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Sample records for korrelation zwischen mrt

  1. Exploiting geometrical irradiation possibilities in MRT application

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Requardt, H.; Régnard, P.; Corde, S.; Siegbahn, E. A.; LeDuc, G.; Blattmann, H.; Laissue, J.; Bravin, A.

    2005-08-01

    Microbeam Radiation Therapy (MRT) has the potential to treat infantile brain tumors when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of X-rays but provides unusual resistance to radioneurotoxicity, presumably from the rapid migration of regenerative endothelial cells from dose "valleys" into dose "peaks", i.e., into directly irradiated micro-slices of tissues. We will present a novel irradiation geometry which results in a tolerable valley dose for the normal tissue and a decreased peak-to-valley dose ratio (PVDR) in the tumor area by applying an innovative cross-firing technique. We propose an MRT technique to orthogonally crossfire two arrays of parallel, nonintersecting, mutually interspersed microbeams that produces tumoricidal doses with small PVDRs where the arrays meet and tolerable radiation doses to normal tissues between the microbeams proximal and distal to the tumor in the paths of the arrays.

  2. 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

  3. 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

  4. A Comparison of Multiphase LBGK and MRT LBE Models

    NASA Astrophysics Data System (ADS)

    Peng, Yan; Luo, Li-Shi

    2009-11-01

    One undesirable feature of LBE methods as diffuse interface methods is the existence of parasitic currents. Recently, Lee and Fischer have shown that if the potential form of the intermolecular force is used, the parasitic currents can be eliminated. In their study, the LBGK collision model is used. As we know that multiple-relaxation-time (MRT) collision model has a number of advantages over the lattice Bhatnagar-Gross-Krook (LBGK) model. In this study, we will replace the LBGK with MRT collision model. We compared the stability and Galilean invariance of the two models. The test case is a circular bubble. We found that LBGK is very sensitive to the initial given density values. For the Galilean invariance property, we first get the converged equilibrium solution. Then we add an external velocity. We found that LBGK scheme diverges even a very small velocity is given. From these comparisons, we conclude that MRT is more stable and preserve Galilean invariance better than LBGK.

  5. Modeling MRT for well-characterized thermal imagers

    NASA Astrophysics Data System (ADS)

    Burks, Stephen D.; Reynolds, Joseph P.; Garner, Kenneth

    2011-05-01

    Predicting an accurate Minimum Resolvable Temperature Difference (MRTD) for a thermal imaging system is often hindered by inaccurate measurements of system gain and display characteristics. Variations in these terms are often blamed for poor agreement between model predictions and measured MRTD. By averaging over repeated human measurements, and carefully recording all system parameters affecting image quality, it should be possible to make an accurate prediction of MRTD performance for any resolvable frequency. Utilizing the latest NVESD performance models with updates for noise, apparent target angle, and human vision, predicted MRT are compared with measured curves. We present results for one well characterized mid-wave thermal staring system.

  6. Practising Mental Rotation Using Interactive Desktop Mental Rotation Trainer (iDeMRT)

    ERIC Educational Resources Information Center

    Rafi, Ahmad; Samsudin, Khairulanuar

    2009-01-01

    An experimental study involving 30 undergraduates (mean age = 20.5 years) in mental rotation (MR) training was conducted in an interactive Desktop Mental Rotation Trainer (iDeMRT). Stratified random sampling assigned students into one experimental group and one control group. The former trained in iDeMRT and the latter trained in conventional…

  7. Validating machine vision MRT performance against trained observer performance for linear shift invariant sensors

    NASA Astrophysics Data System (ADS)

    Burks, Stephen D.; Doe, Joshua M.; Teaney, Brian P.

    2015-05-01

    Researchers at the US Army Night Vision and Electronic Sensors Directorate have added the functionality of Machine Vision MRT (MV-MRT) to the NVLabCap software package. While the original calculations of MV-MRT were compared to human observers performance using digital imagery in a previous effort,1 the technical approach was not tested on 8-bit imagery using a variety of sensors in a variety of gain and level settings. Now that it is more simple to determine the MV-MRT for a sensor in multiple gain settings, it is prudent to compare the results of MV-MRT in multiple gain settings to the performance of human observers for thermal imaging systems that are linear and shift invariant. Here, a comparison of the results for a LWIR system to trained human observers is presented.

  8. SNR analysis of 3D magnetic resonance tomosynthesis (MRT) imaging

    NASA Astrophysics Data System (ADS)

    Kim, Min-Oh; Kim, Dong-Hyun

    2012-03-01

    In conventional 3D Fourier transform (3DFT) MR imaging, signal-to-noise ratio (SNR) is governed by the well-known relationship of being proportional to the voxel size and square root of the imaging time. Here, we introduce an alternative 3D imaging approach, termed MRT (Magnetic Resonance Tomosynthesis), which can generate a set of tomographic MR images similar to multiple 2D projection images in x-ray. A multiple-oblique-view (MOV) pulse sequence is designed to acquire the tomography-like images used in tomosynthesis process and an iterative back-projection (IBP) reconstruction method is used to reconstruct 3D images. SNR analysis is performed and shows that resolution and SNR tradeoff is not governed as with typical 3DFT MR imaging case. The proposed method provides a higher SNR than the conventional 3D imaging method with a partial loss of slice-direction resolution. It is expected that this method can be useful for extremely low SNR cases.

  9. [The diagnosis of inflammatory muscular and vascular diseases using MRT with STIR sequences].

    PubMed

    Beese, M S; Winkler, G; Nicolas, V; Maas, R; Kress, D; Kunze, K; Bücheler, E

    1993-06-01

    The role of MRT in the prebiopsy diagnosis of muscular and vascular inflammatory conditions was evaluated prospectively and an optimal method of examination was investigated. 92 patients with a suspected diagnosis of myositis (60 cases) or vasculitis (32 cases) were examined, in each case two extremities were studied using transverse T1 and T2 weighted SE sequences and double echo STIR sequences on a 0.5 Tesla (56 patients) or 1.5 Tesla magnet (36 patients; T5/S15 Gyroscan, Philips). The site of the biopsy depended on the MRT findings. In 41 patients the suspected diagnosis was confirmed histologically, in two patients an infective myositis was diagnosed on clinical grounds despite negative histology. MRT demonstrated muscle oedema in 86% of patients. There were negative findings after immuno-suppressive therapy (two patients), in focal myositis (3 out of 4 patients) and in one of 7 patients with untreated vasculitis. Amongst 49 patients in whom the suspected diagnosis could not be confirmed there was muscle oedema in 11 cases (9 neuropathies out of 22, two myopathies out of 10). Oedema indicated inflammatory muscular or vascular disease with a sensitivity of 97% (except in treated patients and for focal myositis). The number of false negative biopsies can be greatly reduced by the use of MRT. PMID:8507845

  10. [Legg-Calvé-Perthes disease. The value of MRT in its early diagnosis and the assessment of its course].

    PubMed

    Rix, J; Maas, R; Eggers-Stroeder, G; Bruns, J

    1992-01-01

    We report on the value of MRT in diagnosis and follow-up of Perthes' disease. 38 children who were clinically suspect of suffering from Perthes' disease were examined by conventional x-ray and MRT. 25 children were proven to have Perthes' disease, 12 of them in an early stage. During the onset of the disease MRT showed a higher sensitivity (58% vs 50%) and accuracy (74% vs 71%) than conventional x-ray while specificity was equal (83% for both). Additionally, MRT in combination with the still obligatory x-ray gave no false-positive results. In some cases, the diagnosis may be found up to 6 weeks earlier using MRT. Conservative therapeutic regimens obviously will not profit from this. Although excluding other diseases is certainly helpful, the value of MRT as a primary diagnostic procedure is limited. During follow-up, MRT helps to reduce the number of x-ray examinations since it can easily assess the containment of the hip and the bone marrow revitalisation. Scintigraphy, another valuable method to judge revitalisation, should remain limited to selected cases, as it requires significant amounts of radiation. PMID:1733479

  11. The GEANT4 toolkit for microdosimetry calculations: application to microbeam radiation therapy (MRT).

    PubMed

    Spiga, J; Siegbahn, E A; Bräuer-Krisch, E; Randaccio, P; Bravin, A

    2007-11-01

    Theoretical dose distributions for microbeam radiation therapy (MRT) are computed in this paper using the GEANT4 Monte Carlo (MC) simulation toolkit. MRT is an innovative experimental radiotherapy technique carried out using an array of parallel microbeams of synchrotron-wiggler-generated x rays. Although the biological mechanisms underlying the effects of microbeams are still largely unknown, the effectiveness of MRT can be traced back to the natural ability of normal tissues to rapidly repair small damages to the vasculature, and on the lack of a similar healing process in tumoral tissues. Contrary to conventional therapy, in which each beam is at least several millimeters wide, the narrowness of the microbeams allows a rapid regeneration of the blood vessels along the beams' trajectories. For this reason the calculation of the "valley" dose is of crucial importance and the correct use of MC codes for such purposes must be understood. GEANT4 offers, in addition to the standard libraries, a specialized package specifically designed to deal with electromagnetic interactions of particles with matter for energies down to 250 eV. This package implements two different approaches for electron and photon transport, one based on evaluated data libraries, the other adopting analytical models. These features are exploited to cross-check theoretical computations for MRT. The lateral and depth dose profiles are studied for the irradiation of a 20 cm diameter, 20 cm long cylindrical phantom, with cylindrical sources of different size and energy. Microbeam arrays are simulated with the aid of superposition algorithms, and the ratios of peak-to-valley doses are computed for typical cases used in preclinical assays. Dose profiles obtained using the GEANT4 evaluated data libraries and analytical models are compared with simulation results previously obtained using the PENELOPE code. The results show that dose profiles computed with GEANT4's analytical model are almost

  12. The GEANT4 toolkit for microdosimetry calculations: Application to microbeam radiation therapy (MRT)

    SciTech Connect

    Spiga, J.; Siegbahn, E. A.; Braeuer-Krisch, E.; Randaccio, P.; Bravin, A.

    2007-11-15

    Theoretical dose distributions for microbeam radiation therapy (MRT) are computed in this paper using the GEANT4 Monte Carlo (MC) simulation toolkit. MRT is an innovative experimental radiotherapy technique carried out using an array of parallel microbeams of synchrotron-wiggler-generated x rays. Although the biological mechanisms underlying the effects of microbeams are still largely unknown, the effectiveness of MRT can be traced back to the natural ability of normal tissues to rapidly repair small damages to the vasculature, and on the lack of a similar healing process in tumoral tissues. Contrary to conventional therapy, in which each beam is at least several millimeters wide, the narrowness of the microbeams allows a rapid regeneration of the blood vessels along the beams' trajectories. For this reason the calculation of the 'valley' dose is of crucial importance and the correct use of MC codes for such purposes must be understood. GEANT4 offers, in addition to the standard libraries, a specialized package specifically designed to deal with electromagnetic interactions of particles with matter for energies down to 250 eV. This package implements two different approaches for electron and photon transport, one based on evaluated data libraries, the other adopting analytical models. These features are exploited to cross-check theoretical computations for MRT. The lateral and depth dose profiles are studied for the irradiation of a 20 cm diameter, 20 cm long cylindrical phantom, with cylindrical sources of different size and energy. Microbeam arrays are simulated with the aid of superposition algorithms, and the ratios of peak-to-valley doses are computed for typical cases used in preclinical assays. Dose profiles obtained using the GEANT4 evaluated data libraries and analytical models are compared with simulation results previously obtained using the PENELOPE code. The results show that dose profiles computed with GEANT4's analytical model are almost

  13. 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

  14. 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

  15. Medical physics aspects of the synchrotron radiation therapies: Microbeam radiation therapy (MRT) and synchrotron stereotactic radiotherapy (SSRT).

    PubMed

    Bräuer-Krisch, Elke; Adam, Jean-Francois; Alagoz, Enver; Bartzsch, Stefan; Crosbie, Jeff; DeWagter, Carlos; Dipuglia, Andrew; Donzelli, Mattia; Doran, Simon; Fournier, Pauline; Kalef-Ezra, John; Kock, Angela; Lerch, Michael; McErlean, Ciara; Oelfke, Uwe; Olko, Pawel; Petasecca, Marco; Povoli, Marco; Rosenfeld, Anatoly; Siegbahn, Erik A; Sporea, Dan; Stugu, Bjarne

    2015-09-01

    Stereotactic Synchrotron Radiotherapy (SSRT) and Microbeam Radiation Therapy (MRT) are both novel approaches to treat brain tumor and potentially other tumors using synchrotron radiation. Although the techniques differ by their principles, SSRT and MRT share certain common aspects with the possibility of combining their advantages in the future. For MRT, the technique uses highly collimated, quasi-parallel arrays of X-ray microbeams between 50 and 600 keV. Important features of highly brilliant Synchrotron sources are a very small beam divergence and an extremely high dose rate. The minimal beam divergence allows the insertion of so called Multi Slit Collimators (MSC) to produce spatially fractionated beams of typically ∼25-75 micron-wide microplanar beams separated by wider (100-400 microns center-to-center(ctc)) spaces with a very sharp penumbra. Peak entrance doses of several hundreds of Gy are extremely well tolerated by normal tissues and at the same time provide a higher therapeutic index for various tumor models in rodents. The hypothesis of a selective radio-vulnerability of the tumor vasculature versus normal blood vessels by MRT was recently more solidified. SSRT (Synchrotron Stereotactic Radiotherapy) is based on a local drug uptake of high-Z elements in tumors followed by stereotactic irradiation with 80 keV photons to enhance the dose deposition only within the tumor. With SSRT already in its clinical trial stage at the ESRF, most medical physics problems are already solved and the implemented solutions are briefly described, while the medical physics aspects in MRT will be discussed in more detail in this paper. PMID:26043881

  16. N-to-One-Provisionierung zwischen internen Satellitenverzeichnissen des IntegraTUM-Metadirectory

    NASA Astrophysics Data System (ADS)

    Boursas, Latifa

    Dieser Beitrag beschreibt und analysiert die Synchronisationslösungen zur Verwaltung von Benutzerdaten, die Konnektoren aus verschiedenen Quellsystemen und zwischen Verzeichnisdiensten übertragen müssen. Der Schwerpunkt dieser Analyse liegt dabei auf den Transformationen, die zwei Datenmodelle mit unterschiedlichen Strukturen des Directory Information Tree (DIT) innerhalb des IntegraTUM-Metadirectory miteinander abgleichen. Besonders herausfordernd ist, diesen Abgleich mittels des Novell DirXML-Treibers zu realisieren, weil das DirXML-Datenmodell für die Synchronisation der LDAP-Objekte auf eins zu eins Synchronisation ausgelegt ist. In diesem Beitrag wird unsere Lösung für die Synchronisation mehreren LDAP-Objekte auf ein einziges Objekt detailliert und ihre Integrierbarkeit in anderen Hochschulen vorgestellt.

  17. 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.

  18. On Methods for the Analysis of Indefinite Stimuli Perception Characteristics: an fMRT Study of Gender-Specific Differences.

    PubMed

    Fyodorov, A A; Pervushina, O N; Bliznyuk, M V; Khoroshilov, B M; Melnikov, M E; Mazhirina, K G; Stark, M B; Savelov, A A; Petrovsky, E D; Kozlova, L I

    2016-07-01

    Comparative identification of cerebral regions activated in men and women during perception of indefinite images was carried out by fMRT and psychological testing. Nine men and nine women aged 20-26 years took part in the study. The volunteers examined simple geometric figures, slightly structurized images (tables from Rorschach's test), and images of impossible figures. Activation in the cerebellum and visual cortex (bilateral) was more pronounced in women in response to all types of images and less so in the right G. temporalis medius. The right frontal regions (G. precentralis, G. frontalis superior, G. frontalis medius) were also stronger activated in women in response to indefinite stimuli. PMID:27492400

  19. Modelling Escherichia coli concentration in a wastewater reservoir using an operational parameter MRT%FE and first order kinetics.

