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Sample records for korrelation zwischen mrt

  1. Potential High Resolution Dosimeters For MRT

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Brochard, T.; Kamlowski, A.; Cellere, G.; Paccagnella, A.; Siegbahn, E. A.; Prezado, Y.; Martinez-Rovira, I.; Bravin, A.; Dusseau, L.; Berkvens, P.

    2010-07-01

    Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow (˜25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators in the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 μm microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy/s, micron

  2. Potential High Resolution Dosimeters For MRT

    SciTech Connect

    Braeuer-Krisch, E.; Brochard, T.; Prezado, Y.; Bravin, A.; Berkvens, P.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Kamlowski, A.; Cellere, G.

    2010-07-23

    Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow ({approx}25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators in the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 {mu}m microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy

  3. Homography-Based Correction of Positional Errors in MRT Survey

    NASA Astrophysics Data System (ADS)

    Nayak, A.; Daiboo, S.; Udaya Shankar, N.

    2009-09-01

    The Mauritius Radio Telescope (MRT) images show systematics in the positional errors of sources when compared to source positions in the Molonglo Reference Catalogue (MRC). We have applied two-dimensional homography to correct positional errors in the image domain and avoid re-processing the visibility data. Positions of bright (above 15 σ) sources, common to MRT and MRC catalogues, are used to set up an over-determined system to solve for the 2-D homography matrix. After correction, the errors are found to be within 10% of the beamwidth for these bright sources and the systematics are eliminated from the images.

  4. High Altitude Platforms Mobile Robotic Telesurgery (HAPsMRT)

    DTIC Science & Technology

    2006-09-01

    improve soldier survival as well as decrease the cost and risk of delivering medical care. Remote robotic surgery , or telesurgery, has not been...Medical Center MEO Mid Earth Orbit MIM Mission Information Management Mbps Mega bits per second MOR Mobile Operating Room MRT Mobile Robotic ... Surgery NASA National Aeronautics and Space Administration NEEMO NASA Extreme Environments Mission Operations NIH National Institutes of Health

  5. Segmentierung des Femurs aus MRT-Daten mit Shape-Based Level-Sets

    NASA Astrophysics Data System (ADS)

    Dekomien, Claudia; Busch, Martin; Teske, Wolfram; Winter, Susanne

    Inhalt dieser Arbeit ist die Segmentierung des Femurs aus MRT-Datensätzen mit einem Shape-based Level-Set-Ansatz. Der Algorithmus besteht aus zwei Phasen, der Modellerstellung und der Segmentierungsphase. In der Segmentierungsphase wurde ein kantenbasiertes und ein auf Intensitäten basierendes Optimierungskriterium mit einander kombiniert. Für eine lokale Verbesserung des Ergebnisses wurde zusätzlich ein Laplacian Level-Set-Verfahren angewendet. Der Femur konnte mit diesem Ansatz in drei verschiedenen MRT-Sequenzen und einem Fusionsdatensatz gut segmentiert werden.

  6. Generierung korrespondierender Schichtbilder zur verbesserten lokalen Analyse des linken Ventrikels in 4D-MRT-Bildsequenzen

    NASA Astrophysics Data System (ADS)

    Säring, D.; Müllerleile, K.; Groth, M.; Handels, H.

    Die genaue Erfassung lokaler Veränderungen des linken Ventrikels insbesondere bei der Verlaufskontrolle nach einem Infarkt erfordert die Extraktion lokaler Form- und Funktionsparameter. Die für den Inter- und Intrapatientenvergleich notwendige räumliche Korrespondenz der MRT-Schichtbilder ist durch die manuelle Planung der Schichtpositionen beim Aufnahmeverfahren i.A. nicht gewährleistet. In dieser Arbeit wird daher ein Verfahren vorgestellt, das unter Berücksichtigung der anatomischen Grenzen des linken Ventrikels räumlich korrespondierende Positionen bestimmt, zu denen anschließend unter Verwendung der originären Daten und der strukturerhaltenden Interpolation neue Schichtbilder generiert werden. Dadurch wird eine bessere Übereinstimmung der räumlichen Position der zu vergleichenden Schichten erzielt. Das Verfahren wurde an zu Evaluationszwecken generierten Probandendatensätzen getestet. Dabei konnte gezeigt werden, dass die Generierung korrespondierender Kurzachsen-MRT-Schichtbilder zu einer verbesserten Extraktion lokaler Parameter führt.

  7. SU-C-BRE-04: Microbeam-Radiation-Therapy (MRT): Characterizing a Novel MRT Device Using High Resolution 3D Dosimetry

    SciTech Connect

    Li, Q; Juang, T; Bache, S; Chang, S; Oldham, M

    2014-06-15

    Purpose: The feasibility of MRT has recently been demonstrated utilizing a new technology of Carbon-Nano-Tube(CNT) field emission x-ray sources.This approach can deliver very high dose(10's of Gy) in narrow stripes(sub-mm) of radiation which enables the study of novel radiation treatment approaches. Here we investigate the application of highresolution (50um isotropic) PRESAGE/Optical-CT 3D dosimetry techniques to characterize the radiation delivered in this extremely dosimetrically challenging scenario. Methods: The CNT field emission x-ray source irradiator comprises of a linear cathode array and a novel collimator alignment system. This allows a precise delivery of high-energy small beams up to 160 kVp. A cylindrical dosimeter (∼2.2cm in height ∼2.5cm in diameter) was irradiated by CNT MRT delivering 3 strips of radiation with a nominal entrance dose of 32 Gy.A second dosimeter was irradiated with similar entrance dose, with a regular x-ray irradiator collimated to microscopical strip-beams. 50um (isotropic) 3D dosimetry was performed using an in-house optical-CT system designed and optimized for high resolution imaging (including a stray light deconvolution correction).The percentage depth dose (PDD), peak-to-valley ratio (PVR) and beam width (FWHM) data were obtained and analyzed in both cases. Results: High resolution 3D images were successfully achieved with the prototype system, enabling extraction of PDD and dose profiles. The PDDs for the CNT irradiation showed pronounced attenuation, but less build-up effect than that from the multibeam irradiation. The beam spacing between the three strips has an average value of 0.9mm while that for the 13 strips is 1.5 mm at a depth of 16.5 mm. The stray light corrected image shows line profiles with reduced noise and consistent PVR values. Conclusion: MRT dosimetry is extremely challenging due to the ultra small fields involved.This preliminary application of a novel, ultra-high resolution, optical-CT 3D

  8. Identification of a developmentally-regulated and psychostimulant-inducible novel rat gene mrt3 in the neocortex.

    PubMed

    Yamamoto, Naoki; Muraoka, Shin-ichiro; Kajii, Yasushi; Umino, Asami; Nishikawa, Toru

    2014-10-01

    The psychotomimetic effects of stimulant drugs including amphetamines and cocaine are known to change during the postnatal development in humans and experimental animals. To obtain an insight into the molecular basis of the onset of stimulant-induced psychosis, we have explored the gene transcripts that differentially respond to methamphetamine (MAP) in the developing rat brains using a differential cloning technique, the RNA arbitrarily-primed PCR. We identified from the rat neocortex a novel and developmentally regulated MAP-inducible gene mrt3 (MAP responsive transcript 3) that is transcribed to a presumable non-coding RNA of 3.8kb and is located on the reverse strand of the F-box/LRR-repeat protein 17-like gene mapped on the rat chromosome Xq12. The mrt3 mRNAs are predominantly expressed in the brain and lung. Acute MAP injection upregulated the mrt3 expression in the neocortex at postnatal day 50, but not days 8, 15 and 23, in a D1 receptor antagonist-sensitive manner. This upregulation was mimicked by another stimulant, cocaine, whereas pentobarbital and D1 antagonist failed to alter the mrt3 expression. Moreover, repeated treatment with MAP for 5 days inhibited the ability of the challenge dose of MAP or cocaine to increase the neocortical mrt3 expression without affecting the basal mrt3 mRNA levels on day 14 of withdrawal. These late-developing, cocaine-cross reactive, D1 antagonist-sensitive and long-term regulations of mrt3 by MAP are similar to those of stimulant-induced behavioral sensitization, a model of the onset and relapse of stimulant-induced psychosis and schizophrenia, and therefore may be associated with the pathophysiology of the model.

  9. Two-dimensional homography-based correction of positional errors in widefield MRT images

    NASA Astrophysics Data System (ADS)

    Nayak, Arvind; Daiboo, Soobash; Shankar, N. Udaya

    2010-10-01

    A steradian of the southern sky has been imaged at 151.5 MHz using the Mauritius Radio Telescope (MRT). These images show systematics in the positional errors of sources when compared to source positions in the Molonglo Reference Catalogue (MRC). We have applied two-dimensional homography to correct for systematic positional errors in the image domain and thereby avoid re-processing the visibility data. Positions of bright (above 15σ) point sources, common to the MRT catalogue and MRC, are used to set up an over-determined system to solve for the homography matrix. After correction, the errors are found to be within 10 per cent of the beamwidth for these bright sources and the systematics are eliminated from the images. This technique will be of relevance to the new generation radio telescopes where, owing to huge data rates, only images after a certain integration would be recorded as opposed to raw visibilities. It is also interesting to note how our investigations cued to possible errors in the array geometry. The analysis of positional errors of sources showed that MRT images are stretched in declination by ~1 part in 1000. This translates to compression of the baseline scale in the visibility domain. The array geometry was re-estimated using the astrometry principle. The estimates show an error of ~1 mmm-1, which results in an error of about half a wavelength at 150 MHz for a 1-km north-south baseline. The estimates also indicate that the east-west arm is inclined by an angle of ~40 arcsec to the true east-west direction.

  10. Influence of polarization and a source model for dose calculation in MRT

    SciTech Connect

    Bartzsch, Stefan Oelfke, Uwe; Lerch, Michael; Petasecca, Marco; Bräuer-Krisch, Elke

    2014-04-15

    Purpose: Microbeam Radiation Therapy (MRT), an alternative preclinical treatment strategy using spatially modulated synchrotron radiation on a micrometer scale, has the great potential to cure malignant tumors (e.g., brain tumors) while having low side effects on normal tissue. Dose measurement and calculation in MRT is challenging because of the spatial accuracy required and the arising high dose differences. Dose calculation with Monte Carlo simulations is time consuming and their accuracy is still a matter of debate. In particular, the influence of photon polarization has been discussed in the literature. Moreover, it is controversial whether a complete knowledge of phase space trajectories, i.e., the simulation of the machine from the wiggler to the collimator, is necessary in order to accurately calculate the dose. Methods: With Monte Carlo simulations in the Geant4 toolkit, the authors investigate the influence of polarization on the dose distribution and the therapeutically important peak to valley dose ratios (PVDRs). Furthermore, the authors analyze in detail phase space information provided byMartínez-Rovira et al. [“Development and commissioning of a Monte Carlo photon model for the forthcoming clinical trials in microbeam radiation therapy,” Med. Phys. 39(1), 119–131 (2012)] and examine its influence on peak and valley doses. A simple source model is developed using parallel beams and its applicability is shown in a semiadjoint Monte Carlo simulation. Results are compared to measurements and previously published data. Results: Polarization has a significant influence on the scattered dose outside the microbeam field. In the radiation field, however, dose and PVDRs deduced from calculations without polarization and with polarization differ by less than 3%. The authors show that the key consequences from the phase space information for dose calculations are inhomogeneous primary photon flux, partial absorption due to inclined beam incidence outside

  11. A hydrodynamically-consistent MRT lattice Boltzmann model on a 2D rectangular grid

    NASA Astrophysics Data System (ADS)

    Peng, Cheng; Min, Haoda; Guo, Zhaoli; Wang, Lian-Ping

    2016-12-01

    A multiple-relaxation time (MRT) lattice Boltzmann (LB) model on a D2Q9 rectangular grid is designed theoretically and validated numerically in the present work. By introducing stress components into the equilibrium moments, this MRT-LB model restores the isotropy of diffusive momentum transport at the macroscopic level (or in the continuum limit), leading to moment equations that are fully consistent with the Navier-Stokes equations. The model is derived by an inverse design process which is described in detail. Except one moment associated with the energy square, all other eight equilibrium moments can be theoretically and uniquely determined. The model is then carefully validated using both the two-dimensional decaying Taylor-Green vortex flow and lid-driven cavity flow, with different grid aspect ratios. The corresponding results from an earlier model (Bouzidi et al. (2001) [28]) are also presented for comparison. The results of Bouzidi et al.'s model show problems associated with anisotropy of viscosity coefficients, while the present model exhibits full isotropy and is accurate and stable.

  12. Vorhersage des Krankheitsverlaufes von leichten kognitiven Beeinträchtigungen durch automatisierte MRT Morphometrie

    NASA Astrophysics Data System (ADS)

    Fritzsche, Klaus H.; Schlindwein, Sarah; Stieltjes, Bram; Essig, Marco; Meinzer, Hans-Peter

    Die leichte kognitive Beeinträchtigung (LKB) gilt als Anzeichen für ein erhöhtes Risiko der Entwicklung einer Alzheimerdemenz. Eine fundierte klinische Prognose für den Krankheitsverlauf kann aber bis dato nicht gegeben werden. Das Ziel dieser Arbeit besteht darin, eine möglichst präzise Vorhersage mittels automatisierter Morphometrie des Hippokampus im MRT-Bild zu treffen. In einer Studie mit 18 Probanden mit LKB wurde eine Prädiktionsgenauigkeit für die Entwicklung einer späteren Demenz von 83.3% erzielt. Eine manuelle Vergleichsmethode erreichte mit 55.6% Trefferquote keine signifikante Vorhersagegenauigkeit. Das automatische Verfahren erfüllt viele wichtige Voraussetzungen für den routinemäßigen klinischen Einsatz mit dem Potential, die klinische Vorhersage des Krankheitsverlaufes bei der LKB zu verbessern.

  13. Tanzendes Tier oder exzentrische Positionalität - Philosophische Anthropologie zwischen Darwinismus und Kulturalismus

    NASA Astrophysics Data System (ADS)

    Fischer, Joachim

    Zunächst kurz vorweg zu den Formeln im Titel: "exzentrische Positionalität“ ist der Kategorienvorschlag der Philosophischen Anthropologie (genauer: von Helmuth Plessner) für den Menschen, für seine "Sonderstellung“ unter den Lebewesen - ich werde diesen Begriff erläutern. So viel kann man sagen: Der Terminus ist nicht schwieriger als "Transzendentalität“ oder das "Apriori“ oder "Autopoiesis“, also Begriffe, mit deren Orientierungswert in der intellektuellen Öffentlichkeit bereits gespielt wird, bietet aber möglicherweise mehr Erschließungskraft als die Kunstbegriffe z. B. von Kant, Maturana oder Luhmann. Und "tanzendes Tier“ ist ein glücklicher Anschauungsbegriff, eine Art Übersetzung für "exzentrische Positionalität“ - also ein "verrücktes“ Lebewesen, eine Verrückung im evolutionären Leben, die dieses Lebewesen von Natur aus zu einer bestimmten Art von Lebensführung, nämlich Kultur nötigt. Die Absicht des Beitrages ist es, die Philosophische Anthropologie als eine spezifische Theorietechnik zu präsentieren, um einen adäquaten Begriff des Menschen zu erreichen, und zwar eine Theoriestrategie angesichts des cartesianischen Dualismus - also des Dualismus zwischen Naturalismus und Kulturalismus.

  14. Demonstration of Removal, Separation, and Recovery of Heavy Metals from Industrial Wastestreams Using Molecular Recognition Technology (MRT)

    DTIC Science & Technology

    2002-11-01

    Treatment Plant”, TM-2123-ENV, April 1995. 3. Ford, K.H., 1996, “ Heavy Metal Adsorption/ Biosorption Studies for Zero Discharge Industrial Wastewater...SEPARATION, AND RECOVERY OF HEAVY METALS FROM INDUSTRIAL WASTESTREAMS USING MOLECULAR RECOGNITION TECHNOLOGY (MRT) Final Report by Dr. Katherine...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER DEMONSTRATION OF REMOVAL, SEPARATION, AND RECOVERY OF HEAVY METALS FROM INDUSTRIAL WASTEWATERS USING

  15. Weanling piglet cerebellum: a surrogate for tolerance to MRT (microbeam radiation therapy) in pediatric neuro-oncology

    NASA Astrophysics Data System (ADS)

    Laissue, Jean A.; Blattmann, Hans; Di Michiel, Marco; Slatkin, Daniel N.; Lyubimova, Nadia; Guzman, Raphael; Zimmermann, Werner; Birrer, Stephan; Bley, Tim; Kircher, Patrick; Stettler, Regina; Fatzer, Rosmarie; Jaggy, Andre; Smilowitz, Henry; Brauer, Elke; Bravin, Alberto; Le Duc, Geraldine; Nemoz, Christian; Renier, Michel; Thomlinson, William C.; Stepanek, Jiri; Wagner, Hans-Peter

    2001-12-01

    The cerebellum of the weanling piglet (Yorkshire) was used as a surrogate for the radiosensitive human infant cerebellum in a Swiss-led program of experimental microbeam radiation therapy (MRT) at the ESRF. Five weanlings in a 47 day old litter of seven, and eight weanlings in a 40 day old litter of eleven were irradiated in November, 1999 and June, 2000, respectively. A 1.5 cm-wide x 1.5 xm-high array of equally space approximately equals 20-30 micrometers wide, upright microbeams spaced at 210 micrometers intervals was propagated horizontally, left to right, through the cerebella of the prone, anesthetized piglets. Skin-entrance intra-microbeam peak adsorbed doses were uniform, either 150, 300, 425, or 600 gray (Gy). Peak and inter-microbeam (valley) absorbed doses in the cerebellum were computed with the PSI version of the Monte Carlo code GEANT and benchmarked using Gafchromic and radiochromic film microdosimetry. For approximately equals 66 weeks [first litter; until euthanasia], or approximately equals 57 weeks [second litter; until July 30, 2001] after irradiation, the littermates were developmentally, behaviorally, neurologically and radiologically normal as observed and tested by experienced farmers and veterinary scientists unaware of which piglets were irradiated or sham-irradiated. Morever, MRT implemented at the ESRF with a similar array of microbeams and a uniform skin-entrance peak dose of 625 Gy, followed by immunoprophylaxis, was shown to be palliative or curative in young adult rats bearing intracerebral gliosarcomas. These observations give further credence to MRT's potential as an adjunct therapy for brain tumors in infancy, when seamless therapeutic irradiation of the brain is hazardous.

  16. Development and validation of a new LBM-MRT hybrid model with enthalpy formulation for melting with natural convection

    NASA Astrophysics Data System (ADS)

    Miranda Fuentes, Johann; Kuznik, Frédéric; Johannes, Kévyn; Virgone, Joseph

    2014-01-01

    This article presents a new model to simulate melting with natural convection of a phase change material. For the phase change problem, the enthalpy formulation is used. Energy equation is solved by a finite difference method, whereas the fluid flow is solved by the multiple relaxation time (MRT) lattice Boltzmann method. The model is first verified and validated using the data from the literature. Then, the model is applied to a tall brick filled with a fatty acid eutectic mixture and the results are presented. The main results are (1) the spatial convergence rate is of second order, (2) the new model is validated against data from the literature and (3) the natural convection plays an important role in the melting process of the fatty acid mixture considered in our work.

  17. Completion Report for Multi-Site Incentive MRT 2779 Implement ASC Tripod Initiative by 30SEP08

    SciTech Connect

    East, D; Cerutti, J; Noe, J; Cupps, K; Loncaric, J; Sturtevant, J

    2008-09-22

    This report provides documentation and evidence for the completion of the deployment of the Tripod common operating system (TripodOS, also known as and generally referred to below as TOSS). Background documents for TOSS are provided in Appendices A and B, including the initial TOSS proposal accepted by ASC HQ and Executives in July 2007 and a Governance Model defined by a Tri-Lab working group in September 2007. Appendix C contains a document that clarifies the intent and requirements for the completion criteria associated with MRT 2779. The deployment of TOSS is a Multi-Site Incentive from the ASC FY08-09 Implementation Plan due at the end of Quarter 4 in FY08.

  18. Temperature-sensitive mutations in the Saccharomyces cerevisiae MRT4, GRC5, SLA2 and THS1 genes result in defects in mRNA turnover.

    PubMed Central

    Zuk, D; Belk, J P; Jacobson, A

    1999-01-01

    In a screen for factors involved in mRNA turnover, four temperature-sensitive yeast strains (ts1189, ts942, ts817, and ts1100) exhibited defects in the decay of several mRNAs. Complementation of the growth and mRNA decay defects, and genetic experiments, revealed that ts1189 is mutated in the previously unknown MRT4 gene, ts942 is mutated in GRC5 (encoding the L9 ribosomal protein), ts817 contains a mutation in SLA2 (encoding a membrane protein), and ts1100 contains a mutation in THS1 (encoding the threonyl-tRNA synthetase). Three of the four mutants (mrt4, grc5, and sla2) were not defective in protein synthesis, suggesting that these strains contain mutations in factors that may play a specific role in mRNA decay. The mRNA stabilization observed in the ths1 strain, however, could be due to the significant drop in translation observed in this mutant at 37 degrees. While the three interesting mutants appear to encode novel mRNA decay factors, at least one could be linked to a previously characterized mRNA decay pathway. The growth and mRNA decay defects of ts942 (grc5) cells were suppressed by overexpression of the NMD3 gene, encoding a protein shown to participate in a two-hybrid interaction with the nonsense-mediated decay protein Upf1p. PMID:10471698

  19. Coarse- and fine-grid numerical behavior of MRT/TRT lattice-Boltzmann schemes in regular and random sphere packings

    NASA Astrophysics Data System (ADS)

    Khirevich, Siarhei; Ginzburg, Irina; Tallarek, Ulrich

    2015-01-01

    We analyze the intrinsic impact of free-tunable combinations of the relaxation rates controlling viscosity-independent accuracy of the multiple-relaxation-times (MRT) lattice-Boltzmann models. Preserving all MRT degrees of freedom, we formulate the parametrization conditions which enable the MRT schemes to provide viscosity-independent truncation errors for steady state solutions, and support them with the second- and third-order accurate ("linear" and "parabolic", respectively) boundary schemes. The parabolic schemes demonstrate the advanced accuracy with weak dependency on the relaxation rates, as confirmed by the simulations with the D3Q15 model in three regular arrays (SC, BCC, FCC) of touching spheres. Yet, the low-order, bounce-back boundary rule remains appealing for pore-scale simulations where the precise distance to the boundaries is undetermined. However, the effective accuracy of the bounce-back crucially depends on the free-tunable combinations of the relaxation rates. We find that the combinations of the kinematic viscosity rate with the available "ghost" antisymmetric collision mode rates mainly impact the accuracy of the bounce-back scheme. As the first step, we reduce them to the one combination (presented by so-called "magic" parameter Λ in the frame of the two-relaxation-times (TRT) model), and study its impact on the accuracy of the drag force/permeability computations with the D3Q19 velocity set in two different, dense, random packings of 8000 spheres each. We also run the simulations in the regular (BCC and FCC) packings of the same porosity for the broad range of the discretization resolutions, ranging from 5 to 750 lattice nodes per sphere diameter. A special attention is given to the discretization procedure resulting in significantly reduced scatter of the data obtained at low resolutions. The results reveal the identical Λ-dependency versus the discretization resolution in all four packings, regular and random. While very small

  20. Performance Analysis of Dual-hop MIMO Relay Systems with MRT&RAS in the Presence of Co-channel Interference

    NASA Astrophysics Data System (ADS)

    Xu, Xiaoming; Cai, Yueming; Yang, Weiwei

    2013-09-01

    This paper focuses on the downlink dual-hop multiple-input multiple-output (MIMO) amplify-and-forward (AF) relay systems that employ the maximal-ratio transmission and receive antenna selection scheme (MRT&RAS) for use in each hop. The system under consideration is equipped with arbitrary NS, NR, and ND antennas at the base station (BS), relay station (RS), and mobile station (MS), respectively. The system performance has been investigated over Nakagami-m fading in presence of independent but not necessarily identically distributed co-channel interferences (CCIs) at both the RS and MS. First, we derive an accurate closed-form approximate expression for the outage probability and a single-integral expression for the average symbol error rate (SER), respectively. Besides, to render direct insights into the combined effect of multiple-antenna and interference on the system performance, the asymptotic expressions for the outage probability and the average SER are also presented. Furthermore, we determine the optimal power allocation (OPA) by using the exact and asymptotic methods, respectively, such that the outage probability is minimized. Finally, numerical results validate the correctness of the derived expressions and show that OPA offers superior performance over uniform power allocation. Our analysis and results provide insights on investigating and optimizing the performance of the downlink MIMO relay transmission in practical interference-limited wireless networks.

  1. Reuse of the NASA LP DAAC MODIS Reprojection Tool (MRT) and the USGS Global Visualization Viewer (GloVis) for the Development of the LP DAAC Web-Based MODIS Reprojection Tool (MRTWeb)

    NASA Astrophysics Data System (ADS)

    Sohre, T.; Sauer, B.; Maiersperger, T.; Macie, M.; Miller, W.

    2007-12-01

    The Land Processes Distributed Active Archive Center (LP DAAC) was established as part of NASA's Earth Observing System (EOS) Data and Information System (EOSDIS) initiative to process, archive, and distribute land-related data collected by EOS sensors, thereby promoting the inter-disciplinary study and understanding of the integrated Earth system. The role of the LP DAAC includes the higher-level processing and distribution of ASTER data, and the distribution of MODIS land products derived from data acquired by the Terra and Aqua satellites. The LP DAAC anticipated that the community of land data users would need special software tools for handling the Level-3 MODIS land data products that would be distributed in HDF-EOS format and in the ISIN projection. The development of the MODIS Reprojection Tool (MRT) enabled users to read data files in HDF-EOS format (MODIS Level-2G, Level-3, and Level-4 land data products), specify a geographic subset or specific science data sets as input to processing, perform geographic transformation to a different coordinate system/cartographic projection, write the output to file formats other than HDF-EOS. Additional information regarding the MRT including links to download the software can be found at: http://lpdaac.usgs.gov/landdaac/tools/modis/index.asp. The LP DAAC has utilized the USGS Global Visualization Viewer (GloVis) as one method of data search and order. GloVis is a quick and easy online search and order tool for selected satellite data. The viewer allows user- friendly access to all available browse images from a number of Landsat data collections as well as ASTER, MODIS, and EO-1 data. Through a graphic map display, the user can select any area of interest and quickly view all available browse images within the USGS inventory for the specified location. GloVis can be run online at http://glovis.usgs.gov/ and the source code and be downloaded from: https://glovis.usgs.gov/distribution/. The LP DAAC saw an opportunity to

  2. Introduction and Mission Response Team (MRT)

    NASA Technical Reports Server (NTRS)

    Pool, Sam

    2005-01-01

    On February 1, 2003 the Space Shuttle Columbia, returning to Earth with a crew of seven astronauts, disintegrated along a track extending from California to Louisiana. Observers on the ground filmed breakup of the spacecraft. Debris fell along a 567 statute mile track from Littlefield, Texas to Fort Polk, Louisiana; the largest ever recorded debris field. At the time of the accident the National Aeronautics and Space Administration (NASA) flight surgeon on-duty at the Mission Control Center (MCC) in Houston, Texas initiated the medical contingency response. The DOD surgeon at Patrick Air Force Base was notified, NASA medical personnel were recalled and the services of Armed Forces Institute of Pathology (AFIP) were requested. Subsequent to the accident the NASA flight surgeons that had supported the crew on orbit now provided medical support to the crewmember s families. Federal Emergency Management Agency (FEMA), the National Transportation Safety Board (NTSB), the Federal Bureau of Investigation (FBI) and numerous other federal, state and local agencies along with the citizens of Texas and Louisiana responded to the disaster. Search and recovery was managed from a Disaster Field Office (DFO) established in Lufkin, Texas. Mishap Investigation Team (MIT) medical operations were managed from Barksdale Air Force Base, Louisiana. Accident investigation teams (Columbia Accident Investigation Task Force (CAITF) and Columbia Accident Investigation Board (CAIB)) appointed immediately after the disaster included current and former authorities in space medicine. In August 2003, the CAIB concluded its investigation and released its findings in a report published in February 2004.

  3. MRT fuel element inspection at Dounreay

    SciTech Connect

    Gibson, J.

    1997-08-01

    To ensure that their production and inspection processes are performed in an acceptable manner, ie. auditable and traceable, the MTR Fuel Element Fabrication Plant at Dounreay operates to a documented quality system. This quality system, together with the fuel element manufacturing and inspection operations, has been independently certified to ISO9002-1987, EN29002-1987 and BS5750:Pt2:1987 by Lloyd`s Register Quality Assurance Limited (LRQA). This certification also provides dual accreditation to the relevant German, Dutch and Australian certification bodies. This paper briefly describes the quality system, together with the various inspection stages involved in the manufacture of MTR fuel elements at Dounreay.

  4. [MRT of the liver in Wilson's disease].

    PubMed

    Vogl, T J; Steiner, S; Hammerstingl, R; Schwarz, S; Kraft, E; Weinzierl, M; Felix, R

    1994-01-01

    To show that Wilson's disease is one likely cause of multiple low-intensity nodules of the liver we obtained MR images in 16 patients with clinically and histopathologically confirmed Wilson's disease. Corresponding to morphological changes MRI enabled the subdivision of the patients into two groups. Using a T2-weighted spin-echo sequence (TR/TE = 2000/45-90) liver parenchyma showed multiple tiny low-intensity-nodules surrounded by high-intensity septa in 10 out of 16 patients. 5 patients had also low-intensity nodules in T1-weighted images (TR/TE = 600/20). In patients of this group histopathology revealed liver cirrhosis (n = 7) and fibrosis (n = 2). Common feature of this patient group was marked inflammatory cell infiltration into fibrous septa, increase of copper concentration in liver parenchyma and distinct pathological changes of laboratory data. In the remaining 6 patients no pathological change of liver morphology was demonstrated by MRI corresponding to slight histopathological changes of parenchyma and normal laboratory data. As low-intensity nodules surrounded by high intensity septa can be demonstrated in patients with marked inflammatory infiltration of liver parenchyma MRI may help to define Wilson patients with poorer prognosis. In patients with low-intensity nodules of the liver and unknown cause of liver cirrhosis laboratory data and histopathology should be checked when searching for disorders of copper metabolism.

  5. Black Hawk Down: Film Zwischen Reflektion und Konstruktion Gesellschaftlicher Wirklichkeit

    NASA Astrophysics Data System (ADS)

    Pötzsch, Holger

    2009-05-01

    BLACK HAWK DOWN: FILM BETWEEN THE REFLECTION AND CONSTRUCTION OF SOCIAL REALITY - In this article, Ridley Scott's film Black Hawk Down (USA 2001) is read in the context of contemporary theories concerning cultural memory (Jan and Aleida Assmann) and media culture (Douglas Kellner). It is argued that film (and representation in general) does not merely reflect a preceding reality; it also actively serves to construct it. It is shown how Scott's film privileges one particular perspective on an actual event and how this point of view is objectified and installed in the memory of Western media culture. What potential implications does an increased blurring of fact and fiction in the representation of war have? What are the consequences for political and pedagogical practice? What role can cultural studies play in these processes?

  6. Gluck zwischen Okonomie und Padagogik (Happiness between Economics and Pedagogics).

    ERIC Educational Resources Information Center

    Keller, Sarah; Mangold, Max

    2002-01-01

    Focuses on the concept of happiness as neither formed independent from economic considerations, nor is it foreign to them. Argues that in the history of pedagogy and economics, happiness constitutes an important and at times a problematic quality. (CAJ)

  7. [Agreement between self-report and clinician's assessment in depressed adolescents, using the example of BDI-II and CDRS-R].

    PubMed

    Straub, Joana; Plener, Paul L; Koelch, Michael; Keller, Ferdinand

    2014-07-01

    Fragestellung: Vorhergehende Studien zeigen eine hohe Übereinstimmung von Selbst- und Klinikerurteil bei der Erfassung von Depressivität. Die Übereinstimmung auf Summen-, Subskalen- und Einzelitemebene wurde aber bisher nicht bei einer psychiatrischen jugendlichen Stichprobe untersucht. Der Einfluss von Drittvariablen, wie Alter, Geschlecht, IQ und Behandlungssetting wurde bei Jugendlichen bisher unzureichend überprüft. Methodik: Untersucht wurden 105 depressive Jugendliche (mittleres Alter = 15.94) bei welchen innerhalb einer Woche das BDI-II und CDRS-R durchgeführt wurde. Korrelationsanalysen erfolgten auf Ebene der Summenwerte, Subskalen und Einzelitems. Ergebnisse: Es zeigte sich eine hohe Korrelation zwischen Selbst- und Klinikerurteil (r = .67). Auf Subskalen-Ebene zeigten Items, die somatische Inhalte erfassen, keine höhere Konkordanz als Subskalen, die kognitive oder affektive Inhalte messen. Auf Symptom-Ebene zeigte sich die höchste Übereinstimmung bei dem Item Selbstmordgedanken. Drittvariablen hatten keinen signifikanten Einfluss auf die Höhe der Korrelation aber Jugendliche mit einem eher hohen IQ und ambulant Behandelte neigten zur relativen Überschätzung ihrer Symptomatik. Schlussfolgerungen: Die Gesamtkorrelation war hoch und unterschied sich nicht von Ergebnissen vergleichbarer Korrelationsstudien. Die höchste Übereinstimmung bei dem Item «Selbstmordgedanken» spricht für die gute Erfassbarkeit von Suizidalität auch im Klinikerurteil. Der Fragebogen kann somit deutliche Hinweise auf das Vorliegen einer Depression liefern, jedoch sollte trotz hoher Korrelationen nicht ein Verfahren durch ein anderes ersetzt werden.

  8. Zwischen Copernicus und Kepler - M. Michael Maestlinus Mathematicus Goeppingensis 1550-1631.

    NASA Astrophysics Data System (ADS)

    Betsch, Gerhard; Hamel, Jürgen

    This book contains the written versions of talks given at a symposium held in Tübingen between 2000 October 11 - 13, and organized by the faculty of physics of Tübingen University. Michael Mästlin (1550 - 1631) was an esteemed astronomer. He was among the first who described comets as cosmic bodies, and who attempted an orbital determination. Already at an early stage, he adhered to Copernicus' heliocentric system, which he transmitted to Kepler. During 47 years, Mästlin was a professor of mathematical sciences in Tübingen, and played an outstanding role in the scientific life of his university. The contributions deal with various aspects of the life and works of Mästlin: his well-received textbook of astronomy, his role in the rejection of the 1582 calender reform by the protestants, his celestial observations, his relation to Kepler and to Galilei, his position to the progress of science of his time. Other contributions analyze contemporary attempts of the quadrature of the circle, give an overview of Mästlin's surviving published and manuscript works, and provide a vivid decription of the everyday life of a Tübingen professor around 1600. All papers are written in German, and have English abstracts.

  9. Diskrepanzen und Kongruenzen: Das Dilemma des afrikanischen Kindes zwischen Familie und Schule

    NASA Astrophysics Data System (ADS)

    Bauer, Annemarie

    1986-03-01

    This article expounds the theory that the failure of school is due to the incompatibility of the educational goals of school and traditional upbringing in Africa. The thesis is put forward by adherents of the psychoanalytical model of child development and seeks to emphasize the discrepancies between the childhood where children are not frustrated and where their needs are cared for and the school education which represses the drives and its socialization of children. Finding a number of anthropological studies are discussed and reinterpretations of the ethno-psychoanalytical materials attempted. Neither the evaluation of childhood in Africa nor the theory that with school come wholly new expectations of behaviour (e.g., a performance requirement) can no longer be maintained. In conclusion, other explanations for the difficulties encountered by school in Africa are offered.

  10. Wer entdeckte die Allgemeine Relativitätstheorie? Prioritätsstreit zwischen Hilbert und Einstein

    NASA Astrophysics Data System (ADS)

    Sommer, Klaus P.

    2005-09-01

    Im November 1915 arbeiteten Albert Einstein und David Hilbert an den Feldgleichungen der Gravitationstheorie. Im Jahre 1997 behaupteten die Wissenschaftshistoriker Corry, Renn und Stachel in einer viel beachteten Arbeit, Hilbert habe die entscheidenden Formeln von Einstein gestohlen. Grundlage ihrer Argumentation war eine wieder gefundene Korrekturfahne von Hilberts entscheidender Arbeit. Die Physikhistorikerin Daniela Wuensch bringt jedoch detaillierte Argumente dafür vor, dass die entscheidende Quelle, nämlich die Korrekturfahne, in neuerer Zeit manipuliert worden ist, um Einsteins Priorität unangetastet zu lassen. Einstein bleibt aber der Entdecker der Allgemeinen Relativitätstheorie.

  11. Das Gymnasium Zwischen Tradition und Modernen Bildungsanspruchen (The Gymnasium between Tradition and Modern Educational Requirements).

    ERIC Educational Resources Information Center

    Heller, Kurt A.

    2003-01-01

    Provides brief history of the German Gymnasium as a traditional European secondary school system with a preparatory function for higher education. Reviews the main goals of the gymnasium. Asks what role the gymnasium plays as a learning environment for gifted students. Discusses the politico-educational consequences and demands on the gymnasium.…

  12. Wechselwirkungen zwischen Grundwasser und Oberflächenwasser an einem Tieflandfluss (Spree)

    NASA Astrophysics Data System (ADS)

    Nützmann, G.; Lewandowski, J.

    2009-09-01

    Water exchange processes in the floodplain of a lowland groundwater-surface water system are studied on the basis of a study site near Freienbrink, NE Germany. The boundaries of this site are formed by an oxbow and the current bed of the river Spree, section Müggelspree. Surface and ground water levels were collected in 12 piezometers and at two recording stage gauges of a 300 m long transect throughout a one-year-period. Due to water level fluctuations, alternating periods of infiltration and exfiltration have been observed. However, most of the time groundwater flux is directed into the river Spree and river water infiltration events into the aquifer are usually short and of minor importance. Due to clogging of the oxbow bed, the hydraulic contact between the oxbow and the adjacent aquifer is marginal. These features are modelled quantitatively using MODFLOW in order to simulate ground water flow in the local aquifer.

  13. MRT letter: An extended scanning probe microscopy system for macroscopic topography imaging.

    PubMed

    Fu, Ji; Li, Faxin

    2014-10-01

    Enlightened by the principle of scanning probe microscopy or atomic force microscope (AFM), we proposed a novel surface topography imaging system based on the scanning of a piezoelectric unimorph cantilever. The height of sample surface can be obtained by recording the cantilever's strain using an ultra-sensitive strain gauge and the Z-axis movement is realized by electric bending of the cantilever. This system can be operated in the way similar to the contact mode in AFM, with the practical height detection resolution better than 100 nm. Imaging of the inner surface of a steel tube and on a transparent wing of a honey bee were conducted and the obtained results showed that this proposed system is a very promising solution for in situ topography mapping.

  14. Can the scoring of the walking estimated limitation calculated by history (WELCH) questionnaire be simultaneously simplified and improved?

    PubMed

    Bourdois, Clement; Laporte, Isabelle; Godet, Raphael; Laneelle, Damien; Vielle, Bruno; Abraham, Pierre

    2014-05-01

    Hintergrund: Der WELCH Fragebogen enthält 4 Elemente (A, B, C und D) und schätzt die maximale Gehzeit (MWT) auf dem Laufband bei Patienten mit Schaufensterkrankheit. Seine Punktzahl wurde empirisch definiert. Um heraus zu finden, ob die Wertung des WELCH verbessert oder vereinfacht werden könnte, haben wir verschiedene Methoden untersucht. Patienten und Methoden: Bei 423 Patienten haben wir 8 Methoden (H1 bis H8) getestet, mit Gewichtung von D oder Berechnung von α , β und γ in der Gleichung MWT = (αA + βB + γC) • D. Ergebnisse: Während der WELCH Pearson r 0.639 und die Fläche unter der ROC-Kurve für die Fähigkeit 5 Minuten auf dem Laufband zu gehen 0.795 für die empirische Methode war, reichten die Werte für die verschiedenen getesteten Methoden von 0.566 bis 0.611 für die Pearsons r Werte und 0,750 - 0,809 für die Flächen unter den Kurven. Schlussfolgerungen: Keine der getesteten Methoden verbesserte gleichzeitig die Korrelation zur MWT und blieb dabei einfach genug, um die Werte durch Kopfrechnen zu ermitteln. Das ursprüngliche empirische Scoring ist ein guter Kompromiss zwischen Genauigkeit und Einfachheit.

  15. Fielding the magnetically applied pressure-shear technique on the Z accelerator (completion report for MRT 4519).

    SciTech Connect

    Alexander, C. Scott; Haill, Thomas A.; Dalton, Devon Gardner; Rovang, Dean Curtis; Lamppa, Derek C.

    2013-09-01

    The recently developed Magnetically Applied Pressure-Shear (MAPS) experimental technique to measure material shear strength at high pressures on magneto-hydrodynamic (MHD) drive pulsed power platforms was fielded on August 16, 2013 on shot Z2544 utilizing hardware set A0283A. Several technical and engineering challenges were overcome in the process leading to the attempt to measure the dynamic strength of NNSA Ta at 50 GPa. The MAPS technique relies on the ability to apply an external magnetic field properly aligned and time correlated with the MHD pulse. The load design had to be modified to accommodate the external field coils and additional support was required to manage stresses from the pulsed magnets. Further, this represents the first time transverse velocity interferometry has been applied to diagnose a shot at Z. All subsystems performed well with only minor issues related to the new feed design which can be easily addressed by modifying the current pulse shape. Despite the success of each new component, the experiment failed to measure strength in the samples due to spallation failure, most likely in the diamond anvils. To address this issue, hydrocode simulations are being used to evaluate a modified design using LiF windows to minimize tension in the diamond and prevent spall. Another option to eliminate the diamond material from the experiment is also being investigated.

  16. [Magnetic resonance tomography (MRT) of the scrotum--initial results and comparison with sonography. II: Intratesticular pathology].

    PubMed

    Hajek, P C

    1987-11-01

    The wide differences in signal intensity in the scrotum provide an excellent background for the assessment of intratesticular pathology. Besides hemorrhage, all intratesticular pathologic changes have lower signal intensities than surrounding normal testicular tissue. Proton density- and T1-weighted images are essential for the characterization of hematomas, abscesses and hydroceles. Clear delineation of the tunica albuginea is necessary for precise assessment of trauma and tumors. Because a ruptured tunica albuginea can be visualized and because of its high sensitivity, MRI is superior to sonography in the diagnosis of trauma and orchitis. In addition, MRI is the imaging modality of choice for characterization and precise assessment of tumor size as well as for the exclusion of pathologic changes.

  17. MRT letter: Auto-fluorescence by human alveolar macrophages after in vitro exposure to air pollution particles.

    PubMed

    Ghio, Andrew J; Sangani, Rahul G; Brighton, Luisa E; Carson, John L

    2010-06-01

    Macrophages from smokers demonstrate an increased auto-fluorescence. Similarly, auto-fluorescence follows in vitro exposure of macrophages to cigarette smoke condensate (i.e., the particulate fraction of cigarette smoke). The composition of particles in cigarette smoke can be comparable to air pollution particles. We tested the postulate that macrophages exposed to air pollution particles could demonstrate auto-fluorescence. Healthy nonsmoking and healthy smoking volunteers (both 18-40 years of age) underwent fiberoptic bronchoscopy with bronchoalveolar lavage and alveolar macrophages isolated. Macrophages were incubated at 37 degrees C in 5% CO(2) with either PBS or 100 microg/mL particle for both 1 and 24 h. Particles included a residual oil fly ash, Mt. St. Helens volcanic ash, and ambient air particles collected from St. Louis, Missouri and Salt Lake City, Utah. At the end of incubation, 50 microL of the cell suspension was cytocentrifuged and examined at modes for viewing fluorescein isothiocyanate (FITC) and rhodamine fluorescence. Both emission source air pollution particles demonstrated FITC and rhodamine auto-fluorescence at 1 and 24 h, but the signal following incubation of the macrophages with oil fly ash appeared greater. Similarly, the ambient particles were associated with auto-fluorescence by the alveolar macrophages and this appeared to be dose-dependent. We conclude that exposure of macrophages to air pollution particles can be associated with auto-fluorescence in the FITC and rhodamine modes.

  18. Effects of Speech Intensity on the Callsign Acquisition Test (CAT) and Modified Rhyme Test (MRT) Presented in Noise

    DTIC Science & Technology

    2012-01-01

    Department of Industrial and Systems Engineering, North Carolina Agricultural & Technical State University 1601 E. Market Street, Greensboro, North...Department of Management, North Carolina Agricultural & Technical State University 1601 E. Market Street, Greensboro, North Carolina 27411, USA; e...to-noise ratio. 1. Introduction Speech intelligibility (SI) is defined as the percent- age of speech units (i.e., phonemes, syllables, words, phrases

  19. The Selective Separation of Anions and Cations in Nuclear Waste Using Commercially Available Molecular Recognition Technology (MRT) Products

    SciTech Connect

    Izatt, S. R.; Bruening, R. L.; Krakowiak, K. E.; Izatt, R. M.

    2003-02-25

    This paper describes the use of some of IBC's SuperLig{reg_sign}, MacroLig{reg_sign}, and AnaLig{reg_sign} molecular recognition technology products to effectively and selectively separate and recover cesium, technetium, strontium, and radium from radioactive waste solutions. Distinct advantages are given over conventional separation techniques. Separations are described and results given for the target ions over chemically similar ions often present at much higher concentrations. The separations are performed in solutions of either high or low pH and usually containing high concentrations of salts. Other separations involving components of radioactive and mixed waste are noted.

  20. The German version of the Material Values Scale.

    PubMed

    Müller, Astrid; Smits, Dirk J M; Claes, Laurence; Gefeller, Olaf; Hinz, Andreas; de Zwaan, Martina

    2013-01-01

    Zielsetzung: Die Material Values Scale ist ein Selbsterhebungsinstrument zur Erfassung von materieller Werteorientierung. Der Fragebogen enthält in der Originalversion die folgenden drei Subskalen: ‘Centrality’, ‘Success’ und ‘Happiness’. Das Ziel der Studie bestand in der Untersuchung der psychometrischen Eigenschaften der deutschen Version der MVS (G-MVS). Methodik: Der Fragebogen wurde von einer repräsentativen Bevölkerungsstichprobe (N=2295) beantwortet, um die faktorelle Struktur zu überprüfen. Zur Untersuchung der Konstruktvalidität wurden sowohl die MVS als auch die Compulsive Buying Scale (CBS) und die Depressionsskala des Patient Health Questionnaire (PHQ-8) von kaufsüchtigen Patienten (N=52) und von Studenten (N=347) beantwortet. Ergebnisse: In der deutschen Bevölkerungsstichprobe konnte die 3-Faktorenstruktur nicht bestätigt werden. Stattdessen verfügte ein 2-Faktorenmodell mit den Subskalen ‘Centrality/Success’ und ‘Happiness’ über die beste Anpassungsgüte. Kaufsüchtige Patienten zeigten erwartungsgemäß die höchsten Werte auf der G-MVS. Zusammenhangsanalysen ergaben eine signifikante Korrelation zwischen der G-MVS und dem Fragebogen zum pathologischen Kaufen, nicht jedoch mit der Depressionsskala bei Kaufsüchtigen und Studenten. In keiner der drei Stichproben ergaben sich Geschlechtsunterschiede, allerdings scheinen G-MVS-Scores negativ mit dem Alter zu korrelieren. Fazit: Die deutsche Version des Fragebogens eignet sich zur Erfassung von materieller Werteorientierung, wobei konfirmatorische Faktorenanalysen ein 2-Faktorenmodell nahelegen.

  1. "Astronomica" in the Correspondence between Leonhard Euler and Daniel Bernoull (German Title: "Astronomica" im Briefwechsel zwischen Leonhard Euler und Daniel Bernoulli)

    NASA Astrophysics Data System (ADS)

    Verdun, Andreas

    2010-12-01

    The Euler Commission of the Swiss Academy of Sciences intends to terminate the edition of Leonhard Euler's works in the next year 2011 after nearly one hundred years since the beginning of the editorial works. These works include, e.g., Volume 3 of the Series quarta A which will contain the correspondence between Leonhard Euler (1707-1783) and Daniel Bernoulli (1700-1783) and which is currently being edited by Dr. Emil A. Fellmann (Basel) and Prof. Dr. Gleb K. Mikhailov (Moscow). This correspondence contains more than hundred letters, principally from Daniel Bernoulli to Euler. Parts of this correspondence were published uncommented already in 1843. It is astonishing that, apart from mathematics and physics (mainly mechanics and hydrodynamics), many topics addressed concern astronomy. The major part of the preserved correspondence between Euler and Daniel Bernoulli, in which astronomical themes are discussed, concerns celestial mechanics as the dominant discipline of theoretical astronomy of the eighteenth century. It was triggered and coined mainly by the prize questions of the Paris Academy of Science. In more than two thirds of the letters current problems and questions concerning celestial mechanics of that time are treated, focusing on the lunar theory and the great inequality in the motions of Jupiter and Saturn as special applications of the three body problem. In the remaining letters, problems concerning spherical astronomy are solved and attempts are made to explain certain phenomena in the field of "cosmic physics" concerning astronomical observations.

  2. Wortbildung und Fremdsprachenunterricht. Ein Beitrag zur Vermittlung zwischen Theorie und Praxis [Word Formation and Foreign Language Teaching. A Contribution to Bridging between Theory and Practice (Part 2)].

    ERIC Educational Resources Information Center

    Storch, Guenther

    1979-01-01

    Only regular word-building patterns are considered. Patterns are chosen for their communicative value, degree of difficulty, and applicability. Examples of word-building exercises are given, taken from actual texts. Work in word formation is recommended even for the beginners' level. (IFS/WGA)

  3. Wortbildung und Fremdsprachenunterricht. Ein Beitrag zur Vermittlung zwischen Theorie und Praxis [Word Formation and Foreign Language Teaching. A Contribution to Bridging between Theory and Practice (Part 1)].

    ERIC Educational Resources Information Center

    Storch, Guenther

    1979-01-01

    Sees word formation as an economical, important means of building vocabulary. Gives examples showing several different word-building patterns. Sees as a reasonable teaching goal the gaining of competence only in "receptive" word formation, i.e., recognition. The student can learn to build new words only from simple, frequently recurring…

  4. Zwischen "Fassade" und "wirklicher Absicht": Eine Betrachtung uber die dritte Erziehungsreform in Japan = Between "Facade" and "Real Intent": Observations on Japan's Third Educational Reform.

    ERIC Educational Resources Information Center

    Ito, Toshiko

    1997-01-01

    Asserts that the Japanese educational system consists of the "facade" of ministerially-decreed harmony and the "real intent" of competition. Argues that the balance between the two has been endangered by recent reforms that seek to promote "creativity and diversification." Suggests that policymakers did not analyze…

  5. Zwischen Gesetz und Fall. Mutmassungen uber Typologien als Padagogische Wissensform (Between General Law and the Individual Case. Conjectures Concerning Typologies as a Form of Pedagogical Knowledge).

    ERIC Educational Resources Information Center

    Herzog, Walter

    2003-01-01

    Considers the mediation between scientific knowledge and practical action as a crucial feature of professional teaching. Investigates the assumption that typologies represent a form of knowledge which can bridge the gap between theory and practice. Differentiates between two forms of typological thinking and discusses reservations concerning…

  6. International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) & European Competence Network on Mastocytosis (ECNM) consensus response criteria in advanced systemic mastocytosis

    PubMed Central

    Pardanani, Animesh; Akin, Cem; Reiter, Andreas; George, Tracy; Hermine, Olivier; Kluin-Nelemans, Hanneke; Hartmann, Karin; Sperr, Wolfgang R.; Brockow, Knut; Schwartz, Lawrence B.; Orfao, Alberto; DeAngelo, Daniel J.; Arock, Michel; Sotlar, Karl; Horny, Hans-Peter; Metcalfe, Dean D.; Escribano, Luis; Verstovsek, Srdan; Tefferi, Ayalew; Valent, Peter

    2013-01-01

    Systemic mastocytosis (SM) is characterized by accumulation of neoplastic mast cells and is classified into indolent and aggressive forms. The latter include aggressive SM (ASM), mast cell leukemia (MCL), and SM associated with a myeloid neoplasm wherein 1 or both disease compartments exhibit advanced features. These variants, henceforth collectively referred to as advanced SM for the purposes of this report, are typically characterized by organ damage and shortened survival duration. In contrast to indolent SM, in which symptoms are usually managed by noncytotoxic antimediator therapy, cytoreduction is usually necessary for disease control in advanced SM. Unfortunately, current drug treatment of these patients rarely results in complete clinical and histopathologic remissions or improved survival time. Previously defined response criteria were adapted to the heterogeneous presentations of advanced SM and the limited effects of available drugs. However, recent advances in understanding the molecular pathogenesis of SM and the corresponding prospect in targeted therapy make it a priority to modify these criteria. Our current study is the product of an international group of experts and summarizes the challenges in accomplishing this task and forwards a new proposal for response criteria, which builds on prior proposals and should facilitate response evaluation in clinical trials. PMID:23325841

  7. International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) & European Competence Network on Mastocytosis (ECNM) consensus response criteria in advanced systemic mastocytosis.

    PubMed

    Gotlib, Jason; Pardanani, Animesh; Akin, Cem; Reiter, Andreas; George, Tracy; Hermine, Olivier; Kluin-Nelemans, Hanneke; Hartmann, Karin; Sperr, Wolfgang R; Brockow, Knut; Schwartz, Lawrence B; Orfao, Alberto; Deangelo, Daniel J; Arock, Michel; Sotlar, Karl; Horny, Hans-Peter; Metcalfe, Dean D; Escribano, Luis; Verstovsek, Srdan; Tefferi, Ayalew; Valent, Peter

    2013-03-28

    Systemic mastocytosis (SM) is characterized by accumulation of neoplastic mast cells and is classified into indolent and aggressive forms. The latter include aggressive SM (ASM), mast cell leukemia (MCL), and SM associated with a myeloid neoplasm wherein 1 or both disease compartments exhibit advanced features. These variants, henceforth collectively referred to as advanced SM for the purposes of this report, are typically characterized by organ damage and shortened survival duration. In contrast to indolent SM, in which symptoms are usually managed by noncytotoxic antimediator therapy, cytoreduction is usually necessary for disease control in advanced SM. Unfortunately, current drug treatment of these patients rarely results in complete clinical and histopathologic remissions or improved survival time. Previously defined response criteria were adapted to the heterogeneous presentations of advanced SM and the limited effects of available drugs. However, recent advances in understanding the molecular pathogenesis of SM and the corresponding prospect in targeted therapy make it a priority to modify these criteria. Our current study is the product of an international group of experts and summarizes the challenges in accomplishing this task and forwards a new proposal for response criteria, which builds on prior proposals and should facilitate response evaluation in clinical trials.

  8. Neck Rhabdoid Tumors: Clinical Features and Consideration of Autologous Stem Cell Transplant.

    PubMed

    Wolfe, Adam D; Capitini, Christian M; Salamat, Shahriar M; DeSantes, Kenneth; Bradley, Kristin A; Kennedy, Tabassum; Dehner, Louis P; Patel, Neha J

    2017-04-03

    Extrarenal malignant rhabdoid tumors (MRT) have a poor prognosis despite aggressive therapy. Adding high-dose chemotherapy with autologous stem cell rescue (HDC-ASCR) as consolidative therapy for MRT is controversial. We describe 2 patients, age 13 years and 19 months, with unresectable neck MRT. After chemotherapy and radiotherapy, both underwent HDC-ASCR and remain in remission over 4 years later. We reviewed all published cases of neck MRT, and found poorer outcomes and more variable age of presentation and time to progression than MRT at other sites. Neck MRT may represent a higher-risk subset of MRT, and addition of HDC-ASCR merits consideration.

  9. Sensitivity of malignant rhabdoid tumor cell lines to PD 0332991 is inversely correlated with p16 expression

    SciTech Connect

    Katsumi, Yoshiki; Iehara, Tomoko; Miyachi, Mitsuru; Yagyu, Shigeki; Tsubai-Shimizu, Satoko; Kikuchi, Ken; Tamura, Shinichi; Kuwahara, Yasumichi; Tsuchiya, Kunihiko; Kuroda, Hiroshi; Sugimoto, Tohru; Houghton, Peter J.; Hosoi, Hajime

    2011-09-16

    Highlights: {yields} PD 0332991 (PD) could suppress four of five malignant rhabdoid tumor (MRT) cell lines. {yields} The sensitivity of the MRT cell lines to PD was inversely correlated with p16 expression (r = 0.951). {yields} p16 expression in MRT could be used to predict its sensitivity to PD. {yields} PD may be an attractive agent for patients with MRT whose tumors express low levels of p16. -- Abstract: Malignant rhabdoid tumor (MRT) is a rare and highly aggressive neoplasm of young children. MRT is characterized by inactivation of integrase interactor 1 (INI1). Cyclin-dependent kinase 4 (CDK4), which acts downstream of INI1, is required for the proliferation of MRT cells. Here we investigated the effects of PD 0332991 (PD), a potent inhibitor of CDK4, against five human MRT cell lines (MP-MRT-AN, KP-MRT-RY, G401, KP-MRT-NS, KP-MRT-YM). In all of the cell lines except KP-MRT-YM, PD inhibited cell proliferation >50%, (IC{sub 50} values 0.01 to 0.6 {mu}M) by WST-8 assay, and induced G1-phase cell cycle arrest, as shown by flow cytometry and BrdU incorporation assay. The sensitivity of the MRT cell lines to PD was inversely correlated with p16 expression (r = 0.951). KP-MRT-YM cells overexpress p16 and were resistant to the growth inhibitory effect of PD. Small interfering RNA against p16 significantly increased the sensitivity of KP-MRT-YM cells to PD (p < 0.05). These results suggest that p16 expression in MRT could be used to predict its sensitivity to PD. PD may be an attractive agent for patients with MRT whose tumors express low levels of p16.

  10. The master and the telescopes - the interplay between astronomy and optics in history (German Title: Der Meister und die Fernrohre - Das Wechselspiel zwischen Astronomie und Optik in der Geschichte)

    NASA Astrophysics Data System (ADS)

    Hamel, Jürgen; Keil, Inge

    The use of the telescope for astronomical observations since 1609 was one of the milestones in the celestial research. The contributions in this volume present new insights into the invention of the telescope and its relations to reading stones and spectacles, present investigations of special telescope types of early manufacturers, and analyze the telescopes of some historical observatories and the investigations carried out with them. Other contributions deal with the pictorial appearance of telescopes in baroque art, the connection of telescopes with photography, as well as the development of reflectors in the 20th century. The volume is dedicated to Rolf Riekher, an internationally established specialist ior the history of the telescope, on the occasion of his 85th birthday.

  11. Zwischen Wollen, aber nicht können und Können, aber nicht wollen: Übergangsprobleme von Jugendlichen in Japan am Beispiel der „Freeter`` und „NEETs``

    NASA Astrophysics Data System (ADS)

    Eswein, Mikiko; Pilz, Matthias

    2012-08-01

    Caught between wanting but not being able to, and being able, but not wanting to: Transitional problems among Japanese youths based on the examples of "Freeters" and "NEETs" - The study of processes of transition from the education system to employment is particularly important in light of youth unemployment. In Japan this transition process is often declared to be successful. In recent years, however, numerous signs have indicated a change in the situation. This article analyses this problem based on the examples of two Japanese social groups, "Freeters" and "NEETs". These terms refer to young adults who do not immediately move into to regular employment. The article begins by analysing the causes, then comments on education policy measures undertaken to tackle the issue. Drawing on scientifically grounded models it is shown that both social groups are characterised by meagre formal school qualifications. Social background, by contrast, is not particularly relevant; although there are hints that parents' financial means play an increasingly important role in determining whether a young person attends a high-level educational institution. Although public opinion in Japan frequently attributes values and attitudes to these groups that deviate from the norm, this is not conclusively supported by existing empirical findings. Consequently, the reasons for these transitional problems tend to be perceived as being connected to the difficult labour market situation resulting from the ongoing economic crisis. In addition to certain education policy initiatives, Japan will therefore rely heavily in future on the ability to effectively manage the integration of its shrinking cohorts of school and university graduates.

  12. Der Begriff des "Ki" und die japanische Padagogik: Uber Konflikte zwischen westlicher und japanischer Padagogik (The Concept of "Ki" and Japanese Pedagogy: On Conflicts between Western and Japanese Pedagogics).

    ERIC Educational Resources Information Center

    Fujikawa, Nobuo

    1997-01-01

    Sketches the characteristics of the Japanese educational tradition and analyzes conflicts between modern western pedagogies and traditional education. Argues that Japanese socialization processes stress a specifically Japanese construction of the "self" and of behavior. Concludes that Japanese educators should be more aware of this…

  13. Controlling betrieblicher Weiterbildung zwischen Hoffnung und Illuson - oder: Auch im Westen nicht viel Neues (The Controlling of Within-Company Further Education between Hope and Illusion, or: Nothing New in the West).

    ERIC Educational Resources Information Center

    Bank, Volker

    2002-01-01

    Discusses a survey of recent within-company further education publications available in German speaking areas, Anglo-Saxon countries, France, and Switzerland. Argues that there is a basic consensus evident in these publications. Critiques published patent remedies for controlling within-company further education. Searches for new methods of…

  14. Zwischen den Stuhlen: Untersuchungen zur Situation der Korrektoren an der Fernuniversitat 1980, (In between Chairs: The Situation of Tutors (Correctors) at the FernUniversitat in 1980). ZIFF Papiere 34.

    ERIC Educational Resources Information Center

    Fritsch, Helmut; And Others

    An empirical study of tutors responsible for evaluating students' assignments at the Fernuniversitat in 1980 employed an 18-item questionnaire, analysis of open-ended responses, analysis of graders' comments on more than 1,000 assignments, and interviews with staff. The process of evaluating students' work was shown to be inefficient, with minimal…

  15. H.C. Schumacher - Center of international communication in astronomy and mediator betwen Denmark an Germany. (German Title: H.C. Schumacher - Zentrum der internationalen Kommunikation in der Astronomie und Mittler zwischen Dänemark und Deutschland)

    NASA Astrophysics Data System (ADS)

    Hamel, Jürgen

    As the editor of the ``Astronomische Nachrichten'', H.C. Schumacher played an outstanding role among the astronomers of the first half of the 19th century. Altona, his place of activity, belonged to the kingdom of Denmark. Both the foundation of the ``Astronomische Nachrichten'' and its existence depended for several decades on the support by the Danish kings and high-ranking officials at the Copenhagen court. This paper analyses these questions on the basis of previously unused archival sources and discusses also Schumacher's life and his relations to the royal dynasty.

  16. The controversy between Alexander Friedmann and Albert Einstein about the possibility of a non-static world (German Title: Die Kontroverse zwischen Alexander Friedmann und Albert Einstein um die Möglichkeit einer nichtstatischen Welt)

    NASA Astrophysics Data System (ADS)

    Singer, Georg

    Einstein's treatment of the cosmological problem as well as his unshakeable adherence to his own static solution of the complete field equations was throughout determined by Ernst Mach's idea of relativity of inertia. Friedmann, however, like Eddington, Weyl and others did not consider Mach's principle to be a part of general relativity, and so he regarded a time dependent developing spatial geometry as being consistent with world matter at relative rest. In his final statement to the controversy, Einstein acknowledged just formal correctness of Friedmann's results. Actually his criticism was not due ``to a miscalculation'', as he was ready to admit, but was owed to a fundamental fixed idea which continued to exist and which was the cause of his disavowal of physical significance of dynamical solutions.

  17. Mitochondrial Replacement Techniques: Divergence in Global Policy.

    PubMed

    Schandera, Johanna; Mackey, Tim K

    2016-07-01

    In 2015, the UK became the first country permitting the clinical application of mitochondrial replacement techniques (MRT). Here, we explore how MRT have led to diverging international policy. In response, we recommend focused regulatory efforts coupled with United Nations (UN) leadership to build international consensus on the future of MRT.

  18. Predicting mass rapid transit noise levels on an elevated station.

    PubMed

    Pamanikabud, Pichai; Paoprayoon, Suwajchai

    2003-04-01

    This study developed a noise prediction model for elevated mass rapid transit (MRT) platforms. Relevant physical and operational parameters (e.g. cruise speed, acceleration and deceleration rates for trains, building façade setbacks and so on) were collected from the Bangkok mass transit system (BTS), the first elevated MRT system operated in Bangkok, Thailand. The equivalent continuous sound pressure levels (L(Aeq)) were collected from both sides of the MRT stations at the center of each platform. The relevant parameters were collected on both platforms and ground level, on both sides of MRT stations. These parameters were statistically tested to determine their correlation with MRT noise. The final model was built from highly correlated parameters using multiple regression analysis with a stepwise regression technique. Statistical evaluation showed a high degree of goodness-of-fit test for the model to the observed data. Therefore, it can be efficiently used for the projection of MRT noise in the affected areas.

  19. Sellar reconstruction without intrasellar packing after endoscopic surgery of pituitary macroadenomas is better than its reputation.

    PubMed

    Ismail, Mostafa; Fares, Abd Alla; Abdelhak, Balegh; D'Haens, Jean; Michel, Olaf

    2016-01-01

    Ziele: Die Rekonstruktion der Sella mit intrasellärer Tamponade nach endoskopischer Resektion von Hypophysenmakroadenomen bleibt in der klinischen und radiologischen Diskussion umstritten, besonders wenn keine Liquorfistel vorhanden ist. Diese Studie wurde durchgeführt, um unsere Erfahrungen mit der Sellarekonstruktion nach einer endoskopischen Standardresektion von Hypophysenmakroadenomen ohne intraoperative Liquorfistel zur laufenden Diskussion über Techniken mit und ohne intrasellärer Tamponade beizutragen.Methoden: Eine konsekutive Serie von 47 Hypophysenmakroadenomen, die in einem chirurgischen Standardverfahren endoskopisch über einen endonasalen transsphenoidalen Zugang ohne ersichtliche intraoperative Liquorfistel entfernt wurden, wurde nachträglich während einer durchschnittlich zehnmonatigen Nachbeobachtungszeit ausgewertet. Bezüglich der sellären Rekonstuktionstechnik konnten drei Gruppen identifiziert werden: Gruppe A – ohne intraselläre Tamponade, Gruppe B – mit Tamponade aus hämostatischen Materialien und Gruppe C – mit Bauchfetttamponade. Die postoperative klinische und radiologische Bewertung der drei Gruppen wurde dokumentiert und auf Unterschiede in den Ergebnissen hin analysiert.Ergebnisse: Die postoperative klinische Beurteilung ergab keine signifikanten Unterschiede zwischen den drei Gruppen. In der Gruppe A wurden postoperativ weder Liquorfistel noch Keilbeinhöhlenentzündung oder Empty-Sella-Syndrom beobachtet. Allerdings konnte ein signifikanter Unterschied in der radiologischen Bewertung identifiziert werden: die Interpretation von sellären Inhalten bei der postoperativen MRT der Gruppe A gelang früher und zuverlässiger als in anderen Gruppen mit intrasellärer Tamponade.Schlussfolgerung: Es gibt keinen Unterschied in der Inzidenz von postoperativen Liquorfisteln und Empty-Sella-Syndromen bei den verschiedenen rekonstruktiven Techniken mit und ohne intrasellärer Tamponade, unabhängig von Größe und Ausdehnung des

  20. High resolution 3D dosimetry for microbeam radiation therapy using optical CT

    NASA Astrophysics Data System (ADS)

    McErlean, C.; Bräuer-Krisch, E.; Adamovics, J.; Leach, M. O.; Doran, S. J.

    2015-01-01

    Optical Computed Tomography (CT) is a promising technique for dosimetry of Microbeam Radiation Therapy (MRT), providing high resolution 3D dose maps. Here different MRT irradiation geometries are visualised showing the potential of Optical CT as a tool for future MRT trials. The Peak-to-Valley dose ratio (PVDR) is calculated to be 7 at a depth of 3mm in the radiochromic dosimeter PRESAGE®. This is significantly lower than predicted values and possible reasons for this are discussed.

  1. Theoretical and Experimental Studies of Magneto-Rayleigh-Taylor Instabilities

    SciTech Connect

    Lau, Yue Ying; Gilgenbach, Ronald

    2013-07-07

    Magneto-Rayleigh-Taylor instability (MRT) is important to magnetized target fusion, wire-array z-pinches, and equation-of-state studies using flyer plates or isentropic compression. It is also important to the study of the crab nebula. The investigators performed MRT experiments on thin foils, driven by the mega-ampere linear transformer driver (LTD) facility completed in their laboratory. This is the first 1-MA LTD in the USA. Initial experiments on the seeding of MRT were performed. Also completed was an analytic study of MRT for a finite plasma slab with arbitrary magnetic fields tangential to the interfaces. The effects of magnetic shear and feedthrough were analyzed.

  2. Engineered Modular Recombinant Transporters: Application of New Platform for Targeted Radiotherapeutic Agents to {alpha}-Particle Emitting {sup 211}At

    SciTech Connect

    Rosenkranz, Andrey A.; Vaidyanathan, Ganesan; Pozzi, Oscar R.; Lunin, Vladimir G.; Zalutsky, Michael R. Sobolev, Alexander S.

    2008-09-01

    Purpose: To generate and evaluate a modular recombinant transporter (MRT) for targeting {sup 211}At to cancer cells overexpressing the epidermal growth factor receptor (EGFR). Methods and Materials: The MRT was produced with four functional modules: (1) human epidermal growth factor as the internalizable ligand, (2) the optimized nuclear localization sequence of simian vacuolating virus 40 (SV40) large T-antigen, (3) a translocation domain of diphtheria toxin as an endosomolytic module, and (4) the Escherichia coli hemoglobin-like protein (HMP) as a carrier module. MRT was labeled using N-succinimidyl 3-[{sup 211}At]astato-5-guanidinomethylbenzoate (SAGMB), its {sup 125}I analogue SGMIB, or with {sup 131}I using Iodogen. Binding, internalization, and clonogenic assays were performed with EGFR-expressing A431, D247 MG, and U87MG.wtEGFR human cancer cell lines. Results: The affinity of SGMIB-MRT binding to A431 cells, determined by Scatchard analysis, was 22 nM, comparable to that measured before labeling. The binding of SGMIB-MRT and its internalization by A431 cancer cells was 96% and 99% EGFR specific, respectively. Paired label assays demonstrated that compared with Iodogen-labeled MRT, SGMIB-MRT and SAGMB-MRT exhibited more than threefold greater peak levels and durations of intracellular retention of activity. SAGMB-MRT was 10-20 times more cytotoxic than [{sup 211}At]astatide for all three cell lines. Conclusion: The results of this study have demonstrated the initial proof of principle for the MRT approach for designing targeted {alpha}-particle emitting radiotherapeutic agents. The high cytotoxicity of SAGMB-MRT for cancer cells overexpressing EGFR suggests that this {sup 211}At-labeled conjugate has promise for the treatment of malignancies, such as glioma, which overexpress this receptor.

  3. Brain tumor vessel response to synchrotron microbeam radiation therapy: a short-term in vivo study

    NASA Astrophysics Data System (ADS)

    Serduc, Raphaël; Christen, Thomas; Laissue, Jean; Farion, Régine; Bouchet, Audrey; van der Sanden, Boudewijn; Segebarth, Christoph; Bräuer-Krisch, Elke; LeDuc, Géraldine; Bravin, Alberto; Rémy, Chantal; Barbier, Emmanuel L.

    2008-07-01

    The aim of this work focuses on the description of the short-term response of a 9L brain tumor model and its vasculature to microbeam radiation therapy (MRT) using magnetic resonance imaging (MRI). Rat 9L gliosarcomas implanted in nude mice brains were irradiated by MRT 13 days after tumor inoculation using two orthogonal arrays of equally spaced 28 planar microbeams (25 µm width, 211 µm spacing and dose 500 Gy). At 1, 7 and 14 days after MRT, apparent diffusion coefficient, blood volume and vessel size index were mapped by MRI. Mean survival time after tumor inoculation increased significantly between MRT-treated and untreated groups (23 and 28 days respectively, log-rank test, p < 0.0001). A significant increase of apparent diffusion coefficient was observed 24 h after MRT in irradiated tumors versus non-irradiated ones. In the untreated group, both tumor size and vessel size index increased significantly (from 7.6 ± 2.2 to 19.2 ± 4.0 mm2 and +23%, respectively) between the 14th and the 21st day after tumor cell inoculation. During the same period, in the MRT-treated group, no difference in tumor size was observed. The vessel size index measured in the MRT-treated group increased significantly (+26%) between 14 and 28 days of tumor growth. We did not observe the significant difference in blood volume between the MRT-treated and untreated groups. MRT slows 9L tumor growth in a mouse brain but MRI results suggest that the increase in survival time after our MRT approach may be rather due to a cytoreduction than to early direct effects of ionizing radiation on tumor vessels. These results suggest that MRT parameters need to be optimized to further damage tumor vessels.

  4. Sparing of tissue by using micro-slit-beam radiation therapy reduces neurotoxicity compared with broad-beam radiation therapy

    PubMed Central

    Mukumoto, Naritoshi; Nakayama, Masao; Akasaka, Hiroaki; Shimizu, Yasuyuki; Osuga, Saki; Miyawaki, Daisuke; Yoshida, Kenji; Ejima, Yasuo; Miura, Yasushi; Umetani, Keiji; Kondoh, Takeshi; Sasaki, Ryohei

    2017-01-01

    Micro-slit-beam radiation therapy (MRT) using synchrotron-generated X-ray beams allows for extremely high-dose irradiation. However, the toxicity of MRT in central nervous system (CNS) use is still unknown. To gather baseline toxicological data, we evaluated mortality in normal mice following CNS-targeted MRT. Male C57BL/6 J mice were head-fixed in a stereotaxic frame. Synchrotron X-ray-beam radiation was provided by the SPring-8 BL28B2 beam-line. For MRT, radiation was delivered to groups of mice in a 10 × 12 mm unidirectional array consisting of 25-μm-wide beams spaced 100, 200 or 300 μm apart; another group of mice received the equivalent broad-beam radiation therapy (BRT) for comparison. Peak and valley dose rates of the MRT were 120 and 0.7 Gy/s, respectively. Delivered doses were 96–960 Gy for MRT, and 24–120 Gy for BRT. Mortality was monitored for 90 days post-irradiation. Brain tissue was stained using hematoxylin and eosin to evaluate neural structure. Demyelination was evaluated by Klüver–Barrera staining. The LD50 and LD100 when using MRT were 600 Gy and 720 Gy, respectively, and when using BRT they were 80 Gy and 96 Gy, respectively. In MRT, mortality decreased as the center-to-center beam spacing increased from 100 μm to 300 μm. Cortical architecture was well preserved in MRT, whereas BRT induced various degrees of cerebral hemorrhage and demyelination. MRT was able to deliver extremely high doses of radiation, while still minimizing neuronal death. The valley doses, influenced by beam spacing and irradiated dose, could represent important survival factors for MRT. PMID:27422939

  5. Schule in der Transformation--Transformation der Schule? Was man aus Gesprachen mit ehemaligen Schulern uber die Schule "zwischen zwei Diktaturen" erfahren kann (Schools in Transitions--Transformation of the School? What Can Be Learnt from Former Students Who Experienced Schooling under Two Dictatorial Regimes).

    ERIC Educational Resources Information Center

    Kluchert, Gerhard; Leschinsky, Achim

    1998-01-01

    Addresses interviews that focused on former students' educations under two dictatorial regimes. All the interviewees took their school-leaving examinations between 1951 and 1954. Explains that the interviews are evaluated according to the preconditions, limits, and mechanisms of the school's influence on children and adolescents. (CMK)

  6. "Bringing Boys Back In". Soziale Ungleichheit Zwischen den Geschlechtern im Bildungssystem Zuungunsten von Jungen am Beispiel der Sekundarschulabschlusse ("Bringing Boys Back In". Social Inequality between the Sexes in the Educational System to the Disadvantage of Boys as Illustrated by Graduation from Secondary Schools).

    ERIC Educational Resources Information Center

    Diefenbach, Heike; Klein, Michael

    2002-01-01

    Shows that in the German educational system, boys are at a disadvantage with girls. Explains that boys often leave secondary school without a final degree. Concludes that the smaller the proportion of male elementary teachers and the higher the rate of unemployment, the lower the achievement of boys in secondary schools. (CAJ)

  7. Beyond Genetics in Mental Rotation Test Performance: The Power of Effort Attribution

    ERIC Educational Resources Information Center

    Moe, Angelica; Pazzaglia, Francesca

    2010-01-01

    This study compares the effects on Mental Rotation Test (MRT) performance of instructions that stress the importance of (a) personal effort, and (b) genetically driven ability. A total of 120 high-school students were assigned to three groups, and administered two sub-tests of the MRT. Between the first and second sub-tests, the groups received…

  8. Sex-Specific Response Strategies in Mental Rotation

    ERIC Educational Resources Information Center

    Hirnstein, Marco; Bayer, Ulrike; Hausmann, Markus

    2009-01-01

    The present study investigated whether the marked sex difference in the original mental rotation test (MRT) is simply a result of sex differences in response strategies. Thirty-four participants (17 males, 17 females) completed the revised Vandenberg and Kuse MRT [Peters, M., Laeng, B., Latham, K., Jackson, M., Zaiyouna, R., & Richardson, C.…

  9. Item Type and Gender Differences on the Mental Rotations Test

    ERIC Educational Resources Information Center

    Voyer, Daniel; Doyle, Randi A.

    2010-01-01

    This study investigated gender differences on the Mental Rotations Test (MRT) as a function of item and response types. Accordingly, 86 male and 109 female undergraduate students completed the MRT without time limits. Responses were coded as reflecting two correct (CC), one correct and one wrong (CW), two wrong (WW), one correct and one blank…

  10. Master Resilience Training in the U.S. Army

    ERIC Educational Resources Information Center

    Reivich, Karen J.; Seligman, Martin E. P.; McBride, Sharon

    2011-01-01

    The U.S. Army Master Resilience Trainer (MRT) course, which provides face-to-face resilience training, is one of the foundational pillars of the Comprehensive Soldier Fitness program. The 10-day MRT course is the foundation for training resilience skills to sergeants and for teaching sergeants how to teach these skills to their soldiers. The…

  11. Constructive Play: Building Symbolic Competence through Physical Activity and Social Interaction.

    ERIC Educational Resources Information Center

    Fennel, Linda

    Whether physical activity and verbal communication would affect kindergarten students' scores on the Metropolitan Readiness Tests (MRT) was investigated. Twenty subjects were administered Level I of the MRT when they entered kindergarten. For 5 days per week for 4 weeks, the 10 subjects in the experimental group worked at constructive play tasks…

  12. Learning Anatomy Enhances Spatial Ability

    ERIC Educational Resources Information Center

    Vorstenbosch, Marc A. T. M.; Klaassen, Tim P. F. M.; Donders, A. R. T.; Kooloos, Jan G. M.; Bolhuis, Sanneke M.; Laan, Roland F. J. M.

    2013-01-01

    Spatial ability is an important factor in learning anatomy. Students with high scores on a mental rotation test (MRT) systematically score higher on anatomy examinations. This study aims to investigate if learning anatomy also oppositely improves the MRT-score. Five hundred first year students of medicine ("n" = 242, intervention) and…

  13. Tumor Cell Response to Synchrotron Microbeam Radiation Therapy Differs Markedly From Cells in Normal Tissues

    SciTech Connect

    Crosbie, Jeffrey C.; Anderson, Robin L.; Rothkamm, Kai; Restall, Christina M.; Cann, Leonie; Ruwanpura, Saleela; Meachem, Sarah; Yagi, Naoto; Svalbe, Imants; Lewis, Robert A.; Williams, Bryan R.G.; Rogers, Peter A.W.

    2010-07-01

    Purpose: High-dose synchrotron microbeam radiation therapy (MRT) can be effective at destroying tumors in animal models while causing very little damage to normal tissues. The aim of this study was to investigate the cellular processes behind this observation of potential clinical importance. Methods and Materials: MRT was performed using a lattice of 25 {mu}m-wide, planar, polychromatic, kilovoltage X-ray microbeams, with 200-{mu}m peak separation. Inoculated EMT-6.5 tumor and normal mouse skin tissues were harvested at defined intervals post-MRT. Immunohistochemical detection of {gamma}-H2AX allowed precise localization of irradiated cells, which were also assessed for proliferation and apoptosis. Results: MRT significantly reduced tumor cell proliferation by 24 h post-irradiation (p = 0.002). An unexpected finding was that within 24 h of MRT, peak and valley irradiated zones were indistinguishable in tumors because of extensive cell migration between the zones. This was not seen in MRT-treated normal skin, which appeared to undergo a coordinated repair response. MRT elicited an increase in median survival times of EMT-6.5 and 67NR tumor-inoculated mice similar to that achieved with conventional radiotherapy, while causing markedly less normal tissue damage. Conclusions: This study provides evidence of a differential response at a cellular level between normal and tumor tissues after synchrotron MRT.

  14. Comments on "A modified reachability tree approach to analysis of unbounded Petri nets".

    PubMed

    Ru, Yu; Wu, Weimin; Hadjicostis, Christoforos N

    2006-10-01

    The above paper introduced the construction of a modified reachability tree (MRT) for (unbounded) Petri nets and its application to reachability, liveness, and deadlock analysis. This note shows via a counterexample that some of the MRT properties claimed in the above paper are incorrect.

  15. A Mitochondrial Story: Mitochondrial Replacement, Identity and Narrative.

    PubMed

    Scully, Jackie Leach

    2017-01-01

    Mitochondrial replacement techniques (MRT) are intended to avoid the transmission of mitochondrial diseases from mother to child. MRT represent a potentially powerful new biomedical technology with ethical, policy, economic and social implications. Among other ethical questions raised are concerns about the possible effects on the identity of children born from MRT, their families, and the providers or donors of mitochondria. It has been suggested that MRT can influence identity (i) directly, through altering the genetic makeup and physical characteristics of the child, or (ii) indirectly through changing the child's experience of disease, and by generating novel intrafamilial relationships that shape the sense of self. In this article I consider the plausibility and ethical implications of these proposed identity effects, but I focus instead on a third way in which identity may be affected, through the mediating influence of the wider social world on MRT effects on identity. By taking a narrative approach, and examining the nature and availability of identity narratives, I conclude that while neither direct genetic nor indirect experiential effects can be excluded, social responses to MRT are more likely to have a significant and potentially damaging influence on the generation of MRT children's narratives of identity. This conclusion carries some implications for the collective moral responsibility we hold to ensure that MRT, if implemented, are practised in ethically justifiable ways.

  16. "Mitochondrial Replacement" Technologies and Human Germline Nuclear Modification.

    PubMed

    Lane, Alyssa; Nisker, Jeff

    2016-08-01

    In 2015 the United Kingdom became the first jurisdiction to approve "mitochondrial replacement techniques" (MRT), thereby dropping prohibitions against creating human embryos with a permanently altered genetic make-up for purposes of reproduction. MRT is a misnomer because in fact it is the nucleus of the oocyte of the woman who wants a genetically related child that is transferred to the enucleated oocyte of a woman paid to undergo IVF to provide the oocyte. MRT thus constitutes nuclear transfer, which is prohibited by criminal sanctions under sections of laws on reproductive cloning in Canada, the United States, Australia, and European countries that regulate assisted reproduction. By adopting policies permitting the use of MRT, the United Kingdom has become the first jurisdiction to counteract an international consensus prohibiting germline modification. Analyses of the legal, ethical, and societal implications of MRT in assisted human reproduction are essential.

