014-12-01

    A method to detect automatically the location of innervation zones (IZs) from 16-channel surface EMG (sEMG) recordings from the external anal sphincter (EAS) muscle is presented in order to guide episiotomy during child delivery. The new algorithm (2DCorr) is applied to individual motor unit action potential (MUAP) templates and is based on bidimensional cross correlation between the interpolated image of each MUAP template and two images obtained by flipping upside-down (around a horizontal axis) and left-right (around a vertical axis) the original one. The method was tested on 640 simulated MUAP templates of the sphincter muscle and compared with previously developed algorithms (Radon Transform, RT; Template Match, TM). Experimental signals were detected from the EAS of 150 subjects using an intra-anal probe with 16 equally spaced circumferential electrodes. The results of the three algorithms were compared with the actual IZ location (simulated signal) and with IZ location provided by visual analysis (VA) (experimental signals). For simulated signals, the inter quartile error range (IQR) between the estimated and the actual locations of the IZ was 0.20, 0.23, 0.42, and 2.32 interelectrode distances (IED) for the VA, 2DCorr, RT and TM methods respectively. PMID:24948528

  16. ANÁLISE DA INSERÇÃO DOS TEMAS DE HUMANIDADES E ÉTICA, COM METODOLOGIA DE APRENDIZAGEM BASEADA EM PROBLEMAS, EM CURRICULO MÉDICO INTEGRADO EM ESCOLA PÚBLICA NO DISTRITO FEDERAL, BRASIL

    PubMed Central

    Novaes, Maria Rita Carvalho Garbi; Novaes, Luiz Carlos Garcez; Guilhem, Dirce; Lolas, Fernando; Silveira, Carla; Guiotti, Murilo

    2009-01-01

    Objetivo Realizar uma análise da inserção da ética e humanidades no currículo do Curso de Medicina da Escola Superior em Ciências da Saúde - ESCS, escola pública do Distrito Federal, Brasil, de forma a contribuir com o processo de gestão curricular. Metodologia O Estudo é de coorte e documental. Foram pesquisados 37 termos relacionados à ética e 36 referentes à humanização nos objetivos educacionais e conteúdo dos módulos temáticos, habilidades e atitudes e interação ensino-serviço-comunidade, de 1a a 4a série e no programa do internato no currículo (ano 2006) e no projeto pedagógico do Curso de Medicina (2001). Resultados Maior inserção da humanização, ética e bioética na 1a e 2a série, quando comparado à inserção na 3a e 4a série e no internato, (IC95%-α=0,034, pvalue=0,007). Unidade de habilidades e atitudes: freqüência das 3 temáticas no currículo da 1a a 4a séries (IC95%-α=0,026, pvalue=0,013). Quando comparada a inserção entre o internato e as quatro primeiras séries, observa-se que nestas a inserção da temática humanização é superior (IC95%-α=0,042, pvalue=0,029). Conclusão O currículo desenvolvido no ano de 2006 na ESCS apresentou correlação com o projeto pedagógico do curso e contemplou a temática de forma abrangente, em todas as séries e internato. PMID:20396594

  17. Quantification and modification of the equilibrium dynamics and mechanics of a viral capsid lattice self-assembled as a protein nanocoating

    NASA Astrophysics Data System (ADS)

    Valbuena, Alejandro; Mateu, Mauricio G.

    2015-09-01

    Self-assembling, protein-based bidimensional lattices are being developed as functionalizable, highly ordered biocoatings for multiple applications in nanotechnology and nanomedicine. Unfortunately, protein assemblies are soft materials that may be too sensitive to mechanical disruption, and their intrinsic conformational dynamism may also influence their applicability. Thus, it may be critically important to characterize, understand and manipulate the mechanical features and dynamic behavior of protein assemblies in order to improve their suitability as nanomaterials. In this study, the capsid protein of the human immunodeficiency virus was induced to self-assemble as a continuous, single layered, ordered nanocoating onto an inorganic substrate. Atomic force microscopy (AFM) was used to quantify the mechanical behavior and the equilibrium dynamics (``breathing'') of this virus-based, self-assembled protein lattice in close to physiological conditions. The results uniquely provided: (i) evidence that AFM can be used to directly visualize in real time and quantify slow breathing motions leading to dynamic disorder in protein nanocoatings and viral capsid lattices; (ii) characterization of the dynamics and mechanics of a viral capsid lattice and protein-based nanocoating, including flexibility, mechanical strength and remarkable self-repair capacity after mechanical damage; (iii) proof of principle that chemical additives can modify the dynamics and mechanics of a viral capsid lattice or protein-based nanocoating, and improve their applied potential by increasing their mechanical strength and elasticity. We discuss the implications for the development of mechanically resistant and compliant biocoatings precisely organized at the nanoscale, and of novel antiviral agents acting on fundamental physical properties of viruses.Self-assembling, protein-based bidimensional lattices are being developed as functionalizable, highly ordered biocoatings for multiple applications

  18. Stochastic volatility models at ρ=±1 as second class constrained Hamiltonian systems

    NASA Astrophysics Data System (ADS)

    Contreras G., Mauricio

    2014-07-01

    The stochastic volatility models used in the financial world are characterized, in the continuous-time case, by a set of two coupled stochastic differential equations for the underlying asset price S and volatility σ. In addition, the correlations of the two Brownian movements that drive the stochastic dynamics are measured by the correlation parameter ρ (-1≤ρ≤1). This stochastic system is equivalent to the Fokker-Planck equation for the transition probability density of the random variables S and σ. Solutions for the transition probability density of the Heston stochastic volatility model (Heston, 1993) were explored in Dragulescu and Yakovenko (2002), where the fundamental quantities such as the transition density itself, depend on ρ in such a manner that these are divergent for the extreme limit ρ=±1. The same divergent behavior appears in Hagan et al. (2002), where the probability density of the SABR model was analyzed. In an option pricing context, the propagator of the bi-dimensional Black-Scholes equation was obtained in Lemmens et al. (2008) in terms of the path integrals, and in this case, the propagator diverges again for the extreme values ρ=±1. This paper shows that these similar divergent behaviors are due to a universal property of the stochastic volatility models in the continuum: all of them are second class constrained systems for the most extreme correlated limit ρ=±1. In this way, the stochastic dynamics of the ρ=±1 cases are different of the -1<ρ<1 case, and it cannot be obtained as a continuous limit from the ρ≠±1 regimen. This conclusion is achieved by considering the Fokker-Planck equation or the bi-dimensional Black-Scholes equation as a Euclidean quantum Schrödinger equation. Then, the analysis of the underlying classical mechanics of the quantum model, implies that stochastic volatility models at ρ=±1 correspond to a constrained system. To study the dynamics in an appropriate form, Dirac's method for constrained

  19. Bubble Rise and Break-Up in Volcanic Conduits

    NASA Astrophysics Data System (ADS)

    Soldati, A.; Cashman, K. V.; Rust, A.; Rosi, M.

    2013-12-01

    The continual passive degassing occurring at open-vent mafic volcanoes is often punctuated by bursts of active degassing. The latter are generally thought to be the result of slug flow: large, conduit-filling bubbles periodically rising up the feeder conduit and bursting at the magma-air interface. Existing models of volcanic degassing systems make the simplifying assumption that the conduit is cylindrical; however, while this may be true at shallow levels, a flaring probably connects it to a dyke-like geometry at depth. The overall goal of this research is to assess the influence of conduit geometry on the speed and stability of bubbles rising in open-vent systems, and ultimately to devise a model to infer conduit shape from emerging bubbles size. In order to do that an analogue experimental approach was used. All of the experiments were two-phase (melt+volatiles); the analogue materials of choice were golden syrup-water mixtures ranging in viscosity from 10-1 to 104 Pa*s and air. Two experimental apparatuses were used: a bi-dimensional and a tri-dimensional one. The bi-dimensional set-up is a cell made of two flat transparent PVC plates (44x23cm) 10mm or 5mm apart (the front one having a hole at the bottom permitting bubble injection) containing a variety of parallelepipeds apt to outline different plumbing system geometries. The tri-dimensional one consists of a cylindrical tube (r=1,5cm; l=7cm) allowing bubble injection through the bottom rubber tap and terminating into a square tank (l=22cm). Results indicate that conduit geometry directly controls the slug rise velocity and the surrounding liquid descending speed, which in turn control the slug stability. Small enough bubbles simply deform as they go through the flaring, while bigger ones split into two daughter bubbles. A regime diagram has been constructed, illustrating the bubble break-up threshold dependence on the flare geometry and initial slug size, the two main controlling factors. The phenomenon of

  20. Planes coordinates transformation between PSAD56 to SIRGAS using a Multilayer Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    Tierra, Alfonso; Romero, Ricardo

    2014-12-01

    Prior any satellite technology developments, the geodetic networks of a country were realized from a topocentric datum, and hence the respective cartography was performed. With availability of Global Navigation Satellite Systems-GNSS, cartography needs to be updated and referenced to a geocentric datum to be compatible with this technology. Cartography in Ecuador has been performed using the PSAD56 (Provisional South American Datum 1956) systems, nevertheless it's necessary to have inside the system SIRGAS (SIstema de Referencia Geocéntrico para las AmericaS). This transformation between PSAD56 to SIRGAS use seven transformation parameters calculated with the method Helmert. These parameters, in case of Ecuador are compatible for scales of 1:25 000 or less, that does not satisfy the requirements on applications for major scales. In this study, the technique of neural networks is demonstrated as an alternative for improving the processing of UTM planes coordinates E, N (East, North) from PSAD56 to SIRGAS. Therefore, from the coordinates E, N, of the two systems, four transformation parameters were calculated (two of translation, one of rotation, and one scale difference) using the technique bidimensional transformation. Additionally, the same coordinates were used to training Multilayer Artificial Neural Network -MANN, in which the inputs are the coordinates E, N in PSAD56 and output are the coordinates E, N in SIRGAS. Both the two-dimensional transformation and ANN were used as control points to determine the differences between the mentioned methods. The results imply that, the coordinates transformation obtained with the artificial neural network multilayer trained have been improving the results that the bidimensional transformation, and compatible to scales 1:5000. Dostęp do nowoczesnych technologii, w tym GNSS umożliwiły dokładniejsze zdefi niowanie systemów odniesień przestrzennych wykorzystywanych m.in. w defi niowaniu krajowych układów odniesień i

  1. Heat shock protein 60 protects skeletal tissue against glucocorticoid-induced bone mass loss by regulating osteoblast survival.

    PubMed

    Wang, Feng-Sheng; Wu, Re-Wen; Ko, Jih-Yang; Tai, Ming-Hong; Ke, Huei-Ching; Yeh, Da-Wei; Wu, Shin-Long; Chen, Ming-Wen

    2011-11-01

    Excessive glucocorticoid administration accelerates osteoblast apoptosis and skeletal deterioration. Heat shock proteins (HSPs) regulate metabolic activities in osteoblastic cells. This study characterized the biological significance of HSP60 in glucocorticoid-induced bone loss. Rats were treated with glucocorticoid, HSP60 antisense oligonucleotides, or adenovirus-mediated HSP60 gene transfer. Bone mineral density, metaphyseal trabecular micro-architecture, and fragility were analyzed by dual X-ray absorptiometry, micro-computed tomography, and material testing, respectively. Differential proteomic profiles of bone tissue extracts were detected by bi-dimensional electrophoresis and mass spectrometry. Survival and proapoptotic signal transduction were quantified by immunoblotting. Glucocorticoid-treated rats had low bone mineral density and metaphyseal trabecular microstructure in association with downregulation of collagen 1α1 and HSP60 expressions in bone tissue. Gain of HSP60 function by adenovirus-mediated HSP60 gene transfer abrogated the deleterious effects of glucocorticoid treatment on bone mass, trabecular microstructure, and mechanical strength. Enhancement of HSP60 signaling attenuated the glucocorticoid-induced loss of trabecular bone volume, mineral acquisition reactions and osteoblast surface. HSP60 gene transfer activated ERK and Akt and reduced Bax and cytochrome c release, as well as caspase-3 cleavage, which attenuated the inhibitory effects of glucocorticoid treatment on osteoblast survival. Loss of HSP60 function by HSP60 antisense oligonucleotides accelerated mitochondrial apoptotic programs and osteoblast apoptosis. Knockdown of HSP60 induced loss of bone mass, micro-architecture integrity, and mechanical property. Taken together, loss of HSP60 signaling contributes to the glucocorticoid-induced enhancement of pro-apoptotic reactions, thereby accelerating osteoblast apoptosis and bone mass loss. Enhancement of HSP60 function is beneficial for

  2. Nasopharyngeal Cancers: Which Method Should be Used to Measure these Irregularly Shaped Tumors on Cross-Sectional Imaging?

    SciTech Connect

    King, Ann D. Zee, Benny; Yuen, Edmund H.Y.; Leung Singfai; Yeung, David K.W.; Ma, Brigette B.; Wong, Jeffrey K.T.; Kam, Michael K.M.; Ahuja, Anil T.; Chan, Anthony T.C.

    2007-09-01

    Purpose: To determine whether the standard techniques of measuring tumor size and change in size after treatment could be applied to the measurement of nasopharyngeal cancers, which are often irregular in shape. Methods and Materials: The standard measurements of bidimensional (BDM) (World Health Organization criteria) and unidimensional (UDM) (Response Evaluation Criteria in Solid Tumors [RECIST] criteria), together with the maximum depth of the tumor perpendicular to the pharyngeal wall (DM), were acquired from axial magnetic resonance images of primary nasopharyngeal carcinoma in 44 patients at diagnosis and in 29 of these patients after treatment. Tumor volume measurements (VM), acquired from the summation of areas from the axial magnetic resonance images, were used as the reference standard. Results: There was a significant association between VM and BDM with respect to tumor size at diagnosis (p = 0.002), absolute change in tumor size after treatment (p < 0.001), and percentage change in tumor size after treatment (p = 0.044), but not between VM and UDM. There was also a significant association between VM and DM with respect to percentage change in tumor size after treatment (p = <0.0001) but not absolute change (p = 0.222). Conclusion: When using simple measurements to assess irregularly shaped nasopharyngeal cancers, the BDM should be used to measure size at diagnosis and the BDM and percentage change in size with treatment. Unidimensional measurement does not reflect size or change in size, and therefore the RECIST criteria may not be applicable to all tumor shapes. The use of DM requires further evaluation.

  3. Force Generation upon T Cell Receptor Engagement

    PubMed Central

    Husson, Julien; Chemin, Karine; Bohineust, Armelle; Hivroz, Claire; Henry, Nelly

    2011-01-01

    T cells are major players of adaptive immune response in mammals. Recognition of an antigenic peptide in association with the major histocompatibility complex at the surface of an antigen presenting cell (APC) is a specific and sensitive process whose mechanism is not fully understood. The potential contribution of mechanical forces in the T cell activation process is increasingly debated, although these forces are scarcely defined and hold only limited experimental evidence. In this work, we have implemented a biomembrane force probe (BFP) setup and a model APC to explore the nature and the characteristics of the mechanical forces potentially generated upon engagement of the T cell receptor (TCR) and/or lymphocyte function-associated antigen-1 (LFA-1). We show that upon contact with a model APC coated with antibodies towards TCR-CD3, after a short latency, the T cell developed a timed sequence of pushing and pulling forces against its target. These processes were defined by their initial constant growth velocity and loading rate (force increase per unit of time). LFA-1 engagement together with TCR-CD3 reduced the growing speed during the pushing phase without triggering the same mechanical behavior when engaged alone. Intracellular Ca2+ concentration ([Ca2+]i) was monitored simultaneously to verify the cell commitment in the activation process. [Ca2+]i increased a few tens of seconds after the beginning of the pushing phase although no strong correlation appeared between the two events. The pushing phase was driven by actin polymerization. Tuning the BFP mechanical properties, we could show that the loading rate during the pulling phase increased with the target stiffness. This indicated that a mechanosensing mechanism is implemented in the early steps of the activation process. We provide here the first quantified description of force generation sequence upon local bidimensional engagement of TCR-CD3 and discuss its potential role in a T cell mechanically

  4. Contact processes with competitive dynamics in bipartite lattices: effects of distinct interactions

    NASA Astrophysics Data System (ADS)

    Pianegonda, Salete; Fiore, Carlos E.

    2014-05-01

    The two-dimensional contact process (CP) with a competitive dynamics proposed by Martins et al (2011 Phys. Rev. E 84 011125) leads to the appearance of an unusual active-asymmetric phase, in which the system sublattices are unequally populated. It differs from the usual CP only by the fact that particles also interact with their next-nearest neighbor sites via a distinct strength creation rate, and for the inclusion of an inhibition effect, proportional to the local density. Aimed at investigating the robustness of such an asymmetric phase, in this paper we study the influence of distinct interactions for two bidimensional CPs. In the first model, the interaction between first neighbors requires a minimal neighborhood of adjacent particles for creating new offspring, whereas second neighbors interact as usual (e.g. at least one neighboring particle is required). The second model takes the opposite situation, in which the restrictive dynamics is in the interaction between next-nearest neighbor sites. Both models are investigated under mean field theory (MFT) and Monte Carlo simulations. In similarity with results by Martins et al, the inclusion of distinct sublattice interactions maintains the occurrence of an asymmetric active phase and re-entrant transition lines. In contrast, remarkable differences are presented, such as discontinuous phase transitions (even between the active phases), the appearance of tricritical points and the stabilization of active phases under larger values of control parameters. Finally, we have shown that the critical behaviors are not altered due to the change of interactions, in which the absorbing transitions belong to the directed percolation (DP) universality class, whereas second-order active phase transitions belong to the Ising universality class.

  5. Novel lightweight uncooled thermal weapon sight

    NASA Astrophysics Data System (ADS)

    Bergeron, Alain; Jerominek, Hubert; Lacoursiere, Jean; Desnoyers, Nichola; Alain, Christine; Laou, Philips

    2004-08-01

    INO in collaboration with DRDC Valcartier has been involved in the design and development of uncooled IR bolometric detector technology since the early 1990s for a broad range of military and commercial applications. From the beginning, the strategy has been to develop small-size bidimensional detector arrays and specialty linear arrays, both equipped with on-chip readout electronics. The detector arrays have been implemented in various instruments for both imaging and non-imaging applications. This paper describes two TWS1 and TWS2 prototypes of single band thermal weapon sights (TWS) making use of a novel catadioptric, i.e. refractive/reflective, optics and INO's miniature IR cameras. These cameras employ a 160x120 pixel uncooled bolometric FPA with a 52 μm pitch and NETD at 50 mK, and modular electronics consisting of three boards stacked together to fit into a 3-inch cube volume. The ultra lightweight catadioptric objective is inherently athermalized in the -30°C to +40°C range. The TWS1 is also equipped with a miniature RF link allowing bi-directional video transmission. This TWS1 weighs only 900 g and has a total volume of about 75 in3. Its power consumption is 2 W. The experimental performance showed that human detection, recognition and identification could be achieved at 800 m, 200 m, and 120 m, respectively. Construction of an improved TWS2 model is in progress. The objective is the reduction of TWS2 model weight down to 700 g, its volume down to 50 in3, replacing the RF video link with a wireless digital link, and increasing resolution to 320x240 pixels.

  6. Crystal structure, magnetic, thermal behavior, and spectroscopic studies of two new bimetallic hydrogenselenites: [Cu2-xNix (HSeO3)2Cl2.4H2O], (x = 0.62; 0.91)

    NASA Astrophysics Data System (ADS)

    Hentech, I.; Zehani, K.; Kabadou, A.; Ben Salah, A.; Loukil, M.; Bessais, L.

    2016-08-01

    Two new iso-structural bimetallic hydrogenselenites [Cu2-xNix(HSeO3)2Cl2.4H2O] (x = 0.62; 0.91) have been synthesized from solution and characterized by single-crystal and powder X-ray diffraction. They crystallized in the orthorhombic Pnma space group with the following lattice parameters: for Cu1.09Ni0.91(HSeO3)2Cl2.4H2O: a = 9.0931 (2) Å, b = 17.7717 (4) Å, c = 7.1620 (2) Å, Z = 4, and for Cu1.38Ni0.62(HSeO3)2Cl2.4H2O: a = 9.0931 (4) Å, b = 17.7467 (7) Å, c = 7.1717 (3) Å; Z = 4. The crystal structure of this compound consists by a three-dimensional framework, but it may be described as a bi-dimensional structure consisting of layers, parallel to the (010) plane formed by two types of (Cu/Ni) octahedral and (HSeO3)- trigonal pyramids. The magnetic measurement, thermal and spectroscopic studies were performed for these compounds. The magnetic results reveal the appearance of a weak ferromagnetic behavior at low temperature (Tc = 16 K for x = 0.91 and 18.8 K for x = 0.62). The DSC analysis enabled us to locate two endothermic peaks. The first peak can be attributed to a completely dehydration of the material, in this transformation, the compounds undergo a structural phase transition which can favor a non-centrosymmetric phase at high temperature confirmed by the thermodiffractograms measurement. The second peak for these samples is due to the ferro-paraelectric phase transition which can be explained by an order- disorder transition.

  7. Real-time ultrasound-tagging to track the 2D motion of the common carotid artery wall in vivo

    SciTech Connect

    Zahnd, Guillaume; Salles, Sébastien; Liebgott, Hervé; Vray, Didier; Sérusclat, André; Moulin, Philippe

    2015-02-15

    Purpose: Tracking the motion of biological tissues represents an important issue in the field of medical ultrasound imaging. However, the longitudinal component of the motion (i.e., perpendicular to the beam axis) remains more challenging to extract due to the rather coarse resolution cell of ultrasound scanners along this direction. The aim of this study is to introduce a real-time beamforming strategy dedicated to acquire tagged images featuring a distinct pattern in the objective to ease the tracking. Methods: Under the conditions of the Fraunhofer approximation, a specific apodization function was applied to the received raw channel data, in real-time during image acquisition, in order to introduce a periodic oscillations pattern along the longitudinal direction of the radio frequency signal. Analytic signals were then extracted from the tagged images, and subpixel motion tracking of the intima–media complex was subsequently performed offline, by means of a previously introduced bidimensional analytic phase-based estimator. Results: The authors’ framework was applied in vivo on the common carotid artery from 20 young healthy volunteers and 6 elderly patients with high atherosclerosis risk. Cine-loops of tagged images were acquired during three cardiac cycles. Evaluated against reference trajectories manually generated by three experienced analysts, the mean absolute tracking error was 98 ± 84 μm and 55 ± 44 μm in the longitudinal and axial directions, respectively. These errors corresponded to 28% ± 23% and 13% ± 9% of the longitudinal and axial amplitude of the assessed motion, respectively. Conclusions: The proposed framework enables tagged ultrasound images of in vivo tissues to be acquired in real-time. Such unconventional beamforming strategy contributes to improve tracking accuracy and could potentially benefit to the interpretation and diagnosis of biomedical images.

  8. Isotopic Niche Variation in a Higher Trophic Level Ectotherm: Highlighting the Role of Succulent Plants in Desert Food Webs

    PubMed Central

    Delibes, Miguel; Blazquez, Ma Carmen; Fedriani, Jose Maria; Granados, Arsenio; Soriano, Laura; Delgado, Antonio

    2015-01-01

    Stable isotope analysis of animal tissues allows description of isotopic niches, whose axes in an n-dimensional space are the isotopic ratios, compared to a standard, of different isotope systems (e.g. δ13C, δ15N). Isotopic niches are informative about where an animal, population or species lives and about what it consumes. Here we describe inter- and intrapopulation isotopic niche (bidimensional δ13C-δ15N space) of the Orange-throated whiptail (Aspidoscelis hyperythra), an arthropodivorous small lizard, in ten localities of Baja California Sur (Mexico). These localities range from extreme arid to subtropical conditions. Between 13 and 20 individuals were sampled at each locality and 1 cm of tail-tip was collected for isotope analysis. As expected, interpopulation niche width variation was much larger than intrapopulation one. Besides, isotopic variation was not related to age, sex or individual size of lizards. This suggests geographic variation of the isotopic niche was related to changes in the basal resources that fuel the trophic web at each locality. The position of Bayesian isotope ellipses in the δ-space indicated that whiptails in more arid localities were enriched in 13C, suggesting most of the carbon they ingested came from CAM succulent plants (cacti, agaves) and in minor degree in C4 grasses. Contrarily, whiptails in subtropical areas were depleted in 13C, as they received more carbon from C3 scrubs and trees. Localities closer to sea-level tended to be enriched in 15N, but a clear influence of marine subsidies was detected only at individual level. The study contributes to identify the origin and pathways through which energy flows across the trophic webs of North American deserts. PMID:25973609

  9. Probabilistic Constraints on Structural Lineament Best Fit Plane Precision Obtained through Numerical Analysis

    NASA Astrophysics Data System (ADS)

    Seers, Thomas; Hodgetts, David

    2015-04-01

    Recent advances in geological trace extraction procedures now enable three dimensional representations of structural lineaments to be delineated from digital elevation models (DEMs), orthophotos and mesh based surface reconstructions. The principle advantage of obtaining higher dimensional representations of lineaments from remotely sensed data is that they allow best fit plane estimates to be made for their corresponding discontinuities which cannot be obtained from conventional bi-dimensional datasets. These orientation estimates yield deterministic constraints upon structural architecture and enable spatially dependent discontinuity network properties, such as volumetric intensity and connectivity, known to govern key rock mass physical properties (i.e. strength, elastic modulus and permeability) to be assessed. However, the eigen characteristics of 3D structural lineaments mapped at decimetre to regional scales indicates that discontinuity plane estimates from such datasets tend to be unreliable. Here, we investigate the relationship between digitised lineament vertex geometry (coplanarity/collinearity) and the reliability of their estimated best fitting plane using Monte Carlo experiments. Lineaments are modelled as the intersection curve between two orthonormally oriented fractional Brownian surfaces representing the outcrop and discontinuity plane. Commensurate to increasing lineament vertex collinearity (K), systematic decay in estimated pole vector precision is observed from our experiments. Pole vector distributions are circumferentially constrained around the axis of rotation set by the end nodes of the synthetic lineaments, effectively reducing the rotational degrees of freedom of the vertex set from three to one. Vectors on the unit circle formed perpendicular to this arbitrary axis of rotation conform to von Mises (circular normal) distributions, only transforming to uniform at extreme values of K. This latter observation suggests that whilst

  10. Three dimensional macroporous architectures and aerogels built of carbon nanotubes and/or graphene: synthesis and applications.

    PubMed

    Nardecchia, Stefania; Carriazo, Daniel; Ferrer, M Luisa; Gutiérrez, María C; del Monte, Francisco

    2013-01-21

    Carbon nanotubes and graphene are some of the most intensively explored carbon allotropes in materials science. This interest mainly resides in their unique properties with electrical conductivities as high as 10(4) S cm(-1), thermal conductivities as high as 5000 W m(-1) K and superior mechanical properties with elastic moduli on the order of 1 TPa for both of them. The possibility to translate the individual properties of these monodimensional (e.g. carbon nanotubes) and bidimensional (e.g. graphene) building units into two-dimensional free-standing thick and thin films has paved the way for using these allotropes in a number of applications (including photocatalysis, electrochemistry, electronics and optoelectronics, among others) as well as for the preparation of biological and chemical sensors. More recently and while recognizing the tremendous interest of these two-dimensional structures, researchers are noticing that the performance of certain devices can experience a significant enhancement by the use of three-dimensional architectures and/or aerogels because of the increase of active material per projected area. This is obviously the case as long as the nanometre-sized building units remain accessible so that the concept of hierarchical three-dimensional organization is critical to guarantee the mass transport and, as consequence, performance enhancement. Thus, this review aims to describe the different synthetic processes used for preparation of these three-dimensional architectures and/or aerogels containing either any or both allotropes, and the different fields of application in which the particular structure of these materials provided a significant enhancement in the efficacy as compared to their two-dimensional analogues or even opened the path to novel applications. The unprecedented compilation of information from both CNT- and graphene-based three-dimensional architectures and/or aerogels in a single revision is also of interest because it allows

  11. Identification in human urine and blood of a novel selenium metabolite, Se-methylselenoneine, a potential biomarker of metabolization in mammals of the naturally occurring selenoneine, by HPLC coupled to electrospray hybrid linear ion trap-orbital ion trap MS.