    PubMed

    Cirelli, Giuseppe Luigi; Consoli, Simona; Juanicó, Marcelo

    2009-01-01

    The operational parameter MRT%FE, representing the mean residence time of different ages fractions of effluent within a completely mixed reactor, was evaluated and integrated with first order kinetics. The parameter was used to model Escherichia coli concentrations in a municipal wastewater reservoir managed under different operating conditions (continuous and discontinuous). The study was conducted during 2004-2005 in a reservoir receiving effluents from the activated sludge treatment plant of Caltagirone (Eastern Sicily - Italy). The analytical approach is applied to the hydraulic state variables of the system (daily stored volumes, inlet and outlet flows), and the physical-chemical (pH, temperature, EC, TSS, BOD(5), COD) and bacteriological wastewater parameters (E. coli, FC, FS). In order to evaluate the reliability of the proposed approach, predicted E. coli concentrations within the reservoir were compared with measured ones by the correlation coefficient, F-test and Sperman's index. The study included the evaluation of die-off coefficient K(T) (d(-1)), light extinction coefficient K (m(-1)) and their relationships with climatic factors. Results of the study confirm that E. coli removal is related to the fractions of fresh effluent remaining each day within the reservoir with MRT%FE of about 5-8d, significantly lower than the nominal detention time (about 27d). The E. coli die-off coefficient (K(T)) was higher during system discontinuous operations and correlated with incident solar radiation and water temperature. PMID:18222594

  20. 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.

  1. 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.

  2. 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.

  3. Supraleitung und Interkontinentalraketen „On-line computing“ zwischen Militär, Industrie und Wissenschaft

    NASA Astrophysics Data System (ADS)

    Knolle, Johannes; Joas, Christian

    Der zweite Weltkrieg und der Kalte Krieg veränderten nicht nur das Verhältnis zwischen Militär, Industrie und Wissenschaft, sondern auch die wissenschaftliche Praxis von Physikern und anderen Wissenschaftlern. In den 1950er Jahren stellte die Entwicklung von Interkontinentalraketen die Auftragnehmer des Militärs in der Industrie vor komplexe Fragestellungen, zu deren Lösung sie auf die Expertise von Wissenschaftlern angewiesen waren. Industrieunternehmen gründeten eigene Forschungseinheiten zur Lösung technischer und wissenschaftlicher Probleme.

  4. TU-F-BRF-09: Feasibility Study of Spatial and Temporal Fractionation Using a Table-Top Image-Guided MRT System

    SciTech Connect

    Zhang, L; Inscoe, C; Yuan, H; Burk, L; Ger, R; Chtcheprov, P; Lu, J; Chang, S; Zhou, O

    2014-06-15

    Purpose: Microbeam radiation therapy is a promising experimental radiotherapy method for cancer treatment. Synchrotron studies have shown that MRT can preferentially ablate tumors while mostly preserving the surrounding normal tissues. Our purpose is to develop a compact microbeam irradiator that can be accessible for laboratory research on MRT's therapeutic mechanism, with the ultimate goal of translating this technique for clinical applications. Utilizing a carbon nanotube field emission X-ray source array, our lab has developed a first of its kind table-top microbeam irradiator. The purpose of this study is to investigate the possibility of increasing the total dose to the tumor region using spatial and temporal fractionation. Methods: MRI and CT scans were acquired and registered to locate both the target region and the landmark in the treatment coordinate space. A crossbeam treatment configuration was planned to achieve the desired dosage and tumor coverage. One array of 300 μm-thick microbeams was delivered to the target on the first day. Another array, perpendicular to the first one, was delivered the next day targeting the same region. The feasibility of this image-guided MRT procedure was evaluated using a phantom. Gafchromic EBT2 film was employed to characterize the targeting accuracy and the delivered tumor dose. Results: The preliminary phantom study showed that a cross-pattern of microbeam arrays was successfully delivered with sub-millimeter targeting accuracy. The delivered dose in the target region was doubled. The fraction of tumor volume that received the peak dose was increased. Conclusion: Temporal fractionation of crosspatterned microbeams can be delivered to the same target region. The feasibility of this procedure was investigated with a phantom study. Once implemented, this procedure has the potential of increasing the tumor control effect of MRT and of achieving better normal tissue recovery.

  5. Hybrid LBM-MRT model coupled with finite difference method for double-diffusive mixed convection in rectangular enclosure with insulated moving lid

    NASA Astrophysics Data System (ADS)

    Bettaibi, Soufiene; Kuznik, Frédéric; Sediki, Ezeddine

    2016-02-01

    This paper presents a numerical study of thermosolutal mixed convection in rectangular enclosure with sliding top lid. The fluid flow is solved by the multiple relaxation time (MRT) lattice Boltzmann method (LBM), whereas the temperature and concentration fields are computed by finite difference method (FDM). The main objective of this study is to investigate the accuracy and the effectiveness of such model to predict thermodynamics for heat and mass transfer in a driven cavity. This model is validated with different numerical methods in the current literature. A good agreement is obtained between our results and previous works. The different comparisons demonstrate the robustness and the accuracy of the proposed approach.

  6. Revised response criteria for myelofibrosis: International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) and European LeukemiaNet (ELN) consensus report

    PubMed Central

    Cervantes, Francisco; Mesa, Ruben; Passamonti, Francesco; Verstovsek, Srdan; Vannucchi, Alessandro M.; Gotlib, Jason; Dupriez, Brigitte; Pardanani, Animesh; Harrison, Claire; Hoffman, Ronald; Gisslinger, Heinz; Kröger, Nicolaus; Thiele, Juergen; Barbui, Tiziano; Barosi, Giovanni

    2013-01-01

    The current document is a revision of the International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) criteria for treatment response in myelofibrosis (MF) and represents a collaborative effort by the IWG-MRT and the European LeukemiaNet to objectively assess the value of new drugs in inducing morphologic remission or improvement in MF-associated symptomatic burden (MF-SB). Some of the changes in the current revision include stricter definitions of red cell transfusion dependency and independency and consideration of the Myeloproliferative Neoplasm Symptom Assessment Form as a tool to quantify meaningful changes in disease-related symptoms. Six response categories are listed: complete remission (CR) and partial remission signify treatment effects that are consistent with disease modification, whereas drug-induced improvements in MF-SB were annotated as clinical improvement, anemia response, spleen response, or symptoms response. Additional criteria are provided for progressive disease, stable disease, and relapse. The document also includes recommendations for assessing cytogenetic and molecular remissions, without mandating their inclusion for CR assignment. PMID:23838352

  7. Austauschskräfte zwischen Elementarteilchen und Fermische Theorie des β-Zerfalls als Konsquenzen einer möglichen Feldtheorie der Materie [26

    NASA Astrophysics Data System (ADS)

    Inhalt: Elektron, Neutrino, Proton und Neutron werden als vier verschiedene Quantenzustände einer einzigen Elementpartikel angesehen. Quantensprünge zwischen diesen Zuständen erklären den β-Zerfall (gemäss der Theorie von Fermi) und geben zur HEISENBEBe-MAJOKANA'schen Neutron-Proton-Austauschkraft Anlass. Die Pestsetzung, dass negatives Elektron und positives Proton "Partikel"-Zustände (im Gegensatz zu "Antipartikel") sind, verbietet Zerstrahlungsprozesse der schweren Teilchen. Die umgekehrte Festsetzung (positives Elektron und positives Proton sind Partikel) führt zu Zerstrahlungsprozessen (siehe Zusammenfassung).

  8. Calculation of friction coefficient and analysis of fluid flow in a stepped micro-channel for wide range of Knudsen number using Lattice Boltzmann (MRT) method

    NASA Astrophysics Data System (ADS)

    Bakhshan, Younes; Omidvar, Alireza

    2015-12-01

    Micro scale gas flows have attracted significant research interest in the last two decades. In this research, the fluid flow of gases in a stepped micro-channel has been conducted. Wide range of Knudsen number has been implemented using the Lattice Boltzmann (MRT) method in this study. A modified second-order slip boundary condition and a Bosanquet-type effective viscosity are used to consider the velocity slip at the boundaries and to cover the slip and transition regimes of flow to obtain an accurate simulation of rarefied gases. The flow specifications such as pressure loss, velocity profile, stream lines and friction coefficient at different conditions have been presented. The results show, good agreement with available experimental data. The calculation shows, that the friction coefficient decreases with increasing the Knudsen number and stepping the micro-channel has an inverse effect on the friction coefficient value. Furthermore, a new correlation is suggested for calculation of the friction coefficient in the stepped micro-channel flows as below;

  9. Pore-scale simulation of fluid flow passing over a porously covered square cylinder located at the middle of a channel, using a hybrid MRT-LBM-FVM approach

    NASA Astrophysics Data System (ADS)

    Salimi, Mohammad Reza; Taeibi Rahni, Mohammad; Jam, Freydun

    2015-06-01

    A comprehensive study was performed to analyze the unsteady laminar flow characteristics around a porously covered, a fully porous, and a solid squared section cylinder located in the middle of a plane channel. In order to simulate fluid flow inside porous media and porous-fluid interface accurately (minimizing modeling error), the porous region was analyzed in pore scale, using LBM. Additionally, to minimize the LBM-related compressibility error through the porous region, a multi-block multiple relaxation time lattice Boltzmann method (MRT-LBM) was used. Also, to decrease CPU time, a Navier-Stokes flow solver, based on finite volume method and SIMPLE algorithm, was coupled with MRT-LBM to simulate flow around the porous obstacle. It should be noted that the flow inside the porous layer is in continuum regime, and hence, the no-slip boundary condition was used to treat the solid walls inside the porous media. In our simulations, we considered variations of porosity and Reynolds number ranging from 0.75 to 0.94 and from 60 to 240, respectively. The effects of porosity and Reynolds number on vortex pattern, mean drag coefficient, amplitude of lift coefficient, and Strouhal number were investigated. Comparison of our results with the ones obtained using Open FOAM, as well as published by others, shows the suitable accuracy of our computations. It is seen that at low Reynolds numbers or at low porosities, where the mean flow does not have large enough momentum to penetrate porous media, the resulting flow field and aerodynamic coefficients are relatively close for three different configurations used. However, as the flow Reynolds number or permeability increases, the mean flow penetrates easier into the porous media and thus provides different shedding characteristics and aerodynamic coefficients for different obstacle shapes.

  10. Clinical end points for drug treatment trials in BCR-ABL1-negative classic myeloproliferative neoplasms: consensus statements from European LeukemiaNET (ELN) and Internation Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT).

    PubMed

    Barosi, G; Tefferi, A; Besses, C; Birgegard, G; Cervantes, F; Finazzi, G; Gisslinger, H; Griesshammer, M; Harrison, C; Hehlmann, R; Hermouet, S; Kiladjian, J-J; Kröger, N; Mesa, R; Mc Mullin, M F; Pardanani, A; Passamonti, F; Samuelsson, J; Vannucchi, A M; Reiter, A; Silver, R T; Verstovsek, S; Tognoni, G; Barbui, T

    2015-01-01

    The discovery of somatic mutations, primarily JAK2V617F and CALR, in classic BCR-ABL1-negative myeloproliferative neoplasms (MPNs) has generated interest in the development of molecularly targeted therapies, whose accurate assessment requires a standardized framework. A working group, comprised of members from European LeukemiaNet (ELN) and International Working Group for MPN Research and Treatment (IWG-MRT), prepared consensus-based recommendations regarding trial design, patient selection and definition of relevant end points. Accordingly, a response able to capture the long-term effect of the drug should be selected as the end point of phase II trials aimed at developing new drugs for MPNs. A time-to-event, such as overall survival, or progression-free survival or both, as co-primary end points, should measure efficacy in phase III studies. New drugs should be tested for preventing disease progression in myelofibrosis patients with early disease in randomized studies, and a time to event, such as progression-free or event-free survival should be the primary end point. Phase III trials aimed at preventing vascular events in polycythemia vera and essential thrombocythemia should be based on a selection of the target population based on new prognostic factors, including JAK2 mutation. In conclusion, we recommended a format for clinical trials in MPNs that facilitates communication between academic investigators, regulatory agencies and drug companies. PMID:25151955

  11. 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.

  12. [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. PMID:8305691

  13. 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.

  14. 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?

  15. Vom Urknall zum Zerfall. Die Welt zwischen Anfang und Ende.

    NASA Astrophysics Data System (ADS)

    Fritzsch, H.

    Contents: Der Tanz mit dem Ozean. Galaktische Landkarte. Das Maß der Dinge. Der würfelnde Gott der Quantenphysik. Geheimnisvolle Felder. Materie und Antimaterie. Quarks - Urstoff unserer Welt. Zerfallende Protonen und die Einheit der Physik. Der Zauberofen. Das überschaubare Universum. Das explodierende Universum. Nachhall der Schöpfung. Der achtfache Weg der kosmischen Entwicklung. Das Ende der Welt. Einheit in der Vielfalt. Das geistige Universum. Gott und das absurde Universum.

  16. 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)

  17. Morbus Coats

    PubMed Central

    Förl, B.; Schmack, I.; Grossniklaus, H.E.; Rohrschneider, K.

    2010-01-01

    Der fortgeschrittene Morbus Coats stellt im Kleinkindalter eine der schwierigsten Differenzialdiagnosen zum Retinoblastom dar. Wir beschreiben die klinischen und histologischen Befunde zweier Jungen im Alter von 9 und 21 Monaten mit einseitiger Leukokorie. Trotz umfassender Diagnostik mittels Narkoseuntersuchung, MRT und Ultraschall konnte ein Retinoblastom nicht sicher ausgeschlossen werden, und es erfolgte eine Enukleation. Histologisch wurde die Diagnose eines Morbus Coats gesichert. Da eine differenzialdiagnostische Abgrenzung zwischen Morbus Coats und Retinoblastom schwierig sein kann, halten wir in zweifelhaften Fällen auch angesichts der eingeschränkten Visusprognose und potenzieller Sekundärkomplikationen beim fortgeschrittenen Morbus Coats eine Enukleation für indiziert. PMID:18299842

  18. [Diagnostic possibilities of magnetic resonance tomography (MRT) in the retroperitoneal space].

    PubMed

    Zilch, H G; Held, P

    1989-08-01

    The diagnostic value of MR-imaging is tested on 130 patients with pathological retroperitoneal processes. Improved imaging techniques resulted in a more accurate delineation of tumor extension than seen with CT-imaging. Using a ratio of signal intensity from the adrenal tumors and the liver on T2-weighted images, it is usually possible to differentiate adenomas from metastases, carcinomas or phaeochromocytomas. New indications for renal MR-imaging would be parenchymal renal disease and transplant rejections. Moreover, MR allows visualization of lumbar lymph node-chains in the coronal view corresponding to the situs during surgery, thus, facilitating preoperative orientation for the surgeon. PMID:2807972

  19. 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.

  20. Einstellung und Wissen von Lehramtsstudierenden zur Evolution - ein Vergleich zwischen Deutschland und der Türkei

    NASA Astrophysics Data System (ADS)

    Graf, Dittmar; Soran, Haluk

    Es wird eine Untersuchung vorgestellt, in der Wissen und Überzeugungen von Lehramtsstudierenden aller Fächer zum Thema Evolution an zwei Universitäten in Deutschland und der Türkei erhoben worden sind. Die Befragung wurde in Dortmund und in Ankara durchgeführt. Es stellte sich heraus, dass ausgeprägte Defizite im Verständnis der Evolutionsmechanismen herrschen. Viele Studierende, insbesondere aus der Türkei, sind nicht von der Faktizität der Evolution überzeugt. Dies gilt sowohl für Studierende mit Fach Biologie als auch für Studierende mit anderen Fächern. Näher untersucht worden sind die Faktoren, die die Überzeugungen zur Evolution beeinflussen können, was ja in Anbetracht der hohen Ablehnungsrate der Evolution von besonderem Interesse ist. Das Vertrauen in die Wissenschaft spielt hierbei eine besondere Rolle: Wer der Wissenschaft vertraut, ist auch eher von der Evolution überzeugt, als diejenigen, die skeptisch gegenüber der Wissenschaft sind.