  17. WAIS-III Matrix Reasoning test performance in a mixed clinical sample.

    PubMed

    Dugbartey, A T; Sanchez, P N; Rosenbaum, J G; Mahurin, R K; Davis, J M; Townes, B D

    1999-11-01

    This study examined the relationship between the Matrix Reasoning subtest (MRT) of the WAIS-III and a selected number of neuropsychological tests in a heterogeneous clinical sample of English-speaking American (n = 41), and non-English-speaking immigrant (n = 14) adults. A moderate association between the Halstead Category Test and the MRT (-.58) was found in the English-speaking sample. Multiple regression analysis revealed a significant association between measures of verbal abstract reasoning and verbal fluency, and performance on the MRT. Among the immigrant sample, the MRT was also found to be significantly associated with verbal fluency task performance, as well as with the Comprehensive Test of Nonverbal Intelligence. Correlational analyses therefore suggest a strong verbal mediation element in the MRT, and that labeling it a nonverbal task may be misleading.

  18. Comparative Evaluation of Partial α2 -Adrenoceptor Agonist and Pure α2 -Adrenoceptor Antagonist on the Behavioural Symptoms of Withdrawal after Chronic Alcohol Administration in Mice.

    PubMed

    Arora, Shivani; Vohora, Divya

    2016-08-01

    As an addictive drug, alcohol produces withdrawal symptoms if discontinued abruptly after chronic use. Clonidine (CLN), a partial α2 -adrenergic agonist, and mirtazapine (MRT), an antagonist of α2 -adrenoceptor, both clinically aid alcohol withdrawal. Considering different mechanisms of action of the two drugs, this study was designed to see how far these two mechanistically different drugs differ in their ability to decrease the severity of ethanol withdrawal syndrome. The effect of CLN and MRT on ethanol withdrawal-induced anxiety, depression and memory impairment was analysed using EPM, FST and PAR tests, respectively. Animals received distilled water, ethanol and/or either of the drugs (CLN and MRT) in different doses. Relapse to alcohol use was analysed by CPP test. Animals received ethanol as a conditioning drug and distilled water, CLN or MRT as test drug. CLN and MRT both alleviated anxiety in a dose-dependent manner. MRT (4 mg/kg) was more effective than CLN (0.1 mg/kg) in ameliorating the anxiogenic effect of alcohol withdrawal. However, CLN treatment increased depression. It significantly decreased swimming time and increased immobility time, whereas MRT treatment decreased immobility time and increased climbing and swimming time during abstinence. The effect was dose dependent for both drugs. The results of PAR test show that CLN treatment worsens working memory. Significant increase in SDE and TSZ and decrease in SDL were observed in CLN-treated animals. MRT treatment, on the other hand, improved working memory at both doses. Further, both CLN and MRT alleviated craving. A significant decrease in time spent in the ethanol-paired chamber was seen. MRT treatment at both doses showed better effect than CLN in preventing the development of preference in CPP test. These findings indicate a potential therapeutic use and better profile of mirtazapine over clonidine in improving memory, as well as in alleviating depression, anxiety and craving associated

  19. Validation of the mean radiant temperature simulated by the RayMan software in urban environments

    NASA Astrophysics Data System (ADS)

    Lee, Hyunjung; Mayer, Helmut

    2016-11-01

    The RayMan software is worldwide applied in investigations on different issues in human-biometeorology. However, only the simulated mean radiant temperature ( T mrt) has been validated so far in a few case studies. They are based on T mrt values, which were experimentally determined in urban environments by use of a globe thermometer or applying the six-directional method. This study analyses previous T mrt validations in a comparative manner. Their results are extended by a recent validation of T mrt in an urban micro-environment in Freiburg (southwest Germany), which can be regarded as relatively heterogeneous due to different shading intensities by tree crowns. In addition, a validation of the physiologically equivalent temperature (PET) simulated by RayMan is conducted for the first time. The validations are based on experimentally determined T mrt and PET values, which were calculated from measured meteorological variables in the daytime of a clear-sky summer day. In total, the validation results show that RayMan is capable of simulating T mrt satisfactorily under relatively homogeneous site conditions. However, the inaccuracy of simulated T mrt is increasing with lower sun elevation and growing heterogeneity of the simulation site. As T mrt represents the meteorological variable that mostly governs PET in the daytime of clear-sky summer days, the accuracy of simulated T mrt is mainly responsible for the accuracy of simulated PET. The T mrt validations result in some recommendations, which concern an update of physical principles applied in the RayMan software to simulate the short- and long-wave radiant flux densities, especially from vertical building walls and tree crowns.

  20. WE-EF-BRA-09: Microbeam Radiation Therapy Enhances Tumor Drug Uptake of PEGylated Liposomal Doxorubicin (PLD) in a Triple Negative Breast Cancer GEM Model

    SciTech Connect

    Chang, SX; Madden, AJ; Rivera, JN; Santos, CM; Hunter, LM; Darr, DB; Zamboni, WC

    2015-06-15

    Purpose: Overcoming low anti-cancer drug uptake in tumors is a key challenge limiting its clinical use. We propose to enhance the drug delivery using upfront Microbeam Radiation Therapy (MRT). MRT is a preclinical cancer therapy that utilizes microplanar beams to deliver spatially oscillating planes of high and low doses. Animal studies have demonstrated that ultrahigh dose (100s Gy) MRT eradicates tumors without damaging the function of normal tissue exposed to the same radiation. Our previous study indicated that MRT induces intense angiogenesis in tumor rim and surrounding normal tissue 1–2 days post radiation. We hypothesize that the tumor microenvironment modulation induced by MRT may enhance carrier-mediated agent drug delivery to tumors with inherent poor drug uptake. We thus investigated MRT-induced pharmacokinetics (PK) of PEGylated liposomal doxorubicin (PLD), a nano-scale doxorubicin, in T11 genetically engineered mouse model of triple negative breast cancer. Methods: A research irradiator (160kVp, RadSource Technologies) with a customized collimator was used to produce the MRT microbeam of in average 390µm width and 1190µm peak-to-peak distance. The peak dose rate of 1–2Gy/min. Dosimetry is by EBT3 film cross-calibrated with ion chamber at large fields. All mice were administered PLD at 6mg/kg IV x1 at 16h post MRT and sacrificed at 5min, 6h, 24h, and 96h post PLD administration (n=3 or 4 per group). Results: The MRT(28Gy)+PLD group mice had a total doxorubicin tumor concentration (area-under-the concentration-curve, AUC) of 206,040ng/mL•h, 3.71 times the concentration of the PLD-alone group. The MRT(34Gy)+PLD group had a higher mean total doxorubicin concentration in tumor (20,779ng/ml) than the MRT(28Gy)+PLD group (10,665ng/ml). Conclusion: Our preliminary results indicate that microbeam radiation therapy (MRT) can enhance nano-scale anti-cancer drug delivery to tumors approximately 4-fold. The exact working mechanism, the comparison with

  1. A mutant cell line resistant to Vibrio parahaemolyticus thermostable direct hemolysin (TDH): its potential in identification of putative receptor for TDH.

    PubMed

    Tang, G; Iida, T; Inoue, H; Yutsudo, M; Yamamoto, K; Honda, T

    1997-05-24

    Thermostable direct hemolysin (TDH), a pore-forming toxin produced by Vibrio parahaemolyticus, is cytotoxic to Rat-1, a fibroblast cell line derived from rat embryo. Through mutagenesis of Rat-1 with nitrosoguanidine, we established a mutant cell line, MR-T1. MR-T1 was over 200 times more resistant to the cytotoxic activity of TDH than Rat-1. TDH increased membrane permeability of Rat-1 but not of MR-T1. Binding analysis showed that, while being able to bind to Rat-1. TDH failed to bind to MR-T1, indicating that MR-T1 is deficient in the putative receptor for TDH. Somatic hybrid cells between Rat-1 and MR-T1 were similarly sensitive to TDH as Rat-1. Moreover, TDH could bind to the hybrid cells as well as to Rat-1 cells. These results indicate that MR-T1 is promising for complementation cloning of a gene related to the putative receptor for TDH.

  2. [Effect of dietary fiber content reduction on digestive transit in the rabbit. Comparison and validation of models fitted to fecal marker excretion kinetics].

    PubMed

    Gidenne, T

    1994-01-01

    The rate of passage (RP) in several digestive compartments was studied in 4 adult female rabbits cannulated at ileum, and receiving ad libitum 3 diets with decreasing fibre content (40, 30 and 22% NDF). The RP values in the whole digestive tract and between ileum and rectum were simultaneously measured by following the fecal kinetics of 2 markers (169Yb and 141Ce adsorbed on the NDF fraction of the diets) given as single doses. The mean retention time (MRT) in the whole tract provided by modelling methods (models: Grovum and Williams or Ellis) were similar to those obtained by reference method (numeric integration). MRT values in the caecum and the stomach were provided by models and were in good agreement with those deduced from reference measurements. Compared with the Ellis model, the Grovum and Williams model estimated more precisely the RP in tubular compartments (ie small intestine and distal colon); but the increasing part of the kinetics was better fitted using the Ellis model, particularly for low-fibre diets. The decrease in fibre intake (-50%) led to a 12 h increase (+72%) of the whole tract MRT, originating mainly from a 2-fold increase of ileo-rectal MRT. The MRT in the stomach decreased from 3 to 1 h, whereas the RP in the small intestine increased. Therefore, the oro-ileal MRT (mean 5 h) was not affected. A low dietary fibre induces a longer cecal MRT of large particles, without significant change for fine particles.

  3. Retention of fluid and particles in captive tapirs (Tapirus sp.).

    PubMed

    Clauss, Marcus; Lang-Deuerling, Stefanie; Müller, Dennis W H; Kienzle, Ellen; Steuer, Patrick; Hummel, Jürgen

    2010-09-01

    The retention of ingesta in the digestive tract is a major characteristic of herbivorous animals. We measured particle and fluid mean retention times (MRT) in 13 lowland tapirs (Tapirus terrestris) and 5 Malayan tapirs (Tapirus indicus) from five zoological institutions on their usual zoo diet and 2 lowland and 4 Malayan tapirs additionally on roughage-only diets (total n of trials=24) with cobalt-EDTA as fluid and chromium-mordanted fibre (<2 mm) as particle markers. MRT for fluid and particles averaged 42+/-16 h and 55+/-18 h in lowland and 40+/-13 h and 56+/-14 h in Malayan tapirs. In a General Linear Model, neither Tapir species, body mass or diet (characterised by the proportion of roughage) was significantly related to MRT, but dry matter intake was, with a steep decline in MRT with higher intake levels. Compared to other hindgut fermenters, tapirs have a low defecation frequency, which might be linked to their comparatively low food intake. Their gastrointestinal capacity (in dry matter: 1.63+/-0.63% of body mass) is similar to that calculated for horses. A comparison of the difference in fluid and particle MRT in large hindgut fermenters (horses, rhinoceroses, elephants, and the tapirs of this study) shows that longer absolute particle MRT are linked to shorter relative fluid MRT, possibly indicating a more thorough 'washing' of particulate ingesta with digestive fluids at longer particle MRT. The only outlier to this general pattern, with an exceptionally high difference between fluid and particle MRT, indicating a particularly efficient ingesta washing, is the white rhinoceros (Ceratotherium simum). If possible, results of this study should be compared to findings in tapirs on natural diets.

  4. A modified reachability tree approach to analysis of unbounded Petri nets.

    PubMed

    Wang, Fei-Yue; Gao, Yanqing; Zhou, MengChu

    2004-02-01

    Reachability trees, especially the corresponding Karp-Miller's finite reachability trees generated for Petri nets are fundamental for systematically investigating many characteristics such as boundedness, liveness, and performance of systems modeled by Petri nets. However, too much information is lost in a FRT to render it useful for many applications. In this paper, modified reachability trees (MRT) of Petri nets are introduced that extend the capability of Karp-Miller's FRTs in solving the liveness, deadlock, and reachability problems, and in defining or determining possible firing sequences. The finiteness of MRT is proved and several examples are presented to illustrate the advantages of MRT over FRT.

  5. Tazemetostat Rollover Study (TRuST): An Open-Label Rollover Study

    ClinicalTrials.gov

    2016-09-13

    Diffuse Large B-cell Lymphoma; Follicular Lymphoma; Malignant Rhabdoid Tumors (MRT); Rhabdoid Tumors of the Kidney (RTK); Atypical Teratoid Rhabdoid Tumors (ATRT); Synovial Sarcoma; Epitheliod Sarcoma; Mesothelioma; Advanced Solid Tumors

  6. Development of Multiple-Frequency Ultrasonic Imaging System Using Multiple Resonance Piezoelectric Transducer

    NASA Astrophysics Data System (ADS)

    Akiyama, Iwaki; Yoshizumi, Natsuki; Saito, Shigemi; Wada, Yuji; Koyama, Daisuke; Nakamura, Kentaro

    2012-07-01

    The authors have developed a multiple frequency imaging system using a multiple resonance transducer (MRT) consisting of 1-3 composite materials with a low mechanical quality factor Q bonded together. The MRT has a structure consisting of thin and thick piezoelectric plates, two matching layers, and a backing layer. This makes it possible to obtain B-mode images of satisfactory resolution using ultrasonic pulses owing to their short duration. In this paper, the vibration property of the MRT derived through equivalent-circuit analysis is first shown. By utilizing the result, an MRT capable of transmitting ultrasonic pulses for generation of the images of biological tissues with satisfactory resolution is designed and prototyped. Setting the prototype transducer in the mechanical sector probe of commercial ultrasonic diagnosis equipment, the speckle reduction effect is demonstrated using images of various phantoms to mimic biological tissues and a human thyroid.

  7. SU-E-T-45: Antibody Mean Residence Time in Blood and Its Correlation with Protein Molecular Weight

    SciTech Connect

    Kwok, C; Williams, L

    2014-06-01

    Purpose: Animal biodistribution data are required prior to introducing a new radiopharmaceutical into clinical trials. Protein engineering, using recombinant DNA techniques can produce a large number of related (cognate) antibodies to a given molecular target. Thus, it is important that these constructs be numerically related to one another via a single criterion. In the following, we use the mean residence time (MRT) in murine blood as this criterion. Methods: Five cognate anti-CEA (Carcinoembryonic Antigen) antibodies were compared with regard to their MRT in whole blood of CEA-positive tumor-bearing (LS174T) mice. MRT was defined by blood AUC (area under the curve) divided by the initial blood uptake value; all in units of percent injected dose per gram (%ID/g). Cognates included single chain scFv (25 kDa), diabody (50 kDa), minibody (80 kDa), F(ab')2 (120 kDa), and intact (155 kDa) forms of the murine cT84.66 antibody against CEA. All were labeled with radioactive iodine. Results: The agents, in the sequence listed, exhibited MRT values of 1.16 +/- 0.01 h, 0.99 h, 5.06 +/- 0.70 h, 6.61 +/- 0.36 h, and 59.3 +/- 2.4 h respectively. Because of the monotonic nature of the sequence, a linear correlation analysis was performed between molecular weight (MW) and MRT or ln(MRT) of the 5 proteins. Probability of random correlation was 0.10 for MRT and 0.01 for ln(MRT). Conclusion: MRT values of cognate anti-CEA antibodies were found to be a monotonically increasing sequence with respect to MW. Cognate MW values correlated best to ln(MRT) of the protein species. Thus MRT was proportional to an exponential function of molecular weight. The extended intact antibody circulation time presumably reflected its relatively maximal MW. Presence of an intact FC segment on this native antibody may also have influenced these results.

  8. An Evaluation of Dose Equivalence between Synchrotron Microbeam Radiation Therapy and Conventional Broadbeam Radiation Using Clonogenic and Cell Impedance Assays

    PubMed Central

    Ibahim, Mohammad Johari; Crosbie, Jeffrey C.; Yang, Yuqing; Zaitseva, Marina; Stevenson, Andrew W.; Rogers, Peter A. W.; Paiva, Premila

    2014-01-01

    Background High-dose synchrotron microbeam radiation therapy (MRT) has shown the potential to deliver improved outcomes over conventional broadbeam (BB) radiation therapy. To implement synchrotron MRT clinically for cancer treatment, it is necessary to undertake dose equivalence studies to identify MRT doses that give similar outcomes to BB treatments. Aim To develop an in vitro approach to determine biological dose equivalence between MRT and BB using two different cell-based assays. Methods The acute response of tumour and normal cell lines (EMT6.5, 4T1.2, NMuMG, EMT6.5ch, 4T1ch5, SaOS-2) to MRT (50–560 Gy) and BB (1.5–10 Gy) irradiation was investigated using clonogenic and real time cell impedance sensing (RT-CIS)/xCELLigence assays. MRT was performed using a lattice of 25 or 50 µm-wide planar, polychromatic kilovoltage X-ray microbeams with 200 µm peak separation. BB irradiations were performed using a Co60 teletherapy unit or a synchrotron radiation source. BB doses that would generate biological responses similar to MRT were calculated by data interpolation and verified by clonogenic and RT-CIS assays. Results For a given cell line, MRT equivalent BB doses identified by RT-CIS/xCELLigence were similar to those identified by clonogenic assays. Dose equivalence between MRT and BB were verified in vitro in two cell lines; EMT6.5ch and SaOS-2 by clonogenic assays and RT-CIS/xCELLigence. We found for example, that BB doses of 3.4±0.1 Gy and 4.40±0.04 Gy were radiobiologically equivalent to a peak, microbeam dose of 112 Gy using clonogenic and RT-CIS assays respectively on EMT6.5ch cells. Conclusion Our data provides the first determination of biological dose equivalence between BB and MRT modalities for different cell lines and identifies RT-CIS/xCELLigence assays as a suitable substitute for clonogenic assays. These results will be useful for the safe selection of MRT doses for future veterinary and clinical trials. PMID:24945301

  9. Hydraulic Geometry Analysis of the Lower Mississippi River

    DTIC Science & Technology

    2005-10-28

    the Mississippi River and Tributaries (MR&T) Project, the Lower Mississippi River was free to adjust its energy gradient through a combination of...surveys taken ten or more years apart. For this reason it is important to investigate changes in channel form based on analysis of annual... energy slope through planform adjustments, but instead is, instead, restricted to making adjustments to its longitudinal profile. MR&T work, as the

  10. Fluid and particle retention in the digestive tract of the addax antelope (Addax nasomaculatus)--adaptations of a grazing desert ruminant.

    PubMed

    Hummel, Jürgen; Steuer, Patrick; Südekum, Karl-Heinz; Hammer, Sven; Hammer, Catrin; Streich, W Jürgen; Clauss, Marcus

    2008-02-01

    Retention time of food in the digestive tract is a major aspect describing the digestive physiology of herbivores. Differences in feed retention times have been described for different ruminant feeding types. In this study, a dominantly grazing desert ruminant, the addax (Addax nasomaculatus), was investigated in this respect. Eight animals with a body weight (BW) of 87+/-5.3 kg on an ad libitum grass hay (Chloris gayana) diet were available. Co-EDTA and Cr-mordanted fibers (<2 mm) were used as pulse-dose markers. Mean retention time (MRT) in the digestive tract was calculated from faecal marker excretion. Average daily intake of the addax was found to be 1.7 kg dry matter (DM) or 60+/-8.3 g DM/kg BW(0.75). The MRT of fluid and particles in the reticulo-rumen (MRT(fluid)RR and MRT(particle)RR) were quantified to be 20+/-5.8 and 42+/-7.0 h respectively. When compared to literature data, MRT(fluid)RR was significantly longer than in cattle species, and MRT(particle)RR was significantly longer than in 11 taxa of all feeding types. The ratio of MRT(particle)RR/MRT(fluid)RR (2.3+/-0.5) was found to be within the range described for grazing ruminants. The long retention times found in the addax can be interpreted as an adaptation to a diet including a high proportion of slow fermenting grasses, while the long retention time of the fluid phase can be interpreted as a consequence of water saving mechanisms of the desert-adapted addax with a potentially low water turnover and capacious water storing rumen.

  11. Principles and Application of Magnetic Rubber Testing for Crack Detection in High-Strength Steel Components: I. Active-Field Inspection

    DTIC Science & Technology

    2014-12-01

    D6ac Denotes a grade of high strength steel MLE Maximum likelihood estimate MPI Magnetic particle inspection MRT Magnetic rubber testing NDE...crack detection if the coercive field of the grade of steel is increased [45]. Field values quoted in the general MRT literature† are of limited value...UNCLASSIFIED UNCLASSIFIED Principles and Application of Magnetic Rubber Testing for Crack Detection in High-Strength Steel Components: I

  12. The effect of electro-thermal and electro-choric instabilities and material strength on MagLIF liner stability

    NASA Astrophysics Data System (ADS)

    Pecover, James; Chittenden, Jeremy

    2015-11-01

    Magnetized liner inertial fusion (MagLIF) is a promising route to controlled thermonuclear fusion. The concept involves magnetically imploding a metal liner containing fuel with an azimuthal magnetic field (Bz) ; a key limitation of such systems is the magneto-Rayleigh-Taylor (MRT) instability. MagLIF relevant liner implosions with Bz = 0 carried out at SNL showed high amplitude MRT growth; we present a quantitative comparison between experimental results and 3D results from our MHD code Gorgon, demonstrating closer agreement for the MRT properties with the inclusion of electro-thermal and electro-choric instabilities (ETI and ECI) and material strength. The ETI and ECI result in early time azimuthally correlated structures which provide a seed for the MRT. Material strength increases the ETI amplitude due to positive feedback during the solid phase of the liner. Similar liner implosions with Bz exhibited a re-orientation of the MRT into helical structures, which are yet to be reproduced by simulations without an artificial helical initialisation. Our 3D Gorgon results with Bz show helices prior to vapourisation; these occur at initially positive angles before changing sign, tending to zero later in time. This angle does not follow the relative magnitudes of Bz and Bθ as would be expected for the MRT. The angle instead follows the ratio of axial and azimuthal currents (induced by compression or rarefaction of the initial Bz) , indicating an electro-thermal origin.

  13. Medical training therapy in lumbar syndromes.

    PubMed

    Broll-Zeitvogel, E; Grifka, J; Bauer, J; Roths, P H; Degryse, P

    1999-11-01

    Chronic low back pain can be considered to be one of the most frequently treated and most costly diseases in modern industrial societies. Dysfunctions and imbalances of the spine-supporting muscles increase the risk of low back pain. Consequently preventive treatment and rehabilitation have to aim at preserving and restoring the full capacity of the spine-supporting muscles as well as training coordination and spine-friendly behaviour. In addition to various measures of pain therapy, physiotherapeutic treatment including neuro-physiotherapy, physical treatment (eg electrotherapy), balneotherapy and supportive behavioural training, medical rehabilitation therapy (MRT) ranks among the most effective ways of treating low back pain. MRT applies guidelines and methods of exercise methodology within medically indicated programmes of preventive treatment and rehabilitation. Various objectives of MRT are outlined with special regard to the stages of MRT treatment, emphasizing positive adaptation of the neuro-muscular system in the course of rehabilitation. Physicians are responsible for MRT diagnosis and control. Taking into account the base disorder and the progress of therapy physiotherapists and the physicians in charge determine MRT objectives and treatment strategies.

  14. [Medical training therapy in lumbar syndromes].

    PubMed

    Broll-Zeitvogel, E; Grifka, J; Bauer, J; Roths, P H; Degryse, P

    1999-11-01

    Chronic low back pain can be considered to be one of the most frequently treated and most costly diseases in modern industrial societies. Dysfunctions and imbalances of the spine-supporting muscles increase the risk of low back pain. Consequently preventive treatment and rehabilitation have to aim at preserving and restoring the full capacity of the spine-supporting muscles as well as training coordination and spine-friendly behaviour. In addition to various measures of pain therapy, physiotherapeutic treatment including neuro-physiotherapy, physical treatment (eg electrotherapy), balneotherapy and supportive behavioural training, medical rehabilitation therapy (MRT) ranks among the most effective ways of treating low back pain. MRT applies guidelines and methods of exercise methodology within medically indicated programmes of preventive treatment and rehabilitation. Various objectives of MRT are outlined with special regard to the stages of MRT treatment, emphasizing positive adaptation of the neuro-muscular system in the course of rehabilitation. Physicians are responsible for MRT diagnosis and control. Taking into account the base disorder and the progress of therapy physiotherapists and the physicians in charge determine MRT objectives and treatment strategies.

  15. The Effects of Manual Resistance Training on Fitness in Adolescents

    PubMed Central

    Dorgo, Sandor; King, George A.; Candelaria, Norma; Bader, Julia O.; Brickey, Gregory D.; Adams, Carolyn E.

    2010-01-01

    Manual Resistance Training (MRT), an alternative to traditional resistance training, requires minimal equipment and may be effective when applied in school-based physical education (PE) classes. The purpose of this study was to document the physical changes in adolescents (N = 222) using MRT in school-based PE settings. Six fitness tests from the Fitnessgram assessment tool were selected to assess students' cardiovascular and muscular fitness and skin-fold tests were used to assess body composition. One Control and two Experimental Groups were defined. The Control group of students (N = 129) attended regular PE classes. One Experimental group (N = 63) attended PE that was complemented by the MRT system. A second Experiment group (N = 30) attended PE complemented by MRT and cardiovascular endurance training. Using the selected Fitnessgram tests post-test measurements were done after 9 and 18 weeks of PE. At baseline, there were no significant differences between the three groups for most measures. Compared to baseline, experimental groups improved significantly in all six fitness measures and showed more improvements than the Control group in most fitness measures both at 9 and 18 weeks. None of the groups showed significant improvement in body composition. The results documented that an MRT complemented PE program was effective in improving adolescents' muscular fitness. An 18-week combined MRT and cardiovascular endurance training program effectively improved cardiovascular and muscular fitness but was ineffective in improving adolescent body composition. An MRT based exercise session requires minimal equipment and set-up, and can be performed in a short period of time, therefore it is suitable for application in regular PE settings. PMID:19826296

  16. Optimizing dose enhancement with Ta2O5 nanoparticles for synchrotron microbeam activated radiation therapy.

    PubMed

    Engels, Elette; Corde, Stéphanie; McKinnon, Sally; Incerti, Sébastien; Konstantinov, Konstantin; Rosenfeld, Anatoly; Tehei, Moeava; Lerch, Michael; Guatelli, Susanna

    2016-12-01

    Microbeam Radiation Therapy (MRT) exploits tumour selectivity and normal tissue sparing with spatially fractionated kilovoltage X-ray microbeams through the dose volume effect. Experimental measurements with Ta2O5 nanoparticles (NPs) in 9L gliosarcoma treated with MRT at the Australian Synchrotron, increased the treatment efficiency. Ta2O5 NPs were observed to form shells around cell nuclei which may be the reason for their efficiency in MRT. In this article, our experimental observation of NP shell formation is the basis of a Geant4 radiation transport study to characterise dose enhancement by Ta2O5 NPs in MRT. Our study showed that NP shells enhance the physical dose depending microbeam energy and their location relative to a single microbeam. For monochromatic microbeam energies below ∼70keV, NP shells show highly localised dose enhancement due to the short range of associated secondary electrons. Low microbeam energies indicate better targeted treatment by allowing higher microbeam doses to be administered to tumours and better exploit the spatial fractionation related selectivity observed with MRT. For microbeam energies above ∼100keV, NP shells extend the physical dose enhancement due to longer-range secondary electrons. Again, with NPs selectively internalised, the local effectiveness of MRT is expected to increase in the tumour. Dose enhancement produced by the shell aggregate varied more significantly in the cell population, depending on its location, when compared to a homogeneous NP distribution. These combined simulation and experimental data provide first evidence for optimising MRT through the incorporation of newly observed Ta2O5 NP distributions within 9L cancer cells.

  17. High resolution 3D imaging of synchrotron generated microbeams

    SciTech Connect

    Gagliardi, Frank M.; Cornelius, Iwan; Blencowe, Anton; Franich, Rick D.; Geso, Moshi

    2015-12-15

    Purpose: Microbeam radiation therapy (MRT) techniques are under investigation at synchrotrons worldwide. Favourable outcomes from animal and cell culture studies have proven the efficacy of MRT. The aim of MRT researchers currently is to progress to human clinical trials in the near future. The purpose of this study was to demonstrate the high resolution and 3D imaging of synchrotron generated microbeams in PRESAGE® dosimeters using laser fluorescence confocal microscopy. Methods: Water equivalent PRESAGE® dosimeters were fabricated and irradiated with microbeams on the Imaging and Medical Beamline at the Australian Synchrotron. Microbeam arrays comprised of microbeams 25–50 μm wide with 200 or 400 μm peak-to-peak spacing were delivered as single, cross-fire, multidirectional, and interspersed arrays. Imaging of the dosimeters was performed using a NIKON A1 laser fluorescence confocal microscope. Results: The spatial fractionation of the MRT beams was clearly visible in 2D and up to 9 mm in depth. Individual microbeams were easily resolved with the full width at half maximum of microbeams measured on images with resolutions of as low as 0.09 μm/pixel. Profiles obtained demonstrated the change of the peak-to-valley dose ratio for interspersed MRT microbeam arrays and subtle variations in the sample positioning by the sample stage goniometer were measured. Conclusions: Laser fluorescence confocal microscopy of MRT irradiated PRESAGE® dosimeters has been validated in this study as a high resolution imaging tool for the independent spatial and geometrical verification of MRT beam delivery.

  18. Synchrotron microbeam radiation therapy for rat brain tumor palliation-influence of the microbeam width at constant valley dose.

    PubMed

    Serduc, Raphaël; Bouchet, Audrey; Bräuer-Krisch, Elke; Laissue, Jean A; Spiga, Jenny; Sarun, Sukhéna; Bravin, Alberto; Fonta, Caroline; Renaud, Luc; Boutonnat, Jean; Siegbahn, Erik Albert; Estève, François; Le Duc, Géraldine

    2009-11-07

    To analyze the effects of the microbeam width (25, 50 and 75 microm) on the survival of 9L gliosarcoma tumor-bearing rats and on toxicity in normal tissues in normal rats after microbeam radiation therapy (MRT), 9L gliosarcomas implanted in rat brains, as well as in normal rat brains, were irradiated in the MRT mode. Three configurations (MRT25, MRT50, MRT75), each using two orthogonally intersecting arrays of either 25, 50 or 75 microm wide microbeams, all spaced 211 microm on center, were tested. For each configuration, peak entrance doses of 860, 480 and 320 Gy, respectively, were calculated to produce an identical valley dose of 18 Gy per individual array at the center of the tumor. Two, 7 and 14 days after radiation treatment, 42 rats were killed to evaluate histopathologically the extent of tumor necrosis, and the presence of proliferating tumors cells and tumor vessels. The median survival times of the normal rats were 4.5, 68 and 48 days for MRT25, 50 and 75, respectively. The combination of the highest entrance doses (860 Gy per array) with 25 microm wide beams (MRT25) resulted in a cumulative valley dose of 36 Gy and was excessively toxic, as it led to early death of all normal rats and of approximately 50% of tumor-bearing rats. The short survival times, particularly of rats in the MRT25 group, restricted adequate observance of the therapeutic effect of the method on tumor-bearing rats. However, microbeams of 50 microm width led to the best median survival time after 9L gliosarcoma MRT treatment and appeared as the better compromise between tumor control and normal brain toxicity compared with 75 microm or 25 microm widths when used with a 211 microm on-center distance. Despite very high radiation doses, the tumors were not sterilized; viable proliferating tumor cells remained present at the tumor margin. This study shows that microbeam width and peak entrance doses strongly influence tumor responses and normal brain toxicity, even if valley doses are

  19. Pilot study for compact microbeam radiation therapy using a carbon nanotube field emission micro-CT scanner

    SciTech Connect

    Hadsell, Mike Cao, Guohua; Zhang, Jian; Burk, Laurel; Schreiber, Torsten; Lu, Jianping; Zhou, Otto; Schreiber, Eric; Chang, Sha

    2014-06-15

    Purpose: Microbeam radiation therapy (MRT) is defined as the use of parallel, microplanar x-ray beams with an energy spectrum between 50 and 300 keV for cancer treatment and brain radiosurgery. Up until now, the possibilities of MRT have mainly been studied using synchrotron sources due to their high flux (100s Gy/s) and approximately parallel x-ray paths. The authors have proposed a compact x-ray based MRT system capable of delivering MRT dose distributions at a high dose rate. This system would employ carbon nanotube (CNT) field emission technology to create an x-ray source array that surrounds the target of irradiation. Using such a geometry, multiple collimators would shape the irradiation from this array into multiple microbeams that would then overlap or interlace in the target region. This pilot study demonstrates the feasibility of attaining a high dose rate and parallel microbeam beams using such a system. Methods: The microbeam dose distribution was generated by our CNT micro-CT scanner (100μm focal spot) and a custom-made microbeam collimator. An alignment assembly was fabricated and attached to the scanner in order to collimate and superimpose beams coming from different gantry positions. The MRT dose distribution was measured using two orthogonal radiochromic films embedded inside a cylindrical phantom. This target was irradiated with microbeams incident from 44 different gantry angles to simulate an array of x-ray sources as in the proposed compact CNT-based MRT system. Finally, phantom translation in a direction perpendicular to the microplanar beams was used to simulate the use of multiple parallel microbeams. Results: Microbeams delivered from 44 gantry angles were superimposed to form a single microbeam dose distribution in the phantom with a FWHM of 300μm (calculated value was 290 μm). Also, during the multiple beam simulation, a peak to valley dose ratio of ∼10 was found when the phantom translation distance was roughly 4x the beam width

  20. Synchrotron microbeam radiation therapy for rat brain tumor palliation—influence of the microbeam width at constant valley dose

    NASA Astrophysics Data System (ADS)

    Serduc, Raphaël; Bouchet, Audrey; Bräuer-Krisch, Elke; Laissue, Jean A.; Spiga, Jenny; Sarun, Sukhéna; Bravin, Alberto; Fonta, Caroline; Renaud, Luc; Boutonnat, Jean; Siegbahn, Erik Albert; Estève, François; Le Duc, Géraldine

    2009-11-01

    To analyze the effects of the microbeam width (25, 50 and 75 µm) on the survival of 9L gliosarcoma tumor-bearing rats and on toxicity in normal tissues in normal rats after microbeam radiation therapy (MRT), 9L gliosarcomas implanted in rat brains, as well as in normal rat brains, were irradiated in the MRT mode. Three configurations (MRT25, MRT50, MRT75), each using two orthogonally intersecting arrays of either 25, 50 or 75 µm wide microbeams, all spaced 211 µm on center, were tested. For each configuration, peak entrance doses of 860, 480 and 320 Gy, respectively, were calculated to produce an identical valley dose of 18 Gy per individual array at the center of the tumor. Two, 7 and 14 days after radiation treatment, 42 rats were killed to evaluate histopathologically the extent of tumor necrosis, and the presence of proliferating tumors cells and tumor vessels. The median survival times of the normal rats were 4.5, 68 and 48 days for MRT25, 50 and 75, respectively. The combination of the highest entrance doses (860 Gy per array) with 25 µm wide beams (MRT25) resulted in a cumulative valley dose of 36 Gy and was excessively toxic, as it led to early death of all normal rats and of ~50% of tumor-bearing rats. The short survival times, particularly of rats in the MRT25 group, restricted adequate observance of the therapeutic effect of the method on tumor-bearing rats. However, microbeams of 50 µm width led to the best median survival time after 9L gliosarcoma MRT treatment and appeared as the better compromise between tumor control and normal brain toxicity compared with 75 µm or 25 µm widths when used with a 211 µm on-center distance. Despite very high radiation doses, the tumors were not sterilized; viable proliferating tumor cells remained present at the tumor margin. This study shows that microbeam width and peak entrance doses strongly influence tumor responses and normal brain toxicity, even if valley doses are kept constant in all groups. The use of

  1. Magneto-Rayleigh-Taylor Instability: Theory and simulation in planar and cylindrical pulsed power targets

    NASA Astrophysics Data System (ADS)

    Weis, Matthew R.

    Cylindrical liner implosions in the Magnetized Liner Inertial Fusion (MagLIF) concept are susceptible to the magneto-Rayleigh-Taylor instability (MRT). The danger of MRT enters in two phases, (1) during the main implosion, the outer surface of the liner is MRT unstable, and (2) during the short time period when the liner decelerates onto hot fuel, the inner surface becomes unstable. Growth of MRT on the outer surface may also feedthrough, which may seed the inner surface leading to high MRT growth in the second phase. If MRT growth becomes large enough, confinement of the fuel is lost. To characterize MRT we solve the linearized, ideal MHD equations in both planar and cylindrical geometries, including the presence of an axial magnetic field and the effects of sausage and kink modes (present in cylindrical coordinates only). In general, the total instability growth rates in cylindrical geometry are found to be larger than those in planar geometry. MRT and feedthrough is shown to be suppressed by strong magnetic field line bending (tension). However, for the same amount of field line bending, feedthrough is the most stabilized. Application of the planar and the cylindrical model to results from the Z-machine at Sandia National Laboratories is presented. Analytic MRT growth rates for a typical magnetized MagLIF-like implosion show the kink mode to be the fastest growing early and very late in the liner implosion (during deceleration). 1D HYDRA MHD simulations are used to generate realistic, evolving profiles (in density, pressure, and magnetic field) during the implosion from which instantaneous growth rates can be computed exactly, using either the planar or cylindrical analytic formulae developed in this thesis. Sophisticated 2D HYDRA MHD simulations were also performed to compare with the analytic theory and experimental results. In 2D, highly compressed axial magnetic fields can reduce the growth of perturbations at the fuel/liner interface during the implosion

  2. Astrophysical results of the Mauritius radio telescope

    NASA Astrophysics Data System (ADS)

    Somanah, R.; Issur, N.; Oozeer, N.

    2013-04-01

    One of the first scientific justifications of building the Mauritius Radio Telescope (hereafter referred to as MRT) was to complement the Cambridge 6C survey, which is a radio map of most of the northern sky at 150 MHz [1]; the MRT would then be the equivalent of the 6C survey for the southern sky and together we would obtain a whole sky radio map at 150 MHz. When the MRT was built, there were no radio surveys of the southern sky at frequencies less than 408 MHz; the frequency of 150 MHz was also chosen to complement the other radio surveys of the southern sky, which have been done at higher frequencies. Furthermore low radio frequencies like 150 MHz are bound to see new sources that would have been missed at higher frequencies due to the form of their spectra. Interesting features of resolved objects can also be studied in more details. In this paper, a brief description of the MRT will be made as well as the observations and imaging with the MRT data, and some astrophysical results obtained since its commissioning in 1992 (20 years of existence this year 2012).

  3. Pulsed power driven Magneto-Rayleigh-Taylor experiments.

    SciTech Connect

    Sefkow, Adam B.; Peterson, Kyle J.; Rovang, Dean Curtis; Slutz, Stephen A.; Cuneo, Michael Edward; Vesey, Roger Alan; Herrmann, Mark C.; Sinars, Daniel Brian

    2010-03-01

    Numerical simulations indicate that significant fusion yields (>100 kJ) may be obtained by pulsed-power-driven implosions of cylindrical metal liners onto magnetized and preheated deuterium-tritium fuel. The primary physics risk to this approach is the Magneto-Rayleigh-Taylor (MRT) instability, which operates during both the acceleration and deceleration phase of the liner implosion. We have designed and performed some experiments to study the MRT during the acceleration phase, where the light fluid is purely magnetic. Results from our first series of experiments and plans for future experiments will be presented. According to simulations, an initial axial magnetic field of 10 T is compressed to >100 MG within the liner during the implosion. The magnetic pressure becomes comparable to the plasma pressure during deceleration, which could significantly affect the growth of the MRT instability at the fuel/liner interface. The MRT instability is also important in some astronomical objects such as the Crab Nebula (NGC1962). In particular, the morphological structure of the observed filaments may be determined by the ratio of the magnetic to material pressure and alignment of the magnetic field with the direction of acceleration [Hester, ApJ, 456, 225 1996]. Potential experiments to study this MRT behavior using the Z facility will be presented.

  4. Coupling of sausage, kink, and magneto-Rayleigh-Taylor instabilities in a cylindrical liner

    NASA Astrophysics Data System (ADS)

    Weis, M. R.; Zhang, P.; Lau, Y. Y.; Schmit, P. F.; Peterson, K. J.; Hess, M.; Gilgenbach, R. M.

    2015-03-01

    This paper analyzes the coupling of magneto-Rayleigh-Taylor (MRT), sausage, and kink modes in an imploding cylindrical liner, using ideal MHD. A uniform axial magnetic field of arbitrary value is included in each region: liner, its interior, and its exterior. The dispersion relation is solved exactly, for arbitrary radial acceleration (-g), axial wavenumber (k), azimuthal mode number (m), liner aspect ratio, and equilibrium quantities in each region. For small k, a positive g (inward radial acceleration in the lab frame) tends to stabilize the sausage mode, but destabilize the kink mode. For large k, a positive g destabilizes both the kink and sausage mode. Using the 1D-HYDRA simulation results for an equilibrium model that includes a pre-existing axial magnetic field and a preheated fuel, we identify several stages of MRT-sausage-kink mode evolution. We find that the m = 1 kink-MRT mode has a higher growth rate at the initial stage and stagnation stage of the implosion, and that the m = 0 sausage-MRT mode dominates at the main part of implosion. This analysis also sheds light on a puzzling feature in Harris' classic paper of MRT [E. G. Harris, Phys. Fluids 5, 1057 (1962)]. An attempt is made to interpret the persistence of the observed helical structures [Awe et al., Phys. Rev. Lett. 111, 235005 (2013)] in terms of non-axisymmetric eigenmode.

  5. Coupling of sausage, kink, and magneto-Rayleigh-Taylor instabilities in a cylindrical liner

    SciTech Connect

    Weis, M. R.; Zhang, P.; Lau, Y. Y. Gilgenbach, R. M.; Schmit, P. F.; Peterson, K. J.; Hess, M.

    2015-03-15

    This paper analyzes the coupling of magneto-Rayleigh-Taylor (MRT), sausage, and kink modes in an imploding cylindrical liner, using ideal MHD. A uniform axial magnetic field of arbitrary value is included in each region: liner, its interior, and its exterior. The dispersion relation is solved exactly, for arbitrary radial acceleration (-g), axial wavenumber (k), azimuthal mode number (m), liner aspect ratio, and equilibrium quantities in each region. For small k, a positive g (inward radial acceleration in the lab frame) tends to stabilize the sausage mode, but destabilize the kink mode. For large k, a positive g destabilizes both the kink and sausage mode. Using the 1D-HYDRA simulation results for an equilibrium model that includes a pre-existing axial magnetic field and a preheated fuel, we identify several stages of MRT-sausage-kink mode evolution. We find that the m = 1 kink-MRT mode has a higher growth rate at the initial stage and stagnation stage of the implosion, and that the m = 0 sausage-MRT mode dominates at the main part of implosion. This analysis also sheds light on a puzzling feature in Harris' classic paper of MRT [E. G. Harris, Phys. Fluids 5, 1057 (1962)]. An attempt is made to interpret the persistence of the observed helical structures [Awe et al., Phys. Rev. Lett. 111, 235005 (2013)] in terms of non-axisymmetric eigenmode.

  6. Developing a methodology for estimating the drag in front-crawl swimming at various velocities.

    PubMed

    Narita, Kenzo; Nakashima, Motomu; Takagi, Hideki

    2017-02-10

    We aimed to develop a new method for evaluating the drag in front-crawl swimming at various velocities and at full stroke. In this study, we introduce the basic principle and apparatus for the new method, which estimates the drag in swimming using measured values of residual thrust (MRT). Furthermore, we applied the MRT to evaluate the active drag (Da) and compared it with the passive drag (Dp) measured for the same swimmers. Da was estimated in five-stages for velocities ranging from 1.0 to 1.4ms(-1); Dp was measured at flow velocities ranging from 0.9 to 1.5ms(-1) at intervals of 0.1ms(-1). The variability in the values of Da at MRT was also investigated for two swimmers. According to the results, Da (Da=32.3 v(3.3), N=30, R(2)=0.90) was larger than Dp (Dp=23.5 v(2.0), N=42, R(2)=0.89) and the variability in Da for the two swimmers was 6.5% and 3.0%. MRT can be used to evaluate Da at various velocities and is special in that it can be applied to various swimming styles. Therefore, the evaluation of drag in swimming using MRT is expected to play a role in establishing the fundamental data for swimming.

  7. New 3D Silicon detectors for dosimetry in Microbeam Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Lerch, M. L. F.; Dipuglia, A.; Cameron, M.; Fournier, P.; Davis, J.; Petasecca, M.; Cornelius, I.; Perevertaylo, V.; Rosenfeld, A. B.

    2017-01-01

    Microbeam Radiation Therapy (MRT) involves the use of a spatially fractionated beam of synchrotron generated X-rays to treat tumours. MRT treatment is delivered via an array of high dose ‘peaks’ separated by low dose ‘valleys’. A good Peak to Valley Dose Ratio (PVDR) is an important indicator of successful treatment outcomes. MRT dosimetry requires a radiation hard detector with high spatial resolution, large dynamic range, which is ideally real-time and tissue equivalent. We have developed a Silicon Strip Detector (SSD) and very recently, a new 3D MESA SSD to meet the very stringent requirements of MRT dosimetry. We have compared these detectors through the characterisation of the MRT radiation field at the Australian Synchrotron Imaging and Medical Beamline. The EPI SSD was able to measure the microbeam profiles and PVDRs, however the effective spatial resolution was limited by the detector alignment options available at the time. The geometry of the new 3D MESA SSD is less sensitive to this alignment restriction was able to measure the microbeam profiles within 2 μm of that expected. The 3D MESA SSD measured PVDRs were possibly affected by undesired and slow charge collection outside the sensitive volume and additional scattering from the device substrate.

  8. Psychological treatment of comorbid asthma and panic disorder in Latino adults: Results from a randomized controlled trial.

    PubMed

    Feldman, Jonathan M; Matte, Lynne; Interian, Alejandro; Lehrer, Paul M; Lu, Shou-En; Scheckner, Bari; Steinberg, Dara M; Oken, Tanya; Kotay, Anu; Sinha, Sumita; Shim, Chang

    2016-12-01

    Confusion between panic and asthma symptoms can result in serious self-management errors. A cognitive behavior psychophysiological therapy (CBPT) intervention was culturally adapted for Latinos consisting of CBT for panic disorder (PD), asthma education, differentiation between panic and asthma symptoms, and heart rate variability biofeedback. An RCT compared CBPT to music and relaxation therapy (MRT), which included listening to relaxing music and paced breathing at resting respiration rates. Fifty-three Latino (primarily Puerto Rican) adults with asthma and PD were randomly assigned to CBPT or MRT for 8 weekly sessions. Both groups showed improvements in PD severity, asthma control, and several other anxiety and asthma outcome measures from baseline to post-treatment and 3-month follow-up. CBPT showed an advantage over MRT for improvement in adherence to inhaled corticosteroids. Improvements in PD severity were mediated by anxiety sensitivity in CBPT and by depression in MRT, although earlier levels of these mediators did not predict subsequent improvements. Attrition was high (40%) in both groups, albeit comparable to CBT studies targeting anxiety in Latinos. Additional strategies are needed to improve retention in this high-risk population. Both CBPT and MRT may be efficacious interventions for comorbid asthma-PD, and CBPT may offer additional benefits for improving medication adherence.

  9. Communicating astronomy in a small island state: The unique role of the Mauritius Radio Telescope

    NASA Astrophysics Data System (ADS)

    Saddul-Hauzaree, S.

    2008-06-01

    The Mauritius Radio Telescope (MRT) is a 2 km x 1 km T-shaped aperture synthesis array that can generate radio images of the southern sky at 151.6 MHz. The sky surveyed can be in the declination range of -70o to -10o. It is located at Bras d'Eau, northeast of Mauritius at latitude 20oS and longitude 60oE. The MRT is a joint project of the University of Mauritius, the Indian Institute of Astrophysics and the Raman Research Institute. One of the main objectives of the MRT is to generate public interest in astronomy. Thus, it is involved in a wide range of onsite outreach activities for young school children. More mature students visiting the telescope learn about sky observation with a radio telescope, get to explore some sets of data, interact with the scientific personnel, get the opportunity to have hands-on experience with image manipulation and can ask a lot of questions on astronomy. This poster gives an overview of the Mauritius Radio Telescope and the attempts of MRT ito communicate astronomy to students as a process and not just as a vast expanse of knowledge. The challenges and dilemmas faced by MRT in conveying astronomy to the general public in a small island state are investigated and presented.

  10. Comparison of the dot-immunobinding assay with the serum agglutination test, the rose bengal plate test and the milk ring test for the detection of Brucella antibodies in bovine sera and milk.

    PubMed

    Gürtürk, K; Boynukara, B; Ilhan, Z; Hakki Ekin, I; Gülhan, T

    1999-05-01

    In this study, Brucella antibodies in bovine sera and milk were detected using the dot-immunobinding assay (DIA), the serum agglutination test (SAT), the Rose Bengal plate test (RBPT) and the milk ring test (MRT). For this purpose, a total of 116 paired blood and milk samples collected at the same time from 56 aborted and from 60 healthy dairy cows was examined. In DIA, a nitrocellulose membrane (NCM) was used as the solid phase. Antigen adsorbed on the NCM was extracted from Brucella abortus S99 by heat treatment. The results obtained by DIA were compared with those of SAT, RBPT and MRT. Of the 116 paired blood and milk samples, 24 were positive and 72 were negative by all tests used. Serum samples of six aborted cows were positive by DIA, SAT and RBPT but the milk samples were negative by DIA and MRT. Serum and milk samples of four aborted cows gave positive reaction only by DIA tests. The remaining six aborted cows were negative only by MRT and two of them were negative by both RBPT and MRT. Four sera of healthy cows were found to be positive only by SAT.

  11. Kommunikation mit Mitarbeitern

    NASA Astrophysics Data System (ADS)

    Spychala, Anne; Fleischmann, Jürgen

    Kommunikation ist der Austausch von Nachrichten und Informationen zwischen Mitarbeitern eines Unternehmens (O'Hair et al. 1997). Dieser Austausch kann persönlich, aber z.B. auch per Telefon, E-Mail oder durch Computersysteme erfolgen. In diesem Kapitel betrachten wir die persönliche Kommunikation zwischen Vorgesetzten und Mitarbeitern. Zur persönlichen Kommunikation mit Mitarbeitern zählen sowohl formelle Gespräche mit Mitarbeitern als auch eher informelle Gespräche zwischen Tür und Angel. Die Gespräche können dabei mit einzelnen Mitarbeitern (z.B. jährliches Mitarbeitergespräch) oder mit Gruppen von Mitarbeitern (z.B. regelmäßige Projekt- oder Teambesprechungen) stattfinden.

  12. Electrothermal instability growth in magnetically driven pulsed power liners

    SciTech Connect

    Peterson, Kyle J.; Sinars, Daniel B.; Yu, Edmund P.; Herrmann, Mark C.; Cuneo, Michael E.; Slutz, Stephen A.; Smith, Ian C.; Atherton, Briggs W.; Knudson, Marcus D.; Nakhleh, Charles

    2012-09-15

    This paper explores the role of electro-thermal instabilities on the dynamics of magnetically accelerated implosion systems. Electro-thermal instabilities result from non-uniform heating due to temperature dependence in the conductivity of a material. Comparatively little is known about these types of instabilities compared to the well known Magneto-Rayleigh-Taylor (MRT) instability. We present simulations that show electrothermal instabilities form immediately after the surface material of a conductor melts and can act as a significant seed to subsequent MRT instability growth. We also present the results of several experiments performed on Sandia National Laboratories Z accelerator to investigate signatures of electrothermal instability growth on well characterized initially solid aluminum and copper rods driven with a 20 MA, 100 ns risetime current pulse. These experiments show excellent agreement with electrothermal instability simulations and exhibit larger instability growth than can be explained by MRT theory alone.

  13. Lattice Boltzmann simulations of convection heat transfer in porous media

    NASA Astrophysics Data System (ADS)

    Liu, Qing; He, Ya-Ling

    2017-01-01

    A non-orthogonal multiple-relaxation-time (MRT) lattice Boltzmann (LB) method is developed to study convection heat transfer in porous media at the representative elementary volume scale based on the generalized non-Darcy model. In the method, two different LB models are constructed: one is constructed in the framework of the double-distribution-function approach, and the other is constructed in the framework of the hybrid approach. In particular, the transformation matrices used in the MRT-LB models are non-orthogonal matrices. The present method is applied to study mixed convection flow in a porous channel and natural convection flow in a porous cavity. It is found that the numerical results are in good agreement with the analytical solutions and/or other results reported in previous studies. Furthermore, the non-orthogonal MRT-LB method shows better numerical stability in comparison with the BGK-LB method.

  14. Calculations of first passage time of delayed tree-like networks

    NASA Astrophysics Data System (ADS)

    Wang, Shuai; Sun, Weigang; Zheng, Song

    2015-10-01

    In this paper, we study random walks in a family of delayed tree-like networks controlled by two network parameters, where an immobile trap is located at the initial node. The novel feature of this family of networks is that the existing nodes have a time delay to give birth to new nodes. By the self-similar network structure, we obtain exact solutions of three types of first passage time (FPT) measuring the efficiency of random walks, which includes the mean receiving time (MRT), mean sending time (MST) and mean first passage time (MFPT). The obtained results show that the MRT, MST and MFPT increase with the network parameters. We further show that the values of MRT, MST and MFPT are much shorter than the nondelayed counterpart, implying that the efficiency of random walks in delayed trees is much higher.

  15. Studies on Morphological and Physio-Ecological Variations of the Reniform Nematode, Rotylenchulus reniformis Linford and Oliveira, 1940 with an Emphasis on Differential Geographical Distribution of Amphimictic and Parthenogenetic Populations in Japan

    PubMed Central

    Nakasono, Kazutoshi

    2004-01-01

    The geographical distribution and polymorphism in morphological and biological characters of the reniform nematode, Rotylenchulus reniformis, in Japan were studied. The northern limit of habitat of this nematode was found on the 14 °C isothermal line of annual average-air temperature. Three morphologically different groups were ascertained which corresponded to three biological types based on male frequency. Incidence of males was consistent within populations and was not affected by environmental factors. Sexual attraction of males by females indicated reproductive isolation between the male-numerous type (MNT) and male-rare type (MRT) or male-absent type (MAT). Reproduction was amphimictic in the MNT and parthenogenetic in the MRT and MAT. Larval development in both MRT and MAT, but not that of MNT popula-tions, was inhibited at 34 °C. Differences in host preference were also observed among populations. PMID:19262821

  16. Deadlock checking for one-place unbounded Petri nets based on modified reachability trees.

    PubMed

    Ding, ZhiJun; Jiang, ChangJun; Zhou, MengChu

    2008-06-01

    A deadlock-checking approach for one-place unbounded Petri nets is presented based on modified reachability trees (MRTs). An MRT can provide some useful information that is lost in a finite reachability tree, owing to MRT's use of the expression a + bn(i) rather than symbol omega to represent the value of the components of a marking. The information is helpful to property analysis of unbounded Petri nets. For the deadlock-checking purpose, this correspondence paper classifies full conditional nodes in MRT into two types: true and fake ones. Then, an algorithm is proposed to determine whether a full conditional node is true or not. Finally, a necessary and sufficient condition of deadlocks is presented. Examples are given to illustrate the method.

  17. Absorbed dose-to-water protocol applied to synchrotron-generated x-rays at very high dose rates

    NASA Astrophysics Data System (ADS)

    Fournier, P.; Crosbie, J. C.; Cornelius, I.; Berkvens, P.; Donzelli, M.; Clavel, A. H.; Rosenfeld, A. B.; Petasecca, M.; Lerch, M. L. F.; Bräuer-Krisch, E.

    2016-07-01

    Microbeam radiation therapy (MRT) is a new radiation treatment modality in the pre-clinical stage of development at the ID17 Biomedical Beamline of the European synchrotron radiation facility (ESRF) in Grenoble, France. MRT exploits the dose volume effect that is made possible through the spatial fractionation of the high dose rate synchrotron-generated x-ray beam into an array of microbeams. As an important step towards the development of a dosimetry protocol for MRT, we have applied the International Atomic Energy Agency’s TRS 398 absorbed dose-to-water protocol to the synchrotron x-ray beam in the case of the broad beam irradiation geometry (i.e. prior to spatial fractionation into microbeams). The very high dose rates observed here mean the ion recombination correction factor, k s , is the most challenging to quantify of all the necessary corrections to apply for ionization chamber based absolute dosimetry. In the course of this study, we have developed a new method, the so called ‘current ramping’ method, to determine k s for the specific irradiation and filtering conditions typically utilized throughout the development of MRT. Using the new approach we deduced an ion recombination correction factor of 1.047 for the maximum ESRF storage ring current (200 mA) under typical beam spectral filtering conditions in MRT. MRT trials are currently underway with veterinary patients at the ESRF that require additional filtering, and we have estimated a correction factor of 1.025 for these filtration conditions for the same ESRF storage ring current. The protocol described herein provides reference dosimetry data for the associated Treatment Planning System utilized in the current veterinary trials and anticipated future human clinical trials.

  18. WE-G-BRE-01: A High Power Nanotube X-Ray Microbeam Irradiator for Preclinical Brain Tumor Treatment

    SciTech Connect

    Chtcheprov, P; Inscoe, C; Zhang, L; Lu, J; Zhou, O; Chang, S; Sprenger, F; Laganis, P

    2014-06-15

    Purpose: Microbeam radiation therapy (MRT) is a new type of cancer treatment undergoing studies at various synchrotron facilities. The principle of MRT is using arrays of microscopically small, low-energy X-radiation for the treatment of various radio-resistant, deep-seated tumors. Our motivation is to develop a compact and inexpensive image guided MRT irradiator to use in the research lab setting. After a successful initial demonstration, here we report a second generation carbon nanotube (CNT) cathode based MRT tube, capable of producing multiple microbeam lines with an anticipated dose rate of 11 Gy/min per line. Methods: The system uses multiple line CNT source arrays to generate multiple focal lines on the anode. The increase in dose-rate, compared to our first generation system, is achieved by increasing the operating voltage from 160 kVp to 225kVp, adding multiple simultaneous focal lines on the anode, and a more efficient cooling mechanism using a 6kW oil-cooled anode. Results: This work will present the design and development process, challenges and solutions to meeting operating specifications, and the final design of the tube and collimator, along with optimization and stabilization of its use. A detailed characterization of its capabilities will be included with a comprehensive measurement of its X-ray focal line dimensions, an evaluation of its collimator alignment and microbeam dimensions, and phantom-based quantification of its dosimetric output. Conclusion: The development of a second generation, compact, multiple line MRT device using carbon nanotube (CNT) cathode based X-ray technology and a novel oil cooled anode design is presented here. With this new source, we are capable of delivering a total microbeam radiation dose comparable to the low end of the synchrotron based MRT systems for small animal brain tumor models.

  19. Preferential Effect of Synchrotron Microbeam Radiation Therapy on Intracerebral 9L Gliosarcoma Vascular Networks

    SciTech Connect

    Bouchet, Audrey; Lemasson, Benjamin; Le Duc, Geraldine; Maisin, Cecile; Braeuer-Krisch, Elke; Siegbahn, Erik Albert; Renaud, Luc; Khalil, Enam; Remy, Chantal; Poillot, Cathy; Bravin, Alberto; Laissue, Jean A.; Barbier, Emmanuel L.; Serduc, Raphael

    2010-12-01

    Purpose: Synchrotron microbeam radiation therapy (MRT) relies on spatial fractionation of the incident photon beam into parallel micron-wide beams. Our aim was to analyze the effects of MRT on normal brain and 9L gliosarcoma tissues, particularly on blood vessels. Methods and Materials: Responses to MRT (two arrays, one lateral, one anteroposterior (2 x 400 Gy), intersecting orthogonally in the tumor region) were studied during 6 weeks using MRI, immunohistochemistry, and vascular endothelial growth factor Western blot. Results: MRT increased the median survival time of irradiated rats (x3.25), significantly increased blood vessel permeability, and inhibited tumor growth; a cytotoxic effect on 9L cells was detected 5 days after irradiation. Significant decreases in tumoral blood volume fraction and vessel diameter were measured from 8 days after irradiation, due to loss of endothelial cells in tumors as detected by immunochemistry. Edema was observed in the normal brain exposed to both crossfired arrays about 6 weeks after irradiation. This edema was associated with changes in blood vessel morphology and an overexpression of vascular endothelial growth factor. Conversely, vascular parameters and vessel morphology in brain regions exposed to one of the two arrays were not damaged, and there was no loss of vascular endothelia. Conclusions: We show for the first time that preferential damage of MRT to tumor vessels versus preservation of radioresistant normal brain vessels contributes to the efficient palliation of 9L gliosarcomas in rats. Molecular pathways of repair mechanisms in normal and tumoral vascular networks after MRT may be essential for the improvement of such differential effects on the vasculature.

  20. Exercise-mediated vasodilation in human obesity and metabolic syndrome: effect of acute ascorbic acid infusion.

    PubMed

    Limberg, Jacqueline K; Kellawan, J Mikhail; Harrell, John W; Johansson, Rebecca E; Eldridge, Marlowe W; Proctor, Lester T; Sebranek, Joshua J; Schrage, William G

    2014-09-15

    We tested the hypothesis that infusion of ascorbic acid (AA), a potent antioxidant, would alter vasodilator responses to exercise in human obesity and metabolic syndrome (MetSyn). Forearm blood flow (FBF, Doppler ultrasound) was measured in lean, obese, and MetSyn adults (n = 39, 32 ± 2 yr). A brachial artery catheter was inserted for blood pressure monitoring and local infusion of AA. FBF was measured during dynamic handgrip exercise (15% maximal effort) with and without AA infusion. To account for group differences in blood pressure and forearm size, and to assess vasodilation, forearm vascular conductance (FVC = FBF/mean arterial blood pressure/lean forearm mass) was calculated. We examined the time to achieve steady-state FVC (mean response time, MRT) and the rise in FVC from rest to steady-state exercise (Δ, exercise - rest) before and during acute AA infusion. The MRT (P = 0.26) and steady-state vasodilator responses to exercise (ΔFVC, P = 0.31) were not different between groups. Intra-arterial infusion of AA resulted in a significant increase in plasma total antioxidant capacity (174 ± 37%). AA infusion did not alter MRT or steady-state FVC in any group (P = 0.90 and P = 0.85, respectively). Interestingly, higher levels of C-reactive protein predicted longer MRT (r = 0.52, P < 0.01) and a greater reduction in MRT with AA infusion (r = -0.43, P = 0.02). We concluded that AA infusion during moderate-intensity, rhythmic forearm exercise does not alter the time course or magnitude of exercise-mediated vasodilation in groups of young lean, obese, or MetSyn adults. However, systemic inflammation may limit the MRT to exercise, which can be improved with AA.

  1. High resolution X-ray fluorescence imaging for a microbeam radiation therapy treatment planning system

    NASA Astrophysics Data System (ADS)

    Chtcheprov, Pavel; Inscoe, Christina; Burk, Laurel; Ger, Rachel; Yuan, Hong; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) uses an array of high-dose, narrow (~100 μm) beams separated by a fraction of a millimeter to treat various radio-resistant, deep-seated tumors. MRT has been shown to spare normal tissue up to 1000 Gy of entrance dose while still being highly tumoricidal. Current methods of tumor localization for our MRT treatments require MRI and X-ray imaging with subject motion and image registration that contribute to the measurement error. The purpose of this study is to develop a novel form of imaging to quickly and accurately assist in high resolution target positioning for MRT treatments using X-ray fluorescence (XRF). The key to this method is using the microbeam to both treat and image. High Z contrast media is injected into the phantom or blood pool of the subject prior to imaging. Using a collimated spectrum analyzer, the region of interest is scanned through the MRT beam and the fluorescence signal is recorded for each slice. The signal can be processed to show vascular differences in the tissue and isolate tumor regions. Using the radiation therapy source as the imaging source, repositioning and registration errors are eliminated. A phantom study showed that a spatial resolution of a fraction of microbeam width can be achieved by precision translation of the mouse stage. Preliminary results from an animal study showed accurate iodine profusion, confirmed by CT. The proposed image guidance method, using XRF to locate and ablate tumors, can be used as a fast and accurate MRT treatment planning system.

  2. Mathematical modelling of digesta passage rate, mean retention time and in vivo apparent digestibility of two different lengths of hay and big-bale grass silage in ponies.

    PubMed

    Moore-Colyer, M J S; Morrow, H J; Longland, A C

    2003-07-01

    Welsh-cross pony geldings (about 300 kg live weight) were used in a 4x4 Latin square experiment to determine the rate of passage and apparent digestibility of unchopped big-bale grass silage (BBL), chopped big-bale grass silage (BBS), unchopped grass hay (HL) and chopped grass hay (HS) offered at approximately 15 g/kg live weight per d. On day 1 of collection weeks, ponies were fed 85 g ytterbium chloride hexahydrate-marked feed 1.5 h after the morning meal. Total faecal collections commenced 8 h later and continued for 168 h. Apparent digestibilities of feed DM, organic matter (OM), crude protein (CP, Nx6.25), acid-detergent fibre (ADF) and neutral-detergent fibre (NDF) were also determined. Faecal excretion data were subjected to the models of Pond et al. (1988) and digesta mean retention time (MRT) calculated from these models and using the algebraic method of Thielmans et al. (1978). Silage had significantly (P<0.05) higher digestibilities of DM, OM, CP, ADF and NDF than hay; however, chop length had no effect. All the models of Pond et al. (1988) accurately described (R(2)>0.8) the pattern of faecal marker excretion. MRT of BBL (29.0 h)>BBS(27 h)>HS and HL (26 h). Compartmental analysis using the G3 model of Pond et al. (1988) showed BBL and HS diets had longer MRT in the time-dependent compartment, whereas BBS and HL had longer MRT in the time-independent compartment. Results from this experiment indicate that BBL and BBS are readily accepted and digested by ponies. While Yb is a successful external marker for determining total tract MRT and for modelling faecal excretion curves in horses, the results did not allow any definite conclusions to be drawn on digesta MRT within the different compartments of the equid gut.

  3. Comparison of different methods of estimating the mean radiant temperature in outdoor thermal comfort studies.

    PubMed

    Krüger, E L; Minella, F O; Matzarakis, A

    2014-10-01

    Correlations between outdoor thermal indices and the calculated or measured mean radiant temperature T(mrt) are in general of high importance because of the combined effect on human energy balance in outdoor spaces. The most accurate way to determine T(mrt) is by means of integral radiation measurements, i.e. measuring the short- and long-wave radiation from six directions using pyranometers and pyrgeometers, an expensive and not always an easily available procedure. Some studies use globe thermometers combined with air temperature and wind speed sensors. An alternative way to determine T(mrt) is based on output from the RayMan model from measured data of incoming global radiation and morphological features of the monitoring site in particular sky view factor (SVF) data. The purpose of this paper is to compare different methods to assess the mean radiant temperature T(mrt) in terms of differences to a reference condition (T(mrt) calculated from field measurements) and to resulting outdoor comfort levels expressed as PET and UTCI values. The T(mrt) obtained from field measurements is a combination of air temperature, wind speed and globe temperature data according to the forced ventilation formula of ISO 7726 for data collected in Glasgow, UK. Four different methods were used in the RayMan model for T(mrt) calculations: input data consisting exclusively of data measured at urban sites; urban data excluding solar radiation, estimated SVF data and solar radiation data measured at a rural site; urban data excluding solar radiation with SVF data for each site; urban data excluding solar radiation and including solar radiation at the rural site taking no account of SVF information. Results show that all methods overestimate T(mrt) when compared to ISO calculations. Correlations were found to be significant for the first method and lower for the other three. Results in terms of comfort (PET, UTCI) suggest that reasonable estimates could be made based on global radiation

  4. Die Gasultrazentrifuge als mediale Projektion des Kalten Krieges

    NASA Astrophysics Data System (ADS)

    Helmbold, Bernd

    Studien der letzten Dekaden nach der Wiedervereinigung von BRD und DDR erweitern die Perspektive der Wissenschaftsgeschichte vom Fokus des Big Science und der technisch-militärisch-industriellen Auseinandersetzung zwischen den zwei Blöcken zu einer globalen Transformation im Konflikt der Supermächte geprägt durch lokale und auch interne Ausformungen.

  5. The Political Views of Students at the Universities of the Armed Forces in Comparison to Those of Students at Public Institutions (Die politischen Orientierungen der Studenten an den Universitaeten der Bundeswehr im Vergleich zu den Studenten an oeffentlichen Hochschulen)

    DTIC Science & Technology

    2001-12-01

    zu sein scheint" ( Noelle - Neumann , E. und Petersen, Th., S. 40).5 4 Gerade auch bei den rasant zunehmenden Aufgaben der Bundeswehr bei...Bonnemann A., Hoffmann-Broll U., 1999 Studentische Orientierungen zwischen akademischer und soldatischer Lebenswelt. Noelle - Neumann E., Petersen Th

  6. An Unstructured Grid Morphodynamic Model with a Discontinuous Galerkin Method for Bed Evolution

    DTIC Science & Technology

    2005-04-24

    3), 193-224. Exner, F.M., 1925. Uber die wechselwirkung zwischen wasser und geschiebe in flussen. Sitzenberichte Akad. Wiss. Wien. 165 (3-4...Westerink, J.J., Luettich, R.A., Mark, D.J. 2002. A tidal constituent database for the western north Atlantic Ocean, Gulf of Mexico and Caribbean Sea

  7. Mikrowellenspektroskopie Genauere Hyperfeinstruktur

    NASA Astrophysics Data System (ADS)

    Vogel, Manuel; Winters, Danyal F. A.; Thompson, Richard C.

    2005-07-01

    Übergänge zwischen Hyperfeinstruktur-Niveaus liegen im Bereich der Mikrowellen und entziehen sich daher hoch genauen Messungen mit Lasern. Am Imperial College London wird derzeit in Zusammenarbeit mit der Gesellschaft für Schwerionenforschung (GSI) in Darmstadt ein Experiment aufgebaut, das solche Messungen an gespeicherten, nahezu ruhenden Ionen zulässt.

  8. Mitochondrial Replacement Therapy: Are Mito-nuclear Interactions Likely To Be a Problem?

    PubMed

    Eyre-Walker, Adam

    2017-04-01

    It has been suggested that deleterious interactions between the mitochondrial and nuclear genomes could pose a problem for mitochondrial replacement therapy (MRT). This is because the mitochondrial genome is placed in a novel nuclear environment using this technique. In contrast, it is inherited with half the mother's genome during normal reproduction, a genome that it is relatively compatible with, since the mother is alive. Here, I review the evidence of whether mito-nuclear interactions are likely to pose a problem for MRT. The majority of the available experimental evidence, both in humans and other species, suggests that MRT is not harmful. These results are consistent with population genetic theory, which predicts that deleterious mito-nuclear interactions are unlikely to be much more prevalent in individuals born to MRT than normal reproduction, particularly in a species such as humans with low population differentiation. This is because selection is unlikely to be strong enough to establish significant linkage disequilibrium between the mitochondrial and nuclear genomes. These results are supported by a meta-analysis of 231 cases, from a variety of animals, in which the mitochondrial DNA (mtDNA) from one strain has been introgressed into the nuclear background of another strain of the same species. Overall, there is little tendency for introgression of mtDNA to be harmful.

  9. Are Males Always Better than Females in Mental Rotation? Exploring a Gender Belief Explanation

    ERIC Educational Resources Information Center

    Moe, Angelica

    2009-01-01

    Males outperform females in the Mental Rotation Test (MRT) for biological, strategic and cultural reasons. The present research tested a motivational explanation with the hypothesis that females could do better when induced to have positive beliefs and expectations. All-female and all-male samples were divided into six groups, each having listened…

  10. Following the Instructions! Effects of Gender Beliefs in Mental Rotation

    ERIC Educational Resources Information Center

    Moe, Angelica; Pazzaglia, Francesca

    2006-01-01

    Research has widely demonstrated male superiority in the Mental Rotation Test (MRT). Various explanations have been put forward to account for these differences. We considered gender beliefs and argued that women may fare less well than men partly because they are considered unable to perform this kind of task. Beliefs about spatial ability were…

  11. Effects of Kindergarten Attendance on Development of School Readiness and Language Skills. Interim Report.

    ERIC Educational Resources Information Center

    Rubin, Rosalyn

    This study was made to find out to what extent kindergartens contribute to school readiness. Ninety children with a mean chronological age of 4.9 were tested with the Metropolitan Readiness Test (MRT), the Illinois Test of Psycholinguistic Abilities (ITPA), and a Behavior Rating Scale and were retested one year later. During the intervening year,…

  12. Aeromedical Lessons from the Space Shuttle Columbia Accident Investigation

    NASA Technical Reports Server (NTRS)

    Pool, Sam L.

    2005-01-01

    This paper presents the aeromedical lessons learned from the Space Shuttle Columbia Accident Investigation. The contents include: 1) Introduction and Mission Response Team (MRT); 2) Primary Disaster Field Office (DFO); 3) Mishap Investigation Team (MIT); 4) Kennedy Space Center (KSC) Mishap Response Plan; 5) Armed Forces Institute of Pathology (AFIP); and 6) STS-107 Crew Surgeon.

  13. Automated Speech Intelligibility System for Head-Borne Personal Protective Equipment: Proof of Concept

    DTIC Science & Technology

    2008-04-01

    hang, sang, gang, rang will, hill, kill, bill, fill, till map, mat, math, mad , mass, man pale, sale, bale, gale, male, tale MRT Set 2 (spoken word...lake, lay, lame, lane, lace run, bun, fun, sun, nun , gun dust, gust, must, bust, just, rust path, pack, pass, pat, pad, pan dip, dim, din, dill, did

  14. Experimental Investigation of the Effects of an Axial Magnetic Field on the Magneto-Rayleigh-Taylor Instability in Ablating Planar Foils

    NASA Astrophysics Data System (ADS)

    Yager-Elorriaga, D. A.; Patel, S. G.; Steiner, A. M.; Jordan, N. M.; Weiss, M. R.; Gilgenbach, R. M.; Lau, Y. Y.

    2014-10-01

    Experiments are underway to study the effects an axial magnetic field on the magneto-Rayleigh-Taylor instability (MRT) in ablating planar foils on the 1-MA LTD at the Michigan Accelerator for Inductive Z-pinch Experiments (MAIZE) facility at the University of Michigan. For 600 kA drive current, a 15 T axial magnetic field is produced using helical return current posts. During the current pulse, the magnetic field may diffuse into the foil, creating a sheared magnetic field along with the possibility of shear stabilization of the MRT instability. Theoretical investigation at UM has shown that a sheared azimuthal magnetic field coupled with an axial magnetic field reduces the MRT growth rate in general. In order to study this effect, the amount of magnetic shear is controlled by offsetting the initial position of the foil. A 775 nm Ti:sapphire laser will be used to shadowgraph the foil in order to measure the MRT growth rate. By comparing these results to previous experiments at UM, the effects of magnetic shear and an axial magnetic field will be determined. This work was supported by US DoE. S.G. Patel and A.M. Steiner supported by NPSC funded by Sandia. D.A. Yager-Elorriaga supported by NSF fellowship Grant DGE 1256260.

  15. Targeted magnetic delivery and tracking of cells using a magnetic resonance imaging system.

    PubMed

    Riegler, Johannes; Wells, Jack A; Kyrtatos, Panagiotis G; Price, Anthony N; Pankhurst, Quentin A; Lythgoe, Mark F

    2010-07-01

    The success of cell therapies depends on the ability to deliver the cells to the site of injury. Targeted magnetic cell delivery is an emergent technique for localised cell transplantation therapy. The use of permanent magnets limits such a treatment to organs close to the body surface or an implanted magnetic source. A possible alternative method for magnetic cell delivery is magnetic resonance targeting (MRT), which uses magnetic field gradients inherent to all magnetic resonance imaging system, to steer ferromagnetic particles to their target region. In this study we have assessed the feasibility of such an approach for cell targeting, using a range of flow rates and different super paramagnetic iron oxide particles in a vascular bifurcation phantom. Using MRT we have demonstrated that 75% of labelled cells could be guided within the vascular bifurcation. Furthermore we have demonstrated the ability to image the labelled cells before and after magnetic targeting, which may enable interactive manipulation and assessment of the distribution of cellular therapy. This is the first demonstration of cellular MRT and these initial findings support the potential value of MRT for improved targeting of intravascular cell therapies.

  16. The Development and Testing of Guidelines for Designing School Classrooms to Maximize Hearing Conditions and Provide for Effective Noise Control. Final Report.

    ERIC Educational Resources Information Center

    Kingsbury, H. F.; Strumpf, F. M.

    Speech intelligibility was tested in three classroom type spaces, one of 700 square feet, and two of 200 square feet, using student listeners and recorded test material. One of the latter two classrooms was fully carpeted. The test material used was Modified Rhyme Test (MRT) tapes, presented via tape reproducer and loudspeaker. Also investigated…

  17. Physiologically gated micro-beam radiation therapy using electronically controlled field emission x-ray source array

    NASA Astrophysics Data System (ADS)

    Chtcheprov, Pavel; Hadsell, Michael; Burk, Laurel; Ger, Rachel; Zhang, Lei; Yuan, Hong; Lee, Yueh Z.; Chang, Sha; Lu, Jianping; Zhou, Otto

    2013-03-01

    Micro-beam radiation therapy (MRT) uses parallel planes of high dose narrow (10-100 um in width) radiation beams separated by a fraction of a millimeter to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000Gy of entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during the treatment can result in significant movement of micro beam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), and thus can reduce the effectiveness of the MRT. Recently we have developed the first bench-top image guided MRT system for small animal treatment using a high powered carbon nanotube (CNT) x-ray source array. The CNT field emission x-ray source can be electronically synchronized to an external triggering signal to enable physiologically gated firing of x-ray radiation to minimize motion blurring. Here we report the results of phantom study of respiratory gated MRT. A simulation of mouse breathing was performed using a servo motor. Preliminary results show that without gating the micro beam full width at tenth maximum (FWTM) can increase by 70% and PVDR can decrease up to 50%. But with proper gating, both the beam width and PVDR changes can be negligible. Future experiments will involve irradiation of mouse models and comparing histology stains between the controls and the gated irradiation.

  18. Individual Differences in the Mental Rotation Skills of Turkish Prospective Teachers

    ERIC Educational Resources Information Center

    Turgut, Melih

    2015-01-01

    This study investigated the effects of gender, academic performance and preschool education on mental rotation skills among Turkish prospective teachers. A total of 525 undergraduate students (364 female) from a government university located in western Turkey completed the Mental Rotation Test (MRT). A three-way [2 (gender) × 5 (academic…

  19. Rehabilitation of aphasia: application of melodic-rhythmic therapy to Italian language

    PubMed Central

    Cortese, Maria Daniela; Riganello, Francesco; Arcuri, Francesco; Pignataro, Luigina Maria; Buglione, Iolanda

    2015-01-01

    Aphasia is a complex disorder, frequent after stroke (with an incidence of 38%), with a detailed pathophysiological characterization. Effective approaches are crucial for devising an efficient rehabilitative strategy, in order to address the everyday life and professional disability. Several rehabilitative procedures are based on psycholinguistic, cognitive, psychosocial or pragmatic approaches, including amongst those with a neurobehavioral approach the Melodic Intonation Therapy (MIT). Van Eeckhout’s adaptation of MIT to French language (Melodic-Rhythmic Therapy: MRT) has implemented the training strategy by adding a rhythmic structure reproducing French prosody. The purpose of this study was to adapt MRT rehabilitation procedures to Italian language and to verify its efficacy in a group of six chronic patients (five males) with severe non-fluent aphasia and without specific aphasic treatments during the previous 9 months. The patients were treated 4 days a week for 16 weeks, with sessions of 30–40 min. They were assessed 6 months after the end of the treatment (follow-up). The patients showed a significant improvement at the Aachener Aphasie Test (AAT) in different fields of spontaneous speech, with superimposable results at the follow-up. Albeit preliminary, these findings support the use of MRT in the rehabilitation after stroke. Specifically, MRT seems to benefit from its stronger structure than the available stimulation-facilitation procedures and allows a better quantification of the rehabilitation efficacy. PMID:26441615

  20. Respirator Speech Intelligibility Testing with an Experienced Speaker

    DTIC Science & Technology

    2015-05-01

    RESPIRATOR SPEECH INTELLIGIBILITY TESTING WITH AN EXPERIENCED...2. REPORT TYPE Final 3. DATES COVERED (From - To) Oct 2008 - Jun 2009 4. TITLE AND SUBTITLE Respirator Speech Intelligibility Testing with an...14. ABSTRACT The Modified Rhyme Test (MRT) is used by the National Institute for Occupational Safety and Health (NIOSH) to assess speech

  1. Gender-Specific Effects of Artificially Induced Gender Beliefs in Mental Rotation

    ERIC Educational Resources Information Center

    Heil, Martin; Jansen, Petra; Quaiser-Pohl, Claudia; Neuburger, Sarah

    2012-01-01

    Men outperform women in the Mental Rotation Test (MRT) by about one standard deviation. The present study replicated a gender belief account [Moe, A., & Pazzaglia, F. (2006). Following the instructions! Effects of gender beliefs in mental rotation. Learning and Individual Differences, 16, 369-377.] for (part of) this effect. A sample of 300…

  2. Validation of Magnetic Resonance Thermometry by Computational Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Rydquist, Grant; Owkes, Mark; Verhulst, Claire M.; Benson, Michael J.; Vanpoppel, Bret P.; Burton, Sascha; Eaton, John K.; Elkins, Christopher P.

    2016-11-01

    Magnetic Resonance Thermometry (MRT) is a new experimental technique that can create fully three-dimensional temperature fields in a noninvasive manner. However, validation is still required to determine the accuracy of measured results. One method of examination is to compare data gathered experimentally to data computed with computational fluid dynamics (CFD). In this study, large-eddy simulations have been performed with the NGA computational platform to generate data for a comparison with previously run MRT experiments. The experimental setup consisted of a heated jet inclined at 30° injected into a larger channel. In the simulations, viscosity and density were scaled according to the local temperature to account for differences in buoyant and viscous forces. A mesh-independent study was performed with 5 mil-, 15 mil- and 45 mil-cell meshes. The program Star-CCM + was used to simulate the complete experimental geometry. This was compared to data generated from NGA. Overall, both programs show good agreement with the experimental data gathered with MRT. With this data, the validity of MRT as a diagnostic tool has been shown and the tool can be used to further our understanding of a range of flows with non-trivial temperature distributions.

  3. Influence of ground surface characteristics on the mean radiant temperature in urban areas

    NASA Astrophysics Data System (ADS)

    Lindberg, Fredrik; Onomura, Shiho; Grimmond, C. S. B.

    2016-09-01

    The effect of variations in land cover on mean radiant temperature ( T mrt ) is explored through a simple scheme developed within the radiation model SOLWEIG. Outgoing longwave radiation is parameterised using surface temperature observations on a grass and an asphalt surface, whereas outgoing shortwave radiation is modelled through variations in albedo for the different surfaces. The influence of ground surface materials on T mrt is small compared to the effects of shadowing. Nevertheless, altering ground surface materials could contribute to a reduction in T mrt to reduce the radiant load during heat-wave episodes in locations where shadowing is not an option. Evaluation of the new scheme suggests that despite its simplicity it can simulate the outgoing fluxes well, especially during sunny conditions. However, it underestimates at night and in shadowed locations. One grass surface used to develop the parameterisation, with very different characteristics compared to an evaluation grass site, caused T mrt to be underestimated. The implications of using high temporal resolution (e.g. 15 minutes) meteorological forcing data under partly cloudy conditions are demonstrated even for fairly proximal sites.