    PubMed

    Klein, Marlène; Ouerdane, Laurent; Bueno, Maïté; Pannier, Florence

    2011-05-01

    Speciation analysis of selenium in human urine allowed for the first time the identification of a novel selenium metabolite, Se-methylselenoneine. Despite a concentration at low ppb level, its characterization was achieved after sample purification by solid phase extraction (SPE) followed by the parallel coupling of the bidimensional RP/HILIC chromatography with ICP-MS and ESI-LTQ Orbitrap MS detection. To confirm its biological significance with regards to selenoneine, the recently discovered analog of ergothioneine, and to discard the possibility of sample preparation artifacts, a new method was developed to monitor its actual presence, as well as the occurrence of its sulfur and/or non-methylated analogs, in non-preconcentrated urine and blood samples of non-supplemented humans. It consisted in a HILIC ESI-MS(3) method in high resolution mode (resolution 30 000 at m/z 400) with large isolation width windows for precursor ions. These two particular settings allowed respectively to keep observing the specific mass defect of selenium- and sulfur-containing molecules and to maintain the characteristic selenium pattern in product ions created through MS(n) fragmentations. As a result, all four metabolites were detected in blood and three of them in urine. Moreover, different ratios "methylated/non-methylated" were observed between urine and blood samples, which seemed to indicate their active metabolization. The analytical tool developed here will be of a great importance to further study the occurrence and the potential metabolic role in mammalian organelles, cells and fluids of these very particular and promising redox metabolites. PMID:21331438

  12. Structure and Optical Properties of the Atmospheric Boundary Layer over Dusty Hot Deserts

    NASA Astrophysics Data System (ADS)

    Chalermthai, B.; Al Marzooqi, M.; Basha, G.; Ouarda, T.; Armstrong, P.; Molini, A.

    2014-12-01

    Strong sensible heat fluxes and deep turbulent mixing - together with marked dustiness and a low substrate water content - represent a characteristic signature of the atmospheric boundary layer (ABL) over hot deserts, resulting in "thicker" mixing layers and peculiar optical properties. Beside these main common features however, desert boundary layers present extremely complex local structures that have been scarcely addressed in the literature, and whose understanding is essential in modeling processes such as transport and deposition of dust and pollutants, local wind fields, turbulent fluxes and their impacts on the sustainable development, human health and solar energy harvesting in these regions. In this study, we explore the potential of the joint usage of Lidar Ceilometer backscattering profiles and sun-photometer optical depth retrievals to quantitatively determine the vertical aerosol profile over dusty hot desert regions. Toward this goal, we analyze a continuous record of observations of the atmospheric boundary layer height from a single lens LiDAR ceilometer operated at Masdar Institute Field Station (24.4425N 54.6163E, Abu Dhabi, United Arab Emirates), starting March 2013, and the concurrent measurements of aerosol optical depth derived independently from the Masdar Institute AERONET sun-photometer. The main features of the desert ABL are obtained from the ceilometer range corrected backscattering profiles through bi-dimensional clustering technique we developed as a modification of the recently proposed single-profile clustering method, and therefore "directly" and "indirectly" calibrated to obtain a full diurnal cycle climatology of the aerosol optical depth and aerosol profiles. The challenges and the advantages of applying a similar methodology to the monitoring of aerosols and dust over hyper-arid regions are also discussed, together with the issues related to the sensitivity of commercial ceilometers to changes in the solar background.

  13. Plasmonic 3D-structures based on silver decorated nanotips for biological sensing

    NASA Astrophysics Data System (ADS)

    Coluccio, M. L.; Francardi, M.; Gentile, F.; Candeloro, P.; Ferrara, L.; Perozziello, G.; Di Fabrizio, E.

    2016-01-01

    Recent progresses in nanotechnology fabrication gives the opportunity to build highly functional nano-devices. 3D structures based on noble metals or covered by them can be realized down to the nano-scales, obtaining different devices with the functionalities of plasmonic nano-lenses or nano-probes. Here, nano-cones decorated with silver nano-grains were fabricated using advanced nano-fabrication techniques. In fabricating the cones, the angle of the apex was varied over a significant range and, in doing so, different geometries were realized. In depositing the silver nano-particles, the concentration of solution was varied, whereby different growth conditions were realized. The combined effect of tip geometry and growth conditions influences the size and distribution of the silver nano grains. The tips have the ability to guide or control the growth of the grains, in the sense that the nano-particles would preferentially distribute along the cone, and especially at the apex of the cone, with no o minor concentration effects on the substrate. The arrangement of metallic nano-particles into three-dimensional (3D) structures results in a Surface Enhanced Raman Spectroscopy (SERS) device with improved interface with analytes compared to bi-dimensional arrays of metallic nanoparticles. In the future, similar devices may find application in microfluidic devices, and in general in flow chambers, where the system can be inserted as to mimic a a nano-bait, for the recognition of specific biomarkers, or the manipulation and chemical investigation of single cells directly in native environments with good sensitivity, repeatability and selectivity.

  14. The geologic setting of the Mars north polar cap's Basal Unit from the three dimensional analysis of MARSIS planetary radar sounder data

    NASA Astrophysics Data System (ADS)

    Frigeri, A.; Orosei, R.; Cartacci, M.; Cicchetti, A.; Giuppi, S.; Noschese, R.; Plaut, J.

    2012-12-01

    Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) is the orbital subsurface sounder aboard ESA's Mars Express spacecraft. It transmits a low-frequency radar pulse capable of penetrating below the surface, where subsurface dielectric discontinuities originate secondary echoes. MARSIS has been used to probe both the south and the north polar caps of Mars, revealing their thickness and structure. We report on the results of a campaign of observations of the north polar ice cap of Mars that took place between May and December 2011 in uniquely favorable conditions, and produced data of unprecedented quality. The focus of our work is the detection of signals from the Basal Unit, the dark, ice-rich, complexely layered geologic unit lying stratigraphically between the polar layered deposits and the Vastitas Borealis Formation, and extending beneath most of Planum Boreum and Olympia Planitia. The objective of this work is the study of the full three dimensional structure of the Northern Polar Deposit and in particular of the Basal Unit (BU). The analysis of signals in bi-dimensional radargrams sounding the BU reveal a layering of the unit, probably correlated with the Rupes Tenuis - Planum Boreum Cavi units' boundary. Using the density of data available from the 2011 polar campaign, we assembled radar observations into a three dimensional volume of data. The use of visualization techniques allow to explore these data interactively, identifying patterns that can be problematic to detect with unsupervised automatic methods. This way, specific areas, or sub-volumes, are being selected to be studied in detail. We will present MARSIS data from the Mars North Polar campaign, as well as the preliminary interpretation of these data in three dimensions, and the possible implications for the geologic history of the northern Martian ice-cap.

  15. Modeling the Impact of Alternative Immunization Strategies: Using Matrices as Memory Lanes

    PubMed Central

    Alonso, Wladimir J.; Rabaa, Maia A.; Giglio, Ricardo; Miller, Mark A.; Schuck-Paim, Cynthia

    2015-01-01

    Existing modeling approaches are divided between a focus on the constitutive (micro) elements of systems or on higher (macro) organization levels. Micro-level models enable consideration of individual histories and interactions, but can be unstable and subject to cumulative errors. Macro-level models focus on average population properties, but may hide relevant heterogeneity at the micro-scale. We present a framework that integrates both approaches through the use of temporally structured matrices that can take large numbers of variables into account. Matrices are composed of several bidimensional (time×age) grids, each representing a state (e.g. physiological, immunological, socio-demographic). Time and age are primary indices linking grids. These matrices preserve the entire history of all population strata and enable the use of historical events, parameters and states dynamically in the modeling process. This framework is applicable across fields, but particularly suitable to simulate the impact of alternative immunization policies. We demonstrate the framework by examining alternative strategies to accelerate measles elimination in 15 developing countries. The model recaptured long-endorsed policies in measles control, showing that where a single routine measles-containing vaccine is employed with low coverage, any improvement in coverage is more effective than a second dose. It also identified an opportunity to save thousands of lives in India at attractively low costs through the implementation of supplementary immunization campaigns. The flexibility of the approach presented enables estimating the effectiveness of different immunization policies in highly complex contexts involving multiple and historical influences from different hierarchical levels. PMID:26509976

  16. The Microwave Spectrum of Partially Deuterated Species of Dimethyl Ether

    NASA Astrophysics Data System (ADS)

    Lauvergnat, D.; Margulès, L.; Motiyenko, R. A.; Guillemin, J.-C.; Coudert, L. H.

    2011-06-01

    Dimethyl ether is a molecule of astrophysical interest spectroscopically well characterized. It is one of the simplest molecules with two methyl groups undergoing large amplitude internal rotations. Due to deuterium enrichment in the interstellar medium, one can reasonably expect that partially deuterated species of dimethyl ether might be detected. However, there are no spectroscopic results about the microwave spectrum of such species. A theoretical calculation of the rotation-torsion energy levels of the partially deuterated species of dimethyl ether has been undertaken aided by ab initio calculations. The approach accounts for the complicated torsion-rotation interactions displayed by this molecule and for the fact that deuteration leads to changes of the bidimensional internal rotation effective potential energy surface. Due to zero-point energy contributions from the 19 small amplitude vibrational modes, this surface no longer displays G36 symmetry. Rotation-torsion energy levels are computed treating the two angles of internal rotation as active coordinates and evaluating Hamiltonian matrix elements with the help of Gaussian quadrature. It is hoped that the present results will allow us to understand the microwave spectrum of the mono deuterated species CH_2DOCH_3 which has been recorded in Lille with the new sub millimeter wave spectrometer (150--950 GHz) based on harmonic generation of solid-state sources. [2] Snyder, Buhl, and Schwartz, Astrophys. J. Letters 191 (1974) L79. [3] Endres, Drouin, Pearson, Müller, Lewen, Schlemmer, and Giesen, A&A 504 (2009) 635. [4] Solomon and Woolf, Astrophys. J. Letters 180 (1973) L89. [5] Lauvergnat and Nauts, J. Chem. Phys. 116 (2002) 8560; and Light and Bačić, J. Chem. Phys. 87 (1987) 4008.

  17. Cognitive distortions based on MDS configuration and sketch mapping: a case study in Beijing

    NASA Astrophysics Data System (ADS)

    Shen, Si; Xue, Lulu; Wu, Lun; Liu, Yu

    2007-06-01

    As an emerging field, cognitive map kept playing a significant role in geography these decades. To date, there are two dominant methods to externalize human's internal cognitive map, namely, multidimensional scaling (MDS) and skech mapping. However, among most recent researches on cognitive map, the differences between both methods are always ignored. The usage of one method over another is still under scrutiny. In order to shed light on the similarity or distinctions of MDS configuration and sketch mapping, we conducted an experiment on Beijing residents by requesting a sketch of the region within 3rd Ring and meanwhile extracting distance estimates between 8 landmarks. Employing the Bidimensional regression along with standard deviational ellipse, we studied the global and local distortions among two kinds of cognitive maps and quantitatively measure the overall and local cognitive maps distortions. Besides, we use Monte Carlo simulation method to calculate the radius of distortion for the Distortion Index (DI). It shows that the average cognitive distortion of habitants in Beijing is 2km to 3km, and the distortion takes 2nd-ring road as a border, displaying a southwest-northeast diagonal stretch and an east-west contracted tendency. The distortion in the two methods is remarkably both correlated with factors, such as travel frequency and years of residence. Comparing two methods, it turned out that sketch map was more consistent with real map, while the distortion orientations of sketch map resembled MDS configuration. Finally, we gave possible reasons with regard to above conclusions and advices for future usage of two methods.

  18. Edge detection, color quantization, segmentation, texture removal, and noise reduction of color image using quaternion iterative filtering

    NASA Astrophysics Data System (ADS)

    Hsiao, Yu-Zhe; Pei, Soo-Chang

    2014-07-01

    Empirical mode decomposition (EMD) is a simple, local, adaptive, and efficient method for nonlinear and nonstationary signal analysis. However, for dealing with multidimensional signals, EMD and its variants such as bidimensional EMD (BEMD) and multidimensional EMD (MEMD) are very slow due to the needs of a large amount of envelope interpolations. Recently, a method called iterative filtering has been proposed. This filtering-based method is not as precise as EMD but its processing speed is very fast and can achieve comparable results as EMD does in many image and signal processing applications. We combine quaternion algebra and iterative filtering to achieve the edge detection, color quantization, segmentation, texture removal, and noise reduction task of color images. We can obtain similar results by using quaternion combined with EMD; however, as mentioned before, EMD is slow and cumbersome. Therefore, we propose to use quaternion iterative filtering as an alternative method for quaternion EMD (QEMD). The edge of color images can be detected by using intrinsic mode functions (IMFs) and the color quantization results can be obtained from residual image. The noise reduction algorithm of our method can be used to deal with Gaussian, salt-and-pepper, speckle noise, etc. The peak signal-to-noise ratio results are satisfactory and the processing speed is also very fast. Since textures in a color image are high-frequency components, we also can use quaternion iterative filtering to decompose a color image into many high- and low-frequency IMFs and remove textures by eliminating high-frequency IMFs.

  19. MuSICa at GRIS: a prototype image slicer for EST at GREGOR

    NASA Astrophysics Data System (ADS)

    Calcines, A.; Collados, M.; López, R. L.

    2013-05-01

    This communication presents a prototype image slicer for the 4-m European Solar Telescope (EST) designed for the spectrograph of the 1.5-m GREGOR solar telescope (GRIS). The design of this integral field unit has been called MuSICa (Multi-Slit Image slicer based on collimator-Camera). It is a telecentric system developed specifically for the integral field, high resolution spectrograph of EST and presents multi-slit capability, reorganizing a bidimensional field of view of 80 arcsec^{2} into 8 slits, each one of them with 200 arcsec length × 0.05 arcsec width. It minimizes the number of optical components needed to fulfil this multi-slit capability, three arrays of mirrors: slicer, collimator and camera mirror arrays (the first one flat and the other two spherical). The symmetry of the layout makes it possible to overlap the pupil images associated to each part of the sliced entrance field of view. A mask with only one circular aperture is placed at the pupil position. This symmetric characteristic offers some advantages: facilitates the manufacturing process, the alignment and reduces the costs. In addition, it is compatible with two modes of operation: spectroscopic and spectro-polarimetric, offering a great versatility. The optical quality of the system is diffraction-limited. The prototype will improve the performances of GRIS at GREGOR and is part of the feasibility study of the integral field unit for the spectrographs of EST. Although MuSICa has been designed as a solar image slicer, its concept can also be applied to night-time astronomical instruments (Collados et al. 2010, Proc. SPIE, Vol. 7733, 77330H; Collados et al. 2012, AN, 333, 901; Calcines et al. 2010, Proc. SPIE, Vol. 7735, 77351X)

  20. Fusion of infrared and visible images based on BEMD and NSDFB

    NASA Astrophysics Data System (ADS)

    Zhu, Pan; Huang, Zhanhua; Lei, Hai

    2016-07-01

    This paper presents a new fusion method based on the adaptive multi-scale decomposition of bidimensional empirical mode decomposition (BEMD) and the flexible directional expansion of nonsubsampled directional filter banks (NSDFB) for visible-infrared images. Compared with conventional multi-scale fusion methods, BEMD is non-parametric and completely data-driven, which is relatively more suitable for non-linear signals decomposition and fusion. NSDFB can provide direction filtering on the decomposition levels to capture more geometrical structure of the source images effectively. In our fusion framework, the entropies of the two patterns of source images are firstly calculated and the residue of the image whose entropy is larger is extracted to make it highly relevant with the other source image. Then, the residue and the other source image are decomposed into low-frequency sub-bands and a sequence of high-frequency directional sub-bands in different scales by using BEMD and NSDFB. In this fusion scheme, two relevant fusion rules are used in low-frequency sub-bands and high-frequency directional sub-bands, respectively. Finally, the fused image is obtained by applying corresponding inverse transform. Experimental results indicate that the proposed fusion algorithm can obtain state-of-the-art performance for visible-infrared images fusion in both aspects of objective assessment and subjective visual quality even for the source images obtained in different conditions. Furthermore, the fused results have high contrast, remarkable target information and rich details information that are more suitable for human visual characteristics or machine perception.

  1. 'Breast is not always best': South Asian women's experiences of infant feeding in the UK within an acculturation framework.

    PubMed

    Choudhry, Kubra; Wallace, Louise M

    2012-01-01

    Acculturating to a host country has a negative impact on immigrant women's breastfeeding practices, particularly when coming from countries where breastfeeding rates are higher than Western countries. Whether this is true of those immigrating to the UK remains to be investigated. The study aimed to explore whether acculturating to the UK had detrimental effects on breastfeeding practices of South Asian women, and to provide explanations as to how acculturation may have exerted its influence. Twenty South Asian women completed semi-structured interviews exploring infant feeding experiences. Data were thematically analysed. A bidimensional measure assessed women's acculturation status. Women displaying low acculturation levels were aware of living in a formula-feeding culture but this had little influence on breastfeeding intentions/behaviours; drawing upon South Asian cultural teachings of the psychological benefits of breast milk. These women opted to formula-feed in response to their child's perceived demands or in a bid to resolve conflict; either when receiving information about the best feeding method or between their roles as a mother and daughter-in-law. Highly acculturated women also experienced such conflict; their awareness of the formula-feeding culture governed feeding choice. The findings provide a picture of how acculturation may affect South Asian women's breastfeeding intentions and behaviours; encouraging health service providers to meet the varying needs of an acculturating population. If breastfeeding is to be encouraged, it is necessary to understand factors influencing feeding choice; with particular attention to the acculturation pathways that may govern such decisions. This paper highlights ways to tailor information for South Asian women depending on levels of acculturation. PMID:22136221

  2. Quick mapping of flood-prone areas in plain terrain using GIS analysis: applications for flood management plans over large areas

    NASA Astrophysics Data System (ADS)

    Pistocchi, A.; Mazzoli, P.; Bagli, S.

    2012-04-01

    Flood management plans, as required under the provisions of the "Flood Directive" 2007/60/EC, ground on the mapping of flood-prone areas. When dealing with plain terrains, inundation modeling using bi-dimensional models may entail considerable efforts both in terms of data collection and processing, and of hydraulic computation. The resolution of numerical models may be limited if working on large areas, or conversely a model can tackle only relatively limited areas with a high resolution. On the other hand, a dynamic simulation of overland floods may be necessary for certain applications, but may be beyond the practical requirements of a flood management plan, for which it may be sufficient to identify the general characteristics of flow that drive potential risks, such as the type of flooding (slow or with significant dynamic component) and an indication of depth and velocity of flow. In this contribution we present criteria for the classification of flooding type and for the mapping of first-approximation depth and velocity fields in case of floods, and we illustrate a few applications of simple GIS analyses entailing the use of hydrologic functions and mathematical morphology, that can be implemented in most GIS packages and can be used for quick mapping of flood hazards on plain terrain. In this way, no dynamic model implementation is required and computing time is irrelevant even at high resolution as allowed e.g. by LiDAR terrain models. These applications refer to contexts in Italy including the Emilia Romagna regional basins flood management plan, the Province of Ravenna civil protection plan, hydraulic hazards on Northern Adriatic coastal areas and the assessment of hazards for a windfarm to be located in a flood-prone area in Puglia, Southern Italy. We discuss how the approach can be generally applied in Europe with relatively limited and/or uncertain information, within the framework of the Floods Directive in support of flood hazards for subsequent

  3. cuTauLeaping: A GPU-Powered Tau-Leaping Stochastic Simulator for Massive Parallel Analyses of Biological Systems

    PubMed Central

    Besozzi, Daniela; Pescini, Dario; Mauri, Giancarlo

    2014-01-01

    Tau-leaping is a stochastic simulation algorithm that efficiently reconstructs the temporal evolution of biological systems, modeled according to the stochastic formulation of chemical kinetics. The analysis of dynamical properties of these systems in physiological and perturbed conditions usually requires the execution of a large number of simulations, leading to high computational costs. Since each simulation can be executed independently from the others, a massive parallelization of tau-leaping can bring to relevant reductions of the overall running time. The emerging field of General Purpose Graphic Processing Units (GPGPU) provides power-efficient high-performance computing at a relatively low cost. In this work we introduce cuTauLeaping, a stochastic simulator of biological systems that makes use of GPGPU computing to execute multiple parallel tau-leaping simulations, by fully exploiting the Nvidia's Fermi GPU architecture. We show how a considerable computational speedup is achieved on GPU by partitioning the execution of tau-leaping into multiple separated phases, and we describe how to avoid some implementation pitfalls related to the scarcity of memory resources on the GPU streaming multiprocessors. Our results show that cuTauLeaping largely outperforms the CPU-based tau-leaping implementation when the number of parallel simulations increases, with a break-even directly depending on the size of the biological system and on the complexity of its emergent dynamics. In particular, cuTauLeaping is exploited to investigate the probability distribution of bistable states in the Schlögl model, and to carry out a bidimensional parameter sweep analysis to study the oscillatory regimes in the Ras/cAMP/PKA pathway in S. cerevisiae. PMID:24663957

  4. Pre- and perioperative predictors of short-term clinical outcomes in patients undergoing percutaneous nephrolitholapaxy.

    PubMed

    Olbert, Peter J; Hegele, Axel; Schrader, Andres J; Scherag, André; Hofmann, Rainer

    2007-10-01

    Percutaneous nephrolitholapaxy (PCNL) with modern stone disintegration technologies is the treatment of choice for patients with extensive stone burden or stones refractory to extracorporeal shock wave lithotripsy. However, little is known about factors predicting unfavourable outcome in terms of perioperative complications, residual stone burden or prolonged hospitalization. The aim of this study was to evaluate preoperative, patient- and stone-related parameters that might influence the perioperative course and short-term clinical outcomes. In a prospective study, age, sex, body mass index (BMI), bidimensional size, side, pre-existent urinary tract infection, pre-existent hydronephrosis and previous kidney surgery were used as independent variables in both univariate and multiple regression models in 109 PCNL patients in order to predict the partition of patients rendered stone free at hospital discharge, duration of surgery, length of inpatient hospital stay and the occurrence of major complications. Univariate and multiple regression analysis revealed that stone size was the only factor influencing duration of surgery (P < 0.001) and hospitalization (P = 0.02), but had no predictive potential for major complications. Univariate analysis showed a trend towards longer inpatient hospital stay and clinically relevant residuals in patients with lower BMI (P = 0.05 and 0.06); however, after controlling for the other confounding variables, this was only reproducible for residual stone burden. The other patient- and stone-related factors did not adversely affect the outcome measures. In our patient sample treated with PCNL by LithoClast Master/Ultra we found evidence that large stone burden is a prognostic factor predicting longer surgery and prolonged hospitalization. In addition, patients with lower BMIs might be at higher risk of not being stone free at hospital discharge accompanied by prolonged inpatient treatment. PMID:17786419

  5. Adaptation and validation of the patient assessment of chronic illness care in the French context

    PubMed Central

    2014-01-01

    Background Chronic diseases are major causes of disability worldwide with rising prevalence. Most patients suffering from chronic conditions do not always receive optimal care. The Chronic Care Model (CCM) has been developed to help general practitioners making quality improvements. The Patient Assessment of Chronic Illness Care (PACIC) questionnaire was increasingly used in several countries to appraise the implementation of the CCM from the patients’ perspective. The objective of this study was to adapt the PACIC questionnaire in the French context and to test the validity of this adaptation in a sample of patients with multiple chronic conditions. Methods The PACIC was translated into French language using a forward/backward procedure. The French version was validated using a sample of 150 patients treated for obstructive sleep apnea syndrome (OSAS) and having multiple chronic co-morbidities. Several forms of validity were analysed: content; face; construct; and internal consistency. The construct validity was investigated with an exploratory factorial analysis. Results The French-version of the PACIC consisted in 18 items, after merging two pairs of items due to redundancy. The high number of items exhibiting floor/ceiling effects and the non-normality of the ratings suggested that a 5-points rating scale was somewhat inappropriate to assess the patients’ experience of care. The construct validity of the French-PACIC was verified and resulted in a bi-dimensional structure. Overall this structure showed a high level of internal consistency. The PACIC score appeared to be significantly related to the age and self-reported health of the patients. Conclusions A French-version of the PACIC questionnaire is now available to evaluate the patients’ experience of care and to monitor the quality improvements realised by the medical structures. This study also pointed out some methodological issues about the PACIC questionnaire, related to the format of the rating

  6. The Peritraumatic Behavior Questionnaire: development and initial validation of a new measure for combat-related peritraumatic reactions

    PubMed Central

    2013-01-01

    Background Posttraumatic stress disorder (PTSD) is one of the most commonly observed stress-related conditions following combat exposure and its effective prevention is a high health-care priority. Reports of peritraumatic reactions have been shown to be highly associated with PTSD among combat exposed service members. However, existing instruments measuring peritraumatic symptoms were not specifically developed to assess combat-related peritraumatic stress and each demonstrates a different peritraumatic focus. We therefore developed the Peritraumatic Behavior Questionnaire (PBQ), a new military-specific rating scale focused upon the wide range of symptoms suggestive of combat-related peritraumatic distress in actively deployed Service Members. This study describes the development of the PBQ and reports on the psychometric properties of its self-rated version (PBQ-SR). Methods 688 Marine infantry service members were retrospectively assessed by the PBQ-SR within the scope of the Marine Resiliency Study after their deployment to war zone. Participants have been additionally assessed by a variety of questionnaires, as well as clinical interviews both pre and post-deployment. Results The PBQ-SR demonstrated satisfactory internal consistency, convergent and discriminant validity, as well as high correlation with trait dissociation prior to deployment. Component analysis suggested a latent bi-dimensional structure separating a peritraumatic emotional distress and physical awareness factor. The PBQ-SR total score showed high correlation to general anxiety, depression, poorer general health and posttraumatic symptoms after deployment and remained a significant predictor of PTSD severity, after controlling for those measures. The suggested screening cut-off score of 12 points demonstrated satisfactory predictive power. Conclusions This study confirms the ability of the PBQ-SR to unify the underlying peritraumatic symptom dimensions and reliably assess combat

  7. CHROMOSPHERIC RAPID BLUESHIFTED EXCURSIONS OBSERVED WITH IBIS AND THEIR ASSOCIATION WITH PHOTOSPHERIC MAGNETIC FIELD EVOLUTION

    SciTech Connect

    Deng, Na; Chen, Xin; Liu, Chang; Jing, Ju; Wang, Shuo; Wang, Haimin; Tritschler, Alexandra; Reardon, Kevin P.; Lamb, Derek A.; Deforest, Craig E.; Denker, Carsten; Liu, Rui

    2015-02-01

    Chromospheric rapid blueshifted excursions (RBEs) are suggested to be the disk counterparts of type II spicules at the limb and believed to contribute to the coronal heating process. Previous identification of RBEs was mainly based on feature detection using Dopplergrams. In this paper, we study RBEs on 2011 October 21 in a very quiet region at the disk center, which were observed with the high-cadence imaging spectroscopy of the Ca II 8542 Å line from the Interferometric Bidimensional Spectrometer (IBIS). By using an automatic spectral analysis algorithm, a total of 98 RBEs are identified during an 11 minute period. Most of these RBEs have either a round or elongated shape, with an average area of 1.2 arcsec{sup 2}. The detailed temporal evolution of spectra from IBIS makes possible a quantitative determination of the velocity (∼16 km s{sup –1}) and acceleration (∼400 m s{sup –2}) of Ca II 8542 RBEs, and reveals an additional deceleration (∼–160 m s{sup –2}) phase that usually follows the initial acceleration. In addition, we also investigate the association of RBEs with the concomitant photospheric magnetic field evolution, using coordinated high-resolution and high-sensitivity magnetograms made by Hinode. Clear examples are found where RBEs appear to be associated with the preceding magnetic flux emergence and/or the subsequent flux cancellation. However, further analysis with the aid of the Southwest Automatic Magnetic Identification Suite does not yield a significant statistical association between these RBEs and magnetic field evolution. We discuss the implications of our results in the context of understanding the driving mechanism of RBEs.