  1. Zwischen Commonsense und Wissenschaft Mathematik in der Erziehungsphilosophie A. N. Whiteheads

    NASA Astrophysics Data System (ADS)

    Sölch, Dennis

    Obwohl Whitehead heute wie selbstverständlich als Philosoph rezipiert wird, so hat er seine wissenschaftliche Laufbahn doch als Mathematiker begonnen. Lange Zeit war er gemeinsam mit Bertrand Russell als Autor der Principia Mathematica unter Mathematikern und mathematischen Logikern deutlich besser bekannt als unter Philosophen. Doch selbst von denjenigen, die sich mit Whiteheads Überlegungen zur Metaphysik, zur Wissenschaftsgeschichte und zur Theologie befassen, werden seine Schriften zur Philosophie von Erziehung und Bildung häufig kaum beachtet. So entgeht es leicht, dass Whitehead nicht nur ein auf theoretischem Gebiet brillanter Mathematiker war, sondern sein theoretisches Fachwissen im Hinblick auf pädagogische und didaktische Relevanz fortwährend reflektiert hat.

  2. 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.

  3. Christoph Scheiner's life between 1633 and 1650. (German Title: Christoph Scheiners Lebensjahre zwischen 1633 und 1650)

    NASA Astrophysics Data System (ADS)

    Daxecker, Franz

    In 1636, Christoph Scheiner left Rome where the trial of Galilei had taken place, and went to Vienna. The financing of his main work ``Rosa Ursina'' had to be clarified. Until 1636, Scheiner was not in office From 1636 onward, he was alternatively living in Neiße -- today Nysa (Silesia, Poland) -- and Vienna, from 1637 onward, he took his permanent residence in Neiße. Here, Scheiner worked as an advisor of the rector and as father confessor, in addition he gave religious lectures and looked after the garden.

  4. 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.

  5. MRT letter: extended depth from focus reconstruction method for stretch zone measurement in 15-5PH steel.

    PubMed

    De Oliveira Caltabiano, Pietro Carelli Reis; Rosa, Paulo Henrique Santos; De Campos, Kamila Amato; De Oliveira Hein, Luis Rogerio

    2012-09-01

    The stretch zone width (SZW) data for 15-5PH steel CTOD specimens fractured at -150°C to + 23°C temperature were measured based on focused images and 3D maps obtained by extended depth-of-field reconstruction from light microscopy (LM) image stacks. This LM-based method, with a larger lateral resolution, seems to be as effective for quantitative analysis of SZW as scanning electron microscopy (SEM) or confocal scanning laser microscopy (CSLM), permitting to clearly identify stretch zone boundaries. Despite the worst sharpness of focused images, a robust linear correlation was established to fracture toughness (K(C) ) and SZW data for the 15-5PH steel tested specimens, measured at their center region. The method is an alternative to evaluate the boundaries of stretched zones, at a lower cost of implementation and training, since topographic data from elevation maps can be associated with reconstructed image, which summarizes the original contrast and brightness information. Finally, the extended depth-of-field method is presented here as a valuable tool for failure analysis, as a cheaper alternative to investigate rough surfaces or fracture, compared to scanning electron or confocal light microscopes. PMID:22434578

  6. Dilemmata der ErzieherInnenausbildung Zwischen Institution und Profession (The Dilemma of Educational Training between Institution and Profession).

    ERIC Educational Resources Information Center

    Engelhardt, Walter Josef; Ernst, Heinz

    1992-01-01

    Discusses the change in kindergarten from an emergency or welfare institution to an integral part of family life and early education. Argues that, although the nature of kindergarten has changed, the training of kindergarten teachers has not. Suggests that future kindergarten teachers be trained in teaching theory rather than just personality…

  7. MRT letter: high resolution SEM imaging of nano-architecture of cured urea-formaldehyde resin using plasma coating of osmium.

    PubMed

    Park, Byung-Dae; Singh, Adya P; Nuryawan, Arif; Hwang, Kiju

    2013-11-01

    Nanoarchitecture of cured urea-formaldehyde (UF) resins was examined with a field-emission scanning electron microscope (FE-SEM) after coating samples with osmium, which is considered to produce particles of considerably smaller size compared to other metal coatings used in SEM studies. This method enabled comparison of the nanoarchitecture of UF resins of low (1.0) and high (1.6) formaldehyde/urea (F/U) mole ratios to be made, based on imaging of extremely small size particles as part of UF resin architecture, not described before. Imaging revealed presence of relatively large globular particles (148.084-703.983 nm size range) as well as smaller substructures (28.004-39.604 nm size range) as part of the architecture of 1.0-mole UF resin. Globular particles were also present in 1.6 mole UF resin, but of considerably smaller size (14.760-50.269 nm). The work presented demonstrates usefulness of osmium coating in unraveling the intricacies of the nanostructural organization of cured UF resins, prompting wider application of this immensely useful but grossly underutilized metal coating type in high resolution SEM examination of biological and materials samples. PMID:23922188

  8. Effect of random structure on permeability and heat transfer characteristics for flow in 2D porous medium based on MRT lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Yang, PeiPei; Wen, Zhi; Dou, RuiFeng; Liu, Xunliang

    2016-08-01

    Flow and heat transfer through a 2D random porous medium are studied by using the lattice Boltzmann method (LBM). For the random porous medium, the influence of disordered cylinder arrangement on permeability and Nusselt number are investigated. Results indicate that the permeability and Nusselt number for different cylinder locations are unequal even with the same number and size of cylinders. New correlations for the permeability and coefficient b‧Den of the Forchheimer equation are proposed for random porous medium composed of Gaussian distributed circular cylinders. Furthermore, a general set of heat transfer correlations is proposed and compared with existing experimental data and empirical correlations. Our results show that the Nu number increases with the increase of the porosity, hence heat transfer is found to be accurate considering the effect of porosity.

  9. "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.

  10. 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…

  11. 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 factors that might impede…

  12. 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.

  13. Looking for simple correction functions between the mean radiant temperature from the "standard black globe" and the "six-directional" techniques in Taiwan

    NASA Astrophysics Data System (ADS)

    Kántor, Noémi; Kovács, Attila; Lin, Tzu-Ping

    2015-07-01

    Mean radiant temperature ( T mrt) values were calculated and compared to each other in Taiwan based on the six-directional and globe techniques. In the case of the six-directional technique (measurements with pyranometers and pyrgeometers), two different T mrt values were calculated: one representing the radiation load on a standing man [ T mrt(st)] and the other which refers to a spherical reference shape [ T mrt(sp)]. Moreover, T mrt( T g ) was obtained through the globe thermometer technique applying the standard black globe. Comparing T mrt values based on the six-directional technique but with different reference shapes revealed that the difference was always in the +/-5 °C domain. Of the cases, 75 % fell into the +/-5 °C Delta Tmrt range when we compared different techniques with similar reference shapes [ T mrt(sp) and T mrt( T g )] and only 69 % when we compared the different techniques with different reference shapes [ T mrt(st) and T mrt( T g )]. Based on easily accessible factors, simple correction functions were determined to make the T mrt( T g ) values of already existing outdoor thermal comfort databases comparable with other databases which involve sixdirectional T mrt. The corrections were conducted directly between the T mrt( T g ) and T mrt(sp) values and also indirectly, i.e., by using the values of T g to reduce the differences between T mrt(sp) and T mrt( T g ). Both correction methods resulted in considerable improvement and reduced the differences between the T mrt(sp) and the T mrt( T g ) values. However, validations with an independent database from Hungary revealed that it is not suggested to apply the correction functions under totally different background climate conditions.

  14. Confidence and Gender Differences on the Mental Rotations Test

    ERIC Educational Resources Information Center

    Cooke-Simpson, Amanda; Voyer, Daniel

    2007-01-01

    The present study examined the relation between self-reported confidence ratings, performance on the Mental Rotations Test (MRT), and guessing behavior on the MRT. Eighty undergraduate students (40 males, 40 females) completed the MRT while rating their confidence in the accuracy of their answers for each item. As expected, gender differences in…

  15. 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. PMID:27206380

  16. [Value of nuclear magnetic resonance tomography and first-pass radionuclide ventriculography in cardiomyopathies].

    PubMed

    Baumgartl, W; Maccio, A; Zilch, H G; Held, P; Schad, N; Hötzinger, H

    1986-01-01

    12 patients with cardiomyopathy were examined by MRT and first pass angiocardiography. MRT provides detailed images of cardiac anatomy and abnormalities without using any contrast medium. The first pass method is an excellent complement to MRT. The functional imaging describes regional wall motion of myocardium exactly. Both non-invasive methods are useful for the diagnosis of cardiomyopathy. PMID:3033967

  17. The influence of natural diet composition, food intake level, and body size on ingesta passage in primates.

    PubMed

    Clauss, Marcus; Streich, W Jürgen; Nunn, Charles L; Ortmann, Sylvia; Hohmann, Gottfried; Schwarm, Angela; Hummel, Jürgen

    2008-07-01

    An important component of digestive physiology involves ingesta mean retention time (MRT), which describes the time available for digestion. At least three different variables have been proposed to influence MRT in herbivorous mammals: body mass, diet type, and food intake (dry matter intake, DMI). To investigate which of these parameters influences MRT in primates, we collated data for 19 species from trials where both MRT and DMI were measured in captivity, and acquired data on the composition of the natural diet from the literature. We ran comparative tests using both raw species values and phylogenetically independent contrasts. MRT was not significantly associated with body mass, but there was a significant correlation between MRT and relative DMI (rDMI, g/kg(0.75)/d). MRT was also significantly correlated with diet type indices. Thus, both rDMI and diet type were better predictors of MRT than body mass. The rDMI-MRT relationship suggests that primate digestive differentiation occurs along a continuum between an "efficiency" (low intake, long MRT, high fiber digestibility) and an "intake" (high intake, short MRT, low fiber digestibility) strategy. Whereas simple-stomached (hindgut fermenting) species can be found along the whole continuum, foregut fermenters appear limited to the "efficiency" approach. PMID:18450489

  18. 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…

  19. 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 element in the…

  20. 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.

  1. 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.

  2. 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.

  3. Diglossische Prozesse (Zwischen Deutsch und Spanisch) unter den Spanischen Emigranten der 2. Generation in Deutschland: Eine Soziolinguistische Studie (Diglossia Processes (Between German and Spanish) Among Second Generation Spanish Immigrants in Germany: A Sociolinguistic Study).

    ERIC Educational Resources Information Center

    Sanchez, Karin Vilar

    1998-01-01

    Presents a sociolinguistic study of second-generation Spanish immigrants in Germany. Specific focus is on "diglossia processes," or how Spanish and German are used for different sociolinguistic situations. (Author/VL)

  4. Zwischen Marginalitat und Allmachtsfantasien - Neuere Publikationen zum Padagogikunterricht in der Gymnasialen Oberstufe (Between Marginalization and Phantasies of Omnipotence- Recent Publications on the Teaching of Pedagogics on the Upper Secondary Level).

    ERIC Educational Resources Information Center

    Baumgart, Franzjorg; Bubenzer, Kirsten

    2001-01-01

    Sketches the institutionalization of the school subject pedagogics, the situation of the didactics of pedagogical instruction, a short survey on the recent differentiation of the field of discourse. Reports on studies that are characteristic of recent discussion on pedagogical didactics. (CMK)

  5. TissuePatch™ as a novel synthetic sealant for repair of superficial lung defect: in vitro tests results

    PubMed Central

    2012-01-01

    frisch entnommenen Schweinlungen (n = 10) wurde intubiert und beatmet. Eine pleurale Läsion (40 × 25 mm) wurde erstellt und APL mit steigendem inspiratorischem Tidalvolumen (TVi) untersucht. Nach Applikation von TissuePatch™ wurde APL auf die gleiche Weise gemessen bis zur Auftritt von Kleberbruch. Zur Untersuchung der Elastizität des Klebers wurde die Länge der pleuralen Läsion gemessen. Ergebnis Pleurale Läsion führte bei aufsteigendem maximalem inspiratorischem Druck (Pmax) zu überproportionalem Anstieg von APL. Multiple lineare Regressionsanalyse ergab eine starke Korrelation zwischen APL und Pmax, Lungencompliance sowie Widerstand. Nach der Applikation von Klebstoff wurde APL bei TVi = 400 ml in allen zehn Testen versiegelt, bei TVi = 500 ml in neun Testen, bei TVi = 600 ml in sieben und bei TVi = 700 ml in fünf Testen. Der mittlere Pmax, der zu Kleberbruch führte, betrug 42 ± 9 mBar. Bei den Versuchen wurden adhäsiver und kohäsiver Kleberbruch in jeweils sechs und drei Testen gefunden. Die Länge der pleuralen Läsion vor dem Kleberbruch war 8,9 ± 4,9% größer als die bei TVi = 400 ml. Schlussfolgerung Unsere Versuche zeigten eine zuverlässige Versiegelung von TissuePatch™ unter mechanischer Ventilation. Die klinische Nützlichkeit vom Kleber als unterstützende Maßnahme zur Prävention von alveolo-pleuralem Luftleck in Lungenchirurgie sollte durch prospektive, randomisierte kontrollierte klinische Studien bestätigt werden. PMID:23164337

  6. Identification of AREG and PLK1 pathway modulation as a potential key of the response of intracranial 9L tumor to microbeam radiation therapy.

    PubMed

    Bouchet, Audrey; Sakakini, Nathalie; Atifi, Michèle El; Le Clec'h, Céline; Bräuer-Krisch, Elke; Rogalev, Léonid; Laissue, Jean Albert; Rihet, Pascal; Le Duc, Géraldine; Pelletier, Laurent

    2015-06-01

    Synchrotron microbeam radiation therapy (MRT) relies on the spatial fractionation of a synchrotron beam into parallel micron-wide beams allowing deposition of hectogray doses. MRT controls the intracranial tumor growth in rodent models while sparing normal brain tissues. Our aim was to identify the early biological processes underlying the differential effect of MRT on tumor and normal brain tissues. The expression of 28,000 transcripts was tested by microarray 6 hr after unidirectional MRT (400 Gy, 50 µm-wide microbeams, 200 µm spacing). The specific response of tumor tissues to MRT consisted in the significant transcriptomic modulation of 431 probesets (316 genes). Among them, 30 were not detected in normal brain tissues, neither before nor after MRT. Areg, Trib3 and Nppb were down-regulated, whereas all others were up-regulated. Twenty-two had similar expression profiles during the 2 weeks observed after MRT, including Ccnb1, Cdc20, Pttg1 and Plk1 related to the mitotic role of the Polo-like kinase (Plk) pathway. The up-regulation of Areg expression may indicate the emergence of survival processes in tumor cells triggered by the irradiation; while the modulation of the "mitotic role of Plk1" pathway, which relates to cytokinetic features of the tumor observed histologically after MRT, may partially explain the control of tumor growth by MRT. The identification of these tumor-specific responses permit to consider new strategies that might potentiate the antitumoral effect of MRT. PMID:25382544

  7. Malignant Rhabdoid Tumor of the Liver: A Case Report and Literature Review

    PubMed Central

    Oita, Satoru; Terui, Keita; Komatsu, Syugo; Hishiki, Tomoro; Saito, Takeshi; Mitsunaga, Tetsuya; Nakata, Mitsuyuki; Yoshida, Hideo

    2015-01-01

    Malignant rhabdoid tumor (MRT) is a rare and aggressive malignancy associated with poor outcomes. MRT of the liver is even rarer, and little information has been described. We report the case of an 8-month-old boy with MRT of the liver. The tumor showed aggressive progression despite a multidisciplinary approach, and the patient died due to multiple organ failure 14 days after admission. Autopsy revealed the liver tumor and multiple metastases with negative immunohistochemistry for INI1/BAF47. A review of 53 cases of pediatric MRT of the liver is provided. PMID:25918621

  8. 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.

  9. 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.