  4. Biocrust morphogroups provide an effective and rapid assessment tool for drylands

    PubMed Central

    Read, Cassia F; Duncan, David H; Vesk, Peter A; Elith, Jane; Wan, Shiqiang

    2014-01-01

    Biological soil crusts (biocrusts) occur across most of the world's drylands and are sensitive indicators of dryland degradation. Accounting for shifts in biocrust composition is important for quantifying integrity of arid and semi-arid ecosystems, but the best methods for assessing biocrusts are uncertain. We investigate the utility of surveying biocrust morphogroups, a reduced set of biotic classes, compared to species data, for detecting shifts in biocrust composition and making inference about dryland degradation. We used multivariate regression tree (MRT) analyses to model morphogroup abundance, species abundance and species occurrence data from two independent studies in semi-arid open woodlands of south-eastern Australia. We advanced the MRT method with a ‘best subsets’ model selection procedure, which improved model stability and prediction. Biocrust morphogroup composition responded strongly to surrogate variables of ecological degradation. Further, MRT models of morphogroup data had stronger explanatory power and predictive power than MRT models of species abundance or occurrence data. We also identified morphogroup indicators of degraded and less degraded sites in our study region. Synthesis and applications. Sustainable management of drylands requires methods to assess shifts in ecological integrity. We suggest that biocrust morphogroups are highly suitable for assessment of dryland integrity because they allow for non-expert, rapid survey and are informative about ecological function. Furthermore, morphogroups were more robust than biocrust species data, showed a strong response to ecological degradation and were less influenced by environmental variation, and models of morphogroup abundance were more predictive. PMID:25598550

  5. MRI Based Diagnostics for Temperature Measurements in Turbulent Flows

    NASA Astrophysics Data System (ADS)

    Burton, Lauren Sascha; Elkins, Christopher J.; Eaton, John K.

    2014-11-01

    Accurate modeling of the thermal diffusion in the complex turbulent flows related to cooling high temperature gas turbine blades is critical to optimize the performance and predict the lifetime of the blades. Magnetic Resonance Imaging (MRI) techniques for temperature measurement in simple but related flows are being developed in an effort to obtain full field thermal measurements to better understand diffusion processes and support the development of more accurate computational models in these flows. Magnetic Resonance Thermometry (MRT) utilizes the temperature dependence of the hydrogen proton resonant frequency (PRF) in water. MRT is now routinely used to measure tissue temperatures during medical procedures, and a few previous studies have made velocity and temperature measurements in turbulent pipe flows. In this study, MRT is applied to the flow of a heated single hole film cooling jet (Reynolds number 3000) inclined at 30 degrees injected into a cold developing turbulent channel flow (Reynolds number 25,000 based on bulk velocity and channel height.) The jet fluid temperature is 30 degrees Celsius above the temperature in the channel. The temperature measurements compare well to previously published results for measured passive scalar concentration in the same flow although the temperature measurements show higher uncertainties of 5--10 % of the temperature difference. Techniques for reducing this uncertainty will be presented as well as procedures for applying MRT to quantify the turbulent heat transfer coefficient in turbulent internal flows.

  6. Proceedings of the Conference on the Standardization of Safety and Performance Tests for Energetic Materials. Volume 1

    DTIC Science & Technology

    1977-09-01

    Design hanaoook, Ammunition Series, Fuzes, AMPC 70o-210, Navemoer 1969, p 10-11 7* -IL-STL-351 2:» Environmental and Performance rests for ;-uie...drains, AMPC 70o-179, January 197^, P 3-19 575 MM s«^.-^..-».. - . ■ - : - --. _--.. - iHrtiMrtM 10. R.H. Dinegar, M.S. Millican, "The

  7. Timing conditions and the magnitude of gender differences on the Mental Rotations Test.

    PubMed

    Voyer, Daniel; Rodgers, Marguerite A; McCormick, Peter A

    2004-01-01

    In two experiments, we examined the effect of timing conditions on the magnitude of gender differences in performance on the Mental Rotations Test (MRT). In Experiment 1, each of 196 females and 119 males was administered the MRT via a Microsoft PowerPoint presentation in one of five timing conditions (15, 20, 25, 30, and 40 sec). The participants were exposed to each MRT item for the period specified in the assigned timing condition. Experiment 2 was conducted to address flaws found in Experiment 1. Accordingly, each of 105 females and 105 males was individually administered the task in one of three timing conditions (15 sec, 25 sec, or unlimited duration). The results of both experiments showed that the magnitude of gender differences was similar across timing conditions when a conventional scoring method was used. An analysis of guessing behavior generally indicated that men tend to show little effect of timing conditions, whereas women's propensity to guess increases when they are given more time to respond. In general, the results supported an interpretation of gender differences on the MRT that relies on the joint operation of performance factors and level of spatial ability.

  8. Genome-Wide Profiles of Extra-cranial Malignant Rhabdoid Tumors Reveal Heterogeneity and Dysregulated Developmental Pathways | Office of Cancer Genomics

    Cancer.gov

    Malignant rhabdoid tumors (MRTs) are rare lethal tumors of childhood that most commonly occur in the kidney and brain. MRTs are driven by SMARCB1 loss, but the molecular consequences of SMARCB1 loss in extra-cranial tumors have not been comprehensively described and genomic resources for analyses of extra-cranial MRT are limited.

  9. Enhancement of Spatial Ability in Girls in a Single-Sex Environment through Spatial Experience and the Impact on Information Seeking

    ERIC Educational Resources Information Center

    Swarlis, Linda L.

    2008-01-01

    The test scores of spatial ability for women lag behind those of men in many spatial tests. On the Mental Rotations Test (MRT), a significant gender gap has existed for over 20 years and continues to exist. High spatial ability has been linked to efficiencies in typical computing tasks including Web and database searching, text editing, and…

  10. Restless Mind, Restless Body

    ERIC Educational Resources Information Center

    Seli, Paul; Carriere, Jonathan S. A.; Thomson, David R.; Cheyne, James Allan; Martens, Kaylena A. Ehgoetz; Smilek, Daniel

    2014-01-01

    In the present work, we investigate the hypothesis that failures of task-related executive control that occur during episodes of mind wandering are associated with an increase in extraneous movements (fidgeting). In 2 studies, we assessed mind wandering using thought probes while participants performed the metronome response task (MRT), which…

  11. Medical Readers' Theater: Relevance to Geriatrics Medical Education

    ERIC Educational Resources Information Center

    Shapiro, Johanna; Cho, Beverly

    2011-01-01

    Medical Readers' Theater (MRT) is an innovative and simple way of helping medical students to reflect on difficult-to-discuss topics in geriatrics medical education, such as aging stereotypes, disability and loss of independence, sexuality, assisted living, relationships with adult children, and end-of-life issues. The authors describe a required…

  12. SOLWEIG 1.0--modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings.

    PubMed

    Lindberg, Fredrik; Holmer, Björn; Thorsson, Sofia

    2008-09-01

    The mean radiant temperature, T(mrt), which sums up all shortwave and longwave radiation fluxes (both direct and reflected) to which the human body is exposed is one of the key meteorological parameters governing human energy balance and the thermal comfort of man. In this paper, a new radiation model (SOLWEIG 1.0), which simulates spatial variations of 3D radiation fluxes and T(mrt) in complex urban settings, is presented. The T(mrt) is derived by modelling shortwave and longwave radiation fluxes in six directions (upward, downward and from the four cardinal points) and angular factors. The model requires a limited number of inputs, such as direct, diffuse and global shortwave radiation, air temperature, relative humidity, urban geometry and geographical information (latitude, longitude and elevation). The model was evaluated using 7 days of integral radiation measurements at two sites with different building geometries--a large square and a small courtyard in Göteborg, Sweden (57 degrees N)--across different seasons and in various weather conditions. The evaluation reveals good agreement between modelled and measured values of T(mrt), with an overall good correspondence of R (2) = 0.94, (p < 0.01, RMSE = 4.8 K). SOLWEIG 1.0 is still under development. Future work will incorporate a vegetation scheme, as well as an improvement of the estimation of fluxes from the four cardinal points.

  13. Patients’ Effect on Nurses’ Job Satisfaction at Tripler Army Medical Center, Honolulu, Hawaii

    DTIC Science & Technology

    1991-06-01

    Emotional SUpport ( esteem , affect, trust, concern, listening). 2. Appraisal sUppOrt (affirmation, feedback, social comparison). 3. Informational sMrt...is a lot of arank consciousness’ on my unit, - Nurging nersonnel seld W mingle with others of lower rank-" Oziulative Cumulative Response scale

  14. Relationship between Spatial Abilities, Mental Rotation and Functional Anatomy Learning

    ERIC Educational Resources Information Center

    Guillot, Aymeric; Champely, Stephane; Batier, Christophe; Thiriet, Patrice; Collet, Christian

    2007-01-01

    This study investigated the relationship between visuo-spatial representation, mental rotation (MR) and functional anatomy examination results. A total of 184 students completed the Group Embedded Figures Test (GEFT), Mental Rotation Test (MRT) and Gordon Test of Visual Imagery Control. The time spent on personal assignment was also considered.…

  15. Passage rates in poultry digestion using stable isotope markers and INAA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method has been developed for the study of passage rates and mean residence times (MRT) of test rations through the gastrointestinal tracts of layer hens. The use of rare earth elements as stable indigestible markers monitored by neutron activation analysis has been previously demonstrated in num...

  16. Magnetic Resonance Thermometry at 7T for Real-Time Monitoring and Correction of Ultrasound Induced Mild Hyperthermia

    PubMed Central

    Fite, Brett Z.; Liu, Yu; Kruse, Dustin E.; Caskey, Charles F.; Walton, Jeffrey H.; Lai, Chun-Yen; Mahakian, Lisa M.; Larrat, Benoit; Dumont, Erik; Ferrara, Katherine W.

    2012-01-01

    While Magnetic Resonance Thermometry (MRT) has been extensively utilized for non-invasive temperature measurement, there is limited data on the use of high field (≥7T) scanners for this purpose. MR-guided Focused Ultrasound (MRgFUS) is a promising non-invasive method for localized hyperthermia and drug delivery. MRT based on the temperature sensitivity of the proton resonance frequency (PRF) has been implemented in both a tissue phantom and in vivo in a mouse Met-1 tumor model, using partial parallel imaging (PPI) to speed acquisition. An MRgFUS system capable of delivering a controlled 3D acoustic dose during real time MRT with proportional, integral, and derivative (PID) feedback control was developed and validated. Real-time MRT was validated in a tofu phantom with fluoroptic temperature measurements, and acoustic heating simulations were in good agreement with MR temperature maps. In an in vivo Met-1 mouse tumor, the real-time PID feedback control is capable of maintaining the desired temperature with high accuracy. We found that real time MR control of hyperthermia is feasible at high field, and k-space based PPI techniques may be implemented for increasing temporal resolution while maintaining temperature accuracy on the order of 1°C. PMID:22536396

  17. Temperature mapping of laser-induced hyperthermia in an ocular phantom using magnetic resonance thermography.

    PubMed

    Maswadi, Saher M; Dodd, Stephen J; Gao, Jia-Hong; Glickman, Randolph D

    2004-01-01

    Laser-induced heating in an ocular phantom is measured with magnetic resonance thermography (MRT) using temperature-dependent phase changes in proton resonance frequency. The ocular phantom contains a layer of melanosomes isolated from bovine retinal pigment epithelium. The phantom is heated by the 806-nm output of a continuous wave diode laser with an irradiance of 2.4 to 21.6 W/cm2 in a beam radius of 0.8 or 2.4 mm, depending on the experiment. MRT is performed with a 2 T magnet, and a two-turn, 6-cm-diam, circular radio frequency coil. Two-dimensional temperature gradients are measured within the plane of the melanin layer, as well as normal to it, with a temperature resolution of 1 degrees C or better. The temperature gradients extending within the melanin layer are broader than those orthogonal to the layer, consistent with the higher optical absorption and consequent heating in the melanin. The temperature gradients in the phantom measured by MRT closely approximate the predictions of a classical heat diffusion model. Three-dimensional temperature maps with a spatial resolution of 0.25 mm in all directions are also made. Although the temporal resolution is limited in the prototype system (22.9 s for a single image "slice"), improvements in future implementations are likely. These results indicate that MRT has sufficient spatial and temperature resolution to monitor target tissue temperature during transpupillary thermotherapy in the human eye.

  18. Synchrotron Radiation Therapy from a Medical Physics point of view

    SciTech Connect

    Prezado, Y.; Berkvens, P.; Braeuer-Krisch, E.; Renier, M.; Bravin, A.; Adam, J. F.; Martinez-Rovira, I.; Fois, G.; Thengumpallil, S.; Edouard, M.; Deman, P.; Vautrin, M.

    2010-07-23

    Synchrotron radiation (SR) therapy is a promising alternative to treat brain tumors, whose management is limited due to the high morbidity of the surrounding healthy tissues. Several approaches are being explored by using SR at the European Synchrotron Radiation Facility (ESRF), where three techniques are under development Synchrotron Stereotactic Radiation Therapy (SSRT), Microbeam Radiation Therapy (MRT) and Minibeam Radiation Therapy (MBRT).The sucess of the preclinical studies on SSRT and MRT has paved the way to clinical trials currently in preparation at the ESRF. With this aim, different dosimetric aspects from both theoretical and experimental points of view have been assessed. In particular, the definition of safe irradiation protocols, the beam energy providing the best balance between tumor treatment and healthy tissue sparing in MRT and MBRT, the special dosimetric considerations for small field dosimetry, etc will be described. In addition, for the clinical trials, the definition of appropiate dosimetry protocols for patients according to the well established European Medical Physics recommendations will be discussed. Finally, the state of the art of the MBRT technical developments at the ESRF will be presented. In 2006 A. Dilmanian and collaborators proposed the use of thicker microbeams (0.36-0.68 mm). This new type of radiotherapy is the most recently implemented technique at the ESRF and it has been called MBRT. The main advantage of MBRT with respect to MRT is that it does not require high dose rates. Therefore it can be more easily applied and extended outside synchrotron sources in the future.

  19. Factor Structure and Validation of a Set of Readiness Measures.

    ERIC Educational Resources Information Center

    Kaufman, Maurice; Lynch, Mervin

    A study was undertaken to identify the factor structure of a battery of readiness measures and to demonstrate the concurrent and predictive validity of one instrument in that battery--the Pre-Reading Screening Procedures (PSP). Concurrent validity was determined by examining the correlation of the PSP with the Metropolitan Readiness Test (MRT),…

  20. Leaf-level nitrogen use efficiency: definition and importance.

    PubMed

    Hirose, Tadaki

    2012-07-01

    Nitrogen use efficiency (NUE) has been widely used to study the relationship between nitrogen uptake and dry mass production in the plant. As a subsystem of plant nitrogen use efficiency (NUE), I have defined leaf-level NUE as the surplus production (gross production minus leaf respiration) per unit amount of nitrogen allocated to the leaf, with factorization into leaf nitrogen productivity (NP) and mean residence time of leaf nitrogen (MRT). These concepts were applied to two herbaceous stands: a perennial Solidago altissima stand and an annual Amaranthus patulus stand. S. altissima had more than three times higher leaf NUE than A. patulus due to nearly three times longer MRT of leaf N. In both species, NUE and NP were higher at the leaf level than at the plant level, because most leaf N is involved directly in the photosynthetic activity and because leaf surplus production is higher than the plant net production. MRT was longer at the plant level. The more than twice as long MRT at the plant level as at the leaf level in S. altissima was due to a large contribution of nitrogen storage belowground in the winter in this species. Thus, comparisons between a perennial and an annual system and between plant- and leaf-level NUE with their components revealed the importance of N allocation, storage, recycling, and turnover of organs for leaf photosynthetic production and plant dry mass growth.

  1. Nitrogen use efficiency revisited.

    PubMed

    Hirose, Tadaki

    2011-08-01

    Nitrogen use efficiency (NUE) was originally defined as the dry mass productivity per unit N taken up from soil. The term was subsequently redefined as the product of nitrogen productivity (NP) and mean residence time of nitrogen (MRT). However, this redefinition was found to contradict the original definition under certain conditions, and confusion arose when the MRT defined for a steady-state system was applied to a system that was actually not at steady state. As MRT is the expected length of time that a unit of N newly taken up from soil is retained before being lost, it can be translated into the plant nitrogen duration (PND) divided by the total N uptake. This MRT is determined equally well for a steady state- and a non-steady state system and is in accordance with the original definition of NUE. It can be applied to a herbaceous perennial stand (that was at a steady state) and to an annual stand (that was not at a steady state) to determine NUE. NUE is also applicable when plant growth and reproduction are analyzed in relation to N use.

  2. Effects of white noise on Callsign Acquisition Test and Modified Rhyme Test scores.

    PubMed

    Blue-Terry, Misty; Letowski, Tomasz

    2011-02-01

    The Callsign Acquisition Test (CAT) is a speech intelligibility test developed by the US Army Research Laboratory. The test has been used to evaluate speech transmission through various communication systems but has not been yet sufficiently standardised and validated. The aim of this study was to compare CAT and Modified Rhyme Test (MRT) performance in the presence of white noise across a range of signal-to-noise ratios (SNRs). A group of 16 normal-hearing listeners participated in the study. The speech items were presented at 65 dB(A) in the background of white noise at SNRs of -18, -15, -12, -9 and -6 dB. The results showed a strong positive association (75.14%) between the two tests, but significant differences between the CAT and MRT absolute scores in the range of investigated SNRs. Based on the data, a function to predict CAT scores based on existing MRT scores and vice versa was formulated. STATEMENT OF RELEVANCE: This work compares performance data of a common speech intelligibility test (MRT) with a new test (CAT) in the presence of white noise. The results here can be used as a part of the standardisation procedures and provide insights to the predictive capabilities of the CAT to quantify speech intelligibility communication in high-noise military environments.

  3. Early and Late Inhibitions Elicited by a Peripheral Visual Cue on Manual Response to a Visual Target: Are They Based on Cartesian Coordinates?

    ERIC Educational Resources Information Center

    Gawryszewski, Luiz G.; Carreiro, Luiz Renato R.; Magalhaes, Fabio V.

    2005-01-01

    A non-informative cue (C) elicits an inhibition of manual reaction time (MRT) to a visual target (T). We report an experiment to examine if the spatial distribution of this inhibitory effect follows Polar or Cartesian coordinate systems. C appeared at one out of 8 isoeccentric (7[degrees]) positions, the C-T angular distances (in polar…

  4. Multi-rate time stepping schemes for hydro-geomechanical model for subsurface methane hydrate reservoirs

    NASA Astrophysics Data System (ADS)

    Gupta, Shubhangi; Wohlmuth, Barbara; Helmig, Rainer

    2016-05-01

    We present an extrapolation-based semi-implicit multi-rate time stepping (MRT) scheme and a compound-fast MRT scheme for a naturally partitioned, multi-time-scale hydro-geomechanical hydrate reservoir model. We evaluate the performance of the two MRT methods compared to an iteratively coupled solution scheme and discuss their advantages and disadvantages. The performance of the two MRT methods is evaluated in terms of speed-up and accuracy by comparison to an iteratively coupled solution scheme. We observe that the extrapolation-based semi-implicit method gives a higher speed-up but is strongly dependent on the relative time scales of the latent (slow) and active (fast) components. On the other hand, the compound-fast method is more robust and less sensitive to the relative time scales, but gives lower speed up as compared to the semi-implicit method, especially when the relative time scales of the active and latent components are comparable.

  5. A Phase II, Multicenter Study of the EZH2 Inhibitor Tazemetostat in Adult Subjects With INI1-Negative Tumors or Relapsed/Refractory Synovial Sarcoma

    ClinicalTrials.gov

    2017-01-17

    Malignant Rhabdoid Tumors (MRT); Rhabdoid Tumors of the Kidney (RTK); Atypical Teratoid Rhabdoid Tumors (ATRT); Selected Tumors With Rhabdoid Features; Synovial Sarcoma; INI1-negative Tumors; Malignant Rhabdoid Tumor of Ovary; Renal Medullary Carcinoma; Epithelioid Sarcoma; Any Solid Tumor With an EZH2 GOF Mutation

  6. Contribution of different segments of the gastrointestinal tract to digestion in growing Saanen goats.

    PubMed

    Leite, R F; Krizsan, S J; Figueiredo, F O M; Carvalho, V B; Teixeira, I A M A; Huhtanen, P

    2015-04-01

    This study examined mean retention time (MRT) of particulate and liquid matter in different segments of the gastrointestinal tract (GIT) of growing Saanen goats of different sexes and subjected to different levels of feed restriction. In addition, feeding behavior and total tract digestibility were determined for all animals ahead of slaughter. In total, 54 Saanen goats (18 each of females, castrated males, and intact males) with initial BW 15.3 ± 0.4 kg were used in a 3 × 3 factorial arrangement comprising the 3 sexes and 3 levels of feed restriction (unrestricted/ad libitum, moderate, and severe restriction). Six blocks per sex group, each consisting of 3 goats, were randomly formed and the goats within each block were randomly allocated to 1 of 3 different feed restrictions. The daily amounts of feed offered to animals subjected to moderate and severe feed restriction (approximately 75% and 50% of ad libitum rate, respectively) were determined within block based on the DMI by ad libitum fed goats on the previous day. The MRT of particulate matter was determined either using Yb-labeled diet or indigestible NDF (iNDF) determined in situ as markers. Mean retention time of the liquid phase was determined by Cr-EDTA. Orthogonal polynomial contrasts were used to determine linear and quadratic effect of feed restriction, while the effect of sex was compared by Tukey test. The effects of sex and the interaction between sex and feed restriction were not significant on most of variables evaluated. Eating, ruminating, and total chewing time per g DM and NDF intake increased linearly as feed restriction increased (P ≤ 0.03). Diet digestibility increased quadratically for DM and OM, and linearly for NDF as feed intake decreased (P ≤ 0.03). The MRT of iNDF in the reticulorumen, omasum, abomasum, colon, and total GIT increased linearly with increased feed restriction (P ≤ 0.01). Mean retention time in the cecum varied quadratically, being greatest for animals with

  7. A comparison of three different physiotherapy modalities used in the physiotherapy of burns.

    PubMed

    Sar, Zübeyir; Polat, Mine Gülden; Özgül, Bahar; Aydoğdu, Onur; Camcoğlu, Burcu; Acar, Ahmet Hakan; Yurdalan, Saadet Ufuk

    2013-01-01

    The present study compared the effectiveness of matrix rhythm therapy, ultrasound treatment (UT), laser treatment (LT) used in the physiotherapy of burns. The study was conducted at the Wound and Burn Healing Center, Dr. Lütfi Kırdar Kartal Education and Research Hospital (Turkey) from June 2009 to January 2012. The case series comprised 39 individuals with second- and third-degree upper-limb burns, whose burn traumas ended approximately 1 to 3 months previously. Participants were separated into three groups: matrix rhythm treatment (MRT), UT and LT; each group was also applied a treatment protocol including whirlpool and exercise. Pain, range of motion (ROM), muscular strength, skin elasticity, and sensory functions were evaluated before and after the treatment. Pressure sense and passive ROM were higher in the MRT group than in the LT group (P < .05). Pain was lower in the LT group than in the UT group, and passive ROM was higher in the UT group than the in LT group (P < .05). Active ROM was found to increase in all treatment groups, whereas passive ROM increased only in the MRT and UT groups; pressure sense increased only in the MRT group, and pain decreased only in the LT group (P < .05). MRT was found to be more effective in the restoration of sensory functions than LT, whereas LT was more effective in reducing pain than UT. No significant difference was observed in terms of skin elasticity according to the results of three treatment modalities. It is suggested that further research with more cases should be conducted to examine the long-term effect of treatment modalities.

  8. Solute and particle retention in a small grazing antelope, the blackbuck (Antilope cervicapra).

    PubMed

    Hummel, Jürgen; Hammer, Sven; Hammer, Catrin; Ruf, Julia; Lechenne, Monique; Clauss, Marcus

    2015-04-01

    Digesta retention patterns have been suggested to play a major role in ruminant diversification. Two major digestion types have been proposed, termed 'cattle-type' and 'moose-type', that broadly correspond to the feeding categories of grazers and intermediate feeders on the one, and browsers on the other hand. We measured and calculated the mean retention time (MRT) of a solute and a particle (<2 mm) marker in the gastrointestinal tract (GIT) and the reticulorumen (RR) of a small grazer, the Indian blackbuck (Antilope cervicapra, n=5, body mass of 26±4 kg) and an intermediate feeder, the nilgai (Boselaphus tragocamelus, n=5, body mass of 168±21 kg). MRT(solute) and MRT(particle) were 29±4.1 h and 60±6.6 h in blackbuck and 28±2.5 h and 54±8.9 h in the nilgai for the GIT, and 14±1.7 h, 45±5.0 h, 19±2.0 h and 45±8.4 h for the RR, respectively. With a selectivity factor (SF, the ratio of MRT(particle) to MRT(solute)) in the RR of 3.2±0.28 for blackbuck and 2.3±0.36 for nilgai, both species are clearly in the category of 'cattle-type' ruminants. In particular, the high SFRR of blackbuck, in spite of its small body size, is remarkable, and leads to specific predictions on the RR anatomy of this species (such as a particularly large omasum), which can be tested in further studies. The adaptive value of a high SFRR is mainly considered as an increase in microbial productivity in the RR.

  9. Proton microbeam radiotherapy with scanned pencil-beams--Monte Carlo simulations.

    PubMed

    Kłodowska, M; Olko, P; Waligórski, M P R

    2015-09-01

    Irradiation, delivered by a synchrotron facility, using a set of highly collimated, narrow and parallel photon beams spaced by 1 mm or less, has been termed Microbeam Radiation Therapy (MRT). The tolerance of healthy tissue after MRT was found to be better than after standard broad X-ray beams, together with a more pronounced response of malignant tissue. The microbeam spacing and transverse peak-to-valley dose ratio (PVDR) are considered to be relevant biological MRT parameters. We investigated the MRT concept for proton microbeams, where we expected different depth-dose profiles and PVDR dependences, resulting in skin sparing and homogeneous dose distributions at larger beam depths, due to differences between interactions of proton and photon beams in tissue. Using the FLUKA Monte Carlo code we simulated PVDR distributions for differently spaced 0.1 mm (sigma) pencil-beams of entrance energies 60, 80, 100 and 120 MeV irradiating a cylindrical water phantom with and without a bone layer, representing human head. We calculated PVDR distributions and evaluated uniformity of target irradiation at distal beam ranges of 60-120 MeV microbeams. We also calculated PVDR distributions for a 60 MeV spread-out Bragg peak microbeam configuration. Application of optimised proton MRT in terms of spot size, pencil-beam distribution, entrance beam energy, multiport irradiation, combined with relevant radiobiological investigations, could pave the way for hypofractionation scenarios where tissue sparing at the entrance, better malignant tissue response and better dose conformity of target volume irradiation could be achieved, compared with present proton beam radiotherapy configurations.

  10. Comparison of two methods for measuring γ-H2AX nuclear fluorescence as a marker of DNA damage in cultured human cells: applications for microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Anderson, D.; Andrais, B.; Mirzayans, R.; Siegbahn, E. A.; Fallone, B. G.; Warkentin, B.

    2013-06-01

    Microbeam radiation therapy (MRT) delivers single fractions of very high doses of synchrotron x-rays using arrays of microbeams. In animal experiments, MRT has achieved higher tumour control and less normal tissue toxicity compared to single-fraction broad beam irradiations of much lower dose. The mechanism behind the normal tissue sparing of MRT has yet to be fully explained. An accurate method for evaluating DNA damage, such as the γ-H2AX immunofluorescence assay, will be important for understanding the role of cellular communication in the radiobiological response of normal and cancerous cell types to MRT. We compare two methods of quantifying γ-H2AX nuclear fluorescence for uniformly irradiated cell cultures: manual counting of γ-H2AX foci by eye, and an automated, MATLAB-based fluorescence intensity measurement. We also demonstrate the automated analysis of cell cultures irradiated with an array of microbeams. In addition to offering a relatively high dynamic range of γ-H2AX signal versus irradiation dose ( > 10 Gy), our automated method provides speed, robustness, and objectivity when examining a series of images. Our in-house analysis facilitates the automated extraction of the spatial distribution of the γ-H2AX intensity with respect to the microbeam array — for example, the intensities in the peak (high dose area) and valley (area between two microbeams) regions. The automated analysis is particularly beneficial when processing a large number of samples, as is needed to systematically study the relationship between the numerous dosimetric and geometric parameters involved with MRT (e.g., microbeam width, microbeam spacing, microbeam array dimensions, peak dose, valley dose, and geometric arrangement of multiple arrays) and the resulting DNA damage.

  11. Influence of ruminal methane on digesta retention and digestive physiology in non-lactating dairy cattle.

    PubMed

    Dittmann, Marie T; Hammond, Kirsty J; Kirton, Paul; Humphries, David J; Crompton, Les A; Ortmann, Sylvia; Misselbrook, Tom H; Südekum, Karl-Heinz; Schwarm, Angela; Kreuzer, Michael; Reynolds, Christopher K; Clauss, Marcus

    2016-09-01

    Enteric methane (CH4) production is a side-effect of herbivore digestion, but it is unknown whether CH4 itself influences digestive physiology. We investigated the effect of adding CH4 to, or reducing it in, the reticulorumen (RR) in a 4×4 Latin square experiment with rumen-fistulated, non-lactating cows, with four treatments: (i) control, (ii) insufflation of CH4 (iCH4), (iii) N via rumen fistula, (iv) reduction of CH4 via administration of bromochloromethane (BCM). DM intake (DMI), apparent total tract digestibility, digesta mean retention times (MRT), rumen motility and chewing activity, spot breath CH4 emission (CH4exhal, litre/kg DMI) as well as CH4 dissolved in rumen fluid (CH4RRf, µg/ml) were measured. Data were analysed using mixed models, including treatment (or, alternatively, CH4exhal or CH4RRf) and DMI relative to body mass0·85 (rDMI) as covariates. rDMI was the lowest on the BCM treatment. CH4exhal was highest for iCH4 and lowest for BCM treatments, whereas only BCM affected (reduced) CH4RRf. After adjusting for rDMI, CH4RRf had a negative association with MRT in the gastrointestinal tract but not in the RR, and negative associations with fibre digestibility and measures of rumination activity. Adjusting for rDMI, CH4exhal had additionally a negative association with particle MRT in the RR and a positive association with rumen motility. Thus, higher rumen levels of CH4 (CH4exhal or CH4RRf) were associated with shorter MRT and increased motility. These findings are tentatively interpreted as a feedback mechanism in the ruminant digestive tract that aims at mitigating CH4 losses by shortening MRT at higher CH4.

  12. Heterogeneity of Monosymptomatic Resting Tremor in a Prospective Study: Clinical Features, Electrophysiological Test, and Dopamine Transporter Positron Emission Tomography

    PubMed Central

    Zheng, Hua-Guang; Zhang, Rong; Li, Xin; Li, Fang-Fei; Wang, Ya-Chen; Wang, Xue-Mei; Lu, Ling-Long; Feng, Tao

    2015-01-01

    Background: The relationship between monosymptomatic resting tremor (mRT) and Parkinson's disease (PD) remains controversial. In this study, we aimed to assess the function of presynaptic dopaminergic neurons in patients with mRT by dopamine transporter positron emission tomography (DAT-PET) and to evaluate the utility of clinical features or electrophysiological studies in differential diagnosis. Methods: Thirty-three consecutive patients with mRT were enrolled prospectively. The Unified Parkinson's Disease Rating Scale and electromyography were tested before DAT-PET. Striatal asymmetry index (SAI) was calculated, and a normal DAT-PET was defined as a SAI of <15%. Scans without evidence of dopaminergic deficits (SWEDDs) were diagnosed in patients with a subsequent normal DAT-PET and structural magnetic resonance imaging. Results: Twenty-eight mRT patients with a significant reduction in uptake of DAT binding in the striatum were diagnosed with PD, while the remained 5 with a normal DAT-PET scan were SWEDDs. As for UPRDS, the dressing and hygiene score, walking in motor experiences of daily living (Part II) and motor examination (Part III) were significant different between two groups (P < 0.05 and P < 0.01, respectively). Bilateral tremor was more frequent in the SWEDDs group (P < 0.05). The frequency of resting tremor and the amplitude of postural tremor tend to be higher in the SWEDDs group (P = 0.08 and P = 0.05, respectively). Conclusions: mRT is heterogeneous in presynaptic nigrostriatal dopaminergic degeneration, which can be determined by DAT-PET brain imaging. Clinical and electrophysiological features may provide clues to distinguish PD from SWEDDs. PMID:26112718

  13. Impact of fibre intake and fibre source on digestibility, gut development, retention time and growth performance of indigenous and exotic pigs.

    PubMed

    Ngoc, T T B; Len, N T; Lindberg, J E

    2013-05-01

    The impact of fibre level and fibre source on digestibility, gastrointestinal tract (GIT) development, total tract mean retention time (MRT) and growth performance was studied in indigenous Mong Cai (MC) and exotic Landrace × Yorkshire (LY) pigs. The diets were based on maize, rice bran, soyabean meal, fish meal and soyabean oil, and cassava residue (CR) or brewer's grain (BG) as fibrous ingredient sources in the high-fibre diets (HF) and were fed ad libitum. A low-fibre diet (LF), containing around 200 g NDF/kg dry matter (DM), was formulated without CR and BG as feed ingredients. The HF diets (HF-CR and HF-BG) were formulated to contain around 270 g NDF/kg DM. The experiment was arranged as a 2 × 3 factorial completely randomized design with six replications, and lasted 27 days. Increased dietary fibre level resulted in a reduction (P < 0.05) in average daily gain, digestibility of organic matter (OM), CP and gross energy (GE) at the ileum and in the total tract, and in MRT, and an increase (P < 0.05) in the feed conversion ratio and in the weight of the GIT (except for small intestine and caecum). The coefficients of total tract digestibility of fibre fractions were higher in HF diets than in the LF diet, with highest values for diet HF-CR, which had a high proportion of soluble non-starch polysaccharides. MC pigs had longer MRT of digesta than LY pigs (P < 0.05), resulting in higher digestibility at the ileum and in the total tract. Across diets and breeds, the total tract apparent digestibility of OM, CP and GE was positively related (R 2 = 0.80 to 0.84) to the MRT of solids, whereas the MRT was negatively related to the DM intake (R 2 = 0.60).

  14. Transit times of baseflow in New Zealand rivers

    NASA Astrophysics Data System (ADS)

    Morgenstern, Uwe; Stewart, Mike; Daughney, Chris; Townsend, Dougal

    2015-04-01

    Water quantity and quality responses of catchments to climate and land-use changes are difficult to understand and predict due to complexities of subsurface water flow paths and potentially large groundwater stores. It is difficult to relate the hydrologic responses of catchments to measurable catchment properties. Tritium is ideally suited to provide a measurable parameter of hydrologic response. Tritium, a component of meteoric water, decays with a half-life of 12.32 years after the water enters the groundwater system, and can therefore provide information on transit time of water through the groundwater system over the time range 0 to 200 years mean residence time (MRT). Transit time of the water discharge is one of the most crucial parameters for understanding the response of catchments. In recent years it has become possible to use tritium in a straightforward way for dating of stream and river water due to the decay of the bomb-tritium from atmospheric thermo-nuclear weapons testing, and to improved measurement accuracy for the extremely low natural tritium concentrations. Tritium dating of river water during baseflow conditions from over 120 sites throughout New Zealand show consistent patterns and a good correlation between geology and residence times of the water discharges. Basement rock catchments (greywacke, schist) have very young water of MRT less than 1year, sand-, mud-, limestone catchments have moderately old water of MRT 3-15 years, and porous ignimbrite catchments have very old water of MRT greater than 100 years. For example, the tritium data indicate MRT of 6 - 7 years in the Whanganui River, 3 - 3.5 years in the Rangitikei River, and 9 - 11 years in the large discharges from the Tertiary sediments in the Manawatu catchment. The discharges from the greywacke Ruahine and Tararua Ranges contain very young water with MRT of 0 - 2 years. Associated groundwater stores for the Rangitikei, Manawatu, and Whanganui Rivers are 1, 2, and 5 x 109 m3 of

  15. Do different medical curricula influence self-assessed clinical thinking of students?

    PubMed

    Gehlhar, Kirsten; Klimke-Jung, Kathrin; Stosch, Christoph; Fischer, Martin R

    2014-01-01

    Zielsetzung: Das klinische Denken ist eine zentrale Grundlage des ärztlichen Handelns und sollte durch das Studium in den humanmedizinischen Studiengängen gefördert werden. Welche Lehr- und Lernformen hierzu vor allem beitragen, ist bis heute allerdings noch nicht abschließend gezeigt. Zur Messung der wissensunabhängigen Komponente des klinischen Denkens wurde das Diagnostic Thinking Inventory (DTI) entwickelt. Die vorliegende Pilotstudie untersucht, ob dieses Instrument dazu geeignet ist, Unterschiede im klinischen Denken von Studierenden in unterschiedlichen Ausbildungsabschnitten dreier medizinischer Curricula aufzuzeigen. Methodik: Das Diagnostic Thinking Inventory (DTI) umfasst 41 Items in zwei Subskalen („Flexibilität des Denkens“ und „Strukturierung des Wissens“). Jedes Item enthält eine Aussage oder Feststellung über das klinische Denken in Form eines Stammes und darunter jeweils eine 6-Punkt-Skala an deren beiden Enden gegensätzliche Aussagen stehen. Zwischen diesen beiden Extremen sollen die Probanden ihr eigenes klinisches Denken einordnen. Die deutsche Übersetzung des DTI wurde von 247 freiwilligen Studierenden aus drei Fakultäten und verschiedenen klinischen Semestern ausgefüllt. In einem quasi experimentellen Design waren 219 Teilnehmer aus Regel- und Modellstudiengängen in Nordrheinwestfalen beteiligt, genauer aus dem 5., 6. und 8. Semester des Modellstudiengangs der Universität Witten/Herdecke (UW/H), aus dem Modell- (7. und 9. Semester) und Regelstudiengang (7. Semester) der Ruhr-Universität Bochum (RUB) und aus dem Modellstudiengang (9. Semester) der Universität zu Köln (UzK). Die gewonnenen Daten wurden quantitativ ausgewertet.Ergebnisse: Die Reliabilität des Gesamt-Fragebogens war gut (Cronbachs alpha zwischen 0,71 und 0,83); die Reliabilität der Subskalen lag zwischen 0,49 und 0,75. Die unterschiedlichen Gruppen wurden mittels Mann-Whitney Test miteinander verglichen. Dabei wurden signifikante Unterschiede sowohl

  16. Reduktion der Invasivität bei nadelbasierter Bewegungskompensation für navigierte Eingriffe im Abdomen

    NASA Astrophysics Data System (ADS)

    Maier-Hein, L.; Tekbas, A.; Franz, A. M.; Tetzlaff, R.; Müller, S. A.; Pianka, F.; Wolf, I.; Kauczor, H.-U.; Schmied, B. M.; Meinzer, H.-P.

    Diese Arbeit stellt eine in-vivo Genauigkeitsstudie über das Kombinieren interner und externer Marker für die Bewegungskompensation bei Leberinterventionen vor. Abhängig von der Anzahl und Anordnung der verwendeten Marker sowie der angewandten Echtzeittransformation wurde bei kontinuierlicher Atmung eine Schätzgenauigkeit der Zielposition zwischen 1 und 5 mm erreicht. Das Hinzufügen einer einzigen Hilfsnadel zu einer Menge von Hautmarkern führte zu einer Fehlerreduktion von über 50%. Die Ergebnisse dieser Studie können in der Praxis verwendet werden, um basierend auf dem Tradeoff zwischen geringer Invasivität und hoher Genauigkeit eine geeignete Kombination von internen und externen Markern für eine gegebene Fragestellung zu wählen.

  17. The Analytical Exponential Decay Coefficient of the Submarine Light Field.

    DTIC Science & Technology

    1986-01-01

    fundamental optical terms is required. An exact expression can be derived from Schellenberger 14 which is Kd = (a/p)(l - R) + RK (10) UU where R is...Bingham Oceanogr. Coll. 15, 15 (1956). -, 33 *1% * .~.., 5-. .;.~.*4(5%~Ilk 10. G. Schellenberger , "Uber Zusammenhange Zwischen Optischen Parametern Von...Oceanogr. 20, 976 (1975). 14. G. Schellenberger , "Die Form der Raumlichen Strahlungsver- teilung in Gewassern", Acta Hydrophys. 14, 207 (1969). 15. A

  18. Toolmanagement - Werkzeuge und Prozesse als Schlüssel für eine effiziente Produktion

    NASA Astrophysics Data System (ADS)

    Enßle, Magnus

    In Bezug auf die Fertigungskosten nehmen die Werkzeugkosten mit 3% einen sehr kleinen und daher vermeintlich unwichtigen Posten ein. HoheKosten ergeben sich aber meist indirekt durch Maschinenstillstandszeiten wegen fehlender oder falscher Werkzeuge, wegen ineffektiven Rüstvorgängen, umständlicher Werkzeuglogistik, unnötig hoher Bestände, unabgestimmter Abläufe, nicht aktueller Fertigungsunterlagen sowie mangelhafter Informationsflüsse zwischen Planung, Vorbereitung und Ausführung in der Fertigung [1].

  19. Ein Framework für echtzeitfähige Ethernet-Netzwerke

    NASA Astrophysics Data System (ADS)

    Dopatka, Frank

    Im Rahmen dieser Arbeit wird die Entwicklung eines formalen Framewoks vorgestellt, mit dessen Hilfe zwischen der Kompatibilität zum verbreiteten baumförmigen Standard-Ethernet und der Einhaltung von Echtzeitanforderungen einer automatisierten Anlage variiert werden kann. Damit kann bereits vor der Auswahl einer bestimmten Technologie eine Schedule der Echtzeit-Übertragungen offline kalkuliert und simuliert werden, sobald die Anforderungen der Geräte im industriellen Echtzeit-Netzwerk bekannt sind.

  20. Ökonometrie

    NASA Astrophysics Data System (ADS)

    Frohn, Joachim

    Die Ökonometrie, als eine Wissenschaft auf der Schnittstelle zwischen Mathematik, Statistik und den Wirtschaftswissenschaften, ist auch in der Deutschen Statistischen Gesellschaft (DStatG) zu einer tragenden Säule geworden. Das vorliegende Kapitel gibt einen kurzen Überblick über die Entwicklung der wichtigsten Gebiete der Ökonometrie und die Arbeit im "Ausschuss für Empirische Wirtschaftsforschung und Angewandte Ökonometrie".

  1. Analyse der Störfestigkeit nichtlinearer Schaltungen gegenüber leitungsgebundenen elektromagnetischen Störungen mit multi-input Wiener/Hammerstein-Modellen

    NASA Astrophysics Data System (ADS)

    Stegemann, S.; John, W.; Mathis, W.

    2012-09-01

    In dieser Arbeit wird der Einfluss von leitungsgebundenen Störungen untersucht, welche in einen beliebigen Eingang (Signaleingang, Spannungsversorgung, Masse-Potenzial, etc.) einer Analogschaltung einkoppeln. Die zu untersuchende Schaltung wird dazu durch einen Wiener/Hammerstein-Ansatz als nichtlineares System mit zwei Eingängen modelliert. Mit Hilfe dieses Blockmodells werden analytische Ausdrücke derjenigen Frequenzanteile bestimmt, die durch Intermodulationen zwischen Stör- und Eingangssignal am Ausgang einer Schaltung entstehen.

  2. Die Arbeitsunfähigkeit in der Statistik der GKV

    NASA Astrophysics Data System (ADS)

    Busch, Klaus

    Der vorliegende Beitrag gibt anhand der Statistiken des Bundesministeriums für Gesundheit (BMG) einen Überblick über die Arbeitsunfähigkeitsdaten der Gesetzlichen Krankenkassen (GKV). Zunächst werden die Arbeitsunfähigkeitsstatistiken der Krankenkassen und die Erfassung der Arbeitsunfähigkeit erläutert. Hiernach wird auf die Entwicklung der Fehlzeiten auf GKV-Ebene eingegangen. Ebenfalls wird Bezug auf die Unterschiede der Fehlzeiten zwischen den verschiedenen Kassen genommen.

  3. Internet Economics IV

    DTIC Science & Technology

    2004-08-01

    B2C Mit B2C, also Business to Consumer (oft auch als Business to Customer bezeich- net) sind Geschaftsbeziehungen zwischen einem gewerblichen Partner...support and do business . Starting the talks, a view onto techniques of a public key infrastructure is presented. It is discussed with respect to its...Those key business -enabling prerequisites and mechanisms are defined, their main characteristics are outlined, and practical examples are presented

  4. [Association of peer victimization, coping, and pathological internet use among adolescents].

    PubMed

    Strittmatter, Esther; Brunner, Romuald; Fischer, Gloria; Parzer, Peter; Resch, Franz; Kaess, Michael

    2014-03-01

    Fragestellung: In der vorliegenden Studie wurde untersucht, ob ein Zusammenhang zwischen pathologischem Internetgebrauch, Mobbing und Copingstilen bei Jugendlichen mit Mobbingerfahrungen besteht. Methodik: Im Rahmen einer europäischen schulbasierten Studie (SEYLE) wurde eine repräsentative Querschnittsuntersuchung an 1357 Schülern aus Heidelberg und Umgebung durchgeführt (710 weibliche/647 männlich Jugendliche; mittleres Alter 14.7; SD 0.8). Pathologischer Internetgebrauch wurde mit dem Young Diagnostic Questionnaire erhoben. Mobbing wurde in verbales, körperliches Mobbing und Mobbing in der Beziehung unterteilt. Hinsichtlich der Copingstile wurden aktives Coping, Vermeidung, Hilfe suchen und sonstige Strategien unterschieden. Als Kovariate wurde die psychische Symptombelastung mittels Strengths and Difficulties Questionnaire erfasst. Ergebnisse: 4.8 % der Schüler wiesen einen pathologischen Internetgebrauch auf, 14.4 % zeigten einen problematischen Internetgebrauch. Insgesamt berichteten 52.3 % der Jugendlichen über Erfahrungen mit Mobbing (38.7 % verbales Mobbing, 19.8 % körperliches Mobbing, 34.1 % Mobbing in der Beziehung). Es bestand ein signifikanter Zusammenhang von Mobbingerfahrungen und pathologischem Internetgebrauch, der zum Teil durch die psychische Symptombelastung erklärt werden konnte. Hinsichtlich der Copingstile bei stattgefundenem Mobbing bestand kein signifikanter Unterschied zwischen Schülern mit normalem, problematischem und pathologischem Internetgebrauch. Schlussfolgerungen: Aufgrund des Zusammenhanges zwischen Mobbing, psychischer Symptombelastung und pathologischem Internetgebrauch sind in der Zukunft schulbasierte sowie familienbezogene Präventionsmaßnahmen und evaluierte Therapieprogramme erforderlich.

  5. Optimization of integrated impeller mixer via radiotracer experiments.

    PubMed

    Othman, N; Kamarudin, S K; Takriff, M S; Rosli, M I; Engku Chik, E M F; Adnan, M A K

    2014-01-01

    Radiotracer experiments are carried out in order to determine the mean residence time (MRT) as well as percentage of dead zone, V dead (%), in an integrated mixer consisting of Rushton and pitched blade turbine (PBT). Conventionally, optimization was performed by varying one parameter and others were held constant (OFAT) which lead to enormous number of experiments. Thus, in this study, a 4-factor 3-level Taguchi L9 orthogonal array was introduced to obtain an accurate optimization of mixing efficiency with minimal number of experiments. This paper describes the optimal conditions of four process parameters, namely, impeller speed, impeller clearance, type of impeller, and sampling time, in obtaining MRT and V dead (%) using radiotracer experiments. The optimum conditions for the experiments were 100 rpm impeller speed, 50 mm impeller clearance, Type A mixer, and 900 s sampling time to reach optimization.

  6. Implicit versus explicit momentum relaxation time solution for semiconductor nanowires

    SciTech Connect

    Marin, E. G. Ruiz, F. G. Godoy, A. Tienda-Luna, I. M.; Gámiz, F.

    2015-07-14

    We discuss the necessity of the exact implicit Momentum Relaxation Time (MRT) solution of the Boltzmann transport equation in order to achieve reliable carrier mobility results in semiconductor nanowires. Firstly, the implicit solution for a 1D electron gas with a isotropic bandstructure is presented resulting in the formulation of a simple matrix system. Using this solution as a reference, the explicit approach is demonstrated to be inaccurate for the calculation of inelastic anisotropic mechanisms such as polar optical phonons, characteristic of III-V materials. Its validity for elastic and isotropic mechanisms is also evaluated. Finally, the implications of the MRT explicit approach inaccuracies on the total mobility of Si and III-V NWs are studied.

  7. Monitoring of Brucella reactor does following milk examination using different techniques.

    PubMed

    el-Razik, K A Abd; Ghazi, Y A; Salama, E M

    2007-01-15

    Milk samples from 129 does were collected and monitored for Brucella antibodies using immunological tests such as Milk Ring Test (MRT), Whey Agglutination Test (WAT), Whey Antiglobulin Coombs Test (WCT) and milk ELISA (m ELISA) using Brucella Periplasmic protein antigen. Results obtained from these tests were compared to PCR and bacterial isolation. The highest incidence of positive reactors was given by Whey Antiglobulin and Whey Agglutination Test (9.3%) while the lowest incidence was given by bacterial isolation (Br. melitensis biovars 3, 3.8%). PCR showed the highest agreement with the bacterial isolation, while WAT and WCT showed the lowest one. PCR showed a high sensitivity of 1 x 10 B. melitensis CFU mL(-1) of milk. The results of mELISA here suggests its efficiency to be used as a screening test and/or confirmatory test, while the modified MRT still need more investigations to diagnosis caprine brucellosis.

  8. Multi-strip silicon sensors for beam array monitoring in micro-beam radiation therapy.

    PubMed

    Alagoz, E; Brauer-Krisch, E; Bravin, A; Cornelius, I; Fournier, P; Hansen, T E; Kok, A; Lerch, M; Monakhov, E; Morse, J; Pacifico, N; Petasecca, M; Povoli, M; Requard, H; Rozenfeld, A D; Salome, M; Sandaker, H; Stugu, B

    2016-12-01

    We present here the latest results from tests performed at the ESRF ID17 and ID21 beamlines for the characterization of novel beam monitors for Microbeam Radiation Therapy (MRT), which is currently being implemented at ID17. MRT aims at treating solid tumors by exploiting an array of evenly spaced microbeams, having an energy spectrum distributed between 27 and 600keV and peaking at 100keV. Given the high instantaneous dose delivered (up to 20kGy/s), the position and the intensity of the microbeams has to be precisely and instantly monitored. For this purpose, we developed dedicated silicon microstrip beam monitors. We have successfully characterized them, both with a microbeam array at ID17, and a submicron scanning beam at ID21. We present here the latest results obtained in recent tests along with an outlook on future developments.

  9. Real-time photo-magnetic imaging

    PubMed Central

    Nouizi, Farouk; Erkol, Hakan; Luk, Alex; Unlu, Mehmet B.; Gulsen, Gultekin

    2016-01-01

    We previously introduced a new high resolution diffuse optical imaging modality termed, photo-magnetic imaging (PMI). PMI irradiates the object under investigation with near-infrared light and monitors the variations of temperature using magnetic resonance thermometry (MRT). In this paper, we present a real-time PMI image reconstruction algorithm that uses analytic methods to solve the forward problem and assemble the Jacobian matrix much faster. The new algorithm is validated using real MRT measured temperature maps. In fact, it accelerates the reconstruction process by more than 250 times compared to a single iteration of the FEM-based algorithm, which opens the possibility for the real-time PMI. PMID:27867701

  10. Pharmacokinetics of indomethacin in poultry.

    PubMed

    Cristòfol, C; Valladares, J E; Martí, G; Arboix, M

    2000-01-01

    Indomethacin (INDO) is a nonsteroidal antiinflammatory drug widely used since the 1970s. The pharmacokinetic behavior of INDO (2 mg/kg) has been studied after intravenous (i.v.) and oral administration to broiler chickens. After i.v. administration, a first fast distribution phase and a later and slower elimination phase were observed. The elimination half-life and mean residence time (MRT) obtained were 1.0 hr and 0.8 hr, respectively. After oral administration, a flip-flop phenomenon was observed giving an elimination half-life and MRT approximately three times and six times higher, respectively, than the i.v. administration. The plasma concentrations after oral administration were sustained during 8-10 hr, giving an antinflammatory cover over the dose producing 50% of maximal effect during this time period.

  11. Attractiveness in African American and Caucasian Women: Is Beauty in the Eyes of the Observer?

    PubMed Central

    Davis, Dawnavan S.; Sbrocco, Tracy; Odoms-Young, Angela; Smith, Dionne M.

    2010-01-01

    Traditional body image studies have been constrained by focusing on body thinness as the sole component of attractiveness. Evidence suggests that African American women may hold a multifactorial view of attractiveness that extends beyond size to include factors such as dress attire and race. The current study employed a culturally sensitive silhouette Model Rating Task (MRT) to examine the effects of attire, body size, and race on attractiveness. Unexpectedly, minimal differences on attractiveness ratings emerged by attire, body size, or model race between African American and Caucasian women. Overall, participants preferred the dressed, underweight, and African American models. Factors such as exposure to diverse groups and changes in African American culture may explain the present findings. Future studies to delineate the components of attractiveness for African American and Caucasian women using the MRT are needed to broaden our understanding and conceptualization of attractiveness across racial groups. PMID:19962117

  12. The effect of gender and age differences on media selection in small and medium tourism enterprises.

    PubMed

    Dehkordi, Majid A; Zarei, Behrouz; Dehkordi, Shabnam A

    2008-12-01

    The purpose of this study is to examine the impact that gender and age differences have on the communication media selection within the context of small and medium tourism enterprises (SMEs). Media Richness Theory (MRT) was used to assess media preferences in the firms. Using a mail questionnaire, data from 78 firms were collected on seven popular media in use. Historical data of the firms, media characteristics, and other firm-specific factors were included in the analysis. The results indicated that there are substantial gender and age differences in term of communication media selection. This is consistent with MRT and highlights the importance of choosing the appropriate media in SMEs, according with the employee's behaviors, in order to achieve better outcomes and to smooth the path towards good performance in the future.

  13. An accelerated photo-magnetic imaging reconstruction algorithm based on an analytical forward solution and a fast Jacobian assembly method

    NASA Astrophysics Data System (ADS)

    Nouizi, F.; Erkol, H.; Luk, A.; Marks, M.; Unlu, M. B.; Gulsen, G.

    2016-10-01

    We previously introduced photo-magnetic imaging (PMI), an imaging technique that illuminates the medium under investigation with near-infrared light and measures the induced temperature increase using magnetic resonance thermometry (MRT). Using a multiphysics solver combining photon migration and heat diffusion, PMI models the spatiotemporal distribution of temperature variation and recovers high resolution optical absorption images using these temperature maps. In this paper, we present a new fast non-iterative reconstruction algorithm for PMI. This new algorithm uses analytic methods during the resolution of the forward problem and the assembly of the sensitivity matrix. We validate our new analytic-based algorithm with the first generation finite element method (FEM) based reconstruction algorithm previously developed by our team. The validation is performed using, first synthetic data and afterwards, real MRT measured temperature maps. Our new method accelerates the reconstruction process 30-fold when compared to a single iteration of the FEM-based algorithm.

  14. Mechanism-based model of a mass rapid transit system: A perspective

    NASA Astrophysics Data System (ADS)

    Legara, Erika Fille; Khoon, Lee Kee; Guang, Hung Gih; Monterola, Christopher

    2015-01-01

    In this paper, we discuss our findings on the spatiotemporal dynamics within the mass rapid transit (MRT) system of Singapore. We show that the trip distribution of Origin-Destination (OD) station pairs follows a power-law, implying the existence of critical OD pairs. We then present and discuss the empirically validated agent-based model (ABM) we have developed. The model allows recreation of the observed statistics and the setting up of various scenarios and their effects on the system, such as increasing the commuter population and the propagation of travel delays within the transportation network. The proposed model further enables identification of bottlenecks that can cause the MRT to break down, and consequently provide foresight on how such disruptions can possibly be managed. This can potentially provide a versatile approach for transport planners and government regulators to make quantifiable policies that optimally balance cost and convenience as a function of the number of the commuting public.

  15. Compact cryogenic system with mechanical cryocoolers for antihydrogen synthesis.

    PubMed

    Shibata, M; Mohri, A; Kanai, Y; Enomoto, Y; Yamazaki, Y

    2008-01-01

    We have developed a compact cryogenic system which cools a vacuum chamber housing multi-ring trap electrodes (MRTs) of an antihydrogen synthesis trap using mechanical cryocoolers to achieve background pressure less than 10(-12) Torr. The vacuum chamber and the cryocoolers are thermally connected by copper strips of 99.9999% in purity. All components are installed within a diametric gap between the MRT of phi108 mm and a magnet bore of phi160 mm. An adjusting mechanism is prepared to align the MRT axis to the magnet axis. The vacuum chamber was successfully cooled down to 4.0 K after 14 h of cooling with heat load of 0.8 W.

  16. SPECT measurements with /sup 99m/Tc-HM-PAO in focal epilepsy

    SciTech Connect

    Ryding, E.; Rosen, I.; Elmqvist, D.; Ingvar, D.H.

    1988-12-01

    The ability of SPECT measurements with (/sup 99m/Tc)-HM-PAO (Ceretec) to find the location of the epileptic focus was studied in patients under consideration for neurosurgical treatment for therapy-resistant focal epilepsy. The location of low (/sup 99m/Tc)-HM-PAO uptake regions found at interictal measurements, and of high (/sup 99m/Tc)-HM-PAO uptake regions found at ictal measurements, was compared to the findings of extensive ictal and interictal EEG examinations, and to the results of CT and MRT. While EEG revealed focal epileptic activity in all of the 14 patients, SPECT showed regional abnormalities in 13 (93%). CT and MRT showed abnormal findings in 30%.

  17. Optimization of Integrated Impeller Mixer via Radiotracer Experiments

    PubMed Central

    Othman, N.; Kamarudin, S. K.; Takriff, M. S.; Rosli, M. I.; Engku Chik, E. M. F.; Adnan, M. A. K.

    2014-01-01

    Radiotracer experiments are carried out in order to determine the mean residence time (MRT) as well as percentage of dead zone, Vdead (%), in an integrated mixer consisting of Rushton and pitched blade turbine (PBT). Conventionally, optimization was performed by varying one parameter and others were held constant (OFAT) which lead to enormous number of experiments. Thus, in this study, a 4-factor 3-level Taguchi L9 orthogonal array was introduced to obtain an accurate optimization of mixing efficiency with minimal number of experiments. This paper describes the optimal conditions of four process parameters, namely, impeller speed, impeller clearance, type of impeller, and sampling time, in obtaining MRT and Vdead (%) using radiotracer experiments. The optimum conditions for the experiments were 100 rpm impeller speed, 50 mm impeller clearance, Type A mixer, and 900 s sampling time to reach optimization. PMID:24741344

  18. Monte Carlo-based treatment planning system calculation engine for microbeam radiation therapy

    SciTech Connect

    Martinez-Rovira, I.; Sempau, J.; Prezado, Y.

    2012-05-15

    Purpose: Microbeam radiation therapy (MRT) is a synchrotron radiotherapy technique that explores the limits of the dose-volume effect. Preclinical studies have shown that MRT irradiations (arrays of 25-75-{mu}m-wide microbeams spaced by 200-400 {mu}m) are able to eradicate highly aggressive animal tumor models while healthy tissue is preserved. These promising results have provided the basis for the forthcoming clinical trials at the ID17 Biomedical Beamline of the European Synchrotron Radiation Facility (ESRF). The first step includes irradiation of pets (cats and dogs) as a milestone before treatment of human patients. Within this context, accurate dose calculations are required. The distinct features of both beam generation and irradiation geometry in MRT with respect to conventional techniques require the development of a specific MRT treatment planning system (TPS). In particular, a Monte Carlo (MC)-based calculation engine for the MRT TPS has been developed in this work. Experimental verification in heterogeneous phantoms and optimization of the computation time have also been performed. Methods: The penelope/penEasy MC code was used to compute dose distributions from a realistic beam source model. Experimental verification was carried out by means of radiochromic films placed within heterogeneous slab-phantoms. Once validation was completed, dose computations in a virtual model of a patient, reconstructed from computed tomography (CT) images, were performed. To this end, decoupling of the CT image voxel grid (a few cubic millimeter volume) to the dose bin grid, which has micrometer dimensions in the transversal direction of the microbeams, was performed. Optimization of the simulation parameters, the use of variance-reduction (VR) techniques, and other methods, such as the parallelization of the simulations, were applied in order to speed up the dose computation. Results: Good agreement between MC simulations and experimental results was achieved, even at

  19. Attractiveness in African American and Caucasian women: is beauty in the eyes of the observer?

    PubMed

    Davis, Dawnavan S; Sbrocco, Tracy; Odoms-Young, Angela; Smith, Dionne M

    2010-01-01

    Traditional body image studies have been constrained by focusing on body thinness as the sole component of attractiveness. Evidence suggests that African American women may hold a multifactorial view of attractiveness that extends beyond size to include factors such as dress attire and race. The current study employed a culturally sensitive silhouette Model Rating Task (MRT) to examine the effects of attire, body size, and race on attractiveness. Unexpectedly, minimal differences on attractiveness ratings emerged by attire, body size, or model race between African American and Caucasian women. Overall, participants preferred the dressed, underweight, and African American models. Factors such as exposure to diverse groups and changes in African American culture may explain the present findings. Future studies to delineate the components of attractiveness for African American and Caucasian women using the MRT are needed to broaden our understanding and conceptualization of attractiveness across racial groups.

  20. Malignant rhabdoid tumor of the floor of mouth: first reported case in the oral cavity of an adult.

    PubMed

    Wetzel, Stephanie L; Kerpel, Stanley; Reich, Renee F; Freedman, Paul D

    2015-06-01

    Malignant rhabdoid tumors (MRTs) are exceedingly rare lesions. To our knowledge, only 2 cases have been reported in the oral cavity, with both examples occurring in infants. The current case is the third reported case of MRT of the oral cavity and the first reported case to occur in an adult at this location. The following report describes the clinical, histologic and immunohistochemical features of this tumor.

  1. Bone Conduction Systems for Full-Face Respirators: Speech Intelligibility Analysis

    DTIC Science & Technology

    2014-04-01

    background noise. A bone conduction earpiece performed best, followed by a mask-mounted bone conduction system. Both bone conduction systems outperformed...all-in-one bone microphone-bone vibrator system designed to be worn in the ear (figure 4). The earpiece does not interfere with the respirator and...bone conduction earpiece yielded the highest MRT scores, followed by the modified HRE-5673 bone conduction system (tables 1 and 2, figure 12). Pairwise

  2. Attentional Drift: An Exploratory Study into the Development of an Attention Level Monitoring System Based on Human Eye Fixation

    DTIC Science & Technology

    2010-03-01

    The results of these studies support the choice to omit the use of a cellular handset during the present study. Secondary-task questioning took...processing: encoding, central processing, and responding. All three stages tap an individuals’ mental workload capacity. Wickens (1992) also stated that MRT...pertains not only to central cognitive processes but to sensory processes and response processes, as well. This is particularly important in

  3. Classification of Chronic Whiplash Associated Disorders With Artificial Neural Networks

    DTIC Science & Technology

    2007-11-02

    J. Hayek, T. Ettlin, “"Whiplash" injury of the cervical spine: value of modern diagnostic imaging ”, Schweiz -Med- Wochenschr, vol 127, pp 1643-51...standard X-ray. Instead other imaging techniques e.g., MRT can in some instances show changes [10]. Despite absence of abnormal imaging findings, patients...1997. [11] C.W. Pfirrmann, C.A. Binkert, M. Zanetti, N. Boos, J. Hodler, “Functional MR imaging of the craniocervical junction. Correlation with alar

  4. Early gene expression analysis in 9L orthotopic tumor-bearing rats identifies immune modulation in molecular response to synchrotron microbeam radiation therapy.

    PubMed

    Bouchet, Audrey; Sakakini, Nathalie; El Atifi, Michèle; Le Clec'h, Céline; Brauer, Elke; Moisan, Anaïck; Deman, Pierre; Rihet, Pascal; Le Duc, Géraldine; Pelletier, Laurent

    2013-01-01

    Synchrotron Microbeam Radiation Therapy (MRT) relies on the spatial fractionation of the synchrotron photon beam into parallel micro-beams applying several hundred of grays in their paths. Several works have reported the therapeutic interest of the radiotherapy modality at preclinical level, but biological mechanisms responsible for the described efficacy are not fully understood to date. The aim of this study was to identify the early transcriptomic responses of normal brain and glioma tissue in rats after MRT irradiation (400Gy). The transcriptomic analysis of similarly irradiated normal brain and tumor tissues was performed 6 hours after irradiation of 9 L orthotopically tumor-bearing rats. Pangenomic analysis revealed 1012 overexpressed and 497 repressed genes in the irradiated contralateral normal tissue and 344 induced and 210 repressed genes in tumor tissue. These genes were grouped in a total of 135 canonical pathways. More than half were common to both tissues with a predominance for immunity or inflammation (64 and 67% of genes for normal and tumor tissues, respectively). Several pathways involving HMGB1, toll-like receptors, C-type lectins and CD36 may serve as a link between biochemical changes triggered by irradiation and inflammation and immunological challenge. Most immune cell populations were involved: macrophages, dendritic cells, natural killer, T and B lymphocytes. Among them, our results highlighted the involvement of Th17 cell population, recently described in tumor. The immune response was regulated by a large network of mediators comprising growth factors, cytokines, lymphokines. In conclusion, early response to MRT is mainly based on inflammation and immunity which appear therefore as major contributors to MRT efficacy.

  5. Noninvasive thermography of laser-induced hyperthermia using magnetic resonance

    NASA Astrophysics Data System (ADS)

    Maswadi, Saher M.; Glickman, Randolph D.; Dodd, Stephen J.; Gao, Jia Hong

    2004-07-01

    The possibility to induce selective hyperthermia in a target tissue or organ is of great interest for the treatment of cancer and other diseases. An emerging application of thermotherapy is for choroidal neovascularization, a complication of age-related macular degeneration. The therapy is currently limited because the temperature required for optimal tissue response is unknown. We report here an investigation of near infrared laser-induced heating in an ocular phantom. Magnetic resonance thermography (MRT) was used as a non-invasive method to determine the temperature distribution inside the phantom during exposure to a continuous wave diode laser at 806 nm wavelength with 1 watt maximum output. The laser beam had a quasi-gaussian profile, with a radius of 0.8-2.4 mm at target. High quality temperature images were obtained from temperature-dependent phase shifts in the proton resonance frequency with a resolution of 1deg C or better, using a 2T magnet. A phantom with a layer of bovine RPE melanin of 1.5 mm thickness was used to determine the spatial resolution of the MRT measurements. Three dimensional temperature maps were also constructed showing a spatial resolution of 0.25 mm in all direction. The heat distribution depended on the laser parameters, as well as the orientation of the melanin layer with respect to the incident laser beam. The temperature profiles determined by MRT closely followed predictions of a heat diffusion model, based on the optical properties of infrared light in melanin. These results support the use of MRT to optimize laser-induced hyperthermia in a small organ such as the eye.

  6. In vivo efficacy of the histone deacetylase inhibitor suberoylanilide hydroxamic acid in combination with radiotherapy in a malignant rhabdoid tumor mouse model

    PubMed Central

    2012-01-01

    Purpose Histone deacetylase inhibitors are promising new substances in cancer therapy and have also been shown to sensitize different tumor cells to irradiation (XRT). We explored the effect as well as the radiosensitizing properties of suberoylanilide hydroxamic acid (SAHA) in vivo in a malignant rhabdoid tumor (MRT) mouse model. Methods and material Potential radiosensitization by SAHA was assessed in MRT xenografts by analysis of tumor growth delay, necrosis (HE), apoptosis (TUNEL), proliferation (ki-67) and γH2AX expression as well as dynamic 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG -PET) after treatment with either SAHA alone, single-dose (10 Gy) or fractionated XRT (3 × 3Gy) solely as well as in combination with SAHA compared to controls. Results SAHA only had no significant effect on tumor growth. Combination of SAHA for 8 days with single-dose XRT resulted in a higher number of complete remissions, but failed to prove a significant growth delay compared to XRT only. In contrast fractionated XRT plus SAHA for 3 weeks did induce significant tumor growth delay in MRT-xenografts. The histological examination showed a significant effect of XRT in tumor necrosis, expression of Ki-67, γH2AX and apoptosis. SAHA only had no significant effect in the histological examination. Comparison of xenografts treated with XRT and XRT plus SAHA revealed a significantly increased γH2AX expression and apoptosis induction in the mice tumors after combination treatment with single-dose as well as fractionated XRT. The combination of SAHA with XRT showed a tendency to increased necrosis and decrease of proliferation compared to XRT only, which, however, was not significant. The 18F-FDG-PET results showed no significant differences in the standard uptake value or glucose transport kinetics after either treatment. Conclusion SAHA did not have a significant effect alone, but proved to enhance the effect of XRT in our MRT in vivo model. PMID:22458853

  7. Comparison of gastrointestinal transit times between chickens from D+ and D- genetic lines selected for divergent digestion efficiency.

    PubMed

    Rougière, N; Carré, B

    2010-11-01

    D+ (high digestion efficiency) and D- (low digestion efficiency) genetic chicken lines selected for divergent digestion efficiency were compared in this experiment. Gizzard functions were tested in terms of digesta mean retention time and reactions to high dilution of a corn diet with 15% coarse sunflower hulls. The corn standard (S) and high fibre (F) experimental diets were given from 9 days of age to chickens from both lines. Besides the measurements of growth efficiencies (9 to 20 days), digestibilities (20 to 23 days) and gut anatomy (0, 9, 29, 42 and 63 days), two digestive transit studies were performed at 9 and 29 days of age. For the transit studies, the S and F diets were labelled with 0.5% TiO2 and 1% Cr-mordanted sunflower hulls. These diets were fed ad libitum during 3 days, and then the birds were euthanized. The digestive contents were analysed for the determination of marker concentrations and mean retention times (MRTs) in digestive compartments (crop + oesophagus, proventriculus + gizzard, duodenum + jejunum, ileum, rectum + cloaca and caeca) were determined. D+ birds were confirmed as better digesters than D- birds during the growth period, in association with larger gizzard and pancreas, and lighter small intestine in D+ than in D-birds. The MRT in the proventriculus-gizzard system, higher in D+ than in D- birds, was a major factor associated with differences between D+ and D- birds regarding digestion efficiencies and gut anatomy. Diet dilution with fibres reduced differences in digestion efficiencies and proventriculus-gizzard MRT between lines. Differences in gut anatomy between lines tended to disappear after 8 weeks of age. In conclusion, this study showed that MRT in the proventriculus-gizzard system was a major factor associated with genotype differences between the D+ and D- genetic chicken lines selected for divergent digestion efficiency, with longer MRT found in D+ than in D- birds.

  8. Proton Resonance Frequency Chemical Shift Thermometry: Experimental Design and Validation Towards High-Resolution Non-Invasive Temperature Monitoring, and in vivo Experience in a Non-human Primate Model of Acute Ischemic Stroke

    PubMed Central

    Dehkharghani, Seena; Mao, Hui; Howell, Leonard; Zhang, Xiaodong; Pate, K S; Magrath, P R; Tong, Frank; Wei, L; Qiu, D; Fleischer, C; Oshinski, J N

    2016-01-01

    BACKGROUND AND PURPOSE Applications for non-invasive biological temperature monitoring are widespread in biomedicine, and of particular interest in the context of brain temperature regulation, where traditionally costly and invasive monitoring schemes limit their applicability in many settings. Brain thermal regulation therefore remains controversial, motivating the development of non-invasive approaches such as temperature-sensitive NMR phenomena. The purpose of this work was to compare the utility of competing approaches to MR thermometry (MRT) employing proton resonance frequency chemical shift. Three methodologies were tested, hypothesizing the feasibility of a fast and accurate approach to chemical shift thermometry, in a phantom study at 3.0 Tesla. MATERIALS AND METHODS A conventional, paired approach (DIFF-1), an accelerated single-scan approach (DIFF-2), and a new, further accelerated strategy (DIFF-3) were tested. Phantom temperatures were modulated during real-time fiber optic temperature monitoring, with MRT derived simultaneously from temperature-sensitive changes in the water proton chemical shift (~0.01 ppm/°C). MRT was subsequently performed in a series of in vivo non-human primate experiments under physiologic and ischemic conditions testing its reproducibility and overall performance. RESULTS Chemical shift thermometry demonstrated excellent agreement with phantom temperatures for all three approaches (DIFF-1 linear regression R2=0.994, p<0.001, acquisition time 4 min 40 s; DIFF-2 R2=0.996, p<0.001, acquisition time 4 min; DIFF-3 R2=0.998, p<0.001, acquisition time 40 s). CONCLUSION These findings confirm the comparability in performance of three competing approaches MRT, and present in vivo applications under physiologic and ischemic conditions in a primate stroke model. PMID:25655874

  9. Methodology for Validating Building Energy Analysis Simulations

    SciTech Connect

    Judkoff, R.; Wortman, D.; O'Doherty, B.; Burch, J.

    2008-04-01

    The objective of this report was to develop a validation methodology for building energy analysis simulations, collect high-quality, unambiguous empirical data for validation, and apply the validation methodology to the DOE-2.1, BLAST-2MRT, BLAST-3.0, DEROB-3, DEROB-4, and SUNCAT 2.4 computer programs. This report covers background information, literature survey, validation methodology, comparative studies, analytical verification, empirical validation, comparative evaluation of codes, and conclusions.

  10. The effect of size and density on the mean retention time of particles in the reticulorumen of cattle ( Bos primigenius f. taurus), muskoxen ( Ovibos moschatus) and moose ( Alces alces).

    PubMed

    Clauss, Marcus; Lechner, Isabel; Barboza, Perry; Collins, William; Tervoort, Theo A; Südekum, Karl-Heinz; Codron, Daryl; Hummel, Jürgen

    2011-02-01

    Particle passage from the reticulorumen (RR) depends on particle density and size. Forage particle density and size are related and change over time in the RR. Particle density mainly influences sorting in the reticulum, whereas particle size influences particle retention in the fibre mat of stratified rumen contents ('filter-bed' effect). We investigated these effects independently, by inserting plastic particles of different sizes (1, 10 and 20 mm) and densities (1·03, 1·20 and 1·44 mg/ml) in the RR of cattle (Bos primigenius f. taurus) as a pilot study, and of muskoxen (Ovibos moschatus; n 4) and moose (Alces alces; n 2) both fed two diets (browse and grass). Faeces were analysed for plastic residues for 13 d after dosing to calculate mean retention times (MRT). The results confirmed previous findings of differences in absolute MRT between species. Comparing muskoxen with moose, there was no difference in the effect of particle density on the MRT between species but particle size had a more pronounced effect on the MRT in muskoxen than in moose. This indicated a stronger 'filter-bed effect' in muskoxen, in accord with the reports of stratified RR contents in this species v. the absence of RR content stratification in moose. Low-density particles were retained longer in both species fed on grass diets, indicating a contribution of forage type to the 'filter-bed effect'. The results indicate that retention based on particle size may differ between ruminant species, depending on the presence of a fibre mat in the RR, whereas the density-dependent mechanism of sedimentation in the RR is rather constant across species.

  11. Competitive-level differences in Yo-Yo intermittent recovery and twelve minute run test performance in soccer referees.

    PubMed

    Castagna, Carlo; Abt, Grant; D'Ottavio, Stefano

    2005-11-01

    The aim of this study was to examine yo-yo intermittent recovery test (Yo-Yo test) and 12-minute run test (12MRT) performances in experienced soccer referees of different competitive levels. Three groups (n = 14 each) of experienced Italian soccer referees officiating in the first (series AB, top-level), third (series C, medium-level), and fourth (series D, low-level) division, were randomly submitted to the 12MRT and the Yo-Yo test during 2 testing sessions, 48-hours apart. 12MRT performances were 3,000 +/- 112 m; 2,894 +/- 99 m; and 2,896 +/- 171 m for top-level, medium-level and low-level referees, respectively (p > 0.05). In the Yo-Yo test, the top-level, medium-level, and low-level referees covered 1,874 +/- 431 m; 1,360 +/- 172 m; and 1,272 +/- 215 m, respectively. The test performances of top-level referees in the Yo-Yo test was significantly different from those scored by medium-level and low-level referees (p < 0.05). After the Yo-Yo test, blood lactate concentrations (BLC) were higher in the medium-level and low-level referees compared with the top-level referees (p < 0.05). The results of the present study show that the Yo-Yo test and not the 12MRT can discriminate endurance performance in experienced elite level soccer referees. With respect to its discriminative and match performance validity, the Yo-Yo test may be considered a relevant field test to assess endurance preparedness for experienced soccer referees and a useful tool in talent selection.

  12. Effects of various axial flow profiles on the magneto-Rayleigh-Taylor instability in Z-pinch implosions

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Ding, N.

    2006-06-01

    The stabilizing effect of different axial flow profiles on the magneto-Rayleigh-Taylor (MTR) instability in Z-pinch implosions is investigated with a compressible skin-current model. The numerical results show that the mitigation effect of the axial flow on the MRT instability is caused by the radial velocity shear, and it is highly susceptible to the shear value nearby the plasma outer surface. By adjusting the flow profile, the mitigation effect can be improved markedly.

  13. [Optimized study technic in meniscopathies by NMR tomographic 3D imaging at 1.5 tesla].

    PubMed

    Skalej, M; Klose, U; Küper, K

    1988-02-01

    Traumatic and degenerative changes in the meniscus can be demonstrated well by MRT, but the small size and complex anatomical structure of the menisci present practical problems. A correct understanding is only possible by images in several planes and good resolution, making the examination a lengthy procedure. A technique is therefore described using 3-D images and reconstruction of high-resolution films, which allows rapid examination of the menisci in optimal planes.

  14. MR Imaging Based Treatment Planning for Radiotherapy of Prostate Cancer

    DTIC Science & Technology

    2005-02-01

    treatment planning for radiotherapy : Dosimetric verification for prostate IiMRT" and " Dosimetric evaluation of MRI-based treatment planning for...Shawn M, Ma C-M, Freedman GM and Pollack A. MRI-Based Treatment Planning for Radiotherapy : Dosimetric Verification for Prostate IMRT. International...Freedman GM and Pollack A. MRI- Based Treatment Planning for Radiotherapy : Dosimetric Verification for Prostate ]IMRT. International Journal of Radiation

  15. Effects of Voice Coding and Speech Rate on a Synthetic Speech Display in a Telephone Information System

    DTIC Science & Technology

    1988-05-01

    particular. O’Malley and Caisse (1987) point out the original MRT was never intended to be a measure of human speakers’ ability to produce intelligible...O’Malley and Caisse , 1987). Also, no study has systematically investigated the possible interaction of voice type and speech rate on intelligibility. This...the university community were provided monetary compensation for their par- ticipation. Average age was 19.9 years with a range from 18 to 27

  16. Mixing effects on nitrogen and oxygen concentrations and the relationship to mean residence time in a hyporheic zone of a riffle-pool sequence

    USGS Publications Warehouse

    Naranjo, Ramon C.; Niswonger, Richard G.; Clinton Davis,

    2015-01-01

    Flow paths and residence times in the hyporheic zone are known to influence biogeochemical processes such as nitrification and denitrification. The exchange across the sediment-water interface may involve mixing of surface water and groundwater through complex hyporheic flow paths that contribute to highly variable biogeochemically active zones. Despite the recognition of these patterns in the literature, conceptualization and analysis of flow paths and nitrogen transformations beneath riffle-pool sequences often neglect to consider bed form driven exchange along the entire reach. In this study, the spatial and temporal distribution of dissolved oxygen (DO), nitrate (NO3-) and ammonium (NH4+) were monitored in the hyporheic zone beneath a riffle-pool sequence on a losing section of the Truckee River, NV. Spatially-varying hyporheic exchange and the occurrence of multi-scale hyporheic mixing cells are shown to influence concentrations of DO and NO3- and the mean residence time (MRT) of riffle and pool areas. Distinct patterns observed in piezometers are shown to be influenced by the first large flow event following a steady 8 month period of low flow conditions. Increases in surface water discharge resulted in reversed hydraulic gradients and production of nitrate through nitrification at small vertical spatial scales (0.10 to 0.25 m) beneath the sediment-water interface. In areas with high downward flow rates and low MRT, denitrification may be limited. The use of a longitudinal two-dimensional flow model helped identify important mechanisms such as multi-scale hyporheic mixing cells and spatially varying MRT, an important driver for nitrogen transformation in the riverbed. Our observations of DO and NO3- concentrations and model simulations highlight the role of multi-scale hyporheic mixing cells on MRT and nitrogen transformations in the hyporheic zone of riffle-pool sequences. This article is protected by copyright. All rights reserved.

  17. Objective assessment of drowsiness and reaction time during intermittent Ramadan fasting in young men: a case-crossover study

    PubMed Central

    2013-01-01

    Background Ramadan fasting and its attendant lifestyle changes induce changes in the circadian rhythm and in associated physiological and metabolic functions. Previous studies that have assessed psychomotor performance during Ramadan fasting have reported conflicting results. Therefore, we designed this study to objectively assess the effects of intermittent fasting during and outside Ramadan (to control for lifestyle changes) on drowsiness, blink total duration and mean reaction time (MRT) test while controlling for potential confounders. Methods Eight healthy volunteers with a mean age of 25.3 ± 2.9 years and a mean body mass index (BMI) of 23.4 ± 3.2 kg/m2 reported to the sleep laboratory on four occasions for polysomnography (PSG) and drowsiness and psychomotor assessments as follows: 1) adaptation; 2) 4 weeks before Ramadan while performing the Islamic fasting for 1 week (baseline fasting) (BLF); 3) 1 week before Ramadan (non-fasting baseline) (BL); and 4) during the second week of Ramadan while fasting (Ramadan). OPTALERT™ was used to objectively assess daytime drowsiness using the Johns Drowsiness Scale (JDS), and blink total duration and a visual reaction time test were used to assess MRT. Results Rapid eye movement (REM) sleep percentage was significantly lower at BLF (17.7 ± 8.1%) and at Ramadan (18.6 ± 10.7%) compared with BL (25.6 ± 4.8%) (p < 0.05). There were no significant differences between JDS scores and blink total duration during the two test periods in BL, BLF and Ramadan. There were no significant changes in MRT during BL, BLF and Ramadan. Conclusions Under controlled conditions of fixed light/dark exposure, caloric intake, sleep/wake schedule and sleep quality, the Islamic intermittent fasting has no impact on drowsiness and vigilance as measured by the JDS, total blink duration and MRT. PMID:23937904

  18. Detecting the impact of bank and channel modification on invertebrate communities in Mediterranean temporary streams (Sardinia, SW Italy).