  8. MATISSE a web-based tool to access, visualize and analyze high resolution minor bodies observation

    NASA Astrophysics Data System (ADS)

    Zinzi, Angelo; Capria, Maria Teresa; Palomba, Ernesto; Antonelli, Lucio Angelo; Giommi, Paolo

    2016-07-01

    In the recent years planetary exploration missions acquired data from minor bodies (i.e., dwarf planets, asteroid and comets) at a detail level never reached before. Since these objects often present very irregular shapes (as in the case of the comet 67P Churyumov-Gerasimenko target of the ESA Rosetta mission) "classical" bidimensional projections of observations are difficult to understand. With the aim of providing the scientific community a tool to access, visualize and analyze data in a new way, ASI Science Data Center started to develop MATISSE (Multi-purposed Advanced Tool for the Instruments for the Solar System Exploration - http://tools.asdc.asi.it/matisse.jsp) in late 2012. This tool allows 3D web-based visualization of data acquired by planetary exploration missions: the output could either be the straightforward projection of the selected observation over the shape model of the target body or the visualization of a high-order product (average/mosaic, difference, ratio, RGB) computed directly online with MATISSE. Standard outputs of the tool also comprise downloadable files to be used with GIS software (GeoTIFF and ENVI format) and 3D very high-resolution files to be viewed by means of the free software Paraview. During this period the first and most frequent exploitation of the tool has been related to visualization of data acquired by VIRTIS-M instruments onboard Rosetta observing the comet 67P. The success of this task, well represented by the good number of published works that used images made with MATISSE confirmed the need of a different approach to correctly visualize data coming from irregular shaped bodies. In the next future the datasets available to MATISSE are planned to be extended, starting from the addition of VIR-Dawn observations of both Vesta and Ceres and also using standard protocols to access data stored in external repositories, such as NASA ODE and Planetary VO.

  9. IMAGING SPECTROPOLARIMETRY WITH IBIS. II. ON THE FINE STRUCTURE OF G-BAND BRIGHT FEATURES

    SciTech Connect

    Viticchie, B.; Criscuoli, S.

    2010-11-01

    We present new results from first observations of the quiet solar photosphere performed through the Interferometric BIdimensional Spectrometer (IBIS) in spectropolarimetric mode. IBIS allowed us to measure the four Stokes parameters in the Fe I 630.15 nm and Fe I 630.25 nm lines with high spatial and spectral resolutions for 53 minutes; the polarimetric sensitivity achieved by the instrument is 3 x 10{sup -3} the continuum intensity level. We focus on the correlation which emerges between the G-band bright feature brightness and magnetic filling factor of {approx}10{sup 3} G (kG) fields derived by inverting the Stokes I and V profiles. In more detail, we present the correlation first in a pixel-by-pixel study of a {approx_equal}3'' wide bright feature (a small network patch) and then we show that such a result can be extended to all the bright features found in the data set at any instant of the time sequence. The higher the kilo-Gauss filling factor associated to a feature, the higher the brightness of the feature itself. Filling factors up to {approx_equal}35% are obtained for the brightest features. Considering the values of the filling factors derived from the inversion analysis of spectropolarimetric data and the brightness variation observed in the G-band data we put forward an upper limit for the smallest scale over which magnetic flux concentrations in intergranular lanes produce a G-band brightness enhancement ({approx_equal}0.''1). Moreover, the brightness saturation observed for feature sizes comparable to the resolution of the observations is compatible with the large G-band bright features being clusters of sub-arcsecond bright points. This conclusion deserves to be confirmed by forthcoming spectropolarimetric observations at higher spatial resolution.

  10. [Network of researchers on the health aspects of reproduction].

    PubMed

    1990-07-01

    A symposium held 3-5 May 1990 commemorated the anniversary of the "Network" by presentations on the health aspects of reproduction in Africa. Prof. Sambra Diarra of the Ivory Coast presented a paper on "Health of Reproduction in Africa, Bi-Dimensional Problems: Biomedical and Social." He stressed the need to emphasize both maternal (MM) and infant mortality (IM) in Africa, where MM rates are 640/100,000 and IMR are 130/1000, because they remain so high. Prof. Fadel Diadhiou of Senegal followed with a paper on "Operations Research on Women's Reproductive Health in Africa." The major themes were that problems in reproductive health have resulted because of the fragmentation between the ecosystem and development and the lack of research is due to the isolation of institutions that lack human and material resources. The 3rd presentation by Prof. Mouhamadou Fall of Senegal on "The Health of Children and the Perspectives for Senegal," focused on the increasing infant and child mortality rates in Senegal (238/1000 in 1981) due to the combination of factors caused by the mother-child syndrome. These are: 1) congenital malformations caused by incest, young or advanced age of mothers; 2) diseases of the mother that cause fetal mortality: diabetes, arterial hypertension, eclampsia; 3) lack of breastfeeding and illiteracy of mothers; 4) public health diseases such as measles, malaria, diarrhea; 5) streptococcic infections and their complications such as anemia and tuberculosis. The last presentation made by Prof. Eusebe Alihonou from Benin on the "Perspectives and Priorities of Reproductive Health in Africa," concluded that the research priorities in Africa should be on health systems that lower utilization rates of services and resources and on epidemiological studies that identify health problems and analyze the risk factors. The Symposium concluded that the research priorities should be: maternal morbidity and mortality; adolescents and reproduction and the morbidity and

  11. Observation of Neutral Sodium above Mercury During the Transit of November 8, 2006

    NASA Astrophysics Data System (ADS)

    Potter, Andrew E.; Killen, R. M.; Reardon, K. P.; Bida, T. A.

    2012-10-01

    We mapped the absorption of sunlight by sodium vapor in the exosphere of Mercury during the transit of Mercury on November 8, 2006, using the IBIS Interferometric BIdimensional Spectrometer at the Dunn solar telescope operated by the National Solar Observatory at Sunspot, New Mexico. The measurements were reduced to line-of-sight equivalent widths for absorption at the sodium D2 line, and mapped in thirty degree increments around the shadow of Mercury. We observed north and south polar enhancements of sodium absorption. The sodium absorptions fell off exponentially with altitude up to about 600 km, and we analyzed the altitude distributions to determine surface densities, zenith column densities, temperatures and scale heights for sodium. The average surface concentration of sodium atoms was about 900 atoms/cm3, and the average zenith column density was 0.8 x 1010 atoms/cm2. The average temperature was about 1100 K, with excursions to 1750 and 700 K. The 2003 transit was observed by Schleicher et al. [2004], using instrumentation similar to that employed for this research. They reported the appearance of a streamer-like feature extending a thousand kilometers above the north polar region, and a similar but smaller feature above the south polar region. Our observations did not detect similar features. They observed considerably more sodium absorption over the dawn terminator than over the dusk terminator. In contrast, we observed slightly larger sodium absorption on the dawn relative to the dusk side. The difference might be due to the slow advance of the dawn terminator at during the 2006 transit (0.13 degrees/day) relative to the 2003 transit (3.27 degrees/day). Reference Schleicher, H.; Wiedemann, G.; Wöhl, H.; Berkefeld, T.; Soltau, D. (2004), Detection of neutral sodium above Mercury during the transit on 2003 May 7. Astronomy and Astrophysics, 425, 1119-1124

  12. Dielectric resonances in disordered media

    NASA Astrophysics Data System (ADS)

    Raymond, L.; Laugier, J.-M.; Schäfer, S.; Albinet, G.

    2003-02-01

    Binary disordered systems are usually obtained by mixing two ingredients in variable proportions: conductor and insulator, or conductor and super-conductor. They present very specific properties, in particular the second-order percolation phase transition, with its fractal geometry and the multi-fractal properties of the current moments. These systems are naturally modeled by regular bi-dimensional or tri-dimensional lattices, on which sites or bonds are chosen randomly with given probabilities. The two significant parameters are the ratio h = σ1/σ of the complex conductances, σ and σ1, of the two components, and their relative abundances p (or, respectively, 1 - p). In this article, we calculate the impedance of the composite by two independent methods: the so-called spectral method, which diagonalises Kirchhoff's Laws via a Green function formalism, and the Exact Numerical Renormalization method (ENR). These methods are applied to mixtures of resistors and capacitors (R-C systems), simulating e.g. ionic conductor-insulator systems, and to composites constituted of resistive inductances and capacitors (LR-C systems), representing metal inclusions in a dielectric bulk. The frequency dependent impedances of the latter composites present very intricate structures in the vicinity of the percolation threshold. In this paper, we analyse the LR-C behavior of compounds formed by the inclusion of small conducting clusters (``n-legged animals'') in a dielectric medium. We investigate in particular their absorption spectra who present a pattern of sharp lines at very specific frequencies of the incident electromagnetic field, the goal being to identify the signature of each animal. This enables us to make suggestions of how to build compounds with specific absorption or transmission properties in a given frequency domain.

  13. A proposal of microtomography evaluation for restoration interface gaps.

    PubMed

    Meleo, Deborah; Manzon, Licia; Pecci, Raffaella; Zuppante, Francesca; Bedini, Rossella

    2012-01-01

    Nowadays, several adhesive systems are used in dental restoration and they are evaluated by clinical research. In vitro evaluations are often made by means of traditional observation techniques (for example scanning electron microscope (SEM), while 3D cone-beam microtomography technique (3D micro-CT), that can be able to generate 3D sample images without any sample treatment during acquisition data, is going to be used a lot in the next few years. In dental cavity restored with composite, it is possible to predict the presence of gaps due to polymerization shrinkage; that is the reason this work purpose is to reveal by 3D images and measure by micro-CT analysis the voids generated applying the most used adhesive systems at the moment. By means of microtomographic analysis is proposed an aid to overcome bidimensional SEM investigation limits like random observation of sample surface, sample sectioning (to see inside it with the relative possible structural alterations induced on the same sample) and the gold sputtering treatment. For this experimental work, human crown teeth have been selected, all restored with the same composite material, using five adhesive systems. After about 48 hours each tooth has been acquired by means of Skyscan 1072 micro-CT instrument and then processed by 3D reconstruction and micro-CT analyser software. Three adhesive systems have showed 3D micro-CT images with not as much voids as expected, with a very little extent. This kind of micro-CT in vitro evaluation proposal suggests a method to observe and quantify the voids generated after polymerization shrinkage during tooth restoration. PMID:22456021

  14. Heterogeneity of serum gelatinases MMP-2 and MMP-9 isoforms and charge variants.

    PubMed

    Rossano, Rocco; Larocca, Marilena; Riviello, Lea; Coniglio, Maria Gabriella; Vandooren, Jennifer; Liuzzi, Grazia Maria; Opdenakker, Ghislain; Riccio, Paolo

    2014-02-01

    The matrix metalloproteinases (MMPs) gelatinase A (MMP-2) and gelatinase B (MMP-9) are mediators of brain injury in multiple sclerosis (MS) and valuable biomarkers of disease activity. We applied bidimensional zymography (2-DZ) as an extension of classic monodimensional zymography (1-DZ) to analyse the complete pattern of isoforms and post-translational modifications of both MMP-9 and MMP-2 present in the sera of MS patients. The enzymes were separated on the basis of their isoelectric points (pI) and apparent molecular weights (Mw) and identified both by comparison with standard enzyme preparations and by Western blot analysis. Two MMP-2 isoforms, and at least three different isoforms and two different states of organization of MMP-9 (the multimeric MMP-9 and the N-GAL-MMP-9 complex) were observed. In addition, 2-DZ revealed for the first time that all MMP-9 and MMP-2 isoforms actually exist in the form of charge variants: four or five variants in the NGAL complex, more charge variants in the case of MMP-9; and five to seven charge variants for MMP-2. Charge variants were also observed in recombinant enzymes and, after concentration, also in sera from healthy individuals. Sialylation (MMP-9) and phosphorylation (MMP-2) contributed to molecular heterogeneity. The detection of charge variants of MMP-9 and MMP-2 in MS serum samples illustrates the power of 2-DZ and demonstrates that in previous studies MMP mixtures, rather than single molecules, were analysed. These observations open perspectives for better diagnosis and prognosis of many diseases and need to be critically interpreted when applying other methods for MS and other diseases. PMID:24616914

  15. Hierarchical simulation of aquifer heterogeneity: implications of different simulation settings on solute-transport modeling

    NASA Astrophysics Data System (ADS)

    Comunian, Alessandro; De Micheli, Leonardo; Lazzati, Claudio; Felletti, Fabrizio; Giacobbo, Francesca; Giudici, Mauro; Bersezio, Riccardo

    2016-03-01

    The fine-scale heterogeneity of porous media affects the large-scale transport of solutes and contaminants in groundwater and it can be reproduced by means of several geostatistical simulation tools. However, including the available geological information in these tools is often cumbersome. A hierarchical simulation procedure based on a binary tree is proposed and tested on two real-world blocks of alluvial sediments, of a few cubic meters volume, that represent small-scale aquifer analogs. The procedure is implemented using the sequential indicator simulation, but it is so general that it can be adapted to various geostatistical simulation tools, improving their capability to incorporate geological information, i.e., the sedimentological and architectural characterization of heterogeneity. When compared with a standard sequential indicator approach on bi-dimensional simulations, in terms of proportions and connectivity indicators, the proposed procedure yields reliable results, closer to the reference observations. Different ensembles of three-dimensional simulations based on different hierarchical sequences are used to perform numerical experiments of conservative solute transport and to obtain ensembles of equivalent pore velocity and dispersion coefficient at the scale length of the blocks (meter). Their statistics are used to estimate the impact of the variability of the transport properties of the simulated blocks on contaminant transport modeled on bigger domains (hectometer). This is investigated with a one-dimensional transport modeling based on the Kolmogorov-Dmitriev theory of branching stochastic processes. Applying the proposed approach with diverse binary trees and different simulation settings provides a great flexibility, which is revealed by the differences in the breakthrough curves.

  16. Comparative Proteome of Acetobacter pasteurianus Ab3 During the High Acidity Rice Vinegar Fermentation.

    PubMed

    Wang, Zhe; Zang, Ning; Shi, Jieyan; Feng, Wei; Liu, Ye; Liang, Xinle

    2015-12-01

    As a traditional Asian food for several centuries, vinegar is known to be produced by acetic acid bacteria. The Acetobacter species is the primary starter for vinegar fermentation and has evolutionarily acquired acetic acid resistance, in which Acetobacter pasteurianus Ab3 is routinely used for industrial production of rice vinegar with a high acidity (9 %, w/v). In contrast to the documented short-term and low acetic acid effects on A. pasteurianus, here we investigated the molecular and cellular signatures of long-term and high acetic acid responses by proteomic profiling with bidimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF/MS) analyses. Protein spots of interest were selected based on the threshold ANOVA p value of 0.05 and minimal twofold of differential expression, leading to the identification of 26 proteins that are functionally enriched in oxidoreductase activity, cell membrane, and metabolism. The alterations in protein functioning in respiratory chain and protein denaturation may underlay cellular modifications at the outer membrane. Significantly, we found that at higher acidity fermentation phase, the A. pasteurianus Ab3 cells would adapt to distinct physiological processes from that of an ordinary vinegar fermentation with intermediate acidity, indicating increasing energy requirement and dependency of membrane integrity during the transition of acetic acid production. Together, our study provided new insights into the adaptation mechanisms in A. pasteurianus to high acetic acid environments and yield novel regulators and key pathways during the development of acetic acid resistance. PMID:26369782

  17. Improving FTIR imaging speciation of organic compound residues or their degradation products in wall painting samples, by introducing a new thin section preparation strategy based on cyclododecane pre-treatment.

    PubMed

    Papliaka, Zoi Eirini; Vaccari, Lisa; Zanini, Franco; Sotiropoulou, Sophia

    2015-07-01

    Fourier transform infrared (FTIR) imaging in transmission mode, employing a bidimensional focal plane array (FPA) detector, was applied for the detection and spatially resolved chemical characterisation of organic compounds or their degradation products within the stratigraphy of a critical group of fragments, originating from prehistoric and roman wall paintings, containing a very low concentration of subsisted organic matter or its alteration products. Past analyses using attenuated total reflection (ATR) or reflection FTIR on polished cross sections failed to provide any evidence of any organic material assignable as binding medium of the original painting. In order to improve the method's performance, in the present study, a new method of sample preparation in thin section was developed. The procedure is based on the use of cyclododecane C12H24 as embedding material and a subsequent double-side polishing of the specimen. Such procedure provides samples to be studied in FTIR transmission mode without losing the information on the spatial distribution of the detected materials in the paint stratigraphy. For comparison purposes, the same samples were also studied after opening their stratigraphy with a diamond anvil cell. Both preparation techniques offered high-quality chemical imaging of the decay products of an organic substance, giving clues to the painting technique. In addition, the thin sections resulting from the cyclododecane pre-treatment offered more layer-specific data, as the layer thickness and order remained unaffected, whereas the samples resulting from compression within the diamond cell were slightly deformed; however, since thinner and more homogenous, they provided higher spectral quality in terms of S/N ratio. In summary, the present study illustrates the appropriateness of FTIR imaging in transmission mode associated with a new thin section preparation strategy to detect and localise very low-concentrated organic matter subjected to

  18. Data-driven Radiative Hydrodynamic Modeling of the 2014 March 29 X1.0 Solar Flare

    NASA Astrophysics Data System (ADS)

    Rubio da Costa, Fatima; Kleint, Lucia; Petrosian, Vahé; Liu, Wei; Allred, Joel C.

    2016-08-01

    Spectroscopic observations of solar flares provide critical diagnostics of the physical conditions in the flaring atmosphere. Some key features in observed spectra have not yet been accounted for in existing flare models. Here we report a data-driven simulation of the well-observed X1.0 flare on 2014 March 29 that can reconcile some well-known spectral discrepancies. We analyzed spectra of the flaring region from the Interface Region Imaging Spectrograph (IRIS) in Mg ii h&k, the Interferometric BIdimensional Spectropolarimeter at the Dunn Solar Telescope (DST/IBIS) in Hα 6563 Å and Ca ii 8542 Å, and the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) in hard X-rays. We constructed a multithreaded flare loop model and used the electron flux inferred from RHESSI data as the input to the radiative hydrodynamic code RADYN to simulate the atmospheric response. We then synthesized various chromospheric emission lines and compared them with the IRIS and IBIS observations. In general, the synthetic intensities agree with the observed ones, especially near the northern footpoint of the flare. The simulated Mg ii line profile has narrower wings than the observed one. This discrepancy can be reduced by using a higher microturbulent velocity (27 km s‑1) in a narrow chromospheric layer. In addition, we found that an increase of electron density in the upper chromosphere within a narrow height range of ≈800 km below the transition region can turn the simulated Mg ii line core into emission and thus reproduce the single peaked profile, which is a common feature in all IRIS flares.

  19. Tracing the Chromospheric and Coronal Magnetic Field with AIA, IRIS, IBIS, and ROSA Data

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.; Reardon, Kevin; Jess, Dave B.

    2016-07-01

    The aim of this study is to explore the suitability of chromospheric images for magnetic modeling of active regions. We use high-resolution images (≈ 0\\buildrel{\\prime\\prime}\\over{.} 2{--}0\\buildrel{\\prime\\prime}\\over{.} 3), from the Interferometric Bidimensional Spectrometer in the Ca ii 8542 Å line, the Rapid Oscillations in the Solar Atmosphere instrument in the Hα 6563 Å line, the Interface Region Imaging Spectrograph in the 2796 Å line, and compare non-potential magnetic field models obtained from those chromospheric images with those obtained from images of the Atmospheric Imaging Assembly in coronal (171 Å, etc.) and in chromospheric (304 Å) wavelengths. Curvi-linear structures are automatically traced in those images with the OCCULT-2 code, to which we forward-fitted magnetic field lines computed with the Vertical-current Approximation Nonlinear Force Free Field code. We find that the chromospheric images: (1) reveal crisp curvi-linear structures (fibrils, loop segments, spicules) that are extremely well-suited for constraining magnetic modeling; (2) that these curvi-linear structures are field-aligned with the best-fit solution by a median misalignment angle of {μ }2≈ 4^\\circ –7° (3) the free energy computed from coronal data may underestimate that obtained from cromospheric data by a factor of ≈ 2–4, (4) the height range of chromospheric features is confined to h≲ 4000 km, while coronal features are detected up to h = 35,000 km; and (5) the plasma-β parameter is β ≈ {10}-5{--}{10}-1 for all traced features. We conclude that chromospheric images reveal important magnetic structures that are complementary to coronal images and need to be included in comprehensive magnetic field models, something that is currently not accomodated in standard NLFFF codes.

  20. Linguistic Acculturation and Skin Cancer-Related Behaviors Among Hispanics in the Southern and Western United States

    PubMed Central

    Coups, Elliot J.; Stapleton, Jerod L.; Hudson, Shawna V.; Medina-Forrester, Amanda; Rosenberg, Stephen A.; Gordon, Marsha; Natale-Pereira, Ana; Goydos, James S.

    2012-01-01

    Objective To examine the association between linguistic acculturation (assessed using the Language Use and Linguistic Preference subscales from the Bidimensional Acculturation Scale for Hispanics) and skin cancer-related behaviors among U.S. Hispanic adults. We hypothesized that, compared to Hispanics denoted as Spanish acculturated, English acculturated Hispanics would report less frequent shade seeking and use of sun protective clothing and higher rates of sunscreen use, sunbathing, and indoor tanning. Design Online survey study conducted in September, 2011. Setting Survey of Hispanic adults residing in five southern and western U.S. states. Participants A population-based sample of 788 Hispanic adults drawn from a nationally representative web panel. Main Outcome Measures Self-reported sunscreen use, shade seeking, use of sun protective clothing, sunbathing, and indoor tanning. Results Multivariable regression analyses were conducted to examine predictors of the skin cancer-related behaviors. As hypothesized, English acculturated Hispanics had lower rates of shade seeking and use of sun protective clothing and reported higher rates of sunbathing and indoor tanning than Spanish acculturated Hispanics. English acculturated Hispanics and bicultural Hispanics (i.e., those with high Spanish and high English acculturation) reported comparably high rates of sunbathing and indoor tanning. Results suggested that bicultural Hispanics seek shade and wear sun protective clothing less often than Spanish acculturated Hispanics but more often than English acculturated Hispanics. Acculturation was not associated with sunscreen use. Conclusions Hispanic adults do not routinely engage in behaviors that reduce their risk of skin cancer. Bicultural and English acculturated Hispanics are particularly in need of skin cancer prevention interventions. PMID:23752366

  1. Dynamical study of nonadiabatic unimolecular reactions: The conical intersection between the B-tilde 2B2 and A-tilde 2A1 states of H2O +

    NASA Astrophysics Data System (ADS)

    Dehareng, Dominique; Chapuisat, Xavier; Lorquet, Jean-Claude; Galloy, Claudine; Raseev, Gheorghe

    1983-02-01

    The conical intersection connecting the B˜ 2A' and à 2A' states of the H2O+ ion is studied. The two potential energy surfaces are calculated ab initio by the SCF/CI method within the CS point group. The nonadiabatic coupling matrix elements <Ã‖∂/∂q‖B˜> are computed for several cross sections throughout the potential energy surfaces. A transformation to the diabatic representation is performed. The linear model is found to be a good approximation in the region close to the apex of the cone. The global functions t(s) and T(S) governing the nonadiabatic transition probability are calculated; their shapes are those predicted by the Landau-Zener model (in the Nikitin bidimensional version). A dynamical study is undertaken by means of classical trajectory calculations on the upper adiabatic potential energy surface. An averaged transition probability P¯tr is derived. Excitation of rotation or of the bending mode of H2O before photon impact has no influence on P¯tr. Excitation of the symmetrical or antisymmetrical valence modes of H2O lowers P¯tr. The shape of ln (1-P¯tr) as a function of time indicates the existence of two distinct regimes at short and intermediate time ranges, characterized by two different rate constants k1 and k2, respectively. The rate constants are of the order of 1014 s-1. k1 exhibits a maximum as a function of the absorbed energy Eabs, whereas k2 decreases as a function of Eabs.

  2. Comprehensive two-dimensional gas chromatography for fingerprint pattern recognition in olive oils produced by two different techniques in Portuguese olive varieties Galega Vulgar, Cobrançosa e Carrasquenha.