  10. Assessment of Valvular Disorders in Survivors of Hodgkin's Lymphoma Treated by Mediastinal Radiotherapy ± Chemotherapy.

    PubMed

    Bijl, Jesse M; Roos, Marleen M; van Leeuwen-Segarceanu, Elena M; Vos, Josephine M; Bos, Willem-Jan W; Biesma, Douwe H; Post, Marco C

    2016-02-15

    As the number of Hodgkin's lymphoma (HL) survivors grows, understanding long-term complications becomes more important. Mediastinal radiotherapy (MRT) seems to cause valvular disease, and the prevalence might increase during follow-up. In this cross-sectional study 82 HL survivors participated (52% men, mean age 47.8 years, 50 treated with MRT). Valvular disease was diagnosed by transthoracic echocardiography and compared between HL survivors treated with and without MRT. Univariate and multivariate logistic regression analysis was used to identify predictors for valvular disease. During a median follow-up of 13.4 years (range 2 to 39 years), ≥ mild valvular disease was present in 61.2% of HL survivors with MRT (n = 30), compared with 31.0% of HL survivors without MRT (n = 9; odds ratio [OR] 3.51, 95% CI 1.32 to 9.30, p = 0.01). In multivariate analysis, only current age remained predictive for ≥ mild valvular disease (OR 1.08 per year, 95% CI 1.01 to 1.14, p = 0.023). Aortic regurgitation (AR) was most prevalent and irradiated patients had significantly more ≥ mild AR (38.2% vs 6.8%, p = 0.007). Within the MRT subgroup, time after radiation of >15 years was associated with AR (OR 4.70, 95% CI 1.05 to 21.03, p = 0.043), after adjusting for current age and hypertension. Severe valvular disease was present in 24.5% of HL survivors with MRT compared with 3.4% without MRT (p = 0.016). Valvular surgery was performed in 9 HL survivors (18.0%) with MRT and in none without MRT. In conclusion, the prevalence of valvular disease in HL survivors treated with MRT is high and increases with time after irradiation. Long-time screening for valvular disease by transthoracic echocardiography might be worthwhile. PMID:26772441

  11. Mean residence time of leaf number, area, mass, and nitrogen in canopy photosynthesis.

    PubMed

    Hirose, Tadaki; Oikawa, Shimpei

    2012-08-01

    Mean residence time (MRT) of plant nitrogen (N), which is an indicator of the expected length of time N newly taken up is retained before being lost, is an important component in plant nitrogen use. Here we extend the concept MRT to cover such variables as leaf number, leaf area, leaf dry mass, and nitrogen in the canopy. MRT was calculated from leaf duration (i.e., time integral of standing amount) divided by the total production of leaf variables. We determined MRT in a Xanthium canadense stand established with high or low N availability. The MRT of leaf number may imply longevity of leaves in the canopy. We found that the MRT of leaf area and dry mass were shorter than that of leaf number, while the MRT of leaf N was longer. The relatively longer MRT of leaf N was due to N resorption before leaf shedding. The MRT of all variables was longer at low N availability. Leaf productivity is the rate of canopy photosynthesis per unit amount of leaf variables, and multiplication of leaf productivity by MRT gives the leaf photosynthetic efficiency (canopy photosynthesis per unit production of leaf variables). The photosynthetic efficiency of leaf number implies the lifetime carbon gain of a leaf in the canopy. The analysis of plant-level N use efficiency by evaluating the N productivity and MRT is a well-established approach. Extension of these concepts to leaf number, area, mass, and N in the canopy will clarify the underlying logic in the study of leaf life span, leaf area development, and dry mass and N use in canopy photosynthesis. PMID:22349752

  12. 47 CFR 1.1104 - Schedule of charges for applications and other filings for media services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Payment typecode 1. Commercial TV Services: a. New and Major Change Construction Permits (per application...) (Electronic Filing) 302-TV & 159 $315.00 MJT 302-DTV & 159 $315.00 MJT e. License Renewal (per application... & 159 $2,900.00 MRT 302-TV & 159 $2,900.00 MRT k. Ownership Report (Electronic Filing) 323 & 159...

  13. Genome-wide approach to identify second gene targets for malignant rhabdoid tumors using high-density oligonucleotide microarrays

    PubMed Central

    Takita, Junko; Chen, Yuyan; Kato, Motohiro; Ohki, Kentaro; Sato, Yusuke; Ohta, Shigeru; Sugita, Kanji; Nishimura, Riki; Hoshino, Noriko; Seki, Masafumi; Sanada, Masashi; Oka, Akira; Hayashi, Yasuhide; Ogawa, Seishi

    2014-01-01

    Malignant rhabdoid tumor (MRT) is a rare and highly lethal cancer that mainly affects infants and young children. The majority of MRT are characterized by loss of function of SMARCB1 on chromosome 22q11.2. However, little is known about genetic changes other than SMARCB1 alterations that are responsible for the development and/or progression of MRT. To explore additional gene targets in MRT, we analyzed 21 MRT specimens (12 fresh tumors and 9 MRT-derived cell lines) using high-density single nucleotide polymorphism genotyping microarrays. Although MRT genomes are characterized by common 22q11.2 deletions, affecting the SMARCB1 locus with a frequency of 95.2% (20/21 specimens), other genetic changes have been less frequent. Of the 20 specimens with deletions of 22q11.2, eight specimens showed uniparental disomy of the SMARCB1 locus with homozygous deletions or gene mutations. High-resolution analysis also disclosed the recurrent hemizygous/homozygous deletions of 7q35–q36.1, involving the CNTNAP2 locus in three specimens. Mutations analysis of CNTNAP2 showed a novel R157C missense mutation in a primary case, and methylation analysis showed recurrent hypermethylation of CNTNAP2 in three of nine cell lines. These results demonstrated that CNTNAP2 is one of the additional gene targets, other than SMARCB1, in MRT. PMID:24418192

  14. 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…

  15. 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…

  16. A meta-analysis of moral reconation therapy.

    PubMed

    Ferguson, L Myles; Wormith, J Stephen

    2013-09-01

    This study reports on a meta-analysis of moral reconation therapy (MRT). Recipients of MRT included adult and juvenile offenders who were in custody or in the community, typically on parole or probation. The study considered criminal offending subsequent to treatment as the outcome variable. The overall effect size measured by the correlation across 33 studies and 30,259 offenders was significant (r = .16), indicating that MRT had a small but important effect on recidivism. Moderator analyses were conducted to detect the possible factors affecting the relationship between MRT and recidivism. Moderators included setting, age, gender, research design, sample size, type of recidivism, follow-up period, publisher, and year of publication. Moderator analysis demonstrated that MRT was more successful with adult than juvenile offenders in institutional settings as opposed to the community, and where researchers in the primary studies used randomization to allocate participants to either a treatment or control condition. The treatment effect size was greater when the type of recidivism used was rearrest rather than rearrest followed by conviction or reincarceration. The benefits of MRT were strongest with a relatively short follow-up period. MRT was more successful for relatively small samples and for large samples rather than medium-sized samples. The effect size was smaller for studies published by the owners of MRT than by other independent studies. The effect size was also smaller for studies published after 1999. PMID:22744908

  17. An Investigation of the Relationship Between Readiness Test Scores for Kindergarten Children and Achievement Scores Obtained at the End of Grades One and Two. S.S.T.A. Research Centre Report No. 62.

    ERIC Educational Resources Information Center

    Warkentin, Lena

    The primary purpose of this study was to investigate the relationship between Metropolitan Readiness Test (MRT) scores in kindergarten (MRTK) and grade one (MRT1) with the reading scores of the Canadian Tests of Basic Skills (CTBS) at the end of grades one (CTBSR1) and two (CTBSR2). A secondary purpose of the study was to determine whether the…

  18. A Further Examination of the Effects of Administering the Metropolitan Reading Tests in Spanish and English to Spanish-Speaking School Entrants.

    ERIC Educational Resources Information Center

    Cruz, Sylvia; And Others

    In a study designed to assess effects of administering the Metropolitan Reading Test (MRT) in Spanish versus English, 100 Puerto Rican kindergarten pupils were randomly split into two groups. The MRT was administered in English to one group and in a Spanish translation to the other group. The group who took the Spanish version significantly…

  19. 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.

  20. 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…

  1. The normal tissue effects of microbeam radiotherapy: What do we know, and what do we need to know to plan a human clinical trial?

    PubMed

    Smyth, Lloyd M L; Senthi, Sashendra; Crosbie, Jeffrey C; Rogers, Peter A W

    2016-06-01

    Purpose Microbeam Radiotherapy (MRT) is a promising pre-clinical cancer therapy which represents a radical departure from the radiobiological principles of conventional radiotherapy (CRT). In order to translate MRT to human clinical trials, robust normal tissue toxicity data are required. This review summarizes the normal tissue effects reported by pre-clinical MRT animal studies and compares these data to clinical recommendations in CRT. Conclusion Few pre-clinical studies are specifically designed to evaluate the dose-response of normal tissue to MRT. However, it remains clear that a range of normal tissues can tolerate peak MRT doses at least an order of magnitude higher than CRT. Furthermore, the dose deposited in the valley regions, predominantly determined by microbeam spacing, has a greater influence on the normal tissue response to MRT compared to the peak regions. The development of a new normal tissue complication probability model for MRT, in conjunction with a treatment planning system, will be pivotal in the collection of robust normal tissue toxicity data and the translation of MRT to clinical use. PMID:26982077

  2. A NOXA/MCL-1 Imbalance Underlies Chemoresistance of Malignant Rhabdoid Tumor Cells.

    PubMed

    Ouchi, Kazutaka; Kuwahara, Yasumichi; Iehara, Tomoko; Miyachi, Mitsuru; Katsumi, Yoshiki; Tsuchiya, Kunihiko; Konishi, Eiichi; Yanagisawa, Akio; Hosoi, Hajime

    2016-09-01

    Malignant rhabdoid tumor (MRT) is a rare aggressive pediatric cancer characterized by inactivation of SNF5, a core subunit of SWI/SNF complexes. Previously, we showed that SNF5 contributes to transcriptional activation of NOXA, a pro-apoptotic protein that binds and inhibits the anti-apoptotic protein MCL-1. In this study, we found that NOXA expression was downregulated in MRT cell lines as well as in clinical MRT samples and that ectopically expressed NOXA bound MCL-1 and increased the sensitivity of MRT cell lines to doxorubicin (DOX) by promoting apoptosis. Consistent with this finding, knockdown of MCL-1 in MRT cell lines induced apoptosis and increased DOX sensitivity in MRT cells, and the MCL-1 inhibitor TW-37 synergized with DOX to induce MRT cell death. Our results suggest that modulation of the NOXA/MCL-1 pathway may be a potential strategy for the treatment of patients with MRT. J. Cell. Physiol. 231: 1932-1940, 2016. © 2015 Wiley Periodicals, Inc. PMID:26680268

  3. 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.…

  4. 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…

  5. 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…

  6. Treating Brain Tumor with Microbeam Radiation Generated by a Compact Carbon-Nanotube-Based Irradiator: Initial Radiation Efficacy Study.

    PubMed

    Yuan, Hong; Zhang, Lei; Frank, Jonathan E; Inscoe, Christina R; Burk, Laurel M; Hadsell, Mike; Lee, Yueh Z; Lu, Jianping; Chang, Sha; Zhou, Otto

    2015-09-01

    Microbeam radiation treatment (MRT) using synchrotron radiation has shown great promise in the treatment of brain tumors, with a demonstrated ability to eradicate the tumor while sparing normal tissue in small animal models. With the goal of expediting the advancement of MRT research beyond the limited number of synchrotron facilities in the world, we recently developed a compact laboratory-scale microbeam irradiator using carbon nanotube (CNT) field emission-based X-ray source array technology. The focus of this study is to evaluate the effects of the microbeam radiation generated by this compact irradiator in terms of tumor control and normal tissue damage in a mouse brain tumor model. Mice with U87MG human glioblastoma were treated with sham irradiation, low-dose MRT, high-dose MRT or 10 Gy broad-beam radiation treatment (BRT). The microbeams were 280 μm wide and spaced at 900 μm center-to-center with peak dose at either 48 Gy (low-dose MRT) or 72 Gy (high-dose MRT). Survival studies showed that the mice treated with both MRT protocols had a significantly extended life span compared to the untreated control group (31.4 and 48.5% of life extension for low- and high-dose MRT, respectively) and had similar survival to the BRT group. Immunostaining on MRT mice demonstrated much higher DNA damage and apoptosis level in tumor tissue compared to the normal brain tissue. Apoptosis in normal tissue was significantly lower in the low-dose MRT group compared to that in the BRT group at 48 h postirradiation. Interestingly, there was a significantly higher level of cell proliferation in the MRT-treated normal tissue compared to that in the BRT-treated mice, indicating rapid normal tissue repairing process after MRT. Microbeam radiation exposure on normal brain tissue causes little apoptosis and no macrophage infiltration at 30 days after exposure. This study is the first biological assessment on MRT effects using the compact CNT-based irradiator. It provides an alternative

  7. Nanotube x-ray for cancer therapy: a compact microbeam radiation therapy system for brain tumor treatment

    PubMed Central

    Zhang, Lei; Yuan, Hong; Inscoe, Christina; Chtcheprov, Pavel; Hadsell, Michael; Lee, Yueh; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-01-01

    Microbeam radiation therapy (MRT) is a promising preclinical modality for cancer treatment, with remarkable preferential tumoricidal effects, that is, tumor eradication without damaging normal tissue functions. Significant lifespan extension has been demonstrated in brain tumor-bearing small animals treated with MRT. So far, MRT experiments can only be performed in a few synchrotron facilities around the world. Limited access to MRT facilities prevents this enormously promising radiotherapy technology from reaching the broader biomedical research community and hinders its potential clinical translation. We recently demonstrated, for the first time, the feasibility of generating microbeam radiation in a laboratory environment using a carbon nanotube x-ray source array and performed initial small animal studies with various brain tumor models. This new nanotechnology-enabled microbeam delivery method, although still in its infancy, has shown promise for achieving comparable therapeutic effects to synchrotron MRT and has offered a potential pathway for clinical translation. PMID:25417729

  8. Nanotube x-ray for cancer therapy: a compact microbeam radiation therapy system for brain tumor treatment.

    PubMed

    Zhang, Lei; Yuan, Hong; Inscoe, Christina; Chtcheprov, Pavel; Hadsell, Michael; Lee, Yueh; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-12-01

    Microbeam radiation therapy (MRT) is a promising preclinical modality for cancer treatment, with remarkable preferential tumoricidal effects, that is, tumor eradication without damaging normal tissue functions. Significant lifespan extension has been demonstrated in brain tumor-bearing small animals treated with MRT. So far, MRT experiments can only be performed in a few synchrotron facilities around the world. Limited access to MRT facilities prevents this enormously promising radiotherapy technology from reaching the broader biomedical research community and hinders its potential clinical translation. We recently demonstrated, for the first time, the feasibility of generating microbeam radiation in a laboratory environment using a carbon nanotube x-ray source array and performed initial small animal studies with various brain tumor models. This new nanotechnology-enabled microbeam delivery method, although still in its infancy, has shown promise for achieving comparable therapeutic effects to synchrotron MRT and has offered a potential pathway for clinical translation. PMID:25417729

  9. 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

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

    NASA Astrophysics Data System (ADS)

    Lee, Hyunjung; Mayer, Helmut

    2016-04-01

    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.

  11. The effect of urban geometry on mean radiant temperature under future climate change: a study of three European cities.