    PubMed

    Buffagni, Andrea; Tenchini, Roberta; Cazzola, Marcello; Erba, Stefania; Balestrini, Raffaella; Belfiore, Carlo; Pagnotta, Romano

    2016-09-15

    We hypothesized that reach-scale, bank and channel modification would impact benthic communities in temporary rivers of Sardinia, when pollution and water abstraction are not relevant. A range of variables were considered, which include both artificial structures/alterations and natural features observed in a stream reach. Multivariate regression trees (MRT) were used to assess the effects of the explanatory variables on invertebrate assemblages and five groups, characterized by different habitat modification and/or features, were recognized. Four node variables determined the splits in the MRT analysis: channel reinforcement, tree-related bank and channel habitats, channel modification and bank modification. Continuity of trees in the river corridor diverged among MRT groups and significant differences among groups include presence of alders, extent of channel shading and substrate diversity. Also, the percentage of in-stream organic substrates, in particular CPOM/Xylal, showed highly significant differences among groups. For practical applications, thresholds for the extent of channel reinforcement (40%) and modification (10%) and for bank alteration (≈30%) were provided, that can be used to guide the implementation of restoration measures. In moderately altered river reaches, a significant extent of tree-related habitats (≈5%) can noticeably mitigate the effects of morphological alteration on aquatic invertebrates. The outcomes highlight the importance of riparian zone management as an opportune, achievable prospect in the restoration of Mediterranean temporary streams. The impact of bank and channel modification on ecological status (sensu WFD) was investigated and the tested benthic metrics, especially those based on abundance data, showed legible differences among MRT groups. Finally, bank and channel modification appears to be a potential threat for the conservation of a few Sardo-Corsican endemic species. The introduction of management criteria that

  19. Tanker Avionics/Aircrew Complement Evaluation (TAACE). Phase I. Simulation Evaluation. Volume II. Crew System Design

    DTIC Science & Technology

    1981-11-01

    is no longer enployed by your organization please notify AFWAL/FIGR, W-PAFB, OH 45433 to help us maintain a current mailing list. Copies of this...PERFORMING ORGANIZATION NAME AND ADDRESS 10 PROGRAM ELEMEUNIT NUMBEROJECT TASK Bunker Rawo Corporation, Electronic Systems 11142F 4130 Linden Avenue, Suite...MegaHei:tz MPD Multipurpose Display MRT Military Rated Thrust N North NATO North Atlantic Treaty Organization NAV Navigation/Navigator ix LIST OF

  20. Benchmarking and validation of a Geant4-SHADOW Monte Carlo simulation for dose calculations in microbeam radiation therapy.

    PubMed

    Cornelius, Iwan; Guatelli, Susanna; Fournier, Pauline; Crosbie, Jeffrey C; Sanchez Del Rio, Manuel; Bräuer-Krisch, Elke; Rosenfeld, Anatoly; Lerch, Michael

    2014-05-01

    Microbeam radiation therapy (MRT) is a synchrotron-based radiotherapy modality that uses high-intensity beams of spatially fractionated radiation to treat tumours. The rapid evolution of MRT towards clinical trials demands accurate treatment planning systems (TPS), as well as independent tools for the verification of TPS calculated dose distributions in order to ensure patient safety and treatment efficacy. Monte Carlo computer simulation represents the most accurate method of dose calculation in patient geometries and is best suited for the purpose of TPS verification. A Monte Carlo model of the ID17 biomedical beamline at the European Synchrotron Radiation Facility has been developed, including recent modifications, using the Geant4 Monte Carlo toolkit interfaced with the SHADOW X-ray optics and ray-tracing libraries. The code was benchmarked by simulating dose profiles in water-equivalent phantoms subject to irradiation by broad-beam (without spatial fractionation) and microbeam (with spatial fractionation) fields, and comparing against those calculated with a previous model of the beamline developed using the PENELOPE code. Validation against additional experimental dose profiles in water-equivalent phantoms subject to broad-beam irradiation was also performed. Good agreement between codes was observed, with the exception of out-of-field doses and toward the field edge for larger field sizes. Microbeam results showed good agreement between both codes and experimental results within uncertainties. Results of the experimental validation showed agreement for different beamline configurations. The asymmetry in the out-of-field dose profiles due to polarization effects was also investigated, yielding important information for the treatment planning process in MRT. This work represents an important step in the development of a Monte Carlo-based independent verification tool for treatment planning in MRT.

  1. Design, construction, and optimization of a novel, modular, and scalable incubation chamber for continuous viral inactivation.

    PubMed

    Orozco, Raquel; Godfrey, Scott; Coffman, Jon; Amarikwa, Linus; Parker, Stephanie; Hernandez, Lindsay; Wachuku, Chinenye; Mai, Ben; Song, Brian; Hoskatti, Shashidhar; Asong, Jinkeng; Shamlou, Parviz; Bardliving, Cameron; Fiadeiro, Marcus

    2017-02-11

    We designed, built or 3D printed, and screened tubular reactors that minimize axial dispersion to serve as incubation chambers for continuous virus inactivation of biological products. Empirical residence time distribution data were used to derive each tubular design's volume equivalent to a theoretical plate (VETP) values at a various process flow rates. One design, the Jig in a Box (JIB), yielded the lowest VETP, indicating optimal radial mixing and minimal axial dispersion. A minimum residence time (MRT) approach was employed, where the MRT is the minimum time the product spends in the tubular reactor. This incubation time is typically 60 minutes in a batch process. We provide recommendations for combinations of flow rates and device dimensions for operation of the JIB connected in series that will meet a 60-min MRT. The results show that under a wide range of flow rates and corresponding volumes, it takes 75 ± 3 min for 99% of the product to exit the reactor while meeting the 60-min MRT criterion and fulfilling the constraint of keeping a differential pressure drop under 5 psi. Under these conditions, the VETP increases slightly from 3 to 5 mL though the number of theoretical plates stays constant at about 1326 ± 88. We also demonstrated that the final design volume was only 6% ± 1% larger than the ideal plug flow volume. Using such a device would enable continuous viral inactivation in a truly continuous process or in the effluent of a batch chromatography column. Viral inactivation studies would be required to validate such a design. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 2017.

  2. Modeling, measuring, and mitigating instability growth in liner implosions on Z

    NASA Astrophysics Data System (ADS)

    Peterson, Kyle

    2015-11-01

    Electro-thermal instabilities result from non-uniform heating due to temperature dependence in the conductivity of a material. In this talk, we will discuss the role of electro-thermal instabilities on the dynamics of magnetically accelerated implosion systems. We present simulations that show electro-thermal instabilities form immediately after the surface material of a conductor melts and can act as a significant seed to subsequent magneto-Rayleigh-Taylor (MRT) instability growth. We discuss measurement results from experiments performed on Sandia National Laboratories Z accelerator to investigate signatures of electro-thermal instability growth on well-characterized initially solid aluminum or beryllium rods driven with a 20 MA, 100 ns risetime current pulse. These measurements show good agreement with electro-thermal instability simulations and exhibit larger instability growth than can be explained by MRT theory alone. Recent experiments have confirmed simulation predictions of dramatically reduced instability growth in solid metallic rods when thick dielectric coatings are used to mitigate density perturbations arising from the electro-thermal instability. These results provide further evidence that the inherent surface roughness of the target is not the dominant seed for the MRT instability, in contrast with most inertial confinement fusion approaches. These results suggest a new technique for substantially reducing the integral MRT growth in magnetically driven implosions. Indeed, recent results on the Z facility with 100 km/s Al and Be liner implosions show substantially reduced growth. These new results include axially magnetized, CH-coated beryllium liner radiographs in which the inner liner surface is observed to be remarkably straight and uniform at a radius of about 120 microns (convergence ratio ~20). Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under

  3. Digesta retention patterns of solute and different-sized particles in camelids compared with ruminants and other foregut fermenters.

    PubMed

    Dittmann, Marie T; Runge, Ullrich; Ortmann, Sylvia; Lang, Richard A; Moser, Dario; Galeffi, Cordula; Schwarm, Angela; Kreuzer, Michael; Clauss, Marcus

    2015-07-01

    The mean retention times (MRT) of solute or particles in the gastrointestinal tract and the forestomach (FS) are crucial determinants of digestive physiology in herbivores. Besides ruminants, camelids are the only herbivores that have evolved rumination as an obligatory physiological process consisting of repeated mastication of large food particles, which requires a particle sorting mechanism in the FS. Differences between camelids and ruminants have hardly been investigated so far. In this study we measured MRTs of solute and differently sized particles (2, 10, and 20 mm) and the ratio of large-to-small particle MRT, i.e. the selectivity factors (SF(10/2mm), SF(20/2mm), SF(20/10mm)), in three camelid species: alpacas (Vicugna pacos), llamas (Llama glama), and Bactrian camels (Camelus bactrianus). The camelid data were compared with literature data from ruminants and non-ruminant foregut fermenters (NRFF). Camelids and ruminants both had higher SF(10/2mm)FS than NRFF, suggesting convergence in the function of the FS sorting mechanism in contrast to NRFF, in which such a sorting mechanism is absent. The SF(20/10mm)FS did not differ between ruminants and camelids, indicating that there is a particle size threshold of about 1 cm in both suborders above which particle retention is not increased. Camelids did not differ from ruminants in MRT(2mm)FS, MRTsoluteFS, and the ratio MRT(2mm)FS/MRTsoluteFS, but they were more similar to 'cattle-' than to 'moose-type' ruminants. Camelids had higher SF(10/2mm)FS and higher SF(20/2mm)FS than ruminants, indicating a potentially slower particle sorting in camelids than in ruminants, with larger particles being retained longer in relation to small particles.

  4. Principles and Application of Magnetic Rubber Testing for Crack Detection in High-Strength Steel Components: II. Residual-Field Inspection

    DTIC Science & Technology

    2014-12-01

    DSTO Defence Science and Technology Organisation D6ac Denotes a grade of high strength steel FEM Finite element modelling (for calculating magnetic...UNCLASSIFIED UNCLASSIFIED Principles and Application of Magnetic Rubber Testing for Crack Detection in High-Strength Steel Components: II...ABSTRACT Since its introduction in the 1970s, magnetic rubber testing (MRT) has been used successfully to inspect critical high-strength steel

  5. Multiple-relaxation-time lattice Boltzmann method for study of two-lid-driven cavity flow solution multiplicity

    NASA Astrophysics Data System (ADS)

    Guo, Xixiong; Zhong, Chengwen; Zhuo, Congshan; Cao, Jun

    2014-04-01

    As a fundamental subject in fluid mechanics, sophisticated cavity flow patterns due to the movement of multi-lids have been routinely analyzed by the computational fluid dynamics community. Unlike those reported computational studies that were conducted using more conventional numerical methods, this paper features employing the multiple-relaxation-time (MRT) lattice Boltzmann method (LBM) to numerically investigate the two-dimensional cavity flows generated by the movements of two adjacent lids. The obtained MRT-LBM results reveal a number of important bifurcation flow features, such as the symmetry and steadiness of cavity flows at low Reynolds numbers, the multiplicity of stable cavity flow patterns when the Reynolds number exceeds its first critical value, as well as the periodicity of the cavity flow after the second critical Reynolds number is reached. Detailed flow characteristics are reported that include the critical Reynolds numbers, the locations of the vortex centers, and the values of stream function at the vortex centers. Through systematic comparison against the simulation results obtained elsewhere by using the lattice Bhatnagar-Gross-Krook model and other numerical schemes, not only does the MRT-LBM approach exhibit fairly satisfactory accuracy, but also demonstrates its remarkable flexibility that renders the adjustment of its multiple relaxation factors fully manageable and, thus, particularly accommodates the need of effectively investigating the multiplicity of flow patterns with complex behaviors.

  6. Creating a Three-Parent Child: An Educational Paradigm for the Responsible Conduct of Research

    PubMed Central

    Fischbach, Ruth L.; Benston, Shawna; Loike, John D.

    2014-01-01

    The field of assisted reproduction is renowned for its remarkable advances and constant pushing forward of research boundaries in an effort to offer innovative and effective methods for enhancing fertility. Accompanying these advances, however, are physiological, psychological, and bioethical consequences that must be considered. These concomitant advances and consequences make assisted reproduction an excellent educational paradigm for inculcating responsible conduct in both research and clinical practice. Ultimately, responsible conduct rests on the ethical researcher and clinician. Here, we present the as-yet unapproved, contentious assisted reproductive technology of mitochondrial replacement transfer (MRT) as an ideal educational platform to foster the responsible conduct of research by advancing dialogue among multi-disciplinary scholars, researchers, and students. Using a likely future case, we present the basic science, legal, and ethical considerations, and the pedagogical principles and strategies for using MRT as an effective educational paradigm. Society will benefit when the ethical issues inherent in creating children with three genetic parents as well as germline interference are discussed across multiple academic levels that include researchers, legal experts, bioethicists, and government-appointed commissions. Furthermore, undergraduate and graduate students should be included because they will likely determine the ethical fates of these biotechnologies. While emerging assisted reproduction technologies such as MRT are highly complex and will take years to be readily available for patients in need, now is the time to consider their scientific, legal, ethical, and cultural/religious implications for ensuring the responsible conduct of research. PMID:25574276

  7. You Should Be the Specialist! Weak Mental Rotation Performance in Aviation Security Screeners - Reduced Performance Level in Aviation Security with No Gender Effect.

    PubMed

    Krüger, Jenny K; Suchan, Boris

    2016-01-01

    Aviation security screeners analyze a large number of X-ray images per day and seem to be experts in mentally rotating diverse kinds of visual objects. A robust gender-effect that men outperform women in the Vandenberg & Kuse mental rotation task has been well documented over the last years. In addition it has been shown that training can positively influence the overall task-performance. Considering this, the aim of the present study was to investigate whether security screeners show better performance in the Mental Rotation Test (MRT) independently of gender. Forty-seven security screeners of both sexes from two German airports were examined with a computer based MRT. Their performance was compared to a large sample of control subjects. The well-known gender-effect favoring men on mental rotation was significant within the control group. However, the security screeners did not show any sex differences suggesting an effect of training and professional performance. Surprisingly this specialized group showed a lower level of overall MRT performance than the control participants. Possible aviation related influences such as secondary effects of work-shift or expertise which can cumulatively cause this result are discussed.

  8. Structural organization of human replication timing domains.

    PubMed

    Boulos, Rasha E; Drillon, Guénola; Argoul, Françoise; Arneodo, Alain; Audit, Benjamin

    2015-10-07

    Recent analysis of genome-wide epigenetic modification data, mean replication timing (MRT) profiles and chromosome conformation data in mammals have provided increasing evidence that flexibility in replication origin usage is regulated locally by the epigenetic landscape and over larger genomic distances by the 3D chromatin architecture. Here, we review the recent results establishing some link between replication domains and chromatin structural domains in pluripotent and various differentiated cell types in human. We reconcile the originally proposed dichotomic picture of early and late constant timing regions that replicate by multiple rather synchronous origins in separated nuclear compartments of open and closed chromatins, with the U-shaped MRT domains bordered by "master" replication origins specified by a localized (∼200-300 kb) zone of open and transcriptionally active chromatin from which a replication wave likely initiates and propagates toward the domain center via a cascade of origin firing. We discuss the relationships between these MRT domains, topologically associated domains and lamina-associated domains. This review sheds a new light on the epigenetically regulated global chromatin reorganization that underlies the loss of pluripotency and the determination of differentiation properties.

  9. Experimental Studies of the Electrothermal and Magneto-Rayleigh Taylor Instabilities on Thin Metal Foil Ablations

    NASA Astrophysics Data System (ADS)

    Steiner, Adam; Yager-Elorriaga, David; Patel, Sonal; Jordan, Nicholas; Gilgenbach, Ronald; Lau, Y. Y.

    2015-11-01

    The electrothermal instability (ETI) and magneto-Rayleigh Taylor instability (MRT) are important in the implosion of metallic liners, such as magnetized liner implosion fusion (MagLIF). The MAIZE linear transformer driver (LTD) at the University of Michigan generates 200 ns risetime-current pulses of 500 to 600 kA into Al foil liners to study plasma instabilities and implosion dynamics, most recently MRT growth on imploding cylindrical liners. A full circuit model of MAIZE, along with I-V measurements, yields time-resolved load inductance. This has enabled measurements of an effective current-carrying radius to determine implosion velocity and plasma-vacuum interface acceleration. Measurements are also compared to implosion data from 4-time-frame laser shadowgraphy. Improved resolution measurements on the laser shadowgraph system have been used to examine the liner interface early in the shot to examine surface perturbations resulting from ETI for various seeding conditions. Fourier analysis examines the growth rates of wavelength bands of these structures to examine the transition from ETI to MRT. This work was supported by the U.S. DoE through award DE-SC0012328. S.G. Patel is supported by Sandia National Labs. D.A. Yager is supported by NSF fellowship grant DGE 1256260.

  10. Instability growth for magnetized liner inertial fusion seeded by electro-thermal, electro-choric, and material strength effects

    NASA Astrophysics Data System (ADS)

    Pecover, J. D.; Chittenden, J. P.

    2015-10-01

    A critical limitation of magnetically imploded systems such as magnetized liner inertial fusion (MagLIF) [Slutz et al., Phys. Plasmas 17, 056303 (2010)] is the magneto-Rayleigh-Taylor (MRT) instability which primarily disrupts the outer surface of the liner. MagLIF-relevant experiments have showed large amplitude multi-mode MRT instability growth growing from surface roughness [McBride et al., Phys. Rev. Lett. 109, 135004 (2012)], which is only reproduced by 3D simulations using our MHD code Gorgon when an artificially azimuthally correlated initialisation is added. We have shown that the missing azimuthal correlation could be provided by a combination of the electro-thermal instability (ETI) and an "electro-choric" instability (ECI); describing, respectively, the tendency of current to correlate azimuthally early in time due to temperature dependent Ohmic heating; and an amplification of the ETI driven by density dependent resistivity around vapourisation. We developed and implemented a material strength model in Gorgon to improve simulation of the solid phase of liner implosions which, when applied to simulations exhibiting the ETI and ECI, gave a significant increase in wavelength and amplitude. Full circumference simulations of the MRT instability provided a significant improvement on previous randomly initialised results and approached agreement with experiment.

  11. Characterization of surface and ground water δ18O seasonal variation and its use for estimating groundwater residence times

    USGS Publications Warehouse

    Reddy, Michael M.; Schuster, Paul; Kendall, Carol; Reddy, Micaela B.

    2006-01-01

    18O is an ideal tracer for characterizing hydrological processes because it can be reliably measured in several watershed hydrological compartments. Here, we present multiyear isotopic data, i.e. 18O variations (δ18O), for precipitation inputs, surface water and groundwater in the Shingobee River Headwaters Area (SRHA), a well-instrumented research catchment in north-central Minnesota. SRHA surface waters exhibit δ18O seasonal variations similar to those of groundwaters, and seasonal δ18O variations plotted versus time fit seasonal sine functions. These seasonal δ18O variations were interpreted to estimate surface water and groundwater mean residence times (MRTs) at sampling locations near topographically closed-basin lakes. MRT variations of about 1 to 16 years have been estimated over an area covering about 9 km2 from the basin boundary to the most downgradient well. Estimated MRT error (±0·3 to ±0·7 years) is small for short MRTs and is much larger (±10 years) for a well with an MRT (16 years) near the limit of the method. Groundwater transit time estimates based on Darcy's law, tritium content, and the seasonal δ18O amplitude approach appear to be consistent within the limits of each method. The results from this study suggest that use of the δ18O seasonal variation method to determine MRTs can help assess groundwater recharge areas in small headwaters catchments.

  12. Characterization of surface and ground water δ18O seasonal variation and its use for estimating groundwater residence times

    USGS Publications Warehouse

    Reddy, Michael M.; Schuster, Paul F.; Kendall, Carol; Reddy, Micaela B.

    2006-01-01

    18O is an ideal tracer for characterizing hydrological processes because it can be reliably measured in several watershed hydrological compartments. Here, we present multiyear isotopic data, i.e. 18O variations (δ18O), for precipitation inputs, surface water and groundwater in the Shingobee River Headwaters Area (SRHA), a well-instrumented research catchment in north-central Minnesota. SRHA surface waters exhibit δ18O seasonal variations similar to those of groundwaters, and seasonal δ18O variations plotted versus time fit seasonal sine functions. These seasonal δ18O variations were interpreted to estimate surface water and groundwater mean residence times (MRTs) at sampling locations near topographically closed-basin lakes. MRT variations of about 1 to 16 years have been estimated over an area covering about 9 km2 from the basin boundary to the most downgradient well. Estimated MRT error (±0·3 to ±0·7 years) is small for short MRTs and is much larger (±10 years) for a well with an MRT (16 years) near the limit of the method. Groundwater transit time estimates based on Darcy's law, tritium content, and the seasonal δ18O amplitude approach appear to be consistent within the limits of each method. The results from this study suggest that use of the δ18O seasonal variation method to determine MRTs can help assess groundwater recharge areas in small headwaters catchments.

  13. Phoneme contrasts with two, same-talker speakers

    NASA Astrophysics Data System (ADS)

    Ericson, Mark; Mishler, Pamela

    2003-04-01

    People often have difficulty hearing speech in the presence of concurrent conversations. This well-known cocktail-party effect can be parsed into energetic and informational masking effects. The purpose of this study was to measure and model the effects of energetic and informational masking that occur when two words, spoken by the same talker are heard at the same time. The word identification test used in the experiments was the Modified Rhyme Test (MRT). The MRT was used as both the stimulus and the masker, which afforded a multitude of consonant contrasts. The phrases were presented monaurally at 75 dB SPL over Sennheiser HD-520 headphones to four normal hearing listeners. The independent variables included 30 pairs of MRT word lists spoken by three male and three female talkers. The dependent variable was the percent correct identifications of the two consonants. Listeners performed at 94% correct for the first word choice and 72% correct for the second word choice. The distribution of errors was analyzed by place of articulation, manner of articulation, and speech-to-speech-ratio of the phoneme pairs and compared to articulation index predictions for speech intelligibility.

  14. Optimization of X-ray microplanar beam radiation therapy for deep-seated tumors by a simulation study.

    PubMed

    Shinohara, Kunio; Kondoh, Takeshi; Nariyama, Nobuteru; Fujita, Hajime; Washio, Masakazu; Aoki, Yukimasa

    2014-01-01

    A Monte Carlo simulation was applied to study the energy dependence on the transverse dose distribution of microplanar beam radiation therapy (MRT) for deep-seated tumors. The distribution was found to be the peak (in-beam) dose and the decay from the edge of the beam down to the valley. The area below the same valley dose level (valley region) was decreased with the increase in the energy of X-rays at the same beam separation. To optimize the MRT, we made the following two assumptions: the therapeutic gain may be attributed to the efficient recovery of normal tissue caused by the beam separation; and a key factor for the efficient recovery of normal tissue depends on the area size of the valley region. Based on these assumptions and the results of the simulated dose distribution, we concluded that the optimum X-ray energy was in the range of 100-300 keV depending on the effective peak dose to the target tumors and/or tolerable surface dose. In addition, we proposed parameters to be studied for the optimization of MRT to deep-seated tumors.

  15. Media multitasking and behavioral measures of sustained attention.

    PubMed

    Ralph, Brandon C W; Thomson, David R; Seli, Paul; Carriere, Jonathan S A; Smilek, Daniel

    2015-02-01

    In a series of four studies, self-reported media multitasking (using the media multitasking index; MMI) and general sustained-attention ability, through performance on three sustained-attention tasks: the metronome response task (MRT), the sustained-attention-to-response task (SART), and a vigilance task (here, a modified version of the SART). In Study 1, we found that higher reports of media multitasking were associated with increased response variability (i.e., poor performance) on the MRT. However, in Study 2, no association between reported media multitasking and performance on the SART was observed. These findings were replicated in Studies 3a and 3b, in which we again assessed the relation between media multitasking and performance on both the MRT and SART in two large online samples. Finally, in Study 4, using a large online sample, we tested whether media multitasking was associated with performance on a vigilance task. Although standard vigilance decrements were observed in both sensitivity (A') and response times, media multitasking was not associated with the size of these decrements, nor was media multitasking associated with overall performance, in terms of either sensitivity or response times. Taken together, the results of the studies reported here failed to demonstrate a relation between habitual engagement in media multitasking in everyday life and a general deficit in sustained-attention processes.

  16. Nonequilibrium scheme for computing the flux of the convection-diffusion equation in the framework of the lattice Boltzmann method.

    PubMed

    Chai, Zhenhua; Zhao, T S

    2014-07-01

    In this paper, we propose a local nonequilibrium scheme for computing the flux of the convection-diffusion equation with a source term in the framework of the multiple-relaxation-time (MRT) lattice Boltzmann method (LBM). Both the Chapman-Enskog analysis and the numerical results show that, at the diffusive scaling, the present nonequilibrium scheme has a second-order convergence rate in space. A comparison between the nonequilibrium scheme and the conventional second-order central-difference scheme indicates that, although both schemes have a second-order convergence rate in space, the present nonequilibrium scheme is more accurate than the central-difference scheme. In addition, the flux computation rendered by the present scheme also preserves the parallel computation feature of the LBM, making the scheme more efficient than conventional finite-difference schemes in the study of large-scale problems. Finally, a comparison between the single-relaxation-time model and the MRT model is also conducted, and the results show that the MRT model is more accurate than the single-relaxation-time model, both in solving the convection-diffusion equation and in computing the flux.

  17. Microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Laissue, Jean A.; Lyubimova, Nadia; Wagner, Hans-Peter; Archer, David W.; Slatkin, Daniel N.; Di Michiel, Marco; Nemoz, Christian; Renier, Michel; Brauer, Elke; Spanne, Per O.; Gebbers, Jan-Olef; Dixon, Keith; Blattmann, Hans

    1999-10-01

    The central nervous system of vertebrates, even when immature, displays extraordinary resistance to damage by microscopically narrow, multiple, parallel, planar beams of x rays. Imminently lethal gliosarcomas in the brains of mature rats can be inhibited and ablated by such microbeams with little or no harm to mature brain tissues and neurological function. Potentially palliative, conventional wide-beam radiotherapy of malignant brain tumors in human infants under three years of age is so fraught with the danger of disrupting the functional maturation of immature brain tissues around the targeted tumor that it is implemented infrequently. Other kinds of therapy for such tumors are often inadequate. We suggest that microbeam radiation therapy (MRT) might help to alleviate the situation. Wiggler-generated synchrotron x-rays were first used for experimental microplanar beam (microbeam) radiation therapy (MRT) at Brookhaven National Laboratory's National Synchrotron Light Source in the early 1990s. We now describe the progress achieved in MRT research to date using immature and adult rats irradiated at the European Synchrotron Radiation Facility in Grenoble, France, and investigated thereafter at the Institute of Pathology of the University of Bern.

  18. The unexpected discovery of Brucella abortus Buck 19 vaccine in goats from Ecuador underlines the importance of biosecurity measures.

    PubMed

    Ron-Román, Jorge; Berkvens, Dirk; Barzallo-Rivadeneira, Daniela; Angulo-Cruz, Alexandra; González-Andrade, Pablo; Minda-Aluisa, Elizabeth; Benítez-Ortíz, Washington; Brandt, Jef; Rodríguez-Hidalgo, Richar; Saegerman, Claude

    2017-03-01

    Very few, mostly old, and only preliminary serological studies of brucellosis in goats exist in Ecuador. In order to assess the current epidemiological situation, we performed a cross-sectional serological study in the goat populations of Carchi (n = 160 animals), Pichincha (n = 224 animals), and Loja provinces (n = 2024 animals). Only two positive serological results (RB negative and SAT-EDTA ≥400 IU/ml) were obtained in lactating goats from the same farm in Quito (Pichincha province). Additionally, milk was sampled from 220 animals in Pichincha province. The present study indicates a low apparent prevalence in Pichincha province and absence in Carchi and Loja provinces. A total of 25 positive milk ring tests (MRT) were obtained in Pichincha province yielding a prevalence of MRT of 11.16%. Subsequent culture was performed on the positive MRT samples. All results were negative, apart from a single sample, obtained from a serologically positive goat in Quito, that was positive for Brucella abortus strain 19 (B19). Several hypotheses are forwarded concerning this unexpected result. The most likely hypothesis is the possible accidental use of a needle, previously used for vaccination of cattle with the said vaccine, for the administration of drug treatment to the goat. This hypothesis underlines the necessity of biosecurity measures to prevent this type of accidents.

  19. Effects of a heavy and a moderate resistance training on functional performance in older adults.

    PubMed

    Kalapotharakos, Vasilios I; Michalopoulos, Maria; Tokmakidis, Savvas P; Godolias, George; Gourgoulis, Vasilios

    2005-08-01

    Resistance training can improve strength and functional performance, but there is little information about the effect of training intensity on functional performance in older adults. The purpose of this study was to determine the effect of 12 weeks of heavy (80% of 1 repetition maximum [1RM]) and moderate (60% of 1RM) resistance training on functional performance in healthy, inactive older adults, ages 60-74 years. Volunteer subjects were assigned randomly to a control group (CS, n = 10), heavy resistance training group (HRT, n = 11), or moderate resistance training group (MRT, n = 12) and participated in 12 weeks of strength training, 3 times per week. Performance measurements included 1RM lower-body strength, chair-rising time, walking velocity, stair-climbing time, and flexibility. Significant differences between HRT and MRT were found for 1RM strength of the lower limbs after the training period. Functional performance improved similarly for both HRT and MRT after the training period. Functional performance can be improved significantly with either heavy or moderate resistance training, without significant differences in the effectiveness of the 2 training protocols.

  20. Multi-gradient echo MR thermometry for monitoring of the near-field area during MR-guided high intensity focused ultrasound heating.

    PubMed

    Lam, Mie K; de Greef, Martijn; Bouwman, Job G; Moonen, Chrit T W; Viergever, Max A; Bartels, Lambertus W

    2015-10-07

    The multi-gradient echo MR thermometry (MGE MRT) method is proposed to use at the interface of the muscle and fat layers found in the abdominal wall, to monitor MR-HIFU heating. As MGE MRT uses fat as a reference, it is field-drift corrected. Relative temperature maps were reconstructed by subtracting absolute temperature maps. Because the absolute temperature maps are reconstructed of individual scans, MGE MRT provides the flexibility of interleaved mapping of temperature changes between two arbitrary time points. The method's performance was assessed in an ex vivo water bath experiment. An ex vivo HIFU experiment was performed to show the method's ability to monitor heating of consecutive HIFU sonications and to estimate cooling time constants, in the presence of field drift. The interleaved use between scans of a clinical protocol was demonstrated in vivo in a patient during a clinical uterine fibroid treatment. The relative temperature measurements were accurate (mean absolute error 0.3 °C) and provided excellent visualization of the heating of consecutive HIFU sonications. Maps were reconstructed of estimated cooling time constants and mean ROI values could be well explained by the applied heating pattern. Heating upon HIFU sonication and subsequent cooling could be observed in the in vivo demonstration.

  1. Conceptualization and validation of an open-source closed-loop deep brain stimulation system in rat

    PubMed Central

    Wu, Hemmings; Ghekiere, Hartwin; Beeckmans, Dorien; Tambuyzer, Tim; van Kuyck, Kris; Aerts, Jean-Marie; Nuttin, Bart

    2015-01-01

    Conventional deep brain stimulation (DBS) applies constant electrical stimulation to specific brain regions to treat neurological disorders. Closed-loop DBS with real-time feedback is gaining attention in recent years, after proved more effective than conventional DBS in terms of pathological symptom control clinically. Here we demonstrate the conceptualization and validation of a closed-loop DBS system using open-source hardware. We used hippocampal theta oscillations as system input, and electrical stimulation in the mesencephalic reticular formation (mRt) as controller output. It is well documented that hippocampal theta oscillations are highly related to locomotion, while electrical stimulation in the mRt induces freezing. We used an Arduino open-source microcontroller between input and output sources. This allowed us to use hippocampal local field potentials (LFPs) to steer electrical stimulation in the mRt. Our results showed that closed-loop DBS significantly suppressed locomotion compared to no stimulation, and required on average only 56% of the stimulation used in open-loop DBS to reach similar effects. The main advantages of open-source hardware include wide selection and availability, high customizability, and affordability. Our open-source closed-loop DBS system is effective, and warrants further research using open-source hardware for closed-loop neuromodulation. PMID:25897892

  2. Multi-gradient echo MR thermometry for monitoring of the near-field area during MR-guided high intensity focused ultrasound heating

    NASA Astrophysics Data System (ADS)

    Lam, Mie K.; de Greef, Martijn; Bouwman, Job G.; Moonen, Chrit T. W.; Viergever, Max A.; Bartels, Lambertus W.

    2015-10-01

    The multi-gradient echo MR thermometry (MGE MRT) method is proposed to use at the interface of the muscle and fat layers found in the abdominal wall, to monitor MR-HIFU heating. As MGE MRT uses fat as a reference, it is field-drift corrected. Relative temperature maps were reconstructed by subtracting absolute temperature maps. Because the absolute temperature maps are reconstructed of individual scans, MGE MRT provides the flexibility of interleaved mapping of temperature changes between two arbitrary time points. The method’s performance was assessed in an ex vivo water bath experiment. An ex vivo HIFU experiment was performed to show the method’s ability to monitor heating of consecutive HIFU sonications and to estimate cooling time constants, in the presence of field drift. The interleaved use between scans of a clinical protocol was demonstrated in vivo in a patient during a clinical uterine fibroid treatment. The relative temperature measurements were accurate (mean absolute error 0.3 °C) and provided excellent visualization of the heating of consecutive HIFU sonications. Maps were reconstructed of estimated cooling time constants and mean ROI values could be well explained by the applied heating pattern. Heating upon HIFU sonication and subsequent cooling could be observed in the in vivo demonstration.

  3. You Should Be the Specialist! Weak Mental Rotation Performance in Aviation Security Screeners – Reduced Performance Level in Aviation Security with No Gender Effect

    PubMed Central

    Krüger, Jenny K.; Suchan, Boris

    2016-01-01

    Aviation security screeners analyze a large number of X-ray images per day and seem to be experts in mentally rotating diverse kinds of visual objects. A robust gender-effect that men outperform women in the Vandenberg & Kuse mental rotation task has been well documented over the last years. In addition it has been shown that training can positively influence the overall task-performance. Considering this, the aim of the present study was to investigate whether security screeners show better performance in the Mental Rotation Test (MRT) independently of gender. Forty-seven security screeners of both sexes from two German airports were examined with a computer based MRT. Their performance was compared to a large sample of control subjects. The well-known gender-effect favoring men on mental rotation was significant within the control group. However, the security screeners did not show any sex differences suggesting an effect of training and professional performance. Surprisingly this specialized group showed a lower level of overall MRT performance than the control participants. Possible aviation related influences such as secondary effects of work-shift or expertise which can cumulatively cause this result are discussed. PMID:27014142

  4. Combining microwave resonance technology to multivariate data analysis as a novel PAT tool to improve process understanding in fluid bed granulation.

    PubMed

    Lourenço, Vera; Herdling, Thorsten; Reich, Gabriele; Menezes, José C; Lochmann, Dirk

    2011-08-01

    A set of 192 fluid bed granulation batches at industrial scale were in-line monitored using microwave resonance technology (MRT) to determine moisture, temperature and density of the granules. Multivariate data analysis techniques such as multiway partial least squares (PLS), multiway principal component analysis (PCA) and multivariate batch control charts were applied onto collected batch data sets. The combination of all these techniques, along with off-line particle size measurements, led to significantly increased process understanding. A seasonality effect could be put into evidence that impacted further processing through its influence on the final granule size. Moreover, it was demonstrated by means of a PLS that a relation between the particle size and the MRT measurements can be quantitatively defined, highlighting a potential ability of the MRT sensor to predict information about the final granule size. This study has contributed to improve a fluid bed granulation process, and the process knowledge obtained shows that the product quality can be built in process design, following Quality by Design (QbD) and Process Analytical Technology (PAT) principles.

  5. The use of point-of-decision prompts to increase stair climbing in Singapore.

    PubMed

    Sloan, Robert Alan; Haaland, Benjamin Adam; Leung, Carol; Müller-Riemenschneider, Falk

    2013-01-07

    Physical inactivity is a significant contributor to worldwide mortality and morbidity associated with non-communicable diseases. An excellent avenue to incorporate lifestyle physical activity into regular routine is to encourage the use of stairs during daily commutes. We evaluated the effectiveness of point-of-decision prompts (PODPs) in promoting the use of stairs instead of the escalators in a Singapore Mass Rapid Transit (MRT) station. We measured the number of stair climbers before the PODPs were put up, during the 4 weeks that they were in use, and 2 weeks after they were removed. Measurements at a no intervention control site were additionally taken. The use of stair-riser banners was associated with an increase in the number of people using the stairs by a factor of 1.49 (95% CI 1.34-1.64). After the banners were removed, the number of stair climbers at the experimental station dropped to slightly below baseline levels. The Singapore MRT serves a diverse multi-ethnic population with an average daily ridership of over 2 million and 88 stations island-wide. An increase of physical activity among these MRT commuters would have a large impact at the population level. Our findings can be translated into part of the national strategy to encourage an active lifestyle in Singaporeans.

  6. Conceptualization and validation of an open-source closed-loop deep brain stimulation system in rat.

    PubMed

    Wu, Hemmings; Ghekiere, Hartwin; Beeckmans, Dorien; Tambuyzer, Tim; van Kuyck, Kris; Aerts, Jean-Marie; Nuttin, Bart

    2015-04-21

    Conventional deep brain stimulation (DBS) applies constant electrical stimulation to specific brain regions to treat neurological disorders. Closed-loop DBS with real-time feedback is gaining attention in recent years, after proved more effective than conventional DBS in terms of pathological symptom control clinically. Here we demonstrate the conceptualization and validation of a closed-loop DBS system using open-source hardware. We used hippocampal theta oscillations as system input, and electrical stimulation in the mesencephalic reticular formation (mRt) as controller output. It is well documented that hippocampal theta oscillations are highly related to locomotion, while electrical stimulation in the mRt induces freezing. We used an Arduino open-source microcontroller between input and output sources. This allowed us to use hippocampal local field potentials (LFPs) to steer electrical stimulation in the mRt. Our results showed that closed-loop DBS significantly suppressed locomotion compared to no stimulation, and required on average only 56% of the stimulation used in open-loop DBS to reach similar effects. The main advantages of open-source hardware include wide selection and availability, high customizability, and affordability. Our open-source closed-loop DBS system is effective, and warrants further research using open-source hardware for closed-loop neuromodulation.

  7. Sex differences in spatial navigation and perception in human adolescents and emerging adults

    PubMed Central

    Sneider, Jennifer Tropp; Hamilton, Derek A.; Cohen-Gilbert, Julia E.; Crowley, David J.; Rosso, Isabelle M.; Silveri, Marisa M.

    2014-01-01

    Males typically outperform females on spatial tasks, beginning early in life and continuing into adulthood. This study aimed to characterize age and sex differences in human spatial ability using a virtual Water Maze Task (vWMT), which is based on the classic Morris water maze spatial navigation task used in rodents. Performance on the vWMT and on a task assessing visuospatial perception, Mental Rotations Test (MRT), was examined in 33 adolescents and 39 emerging adults. For the vWMT, significant effects of age and sex were observed for path length in the target region (narrower spatial sampling), and heading error, with emerging adults performing better than adolescents, and an overall male advantage. For the MRT, males scored higher than females, but only in emerging adulthood. Overall, sex differences in visuospatial perception (MRT) emerge differently from those observed on a classic navigation task, with age and sex-specific superior vWMT performance likely related to the use of more efficient strategies. Importantly, these results extend the developmental timeline of spatial ability characterization to include adolescent males and females performing a virtual version of the classic vWMT. PMID:25464337

  8. Fundamentals of the route theory for satellite constellation design for Earth discontinuous coverage. Part 3: Low-cost Earth observation with minimal satellite swath

    NASA Astrophysics Data System (ADS)

    Razoumny, Yury N.

    2016-12-01

    Continuing the series of papers with description of the fundamentals of the Route Theory for satellite constellation design, the general method for minimization of the satellite swath width required under given constraint on the maximum revisit time (MRT), the main quality characteristic of the satellite constellation discontinuous coverage, is presented. The interrelation between MRT and multiplicity of the periodic coverage - the minimum number of the observation sessions realized for the points of observation region during the satellite tracks' repetition period - is revealed and described. In particular, it is shown that a change of MRT can occur only at points of coverage multiplicity changing. Basic elements of multifold Earth coverage theory are presented and used for obtaining analytical relations for the minimum swath width providing given multifold coverage. The satellite swath width calculation procedure for the multifold coverage of rotating Earth using the iterations on the sphere of stationary coverage is developed. The numerical results for discontinuous coverage with minimal satellite swath, including comparison with some known particular cases and implementations of the method, are presented.

  9. A lattice-Boltzmann scheme of the Navier-Stokes equations on a 3D cuboid lattice

    NASA Astrophysics Data System (ADS)

    Min, Haoda; Peng, Cheng; Wang, Lian-Ping

    2015-11-01

    The standard lattice-Boltzmann method (LBM) for fluid flow simulation is based on a square (in 2D) or cubic (in 3D) lattice grids. Recently, two new lattice Boltzmann schemes have been developed on a 2D rectangular grid using the MRT (multiple-relaxation-time) collision model, by adding a free parameter in the definition of moments or by extending the equilibrium moments. Here we developed a lattice Boltzmann model on 3D cuboid lattice, namely, a lattice grid with different grid lengths in different spatial directions. We designed our MRT-LBM model by matching the moment equations from the Chapman-Enskog expansion with the Navier-Stokes equations. The model guarantees correct hydrodynamics. A second-order term is added to the equilibrium moments in order to restore the isotropy of viscosity on a cuboid lattice. The form and the coefficients of the extended equilibrium moments are determined through an inverse design process. An additional benefit of the model is that the viscosity can be adjusted independent of the stress-moment relaxation parameter, thus improving the numerical stability of the model. The resulting cuboid MRT-LBM model is then validated through benchmark simulations using laminar channel flow, turbulent channel flow, and the 3D Taylor-Green vortex flow.

  10. Effects of Medical Resonance Therapy Music on patients with psoriasis and neurodermatitis--a pilot study.

    PubMed

    Lazaroff, I; Shimshoni, R

    2000-01-01

    Stress medicine has shown that emotional disharmony can be a substantial factor for skin diseases. The harmonisation of the emotional status and a corresponding reduction of stress hormones by the Medical Resonance Therapy Music (MRT-Music) as shown in other studies (1,2,3,4) inspired us to investigate its benefits for patients with psoriasis vulgaris and neurodermatitis (neurodermatitis constitutionalis atopica). Over a period of 14 days we measured the parameters of blood pressure, heart rate, stimulus to scratch and the degree of sickness in two, respectively four groups of 68 patients in total: two experimental groups (psoriasis/neurodermatitis) and two control groups. All patients received the normal treatment of our hospital, the experimental groups were additionally treated with 3 x 30 minutes of MRT-Music per day, while the controls were asked to somehow relax during this time. In the experimental groups the measurements showed a reduction of blood pressure and heart rate and revealed an enhanced reduction of the stimulus to scratch and an enhanced reduction in the degree of sickness. Interestingly the effects of MRT-Music were stronger with the psoriasis patients than with the neurodermatitis patients. The results of this pilot study convinced us to offer the treatment with the Medical Resonance Therapy Music to all our patients.

  11. Thermally stable magnetic media based on antiferromagnetically coupled layers

    NASA Astrophysics Data System (ADS)

    Fullerton, Eric E.

    2001-03-01

    The combination of signal-to-noise requirements, write field limitations, and thermal activation of small particles is thought to limit the potential areal density of longitudinal media and is commonly referred to as the "superparamagnetic limit". Recording media composed of antiferromagnetically coupled (AFC) magnetic recording layers is a promising approach to extend areal densities of longitudinal media beyond these perceived limits [1,2]. The recording medium is made up of two ferromagnetic recording layer separated by a nonmagnetic layer whose thickness is tuned to couple the layers antiferromagnetically. For such a structure, the effective areal moment density (Mrt) of the composite structure is given by the difference between the ferromagnetic layers allowing the effective magnetic thickness to scale independently of the physical thickness of the media. The resulting media appears magnetically thin while being physically thick and, thus, allows AFC media to maintain thermal stability even for low Mrt values. Experimental realization of this concept using CoPtCrB alloy layers that demonstrates thermally stable low-Mrt media suitable for high-density recording will be discussed. This work is done in collaboration with D. T. Margulies, M. E. Schabes,M. Doerner, M. Carey, B. Gurney, A. Moser, M. Best, G. Zeltzer, K. Rubin, and H. Rosen. [1]. Fullerton et al., Appl. Phys. Lett. 77, 3806 (2000). [2]. Abarra et al., Appl. Phys. Lett. 77, 2581 (2000).

  12. Instability growth for magnetized liner inertial fusion seeded by electro-thermal, electro-choric, and material strength effects

    SciTech Connect

    Pecover, J. D.; Chittenden, J. P.

    2015-10-15

    A critical limitation of magnetically imploded systems such as magnetized liner inertial fusion (MagLIF) [Slutz et al., Phys. Plasmas 17, 056303 (2010)] is the magneto-Rayleigh-Taylor (MRT) instability which primarily disrupts the outer surface of the liner. MagLIF-relevant experiments have showed large amplitude multi-mode MRT instability growth growing from surface roughness [McBride et al., Phys. Rev. Lett. 109, 135004 (2012)], which is only reproduced by 3D simulations using our MHD code Gorgon when an artificially azimuthally correlated initialisation is added. We have shown that the missing azimuthal correlation could be provided by a combination of the electro-thermal instability (ETI) and an “electro-choric” instability (ECI); describing, respectively, the tendency of current to correlate azimuthally early in time due to temperature dependent Ohmic heating; and an amplification of the ETI driven by density dependent resistivity around vapourisation. We developed and implemented a material strength model in Gorgon to improve simulation of the solid phase of liner implosions which, when applied to simulations exhibiting the ETI and ECI, gave a significant increase in wavelength and amplitude. Full circumference simulations of the MRT instability provided a significant improvement on previous randomly initialised results and approached agreement with experiment.

  13. Observations of ETI under dielectric-overcoated aluminum pulsed to hundreds of Tesla

    NASA Astrophysics Data System (ADS)

    Hutchinson, Trevor; Bauer, Bruno; Fuelling, Stephan; Yates, Kevin; Awe, Thomas; Yelton, Graham

    2016-10-01

    MagLIF is an inertial confinement concept that takes advantage of relaxed fusion criteria due to premagnetized and preheated fuel. The drive surface is particularly susceptible to highly azimuthally correlated magneto-Rayleigh Taylor (MRT) instabilities, which section the liner wall and compromise confinement. This degree of azimuthal correlation is not due to residual lathe machining or surface roughness and a growing body of evidence suggest electrothermal instabilities (ETI) seed the MRT instability and allow for levels of azimuthal correlation that have been observed experimentally. Implementation of dielectric coatings on Sandia's Z accelerator has reduced MRT amplitudes by at least a factor of ten, which simulations suggest is due to mass tamping of the ETI. However, neither ETI nor its theorized suppression via an applied dielectric overcoat has been experimentally observed on a thick wire. We will report on experimental observations of ETI on the surface of 500 um radius aluminum rods with a 70 um parylene-N overcoat pulsed with 1 MA in 100 ns. This work was funded in part by Sandia's Laboratory Directed Research and Development Program (Project No. 178661).

  14. Dosimetry And Its Enhancement Using Gold Nanoparticles In Synchrotron Based Microbeam And Stereotactic Radiosurgery

    SciTech Connect

    Rahman, Wan Nordiana; Davidson, Robert; Geso, Moshi; Wong, Christopher James; Yagi, Naoto

    2010-07-23

    Research into the areas of synchrotron generated microbeam radiotherapy (MRT) and stereotactic radiosurgery is increasing. Such MRT techniques are showing potential of tackling some of the more difficult radiotherapy cases such as certain type of brain tumours. Two challenging aspects of these techniques are addressed in this investigation; the difficulty of dose determination and the delivery of the treatments at lower dose levels. In this research polymer gels were used as phantoms and dosimeters and cells were used to confirm outcomes. Normoxic polyacrylamide gels (nPAG) were tested as potential dosimeters for microbeam dosimetry. Following irradiation using microbeam and minibeam radiation from the BL28BU beam-line at Spring-8, Japan, the nPAG were scanned using a Raman spectroscopy technique. Dose enhancement caused by the inclusion of the gold nanoparticles (AuNPs) in the target was investigated using both cells and polymer gels. The use of AuNP could potentially reduce the dose required for the delivery of MRT. In this study it was shown that using endothelial cells with AuNPs, the minimal dose for clear cell killing along the beam line was reduced to 10 Gy. Both studies cell and gel studies indicates significant dose enhancement caused by the gold atoms in the target.

  15. Residence time distribution in a large unconfined-semiconfined aquifer in the Argentine Pampas using 3H/3He and CFC tracers

    NASA Astrophysics Data System (ADS)

    Martínez, D. E.; Fourré, E.; Londoño, O. M. Quiroz; Jean-Baptiste, P.; Galli, M. Glok; Dapoigny, A.; Grondona, S. I.

    2016-08-01

    The Pampa region in Argentina includes vast unconfined-semiconfined aquifers that local economies depend upon, but detailed knowledge of the associated water resources is still lacking. The Pampeano aquifer in the Pampa plain of Argentina covers around 1.5 million km2. In order to achieve a better understanding of the hydrogeological system through the estimation of mean residence times (MRT), water samples were taken from 12 monitoring wells, drilled at different depths in four locations, and analyzed for environmental tracers. The concentrations of 3H, tritiogenic 3He and chlorofluorocarbons (CFCs) can be explained by mixtures of young waters adjusted to exponential piston flow models (EPM) or dispersion models (DM), and different proportions of tracer-free waters (dead water). The sampling site located very close to the water divide shows a dominance of young waters: 85 % of water best represented by a DM model with a MRT of 3 years. For the shallow wells at other sites, best-fitting models result in a DM with MRT between 20 and 35 years, and proportions of dead water between 40 and 60 %. These results lead to important updates in the conceptual model of the Pampeano aquifer. Large proportions of dead water at a few meters depth can be the consequence of upward flows in a multilayered aquifer or diffusive retardation in the inter-bedded clay layers.

  16. Total enthalpy-based lattice Boltzmann method with adaptive mesh refinement for solid-liquid phase change

    NASA Astrophysics Data System (ADS)

    Huang, Rongzong; Wu, Huiying

    2016-06-01

    A total enthalpy-based lattice Boltzmann (LB) method with adaptive mesh refinement (AMR) is developed in this paper to efficiently simulate solid-liquid phase change problem where variables vary significantly near the phase interface and thus finer grid is required. For the total enthalpy-based LB method, the velocity field is solved by an incompressible LB model with multiple-relaxation-time (MRT) collision scheme, and the temperature field is solved by a total enthalpy-based MRT LB model with the phase interface effects considered and the deviation term eliminated. With a kinetic assumption that the density distribution function for solid phase is at equilibrium state, a volumetric LB scheme is proposed to accurately realize the nonslip velocity condition on the diffusive phase interface and in the solid phase. As compared with the previous schemes, this scheme can avoid nonphysical flow in the solid phase. As for the AMR approach, it is developed based on multiblock grids. An indicator function is introduced to control the adaptive generation of multiblock grids, which can guarantee the existence of overlap area between adjacent blocks for information exchange. Since MRT collision schemes are used, the information exchange is directly carried out in the moment space. Numerical tests are firstly performed to validate the strict satisfaction of the nonslip velocity condition, and then melting problems in a square cavity with different Prandtl numbers and Rayleigh numbers are simulated, which demonstrate that the present method can handle solid-liquid phase change problem with high efficiency and accuracy.

  17. Residence times in shallow waters help explain regional differences in Wadden Sea eutrophication

    NASA Astrophysics Data System (ADS)

    Schwichtenberg, Fabian; Callies, Ulrich; van Beusekom, Justus E. E.

    2016-11-01

    Regional variations in eutrophication levels of tidal basins in the Wadden Sea can be caused by external factors, like organic matter import, and internal factors like the morphology and hydrodynamics of the receiving tidal basin. For instance, benthic nutrients from remineralized organic matter may be more concentrated in shallow basins or diluted in basins with high exchange rates. In addition, the location of a monitoring station may determine which basin-specific water masses are actually observed. In the present paper a hydrodynamic intertidal imprint (IMP) is estimated for ten stations in various tidal basins of the Wadden Sea. The fraction of time water masses spent in intertidal areas prior to observation is calculated by linking the Lagrangian transport module PELETS to already existing hourly reconstructions of currents between 1959 and 2003. Irrespective of water depth, additional calculations of mean residence times (MRT) in the Wadden Sea indicate whether, in the case of low IMP values, water masses originate from coastal areas or tidal channels. Results show distinct regional differences, with highest values in the eastern part of the Dutch sector of the southern Wadden Sea (IMP=77%, MRT=99%) and lowest values in the German/Danish sector of the northern Wadden Sea (IMP=1.1%, MRT=21%). The IMP correlates positively with observed nutrient levels (R2=0.83). Evidently, this residence time-based intertidal signal is pivotal in explaining regional variations in eutrophication levels revealed by long-term comparative data from different monitoring stations.

  18. The effect of insertion angle on orthodontic mini-screw torque

    PubMed Central

    Raji, Seyed Hamid; Noorollahian, Saeed; Niknam, Seyed Mohsen

    2014-01-01

    Background: Primary stability is an important factor for the clinical success of orthodontic mini-screws. The present study made an attempt to evaluate the effect of insertion angle changes on the maximum insertion and removal torque of orthodontic mini-screws. Materials and Methods: In this experimental study, 72 mini-screws (Dual Top Anchor System, Jeil, 1.6 mm diameter, 8 mm length) were used. They were randomly divided into four equal groups and inserted in poly-carbonate plates with 3 mm thickness. Then, their maximum insertion torque (MIT) and maximum removal torque (MRT) were recorded using a digital torque tester/screwdriver. Each group had a different insertion angle (90°, 75°, 60° and 45°). The data were analyzed by SPSS software (version 18) using one-way ANOVA and post-hoc Tukey's tests. The level of significance was set at 0.05. Results: The maximum MIT was observed in 45° insertion angle (14.84 Ncm) and the minimum MIT was reported in 75° insertion angle (12.66 Ncm). The maximum MRT was observed in 45° insertion angle (23.21 Ncm) and the minimum MRT was reported in the 90° insertion angle (17.43 Ncm). Conclusion: Oblique insertion of the mini-screws results in higher insertion and removal torques and probably more primary stability compared to the vertical insertion. PMID:25225557

  19. The key to success in elite athletes? Explicit and implicit motor learning in youth elite and non-elite soccer players.

    PubMed

    Verburgh, L; Scherder, E J A; van Lange, P A M; Oosterlaan, J

    2016-09-01

    In sports, fast and accurate execution of movements is required. It has been shown that implicitly learned movements might be less vulnerable than explicitly learned movements to stressful and fast changing circumstances that exist at the elite sports level. The present study provides insight in explicit and implicit motor learning in youth soccer players with different expertise levels. Twenty-seven youth elite soccer players and 25 non-elite soccer players (aged 10-12) performed a serial reaction time task (SRTT). In the SRTT, one of the sequences must be learned explicitly, the other was implicitly learned. No main effect of group was found for implicit and explicit learning on mean reaction time (MRT) and accuracy. However, for MRT, an interaction was found between learning condition, learning phase and group. Analyses showed no group effects for the explicit learning condition, but youth elite soccer players showed better learning in the implicit learning condition. In particular, during implicit motor learning youth elite soccer showed faster MRTs in the early learning phase and earlier reached asymptote performance in terms of MRT. Present findings may be important for sports because children with superior implicit learning abilities in early learning phases may be able to learn more (durable) motor skills in a shorter time period as compared to other children.

  20. Effects of pH regulators used as additives on the bioavailability of ibuprofen from hard gelatin capsules.

    PubMed

    Hannula, A M; Marvola, M; Rajamaeki, M; Ojantakanen, S

    1991-01-01

    In our previous study the reasons for fast absorption of ibuprofen from sodium bicarbonate based hard gelatin capsules stayed unclear. These were not investigated using pH regulators (aluminium hydroxide, calcium carbonate, tartaric acid) with different chemical and physical properties. Ibuprofen absorption was much slower with aluminium hydroxide capsules (MRT 5.3, Tmax 3.1 h, Cmax 25.6 mg l-1, lag time 37.5 min) than with sodium bicarbonate capsules of the previous study (MRT 2.6 h, tmax 0.4 h, Cmax 51.4 mg l-1), lag time 0 min). The corresponding values for calcium carbonate and tartaric acid capsules were: MRT 3.7 h and 3.9 h, Tmax 1.7 h and 2.0 h, Cmax 32.2 mg l-1 and 30.8 mg l-1 and lag time 3.1 min and 7.6 min. No differences were noted in the AUC values. A rank order correlation existed between dissolution parameters and the in vivo parameters reflecting the rate of bioavailability. It was concluded that the rapid absorption of ibuprofen from capsules containing sodium carbonate is due to enhanced in vivo disintegration of the capsule, enhanced in vivo dissolution of the drug and enhanced gastric emptying rate.

  1. Residence times in shallow waters help explain regional differences in Wadden Sea eutrophication

    NASA Astrophysics Data System (ADS)

    Schwichtenberg, Fabian; Callies, Ulrich; van Beusekom, Justus E. E.

    2017-04-01

    Regional variations in eutrophication levels of tidal basins in the Wadden Sea can be caused by external factors, like organic matter import, and internal factors like the morphology and hydrodynamics of the receiving tidal basin. For instance, benthic nutrients from remineralized organic matter may be more concentrated in shallow basins or diluted in basins with high exchange rates. In addition, the location of a monitoring station may determine which basin-specific water masses are actually observed. In the present paper a hydrodynamic intertidal imprint (IMP) is estimated for ten stations in various tidal basins of the Wadden Sea. The fraction of time water masses spent in intertidal areas prior to observation is calculated by linking the Lagrangian transport module PELETS to already existing hourly reconstructions of currents between 1959 and 2003. Irrespective of water depth, additional calculations of mean residence times (MRT) in the Wadden Sea indicate whether, in the case of low IMP values, water masses originate from coastal areas or tidal channels. Results show distinct regional differences, with highest values in the eastern part of the Dutch sector of the southern Wadden Sea (IMP=77%, MRT=99%) and lowest values in the German/Danish sector of the northern Wadden Sea (IMP=1.1%, MRT=21%). The IMP correlates positively with observed nutrient levels (R2=0.83). Evidently, this residence time-based intertidal signal is pivotal in explaining regional variations in eutrophication levels revealed by long-term comparative data from different monitoring stations.

  2. The development and characterization of a first generation carbon nanotube x-ray based microbeam radiation therapy system

    NASA Astrophysics Data System (ADS)

    Hadsell, Michael John, Jr.

    Microbeam radiation therapy (MRT) is a new type of cancer treatment currently being studied at scattered synchrotron sites throughout the world. It has been shown to be capable of ablating aggressive brain tumors in rats while almost completely sparing the surrounding normal tissue. This promising technique has yet to find its way to the clinic, however, because the radiobiological mechanisms behind its efficacy are still largely unknown. This is partly due to the lack of a compact device that could facilitate more large scale research. The challenges inherent to creating a compact device lie within the structure of MRT, which uses parallel arrays of ultra high-dose, orthovoltage, microplanar beams on the order of 100mum thick and separated by four to ten times their width. Because of focal spot limitations, current commercial orthovoltage devices are simply not capable of creating such arrays at dose rates high enough for effective treatment while maintaining the microbeam pattern necessary to retain the high therapeutic ratio of the technique. Therefore, the development of a compact MRT device using carbon nanotube (CNT) cathode based X-ray technology is presented here. CNT cathodes have been shown to be capable of creating novel focal spot arrays on a single anode while being robust enough for long-term use in X-ray tubes. Using these cathodes, an X-ray tube with a single focal line has been created for the delivery of MRT dose distributions in radiobiological studies on small animals. In this work, the development process and final design of this specialized device will be detailed, along with the optimization and stabilization of its use for small animal studies. In addition, a detailed characterization of its final capabilities will be given; including a comprehensive measurement of its X-ray focal line dimensions, a description and evaluation of its collimator alignment and microbeam dimensions, and a full-scale phantom-based quantification of its dosimetric

  3. Intra and interindividual variability in the kinetics of a poorly and highly metabolising solvent.

    PubMed Central

    Opdam, J J

    1989-01-01

    Human subjects were experimentally exposed three times simultaneously to tetrachloroethene (PER) and trichloroethene (TRI) under conditions of rest and exercise. In each subject the individual kinetics for both PER and TRI were determined three times by means of frequent sampling of alveolar air up to 70-500 and 20-310 hours respectively. For PER the following parameters were found: the weighted pulmonary clearance (Clpul) = 0.27-0.64 l/min, terminal half time (t1/2(z] = 54-250 hours, mean residence time (MRT) = 35-155 hours, and volume of distribution (Vdss) = 1100-3570 1. For TRI the apparent hepatic clearance (CLhep) = 0.5-1.7 l/min, weighted Clpul = 0.41-1.48 l/min, t1/2(z) = 13-55 hours, MRT = 2.3-22 hours, and the Vdss = 420-3100 1. The intra and intersubject variation in the kinetics were reflected in the predictions of the individual time course of the solvent in the blood at repeated exposure up to five weeks (eight hours a day, five days a week). For PER the intrasubject variation in the predicted concentrations on the Monday mornings was within 5-15% whereas the intersubject variation was about twofold. For TRI the intrasubject variation in the predicted morning concentrations was substantial (two to threefold), whereas the intersubject variation was about 10-fold. The intrasubject variation was probably caused mainly by the level of exercise during exposure. The Clhep was not greatly influenced by the level of exercise, whereas exercise during exposure increased the MRT. Exercise during exposure probably speeds up the process of distribution and, therefore, there is a lower concentration in the blood relative to the increased respiratory intake. As a consequence, despite the increased Clpul and the rather unchanged Clhep, pulmonary and metabolic excretion will be delayed and the MRT increased. The MRT is more suited to predict the individual cumulation of both PER and TRI than the terminal t1/2(z). PMID:2611156

  4. Effect of grass hay intake on fiber digestion and digesta retention time in the hindgut of horses.

    PubMed

    Miyaji, M; Ueda, K; Hata, H; Kondo, S

    2014-04-01

    Eight Thoroughbred horses were used to examine the effects of grass hay intake on the fiber digestion and the retention time of digesta in the total gastrointestinal tract and the hindgut segments. The horses were randomly assigned to 2 groups and offered 2.0 (high intake [HI]) or 1.3 kg DM/(100 kg BW • d; low intake [LI]) of timothy hay in equal amounts every 3 h for 17 d. The digestibility and total tract mean retention time of digesta (tMRT) in the total gastrointestinal tract were measured from d 11 to d 15. To measure the mean retention time of digesta in each hindgut segment (sMRT), the horses were euthanized on d 17, after being fed a series of hay markers that were labeled with different rare earth elements. The digesta were collected from the ileum, cecum, right ventral colon (RVC), left ventral colon (LVC), left dorsal colon, right dorsal colon (RDC), and small colon (SC) to measure fiber digestibility, sMRT, VFA concentration, and fibrolytic activities. The digestibility of NDF and ADF in the total gastrointestinal tract was lower (P < 0.01) for HI than for LI. The cumulative disappearance of NDF and ADF from the ileum to the LVC attained 90% of total tract digestion regardless of hay intake. Values did not differ according to treatments in the ileum and the cecum but were lower (P < 0.01) for HI than for LI in the postcecal segments. This was caused by the smaller increase in the cumulative NDF and ADF disappearance from the cecum to the RVC for HI than for LI. The solid phase tMRT was shorter (P = 0.04) for HI than for LI. Although sMRT in the RDC and SC were shorter (P = 0.04 and P < 0.01, respectively) for HI than for LI, no differences were observed in the other hindgut segments. There was no difference between treatments in the total VFA concentration, VFA proportions, or the specific activity of carboxymethyl cellulase and xylanase in each hindgut segment. The fibrolytic activity for the cecum and RVC were greatest and decreased beyond the LVC

  5. „Überholen ohne einzuholen“ Die Entwicklung von Technologien für übermorgen in Kernenergie und Mikroelektronik der DDR

    NASA Astrophysics Data System (ADS)

    Barkleit, Gerhard

    Dem nuklearen Patt zwischen Ostblock und westlichem Staatenbündnis ist es nach weitgehend übereinstimmender Auffassung von Politik und Wissenschaft zu danken, dass der "Kalte Krieg" in der zweiten Hälfte des 20. Jahrhunderts nicht zum weltumfassenden Flächenbrand eskalierte. An der raschen Herstellung dieses Patts waren zwei Dresdner Physiker maßgeblich beteiligt, deren einer im Manhattan-Projekt in den USA gearbeitet hatte und später in England der Spionage für die Sowjetunion und des Verrats des Know-how der Atombombe überführt wurde.

  6. Nutzergerechte Entwicklung der Mensch-Maschine-Interaktion von Fahrerassistenzsystemen

    NASA Astrophysics Data System (ADS)

    König, Winfried

    Durch langjährige Forschungen bei Kfz-Herstellern, Zulieferfirmen und an Hochschulen sind umfangreiche, aber dennoch lückenhafte Erkenntnisse über das Zusammenspiel zwischen FAS und Nutzer gewonnen worden. In deutschen und internationalen Projekten wie z. B. PROMETHEUS, DRIVE, MOTIV, INVENT, RESPONSE und AKTIV haben sich Kfz-Hersteller, Zulieferfirmen, Hochschulen und weitere staatliche und private Forschungseinrichtungen zusammengefunden, um die vorwettbewerbliche Forschung für derartige Systeme voranzutreiben. Im folgenden Kapitel sollen einige der gewonnenen Kenntnisse dargelegt werden, um die Entwicklung des HMI von FAS zu erleichtern.

  7. Bedeutung der Informationsqualität bei Kaufentscheidungen im Internet

    NASA Astrophysics Data System (ADS)

    Gräfe, Gernot; Maaß, Christian

    Bei Kauf- und Verkaufsentscheidungen ist das Internet eine bedeutende Informationsquelle für Anbieter und Nachfrager. Während Anbieter ihre Produkte und Dienstleistungen sehr gut kennen und dazu Informationen bereitstellen, sehen sich Nachfrager oft mit einem Informationsdefizit konfrontiert. Sie haben unvollständige Kenntnisse über die Anbieter, ihre Produkte, Preise und weitere Geschäftsbedingungen und informieren sich daher im Internet. Die unausgewogene Informationsverteilung zwischen beiden Parteien wird als Informationsasymmetrie bezeichnet [Kaas 1991, S. 360], [Kleinaltenkamp 1992, S. 812], [Rohrbach 1997, S. 49].

  8. The Final Oral/Practical State Examination at Freiburg Medical Faculty in 2012--Analysis of grading to test quality assurance.

    PubMed

    Schickler, Angela; Brüstle, Peter; Biller, Silke

    2015-01-01

    Zielsetzung: Von der Medizinischen Fakultät Freiburg werden verschiedene Maßnahmen zur Qualitätssicherung des mündlich-praktischen Teils des Zweiten Abschnitts der Ärztlichen Prüfung (M2) betrieben. Insbesondere werden die Prüfenden in einem Baden-Württemberg-weit standardisierten M2-Prüferworkshop fortgebildet.Ziel der vorliegenden Studie war es die Notenvergabe zu analysieren. Es wurde geprüft, welcher Zusammenhang zwischen der schriftlichen und der mündlich-praktischen Notenvergabe besteht und ob sich ein Unterschied in der Notenvergabe zwischen Universitätsklinikum (UKL) und den Akademischen Lehrkrankenhäusern (ALKs) findet. Darüber hinaus wurde untersucht, ob sich die Notenvergabe von fortgebildeten und nicht fortgebildeten Prüfenden unterscheidet und inwieweit diese Unterschiede sich im zeitlichen Abstand zum Workshop verändern. Methodik: Die analysierte Stichprobe (N=315) umfasst die Frühjahrs- und Herbstprüfungskohorte 2012. Der Datensatz wurde vom Landesprüfungsamt zur Verfügung gestellt und mittels deskriptiver und Inferenzstatistik ausgewertet.Ergebnisse: Zwischen der schriftlichen und mündlich-praktischen M2-Prüfungsnote konnte ein Zusammenhang von ρ=0,460** ermittelt werden. Es konnte kein signifikanter Unterschied in der Verteilung der Noten zwischen UKL und den ALKs festgestellt werden. Die Daten zu den Variablen fortgebildete versus nicht fortgebildete Prüfende zeigen, dass Prüfende mit Absolvierung eines Prüferworkshops seltener die Note „sehr gut“ sowie ein breiteres Notenspektrum vergeben. In der Verteilung der Noten zeigt sich ein signifikanter Unterschied (p=0,007, phi=0,165). Dieses Ergebnis wird deutlicher bei Betrachtung von Prüfenden, deren Workshopteilnahme nicht länger als ein Jahr zurücklag. Schlussfolgerungen: Die Ergebnisse der Analyse weisen darauf hin, dass der Prüferworkshop an der Medizinischen Fakultät Freiburg eine wirksame Qualitätssicherungsmaßnahme ist. Die Ergebnisse lassen den Schluss zu

  9. Ingenieurgeologie: Grundlagen und Anwendung

    NASA Astrophysics Data System (ADS)

    Genske, Dieter D.

    Geplünderter Planet? Die Ingenieurgeologie ist ein junges, interdisziplinäres Fachgebiet. Es befasst sich mit der Wechselwirkung zwischen Geosphäre und Mensch. Der Autor stellt Georisiken vor und diskutiert die Folgen menschlicher Eingriffe in die Natur. Er thematisiert aktuelle Herausforderungen und entwirft nachhaltige Lösungskonzepte für verschiedene Problembereiche: z.B. Naturgefahren wie Hangrutschungen und Bergfälle, die Ausbeute natürlicher Ressourcen, Bau- und Sanierungsvorhaben. Fallbeschreibungen und ausgearbeitete Beispiele vertiefen das Verständnis für diesen neuen, zukunftsweisenden Zweig der Wissenschaft.

  10. New oral anticoagulants in the treatment of acute venous thromboembolism - a systematic review with indirect comparisons.

    PubMed

    Hirschl, Mirko; Kundi, Michael

    2014-09-01

    Hintergrund: Für Jahrzehnte waren Heparine und Vitamin K Antagonisten (VKA) der Goldstandard der Therapie der venösen Thromboembolie (VTE). Nun stehen mit Faktor IIa und Xa Inhibitoren neue Therapiemöglichkeiten zur Verfügung. Ziel dieser Analyse ist ein Vergleich dieser neuen oralen Antikoagulantien (NOACs) mit der Standardtherapie und - da es wahrscheinlich nie direkte Vergleichsstudien geben wird - ein indirekter Vergleich zwischen den NOACs. Patienten und Methoden: Insgesamt 27024 Patienten wurden in RE-COVER, RE-COVER II, EINSTEIN DVT und PE, AMPLIFY und HOKUSAI eingeschlossen, 13511 im VKA-Arm und 13513 im NOAC-Arm. Relative Risiken (RR) und absolute Risikoreduktionen (ARR) wurden für Effizienz- und Sicherheitsendpunkte in Relation zu VKA berechnet. Der indirekte Vergleich zwischen den NOACs erfolgte nach ISPOR Leitlinie. Ergebnisse: Bezüglich rekurrenter VTE und Tod findet sich zwischen NOACs und VKA kein Unterschied. Blutungen waren bei NOACs signifikant seltener: schwere Blutungen bei Rivaroxaban (RR 0,55; 0,38 - 0,81) und Apixaban (RR 0,31; 0,17 - 0,55), schwere Blutungen kombiniert mit klinisch relevanten nicht schweren Blutungen bei Dabigatran (RR 0,63; 0,51 - 0,77), bei Apixaban (RR 0,44; 0,36 - 0,55) und Edoxaban (RR 0,81; 0,71 - 0,93). Die ARR beträgt für Rivaroxaban und Apixaban etwa 1 % für schwere Blutungen, für die klinisch relevanten Blutungen war die ARR 3,2 % für Dabigatran, 5,4 % für Apixaban und 1.9 % für Edoxaban. Der indirekte Vergleich zeigt bzgl. der Effizienz keine Unterschiede zwischen den NOACs. Apixaban reduziert schwere Blutungen mehr als Dabigatran und Edoxaban. Den kombinierten Blutungsendpunkt senkt Dabigatran besser als Rivaroxaban und Edoxaban und Apixaban mehr als alle anderen NOACs. Schlussfolgerungen: NOACs sind zur Behandlung der VTE gleich effizient wie VKA, bei seltener auftretenden Blutungskomplikationen. Der indirekte Vergleich zeigt verschieden stark ausgeprägte Reduktion der Blutungskomplikationen

  11. Sugars in soil: Review of sources, contents, fate and functions

    NASA Astrophysics Data System (ADS)

    Gunina, Anna; Kuzyakov, Yakov

    2015-04-01

    Sugars are the most abundant organic compounds in the biosphere because they are monomers of all polysaccharides. We summarized the results of the last 40 years on sources, content and fate of sugars in soil and discussed their main functions in soil. We especially focused on uptake and utilization of sugars by microorganisms as this is by far the dominating process of sugars transformation in soil. Two databases have been created and analyzed. The 1st database was focused on the contents of cellulose, non-cellulose, hot water and cold water extractable sugars in soils (348 data from 32 studies). This database was also used to determine the primary (plant derived) and secondary (microbially and soil organic matter (SOM) derived) sources of carbohydrates in soil. The galactose+mannose/arabinose+xylose (GM/AX) ratio was calculated to analyze the origin of sugars in soil. The 2nd database was focused on the fate of sugar C in soil (734 data pairs from 32 studies), and only the papers used 13C or 14C labelled sugars were included. All data to the fate were analyzed and presented in dynamics. This allowed to calculate: 1) maximal rate of glucose-C decomposition, 2) mean residence time (MRT) of C of the initially applied sugars, 3) MRT of glucose-C incorporated into microbial biomass (MB) and SOM pools. Content of hexoses was 3-4 times higher than that of pentoses for both cellulose and non-cellulose sugars, because hexoses have two sources in soil: plants and microorganisms. The GM/AX ratio revealed higher contribution of hexoses in forest (ratio was 1.5) than in cropland and grassland soils (ratio was 0.7-1), reflecting high input of hexoses with forest litter. The MRT of sugars in soil solution was much less than 30 minutes. Based on the experiments with 13C or 14C labelled glucose, the maximal rate of glucose C decomposition in microbial biomass was ˜ 1min-1. Considering this rate, the glucose input from plants and content of sugar C in soil, we estimated that only

  12. Experiences with Testing the Largest Ground System NASA Has Ever Built

    NASA Technical Reports Server (NTRS)

    Lehtonen, Ken; Messerly, Robert

    2003-01-01

    In the 1980s, the National Aeronautics and Space Administration (NASA) embarked upon a major Earth-focused program called Mission to Planet Earth. The Goddard Space Flight Center (GSFC) was selected to manage and develop a key component - the Earth Observing System (EOS). The EOS consisted of four major missions designed to monitor the Earth. The missions included 4 spacecraft. Terra (launched December 1999), Aqua (launched May 2002), ICESat (Ice, Cloud, and Land Elevation Satellite, launched January 2003), and Aura (scheduled for launch January 2004). The purpose of these missions was to provide support for NASA s long-term research effort for determining how human-induced and natural changes affect our global environment. The EOS Data and Information System (EOSDIS), a globally distributed, large-scale scientific system, was built to support EOS. Its primary function is to capture, collect, process, and distribute the most voluminous set of remotely sensed scientific data to date estimated to be 350 Gbytes per day. The EOSDIS is composed of a diverse set of elements with functional capabilities that require the implementation of a complex set of computers, high-speed networks, mission-unique equipment, and associated Information Technology (IT) software along with mission-specific software. All missions are constrained by schedule, budget, and staffing resources, and rigorous testing has been shown to be critical to the success of each mission. This paper addresses the challenges associated with the planning, test definition. resource scheduling, execution, and discrepancy reporting involved in the mission readiness testing of a ground system on the scale of EOSDIS. The size and complexity of the mission systems supporting the Aqua flight operations, for example, combined with the limited resources available, prompted the project to challenge the prevailing testing culture. The resulting success of the Aqua Mission Readiness Testing (MRT) program was due in no

  13. Whole-tract digesta kinetics and comparison of techniques for the estimation of fecal output in steers fed coastal bermudagrass hay at four levels of intake.

    PubMed

    Luginbuhl, J M; Pond, K R; Burns, J C

    1994-01-01

    Coastal bermudagrass (Cynodon dactylon [L.] Pers) hay was fed to four ruminally cannulated steers (380 +/- 14 kg BW) of evaluate the effects of intake level on digesta flow kinetics in a 4 x 4 Latin square design. Forage intakes represented 50, 70, 88, and 99% of feed voluntarily consumed per animal during a pre-experimental period. Masticated boli and wet-sieved masticated leaves (ML) and stems (MS) retained by a 4.0-mm sieve and feces retained by a .063-mm sieve were mordanted with chromium or marked with erbium, ytterbium, or dysprosium, respectively. Particle markers and a solution of Co-EDTA were pulse-dosed via the ruminal cannula. A continuous infusion of Co-EDTA was later delivered with peristaltic pumps. Intake level had no effect (P > .10) on fluid and particle passage rate (PR; percentage/hour) of any fractions marked. For all particle fractions, increasing intake level caused linear decreases in mean retention time (MRT; P < .03 to P < .07) and linear increases in gastrointestinal tract fill (FILL; P < .003 to P < .02) and fecal output (FO; P < .001). Estimates of FO and DM digestibility from the pulse dose of Cr mordant and continuous infusion of Co-EDTA did not differ. Kinetic estimates differed in magnitude according to the characteristics of the particle fractions marked. Marked feces gave the shortest estimate of MRT and the smallest estimate of FILL and FO. Kinetics of ML and MS also differed (P < .001), the former having faster PR, shorter MRT, and smaller FILL and FO. Use of representative samples of ingested feed should give more realistic estimates of digesta kinetics than estimates derived from ingesta fractions because kinetics of separated leaf and stem fractions differed.

  14. Mercury in coniferous and deciduous upland forests in Northern New England, USA: implications from climate change

    NASA Astrophysics Data System (ADS)

    Richardson, J. B.; Friedland, A. J.

    2015-07-01

    Climatic changes in the northeastern US are expected to cause coniferous stands to transition to deciduous stands over the next hundred years. Mercury (Hg) sequestration in forest soils may change as a result. In order to understand potential effects of this transition, we studied aboveground vegetation and soils at paired coniferous and deciduous stands on eight mountains in Vermont and New Hampshire, US. Organic horizons at coniferous stands accumulated more Total Hg (THg) (42 ± 6 g ha-1) than deciduous stands (30 ± 4 g ha-1). Total Hg pools in the mineral horizons were similar for coniferous (46 ± 8 g ha-1) and deciduous stands (45 ± 7 g ha-1). Soil properties (C, % clay, and pH) explained 56 % of the variation in mineral soil Hg concentration when multiple regressed. Foliar and bole wood Hg concentrations were generally greater for coniferous species than deciduous species. We estimated Hg mean residence time (MRT) in the organic and mineral horizons at coniferous and deciduous stands using a simple two-box model. Organic horizon MRT were longer at coniferous stands (183 ± 44 yr) than deciduous stands (65 ± 15 yr). Mineral soil horizon MRT values were also longer for coniferous stands (386 ± 57 yr) than for deciduous stands (188 ± 27 yr). We concluded that organic horizon Hg accumulation is influenced by vegetation type but mineral horizons are primarily affected by soil properties. Further investigations into the effect of vegetation type on volatilization, atmospheric deposition, and leaching rates are needed to constrain regional Hg cycling rates.

  15. THE INFLUENCE OF SUBMERGED MACROPHYTES ON SEDIMENTARY DIATOM ASSEMBLAGES(1).

    PubMed

    Vermaire, Jesse C; Prairie, Yves T; Gregory-Eaves, Irene

    2011-12-01

    Submerged macrophytes are a central component of lake ecosystems; however, little is known regarding their long-term response to environmental change. We have examined the potential of diatoms as indicators of past macrophyte biomass. We first sampled periphyton to determine whether habitat was a predictor of diatom assemblage. We then sampled 41 lakes in Quebec, Canada, to evaluate whether whole-lake submerged macrophyte biomass (BiomEpiV) influenced surface sediment diatom assemblages. A multivariate regression tree (MRT) was used to construct a semiquantitative model to reconstruct past macrophyte biomass. We determined that periphytic diatom assemblages on macrophytes were significantly different from those on wood and rocks (ANOSIM R = 0.63, P < 0.01). A redundancy analysis (RDA) of the 41-lake data set identified BiomEpiV as a significant (P < 0.05) variable in structuring sedimentary diatom assemblages. The MRT analysis classified the lakes into three groups. These groups were (A) high-macrophyte, nutrient-limited lakes (BiomEpiV ≥525 μg · L(-1) ; total phosphorus [TP] <35 μg · L(-1) ; 23 lakes); (B) low-macrophyte, nutrient-limited lakes (BiomEpiV <525 μg · L(-1) ; TP <35 μg · L(-1) ; 12 lakes); and (C) eutrophic lakes (TP ≥35 μg · L(-1) ; six lakes). A semiquantitative model correctly predicted the MRT group of the lake 71% of the time (P < 0.001). These results suggest that submerged macrophytes have a significant influence on diatom community structure and that sedimentary diatom assemblages can be used to infer past macrophyte abundance.

  16. Assessment of optical CT as a future QA tool for synchrotron x-ray microbeam therapy

    NASA Astrophysics Data System (ADS)

    McErlean, Ciara M.; Bräuer-Krisch, Elke; Adamovics, John; Doran, Simon J.

    2016-01-01

    Synchrotron microbeam radiation therapy (MRT) is an advanced form of radiotherapy for which it is extremely difficult to provide adequate quality assurance. This may delay or limit its clinical uptake, particularly in the paediatric patient populations for whom it could be especially suitable. This study investigates the extent to which new developments in 3D dosimetry using optical computed tomography (CT) can visualise MRT dose distributions, and assesses what further developments are necessary before fully quantitative 3D measurements can be achieved. Two experiments are reported. In the first cylindrical samples of the radiochromic polymer PRESAGE® were irradiated with different complex MRT geometries including multiport treatments of collimated ‘pencil’ beams, interlaced microplanar arrays and a multiport treatment using an anthropomorphic head phantom. Samples were scanned using transmission optical CT. In the second experiment, optical CT measurements of the biologically important peak-to-valley dose ratio (PVDR) were compared with expected values from Monte Carlo simulations. The depth-of-field (DOF) of the optical CT system was characterised using a knife-edge method and the possibility of spatial resolution improvement through deconvolution of a measured point spread function (PSF) was investigated. 3D datasets from the first experiment revealed excellent visualisation of the 50 μm beams and various discrepancies from the planned delivery dose were found. The optical CT PVDR measurements were found to be consistently 30% of the expected Monte Carlo values and deconvolution of the microbeam profiles was found to lead to increased noise. The reason for the underestimation of the PVDR by optical CT was attributed to lack of spatial resolution, supported by the results of the DOF characterisation. Solutions are suggested for the outstanding challenges and the data are shown already to be useful in identifying potential treatment anomalies.