    PubMed

    Vaz-Freire, L Torres; da Silva, M D R Gomes; Freitas, A M Costa

    2009-02-01

    For olive oil production a metal hammer-decanter olive processing line was compared to a traditional metal hammer-press line, a discontinuous method which, if properly used, yields high-quality virgin olive oils. Galega, Carrasquenha and Cobrançosa olives (traditional Portuguese varieties) were studied. The analysis of the aroma compounds was performed after headspace-solid phase micro extraction. The analytical results obtained after comprehensive gas chromatography in tandem with time of flight mass spectrometry (GCxGC/ToFMS) for these three different olive oil varieties, from a single year harvest and processed with two different extraction technologies, were compared using statistical image treatment, by means of ImageJ software, for fingerprint recognitions and compared with principal component analysis when the area data of each chromatographic spot of the contour plots were considered. The differences used to classify the olive oils studied under different groups after principal component analysis were observed independently of the treatment used (peak areas or the sum of the pixels counts). When the individual peak areas were considered, more then 75.7% of the total variance is explained by the first two principal components while in the case where the data were subjected to image treatment 84.0% of the total variance is explained by the first two principal components. In both cases the first and second principal components present eigenvalues higher then 1.0. Fingerprint image monitoring of the aroma compounds of the olive oil allowed a rapid differentiation of the three varieties studied as well as the extraction methods used. The volatile compounds responsible for their characterization were tentatively identified in a bi-dimensional polar/non-polar column set in the GCxGC/Tof-MS apparatus. This methodology allowed the reduction of the number of compounds needed for matrices characterization, preserving the efficiency of the discrimination, when

  3. Surface characterization of platinum electrodes.

    PubMed

    Solla-Gullón, José; Rodríguez, Paramaconi; Herrero, Enrique; Aldaz, Antonio; Feliu, Juan M

    2008-03-14

    The quantitative analysis of the different surface sites on platinum samples is attempted from pure voltammetric data. This analysis requires independent knowledge of the fraction of two-dimensional (111) and (100) domains. Specific site-probe reactions are employed to achieve this goal. Irreversibly-adsorbed bismuth and tellurium have been revealed to be sensitive to the presence of (111) terrace domains of different width whereas almost all sites involved in (100) ordered domains have been characterized through germanium adatoms. The experimental protocol follows that used with well-defined single-crystal electrodes and, therefore, requires careful control of the surface cleanliness. Platinum basal planes and their vicinal stepped surfaces have been employed to obtain calibration plots between the charge density measured under the adatom redox peak, specific for the type of surface site, and the corresponding terrace size. The evaluation of the (100) bidimensional domains can also be achieved using the voltammetric profiles, once the fraction of (111) ordered domains present in the polyoriented platinum has been determined and their featureless contribution has been subtracted from the whole voltammetric response. Using that curve, it is possible to perform a deconvolution of the adsorption states of the polycrystalline sample different from those related to (111) domains. The fraction of (100)-related states in the deconvoluted voltammogram can then be compared to that expected from the independent estimation coming from the charge involved in the redox process undergone by the irreversibly-adsorbed germanium and thus check the result of the deconvolution. The information about the surface-site distribution can also be applied to analyze the voltammetric profile of nanocrystalline platinum electrodes. PMID:18309392

  4. Left atrial reservoir function predicts atrial fibrillation recurrence after catheter ablation: a two-dimensional speckle strain study

    PubMed Central

    Mirza, Mahek; Caracciolo, Giuseppe; Khan, Uzma; Mori, Naoyo; Saha, Samir K.; Srivathsan, Komandoor; Altemose, Gregory; Scott, Luis; Sengupta, Partho

    2011-01-01

    Background Predictors of atrial fibrillation (AF) recurrence after catheter ablation (CA) are not fully defined. We hypothesized that 2D left atrial (LA) regional strain maps would help identify abnormal atrial substrate that increases susceptibility to AF recurrence post-CA. Methods and Results Sixty-three patients (63±10 years, 60% male) underwent CA for symptomatic paroxysmal (75%) or persistent (25%) AF. Baseline LA mechanical function determined using speckle tracking echocardiography was compared between those with AF recurrence (AFR) and no recurrence post-CA. Bi-dimensional global and regional maps of LA wall velocity, strain, and strain rate (SR) were obtained during end ejection and early diastole. After 18±12 months of follow-up, 34 patients were free of AFR post-CA. There were no differences in clinical characteristics, LA and LV volumes, and Doppler estimates of LV diastolic function and filling pressures at baseline between patients with recurrent AF and those that maintained sinus rhythm. However, the LA emptying fraction (55±17% vs. 64±14%, p=0.04), global and regional systolic and diastolic strains, SR, and velocities were reduced in patients with recurrent AF. There was marked attenuation of peak LA lateral wall longitudinal strain (LS; 11±7% vs. 20±14%, p=0.007) and SR (0.9±0.4 vs. 1.3±0.6 s−1, p=0.01). Multivariate analysis revealed lateral wall LS (odds ratio=1.15, 95% CI=1.02–1.28, p=0.01) as an independent predictor of AFR. Conclusions Regional LA lateral wall LS is a pre-procedural determinant of AFR in patients undergoing CA, independent of LA enlargement. Characterization of atrial myocardial tissue properties by speckle tracking echo may aid the appropriate selection of adjunctive strategies and prognostication of patients undergoing CA. PMID:21424845

  5. Phase II trial of pazopanib (GW786034), an oral multi-targeted angiogenesis inhibitor, for adults with recurrent glioblastoma (North American Brain Tumor Consortium Study 06-02).

    PubMed

    Iwamoto, Fabio M; Lamborn, Kathleen R; Robins, H Ian; Mehta, Minesh P; Chang, Susan M; Butowski, Nicholas A; Deangelis, Lisa M; Abrey, Lauren E; Zhang, Wei-Ting; Prados, Michael D; Fine, Howard A

    2010-08-01

    The objective of this phase II single-arm study was to evaluate the efficacy and safety of pazopanib, a multi-targeted tyrosine kinase inhibitor, against vascular endothelial growth factor receptor (VEGFR)-1, -2, and -3, platelet-derived growth factor receptor-alpha and -beta, and c-Kit, in recurrent glioblastoma. Patients with < or =2 relapses and no prior anti-VEGF/VEGFR therapy were treated with pazopanib 800 mg daily on 4-week cycles without planned interruptions. Brain magnetic resonance imaging and clinical reassessment were made every 8 weeks. The primary endpoint was efficacy as measured by 6-month progression-free survival (PFS6). Thirty-five GBM patients with a median age of 53 years and median Karnofsky performance scale of 90 were accrued. Grade 3/4 toxicities included leukopenia (n = 1), lymphopenia (n = 2), thrombocytopenia (n = 1), ALT elevation (n = 3), AST elevation (n = 1), CNS hemorrhage (n = 1), fatigue (n = 1), and thrombotic/embolic events (n = 3); 8 patients required dose reduction. Two patients had a partial radiographic response by standard bidimensional measurements, whereas 9 patients (6 at the 8-week point and 3 only within the first month of treatment) had decreased contrast enhancement, vasogenic edema, and mass effect but <50% reduction in tumor. The median PFS was 12 weeks (95% confidence interval [CI]: 8-14 weeks) and only 1 patient had a PFS time > or =6 months (PFS6 = 3%). Thirty patients (86%) had died and median survival was 35 weeks (95% CI: 24-47 weeks). Pazopanib was reasonably well tolerated with a spectrum of toxicities similar to other anti-VEGF/VEGFR agents. Single-agent pazopanib did not prolong PFS in this patient population but showed in situ biological activity as demonstrated by radiographic responses. ClinicalTrials.gov identifier: NCT00459381. PMID:20200024

  6. Phase II trial of pazopanib (GW786034), an oral multi-targeted angiogenesis inhibitor, for adults with recurrent glioblastoma (North American Brain Tumor Consortium Study 06-02)

    PubMed Central

    Iwamoto, Fabio M.; Lamborn, Kathleen R.; Robins, H. Ian; Mehta, Minesh P.; Chang, Susan M.; Butowski, Nicholas A.; DeAngelis, Lisa M.; Abrey, Lauren E.; Zhang, Wei-Ting; Prados, Michael D.; Fine, Howard A.

    2010-01-01

    The objective of this phase II single-arm study was to evaluate the efficacy and safety of pazopanib, a multi-targeted tyrosine kinase inhibitor, against vascular endothelial growth factor receptor (VEGFR)-1, -2, and -3, platelet-derived growth factor receptor-α and -β, and c-Kit, in recurrent glioblastoma. Patients with ≤2 relapses and no prior anti-VEGF/VEGFR therapy were treated with pazopanib 800 mg daily on 4-week cycles without planned interruptions. Brain magnetic resonance imaging and clinical reassessment were made every 8 weeks. The primary endpoint was efficacy as measured by 6-month progression-free survival (PFS6). Thirty-five GBM patients with a median age of 53 years and median Karnofsky performance scale of 90 were accrued. Grade 3/4 toxicities included leukopenia (n = 1), lymphopenia (n = 2), thrombocytopenia (n = 1), ALT elevation (n = 3), AST elevation (n = 1), CNS hemorrhage (n = 1), fatigue (n = 1), and thrombotic/embolic events (n = 3); 8 patients required dose reduction. Two patients had a partial radiographic response by standard bidimensional measurements, whereas 9 patients (6 at the 8-week point and 3 only within the first month of treatment) had decreased contrast enhancement, vasogenic edema, and mass effect but <50% reduction in tumor. The median PFS was 12 weeks (95% confidence interval [CI]: 8–14 weeks) and only 1 patient had a PFS time ≥6 months (PFS6 = 3%). Thirty patients (86%) had died and median survival was 35 weeks (95% CI: 24–47 weeks). Pazopanib was reasonably well tolerated with a spectrum of toxicities similar to other anti-VEGF/VEGFR agents. Single-agent pazopanib did not prolong PFS in this patient population but showed in situ biological activity as demonstrated by radiographic responses. ClinicalTrials.gov identifier: NCT00459381. PMID:20200024

  7. Unbinding free energy of acetylcholinesterase bound oxime drugs along the gorge pathway from metadynamics-umbrella sampling investigation.

    PubMed

    Pathak, Arup K; Bandyopadhyay, Tusar

    2014-09-01

    Because of the pivotal role that the nerve enzyme, acetylcholinesterase plays in terminating nerve impulses at cholinergic synapses. Its active site, located deep inside a 20 Å gorge, is a vulnerable target of the lethal organophosphorus compounds. Potent reactivators of the intoxicated enzyme are nucleophiles, such as bispyridinium oxime that binds to the peripheral anionic site and the active site of the enzyme through suitable cation-π interactions. Atomic scale molecular dynamics and free energy calculations in explicit water are used to study unbinding pathways of two oxime drugs (Ortho-7 and Obidoxime) from the gorge of the enzyme. The role of enzyme-drug cation-π interactions are explored with the metadynamics simulation. The metadynamics discovered potential of mean force (PMF) of the unbinding events is refined by the umbrella sampling (US) corrections. The bidimensional free energy landscape of the metadynamics runs are further subjected to finite temperature string analysis to obtain the transition tube connecting the minima and bottlenecks of the unbinding pathway. The PMF is also obtained from US simulations using the biasing potential constructed from the transition tube and are found to be consistent with the metadynamics-US corrected results. Although experimental structural data clearly shows analogous coordination of the two drugs inside the gorge in the bound state, the PMF of the drug trafficking along the gorge pathway point, within an equilibrium free energy context, to a multistep process that differs from one another. Routes, milestones and subtlety toward the unbinding pathway of the two oximes at finite temperature are identified. PMID:24549829

  8. Standard fluctuation-dissipation process from a deterministic mapping

    NASA Astrophysics Data System (ADS)

    Bianucci, Marco; Mannella, Riccardo; Fan, Ximing; Grigolini, Paolo; West, Bruce J.

    1993-03-01

    We illustrate a derivation of a standard fluctuation-dissipation process from a discrete deterministic dynamical model. This model is a three-dimensional mapping, driving the motion of three variables, w, ξ, and π. We show that for suitable values of the parameters of this mapping, the motion of the variable w is indistinguishable from that of a stochastic variable described by a Fokker-Planck equation with well-defined friction γ and diffusion D. This result can be explained as follows. The bidimensional system of the two variables ξ and π is a nonlinear, deterministic, and chaotic system, with the key property of resulting in a finite correlation time for the variable ξ and in a linear response of ξ to an external perturbation. Both properties are traced back to the fully chaotic nature of this system. When this subsystem is coupled to the variable w, via a very weak coupling guaranteeing a large-time-scale separation between the two systems, the variable w is proven to be driven by a standard fluctuation-dissipation process. We call the subsystem a booster whose chaotic nature triggers the standard fluctuation-dissipation process exhibited by the variable w. The diffusion process is a trivial consequence of the central-limit theorem, whose validity is assured by the finite time scale of the correlation function of ξ. The dissipation affecting the variable w is traced back to the linear response of the booster, which is evaluated adopting a geometrical procedure based on the properties of chaos rather than the conventional perturbation approach.

  9. Gardony Map Drawing Analyzer: Software for quantitative analysis of sketch maps.

    PubMed

    Gardony, Aaron L; Taylor, Holly A; Brunyé, Tad T

    2016-03-01

    Sketch maps are effective tools for assessing spatial memory. However, despite their widespread use in cognitive science research, sketch map analysis techniques remain unstandardized and carry limitations. In the present article, we present the Gardony Map Drawing Analyzer (GMDA), an open-source software package for sketch map analysis. GMDA combines novel and established analysis techniques into a graphical user interface that permits rapid computational sketch map analysis. GMDA calculates GMDA-unique measures based on pairwise comparisons between landmarks, as well as bidimensional regression parameters (Friedman & Kohler, 2003), which together reflect sketch map quality at two levels: configural and individual landmark. The configural measures assess the overall landmark configuration and provide a whole-map analysis. Individual landmark measures, introduced in GMDA, assess individual landmark placement and indicate how individual landmarks contribute to the configural scores. Together, these measures provide a more complete psychometric picture of sketch map analysis, allowing for comparisons between sketch maps and between landmarks. The calculated measures reflect specific and cognitively relevant aspects of interlandmark spatial relationships, including distance and angular representation. GMDA supports complex environments (up to 48 landmarks) and two software modes that capture aspects of maps not addressed by existing techniques, such as landmark size and shape variation and interlandmark containment relationships. We describe the software and its operation and present a formal specification of calculation procedures for its unique measures. We then validate the software by demonstrating the capabilities and reliability of its measures using simulation and experimental data. The most recent version of GMDA is available at www.aarongardony.com/tools/map-drawing-analyzer. PMID:25673320

  10. Experimental velocity fields and forces for a cylinder penetrating into a granular medium.

    PubMed

    Seguin, A; Bertho, Y; Martinez, F; Crassous, J; Gondret, P

    2013-01-01

    We present here a detailed granular flow characterization together with force measurements for the quasi-bidimensional situation of a horizontal cylinder penetrating vertically at a constant velocity in dry granular matter between two parallel glass walls. In the velocity range studied here, the drag force on the cylinder does not depend on the velocity V(0) and is mainly proportional to the cylinder diameter d. While the force on the cylinder increases with its penetration depth, the granular velocity profile around the cylinder is found to be stationary with fluctuations around a mean value leading to the granular temperature profile. Both mean velocity profile and temperature profile exhibit strong localization near the cylinder. The mean flow perturbation induced by the cylinder decreases exponentially away from the cylinder on a characteristic length λ that is mainly governed by the cylinder diameter for a large enough cylinder/grain size ratio d/d(g): λ~d/4+2d(g). The granular temperature exhibits a constant plateau value T(0) in a thin layer close to the cylinder of extension δ(T(0))~λ/2 and decays exponentially far away with a characteristic length λ(T) of a few grain diameters (λ(T)~3d(g)). The granular temperature plateau T(0) that scales as V(0)(2)d(g)/d is created by the flow itself from the balance between the "granular heat" production by the shear rate V(0)/λ over δ(T(0)) close to the cylinder and the granular dissipation far away. PMID:23410320

  11. MALDI-TOF mass spectrometry and reversed-phase HPLC-ELSD chromatography for structural and quantitative studies of major steroid saponins in commercial extracts of Yucca schidigera Roezl.

    PubMed

    Sastre, F; Ferreira, F; Pedreschi, F

    2016-02-20

    This paper describes a new, improved systematic qualitative analysis of yucca saponins in commercial products by combined use of high-pressure liquid chromatography (HPLC) coupled to an evaporative light scattering detector (ELSD) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Three groups with four saponins in each were completely resolved by HPLC-ELSD under C18 reversed-phase conditions using a linear gradient composed of methanol and water. The selectivity of the described HPLC-ELSD method is given by the sapogenin differences at C12 (carbonyl group) and at C2 (hydroxyl group), followed by the presence or absence of an exomethylene group at C25, and the composition and length of the oligosaccharidic chain at C3 in the sapogenins. The saponins were identified by chemical and spectroscopic methods including MALDI-TOF MS(1) and MS(2), high resolution MS, and one and bi-dimensional nuclear magnetic resonance (NMR) experiments. Among the twelve saponins identified, eleven were previously reported, and one is reported for the first time in Yucca schidigera. An identification flowchart procedure based on the analysis of the sodium adducts of intact saponins [M+Na](+) and the oligosaccharidic chain ions obtained in the MALDI-TOF MS(1) and the MS(2) spectrums, was developed for the analysis of Y. schidigera saponins. Two intact isomeric saponins were differentiated by this method, which could also be applied to the structural assignment of other steroid and triterpenic saponins. Using the four-major saponins as reference standards, a C18 reversed-phase HPLC-ELSD method was validated for their specific analysis in commercial extracts of Y. schidigera. Finally, the applicability of the HPLC-ELSD method for the relative quantification of yucca saponins is discussed. PMID:26760245

  12. A triangle model of criminality

    NASA Astrophysics Data System (ADS)

    Nuño, Juan C.; Herrero, Miguel A.; Primicerio, Mario

    2008-05-01

    This paper is concerned with a quantitative model describing the interaction of three sociological species, termed as owners, criminals and security guards, and denoted by X, Y and Z respectively. In our model, Y is a predator of the species X, and so is Z with respect to Y. Moreover, Z can also be thought of as a predator of X, since this last population is required to bear the costs of maintaining Z. We propose a system of three ordinary differential equations to account for the time evolution of X(t), Y(t) and Z(t) according to our previous assumptions. Out of the various parameters that appear in that system, we select two of them, denoted by H, and h, which are related with the efficiency of the security forces as a control parameter in our discussion. To begin with, we consider the case of large and constant owners population, which allows us to reduce (3)-(5) to a bidimensional system for Y(t) and Z(t). As a preliminary step, this situation is first discussed under the additional assumption that Y(t)+Z(t) is constant. A bifurcation study is then performed in terms of H and h, which shows the key role played by the rate of casualties in Y and Z, that results particularly in a possible onset of bistability. When the previous restriction is dropped, we observe the appearance of oscillatory behaviours in the full two-dimensional system. We finally provide a exploratory study of the complete model (3)-(5), where a number of bifurcations appear as parameter H changes, and the corresponding solutions behaviours are described.

  13. Brazil nut effect: Influence of friction and jamming on the transition line

    NASA Astrophysics Data System (ADS)

    Cordero, P.; Godoy, S.; Risso, D.; Soto, R.

    2009-01-01

    We report a molecular dynamics study of the behavior of a bidimensional system consisting of a large disk (the intruder) immersed in a bed of many small disks. All collisions are instantaneous and inelastic and all possible parameters of the system are kept fixed except for two dimensionless parameters determining the frequency and amplitude of the vibrating base. A systematic exploration of this parameter space leads to determining a transition line separating a zone in which the Brazil nut effect is observed and one in which it is not. It is observed for the BNE to be present it is necessary that the characteristic velocity of the vibrating base is above a certain threshold. This threshold increases as the characteristic acceleration of the base gets larger. The results strongly suggest that, in the region of the parameter space in which the study is made, there is a minimum amplitude and a maximum frequency for the Brazil nut effect to take place. The shape of the transition line is understood in connection with the friction of the system with the lateral walls and with jamming. Friction with the lateral walls produces a net downward force, eventually leading to a convective current that pushes the intruder up. Although the energy injection rate, that helps the development of the convective current, is proportional mainly to the square of the velocity of the base, it is found that the average frictional force decreases when increasing the base acceleration. Therefore, for large base accelerations, higher values of the base velocity are needed to produce a convective current sufficiently strong. But if the system is not excited enough the friction which would produced convective currents are balanced by the reaction forces that result from jamming.

  14. Multiplexed Detection of O-GlcNAcome, Phosphoproteome, and Whole Proteome within the Same Gel

    PubMed Central

    Cieniewski-Bernard, Caroline; Dupont, Erwan; Deracinois, Barbara; Lambert, Matthias; Bastide, Bruno

    2014-01-01

    The cellular diversity of proteins results in part from their post-translational modifications. Among all of them, the O-GlcNAcylation is an atypical glycosylation, more similar to phosphorylation than classical glycosylations. Highly dynamic, reversible, and exclusively localized on cytosolic, nuclear, and mitochondrial proteins, O-GlcNAcylation is known to regulate almost all if not all cellular processes. Fundamental for the cell life, O-GlcNAcylation abnormalities are involved in the etiology of several inherited diseases. Assessing to O-GlcNAcylation pattern will permit to get relevant data about the role of O-GlcNAcylation in cell physiology. To get understanding about the role of O-GlcNAcylation, as also considering its interplay with phosphorylation, the O-GlcNAc profiling remains a real challenge for the community of proteomists/glycoproteomists. The development of multiplexed proteomics based on fluorescent detection of proteins permits to go further in the understanding of the proteome complexity. We propose herein a multiplexed proteomic strategy to detect O-GlcNAcylated proteins, phosphoproteins, and the whole proteome within the same bidimensional gel. In particular, we investigated the phosphoproteome through the ProQ Diamond staining, while the whole proteome was visualized through Sypro Ruby staining, or after the labeling of proteins with a T-Dye fluorophore. The O-GlcNAcome was revealed by the way of the Click chemistry and the azide–alkyne cycloaddition of a fluorophore on GlcNAc moieties. This method permits, after sequential image acquisition, the direct in-gel detection of O-GlcNAcome, phosphoproteome, and whole proteome. PMID:25389416

  15. A Randomized Double-Blind Placebo-Controlled Phase IIB Trial of Curcumin in Oral Leukoplakia.

    PubMed

    Kuriakose, Moni Abraham; Ramdas, Kunnambath; Dey, Bindu; Iyer, Subramanya; Rajan, Gunaseelan; Elango, Kalavathy K; Suresh, Amritha; Ravindran, Divya; Kumar, Rajneesh R; R, Prathiba; Ramachandran, Surya; Kumar, Nisha Asok; Thomas, Gigi; Somanathan, Thara; Ravindran, Hiran K; Ranganathan, Kannan; Katakam, Sudhakar Babu; Parashuram, Shivashankar; Jayaprakash, Vijayvel; Pillai, M Radhakrishna

    2016-08-01

    Oral leukoplakia is a potentially malignant lesion of the oral cavity, for which no effective treatment is available. We investigated the effectiveness of curcumin, a potent inhibitor of NF-κB/COX-2, molecules perturbed in oral carcinogenesis, to treat leukoplakia. Subjects with oral leukoplakia (n = 223) were randomized (1:1 ratio) to receive orally, either 3.6 g/day of curcumin (n = 111) or placebo (n = 112), for 6 months. The primary endpoint was clinical response obtained by bi-dimensional measurement of leukoplakia size at recruitment and 6 months. Histologic response, combined clinical and histologic response, durability and effect of long-term therapy for an additional six months in partial responders, safety and compliance were the secondary endpoints. Clinical response was observed in 75 (67.5%) subjects [95% confidence interval (CI), 58.4-75.6] in the curcumin and 62 (55.3%; 95% CI, 46.1-64.2) in placebo arm (P = 0.03). This response was durable, with 16 of the 18 (88.9%; 95% CI, 67.2-96.9) subjects with complete response in curcumin and 7 of 8 subjects (87.5%) in placebo arm, demonstrating no relapse after 6 months follow-up. Difference in histologic response between curcumin and placebo was not significant (HR, 0.88, 95% CI, 0.45-1.71; P = 0.71). Combined clinical and histologic response assessment indicated a significantly better response with curcumin (HR, 0.50; 95% CI, 0.27-0.92; P = 0.02). Continued therapy, in subjects with partial response at 6 months, did not yield additional benefit. The treatment did not raise any safety concerns. Treatment of oral leukoplakia with curcumin (3.6 g for six months), thus was well tolerated and demonstrated significant and durable clinical response for 6 months. Cancer Prev Res; 9(8); 683-91. ©2016 AACR. PMID:27267893

  16. INTEGRAL FIELD SPECTROSCOPY AND MULTI-WAVELENGTH IMAGING OF THE NEARBY SPIRAL GALAXY NGC 5668 : AN UNUSUAL FLATTENING IN METALLICITY GRADIENT

    SciTech Connect

    Marino, R. A.; Gil de Paz, A.; Castillo-Morales, A.; Perez-Gonzalez, P. G.; Gallego, J.; Zamorano, J.; Sanchez, S. F.

    2012-07-20

    We present an analysis of the full bidimensional optical spectral cube of the nearby spiral galaxy NGC 5668, observed with the Pmas fiber PAcK Integral Field Unit (IFU) at the Calar Alto observatory 3.5 m telescope. We make use of broadband imaging to provide further constraints on the evolutionary history of the galaxy. This data set will allow us to improve our understanding of the mechanisms that drive the evolution of disks. We investigated the properties of 62 H II regions and concentric rings in NGC 5668 and derived maps in ionized-gas attenuation and chemical (oxygen) abundances. We find that while inward of r {approx}36'' {approx} 4.4 kpc {approx} 0.36 (D{sub 25}/2) the derived O/H ratio follows the radial gradient typical of spiral galaxies, the abundance gradient beyond r {approx} 36'' flattens out. The analysis of the multi-wavelength surface brightness profiles of NGC 5668 is performed by fitting these profiles with those predicted by chemo-spectrophotometric evolutionary models of galaxy disks. From this, we infer a spin and circular velocity of {lambda} = 0.053 and v{sub c} = 167 km s{sup -1}, respectively. The metallicity gradient and rotation curve predicted by this best-fitting galaxy model nicely match the values derived from the IFU observations, especially within r {approx}36''. The same is true for the colors despite some small offsets and a reddening in the bluest colors beyond that radius. On the other hand, deviations of some of these properties in the outer disk indicate that a secondary mechanism, possibly gas transfer induced by the presence of a young bar, must have played a role in shaping the recent chemical and star formation histories of NGC 5668.

  17. Differentially delayed root proteome responses to salt stress in sugar cane varieties.

    PubMed

    Pacheco, Cinthya Mirella; Pestana-Calsa, Maria Clara; Gozzo, Fabio Cesar; Mansur Custodio Nogueira, Rejane Jurema; Menossi, Marcelo; Calsa, Tercilio

    2013-12-01

    Soil salinity is a limiting factor to sugar cane crop development, although in general plants present variable mechanisms of tolerance to salinity stress. The molecular basis underlying these mechanisms can be inferred by using proteomic analysis. Thus, the objective of this work was to identify differentially expressed proteins in sugar cane plants submitted to salinity stress. For that, a greenhouse experiment was established with four sugar cane varieties and two salt conditions, 0 mM (control) and 200 mM NaCl. Physiological and proteomics analyses were performed after 2 and 72 h of stress induction by salt. Distinct physiological responses to salinity stress were observed in the varieties and linked to tolerance mechanisms. In proteomic analysis, the roots soluble protein fraction was extracted, quantified, and analyzed through bidimensional electrophoresis. Gel images analyses were done computationally, where in each contrast only one variable was considered (salinity condition or variety). Differential spots were excised, digested by trypsin, and identified via mass spectrometry. The tolerant variety RB867515 showed the highest accumulation of proteins involved in growth, development, carbohydrate and energy metabolism, reactive oxygen species metabolization, protein protection, and membrane stabilization after 2 h of stress. On the other hand, the presence of these proteins in the sensitive variety was verified only in stress treatment after 72 h. These data indicate that these stress responses pathways play a role in the tolerance to salinity in sugar cane, and their effectiveness for phenotypical tolerance depends on early stress detection and activation of the coding genes expression. PMID:24251627

  18. Reconstruction of Val Molinara 2010 debris flow and validation of the hazard mapping methodology

    NASA Astrophysics Data System (ADS)

    Zorzi, Nadia; Begnudelli, Lorenzo; Rosatti, Giorgio

    2013-04-01

    In this work, a real debris flow over an urbanized conoid is studied and reconstructed using the bidimensional finite-volume mathematical model Trent2D (Armanini et. al, Computer & Geosciences 2009). The event occurred in August 2010 in the village of Campolongo (Province of Trento, Italy) as a result of torrential rains and is particularly well documented thanks to the availability of aerial pictures, ground surveys, sediment deposition measurements, and data of two nearby rain gauges as well of radar. The 2D mathematical model adopted in the study is based on a two-phase description of the debris flow with immediate adaptation of the transport to the local flow conditions. It adopts a rheological closure valid in the grain-inertia regime. The equations are solved on a structured quadrilateral grid using a Godunov-type scheme, where inter-cell fluxes are evaluated using a MUSCL-Hancock approach with second order spatial and temporal accuracy. In order to reconstruct the event, the following tasks have been carried out: a) computation of liquid discharge through a rainfall-runoff model; b) evaluation of the debris flow discharge (and therefore of the discharge of solid mass); c) estimation of the model's parameters; d) execution of simulation and comparison with available data. Model's predictions are compared with surveys in order to show its capabilities as well as understand its possible limitations arising from the hypothesis the model is based on. Moreover, the sensitivity of model to variations of parameters and boundary conditions (i.e. discharge) is tested showing interesting results. Finally, the hazard map for the area is generated adopting the standard procedure as required by national and local regulations in order to study how predictive simulations compare to the results of a back analysis process.