    PubMed

    Lau, Kevin Ka-Lun; Lindberg, Fredrik; Rayner, David; Thorsson, Sofia

    2015-07-01

    Future anthropogenic climate change is likely to increase the air temperature (T(a)) across Europe and increase the frequency, duration and magnitude of severe heat stress events. Heat stress events are generally associated with clear-sky conditions and high T(a), which give rise to high radiant heat load, i.e. mean radiant temperature (T(mrt)). In urban environments, T mrt is strongly influenced by urban geometry. The present study examines the effect of urban geometry on daytime heat stress in three European cities (Gothenburg in Sweden, Frankfurt in Germany and Porto in Portugal) under present and future climates, using T(mrt) as an indicator of heat stress. It is found that severe heat stress occurs in all three cities. Similar maximum daytime T(mrt) is found in open areas in all three cities despite of the latitudinal differences in average daytime T(mrt). In contrast, dense urban structures like narrow street canyons are able to mitigate heat stress in the summer, without causing substantial changes in T(mrt) in the winter. Although the T(mrt) averages are similar for the north-south and east-west street canyons in each city, the number of hours when T(mrt) exceeds the threshold values of 55.5 and 59.4 °C-used as indicators of moderate and severe heat stress-in the north-south canyons is much higher than that in the east-west canyons. Using statistically downscaled data from a regional climate model, it is found that the study sites were generally warmer in the future scenario, especially Porto, which would further exacerbate heat stress in urban areas. However, a decrease in solar radiation in Gothenburg and Frankfurt reduces T(mrt) in the spring, while the reduction in T(mrt) is somewhat offset by increasing T(a) in other seasons. It suggests that changes in the T(mrt) under the future scenario are dominated by variations in T(a). Nonetheless, the intra-urban differences remain relatively stable in the future. These findings suggest that dense urban

  12. The effect of urban geometry on mean radiant temperature under future climate change: a study of three European cities

    NASA Astrophysics Data System (ADS)

    Lau, Kevin Ka-Lun; Lindberg, Fredrik; Rayner, David; Thorsson, Sofia

    2015-07-01

    Future anthropogenic climate change is likely to increase the air temperature ( T a ) across Europe and increase the frequency, duration and magnitude of severe heat stress events. Heat stress events are generally associated with clear-sky conditions and high T a , which give rise to high radiant heat load, i.e. mean radiant temperature ( T mrt ). In urban environments, T mrt is strongly influenced by urban geometry. The present study examines the effect of urban geometry on daytime heat stress in three European cities (Gothenburg in Sweden, Frankfurt in Germany and Porto in Portugal) under present and future climates, using T mrt as an indicator of heat stress. It is found that severe heat stress occurs in all three cities. Similar maximum daytime T mrt is found in open areas in all three cities despite of the latitudinal differences in average daytime T mrt . In contrast, dense urban structures like narrow street canyons are able to mitigate heat stress in the summer, without causing substantial changes in T mrt in the winter. Although the T mrt averages are similar for the north-south and east-west street canyons in each city, the number of hours when T mrt exceeds the threshold values of 55.5 and 59.4 °C—used as indicators of moderate and severe heat stress—in the north-south canyons is much higher than that in the east-west canyons. Using statistically downscaled data from a regional climate model, it is found that the study sites were generally warmer in the future scenario, especially Porto, which would further exacerbate heat stress in urban areas. However, a decrease in solar radiation in Gothenburg and Frankfurt reduces T mrt in the spring, while the reduction in T mrt is somewhat offset by increasing T a in other seasons. It suggests that changes in the T mrt under the future scenario are dominated by variations in T a . Nonetheless, the intra-urban differences remain relatively stable in the future. These findings suggest that dense urban structure

  13. SYRA3 COST Action--Microbeam radiation therapy: Roots and prospects.

    PubMed

    Bravin, Alberto; Olko, Pawel; Schültke, Elisabeth; Wilkens, Jan J

    2015-09-01

    Microbeam radiation therapy (MRT) is an irradiation modality for therapeutic purposes which uses arrays of collimated quasi parallel microbeams, each up to 100 μm wide, to deliver high radiation doses. Several studies have reported the extraordinary tolerance of normal tissues to MRT irradiation; conversely, MRT has been shown to be highly efficient on tumor growth control. The original and most widely developed application of MRT, yet in the preclinical phase, consists in using spatially fractionated X-ray beams issued from a synchrotron radiation source in the treatment of brain tumors. More recently, MRT has been tested in successful pioneering assays to reduce or interrupt seizures in preclinical models of epilepsy. The MRT concept has also been extended to proton therapy. The development of MRT towards its clinical implementation is presently driven by an EU-supported consortium of laboratories from 16 countries within the COST Action TD1205 (SYRA3). The results of the first SYRA3 workshop on "Radiation Therapy with Synchrotron Radiation: Achievements and Challenges" held in Krakow (Poland) during March 25-26 2014 are summarized in this issue with an overview presented in this paper. The papers reflect the multidisciplinary international activities of SYRA3. The topics covered in this focus issue include medical physics aspects, pre-clinical studies, clinical applications, and an industrial perspective; finally an outlook towards future prospects of compact sources and proton microbeams. PMID:26123367

  14. 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. PMID:20363350

  15. Synchronous perivesical and renal malignant rhabdoid tumor in a 9-year-old boy: a case report and review of literature.

    PubMed

    Szymanski, Konrad M; Tabib, Christian H; Idrees, Muhammad T; Cain, Mark P

    2013-11-01

    Pediatric extrarenal malignant rhabdoid tumors (MRTs) are rare and aggressive (20% 5-year survival). Only 2 cases of bladder MRTs have been published. We report on a 9-year-old boy presenting with gross hematuria, palpable pelvic mass, and an obstructed, nonfunctional kidney. Evaluation was consistent with a 9.7 cm extrarenal MRT invading the bladder and prostate. He underwent a cystoprostatectomy, Indiana pouch continent urinary reservoir creation, and a left nephroureterectomy. A discrete 2.5 cm focus of renal MRT was found. To our knowledge, this is the first case of simultaneous perivesical and renal MRT. We review the current management of pediatric extrarenal MRTs. PMID:23830079

  16. All children with malignant rhabdoid tumors should be treated initially with intensive chemotherapy.

    PubMed

    Hernández-Marqués, C; Lassaletta, A; Cormenzana, M; García-Esparza, E; Madero-López, L

    2015-04-01

    Malignant rhabdoid tumors (MRT) of soft tissues are aggressive tumors, which can be detected in almost any part of the body. MRT are rare, and very few cases have been reported in the literature. Prognosis of these tumors is extremely poor despite intensive therapy. Some risk factors such as young age or disseminated disease are associated with an aggressive and almost always lethal clinical course. Some clinicians even recommend initial palliative care due to this outcome. We report a case of metastatic MRT in a 6-month-old child with excellent initial response to chemotherapy. PMID:24852450

  17. 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)

  18. Astronomical discoveries and the renown of a late humanistic scholar - Marx Welser's role in the discussion on sunspots between Scheiner, Galilei and Kepler. (German Title: Astronomische Entdeckungen und das Renommee eies späthumanistischen Gelehrten - Marx Welsers Rolle in der Sonnenfleckendiskussion zwischen Scheiner, Galilei und Kepler)

    NASA Astrophysics Data System (ADS)

    Ferber, Magnus Ulrich

    The example of the late humanistic scholar Max Welser (1558-1614) from Augsburg proves the gain of recognition of astronomy in the scholarly surroundings, which arose through its new results after the invention of the telescope. This explains why an exponent of the humanistic ideal of education worked towards appearing as the patron of a professional astronomical debate, as it was done by Welser, in 1611-1613, in the debate on sunspots between Christoph Scheiner and Galileo Galilei. Nevertheless, the split in the scholarly world between humanists and scientists proved to be so fundamental at that time, that Welser, in order to be accepted also by the mathematici, had to establish anew his renown in these circles independent of his philological achievements. At the same time, he did not undertake anything to integrate the astronomers into the humanistic res publica litteraria.

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

    ClinicalTrials.gov

    2016-08-17

    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

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

    ClinicalTrials.gov

    2016-09-08

    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

  1. 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.

  2. Characteristics of the mean radiant temperature in high latitude cities—implications for sensitive climate planning applications

    NASA Astrophysics Data System (ADS)

    Lindberg, Fredrik; Holmer, Björn; Thorsson, Sofia; Rayner, David

    2014-07-01

    Knowledge of how the mean radiant temperature ( T mrt ) is affected by factors such as location, climate and urban setting contributes to the practice of climate sensitive planning. This paper examines how T mrt varies within an urban setting and how it is influenced by cloudiness. In addition, variations of T mrt in three high latitude cities are investigated in order to analyse the impact of geographical context and climate conditions. Results showed large spatial variations between sunlit and shaded areas during clear weather conditions, with the highest values of T mrt close to sunlit walls and the lowest values in the areas shaded by buildings and vegetation. As cloudiness increases, the spatial pattern is altered and the differences are reduced. The highest T mrt under cloudy conditions is instead found in open areas where the proportion of shortwave diffuse radiation from the sky vault is high. A regional comparison between three Swedish coastal cities showed that T mrt during summer is similar regardless of latitudinal location. On the other hand, large differences in T mrt during winter were found. Shadows, both from buildings and vegetation are the most effective measure to reduce extreme values of T mrt . However, extensive areas of shadow are usually not desired within outdoor urban environments at high latitude cities. One solution is to create diverse outdoor urban spaces in terms of shadow and also ventilation. This would provide individuals with access to a choice of thermal environments which they can use to assist their thermal regulation, based on personal needs and desires.

  3. Characteristics of the mean radiant temperature in high latitude cities—implications for sensitive climate planning applications

    NASA Astrophysics Data System (ADS)

    Lindberg, Fredrik; Holmer, Björn; Thorsson, Sofia; Rayner, David

    2013-02-01

    Knowledge of how the mean radiant temperature (T mrt ) is affected by factors such as location, climate and urban setting contributes to the practice of climate sensitive planning. This paper examines how T mrt varies within an urban setting and how it is influenced by cloudiness. In addition, variations of T mrt in three high latitude cities are investigated in order to analyse the impact of geographical context and climate conditions. Results showed large spatial variations between sunlit and shaded areas during clear weather conditions, with the highest values of T mrt close to sunlit walls and the lowest values in the areas shaded by buildings and vegetation. As cloudiness increases, the spatial pattern is altered and the differences are reduced. The highest T mrt under cloudy conditions is instead found in open areas where the proportion of shortwave diffuse radiation from the sky vault is high. A regional comparison between three Swedish coastal cities showed that T mrt during summer is similar regardless of latitudinal location. On the other hand, large differences in T mrt during winter were found. Shadows, both from buildings and vegetation are the most effective measure to reduce extreme values of T mrt . However, extensive areas of shadow are usually not desired within outdoor urban environments at high latitude cities. One solution is to create diverse outdoor urban spaces in terms of shadow and also ventilation. This would provide individuals with access to a choice of thermal environments which they can use to assist their thermal regulation, based on personal needs and desires.

  4. Immersive virtual reality platform for medical training: a "killer-application".

    PubMed

    2000-01-01

    The Medical Readiness Trainer (MRT) integrates fully immersive Virtual Reality (VR), highly advanced medical simulation technologies, and medical data to enable unprecedented medical education and training. The flexibility offered by the MRT environment serves as a practical teaching tool today and in the near future the will serve as an ideal vehicle for facilitating the transition to the next level of medical practice, i.e., telepresence and next generation Internet-based collaborative learning. PMID:10977542

  5. 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. PMID:18083600

  6. Eosinophil-Associated Gene Pathways but not Eosinophil Numbers are Differentially Regulated between Synchrotron Microbeam Radiation Treatment and Synchrotron Broad-Beam Treatment by 48 Hours Postirradiation.

    PubMed

    Ibahim, M J; Yang, Y; Crosbie, J C; Stevenson, A; Cann, L; Paiva, P; Rogers, P A

    2016-01-01

    Synchrotron microbeam radiation treatment (MRT) is a preclinical radiotherapy technique with considerable clinical promise, although some of the underlying radiobiology of MRT is still not well understood. In recently reported studies, it has been suggested that MRT elicits a different tumor immune profile compared to broad-beam treatment (BB). The aim of this study was to investigate the effects of synchrotron MRT and BB on eosinophil-associated gene pathways and eosinophil numbers within and around the tumor in the acute stage, 48 h postirradiation. Balb/C mice were inoculated with EMT6.5 mouse mammary tumors and irradiated with microbeam radiation (112 and 560 Gy) and broad-beam radiation (5 and 9 Gy) at equivalent doses determined from a previous in vitro study. After tumors were collected 24 and 48 h postirradiation, RNA was extracted and quantitative PCR performed to assess eosinophil-associated gene expression. Immunohistochemistry was performed to detect two known markers of eosinophils: eosinophil-associated ribonucleases (EARs) and eosinophil major basic protein (MBP). We identified five genes associated with eosinophil function and recruitment (Ear11, Ccl24, Ccl6, Ccl9 and Ccl11) and all of them, except Ccl11, were differentially regulated in synchrotron microbeam-irradiated tumors compared to broad-beam-irradiated tumors. However, immunohistochemical localization demonstrated no significant differences in the number of EAR- and MBP-positive eosinophils infiltrating the primary tumor after MRT compared to BB. In conclusion, our work demonstrates that the effects of MRT on eosinophil-related gene pathways are different from broad-beam radiation treatment at doses previously demonstrated to be equivalent in an in vitro study. However, a comparison of the microenvironments of tumors, which received MRT and BB, 48 h after exposure showed no difference between them with respect to eosinophil accumulation. These findings contribute to our understanding of the

  7. 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.

  8. Continuous automatic classification of seismic signals of volcanic origin at Mt. Merapi, Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Ohrnberger, Matthias

    2001-07-01

    performs therefore best for VTB-type events, with almost 89% recognition accuracy and 2 FA/day. Seismic signals of the MP- and Guguran-classes are more difficult to detect and classify. Around 64% of MP-events and 74% of Guguran signals are recognized correctly. The average false alarm rate for MP-events is 87 FA/day, whereas for Guguran signals 33 FA/day are obtained. However, the majority of missed events and false alarms for both MP and Guguran events are due to confusion errors between these two event classes in the recognition process. The confusion of MP and Guguran events is interpreted as being a consequence of the selected parametrization approach for the continuous seismic data streams. The observed patterns of the analyzed wavefield attributes for MP and Guguran events show a significant amount of similarity, thus providing not sufficient discriminative information for the numerical classification. The similarity of wavefield parameters obtained for seismic events of MP and Guguran type reflect the commonly observed dominance of path effects on the seismic wave propagation in volcanic environments. The recognition rates obtained for the five-day period of increasing seismicity show, that the presented DHMM-based automatic classification system is a promising approach for the difficult task of classifying volcano-seismic signals. Compared to standard signal detection algorithms, the most significant advantage of the discussed technique is, that the entire seismogram is detected and classified in a single step. Aufgrund seiner nahezu kontinuierlichen eruptiven Aktivität zählt der Merapi zu den gefährlichsten Vulkanen der Welt. Der Merapi befindet sich im Zentralteil der dicht bevölkerten Insel Java (Indonesien). Selbst kleinere Ausbrüche des Merapi stellen deswegen eine große Gefahr für die ansässige Bevölkerung in der Umgebung des Vulkans dar. Die am Merapi beobachtete enge Korrelation zwischen seismischer und vulkanischer Aktivität erlaubt es, mit

  9. Gestaltung von Mensch-Maschine-Schnittstellen

    NASA Astrophysics Data System (ADS)

    Bruder, Ralph; Didier, Muriel

    Die Interaktion zwischen Mensch und Maschine erfolgt über Schnittstellen, die dem Fahrer Informationen liefern und ihm behilfich sein sollen, die Fahraufgabe sicher, effektiv und effzient zu bewältigen. Wie die Gestaltung von Anzeigen und Bedienelementen vorgenommen werden muss und worauf während des Entwicklungsprozesses in Bezug auf die Interaktion zwischen Mensch und Maschine Rücksicht genommen werden muss, soll hier geklärt werden.

  10. 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.

  11. A case of non-scaling in mammalian physiology? Body size, digestive capacity, food intake, and ingesta passage in mammalian herbivores.