  17. Heart rate kinetics during exercise in patients with subclinical hypothyroidism.

    PubMed

    Almas, Saulo Peters; Werneck, Francisco Zacaron; Coelho, Emerson Filipino; Teixeira, Patrícia de Fátima Dos Santos; Vaisman, Mario

    2017-04-01

    Studies suggest that patients with subclinical hypothyroidism (SH) have sympathovagal imbalance, which could lead to a slower heart rate (HR) response in the transition from rest to exercise. Thus the objective of this study was to investigate the behavior of the HR kinetics in patients with SH during the transition from rest to exercise. The study included 18 SH women [thyroid stimulating hormone (TSH) = 6.95 ± 2.94 μIU/ml and free thyroxine (FT4) = 0.96 ± 0.15 ng/dl] and 17 euthyroid women (TSH = 2.28 ± 0.84 μIU/ml and FT4 = 0.98 ± 0.07 ng/dl). Both groups were matched for physical activity, menopausal status, and age. The HR kinetics was obtained during the course of a constant-load exercise (50 W), for 6 min, in a cycle ergometer, and quantified from the mean response time (MRT), which is equivalent to the time taken to reach 63% of the HR at steady state. SH patients showed slower HR kinetics than the control group (MRT = 48.5 ± 17.6 vs. 36.0 ± 10.3 s, P = 0.015). The MRT has been shown to correlate with the level of physical activity (r = -0.361; P = 0.033) and with the subjective perception of exertion at the end of the exercise (r = 0.365; P = 0.031). It is concluded that SH patients have slower HR kinetics in the transition from rest to exercise compared with euthyroid women, with this impairment being associated with lower levels of physical activity.NEW & NOTEWORTHY Subclinical hypothyroidism patients have slower heart rate kinetics in the transition from rest to exercise when performing a constant-load exercise at 50 W.

  18. Clinical application of Medical Resonance Therapy Music in high-risk pregnancies.

    PubMed

    Sidorenko, V N

    2000-01-01

    Music is an ancient method for healing. In the year 550 B.C., Pythagoras from Greece developed a concept for the use of music in medicine, esteeming music higher than many other medical treatments. The Medical Resonance Therapy Music (MRT-Music) of the German classical composer and musicologist Peter Huebner is built on this concept of Pythagorean music medicine. Its therapeutic effect may be best explained by the natural phenomenon of resonance between the harmony laws of the microcosm of music and the biological laws of the body. Results received after application of MRT-Music indicate multiple positive effects on the organism of pregnant women both with a healthy pregnancy as with a pathologic one, reducing the rate of premature births very effectively. Furthermore, MRT-Music came out to be an effective method in the complex therapy of late gestoses and a nearly irreplaceable method for preoperative preparation of pregnant woman for caesarean section. It demonstrated a powerful anti-stress effect and allowed to reduce the amount of administered pain-killers to pregnant women by the factor 1.5 to 2.0, thus reducing the negative pharmacological load to the foetus. It furthermore reduced labour time and shortened hospital stay. It helped to create optimal conditions for the course of pregnancy and heightened pain sensitivity threshold by means of improving the functional, hormonal, and psycho-emotional conditions of pregnant and lying-in women. Thus, the labour process became more natural, the delivery non-traumatic, and motherhood more happy and safe.

  19. Mitochondrial replacement in human oocytes carrying pathogenic mitochondrial DNA mutations.

    PubMed

    Kang, Eunju; Wu, Jun; Gutierrez, Nuria Marti; Koski, Amy; Tippner-Hedges, Rebecca; Agaronyan, Karen; Platero-Luengo, Aida; Martinez-Redondo, Paloma; Ma, Hong; Lee, Yeonmi; Hayama, Tomonari; Van Dyken, Crystal; Wang, Xinjian; Luo, Shiyu; Ahmed, Riffat; Li, Ying; Ji, Dongmei; Kayali, Refik; Cinnioglu, Cengiz; Olson, Susan; Jensen, Jeffrey; Battaglia, David; Lee, David; Wu, Diana; Huang, Taosheng; Wolf, Don P; Temiakov, Dmitry; Belmonte, Juan Carlos Izpisua; Amato, Paula; Mitalipov, Shoukhrat

    2016-12-08

    Maternally inherited mitochondrial (mt)DNA mutations can cause fatal or severely debilitating syndromes in children, with disease severity dependent on the specific gene mutation and the ratio of mutant to wild-type mtDNA (heteroplasmy) in each cell and tissue. Pathogenic mtDNA mutations are relatively common, with an estimated 778 affected children born each year in the United States. Mitochondrial replacement therapies or techniques (MRT) circumventing mother-to-child mtDNA disease transmission involve replacement of oocyte maternal mtDNA. Here we report MRT outcomes in several families with common mtDNA syndromes. The mother's oocytes were of normal quality and mutation levels correlated with those in existing children. Efficient replacement of oocyte mutant mtDNA was performed by spindle transfer, resulting in embryos containing >99% donor mtDNA. Donor mtDNA was stably maintained in embryonic stem cells (ES cells) derived from most embryos. However, some ES cell lines demonstrated gradual loss of donor mtDNA and reversal to the maternal haplotype. In evaluating donor-to-maternal mtDNA interactions, it seems that compatibility relates to mtDNA replication efficiency rather than to mismatch or oxidative phosphorylation dysfunction. We identify a polymorphism within the conserved sequence box II region of the D-loop as a plausible cause of preferential replication of specific mtDNA haplotypes. In addition, some haplotypes confer proliferative and growth advantages to cells. Hence, we propose a matching paradigm for selecting compatible donor mtDNA for MRT.

  20. Effects of season and nitrogen supply on the partitioning of recently fixed carbon in understory vegetation using a 13CO2 pulse labeling technique

    NASA Astrophysics Data System (ADS)

    Hasselquist, Niles; Metcalfe, Daniel; Högberg, Peter

    2013-04-01

    Vegetation research in boreal forests has traditionally been focused on trees, with little attention given to understory vegetation. However, understory vegetation has been identified as a key driver for the functioning of boreal forests and may play an important role in the amount of carbon (C) that is entering and leaving these forested ecosystems. We conducted a large-scale 13C pulse labeling experiment to better understand how recently fixed C is allocated in the understory vegetation characteristic of boreal forests. We used transparent plastic chambers to pulse label the understory vegetation with enriched 13CO2 in the early (June) and late (August) growing seasons. This study was also replicated across a nitrogen (N) fertilization treatment to better understand the effects of N availability on C allocation patterns. We present data on the amount of 13C label found in different components of the understory vegetation (i.e. leaves, stems, lichens, mosses, rhizomes and fine roots) as well as CO2 efflux. Additionally, we provide estimates of C residence time (MRT) among the different components and examine how MRT of C is affected by seasonality and N availability. Seasonality had a large effect on how recently fixed C is allocated in understory vegetation, whereas N fertilization influenced the MRT of C in the different components of ericaceous vegetation. Moreover, there was a general trend that N additions increased the amount of 13C in CO2 efflux compared to the amount of 13C in biomass, suggesting that N fertilization may lead to an increase in the utilization of recently fixed C, whereas N-limitation promotes the storage of recently fixed C.

  1. Factors related to child maltreatment in children presenting with burn injuries.

    PubMed

    Wibbenmeyer, Lucy; Liao, Junlin; Heard, Jason; Kealey, Lyn; Kealey, Gerald; Oral, Resmiye

    2014-01-01

    The underpinnings of maltreatment in children presenting with burn injuries are necessary to discern as detection and prevention rest on a clear delineation of factors associated with maltreatment. Inaccurate identification of child victims can result in perpetuation of the maltreatment and its attendant neuropsychological sequela. The authors sought to determine factors associated with maltreatment in children presenting with burn injuries, which would guide the burn team in assessing the likelihood of maltreatment. All consenting children admitted with burn injuries were surveyed regarding their injury mechanism and current sociodemographic status. Suspicious injuries were referred by the burn team to the multidisciplinary review team (MRT). The MRT reported injuries with signs of physical abuse, supervision neglect, neglect of other basic needs, or sexual abuse. These children constituted the cases in our study. Variables related to maltreatment were entered into stepwise logistic regression to identify independent predicting variables. P< .05 was considered significant. MRT identified 16 children (24%) admitted with burn injuries with suspicions of maltreatment. Risk factors related to suspicions of maltreatment included: young age, large burns, tap water injury, immersion lines, delay in care, absence of a two-parent family (unconventional family structure), young parents, inconsistent history, and injury pattern. In this single-center prospective study, the authors identified several factors that, when present in injuries with initial suspicion of maltreatment, should trigger a child maltreatment workup. Burn clinicians have an important role as advocates for children and their families. It is important to continue to further the knowledge of maltreatment detection and prevention among children presenting with burn injuries.

  2. Captopril and its dimer captopril disulfide: photodegradation, aerobic biodegradation and identification of transformation products by HPLC-UV and LC-ion trap-MS(n).

    PubMed

    Mahmoud, Waleed M M; Kümmerer, Klaus

    2012-08-01

    In some countries effluents from hospitals and households are directly emitted into open ditches without any further treatment and with very little dilution. Under such circumstances photo- and biodegradation in the environment can occur. However, these processes do not necessarily end up with the complete mineralization of a chemical. Therefore, the biodegradability of photoproduct(s) by environmental bacteria is of interest. Cardiovascular diseases are the number one cause of death globally. Captopril (CP) is used in this study as it is widely used in Egypt and stated as one of the essential drugs in Egypt for hypertension. Three tests from the OECD series were used for biodegradation testing: Closed Bottle test (CBT; OECD 301 D), Manometric Respirometry test (MRT; OECD 301 F) and the modified Zahn-Wellens test (ZWT; OECD 302 B). Photodegradation (150 W medium-pressure Hg-lamp) of CP was studied. Also CBT was performed for captopril disulfide (CPDS) and samples received after 64 min and 512 min of photolysis. The primary elimination of CP and CPDS was monitored by LC-UV at 210 nm and structures of photoproducts were assessed by LC-UV-MS/MS (ion trap). Analysis of photodegradation samples by LC-MS/MS revealed CP sulfonic acid as the major photodegradation product of CP. No biodegradation was observed for CP, CPDS and of the mixture resulting from photo-treatment after 64 min in CBT. Partial biodegradation in the CBT and MRT was observed in samples taken after 512 min photolysis and for CP itself in MRT. Complete biodegradation and mineralization of CP occurred in the ZWT.

  3. Independent effect of type 2 diabetes beyond characteristic comorbidities and medications on immediate but not continued knee extensor exercise hyperemia

    PubMed Central

    Poitras, Veronica J.; Bentley, Robert F.; Hopkins-Rosseel, Diana H.; LaHaye, Stephen A.

    2015-01-01

    We tested the hypothesis that type 2 diabetes (T2D), when present in the characteristic constellation of comorbidities (obesity, hypertension, dyslipidemia) and medications, slows the dynamic adjustment of exercising muscle perfusion and blunts the steady state relative to that of controls matched for age, body mass index, fitness, comorbidities, and non-T2D medications. Thirteen persons with T2D and 11 who served as controls performed rhythmic single-leg isometric quadriceps exercise (rest-to-6 kg and 6-to-12 kg transitions, 5 min at each intensity). Measurements included leg blood flow (LBF, femoral artery ultrasound), mean arterial pressure (MAP, finger photoplethysmography), and leg vascular conductance (LVK, calculated). Dynamics were quantified using mean response time (MRT). Measures of amplitude were also used to compare response adjustment: the change from baseline to 1) the peak initial response (greatest 1-s average in the first 10 s; ΔLBFPIR, ΔLVKPIR) and 2) the on-transient (average from curve fit at 15, 45, and 75 s; ΔLBFON, ΔLVKON). ΔLBFPIR was significantly blunted in T2D vs. control individuals (P = 0.037); this was due to a tendency for reduced ΔLVKPIR (P = 0.063). In contrast, the overall response speed was not different between groups (MRT P = 0.856, ΔLBFON P = 0.150) nor was the change from baseline to steady state (P = 0.204). ΔLBFPIR, ΔLBFON, and LBF MRT did not differ between rest-to-6 kg and 6-to-12 kg workload transitions (all P > 0.05). Despite a transient amplitude impairment at the onset of exercise, there is no robust or consistent effect of T2D on top of the comorbidities and medications typical of this population on the overall dynamic adjustment of LBF, or the steady-state levels achieved during low- or moderate-intensity exercise. PMID:26048976

  4. Bronchodilator effect on ventilatory, pulmonary gas exchange, and heart rate kinetics during high-intensity exercise in COPD.

    PubMed

    Laveneziana, Pierantonio; Palange, Paolo; Ora, Josuel; Martolini, Dario; O'Donnell, Denis E

    2009-12-01

    Respiratory mechanical abnormalities in patients with chronic obstructive pulmonary disease (COPD) may impair cardiodynamic responses and convective oxygen delivery during exercise, resulting in slower ventilatory, pulmonary gas exchange (PGE), and heart rate (HR) kinetics compared with normal. We reasoned that bronchodilators and the attendant reduction of operating lung volumes should accelerate ventilatory, PGE, and HR kinetics in the transition from rest to high-intensity exercise. Twelve clinically stable COPD patients undertook constant-work rate cycle testing at 75% of each individual's maximum work capacity after receiving either combined nebulized bronchodilators (BD) or placebo (PL), randomly. Mean response time (MRT) and amplitude of slow component for oxygen uptake (V'O(2)), carbon dioxide production (V'CO(2)), ventilation (V'(E)), and HR together with operating dynamic end-expiratory lung volume (EELV) were measured. Resting and exercise EELV decreased significantly by 0.38 L after BD compared with PL. After BD, V'O(2), V'CO(2), V'(E), and HR MRT accelerated (p < 0.05) by an average of 12, 22, 27, and 22 s, respectively (i.e., 15, 18, 22 and 27%, respectively). The slow component for V'O(2) declined by an average of 55 ml/min compared with PL. Speeded MRT for V'O(2) correlated with indices of reduced lung hyperinflation, such as resting EELV (r = -0.64, p = 0.025) and EELV at isotime (r = -0.77, p = 0.0032). The results confirm an important interaction between abnormal dynamic respiratory mechanics and indices of cardio-circulatory function in the rest-to-exercise transition in COPD patients.

  5. Pharmacokinetics and bioavailability of oral acetylcysteine in healthy volunteers.

    PubMed

    De Caro, L; Ghizzi, A; Costa, R; Longo, A; Ventresca, G P; Lodola, E

    1989-03-01

    The plasma pharmacokinetics of oral acetylcysteine(N-acetylcysteine, NAC) after the administration of single 600 mg and repeated 200 mg doses and the relative bioavailability of the two regimens were studied in 12 adult subjects. On two different occasions in a cross-over, balanced fashion the subjects were administered orally either a single dose of NAC 600 mg as effervescent tablets or 4 repeated doses of NAC as granules in sachets at the regimen of 200 mg t.i.d. Venous blood samples were obtained just before dosing and 20, 40 min, 1, 1.5, 2, 3, 4, 6, 8, 10 and 12 h after the administration of NAC 600 mg; with the 1st, the 2nd and the 4th doses of NAC 200 mg samples were taken just before dosing and after 20, 40 min, 1, 1.5, 2, 3, 4, 6 and 8 h, the last sampling after the 1st dose being the one before the 2nd dose. A detailed description of the assaying methods of NAC is given in the text. As indexes of bioavailability Cmax' tmax and AUC of NAC plasma concentrations were considered and MRT was taken as an estimate of its persistence in plasma. NAC was quickly absorbed without any significant difference in tmax among the doses. With the 600 mg dose Cmax' AUC and MRT were greater than with a single 200 mg dose; after summing up the values of these parameters for the 200 mg doses no significant differences were observed in comparison to the single 600 mg dose in Cmax and AUC, while MRT resulted significantly higher.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Characterization and quantification of cerebral edema induced by synchrotron x-ray microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Serduc, Raphaël; van de Looij, Yohan; Francony, Gilles; Verdonck, Olivier; van der Sanden, Boudewijn; Laissue, Jean; Farion, Régine; Bräuer-Krisch, Elke; Siegbahn, Erik Albert; Bravin, Alberto; Prezado, Yolanda; Segebarth, Christoph; Rémy, Chantal; Lahrech, Hana

    2008-03-01

    Cerebral edema is one of the main acute complications arising after irradiation of brain tumors. Microbeam radiation therapy (MRT), an innovative experimental radiotherapy technique using spatially fractionated synchrotron x-rays, has been shown to spare radiosensitive tissues such as mammal brains. The aim of this study was to determine if cerebral edema occurs after MRT using diffusion-weighted MRI and microgravimetry. Prone Swiss nude mice's heads were positioned horizontally in the synchrotron x-ray beam and the upper part of the left hemisphere was irradiated in the antero-posterior direction by an array of 18 planar microbeams (25 mm wide, on-center spacing 211 mm, height 4 mm, entrance dose 312 Gy or 1000 Gy). An apparent diffusion coefficient (ADC) was measured at 7 T 1, 7, 14, 21 and 28 days after irradiation. Eventually, the cerebral water content (CWC) was determined by microgravimetry. The ADC and CWC in the irradiated (312 Gy or 1000 Gy) and in the contralateral non-irradiated hemispheres were not significantly different at all measurement times, with two exceptions: (1) a 9% ADC decrease (p < 0.05) was observed in the irradiated cortex 1 day after exposure to 312 Gy, (2) a 0.7% increase (p < 0.05) in the CWC was measured in the irradiated hemispheres 1 day after exposure to 1000 Gy. The results demonstrate the presence of a minor and transient cellular edema (ADC decrease) at 1 day after a 312 Gy exposure, without a significant CWC increase. One day after a 1000 Gy exposure, the CWC increased, while the ADC remained unchanged and may reflect the simultaneous presence of cellular and vasogenic edema. Both types of edema disappear within a week after microbeam exposure which may confirm the normal tissue sparing effect of MRT. For more information on this article, see medicalphysicsweb.org

  7. Hierarchical RFI Mitigation System at the Mauritius Radio Telescope

    NASA Astrophysics Data System (ADS)

    Udaya Shankar, N.; Pandey, V. N.

    2006-08-01

    In this paper, we present salient features of the hierarchical RFI mitigation system developed and implemented for offline processing of the visibilities recorded at MRT. Its aim is to achieve effective, reliable and non-toxic automatic RFI mitigation with minimal human intervention. RFI poses a serious problem at MRT due to its low frequency of operation, wide primary beam  (EWxNS~2°x56°) and large amount of data collected for a low frequency survey. Even though several signal processing methods are used to handle RFI, in practice there is no universal foolproof technique. The developed system uses a conjunction of a variety of techniques involving linear and non-linear methods in the visibility as well as in the image domain. These include Thresholding, Fourier filtering, Hampel filtering, Model fitting, Visual inspection, multi-parameter decision based algorithm which uses cumulative interference statistics, and the fact that the sky signal is correlated in each day's images but interference is most likely not. More than 99.7% of the interference is detected automatically, the remaining is detected by semi-automatic methods. The images obtained after applying the RFI mitigation system are free from any perceivable interference and demonstrate its effectiveness. The principles and techniques used in the RFI mitigation system are of general nature. We believe that such an approach based on a conjunction of techniques exploiting their natural strengths and judiciously applying them at various stages of data processing is an important step in the future direction of research to accomplish the ultimate goal of achieving completely automatic data flagging. Use of an RFI database is valuable to investigate the nature of interference at an observatory site and develop appropriate techniques based on its statistics for its mitigation. The 20,000 hours of astronomical observations for the MRT survey have been used for such an analysis. The interesting aspects of

  8. The Infrared & Electro-Optical Systems Handbook. Emerging Systems and Technologies, Volume 8

    DTIC Science & Technology

    1993-01-01

    Zerodur , 3-62 77, 7-475-476, 7-489 Mirrors , mounting, 3-172, 4-172-177, 4-187- Minimum resolvable temperature (MRT), 3- 188 115, 3-456, 4-49, 4-81-83...image is superimposed on its mirror image [Fig. 1.20(b)]. Several baselines still measure the same spatial frequency. All the baselines measure spatial...a flat mirror with a roof prism in a Michelson interferometer. 30 6-30 8 In a rotational shear interferometer, one pupil image is rotated with respect

  9. [Post-traumatic aneurysm of the dorsal nasal artery. A rarity following blunt trauma].

    PubMed

    Schuldt, T

    2010-12-01

    We report the case of a 69-year-old male patient who appeared in our clinic with persistent swelling on the right middle nasal bridge of 3 months' standing following blunt trauma. On physical examination the swelling was pulsatile and a flow was identified on color Doppler sonography. MRT of the head demonstrated an aneurysm of the dorsal nasal artery. We treated the aneurysm in an open surgical procedure under local anaesthesia. Due to the superficial position of this artery, open injuries are common after blunt nasal trauma. Some cases of aneurysm of the temporal artery have been described. Aneurysm of the dorsal nasal artery is a rare result of nasal trauma.

  10. Comparative investigations on digestion in grazing (Ceratotherium simum) and browsing (Diceros bicornis) rhinoceroses.

    PubMed

    Steuer, P; Clauss, M; Südekum, K-H; Hatt, J-M; Silinski, S; Klomburg, S; Zimmermann, W; Fickel, J; Streich, W J; Hummel, J

    2010-08-01

    Rhinoceroses represent the largest extant herbivores with extensive dietary specialization for plant groups like browse (black rhino Diceros bicornis) or grass (white rhino Ceratotherium simum). However, it is not clear to what extent such diet selection patterns are reflected in adaptations of digestive physiology of the respective feeding types. In this study, feeding trials with four black and five white rhinos were conducted in four zoos. The animals had ad libitum access to the same batch of grass hay (second cut; neutral detergent fiber (NDF) 63% dry matter (DM), crude protein 10.2% DM). Total intake, fecal N content, in vitro digestibility of NDF residues of feces, fecal particle size and mean retention time (MRT) of particles (Cr-mordanted fiber; 1-2mm) and fluid (Co-EDTA) were quantified. The average daily DM intake was 70+/-12 g/kg BW(0.75) for white and 73+/-10 g/kg BW(0.75) for black rhinos. In the in vitro fermentation test fecal NDF residues of black rhinos resulted in higher gas productions at fermentation times of 12 to 24h, indicating that white rhinos have a superior capacity to digest NDF. Average MRT for fluids and particles was 28+/-4h and 43+/-5h in white and 34+/-4h and 39+/-4h in black rhinos. The selectivity factor (SF=MRT(particle)/MRT(fluid)) was higher for white (1.5+/-0.2) than for black rhinos (1.2+/-0.1) (p=0.016). In a comparison of 12 ruminant and 3 rhino species, SF was correlated to percentage of grass in diet (R=0.75). Mean fecal particle size was higher in white (9.1+/-1.94 mm) than in black rhinos (6.1+/-0.79 mm) (p=0.016). The results demonstrate differences between white and black rhinos in terms of retention times and fiber digestibility. The more selective retention of particles by the white rhino corresponds with the higher digestion of fiber measured indirectly. Furthermore there is indication for a general pattern of high SF in grazing ruminants and rhinos. The difference in fecal particle size between both rhino species

  11. Micrometer-resolved film dosimetry using a microscope in microbeam radiation therapy

    SciTech Connect

    Bartzsch, Stefan Oelfke, Uwe; Lott, Johanna; Welsch, Katrin; Bräuer-Krisch, Elke

    2015-07-15

    Purpose: Microbeam radiation therapy (MRT) is a still preclinical tumor therapy approach that uses arrays of a few tens of micrometer wide parallel beams separated by a few 100 μm. The production, measurement, and planning of such radiation fields are a challenge up to now. Here, the authors investigate the feasibility of radiochromic film dosimetry in combination with a microscopic readout as a tool to validate peak and valley doses in MRT, which is an important requirement for a future clinical application of the therapy. Methods: Gafchromic{sup ®} HD-810 and HD-V2 films are exposed to MRT fields at the biomedical beamline ID17 of the European Synchrotron Radiation Facility (ESRF) and are afterward scanned with a microscope. The measured dose is compared with Monte Carlo calculations. Image analysis tools and film handling protocols are developed that allow accurate and reproducible dosimetry. The performance of HD-810 and HD-V2 films is compared and a detailed analysis of the resolution, noise, and energy dependence is carried out. Measurement uncertainties are identified and analyzed. Results: The dose was measured with a resolution of 5 × 1000 μm{sup 2} and an accuracy of 5% in the peak and between 10% and 15% in the valley region. As main causes for dosimetry uncertainties, statistical noise, film inhomogeneities, and calibration errors were identified. Calibration errors strongly increase at low doses and exceeded 3% for doses below 50 and 70 Gy for HD-V2 and HD-810 films, respectively. While the grain size of both film types is approximately 2 μm, the statistical noise in HD-V2 is much higher than in HD-810 films. However, HD-810 films show a higher energy dependence at low photon energies. Conclusions: Both film types are appropriate for dosimetry in MRT and the microscope is superior to the microdensitometer used before at the ESRF with respect to resolution and reproducibility. However, a very careful analysis of the image data is required

  12. WE-AB-BRB-12: Nanoscintillator Fiber-Optic Detector System for Microbeam Radiation Therapy Dosimetry

    SciTech Connect

    Rivera, J; Dooley, J; Chang, S; Belley, M; Yoshizumi, T; Stanton, I; Langloss, B; Therien, M

    2015-06-15

    Purpose: Microbeam Radiation Therapy (MRT) is an experimental radiation therapy that has demonstrated a higher therapeutic ratio than conventional radiation therapy in animal studies. There are several roadblocks in translating the promising treatment technology to clinical application, one of which is the lack of a real-time, high-resolution dosimeter. Current clinical radiation detectors have poor spatial resolution and, as such, are unsuitable for measuring microbeams with submillimeter-scale widths. Although GafChromic film has high spatial resolution, it lacks the real-time dosimetry capability necessary for MRT preclinical research and potential clinical use. In this work we have demonstrated the feasibility of using a nanoscintillator fiber-optic detector (nanoFOD) system for real-time MRT dosimetry. Methods: A microplanar beam array is generated using a x-ray research irradiator and a custom-made, microbeam-forming collimator. The newest generation nanoFOD has an effective size of 70 µm in the measurement direction and was calibrated against a kV ion chamber (RadCal Accu-Pro) in open field geometry. We have written a computer script that performs automatic data collection with immediate background subtraction. A computer-controlled detector positioning stage is used to precisely measure the microbeam peak dose and beam profile by translating the stage during data collection. We test the new generation nanoFOD system, with increased active scintillation volume, against the previous generation system. Both raw and processed data are time-stamped and recorded to enable future post-processing. Results: The real-time microbeam dosimetry system worked as expected. The new generation dosimeter has approximately double the active volume compared to the previous generation resulting in over 900% increase in signal. The active volume of the dosimeter still provided the spatial resolution that meets the Nyquist criterion for our microbeam widths. Conclusion: We have

  13. Computer-Based Weather Research.

    DTIC Science & Technology

    1980-02-29

    F D-A994 020 SYSTEMS AND APPLZED SCIENCES CORP RIVERDALE MD FIG q/ COMPUTER BASED WEATHER RESEARCH.(U) FEB 80 A M GERLACH F19628-79-C-0033 Mrt F P0...AFGL-TR-80-0069 Na EIIIETEEII IBIBIIfIIIINI 0 Alan M4. Gerlach (ed.) I ~ stems and Applied Sciences Corporationl N~i eiworth Avenue I Riverdale...TITLE (and Si~bt,tle) 5 TYPE OF REPORT & PERIOD COVERED 7 cientific X’epaartVo. 2. COMPUTER-BASED WEATHER RESEARCH I Dee 78 - 3/’ Nov 79 \\ 7AUTHOR B ~MER

  14. Elaboration over a Discourse Facilitates Retrieval in Sentence Processing.

    PubMed

    Troyer, Melissa; Hofmeister, Philip; Kutas, Marta

    2016-01-01

    Language comprehension requires access to stored knowledge and the ability to combine knowledge in new, meaningful ways. Previous work has shown that processing linguistically more complex expressions ('Texas cattle rancher' vs. 'rancher') leads to slow-downs in reading during initial processing, possibly reflecting effort in combining information. Conversely, when this information must subsequently be retrieved (as in filler-gap constructions), processing is facilitated for more complex expressions, possibly because more semantic cues are available during retrieval. To follow up on this hypothesis, we tested whether information distributed across a short discourse can similarly provide effective cues for retrieval. Participants read texts introducing two referents (e.g., two senators), one of whom was described in greater detail than the other (e.g., 'The Democrat had voted for one of the senators, and the Republican had voted for the other, a man from Ohio who was running for president'). The final sentence (e.g., 'The senator who the {Republican/Democrat}had voted for…') contained a relative clause picking out either the Many-Cue referent (with 'Republican') or the One-Cue referent (with 'Democrat'). We predicted facilitated retrieval (faster reading times) for the Many-Cue condition at the verb region ('had voted for'), where readers could understand that 'The senator' is the object of the verb. As predicted, this pattern was observed at the retrieval region and continued throughout the rest of the sentence. Participants also completed the Author/Magazine Recognition Tests (ART/MRT; Stanovich and West, 1989), providing a proxy for world knowledge. Since higher ART/MRT scores may index (a) greater experience accessing relevant knowledge and/or (b) richer/more highly structured representations in semantic memory, we predicted it would be positively associated with effects of elaboration on retrieval. We did not observe the predicted interaction between ART/MRT

  15. Comparison of a GLC-NPD method with a GLC-MS-SIM procedure for the determination of tilidine and its metabolites in plasma.

    PubMed

    Cordonnier, J; Wauters, A; Heyndrickx, A

    1987-01-01

    A gas liquid chromatographic method with nitrogen-phosphorus detection (GLC-NPD) is compared to a GLC-mass spectrometric determination employing selected ion monitoring (GLC-MS-SIM). These two methods of gas chromatographic separation were shown to be suitable for therapeutic monitoring of tilidine, nortilidine, and bisnortilidine in patients. The pharmacokinetic profile of tilidine was also studied in three normal humans after a single oral dose. Pharmacokinetic parameters such as Cmax, tmax, (t1/2) beta, AUC, AUMC, Vd beta, Cltot, beta, and MRT are derived from model independent pharmacokinetic techniques.

  16. Building a Middle-Range Theory of Adaptive Spirituality.

    PubMed

    Dobratz, Marjorie C

    2016-04-01

    The purpose of this article is to describe a Roy adaptation model based- research abstraction, the findings of which were synthesized into a middle-range theory (MRT) of adaptive spirituality. The published literature yielded 21 empirical studies that investigated religion/spirituality. Quantitative results supported the influence of spirituality on quality of life, psychosocial adjustment, well-being, adaptive coping, and the self-concept mode. Qualitative findings showed the importance of spiritual expressions, values, and beliefs in adapting to chronic illness, bereavement, death, and other life transitions. These findings were abstracted into six theoretical statements, a conceptual definition of adaptive spirituality, and three hypotheses for future testing.

  17. Methodology, and the Statistician’s Responsibility for BOTH Accuracy and Relevance

    DTIC Science & Technology

    1975-12-01

    John W. Tukey is also Associate Executive Director- Research , Beel Telephone Laboratories . I ! u I». Ktv UBS fSSSi m m!mSi S5 i wtiwrii S...eoNmokkiNO erriet NAM AND ACOHCM Office of Naval Research (Code «»36) Arlington, VA 22217 Z^lp&wlliMCTioiii -./ r^ aCII>l«Mrt CATALÖO...558» ir SS3 mSSm ~~~’ level or change, least squares, fit PLUS residuals, Phillips curve, patch maps, standardization ■A AMTRACT

  18. Application of isotopes to estimate water ages in variable time scales in surface and groundwaters

    NASA Astrophysics Data System (ADS)

    Kralik, Martin

    2014-05-01

    Water-Isotopes (2H, 3H, 18O) are ideal tracers not only to determine the origin of waters in precipitation, surface water (river + lakes) as well as in groundwater close to the surface and in deep groundwater but also the mean residence time (MRT) in many applied projects as drinking water supply, hydroelectric power plants, road tunnels etc. . Their application has a long history, but must be always evaluated by a feasible hydrogeological concept and/or other isotope and geochemical tracers. In Alpine areas the retention of precipitation in form of snow and ice in the winter half year is indicated by the lowest 18O-values. The snow melt of the highest part of the recharge area is marked by the lowest 18O-values in the river water, but may not coincide with the maximum flow. Time-series of precipitation station in the mountain and on river station indicate the arrival of the peak snow-melt water in the river and in Low-land areas 4-7 month later. Tritium series indicate that MRTs of several Austrian rivers are in the range of 4 - 6 years. The seasonal input variation of in 18O in precipitation and/or river waters can be used to calculate by lumped parameter models MRT of groundwater at a certain well and compare it with lysimeter measurements and transient model simulations. The MRT of the dispersion model is in good agreement with the estimated time calculated by the numerical transport model and the vertical lysimeter measurements. The MRT of spring water was studied by several methods (3H/3He, SF6 and 85Kr) and a long time series of 3H-measurements. The gas tracers are in good agreement in the range of 6-10 year whereas the 3H-series model (dispersion model) indicate ages in the range of 18-23 years. The hydrogeological concept indicate that the precipitation infiltrates in a mountainous karst area, but the transfer into the porous aquifer in the Vienna Basin occurs either through rivers draining away in the basin or through the lateral transport from the karst

  19. Ecological Risk Assessment of Perchlorate in Avian Species, Rodents, Amphibians and Fish: FY2003

    DTIC Science & Technology

    2005-10-01

    REPRODUCTIVE AND MOLECULAR TOXICITY OF TNX IN DEER MICE …………………………………………………………………….. 1 DEVELOPMENTAL RESPONSE OF LARVAL XENOPUS LAEVIS TO TNX ….…. 21... Reproductive and Molecular Toxicity of TNX in Deer Mice. STUDY NUMBER: MRT-03-01 SPONSOR: Strategic Environmental and Research...TIEHH Protocol No. FINCH-04-01 U.S. Air Force Coop. Agreement CU 1235 Page 5 of 225 1.0 DESCRIPTIVE STUDY TITLE: Reproductive and Molecular

  20. Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 1. Noise Sources

    DTIC Science & Technology

    1991-08-01

    coso kl (32) -2 [mB(Mr2cosO- M,) ] = t 1 +kMx BD (33) and the phase lag due to sweep is 2Mrt mB MCA _r I _ _’cs - k - (34)Ms- r k1-Mzcos6 k D In equation...indicates sound at blade-passage frequency and its multiples, just as with the steady-loading formulas discussed previously. The factor ( r /C%) - t indicates...Pressures. AIAA-80-0977, June 1980 36 Chou, S - T .; and George, A. R .. Effect of Angle of Attack on Rotor Trading-Edge Noise. AIAA J, vol. 22, no 12, Dec

  1. NPS Field Experimentation Program For Special Operations (FEPSO) TNT 13-2 Report

    DTIC Science & Technology

    2013-04-01

    Dynetics ,  Inc.     712.  Concealment  and...CERDEC,  CP&I 701 Rockwell  Collins  Inc. Revision 771 Dynetics FlexTech  Alliance  &   Physical  Optics  Corp Rockwell  Collins  Inc...CERDEC Revision Dynetics L-­‐3  KEO  &  MRT 776 Lunch  Brief Textron  Defense   Systems 776 731 710 MegaWave Defense

  2. Generalization of the Landau-Lifshitz-Gilbert equation for conducting ferromagnets.

    PubMed

    Zhang, Shufeng; Zhang, Steven S-L

    2009-02-27

    We propose an extension of the Landau-Lifshitz-Gilbert (LLG) equation by explicitly including the role of conduction electrons in magnetization dynamics of conducting ferromagnets. The temporal and spatial dependent magnetization order parameter m(r,t) generates both electrical and spin currents that provide dissipation of the energy and angular momentum of the processing magnet. The resulting LLG equation contains highly spatial dependence of damping term and thus micromagnetic simulations based on the standard LLG equation should be reexamined for magnetization dynamics involving narrow domain walls and spin waves with short wavelengths.

  3. Influence of exercise intensity on skeletal muscle blood flow, O2 extraction and O2 uptake on-kinetics.

    PubMed

    Jones, Andrew M; Krustrup, Peter; Wilkerson, Daryl P; Berger, Nicolas J; Calbet, José A; Bangsbo, Jens

    2012-09-01

    Following the start of low-intensity exercise in healthy humans, it has been established that the kinetics of skeletal muscle O(2) delivery is faster than, and does not limit, the kinetics of muscle O(2) uptake (V(O(2)(m))). Direct data are lacking, however, on the question of whether O(2) delivery might limit (V(O(2)(m))) kinetics during high-intensity exercise. Using multiple exercise transitions to enhance confidence in parameter estimation, we therefore investigated the kinetics of, and inter-relationships between, muscle blood flow (Q(m)), a-(V(O(2))) difference and (V(O(2)(m))) following the onset of low-intensity (LI) and high-intensity (HI) exercise. Seven healthy males completed four 6 min bouts of LI and four 6 min bouts of HI single-legged knee-extension exercise. Blood was frequently drawn from the femoral artery and vein during exercise and Q(m), a-(V(O(2))) difference and (V(O(2)(m))) were calculated and subsequently modelled using non-linear regression techniques. For LI, the fundamental component mean response time (MRT(p)) for Q(m) kinetics was significantly shorter than (V(O(2)(m))) kinetics (mean ± SEM, 18 ± 4 vs. 30 ± 4 s; P < 0.05), whereas for HI, the MRT(p) for Q(m) and (V(O(2)(m))) was not significantly different (27 ± 5 vs. 29 ± 4 s, respectively). There was no difference in the MRT(p) for either Q(m) or (V(O(2)(m))) between the two exercise intensities; however, the MRT(p)for a-(V(O(2)) difference was significantly shorter for HI compared with LI (17 ± 3 vs. 28 ± 4 s; P < 0.05). Excess O(2), i.e. oxygen not taken up (Q(m) x (V(O(2))), was significantly elevated within the first 5 s of exercise and remained unaltered thereafter, with no differences between LI and HI. These results indicate that bulk O(2) delivery does not limit (V(O(2)(m))) kinetics following the onset of LI or HI knee-extension exercise.

  4. Effects of stimulus color, pattern, and practice on sex differences in mental rotations task performance.

    PubMed

    Alington, D E; Leaf, R C; Monaghan, J R

    1992-09-01

    Redundant color information improved performance for both sexes on the Shepard Mental Rotations Task (MRT; Shepard & Metzler, 1971). Absolute score gains for women were larger than those for men; therefore, relative improvement was greater. Substantial practice effects, also favoring women, were apparent in both studies. Study 1 showed that redundant color improved performance by 0.25 SD. Study 2 demonstrated that redundant black-and-white pattern information did not have any effect; a second visuospatial channel, redundant color, was a critical factor in improving scores of men and women on difficult mental rotations tasks.

  5. Microbial carbon recycling: an underestimated process controlling soil carbon dynamics - Part 2: A C3-C4 vegetation change field labelling experiment

    NASA Astrophysics Data System (ADS)

    Basler, A.; Dippold, M.; Helfrich, M.; Dyckmans, J.

    2015-11-01

    The mean residence times (MRT) of different compound classes of soil organic matter (SOM) do not match their inherent recalcitrance to decomposition. One reason for this is the stabilization within the soil matrix, but recycling, i.e. the reuse of "old" organic material to form new biomass may also play a role as it uncouples the residence times of organic matter from the lifetime of discrete molecules in soil. We analysed soil sugar dynamics in a natural 30-year old labelling experiment after a wheat-maize vegetation change to determine the extent of recycling and stabilization by assessing differences in turnover dynamics between plant and microbial-derived sugars: while plant-derived sugars are only affected by stabilization processes, microbial sugars may be subject to both, stabilization and recycling. To disentangle the dynamics of soil sugars, we separated different density fractions (free particulate organic matter (fPOM), light occluded particulate organic matter (≤ 1.6 g cm-3; oPOM1.6), dense occluded particulate organic matter (≤ 2 g cm-3; oPOM2) and mineral-associated organic matter (> 2 g cm-3; mineral)) of a silty loam under long-term wheat and maize cultivation. The isotopic signature of neutral sugars was measured by high pressure liquid chromatography coupled to isotope ratio mass spectrometry (HPLC/IRMS), after hydrolysis with 4 M Trifluoroacetic acid. While apparent MRT of sugars were comparable to total organic carbon in the bulk soil and mineral fraction, the apparent MRT of sugar carbon in the oPOM fractions were considerably lower than those of the total carbon of these fractions. This indicates that oPOM formation was fuelled by microbial activity feeding on new plant input. In the bulk soil, MRT of the mainly plant-derived xylose were significantly lower than those of mainly microbial-derived sugars like galactose, rhamnose, fucose, indicating that recycling of organic matter is an important factor regulating organic matter dynamics in

  6. Discrepancy between femoral and capillary blood flow kinetics during knee extension exercise.

    PubMed

    Schlup, S J; Ade, C J; Broxterman, R M; Barstow, T J

    2015-12-01

    Capillary blood flow (QCAP) kinetics have previously been shown to be significantly slower than femoral artery (QFA) kinetics following the onset of dynamic knee extension exercise. If the increase in QCAP does not follow a similar time course to QFA, then a substantial proportion of the available blood flow is not distributed to the working muscle. One possible explanation for this discrepancy is that blood flow also increases to the nonworking lower leg muscles. Therefore, the present study aimed to determine if a reduction in lower limb blood flow, via arterial occlusion below the knee, alters the kinetics of QFA and QCAP during knee extension exercise, and thus provide insight into the potential mechanisms controlling the rapid increase in QFA. Subjects performed a ramp max test to determine the work rate at which gas exchange threshold (GET) occurred. At least four constant work rate trials with and without below-knee occlusion were conducted at work rates eliciting ∼ 80% GET. Pulmonary gas exchange, near-infrared spectroscopy and QFA measurements were taken continuously during each exercise bout. Muscle oxygen uptake (VO2m) and deoxy[hemoglobin+myoglobin] were used to estimate QCAP. There was no significant difference between the uncuffed and cuffed conditions in any response (P>0.05). The mean response times (MRT) of QFA were 18.7 ± 14.2s (uncuffed) and 24.6 ± 14.9s (cuffed). QCAP MRTs were 51.8 ± 23.4s (uncuffed) and 56.7 ± 23.2s (cuffed), which were not significantly different from the time constants (τ) of VO2m (39.7 ± 23.2s (uncuffed) and 46.3 ± 24.1s (cuffed). However, the MRT of QFA was significantly faster (P<0.05) than the MRT of QCAP and τVO2m. τVO2m and MRT QCAP were significantly correlated and estimated QCAP kinetics tracked VO2m following exercise onset. Cuffing below the knee did not significantly change the kinetics of QFA, QCAP or VO2m, although an effect size of 1.02 suggested that a significant effect on QFA may have been hidden

  7. Elaboration over a Discourse Facilitates Retrieval in Sentence Processing

    PubMed Central

    Troyer, Melissa; Hofmeister, Philip; Kutas, Marta

    2016-01-01

    Language comprehension requires access to stored knowledge and the ability to combine knowledge in new, meaningful ways. Previous work has shown that processing linguistically more complex expressions (‘Texas cattle rancher’ vs. ‘rancher’) leads to slow-downs in reading during initial processing, possibly reflecting effort in combining information. Conversely, when this information must subsequently be retrieved (as in filler-gap constructions), processing is facilitated for more complex expressions, possibly because more semantic cues are available during retrieval. To follow up on this hypothesis, we tested whether information distributed across a short discourse can similarly provide effective cues for retrieval. Participants read texts introducing two referents (e.g., two senators), one of whom was described in greater detail than the other (e.g., ‘The Democrat had voted for one of the senators, and the Republican had voted for the other, a man from Ohio who was running for president’). The final sentence (e.g., ‘The senator who the {Republican/Democrat}had voted for…’) contained a relative clause picking out either the Many-Cue referent (with ‘Republican’) or the One-Cue referent (with ‘Democrat’). We predicted facilitated retrieval (faster reading times) for the Many-Cue condition at the verb region (‘had voted for’), where readers could understand that ‘The senator’ is the object of the verb. As predicted, this pattern was observed at the retrieval region and continued throughout the rest of the sentence. Participants also completed the Author/Magazine Recognition Tests (ART/MRT; Stanovich and West, 1989), providing a proxy for world knowledge. Since higher ART/MRT scores may index (a) greater experience accessing relevant knowledge and/or (b) richer/more highly structured representations in semantic memory, we predicted it would be positively associated with effects of elaboration on retrieval. We did not observe the

  8. Regional Groundwater Processes and Flow Dynamics from Age Tracer Data

    NASA Astrophysics Data System (ADS)

    Morgenstern, Uwe; Stewart, Mike K.; Matthews, Abby

    2016-04-01

    Age tracers are now used in New Zealand on regional scales for quantifying the impact and lag time of land use and climate change on the quantity and quality of available groundwater resources within the framework of the National Policy Statement for Freshwater Management 2014. Age tracers provide measurable information on the dynamics of groundwater systems and reaction rates (e.g. denitrification), essential for conceptualising the regional groundwater - surface water system and informing the development of land use and groundwater flow and transport models. In the Horizons Region of New Zealand, around 200 wells have tracer data available, including tritium, SF6, CFCs, 2H, 18O, Ar, N2, CH4 and radon. Well depths range from shallower wells in gravel aquifers in the Horowhenua and Tararua districts, and deeper wells in the aquifers between Palmerston North and Wanganui. Most of the groundwater samples around and north of the Manawatu River west of the Tararua ranges are extremely old (>100 years), even from relatively shallow wells, indicating that these groundwaters are relatively disconnected from fresh surface recharge. The groundwater wells in the Horowhenua tap into a considerably younger groundwater reservoir with groundwater mean residence time (MRT) of 10 - 40 years. Groundwater along the eastern side of the Tararua and Ruahine ranges is significantly younger, typically <5 years MRT. Vertical groundwater recharge rates, as deduced from groundwater depth and MRT, are extremely low in the central coastal area, consistent with confined groundwater systems, or with upwelling of old groundwater close to the coast. Very low vertical recharge rates along the Manawatu River west of the Manawatu Gorge indicate upwelling groundwater conditions in this area, implying groundwater discharge into the river is more likely here than loss of river water into the groundwater system. High recharge rates observed at several wells in the Horowhenua area and in the area east of

  9. Heteronukleare Spinentkopplung unter dem Einfluß thermischer Bewegungen

    NASA Astrophysics Data System (ADS)

    Ernst, H.; Fenzke, D.; Pfeifer, H.

    Unter der Annahme magnetischer Dipol-IS-Wechselwirkung wird eine Theorie der heteronuklearen Spinentkopplung für kurze Korrelationszeiten entwickelt. Diese enthält als Spezialfälle die kernmagnetischen Relaxationsraten im rotierenden und im festen Koordinatensystem sowie die Kreuzpolarisation zwischen den Spins I und S. In Übereinstimmung mit dieser Theorie tritt für die protonenentkoppelte C-13 Resonanz von Butanol, das in einem NaY-Zeolith adsorbiert ist, ein Maximum der Linienbreite als Funktion der Temperatur zwischen - 150°C und + 90°C auf.Translated AbstractHeteronuclear Spin Decoupling in the Presence of Thermal MotionAssuming magnetic dipolar I-S interaction, a general short -correlation time theory is presented which includes as special cases also well-known formulas for relaxation rates in the rotating and laboratory frame and for the cross polarization between I and S spins. In accordance with this theory for the proton-decoupled C-13 resonance of butanol adsorbed in a NaY zeolite, a maximum of the linewidth is observed as a function of temperature between - 150°C and + 90°C.

  10. Schlusswort

    NASA Astrophysics Data System (ADS)

    Pfeffer, Michael; Reinhardt, Andreas

    Im Rahmen des BMBF-Verbundprojektes ProMoLeS wurde bereits zu Projektbeginn der Industriearbeitskreis Montagelösungen für die Leistungselektronik" gegründet, welcher unter der organisatorischen und fachlichen Leitung vom bayerischen Cluster Leistungselektronik im ECPE e.V. eine Plattform für den Austausch zwischen Unternehmen der Leistungselektronik bietet. Ziel des Industriearbeitskreises ist es daher, mit neuen und innovativen Lösungen einen Beitrag zur Sicherung der Montagearbeitsplätze am Standort Deutschland zu leisten. Der Arbeitskreis richtet sich an Fach- und Führungskräfte von Unternehmen, die leistungselektronische Systeme oder deren Komponenten entwickeln und herstellen: Entwicklungsingenieure, Fertigungsplaner, Fertigungstechnologen, Fertigungsleiter, Arbeitsorganisatoren, Qualitätsbeauftragte sowie Wissenschaftler an Hochschulen, die auf den genannten Gebieten arbeiten. Ziel und Zweck des Arbeitskreises ist es, Wissen und Erfahrung auszutauschen, persönliche Kontakte von Fachleuten zwischen Unternehmen und wissenschaftlichen Einrichtungen zu verstärken, Kooperationen in dem Gebieten der Entwicklung, Fertigung, Logistik oder Qualifizierung aufzubauen, strategisch relevante Themen zu erkennen und gemeinsame Forschungs- und Entwicklungsprojekte zu initiieren. Damit soll die Wettbewerbsfähigkeit der Unternehmen verbessert und Arbeitsplätze am Standort gesichert werden.

  11. [The mental health of only children and of siblings with cancer - first results of a multicenter study in Germany].

    PubMed

    Bojanowski, Sabine; Führer, Daniel; Romer, Georg; Bergelt, Corinna; von Klitzing, Kai; Brähler, Elmar; Keller, Monika; Resch, Franz; Flechtner, Hans-Henning; Lehmkuhl, Ulrike; Weschenfelder-Stachwitz, Heike

    2014-07-01

    Theoretischer Hintergrund: Kinder krebskranker Eltern wurden als Risikogruppe für die Entwicklung von psychischen Störungen identifiziert. Ergebnisse der Scheidungsforschung zeigten, dass auch Geschwisterbeziehungen bei belastenden Lebensereignissen vor psychischen Störungen schützen können. Fragestellung: Kann das Vorhandensein eines Geschwisters die Bewältigung einer elterlichen onkologischen Erkrankung unterstützen und somit auch dort als protektiver Faktor wirken? Methodik: In einer multizentrischen Studie wurden 271 Kinder untersucht. 54 % waren Inanspruchnehmer eines psychosozialen Beratungsangebotes. Einzelkinder (N = 89) und Kinder mit Geschwistern (N = 182) wurden im Hinblick auf ihre psychische Belastung (Strength and Difficulties Questionnaire, SDQ, Selbst- und Fremdurteil) miteinander verglichen. Ergebnisse: Im Gruppenvergleich zeigten sich zwischen Einzelkindern und Kindern mit Geschwistern keine signifikanten Unterschiede im Gesamturteil der Eltern. Dies galt sowohl für die Einschätzung durch den gesunden als auch durch den erkrankten Elternteil. In der Selbsteinschätzung zeigten sich bei 2 % der Einzelkinder und bei 9 % der Geschwister klinisch auffällige Werte im Gesamtproblemwert des SDQ. Der Gruppenvergleich zwischen Einzelkindern und Kindern mit Geschwistern offenbarte im Hinblick auf deren psychische Belastung keine bedeutsamen Unterschiede. Es ergaben sich Hinweise darauf, dass eine negative Beziehungsqualität (Sibling Relationship Questionnaire, SRQ) mit verstärkten Problemen in der Peer-Group assoziiert ist. Schlussfolgerungen: Das Vorhandensein eines Geschwisters ist nicht per se ein protektiver Faktor. Einzelkinder wiesen im Vergleich zu Kindern mit Geschwistern keine höhere psychische Belastung auf.

  12. Herschel und die Zukunft der Fern-Infrarot-Astronomie

    NASA Astrophysics Data System (ADS)

    Linz, Hendrik

    2015-06-01

    Schon lange ist die beobachtende Astronomie den engen Grenzen des optisch Sichbaren entwachsen und hat fast alle Bereiche des elektromagnetischen Spektrums für sich dienstbar gemacht. Im sogenannten nahen und mittleren Infrarot (Wellenlängen zwischen 1-30 μm) sowie im Millimeter- und Radio-Regime (Wellenlängen zwischen 1 mm und 10 m) ist die Erdatmosphäre relativ gut durchlässig für elektromagnetische Signale oder hat zumindest eine Vielzahl von spektral begrenzten Transmissionsfenstern, die astronomische Beobachtungen zumindest von höheren Bergen aus möglich machen. Allerdings ist das sogenannte Ferne Infrarot (FIR, 30-300 μm Wellenlänge) von der Erde aus fast völlig unzugänglich für astronomische Beobachtungen. Selbst für die besten Beobachtungsplätze der Erde bleibt die atmosphärische Transmission durch die immense Wasserdampf- Absorption auf ein absolutes Minimum beschränkt. Jedoch erlaubt uns das FIR Zugang zu Informationen, die sehr nützlich sind für die astrophysikalische Forschung und komplementär zu anderen Wellenlängen-Bereichen.

  13. Water modulates the ultraslow dynamics of hydrated ionic liquids near CG rich DNA: consequences for DNA stability.

    PubMed

    Saha, Debasis; Kulkarni, Mandar; Mukherjee, Arnab

    2016-11-30

    Ionic liquids are known to stabilize DNA for much longer than water can. While the source of this stability has commonly been attributed to thermodynamic aspects, we probe the dynamical aspects of the ionic liquids near DNA to further our understanding of this stability. Using molecular dynamics simulation, we calculated the mean residence time (MRT) of the cations of five different ionic liquids (ILs) in the grooves and around phosphate groups of AT and CG rich DNA segments. We find the residence time of different cations next to CG rich DNA to be much higher compared to that next to AT rich DNA, with a negligible difference with the variation of anions. The interaction energy between cations and DNA, however, shows exactly the opposite trend; it is much lower (indicating a stronger interaction) for AT than for CG. Investigation of DNA parameters reveals an insignificant difference for the DNA sequences under consideration. Analysis of water behavior provides a rationale for the long MRTs of cations; water molecules have been found to be denser and to possess higher MRT when next to CG-rich DNA, thus resulting in a crowded environment. Our results indicate that the dynamics influence the binding of ILs to different DNA sequences, possibly by modulating the entropy of the binding process.

  14. Influence of implant shape, surface morphology, surgical technique and bone quality on the primary stability of dental implants.

    PubMed

    Elias, Carlos Nelson; Rocha, Felipe Assis; Nascimento, Ana Lucia; Coelho, Paulo Guilherme

    2012-12-01

    The primary stability of dental implants has been investigated before, but a study of the influence of implant shape, size and surface morphology (machined, acid etched or anodized), surgical technique (press-fit or undersized) and substrate (natural or simulated bone) on the primary stability of dental implants has not been reported. The present work intends to fill this gap. In this work, six different dental implants were inserted into and removed from synthetic and natural bone while measuring the torque. A total of 255 dental implants with three shapes, four sizes and three surface topographies were inserted into pig rib, PTFE and polyurethane. The implant sites were prepared using straight and tapered drills. The primary stability was estimated from the maximum insertion torque. Comparisons between samples were based on the maximum insertion torque (MIT), the maximum removal torque (MRT) and the torque ratio (TR=MRT/MIT). The insertion torque into pig ribs showed larger dispersion. All parameters (shape, size and surface morphology of the implant, surgical technique and substrate type) were found to have a significant influence on primary stability. The insertion of a tapered implant requires a higher torque than the insertion of a straight implant. Surface treatments improve the primary stability. The influence of the surgical technique is smaller than that of implant size and shape. The highest insertion torque was that of anodized tapered implants inserted into undersized sites. Finally, the primary stability of dental implants is highly dependent on implant design, surgical technique and substrate type.

  15. Multiple-relaxation-time color-gradient lattice Boltzmann model for simulating two-phase flows with high density ratio

    NASA Astrophysics Data System (ADS)

    Ba, Yan; Liu, Haihu; Li, Qing; Kang, Qinjun; Sun, Jinju

    2016-08-01

    In this paper we propose a color-gradient lattice Boltzmann (LB) model for simulating two-phase flows with high density ratio and high Reynolds number. The model applies a multirelaxation-time (MRT) collision operator to enhance the stability of the simulation. A source term, which is derived by the Chapman-Enskog analysis, is added into the MRT LB equation so that the Navier-Stokes equations can be exactly recovered. Also, a form of the equilibrium density distribution function is used to simplify the source term. To validate the proposed model, steady flows of a static droplet and the layered channel flow are first simulated with density ratios up to 1000. Small values of spurious velocities and interfacial tension errors are found in the static droplet test, and improved profiles of velocity are obtained by the present model in simulating channel flows. Then, two cases of unsteady flows, Rayleigh-Taylor instability and droplet splashing on a thin film, are simulated. In the former case, the density ratio of 3 and Reynolds numbers of 256 and 2048 are considered. The interface shapes and spike and bubble positions are in good agreement with the results of previous studies. In the latter case, the droplet spreading radius is found to obey the power law proposed in previous studies for the density ratio of 100 and Reynolds number up to 500.

  16. Ribosome-stalk biogenesis is coupled with recruitment of nuclear-export factor to the nascent 60S subunit.

    PubMed

    Sarkar, Anshuk; Pech, Markus; Thoms, Matthias; Beckmann, Roland; Hurt, Ed

    2016-12-01

    Nuclear export of preribosomal subunits is a key step during eukaryotic ribosome formation. To efficiently pass through the FG-repeat meshwork of the nuclear pore complex, the large pre-60S subunit requires several export factors. Here we describe the mechanism of recruitment of the Saccharomyces cerevisiae RNA-export receptor Mex67-Mtr2 to the pre-60S subunit at the proper time. Mex67-Mtr2 binds at the premature ribosomal-stalk region, which later during translation serves as a binding platform for translational GTPases on the mature ribosome. The assembly factor Mrt4, a structural homolog of cytoplasmic-stalk protein P0, masks this site, thus preventing untimely recruitment of Mex67-Mtr2 to nuclear pre-60S particles. Subsequently, Yvh1 triggers Mrt4 release in the nucleus, thereby creating a narrow time window for Mex67-Mtr2 association at this site and facilitating nuclear export of the large subunit. Thus, a spatiotemporal mark on the ribosomal stalk controls the recruitment of an RNA-export receptor to the nascent 60S subunit.

  17. Experimental Investigation of the Electrothermal Instability on Planar Foil Ablation Experiments

    NASA Astrophysics Data System (ADS)

    Steiner, Adam; Patel, Sonal; Yager-Elorriaga, David; Jordan, Nicholas; Gilgenbach, Ronald; Lau, Y. Y.

    2014-10-01

    The electrothermal instability (ETI) is an important early-time physical effect on pulsed power foil ablation experiments due to its ability to seed the destructive magneto-Rayleigh-Taylor (MRT) instability. ETI occurs whenever electrical resistivity has temperature dependence; when resistivity increases with temperature, as with solid metal liners or foils, ETI forms striation structures perpendicular to current flow. These striations provide an initial perturbation for the MRT instability, which is the dominant late-time instability in planar foil ablations. The MAIZE linear transformer driver was used to drive current pulses of approximately 600 kA into 400 nm-thick aluminum foils in order to study ETI in planar geometry. Shadowgraph images of the aluminum plasmas were taken for multiple shots at various times within approximately 50 ns of current start. Fourier analysis extracted the approximate wavelengths of the instability structures on the plasma-vacuum interface. Surface metrology of pre-shot foils was performed to provide a comparison between surface roughness features and resulting plasma structure. This work was supported by US DoE. S.G. Patel and A.M. Steiner supported by NPSC funded by Sandia. D.A. Yager supported by NSF fellowship Grant # DGE 1256260.

  18. Pharmacokinetics of oxytetracycline in the American horseshoe crab, Limulus polyphemus.

    PubMed

    Nolan, M W; Smith, S A; Jones, D

    2007-10-01

    The American horseshoe crab, Limulus polyphemus, is regularly cultured and maintained in research laboratories and public aquaria. Rising concerns over the health of these captive animals makes the diagnosis and treatment of pathological conditions in L. polyphemus essential. This study investigated the kinetics of oxytetracyline following either intravascular or oral dosing. Oxytetracylcine is a broad-spectrum antibiotic used in the treatment of various bacterial diseases of aquatic animals. A noncompartmental model was developed to describe the pharmacokinetics of oxytetracycline (OTC) in the horseshoe crab. The following parameters were determined for a single intravascular bolus of 25 mg/kg OTC: AUC = 9524.60 microg.h/mL, MRT = 443.65 h, Clb = 0.044 mL/min/kg, Vd(ss) = 1.164 L/kg, t(1/2) = 128.3 h, Cmax = 55.90 microg/mL, C(ave) = 27.39 microg/mL. Following a single oral bolus of 25 mg/kg, these parameters were calculated: AUC = 5861.81 microg.h/mL, MRT = 395.89 h, Clb = 0.071 mL/min/kg, Vd(ss) = 1.688 L/kg, t(1/2) = 210.0 h, Cmax = 7.83 microg/mL, C(ave) = 2.89 microg/mL, F = 61.56%.

  19. Biologically effective dose in fractionated molecular radiotherapy—application to treatment of neuroblastoma with 131I-mIBG

    NASA Astrophysics Data System (ADS)

    Mínguez, Pablo; Gustafsson, Johan; Flux, Glenn; Sjögreen Gleisner, Katarina

    2016-03-01

    In this work, the biologically effective dose (BED) is investigated for fractionated molecular radiotherapy (MRT). A formula for the Lea-Catcheside G-factor is derived which takes the possibility of combinations of sub-lethal damage due to radiation from different administrations of activity into account. In contrast to the previous formula, the new G-factor has an explicit dependence on the time interval between administrations. The BED of tumour and liver is analysed in MRT of neuroblastoma with 131I-mIBG, following a common two-administration protocol with a mass-based activity prescription. A BED analysis is also made for modified schedules, when due to local regulations there is a maximum permitted activity for each administration. Modifications include both the simplistic approach of delivering this maximum permitted activity in each of the two administrations, and also the introduction of additional administrations while maintaining the protocol-prescribed total activity. For the cases studied with additional (i.e. more than two) administrations, BED of tumour and liver decreases at most 12% and 29%, respectively. The decrease in BED of the tumour is however modest compared to the two-administration schedule using the maximum permitted activity, where the decrease compared to the original schedule is 47%.

  20. Advances in Computational Radiation Biophysics for Cancer Therapy: Simulating Nano-Scale Damage by Low-Energy Electrons

    NASA Astrophysics Data System (ADS)

    Kuncic, Zdenka

    2015-10-01

    Computational radiation biophysics is a rapidly growing area that is contributing, alongside new hardware technologies, to ongoing developments in cancer imaging and therapy. Recent advances in theoretical and computational modeling have enabled the simulation of discrete, event-by-event interactions of very low energy (≪ 100 eV) electrons with water in its liquid thermodynamic phase. This represents a significant advance in our ability to investigate the initial stages of radiation induced biological damage at the molecular level. Such studies are important for the development of novel cancer treatment strategies, an example of which is given by microbeam radiation therapy (MRT). Here, new results are shown demonstrating that when excitations and ionizations are resolved down to nano-scales, their distribution extends well outside the primary microbeam path, into regions that are not directly irradiated. This suggests that radiation dose alone is insufficient to fully quantify biological damage. These results also suggest that the radiation cross-fire may be an important clue to understanding the different observed responses of healthy cells and tumor cells to MRT.

  1. Advances in Computational Radiation Biophysics for Cancer Therapy: Simulating Nano-Scale Damage by Low-Energy Electrons

    NASA Astrophysics Data System (ADS)

    Kuncic, Zdenka

    Computational radiation biophysics is a rapidly growing area that is contributing, alongside new hardware technologies, to ongoing developments in cancer imaging and therapy. Recent advances in theoretical and computational modeling have enabled the simulation of discrete, event-by-event interactions of very low energy (≪ 100 eV) electrons with water in its liquid thermodynamic phase. This represents a significant advance in our ability to investigate the initial stages of radiation induced biological damage at the molecular level. Such studies are important for the development of novel cancer treatment strategies, an example of which is given by microbeam radiation therapy (MRT). Here, new results are shown demonstrating that when excitations and ionizations are resolved down to nano-scales, their distribution extends well outside the primary microbeam path, into regions that are not directly irradiated. This suggests that radiation dose alone is insufficient to fully quantify biological damage. These results also suggest that the radiation cross-fire may be an important clue to understanding the different observed responses of healthy cells and tumor cells to MRT.

  2. Seasonal recharge and mean residence times of soil and epikarst water in a small karst catchment of southwest China

    PubMed Central

    Hu, Ke; Chen, Hongsong; Nie, Yunpeng; Wang, Kelin

    2015-01-01

    Soil and epikarst play an important role in the hydrological cycle in karst regions. This paper focuses on investigating the seasonal recharge and mean residence time (MRT) of soil water and epikarst water in a small karst catchment of southwest China. The deuterium contents in precipitation, creek, soil baseflow (direct recharge of the saturated soil water to the stream), epikarst spring, and soil waters were monitored weekly for two years, and MRT was calculated by an exponential model (EM) and a dispersion model (DM). The obvious seasonal variation of deuterium in rainfall was buffered in epikarst water, indicating sufficient water mixing. Soil baseflow contained less rainy-season rainwater than epikarst spring discharge, reflecting the retarded effect of soil thickness on rainwater recharge. MRTs of all water bodies were 41-71 weeks, and soils in the depression extended those of shallow groundwater. This demonstrated that the deep soil layer played an important role in karst hydrological processes in the study catchment. The creek was recharged mostly by rainfall through epikarst, indicating its crucial role in water circulation. These results showed epikarst had a strong water-holding capacity and also delayed water contact time with dolomite. PMID:25959092

  3. Dynamic T2-mapping during magnetic resonance guided high intensity focused ultrasound ablation of bone marrow

    NASA Astrophysics Data System (ADS)

    Waspe, Adam C.; Looi, Thomas; Mougenot, Charles; Amaral, Joao; Temple, Michael; Sivaloganathan, Siv; Drake, James M.

    2012-11-01

    Focal bone tumor treatments include amputation, limb-sparing surgical excision with bone reconstruction, and high-dose external-beam radiation therapy. Magnetic resonance guided high intensity focused ultrasound (MR-HIFU) is an effective non-invasive thermotherapy for palliative management of bone metastases pain. MR thermometry (MRT) measures the proton resonance frequency shift (PRFS) of water molecules and produces accurate (<1°C) and dynamic (<5s) thermal maps in soft tissues. PRFS-MRT is ineffective in fatty tissues such as yellow bone marrow and, since accurate temperature measurements are required in the bone to ensure adequate thermal dose, MR-HIFU is not indicated for primary bone tumor treatments. Magnetic relaxation times are sensitive to lipid temperature and we hypothesize that bone marrow temperature can be determined accurately by measuring changes in T2, since T2 increases linearly in fat during heating. T2-mapping using dual echo times during a dynamic turbo spin-echo pulse sequence enabled rapid measurement of T2. Calibration of T2-based thermal maps involved heating the marrow in a bovine femur and simultaneously measuring T2 and temperature with a thermocouple. A positive T2 temperature dependence in bone marrow of 20 ms/°C was observed. Dynamic T2-mapping should enable accurate temperature monitoring during MR-HIFU treatment of bone marrow and shows promise for improving the safety and reducing the invasiveness of pediatric bone tumor treatments.

  4. The MODIS reprojection tool

    USGS Publications Warehouse

    Dwyer, J.L.; Schmidt, G.L.; Qu, J.J.; Gao, W.; Kafatos, M.; Murphy , R.E.; Salomonson, V.V.

    2006-01-01

    The MODIS Reprojection Tool (MRT) is designed to help individuals work with MODIS Level-2G, Level-3, and Level-4 land data products. These products are referenced to a global tiling scheme in which each tile is approximately 10° latitude by 10° longitude and non-overlapping (Fig. 9.1). If desired, the user may reproject only selected portions of the product (spatial or parameter subsetting). The software may also be used to convert MODIS products to file formats (generic binary and GeoTIFF) that are more readily compatible with existing software packages. The MODIS land products distributed by the Land Processes Distributed Active Archive Center (LP DAAC) are in the Hierarchical Data Format - Earth Observing System (HDF-EOS), developed by the National Center for Supercomputing Applications at the University of Illinois at Urbana Champaign for the NASA EOS Program. Each HDF-EOS file is comprised of one or more science data sets (SDSs) corresponding to geophysical or biophysical parameters. Metadata are embedded in the HDF file as well as contained in a .met file that is associated with each HDF-EOS file. The MRT supports 8-bit, 16-bit, and 32-bit integer data (both signed and unsigned), as well as 32-bit float data. The data type of the output is the same as the data type of each corresponding input SDS.

  5. The preclinical set-up at the ID17 biomedical beamline to achieve high local dose deposition using interlaced microbeams

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Nemoz, C.; Brochard, Th; Berruyer, G.; Renier, M.; Pouyatos, B.; Serduc, R.

    2013-03-01

    Microbeam Radiation Therapy (MRT) uses spatially a fractionated "white beam" (energies 50-350 keV) irradiation from a Synchrotron Source. The typical microbeams used at ID17 are 25-100μm-thick, spaced by 200-400μm, and carry extremely high dose rates (up to about 16 kGy/s). These microbeams are well tolerated by biological tissue, i.e. up to several hundred of Gy in the peaks. When valley doses, caused by Compton scattering in between two microbeams, remain within a dose regime similar to conventional RT, a superior tumour control can be achieved with MRT than with conventional RT. The normal tissue tolerance of these microscopically small beams is outstanding and well documented in the literature. The hypothesis of a differential effect in particular on the vasculature of normal versus tumoral tissue might best be proven by using large animal models with spontaneous tumors instead of small laboratory animals with transplantable tumors, an ongoing project on ID17. An alternative approach to deposit a high dose, while preserving the feature of the spatial separation of these microbeams outside the target has opened up new applications in preclinical research. The instrumentation of this method to produce such interlaced beams is presented with an outlook on the challenges to build a treatment platform for human patients. Dose measurements using Gafchromic films exposed in interlaced geometries with their steep profiles highlight the potential to deposit radiotoxic doses in the vicinity of radiosensitive tissues.

  6. Beryllium liner z-pinches for Magneto-Rayleigh--Taylor studies on Z.

    SciTech Connect

    McBride, Ryan D.; Martin, Matthew Ryan; Vesey, Roger Alan; Lemke, Raymond William; Sinars, Daniel Brian; Herrmann, Mark C.; Jennings, Christopher A.; Cuneo, Michael Edward; Slutz, Stephen A.

    2010-12-01

    Magnetic Liner Inertial Fusion (MagLIF) [S. A. Slutz, et al., Phys. Plasmas 17 056303 (2010)] is a promising new concept for achieving >100 kJ of fusion yield on Z. The greatest threat to this concept is the Magneto-Rayleigh-Taylor (MRT) instability. Thus an experimental campaign has been initiated to study MRT growth in fast-imploding (<100 ns) cylindrical liners. The first sets of experiments studied aluminum liner implosions with prescribed sinusoidal perturbations (see talk by D. Sinars). By contrast, this poster presents results from the latest sets of experiments that used unperturbed beryllium (Be) liners. The purpose for using Be is that we are able to radiograph 'through' the liner using the 6-keV photons produced by the Z-Beamlet backlighting system. This has enabled us to obtain time-resolved measurements of the imploding liner's density as a function of both axial and radial location throughout the field of view. This data is allowing us to evaluate the integrity of the inside (fuel-confining) surface of the imploding liner as it approaches stagnation.

  7. Optimization of frequency lowering algorithms for getting the highest speech intelligibility improvement by hearing loss simulation.

    PubMed

    Arıöz, Umut; Günel, Banu

    2015-06-01

    High frequency hearing loss is a growing problem for both children and adults. To overcome this impairment, different frequency lowering methods (FLMs) were tried from 1930s, however no satisfaction was provided up to now. In this study, for getting higher speech intelligibility, eight combinations of FLMs which were designed originally were tried with simulated sounds onto normal hearing subjects. These improvements were calculated by the difference with standard hearing aid method, amplification. High frequency hearing loss was simulated with the combined suprathreshold effects. An offline study was carried out for each subject for determining the significant methods used in modified rhyme test (MRT) (Subjective measure for intelligibility). Significant methods were determined according to their speech intelligibility index (SII) (Objective measure for intelligibility). All different cases were tried under four noisy environments and a noise free environment. Twelve hearing impaired subjects were simulated by hearing loss simulation (HLS). MRT was developed for Turkish language as a first time. As the results of improvements, total 71 cases were statistically significant for twelve subjects. Eighty-three percent success of FLMs was achieved against amplification for being an alternative method of amplification in noisy environments. For four subjects, all significant methods gave higher improvements than amplification. As conclusion, specific method recommendations for different noisy environments were done for each subject for getting more speech intelligibility.

  8. Sustained in vivo release from imprinted therapeutic contact lenses.

    PubMed

    Tieppo, A; White, C J; Paine, A C; Voyles, M L; McBride, M K; Byrne, M E

    2012-02-10

    In this paper, we demonstrate the successful in vivo extended release of a small molecular weight therapeutic, ketotifen fumarate (MW=425), from molecularly imprinted, therapeutic contact lenses. This is the first time that a steady, effective concentration of drug is maintained in the tear film from a contact lens for an extended period of time for the entire duration of lens wear. Poly(HEMA-co-AA-co-AM-co-NVP-co-PEG200DMA) soft contact lenses were prepared (100±5 μm thickness, diameter 11.8 mm, power zero), and a constant tear film concentration of 170±30 μg/mL was measured for up to 26 hrs in a New Zealand white rabbit model. The results showed a dramatic increase in ketotifen mean residence time (MRT) and bioavailability compared to topical drop therapy and drug soaked lenses. The MRT for imprinted lenses was 12.47±3.99 hrs, ~4 and 50 fold greater than non-imprinted lenses and 0.035% eye drops (Zaditor®), respectively. Furthermore, AUC(0-26 hrs) was 9 and 94 fold greater for imprinted lenses than non-imprinted lenses and eye drops, respectively. The results indicate that molecular imprinting provides an exciting rational engineering strategy for sustained release. It is clear that imprinted lenses are very promising combination devices and are much more effective and efficient delivery devices than eye drops.

  9. Reaction time variability associated with reading skills in poor readers with ADHD.

    PubMed

    Tamm, Leanne; Epstein, Jeffery N; Denton, Carolyn A; Vaughn, Aaron J; Peugh, James; Willcutt, Erik G

    2014-03-01

    Linkages between neuropsychological functioning (i.e., response inhibition, processing speed, reaction time variability) and word reading have been documented among children with attention-deficit/hyperactivity disorder (ADHD) and children with Reading Disorders. However, associations between neuropsychological functioning and other aspects of reading (i.e., fluency, comprehension) have not been well-documented among children with comorbid ADHD and Reading Disorder. Children with ADHD and poor word reading (i.e., ≤25th percentile) completed a stop signal task (SST) and tests of word reading, reading fluency, and reading comprehension. Multivariate multiple regression was conducted predicting the reading skills from SST variables [i.e., mean reaction time (MRT), reaction time standard deviation (SDRT), and stop signal reaction time (SSRT)]. SDRT predicted word reading, reading fluency, and reading comprehension. MRT and SSRT were not associated with any reading skill. After including word reading in models predicting reading fluency and reading comprehension, the effects of SDRT were minimized. Reaction time variability (i.e., SDRT) reflects impairments in information processing and failure to maintain executive control. The pattern of results from this study suggest SDRT exerts its effects on reading fluency and reading comprehension through its effect on word reading (i.e., decoding) and that this relation may be related to observed deficits in higher-level elements of reading.

  10. Monitoring gold nanoparticle distribution with high resolution using photo-magnetic imaging

    NASA Astrophysics Data System (ADS)

    Luk, Alex T.; Nouizi, Farouk; Marks, Michael; Kart, Turkay; Gulsen, Gultekin

    2016-03-01

    One major advantage of using gold nanoparticles is the possibility of tuning their absorption peak by modifying their surface plasma resonance. They are proven to be a promising multi-functional platform that can be used for many imaging and therapeutic applications. As a true multi-modality imaging technique, Photo-Magnetic Imaging (PMI) has a great potential to monitor the distribution of gold nanoparticles non-invasively with MR resolution. With a simple addon of a continuous wave laser to an MRI system, PMI uses the laser induced temperature increase, measured by MR Thermometry (MRT), to provide tissue optical absorption maps at MR resolution. PMI utilizes a Finite Element Method (FEM) based algorithm to solve the combined diffusion and bio-heat equations. This system of combined equations models the photon distribution in the tissue and heat generation due to the absorption of the light and consequent heat diffusion. The key characteristic of PMI is that its spatial resolution is preserved at any depth as long as the temperature change within the imaged medium is detectable by MRT. Agar phantoms containing gold nanoparticles are used to validate the ability of PMI in monitoring their distribution. To make PMI suitable for diagnostic purposes, the laser powers has been kept under the American National Standard Institute maximum skin exposure limits in this study.

  11. Medical Image Fusion Based on Feature Extraction and Sparse Representation

    PubMed Central

    Wei, Gao; Zongxi, Song

    2017-01-01

    As a novel multiscale geometric analysis tool, sparse representation has shown many advantages over the conventional image representation methods. However, the standard sparse representation does not take intrinsic structure and its time complexity into consideration. In this paper, a new fusion mechanism for multimodal medical images based on sparse representation and decision map is proposed to deal with these problems simultaneously. Three decision maps are designed including structure information map (SM) and energy information map (EM) as well as structure and energy map (SEM) to make the results reserve more energy and edge information. SM contains the local structure feature captured by the Laplacian of a Gaussian (LOG) and EM contains the energy and energy distribution feature detected by the mean square deviation. The decision map is added to the normal sparse representation based method to improve the speed of the algorithm. Proposed approach also improves the quality of the fused results by enhancing the contrast and reserving more structure and energy information from the source images. The experiment results of 36 groups of CT/MR, MR-T1/MR-T2, and CT/PET images demonstrate that the method based on SR and SEM outperforms five state-of-the-art methods. PMID:28321246

  12. The ethical challenges of the clinical introduction of mitochondrial replacement techniques.

    PubMed

    Appleby, John B

    2015-11-01

    Mitochondrial DNA (mtDNA) diseases are a group of neuromuscular diseases that often cause suffering and premature death. New mitochondrial replacement techniques (MRTs) may offer women with mtDNA diseases the opportunity to have healthy offspring to whom they are genetically related. MRTs will likely be ready to license for clinical use in the near future and a discussion of the ethics of the clinical introduction of MRTs is needed. This paper begins by evaluating three concerns about the safety of MRTs for clinical use on humans: (1) Is it ethical to use MRTs if safe alternatives exist? (2) Would persons with three genetic contributors be at risk of suffering? and (3) Can society trust that MRTs will be made available for humans only once adequate safety testing has taken place, and that MRTs will only be licensed for clinical use in a way that minimises risks? It is then argued that the ethics debate about MRTs should be reoriented towards recommending ways to reduce the possible risks of MRT use on humans. Two recommendations are made: (1) licensed clinical access to MRTs should only be granted to prospective parents if they intend to tell their children about their MRT conception by adulthood; and (2) sex selection should be used in conjunction with the clinical use of MRTs, in order to reduce transgenerational health risks.

  13. The (Re) Production of the Genetically Related Body in Law, Technology and Culture: Mitochondria Replacement Therapy.

    PubMed

    Griffiths, Danielle

    2016-09-01

    Advances in medicine in the latter half of the twentieth century have dramatically altered human bodies, expanding choices around what we do with them and how they connect to other bodies. Nowhere is this more so than in the area of reproductive technologies (RTs). Reproductive medicine and the laws surrounding it in the UK have reconfigured traditional boundaries surrounding parenthood and the family. Yet culture and regulation surrounding RTs have combined to try to ensure that while traditional boundaries may be pushed, they are reconstructed in similar ways. This paper looks at the most recent RT to be permitted in the UK, mitochondria (mtDNA) replacement therapy (MRT). Despite controversial media headlines surrounding the technique, MRT is in fact an example of how science and regulation seek to expand models of traditional relatedness in a way that doesn't challenge the existing order. Yet, like other RTs, while attempts are made to ensure it doesn't push traditional boundaries too far, fissures and inconsistencies appear in law and culture, which give interesting insights into how genetics, parentage and identity are being mediated in new but familiar ways.

  14. Histogram analysis of pharmacokinetic parameters by bootstrap resampling from one-point sampling data in animal experiments.

    PubMed

    Takemoto, Seiji; Yamaoka, Kiyoshi; Nishikawa, Makiya; Takakura, Yoshinobu

    2006-12-01

    A bootstrap method is proposed for assessing statistical histograms of pharmacokinetic parameters (AUC, MRT, CL and V(ss)) from one-point sampling data in animal experiments. A computer program, MOMENT(BS), written in Visual Basic on Microsoft Excel, was developed for the bootstrap calculation and the construction of histograms. MOMENT(BS) was applied to one-point sampling data of the blood concentration of three physiologically active proteins ((111)In labeled Hsp70, Suc(20)-BSA and Suc(40)-BSA) administered in different doses to mice. The histograms of AUC, MRT, CL and V(ss) were close to a normal (Gaussian) distribution with the bootstrap resampling number (200), or more, considering the skewness and kurtosis of the histograms. A good agreement of means and SD was obtained between the bootstrap and Bailer's approaches. The hypothesis test based on the normal distribution clearly demonstrated that the disposition of (111)In-Hsp70 and Suc(20)-BSA was almost independent of dose, whereas that of (111)In-Suc(40)-BSA was definitely dose-dependent. In conclusion, the bootstrap method was found to be an efficient method for assessing the histogram of pharmacokinetic parameters of blood or tissue disposition data by one-point sampling.

  15. X-Tream: a novel dosimetry system for Synchrotron Microbeam Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Petasecca, M.; Cullen, A.; Fuduli, I.; Espinoza, A.; Porumb, C.; Stanton, C.; Aldosari, A. H.; Bräuer-Krisch, E.; Requardt, H.; Bravin, A.; Perevertaylo, V.; Rosenfeld, A. B.; Lerch, M. L. F.

    2012-07-01

    Microbeam Radiation Therapy (MRT) is a radiation treatment technique under development for inoperable brain tumors. MRT is based on the use of a synchrotron generated X-ray beam with an extremely high dose rate ( ~ 20 kGy/sec), striated into an array of X-ray micro-blades. In order to advance to clinical trials, a real-time dosimeter with excellent spatial resolution must be developed for absolute dosimetry. The design of a real-time dosimeter for such a radiation scenario represents a significant challenge due to the high photon flux and vertically striated radiation field, leading to very steep lateral dose gradients. This article analyses the striated radiation field in the context of the requirements for temporal dosimetric measurements and presents the architecture of a new dosimetry system based on the use of silicon detectors and fast data acquisition electronic interface. The combined system demonstrates micrometer spatial resolution and microsecond real time readout with accurate sensitivity and linearity over five orders of magnitude of input signal. The system will therefore be suitable patient treatment plan verification and may also be expanded for in-vivo beam monitoring for patient safety during the treatment.

  16. Assessment of milk ring test and some serological tests in the detection of Brucella melitensis in Syrian female sheep.

    PubMed

    Al-Mariri, Ayman; Ramadan, Lila; Akel, Rand

    2011-04-01

    Brucella melitensis infection prevalence among Syrian female sheep, to evaluate a number of serological tests and to discuss some epidemiological aspects of brucellosis, was studied. A total of 2,580 unvaccinated Syrian female sheep sera samples were tested for B. melitensis antibodies detection using four serological methods: the Rose Bengal test (RBT), the serum agglutination test (SAT), the complement fixation test (CFT) and an indirect enzyme-linked immunosorbent assay (iELISA). In addition, 2,375 milk samples were collected, then milk ring test (MRT) and bacterial isolation test were employed to evaluate the natural organism shedding. The samples were considered positive in 66%, 64%, and 60% when we employed the RBT, SAT, and iELISA tests, respectively. Whereas, the CFT test revealed the smallest number of positive samples. By using the MRT, the total prevalence of brucellosis was nearly 38% of samples. A large variation was observed concerning the studied areas, ranging from 24% in Tartous to 44% in both Damascus and Damascus rural areas. Brucella was isolated from only 677 samples out of the 2,375 female sheep milk samples.