  19. Evaluation of different retention systems on a distal extension removable partial denture associated with an osseointegrated implant.

    PubMed

    Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; Falcón-Antenucci, Rosse Mary; Goiato, Marcelo Coelho; Gennari Filho, Humberto

    2010-05-01

    The aim of this study was to evaluate the biomechanical behavior of a mandibular distal extension removable partial denture (DERPD) associated with an implant and different retention system, by bidimensional finite element method. Five hemimandible models with a canine and external hexagon implant at second molar region associated with DERPD were simulated: model A, hemimandible with a canine and a DERPD; model B, hemimandible with a canine and implant with a healing abutment associated to a DERPD; model C, hemimandible with a canine and implant with an ERA attachment associated to a DERPD; model D, hemimandible with a canine and implant with an O'ring attachment associated to a DERPD; and model E, hemimandible with a canine and implant-supported prosthesis associated to a DERPD. Cusp tips were loaded with 50 N of axial or oblique force (45 degrees). Finite element analysis was performed in ANSYS 9.0. model E showed the higher displacement and overload in the supporting tissues; the patterns of stress distribution around the dental apex of models B, C, and D were similar. The association between a DERPD and an osseointegrated implant using the ERA or O'ring systems shows lower stress values. Oblique forces showed higher stress values and displacement. Oblique forces increased the displacement and stress levels in all models; model C displayed the best stress distribution in the supporting structures; healing abutment, ERA, and O'ring systems were viable with RPD, but DERPD association with a single implant-supported prosthesis was nonviable. PMID:20485037

  20. Commercial CMOS image sensors as X-ray imagers and particle beam monitors

    NASA Astrophysics Data System (ADS)

    Castoldi, A.; Guazzoni, C.; Maffessanti, S.; Montemurro, G. V.; Carraresi, L.

    2015-01-01

    CMOS image sensors are widely used in several applications such as mobile handsets webcams and digital cameras among others. Furthermore they are available across a wide range of resolutions with excellent spectral and chromatic responses. In order to fulfill the need of cheap systems as beam monitors and high resolution image sensors for scientific applications we exploited the possibility of using commercial CMOS image sensors as X-rays and proton detectors. Two different sensors have been mounted and tested. An Aptina MT9v034, featuring 752 × 480 pixels, 6μm × 6μm pixel size has been mounted and successfully tested as bi-dimensional beam profile monitor, able to take pictures of the incoming proton bunches at the DeFEL beamline (1-6 MeV pulsed proton beam) of the LaBeC of INFN in Florence. The naked sensor is able to successfully detect the interactions of the single protons. The sensor point-spread-function (PSF) has been qualified with 1MeV protons and is equal to one pixel (6 mm) r.m.s. in both directions. A second sensor MT9M032, featuring 1472 × 1096 pixels, 2.2 × 2.2 μm pixel size has been mounted on a dedicated board as high-resolution imager to be used in X-ray imaging experiments with table-top generators. In order to ease and simplify the data transfer and the image acquisition the system is controlled by a dedicated micro-processor board (DM3730 1GHz SoC ARM Cortex-A8) on which a modified LINUX kernel has been implemented. The paper presents the architecture of the sensor systems and the results of the experimental measurements.

  1. Westernization and Tobacco Use Among Young People in Delhi, India

    PubMed Central

    Stigler, Melissa H.; Dhavan, Poonam; Van Dusen, Duncan; Arora, Monika; Reddy, K. Srinath; Perry, Cheryl L.

    2010-01-01

    Few studies have explored the relationship between acculturation and health in non-immigrant populations. The purpose of this study was to investigate the relationship between “westernization” and tobacco use among adolescents living in Delhi, India. A bi-dimensional model of acculturation was adapted for use in this study to examine (a) whether young people's identification with Western culture in this setting is related to tobacco use and (b) whether their maintenance of more traditional Indian ways of living is related to tobacco use, also. Multiple types of tobacco use common in India (e.g., cigarettes, bidis, chewing tobacco) were considered. Socioeconomic status (SES), gender, and grade level were examined as potential effect modifiers of the relationship between “westernization” and tobacco use. The study was cross-sectional by design and included 3,512 students in eighth and tenth grades who were enrolled in 14 Private (higher SES) and Government (lower SES) schools in Delhi, India. A self-report survey was used to collect information on tobacco use and “westernization.” The results suggest that young people's identification with Western influences may increase their risk for tobacco use (p<0.001), while their maintenance of traditional Indian ways of living confers some protection (p<0.001). Importantly, these effects were independent of one another. Boys benefitted more from protective effects than girls, and tenth graders gained more consistent benefits than eighth graders in this regard, too. Negative effects associated with identification with Western ways of living were, in contrast, consistent across gender and grade level. The positive and negative effects of acculturation on adolescent tobacco use generalized across all tobacco products considered here. Future interventions designed to curb youth tobacco use in India may benefit by paying closer attention to cultural preferences of these young consumers. PMID:20598413

  2. Acculturation and the Center for Epidemiological Studies Depression Scale for Hispanic Women

    PubMed Central

    McCabe, Brian E.; Vermeesch, Amber L.; Hall, Rosemary F.; Peragallo, Nilda P.; Mitrani, Victoria B.

    2011-01-01

    Background Culturally valid measures of depression for Spanish-speaking Hispanic women are important for developing and implementing effective interventions to reduce health disparities. The Center for Epidemiological Studies--Depression Scale (CES-D) is a widely used measure of depression. Differential item functioning has been studied using language preference as a proxy for acculturation, but it is unknown if the results were due to acculturation or the language of administration. Objective To evaluate the relationship of acculturation, defined with a dimensional measure, to Spanish CES-D item responses. Method Spanish-speaking Hispanic women (n = 504) were recruited for a randomized controlled trial of Salud, Educación, Prevención y Autocuidado (Health, Education, Prevention and Self-care). Acculturation, an important dimension of variation within the diverse United States Hispanic community, was defined by high or low scores on the Americanism subscale of the Bidimensional Acculturation Scale. Differential item functioning for each of the 20 CES-D items between more acculturated and less acculturated women was tested using ordinal logistic regression. Results No items on the Depressed Affect, Somatic Activity, or Positive Affect subscales showed meaningful differential item functioning, but one item (“People were unfriendly”) on the Interpersonal subscale had small results (R2 = 1.1%). Discussion The majority of CES-D items performed similarly for Spanish-speaking Hispanic women with high and low acculturation. Less acculturated women responded more positively to “People were unfriendly,” despite having an equivalent level of depression, than more acculturated women. Possibilities for improving this item are proposed. PMID:21677596

  3. Tentative detection of clear-air turbulence using a ground-based Rayleigh lidar.

    PubMed

    Hauchecorne, Alain; Cot, Charles; Dalaudier, Francis; Porteneuve, Jacques; Gaudo, Thierry; Wilson, Richard; Cénac, Claire; Laqui, Christian; Keckhut, Philippe; Perrin, Jean-Marie; Dolfi, Agnès; Cézard, Nicolas; Lombard, Laurent; Besson, Claudine

    2016-05-01

    Atmospheric gravity waves and turbulence generate small-scale fluctuations of wind, pressure, density, and temperature in the atmosphere. These fluctuations represent a real hazard for commercial aircraft and are known by the generic name of clear-air turbulence (CAT). Numerical weather prediction models do not resolve CAT and therefore provide only a probability of occurrence. A ground-based Rayleigh lidar was designed and implemented to remotely detect and characterize the atmospheric variability induced by turbulence in vertical scales between 40 m and a few hundred meters. Field measurements were performed at Observatoire de Haute-Provence (OHP, France) on 8 December 2008 and 23 June 2009. The estimate of the mean squared amplitude of bidimensional fluctuations of lidar signal showed excess compared to the estimated contribution of the instrumental noise. This excess can be attributed to atmospheric turbulence with a 95% confidence level. During the first night, data from collocated stratosphere-troposphere (ST) radar were available. Altitudes of the turbulent layers detected by the lidar were roughly consistent with those of layers with enhanced radar echo. The derived values of turbulence parameters Cn2 or CT2 were in the range of those published in the literature using ST radar data. However, the detection was at the limit of the instrumental noise and additional measurement campaigns are highly desirable to confirm these initial results. This is to our knowledge the first successful attempt to detect CAT in the free troposphere using an incoherent Rayleigh lidar system. The built lidar device may serve as a test bed for the definition of embarked CAT detection lidar systems aboard airliners. PMID:27140350

  4. Neural networks as a tool to classify compounds according to aromaticity criteria.

    PubMed

    Alonso, Mercedes; Herradón, Bernardo

    2007-01-01

    Aromaticity is a fundamental concept in chemistry, with many theoretical and practical implications. Although most organic compounds can be categorized as aromatic, non-aromatic, or antiaromatic, it is often difficult to classify borderline compounds as well as to quantify this property. Many aromaticity criteria have been proposed, although none of them gives an entirely satisfactory solution. The inability to fully arrange organic compounds according to a single criterion arises from the fact that aromaticity is a multidimensional phenomenon. Neural networks are computational techniques that allow one to treat a large amount of data, thereby reducing the dimensionality of the input set to a bidimensional output. We present the successful applications of Kohonen's self-organizing maps to classify organic compounds according to aromaticity criteria, showing a good correlation between the aromaticity of a compound and its placement in a particular neuron. Although the input data for the training of the network were different aromaticity criteria (stabilization energy, diamagnetic susceptibility, NICS, NICS(1), and HOMA) for five-membered heterocycles, the method can be extended to other organic compounds. Some useful features of this method are: 1) it is very fast, requiring less than one minute of computational time to place a new compound in the map; 2) the placement of the different compounds in the map is conveniently visualized; 3) the position of a compound in the map depends on its aromatic character, thus allowing us to establish a quantitative scale of aromaticity, based on Euclidean distances between neurons, 4) it has predictive power. Overall, the results reported herein constitute a significant contribution to the longstanding debate on the quantitative treatment of aromaticity. PMID:17323387

  5. Inversion of Three Layers Multi-Scale SPM Model Based on Neural Network Technique for the Retrieval of Soil Multi-Scale Roughness and Moisture Parameters

    NASA Astrophysics Data System (ADS)

    Hosni, I.; JaafriGhamki, M.; Bennaceur Farah, L.; Naceur, M. S.

    2015-04-01

    In this paper, a multi-layered multi-scale backscattering model for a lossy medium and a neural network inversion procedure has been presented. We have used a bi-dimensional multi-scale (2D MLS) roughness description where the surface is considered as a superposition of a finite number of one-dimensional Gaussian processes each one having a spatial scale using the wavelet transform and the Mallat algorithm to describe natural surface roughness. An adapted three layers 2D MLS small perturbations (SPM) model has been used to describe radar backscattering response of semiarid sub-surfaces. The total reflection coefficients of the natural soil are computed using the multilayer model, and volumetric scattering is approximated by the internal reflections between layers. The original multi-scale SPM model includes only the surface scattering of the natural bare soil, while the multilayer soil modified 2D MLS SPM model includes both the surface scattering and the volumetric scattering within the soil. This multi-layered model has been used to calculate the total surface reflection coefficients of a natural soil surface for both horizontal and vertical co-polarizations. A parametric analysis presents the dependence of the backscattering coefficient on multi scale roughness and soil. The overall objective of this work is to retrieve soil surfaces parameters namely roughness and soil moisture related to the dielectric constant by inverting the radar backscattered signal from natural soil surfaces. To perform the inversion of the modified three layers 2D MLS SPM model, we used a multilayer neural network (NN) architecture trained by a back-propagation learning rule.

  6. On The Relationship Between Magnetic Cancellation And UV Burst Formation

    NASA Astrophysics Data System (ADS)

    Nelson, C. J.; Doyle, J. G.; Erdélyi, R.

    2016-08-01

    Burst-like events with signatures in the UV are often observed co-spatial to strong line-of-sight photospheric magnetic fields. Several authors, for example, have noted the spatial relationship between Ellerman bombs (EBs) and Moving Magnetic Features (MMFs), regions of flux which disconnect from a sunspot or pore before propagating away in the moat flow and often displaying evidence of cancellation. In this article, data collected by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager and Atmospheric Imaging Assembly are analysed in an attempt to understand the potential links between such cancellation and UV burst formation. Two MMFs from AR 11579, three bi-poles from AR 11765, and six bi-poles (four of which were co-spatial to IRIS bursts) in AR 11850 were identified for analysis. All of these cancellation features were found to have lifetimes of the order hours and cancellation rates of the order 1014-1015 Mx s-1. Hα line wing data from the Dunn Solar Telescope's Interferometric BIdimensional Spectrometer were also available for AR 11579 facilitating a discussion of links between MMFs and EBs. Using an algebraic model of photospheric magnetic reconnection, the measured cancellation rates are then used to ascertain estimates of certain quantities (such as up-flow speeds, jet extents, and potential energy releases) which compared reasonably to the properties of EBs reported within the literature. Our results suggest that cancellation rates of the order measured here are capable of supplying enough energy to drive certain UV bursts (including EBs), however, they are not a guaranteeing condition for burst formation.

  7. 3D multiple-point statistics simulation using 2D training images

    NASA Astrophysics Data System (ADS)

    Comunian, A.; Renard, P.; Straubhaar, J.

    2012-03-01

    One of the main issues in the application of multiple-point statistics (MPS) to the simulation of three-dimensional (3D) blocks is the lack of a suitable 3D training image. In this work, we compare three methods of overcoming this issue using information coming from bidimensional (2D) training images. One approach is based on the aggregation of probabilities. The other approaches are novel. One relies on merging the lists obtained using the impala algorithm from diverse 2D training images, creating a list of compatible data events that is then used for the MPS simulation. The other (s2Dcd) is based on sequential simulations of 2D slices constrained by the conditioning data computed at the previous simulation steps. These three methods are tested on the reproduction of two 3D images that are used as references, and on a real case study where two training images of sedimentary structures are considered. The tests show that it is possible to obtain 3D MPS simulations with at least two 2D training images. The simulations obtained, in particular those obtained with the s2Dcd method, are close to the references, according to a number of comparison criteria. The CPU time required to simulate with the method s2Dcd is from two to four orders of magnitude smaller than the one required by a MPS simulation performed using a 3D training image, while the results obtained are comparable. This computational efficiency and the possibility of using MPS for 3D simulation without the need for a 3D training image facilitates the inclusion of MPS in Monte Carlo, uncertainty evaluation, and stochastic inverse problems frameworks.

  8. Excitation of an outflow from the lower solar atmosphere and a co-temporal EUV transient brightening

    NASA Astrophysics Data System (ADS)

    Nelson, C. J.; Doyle, J. G.

    2013-12-01

    Aims: We analyse an absorption event within the Hα line wings, which has been identified as a surge, and the co-spatial evolution of an EUV brightening, with spatial and temporal scales analogous to a small blinker. Methods: We conduct a multi-wavelength, multi-instrument analysis using high-cadence, high-resolution data, collected by the Interferometric BIdimensional Spectrometer on the Dunn Solar Telescope, as well as the space-borne Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager instruments on board the Solar Dynamics Observatory. Results: One large absorption event situated within the plage region trailing the lead sunspot of AR 11579 is identified within the Hα line wings. This event is found to be co-spatially linked to a medium-scale (around 4'' in diameter) brightening within the transition region and corona. This ejection appears to have a parabolic evolution, first forming in the Hα blue wing before fading and reappearing in the Hα red wing, and comprises a number of smaller fibril events. The line-of-sight photospheric magnetic field shows no evidence of cancellation leading to this event. Conclusions: Our research has identified clear evidence that at least a subset of transient brightening events in the transition region is linked to the influx of cooler plasma from the lower solar atmosphere during large eruptive events, such as surges. These observations agree with previous numerical researches on the nature of blinkers and, therefore, suggest that magnetic reconnection is the driver of the analysed surge events; however, further research is required to confirm this. A movie attached to Fig. 2 is available in electronic form at http://www.aanda.org

  9. Participatory Gis: Experimentations for a 3d Social Virtual Globe

    NASA Astrophysics Data System (ADS)

    Brovelli, M. A.; Minghini, M.; Zamboni, G.

    2013-08-01

    The dawn of GeoWeb 2.0, the geographic extension of Web 2.0, has opened new possibilities in terms of online dissemination and sharing of geospatial contents, thus laying the foundations for a fruitful development of Participatory GIS (PGIS). The purpose of the study is to investigate the extension of PGIS applications, which are quite mature in the traditional bi-dimensional framework, up to the third dimension. More in detail, the system should couple a powerful 3D visualization with an increase of public participation by means of a tool allowing data collecting from mobile devices (e.g. smartphones and tablets). The PGIS application, built using the open source NASA World Wind virtual globe, is focussed on the cultural and tourism heritage of Como city, located in Northern Italy. An authentication mechanism was implemented, which allows users to create and manage customized projects through cartographic mash-ups of Web Map Service (WMS) layers. Saved projects populate a catalogue which is available to the entire community. Together with historical maps and the current cartography of the city, the system is also able to manage geo-tagged multimedia data, which come from user field-surveys performed through mobile devices and report POIs (Points Of Interest). Each logged user can then contribute to POIs characterization by adding textual and multimedia information (e.g. images, audios and videos) directly on the globe. All in all, the resulting application allows users to create and share contributions as it usually happens on social platforms, additionally providing a realistic 3D representation enhancing the expressive power of data.

  10. Expression profiles in surgically-induced carotid stenosis: a combined transcriptomic and proteomic investigation

    PubMed Central

    Forte, A; Finicelli, M; De Luca, P; Quarto, C; Onorati, F; Santè, P; Renzulli, A; Galderisi, U; Berrino, L; De Feo, M; Rossi, F; Cotrufo, M; Cascino, A; Cipollaro, M

    2008-01-01

    Vascular injury aimed at stenosis removal induces local reactions often leading to restenosis. The aim of this study was a concerted transcriptomic-proteomics analysis of molecular variations in a model of rat carotid arteriotomy, to dissect the molecular pathways triggered by vascular surgical injury and to identify new potential anti-restenosis targets. RNA and proteins extracted from inbred Wistar Kyoro (WKY) rat carotids harvested 4 hrs, 48 hrs and 7 days after arteriotomy were analysed by Affymetrix rat microarrays and by bidi-mensional electrophoresis followed by liquid chromatography and tandem mass spectrometry, using as reference the RNA and the proteins extracted from uninjured rat carotids. Results were classified according to their biological function, and the most significant Kyoro Encyclopedia of Genes and Genomes (KEGG) pathways were identified. A total of 1163 mRNAs were differentially regulated in arteriotomy-injured carotids 4 hrs, 48 hrs and 7 days after injury (P < 0.0001, fold-change ≥2), while 48 spots exhibited significant changes after carotid arteriotomy (P < 0.05, fold-change ≥2). Among them, 16 spots were successfully identified and resulted to correspond to a set of 19 proteins. mRNAs were mainly involved in signal transduction, oxidative stress/inflammation and remodelling, including many new potential targets for limitation of surgically induced (re)stenosis (e.g. Arginase I, Kruppel like factors). Proteome analysis confirmed and extended the microrarray data, revealing time-dependent post-translational modifications of Hsp27, haptoglobin and contrapsin-like protease inhibitor 6, and the differential expression of proteins mainly involved in contractility. Transcriptomic and proteomic methods revealed functional categories with different preferences, related to the experimental sensitivity and to mechanisms of regulation. The comparative analysis revealed correlation between transcriptional and translational expression for 47% of

  11. Clines with partial panmixia across a geographical barrier in an environmental pocket.

    PubMed

    Nagylaki, Thomas; Zeng, Kai

    2016-08-01

    In a geographically structured population, partial global panmixia can be regarded as the limiting case of long-distance migration. On the entire line with homogeneous, isotropic migration, an environmental pocket is bounded by a geographical barrier, which need not be symmetric. For slow evolution, a continuous approximation of the exact, discrete model for the gene frequency p(x) at a diallelic locus at equilibrium, where x denotes position and the barrier is at x=±a, is formulated and investigated. This model incorporates viability selection, local adult migration, adult partial panmixia, and the barrier. The gene frequency and its derivatives are discontinuous at the barrier unless the latter is symmetric, in which case only p(x) is discontinuous. A cline exists only if the scaled rate of partial panmixia β<1; several qualitative results also are proved. Formulas that determine p(x) in a step-environment when dominance is absent are derived. The maximal gene frequency in the cline satisfies p(0)<1-β. A cline exists if and only if 0≤β<1 and the radius a of the pocket exceeds the minimal radius a(∗), for which a simple, explicit formula is deduced. Given numerical solutions for p(0) and p(a±), an explicit formula is proved for p(x) in |x|>a; whereas in (-a,a), an elliptic integral for x must be numerically inverted. The minimal radius a(∗∗) for maintenance of a cline in an isotropic, bidimensional pocket is also examined. PMID:27059473

  12. Molecular interactions between the olive and the fruit fly Bactrocera oleae

    PubMed Central

    2012-01-01

    Background The fruit fly Bactrocera oleae is the primary biotic stressor of cultivated olives, causing direct and indirect damages that significantly reduce both the yield and the quality of olive oil. To study the olive-B. oleae interaction, we conducted transcriptomic and proteomic investigations of the molecular response of the drupe. The identifications of genes and proteins involved in the fruit response were performed using a Suppression Subtractive Hybridisation technique and a combined bi-dimensional electrophoresis/nanoLC-ESI-LIT-MS/MS approach, respectively. Results We identified 196 ESTs and 26 protein spots as differentially expressed in olives with larval feeding tunnels. A bioinformatic analysis of the identified non-redundant EST and protein collection indicated that different molecular processes were affected, such as stress response, phytohormone signalling, transcriptional control and primary metabolism, and that a considerable proportion of the ESTs could not be classified. The altered expression of 20 transcripts was also analysed by real-time PCR, and the most striking differences were further confirmed in the fruit of a different olive variety. We also cloned the full-length coding sequences of two genes, Oe-chitinase I and Oe-PR27, and showed that these are wound-inducible genes and activated by B. oleae punctures. Conclusions This study represents the first report that reveals the molecular players and signalling pathways involved in the interaction between the olive fruit and its most damaging biotic stressor. Drupe response is complex, involving genes and proteins involved in photosynthesis as well as in the production of ROS, the activation of different stress response pathways and the production of compounds involved in direct defence against phytophagous larvae. Among the latter, trypsin inhibitors should play a major role in drupe resistance reaction. PMID:22694925

  13. Wave-processing of long-scale information by neuronal chains.

    PubMed

    Villacorta-Atienza, José Antonio; Makarov, Valeri A

    2013-01-01

    Investigation of mechanisms of information handling in neural assemblies involved in computational and cognitive tasks is a challenging problem. Synergetic cooperation of neurons in time domain, through synchronization of firing of multiple spatially distant neurons, has been widely spread as the main paradigm. Complementary, the brain may also employ information coding and processing in spatial dimension. Then, the result of computation depends also on the spatial distribution of long-scale information. The latter bi-dimensional alternative is notably less explored in the literature. Here, we propose and theoretically illustrate a concept of spatiotemporal representation and processing of long-scale information in laminar neural structures. We argue that relevant information may be hidden in self-sustained traveling waves of neuronal activity and then their nonlinear interaction yields efficient wave-processing of spatiotemporal information. Using as a testbed a chain of FitzHugh-Nagumo neurons, we show that the wave-processing can be achieved by incorporating into the single-neuron dynamics an additional voltage-gated membrane current. This local mechanism provides a chain of such neurons with new emergent network properties. In particular, nonlinear waves as a carrier of long-scale information exhibit a variety of functionally different regimes of interaction: from complete or asymmetric annihilation to transparent crossing. Thus neuronal chains can work as computational units performing different operations over spatiotemporal information. Exploiting complexity resonance these composite units can discard stimuli of too high or too low frequencies, while selectively compress those in the natural frequency range. We also show how neuronal chains can contextually interpret raw wave information. The same stimulus can be processed differently or identically according to the context set by a periodic wave train injected at the opposite end of the chain. PMID:23460856

  14. Modeling the Impact of Alternative Immunization Strategies: Using Matrices as Memory Lanes.

    PubMed

    Alonso, Wladimir J; Rabaa, Maia A; Giglio, Ricardo; Miller, Mark A; Schuck-Paim, Cynthia

    2015-01-01

    Existing modeling approaches are divided between a focus on the constitutive (micro) elements of systems or on higher (macro) organization levels. Micro-level models enable consideration of individual histories and interactions, but can be unstable and subject to cumulative errors. Macro-level models focus on average population properties, but may hide relevant heterogeneity at the micro-scale. We present a framework that integrates both approaches through the use of temporally structured matrices that can take large numbers of variables into account. Matrices are composed of several bidimensional (time×age) grids, each representing a state (e.g. physiological, immunological, socio-demographic). Time and age are primary indices linking grids. These matrices preserve the entire history of all population strata and enable the use of historical events, parameters and states dynamically in the modeling process. This framework is applicable across fields, but particularly suitable to simulate the impact of alternative immunization policies. We demonstrate the framework by examining alternative strategies to accelerate measles elimination in 15 developing countries. The model recaptured long-endorsed policies in measles control, showing that where a single routine measles-containing vaccine is employed with low coverage, any improvement in coverage is more effective than a second dose. It also identified an opportunity to save thousands of lives in India at attractively low costs through the implementation of supplementary immunization campaigns. The flexibility of the approach presented enables estimating the effectiveness of different immunization policies in highly complex contexts involving multiple and historical influences from different hierarchical levels. PMID:26509976

  15. Westernization and tobacco use among young people in Delhi, India.

    PubMed

    Stigler, Melissa; Dhavan, Poonam; Van Dusen, Duncan; Arora, Monika; Reddy, K S; Perry, Cheryl L

    2010-09-01

    Few studies have explored the relationship between acculturation and health in non-immigrant populations. The purpose of this study was to investigate the relationship between "westernization" and tobacco use among adolescents living in Delhi, India. A bi-dimensional model of acculturation was adapted for use in this study to examine (a) whether young people's identification with Western culture in this setting is related to tobacco use, and (b) whether their maintenance of more traditional Indian ways of living is related to tobacco use. Multiple types of tobacco commonly used in India (e.g., cigarettes, bidis, chewing tobacco) were considered. Socioeconomic status (SES), gender, and grade level were examined as potential effect modifiers of the relationship between "westernization" and tobacco use. The study was cross-sectional by design and included 3512 students in eighth and tenth grades who were enrolled in 14 Private (higher SES) and Government (lower SES) schools in Delhi, India. A self-report survey was used to collect information on tobacco use and "westernization." The results suggest that young people's identification with Western influences may increase their risk for tobacco use, while their maintenance of traditional Indian ways of living confers some protection. Importantly, these effects were independent of one another. Boys benefitted more from protective effects than girls, and tenth graders gained more consistent benefits than eighth graders in this regard, too. Negative effects associated with identification with Western ways of living were, in contrast, consistent across gender and grade level. The positive and negative effects of acculturation on adolescent tobacco use held for all tobacco products considered here. Future interventions designed to curb youth tobacco use in India may benefit by paying closer attention to cultural preferences of these young consumers. PMID:20598413

  16. Emotion recognition from single-trial EEG based on kernel Fisher's emotion pattern and imbalanced quasiconformal kernel support vector machine.