    PubMed

    Clauss, Marcus; Schwarm, Angela; Ortmann, Sylvia; Streich, W Jürgen; Hummel, Jürgen

    2007-10-01

    As gut capacity is assumed to scale linearly to body mass (BM), and dry matter intake (DMI) to metabolic body weight (BM(0.75)), it has been proposed that ingesta mean retention time (MRT) should scale to BM(0.25) in herbivorous mammals. We test these assumptions with the most comprehensive literature data collations (n=74 species for gut capacity, n=93 species for DMI and MRT) to date. For MRT, only data from studies was used during which DMI was also recorded. Gut capacity scaled to BM(1.06). In spite of large differences in feeding regimes, absolute DMI (kg/d) scaled to BM(0.76) across all species tested. Regardless of this allometry inherent in the dataset, there was only a very low allometric scaling of MRT with BM(0.14) across all species. If species were divided according to the morphophysiological design of their digestive tract, there was non-significant scaling of MRT with BM(0.04) in colon fermenters, BM(0.08) in non-ruminant foregut fermenters, BM(0.06) in browsing and BM(0.04) in grazing ruminants. In contrast, MRT significantly scaled to BM(0.24) (CI 0.16-0.33) in the caecum fermenters. The results suggest that below a certain body size, long MRTs cannot be achieved even though coprophagy is performed; this supports the assumption of a potential body size limitation for herbivory on the lower end of the body size range. However, above a 500 g-threshold, there is no indication of a substantial general increase of MRT with BM. We therefore consider ingesta retention in mammalian herbivores an example of a biological, time-dependent variable that can, on an interspecific level, be dissociated from a supposed obligatory allometric scaling by the morphophysiological design of the digestive tract. We propose that very large body size does not automatically imply a digestive advantage, because long MRTs do not seem to be a characteristic of very large species only. A comparison of the relative DMI (g/kg(0.75)) with MRT indicates that, on an interspecific

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

    PubMed Central

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

    2014-01-01

    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 (100 μm 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 300 μm (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

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. Measurement of Linear Magneto-Rayleigh-Taylor Instability Growth in Solid Liners

    NASA Astrophysics Data System (ADS)

    Sinars, Daniel; Slutz, Steve; Herrmann, Mark; Peterson, Kyle; Vesey, Roger; Blue, Brent

    2009-11-01

    The magneto-Rayleigh-Taylor (MRT) instability is ubiquitous to pinch plasmas compressed by magnetic pressure, and is an important factor in determining whether a cylindrical liner can reach the axis in a relatively intact form. While there are many RT characterization experiments, there are few well-characterized MRT experiments and none for fast (˜100 ns) z-pinch implosions in which the magnetic pressure quickly dominates over material strength. We present data from an initial series of MRT growth experiments on the 20 MA Z-machine that used solid Al liners with outer radii of 3.16 mm and aspect ratios (radius/thickness) of 10. The MRT instability was seeded with sinusoidal perturbations of 200 and 400 μm and peak-to-valley amplitudes of 5 and 10 μm, respectively. Radiographs showing the evolution of the MRT instability are compared with codes being used to design magnetized liner inertial fusion loads [see S.A. Slutz, ``Magnetized liner inertial fusion,'' this conference.

  18. Simulation and mitigation of the magneto-Rayleigh-Taylor instabilities in Z-pinch gas discharge extreme ultraviolet plasma radiation sources

    SciTech Connect

    Huang, B.; Tomizuka, T.; Xie, B.; Sakai, Y.; Zhu, Q.; Song, I.; Okino, A.; Xiao, F.; Watanabe, M.; Hotta, E.

    2013-11-15

    The development and use of a single-fluid two-temperature approximated 2-D Magneto-Hydrodynamics code is reported. Z-pinch dynamics and the evolution of Magneto-Rayleigh-Taylor (MRT) instabilities in a gas jet type Extreme Ultraviolet (EUV) source are investigated with this code. The implosion and stagnation processes of the Z-pinch dynamics and the influence of initial perturbations (single mode, multi- mode, and random seeds) on MRT instability are discussed in detail. In the case of single mode seeds, the simulation shows that the growth rates for mm-scale wavelengths up to 4 mm are between 0.05 and 0.065 ns{sup −1}. For multi-mode seeds, the mode coupling effect leads to a series of other harmonics, and complicates MRT instability evolution. For perturbation by random seeds, the modes evolve to longer wavelengths and finally converge to a mm-scale wavelength approximately 1 mm. MRT instabilities can also alter the pinch stagnation state and lead to temperature and density fluctuations along the Z axis, which eventually affects the homogeneity of the EUV radiation output. Finally, the simulation results are related to experimental results to discuss the mitigations of MRT instability.

  19. The effects of sex, sexual orientation, and digit ratio (2D:4D) on mental rotation performance.

    PubMed

    Peters, Michael; Manning, John T; Reimers, Stian

    2007-04-01

    In spite of the reduced level of experimental control, this large scale study brought some clarity into the relation between mental rotation task (MRT) performance and a number of variables where contradictory associations had previously been reported in the literature. Clear sex differences in MRT were observed for a sample of 134,317 men and 120,783 women, with men outperforming women. There were also MRT differences as a function of sexual orientation: heterosexual men performed better than homosexual men and homosexual women performed better than heterosexual women. Although bisexual men performed better than homosexual men but less well than heterosexual men, no significant differences were observed between bisexual and homosexual women. MRT performance in both men and women peaked in the 20-30 year range, and declined significantly and markedly thereafter. Both men and women showed a significant negative correlation between left and right digit finger ratio and MRT scores, such that individuals with smaller digit ratios (relatively longer ring finger than index finger) performed better than individuals with larger digit ratios. PMID:17394056

  20. 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

  1. 2D radiation-magnetohydrodynamic simulations of SATURN imploding Z-pinches

    SciTech Connect

    Hammer, J.H.; Eddleman, J.L.; Springer, P.T.

    1995-11-06

    Z-pinch implosions driven by the SATURN device at Sandia National Laboratory are modeled with a 2D radiation magnetohydrodynamic (MHD) code, showing strong growth of magneto-Rayleigh Taylor (MRT) instability. Modeling of the linear and nonlinear development of MRT modes predicts growth of bubble-spike structures that increase the time span of stagnation and the resulting x-ray pulse width. Radiation is important in the pinch dynamics keeping the sheath relatively cool during the run-in and releasing most of the stagnation energy. The calculations give x-ray pulse widths and magnitudes in reasonable agreement with experiments, but predict a radiating region that is too dense and radially localized at stagnation. We also consider peaked initial density profiles with constant imploding sheath velocity that should reduce MRT instability and improve performance. 2D krypton simulations show an output x-ray power > 80 TW for the peaked profile.

  2. Electrothermal instability growth in magnetically driven pulsed power liners

    NASA Astrophysics Data System (ADS)

    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

    2012-09-01

    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.

  3. Type of items and the magnitude of gender differences on the Mental Rotations Test.

    PubMed

    Voyer, Daniel; Hou, Junjie

    2006-06-01

    The present study considered the structure of the drawings used in the Mental Rotations Test (MRT) to examine whether distractors that are either a mirror image or structurally different from the target as well as response alternatives with occluded and nonoccluded parts affect the magnitude of gender differences on this test. One hundred and three women and 100 men undergraduate students were given unlimited time to complete the MRT. A gender by occlusion interaction on correct responses showed that gender differences were larger for occluded than for nonoccluded items. Examination of performance as a function of item placement in the test suggested that it is unlikely that the results could be accounted for by differential practice effects in women and men. Implications of these results for explanations of gender differences on the MRT and for the training of spatial abilities are discussed. PMID:17133885

  4. 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.

  5. New irradiation geometry for microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Requardt, H.; Régnard, P.; Corde, S.; Siegbahn, E.; LeDuc, G.; Brochard, T.; Blattmann, H.; Laissue, J.; Bravin, A.

    2005-07-01

    Microbeam radiation therapy (MRT) has the potential to treat infantile brain tumours when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of x-rays but provides unusual resistance to radioneurotoxicity, presumably from the migration of endothelial cells from 'valleys' into 'peaks', i.e., into directly irradiated microslices of tissues. We present a novel irradiation geometry which results in a tolerable valley dose for the normal tissue and a decreased peak-to-valley dose ratio (PVDR) in the tumour area by applying an innovative cross-firing technique. We propose an MRT technique to orthogonally crossfire two arrays of parallel, nonintersecting, mutually interspersed microbeams that produces tumouricidal doses with small PVDRs where the arrays meet and tolerable radiation doses to normal tissues between the microbeams proximal and distal to the tumour in the paths of the arrays.

  6. 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.

  7. [Diagnosis of thyroid diseases using imaging procedures with reference to nuclear magnetic resonance tomography].

    PubMed

    Held, P; Zilch, H G; Baumgartl, W; Maccio, A

    1986-01-01

    Results of MR imaging performed in 74 patients with diseases of the thyroid gland and in normal persons are compared with nuclear medicine (99mTc 04 and 131J scans) and sonography (5 and 7.5 MHz transducers, linear scans) results. The MR-signal intensity of hot nodules--Plummers' disease--is not specific. Therefore scintigraphy combined with sonography remain the methods of choice for the diagnosis of hyperfunctioning nodules. Morphologic alterations within the thyroid gland are detected by MRT as well as by ultrasound. But when lesions are not limited to the thyroid bed MRT will become the imaging examination of choice. Therefore MRT can be useful for scanning retrotracheal and superior mediastinal extent of thyroid lesions. Also clinically inapparent metastases to the cervical and mediastinal nodes may be detected. PMID:3554875

  8. [Preoperative imaging of the inner ear prior to the implantation of a multichannel cochlear implant using computed and MR technology].

    PubMed

    Czerny, C; Gstoettner, W; Adunka, O; Hamzavi, J; Baumgartner, W D

    2000-06-01

    CT and MRT are now standard examinations prior to insertion of a cochlear implant. Both methods have advantages and disadvantages in terms of discovering potentially pathological structures in the inner ear. The aim of this study was to evaluate the pros and cons of using CT and MRT before cochlear implantation. CT is usually performed using axial planigraphic planes. Like MRT, bone-specific CT is helpful in the diagnosis of congenital and acquired changes within the inner ear. Congenital defects in the meatus acusticus internus, the endolymphatic duct and sac, the cochlea and the vestibulum can be diagnosed and also quantified. Infectious morphologic changes can be seen on CT images in their terminal residual state (sclerotic tissue). However, acute inflammation and fibrotic tissue is not visible on CT. T2-specific MRT images are very fluid sensitive and play a major role in preoperative cochlear implant diagnosis. This examination demonstrates fluid within the peri- and enolymphatic cave and permits the diagnostician to determine whether congenital or acquired diseases have destroyed such fluid-filled cavities. In order to demonstrate pathological changes in the temporal bone and neural structures in the inner ear, MRT is the preferred method. Displaying the modiolus and the cochlear nerve is extremely important because, in their absence, a cochlear implantation may be contra-indicated. MRT also demonstrates other neural structures such as the facial nerve. This information may be important for the surgeon, e.g. the state of the pneumatic system in the mastoid cavity (which is best visualised by bone-specific CT). PMID:10890125

  9. 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.

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

    PubMed

    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

    2016-07-21

    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. PMID:27366861

  11. 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.

  12. 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.

  13. 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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25038148

  15. 21-cm Observations with the Morehead Radio Telescope: Involving Undergraduates in Observing Programs

    NASA Astrophysics Data System (ADS)

    Malphrus, B. K.; Combs, M. S.; Kruth, J.

    2000-12-01

    Herein we report astronomical observations made by undergraduate students with the Morehead Radio Telescope (MRT). The MRT, located at Morehead State University, Morehead, Kentucky, is small aperture (44-ft.) instrument designed by faculty, students, and industrial partners to provide a research instrument and active laboratory for undergraduate astronomy, physics, pre-engineering, and computer science students. Small aperture telescopes like the MRT have numerous advantages as active laboratories and as research instruments. The benefits to students are based upon a hands-on approach to learning concepts in astrophysics and engineering. Students are provided design and research challenges and are allowed to pursue their own solutions. Problem-solving abilities and research design skills are cultivated by this approach. Additionally, there are still contributions that small aperture centimeter-wave instruments can make. The MRT operates over a 6 MHz bandwidth centered at 1420 MHz (21-cm), which corresponds to the hyperfine transition of atomic hydrogen (HI). The HI spatial distribution and flux density associated with cosmic phenomena can be observed and mapped. The dynamics and kinematics of celestial objects can be investigated by observing over a range of frequencies (up to 2.5 MHz) with a 2048-channel back-end spectrometer, providing up to 1 KHz frequency resolution. The sensitivity and versatility of the telescope design facilitate investigation of a wide variety of cosmic phenomena, including supernova remnants, emission and planetary nebulae, extended HI emission from the Milky Way, quasars, radio galaxies, and the sun. Student observations of galactic sources herein reported include Taurus A, Cygnus X, and the Rosette Nebula. Additionally, we report observations of extragalactic phenomena, including Cygnus A, 3C 147, and 3C 146. These observations serve as a performance and capability test-bed of the MRT. In addition to the astronomical results of these

  16. Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology

    PubMed Central

    Schreiber, Eric C.; Chang, Sha X.

    2012-01-01

    Purpose: Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. Methods: Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 μm at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. Results: Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy/min/A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 μm. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 μm. Conclusions: Monte Carlo simulations demonstrate

  17. Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology

    SciTech Connect

    Schreiber, Eric C.; Chang, Sha X.

    2012-08-15

    Purpose: Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. Methods: Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 {mu}m at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. Results: Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy/min/A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 {mu}m. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 {mu}m. Conclusions: Monte Carlo simulations

  18. NYS: Tackling the Issue of High Users of Healthcare.

    PubMed

    Zucker, Howard A

    2014-01-01

    A disproportionate amount of healthcare costs in developed nations are attributed to a small percentage of high-needs patients. New York is no exception. Addressing the needs of this subgroup of Medicaid patients was part of reforms begun in 2011 with the creation of the Medicaid Redesign Team (MRT). The MRT successfully adopted 78 revisions to the Medicaid program. Some broad reforms target all Medicaid enrollees. The state also invested in two specific programs to meet the needs of high users: supportive housing and Health Homes. Close monitoring of both programs is underway and over time, will reveal the value of these two initiatives. PMID:25880864

  19. Investigating the Spatial Abilities of Students Taking Physics in Community College

    NASA Astrophysics Data System (ADS)

    Hossu, M. R.; Cid, X.; Lopez, R.

    2010-10-01

    Two independent tests that involve spatial visualization abilities, the PFT (Paper Folding Test) and the MRT (Mental Rotation Test) were given to different sections of introductory level physics students. The results show a strong correlation between the results of the two tests regardless of the different level of mathematics used in instruction (algebra or calculus). A statistically significant difference was found for both tests between the summer semester students (mostly 4-year university students) and the fall semester students (mostly community college students). No correlation was found between the PFT or MRT and FCI (Force Concept Inventory).

  20. Time to demand dosimetry for molecular radiotherapy?

    PubMed Central

    Guy, M J

    2015-01-01

    Molecular radiotherapy (MRT) has been used clinically for around 75 years. Despite this long history of clinical use, there is no established dosimetry practice for calculating the absorbed dose delivered to tumour targets or to organs at risk. As a result, treatment protocols have often evolved based on experience with relatively small numbers of patients, each receiving a similar administered activity but, potentially, widely varying doses. This is in stark contrast to modern external-beam radiotherapy practice. This commentary describes some of the barriers to MRT dosimetry and gives some opinions on the way forward. PMID:25571916

  1. 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.