  17. Effect of Crop cultivation after Mediterranean maquis on soil carbon stock, δ13C spatial distribution and root turnover

    NASA Astrophysics Data System (ADS)

    Novara, Agata; Gristina, Luciano; Santoro, Antonino; La Mantia, Tommaso

    2013-04-01

    The aim of this work was investigate the effect of land use change on soil organic carbon (SOC) stock and distribution in a Mediterranean succession. A succession composed by natural vegetation, cactus pear crop and olive grove, was selected in Sicily. The land use change from mediterranena maquis (C3 plant) to cactus pear (C4 plant) lead to a SOC decrease of 65% after 28 years of cultivation, and a further decrease of 14% after 7 years since the land use from cactus pear to olive grove (C3 plant). Considering this exchange and decrease as well as the periods after the land use changes we calculated the mean residence time (MRT) of soil C of different age. The MRT of C under Mediterranean maquis was about 142 years, but was 10 years under cactus pear. Total SOC and δ13 C were measured along the soil profile (0-75cm) and in the intra-rows in order to evaluate the distribution of new and old carbon derived and the growth of roots. After measuring of weight of cactus pear root, an approach was developed to estimate the turnover of root biomass. Knowledge of root turnover and carbon input are important to evaluate the correlation between carbon input accumulation and SOC stock in order to study the ability of C sink of soils with different use and managements.

  18. Interaction between affordance and handedness recognition: a chronometric study.

    PubMed

    Lameira, A P; Pereira, A; Conde, E; Gawryszewski, L G

    2015-04-01

    The visualization of tools and manipulable objects activates motor-related areas in the cortex, facilitating possible actions toward them. This pattern of activity may underlie the phenomenon of object affordance. Some cortical motor neurons are also covertly activated during the recognition of body parts such as hands. One hypothesis is that different subpopulations of motor neurons in the frontal cortex are activated in each motor program; for example, canonical neurons in the premotor cortex are responsible for the affordance of visual objects, while mirror neurons support motor imagery triggered during handedness recognition. However, the question remains whether these subpopulations work independently. This hypothesis can be tested with a manual reaction time (MRT) task with a priming paradigm to evaluate whether the view of a manipulable object interferes with the motor imagery of the subject's hand. The MRT provides a measure of the course of information processing in the brain and allows indirect evaluation of cognitive processes. Our results suggest that canonical and mirror neurons work together to create a motor plan involving hand movements to facilitate successful object manipulation.

  19. Thermal sintering: a novel technique used in the design, optimization and biopharmaceutical evaluation of propranolol HCl gastric floating tablets.

    PubMed

    Venkata Srikanth, Meka; Songa, Ambedkar Sunil; Nali, Sreenivasa Rao; Battu, Janaki Ram; Kolapalli, Venkata Ramana Murthy

    2014-01-01

    The objective of the present investigation was to study the applicability of thermal sintering technique for the development of gastric floating tablets of propranolol HCl. Formulations were prepared using four independent variables, namely (i) polymer quantity, (ii) sodium bicarbonate concentration, (iii) sintering temperature and (iv) sintering time. Floating lag time and t95 were taken as dependent variables. Tablets were prepared by the direct compression method and were evaluated for physicochemical properties, in vitro buoyancy and dissolution studies. From the drug release studies, it was observed that drug retarding property mainly depends upon the sintering temperature and time of exposure. The statistically optimized formulation (PTSso) was characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry studies, and no significant chemical interaction between drug and polymer was observed. Optimized formulation was stable at accelerated conditions for a period of six months. PTSso was evaluated for in vivo buoyancy studies in humans for both fed and fasted states and found that gastric residence time of the floating tablets were enhanced by fed stage but not in fasted state. Optimized formulation PTSso and commercial formulation Ciplar LA 80 were subjected to bioavailability studies in healthy human volunteers by estimating pharmacokinetic parameters such as Cmax, Tmax, area under curve (AUC), elimination rate constant (Kel), biological half-life (t1/2) and mean residence time (MRT). There was a significant increase in the bioavailability of the propranolol HCl from PTSso formulation, which was evident from increased AUC levels and larger MRT values than Ciplar LA 80.

  20. Modelling radiation fluxes in simple and complex environments--application of the RayMan model.

    PubMed

    Matzarakis, Andreas; Rutz, Frank; Mayer, Helmut

    2007-03-01

    The most important meteorological parameter affecting the human energy balance during sunny weather conditions is the mean radiant temperature T(mrt). It considers the uniform temperature of a surrounding surface giving off blackbody radiation, which results in the same energy gain of a human body given the prevailing radiation fluxes. This energy gain usually varies considerably in open space conditions. In this paper, the model 'RayMan', used for the calculation of short- and long-wave radiation fluxes on the human body, is presented. The model, which takes complex urban structures into account, is suitable for several applications in urban areas such as urban planning and street design. The final output of the model is, however, the calculated T(mrt), which is required in the human energy balance model, and thus also for the assessment of the urban bioclimate, with the use of thermal indices such as predicted mean vote (PMV), physiologically equivalent temperature (PET) and standard effective temperature (SET*). The model has been developed based on the German VDI-Guidelines 3789, Part II (environmental meteorology, interactions between atmosphere and surfaces; calculation of short- and long-wave radiation) and VDI-3787 (environmental meteorology, methods for the human-biometeorological evaluation of climate and air quality for urban and regional planning. Part I: climate). The validation of the results of the RayMan model agrees with similar results obtained from experimental studies.

  1. The SWI/SNF Complex Protein Snr1 Is a Tumor Suppressor in Drosophila Imaginal Tissues.

    PubMed

    Xie, Gengqiang; Chen, Hanqing; Jia, Dongyu; Shu, Zhiqiang; Palmer, William Hunt; Huang, Yi-Chun; Zeng, Xiankun; Hou, Steven X; Jiao, Renjie; Deng, Wu-Min

    2017-02-15

    Components of the SWI/SNF chromatin-remodeling complex are among the most frequently mutated genes in various human cancers, yet only SMARCB1/hSNF5, a core member of the SWI/SNF complex, is mutated in malignant rhabdoid tumors (MRT). How SMARCB1/hSNF5 functions differently from other members of the SWI/SNF complex remains unclear. Here, we use Drosophila imaginal epithelial tissues to demonstrate that Snr1, the conserved homolog of human SMARCB1/hSNF5, prevents tumorigenesis by maintaining normal endosomal trafficking-mediated signaling cascades. Removal of Snr1 resulted in neoplastic tumorigenic overgrowth in imaginal epithelial tissues, whereas depletion of any other members of the SWI/SNF complex did not induce similar phenotypes. Unlike other components of the SWI/SNF complex that were detected only in the nucleus, Snr1 was observed in both the nucleus and the cytoplasm. Aberrant regulation of multiple signaling pathways, including Notch, JNK, and JAK/STAT, was responsible for tumor progression upon snr1-depletion. Our results suggest that the cytoplasmic Snr1 may play a tumor suppressive role in Drosophila imaginal tissues, offering a foundation for understanding the pivotal role of SMARCB1/hSNF5 in suppressing MRT during early childhood. Cancer Res; 77(4); 862-73. ©2017 AACR.

  2. Bioavailability of theophylline and thiamine disulfide incorporated into mucoadhesive microspheres consisting of dextran derivatives and cellulose acetate butyrate.

    PubMed

    Miyazaki, Yasunori; Ogihara, Kanako; Yakou, Shigeru; Nagai, Tsuneji; Takayama, Kozo

    2003-12-01

    Mucoadhesive microspheres made of oppositely charged dextran derivatives and cellulose acetate butyrate (Ad-MS) were evaluated for their ability to improve the bioavailability of theophylline (TH) and thiamine disulfide (TDS). A drug suspension (or solution) and non-adhesive microspheres (MS) were used as references. In vitro drug release profiles from MS and Ad-MS were similar for each drug, whereas their gastrointestinal transits differed. The plasma concentration after oral administration of drug suspension (or solution), MS and Ad-MS was investigated in rats. In the case of TH, sustained plasma level profiles were observed after MS or Ad-MS administration, with similar C(max), T(max) and MRT( infinity ) values. AUC( infinity ) values of the suspension, MS and Ad-MS were statistically equivalence. These indicated that Ad-MS achieved a sustained plasma level profile without a decrease of AUC. In the case of TDS, MRT( infinity ) and AUC( infinity ) of Ad-MS were significantly larger than those of the solution and MS, indicating that the plasma level was sustained and the extent of bioavailability was increased. These results suggested that Ad-MS is a promising device for improvement of bioavailability of drugs those absorption windows are limited to upper part of the gastrointestinal tract.

  3. Development of azimuthally correlated instabilities for MagLIF seeded by electro-thermal and material strength effects

    NASA Astrophysics Data System (ADS)

    Pecover, James; Weinwurm, Marcus; Chittenden, Jeremy

    2014-10-01

    Magnetized liner inertial fusion (MagLIF) is a promising route to controlled thermonuclear fusion. The concept involves magnetically imploding a metal liner; a key limitation of such systems is the magneto-Rayleigh-Taylor (MRT) instability. MagLIF relevant liner implosions carried out at Sandia showed high amplitude MRT growth. 3D simulations with our MHD code Gorgon have shown that azimuthal correlation required to explain this can be contributed to by early time effects the electro-thermal instability (ETI) and an ``electro-choric instability'' (ECI). Shear forces can damp short wavelength perturbations while the liner remains solid, potentially setting axial wavelengths for the ETI and ECI. We can now model shear stresses in solids with Gorgon using a Johnson-Cook strength model and a bulk modulus calculated from the FEOS equation of state. Gorgon results with the strength model are compared to results from the shock hydrodynamics code iSALE. Results for liners show elongation of perturbations at the outer edge relative to the case without strength. We present results showing the model applied to liner implosions with axial magnetic fields of 0 T and 10 T.

  4. Evaluation of subjective thermal strain in different kitchen working environments using subjective judgment scales.

    PubMed

    Haruyama, Yasuo; Muto, Takashi; Matsuzuki, Hiroe; Ito, Akiyoshi; Tomita, Shigeru; Muto, Shigeki; Haratani, Takashi; Seo, Akihiko; Ayabe, Makoto; Katamoto, Shizuo

    2010-01-01

    To elucidate the subjective thermal strain of workers in kitchen working environments, we performed a cross-sectional study involving 991 workers in 126 kitchen facilities in Japan, using a self-reporting questionnaire survey and subjective judgment scales (SJS). The ambient temperature, mean radiant temperature (MRT), and wet-bulb globe temperature (WBGT) index were measured in 10 kitchen facilities of the 126 kitchens. The association of SJS with the types of kitchen was estimated by multiple logistic regression models. Of the 991 kitchen workers, 809 (81%) responded to the questionnaire survey. Compared with the electric kitchens, the proportion of workers who perceived the room temperature as hot to very hot was significantly higher, and the ambient temperature, MRT, and WBGT were significantly higher in the gas kitchens. Compared with the electric kitchens, workers in gas kitchens had a more than fivefold (males) and tenfold (females) higher SJS adjusted for confounding factors (male odds ratio (OR), 5.13; 95% confidence interval (CI), 1.65-15.9; and female OR, 10.9; 95%CI, 3.89-30.5). Although SJS was affected by some confounding factors, our results suggest that workers in gas kitchens might be exposed to a higher heat strains than those in electric kitchens.

  5. Restless mind, restless body.

    PubMed

    Seli, Paul; Carriere, Jonathan S A; Thomson, David R; Cheyne, James Allan; Martens, Kaylena A Ehgoetz; Smilek, Daniel

    2014-05-01

    In the present work, we investigate the hypothesis that failures of task-related executive control that occur during episodes of mind wandering are associated with an increase in extraneous movements (fidgeting). In 2 studies, we assessed mind wandering using thought probes while participants performed the metronome response task (MRT), which required them to synchronize button presses with tones. Participants performed this task while sitting on a Wii Balance Board providing us with an index of fidgeting. Results of Study 1 demonstrate that relative to on-task periods, mind wandering is indeed accompanied by increases in fidgeting, as well as increased response variability in the MRT. In Study 2, we observed that only deep mind wandering was associated with increases in fidgeting, whereas task-related response variability increased even during mild mind wandering. We interpret these findings in the context of current theories of mind wandering and suggest that (a) mind wandering is associated with costs not only to primary-task performance but also to secondary-task goals (e.g., controlling extraneous movements) and (b) these costs may depend on the degree to which task-related executive control processes are disengaged during mind wandering (i.e., depth of mind wandering).

  6. Interaction between affordance and handedness recognition: a chronometric study

    PubMed Central

    Lameira, A.P.; Pereira, A.; Conde, E.; Gawryszewski, L.G.

    2015-01-01

    The visualization of tools and manipulable objects activates motor-related areas in the cortex, facilitating possible actions toward them. This pattern of activity may underlie the phenomenon of object affordance. Some cortical motor neurons are also covertly activated during the recognition of body parts such as hands. One hypothesis is that different subpopulations of motor neurons in the frontal cortex are activated in each motor program; for example, canonical neurons in the premotor cortex are responsible for the affordance of visual objects, while mirror neurons support motor imagery triggered during handedness recognition. However, the question remains whether these subpopulations work independently. This hypothesis can be tested with a manual reaction time (MRT) task with a priming paradigm to evaluate whether the view of a manipulable object interferes with the motor imagery of the subject's hand. The MRT provides a measure of the course of information processing in the brain and allows indirect evaluation of cognitive processes. Our results suggest that canonical and mirror neurons work together to create a motor plan involving hand movements to facilitate successful object manipulation. PMID:25714894

  7. An axisymmetric multiple-relaxation-time lattice Boltzmann scheme

    NASA Astrophysics Data System (ADS)

    Xie, Wenjun

    2015-01-01

    A multiple-relaxation-time (MRT) lattice Boltzmann (LB) scheme developed for axisymmetric flows recovers the complete continuity and Navier-Stokes equations. This scheme follows the strategy of the standard D2Q9 model by using a single particle distribution function and a simple "collision-streaming" updating rule. The extra terms related to axisymmetry in the macroscopic equations are recovered by adding source terms into the LB equation, which are simple and involve no gradients. The compressible effect retained in the Navier-Stokes equations is recovered by introducing a term related to the reversed transformation matrix for MRT collision operator, so as to produce a correct bulk viscosity, making it suitable for compressible flows with high frequency and low Mach number. The validity of the scheme is demonstrated by testing the Hagen-Poiseuille flow and 3D Womersley flow, as well as the standing acoustic waves in a closed cylindrical chamber. The numerical experiments show desirable stability at low viscosities, enabling to simulate a standing ultrasound field in centimeters space.

  8. A study of the carbon dynamics of Japanese grassland and forest using 14C and 13C

    NASA Astrophysics Data System (ADS)

    Katsuno, Kazumi; Miyairi, Yosuke; Tamura, Kenji; Matsuzaki, Hiroyuki; Fukuda, Kenji

    2010-04-01

    We quantified the carbon contents of grassland and forest soil using conventional methods and studied the changes in their dynamics by measuring δ 13C and Δ 14C. Soil samples were taken from a neighboring Miscanthus sinensis grassland and Pinus densiflora forest in central Japan. Both had been maintained as grassland until the 1960s, when the latter was abandoned and became a pine forest by natural succession. The soil carbon content of the forest was much lower than that of the grassland, implying that the soil carbon decreased as the grassland became forest. The δ 13C values were very similar in the grassland and forest, at approximately -20‰, suggesting that M. sinensis (a C4 plant) contributed to carbon storage, whereas there was little carbon accumulation from P. densiflora (a C3 plant) in forest soil. The Δ 14C values and calculated soil carbon mean residence time (MRT) showed that the soil carbon in the upper A horizon was older, and that in the lower A horizon was younger in forest than in grassland. From these results, we conclude that young, fast-MRT soil carbon is decomposed in the upper A horizon, and old, stable soil carbon was decomposed in the lower A horizon after the pine invasion.

  9. Short-term volcano-tectonic earthquake forecasts based on a moving mean recurrence time algorithm: the El Hierro seismo-volcanic crisis experience

    NASA Astrophysics Data System (ADS)

    García, Alicia; De la Cruz-Reyna, Servando; Marrero, José M.; Ortiz, Ramón

    2016-05-01

    Under certain conditions, volcano-tectonic (VT) earthquakes may pose significant hazards to people living in or near active volcanic regions, especially on volcanic islands; however, hazard arising from VT activity caused by localized volcanic sources is rarely addressed in the literature. The evolution of VT earthquakes resulting from a magmatic intrusion shows some orderly behaviour that may allow the occurrence and magnitude of major events to be forecast. Thus governmental decision makers can be supplied with warnings of the increased probability of larger-magnitude earthquakes on the short-term timescale. We present here a methodology for forecasting the occurrence of large-magnitude VT events during volcanic crises; it is based on a mean recurrence time (MRT) algorithm that translates the Gutenberg-Richter distribution parameter fluctuations into time windows of increased probability of a major VT earthquake. The MRT forecasting algorithm was developed after observing a repetitive pattern in the seismic swarm episodes occurring between July and November 2011 at El Hierro (Canary Islands). From then on, this methodology has been applied to the consecutive seismic crises registered at El Hierro, achieving a high success rate in the real-time forecasting, within 10-day time windows, of volcano-tectonic earthquakes.

  10. Modified helix-like instability structure on imploding z-pinch liners that are pre-imposed with a uniform axial magnetic fielda)

    NASA Astrophysics Data System (ADS)

    Awe, T. J.; Jennings, C. A.; McBride, R. D.; Cuneo, M. E.; Lamppa, D. C.; Martin, M. R.; Rovang, D. C.; Sinars, D. B.; Slutz, S. A.; Owen, A. C.; Tomlinson, K.; Gomez, M. R.; Hansen, S. B.; Herrmann, M. C.; Jones, M. C.; McKenney, J. L.; Robertson, G. K.; Rochau, G. A.; Savage, M. E.; Schroen, D. G.; Stygar, W. A.

    2014-05-01

    Recent experiments at the Sandia National Laboratories Z Facility have, for the first time, studied the implosion dynamics of magnetized liner inertial fusion (MagLIF) style liners that were pre-imposed with a uniform axial magnetic field. As reported [T. J. Awe et al., Phys. Rev. Lett. 111, 235005 (2013)] when premagnetized with a 7 or 10 T axial field, these liners developed 3D-helix-like hydrodynamic instabilities; such instabilities starkly contrast with the azimuthally correlated magneto-Rayleigh-Taylor (MRT) instabilities that have been consistently observed in many earlier non-premagnetized experiments. The helical structure persisted throughout the implosion, even though the azimuthal drive field greatly exceeded the expected axial field at the liner's outer wall for all but the earliest stages of the experiment. Whether this modified instability structure has practical importance for magneto-inertial fusion concepts depends primarily on whether the modified instability structure is more stable than standard azimuthally correlated MRT instabilities. In this manuscript, we discuss the evolution of the helix-like instability observed on premagnetized liners. While a first principles explanation of this observation remains elusive, recent 3D simulations suggest that if a small amplitude helical perturbation can be seeded on the liner's outer surface, no further influence from the axial field is required for the instability to grow.

  11. The effects of meteorological factors on the occurrence of Ganoderma sp. spores in the air

    NASA Astrophysics Data System (ADS)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2011-03-01

    Ganoderma sp. is an airborne fungal spore type known to trigger respiratory allergy symptoms in sensitive patients. Aiming to reduce the risk for allergic individuals, we analysed fungal spore circulation in Szczecin, Poland, and its dependence on meteorological conditions. Statistical models for the airborne spore concentrations of Ganoderma sp.—one of the most abundant fungal taxa in the area—were developed. Aerobiological sampling was conducted over 2004-2008 using a volumetric Lanzoni trap. Simultaneously, the following meteorological parameters were recorded: daily level of precipitation, maximum and average wind speed, relative humidity and maximum, minimum, average and dew point temperatures. These data were used as the explaining variables. Due to the non-linearity and non-normality of the data set, the applied modelling techniques were artificial neural networks (ANN) and mutlivariate regression trees (MRT). The obtained classification and MRT models predicted threshold conditions above which Ganoderma sp. appeared in the air. It turned out that dew point temperature was the main factor influencing the presence or absence of Ganoderma sp. spores. Further analysis of spore seasons revealed that the airborne fungal spore concentration depended only slightly on meteorological factors.

  12. Micromagnetic theory of antiferromagnetically coupled magnetic recording media

    NASA Astrophysics Data System (ADS)

    Schabes, Manfred

    2001-03-01

    The micromagnetic theory of antiferromagnetically coupled magnetic recording media (AFC media) is discussed for the case of AFC media consisting of two ferromagnetic layers and a polarization layer.[1-2] Attention is focused on AFC media where the top layer governs the remanent magnetization while the bottom layer acts as a slave layer. Micromagnetic simulations of recorded bit transitions demonstrate a good anticorrelation of the layer magnetizations at bit transitions for this case. Calculation of MR readback pulses shows that these AFC media have pulse widths of a thin single layer magnetic recording medium with an effective MrT that is approximately given by the difference in MrT's of the top and bottom layers. Magnetic stability is set to first order by the thicker top layer and the interactions between the top and bottom layers. [1] E.E. Fullerton, D.T. Margulies, M.E. Schabes, M. Carey, B. Gurney, A. Moser, M. Best, G. Zeltzer, K. Rubin, H. Rosen, Appl. Phys. Lett. 77 (2000), 3806. [2] E.N. Abarra, A. Inomata, H. Sato, I. Okamoto, Y. Mizoshita, Appl. Phys. Lett. 77 (2000), 2581.

  13. Telesurgery via Unmanned Aerial Vehicle (UAV) with a field deployable surgical robot.

    PubMed

    Lum, Mitchell J H; Rosen, Jacob; King, Hawkeye; Friedman, Diana C W; Donlin, Gina; Sankaranarayanan, Ganesh; Harnett, Brett; Huffman, Lynn; Doarn, Charles; Broderick, Timothy; Hannaford, Blake

    2007-01-01

    Robotically assisted surgery stands to further revolutionize the medical field and provide patients with more effective healthcare. Most robotically assisted surgeries are teleoperated from the surgeon console to the patient where both ends of the system are located in the operating room. The challenge of surgical teleoperation across a long distance was already demonstrated through a wired communication network in 2001. New development has shifted towards deploying a surgical robot system in mobile settings and/or extreme environments such as the battlefield or natural disaster areas with surgeons operating wirelessly. As a collaborator in the HAPs/MRT (High Altitude Platform/Mobile Robotic Telesurgery) project, The University of Washington surgical robot was deployed in the desert of Simi Valley, CA for telesurgery experiments on an inanimate model via wireless communication through an Unmanned Aerial Vehicle (UAV). The surgical tasks were performed telerobotically with a maximum time delay between the surgeon's console (master) and the surgical robot (slave) of 20 ms for the robotic control signals and 200 ms for the video stream. This was our first experiment in the area of Mobile Robotic Telesurgery (MRT). The creation and initial testing of a deployable surgical robot system will facilitate growth in this area eventually leading to future systems saving human lives in disaster areas, on the battlefield or in other remote environments.

  14. Pharmacokinetics of a new ivermectin/praziquantel suspension after intramuscular administration in sheep.

    PubMed

    Tang, Shusheng; Chen, Linlin; Qian, Minyi; Hao, Lihua; Xiao, Xilong

    2016-05-15

    A new oil suspension containing 0.10% ivermectin (IVM) and 15% praziquantel (PZQ) (Tivm+pzq) for intramuscular injection was developed for sheep, and its pharmacokinetics was investigated in sheep. The quality of the new product met the technical standards set by the Ministry of Agriculture of the People's Republic of China. In pharmacokinetics, the commercially available single-component products approved by the Chinese Ministry of Agriculture and widely used in the livestock industry in China were selected as reference products (Rivm and Rpzq). The results showed that all of the IVM pharmacokinetic parameters of Tivm+pzq were similar to those of the reference. However, after adminstration of Tivm+pzq, mean residence time (MRT) and plasma elimination half-life (t1/2z) were 20.36h and 11.65h, which were 2.61 and 3.22 times longer than those of Rpzq (7.81h and 3.62h). In summary, the MRT and t1/2z of PZQ in Tivm+pzq were prolonged and IVM pharmacokinetic parameters were similar to commercial product, therefore the new injection may be an alternative choice for sheep to control parasites sensitive to IVM and PZQ.

  15. Seasonal recharge and mean residence times of soil and epikarst water in a small karst catchment of southwest China.

    PubMed

    Hu, Ke; Chen, Hongsong; Nie, Yunpeng; Wang, Kelin

    2015-05-11

    Soil and epikarst play an important role in the hydrological cycle in karst regions. This paper focuses on investigating the seasonal recharge and mean residence time (MRT) of soil water and epikarst water in a small karst catchment of southwest China. The deuterium contents in precipitation, creek, soil baseflow (direct recharge of the saturated soil water to the stream), epikarst spring, and soil waters were monitored weekly for two years, and MRT was calculated by an exponential model (EM) and a dispersion model (DM). The obvious seasonal variation of deuterium in rainfall was buffered in epikarst water, indicating sufficient water mixing. Soil baseflow contained less rainy-season rainwater than epikarst spring discharge, reflecting the retarded effect of soil thickness on rainwater recharge. MRTs of all water bodies were 41-71 weeks, and soils in the depression extended those of shallow groundwater. This demonstrated that the deep soil layer played an important role in karst hydrological processes in the study catchment. The creek was recharged mostly by rainfall through epikarst, indicating its crucial role in water circulation. These results showed epikarst had a strong water-holding capacity and also delayed water contact time with dolomite.

  16. Disposition and tolerance of suxibuzone in horses.

    PubMed

    Jaraiz, M V; Rodriguez, C; San Andres, M D; Gonzalez, F; San Andres, M I

    1999-09-01

    Suxibuzone (SBZ), a nonsteroidal anti-inflammatory drug, was administered to 6 horses at a dose rate of 7.5 mg/kg bwt by intravenous (i.v.) route. Plasma and synovial fluid concentrations of suxibuzone and its main active metabolites, phenylbutazone (PBZ) and oxyphenbutazone (OPBZ), were measured simultaneously by a sensitive and specific high-performance liquid chromatographic method. The pharmacokinetic parameters were determined by noncompartmental analysis. Plasma SBZ concentrations rapidly decreased and were not detectable beyond 20 min after treatment. The parent drug was not detected in any synovial fluid samples. Average maximum plasma concentrations of PBZ (16.43 microg/ml) and OPBZ (2.37 microg/ml) were attained at 0.76 and 7.17 h, respectively. The mean residence time (MRT) of PBZ was 6.96 h in plasma. Oxyphenbutazone plasma concentrations were below those reached by phenylbutazone during the first 12 h after suxibuzone administration, even though its values were detectable for at least 24 h (MRT = 10.65 h). Plasma concentrations of PBZ and OPBZ exceeding EC50 and IC50 of TXB2 and PGE2 were reached by at least 12 h. Synovial fluid concentrations of PBZ and OPBZ were 2.87+/-0.37 microg/ml and 0.97+/-0.08 microg/ml at 9 h after suxibuzone administration and exceeded IC50 of PGE2 for at least this time. In the present study, suxibuzone was well tolerated following i.v. injection.

  17. Pharmacokinetics of sirolimus (rapamycin) in subjects with severe hepatic impairment.

    PubMed

    Zimmerman, James J; Patat, Alain; Parks, Virginia; Moirand, Romain; Matschke, Kyle

    2008-03-01

    Nine subjects with severe hepatic impairment (Child-Pugh grade C) and 9 healthy matched control subjects were given a single 15-mg dose of sirolimus by oral solution. Increases (P < or = .002) in mean whole-blood sirolimus t(1/2) (168%), AUC(0-infinity) (210%), and MRT(oral) (261%), together with a decrease (P = .001) in CL/F (-67%), were observed in subjects with severe hepatic impairment compared with healthy matched controls. Sirolimus pharmacokinetic data in Child-Pugh grade A (n = 13, mild) and B (n = 5, moderate) subjects from a previous identically designed study were available for an inter-study comparison. Overall, mean t(1/2), weight-normalized AUC, and MRT(oral) increased steadily, whereas mean CL/F decreased steadily, with increasing degrees of hepatic impairment. CL/F showed large intersubject variabilities within subject types and extensive overlap among the subject types. The results of this study suggest that an initial sirolimus dose reduction of approximately 60% is appropriate in patients with acute severe hepatic impairment; this should be followed by further dose adjustment, based on therapeutic drug monitoring, until the trough concentrations have stabilized at sirolimus levels existing prior to the onset of acute liver failure.

  18. Application of back-propagation artificial neural network and curve estimation in pharmacokinetics of losartan in rabbit.

    PubMed

    Lin, Bin; Lin, Gaotong; Liu, Xianyun; Ma, Jianshe; Wang, Xianchuan; Lin, Feiyan; Hu, Lufeng

    2015-01-01

    In order to develop pharmacokinetic model, a well-known multilayer feed-forward algorithm back-propagation artificial neural networks (BP-ANN) was applied to the pharmacokinetics of losartan in rabbit. The plasma concentrations of losartan in twelve rabbits, which were divided into two groups and given losartan 2 mg/kg by intravenous (Iv) and intragastrical (Ig) administration, were determined by LC-MS. The BP-ANN model included one input layer, hidden layers, and one output layer was constructed and compared with curve estimation based on the time-concentration data of losartan. The results showed the BP-ANN model had high goodness of fit index and good coherence (R > 0.99) between forecasted concentration and measured concentration both in Iv and Ig administration. The residuals of each concentrations generated by BP-ANN model were all smaller than Curve estimation. The pharmacokinetic result showed there was no significant difference between measured and simulated pharmacokinetic parameters including AUC(0-t), AUC(0-∞), MRT(0-t), MRT(0-∞), T1/2 V and Cmax (P > 0.05). In conclusion, the BP-ANN model has remarkably accurate predictions ability, which better than Curve estimation, and can be used as a utility tool in pharmacokinetic experiment.

  19. Exploration of MR-guided head and neck hyperthermia by phantom testing of a modified prototype applicator for use with proton resonance frequency shift thermometry.

    PubMed

    Numan, Wouter C M; Hofstetter, Lorne W; Kotek, Gyula; Bakker, Jurriaan F; Fiveland, Eric W; Houston, Gavin C; Kudielka, Guido; Yeo, Desmond T B; Paulides, Margarethus M

    2014-05-01

    Magnetic resonance thermometry (MRT) offers non-invasive temperature imaging and can greatly contribute to the effectiveness of head and neck hyperthermia. We therefore wish to redesign the HYPERcollar head and neck hyperthermia applicator for simultaneous radio frequency (RF) heating and magnetic resonance thermometry. In this work we tested the feasibility of this goal through an exploratory experiment, in which we used a minimally modified applicator prototype to heat a neck model phantom and used an MR scanner to measure its temperature distribution. We identified several distorting factors of our current applicator design and experimental methods to be addressed during development of a fully MR compatible applicator. To allow MR imaging of the electromagnetically shielded inside of the applicator, only the lower half of the HYPERcollar prototype was used. Two of its antennas radiated a microwave signal (150 W, 434 MHz) for 11 min into the phantom, creating a high gradient temperature profile (ΔTmax = 5.35 °C). Thermal distributions were measured sequentially, using drift corrected proton resonance frequency shift-based MRT. Measurement accuracy was assessed using optical probe thermometry and found to be about 0.4 °C (0.1-0.7 °C). Thermal distribution size and shape were verified by thermal simulations and found to have a good correlation (r(2 )= 0.76).

  20. Dual Targeting of PDGFRα and FGFR1 Displays Synergistic Efficacy in Malignant Rhabdoid Tumors.

    PubMed

    Wong, Jocelyn P; Todd, Jason R; Finetti, Martina A; McCarthy, Frank; Broncel, Malgorzata; Vyse, Simon; Luczynski, Maciej T; Crosier, Stephen; Ryall, Karen A; Holmes, Kate; Payne, Leo S; Daley, Frances; Wai, Patty; Jenks, Andrew; Tanos, Barbara; Tan, Aik-Choon; Natrajan, Rachael C; Williamson, Daniel; Huang, Paul H

    2016-10-25

    Subunits of the SWI/SNF chromatin remodeling complex are mutated in a significant proportion of human cancers. Malignant rhabdoid tumors (MRTs) are lethal pediatric cancers characterized by a deficiency in the SWI/SNF subunit SMARCB1. Here, we employ an integrated molecular profiling and chemical biology approach to demonstrate that the receptor tyrosine kinases (RTKs) PDGFRα and FGFR1 are coactivated in MRT cells and that dual blockade of these receptors has synergistic efficacy. Inhibitor combinations targeting both receptors and the dual inhibitor ponatinib suppress the AKT and ERK1/2 pathways leading to apoptosis. MRT cells that have acquired resistance to the PDGFRα inhibitor pazopanib are susceptible to FGFR inhibitors. We show that PDGFRα levels are regulated by SMARCB1 expression, and assessment of clinical specimens documents the expression of both PDGFRα and FGFR1 in rhabdoid tumor patients. Our findings support a therapeutic approach in cancers with SWI/SNF deficiencies by exploiting RTK coactivation dependencies.

  1. Beamlines of the Biomedical Imaging and Therapy Facility at the Canadian Light Source - Part 2

    NASA Astrophysics Data System (ADS)

    Wysokinski, T. W.; Chapman, D.; Adams, G.; Renier, M.; Suortti, P.; Thomlinson, W.

    2013-03-01

    The BioMedical Imaging and Therapy (BMIT) facility provides a world class facility with unique synchrotron-specific imaging and therapy capabilities. This paper describes Insertion Device (ID) beamline 05ID-2 with the beam terminated in the first experimental hutch: POE-2. The experimental methods available in POE-2 include: Microbeam Radiation Therapy (MRT), Synchrotron Stereotactic Radiation Therapy (SSRT) and absorption imaging (projection and Computed Tomography (CT)). The source for the ID beamline is a multi-pole superconductive 4.3 T wiggler, which can generate ~30 kW of radiative power and deliver dose as high as 3000 Gy/s required for MRT program. The optics in POE-1 hutch prepares either monochromatic or filtered white beam that is used in POE-2. The Double Crystal (DC), bent Laue monochromator will prepare a beam over 10 cm wide at sample point, while spanning an energy range appropriate for imaging studies of animals (20-100+ keV). The experimental hutch will have a flexible positioning system that can handle subjects up to 120 kg. Several different cameras will be available with resolutions ranging from 4 μm to 150 μm. The latest update on the status of 05B1-1 bending magnet (BM) beamline, described in Part 1 [1], is also included.

  2. Pharmacokinetics of levofloxacin in Japanese quails (Coturnix japonica) following intravenous and oral administration.

    PubMed

    Aboubakr, M

    2012-01-01

    1. The pharmacokinetics of levofloxacin were investigated in Japanese quails after a single dose of 10 mg/kg BW, given either intravenously or orally. 2. Following intravenous administration, the mean value of distribution at steady state (Vd(ss)), total body clearance (Cl(tot)) and mean residence time (MRT) of levofloxacin were 1·25 l/kg, 0·39 l/h/kg and 2·72 h, respectively. 3. Following oral administration of levofloxacin, the peak plasma concentration (C(max)) was 3·31 µg/ml and was achieved at a maximum time (T(max)) of 2 h. Mean residence time (MRT), mean absorption time (MAT) and bioavailability were 4·26 h, 1·54 h and 69·01%, respectively. In vitro plasma protein binding of levofloxacin was 23·52%. 4. Based on pharmacokinetic and pharmacodynamic integration, an oral dose of 10 mg/kg levofloxacin for every 12 h is recommended for a successful clinical effect in quails.

  3. Development of the electrothermal instability from resistive inclusions

    NASA Astrophysics Data System (ADS)

    Yu, Edmund; Awe, T. J.; Bauer, B. S.; Yates, K. C.; Yelton, W. G.; Hutchinson, T. M.; Fuelling, S.; McKenzie, B. B.; Peterson, K. J.

    2016-10-01

    The magneto Rayleigh-Taylor (MRT) instability limits the performance of all magnetically imploded systems. In the case of compressing metal liners, as in the magnetized liner inertial fusion concept, a dominant seed for MRT is believed to be the electrothermal instability (ETI). Here, linear theory predicts the most unstable mode manifests as horizontal (i.e. perpendicular to current flow) bands of heated and expanded metal. However, how do such bands, known as striations, actually develop from a smooth metal surface? Recent experiments on ETI evolution, performed at the University of Nevada, Reno, provide a possible answer: pre-shot characterization of aluminum rods show numerous resistive inclusions, several microns in diameter and distributed throughout the rod. In this work, we use 3D MHD simulation and analytic theory to explore how current redistribution around these isolated inclusions, combined with ETI, can lead to rapid formation of the global striation structures. Later in time, striations expand and form density perturbations much larger than the initial inclusion size. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the National Nuclear Security Administration under DE-AC04-94AL85000.

  4. Application of back-propagation artificial neural network and curve estimation in pharmacokinetics of losartan in rabbit

    PubMed Central

    Lin, Bin; Lin, Gaotong; Liu, Xianyun; Ma, Jianshe; Wang, Xianchuan; Lin, Feiyan; Hu, Lufeng

    2015-01-01

    In order to develop pharmacokinetic model, a well-known multilayer feed-forward algorithm back-propagation artificial neural networks (BP-ANN) was applied to the pharmacokinetics of losartan in rabbit. The plasma concentrations of losartan in twelve rabbits, which were divided into two groups and given losartan 2 mg/kg by intravenous (Iv) and intragastrical (Ig) administration, were determined by LC-MS. The BP-ANN model included one input layer, hidden layers, and one output layer was constructed and compared with curve estimation based on the time-concentration data of losartan. The results showed the BP-ANN model had high goodness of fit index and good coherence (R > 0.99) between forecasted concentration and measured concentration both in Iv and Ig administration. The residuals of each concentrations generated by BP-ANN model were all smaller than Curve estimation. The pharmacokinetic result showed there was no significant difference between measured and simulated pharmacokinetic parameters including AUC(0-t), AUC(0-∞), MRT(0-t), MRT(0-∞), T1/2 V and Cmax (P > 0.05). In conclusion, the BP-ANN model has remarkably accurate predictions ability, which better than Curve estimation, and can be used as a utility tool in pharmacokinetic experiment. PMID:26885213

  5. Reference-free PRFS MR-thermometry using near-harmonic 2-D reconstruction of the background phase.

    PubMed

    Salomir, Rares; Viallon, Magalie; Kickhefel, Antje; Roland, Joerg; Morel, Denis R; Petrusca, Lorena; Auboiroux, Vincent; Goget, Thomas; Terraz, Sylvain; Becker, Christoph D; Gross, Patrick

    2012-02-01

    Proton resonance frequency shift (PRFS) MR thermometry (MRT) is the generally preferred method for monitoring thermal ablation, typically implemented with gradient-echo (GRE) sequences. Standard PRFS MRT is based on the subtraction of a temporal reference phase map and is, therefore, intrinsically sensitive to tissue motion (including deformation) and to external perturbation of the magnetic field. Reference-free (or reference-less) PRFS MRT has been previously described by Rieke and was based on a 2-D polynomial fit performed on phase data from outside the heated region, to estimate the background phase inside the region of interest. While their approach was undeniably a fundamental progress in terms of robustness against tissue motion and magnetic perturbations, the underlying mathematical formalism requires a thick unheated border and may be subject to numerical instabilities with high order polynomials. A novel method of reference-free PRFS MRT is described here, using a physically consistent formalism, which exploits mathematical properties of the magnetic field in a homogeneous or near-homogeneous medium. The present implementation requires as input the MR GRE phase values along a thin, nearly-closed and unheated border. This is a 2-D restriction of a classic Dirichlet problem, working on a slice per slice basis. The method has been validated experimentally by comparison with the “ground truth” data, considered to be the standard PRFS method for static ex vivo tissue. “Zero measurement” of the gradient-echo phase baseline was performed in healthy volunteer liver with rapid acquisition (300 ms/image). In vivo data acquired in sheep liver during MR-guided high intensity focused ultrasound (MRgHIFU) sonication were post-processed as proof of applicability in a therapeutic scenario. Bland and Altman mean absolute difference between the novel method and the “ground truth” thermometry in ex vivo static tissue ranged between 0.069 °C and 0.968

  6. Physiologically gated microbeam radiation using a field emission x-ray source array

    SciTech Connect

    Chtcheprov, Pavel E-mail: zhou@email.unc.edu; Burk, Laurel; Inscoe, Christina; Ger, Rachel; Hadsell, Michael; Lu, Jianping; Yuan, Hong; Zhang, Lei; Chang, Sha; Zhou, Otto E-mail: zhou@email.unc.edu

    2014-08-15

    Purpose: Microbeam radiation therapy (MRT) uses narrow planes of high dose radiation beams to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000 Gy of peak entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during treatment can lead to significant movement of microbeam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), which reduces the effectiveness of MRT. Recently, the authors have demonstrated the feasibility of generating microbeam radiation for small animal treatment using a carbon nanotube (CNT) x-ray source array. The purpose of this study is to incorporate physiological gating to the CNT microbeam irradiator to minimize motion-induced microbeam blurring. Methods: The CNT field emission x-ray source array with a narrow line focal track was operated at 160 kVp. The x-ray radiation was collimated to a single 280 μm wide microbeam at entrance. The microbeam beam pattern was recorded using EBT2 Gafchromic{sup ©} films. For the feasibility study, a strip of EBT2 film was attached to an oscillating mechanical phantom mimicking mouse chest respiratory motion. The servo arm was put against a pressure sensor to monitor the motion. The film was irradiated with three microbeams under gated and nongated conditions and the full width at half maximums and PVDRs were compared. An in vivo study was also performed with adult male athymic mice. The liver was chosen as the target organ for proof of concept due to its large motion during respiration compared to other organs. The mouse was immobilized in a specialized mouse bed and anesthetized using isoflurane. A pressure sensor was attached to a mouse's chest to monitor its respiration. The output signal triggered the electron extraction voltage of the field emission source such that x-ray was generated only during a

  7. [Pliability and deflection of diagnostic catheters].

    PubMed

    Pelyhe, Liza; Bognár, Eszter

    2014-09-28

    Bevezetés: A szívkatéter olyan intravascularis katéter, amelyet a szívbe vezetnek vagy ültetnek be diagnosztikus vagy terápiás célból. A katéterek felvezetés/eltávolítás közben megtörhetnek vagy eltörhetnek. Célkitűzés: A szerzők két azonos alapanyagú, de különböző átmérőjű katéter hajlékonyságának meghatározását tűzték ki célul a Food and Drug Administration ajánlása alapján. Módszer: Meghatározták a hajlítási pontokat, a pontokon az átmérőcsökkenést, az elhajlás változását, továbbá e két paraméter csúcstól mért távolságának függését, korrelációjukat és a katéter kezdeti átmérőjének hatását. A katétereket 9-9 ponton (120–280 mm-re a páciensbe bevezetett végtől 20 mm-ként), 16 különböző sugarú idomszeren hajlították meg, amelyek sugara 10 mm-től 2,5 mm-ig 0,5 mm-ként csökkent. Eredmények: Megállapították, hogy az átmérőcsökkenés és az elhajlás lineárisan korrelál egymással, és függetlenek a mérési pont helyétől mindkét katéter esetében. A nagyobb átmérőjű katéternél szignifikánsan (p = 0,05) nagyobb volt az átmérőcsökkenés, mint a kisebbnél, de az átmérőcsökkenés és az elhajlási görbék lefutása hasonló. Következtetések: Az alkalmazott módszer alkalmasnak tűnik az adott típusú katéterek lehetséges gyenge pontjainak vizsgálatára. Orv. Hetil., 2014, 155(39), 1544–1548.

  8. [Evaluation of the usefulness of the EOS 2D/3D system for the measurement of lower limbs anatomical and biomechanical parameters in children].

    PubMed

    Schlégl, Adám Tibor; Szuper, Kinga; Somoskeöy, Szabolcs; Than, Péter

    2014-10-26

    Bevezetés: Az alsó végtag anatómiai és biomechanikai paraméterei számos gyermekortopédiai betegség kulcstényezői, így pontos mérésük elengedhetetlen. Célkitűzés: A szerzők célja a rendelkezésükre álló 3D rekonstrukcióra képes képalkotó eszköz, az EOS 2D/3D System gyermekkori alkalmazhatóságának vizsgálata volt. Módszer: A 2–16 éves korcsoportba tartozó 523 egyén 3D modellezését végezték el, akiknél az alsó végtag biomechanikáját befolyásoló eltérés nem igazolódott. Az adatok statisztikai feldolgozásához intraclass korrelációs vizsgálatot, páros t-próbát, Spearman-korrelációt, illetve Welch-tesztet alkalmaztak. Eredmények: A megbízhatósági vizsgálat során az operátor minden paraméter esetében kiváló eredményt ért el. A képalkotás során alkalmazott előrelépett pozíció egyedül a sagittalis tibifemoralis szögnél okozott eltérést. A szerzők által vizsgált összes paraméter összefüggést mutatott a korral és a nemmel. Ezzel szemben a magassággal nem mutatott összefüggést a collodiaphysealis szög, a csípő-térd eltolódás és a femoralis és tibialis torzió. Következtetések: Az EOS-technológia alkalmas módszernek bizonyult az alsó végtag anatómiai paramétereinek mérésére gyermekkorban. Ezek változása összefügg a nemmel és a korral egyaránt. Orv., Hetil., 2014, 155(43), 1701–1711.

  9. [The role of the family in childhood and adolescent binge eating - a systematic review].

    PubMed

    Tetzlaff, Anne; Hilbert, Anja

    2014-01-01

    Fragestellung: Während der Einfluss der Familie bei Anorexia Nervosa und Bulimia Nervosa im Kindes- und Jugendalter belegt ist und bereits in Übersichtsarbeiten zusammengefasst wurde, liegen derzeit wenige Befunde zum Zusammenhang zu Essanfällen ohne kompensatorische Verhaltensweisen vor. Ziel dieser systematischen Übersichtsarbeit ist es daher, familiäre Einflussfaktoren auf die Entstehung und Aufrechterhaltung von Essanfällen zu beschreiben. Methodik: Eine systematische Datenbanksuche für Studien zum Zusammenhang von familiären Faktoren und Essanfällen wurde durchgeführt. Ergebnisse: Die eingeschlossenen Studien zeigten einheitlich, dass eine unsichere Bindung des Kindes, eine geringere Familienfunktionalität und geringere emotionale Unterstützung mit Essanfällen querschnittlich assoziiert sind, elterliche Arbeitslosigkeit sowie elterliche Depressionen retrospektive Korrelate darstellen und weniger Familienmahlzeiten und häufige kritische Kommentare über Figur und Gewicht innerhalb der Familie variable Risikofaktoren für Essanfälle sind. Inkonsistente Befunde fanden sich hingegen bezüglich der Familienstrukturen, dem Vorliegen elterlicher Essstörungen und Diäthalten sowie dem Erkennen von Essanfällen beim eigenen Kind. Geschlechterunterschiede hinsichtlich familiärer Beziehungen und gewichtsbezogener Stigmatisierung wurden identifiziert. Schlussfolgerungen: Ebenso wie bei anderen Essstörungen im Kindes- und Jugendalter spielen familiäre Einflussfaktoren auch bei Essanfällen eine wichtige Rolle. Daher könnten eine Diagnostik familiärer Einflüsse und familientherapeutische Interventionen in der Behandlung von Essanfällen im Kindes- und Jugendalter hilfreich sein. Mithilfe von prospektiven Studiendesigns könnten die divergierenden Ergebnisse aufgeklärt werden.

  10. Fracture severity of distal radius fractures treated with locking plating correlates with limitations in ulnar abduction and inferior health-related quality of life.

    PubMed

    Tsitsilonis, Serafim; Machó, David; Manegold, Sebastian; Krapohl, Björn Dirk; Wichlas, Florian

    2016-01-01

    Einleitung: Die operative Therapie der distalen Radiusfrakturen hat nach der Entwicklung der winkelstabilen Platten signifikant zugenommen. Ziel der vorliegenden Studie war die Evaluation von Lebensqualität sowie funktionellem und radiologischem Outcome von Patienten nach einer winkelstabilen Plattenosteosynthese bei einer distalen Radiusfraktur. Materialien und Methoden: Insgesamt wurden 128 Patienten (130 Frakturen) nach operativer Versorgung mittels Locking Compression Plate (LCP) (2,4 mm/3,5 mm, Synthes(®)) retrospektiv untersucht. Die mittlere Nachbeobachtungszeit betrug 22,7 Monate (SD: 10,6). Die Frakturen wurden prä-, postoperativ und bei der letzten Vorstellung radiologisch evaluiert (radiale Inklination, palmarer Tilt, Ulnavarianz). Der Bewegungsumfang wurde erhoben. Griffkraft wurde mittels eines JAMAR-Dynamometers dokumentiert. Der Disabilities of the Arm, Shoulder and Hand (DASH)-Score und der Gartland-Werley-Score wurden erhoben. Die gesundheitsassoziierte Lebensqualität wurde mittels des SF-36-Health-Survey evaluiert.Ergebnisse: Die postoperative Reposition war exzellent; ein minimaler Repositionsverlust lag bei der letzten Follow-up-Vorstellung vor. Es wurde in jeder Bewegungsrichtung (außer Pronation) eine statistisch signifikante Minderung der Beweglichkeit beobachtet; in den meisten Fällen war dies nicht klinisch relevant. Die verletzte Seite erreichte 83,9% der Griffkraft der Gegenseite. Der Mittel-DASH-Score betrug 18,9 und der Mittel-GWS war 3,5. Die Lebensqualität war insgesamt nicht beeinträchtigt. Allerdings korrelierte die Einschränkung der Ulnarabduktion mit schlechteren Werten der Lebensqualität. Der Schweregrad der Fraktur korrelierte mit schlechterer Lebensqualität, trotz der fehlenden Korrelation mit dem funktionellen und radiologischen Outcome. Die Komplikationsrate war niedrig.Schlussfolgerungen: Der Schweregrad der Fraktur scheint die Ulnarabduktion zu beeinflussen und dadurch die Lebenqualität zu beeintr

  11. [On the relationship between executive functioning and social-emotional problems of deaf and hard-of-hearing students at general schools].

    PubMed

    Hintermair, Manfred; Korneffel, Désirée

    2013-09-01

    Fragestellung: Da im Zuge inklusiver Bestrebungen immer mehr hörgeschädigte Kinder eine allgemeine Schule besuchen werden, gilt es, relevante entwicklungspsychologische Voraussetzungen hierfür genauer zu betrachten. In einer Studie wurden deshalb sozial-emotionale Probleme hörgeschädigter Kinder an allgemeinen Schulen im Zusammenhang mit möglichen Problemen in der Entwicklung exekutiver Funktionen und der kommunikativen Kompetenz diskutiert. Methodik: Eine Stichprobe von 69 Schülern wurde mit einer deutschen Version des «Behavior Rating Inventory of Executive Functions (BRIEF)», einer Kurzskala zur Erfassung der kommunikativen Kompetenz sowie dem Strengths and Difficulties Questionnaire untersucht. Die Daten wurden mit einer Normierungsstichprobe verglichen, weiter wurden korrelative und regressionsanalytische Zusammenhänge der Variablen berechnet. Ebenso wurden Zusammenhänge der exekutiven Funktionen mit soziodemographischen Variablen analysiert. Ergebnisse: Die Ergebnisse zeigen, dass in fast allen Bereichen exekutiver Funktionen die hörgeschädigten Kinder mehr Probleme aufweisen als die Kinder der hörenden Normierungsstichprobe und die Prävalenzrate durchschnittlich ca. dreimal höher ist. Der Index für verhaltensregulierende exekutive Funktionen erweist sich neben dem Geschlecht am besten zur Vorhersage sozial-emotionaler Probleme. Schlussfolgerungen: Für die pädagogische Praxis ergibt sich, dass hörgeschädigte Schüler an allgemeinen Schulen in Bezug auf ihre psychosoziale Entwicklung von einem pädagogischen Konzept profitieren, das neben der Förderung sprachkommunikativer Kompetenzen auch auf die Stärkung von Selbstkontrolle und Selbstwirksamkeit der Kinder fokussiert.

  12. Recurrent urinary tract infections and complications after symptomatic versus antibiotic treatment: follow-up of a randomised controlled trial.

    PubMed

    Bleidorn, Jutta; Hummers-Pradier, Eva; Schmiemann, Guido; Wiese, Birgitt; Gágyor, Ildikó

    2016-01-01

    Hintergrund: Unkomplizierte Harnwegsinfekte (HWI) sind eine häufige Erkrankung in der Allgemeinmedizin und werden üblicherweise antibiotisch behandelt. Rezidive stellen dabei ein ernstzunehmendes Problem für betroffene Frauen dar. Über Rezidive und Komplikationen nach nicht-antibiotischer Behandlung unkomplizierter Harnwegsinfekte ist wenig bekannt.Mit der Studie ICUTI (Immediate vs. conditional antibiotic use in uncomplicated UTI, gefördert vom BMBF 01KG1105) wurde untersucht, ob eine initial symptomatische Behandlung mit Ibuprofen eine alternative Behandlungsmöglichkeit beim Harnwegsinfekt darstellt. Die hier vorgestellte Analyse hatte zum Ziel, den Einfluss einer initialen (nicht)antibiotischen Therapie auf das Auftreten von Rezidiven und Pyelonephritiden zwischen Tag 28 und 6 Monaten nach Einschluss in die Studie darzustellen.Methode: Retrospektive Analyse der 6-Monats-Nachbefragung der ICUTI-Teilnehmer. Durch telefonische Befragung 6 Monate nach Einschluss in die Studie wurde das Auftreten von Rezidiven, Pyelonephritiden und Krankenhausaufnahmen dokumentiert. Die statistische Auswertung erfolgte durch deskriptive und multivariate Analysen mit SPSS 21.Ergebnisse: Bei der 6-Monats-Nachbefragung wurden 386 ICUTI-Teilnehmerinnen erreicht (494 waren in ICUTI eingeschlossen worden, 446 hatten die Studie beendet). Zwischen Tag 28 und 6 Monaten nach Einschluss in ICUTI berichteten 80 Patientinnen insgesamt 84 Rezidive. In der univariaten und in der multivariaten Analyse zeigte sich kein Einfluss der initialen Behandlungsgruppe oder einer antibiotischen Behandlung auf die Zahl der Patientinnen mit Rezidiven. Allerdings zeigten beide Analysen, dass Patientinnen mit vorherigen Harnwegsinfekten signifikant häufiger weitere Rezidive bekamen. Pyelonephritiden traten bei zwei Patientinnen in der antibiotisch behandelten Gruppe und bei einer Patientin in der nicht antibiotisch behandelten Gruppe auf.Schlussfolgerung: Die Follow-up-Analyse der Nachbefragung nach einem

  13. Triglyceride to high density lipoprotein cholesterol ratio, total cholesterol to high density lipoprotein cholesterol ratio and low ankle brachial index in an elderly population.

    PubMed

    Zhan, Yiqiang; Yu, Jinming; Ding, Rongjing; Sun, Yihong; Hu, Dayi

    2014-05-01

    Hintergrund: Der Zusammenhang zwischen den Quotienten aus Triglycerid (TG) und High-density-lipoprotein-cholesterin (HDL‑C) sowie Gesamtcholesterin (TC) und HDL‑C und dem Knöchel-Arm-Index (ABI) wurde selten untersucht. Patienten und Methoden: Insgesamt 2.982 Teinehmer, die über 60 Jahre alt waren, wurden für die bevölkerungsbasierte Querschnittstudie rekrutiert. TG, TC, HDL‑C, und low-density Lipoprotein Cholesterol (LDL-C) wurden bei allen Teilnehmern getestet. Ein niedriger ABI wurde als ABI ≤ 0.9 definiert. Multiple Regressionsmodelle wurden für die Untersuchung der Assoziation zwischen TG/HDL‑C Ratio und TC/HDL‑C Ratio und niedrigem ABI angewendet. Ergebnisse: Die TG/HDL‑C Ratios für ABI > 0.9 und ABI ≤ 0.9 waren 1.28 ± 1.20 und 1.48 ± 1.13 (P < 0.0001), während die TC/HDL‑C Ratios 3.96 ± 1.09 bzw. 4.32 ± 1.15 (P < 0.0001) waren. Nach der Angleichung von Alter, Geschlecht, Body-Mass-Index, Fettleibigkeit, Alkoholkonsum, köperliche Aktivität, Hypertonie, Diabetes, Einnahme von lipidsenkenden Medikamenten, und Herz-Kreislauf-Erkrankungen waren die Odds Ratios (OR) mit 95 % Konfidenzintervall (KI) bei dem niedrigen ABI und TG/HDL‑C Quotient 1,10 (0,96 - 1,26) und 1,34 (1,14 - 1,59) für TC/HDL‑C in der Nichtrauchergruppe. Wenn das TC weiter angeglichen wurde, waren die ORs (95 % CIs) 1.40 (0.79, 2.52) und 1.53 (1.21, 1.93) für die TG/HDL‑C Ratio und TC/HDL‑C Ratio. Nichtlineare Zusammenhänge wurden zwischen der TG/HDL‑C Ratio und TC/HDL‑C Ratio und dem niedrigen ABI in der Raucher- und Nichtrauchergruppe entdeckt. Schlussfolgerungen: Die TC/HDL‑C Ratio war signifikant mit einem niedrigen ABI in der Nichtrauchergruppe verbunden und die Assoziation war unabhängig von TC, TG, HDL‑C und LDL-C. TC/HDL‑C könnte als potentieller Biomarker für die frühe periphere arterielle Verschlusskrankheit beim Screening berücksichtigt werden.

  14. Wissenschaftliche Abhandlungen

    NASA Astrophysics Data System (ADS)

    Boltzmann, Ludwig; Hasenöhrl, Friedrich

    2012-08-01

    Vorwort; 1. Über die Bewegung der Elektrzität in krummen Flächen; 2. Über die mechanische Bedeutung des zweiten Hauptsatzes der Wärmetheorie; 3. Über die Anzahl der Atome; 4. Über die Integrale linearer Differentialgleighungen; 5. Studien über das Gleichgewicht der lebendingen Kraft; 6. Lösung eines mechanischen Problems; 7. Über die Festigkeit zweier mit Druck übereinander gesteckter zylindrischer Röhren; 8. Über die elektrodynamische Wechselwirkung der Reile eines elektrishen Stromes von veränderlicher Gestalt; 9. Bemerkung zur Abhandlung des Herrn R. Most; 10. Erwiderung an Herrn Most; 11. Über die von bewegten Gasmassen geleistete Arbeit; 12. Noch einiges über Kohlrauschs Versuch; 13. Über die Ableitung der Grundgleichungen der Kapillarität; 14. Über eine neue optische Methode; 15. Boiling points of organic bodies; 16. Über die Druckkräfte, welche auf Ringe wriksam sind; 17. Zur Priorität der Auffindung der Beziehung zwischen dem zweiten Hauptsatze der mechanischen Wärmetheorie; 18. Über das Wärmegleichgewicht zwischen mehratomigen Gasmolekülen; 19. Einige allgemeine Sätze über Wärmegleichgewicht; 20. Analytischer Beweis des zweiten Hauptsatzen der mechanischen Wärmetheorie; 21. Über das Wirkungsgesetz der Molekülarkräfte; 22. Weiteren Studien über das Wärmegleichgewicht unter Gasmolekülen; 23. Resultate einer Experimentaluntersuchung; 24. Experimentelle Bestimmung der Dielektrizitätskonstante von Isolatoren; 25. Experimentaluntersuchung über die elektrostatische Fernwirkung dielektrischer Körper; 26. Experimentelle Bestimmung der Dielektrizitätskonstante einiger Gase; 27. Über einige an meinen Versuchen; 28. Über die Verschiedenheit der Dielektrizitätskonstante des Körper unter dem Einflusse elektrische Kräfte; 29. Experimentaluntersuchung über das Verhalten nicht leitender Körper unter dem Einflusse electrischer Kräfte; 30. Zur Theorie der elastische Nachwirkung; 31. Über den Zusammenhang zwischen der Drehung

  15. In Situ Persistence and Migration of Biochar Carbon and Its Impact on Native Carbon Emission in Contrasting Soils under Managed Temperate Pastures

    PubMed Central

    Singh, Bhupinder Pal; Fang, Yunying; Boersma, Mark; Collins, Damian; Van Zwieten, Lukas; Macdonald, Lynne M

    2015-01-01

    Pyrogenic carbon (PyC) is an important component of the global soil carbon (C) pool, but its fate, persistence, and loss dynamics in contrasting soils and environments under planted field conditions are poorly understood. To fill this knowledge gap, a 13C-labelled biochar, as a surrogate material for PyC, produced from Eucalyptus saligna by slow pyrolysis (450°C; δ13C -36.7‰) was surface (0−10 cm) applied in C3 dominated temperate pasture systems across Arenosol, Cambisol and Ferralsol. The results show a low proportion of the applied biochar-C mineralised over 12 months in a relatively clay- and C-poor Arenosol (i.e., 2.0% loss via mineralisation), followed by a clay- and C-rich Cambisol (4.6%), and clay-, C- and earthworm-rich Ferralsol (7.0%). The biochar-C mean residence time (MRT), estimated by different models, varied between 44−1079 (Arenosol), 18−172 (Cambisol), and 11−29 (Ferralsol) years, with the shorter MRT estimated by a one-pool exponential and the longer MRT by an infinite-pool power or a two-pool exponential model. The two-pool model was best fitted to biochar-C mineralisation. The biochar-C recovery in the 12−30 cm soil layer varied from between 1.2% (Arenosol), 2.5−2.7% (Cambisol) and 13.8−15.7% (Ferralsol) of the applied biochar-C after 8−12 months. There was a further migration of biochar-C below the 50-cm depth in the Arenosol, as the combined biochar-C recovery in the mineralised pool and soil profile (up to 30 or 50 cm) was 82%, in contrast to 101% in the Cambisol and 104% in the Ferralsol after 12 months. These results indicate that the downward migration of biochar-C was greatest in the Arenosol (cf. Cambisol and Ferralsol). Cumulative CO2-C emission from native soil-plant sources was lower (p <0.10) in the biochar-amended vs. non-amended Ferralsol. This field-based study shows that the downward migration of biochar-C exceeded its loss via mineralisation in the Arenosol and Ferralsol, but not in the Cambisol. It is thus

  16. Age and thermal stability of particulate organic matter fractions indicate the presence of black carbon in soil

    NASA Astrophysics Data System (ADS)

    Leifeld, Jens; Heiling, Maria; Hajdas, Irka

    2014-05-01

    Black carbon (BC) from incomplete combustion is abundant in many soils. The age of black carbon is often higher than that of typical soil organic carbon (SOC) owing to its higher recalcitrance against microbial decomposition compared to plant residues. Also fossil BC may contribute to the high age of SOC. At the same time, the oxidative thermal stability of BC is known to be higher than that of SOC due to its chemical and physical structure. For a meaningful application of radiocarbon as an indicator for soil carbon age and turnover, the relative contribution of BC needs to be known but BC is difficult to separate physically from soil. Here we analyze particulate organic carbon (POC) fractions from four different field sites in Europe for their thermal stability using oxidative differential scanning calorimetry (DSC) and for their radiocarbon signature. POC may be particularly sensitive to BC 'contamination' because it was gained using a combination of size and density separation. One of these sites is essentially free of measurable amounts of BC. Each of the four sites comprised between five and eight individual POC samples taken from different spots. The radiocarbon signature and the calculated POC mean residence time of samples from three out of four sites indicated the presence of very old carbon, resulting in mean residence times (MRT) of several hundreds and up to 3700 years. In contrast, MRT's of POC from the virtually BC-free site were between 50 and 100 years. Two indicators for thermal stability of the POC fractions, i) the amount of heat released at temperatures > 450 °C and ii) the amount of heat released at 500 °C (where the latter represents the peak temperature of charcoal isolated from one of the samples) correlated both significantly and non-linearly with the samples MRT, indicating that samples with high BC content are older. Hence we can conclude that for an individual site with increasing abundance of BC both the age and the thermal stability

  17. Higher bioavailability of doxycycline in broiler chickens with a novel in-feed pharmaceutical formulation.

    PubMed

    Gutiérrez, Lilia; Zermeño, Juan; Alcalá, Yazmín; Sumano, Héctor

    2017-02-23

    Bioavailability of a new, long-acting (LA) pharmaceutical preparation for administering doxycycline as in-feed medication to broiler chickens was compared to the standard in-feed administration of doxycycline. A commercial poultry house harboring Ross-308 broiler chickens, weighing 450 g, was divided into 7 sections as follows: doxy-FOLA group (n = 6,000 chickens divided into 3 replicates) medicated with 10% doxycyline, long-acting pellets at a dose of 400 g of doxycycline HCl/ton of food, resulting in a calculated dose of 48 mg/kg for 5 d; doxy-ref group (n = 6,000, divided into 3 replicates) medicated as for doxy-FOLA, but using a 20% commercial preparation of doxycycline. A third group of 300 broiler chickens (divided into 3 replicates), received a single IV dose of 48 mg/kg from a 2.4% solution of doxycycline HCl under ketamine anesthesia. Blood samples were obtained at designated times, serum was harvested, and doxycycline concentrations determined by high-performance liquid chromatography (HPLC). Bioavailability values were 156% and 227% on d 1 and 5 for doxy-FOLA and 13% and 23% for doxy-ref, on the same days. Mean residence time (MRT) and elimination half-life (T½β) were statistically different (P < 0.05) in doxy-FOLA group as compared to doxy-ref group (MRT: 26 h and 5.2 h; and T½β: 18 h vs 3 h, on the first day for doxy-FOLA and doxy-ref, respectively). Based on 3 levels of bacterial sensitivity of E. coli derived from a small survey carried out (i.e., 1.0, 2.0, and 4.0 μg/mL) and considering pharmacokinetic/pharmacodynamic (PK/PD) ratios required for this time-dependent antibacterial drug, it is possible to postulate that doxy-FOLA outstrips the reference preparation maintaining higher and more prolonged serum concentrations of doxycycline and consequently complying better with PK/PD ratios regarded as optimal for this drug. The advantages of using doxy-FOLA in poultry medicine include a more comprehensive use of the active principle

  18. Distinct Litter Stabilization Dynamics Pathways for Decomposition of Pine Needle and Fine Root Within Soil

    NASA Astrophysics Data System (ADS)

    Mambelli, S.; Filley, T. R.; Bird, J.; Dawson, T.; Torn, M. S.

    2008-12-01

    The chemical composition of litter imparts a strong control on the initial rates of microbial decay but it is unclear how plant chemistry influences the ultimate stabilization of soil organic matter (SOM) and the nature of the products stabilized. We determined the concentration and 13C enrichment of lignin phenols and substituted fatty acids (SFA) in SOM fractions from an experiment in which 13C- and 15N-labeled needles or fine roots were added to the mineral soil in a Ponderosa pine (Pinus ponderosa) forest in the Sierra Nevada, CA, USA. 1.5 y after litter addition, we analyzed bulk soil (< 2 mm), free light fraction (LF, mean residence time (MRT) ~5 y) and alkali/acid insoluble humin (MRT ~270 y) fractions. Needles contained nearly 2 and 3x the lignin and SFA content per organic carbon unit as did roots. Lignin and SFA decreased from the free LF to the bulk soil to the humin fraction; and molecular properties were more similar within a SOM fraction regardless of the litter source. However, LF and humin from the root addition contained more lignin than from the needle addition. Based upon the relative movement of litter-derived 13C and 15N into SOM fractions during 1.5 y, it was proposed that the 13C accumulation in the humin fraction for needles was derived from high C/N, needle-derived biopolymer molecular fragments that are surficially associated with particles. In contrast, the root-derived material entering SOM fractions was much lower in C/N and was likely from microbial by-products. Consistent with this hypothesis, both lignin and SFA in the LF and humin fractions amended with enriched needles were highly enriched (+ 30-60 permil) with respect to the SOM fractions from soils amended with roots. These differences were large even considering the lower concentration of SFA and lignin in root material. Although the chemistry and MRT of LF and humin were dramatically different, the extent of 13C-enrichment among lignin and SFA were comparable for the needle

  19. The stability of Pyrogenic Organic Matter is dependent upon its wood source and charring temperature

    NASA Astrophysics Data System (ADS)

    Gibson, C. D.; Filley, T. R.; Bird, J.; Nadelhoffer, K. J.; Stark, R. E.; Hatton, P. J.

    2015-12-01

    Fire is a major mediator of carbon (C) cycling in forests and can result in the formation of pyrogenic organic matter (PyOM). The biological reactivity of PyOM is largely dependent upon the physiochemical characteristics of source material and production temperature. As a result, PyOM can persist up to centennial time scales after deposition while simultaneously enhancing or suppressing the mineralization of native soil C (NSC). To investigate the interactive effects of PyOM source and production temperature on NSC, we added 13C-enriched red maple (RM) or jack pine (JP) pyrolyzed at 200, 300, 450 or 600°C to a low C (0.5%;), near-surface soil (0-20 cm-depth) at 60% water holding capacity and 11% of native soil C and then incubated the samples in the dark at 25⁰C for 6 months. We found that PyOM mineralization rates decreased with increasing pyrolysis temperature for either species while NSC mineralization was suppressed across all treatments with the largest decrease observed in JP 300⁰C. RM mineralization rates were consistently greater (˜5 to ˜25%) than for JP <600⁰C during the first 17 days. Mean residence time (MRT) of PyOM-C was significantly higher in PyOM >300°C resulting in MRT of ~300 - 550 y compared to 8-30 y in lower temperature PyOM (0-300 °C). RM exhibited significantly lower MRT in 300°C PyOM than JP corresponding to differences observed in PyOM and NSC mineralization rates. The modelled active and slow pools of PyOM-C mineralized decreased with increasing combustion temperature. JP 300°C had a 20% smaller active pool when compared to RM suggesting that for both species, 300⁰C - 450⁰C represented a thermal transition point which was most evident in jack pine. These results highlight how differences in PyOM physiochemical characteristics linked to a species thermal transformation threshold may be a predictor in determining its biological reactivity in soil.

  20. Digestive physiology, metabolism and methane production of captive Linné's two-toed sloths (Choloepus didactylus).

    PubMed

    Vendl, C; Frei, S; Dittmann, M T; Furrer, S; Osmann, C; Ortmann, S; Munn, A; Kreuzer, M; Clauss, M

    2016-06-01

    Sloths are renowned for their low metabolic rate, low food intake and low defecation frequency. We investigated factors of digestive physiology and energy metabolism in four captive individuals (mean body mass 10.0 ± SD 3.7 kg) of a hitherto mostly unstudied sloth species, Linné's two-toed sloth (Choloepus didactylus), in a 2-week digestion recording and 23-h respiration experiment on animals fed a standard zoo diet of vegetables and starchy components. Dry matter intake, defecation frequency and particle mean retention time (MRT) in the gastrointestinal tract (GIT) were 12 ± 3 g/(kg(0.75)  day), once every 5 days and >140 h in three individuals, but 53 g/(kg(0.75)  day), daily and 82 h in one individual that was apparently compensating for a period of weight loss prior to the experiment. In all animals, solute marker was eliminated at a faster rate than the particle marker, indicating 'digesta washing' in the sloths' GIT. The overall metabolic rate calculated from oxygen consumption matched the metabolisable energy intake in three individuals [173 ± 22 vs. 168 ± 44 kJ/(kg(0.75)  day)] but not in the fourth one [225 vs. 698 kJ/(kg(0.75)  day)], supporting the interpretation that this animal was replenishing body stores. In spite of the low food intake and the low-fibre diet (209 ± 26 g neutral detergent fibre/kg dry matter), methane production was rather high accounting for 9.4 ± 0.8% of gross energy intake (2.7% in the fourth individual), which exceeded literature data for ruminants on forage-only diets. These results corroborate literature reports on low intake, low defecation frequency, low metabolic rate and long MRT in other sloth species. The long MRT is probably responsible for the comparatively high methane production, providing more opportunity for methanogenic archaea than in other non-ruminant mammals to produce significant amounts of methane.

  1. Modeling nonstructural carbohydrate reserve dynamics in forest trees

    NASA Astrophysics Data System (ADS)

    Richardson, A. D.; Keenan, T. F.; Carbone, M. S.; Czimczik, C. I.; Hollinger, D. Y.; Murakami, P.; Schaberg, P.; Xu, X.

    2012-12-01

    Understanding the factors influencing the availability of nonstructural carbohydrate (NSC) reserves is essential for predicting the resilience of forests to climate change and environmental stress. However, carbon allocation processes remain poorly understood and many models either ignore NSC reserves, or use simple and untested representations of NSC allocation and pool dynamics. Using model-data fusion techniques, we combined a parsimonious model of forest ecosystem carbon cycling with novel field sampling and laboratory analyses of NSCs. Simulations were conducted for an evergreen conifer forest and a deciduous broadleaf forest in New England. We used radiocarbon methods based on the 14C "bomb spike" to estimate the age of NSC reserves, and used this to constrain the mean residence time of modeled NSCs. We used additional data, including tower-measured fluxes of CO2, soil and biomass carbon stocks, woody biomass increment, and leaf area index and litterfall, to further constrain the model's parameters and initial conditions. Three years of field measurements indicate that stemwood NSCs are highly dynamic on seasonal time scales. The modeled seasonal dynamics conform to expectations (accumulated in the growing season, depleted in the dormant season) but are inconsistent with the observational data (total stemwood NSC concentrations higher in March than November, lower in August than June). We interpret this contradiction to suggest that stemwood concentrations provide an incomplete picture of the whole-tree NSC budget. A two-pool model structure that accounted for both "fast" (active pool, MRT ≈1 y) and "slow" (passive pool, MRT ≥ 20 y) cycling reserves (1) gives reasonable estimates of the size and MRT of the total NSC pool; (2) greatly improves model predictions of interannual variability in woody biomass increment, compared to zero- or one-pool structures used in the majority of existing models; (3) provides a mechanism by which observations of a one

  2. Nitrogen response efficiency increased monotonically with decreasing soil resource availability: a case study from a semiarid grassland in northern China.

    PubMed

    Yuan, Zhi-You; Li, Ling-Hao; Han, Xing-Guo; Chen, Shi-Ping; Wang, Zheng-Wen; Chen, Quan-Sheng; Bai, Wen-Ming

    2006-07-01

    The concept of nutrient use efficiency is central to understanding ecosystem functioning because it is the step in which plants can influence the return of nutrients to the soil pool and the quality of the litter. Theory suggests that nutrient efficiency increases unimodally with declining soil resources, but this has not been tested empirically for N and water in grassland ecosystems, where plant growth in these ecosystems is generally thought to be limited by soil N and moisture. In this paper, we tested the N uptake and the N use efficiency (NUE) of two Stipa species (S. grandis and S. krylovii) from 20 sites in the Inner Mongolia grassland by measuring the N content of net primary productivity (NPP). NUE is defined as the total net primary production per unit N absorbed. We further distinguished NUE from N response efficiency (NRE; production per unit N available). We found that NPP increased with soil N and water availability. Efficiency of whole-plant N use, uptake, and response increased monotonically with decreasing soil N and water, being higher on infertile (dry) habitats than on fertile (wet) habitats. We further considered NUE as the product of the N productivity (NP the rate of biomass increase per unit N in the plant) and the mean residence time (MRT; the ratio between the average N pool and the annual N uptake or loss). The NP and NUE of S. grandis growing usually in dry and N-poor habitats exceeded those of S. krylovii abundant in wet and N-rich habitats. NUE differed among sites, and was often affected by the evolutionary trade-off between NP and MRT, where plants and communities had adapted in a way to maximize either NP or MRT, but not both concurrently. Soil N availability and moisture influenced the community-level N uptake efficiency and ultimately the NRE, though the response to N was dependent on the plant community examined. These results show that soil N and water had exerted a great impact on the N efficiency in Stipa species. The

  3. On the accuracy of estimation of basic pharmacokinetic parameters by the traditional noncompartmental equations and the prediction of the steady-state volume of distribution in obese patients based upon data derived from normal subjects.

    PubMed

    Berezhkovskiy, Leonid M

    2011-06-01

    The steady-state and terminal volumes of distribution, as well as the mean residence time of drug in the body (V(ss), V(β), and MRT) are the common pharmacokinetic parameters calculated using the drug plasma concentration-time profile C(p) (t) following intravenous (i.v. bolus or constant rate infusion) drug administration. These calculations are valid for the linear pharmacokinetic system with central elimination (i.e., elimination rate being proportional to drug concentration in plasma). Formally, the assumption of central elimination is not normally met because the rate of drug elimination is proportional to the unbound drug concentration at elimination site, although equilibration between systemic circulation and the site of clearance for majority of small molecule drugs is fast. Thus, the assumption of central elimination is practically quite adequate. It appears reasonable to estimate the extent of possible errors in determination of these pharmacokinetic parameters due to the absence of central elimination. The comparison of V(ss), V(β), and MRT calculated by exact equations and the commonly used ones was made considering a simplified physiologically based pharmacokinetic model. It was found that if the drug plasma concentration profile is detected accurately, determination of drug distribution volumes and MRT using the traditional noncompartmental calculations of these parameters from C(p) (t) yields the values very close to that obtained from exact equations. Though in practice, the accurate measurement of C(p) (t), especially its terminal phase, may not always be possible. This is particularly applicable for obtaining the distribution volumes of lipophilic compounds in obese subjects, when the possibility of late terminal phase at low drug concentration is quite likely, specifically for compounds with high clearance. An accurate determination of V(ss) is much needed in clinical practice because it is critical for the proper selection of drug treatment

  4. Methane emission, digestive characteristics and faecal archaeol in heifers fed diets based on silage from brown midrib maize as compared to conventional maize.

    PubMed

    Schwarm, Angela; Schweigel-Röntgen, Monika; Kreuzer, Michael; Ortmann, Sylvia; Gill, Fiona; Kuhla, Björn; Meyer, Ulrich; Lohölter, Malte; Derno, Michael

    2015-01-01

    The aim of the present experiment was to compare silage prepared from maize having a brown midrib (BMR) mutation with control (CTR) maize to identify their effects on enteric methane emission, digesta mean retention time (MRT), ruminal fermentation and digestibility. In addition, the utility of archaeol present in faecal samples was validated as a proxy for methane production. Seven German Holstein heifers were fed total mixed rations with a maize-silage proportion (either BMR or CTR) of 920 g/kg dry matter (DM) in a change-over design. Heifers were fed boluses with markers to measure MRT; faeces were collected for 7 days and rumen fluid was collected on the penultimate day. Methane emission was measured in respiration chambers on one day. Data were analysed by t-test and regression analysis. DM intake did not differ between the two diets. The apparent digestibility of DM and most nutrients was unaffected by diet type, but apparent digestibility of neutral and acid detergent-fibre was higher in those heifers fed BMR than in those fed CTR. Comparisons between diets revealed no difference in particle or solute MRT in the gastro-intestinal tract and the reticulorumen. Concentrations of short-chain fatty acid and ammonia in rumen fluid and its pH were not affected by silage type. Independent of the mode of expression [l/d, l/kg DM intake, l/kg digested organic matter], methane emissions were not affected by maize-silage type, but with BMR, there was a trend towards lower methane production per unit of digested neutral detergent fibre than there was with CTR silage. Results of the present study show that feeding heifers BMR silage does not increase methane emissions despite a higher fibre digestibility as compared to CTR silage. Therefore, it is assumed that improvements in animal productivity achieved by feeding BMR silage, as some studies have reported, can be obtained without extra environmental cost per unit of milk or meat. Neither faecal archaeol content [µg

  5. Stabilization of glucose-C in microbial cell membranes (PLFA) and cell walls (amino sugars) evaluated by 13C-labelling in a field experiment

    NASA Astrophysics Data System (ADS)

    Gunina, Anna; Kuzyakov, Yakov; Glaser, Bruno

    2015-04-01

    Microorganisms control carbon (C) cycle and strongly contribute to formation of soil organic matter. Strong differences in the turnover of microbial groups and cellular compounds complicate the assessment of their contribution to microbial food webs and C sequestration in soil in situ. The uptake and incorporation of 13C labeled glucose by microbial groups were traced during 50 days after the labeling under field conditions. 13C was analysed: i) in the cytosolic pool by chloroform fumigation extraction, ii) in cell membranes by phospholipid fatty acids (PLFA), iii) in cell walls by amino sugars, and iv) remaining in bulk soil. This allowed tracing C in microbial groups as well as cellular compounds. Mean residence times (MRT) of C in PLFA and the cytosol were 47 and 150 days, respectively. Such long cytosol MRT depends on its heterogeneous composition, which includes high and low molecular weight organics. Amino sugars were mainly originated from microbial residues and thus, observation periods higher than 1 year are required for estimation of their MRT. Relative 13C incorporation (13C portion in total pool C) was the highest for PLFAs (~1.5% at day 3), whereas 13C content of the cytosol and amino sugars was one and two orders of magnitude less, respectively. Relative 13C incorporation into amino sugars of living microorganisms showed only 0.57% on day 3. Therefore, the turnover of cell membrane components is two times faster than that of cell walls, even in living microorganisms. Both PLFAs and amino sugars showed that glucose C was preferentially used by bacteria. 13C incorporation into bacterial cell walls and membranes decreased with time, but increased or remained constant for fungi, reflecting faster turnover of bacteria than fungi. Consequently, bacteria contribute more to the decomposition of low molecular weight organics, whereas fungi consume bacterial products or necromass and contribute more to long-term C stabilisation. Thus, tracing of 13C in cellular

  6. Microbial carbon recycling: an underestimated process controlling soil carbon dynamics

    NASA Astrophysics Data System (ADS)

    Basler, A.; Dippold, M.; Helfrich, M.; Dyckmans, J.

    2015-07-01

    The mean residence times (MRT) of different compound classes of soil organic matter (SOM) do not match their inherent recalcitrance to decomposition. One reason for this is the stabilisation within the soil matrix, but recycling, i.e. the reuse of "old" organic material to form new biomass may also play a role as it uncouples the residence times of organic matter from the lifetime of discrete molecules in soil. We analysed soil sugar dynamics in a natural 30 years old labelling experiment after a~wheat-maize vegetation change to determine the extent of recycling and stabilisation in plant and microbial derived sugars: while plant derived sugars are only affected by stabilisation processes, microbial sugars may be subject to both, stabilisation and recycling. To disentangle the dynamics of soil sugars, we separated different density fractions (free particulate organic matter (fPOM), light occluded particulate organic matter (≤1.6 g cm-3; oPOM1.6), dense occluded particulate organic matter (≤2 g cm-3; oPOM2) and mineral-associated organic matter (>2 g cm-3; Mineral)) of a~silty loam under long term wheat and maize cultivation. The isotopic signature of sugars was measured by high pressure liquid chromatography coupled to isotope ratio mass spectrometry (HPLC/IRMS), after hydrolysis with 4 M Trifluoroacetic acid (TFA). While apparent mean residence times (MRT) of sugars were comparable to total organic carbon in the bulk soil and mineral fraction, the apparent MRT of sugars in the oPOM fractions were considerably lower than those of the total carbon of these fractions. This indicates that oPOM formation was fuelled by microbial activity feeding on new plant input. In the bulk soil, mean residence times of the mainly plant derived xylose (xyl) were significantly lower than those of mainly microbial derived sugars like galactose (gal), rhamnose (rha), fucose (fuc), indicating that recycling of organic matter is an important factor regulating organic matter dynamics

  7. How to link soil C pools with CO2 fluxes?

    NASA Astrophysics Data System (ADS)

    Kuzyakov, Y.