    PubMed

    Liu, Yi-Hung; Wu, Chien-Te; Cheng, Wei-Teng; Hsiao, Yu-Tsung; Chen, Po-Ming; Teng, Jyh-Tong

    2014-01-01

    Electroencephalogram-based emotion recognition (EEG-ER) has received increasing attention in the fields of health care, affective computing, and brain-computer interface (BCI). However, satisfactory ER performance within a bi-dimensional and non-discrete emotional space using single-trial EEG data remains a challenging task. To address this issue, we propose a three-layer scheme for single-trial EEG-ER. In the first layer, a set of spectral powers of different EEG frequency bands are extracted from multi-channel single-trial EEG signals. In the second layer, the kernel Fisher's discriminant analysis method is applied to further extract features with better discrimination ability from the EEG spectral powers. The feature vector produced by layer 2 is called a kernel Fisher's emotion pattern (KFEP), and is sent into layer 3 for further classification where the proposed imbalanced quasiconformal kernel support vector machine (IQK-SVM) serves as the emotion classifier. The outputs of the three layer EEG-ER system include labels of emotional valence and arousal. Furthermore, to collect effective training and testing datasets for the current EEG-ER system, we also use an emotion-induction paradigm in which a set of pictures selected from the International Affective Picture System (IAPS) are employed as emotion induction stimuli. The performance of the proposed three-layer solution is compared with that of other EEG spectral power-based features and emotion classifiers. Results on 10 healthy participants indicate that the proposed KFEP feature performs better than other spectral power features, and IQK-SVM outperforms traditional SVM in terms of the EEG-ER accuracy. Our findings also show that the proposed EEG-ER scheme achieves the highest classification accuracies of valence (82.68%) and arousal (84.79%) among all testing methods. PMID:25061837

  17. DTM generation from STC-SIMBIO-SYS images

    NASA Astrophysics Data System (ADS)

    Re, C.; Simioni, E.; Cremonese, G.; Roncella, R.; Forlani, G.; Da Deppo, Vania; Naletto, G.; Salemi, G.

    2015-05-01

    The research group with the responsibility of the STereo Camera (STC) for the ESA BepiColombo mission to Mercury, has realized an innovative and compact camera design in which the light collected independently by two optical channels at ±20° with respect to the nadir direction converges on unique bidimensional detector. STC will provide the 3Dmapping of Mercury surface, acquiring images from two different perspectives. A stereo validation setup has been developed in order to give a much greater confidence to the novel instrument design and to get an on ground verification of the actual accuracies in obtaining elevation information from stereo pairs. A series of stereo-pairs of an anorthosite stone sample (good analogue of the hermean surface) and of a modelled piece of concrete, acquired in calibration clean room by means of an auxiliary optical system, have been processed in the photogrammetric pipeline using image correlation for the 3D model generation. The stereo reconstruction validation has been performed by comparing the STC DTMs (Digital Terrain Models) to an high resolution laser scanning 3D model of the stone samples as reference data. The latter has a much higher precision (ca. 20 μm) of the expected in-lab STC DTM (190 μm). Processing parameters have been varied in order to test their influence on the DTM generation accuracy. The main aim is to define the best illumination conditions and the process settings in order to obtain the best DTMs in terms of accuracy and completeness, seeking the best match between the mission constraints and the specific matching aspects that could affect the mapping process.

  18. Photogrammetric measurement of 3D freeform millimetre-sized objects with micro features: an experimental validation of the close-range camera calibration model for narrow angles of view

    NASA Astrophysics Data System (ADS)

    Percoco, Gianluca; Sánchez Salmerón, Antonio J.

    2015-09-01

    The measurement of millimetre and micro-scale features is performed by high-cost systems based on technologies with narrow working ranges to accurately control the position of the sensors. Photogrammetry would lower the costs of 3D inspection of micro-features and would be applicable to the inspection of non-removable micro parts of large objects too. Unfortunately, the behaviour of photogrammetry is not known when photogrammetry is applied to micro-features. In this paper, the authors address these issues towards the application of digital close-range photogrammetry (DCRP) to the micro-scale, taking into account that in literature there are research papers stating that an angle of view (AOV) around 10° is the lower limit to the application of the traditional pinhole close-range calibration model (CRCM), which is the basis of DCRP. At first a general calibration procedure is introduced, with the aid of an open-source software library, to calibrate narrow AOV cameras with the CRCM. Subsequently the procedure is validated using a reflex camera with a 60 mm macro lens, equipped with extension tubes (20 and 32 mm) achieving magnification of up to 2 times approximately, to verify literature findings with experimental photogrammetric 3D measurements of millimetre-sized objects with micro-features. The limitation experienced by the laser printing technology, used to produce the bi-dimensional pattern on common paper, has been overcome using an accurate pattern manufactured with a photolithographic process. The results of the experimental activity prove that the CRCM is valid for AOVs down to 3.4° and that DCRP results are comparable with the results of existing and more expensive commercial techniques.

  19. Catalysis under Cover: Enhanced Reactivity at the Interface between (Doped) Graphene and Anatase TiO2.

    PubMed

    Ferrighi, Lara; Datteo, Martina; Fazio, Gianluca; Di Valentin, Cristiana

    2016-06-15

    The "catalysis under cover" involves chemical processes which take place in the confined zone between a 2D material, such as graphene, h-BN, or MoS2, and the surface of an underlying support, such as a metal or a semiconducting oxide. The hybrid interface between graphene and anatase TiO2 is extremely important for photocatalytic and catalytic applications because of the excellent and complementary properties of the two materials. We investigate and discuss the reactivity of O2 and H2O on top and at the interface of this hybrid system by means of a wide set of dispersion-corrected hybrid density functional calculations. Both pure and boron- or nitrogen-doped graphene are interfaced with the most stable (101) anatase surface of TiO2 in order to improve the chemical activity of the C-layer. Especially in the case of boron, an enhanced reactivity toward O2 dissociation is observed as a result of both the contribution of the dopant and of the confinement effect in the bidimensional area between the two surfaces. Extremely stable dissociation products are observed where the boron atom bridges the two systems by forming very stable B-O covalent bonds. Interestingly, the B defect in graphene could also act as the transfer channel of oxygen atoms from the top side across the C atomic layer into the G/TiO2 interface. On the contrary, the same conditions are not found to favor water dissociation, proving that the "catalysis under cover" is not a general effect, but rather highly depends on the interfacing material properties, on the presence of defects and impurities and on the specific reaction involved. PMID:27203544

  20. Isotopic niche variation in a higher trophic level ectotherm: highlighting the role of succulent plants in desert food webs.

    PubMed

    Delibes, Miguel; Blazquez, Ma Carmen; Fedriani, Jose Maria; Granados, Arsenio; Soriano, Laura; Delgado, Antonio

    2015-01-01

    Stable isotope analysis of animal tissues allows description of isotopic niches, whose axes in an n-dimensional space are the isotopic ratios, compared to a standard, of different isotope systems (e.g. δ(13)C, δ(15)N). Isotopic niches are informative about where an animal, population or species lives and about what it consumes. Here we describe inter- and intrapopulation isotopic niche (bidimensional δ(13)C-δ(15)N space) of the Orange-throated whiptail (Aspidoscelis hyperythra), an arthropodivorous small lizard, in ten localities of Baja California Sur (Mexico). These localities range from extreme arid to subtropical conditions. Between 13 and 20 individuals were sampled at each locality and 1 cm of tail-tip was collected for isotope analysis. As expected, interpopulation niche width variation was much larger than intrapopulation one. Besides, isotopic variation was not related to age, sex or individual size of lizards. This suggests geographic variation of the isotopic niche was related to changes in the basal resources that fuel the trophic web at each locality. The position of Bayesian isotope ellipses in the δ-space indicated that whiptails in more arid localities were enriched in 13C, suggesting most of the carbon they ingested came from CAM succulent plants (cacti, agaves) and in minor degree in C4 grasses. Contrarily, whiptails in subtropical areas were depleted in 13C, as they received more carbon from C3 scrubs and trees. Localities closer to sea-level tended to be enriched in 15N, but a clear influence of marine subsidies was detected only at individual level. The study contributes to identify the origin and pathways through which energy flows across the trophic webs of North American deserts. PMID:25973609

  1. Joint Entropy for Space and Spatial Frequency Domains Estimated from Psychometric Functions of Achromatic Discrimination

    PubMed Central

    Silveira, Vladímir de Aquino; Souza, Givago da Silva; Gomes, Bruno Duarte; Rodrigues, Anderson Raiol; Silveira, Luiz Carlos de Lima

    2014-01-01

    We used psychometric functions to estimate the joint entropy for space discrimination and spatial frequency discrimination. Space discrimination was taken as discrimination of spatial extent. Seven subjects were tested. Gábor functions comprising unidimensionalsinusoidal gratings (0.4, 2, and 10 cpd) and bidimensionalGaussian envelopes (1°) were used as reference stimuli. The experiment comprised the comparison between reference and test stimulithat differed in grating's spatial frequency or envelope's standard deviation. We tested 21 different envelope's standard deviations around the reference standard deviation to study spatial extent discrimination and 19 different grating's spatial frequencies around the reference spatial frequency to study spatial frequency discrimination. Two series of psychometric functions were obtained for 2%, 5%, 10%, and 100% stimulus contrast. The psychometric function data points for spatial extent discrimination or spatial frequency discrimination were fitted with Gaussian functions using the least square method, and the spatial extent and spatial frequency entropies were estimated from the standard deviation of these Gaussian functions. Then, joint entropy was obtained by multiplying the square root of space extent entropy times the spatial frequency entropy. We compared our results to the theoretical minimum for unidimensional Gábor functions, 1/4π or 0.0796. At low and intermediate spatial frequencies and high contrasts, joint entropy reached levels below the theoretical minimum, suggesting non-linear interactions between two or more visual mechanisms. We concluded that non-linear interactions of visual pathways, such as the M and P pathways, could explain joint entropy values below the theoretical minimum at low and intermediate spatial frequencies and high contrasts. These non-linear interactions might be at work at intermediate and high contrasts at all spatial frequencies once there was a substantial decrease in joint

  2. Methods to obtain the waveform profile from slope measurements

    NASA Astrophysics Data System (ADS)

    Moreno, Alfonso; Espínola, Manuel; Martínez, José; Campos, Juan

    2013-04-01

    There are many optical metrological techniques to determine the profile of a surface or a wave-front. A group of them are based on the measurements of the profile slopes, like deflectometry or wave-front sensors. In both sensors, the profile is then obtained by integrating the gradient information provided by the measurements. The used integration method influences the quality of the obtained results. In this work we compare the performance of different bi-dimensional integration methods to obtain the profile from the slopes, and we propose some new methods. The first kind of methods is based on a path integral, in which the profile in a given point (x,y) is obtained by a 1D integral from (0,0) to (x,0) followed by a 1D integral from (x,0) to (x,y). The second kind of methods is based on finite differences, where the profile in a point is related with the profile in the neighbor points and the slopes of those points. On these methods different interpolations can be used. Finally, the third kind of methods is based on Fourier domain integration. Several simulation results are obtained to study the influence of several parameters: spatial frequency of the signal, local slope errors, random noise, and edge effects. Fourier domain methods could be considered as the gold standard, they suffer from edge effects because the signals are not periodic. Moreover they can only be applied when regular Cartesian sampling is used. Path integral methods create artifacts along the integration paths, when local errors are present. Finite difference methods are more versatile, and their accuracy depends on the used interpolation methods.

  3. Environmental flow in the River Ondas basin in Bahia, Brazilian Cerrado.

    PubMed

    de Souza Castro, Elis Regina Rodrigues; Moreira, Michel Castro; da Silva, Demetrius David

    2016-01-01

    This paper aimed to estimate the environmental flow of a water basin located in the Brazilian Cerrado using the bidimensional model River2D. The study was carried out in a stretch of the lower portion of the River Ondas in the western part of the state of Bahia, Brazil. To carry out the ecohydrological modeling, the following were used: topobathymetry, hydraulic characterization, the streamflows with the probability of non-exceedances (Q50, Q60, Q70, Q80, Q90, and Q95), and the Habitat Suitability Index for species of the genus Hypostomus. In the River2D, the weighted usable areas (WUAs) pertaining to the streamflows associated with different non-exceedances were simulated for the later construction of optimization and identification matrices of the streamflows that maximize the habitat area throughout the year. For juvenile Hypostomus, WUA increased as streamflow increased, with higher values associated with Q50. For adult specimens, lower WUA values were observed associated with Q50, while higher values were associated with Q95, which shows a preference for lower streamflows. The environmental flows found for the stretch of the River Ondas varied over the course of the year. The lowest environmental flows were observed in September (30.31 m(3) s(-1)) and October (29.98 m(3) s(-1)), while the highest were observed in February (44.22 m(3) s(-1)) and March (43.16 m(3) s(-1)). The environmental flow regime obtained restricts the water availability in the basin, for the purpose of water capture, which shows the importance of ecohydrological studies in forming a basis for water resource management actions. PMID:26718949

  4. Quantification and modification of the equilibrium dynamics and mechanics of a viral capsid lattice self-assembled as a protein nanocoating.

    PubMed

    Valbuena, Alejandro; Mateu, Mauricio G

    2015-09-28

    Self-assembling, protein-based bidimensional lattices are being developed as functionalizable, highly ordered biocoatings for multiple applications in nanotechnology and nanomedicine. Unfortunately, protein assemblies are soft materials that may be too sensitive to mechanical disruption, and their intrinsic conformational dynamism may also influence their applicability. Thus, it may be critically important to characterize, understand and manipulate the mechanical features and dynamic behavior of protein assemblies in order to improve their suitability as nanomaterials. In this study, the capsid protein of the human immunodeficiency virus was induced to self-assemble as a continuous, single layered, ordered nanocoating onto an inorganic substrate. Atomic force microscopy (AFM) was used to quantify the mechanical behavior and the equilibrium dynamics ("breathing") of this virus-based, self-assembled protein lattice in close to physiological conditions. The results uniquely provided: (i) evidence that AFM can be used to directly visualize in real time and quantify slow breathing motions leading to dynamic disorder in protein nanocoatings and viral capsid lattices; (ii) characterization of the dynamics and mechanics of a viral capsid lattice and protein-based nanocoating, including flexibility, mechanical strength and remarkable self-repair capacity after mechanical damage; (iii) proof of principle that chemical additives can modify the dynamics and mechanics of a viral capsid lattice or protein-based nanocoating, and improve their applied potential by increasing their mechanical strength and elasticity. We discuss the implications for the development of mechanically resistant and compliant biocoatings precisely organized at the nanoscale, and of novel antiviral agents acting on fundamental physical properties of viruses. PMID:26302823

  5. Multiple Solutions in Natural Convection in an Air Filled Square Enclosure: Fractal Dimension of Attractors

    NASA Astrophysics Data System (ADS)

    Aklouche Benouaguef, S.; Zeghmati, B.; Bouhadef, K.; Daguenet, M.

    In this study, we investigated numerically the transient natural convection in a square cavity with two horizontal adiabatic sides and vertical walls composed of two regions of same size maintained at different temperatures. The flow has been assumed to be laminar and bi-dimensional. The governing equations written in dimensionless form and expressed in terms of stream function and vorticity, have been solved using the Alternating Direction Implicit (ADI) method and the GAUSS elimination method. Calculations were performed for air (Pr = 0.71), with a Rayleigh number varying from 2.5x105 to 3.7x106. We analysed the effect of the Rayleigh number on the route to the chaos of the system. The first transition has been found from steady-state to oscillatory flow and the second is a subharmonic bifurcation as the Rayleigh number is increased further. For sufficiently small Rayleigh numbers, present results show that the flow is characterized by four cells with horizontal and vertical symmetric axes. The attractor bifurcates from a stable fixed point to a limit cycle for a Rayleigh number varying from 2.5x105 to 2.51x105. A limit cycle settles from Ra = 3x105 and persists until Ra = 5x105. At a Rayleigh number of 2.5x105 the temporal evolution of the Nusselt number Nu(t) was stationary. As the Rayleigh number increases, the flow becomes unstable and bifurcates to a time periodic solution at a critical Rayleigh number between 2.5x105 and 2.51x105. After the first HOPF bifurcation at Ra = 2.51x105, the oscillatory flow undergoes several bifurcations and ultimately evolves into a chaotic flow.

  6. Qual o Papel da Escola e da Mídia na Obtenção dos Conhecimentos Astronômicos?

    NASA Astrophysics Data System (ADS)

    da Cunha, W. S.; Voelzke, M. R.; Amaral, L. H.

    2007-08-01

    É amplamente reconhecido que as pessoas em geral têm grande fascínio e interesse pela Astronomia. Por outro lado, o conteúdo dessa área incluído no ensino formal está longe de ser abrangente e suficiente para suprir a demanda. Esse interesse permite aperfeiçoar a divulgação e o ensino não formal de Astronomia através da mídia aliando a adequação do conteúdo à expectativa das pessoas. A reforma do Currículo Básico da Escola Pública da maioria dos Estados brasileiros tem introduzido Astronomia desde a pré-escola até o Ensino Médio. Num estudo realizado com 1180 alunos do Ensino Médio de seis escolas estaduais, revelou-se através da aplicação de um formulário contendo questões que abordavam conhecimentos básicos em Astronomia, como foram adquiridos tais conhecimentos e à infra-estrutura da escola. Para 66,1% dos entrevistados o professor já fez alguma apresentação a respeito de Astronomia. O presente estudo revelou também que 54,4% dos alunos entrevistados adquiriram seus conhecimentos astronômicos na escola, 18,4% através da televisão e 27,1% afirmaram que seus conhecimentos foram obtidos através de outros tipos de mídia (internet, livros didáticos, filmes e revistas). Embora o estudo revele claramente que há certo equilíbrio no meio em que os alunos obtiveram seus conhecimentos astronômicos, a mídia busca não somente sua difusão, mas a disponibilização desse conhecimento de maneira correta, que às vezes, não é atingido, apresentando conceitos sem fundamentação e incorretos. Por outro lado, no dia-a-dia escolar, é comum encontrar professores que vêm para as aulas com concepções prévias, que podem diferir substancialmente das idéias a serem ensinadas, dificultando o aprendizado de futuros conceitos científicos. Uma avaliação criteriosa, avaliando as dificuldades dos professores em determinar o sentido correto dos conceitos e observando a metodologia que utilizam no ensino, poderá proporcionar uma melhor

  7. Multi-GPU and multi-CPU accelerated FDTD scheme for vibroacoustic applications

    NASA Astrophysics Data System (ADS)

    Francés, J.; Otero, B.; Bleda, S.; Gallego, S.; Neipp, C.; Márquez, A.; Beléndez, A.

    2015-06-01

    The Finite-Difference Time-Domain (FDTD) method is applied to the analysis of vibroacoustic problems and to study the propagation of longitudinal and transversal waves in a stratified media. The potential of the scheme and the relevance of each acceleration strategy for massively computations in FDTD are demonstrated in this work. In this paper, we propose two new specific implementations of the bi-dimensional scheme of the FDTD method using multi-CPU and multi-GPU, respectively. In the first implementation, an open source message passing interface (OMPI) has been included in order to massively exploit the resources of a biprocessor station with two Intel Xeon processors. Moreover, regarding CPU code version, the streaming SIMD extensions (SSE) and also the advanced vectorial extensions (AVX) have been included with shared memory approaches that take advantage of the multi-core platforms. On the other hand, the second implementation called the multi-GPU code version is based on Peer-to-Peer communications available in CUDA on two GPUs (NVIDIA GTX 670). Subsequently, this paper presents an accurate analysis of the influence of the different code versions including shared memory approaches, vector instructions and multi-processors (both CPU and GPU) and compares them in order to delimit the degree of improvement of using distributed solutions based on multi-CPU and multi-GPU. The performance of both approaches was analysed and it has been demonstrated that the addition of shared memory schemes to CPU computing improves substantially the performance of vector instructions enlarging the simulation sizes that use efficiently the cache memory of CPUs. In this case GPU computing is slightly twice times faster than the fine tuned CPU version in both cases one and two nodes. However, for massively computations explicit vector instructions do not worth it since the memory bandwidth is the limiting factor and the performance tends to be the same than the sequential version

  8. The modern reef complex, Jeddah area, Red Sea: a facies model for carbonate sedimentation on embryonic passive margins

    NASA Astrophysics Data System (ADS)

    Montaggioni, L. F.; Behairy, A. K. A.; El-Sayed, M. K.; Yusuf, N.

    1986-12-01

    sedimentological attributes, the fringing reef can be regarded as an asymmetrical structure, with bidimensional (lateral and vertical) facies zonation; in contrast, the offshore platform is a symmetrical structure, with one dimensional (depth-dependent) facies zonation. This system is believed to represent a modern example of a laterally undifferentiated, offshore reef tract in a relatively enclosed basin, at an embryonic passive continental margin.

  9. The gas turbulence in planetary nebulae: quantification and multi-D maps from long-slit, wide-spectral range echellograms

    NASA Astrophysics Data System (ADS)

    Sabbadin, F.; Turatto, M.; Benetti, S.; Ragazzoni, R.; Cappellaro, E.

    2008-09-01

    Context: This methodological paper is part of a short series dedicated to the long-standing astronomical problem of de-projecting the bi-dimensional, apparent morphology of a three-dimensional distribution of gas. Aims: We focus on the quantification and spatial recovery of turbulent motions in planetary nebulae (and other classes of expanding nebulae) by means of long-slit echellograms over a wide spectral range. Methods: We introduce some basic theoretical notions, discuss the observational methodology, and develop an accurate procedure disentangling all broadening components (instrumental resolution, thermal motions, turbulence, gradient of the expansion velocity, and fine structure of hydrogen-like ions) of the velocity profile in all spatial positions of each spectral image. This allows us to extract random, non-thermal motions at unprecedented accuracy, and to map them in 1-, 2- and 3-dimensions. Results: We discuss general and specific applications of the method. We present the solution to practical problems in the multi-dimensional turbulence-analysis of a testing-planetary nebula (NGC 7009), using the three-step procedure (spatio-kinematics, tomography, and 3D rendering) developed at the Astronomical Observatory of Padua (Italy). In addition, we introduce an observational paradigm valid for all spectroscopic parameters in all classes of expanding nebulae. Conclusions: Unsteady, chaotic motions at a local scale constitute a fundamental (although elusive) kinematical parameter of each planetary nebula, providing deep insights on its different shaping agents and mechanisms, and on their mutual interaction. The detailed study of turbulence, its stratification within a target and (possible) systematic variation among different sub-classes of planetary nebulae deserve long-slit, multi-position angle, wide-spectral range echellograms containing emissions at low-, medium-, and high-ionization, to be analyzed pixel-to-pixel with a straightforward and versatile

  10. HEC-RAS 5.0 Vs. TELEMAC-2D: a model comparison for flood-hazard and flood-risk estimation

    NASA Astrophysics Data System (ADS)

    Ezzahra Maatar, Fatma; Domeneghetti, Alessio; Brath, Armando

    2015-04-01

    River flooding is considered among the most frequent catastrophic events causing dramatic consequences in terms of loss of human life and economic damages. Therefore, the flood-hazard and flood-risk management appear nowadays the fundamental activities that public bodies and authorities in charge have to implement in order to reduce human and socio-economic losses. In this context, our study specifically refers to a flood event occurred on January 19, 2014, along the Secchia River (a tributary of the Po River; North Italy), with the aim of evaluating the suitability of different numerical tools for the reproduction of the flood dynamics. During this specific event a failure on the main embankment caused the overflowing of an overall volume of about 40•106 m3 within 48 hours inundating nearly 200 km² of the floodplain area. Thus, our study aims at reproducing the inundation dynamics using two different fully bi-dimensional (2D) hydrodynamic models, both based on Saint-Venant equations: Telemac-2D and HEC-RAS 5.0 (Beta version). The former (Telemac-2D) is a widely employed and well known 2D model adopting a finite-element scheme based on triangular elements, while the latter, HEC-RAS 5.0, is the first, recently released, version of a coupled 1D-2D model that enables one to simulate river and floodplains interactions through a finite-volume scheme. Taking advantage of the historical observations, we investigate the suitability of the new 1D-2D model in reproducing the flood patterns testing its performance in case of different mesh resolutions (i.e. cell dimension ranging from 50 m to 200 m) and Digital Elevation Model accuracy (i.e. DEM resolution varying from 1 m to 50 m). Models' performances are thus compared with real observations in terms of flood patterns (i.e. overall flood extent and flood dynamics) and flood-hazard indexes (such as water depth, flow velocity, impulse, etc.). Finally, we compare the accuracy of both models on the reconstruction of recorded

  11. Microtopographic Inspection and Fractal Analysis of Skin Neoplasia

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F. M.; Hipolito, Alberto Valencia; Gutierrez, Gustavo Fidel; Chanona, Jorge; Gallegos, Eva Ramón

    2008-04-01

    Early detection of skin cancer is fundamental to a successful treatment. Changes in the shape, including the relief, of skin lesions are an indicator of a possible malignity. Optical microtopographic inspection of skin lesions can be used to identify diagnostic patterns of benign and malign skin' lesions. Statistical parameters like the mean roughness (Ra) may allow the discrimination between different types of lesions and degree of malignity. Fractal analysis of bi-dimensional and 3D images of skin lesions can validate or complement that assessment by calculation of its fractal dimensions (FD). On the study herein reported the microtopographic inspection of the skin lesions were performed using the optical triangulation based microtopographer developed at the Physics Department of the University of Minho, MICROTOP.03.MFC. The patients that participated in this research work were men and women older than 15 years with the clinical and histopathology diagnoses of: melanoma, basocellular carcinoma, epidermoide carcinoma, actinic keratosis, keratoacantosis and benign nevus. Latex impressions of the lesions were taken and microtopographically analyzed. Characteristic information for each type of studied lesion was obtained. For melanoma it was observed that on the average these tumors present an increased roughness of around 67 percent compared to the roughness of the healthy skin. This feature allows the distinction from other tumors as basocellular carcinoma (were the roughness increase was in the average of 49 percent) and benign lesions as the epidermoide cyst (37 percent) or the seborrhea keratosis (4 percent). Tumor size and roughness are directly proportional to the grade of malignality. The characterization of the fractal geometry of 2D (histological slides) and 3D images of skin lesions was performed by obtaining its FD evaluated by means of the Box counting method. Results obtained showed that the average fractal dimension of histological slide images (FDh

  12. Nest site selection and nutritional provision through excreta: a form of parental care in a tropical endogeic earthworm.