  2. A statistical downscaling algorithm for thermal comfort applications

    NASA Astrophysics Data System (ADS)

    Rayner, David; Lindberg, Fredrik; Thorsson, Sofia; Holmer, Björn

    2015-11-01

    We describe a new two-step modeling framework for investigating the impact of climate change on human comfort in outdoor urban environments. In the first step, climate change scenarios for air temperature and solar radiation (global, diffuse, direct components) are created using a change-factor algorithm. The change factors are calculated by comparing ranked daily regional climate model outputs for a future-period and a present-day period, and then changes consistent with these daily change factors are applied to historical hourly climate observations. In the second step, the mean-radiant-temperature ( T mrt) is calculated using the SOLWEIG (SOlar and LongWave Environmental Irradiance Geometry) model. T mrt, which describes the radiant heat exchange between a person and their surroundings, is one of the most important meteorologically derived parameters governing human energy balance and outdoor thermal comfort, especially during warm and sunny days. We demonstrate that change factors can be applied independently to maximum air temperature and daily global solar radiation, and show that the outputs from the algorithm, when aggregated to daily values, are consistent with the driving regional climate model. Finally, we demonstrate how to obtain quantitative information from the scenarios regarding the potential impact of climate change on outdoor thermal comfort, by calculating changes in the distribution of hourly summer day-time T mrt and changes in the number of hours with T mrt >55 °C.

  3. 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…

  4. 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…

  5. 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),…

  6. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

    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.

  8. 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…

  9. 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…

  10. 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…

  11. 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

  12. Fibroblast Growth Factor Receptors as Novel Therapeutic Targets in SNF5-Deleted Malignant Rhabdoid Tumors

    PubMed Central

    Wöhrle, Simon; Jagani, Zainab; Thuery, Anne; Bauer-Probst, Beatrice; Reimann, Flavia; Stamm, Christelle; Pornon, Astrid; Romanet, Vincent; Guagnano, Vito; Brümmendorf, Thomas; Sellers, William R.; Hofmann, Francesco; Roberts, Charles W. M.; Graus Porta, Diana

    2013-01-01

    Malignant rhabdoid tumors (MRTs) are aggressive pediatric cancers arising in brain, kidney and soft tissues, which are characterized by loss of the tumor suppressor SNF5/SMARCB1. MRTs are poorly responsive to chemotherapy and thus a high unmet clinical need exists for novel therapies for MRT patients. SNF5 is a core subunit of the SWI/SNF chromatin remodeling complex which affects gene expression by nucleosome remodeling. Here, we report that loss of SNF5 function correlates with increased expression of fibroblast growth factor receptors (FGFRs) in MRT cell lines and primary tumors and that re-expression of SNF5 in MRT cells causes a marked repression of FGFR expression. Conversely, siRNA-mediated impairment of SWI/SNF function leads to elevated levels of FGFR2 in human fibroblasts. In vivo, treatment with NVP-BGJ398, a selective FGFR inhibitor, blocks progression of a murine MRT model. Hence, we identify FGFR signaling as an aberrantly activated oncogenic pathway in MRTs and propose pharmacological inhibition of FGFRs as a potential novel clinical therapy for MRTs. PMID:24204904

  13. Discrete effect on the halfway bounce-back boundary condition of multiple-relaxation-time lattice Boltzmann model for convection-diffusion equations

    NASA Astrophysics Data System (ADS)

    Cui, Shuqi; Hong, Ning; Shi, Baochang; Chai, Zhenhua

    2016-04-01

    In this paper, we will focus on the multiple-relaxation-time (MRT) lattice Boltzmann model for two-dimensional convection-diffusion equations (CDEs), and analyze the discrete effect on the halfway bounce-back (HBB) boundary condition (or sometimes called bounce-back boundary condition) of the MRT model where three different discrete velocity models are considered. We first present a theoretical analysis on the discrete effect of the HBB boundary condition for the simple problems with a parabolic distribution in the x or y direction, and a numerical slip proportional to the second-order of lattice spacing is observed at the boundary, which means that the MRT model has a second-order convergence rate in space. The theoretical analysis also shows that the numerical slip can be eliminated in the MRT model through tuning the free relaxation parameter corresponding to the second-order moment, while it cannot be removed in the single-relaxation-time model or the Bhatnagar-Gross-Krook model unless the relaxation parameter related to the diffusion coefficient is set to be a special value. We then perform some simulations to confirm our theoretical results, and find that the numerical results are consistent with our theoretical analysis. Finally, we would also like to point out the present analysis can be extended to other boundary conditions of lattice Boltzmann models for CDEs.

  14. 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.

  15. Primary Mental Abilities and Metropolitan Readiness Tests as Predictors of Achievement in the First Primary Year.

    ERIC Educational Resources Information Center

    University City School District, MO.

    The prediction of achievement provides teachers with necessary information to help children attain optimal achievement. If some skill prerequistites to learning which are not fully developed can be identified and strengthened, higher levels of achievement may result. The Metropolitan Readiness Tests (MRT) are routinely given to all University City…

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

    PubMed

    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. PMID:26852384

  17. The Effects of Written Language Awareness on First Grade Reading Achievement.

    ERIC Educational Resources Information Center

    Taylor, Nancy E.; Blum, Irene H.

    A battery of four reading readiness assessment tasks was administered to 267 first grade students to determine if the tasks predicted reading achievement as well as the Metropolitan Readiness Test (MRT). The four tasks, which were the best predictors in a previous study of seven readiness tasks, were the aural word boundaries task, the…

  18. 78 FR 61843 - Notice of Intent To Prepare an Environmental Impact Statement: Department of the Army Permit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-04

    ... crossings of the Federal Mississippi River and Tributaries (MR&T) Levee and the future New Orleans to Venice (NOV) Hurricane Protection Levee and could impact the Mississippi River Navigation Channel, Davis Pond... connection between the Mississippi River and the Basin to build, sustain, and maintain land. CPRA...

  19. 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.

    2016-02-01

    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.

  20. No sex differences in the TAMI.

    PubMed

    Madan, Christopher R; Singhal, Anthony

    2015-05-01

    The Test of Ability in Movement Imagery (TAMI; Madan and Singhal in J Mot Behav 45:153-166, 2013) has recently been developed as an objective measure for evaluating individual ability in movement imagery. Other tests of imagery have reported sex differences, including the mental rotations test (MRT) and the Vividness of Movement Imagery Questionnaire (VMIQ). However, some have attributed these observed sex differences to other processes, such as difference in spatial abilities and confidence. Here, we tested for sex differences in the TAMI in a large sample of young adults (N = 246). In the same sample, we also administered a modified version of the MRT that included both block configurations and human figures and the VMIQ2. This modified MRT was used, as the imagery processes involved in the TAMI may be more similar to those involved in the rotations of human figures. While strong sex differences were found in both subscales of the modified MRT, no sex differences were observed in the TAMI. PMID:25480111

  1. Lattice Boltzmann simulations of 2D laminar flows past two tandem cylinders

    NASA Astrophysics Data System (ADS)

    Mussa, Alberto; Asinari, Pietro; Luo, Li-Shi

    2009-03-01

    We apply the lattice Boltzmann equation (LBE) with multiple-relaxation-time (MRT) collision model to simulate laminar flows in two-dimensions (2D). In order to simulate flows in an unbounded domain with the LBE method, we need to address two issues: stretched non-uniform mesh and inflow and outflow boundary conditions. We use the interpolated grid stretching method to address the need of non-uniform mesh. We demonstrate that various inflow and outflow boundary conditions can be easily and consistently realized with the MRT-LBE. The MRT-LBE with non-uniform stretched grids is first validated with a number of test cases: the Poiseuille flow, the flow past a cylinder asymmetrically placed in a channel, and the flow past a cylinder in an unbounded domain. We use the LBE method to simulate the flow past two tandem cylinders in an unbounded domain with Re = 100. Our results agree well with existing ones. Through this work we demonstrate the effectiveness of the MRT-LBE method with grid stretching.

  2. Measurements of magneto-Rayleigh-Taylor instability growth in solid liners on the 20 MA Z facility

    NASA Astrophysics Data System (ADS)

    Sinars, Daniel

    2010-11-01

    The magneto-Rayleigh-Taylor (MRT) instability is the most important instability for determining whether a cylindrical liner can be compressed to its axis in a relatively intact form, a requirement for achieving the high pressures needed for inertial confinement fusion (ICF) and other high energy-density physics applications. While there are many published RT studies, there are a handful of well-characterized MRT experiments at time scales >1 μs and none for 100 ns z-pinch implosions. Experiments used solid Al liners with outer radii of 3.16 mm and thicknesses of 292 μm, dimensions similar to magnetically-driven ICF target designs [1]. In most tests the MRT instability was seeded with sinusoidal perturbations (λ=200, 400 μm, peak-to-valley amplitudes of 10, 20 μm, respectively), wavelengths similar to those predicted to dominate near stagnation. Radiographs show the evolution of the MRT instability and the effects of current-induced ablation of mass from the liner surface. Additional Al liner tests used 25-200 μm wavelengths and flat surfaces. Codes being used to design magnetized liner ICF loads [1] match the features seen except at the smallest scales (<50 μm). Recent experiments used Be liners to enable penetrating radiography using the same 6.151 keV diagnostics and provide an in-flight measurement of the liner density profile.[4pt] [1] S.A. Slutz et al., Phys. Plasmas 17, 056303 (2010).

  3. Measurements of Magneto-Rayleigh-Taylor instability growth in solid liners on the 20 MA Z facility.

    SciTech Connect

    Bigman, Verle; Vesey, Roger Alan; Shores, Jonathon; Herrmann, Mark C.; Stamm, Robert; Killebrew, Korbie; Holt, Randy; Blue, Brent; Nakhleh, Charlie; McBride, Ryan D.; Leifeste, Gordon T.; Smith, Ian Craig; Stygar, William A.; Porter, John Larry, Jr.; Cuneo, Michael Edward; Bennett, Guy R.; Schroen, Diana Grace; Sinars, Daniel Brian; Lopez, Mike R.; Slutz, Stephen A.; Atherton, Briggs W.; Tomlinson, Kurt; Edens, Aaron D.; Savage, Mark Edward; Peterson, Kyle J.

    2010-07-01

    The magneto-Rayleigh-Taylor (MRT) instability is the most important instability for determining whether a cylindrical liner can be compressed to its axis in a relatively intact form, a requirement for achieving the high pressures needed for inertial confinement fusion (ICF) and other high energy-density physics applications. While there are many published RT studies, there are a handful of well-characterized MRT experiments at time scales >1 {micro}s and none for 100 ns z-pinch implosions. Experiments used solid Al liners with outer radii of 3.16 mm and thicknesses of 292 {micro}m, dimensions similar to magnetically-driven ICF target designs [1]. In most tests the MRT instability was seeded with sinusoidal perturbations ({lambda} = 200, 400 {micro}m, peak-to-valley amplitudes of 10, 20 {micro}m, respectively), wavelengths similar to those predicted to dominate near stagnation. Radiographs show the evolution of the MRT instability and the effects of current-induced ablation of mass from the liner surface. Additional Al liner tests used 25-200 {micro}m wavelengths and flat surfaces. Codes being used to design magnetized liner ICF loads [1] match the features seen except at the smallest scales (<50 {micro}m). Recent experiments used Be liners to enable penetrating radiography using the same 6.151 keV diagnostics and provide an in-flight measurement of the liner density profile.

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

    PubMed

    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

  5. Discrete effect on the halfway bounce-back boundary condition of multiple-relaxation-time lattice Boltzmann model for convection-diffusion equations.

    PubMed

    Cui, Shuqi; Hong, Ning; Shi, Baochang; Chai, Zhenhua

    2016-04-01

    In this paper, we will focus on the multiple-relaxation-time (MRT) lattice Boltzmann model for two-dimensional convection-diffusion equations (CDEs), and analyze the discrete effect on the halfway bounce-back (HBB) boundary condition (or sometimes called bounce-back boundary condition) of the MRT model where three different discrete velocity models are considered. We first present a theoretical analysis on the discrete effect of the HBB boundary condition for the simple problems with a parabolic distribution in the x or y direction, and a numerical slip proportional to the second-order of lattice spacing is observed at the boundary, which means that the MRT model has a second-order convergence rate in space. The theoretical analysis also shows that the numerical slip can be eliminated in the MRT model through tuning the free relaxation parameter corresponding to the second-order moment, while it cannot be removed in the single-relaxation-time model or the Bhatnagar-Gross-Krook model unless the relaxation parameter related to the diffusion coefficient is set to be a special value. We then perform some simulations to confirm our theoretical results, and find that the numerical results are consistent with our theoretical analysis. Finally, we would also like to point out the present analysis can be extended to other boundary conditions of lattice Boltzmann models for CDEs. PMID:27176432

  6. 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

  7. Progesterone and Mental Rotation Task: Is There Any Effect?

    PubMed Central

    Noreika, Donatas; Griškova-Bulanova, Inga; Alaburda, Aidas; Baranauskas, Mindaugas; Grikšienė, Ramunė

    2014-01-01

    Mental rotation task (MRT) incorporates elements of spatial abilities, important in many professions, with people of both genders involved. Importantly, these are the areas where spatial tasks might be performed for long time periods; thus adverse effects of mental fatigue are highly unwanted. Substantial variation of MRT performance in relation to estrogen levels has been observed in many studies, whereas the role of progesterone remains elusive. Here we aimed to elucidate the effect of progesterone level on the long-duration (1.5 hours) performance of MRT. We included three groups of subjects: a group of males as a control, a group of females in their follicular phase (low progesterone) and a group of females in their luteal phase (high progesterone), MRT accuracy and response time, subjective fatigue ratings and cardiovascular measures together with 17β-estradiol and progesterone concentrations were analyzed. We found that subjective ratings of fatigue increased, performance accuracy increased, and mean response times decreased during the task in all groups. Females in luteal phase were significantly slower not only than men, but also than females in their follicular phase. An increase in subjective fatigue ratings was positively related to progesterone level—at higher progesterone levels, females felt more tired. PMID:24818150

  8. 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.

  9. 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.…

  10. A Preliminary Screening Program to Identify Functioning Strengths and Weaknesses in Preschool Children.

    ERIC Educational Resources Information Center

    Amundson, Marian Stuehrenberg

    The purpose of this study was to compare two instruments for screening preschool children for potential learning problems. The two instruments used were the Metropolitan Readiness Tests (MRT) and the Wizard of Oz Preschool Preliminary Screening Program. The children tested on both measures were members of a self-contained kindergarten class. MRT…

  11. 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.

  12. On the Relationship between Solution Strategies in Two Mental Rotation Tasks

    ERIC Educational Resources Information Center

    Janssen, Anne B.; Geiser, Christian

    2010-01-01

    Individual differences in solution strategies have frequently been reported for different measures of mental rotation (MR) ability. In the present study (N=346 German students), we investigated the relationship between solution strategies on two tests commonly used to identify different patterns of strategies: the Mental Rotations Test (MRT;…

  13. 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.

  14. 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…

  15. Fibroblast growth factor receptors as novel therapeutic targets in SNF5-deleted malignant rhabdoid tumors.

    PubMed

    Wöhrle, Simon; Weiss, Andreas; Ito, Moriko; Kauffmann, Audrey; Murakami, Masato; Jagani, Zainab; Thuery, Anne; Bauer-Probst, Beatrice; Reimann, Flavia; Stamm, Christelle; Pornon, Astrid; Romanet, Vincent; Guagnano, Vito; Brümmendorf, Thomas; Sellers, William R; Hofmann, Francesco; Roberts, Charles W M; Graus Porta, Diana

    2013-01-01

    Malignant rhabdoid tumors (MRTs) are aggressive pediatric cancers arising in brain, kidney and soft tissues, which are characterized by loss of the tumor suppressor SNF5/SMARCB1. MRTs are poorly responsive to chemotherapy and thus a high unmet clinical need exists for novel therapies for MRT patients. SNF5 is a core subunit of the SWI/SNF chromatin remodeling complex which affects gene expression by nucleosome remodeling. Here, we report that loss of SNF5 function correlates with increased expression of fibroblast growth factor receptors (FGFRs) in MRT cell lines and primary tumors and that re-expression of SNF5 in MRT cells causes a marked repression of FGFR expression. Conversely, siRNA-mediated impairment of SWI/SNF function leads to elevated levels of FGFR2 in human fibroblasts. In vivo, treatment with NVP-BGJ398, a selective FGFR inhibitor, blocks progression of a murine MRT model. Hence, we identify FGFR signaling as an aberrantly activated oncogenic pathway in MRTs and propose pharmacological inhibition of FGFRs as a potential novel clinical therapy for MRTs. PMID:24204904

  16. New lifting relations for estimating LBM distribution functions from corresponding macroscopic quantities, based on equilibrium and non-equilibrium moments

    NASA Astrophysics Data System (ADS)

    Salimi, M. R.; Taeibi-Rahni, M.