    2011-06-01

    soil after the input, the discordance of MRT of C in pools and of C released in CO2 was demonstrated. This discordance of MRT between pools and fluxes shows that the use of MRT of pools alone underestimates the fluxes at least for two times. The future challenges include combining two or more promising approaches to elucidate more than two C sources for CO2 fluxes, and linking scientific communities investigating the pools with those investigating the fluxes.

  8. Formal methods in the design of Ada 1995

    NASA Technical Reports Server (NTRS)

    Guaspari, David

    1995-01-01

    Formal, mathematical methods are most useful when applied early in the design and implementation of a software system--that, at least, is the familiar refrain. I will report on a modest effort to apply formal methods at the earliest possible stage, namely, in the design of the Ada 95 programming language itself. This talk is an 'experience report' that provides brief case studies illustrating the kinds of problems we worked on, how we approached them, and the extent (if any) to which the results proved useful. It also derives some lessons and suggestions for those undertaking future projects of this kind. Ada 95 is the first revision of the standard for the Ada programming language. The revision began in 1988, when the Ada Joint Programming Office first asked the Ada Board to recommend a plan for revising the Ada standard. The first step in the revision was to solicit criticisms of Ada 83. A set of requirements for the new language standard, based on those criticisms, was published in 1990. A small design team, the Mapping Revision Team (MRT), became exclusively responsible for revising the language standard to satisfy those requirements. The MRT, from Intermetrics, is led by S. Tucker Taft. The work of the MRT was regularly subject to independent review and criticism by a committee of distinguished Reviewers and by several advisory teams--for example, the two User/Implementor teams, each consisting of an industrial user (attempting to make significant use of the new language on a realistic application) and a compiler vendor (undertaking, experimentally, to modify its current implementation in order to provide the necessary new features). One novel decision established the Language Precision Team (LPT), which investigated language proposals from a mathematical point of view. The LPT applied formal mathematical analysis to help improve the design of Ada 95 (e.g., by clarifying the language proposals) and to help promote its acceptance (e.g., by identifying a

  9. Modellierung und Simulation des Substrat-Rauschens in integrierten RF CMOS-Schaltungen

    NASA Astrophysics Data System (ADS)

    Lin, L.; Xiong, J.; Mathis, W.

    2009-05-01

    Im integrierten CMOS-Schaltungsentwurf kann das Substrat-Rauschen, das vom digitalen Teil entsteht, die Funktionalität des analogen Teils stark beeinflussen. Es wird daher immer wichtiger, das Substrat als ein Medium der Rauschen-Propagation genau zu modellieren. Im vorliegenden Artikel wird ein auf der Finite Elemente Methode (FEM) und Modellordnungsreduktion (MOR) basiertes Modellierungsverfahren zur Admittanzen-Extraktion im Halbleitersubstrat vorgestellt. Nach der Diskretisierung mit FEM wird das Substrat im Allgemeinen als ein resistives/kapazitives Netz angesehen. Durch Bestimmung der Admittanz-Matrix und MOR ist es möglich ein äquivalentes Dreipol-Modell zwischen digitalem und analogem Teil über das Substrat zu bilden. Das Ergebnis der Modellierung wird dargestellt und mit numerischer Simulation des Substrat-Rauschens verglichen. Die Modellierung ermöglicht es, die Einflüsse des Substrat-Rauschens im Schaltungsentwurf zu berücksichtigen und so bestehende CMOS-Schaltungsarchitekturen zu optimieren.

  10. Atomic Basic Blocks

    NASA Astrophysics Data System (ADS)

    Scheler, Fabian; Mitzlaff, Martin; Schröder-Preikschat, Wolfgang

    Die Entscheidung, einen zeit- bzw. ereignisgesteuerten Ansatz für ein Echtzeitsystem zu verwenden, ist schwierig und sehr weitreichend. Weitreichend vor allem deshalb, weil diese beiden Ansätze mit äußerst unterschiedlichen Kontrollflussabstraktionen verknüpft sind, die eine spätere Migration zum anderen Paradigma sehr schwer oder gar unmöglich machen. Wir schlagen daher die Verwendung einer Zwischendarstellung vor, die unabhängig von der jeweils verwendeten Kontrollflussabstraktion ist. Für diesen Zweck verwenden wir auf Basisblöcken basierende Atomic Basic Blocks (ABB) und bauen darauf ein Werkzeug, den Real-Time Systems Compiler (RTSC) auf, der die Migration zwischen zeit- und ereignisgesteuerten Systemen unterstützt.

  11. Berechnung der auftretenden lokalen Kräfte auf der magnetischen Beschichtung eines magnetischen Rasterkraftmikroskops

    NASA Astrophysics Data System (ADS)

    Preisner, T.; Mathis, W.

    2009-05-01

    Die numerische Berechnung entstehender Kraftwirkungen auf Körper aufgrund magnetischer Wechselwirkungen zwischen diesen, ist in Bezug auf die mechanische Deformation dieser Körper ein noch nicht vollständig gelöstes Problem. In dieser Arbeit wird ein Vergleich vorhandener Kraftberechnungsmethoden hinsichtlich der totalen Kraft anhand eines analytisch berechenbaren Beispiels vorgestellt, sowie Unterschiede der lokalen Kraftdichten dieser Methoden in Anwendung auf die magnetische Beschichtung eines magnetischen Rasterkraftmikroskops aufgezeigt. Due to magnetic interactions between magnetic field inducing bodies, force effects occur on the materials. The numerical computation of those occuring forces with respect to a subsequent structural analysis of a deformable material is still a topic of interest in research. In this paper a comparison between several existent force calculation methods regarding the total force is given for an example with two magnetic cubes. Furthermore, differences are shown concerning the local force densities on the magnetic coating of a magnetic force microscope.

  12. Einleitung

    NASA Astrophysics Data System (ADS)

    Rill, Georg; Schaeffer, Thomas

    Mit immer leistungsfähigeren Digitalrechnern war und ist es möglich, dynamische Modelle bestehend aus mehreren Körpern zu berechnen. Die mathematischen Grundlagen der Mehrkörperdynamik haben Newton, Euler, d'Alembert, Lagrange und Hamilton geschaffen. Die ersten Mehrkörperprogramme wurden zwischen 1970 und 1980 entwickelt, (Kre79). Bei den Mehrkörpersystemen (MKS) wurden zunächst nur starre Körper verwendet. Elastische Körper waren der der Finite ElementMethode (FEM) vorbehalten. Kommerzielle Programme zur Simulation vonMehrkörpersystemen wie z. B. MSC.ADAMS, RecurDyn oder Simpack bieten heute die Möglichkeit, neben starren Körpern auch deformierbare Körper einzusetzen. Einen guten Einblick in den augenblicklichen Stand derMehrkörperdynamik bietet die Arbeit von Schiehlen, (Sch06).

  13. Gewebe

    NASA Astrophysics Data System (ADS)

    Shah-Derler, Brigitte; Wintermantel, Erich; Ha, Suk-Woo

    Als Gewebe wird ein durch spezifische Leistungen gekennzeichneter Verband gleichartig differenzierter Zellen bezeichnet. Gewebe entstehen aus jungen, noch nicht differenzierten Zellen, die sich ihrer künftigen Funktion entsprechend umwandeln. Gewebe aus differenzierten Zellen wird als Dauergewebe bezeichnet. Verschiedene Gewebe haben allerdings eine mehr oder weniger starke Potenz, sich neu aufzubauen. Beim Menschen unterscheidet man diesbezüglich zwischen labilem Gewebe, bei dem die Bildung und der Aufbau der Zellen rasch erfolgt, stabilem Gewebe, bei dem der Zellumsatz sehr langsam geschieht und permanentem Gewebe, bei dem absterbende Zellen nicht mehr ersetzt werden können (Tabelle 8.1). Es gibt vier Grundtypen von Geweben: Epithelgewebe, Binde- und Stützgewebe, Muskelgewebe und Nervengewebe. Im Körper treten in der Regel verschiedene Gewebe funktionell zusammen (z. B. Muskeln und Sehnen des Bindegewebes).

  14. Niob

    NASA Astrophysics Data System (ADS)

    Dettner, H. W.; Franssen, H.; Giesen, K.; Hayes, E. T.; Holetzko, H.; Keysselitz, B.; Loebich, O.; Pelzel, E.; Reinsch, W.; Rostoker, W.; Saur, G.; Volk, K. E.; Wallbaum, H. J.; Borchers, Heinz; Schmidt, Ernst

    Niob — im angelsächsischen Schrifttum vielfach auch als "Columbium" (chemisches Zeichen "Cb") bezeichnet — wurde bis vor wenigen Jahren vorwiegend als Legierungselement in den sog. "Superalloys" oder zur Stabilisierung austenitischer Stähle verwendet. In neuerer Zeit wurden zahlreiche hochwarmfeste Legierungen auf Niobbasis für den Triebwerksbau und korrosionsbeständige Legierungen u. a. für die Verwendung als Hüllenwerkstoff im Reaktorbau entwickelt [D 2, G 1, H 2]. Niob-Uran-Legierungen scheinen sich zur Herstellung von Brennstoffelementen in Reaktoren zu bewähren. Vereinzelt wird Niob auch an Stelle des Tantals für hochwertige Senderöhren, Röntgenröhren und Hochspannungsgleichrichter verwendet. In der Vakuumtechnik dient es als wirksames "bulk getter" (nicht verdampfendes Getter) für den Temperaturbereich zwischen 400 und 900 °C [E 5].

  15. Räumliches Hören

    NASA Astrophysics Data System (ADS)

    Blauert, Jens; Braasch, Jonas

    Unsere Hörereignisse (Hörobjekte, Laute) existieren jeweils zu ihrer Zeit an ihrem Ort und sind mit jeweils spezifischen Eigenschaften ausgerüstet. "Räumliches Hören“ als wissenschaftliches Fachgebiet erforscht und beschreibt die Beziehungen zwischen den Orten sowie den räumlichen Ausdehnungen der Hörereignisse untereinander und zu den korrelierten Merkmalen anderer Ereignisse - vorwiegend Schallereignisse, aber z. B. auch physiologische Vorgänge, Ereignisse anderer Sinnesgebiete usw. (s. hierzu Blauert 1974 etc., woraus einige der folgenden Bilder entnommen sind). Übersichtsdarstellungen findet man z. B. auch bei (Bloch 1893, Pierce 1901, von Hornbostel 1926, Trimble 1928, Kietz 1953, Woodworth u. Schlosberg 1954, von Békésy 1960, Aschoff 1963, Keidel 1966, Erulkar 1972, Durlach u. Colburn 1978, Gatehouse 1979, Blauert 1983, Yost u. Gourevitch 1987, Wightman u. Kistler 1993, Begault 1994, Gilkey u. Anderson 1996).

  16. Victor F. Weisskopf (1908 - 2002): Physikgeschichte

    NASA Astrophysics Data System (ADS)

    Jacobi, Manfred

    2002-11-01

    Universal gebildete und interessierte Menschen sind selten geworden in unserer Zeit. Victor F. Weisskopf war einer von ihnen. Sein geistiger Horizont umfasste nicht nur sein eigentliches Fachgebiet, die Physik, wo er sich durch fundamentale Arbeiten in den Bereichen der Quantenfeldtheorie, der Kern- und Elementarteilchenphysik hervortat. Daneben bildeten Kunst und Musik sowie ein außergewöhnliches Engagement in sozialen und politischen Angelegenheiten die Eckpunkte seines Lebens. Der Einsatz für die Verständigung zwischen den Machtblöcken während des Kalten Krieges war für ihn ebenso selbstverständlich wie das Bedürfnis, die neuen Ideen der Physik einem breiten Publikum nahe zu bringen. Die Wissenschaft erschien ihm als das geeignete Mittel, um zum Wohle der Menschheit zu wirken.

  17. Die Struktur von schlankem Materialfluss mit Lean Production Kanban und Innovationen

    NASA Astrophysics Data System (ADS)

    Scheid, Wolf-Michael

    In der Literatur wird Materialfluss überwiegend in Spezialdisziplinen betrachtet, etwa der Steuerungslogik, der Logistiktechnik oder dem Supply Chain Management. Ein charakterisierendes Merkmal des Materialflusses ist jedoch, dass er sich aus vielfältigen Einzelbausteinen zusammensetzt, die alle harmonisch abgestimmt sein müssen. Die maximal erreichbare Effizienz wird nicht durch Höchstleistungen in dem einen oder anderen Spezialthema bestimmt, sondern durch das schwächste Glied im gesamten komplexen Netzwerk. Den Schnittstellen zwischen den betroffenen Fachbereichen in einem Unternehmen kommt hier eine ganz besondere Bedeutung zu: Erst ein harmonischer Einklang ermöglicht hohe Effektivität. Dies setzt umfassendes Verständnis für interdisziplinäre Notwendigkeiten, ein hohes Maß an Abstimmung mit den operativen Prozessen und letztlich einen einvernehmlichen Umgang und den Respekt vor den Problemstellungen des Anderen voraus.

  18. Audience-response systems for evaluation of pediatric lectures--comparison with a classic end-of-term online-based evaluation.

    PubMed

    Bode, Sebastian Felix Nepomuk; Straub, Christine; Giesler, Marianne; Biller, Silke; Forster, Johannes; Krüger, Marcus

    2015-01-01

    Zielsetzung: Lehrveranstaltungsevaluationen werden oft zeitverzögert zur Lehrveranstaltung durchgeführt und ausgewertet. Mit dem elektronischen Evaluationsmedium Audience Response System (ARS) kann unmittelbar während oder nach Ende einer Lehrveranstaltung Feedback eingeholt, dargestellt und diskutiert werden. In dieser Arbeit wird eine studentische ARS-Vorlesungsevaluation analysiert. Es wird überprüft, ob signifikante Unterschiede zwischen den Ergebnissen der ARS-Vorlesungsevaluation und der Online-Evaluation am Ende des Semesters bestehen. Hierbei wird der Zusammenhang des studentischen Vorwissens, der Gestaltung der Lehrveranstaltung durch die Lehrenden sowie der Relevanz des Vorlesungsthemas für die Studierenden in Bezug auf die Gesamtbewertung betrachtet. Methodik: Im Wintersemester 2011/2012 wurde die Pädiatrievorlesung am Zentrum für Kinder- und Jugendmedizin (ZKJ) Freiburg mit Hilfe eines ARS evaluiert. Es wurden 34 Vorlesungen von durchschnittlich 22 (range 8-44) Studierenden mit jeweils vier Fragen evaluiert. Ergebnisse: Auf einer 6-stufigen Likert-Skala (1=sehr gut bis 6=ungenügend) bewerteten die Studierenden ihr Vorwissen im Mittel mit 3,18, die Vorlesungsgestaltung mit 2,44 und die Relevanz des Vorlesungsthemas mit 2,19. Die Gesamtbewertung der Vorlesung mittels ARS-Evaluation ergab die Note 2,31. In der Online Evaluation am Ende des Semesters wurde die Note 2,45 ermittelt. Es zeigt sich hoch signifikante Zusammenhänge zwischen den durch den Einsatz des ARS erhobenen Ergebnissen der Gesamtbewertung, dem Vorwissen der Studierenden, der Vorlesungsgestaltung sowie der selbsteingeschätzten Relevanz des Vorlesungsthemas. Schlussfolgerung: Der Einsatz von ARS ist zur unmittelbaren Vorlesungs- Evaluation, insbesondere im Hinblick auf zeitnahe (lehr-)personenbezogene Rückmeldungen geeignet. Im Vergleich zu einer Semesterende-Evaluation zeigt sich in der ARS-Evaluation eine bessere Bewertung.

  19. [German translation and adaptation of the uncertainty stress scale high risk pregnancy version III (USS-HRPV) for hospitalised women with high-risk pregnancy].

    PubMed

    Amsler, Marlen; König, Claudia; Ikhilor, Paola Origlia; Cignacco, Eva Lucia

    2014-06-01

    Hintergrund: Medizinisch und gesellschaftlich bedingte Faktoren führen zu einer Zunahme hospitalisierter Frauen mit Risikoschwangerschaft. Die Unvorhersehbarkeit des weiteren Schwangerschaftsverlaufs kann zu Ungewissheit und je nach Bewältigungsstrategie auch zu Stress führen. Ziele: Ziele dieser Studie waren die deutsche Übersetzung und Adaptation der USS-HRPV. Methode: Die Übersetzung in die deutsche Sprache erfolgte mittels Vor- und Rückwärtsübersetzung. Die zwei Phasen umfassende Adaptation wurde mit hospitalisierten Frauen mit Risikoschwangerschaft (n = 24) sowie diplomierten Hebammen (n = 10) durchgeführt und beruht sowohl auf kognitiven Interviews wie auch auf einer Testung der Inhaltsvalidität mittels «Content Validity Index» (CVI). Nach jeder Erhebungsphase wurde das Messinstrument mithilfe von Fachexpertinnen (n = 3) modifiziert. Ergebnisse: Der für jedes Item berechnete CVI (I-CVI) ergab in der ersten Phase für beide Teilstichproben Werte zwischen 0,10 und 1,0, der über das gesamte Messinstrument berechnete CVI (S-CVI/Ave) einen Wert von 0,62 respektive 0,70. Die I-CVI-Werte der hospitalisierten Frauen mit Risikoschwangerschaft der zweiten Phase lagen zwischen 0,17 und 1,0, der S-CVI/Ave betrug 0,73. Insgesamt wurden unter Berücksichtigung aller Daten 44 der ursprünglich 86 Items entfernt und 28 sprachlich verändert. Schlussfolgerungen: Aufgrund der methodischen Vorgehensweise konnte eine solide Ausgangslage für die weiteren Validierungsschritte zur Weiterentwicklung des Messinstrumentes für den deutschsprachigen Raum erarbeitet werden.

  20. The Questionnaire D-RECT German: Adaptation and testtheoretical properties of an instrument for evaluation of the learning climate in medical specialist training.

    PubMed

    Iblher, Peter; Zupanic, M; Ostermann, T

    2015-01-01

    Zielsetzung: In der Arbeitsgruppe von Boor et al. [1] wurde der Fragebogen D-RECT (Dutch Residency Educational Climate Test) zur Erfassung des Lernklimas in der ärztlichen Weiterbildung entwickelt und validiert. Die deutschsprachige Version (D-RECT-German) wird in der vorliegenden Studie testtheoretisch überprüft.Fragestellung: Ist eine Replikation der Ergebnisse aus der Originalarbeit von Boor et al. als Beleg der Validität des D-RECT möglich?Methodik: Die Befragung erfolgte onlinebasiert mit dem Fragebogen D-RECT-German. Mit Item- und Reliabilitätsanalysen wurden die Kennwerte der 50 Items in 11 Subskalen sowie die interne Konsistenz (Cronbach’s α) ermittelt. Die Validitätsprüfung erfolgte mit einer konfirmatorischen Faktorenanalyse unter Verwendung eines Maximum likelihood basierten Strukturgleichungsmodells.Ergebnisse: Die Itemanalysen dieser Replikationsstudie mit 255 WBA an 17 deutschen Krankenhäusern ergaben für die Items heterogene Trennschärfen, auch die interne Konsistenz der Subskalen zeigte variable Werte für Cronbach’s α zwischen 0.57 und 0.85. In der konfirmatorischen Faktorenanalyse wiesen 6 Items standardisierte Regressionskoeffizienten <0.5 auf die vorgegebenen Dimensionen auf, von denen zwei im Konstrukt „Einstellung der betreuenden Fachärzte“ zu finden waren. Die Korrelationen der Faktoren untereinander wies mit Korrelationen von über 0.7 starke Interdependenzen zwischen den Faktoren „Supervision“, „Coaching“ und „Einstellung der betreuenden Fachärzte“ auf.Schlussfolgerungen: In der Replikationsstudie mit dem D-RECT-German für den deutschsprachigen Raum zeigten sich strukturelle Unterschiede hinsichtlich der faktoriellen Validität, so dass weitere Validierungsstudien für den internationalen Vergleich notwendig sind.

  1. Conflicts of interest in medical school: missing policies and high need for student information at most German universities.

    PubMed

    Lieb, Klaus; Koch, Cora

    2014-01-01

    Zielsetzung: Studierende der Medizin stehen mit Vertretern pharmazeutischer Unternehmen (PU) schon während des Studiums in Kontakt. Ziel dieser Untersuchung war herauszufinden: Existieren an medizinischen Fakultäten Regelungen zum Umgang von Medizinstudierenden mit Vertretern von PU und werden entsprechende Lehrveranstaltungen angeboten und besucht? und Wie denken Medizinstudierende über die Rolle von PU in der medizinischen Lehre? Methodik: Alle 36 deutschen Studiendekanate und 1.151 Medizinstudierende an acht deutschen Universitäten wurden um die Beantwortung eines Fragebogens mit 4 bzw. 7 Fragen zur oben genannten Thematik gebeten. Ergebnisse: 30 (83,3%) Studiendekane bzw. 1.038 (90,3%) Medizinstudierende füllten den Fragebogen aus. Nach Angaben der Studiendekanate existieren an jeweils nur einer (3,3%) medizinischen Fakultät eine Richtlinie zum Thema Interessenkonflikte bzw. eine Richtlinie, die den Umgang zwischen Medizinstudierenden und der Industrie reguliert. 8 (26,7%) der Studiendekanate äußerten Interesse an der Erarbeitung einer Richtlinie oder Vorlesung zu diesem Thema. 149 (14,4%) der Studierenden hatten bereits an einer Veranstaltung teilgenommen, die Beziehungen zwischen PU und Medizinstudierenden thematisiert und 779 (77,8%) wünschten sich mehr Unterricht dazu. 701 (73,4%) lehnten eine Verbesserung der Lehre durch finanzielle Unterstützung durch PU ab, wohingegen 216 (21,9%) der Meinung waren, dass Studierende sich nicht mit Vertretern von PU treffen sollten. Schlussfolgerungen: Im Gegensatz zu anderen Ländern wie den USA bestehen an deutschen medizinischen Fakultäten von wenigen Ausnahmen abgesehen keine Richtlinien zur Regelung des Umgangs von Medizinstudierenden mit pharmazeutischen Unternehmen. Da die Mehrheit der Studierenden sich mehr Informationen zu diesen Interaktionen wünscht, wäre die Etablierung entsprechender Vorlesungen bzw. Richtlinien sinnvoll.

  2. The effects of anonymity on student ratings of teaching and course quality in a bachelor degree programme.

    PubMed

    Scherer, Theresa; Straub, Jan; Schnyder, Daniel; Schaffner, Noemi

    2013-01-01

    Zielsetzung und Fragestellung: Unterscheiden sich die Ergebnisse anonymisierter und personalisierter Evaluationen? Methodik: Während zweier Jahre wurden bei jeder Modulevaluation alle Studierenden randomisiert den Halbgruppen „anonym“ und „personalisiert“ zugeteilt. Die Qualität des Moduls in seinen relevanten Aspekten wurde mit einem standardisierten Fragebogen erhoben. Zusätzlich konnten optionale Textantworten formuliert werden. Drei unabhängige Personen bewerteten die Aussagequalität der Antworten gemäss einem Leitfaden. Dieser beinhaltete die fünf Dimensionen positiv-negativ, differenziert-absolut, Nennung einer Person-allgemein, Befehl enthaltend-neutral und optisch akzentuiert-blank. Der Datensatz bestand aus 615 Fragebogen, davon waren 306 in anonymer Form. Mit einer multivariaten Varianzanalyse wurde überprüft, ob sich zwischen anonym und personalisiert erhobenen Daten ein Unterschied sowohl bei den durch Skalen bewerteten Aspekten als auch bei der Qualität der optionalen Textantworten zeigte. Zusätzlich wurde untersucht, ob sich die Häufigkeit der optionalen Textantworten unterschied.Ergebnisse: In der Aussagequalität liess sich kein signifikanter Unterschied zwischen anonym und personalisiert erhobenen Daten nachweisen. Hingegen haben Studierende aus der personalisierten Gruppe tendenziell häufiger optionale Textantworten geliefert.Schlussfolgerung: Personalisierte Evaluationen generieren dann keine verfälschten Resultate im Sinne der sozialen Erwünschtheit, wenn der Evaluationszirkel geschlossen und transparent ist: Die Verantwortlichen melden den Studierenden die Evaluationsergebnisse konsequent zurück und Änderungs-, Optimierungswünsche und Umsetzungsmöglichkeiten werden mit ihnen diskutiert. Die Studierenden erfahren so, dass ihre Rückmeldungen ernst genommen werden. So können sie sich echte Kritik erlauben.

  3. The active participation of German-speaking countries in conferences of the Association for Medical Education in Europe (AMEE) between 2005 and 2013: a reflection of the development of medical education research?

    PubMed

    Raes, Patricia; Bauer, Daniel; Schöppe, Franziska; Fischer, Martin R

    2014-01-01

    Zielsetzung: International gewinnt medizinische Ausbildungsforschung an Bedeutung. Seit Anfang der 2000er ist auch in deutschsprachigen Ländern (D-A-CH) ein steigendes Interesse zu beobachten. In einer kontinuierlichen Steigerung der Publikationszahlen deutscher Autoren in internationalen Fachzeitschriften zum Thema „medizinische Ausbildung“ schlug sich das bisher jedoch nicht nieder. Die vorliegende Arbeit untersucht, ob sich jene Entwicklungen aus der aktiven Teilnahme deutschsprachiger Forscher an den Konferenzen der AMEE ablesen lassen.Methoden: Die Tagungsbände der AMEE-Kongresse von 2005-2013 der Kategorien „Postervorträge“, „Short Communications“, „Research Papers“ und „Plenarvorträge“ wurden auf Beteiligung aus D-A-CH hin untersucht. Im Anschluss wurden die Abstracts einer inhaltlichen Analyse unterzogen und nach Studiendesign, Methodik, Untersuchungsgegenstand und Forschungsthema kategorisiert. Ergebnisse: Von 9446 analysierten Abstracts weisen 549 Beiträge mindestens einen Erst-/Co- oder Letztautor aus D-A-CH auf. Die absolute Zahl der Beiträge pro Kongress schwankt zwischen 44 im Jahr 2010 und 77 im Jahr 2013. Der prozentuale Anteil schwankt zwischen 10,0% in 2005 und 4,1% im Jahr 2010. Seit 2010 stieg die Beteiligung jedoch kontinuierlich an. Die Arbeiten sind zumeist deskriptiver Art (62,7%). Studien zu grundlegenden Fragen des Lehrens und Lernens (clarification studies) sind eher selten (4,0%). Angewandt wurden meist quantitative Methoden (51,9%), um Fragestellungen zu Themen wie Lehr- und Lernmethoden (33,0%), Evaluation und Assessment (22,4%) oder Curriculumsentwicklung (14,4%) zu untersuchen. Untersuchungsgegenstand sind meist Studierende (52,5%).Schlussfolgerung: Die Beitragszahlen aus D-A-CH weisen zu Beginn und am Ende des Untersuchungszeitraums ein Maximum auf. Ein kontinuierlicher Anstieg der aktiven Beteiligung seit 2005 ist nicht zu beobachten. Dieser Umstand spiegelt nicht das steigende Interesse an der

  4. Roof sprinkling system sweats down A/C costs

    SciTech Connect

    Not Available

    1984-05-01

    This article describes a roof spray system which enhances the energy efficiency of a building's HVAC system at a nominal cost in relationship to the benefits it yields. Roof spray cooling is based on the fact that water, when it evaporates, absorbs large amounts of heat. The evaporation of one gallon of water will dissipate about 8500 BTU's of heat; and three fallons of water evaporated over one hour's time offers the same cooling capacity as a two-ton airconditioner operated over the same period. By intermittently spraying its surface with water, a direct evaporative cooling system allows a roof to sweat away the sun's radiant heat, cooling an un-airconditioned building from 10 to 12 degrees mrt and reducing summer electric costs by 25%.

  5. Measurement Uncertainty Budget of the PMV Thermal Comfort Equation

    NASA Astrophysics Data System (ADS)

    Ekici, Can

    2016-05-01

    Fanger's predicted mean vote (PMV) equation is the result of the combined quantitative effects of the air temperature, mean radiant temperature, air velocity, humidity activity level and clothing thermal resistance. PMV is a mathematical model of thermal comfort which was developed by Fanger. The uncertainty budget of the PMV equation was developed according to GUM in this study. An example is given for the uncertainty model of PMV in the exemplification section of the study. Sensitivity coefficients were derived from the PMV equation. Uncertainty budgets can be seen in the tables. A mathematical model of the sensitivity coefficients of Ta, hc, T_{mrt}, T_{cl}, and Pa is given in this study. And the uncertainty budgets for hc, T_{cl}, and Pa are given in this study.

  6. Synthesis and pharmacokinetic property improvement of deuterated plinabulin 9

    NASA Astrophysics Data System (ADS)

    Zhao, Jianchun; Cheng, Hejuan; Sun, Tianwen; Wang, Shixiao; Ding, Zhongpeng; Dou, Guifang; Meng, Zhiyun; Guan, Huashi; Li, Wenbao

    2017-04-01

    Plinabulin, a potent microtubule-targeting agent, is derived from marine natural diketopiperazine `phenylahistin'. To develop novel plinabulin analogue that could display better pharmacokinetic properties and less side effects, deuterated plinabulin 9 was synthesized and evaluated in vitro and in vivo. In comparison with plinabulin, in vivo pharmacokinetic studies indicated that the deuterated derivative 9 could alter blood circulation behavior obviously, which was proved by increased area under the plasma concentration- time curve (AUC0-∞), reduced clearance (CL), and prolonged total body mean residence time (MRT). The derivative 9 also has higher inhibition rates against BxPC-3, Jurkat and A-431 tumor cell lines as compared with its prototype plinabulin. Therefore, the deuterated compound 9 might be developed as a potential agent for different cancer treatments.

  7. Mitochondrial Replacement: Ethics and Identity.

    PubMed

    Wrigley, Anthony; Wilkinson, Stephen; Appleby, John B

    2015-11-01

    Mitochondrial replacement techniques (MRTs) have the potential to allow prospective parents who are at risk of passing on debilitating or even life-threatening mitochondrial disorders to have healthy children to whom they are genetically related. Ethical concerns have however been raised about these techniques. This article focuses on one aspect of the ethical debate, the question of whether there is any moral difference between the two types of MRT proposed: Pronuclear Transfer (PNT) and Maternal Spindle Transfer (MST). It examines how questions of identity impact on the ethical evaluation of each technique and argues that there is an important difference between the two. PNT, it is argued, is a form of therapy based on embryo modification while MST is, instead, an instance of selective reproduction. The article's main ethical conclusion is that, in some circumstances, there is a stronger obligation to use PNT than MST.

  8. Sedimentological and geochronological evidences of anthropogenic impacts on river basins in the Northern Latium coastal area (Italy)

    NASA Astrophysics Data System (ADS)

    Piazzolla, Daniele; Paladini de Mendoza, Francesco; Scanu, Sergio; Marcelli, Marco

    2015-04-01

    In this work we aimed to compare sedimentological and geochronological data from three sediment core samples (MIG50, MRT50, and GRT50) taken in the Northern Latium (Italy) coastal area, at -50 m depth, to data regarding rainfall, river flows and the land use in the three most important hydrographic basins (Mignone, Marta and Fiora) and in the coastal area. Different trends of sediment mass accumulation rate (MAR) are detected in the three cores: a strongly increasing trend was identified in MIG50 and MRT50 cores while GRT50 doesn't show significant variation. Data from the sedimentological analysis of GRT50 core identify a progressive decrease in the sandy component, which declined from about 30% to the current level of 7% over the last 36 years, while MRT50 and MIG50 cores (mainly composed by pelitic fraction > 95%) showed slight variations of textural ratio between silt and clay. According to the general decrease of pluviometric trend observed in Italy, related to teleconnection pattern tendency (NAO), the statistical analysis of rain identified significative decrease only in the Fiora river basin, whereas in the other two locations the decrease was not as significant. Regarding the Fiora river flow, a significative decreasing trend of average flow is detected, while the flood regime remained unaffected over the past 30 years. The analysis of the land use shows that the human activities are increased of 6-10% over the available time steps (1990 - 2006) in Fiora and Mignone river basins, while the Marta river basin has a strong human impact since 1990 highligting more than 80% of artificial soil covering. The largest variation is observed on the Fiora basin (10%) where the antrhopic activities have expanded to an area of about 85 Km2. Moreover, in the last ten years a large beach nourishment in 2004 (570000 m3) and dredging activities in the early second half of 2000s (1000000 m3 moved) were performed in Marina di Tarquinia beach and in front of the Torrevaldaliga

  9. [ABSOLUTE AND RELATIVE BIOAVAILABILITY OF GLUTARON--A NEW DERIVATIVE OF GLUTAMIC ACID].

    PubMed

    Smirnova, L A; Ryabukha, A F; Kuznetsov, K A; Suchkov, E A; Perfilova, V N; Tyurenkov, I N

    2015-01-01

    The pharmacokinetics of studies of 3-phenylglutamic acid hydrochloride (glutaron) has been studied in rats. The main pharmacokinetic parameters show low values of the half-life (T1/2 = 3.75 h), mean retention time in the body (MRT = 5.77 h). The medium rate of drug concentration decrease in the blood plasma leads to a low value of the area under pharmacokinetic curve (AUC = 41.18 mg · h/mL). The general volume of distribution (Vd = 3.42 L/kg) is 3.5 times greater than the volume of extracellular fluid in the rat body. These data indicate a high ability of the glutaron to be distributed and accumulated in animal tissues. The value of absolute bioavailability is 84%, and the relative bioavailabity is 100%.

  10. Pharmacokinetics of intramuscular ketamine in young ostriches premedicated with romifidine.

    PubMed

    De Lucas, J J; Rodríguez, C; Marín, M; González, F; Ballesteros, C; San Andrés, M I

    2007-02-01

    Ketamine is a short-acting dissociative anaesthetic for chemical restraint and surgical anaesthesia in domestic and non-domestic animals. The present study was designed to determine the pharmacokinetics of a single dose of ketamine (10 mg/kg) after intramuscular (i.m.) administration to young ostriches premedicated with romifidine. Ketamine was rapidly absorbed after i.m. administration. Maximal ketamine concentration (C(max)) of 2.93 +/- 0.61 microg/ml was reached at 12.5 +/- 2.50 min and thereafter ketamine concentrations decreased rapidly. The elimination half-life (t(1/2 z)) obtained was 62.37 +/- 17.37 min and mean residence time (MRT) was 77.33 +/- 19.12 min. The area under the curve (AUC) was 114.19 +/- 15.76 microg x min/ml.

  11. Comparative pharmacokinetics and bioavailability of two oral formulations of thiocolchicoside, a GABA-mimetic muscle relaxant drug, in normal volunteers.

    PubMed

    Perucca, E; Poitou, P; Pifferi, G

    1995-01-01

    The comparative pharmacokinetic and bioavailability profile of two different formulations (tablets and capsules) of thiocolchicoside was investigated in 8 healthy male volunteers after administration of single oral 8 mg doses. Plasma samples were assayed by a capillary gas chromatography--mass spectrometry (GC-MS) method following enzymatic hydrolysis of thiocolchicoside to its aglycone (3-demethylthiocolchicine) and no attempt was made to account for the possible occurrence of hydrolysis in vivo. Irrespective of the formulation used, the drug was rapidly absorbed from the gastrointestinal tract, peak levels of about 17 ng/ml being detected within 1 h in most subjects. Elimination was rapid, with mean MRT values of 5-6 h. All kinetic parameters showed considerable interindividual variability but none differed significantly between the two formulations. Relative to the tablet formulation, the oral bioavailability of the capsule formulation was 1.06 +/- 0.39.

  12. Mitochondrial Replacement: Ethics and Identity

    PubMed Central

    Wilkinson, Stephen; Appleby, John B.

    2015-01-01

    Abstract Mitochondrial replacement techniques (MRTs) have the potential to allow prospective parents who are at risk of passing on debilitating or even life‐threatening mitochondrial disorders to have healthy children to whom they are genetically related. Ethical concerns have however been raised about these techniques. This article focuses on one aspect of the ethical debate, the question of whether there is any moral difference between the two types of MRT proposed: Pronuclear Transfer (PNT) and Maternal Spindle Transfer (MST). It examines how questions of identity impact on the ethical evaluation of each technique and argues that there is an important difference between the two. PNT, it is argued, is a form of therapy based on embryo modification while MST is, instead, an instance of selective reproduction. The article's main ethical conclusion is that, in some circumstances, there is a stronger obligation to use PNT than MST. PMID:26481204

  13. Mechanisms Controlling Carbon Turnover from Diverse Microbial Groups in Temperate and Tropical Forest Soils

    NASA Astrophysics Data System (ADS)

    Throckmorton, H.; Dane, L.; Bird, J. A.; Firestone, M. K.; Horwath, W. R.

    2010-12-01

    Microorganisms represent an important intermediate along the pathway of plant litter decomposition to the formation of soil organic matter (SOM); yet little is known of the fate and stability of microbial C in soils and the importance of microbial biochemistry as a factor influencing SOM dynamics. This research investigates mechanisms controlling microbial C stabilization in a temperate forest in the Sierra Nevada of California (CA) and a tropical forest in Puerto Rico (PR). Biochemically diverse microbial groups (fungi, actinomycetes, bacteria gram (+), and bacteria gram (-)) were isolated from both sites, grown in the laboratory with C13 media, killed, and nonliving residues were added back to soils as a reciprocal transplant of microbial groups. The native microbial community in CA is dominated by fungi and in PR is dominated by bacteria, which provides an opportunity to asses the metabolic response of distinct microbial communities to the diverse microbial additions. CA and PR soils were sampled five times over a 3 and 2 year period, respectively. In CA there was no significant difference in the mean residence time (MRT) of diverse C13 microbial treatments; whereas in PR there were significant differences, whereby temperate fungi, temperate Gram (+) bacteria, and tropical actinomycetes exhibited a significantly longer MRT as compared with tropical fungi and temperate Gram (-). These results suggest that a bacterial dominated microbial community discriminates more amongst diverse substrates than a fungal-dominated community. MRT for labeled-C in CA was 5.21 ± 1.11 years, and in PR was 2.22 ± 0.45. Despite substantial differences in MRT between sites, physical fractionation of soils into light (LF), aggregated-occluded (OF), and mineral-associated (MF) fractions provided evidence that accelerated decomposition in PR (presumably due to climate) operated primarily on labeled-C unassociated with the mineral matrix (LF); labeled-C occluded within aggregates (OF) or

  14. Lattice Boltzmann Method for Spacecraft Propellant Slosh Simulation

    NASA Technical Reports Server (NTRS)

    Orr, Jeb S.; Powers, Joseph F.; Yang, Hong Q.

    2015-01-01

    A scalable computational approach to the simulation of propellant tank sloshing dynamics in microgravity is presented. In this work, we use the lattice Boltzmann equation (LBE) to approximate the behavior of two-phase, single-component isothermal flows at very low Bond numbers. Through the use of a non-ideal gas equation of state and a modified multiple relaxation time (MRT) collision operator, the proposed method can simulate thermodynamically consistent phase transitions at temperatures and density ratios consistent with typical spacecraft cryogenic propellants, for example, liquid oxygen. Determination of the tank forces and moments relies upon the global momentum conservation of the fluid domain, and a parametric wall wetting model allows tuning of the free surface contact angle. Development of the interface is implicit and no interface tracking approach is required. Numerical examples illustrate the method's application to predicting bulk fluid motion including lateral propellant slosh in low-g conditions.

  15. Analytical Method of Correction of B 1 Errors in Mapping of Magnetization Transfer Ratio in Highfield Magnetic Resonance Tomography

    NASA Astrophysics Data System (ADS)

    Yarnykh, V. L.; Khodanovich, M. Yu.

    2015-04-01

    Magnetization Transfer Ratio (MTR) is a widely used parameter for quantitative estimation of tissues in magnetic resonance tomography (MRT). At the same time, MTR is rather sensitive to errors caused by the nonideal characteristics of magnetic resonance tomographs. In particular, MTR depends strongly on the local inhomogeneities of the radio-frequency field B 1 that limits the MTR application for high magnetic field strengths. In the present research, a simple analytical model of the MTR dependence on B 1 is derived. Based on this model, a correction algorithm is developed using a set of parameters independent of tissue. This algorithm is tested for MTR mapping of the human brain in the field with induction of 3 T. The MTR correction demonstrates high accuracy for a wide range of B 1 inhomogeneities. Combination of the analytical algorithm with fast B 1 mapping enables high-precision MTR brain mapping for neuroimaging applications and analysis of histograms on high-field scanners.

  16. Comparative pharmacokinetic studies of peimine and peiminine in rat plasma by LC-MS-MS after oral administration of Fritillaria thunbergii Miq. and Fritillaria thunbergii Miq. - Glycyrrhiza uralensis Fisch. couple extract.

    PubMed

    Chen, Lihua; Liu, Lili; Zhu, Weifeng; Zhang, Huimin; Yan, Zhihong; Liu, Hongning

    2011-09-01

    A sensitive LC-MS-MS method has been successfully applied to pharmacokinetic study of peimine and peiminine in rat plasma after oral administration of Fritillaria thunbergii Miq. exact and Fritillaria thunbergii Miq. - Glycyrrhiza uralensis Fisch. couple extract. The results indicated that plasma profiles of peimine and peiminine confirmed to two-compartment open model with weighting function of 1/C2 for data fitting and parameter estimation and the utilization with Glycyrrhiza uralensis Fisch. could decrease C(max) and prolong MRT(0-infinity) and t1/2 of peimine remarkly with the bioavailability of peimine remained practically unchanged. Meanwhile, the concentration of peimine in rat plasma was more stable. Nevertheless, there were no significant differences among all calculated parameters of peiminine.

  17. The disposition of free and niosomally encapsulated Rac-flurbiprofen in dairy bovines.

    PubMed

    Confalonieri, E O; Soraci, A L; Becaluba, M; Denzoin, L; Rodriguez, E; Riccio, B; Tapia, O

    2010-02-01

    Pharmacokinetic parameters were established for flurbiprofen (FBP) after intravenous (i.v.) administration (0.5 mg/kg) of niosomal and nonniosomal formulations in dairy cattle. Niosomes of FBP showed a drug loading of 92.0 +/- 0.7% and the intravenous administration of the FBP niosomes to dairy cattle did not produce any immunological reaction associated to niosomal components. Niosomal FBP was slowly eliminated from plasma and mean residual time (MRT) and AUC(0-->t) and t (1/2) values were significantly higher than those for non niosomal FBP formulations. The results presented in this study indicate that the long circulation of FBP niosomes offers a potential application for improving the pharmacokinetic parameters of short half-life drugs for clinical use. Niosomes offer new promising perspectives of drug delivery modules in bovine therapeutics.

  18. Medical support for the North East Line Mass Rapid Transit project by the Republic of Singapore Navy's Naval Medicine Hyperbaric Centre.

    PubMed

    C C, Michael Ong

    2002-09-01

    Naval Medicine Hyperbaric Centre (NMHC) was approached by the Land Transport Authority (LTA) to provide medical support for the North Eastern Line MRT Project. The medical support provided by NMHC focused on providing training, audits and ensuring that safety and health infrastructure were in place even before the commencement of compressed air tunnelling. The extensive use of the EPBM (Earth Pressure Balance Machine) tunnelling machines for the first time in Singapore necessitated a reassessment of the medical support system and paradigm that was based primarily on the older form of tunnelling. The survey results showed that human exposure to compressed air works with the use of EPBM was minimal and no decompression illness was reported. However, there was still a total of 28 cases of barotrauma that were reported which were mainly from the tunnels dug using the open face compressed air tunnelling method. As such, medical providers should still exercise careful planning for the medical support of compressed air works.

  19. A Review of Imaging Techniques for Plant Phenotyping

    PubMed Central

    Li, Lei; Zhang, Qin; Huang, Danfeng

    2014-01-01

    Given the rapid development of plant genomic technologies, a lack of access to plant phenotyping capabilities limits our ability to dissect the genetics of quantitative traits. Effective, high-throughput phenotyping platforms have recently been developed to solve this problem. In high-throughput phenotyping platforms, a variety of imaging methodologies are being used to collect data for quantitative studies of complex traits related to the growth, yield and adaptation to biotic or abiotic stress (disease, insects, drought and salinity). These imaging techniques include visible imaging (machine vision), imaging spectroscopy (multispectral and hyperspectral remote sensing), thermal infrared imaging, fluorescence imaging, 3D imaging and tomographic imaging (MRT, PET and CT). This paper presents a brief review on these imaging techniques and their applications in plant phenotyping. The features used to apply these imaging techniques to plant phenotyping are described and discussed in this review. PMID:25347588

  20. Lattice Boltzmann Method for Spacecraft Propellant Slosh Simulation

    NASA Technical Reports Server (NTRS)

    Orr, Jeb S.; Powers, Joseph F.; Yang, Hong Q

    2015-01-01

    A scalable computational approach to the simulation of propellant tank sloshing dynamics in microgravity is presented. In this work, we use the lattice Boltzmann equation (LBE) to approximate the behavior of two-phase, single-component isothermal flows at very low Bond numbers. Through the use of a non-ideal gas equation of state and a modified multiple relaxation time (MRT) collision operator, the proposed method can simulate thermodynamically consistent phase transitions at temperatures and density ratios consistent with typical spacecraft cryogenic propellants, for example, liquid oxygen. Determination of the tank forces and moments is based upon a novel approach that relies on the global momentum conservation of the closed fluid domain, and a parametric wall wetting model allows tuning of the free surface contact angle. Development of the interface is implicit and no interface tracking approach is required. A numerical example illustrates the method's application to prediction of bulk fluid behavior during a spacecraft ullage settling maneuver.

  1. Numerical solution of optimal departure frequency of Taipei TMS

    NASA Astrophysics Data System (ADS)

    Young, Lih-jier; Chiu, Chin-Hsin

    2016-05-01

    Route Number 5 (Bannan Line) of Taipei Mass Rapid Transit (MRT) is the most popular line in the Taipei Metro System especially during rush hours periods. It has been estimated there are more than 8,000 passengers on the ticket platform during 18:00∼19:00 at Taipei main station. The purpose of this research is to predict a specific departure frequency of passengers per train. Monte Carlo Simulation will be used to optimize departure frequency according to the passenger information provided by 22 stations, i.e., 22 random variables of route number 5. It is worth mentioning that we used 30,000 iterations to get the different samples of the optimization departure frequency, i.e., 10 trains/hr which matches the practical situation.

  2. Quantitative Analyse und Visualisierung der Herzfunktionen

    NASA Astrophysics Data System (ADS)

    Sauer, Anne; Schwarz, Tobias; Engel, Nicole; Seitel, Mathias; Kenngott, Hannes; Mohrhardt, Carsten; Loßnitzer, Dirk; Giannitsis, Evangelos; Katus, Hugo A.; Meinzer, Hans-Peter

    Die computergestützte bildbasierte Analyse der Herzfunktionen ist mittlerweile Standard in der Kardiologie. Die verfügbaren Produkte erfordern meist ein hohes Maß an Benutzerinteraktion und somit einen erhöhten Zeitaufwand. In dieser Arbeit wird ein Ansatz vorgestellt, der dem Kardiologen eine größtenteils automatische Analyse der Herzfunktionen mittels MRT-Bilddaten ermöglicht und damit Zeitersparnis schafft. Hierbei werden alle relevanten herzphysiologsichen Parameter berechnet und mithilfe von Diagrammen und Graphen visualisiert. Diese Berechnungen werden evaluiert, indem die ermittelten Werte mit manuell vermessenen verglichen werden. Der hierbei berechnete mittlere Fehler liegt mit 2,85 mm für die Wanddicke und 1,61 mm für die Wanddickenzunahme immer noch im Bereich einer Pixelgrösse der verwendeten Bilder.

  3. [Comparative efficiency of nootropic drugs in complex treatment of patients with remote consequences of closed craniocereberal trauma].

    PubMed

    Hliebova, O S; Tkachenko, O V

    2008-01-01

    Main data of the research were data obtained after a complex treatment of 120 persons with late consequences of closed craniocereberal trauma (CCRCT). The treatment included administration of one of nootropic agents (noophen, aminolon or entropil), magnesium sulfate, group B vitamins. All patients have passed a complex examination: specially developed questionnaire, anamnesis gathering, neurologic status, neuropsychological status with the use of multiple-aspect scales and questionnaires, examination of fundus of eye, rheoencephalography, echoencephalography, brain MRT. Results of a complex examination proved positive effect of the use of nootropic agents, in particular noophen, entropil and aminolon in complex treatment of late consequences of closed craniocereberal trauma. For optimisation of the use of nootropic agents in the treatment of late consequences of closed craniocereberal trauma it is recommended to consider features of influence of nootropic agents on certain clinical aspects of the disease.

  4. [Application of nootropic agents in complex treatment of patients with concussion of the brain].

    PubMed

    Tkachev, A V

    2007-01-01

    65 patients with a mild craniocereberal trauma have been observed. Medical examination included among general clinical methods the following methods: KT (MRT) of the brain, oculist examination including the observation of eye fundus. For objectification of a patient' complaints the authors used orientation and Galvestona's amnesia tests, feeling scale (psychological test), the table to determine the level of memory. Tests have been carried out on the first, tenth and thirty day of the treatment. Patients of the first group received in a complex treatment -pramistar, patients of the second group - piracetam. Patients of both groups noted considerable improvement during a complex treatment (disappearance of headache, dizziness and nausea) and at the same time patients receiving pramistar had better restoration of orientation and feeling. Pramistar was also more effective in patients with amnesia.

  5. A multiple relaxation time extension of the constant speed kinetic model

    NASA Astrophysics Data System (ADS)

    Zadehgol, Abed; Ashrafizaadeh, Mahmud

    2016-02-01

    In this work, a multiple relaxation time (MRT) extension of the recently introduced constant speed kinetic model (CSKM) is proposed. The CSKM, which is an entropic kinetic model and based on unconventional entropies of Burg and Tssalis, was introduced in [A. Zadehgol and M. Ashrafizaadeh, J. Comput. Phys. 274, 803 (2014)]; [A. Zadehgol Phys. Rev. E 91, 063311 (2015)] as an extension of the model of Boghosian et al. [Phys. Rev. E 68, 025103 (2003)] in the limit of fixed speed continuous velocities. The present extension improves the stability of the previous models at very high Reynolds numbers, while allowing for a more convenient orthogonal lattice. The model is verified by solving the following benchmark problems: (i) the lid driven square cavity and (ii) the Kelvin-Helmholtz instability of thin shear layers in a doubly periodic square domain.

  6. Sex differences in mental rotation and spatial rotation in a virtual environment.

    PubMed

    Parsons, Thomas D; Larson, Peter; Kratz, Kris; Thiebaux, Marcus; Bluestein, Brendon; Buckwalter, J Galen; Rizzo, Albert A

    2004-01-01

    The visuospatial ability referred to as mental rotation has been shown to produce one of the largest and most consistent sex differences, in favor of males, in the cognitive literature. The current study utilizes both a paper-and-pencil version of the mental rotations test (MRT) and a virtual environment for investigating rotational ability among 44 adult subjects. Results replicate sex differences traditionally seen on paper-and-pencil measures, while no sex effects were observed in the virtual environment. These findings are discussed in terms of task demands and motor involvement. Sex differences were also seen in the patterns of correlations between rotation tasks and other neuropsychological measures. Current results suggest men may rely more on left hemisphere processing than women when engaged in rotational tasks.

  7. Low-threshold bistability in nonlinear microring tower resonator.

    PubMed

    Shafiei, Mehdi; Khanzadeh, Mohammad

    2010-12-06

    Microring tower resonators, which are a chain of microring resonators stacked on top of each other, are of great interest for nonlinear optics due to their unique features such as very high compactness, coupling efficiency and quality factor. In this research, we investigate the optical bistability in microring tower (MRT) with Kerr nonlinearity by using the coupled mode theory, and demonstrate how a proper defect into the structure can lead to low threshold bistability. In particular, we observed optical bistability in nonlinear defect modes with switching power as low as 165 μW through numerical calculations in a structure with a overall loss on the order of 0.01 mm. In addition, we also develop an analytical model that excellently gives the position of defect modes in linear regime.

  8. The pharmacokinetic characters of simvastatin after co-administration with Shexiang Baoxin Pill in healthy volunteers' plasma.

    PubMed

    Tao, Jianfei; Jiang, Peng; Peng, Chengcheng; Li, Min; Liu, Runhui; Zhang, Weidong

    2016-07-15

    To investigate the effect of Shexiang Baoxin Pill (SBP), a tranditional Chinese medicine, on the pharmacokinetic (PK) parameters of simvastatin in healthy volunteers' plasma, a quantitative method was developed using an Agilent G6410A rapid performance liquid chromatography (RPLC) coupled with triple quadrupole mass spectrometry system. The established method was rapid with high extraction recovery and successfully applied for the determination of simvastatin in plasma of 16 healthy volunteers. The results demonstrated that the MRT(0-∞), T1/2 and Tmax value of simvastatin were significantly decreased, while the AUC(0-t) and Cmax values of smivastatin were increased by SBP. The pharmacokinetic study demonstrated that the metabolism parameters of simvastatin could be affected by SBP and the potential drug-drug interaction should be noted in the future clinical practice.

  9. Integrated Program of Experimental Diagnostics at the NNSS. An Integrated, Prioritized Work Plan for Diagnostic Development and Maintenance and Supporting Capability

    SciTech Connect

    None, None

    2010-09-01

    This Integrated Program of Experimental Diagnostics at the NNSS is an integrated prioritized work plan for the Nevada National Security Site (NNSS), formerly the Nevada Test Site (NTS), program that is independent of individual National Security Enterprise Laboratories’ (Labs) requests or specific Subprograms being supported. This prioritized work plan is influenced by national priorities presented in the Predictive Capability Framework (PCF) and other strategy documents (Primary and Secondary Assessment Technologies Plans and the Plutonium Experiments Plan). This document satisfies completion criteria for FY 2010 MRT milestone #3496: Document an integrated, prioritized work plan for diagnostic development, maintenance, and supporting capability. This document is an update of the 3-year NNSS plan written a year ago, September 21, 2009, to define and understand Lab requests for diagnostic implementation. This plan is consistent with Lab interpretations of the PCF, Primary Assessment Technologies, and Plutonium Experiment plans.

  10. Adaptation to Room Acoustics Using the Modified Rhyme Test

    PubMed Central

    Brandewie, Eugene; Zahorik, Pavel

    2012-01-01

    The negative effect of reverberant sound energy on speech intelligibility is well documented. Recently, however, prior exposure to room acoustics has been shown to increase intelligibility for a number of listeners in simulated room environments. This room adaptation effect, a possible extension of dynamic echo suppression, has been shown to be specific to reverberant rooms and requires binaural input. Because this effect has been demonstrated only using the Coordinated Response Measure (CRM) corpus it is important to determine whether the increase in intelligibility scores reported previously was due to the specific nature of the CRM task. Here we demonstrate a comparable room-acoustic effect using the Modified Rhyme Test (MRT) corpus in multiple room environments. The results are consistent with the idea that the room adaptation effect may be a natural phenomenon of listening in reverberant environments. PMID:23437415

  11. Enhanced cytotoxicity of melphalan by prolonged exposure to nitroimidazoles: the role of endogenous thiols

    SciTech Connect

    Roizin-Towle, L.; Hall, E.J.; Flynn, M.; Biaglow, J.E.; Varnes, M.E.

    1982-01-01

    The present study shows that a prolonged exposure of V-79 cells to a variety of nitroimidazoles (misonidazole, Ro-05-9963, Sr-2508, and MRT1-80) results in an enhanced cytotoxicity when these cells are subsequently exposed to melphalan. This process of enhanced malphalan toxicity occurred only when cells were pretreated with misonidazole under hypoxic conditions, suggesting that nitroreduction is necessary for chemosensitization as it is for increased radiosensitization. Different nitroimidazoles tested vary in the extent to which they sensitize cells to the subsequent action of melphalan. Repair from a misonidazole pretreatment is essentially complete by six hours. This study demonstrated that cysteamine could reduce the cytotoxicity of misonidazole and the enhancement of melphalan toxicity. This was an effect reversible with time and one implying similar mechanisms for the preincubation effect observed in vitro for radiation and chemotherapy agents.

  12. An Evaluation of the Method and a Study of the Factors Involved in Using Fused Caustic Alkali for Preparing Metal Surfaces for Enameling

    DTIC Science & Technology

    1946-01-01

    a. UM of Iroa •f effeeta at «ill at either or tha «athede -lthl* tha eleotrolr tic oaJl by alaply traUiag tk« dlreetioa of »lo«, far tha of...aoadiUoaa that atal to to aatotoa «an fall/ aUla Ito pr 1« la aparailaa. "to flrai «autiaa la •tar af acattorlag. totor aaa aaaar aaaa In contact...tNfttaMrt •"Ultt M >***1—«Ijr afe. irf^ ti*p ""•I««— tic «teaped by tio •»«lirtteal • «*tal <tt« u **1* •*fc«r»U«d ttr --•• "•• *° —* Pte

  13. Optical coherence tractography using intrinsic contrast

    PubMed Central

    Goergen, Craig J.; Radhakrishnan, Harsha; Sakadžić, Sava; Mandeville, Emiri T.; Lo, Eng H.; Sosnovik, David E.; Srinivasan, Vivek J.

    2013-01-01

    Organs such as the heart and brain possess intricate fiber structures that are best characterized with threedimensional imaging. For instance, diffusion-based, magnetic resonance tractography (MRT) enables studies of connectivity and remodeling during development and disease macroscopically on the millimeter scale. Here we present complementary, high-resolution microscopic optical coherence imaging and analysis methods that, when used in conjunction with clearing techniques, can characterize fiber architecture in intact organs at tissue depths exceeding 1 mm. We anticipate that these techniques can be used to study fiber architecture in situ at microscopic scales not currently accessible to diffusion magentic resonance (MR), and thus, to validate and complement macroscopic structural imaging techniques. Moreover, as these techniques use intrinsic signals and do not require tissue slicing and staining, they can be used for high-throughput, nondestructive evaluation of fiber architecture across large tissue volumes. PMID:23041891

  14. Coupled solutions of one- and two-compartment pharmacokinetic models with first-order absorption.

    PubMed

    Asmanova, N; Koloskov, G; Ilin, A I

    2013-04-01

    This work emphasizes the importance of the fact, that plasma concentration profiles of one- and two-compartment linear pharmacokinetic (PK) models with first-order absorption introduce an uncertainty in data interpretation. PK-curve fitting results in a pair of valid solutions (coupled solutions), for which the derived PK parameters (such as AUC, MRT, Cmax, tmax, initial and terminal slope) are identical. Therefore, to make a proper choice of PK parameters of the drug in question, more information has to be considered, for example, which one of the solutions is more correlated with corresponding data, observed after iv administration. Comparison of different types of PK models and discussion on the transitions between the coupled solutions was carried out using a novel symbolic notation to provide more clarity and to simplify parameter indexing. Presented results were obtained by combined means of the method of statistic moments, Laplace transform and illustrated by the numerical experiment.

  15. Modelling digestive constraints in non-ruminant and ruminant foregut-fermenting mammals.

    PubMed

    Munn, Adam J; Streich, W Jürgen; Hummel, Jürgen; Clauss, Marcus

    2008-09-01

    It has been suggested that large foregut-fermenting marsupial herbivores, the kangaroos and their relatives, may be less constrained by food intake limitations as compared with ruminants, due mainly to differences in their digestive morphology and management of ingesta particles through the gut. In particular, as the quality of forage declines with increasing contents of plant fibre (cellulose, hemicelluloses and lignin; measured as neutral-detergent fibre, NDF), the tubiform foregut of kangaroos may allow these animals to maintain food intakes more so than ruminants like sheep, which appear to be limited by fibrous bulk filling the foregut and truncating further ingestion. Using available data on dry matter intake (DMI, g kg(-0.75) d(-1)), ingesta mean retention time (MRT, h), and apparent digestibility, we modelled digestible dry matter intake (DDMI) and digestible energy intake (DEI) by ruminant sheep (Ovis aries) and by the largest marsupial herbivore, the red kangaroo (Macropus rufus). Sheep achieved higher MRTs on similar DMIs, and hence sheep achieved higher DDMIs for any given level of DMI as compared with kangaroos. Interestingly, MRT declined in response to increasing DMI in a similar pattern for both species, and the association between DMI and plant NDF contents did not support the hypothesis that kangaroos are less affected by increasing fibre relative to sheep. However, when DEI was modelled according to DDMIs and dietary energy contents, we show that the kangaroos could meet their daily maintenance energy requirements (MER) at lower levels of DMI and on diets with higher fibre contents compared with sheep, due largely to the kangaroos' lower absolute maintenance and basal energy metabolisms compared with eutherians. These results suggest that differences in the metabolic set-point of different species can have profound effects on their nutritional niche, even when their digestive constraints are similar, as was the case for these ruminant and non

  16. Improved normal tissue protection by proton and X-ray microchannels compared to homogeneous field irradiation.

    PubMed

    Girst, S; Marx, C; Bräuer-Krisch, E; Bravin, A; Bartzsch, S; Oelfke, U; Greubel, C; Reindl, J; Siebenwirth, C; Zlobinskaya, O; Multhoff, G; Dollinger, G; Schmid, T E; Wilkens, J J

    2015-09-01

    The risk of developing normal tissue injuries often limits the radiation dose that can be applied to the tumour in radiation therapy. Microbeam Radiation Therapy (MRT), a spatially fractionated photon radiotherapy is currently tested at the European Synchrotron Radiation Facility (ESRF) to improve normal tissue protection. MRT utilizes an array of microscopically thin and nearly parallel X-ray beams that are generated by a synchrotron. At the ion microprobe SNAKE in Munich focused proton microbeams ("proton microchannels") are studied to improve normal tissue protection. Here, we comparatively investigate microbeam/microchannel irradiations with sub-millimetre X-ray versus proton beams to minimize the risk of normal tissue damage in a human skin model, in vitro. Skin tissues were irradiated with a mean dose of 2 Gy over the irradiated area either with parallel synchrotron-generated X-ray beams at the ESRF or with 20 MeV protons at SNAKE using four different irradiation modes: homogeneous field, parallel lines and microchannel applications using two different channel sizes. Normal tissue viability as determined in an MTT test was significantly higher after proton or X-ray microchannel irradiation compared to a homogeneous field irradiation. In line with these findings genetic damage, as determined by the measurement of micronuclei in keratinocytes, was significantly reduced after proton or X-ray microchannel compared to a homogeneous field irradiation. Our data show that skin irradiation using either X-ray or proton microchannels maintain a higher cell viability and DNA integrity compared to a homogeneous irradiation, and thus might improve normal tissue protection after radiation therapy.

  17. Optically erasable samarium-doped fluorophosphate glasses for high-dose measurements in microbeam radiation therapy

    SciTech Connect

    Morrell, B.; Okada, G.; Vahedi, S.; Koughia, C. Kasap, S. O.; Edgar, A.; Varoy, C.; Belev, G.; Wysokinski, T.; Chapman, D.; Sammynaiken, R.

    2014-02-14

    Previous work has demonstrated that fluorophosphate (FP) glasses doped with trivalent samarium (Sm{sup 3+}) can be used as a dosimetric detector in microbeam radiation therapy (MRT) to measure high radiation doses and large dose variations with a resolution in the micrometer range. The present work addresses the use of intense optical radiation at 405 nm to erase the recorded dose information in Sm{sup 3+}-doped FP glass plates and examines the underlying physics. We have evaluated both the conversion and optical erasure of Sm{sup 3+}-doped FP glasses using synchrotron-generated high-dose x-rays at the Canadian Light Source. The Sm-ion valency conversion is accompanied by the appearance of x-ray induced optical absorbance due to the trapping of holes and electrons into phosphorus-oxygen hole (POHC) and electron (POEC) capture centers. Nearly complete Sm{sup 2+} to Sm{sup 3+} reconversion (erasure) may be achieved by intense optical illumination. Combined analysis of absorbance and electron spin resonance measurements indicates that the optical illumination causes partial disappearance of the POHC and the appearance of new POEC. The suggested model for the observed phenomena is based on the release of electrons during the Sm{sup 2+} to Sm{sup 3+} reconversion process, the capture of these electrons by POHC (and hence their disappearance), or by PO groups, with the appearance of new and/or additional POEC. Optical erasure may be used as a practical means to erase the recorded data and permits the reuse of these Sm-doped FP glasses in monitoring dose in MRT.

  18. Development of Sustained Release “NanoFDC (Fixed Dose Combination)” for Hypertension – An Experimental Study

    PubMed Central

    Arora, Anjuman; Shafiq, Nusrat; Jain, Sanjay; Khuller, G. K.; Sharma, Sadhana; Malhotra, Samir

    2015-01-01

    Objectives The present study was planned to formulate, characterize and evaluate the pharmacokinetics of a novel “NanoFDC” comprising three commonly prescribed anti-hypertensive drugs, hydrochlorothiazide (a diuretic), candesartan (ARB) and amlodipine (a calcium channel blocker). Basic Methods The candidate drugs were loaded in Poly (DL-lactide-co-gycolide) (PLGA) by emulsion- diffusion-evaporation method. The formulations were evaluated for their size, morphology, drug loading and in vitro release individually. Single dose pharmacokinetic profiles of the nanoformulations alone and in combination, as a NanoFDC, were evaluated in Wistar rats. Results The candidate drugs encapsulated inside PLGA showed entrapment efficiencies ranging from 30%, 33.5% and 32% for hydrochlorothiazide, candesartan and amlodipine respectively. The nanoparticles ranged in size from 110 to 180 nm. In vitro release profile of the nanoformulation showed 100% release by day 6 in the physiological pH 7.4 set up with PBS (phosphate buffer saline) and by day 4-5 in the intestinal pH 1.2 and 8.0 set up SGF (simulated gastric fluid) and SIF (simulated intestinal fluid) respectively. In pharmacokinetic analysis a sustained-release for 6 days and significant increase in the mean residence time (MRT), as compared to the respective free drugs was noted [MRT of amlodipine, hydrochlorothiazide and candesartan changed from 8.9 to 80.59 hours, 11 to 69.20 hours and 9 to 101.49 hours respectively]. Conclusion We have shown for the first time that encapsulating amlodipine, hydrochlorothiazide and candesartan into a single nanoformulation, to get the “NanoFDC (Fixed Dose Combination)” is a feasible strategy which aims to decrease pill burden. PMID:26047011

  19. An investigation of the potential of optical computed tomography for imaging of synchrotron-generated x-rays at high spatial resolution

    NASA Astrophysics Data System (ADS)

    Doran, Simon J.; Brochard, Thierry; Adamovics, John; Krstajic, Nikola; Bräuer-Krisch, Elke

    2010-03-01

    X-ray microbeam radiation therapy (MRT) is a novel form of treatment, currently in its preclinical stage, which uses microplanar x-ray beams from a synchrotron radiation source. It is important to perform accurate dosimetry on these microbeams, but, to date, there has been no accurate enough method available for making 3D dose measurements with isotropic, high spatial resolution to verify the results of Monte Carlo dose simulations. Here, we investigate the potential of optical computed tomography for satisfying these requirements. The construction of a simple optical CT microscopy (optical projection tomography) system from standard commercially available hardware is described. The measurement of optical densities in projection data is shown to be highly linear (r2 = 0.999). The depth-of-field (DOF) of the imaging system is calculated based on the previous literature and measured experimentally using a commercial DOF target. It is shown that high quality images can be acquired despite the evident lack of telecentricity and despite DOF of the system being much lower than the sample diameter. Possible reasons for this are discussed. Results are presented for a complex irradiation of a 22 mm diameter cylinder of the radiochromic polymer PRESAGE™, demonstrating the exquisite 'dose-painting' abilities available in the MRT hutch of beamline ID-17 at the European Synchrotron Radiation Facility. Dose distributions in this initial experiment are equally well resolved on both an optical CT scan and a corresponding transmission image of radiochromic film, down to a line width of 83 µm (6 lp mm-1) with an MTF value of 0.40. A group of 33 µm wide lines was poorly resolved on both the optical CT and film images, and this is attributed to an incorrect exposure time calculation, leading to under-delivery of dose. Image artefacts in the optical CT scan are discussed. PRESAGE™ irradiated using the microbeam facility is proposed as a suitable material for producing phantom

  20. Multiple-relaxation-time lattice Boltzmann kinetic model for combustion

    NASA Astrophysics Data System (ADS)

    Xu, Aiguo; Lin, Chuandong; Zhang, Guangcai; Li, Yingjun

    2015-04-01

    To probe both the hydrodynamic nonequilibrium (HNE) and thermodynamic nonequilibrium (TNE) in the combustion process, a two-dimensional multiple-relaxation-time (MRT) version of lattice Boltzmann kinetic model (LBKM) for combustion phenomena is presented. The chemical energy released in the progress of combustion is dynamically coupled into the system by adding a chemical term to the LB kinetic equation. Aside from describing the evolutions of the conserved quantities, the density, momentum, and energy, which are what the Navier-Stokes model describes, the MRT-LBKM presents also a coarse-grained description on the evolutions of some nonconserved quantities. The current model works for both subsonic and supersonic flows with or without chemical reaction. In this model, both the specific-heat ratio and the Prandtl number are flexible, the TNE effects are naturally presented in each simulation step. The model is verified and validated via well-known benchmark tests. As an initial application, various nonequilibrium behaviors, including the complex interplays between various HNEs, between various TNEs, and between the HNE and TNE, around the detonation wave in the unsteady and steady one-dimensional detonation processes are preliminarily probed. It is found that the system viscosity (or heat conductivity) decreases the local TNE, but increases the global TNE around the detonation wave, that even locally, the system viscosity (or heat conductivity) results in two kinds of competing trends, to increase and to decrease the TNE effects. The physical reason is that the viscosity (or heat conductivity) takes part in both the thermodynamic and hydrodynamic responses.

  1. Identification of the Quorum-Sensing Target DNA Sequence and N-Acyl Homoserine Lactone Responsiveness of the Brucella abortus virB promoter▿

    PubMed Central

    Arocena, Gastón M.; Sieira, Rodrigo; Comerci, Diego J.; Ugalde, Rodolfo A.

    2010-01-01

    VjbR is a LuxR-type quorum-sensing (QS) regulator that plays an essential role in the virulence of the intracellular facultative pathogen Brucella, the causative agent of brucellosis. It was previously described that VjbR regulates a diverse group of genes, including the virB operon. The latter codes for a type IV secretion system (T4SS) that is central for the pathogenesis of Brucella. Although the regulatory role of VjbR on the virB promoter (PvirB) was extensively studied by different groups, the VjbR-binding site had not been identified so far. Here, we identified the target DNA sequence of VjbR in PvirB by DNase I footprinting analyses. Surprisingly, we observed that VjbR specifically recognizes a sequence that is identical to a half-binding site of the QS-related regulator MrtR of Mesorhizobium tianshanense. As shown by DNase I footprinting and electrophoretic mobility shift assays, generation of a palindromic MrtR-like-binding site in PvirB increased both the affinity and the stability of the VjbR-DNA complex, which confirmed that the QS regulator of Brucella is highly related to that of M. tianshanense. The addition of N-dodecanoyl homoserine lactone dissociated VjbR from the promoter, which confirmed previous reports that indicated a negative effect of this signal on the VjbR-mediated activation of PvirB. Our results provide new molecular evidence for the structure of the virB promoter and reveal unusual features of the QS target DNA sequence of the main regulator of virulence in Brucella. PMID:20400542

  2. Influence of a Counterion on the Ion Atmosphere of an Anion: A Molecular Dynamics Study of LiX and CsX (X = F(-), Cl(-), I(-)) in Methanol.

    PubMed

    Kumar, Parveen; Kulkarni, Anant D; Yashonath, S

    2015-08-27

    We report molecular dynamics (MD) simulations to explore the influence of a counterion on the structure and dynamics of cationic and anionic solvation shells for various ions in methanol at 298 K. We show that the variation in ionic size of either the cation or the anion in an ion pair influences the solvation structure of the other ion as well as the diffusivity in an electrolyte solution of methanol. The extent of ionic association between the cation and its counteranion of different ionic sizes has been investigated by analyzing the radial distribution functions (RDFs) and the orientation of methanol molecules in the first solvation shell (FSS) of ions. It is shown that the methanol in the FSS of the anion as well the cation exhibit quite different radial and orientational structures as compared to methanol which lie in the FSS of either the anion or the cation but not both. We find that the coordination number (CN) of F(-), Cl(-), and I(-) ions decreases with increasing size of the anion which is contrary to the trend reported for the anions in H2O. The mean residence time (MRT) of methanol molecules in the FSS of ions has been calculated using the stable states picture (SSP) approach. It is seen that the ion-counterion interaction has a considerable influence on the MRT of methanol molecules in the FSS of ions. We also discuss the stability order of the ion-counterion using the potentials of mean force (PMFs) for ion pairs with ions of different sizes. The PMF plots reveal that the Li(+)-F(-) pair (small-small) is highly stable and the Li(+)-I(-) pair is least stable (small-large) in electrolyte solutions.

  3. Influence of moisture content of forage diets on intake and digestion by sheep.

    PubMed

    Pasha, T N; Prigge, E C; Russell, R W; Bryan, W B

    1994-09-01

    To determine the effect of forage moisture content on intake and digestion kinetics in sheep, a metabolism trial was conducted using 16 mature wethers (44 kg BW) in a completely randomized design. Forage was harvested at two maturities in early spring from a naturalized pasture composed of temperate grass and legume species. Herbage was harvested at either 8 (early) or 16 cm (late) in height and fed after freezing (high-moisture) or as a dried hay. Intakes of DM (grams/[kilogram BW.75.day]), NDF, ADF, and CP (grams/day) (P < .05) and coefficients for DM, NDF, and ADF digestibilities were greater (P < .01) for hay than for high-moisture forage. Mean particulate retention times (MRT) were shorter (P < .05) for high-moisture forage (23.3 h) than for hay (30.7 h) diets. Early-harvested forages had shorter (P < .05) MRT values (23.9 h) than late-cut forages (30.1 h). Fractional passage rates of 1-mm nylon particles of specific gravity (SG) .90, 1.14, and 1.32 through the alimentary tract were influenced by moisture content of the forage (P < .10) and were faster for frozen forages and increased (P < .01) with an increase in SG. Nitrogen retention was greater (P < .01) for the hay than for the high-moisture forage. In situ DM digestion rates, determined using four ruminally fistulated wethers, showed no differences (P = .67) among forages. The results of this study indicate that differences in digestibilities between hays and high-moisture forages are most likely due to differences in digesta passage rates.

  4. Control of pulmonary absorption of water-soluble compounds by various viscous vehicles.

    PubMed

    Yamamoto, Akira; Yamada, Keigo; Muramatsu, Hideaki; Nishinaka, Asako; Okumura, Shigeki; Okada, Naoki; Fujita, Takuya; Muranishi, Shozo

    2004-09-10

    Effects of various viscous vehicles on the pulmonary absorption of water-soluble drugs were examined by an in situ pulmonary absorption experiment. Gelatin, polyvinylacohol (PVA), hydroxypropylcellose (HPC), chondroitin sulfate A sodium salt (CS), polyacrylic acid (PAA), methylcellulose #400 (MC400) and hyaluronic acid sodium salt (HA) were used as models of viscous vehicles. 5(6)-Carboxyfluorescein (CF) and fluorescein isothiocayanate-labeled dextran with an average molecular weight of 4000 (FD4) were used as water-soluble drugs. The plasma concentration of CF was controlled and regulated in the presence of these viscous vehicles, especially gelatin (1-5%) and polyvinyl alcohol (PVA) 1%. In the pharmacokinetic analysis, the Cmax values of CF significantly decreased, and its Tmax values increased in the presence of these viscous vehicles compared with the control. The MRT and MAT values of CF with these vehicles were significantly higher than those without these vehicles. Therefore, these findings indicated that the viscous vehicles were effective to regulate the absorption rate of CF. On the other hand, the pulmonary absorption of FD4 was not so much affected even in the presence of gelatin and PVA, although PVA slightly decreased MRT value, and significantly decreased Tmax value. Furthermore, we examined the release rate of CF from the cellulose tube containing various concentrations of gelatin. The release rate of CF from the cellulose tube with gelatin was inversely related to the viscosity of gelatin. In addition, the release rate of CF was inversely related to DeltaMAT (DeltaMAT = MATgel(MAT with gelatin)-MATsol(MAT without gelatin)) in the presence of varying concentrations of gelatin. These findings indicated that these viscous vehicles were effective to control the pulmonary absorption of CF, a water-soluble drug with low molecular weight and they might be useful to increase the local concentration of drugs in the lung.

  5. Effect of albendazole administration on pharmacokinetic aspects of tylosin in lactating goats.

    PubMed

    Atef, M; Ramadan, A; Darwish, A S; Fahim, Aisha M M

    2009-08-01

    Tylosin concentrations and its disposition kinetics in serum, urine, and milk of lactating goats following a single intravenous (i.v.) or intramuscular (i.m.) injection (10 mg kg(-1) b.wt.) were carried out using high performance liquid chromatography (HPLC).The concentration-time curve of tylosin after i.v. injection could be described by a two-compartment open model. Tylosin was rapidly distributed and eliminated from goat's bodies with t(1/2(beta)) value of 1.25 h. The V((d)) was less than one litre/kg and the MRT was 1.40 h. Concomitant administration with albendazole decreased tylosin concentrations in serum after its i.v. injection and the MRT was 1.17 h. The AUC and AUMC showed a significant decrease in goats given albendazole prior to injection as compared with those given tylosin only. Following i.m. administration, the absorption half-life and the corresponding t(max) revealed rapid absorption rate with systemic bioavailability (F%) of 76.2 %. Albendazole when given concurrently with tylosin decreased its serum concentrations due to lower bioavailability (43.25 %). Following i.v. or i.m. injection, tylosin was excreted rapidly in urine in concentration much higher than those determined in serum and milk. Tylosin administered in goats pretreated with albendazole was excreted at lower concentration in urine, with a significant decrease from 1(st) to 10(th) hours as compared with animals given tylosin only. Following i.v. or i.m. administration of tylosin, the drug was excreted in high concentrations in milk. A significant decrease in milk concentrations was reported in goats pretreated with albendazole.

  6. An event-related analysis of P300 by simultaneous EEG/fMRI

    NASA Astrophysics Data System (ADS)

    Wang, Li-qun; Wang, Mingshi; Mizuhara, Hiroaki

    2006-09-01

    In this study, P300 that induced by visual stimuli was examined with simultaneous EEG/fMRI. For the purpose of combine the best temporary resolution with the best special resolution together to estimate the brain function, event-related analysis contributed to this methodological trial. A 64 channel MRT-compatible MR EEG amplifier (BrainAmp: made of Brain Production GmbH, Gennany) was used in the measurement simultaneously with fMRI scanning. The reference channel is between Fz, Cz and Pz. Sampling rate of raw EEG was 5 kHz, and the MRT noise reduction was performed. EEG recording synchronized with MRI scan by our original stimulus system, and an oddball paradigm (four-oriented Landolt Ring presentation) was performed in the official manner. After P300 segmentation, the timing of P300 was exported to event-related analysis of fMRI data with SPM99 software. In single subject study, the significant activations appear in the left superior frontal, Broca's area and on both sides of the parietal lobule when P300 occurred. It is suggest that P300 may be an integration carried out by top-down signal from frontal to the parietal lobule, which regulates an Attention-Logical Judgment process. Compared with other current methods, the event related analysis by simultaneous EEG/IMRI is excellent in the point that can describe the cognitive process with reality unifying further temporary and spatial information. It is expected that examination and demonstration of the obtained result will supply with the promotion of this powerful methods.

  7. Pharmacokinetics of moxidectin and doramectin in goats.

    PubMed

    Escudero, E; Carceles, C M; Diaz, M S; Sutra, J F; Galtier, P; Alvinerie, M

    1999-10-01

    The pharmacokinetic behaviour of doramectin after a single subcutaneous administration and moxidectin following a single subcutaneous or oral drench were studied in goats at a dosage of 0.2 mg kg(-1). The drug plasma concentration-time data were analysed by compartmental pharmacokinetics and non-compartmental methods. Maximum plasma concentrations of moxidectin were attained earlier and to a greater extent than doramectin (shorter t(max) and greater C(max) and AUC than doramectin). MRT of doramectin (4.91 +/- 0.07 days) was also significantly shorter than that of moxidectin (12.43 +/- 1.28 days). Then, the exposure of animals to doramectin in comparison with moxidectin was significantly shorter. The apparent absorption rate of moxidectin was not significantly different after oral and subcutaneous administration but the extent of absorption, reflected in the peak concentration (C(max)) and the area under the concentration-time curve (AUC), of the subcutaneous injection (24.27 +/- 1.99 ng ml(-1) and 136.72 +/- 7.35 ng d ml(-1) respectively) was significantly greater than that of the oral administration (15.53 +/- 1.27 ng ml(-1) and 36.72 +/- 4.05 ng d ml(-1) respectively). The mean residence time (MRT) of moxidectin didn't differ significantly when administered orally or subcutaneously. Therefore low oral bioavailability and the early emergence of resistance in this minor species may be related. These results deserve to be correlated with efficacy studies for refining dosage requirements of endectocides in this species.

  8. Pharmacokinetics of azithromycin after intravenous and intramuscular administration to goats.

    PubMed

    Cárceles, C M; Font, A; Espuny, A; Fernández-Varón, E; Serrano, J M; Escudero, E

    2005-02-01

    Azithromycin is the first of a class of antimicrobial agents designated azalides. The aim of the present study was to investigate the disposition pharmacokinetics of azithromycin in goats and determine its bioavailability. A cross-over study was carried out in two phases separated by 30 days. Azithromycin was administered at a single dose of 20 mg/kg body weight by i.v. and i.m. routes. Plasma concentrations of azithromycin were determined by a modified agar diffusion bioassay. After a single i.v. dose plasma concentrations were best fitted to a three-compartment open model. A two-compartment open model with first-order absorption fitted best after i.m. administration. The values of the pharmacokinetic parameters after i.v. administration were: half-life 32.5 h, apparent volume of distribution at the steady-state 34.5 L/kg, clearance 0.85 L/kg. and mean residence time (MRT) 40.1 h. After i.m. administration half-life of 45.2 h, a MRT of 60.3 h, maximum plasma concentration 0.64 mg/L and a bioavalability 92.2% were obtained. The pharmacokinetic parameters of azithromycin after i.m. administration, principally its long half-life and high bioavailability, could provide an alternative to the oral route of administration in goats, although more studies are needed to establish a suitable pharmaceutical formulation, propose optimun dosage regimens, investigate clinical efficacy and study the tolerability of repeated doses.