    PubMed

    Ortiz-Ceballos, Angel I; Pérez-Staples, Diana; Pérez-Rodríguez, Paulino

    2016-01-01

    Nest construction is a common form of parental care in soil organisms. However, it is unknown whether the tropical earthworm Pontoscolex corethrurus produces nests in soils with low nutritional quality habitats. Here we studied the reproductive behaviour and nest site selection of P. corethrurus, and tested the hypothesis whether P. corethrurus produces more cocoons in habitats with low nutritional quality. In bidimensional terrariums we evaluated the combined effect of the nutritional quality of habitat: (Poor Quality Habitat = PQH, Medium Quality Habitat = MQH, High Quality Habitat = HQH) and soil depth (Shallow, Intermediate, Deep) in a factorial 3(2) design. The number and biomass of cocoons, progeny and the production of internal and external excreta were evaluated. The quality habitat and depth of soil and their interaction had a significant effect on nest site construction and the deposition of internal excreta. Pontoscolex corethrurus built a higher amount of nests in the PQH-Intermediate and MQH-Intermediate treatments while more internal excreta were found in the HQH-Intermediate treatment. Offspring biomass was positively associated with internal excreta in the PQH (soil only) and MQH (soil + grass) treatments, suggesting that this could be a form of parental care. Since P. corethrurus produces more cocoons in low and medium quality habitats, while produces more internal excreta at high quality habitats, there does not seem to be an association between number of offspring and parental care. We suggest P. corethrurus could have two reproductive strategies that act as diversified bet-hedging (do not put all cocoons in one basket) behavior in unpredictable environment, and thus build a higher amount of nests in low and medium quality habitats; and another where they produce more internal excreta as a form of parental care in high quality habitats. Parental care in the form of internal excreta may be particularly important in poor and medium quality habitats

  13. Nest site selection and nutritional provision through excreta: a form of parental care in a tropical endogeic earthworm

    PubMed Central

    Pérez-Staples, Diana; Pérez-Rodríguez, Paulino

    2016-01-01

    Nest construction is a common form of parental care in soil organisms. However, it is unknown whether the tropical earthworm Pontoscolex corethrurus produces nests in soils with low nutritional quality habitats. Here we studied the reproductive behaviour and nest site selection of P. corethrurus, and tested the hypothesis whether P. corethrurus produces more cocoons in habitats with low nutritional quality. In bidimensional terrariums we evaluated the combined effect of the nutritional quality of habitat: (Poor Quality Habitat = PQH, Medium Quality Habitat = MQH, High Quality Habitat = HQH) and soil depth (Shallow, Intermediate, Deep) in a factorial 32 design. The number and biomass of cocoons, progeny and the production of internal and external excreta were evaluated. The quality habitat and depth of soil and their interaction had a significant effect on nest site construction and the deposition of internal excreta. Pontoscolex corethrurus built a higher amount of nests in the PQH-Intermediate and MQH-Intermediate treatments while more internal excreta were found in the HQH-Intermediate treatment. Offspring biomass was positively associated with internal excreta in the PQH (soil only) and MQH (soil + grass) treatments, suggesting that this could be a form of parental care. Since P. corethrurus produces more cocoons in low and medium quality habitats, while produces more internal excreta at high quality habitats, there does not seem to be an association between number of offspring and parental care. We suggest P. corethrurus could have two reproductive strategies that act as diversified bet-hedging (do not put all cocoons in one basket) behavior in unpredictable environment, and thus build a higher amount of nests in low and medium quality habitats; and another where they produce more internal excreta as a form of parental care in high quality habitats. Parental care in the form of internal excreta may be particularly important in poor and medium quality habitats

  14. A Comparative Analysis of 2D and 3D Tasks for Virtual Reality Therapies Based on Robotic-Assisted Neurorehabilitation for Post-stroke Patients.

    PubMed

    Lledó, Luis D; Díez, Jorge A; Bertomeu-Motos, Arturo; Ezquerro, Santiago; Badesa, Francisco J; Sabater-Navarro, José M; García-Aracil, Nicolás

    2016-01-01

    Post-stroke neurorehabilitation based on virtual therapies are performed completing repetitive exercises shown in visual electronic devices, whose content represents imaginary or daily life tasks. Currently, there are two ways of visualization of these task. 3D virtual environments are used to get a three dimensional space that represents the real world with a high level of detail, whose realism is determinated by the resolucion and fidelity of the objects of the task. Furthermore, 2D virtual environments are used to represent the tasks with a low degree of realism using techniques of bidimensional graphics. However, the type of visualization can influence the quality of perception of the task, affecting the patient's sensorimotor performance. The purpose of this paper was to evaluate if there were differences in patterns of kinematic movements when post-stroke patients performed a reach task viewing a virtual therapeutic game with two different type of visualization of virtual environment: 2D and 3D. Nine post-stroke patients have participated in the study receiving a virtual therapy assisted by PUPArm rehabilitation robot. Horizontal movements of the upper limb were performed to complete the aim of the tasks, which consist in reaching peripheral or perspective targets depending on the virtual environment shown. Various parameter types such as the maximum speed, reaction time, path length, or initial movement are analyzed from the data acquired objectively by the robotic device to evaluate the influence of the task visualization. At the end of the study, a usability survey was provided to each patient to analysis his/her satisfaction level. For all patients, the movement trajectories were enhanced when they completed the therapy. This fact suggests that patient's motor recovery was increased. Despite of the similarity in majority of the kinematic parameters, differences in reaction time and path length were higher using the 3D task. Regarding the success rates

  15. History highlights and future trends of infrared sensors

    NASA Astrophysics Data System (ADS)

    Corsi, Carlo

    2010-10-01

    Infrared (IR) technologies (materials, devices and systems) represent an area of excellence in science and technology and, even if they have been generally confined to a selected scientific community, they have achieved technological and scientific highlights constituting 'innovation drivers' for neighbouring disciplines, especially in the sensors field. The development of IR sensors, initially linked to astronomical observations, since World War II and for many years has been fostered essentially by defence applications, particularly thermo-vision and, later on, smart vision and detection, for surveillance and warning. Only in the last few decades, the impact of silicon technology has changed the development of IR detectors dramatically, with the advent of integrated signal read-outs and the opening of civilian markets (EO communications, biomedical, environmental, transport and energy applications). The history of infrared sensors contains examples of real breakthroughs, particularly true in the case of focal plane arrays that first appeared in the late 1970s, when the superiority of bi-dimensional arrays for most applications pushed the development of technologies providing the highest number of pixels. An impressive impulse was given to the development of FPA arrays by integration with charge coupled devices (CCD), with strong competition from different technologies (high-efficiency photon sensors, Schottky diodes, multi-quantum wells and, later on, room temperature microbolometers/cantilevers). This breakthrough allowed the development of high performance IR systems of small size, light weight and low cost - and therefore suitable for civil applications - thanks to the elimination of the mechanical scanning system and the progressive reduction of cooling requirements (up to the advent of microbolometers, capable of working at room temperature). In particular, the elimination of cryogenic cooling allowed the development and commercialisation of IR Smart Sensors

  16. Risk factors for bloodborne viral hepatitis in healthcare workers of Pakistan: a population based case–control study

    PubMed Central

    Gorar, Zulfikar A; Butt, Zahid A; Aziz, Imrana

    2014-01-01

    Objectives A high prevalence of viral hepatitis B and C was found among healthcare workers during a province-wide screening in Sindh Province, Pakistan. A follow-up study was undertaken to identify risk factors for this high prevalence in healthcare workers. Design Population based case–control design. Setting Public sector healthcare facilities in a rural district of Pakistan. Participants Healthcare workers who were screened for hepatitis B surface antigen (HBsAg) and hepatitis C virus (HCV) antibodies. 178 healthcare workers employed at the public sector clinics and hospitals of the district were approached, of which 14 refused to participate. Cases had detectable serum antibodies against HCV and the presence of HBsAg. Healthcare workers non-reactive to HCV antibodies and with no HBsAg were controls. These were matched in a ratio of 1:1. Outcome measure Detectable serum HBsAg and HCV antibody titer were taken as outcome. OR for various exposures was calculated; those with p<0.25 were entered in a multivariate logistic regression model to find out significant predictors. Results Needle stick injury (OR=6; CI95 1.4 to 23), recapping the needle (OR=5.7; CI95 1.1 to 28), wound care at accident and emergency of a hospital (OR=5.5; CI95 1 to 28), female gender (OR=3.4; CI95 1 to 12) and more than 10 years of formal education (OR=0.25; CI95 0.07 to 0.8) were associated with hepatitis C. Hepatitis B was found to be associated with trying to bend or break a needle after use (OR=4.9; CI95 1 to 24). Conclusions Healthcare workers in Pakistan are at additional risk of exposure to bloodborne pathogens. Bi-dimensional risk factors present at individual and broader health systems levels are responsible. Occupational safety, health trainings and redesigning of the curriculum for allied health professionals are required. PMID:25059968

  17. Phase II study of gemcitabine, doxorubicin and paclitaxel (GAT) as first-line chemotherapy for metastatic breast cancer: a translational research experience

    PubMed Central

    Passardi, Alessandro; Massa, Ilaria; Zoli, Wainer; Gianni, Lorenzo; Milandri, Carlo; Zumaglini, Federica; Nanni, Oriana; Maltoni, Roberta; Frassineti, Giovanni Luca; Amadori, Dino

    2006-01-01

    Background Patients with metastatic breast cancer are frequently treated with anthracyclines and taxanes, which are among the most active agents in this disease. Gemcitabine is an interesting candidate for a three-drug combination because of its different mechanism of action and non-overlapping toxicity with respect to the other two drugs. We aimed to evaluate the activity and toxicity of the GAT (gemcitabine, doxorubicin and paclitaxel) regimen, derived from experimental preclinical studies, as first-line chemotherapy in patients with stage IIIB-IV breast cancer. Methods Patients with locally advanced or metastatic breast cancer and at least one bidimensionally measurable lesion were included in the present study. Adequate bone marrow reserve, normal cardiac, hepatic and renal function, and an ECOG performance status of 0 to 2 were required. Only prior adjuvant non anthracycline-based chemotherapy was permitted. Treatment consisted of doxorubicin 50 mg/m2 on day 1, paclitaxel 160 mg/m2 on day 2 and gemcitabine 800 mg/m2 on day 6, repeated every 21–28 days. Results Thirty-three consecutive breast cancer patients were enrolled onto the trial (7 stage IIIB and 26 stage IV). All patients were evaluable for toxicity and 29 were assessable for response. A total of 169 cycles were administered, with a median of 6 cycles per patient (range 1–8 cycles). Complete and partial responses were observed in 6.9% and 48.3% of patients, respectively, for an overall response rate of 55.2%. A response was reported in all metastatic sites, with a median duration of 16.4 months. Median time to progression and overall survival were 10.2 and 36.4 months, respectively. The most important toxicity was hematological, with grade III-IV neutropenia observed in 69% of patients, sometimes requiring the use of granulocyte colony-stimulating factor (27%). Non hematological toxicity was rare and mild. One patient died from sepsis during the first treatment cycle before the administration of

  18. A Comparative Analysis of 2D and 3D Tasks for Virtual Reality Therapies Based on Robotic-Assisted Neurorehabilitation for Post-stroke Patients

    PubMed Central

    Lledó, Luis D.; Díez, Jorge A.; Bertomeu-Motos, Arturo; Ezquerro, Santiago; Badesa, Francisco J.; Sabater-Navarro, José M.; García-Aracil, Nicolás

    2016-01-01

    Post-stroke neurorehabilitation based on virtual therapies are performed completing repetitive exercises shown in visual electronic devices, whose content represents imaginary or daily life tasks. Currently, there are two ways of visualization of these task. 3D virtual environments are used to get a three dimensional space that represents the real world with a high level of detail, whose realism is determinated by the resolucion and fidelity of the objects of the task. Furthermore, 2D virtual environments are used to represent the tasks with a low degree of realism using techniques of bidimensional graphics. However, the type of visualization can influence the quality of perception of the task, affecting the patient's sensorimotor performance. The purpose of this paper was to evaluate if there were differences in patterns of kinematic movements when post-stroke patients performed a reach task viewing a virtual therapeutic game with two different type of visualization of virtual environment: 2D and 3D. Nine post-stroke patients have participated in the study receiving a virtual therapy assisted by PUPArm rehabilitation robot. Horizontal movements of the upper limb were performed to complete the aim of the tasks, which consist in reaching peripheral or perspective targets depending on the virtual environment shown. Various parameter types such as the maximum speed, reaction time, path length, or initial movement are analyzed from the data acquired objectively by the robotic device to evaluate the influence of the task visualization. At the end of the study, a usability survey was provided to each patient to analysis his/her satisfaction level. For all patients, the movement trajectories were enhanced when they completed the therapy. This fact suggests that patient's motor recovery was increased. Despite of the similarity in majority of the kinematic parameters, differences in reaction time and path length were higher using the 3D task. Regarding the success rates

  19. A new 3D method for measuring cranio-facial relationships with cone beam computed tomography (CBCT)

    PubMed Central

    Cibrián, Rosa; Gandia, Jose L.; Paredes, Vanessa

    2013-01-01

    Objectives: CBCT systems, with their high precision 3D reconstructions, 1:1 images and accuracy in locating cephalometric landmarks, allows us to evaluate measurements from craniofacial structures, so enabling us to replace the anthropometric methods or bidimensional methods used until now. The aims are to analyse cranio-facial relationships in a sample of patients who had previously undergone a CBCT and create a new 3D cephalometric method for assessing and measuring patients. Study Design: 90 patients who had a CBCT (i-Cat®) as a diagnostic register were selected. 12 cephalometric landmarks on the three spatial planes (X,Y,Z) were defined and 21 linear measurements were established. Using these measurements, 7 triangles were described and analysed. With the sides of the triangles: (CdR-Me-CdL); (FzR-Me-FzL); (GoR-N-GoL); and the Gl-Me distance, the ratios between them were analysed. In addition, 4 triangles in the mandible were measured (body: GoR-DB-Me and GoL-DB-Me and ramus: KrR-CdR-GoR and KrL-CdL-GoL). Results: When analyzing the sides of the CdR-Me-CdL triangle, it was found that the 69.33% of the patients could be considered symmetric. Regarding the ratios between the sides of the following triangles: CdR-Me-CdL, FzR-Me-FzL, GoR-N-GoL and the Gl-Me distance, it was found that almost all ratios were close to 1:1 except between the CdR-CdL side with respect the rest of the sides. With regard to the ratios of the 4 triangles of the mandible, it was found that the most symmetrical relationships were those corresponding to the sides of the body of the mandible and the most asymmetrical ones were those corresponding to the base of such triangles. Conclusions: A new method for assessing cranio-facial relationshps using CBCT has been established. It could be used for diverse purposes including diagnosis and treatment planning. Key words:Craniofacial relationship, CBCT, 3D cephalometry. PMID:23524427

  20. From 3D view to 3D print

    NASA Astrophysics Data System (ADS)

    Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.

    2014-08-01

    In the last few years 3D printing is getting more and more popular and used in many fields going from manufacturing to industrial design, architecture, medical support and aerospace. 3D printing is an evolution of bi-dimensional printing, which allows to obtain a solid object from a 3D model, realized with a 3D modelling software. The final product is obtained using an additive process, in which successive layers of material are laid down one over the other. A 3D printer allows to realize, in a simple way, very complex shapes, which would be quite difficult to be produced with dedicated conventional facilities. Thanks to the fact that the 3D printing is obtained superposing one layer to the others, it doesn't need any particular work flow and it is sufficient to simply draw the model and send it to print. Many different kinds of 3D printers exist based on the technology and material used for layer deposition. A common material used by the toner is ABS plastics, which is a light and rigid thermoplastic polymer, whose peculiar mechanical properties make it diffusely used in several fields, like pipes production and cars interiors manufacturing. I used this technology to create a 1:1 scale model of the telescope which is the hardware core of the space small mission CHEOPS (CHaracterising ExOPlanets Satellite) by ESA, which aims to characterize EXOplanets via transits observations. The telescope has a Ritchey-Chrétien configuration with a 30cm aperture and the launch is foreseen in 2017. In this paper, I present the different phases for the realization of such a model, focusing onto pros and cons of this kind of technology. For example, because of the finite printable volume (10×10×12 inches in the x, y and z directions respectively), it has been necessary to split the largest parts of the instrument in smaller components to be then reassembled and post-processed. A further issue is the resolution of the printed material, which is expressed in terms of layers

  1. Photofragmentation Mechanisms of Chlorosulfonyl Isocyanate, ClSO2NCO, Excited with Synchrotron Radiation between 12 and 550 eV.

    PubMed

    Moreno Betancourt, Angélica; Bava, Yanina B; Berrueta Martínez, Yanina; Erben, Mauricio F; Cavasso Filho, Reinaldo L; Della Védova, Carlos O; Romano, Rosana M

    2015-07-23

    The unimolecular photofragmentation mechanisms of chlorosulfonyl isocyanate, ClSO2NCO, excited with tunable synchrotron radiation between 12 and 550 eV, were investigated by means of time-of-flight (TOF) coincidence techniques. The main fragmentation mechanism after single ionization, produced by irradiation of an effusive beam of the sample with synchrotron light in the valence electron region, occurs through the breaking of the Cl-S single bond, giving a chloride radical and a SO2NCO(+) fragment. This mechanism contrasts with the one observed for the related FSO2NCO, in which the rupture of the S-N bond originates the FSO2(+) fragment. The energies of the shallow- (S 2p, Cl 2p, and S 2s) and core-shell (C 1s, N 1s, and O 1s) electrons were determined by X-ray absorption. Transitions between these shallow and core electrons to unoccupied molecular orbitals were also observed in the total ion yield (TIY) spectra. Fourteen different fragmentation mechanisms of the doubly charged parent ion, ClSO2NCO(2+), were inferred from the bidimensional photoelectron-photoion-photoion-coincidence (PEPIPICO) spectra. The rupture of the S-N bond can evolve to form NCO(+)/SO2(•+), NCO(+)/SO(•+), or S(•+)/NCO(+) pairs of ions. The Cl-S bond breaking originates different mechanisms, Cl(+)/SO(•+), Cl(+)/S(•+), CO(•+)/S(•+), O(•+)/SO(•+), O(•+)/Cl(+), O(•+)/S(•+), C(•+)/S(•+), and C(•+)/O(•+) pairs being detected in coincidence as the final species. Another three coincidence islands can only be explained with an initial atomic rearrangement forming ClNCO(2+), ONCO(2+), and ClCO(2+), as precursors of CO(•+)/Cl(+), O(•+)/CO(•+), and C(•+)/Cl(+) pairs, respectively. The formation of Cl(•) radical is deduced from several mechanisms. PMID:26121558

  2. Comparison of different statistical approaches to evaluate the orthogonality of chromatographic separations: application to reverse phase systems.

    PubMed

    Al Bakain, Ramia; Rivals, Isabelle; Sassiat, Patrick; Thiébaut, Didier; Hennion, Marie-Claire; Euvrard, Guillaume; Vial, Jérôme

    2011-05-20

    Selectivity of phase system is of primary concern when designing a bidimensional chromatographic system and looking for the highest degree of orthogonality between the two separations. Several statistical or geometrical criteria can potentially be used to measure the degree of orthogonality. A comparison of eight candidate criteria has been carried out in this study. Analysis of variance (ANOVA) was used to evaluate the relevance of each criterion and its ability to reveal the significance of the influence of factors like pH, stationary phase, and organic modifier. Experimentally, a set of 32 chromatographic systems was evaluated by the same generic gradient with 63 probe solutes, likely to be present in biological and/or environmental samples and covering a wide range of physico-chemical properties: acidic, basic and neutral compounds with different pKa, molecular mass and hydrophobicity (logP). Each chromatographic system was defined by the nature of the stationary phase (8 different silica or grafting chemistries), the pH of the aqueous fraction of the mobile phase (2.5 or 7.0) and the nature of the organic modifier (acetonitrile or methanol). The orthogonality of the 496 couples of chromatographic systems was evaluated and ranked using the eight different approaches: the three correlation coefficients (Pearson, Spearman and Kendall), two geometric criteria characterizing the coverage of the 2D separation space, Slonecker's information similarity and two chi-square statistics of independence between normalized retention times. In fact, there were only seven distinct criteria, since we established the analytical equivalence between the rankings with the likelihood ratio statistics and Slonecker's information similarity. Kendall's correlation coefficient appeared to be the best measure of orthogonality since, according to ANOVA, it exhibited the highest sensitivity to all experimental factors. The chi-square measures, and hence Slonecker's information similarity

  3. The ADAHELI solar mission: Investigating the structure of Sun's lower atmosphere

    NASA Astrophysics Data System (ADS)

    Berrilli, F.; Bigazzi, A.; Roselli, L.; Sabatini, P.; Velli, M.; Alimenti, F.; Cavallini, F.; Greco, V.; Moretti, P. F.; Orsini, S.; Romoli, M.; White, S. M.; ADAHELI Team; Ascani, L.; Carbone, V.; Curti, F.; Consolini, G.; Di Mauro, M.P.; Del Moro, D.; Egidi, A.; Ermolli, I.; Giordano, S.; Pastena, M.; Pulcino, V.; Pietropaolo, E.; Romano, P.; Ventura, P.; Cauzzi, G.; Valdettaro, L.; Zuccarello, F.; ADAHELI Team

    2010-05-01

    ADAHELI (ADvanced Astronomy for HELIophysics) is a small-class (500 kg) low-budget (50 MEuro) satellite mission for the study of the solar photosphere and the chromosphere and for monitoring solar flare emission. ADAHELI's design has completed its Phase-A feasibility study in December 2008, in the framework of ASI's (Agenzia Spaziale Italiana) 2007 "Small Missions" Program (calling for two missions at 50 MEeuros each, plus the launch budget). ADAHELI's main purpose is to explore Sun's lower atmosphere in the near-infrared, a region so far unexplored by solar observations from space. ADAHELI will carry out observations of the solar photosphere and of the chromosphere at high-temporal rate and high spatial and spectral resolutions. ADAHELI will contribute to the understanding of Space Weather through the study of particle acceleration during flares. A radiometer operating in the millimeter radio band will continuously monitor the solar disk, throughout the spacecraft's life time. ADAHELI's baseline instruments are a 50-cm high-resolution telescope operating in the visible and the near-infrared, and a lightweight full-disk radiometer operating at millimeter wavelengths (90 GHz). The core of the telescope's focal plane suite is the spectral imager based on two Fabry-Perot interferometers, flying for the first time on a solar mission. The instrument will return fast-cadence, full bi-dimensional spectral images at high-resolution, thus improving on current slit-scan, mono-dimensional architectures. Moreover, the possibility of working in polarized light will enable full 3D magnetic field reconstruction on the photosphere and the chromosphere. An optional instrumental package is also being proposed to further extend ADAHELI's scope: a full-disk telescope for helioseismology based on a double Magneto-Optical Filter, a Neutral Particle Analyzer for magnetospheric research, an Extreme Ultraviolet imaging and spectro-radiometry instrument. These options fall outside the

  4. Pseudo-Jahn-Teller origin of the low barrier hydrogen bond in N2H7+

    NASA Astrophysics Data System (ADS)

    García-Fernández, P.; García-Canales, L.; García-Lastra, J. M.; Junquera, J.; Moreno, M.; Aramburu, J. A.

    2008-09-01

    -transfer dynamics. This issue was explored by solving numerically the vibrational Schrödinger equation corresponding to the bidimensional E[Q(α2u),Q(α1g)] energy surface calculated at the MP4/6-311++G** level of theory.

  5. Variaciones seculares de período en las RR Lyrae de ω~Centauri

    NASA Astrophysics Data System (ADS)

    Marraco, H. G.; Milesi, G. E.

    Utilizando 689 observaciones de 35 estrellas RR Lyrae del cúmulo globular ω Centauri hemos obtenido nuevas determinaciones de sus períodos y sus correspondientes variaciones seculares. Las observaciones fueron obtenidas de la literatura con la excepción de un grupo 66 determinaciones que se presentan por vez primera aquí. Utilizando el parámetro testigo σ descripto en Marraco & Muzzio (Publ. Astron. Soc. Pacific 92, 700, 1980), hemos realizado un ajuste bidimensional en P y β (donde β es la variación secular del período). Con este fin la totalidad de las 689 observaciones fueron llevadas a un sistema fotométrico común. Para esto se realizó un cuidadoso análisis de los numerosos errores en la identificación de las estrellas de las series de comparación. Los resultados de los ajustes bidimensionales fueron analizados utilizando técnicas de procesamiento de imágenes. Con este fin el parámetro de ajuste σ fue representado como función de P y β. En las imágenes resultantes se buscaron los mínimos y al menor de ellos se lo aceptó como período instantáneo verdadero y su variación secular β. La determinación precisa de cada parámetro se realizó mediante ajuste de gaussianas y se determinaron sus errores. A modo de ejemplo la variable #8 fue analizada en una matriz de 501 × 501 elementos representando el parámetro σ para valores comprendidos entre 0,521034 < P < 0,521534 dias y -150×10-10 < β < +150×10-10 dias/dia. El mejor período instantáneo (correspondiente a la época DJ=2.426.908) y su variación secular son P = 0,5212859±0,0000001 días y β 14,012±,010×10-10 días/día respectivamente. Con estos valores el parámetro testigo resulta σ= 0,127 . Si no se tiene en cuenta la variación secular del período y se busca aquél de mejor ajuste para β = 0, se obtiene P = 0,5212960 días, pero entonces el parámetro de ajuste resulta tan alto como σ = 0,23 .

  6. Isolation of pregnancy-associated glycoproteins from placenta of the American bison (Bison bison) at first half of pregnancy.