  9. Pharmacokinetic interaction of garlic and atorvastatin in dyslipidemic rats

    PubMed Central

    Reddy, G. Dilip; Reddy, A. Gopala; Rao, G.S.; Kumar, M. Vijay

    2012-01-01

    Objective: To assess pharmacokinetic interaction of garlic with atorvastatin in dyslipidemic rats. Materials and Methods: Sprague Dawley rats with induced dyslipidemia were divided into five groups of eight rats each. Group 1 was given atorvastatin (10 mg/kg body weight (b.wt) orally), group 2 was given atorvastatin (10 mg/kg b.wt orally)+garlic (1% w/w in feed), group 3 was maintained on atorvastatin (5 mg/kg b.wt orally)+garlic (0.5% w/w in feed), group 4 was maintained on atorvastatin (7.5 mg/kg b.wt orally)+garlic (0.25% w/w in feed), and group 5 was maintained on atorvastatin (2.5 mg/kg b.wt orally)+garlic (0.75% w/w in feed) for 12 weeks. Blood samples were collected at predetermined time intervals for kinetic analysis after the first and last oral dosing of atorvastatin for single and multiple dose studies, respectively. Plasma samples were assayed for atorvastatin concentration by High-Performance Liquid Chromatography (HPLC) and then the concentration-time data were analyzed. Results: Maximum observed plasma concentration (Cmax), half-life, Area Under Plasma Concentration Time Curve (AUC), and Mean Resident Time (MRT) were significantly (P<0.05) increased during multiple dose kinetic study and elimination rate constant was significantly (P<0.05) decreased in comparison with their respective single-dose values, while there was no significant difference in time to achieve maximum concentration (tmax) in all groups during both phases of the study. The highest values for kinetic parameters were observed in group 2 with correspondingly low activity of Cytochrome P450 (CYP450). Conclusion: The study revealed higher values [Cmax, AUC, Area Under The Moment Curve (AUMC), MRT, and half-life] of atorvastatin in garlic-treated groups. PMID:22529485

  10. The effects of Ramadan fasting on sleep patterns and daytime sleepiness: An objective assessment

    PubMed Central

    BaHammam, Ahmed S.; Alaseem, Abdulrhman M.; Alzakri, Abdulmajid A.; Sharif, Munir M.

    2013-01-01

    Background: Ramadan fasting and its associated lifestyle changes have been linked to changes in sleep and daytime sleepiness. This study was designed to assess the effects of Ramadan fasting on patterns of sleep and daytime sleepiness. Methods: The SenseWear Pro Armband™ was used to assess the duration and distribution of sleep in eight Muslim and eight non-Muslim volunteers during the last week of Shaaban [baseline (BL) and the first (R1) and second (R2) weeks of Ramadan (1430 H)]. OPTALERT™ was used to assess daytime drowsiness objectively using the John Drowsiness Scale (JDS) to assess sleepiness, and a visual reaction time test was used to assess mean reaction time (MRT). Results: The mean ages of Muslims and non-Muslims were 36.25 ± 4.46 and 34.75 ± 3.33 years, respectively. Although the start of work was delayed for Muslims from 0730 to 1000 hours, there was no change in working hours for non-Muslims. During Ramadan, bedtime and wake-up time were delayed, and there was a significant reduction in total sleep time for Muslims (5.91 ± 1.36 hours, 4.95 ± 1.46 hours, and 4.78 ± 1.36 hours during BL, R1, and R2, respectively, P < 0.001), but not for non-Muslims. JDS values in both Muslims and non-Muslims were normal at BL (1.70 ± 1.16 and 1.68 ± 1.07, respectively), and no changes occurred during Ramadan (R1 or R2), indicating no increase in daytime sleepiness. There were no significant changes in MRT during R1 and R2 from BL in either group. Conclusion: Although the sleep cycle of the studied sample shifted during Ramadan among fast observers, there was no objective evidence for increased sleepiness during fasting. PMID:23914215

  11. Disposition and tissue distribution of imatinib in a liposome formulation after intravenous bolus dose to mice.

    PubMed

    Moo, Kai Shing; Radhakrishnan, Shantini; Teoh, Magdalene; Narayanan, Prasad; Bukhari, Nadeem Irfan; Segarra, Ignacio

    2010-07-01

    Imatinib is an efficacious anticancer drug with a spectrum of potential antitumour applications limited by poor biodistribution at therapeutic concentrations to the tissues of interest. We assess the pharmacokinetic and tissue distribution profile of imatinib in a liposome formulation. Its single dose (6.25 mg x kg(-1)) in a liposome formulation was administered iv to male mice. Imatinib concentration was measured in plasma, spleen, liver, kidney and brain using a HPLC assay. Non-compartmental pharmacokinetic approach was used to assess the disposition parameters. The plasma disposition profile was biphasic with a plateau-like second phase. The AUC(0-->infinity) was 11.24 microg x h x mL(-1), the elimination rate constant (k(el)) was 0.348 h(-1) and the elimination half life (t(1/2)) was 2.0 h. The mean residence time (MRT) was 2.59 h, V(SS) was 1.44 L x kg(-1) and clearance was 0.56 L x h x kg(-1). Liver achieved the highest tissue exposure: CMAX = 18.72 microg x mL(-1); AUC(0-->infinity)= 58.18 microg x h x mL(-1) and longest t(1/2) (4.29 h) and MRT (5.31 h). Kidney and spleen AUC(0-->infinity) were 47.98 microg x h x mL(-1) and 23.46 microg x h x mL(-1), respectively. Half-life was 1.83 h for the kidney and 3.37 h for the spleen. Imatinib penetrated into the brain reaching approximately 1 microg x g(-1). Upon correction by organ blood flow the spleen showed the largest uptake efficiency. Liposomal imatinib presented extensive biodistribution. The drug uptake kinetics showed mechanism differences amongst the tissues. These findings encourage the development of novel imatinib formulations to treat other cancers.

  12. Increased rate of positive biopsies using a combination of MR-Tomography, spectroscopy and diffusion-weighted magnetic resonance imaging prior to prostate biopsies in patients with persistent elevated prostate-specific antigen values: A retrospective analysis

    PubMed Central

    Lunacek, A.; Simon, J.; Bernt, R.; Huber, M.; Plas, E.; Mrstik, C.

    2013-01-01

    Purpose: Persistently elevated prostate-specific antigen (PSA) values following negative biopsies result in a diagnostic dilemma. In order to improve detection rates in patients with former negative biopsies and persistently elevated PSA values, magnetic resonance tomography (MRT), magnetic resonance spectroscopy (MRS), and diffusion-weighted magnetic resonance imaging (DW-MRI) were performed prior to prostate rebiopsies. Materials and Methods: Over a 14-month period, 67 patients (mean age of 66 years) with a history of 1-5 negative biopsies underwent endorectal magnetic resonance imaging (MRI) using T2-weighted MRT MRS and DW-MRI before an additional prostate biopsy was performed. Subsequently, 5 contrast-enhanced transrectal ultrasound-guided biopsies were performed according to a 10-core systematic scheme. Out of the 67 men, 25 patients had positive biopsies and opted for radical prostatectomy. Histological evaluation of cancer localization, PSA, diameters of primary tumors, numbers and diameters of satellite tumors, prostate volume, and staging pathology was performed. These findings were compared with MRI and MRS results. Results: Serum PSA levels ranged from 3.1 to 19.5 g/ml (median level of 7.96 ng/ml). After the 25 patients underwent radical prostatectomy, analysis of 20 whole-mount sections of 25 radical retropubic prostatectomy (RPE) specimens presented results agreeing with the tumor location from MRI and MRS data. Conclusions: The aim of image-guided diagnostics should be to provide more critical information prior to biopsy. Furthermore, the acquisition of such data is important for better risk stratification in therapeutic decisions. PMID:23798861

  13. Effect of Concave Sound Reflecting Surfaces on Speech Intelligibility and Articulation Index.

    NASA Astrophysics Data System (ADS)

    Khaiyat, Sami Abdulrahman

    Three different methods are used to assess speech intelligibility in spaces with and without concave sound reflecting surfaces: calculated articulation index (AI), measured rapid speech transmission index (RASTI), and modified rhyme tests (MRT) with occupants. Factors such as the room size, size of curvature, the speaker's position, and the background noise level are considered in the two on -site testing methods. The MRT results show unexpectedly significant deviation from results obtained through the other methods such that they are de-emphasized in all discussions. Results from rooms without curvatures show no significant differences between the AI and RASTI values; whereas, these differences are significant when rooms with curvatures are considered. A modification factor to be subtracted from calculated AI values to account for erosional effects of the curved surfaces is developed according to further analysis of the differences between the AI and RASTI values. The magnitude of the modification factors depends on all the above factors as well as the location of the listeners within the room. There are no clear indications of any dead spots, however, the sound foci from both the 2ft. and 8ft. curvatures have caused certain group locations to have smaller modification factors than that of all other locations. The magnitude of the developed modification factors ranges between 0.01, for the 16ft. curvature in the small rooms, to 0.17, for the 8ft. curvature in the large room with NC-45 and the speaker's position is on the center. This range is of almost the same magnitude as that of the erosional corrections to calculated AI due to elevated reverberation time. This range is also of almost same magnitude as that of improvement in calculated AI due to presence of visual cues.

  14. Characterisation of a CZT detector for dosimetry of molecular radiotherapy

    NASA Astrophysics Data System (ADS)

    McAreavey, L. H.; Harkness-Brennan, L. J.; Colosimo, S. J.; Judson, D. S.; Boston, A. J.; Boston, H. C.; Nolan, P. J.; Flux, G. D.; Denis-Bacelar, A. M.; Harris, B.; Radley, I.; Carroll, M.

    2017-03-01

    A pixelated cadmium zinc telluride (CZT) detector has been characterised for the purpose of developing a quantitative single photon emission computed tomography (SPECT) system for dosimetry of molecular radiotherapy (MRT). This is the aim of the Dosimetric Imaging with CZT (DEPICT) project, which is a collaboration between the University of Liverpool, The Royal Marsden Hospital, The Royal Liverpool and Broadgreen University Hospital, and the commercial partner Kromek. CZT is a direct band gap semiconductor with superior energy resolution and stopping power compared to scintillator detectors used in current SPECT systems. The inherent detector properties have been investigated and operational parameters such as bias voltage and peaking time have been selected to optimise the performance of the system. Good energy resolution is required to discriminate γ-rays that are scattered as they are emitted from the body and within the collimator, and high photon throughput is essential due to the high activities of isotopes administered in MRT. The system has an average measured electronic noise of 3.31 keV full width at half maximum (FWHM), determined through the use of an internal pulser. The energy response of the system was measured across the energy region of interest 59.5 keV to 364.5 keV and found to be linear. The reverse bias voltage and peaking time producing the optimum FWHM and maximum photon throughput were 600 V and 0.5 μs respectively. The average dead time of the system was measured as 4.84 μs and charge sharing was quantified to be 0.71 % at 59.5 keV . A pixel sensitivity calibration map was created and planar images of the medical imaging isotopes 99mTc and 123I were acquired by coupling the device to a prototype collimator, thereby demonstrating the suitability of the detector for the DEPICT project.

  15. Development and optimization of transferrin-conjugated nanostructured lipid carriers for brain delivery of paclitaxel using Box-Behnken design.

    PubMed

    Emami, Jaber; Rezazadeh, Mahboubeh; Sadeghi, Hojjat; Khadivar, Khashayar

    2017-05-01

    The treatment of brain cancer remains one of the most difficult challenges in oncology. The purpose of this study was to develop transferrin-conjugated nanostructured lipid carriers (Tf-NLCs) for brain delivery of paclitaxel (PTX). PTX-loaded NLCs (PTX-NLCs) were prepared using solvent evaporation method and the impact of various formulation variables were assessed using Box-Behnken design. Optimized PTX-NLC was coupled with transferrin as targeting ligand and in vitro cytotoxicity of it was investigated against U-87 brain cancer cell line. As a result, 14.1 mg of cholesterol, 18.5 mg of triolein, and 0.5% poloxamer were used to prepare the optimal formulation. Mean particle size (PS), zeta potential (ZP), entrapment efficiency (EE), drug loading (DL), mean release time (MRT) of adopted formulation were confirmed to be 205.4 ± 11 nm, 25.7 ± 6.22 mV, 91.8 ± 0.5%, 5.38 ± 0.03% and 29.3 h, respectively. Following conjugation of optimized PTX-NLCs with transferrin, coupling efficiency was 21.3 mg transferrin per mmol of stearylamine; PS and MRT were increased while ZP, EE and DL decreased non-significantly. Tf-PTX-NLCs showed higher cytotoxic activity compared to non-targeted NLCs and free drug. These results indicated that the Tf-PTX-NLCs could potentially be exploited as a delivery system in brain cancer cells.

  16. [Surgical safety cheklist at the management of the hybrid operating room].

    PubMed

    Cherkashin, M A; Berezina, N A; Kuplevatsky, V I; Serov, A V; Mefodovsky, A A

    2016-01-01

    An essential aspect of the work of the operating room is the provision of safety of both the patient and staff. The organization of the activity of the surgical service requires serious elaboration of each of its stage, as well as standardization in using various validated instruments. When speaking of a hybrid operating room with the use of intraoperative magnetic resonance tomography, such an approach becomes not merely a recommendation but rather forced and justified necessity. Simultaneous use of various technologies of imaging and treatment with the engagement of physicians of various specialties requires especially thorough control. A generally accepted international standard of the work of the operating block is the use of checklists, and since 2008 the initiative of the World Health Organization "Safe Surgery Saves Lives" has globally been working to promote implementation of the WHO Surgical Safety Checklists (SSCL) to the real clinical practice. The intraoperative MR-diagnostic stage dictates rigid requirements for proper inventory of ferromagnetic and nonmagnetic surgical tools, verified logistics, and routing of the patient in the conditions of high and extremely high (1.5-3.0 T) magnetic field. A separate and not less important problem is anaesthesiological support during MRT. In order to optimise the patient's movements and adequate monitoring of his/her safety inside the operating department, the authors have modified the standard WHO Surgical Safety Checklist. Implementation of the modified checklist for the MRT-equipped hybrid operating room should improve the control over the processes, as well as increase safety of both the patient and personnel.

  17. Long Term Effect of Land Reclamation from Lake on Chemical Composition of Soil Organic Matter and Its Mineralization

    PubMed Central

    He, Dongmei; Ruan, Honghua

    2014-01-01

    Since the late 1950s, land reclamation from lakes has been a common human disturbance to ecosystems in China. It has greatly diminished the lake area, and altered natural ecological succession. However, little is known about its impact on the carbon (C) cycle. We conducted an experiment to examine the variations of chemical properties of dissolved organic matter (DOM) and C mineralization under four land uses, i.e. coniferous forest (CF), evergreen broadleaf forest (EBF), bamboo forest (BF) and cropland (CL) in a reclaimed land area from Taihu Lake. Soils and lake sediments (LS) were incubated for 360 days in the laboratory and the CO2 evolution from each soil during the incubation was fit to a double exponential model. The DOM was analyzed at the beginning and end of the incubation using UV and fluorescence spectroscopy to understand the relationships between DOM chemistry and C mineralization. The C mineralization in our study was influenced by the land use with different vegetation and management. The greatest cumulative CO2-C emission was observed in BF soil at 0–10 cm depth. The active C pool in EBF at 10–25 cm had longer (62 days) mean residence time (MRT). LS showed the highest cumulative CO2-C and shortest MRT comparing with the terrestrial soils. The carbohydrates in DOM were positively correlated with CO2-C evolution and negatively correlated to phenols in the forest soils. Cropland was consistently an outlier in relationships between DOM chemistry and CO2-evolution, highlighting the unique effects that this land use on soil C cycling, which may be attributed the tillage practices. Our results suggest that C mineralization is closely related to the chemical composition of DOM and sensitive to its variation. Conversion of an aquatic ecosystem into a terrestrial ecosystem may alter the chemical structure of DOM, and then influences soil C mineralization. PMID:24905998

  18. Microvascular oxygen delivery-to-utilization mismatch at the onset of heavy-intensity exercise in optimally treated patients with CHF.

    PubMed

    Sperandio, Priscila Abreu; Borghi-Silva, Audrey; Barroco, Adriano; Nery, Luiz Eduardo; Almeida, Dirceu R; Neder, J Alberto

    2009-11-01

    Impaired muscle blood flow at the onset of heavy-intensity exercise may transiently reduce microvascular O(2) pressure and decrease the rate of O(2) transfer from capillary to mitochondria in chronic heart failure (CHF). However, advances in the pharmacological treatment of CHF (e.g., angiotensin-converting enzyme inhibitors and third-generation beta-blockers) may have improved microvascular O(2) delivery to an extent that intramyocyte metabolic inertia might become the main locus of limitation of O(2) uptake (Vo(2)) kinetics. We assessed the rate of change of pulmonary Vo(2) (Vo(2)(p)), (estimated) fractional O(2) extraction in the vastus lateralis (approximately Delta[deoxy-Hb+Mb] by near-infrared spectroscopy), and cardiac output (Qt) during high-intensity exercise performed to the limit of tolerance (Tlim) in 10 optimally treated sedentary patients (ejection fraction = 29 + or - 8%) and 11 controls. Sluggish Vo(2)(p) and Qt kinetics in patients were significantly related to lower Tlim values (P < 0.05). The dynamics of Delta[deoxy-Hb+Mb], however, were faster in patients than controls [mean response time (MRT) = 15.9 + or - 2.0 s vs. 19.0 + or - 2.9 s; P < 0.05] with a subsequent response "overshoot" being found only in patients (7/10). Moreover, tauVo(2)/MRT-[deoxy-Hb+Mb] ratio was greater in patients (4.69 + or - 1.42 s vs. 2.25 + or - 0.77 s; P < 0.05) and related to Qt kinetics and Tlim (R = 0.89 and -0.78, respectively; P < 0.01). We conclude that despite the advances in the pharmacological treatment of CHF, disturbances in "central" and "peripheral" circulatory adjustments still play a prominent role in limiting Vo(2)(p) kinetics and tolerance to heavy-intensity exercise in nontrained patients.

  19. Modelling thermal comfort of visitors at urban squares in hot and arid climate using NN-ARX soft computing method

    NASA Astrophysics Data System (ADS)

    Kariminia, Shahab; Motamedi, Shervin; Shamshirband, Shahaboddin; Piri, Jamshid; Mohammadi, Kasra; Hashim, Roslan; Roy, Chandrabhushan; Petković, Dalibor; Bonakdari, Hossein

    2016-05-01

    Visitors utilize the urban space based on their thermal perception and thermal environment. The thermal adaptation engages the user's behavioural, physiological and psychological aspects. These aspects play critical roles in user's ability to assess the thermal environments. Previous studies have rarely addressed the effects of identified factors such as gender, age and locality on outdoor thermal comfort, particularly in hot, dry climate. This study investigated the thermal comfort of visitors at two city squares in Iran based on their demographics as well as the role of thermal environment. Assessing the thermal comfort required taking physical measurement and questionnaire survey. In this study, a non-linear model known as the neural network autoregressive with exogenous input (NN-ARX) was employed. Five indices of physiological equivalent temperature (PET), predicted mean vote (PMV), standard effective temperature (SET), thermal sensation votes (TSVs) and mean radiant temperature ( T mrt) were trained and tested using the NN-ARX. Then, the results were compared to the artificial neural network (ANN) and the adaptive neuro-fuzzy inference system (ANFIS). The findings showed the superiority of the NN-ARX over the ANN and the ANFIS. For the NN-ARX model, the statistical indicators of the root mean square error (RMSE) and the mean absolute error (MAE) were 0.53 and 0.36 for the PET, 1.28 and 0.71 for the PMV, 2.59 and 1.99 for the SET, 0.29 and 0.08 for the TSV and finally 0.19 and 0.04 for the T mrt.

  20. Magnetic Resonance Therapy Improves Clinical Phenotype and EEG Alpha Power in Posttraumatic Stress Disorder

    PubMed Central

    Taghva, Alexander; Silvetz, Robert; Ring, Alex; Kim, Keun-young A.; Murphy, Kevin T.; Liu, Charles Y.; Jin, Yi

    2015-01-01

    Background: Posttraumatic stress disorder (PTSD) is a disabling and prevalent psychiatric disorder with limited effective treatment options. In addition to the clinical features of the disease, pathologic changes in the electroencephalogram (EEG), including decreased alpha power, have been reported. Objectives: To determine if magnetic brain stimulation can induce normalization of EEG abnormalities and improve clinical symptoms in PTSD in a preliminary, open-label evaluation. Materials and Methods: We reviewed prospectively-collected data on 21 veterans that were consecutively-treated for PTSD. Magnetic resonance therapy (MRT) was administered for two weeks at treatment frequencies based on frequency-domain analysis of each patient’s dominant alpha-band EEG frequencies and resting heart rate. Patients were evaluated on the PTSD checklist (PCL-M) and pre- and post-treatment EEGs before and after MRT. Results: Of the 21 patients who initiated therapy, 16 completed treatment. Clinical improvements on the PCL-M were seen in these 16 patients, with an average pre-treatment score of 54.9 and post-treatment score of 31.8 (P < 0.001). In addition, relative global EEG alpha-band (8 - 13 Hz) power increased from 32.0 to 38.5 percent (P = 0.013), and EEG delta-band (1 - 4 Hz) power decreased from 32.3 percent to 26.8 percent (P = 0.028). Conclusions: These open-label data show trends toward normalization of EEG and concomitant clinical improvement using magnetic stimulation for PTSD. PMID:26839865

  1. [Soil organic carbon pools and their turnover under two different types of forest in Xiao-xing'an Mountains, Northeast China].

    PubMed

    Gao, Fei; Jiang, Hang; Cui, Xiao-yang

    2015-07-01

    Soil samples collected from virgin Korean pine forest and broad-leaved secondary forest in Xiaoxing'an Mountains, Northeast China were incubated in laboratory at different temperatures (8, 18 and 28 °C) for 160 days, and the data from the incubation experiment were fitted to a three-compartment, first-order kinetic model which separated soil organic carbon (SOC) into active, slow, and resistant carbon pools. Results showed that the soil organic carbon mineralization rates and the cumulative amount of C mineralized (all based on per unit of dry soil mass) of the broad-leaved secondary forest were both higher than that of the virgin Korean pine forest, whereas the mineralized C accounted for a relatively smaller part of SOC in the broad-leaved secondary forest soil. Soil active and slow carbon pools decreased with soil depth, while their proportions in SOC increased. Soil resistant carbon pool and its contribution to SOC were both greater in the broad-leaved secondary forest soil than in the virgin Korean pine forest soil, suggesting that the broad-leaved secondary forest soil organic carbon was relatively more stable. The mean retention time (MRT) of soil active carbon pool ranged from 9 to 24 d, decreasing with soil depth; while the MRT of slow carbon pool varied between 7 and 24 a, increasing with soil depth. Soil active carbon pool and its proportion in SOC increased linearly with incubation temperature, and consequently, decreased the slow carbon pool. Virgin Korean pine forest soils exhibited a higher increasing rate of active carbon pool along temperature gradient than the broad-leaved secondary forest soils, indicating that the organic carbon pool of virgin Korean pine forest soil was relatively more sensitive to temperature change.

  2. Hydrogen-limited growth of hyperthermophilic methanogens at deep-sea hydrothermal vents.

    PubMed

    Ver Eecke, Helene C; Butterfield, David A; Huber, Julie A; Lilley, Marvin D; Olson, Eric J; Roe, Kevin K; Evans, Leigh J; Merkel, Alexandr Y; Cantin, Holly V; Holden, James F

    2012-08-21

    Microbial productivity at hydrothermal vents is among the highest found anywhere in the deep ocean, but constraints on microbial growth and metabolism at vents are lacking. We used a combination of cultivation, molecular, and geochemical tools to verify pure culture H(2) threshold measurements for hyperthermophilic methanogenesis in low-temperature hydrothermal fluids from Axial Volcano and Endeavour Segment in the northeastern Pacific Ocean. Two Methanocaldococcus strains from Axial and Methanocaldococcus jannaschii showed similar Monod growth kinetics when grown in a bioreactor at varying H(2) concentrations. Their H(2) half-saturation value was 66 μM, and growth ceased below 17-23 μM H(2), 10-fold lower than previously predicted. By comparison, measured H(2) and CH(4) concentrations in fluids suggest that there was generally sufficient H(2) for Methanocaldococcus growth at Axial but not at Endeavour. Fluids from one vent at Axial (Marker 113) had anomalously high CH(4) concentrations and contained various thermal classes of methanogens based on cultivation and mcrA/mrtA analyses. At Endeavour, methanogens were largely undetectable in fluid samples based on cultivation and molecular screens, although abundances of hyperthermophilic heterotrophs were relatively high. Where present, Methanocaldococcus genes were the predominant mcrA/mrtA sequences recovered and comprised ∼0.2-6% of the total archaeal community. Field and coculture data suggest that H(2) limitation may be partly ameliorated by H(2) syntrophy with hyperthermophilic heterotrophs. These data support our estimated H(2) threshold for hyperthermophilic methanogenesis at vents and highlight the need for coupled laboratory and field measurements to constrain microbial distribution and biogeochemical impacts in the deep sea.

  3. Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube x-ray source array

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Yuan, Hong; Burk, Laurel M.; Inscoe, Christy R.; Hadsell, Michael J.; Chtcheprov, Pavel; Lee, Yueh Z.; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based x-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board x-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 µm measured directly from the histology (537 µm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors.

  4. Rectal Cancer: Mucinous Carcinoma on Magnetic Resonance Imaging Indicates Poor Response to Neoadjuvant Chemoradiation

    SciTech Connect

    Oberholzer, Katja; Menig, Matthias; Kreft, Andreas; Schneider, Astrid; Junginger, Theodor; Heintz, Achim; Kreitner, Karl-Friedrich; Hoetker, Andreas M.; Hansen, Torsten; Dueber, Christoph; Schmidberger, Heinz

    2012-02-01

    Purpose: To assess response of locally advanced rectal carcinoma to chemoradiation with regard to mucinous status and local tumor invasion found at pretherapeutic magnetic resonance imaging (MRI). Methods and Materials: A total of 88 patients were included in this prospective study of patients with advanced mrT3 and mrT4 carcinomas. Carcinomas were categorized by MRI as mucinous (mucin proportion >50% within the tumor volume), and as nonmucinous. Patients received neoadjuvant chemoradiation consisting of 50.4 Gy (1.8 Gy/fraction) and 5-fluorouracil on Days 1 to 5 and Days 29 to 33. Therapy response was assessed by comparing pretherapeutic MRI with histopathology of surgical specimens (minimum distance between outer tumor edge and circumferential resection margin = CRM, T, and N category). Results: A mucinous carcinoma was found in 21 of 88 patients. Pretherapeutic mrCRM was 0 mm (median) in the mucinous and nonmucinous group. Of the 88 patients, 83 underwent surgery with tumor resection. The ypCRM (mm) at histopathology was significantly lower in mucinous carcinomas than in nonmucinous carcinomas (p {<=} 0.001). Positive resection margins (ypCRM {<=} 1 mm) were found more frequently in mucinous carcinomas than in nonmucinous ones (p {<=} 0.001). Treatment had less effect on local tumor stage in mucinous carcinomas than in nonmucinous carcinomas (for T downsizing, p = 0.012; for N downstaging, p = 0.007). Disease progression was observed only in patients with mucinous carcinomas (n = 5). Conclusion: Mucinous status at pretherapeutic MRI was associated with a noticeably worse response to chemoradiation and should be assessed by MRI in addition to local tumor staging to estimate response to treatment before it is initiated.

  5. Indocyanine Green Clearance Varies as a Function of N-Acetylcysteine Treatment in a Murine Model of Acetaminophen Toxicity

    PubMed Central

    Milesi-Hallé, Alessandra; Abdel-Rahman, Susan M.; Brown, Aliza; McCullough, Sandra S.; Letzig, Lynda; Hinson, Jack A.; James, Laura P.

    2011-01-01

    Standard assays to assess acetaminophen (APAP) toxicity in animal models include determination of ALT (alanine aminotransferase) levels and examination of histopathology of liver sections. However, these assays do not reflect the functional capacity of the injured liver. To examine a functional marker of liver injury, the pharmacokinetics of indocyanine green (ICG) were examined in mice treated with APAP, saline, or APAP followed by N-acetylcysteine (NAC) treatment. Male B6C3F1 mice were administered APAP (200 mg/kg IP) or saline. Two additional groups of mice received APAP followed by NAC at 1 or 4 h after APAP. At 24 h, mice were injected with ICG (10 mg/kg IV) and serial blood samples (0, 2, 10, 30, 50 and 75 min) were obtained for determination of serum ICG concentrations and ALT. Mouse livers were removed for measurement of APAP protein adducts and examination of histopathology. Toxicity (ALT values and histology) was significantly increased above saline treated mice in the APAP and APAP/NAC 4 h mice. Mice treated with APAP/NAC 1 h had complete protection from toxicity. APAP protein adducts were increased in all APAP treated groups and were highest in the APAP/NAC 1 h group. Pharmacokinetic analysis of ICG demonstrated that the total body clearance (ClT) of ICG was significantly decreased and the mean residence time (MRT) was significantly increased in the APAP mice compared to the saline mice. Mice treated with NAC at 1 h had ClT and MRT values similar to those of saline treated mice. Conversely, mice that received NAC at 4 h had a similar ICG pharmacokinetic profile to that of the APAP only mice. Prompt treatment with NAC prevented loss of functional activity while late treatment with NAC offered no improvement in ICG clearance at 24 h. ICG clearance in mice with APAP toxicity can be utilized in future studies testing the effects of novel treatments for APAP toxicity. PMID:21145883

  6. Male-typical visuospatial functioning in gynephilic girls with gender dysphoria — organizational and activational effects of testosterone

    PubMed Central

    Burke, Sarah M.; Kreukels, Baudewijntje P.C.; Cohen-Kettenis, Peggy T.; Veltman, Dick J.; Klink, Daniel T.; Bakker, Julie

    2016-01-01

    Background Sex differences in performance and regional brain activity during mental rotation have been reported repeatedly and reflect organizational and activational effects of sex hormones. We investigated whether adolescent girls with gender dysphoria (GD), before and after 10 months of testosterone treatment, showed male-typical brain activity during a mental rotation task (MRT). Methods Girls with GD underwent fMRI while performing the MRT twice: when receiving medication to suppress their endogenous sex hormones before onset of testosterone treatment, and 10 months later during testosterone treatment. Two age-matched control groups participated twice as well. Results We included 21 girls with GD, 20 male controls and 21 female controls in our study. In the absence of any group differences in performance, control girls showed significantly increased activation in frontal brain areas compared with control boys (pFWE = 0.012). Girls with GD before testosterone treatment differed significantly in frontal brain activation from the control girls (pFWE = 0.034), suggesting a masculinization of brain structures associated with visuospatial cognitive functions. After 10 months of testosterone treatment, girls with GD, similar to the control boys, showed increases in brain activation in areas implicated in mental rotation. Limitations Since all girls with GD identified as gynephilic, their resemblance in spatial cognition with the control boys, who were also gynephilic, may have been related to their shared sexual orientation rather than their shared gender identity. We did not account for menstrual cycle phase or contraceptive use in our analyses. Conclusion Our findings suggest atypical sexual differentiation of the brain in natal girls with GD and provide new evidence for organizational and activational effects of testosterone on visuospatial cognitive functioning. PMID:27070350

  7. Dynamic T{sub 2}-mapping during magnetic resonance guided high intensity focused ultrasound ablation of bone marrow

    SciTech Connect

    Waspe, Adam C.; Looi, Thomas; Mougenot, Charles; Amaral, Joao; Temple, Michael; Sivaloganathan, Siv; Drake, James M.

    2012-11-28

    Focal bone tumor treatments include amputation, limb-sparing surgical excision with bone reconstruction, and high-dose external-beam radiation therapy. Magnetic resonance guided high intensity focused ultrasound (MR-HIFU) is an effective non-invasive thermotherapy for palliative management of bone metastases pain. MR thermometry (MRT) measures the proton resonance frequency shift (PRFS) of water molecules and produces accurate (<1 Degree-Sign C) and dynamic (<5s) thermal maps in soft tissues. PRFS-MRT is ineffective in fatty tissues such as yellow bone marrow and, since accurate temperature measurements are required in the bone to ensure adequate thermal dose, MR-HIFU is not indicated for primary bone tumor treatments. Magnetic relaxation times are sensitive to lipid temperature and we hypothesize that bone marrow temperature can be determined accurately by measuring changes in T{sub 2}, since T{sub 2} increases linearly in fat during heating. T{sub 2}-mapping using dual echo times during a dynamic turbo spin-echo pulse sequence enabled rapid measurement of T{sub 2}. Calibration of T{sub 2}-based thermal maps involved heating the marrow in a bovine femur and simultaneously measuring T{sub 2} and temperature with a thermocouple. A positive T{sub 2} temperature dependence in bone marrow of 20 ms/ Degree-Sign C was observed. Dynamic T{sub 2}-mapping should enable accurate temperature monitoring during MR-HIFU treatment of bone marrow and shows promise for improving the safety and reducing the invasiveness of pediatric bone tumor treatments.

  8. A pH-responsive prodrug delivery system of 10-HCPT for controlled release and tumor targeting

    PubMed Central

    Liu, Yang; Li, Dan; Guo, Xinhong; Xu, Haiwei; Li, Zhi; Zhang, Yanling; Song, Chuanjun; Fan, Ruhan; Tang, Xing; Zhang, Zhenzhong

    2017-01-01

    We synthesized a pH-responsive conjugate of 10-hydroxycamptothecin-thiosemicarbazide-linear polyethylene glycol 2000 (PEG2000). The conjugate was confirmed by matrix-assisted laser desorption time of flight mass spectrometry, 1H NMR, and 13C NMR. The water solubility of the prodrug was increased by over 3,000 times; much longer body circulation time, higher tumor-targeting ability, and reduced toxicity were observed, compared with commercial 10-HCPT injection. The linker contains a pH-sensitive hydrazone bond, which breaks under low pH conditions in the tumor microenvironment. The conjugates showed good stability in phosphate-buffered saline (pH 7.4) and rat plasma. This amphiphilic conjugate could self-assemble into nanosized micelles of 80–100 nm. Cytotoxicity assay results indicate significantly higher efficacy of the conjugate (IC50 [half maximal inhibitory concentration] =0.117 µM on SW180 cells) than 10-HCPT solution (IC50 =0.241 µM on SW480 cells). Cellular uptake analysis suggested its rapid internalization and nuclear transport. Pharmacokinetic analysis of the conjugates demonstrated that the conjugate circulated for a longer time in the blood circulation system (T2/1 =10.516±1.158 h) than did 10-HCPT solution (T2/1 =1.859±1.385 h), and that it also enhanced the targeting and mean residence time (MRT0–inf =39.873±4.549 h) in the tumor site, compared with 10-HCPT (MRT0–inf =9.247±1.026 h). Finally, the conjugate demonstrated an increased tumor growth inhibition effect (TIR =82.66%±7.175%) in vivo and lower side effects than 10-HCPT (TIR =63.85%±5.233%). This prodrug holds great promise in improving therapeutic efficacy and overcoming multidrug resistance. PMID:28356739

  9. Weak extremely-low-frequency magnetic fields and regeneration in the planarian Dugesia tigrina

    SciTech Connect

    Jenrow, K.A.; Smith, C.H.; Liboff, A.R.

    1995-06-01

    Extremely-low-frequency (ELF), low-intensity magnetic fields have been shown to influence cell signaling processes in a variety of systems, both in vivo and in vitro. Similar effects have been demonstrated for nervous system development and neurite outgrowth. The authors report that regeneration in planaria, which incorporates many of these processes, is also affected by ELF magnetic fields. The rate of cephalic regeneration, reflected by the mean regeneration time (MRT), for planaria populations regenerating under continuous exposure to combined DC (78.4 {mu}T) and AC (60.0 Hz at 10.0 {mu}T{sub peak}) magnetic fields applied in parallel was found to be significantly delayed (P {much_lt} 0.001) by 48 {+-} 1 h relative to two different types of control populations (MRT {minus}140 {+-} 12 h). One control population was exposed to only the AC component of this field combination, while the other experienced only the ambient geomagnetic field. All measurements were conducted in a low-gradient, low-noise magnetics laboratory under well-maintained temperature conditions. This delay in regeneration was shown to be dependent on the planaria having a fixed orientation with respect to the magnetic field vectors. Results also indicate that this orientation-dependent transduction process does not result from Faraday induction but is consistent with a Ca{sup 2+} cyclotron resonance mechanism. Data interpretation also permits the tentative conclusion that the effect results from an inhibition of events at an early stage in the regeneration process before the onset of proliferation and differentiation.

  10. Microbeam Radiation Therapy: Tissue Dose Penetration and BANG-Gel Dosimetry of Thick-Beams' Array Intelacing

    SciTech Connect

    Dilmanian, F.; Romanelli, P; Zhong, Z; Wang, R; Wagshul, M; Kalef-Ezra, J; Maryanski, M; Rosen, E; Anschel, D

    2008-01-01

    The tissue-sparing effect of parallel, thin (narrower than 100em) synchrotron-generated X-ray planar beams (microbeams) in healthy tissues including the central nervous system (CNS) is known since early 1990s. This, together with a remarkable preferential tumoricidal effect of such beam arrays observed at high doses, has been the basis for labeling the method microbeam radiation therapy (MRT). Recent studies showed that beams as thick as 0.68mm ('thick microbeams') retain part of their sparing effect in the rat's CNS, and that two such orthogonal microbeams arrays can be interlaced to produce an unsegmented field at the target, thus producing focal targeting. We measured the half-value layer (HVL) of our 120-keV median-energy beam in water phantoms, and we irradiated stereotactically bis acrylamide nitrogen gelatin (BANG)-gel-filled phantoms, including one containing a human skull, with interlaced microbeams and imaged them with MRI. A 43-mm water HVL resulted, together with an adequately large peak-to-valley ratio of the microbeams' three-dimensional dose distribution in the vicinity of the 20mmx20mmx20mm target deep into the skull. Furthermore, the 80-20% dose falloff was a fraction of a millimeter as predicted by Monte Carlo simulations. We conclude that clinical MRT will benefit from the use of higher beam energies than those used here, although the current energy could serve certain neurosurgical applications. Furthermore, thick microbeams particularly when interlaced present some advantages over thin microbeams in that they allow the use of higher beam energies and they could conceivably be implemented with high power orthovoltage X-ray tubes.

  11. Development and validation of a rotor-gene real-time PCR assay for detection, identification, and quantification of Chlamydia trachomatis in a single reaction.

    PubMed

    Jalal, Hamid; Stephen, Hannah; Curran, Martin D; Burton, Janet; Bradley, Michelle; Carne, Christopher

    2006-01-01

    A multitarget real-time PCR (MRT-PCR) for detection of Chlamydia trachomatis DNA was developed and validated. There were three targets for amplification in a single reaction: the cryptic plasmid (CP), the major outer membrane protein (MOMP) gene, and an internal control. The assay had the following characteristics: (i) detection and confirmation of the presence of C. trachomatis DNA in a single reaction, (ii) detection of all genovars of C. trachomatis without any cross-reactivity with pathogenic bacteria or commensal organisms of the oropharynx and genital tract, (iii) a 95% probability of detection with three copies of MOMP and one copy of CP per reaction mixture, (iv) identification of the inhibition of amplification, (v) a quantitative dynamic range of 25 to 250,000 genome copies per reaction mixture, (vi) high intra- and interassay reproducibilities, and (vii) correct identification of all samples in the validation panel. There were 146 COBAS Amplicor PCR (Amplicor PCR)-positive samples and 122 Amplicor PCR-negative samples in the panel. MRT-PCR detected CP DNA alone in 6 (4%) Amplicor PCR-positive samples and both CP and MOMP DNAs in 140 (96%) of 146 Amplicor PCR-positive samples. The quantity of MOMP DNA in 95 (68%) of 140 samples was within the dynamic range of the assay. The median C. trachomatis load in these samples was 321 genome copies per reaction mixture (range, 26 to 40,137 genome copies per reaction mixture). Due to the inclusion of two different C. trachomatis-specific targets, the assay confirmed 259 (97%) of 268 results in a single reaction. This assay could be used in the qualitative format for the routine detection of C. trachomatis and in the quantitative format for study of the pathogenesis of C. trachomatis-associated diseases. The assay demonstrated the potential to eliminate the need for confirmatory testing in almost all samples, thus reducing the turnaround time and the workload.

  12. Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube x-ray source array.

    PubMed

    Zhang, Lei; Yuan, Hong; Burk, Laurel M; Inscoe, Christy R; Hadsell, Michael J; Chtcheprov, Pavel; Lee, Yueh Z; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-07

    Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based x-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board x-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 µm measured directly from the histology (537 µm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors.

  13. Hydrogen-limited growth of hyperthermophilic methanogens at deep-sea hydrothermal vents

    PubMed Central

    Ver Eecke, Helene C.; Butterfield, David A.; Huber, Julie A.; Lilley, Marvin D.; Olson, Eric J.; Roe, Kevin K.; Evans, Leigh J.; Merkel, Alexandr Y.; Cantin, Holly V.; Holden, James F.

    2012-01-01

    Microbial productivity at hydrothermal vents is among the highest found anywhere in the deep ocean, but constraints on microbial growth and metabolism at vents are lacking. We used a combination of cultivation, molecular, and geochemical tools to verify pure culture H2 threshold measurements for hyperthermophilic methanogenesis in low-temperature hydrothermal fluids from Axial Volcano and Endeavour Segment in the northeastern Pacific Ocean. Two Methanocaldococcus strains from Axial and Methanocaldococcus jannaschii showed similar Monod growth kinetics when grown in a bioreactor at varying H2 concentrations. Their H2 half-saturation value was 66 μM, and growth ceased below 17–23 μM H2, 10-fold lower than previously predicted. By comparison, measured H2 and CH4 concentrations in fluids suggest that there was generally sufficient H2 for Methanocaldococcus growth at Axial but not at Endeavour. Fluids from one vent at Axial (Marker 113) had anomalously high CH4 concentrations and contained various thermal classes of methanogens based on cultivation and mcrA/mrtA analyses. At Endeavour, methanogens were largely undetectable in fluid samples based on cultivation and molecular screens, although abundances of hyperthermophilic heterotrophs were relatively high. Where present, Methanocaldococcus genes were the predominant mcrA/mrtA sequences recovered and comprised ∼0.2–6% of the total archaeal community. Field and coculture data suggest that H2 limitation may be partly ameliorated by H2 syntrophy with hyperthermophilic heterotrophs. These data support our estimated H2 threshold for hyperthermophilic methanogenesis at vents and highlight the need for coupled laboratory and field measurements to constrain microbial distribution and biogeochemical impacts in the deep sea. PMID:22869718

  14. Excretion patterns of fluid and different sized particle passage markers in banteng (Bos javanicus) and pygmy hippopotamus (Hexaprotodon liberiensis): two functionally different foregut fermenters.

    PubMed

    Schwarm, Angela; Ortmann, Sylvia; Wolf, Christian; Streich, W Jürgen; Clauss, Marcus

    2008-05-01

    Processing of ingesta particles plays a crucial role in the digestive physiology of herbivores. In the ruminant forestomach different sized particles are stratified into a small and a large particle fraction and only the latter is regurgitated and remasticated to smaller, easier-to-digest particles. In contrast, it has been suggested that in non-ruminating foregut fermenters, such as hippopotamuses, larger particles should be selectively excreted since they tend to be digested at a slower rate and hence can be considered intake-limiting bulk. In our study we determined the mean retention time (MRT) of fluids and different sized particles (2 mm and 10 mm) in six pygmy hippos (Hexaprotodon liberiensis) and six banteng (Bos javanicus) on a diet of fresh grass at two intake levels. We used cobalt ethylendiamintetraacetate (Co-EDTA) as fluid and chromium (Cr)-mordanted fibre (2 mm) and cerium (Ce)-mordanted fibre (10 mm) as particle markers, mixed in the food. Average total tract MRT for fluid, small and large particles at the high intake level was 32, 76 and 73 h in pygmy hippos and 25, 56 and 60 h in banteng, and at the low intake level 39, 109, and 105 h in pygmy hippos and 22, 51 and 58 h in banteng, respectively. In accordance with the prediction, large particles moved faster than, or as fast as the small particles, through the gut of pygmy hippos. In contrast, large particles were excreted slower than the small particles in the ruminant of this study, the banteng. Pygmy hippos had longer retention times than the banteng, which probably compensate for the less efficient particle size reduction. Although the results were not as distinct as expected, most likely due to the fact that ingestive mastication of the larger particle marker could not be prevented, they confirm our hypothesis of a functional difference in selective particle retention between ruminating and non-ruminating foregut fermenters.

  15. Tuning the serum persistence of human serum albumin domain III:diabody fusion proteins

    PubMed Central

    Kenanova, Vania E.; Olafsen, Tove; Salazar, Felix B.; Williams, Lawrence E.; Knowles, Scott; Wu, Anna M.

    2010-01-01

    The long circulation persistence of human serum albumin (HSA) is enabled by its domain III (DIII) interaction with the neonatal Fc receptor (FcRn). A protein scaffold based on HSA DIII was designed. To modify the serum half life of the scaffold, residues H535, H510, and H464 were individually mutated to alanine. HSA DIII wild type (WT) and variants were fused to the anti-carcinoembryonic antigen (CEA) T84.66 diabody (Db), radiolabeled with 124I and injected into xenografted athymic mice for serial PET/CT imaging. All proteins targeted the CEA-positive tumor. The mean residence times (MRT) of the proteins, calculated by quantifying blood activity from the PET images, were: Db-DIII WT (56.7 h), H535A (25 h), H510A (20 h), H464A (17 h), compared with Db (2.9 h). Biodistribution confirmed the order of blood clearance from slow to fast: Db-DIII WT > H535A > H510A > H464A > Db with 4.0, 2.0, 1.8, 1.6 and 0.08 %ID/g of remaining blood activity at 51 h, respectively. This study demonstrates that attenuating the DIII–FcRn interaction provides a way of controlling the pharmacokinetics of the entire Db-DIII fusion protein without compromising tumor targeting. H464 appears to be most crucial for FcRn binding (greatest reduction in MRT), followed by H510 and H535. By mutating the DIII scaffold, we can dial serum kinetics for imaging or therapy applications. PMID:20802234

  16. Effects of subchronic malathion exposure on the pharmacokinetic disposition of pefloxacin.

    PubMed

    Suresh Babu, N; Malik, J K; Rao, G S; Aggarwal, Manoj; Ranganathan, V

    2006-09-01

    Malathion is one of the most extensively used organophosphorus pesticides applied in agriculture, mosquito eradication and in the control of animal ectoparasites and human body lice. The widespread use of malathion has raised concern over its potential to cause untoward health effects in humans, animals and birds. Malathion inhibits cytochrome P450 monooxygenases and has the potential to alter pharmacokinetic profiles of therapeutic agents that are metabolized in the liver. The present study was undertaken to evaluate the impact of subchronic exposure of malathion on the pharmacokinetic disposition of pefloxacin. Chickens were given either normal diet or malathion through food at a concentration of 1000ppm for 28 days. Subsequently, pefloxacin was administered either intravenously or orally (control) to birds fed normal diet and orally to malathion-exposed chickens at a dosage of 10mgkg(-1) body weight. Blood samples were drawn from the brachial vein at predetermined time intervals after drug administration. Plasma was separated and analyzed for pefloxacin by reverse-phase high performance liquid chromatography. The plasma concentration-time data were analyzed by non-compartmental techniques. Following intravenous administration of pefloxacin, elimination half-life (t(1/2β)), area under the plasma concentration-time curve (AUC) and mean residence time (MRT) were 8.2±0.7h, 66±9μghml(-1) and 10.5±1.1h, respectively, and when the drug was administered orally, the respective values of pharmacokinetic parameters were 8.2±0.4h, 31±3.1μghml(-1) and 11.7±0.6h. Malathion exposure significantly increased maximum plasma drug concentration, t(1/2β), AUC and MRT of pefloxacin to 54, 22, 117 and 37% of control, respectively. These findings provide evidence that subchronic malathion exposure markedly influences the elimination kinetics of pefloxacin which may be due to malathion-mediated inhibition of metabolism of pefloxacin.

  17. Pharmacokinetic comparisons of Paeoniflorin and Paeoniflorin-6'O-benzene sulfonate in rats via different routes of administration.

    PubMed

    Wang, Chun; Yuan, Jun; Zhang, Ling Ling; Wei, Wei

    2016-12-01

    1. The pharmacokinetics study of Paeoniflorin (Pae) and its acylated derivative (CP-25) was performed. 2. The structure of CP-25 was identified by mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). The rats were injected with CP-25(6, 12, 24 mg/kg) and orally treated with CP-25 (32, 64, 128 mg/kg), respectively. An high-performance liquid chromatography (HPLC) assay was developed to determine the plasma concentrations of Pae and CP-25. 3. The results of MS and NMR showed that the acylated product was Pae-6'O-benzene sulfonate (CP-25). The plasma levels in oral CP-25 groups were detectable, whereas those of Pae in the oral groups (25 and 50 mg/kg) were undetectable. More specifically, the Cmax values of oral CP-25 were 0.12, 0.19 and 0.44 μg/ml, and the corresponding t1/2β of CP-25 were 1.44, 2.12 and 2.11 h, respectively. In addition, the t1/2β values of intravenous CP-25 were 161.99, 152.81 and 153.76 min, respectively. 4. Compared with the venous pharmacokinetics parameters of Pae, those of the t1/2β, MRT, Vd and CL/F in the CP-25 groups increased noticeably. As expected, compared with oral parameters of Pae, those of t1/2a, t1/2β, AUC, MRT and Vd in the CP-25 group increased obviously. Finally, the absolute bioavailability of Pae and CP-25 were 3.6 and 10.6%, respectively. 5. Our results indicate that CP-25 is characterized by improved absorption, well distribution, lower clearance, long mean residence time, and moderate bioavailability in rats.

  18. Combined versus monotherapy or concurrent therapy for treatment of thalassaemia.

    PubMed

    Song, Ta-Shu; Hsieh, Yow-Wen; Peng, Ching-Tien; Chen, Tai-Lin; Lee, Hong-Zin; Chung, Jing-Gung; Hour, Mann-Jen

    2014-01-01

    A combined deferasirox (DFX) and deferiprone (DFP) treatment protocol for relieving thalassemia patients' iron-overload was designed and the pharmacokinetic study was performed by LC-MS/MS. For this open-label, randomized trial, eight patients were recruited and randomly allocated to different treatment regimens: (A) monotherapy with single oral dose of DFX 30 mg/kg, (B) monotherapy with DFP 80 mg/kg/day, twice daily, (C) combined therapy with DFX and DFP (DFX 30 mg/kg for first dose, DFP 40 mg/kg 7 hours later, and DFP 40 mg/kg after another 7 h) and (D) concurrent therapy with DFX 30 mg/kg and DFP 80 mg/kg. Descriptive statistics evaluated pharmacokinetic parameters, AUC0-t, AUC0-inf, Cmax, Tmax, T1/2 and MRT. A positive pharmacokinetic drug interaction was observed in combined therapy. In case of DFX, combined therapy tallied about 2-fold larger than monotherapy in AUC, 1.5-fold larger in Cmax, 1 h longer in Tmax, but 1 h shorter in T1/2. Regarding DFP, most such parameters of combined therapy concurred with monotherapy. Conversely, negative drug interaction was observed in concurrent therapy. With DFX, concurrent therapy attained 1.2- to 2.2-fold lower than monotherapy in AUC0-t and Cmax, 0.6-h shorter in Tmax, and 3-fold longer in T1/2. With DFP, concurrent therapy proved approximately 2-fold larger than monotherapy in AUC and Cmax, 2.5-fold longer in T1/2, and 1.4-fold longer in MRT. Follow-up of subjects' clinical examinations and subjective symptoms showed no adverse events. Our findings showed the combined therapy had advantages, safe, convenient and painless for patients, over the existing concurrent therapy with deferoxamine (DFO) and DFX.

  19. Water ages of 20 groundwater bodies and its relevance for the implementation of the European Water Framework Directive

    NASA Astrophysics Data System (ADS)

    Kralik, Martin; Brielmann, Heike; Humer, Franko; Grath, Johannes; Sültenfuß, Jürgen; Philippitsch, Rudolf

    2015-04-01

    The 'Mean Residence Time' (MRT) of groundwater is required to develop reliable hydrogeological concepts of groundwater bodies as a prerequisite for a qualified monitoring and risk assessment. MRTs from monitoring wells help to assess if groundwater bodies are 'at risk' or 'not at risk' failing to meet good groundwater quantitative and chemical status according to the Water Framework Directive and therefore not being able to use the groundwater as drinking water or industrial water resource. A combination of 18O/2H, 3H, 3H/3He and in some cases additional CFC, SF6, 85Kr and 35S measurements allow to calculate reliable MRTs in 20 groundwater bodies covering 13% (approx.10719 km2) of the Austrian territory. Altogether 401 groundwater wells and springs from the existing groundwater monitoring network were analysed for δ18O (n=1500), 3H (n=800) and 3He (n=327) since 2006. Considering both the fact that monitoring wells may have multiple or long well screens and the inherent uncertainties of groundwater age dating techniques, age estimations were classified into 5 categories of short ( 50years) mean residence times for each monitoring site. Subsequently, median values of the MRT categories were assigned to each investigated groundwater body. These are valuable information to fix extraction rates, to set measures to improve the land use and groundwater protection and to validate hydrogeological concepts. Generally, MRTs of groundwater bodies increase from shallow Alpine groundwater bodies over deeper Alpine valley-aquifers to longer MRTs in the Pannonian climate range in the east of Austria.

  20. Pharmacokinetic comparisons by UPLC-MS/MS of isomer paeoniflorin and albiflorin after oral administration decoctions of single-herb Radix Paeoniae Alba and Zengmian Yiliu prescription to rats.

    PubMed

    Gong, Can; Yang, Hong; Wei, Hai; Qi, Cong; Wang, Chang-Hong

    2015-03-01

    Zengmian Yiliu (ZMYL), a traditional Chinese formula, is designed to improve clinical efficacy and reduce adverse effects in combination with cisplatin in ovarian cancer chemotherapy. In ZMYL, Radix Paeoniae Alba (RPA, made from root of Paeonia lactiflora Pall.) acts as an adjunctive drug in cancer treatment by ameliorating side effects induced by radio- and chemotherapy. The pharmacokinetics differences between isomer albiflorin and paeoniflorin, the main components of RPA, after oral administration decoction of single-herb RPA and ZMYL were compared using a sensitive and accurate UPLC-MS/MS. The results indicate that there are statistically significant differences between the pharmacokinetic parameters: decreasing area under the plasma concentration-time curve (AUC), maximum concentration (Cmax ), elimination rate constant (Ke ) and increasing apparent volume of distribution (Vd ) and clearance (CL) for albiflorin, increasing distribution half-life (T1/2d ) and decreasing elimination half-life (T1/2e ), distribution rate constant (Kd ) and absorption rate constant (Ka ) for paeoniflorin in the ZMYL group compared with the single-herb RPA group. In comparison with albiflorin, the pharmacokinetic parameters of paeoniflorin included significantly increasing mean residence time (MRT) and Vd , decreasing CL and Ke in the single-herb RPA group and increasing MRT and T1/2d and decreasing CL, Ke and Kd in the ZMYL group. Both paeoniflorin and albiflorin are more likely, as the main active ingredients in RPA and ZMYL, to play a variety of pharmacological effects, and herb-herb interactions occur, resulting in different pharmacokinetics of albiflorin and paeoniflorin in RPA and ZMYL.

  1. Genetics of Bladder Malignant Tumors in Childhood

    PubMed Central

    Zangari, Andrea; Zaini, Johan; Gulìa, Caterina

    2016-01-01

    Bladder masses are represented by either benign or malignant entities. Malignant bladder tumors are frequent causes of disease and death in western countries. However, in children they are less common. Additionally, different features are found in childhood, in which non epithelial tumors are more common than epithelial ones. Rhabdomyosarcoma is the most common pediatric bladder tumor, but many other types of lesions may be found, such as malignant rhabdoid tumor (MRT), inflammatory myofibroblastic tumor and neuroblastoma. Other rarer tumors described in literature include urothelial carcinoma and other epithelial neoplasms. Rhabdomyosarcoma is associated to a variety of genetic syndromes and many genes are involved in tumor development. PAX3-FKHR and PAX7-FKHR (P-F) fusion state has important implications in the pathogenesis and biology of RMS, and different genes alterations are involved in the pathogenesis of P-F negative and embryonal RMS, which are the subsets of tumors most frequently affecting the bladder. These genes include p53, MEF2, MYOG, Ptch1, Gli1, Gli3, Myf5, MyoD1, NF1, NRAS, KRAS, HRAS, FGFR4, PIK3CA, CTNNB1, FBXW7, IGF1R, PDGFRA, ERBB2/4, MET, BCOR. Malignant rhabdoid tumor (MRT) usually shows SMARCB1/INI1 alterations. Anaplastic lymphoma kinase (ALK) gene translocations are the most frequently associated alterations in inflammatory myofibroblastic tumor (IMT). Few genes alterations in urothelial neoplasms have been reported in the paediatric population, which are mainly related to deletion of p16/lnk4, overexpression of CK20 and overexpression of p53. Here, we reviewed available literature to identify genes associated to bladder malignancies in children and discussed their possible relationships with these tumors. PMID:27013922

  2. Pharmacokinetics and tissue distribution after intravenous administration of a single dose of amphotericin B cochleates, a new lipid-based delivery system.

    PubMed

    Segarra, Ignacio; Movshin, Diane A; Zarif, Leila

    2002-08-01

    Model independent pharmacokinetic analysis of intravenous (iv) amphotericin B cochleates (CAMB), a new lipid-based drug delivery system, in mice (0.625 mg/kg) shows a two-phase disposition profile in blood [area under the curve of concentration versus time from time zero to infinity (AUC(0-infinity)) = 1.01 microg. h/mL, half-life (t((1/2))) = 11.68 h, volume of distribution at steady state (V(ss)) = 9.59 L/kg, clearance (CL) = 10.36 mL/min/kg and mean residence time from time 0 to infinity (MRT(0-infinity)) = 15.41 h). In target tissues, maximum time (t(max)) ranged from 2 min (spleen and lung) to 10 min (liver) and lungs presented the highest AMB concentration (16.4 microg. h/g) followed by liver (8.56 microg/g), and spleen (6.63 microg/g). In addition, liver and spleen presented the longest elution half-life (75.03 and 66.71 h, respectively), MRT(0-infinity) (98.4 and 86.3 h, respectively), and AMB exposure:liver AUC(0-infinity) = 474 and 116.4 microg. h/g for the spleen. The large V(ss) and the extensive tissue AUC indicate large and efficient ability of cochleates to penetrate and deliver AMB. Differences in tissue uptake mechanism and pharmacokinetic data suggest a crucial role of macrophages in CAMB clearance from blood as well as an essential role of the liver and the spleen in AMB distribution to target tissues.

  3. Interactive control of minerals, wildfire, and erosion on soil carbon stabilization in conifer ecosystems of the western U.S.

    NASA Astrophysics Data System (ADS)

    Rasmussen, C.

    2014-12-01

    Answering the question of what controls the fate and stabilization of organic carbon in forest soils is central to understanding the role of western US ecosystems in mitigating climate change, optimizing forest management, and quantifying local and regional terrestrial carbon budgets. Over half of forest soil C is stored belowground, stabilized by a number of separate, but interacting physical, chemical and biological mechanisms. Here we synthesize data from a series of field and laboratory studies focused on identifying mineral, physical, and landscape position controls on belowground C stabilization mechanisms in western U.S. conifer ecosystems. Results from these studies demonstrate an important for role for short-range-order Fe- and Al-oxyhydroxides and Al-humus complexes in C stabilization, and that the soil mineral assemblage moderates C cycling via control on partitioning of C into physical fractions ("free", "occluded", "mineral") with varying MRT and chemistry. Measures of occluded fraction chemical composition by 13C-NMR indicate this fraction is 2-5 times more enriched in pyrogenic C than the bulk soil and that this fraction is on the order of ~25 to 65% charred materials. Radiocarbon analyses of a large set of conifer soil samples from California and Arizona further indicate the occluded fraction is generally older than either the free light or mineral fraction. In particular, soil C in convergent, water and sediment gathering portions of the landscape are enriched in long MRT charred materials. These results indicate an important role for the interaction of soil mineral assemblage, wildfire, and erosion in controlling belowground C storage and stabilization in western conifer forests. Drought and wildfire are expected to increase with climate change and thus may exert significant control on belowground C storage directly through biochemical and physical changes in aboveground biomass, production of charred materials, and indirectly via post

  4. Multiple-relaxation-time lattice Boltzmann kinetic model for combustion.

    PubMed

    Xu, Aiguo; Lin, Chuandong; Zhang, Guangcai; Li, Yingjun

    2015-04-01

    To probe both the hydrodynamic nonequilibrium (HNE) and thermodynamic nonequilibrium (TNE) in the combustion process, a two-dimensional multiple-relaxation-time (MRT) version of lattice Boltzmann kinetic model (LBKM) for combustion phenomena is presented. The chemical energy released in the progress of combustion is dynamically coupled into the system by adding a chemical term to the LB kinetic equation. Aside from describing the evolutions of the conserved quantities, the density, momentum, and energy, which are what the Navier-Stokes model describes, the MRT-LBKM presents also a coarse-grained description on the evolutions of some nonconserved quantities. The current model works for both subsonic and supersonic flows with or without chemical reaction. In this model, both the specific-heat ratio and the Prandtl number are flexible, the TNE effects are naturally presented in each simulation step. The model is verified and validated via well-known benchmark tests. As an initial application, various nonequilibrium behaviors, including the complex interplays between various HNEs, between various TNEs, and between the HNE and TNE, around the detonation wave in the unsteady and steady one-dimensional detonation processes are preliminarily probed. It is found that the system viscosity (or heat conductivity) decreases the local TNE, but increases the global TNE around the detonation wave, that even locally, the system viscosity (or heat conductivity) results in two kinds of competing trends, to increase and to decrease the TNE effects. The physical reason is that the viscosity (or heat conductivity) takes part in both the thermodynamic and hydrodynamic responses.

  5. Microbial carbon recycling - an underestimated process controlling soil carbon dynamics - Part 1: A long-term laboratory incubation experiment

    NASA Astrophysics Data System (ADS)

    Basler, A.; Dippold, M.; Helfrich, M.; Dyckmans, J.

    2015-10-01

    Independent of its chemical structure carbon (C) persists in soil for several decades, controlled by stabilization and recycling. To disentangle the importance of the two factors on the turnover dynamics of soil sugars, an important compound of soil organic matter (SOM), a 3-year incubation experiment was conducted on a silty loam soil under different types of land use (arable land, grassland and forest) by adding 13C-labelled glucose. The compound-specific isotope analysis of soil sugars was used to examine the dynamics of different sugars during incubation. Sugar dynamics were dominated by a pool of high mean residence times (MRT) indicating that recycling plays an important role for sugars. However, this was not substantially affected by soil C content. Six months after label addition the contribution of the label was much higher for microbial biomass than for CO2 production for all examined land use types, corroborating that substrate recycling was very effective within the microbial biomass. Two different patterns of tracer dynamics could be identified for different sugars: while fucose and mannose showed highest label contribution at the beginning of the incubation with a subsequent slow decline, galactose and rhamnose were characterized by slow label incorporation with subsequently constant levels, which indicates that recycling is dominating the dynamics of these sugars. This may correspond to (a) different microbial growing strategies (r and K-strategist) or (b) location within or outside the cell membrane (lipopolysaccharides vs. exopolysaccharides) and thus be subject of different re-use within the microbial food web. Our results show how the microbial community recycles substrate very effectively and that high losses of substrate only occur during initial stages after substrate addition. This study indicates that recycling is one of the major processes explaining the high MRT observed for many SOM fractions and thus is crucial for understanding the

  6. Modulating mitochondrial quality in disease transmission: towards enabling mitochondrial DNA disease carriers to have healthy children

    PubMed Central

    Diot, Alan; Dombi, Eszter; Lodge, Tiffany; Liao, Chunyan; Morten, Karl; Carver, Janet; Wells, Dagan; Child, Tim; Johnston, Iain G.; Williams, Suzannah; Poulton, Joanna

    2016-01-01

    One in 400 people has a maternally inherited mutation in mtDNA potentially causing incurable disease. In so-called heteroplasmic disease, mutant and normal mtDNA co-exist in the cells of carrier women. Disease severity depends on the proportion of inherited abnormal mtDNA molecules. Families who have had a child die of severe, maternally inherited mtDNA disease need reliable information on the risk of recurrence in future pregnancies. However, prenatal diagnosis and even estimates of risk are fraught with uncertainty because of the complex and stochastic dynamics of heteroplasmy. These complications include an mtDNA bottleneck, whereby hard-to-predict fluctuations in the proportions of mutant and normal mtDNA may arise between generations. In ‘mitochondrial replacement therapy’ (MRT), damaged mitochondria are replaced with healthy ones in early human development, using nuclear transfer. We are developing non-invasive alternatives, notably activating autophagy, a cellular quality control mechanism, in which damaged cellular components are engulfed by autophagosomes. This approach could be used in combination with MRT or with the regular management, pre-implantation genetic diagnosis (PGD). Mathematical theory, supported by recent experiments, suggests that this strategy may be fruitful in controlling heteroplasmy. Using mice that are transgenic for fluorescent LC3 (the hallmark of autophagy) we quantified autophagosomes in cleavage stage embryos. We confirmed that the autophagosome count peaks in four-cell embryos and this correlates with a drop in the mtDNA content of the whole embryo. This suggests removal by mitophagy (mitochondria-specific autophagy). We suggest that modulating heteroplasmy by activating mitophagy may be a useful complement to mitochondrial replacement therapy. PMID:27528757

  7. Herbivorous reptiles and body mass: effects on food intake, digesta retention, digestibility and gut capacity, and a comparison with mammals.

    PubMed

    Franz, Ragna; Hummel, Jürgen; Müller, Dennis W H; Bauert, Martin; Hatt, Jean-Michel; Clauss, Marcus

    2011-01-01

    Differences in the allometric scaling between gut capacity (with body mass, BM¹·⁰⁰) and food intake (with BM⁰·⁷⁵) should theoretically result in a scaling of digesta retention time with BM⁰·²⁵ and therefore a higher digestive efficiency in larger herbivores. This concept is an important part of the so-called 'Jarman-Bell principle' (JBP) that explains niche differentiation along a body size gradient in terms of digestive physiology. Empirical data in herbivorous mammals, however, do not confirm the scaling of retention time, or of digestive efficiency, with body mass. Here, we test these concepts in herbivorous reptiles, adding data of an experiment that measured food intake, digesta retention, digestibility and gut capacity in 23 tortoises (Testudo graeca, T. hermanni , Geochelone nigra, G. sulcata, Dipsochelys dussumieri) across a large BM range (0.5-180 kg) to a literature data collection. While dry matter gut fill scaled to BM¹·⁰⁷ and dry matter intake to BM⁰·⁷⁶, digesta mean retention time (MRT) scaled to BM⁰·¹⁷; the scaling exponent was not significantly different from zero for species > 1 kg. Food intake level was a major determinant of MRT across reptiles and mammals. In contrast to dietary fibre level, BM was not a significant contributor to dry matter digestibility in a General Linear Model. Digestibility coefficients in reptiles depended on diet nutrient composition in a similar way as described in mammals. Although food intake is generally lower and digesta retention longer in reptiles than in mammals, digestive functions scale in a similar way in both clades, indicating universal principles in herbivore digestive physiology. The reasons why the theoretically derived JBP has little empirical support remain to be investigated. Until then, the JBP should not be evoked to explain niche differentiation along a body size axis in terms of digestive physiology.

  8. The influence of triple energy window scatter correction on activity quantification for 1 7 7Lu molecular radiotherapy

    NASA Astrophysics Data System (ADS)

    Robinson, Andrew P.; Tipping, Jill; Cullen, David M.; Hamilton, David

    2016-07-01

    Accurate activity quantification is the foundation for all methods of radiation dosimetry for molecular radiotherapy (MRT). The requirements for patient-specific dosimetry using single photon emission computed tomography (SPECT) are challenging, particularly with respect to scatter correction. In this paper data from phantom studies, combined with results from a fully validated Monte Carlo (MC) SPECT camera simulation, are used to investigate the influence of the triple energy window (TEW) scatter correction on SPECT activity quantification for {{}1 7 7} Lu MRT. Results from phantom data show that; (1) activity quantification for the total counts in the SPECT field-of-view demonstrates a significant overestimation in total activity recovery when TEW scatter correction is applied at low activities (≤slant 200 MBq). (2) Applying the TEW scatter correction to activity quantification within a volume-of-interest with no background activity provides minimal benefit. (3) In the case of activity distributions with background activity, an overestimation of recovered activity of up to 30% is observed when using the TEW scatter correction. Data from MC simulation were used to perform a full analysis of the composition of events in a clinically reconstructed volume of interest. This allowed, for the first time, the separation of the relative contributions of partial volume effects (PVE) and inaccuracies in TEW scatter compensation to the observed overestimation of activity recovery. It is shown, that even with perfect partial volume compensation, TEW scatter correction can overestimate activity recovery by up to 11%. MC data is used to demonstrate that even a localized and optimized isotope-specific TEW correction cannot reflect a patient specific activity distribution without prior knowledge of the complete activity distribution. This highlights the important role of MC simulation in SPECT activity quantification.

  9. Optically erasable samarium-doped fluorophosphate glasses for high-dose measurements in microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Morrell, B.; Okada, G.; Vahedi, S.; Koughia, C.; Edgar, A.; Varoy, C.; Belev, G.; Wysokinski, T.; Chapman, D.; Sammynaiken, R.; Kasap, S. O.

    2014-02-01

    Previous work has demonstrated that fluorophosphate (FP) glasses doped with trivalent samarium (Sm3+) can be used as a dosimetric detector in microbeam radiation therapy (MRT) to measure high radiation doses and large dose variations with a resolution in the micrometer range. The present work addresses the use of intense optical radiation at 405 nm to erase the recorded dose information in Sm3+-doped FP glass plates and examines the underlying physics. We have evaluated both the conversion and optical erasure of Sm3+-doped FP glasses using synchrotron-generated high-dose x-rays at the Canadian Light Source. The Sm-ion valency conversion is accompanied by the appearance of x-ray induced optical absorbance due to the trapping of holes and electrons into phosphorus-oxygen hole (POHC) and electron (POEC) capture centers. Nearly complete Sm2+ to Sm3+ reconversion (erasure) may be achieved by intense optical illumination. Combined analysis of absorbance and electron spin resonance measurements indicates that the optical illumination causes partial disappearance of the POHC and the appearance of new POEC. The suggested model for the observed phenomena is based on the release of electrons during the Sm2+ to Sm3+ reconversion process, the capture of these electrons by POHC (and hence their disappearance), or by PO groups, with the appearance of new and/or additional POEC. Optical erasure may be used as a practical means to erase the recorded data and permits the reuse of these Sm-doped FP glasses in monitoring dose in MRT.

  10. Genetic variation in GABRB3 is associated with Asperger syndrome and multiple endophenotypes relevant to autism

    PubMed Central

    2013-01-01

    Background Autism spectrum conditions (ASC) are associated with deficits in social interaction and communication, alongside repetitive, restricted, and stereotyped behavior. ASC is highly heritable. The gamma-aminobutyric acid (GABA)-ergic system has been associated consistently with atypicalities in autism, in both genetic association and expression studies. A key component of the GABA-ergic system is encoded by the GABRB3 gene, which has been previously implicated both in ASC and in individual differences in empathy. Methods In this study, 45 genotyped single nucleotide polymorphisms (SNPs) within GABRB3 were tested for association with Asperger syndrome (AS), and related quantitative traits measured through the following tests: the Empathy Quotient (EQ), the Autism Spectrum Quotient (AQ), the Systemizing Quotient-Revised (SQ-R), the Embedded Figures Test (EFT), the Reading the Mind in the Eyes Test (RMET), and the Mental Rotation Test (MRT). Two-loci, three-loci, four-loci haplotype analyses, and one seven-loci haplotype analysis were also performed in the AS case–control sample. Results Three SNPs (rs7180158, rs7165604, rs12593579) were significantly associated with AS, and two SNPs (rs9806546, rs11636966) were significantly associated with EQ. Two SNP-SNP pairs, rs12438141-rs1035751 and rs12438141-rs7179514, showed significant association with variation in the EFT scores. One SNP-SNP pair, rs7174437-rs1863455, was significantly associated with variation in the MRT scores. Additionally, a few haplotypes, including a 19 kb genomic region that formed a linkage disequilibrium (LD) block in our sample and contained several nominally significant SNPs, were found to be significantly associated with AS. Conclusion The current study confirms the role of GABRB3 as an important candidate gene in both ASC and normative variation in related endophenotypes. PMID:24321478

  11. Evaluation of the effectiveness of 3D vascular stereoscopic models in anatomy instruction for first year medical students.

    PubMed

    Cui, Dongmei; Wilson, Timothy D; Rockhold, Robin W; Lehman, Michael N; Lynch, James C

    2017-01-01

    The head and neck region is one of the most complex areas featured in the medical gross anatomy curriculum. The effectiveness of using three-dimensional (3D) models to teach anatomy is a topic of much discussion in medical education research. However, the use of 3D stereoscopic models of the head and neck circulation in anatomy education has not been previously studied in detail. This study investigated whether 3D stereoscopic models created from computed tomographic angiography (CTA) data were efficacious teaching tools for the head and neck vascular anatomy. The test subjects were first year medical students at the University of Mississippi Medical Center. The assessment tools included: anatomy knowledge tests (prelearning session knowledge test and postlearning session knowledge test), mental rotation tests (spatial ability; presession MRT and postsession MRT), and a satisfaction survey. Results were analyzed using a Wilcoxon rank-sum test and linear regression analysis. A total of 39 first year medical students participated in the study. The results indicated that all students who were exposed to the stereoscopic 3D vascular models in 3D learning sessions increased their ability to correctly identify the head and neck vascular anatomy. Most importantly, for students with low-spatial ability, 3D learning sessions improved postsession knowledge scores to a level comparable to that demonstrated by students with high-spatial ability indicating that the use of 3D stereoscopic models may be particularly valuable to these students with low-spatial ability. Anat Sci Educ 10: 34-45. © 2016 American Association of Anatomists.

  12. Indocyanine green clearance varies as a function of N-acetylcysteine treatment in a murine model of acetaminophen toxicity.

    PubMed

    Milesi-Hallé, Alessandra; Abdel-Rahman, Susan M; Brown, Aliza; McCullough, Sandra S; Letzig, Lynda; Hinson, Jack A; James, Laura P

    2011-02-01

    Standard assays to assess acetaminophen (APAP) toxicity in animal models include determination of ALT (alanine aminotransferase) levels and examination of histopathology of liver sections. However, these assays do not reflect the functional capacity of the injured liver. To examine a functional marker of liver injury, the pharmacokinetics of indocyanine green (ICG) were examined in mice treated with APAP, saline, or APAP followed by N-acetylcysteine (NAC) treatment.Male B6C3F1 mice were administered APAP (200 mg/kg IP) or saline. Two additional groups of mice received APAP followed by NAC at 1 or 4 h after APAP. At 24 h, mice were injected with ICG (10 mg/kg IV) and serial blood samples (0, 2, 10, 30, 50 and 75 min) were obtained for determination of serum ICG concentrations and ALT. Mouse livers were removed for measurement of APAP protein adducts and examination of histopathology. Toxicity (ALT values and histology) was significantly increased above saline treated mice in the APAP and APAP/NAC 4 h mice. Mice treated with APAP/NAC 1 h had complete protection from toxicity. APAP protein adducts were increased in all APAP treated groups and were highest in the APAP/NAC 1 h group. Pharmacokinetic analysis of ICG demonstrated that the total body clearance (Cl(T)) of ICG was significantly decreased and the mean residence time (MRT) was significantly increased in the APAP mice compared to the saline mice. Mice treated with NAC at 1 h had Cl(T) and MRT values similar to those of saline treated mice. Conversely, mice that received NAC at 4 h had a similar ICG pharmacokinetic profile to that of the APAP only mice. Prompt treatment with NAC prevented loss of functional activity while late treatment with NAC offered no improvement in ICG clearance at 24 h. ICG clearance in mice with APAP toxicity can be utilized in future studies testing the effects of novel treatments for APAP toxicity.

  13. Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube X-ray source array

    PubMed Central

    Zhang, Lei; Yuan, Hong; Burk, Laurel M; Inscoe, Christy R; Hadsell, Michael J; Chtcheprov, Pavel; Lee, Yueh Z; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-01-01

    Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based X-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board X-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 μm measured directly from the histology (537 μm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors. PMID:24556798

  14. Effects of hormonal contraceptives on mental rotation and verbal fluency.

    PubMed

    Griksiene, Ramune; Ruksenas, Osvaldas

    2011-09-01

    Cognitive abilities, such as verbal fluency and mental rotation, are most sensitive to changes in sex steroids but poorly studied in the context of hormonal contraceptive usage. Therefore, we investigated the performance of mental rotation and verbal fluency in young (21.5±1.8 years) healthy oral contraceptive (OC) users (23 women) and non-users (20 women) during the follicular, ovulatory and luteal phases of the menstrual cycle. Salivary 17β-estradiol, progesterone and testosterone levels were assayed to evaluate hormonal differences between groups and the phases of the menstrual cycle. To assess the effects of progestins having androgenic/anti-androgenic properties, OC users were subdivided into the third and new generation OC users. In addition, positive and negative affects as factors possibly affecting cognitive performance were evaluated. Salivary 17β-estradiol and progesterone levels were significantly lower in hormonal contraception users. Level of salivary testosterone was slightly lower in the OC users group with significant difference only during ovulatory phase. Naturally cycling women performed better on verbal fluency task as compared to OC users. Subjects who used the third generation (androgenic) OCs generated significantly fewer words as compared to new generation (anti-androgenic) OC users and non-users. The third generation OC users demonstrated significantly longer RT in MRT task as compared to non-users. The MRT, verbal fluency and mood parameters did not depend on the phase of menstrual cycle. The parameters of the PANAS (Positive and Negative Affect Schedule) scales did not differ between OC users and non-users. Our findings show that hormonal contraception has an impact on verbal and spatial abilities. Different performances between users of oral contraceptives with androgenic and anti-androgenic properties suggest an essential role for the progestins contained in OCs on cognitive performance.

  15. Chronostratigraphical investigations on Pleistocene fluvioglacial terraces of NW-Austria

    NASA Astrophysics Data System (ADS)

    Terhorst, B.

    2009-04-01

    of loess loam and redeposited material. However, four to five interglacial paleosols are developed inside the studied sequences. Paleomagnetical investigations are leading to the assumption that different Middle Pleistocene excursions could provide chronological data in the future. Terhorst, B., 2007. Korrelation von mittelpleistozänen Löß-/Paläobodensequenzen in Oberösterreich mit einer marinen Sauerstoffisotopenkurve. E & G, Quaternary Science Journal, 56/3: 172 - 185. Terhorst, B., Frechen, M. and Reitner, J., 2002 Chronostratigraphische Ergebnisse aus Lößprofilen der Inn- und Traun-Hochterrassen in Oberösterreich. - Z. Geomorph. N.F., Suppl.-Bd., 127: 213 -232, Berlin, Stuttgart (Gebr. Bornträger).

  16. Phenology in Germany in the 20th century : methods, analyses and models

    NASA Astrophysics Data System (ADS)

    Schaber, Jörg

    2002-07-01

    Perioden mit unterschiedlichem Trendverhalten identifiziert werden. - Es gab deutliche Unterschiede in den Trends von frühen und späten Frühjahrsphasen. Die frühen Frühjahrsphasen haben sich stetig verfrüht, mit deutlicher Verfrühung zwischen 1931 und 1948, moderater Verfrühung zwischen 1948 und 1984 und starker Verfrühung zwischen 1984 und 1999. Die späten Frühjahrsphasen hingegen, wechselten ihr Trendverhalten in diesen Perioden von einer Verfrühung zu einer deutlichen Verspätung wieder zu einer starken Verfrühung. Dieser Unterschied in der Trendentwicklung zwischen frühen und späten Frühjahrsphasen konnte auch für ganz Deutschland in den Perioden 1951 bis 1984 und 1984 bis 1999 beobachtet werden. Der bestimmende Einfluss der Temperatur auf die Frühjahrsphasen und ihr modifizierender Einfluss auf die Herbstphasen konnte bestätigt werden. Es zeigt sich jedoch, dass - die Phänologie bestimmende Funktionen der Temperatur nicht mit einem globalen jährlichen CO2 Signal korreliert waren, welches als Index für die globale Erwärmung verwendet wurde - ein Index für grossräumige regionale Zirkulationsmuster (NAO-Index) nur zu einem kleinen Teil die beobachtete phänologischen Variabilität erklären konnte. Das beobachtete unterschiedliche Trendverhalten zwischen frühen und späten Frühjahrsphasen konnte auf die unterschiedliche Entwicklung von März- und Apriltemperaturen zurückgeführt werden. Während sich die Märztemperaturen im Laufe des 20. Jahrhunderts mit einer zunehmenden Variabilität in den letzten 50 Jahren stetig erhöht haben, haben sich die Apriltemperaturen zwischen dem Ende der 1940er und Mitte der 1980er merklich abgekühlt und dann wieder deutlich erwärmt. Es wurde geschlussfolgert, dass die Verfrühungen in der Frühjahrsphänologie in den letzten Dekaden Teile multi-dekadischer Fluktuationen sind, welche sich nach Spezies und relevanter saisonaler Temperatur unterscheiden. Aufgrund dieser Fluktuationen konnte kein Zusammenhang

  17. Indirect comparison of lixisenatide versus neutral protamine Hagedorn insulin as add-on to metformin and sulphonylurea in patients with type 2 diabetes mellitus.

    PubMed

    Fournier, Marie; Germe, Maeva; Theobald, Karlheinz; Scholz, Gerhard H; Lehmacher, Walter

    2014-01-01

    Zielsetzung: Derzeit mangelt es an direkten Vergleichen von Behandlungsergebnissen zwischen Lixisenatid und NPH-Insulin bei Typ-2-Diabetikern (T2DM) mit suboptimaler Blutzuckerkontrolle unter einer oralen Kombinationstherapie aus Metformin und einem Sulfonylharnstoff. Deshalb untersucht der vorliegende adjustierte indirekte Vergleich die verfügbare Evidenz primär zum Hypoglykämierisiko sowie zur Gewichtsveränderung zwischen Lixisenatid und NPH-Insulin auf Basis randomisierter kontrollierter Studien mit den Brückenkomparatoren Exenatide, Insulin glargin und Plazebo. Methoden: Zwei systematische Literaturrecherchen in PubMed, Embase, der Cochrane-Datenbank sowie in klinischen Registern identifizierten englisch- und deutschsprachige Publikationen, die entsprechende Ergebnisdaten aus randomisierten klinischen Studien (RCTs) enthielten und die zwischen Januar 1980 und Oktober 2012 veröffentlicht worden waren. Bestimmt durch die GetGoal-S Studie (Lixisenatid) mit einer Analyse der primären Endpunkte nach 24 Wochen, wurden nur Publikationen eingeschlossen, die Ergebnisse aus 24–30-wöchigen Studien zum Vergleich von GLP-1 Rezeptoragonisten oder Basalinsulinen vs. andere Antidiabetika oder Plazebo umfassten. Für die binären Ergebnisvariablen Hypoglykämiehäufigkeit, Anteil der Patienten mit dem erreichten HbA1c-Zielwert sowie Studienabbrüche wegen unerwünschter Ereignisse wurden die relativen Risiken (RR) sowie die Odds Ratios (OR) als statistische Maße verwendet. Für die kontinuierlichen Ergebnisvariablen glykosyliertes Hämoglobin (HbA1c) und Körpergewicht wurden die Differenzen der mittleren Veränderungen zum Ausgangswert (MD) als statistisches Maß verwendet. Notwendige Metaanalysen wurden auf Basis von Modellen mit zufälligen Effekten durchgeführt, die indirekten Vergleiche nach der M