    PubMed

    Kiewisz, Jolanta; Sousa, Noelita Melo de; Beckers, Jean-Francois; Vervaecke, Hilde; Panasiewicz, Grzegorz; Szafranska, Bozena

    2008-01-01

    This paper describes the successful purification and characterisation of pregnancy-associated glycoproteins (PAG) extracted from placenta (3-4 months) of American bisons (Amb). Chorionic AmbPAG proteins were purified from foetal cotyledonary tissues (CT) and liquid cotyledonary-carrying proteins (LCP) leaking from damaged cells. Our protocols successfully indicated the usefulness of AmbPAG protein identification, especially from LCP fraction. The AmbPAGs were extracted, precipitated and eluted during DEAE cellulose chromatography. The richest protein fractions were further chromatographed on VVA (Vicia villosa agglutinin affinity column), then characterised by mono- and bi-dimensional electrophoresis, Western blot and N-terminal amino acid (aa) sequence. After being transferred to PVDF membranes, three selected VVA-purified AmbPAG isoforms differing in molecular masses and isoelectric points (Ip 4-4.6) were selected for sequencing. One identified N-terminal 25aa sequence of AmbPAG72kDa CT form was identified as completely new (RGSNLTSLPLQNVIDLFYVGNITIG). Two other AmbPAG proteins purified from different sources (74kDa CT and 76kDa LCP forms; RGSNLTIHPLRNIRDIFYVGNITIG) were identical or corresponded to N-terminus of various bovine PAGs (boPAG). The two AmbPAGs (74kDa CT and 76kDa LCP) revealed identical micro-sequence to boPAG7; and were similar mainly to bovine PAG4, -6, -15 and -17 precursors that were identified by full-length sequencing derived from cDNA cloning. The novel sequence of the AmbPAG (72kDa CT) was related to some boPAG and various other ruminant PAG precursors (caprine and ovine). All three identified AmbPAG sequences were also relatively similar to mature forms of purified native boPAG(56-75kDa) proteins. This is the first report indicating aa sequences of native AmbPAG proteins purified from placenta (CT and LCP) of bison species. The N-terminal sequences of the AmbPAGs have been deposited in the EMBL-EBI database (UniProtKB; Accession Nos.: P

  7. High-cadence and high-resolution Hα imaging spectroscopy of a circular flare's remote ribbon with IBIS

    SciTech Connect

    Deng, Na; Jing, Ju; Chen, Xin; Liu, Chang; Xu, Yan; Wang, Haimin; Tritschler, Alexandra; Reardon, Kevin; Denker, Carsten

    2013-06-01

    We present an unprecedented high-resolution Hα imaging spectroscopic observation of a C4.1 flare taken with the Interferometric Bidimensional Spectrometer (IBIS) in conjunction with the adaptive optics system at the 76 cm Dunn Solar Telescope on 2011 October 22 in the active region NOAA 11324. Such a two-dimensional spectroscopic observation covering the entire evolution of a flare ribbon with high spatial (0.''1 pixel{sup –1} image scale), cadence (4.8 s), and spectral (0.1 Å step size) resolution is rarely reported. The flare consists of a main circular ribbon that occurred in a parasitic magnetic configuration and a remote ribbon that was observed by the IBIS. Such a circular-ribbon flare with a remote brightening is predicted in three-dimensional fan-spine reconnection but so far has been rarely studied. During the flare impulsive phase, we define 'core' and 'halo' structures in the observed ribbon based on IBIS narrowband images in the Hα line wing and line center. Examining the Hα emission spectra averaged in the flare core and halo areas, we find that only those from the flare cores show typical nonthermal electron beam heating characteristics that have been revealed by previous theoretical simulations and observations of flaring Hα line profiles. These characteristics include broad and centrally reversed emission spectra, excess emission in the red wing with regard to the blue wing (i.e., red asymmetry), and redshifted bisectors of the emission spectra. We also observe rather quick timescales for the heating (∼30 s) and cooling (∼14-33 s) in the flare core locations. Therefore, we suggest that the flare cores revealed by IBIS track the sites of electron beam precipitation with exceptional spatial and temporal resolution. The flare cores show two-stage motion (a parallel motion along the ribbon followed by an expansion motion perpendicular to the ribbon) during the two impulsive phases of the flare. Some cores jump quickly (30 km s{sup –1

  8. Crystal structure, magnetic, thermal behavior, and spectroscopic studies of two new bimetallic hydrogenselenites: [Cu2-xNix (HSeO3)2Cl2.4H2O], (x = 0.62; 0.91)

    NASA Astrophysics Data System (ADS)

    Hentech, I.; Zehani, K.; Kabadou, A.; Ben Salah, A.; Loukil, M.; Bessais, L.

    2016-08-01

    Two new iso-structural bimetallic hydrogenselenites [Cu2-xNix(HSeO3)2Cl2.4H2O] (x = 0.62; 0.91) have been synthesized from solution and characterized by single-crystal and powder X-ray diffraction. They crystallized in the orthorhombic Pnma space group with the following lattice parameters: for Cu1.09Ni0.91(HSeO3)2Cl2.4H2O: a = 9.0931 (2) Å, b = 17.7717 (4) Å, c = 7.1620 (2) Å, Z = 4, and for Cu1.38Ni0.62(HSeO3)2Cl2.4H2O: a = 9.0931 (4) Å, b = 17.7467 (7) Å, c = 7.1717 (3) Å; Z = 4. The crystal structure of this compound consists by a three-dimensional framework, but it may be described as a bi-dimensional structure consisting of layers, parallel to the (010) plane formed by two types of (Cu/Ni) octahedral and (HSeO3)- trigonal pyramids. The magnetic measurement, thermal and spectroscopic studies were performed for these compounds. The magnetic results reveal the appearance of a weak ferromagnetic behavior at low temperature (Tc = 16 K for x = 0.91 and 18.8 K for x = 0.62). The DSC analysis enabled us to locate two endothermic peaks. The first peak can be attributed to a completely dehydration of the material, in this transformation, the compounds undergo a structural phase transition which can favor a non-centrosymmetric phase at high temperature confirmed by the thermodiffractograms measurement. The second peak for these samples is due to the ferro-paraelectric phase transition which can be explained by an order- disorder transition.

  9. The 27 May 1937 catastrophic flow failure of gold tailings at Tlalpujahua, Michoacan, Mexico

    NASA Astrophysics Data System (ADS)

    Macias, J. L.; Corona-Chavez, P.; Sanchez-Nunez, J. M.; Martinez-Medina, M.; Garduno-Monroy, V. H.; Capra, L.; Garcia-Tenorio, F.; Cisneros-Maximo, G.

    2015-05-01

    On 27 May 1937, after one week of sustained heavy rainfall, a voluminous flood caused the death of at least 300 people and the destruction of the historic El Carmen church and several neighborhoods in the mining region of Tlalpujahua, Michoacan, central Mexico. This destructive flood was triggered by the breaching of the impoundment of the Los Cedros tailings and the sudden release of circa 16 Mt of water-saturated waste materials. The muddy silty flood, moving at estimated speeds of 20-25 m s-1, was channelized along the Dos Estrellas and Tlalpujahua drainages and devastated everything along its flow path. After advancing 2.5 km downstream, the flood slammed into El Carmen church and surrounding houses at estimated speeds of ~ 7 m s-1, destroying many construction walls and covering the church floor with ~ 2 m of mud and debris. Revision of eyewitness accounts and newspaper articles, together with analysis of archived photographic materials, indicated that the flood consisted of three muddy pulses. Stratigraphic relations and granulometric data for selected proximal and distal samples show that the flood behaved as a hyperconcentrated flow along most of its trajectory. A total volume of the Lamas flood deposit was estimated as 1.5 x 106 m3. The physically based bidimensional (2-D) hydraulic model FLO-2D was implemented to reproduce the breached flow (0.5 sediment concentration) with a maximum flow discharge of 8000 m3 s-1 for a total outflow volume (sediment + water) of 2.5 x 106 m3, similar to the calculations obtained using field measurements. Even though premonitory signs of possible impoundment failure were reported days before the flood, and people living downstream were alerted, authorities ordered no evacuations or other mitigative actions. The catastrophic flood at Tlalpujahua provides a well-documented, though tragic, example of impoundment breaching of a tailings dam caused by the combined effects of intense rainfall, dam weakness, and inadequate

  10. Anisotropic magnetotelluric inversion using a mutual information constraint

    NASA Astrophysics Data System (ADS)

    Mandolesi, E.; Jones, A. G.

    2012-12-01

    In recent years, several authors pointed that the electrical conductivity of many subsurface structures cannot be described properly by a scalar field. With the development of field devices and techniques, data quality improved to the point that the anisotropy in conductivity of rocks (microscopic anisotropy) and tectonic structures (macroscopic anisotropy) cannot be neglected. Therefore a correct use of high quality data has to include electrical anisotropy and a correct interpretation of anisotropic data characterizes directly a non-negligible part of the subsurface. In this work we test an inversion routine that takes advantage of the classic Levenberg-Marquardt (LM) algorithm to invert magnetotelluric (MT) data generated from a bi-dimensional (2D) anisotropic domain. The LM method is routinely used in inverse problems due its performance and robustness. In non-linear inverse problems -such the MT problem- the LM method provides a spectacular compromise betwee quick and secure convergence at the price of the explicit computation and storage of the sensitivity matrix. Regularization in inverse MT problems has been used extensively, due to the necessity to constrain model space and to reduce the ill-posedness of the anisotropic MT problem, which makes MT inversions extremely challenging. In order to reduce non-uniqueness of the MT problem and to reach a model compatible with other different tomographic results from the same target region, we used a mutual information (MI) based constraint. MI is a basic quantity in information theory that can be used to define a metric between images, and it is routinely used in fields as computer vision, image registration and medical tomography, to cite some applications. We -thus- inverted for the model that best fits the anisotropic data and that is the closest -in a MI sense- to a tomographic model of the target area. The advantage of this technique is that the tomographic model of the studied region may be produced by any

  11. BUDDA (Bulge/Disk Decomposition Analysis) - um novo programa para análise estrutural de galáxias

    NASA Astrophysics Data System (ADS)

    Gadotti, D. A.; de Souza, R. E.; Dos Anjos, S.

    2003-08-01

    Tem sido prática comum nos últimos anos estudar a distribuição de luminosidade em galáxias fazendo uso da informação contida em toda a imagem da galáxia, já que esta técnica tem se mostrado muito mais confiável do que o simples ajuste de perfis radiais de luminosidade. Através destes estudos bidimensionais, melhores resultados tem sido obtidos na análise e.g. do Plano Fundamental, de correlações entre os parâmetros estruturais de galáxias, de sub-estruturas como barras e anéis nucleares etc. Apresentamos um novo código bidimensional, o BUDDA, de análise estrutural de galáxias, que será disponibilizado para a comunidade. Desenvolvido por nós, o código determina os parâmetros estruturais de galáxias de forma prática e robusta, e pode ser aplicado genericamente em qualquer estudo sobre a formação, evolução e estrutura de galáxias. O programa ainda permite a avaliação direta de sub-estruturas, através de imagens residuais que são obtidas ao se subtrair, das imagens originais, bojo e disco sintéticos que melhor representam essas componentes da galáxia sob consideração. Será apresentada a forma de utilização do código, bem como séries de testes que atestam a sua funcionalidade. Além disso, os resultados da aplicação do código em uma amostra de 51 galáxias serão expostos como exemplo prático, e do seu enorme potencial de uso.

  12. Assessing Negative Automatic Thoughts: Psychometric Properties of the Turkish Version of the Cognition Checklist

    PubMed Central

    Batmaz, Sedat; Ahmet Yuncu, Ozgur; Kocbiyik, Sibel

    2015-01-01

    Background: Beck’s theory of emotional disorder suggests that negative automatic thoughts (NATs) and the underlying schemata affect one’s way of interpreting situations and result in maladaptive coping strategies. Depending on their content and meaning, NATs are associated with specific emotions, and since they are usually quite brief, patients are often more aware of the emotion they feel. This relationship between cognition and emotion, therefore, is thought to form the background of the cognitive content specificity hypothesis. Researchers focusing on this hypothesis have suggested that instruments like the cognition checklist (CCL) might be an alternative to make a diagnostic distinction between depression and anxiety. Objectives: The aim of the present study was to assess the psychometric properties of the Turkish version of the CCL in a psychiatric outpatient sample. Patients and Methods: A total of 425 psychiatric outpatients 18 years of age and older were recruited. After a structured diagnostic interview, the participants completed the hospital anxiety depression scale (HADS), the automatic thoughts questionnaire (ATQ), and the CCL. An exploratory factor analysis was performed, followed by an oblique rotation. The internal consistency, test-retest reliability, and concurrent and discriminant validity analyses were undertaken. Results: The internal consistency of the CCL was excellent (Cronbach’s α = 0.95). The test-retest correlation coefficients were satisfactory (r = 0.80, P < 0.001 for CCL-D, and r = 0.79, P < 0.001 for CCL-A). The exploratory factor analysis revealed that a two-factor solution best fit the data. This bidimensional factor structure explained 51.27 % of the variance of the scale. The first factor consisted of items related to anxious cognitions, and the second factor of depressive cognitions. The CCL subscales significantly correlated with the ATQ (rs 0.44 for the CCL-D, and 0.32 for the CCL-A) as well as the other measures of

  13. Classification of Cryostructures of Basal Glacier Ice Using Tomodensitometry

    NASA Astrophysics Data System (ADS)

    Fortier, D.; Kanevskiy, M.; Dillon, M.; Stephani, E.; Shur, Y.; Jorgenson, T. M.

    2008-12-01

    In permafrost areas, the extent of former glaciations can be inferred from the occurrence of buried glacier ice (Murton et al. 2005). Buried basal glacier ice can only be distinguished from other type of massive ice if the properties and structure of contemporary basal ice are well-known. Several classifications of basal ice have been developed based on the geological facies analysis (Lawson 1979, Knight 1994, Hubbard and Sharp 1995). However, none of them have addressed basal ice descriptions in terms of cryostructures. We used conventional field descriptions and microcomputed tomodensitometry to evaluate structure and properties of sediments including basal ice. The scan images were processed using a thresholding technique which assigns gray scale values to the components of basal ice based on their density. These values were used to determine the volumetric content of each component (ice, sediment, gas). We have used the Mathworks MATLAB R2007a software to produce three-dimensional images of basal ice cryostructures. The main advantage of these is to obtain in a non-destructive manner precise average ice and sediment contents for a given volume of a particular cryostructure. These models allow for a detailed 3D visualization of the cryostructures which is a powerful tool to study their architecture and the geometric relations between ice and sediments. The technical details of these operations have been presented by Dillon et al. (2008). Our cryostructures classification of basal glacier ice and sediments includes seven types of cryostructures observed in the basal ice of the Matanuska Glacier: (1) Porous; (2) Crustal; (3) Reticulate; (4) Lenticular; (5) Layered; (6) Suspended (includes four sub-types: Suspended dispersed, Micro-suspended, Suspended- intergranular, Suspended inter-crystalline); (7) Massive ice. The classification is illustrated by detailed photographs, sketches and bi-dimensional (2D) scan images of the various cryostructures along with their

  14. Analytic Simulation of the Elastic Waves Propagation in the Neighborhood of Fluid Filled Wells with Monopole Sources

    NASA Astrophysics Data System (ADS)

    Ávila-Carrera, R.; Sánchez-Sesma, F. J.; Spurlin, James H.; Valle-Molina, C.; Rodríguez-Castellanos, A.

    2014-09-01

    An analytic formulation to understand the scattering, diffraction and attenuation of elastic waves at the neighborhood of fluid filled wells is presented. An important, and not widely exploited, technique to carefully investigate the wave propagation in exploration wells is the logging of sonic waveforms. Fundamental decisions and production planning in petroleum reservoirs are made by interpretation of such recordings. Nowadays, geophysicists and engineers face problems related to the acquisition and interpretation under complex conditions associated with conducting open-hole measurements. A crucial problem that directly affects the response of sonic logs is the eccentricity of the measuring tool with respect to the center of the borehole. Even with the employment of centralizers, this simple variation, dramatically changes the physical conditions on the wave propagation around the well. Recent works in the numerical field reported advanced studies in modeling and simulation of acoustic wave propagation around wells, including complex heterogeneities and anisotropy. However, no analytical efforts have been made to formally understand the wireline sonic logging measurements acquired with borehole-eccentered tools. In this paper, the Graf's addition theorem was used to describe monopole sources in terms of solutions of the wave equation. The formulation was developed from the three-dimensional discrete wave-number method in the frequency domain. The cylindrical Bessel functions of the third kind and order zero were re-derived to obtain a simplified set of equations projected into a bi-dimensional plane-space for displacements and stresses. This new and condensed analytic formulation allows the straightforward calculation of all converted modes and their visualization in the time domain via Fourier synthesis. The main aim was to obtain spectral surfaces of transfer functions and synthetic seismograms that might be useful to understand the wave motion produced by the

  15. New Antimony Lanthanide Disulfide Dibromides LnSbS

    SciTech Connect

    Gout, D.; Jobic, S.; Evain, M.; Brec, R.

    2001-05-01

    CeSbS{sub 2}Br{sub 2} (I), Ce{sub 1/2}La{sub 1/2}SbS{sub 2}Br{sub 2} (II), and LaSbS{sub 2}Br{sub 2} (III) have been synthesized at 700 C from a mixture of LnBr{sub 3}, Ln{sub 2}S{sub 3}, Sb, and S and characterized by single-crystal X-ray diffraction. The three phases are isostructural (space group P2{sub 1}/c, Z=4) and crystallize in a novel, dense, bidimensional structure with cell parameters a=8.709(3) {angstrom}, b=9.187(2) {angstrom}, c=17.397(5) {angstrom} {beta}=104.26(3) for I, a=8.739(7) {angstrom}, b=9.219(7) {angstrom}, c=17.41(2) {angstrom}, =104.3(1) for II, and a=8.785(1) {angstrom}, b=9.236(2) {angstrom}, c=17.372(3) {angstrom}, {beta}=104.09(2) for III. In these compounds, [Ln S{sub 5}Br{sub 4}] and [Ln S{sub 3}Br{sub 6}] (Ln=Ce, La) distorted tricapped trigonal prisms define infinite {sub {infinity}}{sup 2}[LnS{sub 2}Br{sub 2}] layers counterbalanced and capped by antimony cations. In good accordance with the structural features, the charge balance in these materials is to be written Ln{sup III}Sb{sup III}S{sup -II}{sub 2}Br{sup -I}{sub 2}. These compounds exhibit a yellow hue with a measured absorption threshold of 2.42(1), 2.55(1), and 2.72(1) eV for I, II, and III, respectively. In the two cerium containing bromothioantimonates I and II, the origin of the color is assigned to a Ce-4f{yields}Ce-5d electronic transition, which shifts to higher energy from I to II due either to a matrix effect (increase of the mean Ln-S distances under the substitution of Ce for La) or to an atomic ordering between Ce and La cations on the Ln(1) and Ln(2) crystallographic sites. In contrast, the electronic transition at play in III involves a charge transfer from the bromine and sulfur ions to the antimony ions, the latter contributing substantially to the lowermost levels of the conduction band.

  16. Full 2D observation of water surface elevation from SWOT under different flow conditions

    NASA Astrophysics Data System (ADS)

    Domeneghetti, Alessio; Schumann, Guy; Rui, Wei; Durand, Michael; Pavelsky, Tamlin

    2016-04-01

    The upcoming Surface Water and Ocean Topography (SWOT) satellite mission is a joint project of NASA, Centre National d'Etudes Spatiales (CNES, France), the Canadian Space Agency, and the Space Agency of the UK that will provide a first global, high-resolution observation of ocean and terrestrial water surface heights. Characterized by an observation swath of 120 km and an orbit repeat interval of about 21 days, SWOT will provide unprecedented bi-dimensional observations of rivers wider than 50-100 m. Despite many research activities that have investigated potential uses of remotely sensed data from SWOT, potentials and limitations of the spatial observations provided by the satellite mission for flood modeling still remain poorly understood and investigated. In this study we present a first analysis of the spatial observation of water surface elevation that is expected from SWOT for a 140 km reach of the middle-lower portion of the Po River, in Northern Italy. The river stretch is characterized by a main channel varying from 200-500 m in width and a floodplain that can be as wide as 5 km and that is delimited by a system of major embankments. The reconstruction of the hydraulic behavior of the Po River is performed by means of a quasi-2d model built with detailed topographic and bathymetric information (LiDAR, 2 m resolution), while the simulation of the spatial observation sensed by SWOT is performed with a SWOT simulator that mimics the satellite sensor characteristics. Referring to water surface elevations associated with different flow conditions (maximum, minimum and average flow reproduced by means of the quasi-2d numerical model) this work provides a first characterization of the spatial observations provided by SWOT and highlights the strengths and limitations of the expected products. By referring to a real river reach the analysis provides a credible example of the type of spatial observations that will be available after launch of SWOT and offers a first

  17. High-cadence and High-resolution Hα Imaging Spectroscopy of a Circular Flare's Remote Ribbon with IBIS

    NASA Astrophysics Data System (ADS)

    Deng, Na; Tritschler, Alexandra; Jing, Ju; Chen, Xin; Liu, Chang; Reardon, Kevin; Denker, Carsten; Xu, Yan; Wang, Haimin

    2013-06-01

    We present an unprecedented high-resolution Hα imaging spectroscopic observation of a C4.1 flare taken with the Interferometric Bidimensional Spectrometer (IBIS) in conjunction with the adaptive optics system at the 76 cm Dunn Solar Telescope on 2011 October 22 in the active region NOAA 11324. Such a two-dimensional spectroscopic observation covering the entire evolution of a flare ribbon with high spatial (0.''1 pixel-1 image scale), cadence (4.8 s), and spectral (0.1 Å step size) resolution is rarely reported. The flare consists of a main circular ribbon that occurred in a parasitic magnetic configuration and a remote ribbon that was observed by the IBIS. Such a circular-ribbon flare with a remote brightening is predicted in three-dimensional fan-spine reconnection but so far has been rarely studied. During the flare impulsive phase, we define "core" and "halo" structures in the observed ribbon based on IBIS narrowband images in the Hα line wing and line center. Examining the Hα emission spectra averaged in the flare core and halo areas, we find that only those from the flare cores show typical nonthermal electron beam heating characteristics that have been revealed by previous theoretical simulations and observations of flaring Hα line profiles. These characteristics include broad and centrally reversed emission spectra, excess emission in the red wing with regard to the blue wing (i.e., red asymmetry), and redshifted bisectors of the emission spectra. We also observe rather quick timescales for the heating (~30 s) and cooling (~14-33 s) in the flare core locations. Therefore, we suggest that the flare cores revealed by IBIS track the sites of electron beam precipitation with exceptional spatial and temporal resolution. The flare cores show two-stage motion (a parallel motion along the ribbon followed by an expansion motion perpendicular to the ribbon) during the two impulsive phases of the flare. Some cores jump quickly (30 km s-1) between discrete

  18. Longitudinal displacement of the carotid wall and cardiovascular risk factors: associations with aging, adiposity, blood pressure and periodontal disease independent of cross-sectional distensibility and intima-media thickness.

    PubMed

    Zahnd, Guillaume; Vray, Didier; Sérusclat, André; Alibay, Djhianne; Bartold, Mark; Brown, Alex; Durand, Marion; Jamieson, Lisa M; Kapellas, Kostas; Maple-Brown, Louise J; O'Dea, Kerin; Moulin, Philippe; Celermajer, David S; Skilton, Michael R

    2012-10-01

    The recently discovered longitudinal displacement of the common carotid arterial wall (i.e., the motion along the same plane as the blood flow), may be associated with incident cardiovascular events and represents a novel and relevant clinical information. At present, there have only been a few studies that have been conducted to investigate this longitudinal movement. We propose here a method to assess noninvasively the wall bi-dimensional (two-dimensional [2-D], cross-sectional and longitudinal) motion and present an original approach that combines a robust speckle tracking scheme to guidance by minimal path contours segmentation. Our method is well suited to large clinical population studies as it does not necessitate strong imaging prerequisites. The aim of this study is to describe the association between the longitudinal displacement of the carotid arterial wall and cardiovascular risk factors, among which periodontal disease. Some 126 Indigenous Australians with periodontal disease, an emerging risk factor, and 27 healthy age- and sex-matched non-indigenous control subjects had high-resolution ultrasound scans of the common carotid artery. Carotid intima-media thickness and arterial wall 2-D motion were then assessed using our method in ultrasound B-mode sequences. Carotid longitudinal displacement was markedly lower in the periodontal disease group than the control group (geometric mean (IQR): 0.15 mm (0.13) vs. 0.42 mm (0.30), respectively; p < 0.0001), independent of cardiovascular risk factors, cross-sectional distensibility and carotid intima-media thickness (p < 0.0001). A multivariable model indicated that the strongest correlates of carotid longitudinal displacement in adults with periodontal disease were age (β-coefficient = -.235, p = .03), waist (β-coefficient = -.357, p = 0.001), and pulse pressure (β-coefficient = .175, p = 0.07), independent of other cardiovascular risk factors, cross-sectional distensibility and pulse wave velocity. Carotid

  19. The use of multifractal modelling for targeting resources from soil and stream geochemistry data: the case of the Variscan basement of the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Gonçalves, Mario; Mateus, Antonio

    2016-04-01

    The safeguarding of access/use of many critical raw materials for Society requires that much of previously dismissed areas for exploration must be re-evaluated with new criteria in which the significance of "anomaly" should not be treated independently of the geochemical signals of the ore-forming processes and how the different chemical elements are interrelated. For much of the previous decade, several multifractal methods were methodically being refined as automatic tools to analyze and detect geochemical anomalies. These included the early concentration-area method (Cheng et al., 1994), singularity mapping (Cheng, 2007), and spectrum-area (Cheng et al., 2000), which has been recently combined with the bi-dimensional empirical mode decomposition (Xu et al., 2016) as a tool to separate different contributing sources of an otherwise complex geochemical pattern. We propose yet another approach, the use of geochemical indexes, which links to the geological and ore-forming processes known to define a given region in order to assess much of these numerical approaches. Therefore, we picked several areas from the Variscan basement in Portugal, with different geologic and metallogentic contexts, some of them previously analyzed with multifractal methods (Gonçalves et al., 2001; Jesus et al., 2013) and a multi-element geochemical campaign on which to test the different multifractal methods combined with the geochemical indexes, as an advantageous alternative to principal component mapping, for example. Some preliminary essays with stochastic models similar to those reported in Gonçalves (2001) and Agterberg (2007), with different overprinted pulses are presented as well. Acknowledgments: This is a contribution from UID/GEO/50019/2013 - Instituto Dom Luiz, supported by FCT. Agterberg, 2007, Math. Geol., 39, 1. Cheng et al, 1994, J. Geochem. Explor., 51, 109. Cheng et al., 2000, Nat. Resour. Res, 9, 43. Cheng, 2007, Ore Geol. Rev., 32, 314. Gonçalves, 2001, Math. Geol

  20. Statistical scaling, Shannon entropy, and Generalized space-time q-entropy of rainfall fields in tropical South America

    NASA Astrophysics Data System (ADS)

    Poveda, Germán; Salas, Hernán D.

    2015-07-01

    We study diverse scaling and information theory characteristics of Mesoscale Convective Systems (MCSs) as seen by the Tropical Rainfall Measuring Mission (TRMM) over continental and oceanic regions of tropical South America, and 2-D radar rainfall fields from Amazonia. The bi-dimensional Fourier spectra of MCSs exhibit inverse power laws with respect to the spatial scale, whose scaling exponents, β, capture the type of spatial correlation of rainfall among the study regions, including those over the Andes of Colombia as well as over oceanic and Amazonian regions. The moment-scaling analysis evidences that the structure function deviates from simple scaling at order q > 1.0, thus signaling the multi-scaling nature of rainfall fields within MCSs in tropical South America, with departures from simple scaling associated with the physical characteristics of MCSs over the different study regions. Entropy is estimated for a large set of radar rainfall fields during the distinctive atmospheric regimes (Easterly and Westerly events) in this part of Amazonia. Results evidence that there are significant differences in the dynamics of rainfall among regimes. No clear-cut relationship is found between entropy and the first two statistical moments, but power fits in space and time, S(γ) ˜ γ-η for skewness and, S(κ) ˜ κ-ɛ for kurtosis. The exponents η and ɛ are statistically different between Easterly and Westerly events, although the significance of fits is less when L-moments are used to estimate skewness and kurtosis. Interesting differences are identified between the time and space generalized q-entropy functions of Amazonian rainfall fields. In both cases, the functions are a continuous set of power laws (analogous to the structure function in turbulence), S(T, q) ˜ Tβ, and, S(λ, q) ˜ λβ, covering a broad range of temporal and spatial scales. Both time and space generalized q-entropy functions exhibit linear growth in the range -1.0 < q < -0.5, and