    2015-12-01

    Due to superior accuracy and stability of multiple relaxation time (MRT) collision operator over its single relaxation time (SRT) counterpart, new lifting relations are proposed here to construct single particle distribution functions for MRT-LBM from macroscopic variables. Using these lifting relations, a new hybrid FVM-LB method is presented (called Finite type-LB hybrid method), which is consistent with MRT-LBM. In this new hybrid method, single-particle distribution functions in MRT-LBM sub-domain boundaries are computed, using equilibrium and non-equilibrium moments. These moments are computed in Navier-Stokes/FVM sub-domain boundaries, using macroscopic variables and their derivatives. The new method is validated by solving three benchmark problems, i.e., two- and three-dimensional lid driven cavity flows and two-dimensional unsteady flow around a squared section cylinder. These problems are analyzed with pure FVM, pure LBM, and Finite type-LB hybrid method (FTLBHM) and the related results are compared with each other and with benchmark data. These comparisons clearly demonstrate the accuracy of the present novel methodology for simulating steady/unsteady flow fields in two and three dimensions.

  17. 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…

  18. Progesterone and mental rotation task: is there any effect?

    PubMed

    Noreika, Donatas; Griškova-Bulanova, Inga; Alaburda, Aidas; Baranauskas, Mindaugas; Grikšienė, Ramunė

    2014-01-01

    Mental rotation task (MRT) incorporates elements of spatial abilities, important in many professions, with people of both genders involved. Importantly, these are the areas where spatial tasks might be performed for long time periods; thus adverse effects of mental fatigue are highly unwanted. Substantial variation of MRT performance in relation to estrogen levels has been observed in many studies, whereas the role of progesterone remains elusive. Here we aimed to elucidate the effect of progesterone level on the long-duration (1.5 hours) performance of MRT. We included three groups of subjects: a group of males as a control, a group of females in their follicular phase (low progesterone) and a group of females in their luteal phase (high progesterone), MRT accuracy and response time, subjective fatigue ratings and cardiovascular measures together with 17 β -estradiol and progesterone concentrations were analyzed. We found that subjective ratings of fatigue increased, performance accuracy increased, and mean response times decreased during the task in all groups. Females in luteal phase were significantly slower not only than men, but also than females in their follicular phase. An increase in subjective fatigue ratings was positively related to progesterone level-at higher progesterone levels, females felt more tired. PMID:24818150

  19. 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...

  20. [Stress fracture of the ulna in a table tennis player].

    PubMed

    Dufek, P; Ostendorf, U; Thormählen, F

    1999-06-01

    This case report describes a stress fracture of the ulna in a 26-year-old professional table-tennis player. X-ray films remained negative so that the diagnostic is based on MRT. This stress fracture is caused by changing the intensity of training and changing the table-tennis-racket. PMID:10478391

  1. Radiocarbon-based residence time estimates of soil organic carbon in a temperate forest: Case study for the density fractionation for Japanese volcanic ash soil

    NASA Astrophysics Data System (ADS)

    Kondo, Miyuki; Uchida, Masao; Shibata, Yasuyuki

    2010-04-01

    The world's soils store significantly more carbon than that is present in the atmosphere. To understand the distribution and dynamics of the soil organic carbon (SOC) reservoir and make a prediction about the response of the soil carbon pool to climate change, it is necessary to quantitatively constrain rate of soil carbon cycling. Following previous studies [24], we investigated the method for physically preparation of Japanese volcanic ash soil for the mean residence time (MRT) estimates in a cool-temperate deciduous forest in Japan, at one of Asia Flux monitoring sites. Sequentially isolated density fractions clearly differed in C contents and C/N ratios in soil surface (3-8 cm) and deep soil layer (38-43 cm). In soil surface layer, the light fractions (1.6-1.8, 1.6-1.8, 1.8-2.1 g cm -3) accounted for nearly 90% of SOC and their MRT ranged from 6 to 150 year. In deep layer, the 2.1-2.4 g cm -3 fraction accounted for more than 60% of SOC and its MRT was 3100 year. The lighter fractions (1.6-1.8, 1.8-2.1) comprised small portion of total SOC and were significantly slowly MRT (2038-2335 year), although it seems to consist of labile carbon.

  2. Explaining sex differences in mental rotation: role of spatial activity experience.

    PubMed

    Nazareth, Alina; Herrera, Asiel; Pruden, Shannon M

    2013-05-01

    Males consistently outperform females on mental rotation tasks, such as the Vandenberg and Kuse (1978) Perceptual and Motor Skills, 47(2), 599-604, mental rotation test (MRT; e.g. Voyer et al. 1995) in Psychological Bulletin, 117, 250-265. The present study investigates whether these sex differences in MRT scores can be explained in part by early spatial activity experience, particularly those spatial activities that have been sex-typed as masculine/male-oriented. Utilizing an online survey, 571 ethnically diverse adult university students completed a brief demographic survey, an 81-item spatial activity survey, and the MRT. Results suggest that the significant relation between sex of the participant and MRT score is partially mediated by the number of masculine spatial activities participants had engaged in as youth. Closing the gap between males and females in spatial ability, a skill linked to science, technology, engineering, and mathematics success, may be accomplished in part by encouraging female youth to engage in more particular kinds of spatial activities. PMID:23381194

  3. [Magnetic resonance tomography in late sequelae of spinal and spinal cord injuries].

    PubMed

    Kravtsov, A K; Akhadov, T A; Sachkova, I Iu; Belov, S A; Chernenko, O A; Panova, M M

    1993-01-01

    Magnetic-resonance tomography (MRT) helped obtain a high-resolution image characterized by high sensitivity in respect of soft tissue contrast visualization and providing direct imaging of the spinal cord and its radicles. This method is useful in the diagnosis of injuries to the spine and cord. A total of 64 patients of both sexes aged 6 to 67 were examined. The primary diagnosis of traumatic changes in the spine and cord was confirmed by MRT in only 62% of cases. Two groups of patients were singled out: with acute and chronic injuries, subdivided into subgroups with and without spinal cord dysfunction. The detected changes were divided into extramedullary (traumatic disk hernias, compression of the cord or radicles with a dislocated bone fragment, epidural hematoma) and intramedullary (edema, hemorrhages, spinal cord disruption); MRT diagnosis of intramedullary changes is particularly important, more so in the absence of bone injuries. In remote periods after the trauma the clinical picture was determined by spinal canal stenosis, cicatricial atrophic and adhesive changes eventually blocking the liquor space. Intramedullary changes presented as spinal cord cysts or syringomyelia. A classification of the detected changes by the types of injuries and their aftereffects is presented in the paper. The authors emphasize the desirability of MRT in spinal injuries with signs of cord dysfunction. PMID:7801568

  4. 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

  5. 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…

  6. Validity of the Bracken School Readiness Assessment for Predicting First Grade Readiness

    ERIC Educational Resources Information Center

    Panter, Janet E.; Bracken, Bruce A.

    2009-01-01

    The Bracken School Readiness Assessment (BSRA) was administered to all kindergarten students enrolled in two rural elementary schools in the fall of 2004. Eight months later, the reading portion of the Metropolitan Readiness Tests, 6th Edition (MRT-6) was administered. Teachers were asked to indicate whether they had concerns about each student's…

  7. Computed tomography model-based treatment of atrial fibrillation and atrial macro-re-entrant tachycardia

    PubMed Central

    Piorkowski, Christopher; Kircher, Simon; Arya, Arash; Gaspar, Thomas; Esato, Masahiro; Riahi, Sam; Bollmann, Andreas; Husser, Daniela; Staab, Charlotte; Sommer, Philipp; Hindricks, Gerhard

    2008-01-01

    Aims Accurate orientation within true three-dimensional (3D) anatomies is essential for the successful radiofrequency (RF) catheter ablation of atrial fibrillation (AF) and atrial macro-re-entrant tachycardia (MRT). In this prospective study, ablation of AF and MRT was performed exclusively using a pre-acquired and integrated computed tomography (CT) image for anatomical 3D orientation without electro-anatomic reconstruction of the left atrium (LA). Methods and results Fifty-four consecutive patients suffering from AF (n = 36) and/or MRT (n = 18) underwent RF catheter ablation. A 3D CT image was registered into the NavX-Ensite system without reconstruction of the atrial chamber anatomy. The quality of CT alignment was assessed and validated according to fluoroscopy information, electrogram characteristics, and tactile feedback at 31 pre-defined LA control points. The ablation of AF as well as mapping and ablation of MRT was performed within the 3D CT anatomy. In all patients, mapping and ablation could be performed without the reconstruction of the respective atrial chamber anatomy. The overall CT alignment was highly accurate with true surface contact in 90% (84%; 100%) of the control points. Complete isolation of all pulmonary vein (PV) funnels was achieved in 35 of 36 patients (97%) with AF. In patients with persistent AF (n = 11), additional isolation of the posterior LA (box lesion) and the placement of a mitral isthmus line were performed. The MRT mechanisms were as follows: around a PV ostium (n = 6), perimitral (n = 4), through LA roof (n = 5), septal (n = 2), and around left atrial appendage (n = 1). After a follow-up of 122 ± 33 days, 22/25 (88%) patients with paroxysmal AF, 8/11 (73%) with persistent AF, and 16/18 (89%) with MRT remained free from arrhythmia recurrences. Conclusion For patients with AF and MRT, our study shows the feasibility of successful placement of complex linear ablation line concepts guided by an integrated 3D image anatomy alone

  8. Estradiol and mental rotation: relation to dimensionality, difficulty, or angular disparity?

    PubMed

    Hampson, Elizabeth; Levy-Cooperman, Na'ama; Korman, Jennifer M

    2014-03-01

    Several studies have reported that performance on spatial rotation tests is better at menses than at high estradiol phases of the menstrual cycle in women. These effects are debated because nearly all reports of menstrual cycle variability have relied on a single test, the Mental Rotations Test (MRT, Vandenberg and Kuse, 1978). In the present study, we investigated key features of the MRT that might be responsible for its association with estradiol levels. We hypothesized that associations could be demonstrated for other tasks that share the same characteristics. Forty-four women ages 20-38 years, matched on education and general ability, were assessed at low (n=24) or high (n=20) estradiol stages of the menstrual cycle on a set of spatial tests that varied in dimensionality, plane of rotation, angular disparity, and effortfulness. Saliva was used to quantify estradiol and progesterone. Low estradiol was found to be associated with significantly better accuracy on the MRT and also on a mental rotation task that required large angles of rotation but employed only two-dimensional object representations and rotations limited to the picture plane. In contrast, a task using identical stimuli that required only small angles of rotation did not show an estradiol effect. A group difference also was seen on a test of perceptual closure. The results confirm that the estradiol effect is not limited to the MRT, and identify the rotational element, but also aspects of figural perception, as possible processes that may be responsive to estrogens. These findings advance our understanding by showing an association between estradiol and discrete spatial processes. Implications for understanding the origins of the robust sex difference commonly observed on the MRT are discussed. PMID:24394702

  9. 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

  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. PMID:27452637

  12. Low ambient temperature elevates plasma triiodothyronine concentrations while reducing digesta mean retention time and methane yield in sheep.

    PubMed

    Barnett, M C; McFarlane, J R; Hegarty, R S

    2015-06-01

    Ruminant methane yield (MY) is positively correlated with mean retention time (MRT) of digesta. The hormone triiodothyronine (T3 ), which is negatively correlated with ambient temperature, is known to influence MRT. It was hypothesised that exposing sheep to low ambient temperatures would increase plasma T3 concentration and decrease MRT of digesta within the rumen of sheep, resulting in a reduction of MY. To test this hypothesis, six Merino sheep were exposed to two different ambient temperatures (cold treatment, 9 ± 1 °C; warm control 26 ± 1 °C). The effects on MY, digesta MRT, plasma T3 concentration, CO2 production, DM intake, DM digestibility, change in body weight (BW), rumen volatile fatty acid (VFA) concentrations, estimated microbial protein output, protozoa abundance, wool growth, water intake, urine output and rectal temperature were studied. Cold treatment resulted in a reduction in MY (p < 0.01); digesta MRT in rumen (p < 0.01), hindgut (p = 0.01) and total digestive tract (p < 0.01); protozoa abundance (p < 0.05); and water intake (p < 0.001). Exposure to cold temperature increased plasma T3 concentration (p < 0.05), CO2 production (p = 0.01), total VFA concentrations (p = 0.03) and estimated microbial output from the rumen (p = 0.03). The rate of wool growth increased (p < 0.01) due to cold treatment, but DM intake, DM digestibility and BW change were not affected. The results suggest that exposure of sheep to cold ambient temperatures reduces digesta retention time in the gastrointestinal tract, leading to a reduction in enteric methane yield. Further research is warranted to determine whether T3 could be used as an indirect selection tool for genetic selection of low enteric methane-producing ruminants. PMID:25271888

  13. 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.

  14. Assessing the Jarman-Bell Principle: Scaling of intake, digestibility, retention time and gut fill with body mass in mammalian herbivores.

    PubMed

    Müller, Dennis W H; Codron, Daryl; Meloro, Carlo; Munn, Adam; Schwarm, Angela; Hummel, Jürgen; Clauss, Marcus

    2013-01-01

    Differences in allometric scaling of physiological characters have the appeal to explain species diversification and niche differentiation along a body mass (BM) gradient - because they lead to different combinations of physiological properties, and thus may facilitate different adaptive strategies. An important argument in physiological ecology is built on the allometries of gut fill (assumed to scale to BM(1.0)) and energy requirements/intake (assumed to scale to BM(0.75)) in mammalian herbivores. From the difference in exponents, it has been postulated that the mean retention time (MRT) of digesta should scale to BM(1.0-0.75)=BM(0.25). This has been used to argue that larger animals have an advantage in digestive efficiency and hence can tolerate lower-quality diets. However, empirical data does not support the BM(0.25) scaling of MRT, and the deduction of MRT scaling implies, according to physical principles, no scaling of digestibility; basing assumptions on digestive efficiency on the thus-derived MRT scaling amounts to circular reasoning. An alternative explanation considers a higher scaling exponent for food intake than for metabolism, allowing larger animals to eat more of a lower quality food without having to increase digestive efficiency; to date, this concept has only been explored in ruminants. Here, using data for 77 species in which intake, digestibility and MRT were measured (allowing the calculation of the dry matter gut contents (DMC)), we show that the unexpected shallow scaling of MRT is common in herbivores and may result from deviations of other scaling exponents from expectations. Notably, DMC have a lower scaling exponent than 1.0, and the 95% confidence intervals of the scaling exponents for intake and DMC generally overlap. Differences in the scaling of wet gut contents and dry matter gut contents confirm a previous finding that the dry matter concentration of gut contents decreases with body mass, possibly compensating for the less

  15. 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

  16. Clinical variability of cyclosporine pharmacokinetics in adult and pediatric patients after renal, cardiac, hepatic, and bone-marrow transplants.

    PubMed

    Clardy, C W; Schroeder, T J; Myre, S A; Wadhwa, N K; Pesce, A J; First, M R; McEnery, P T; Balistreri, W F; Harris, R E; Melvin, D B

    1988-10-01

    The most important limitation associated with the clinical use of cyclosporine is the narrow therapeutic range between its efficacy and toxicity. Effective treatment is further complicated by significant variation in intrapatient and interpatient pharmacokinetics of the drug. We describe a practical approach to pharmacokinetic analysis that does not interfere with the cyclosporine dosage regimen or with clinical management of the patient. To optimize therapy, we individualized patient management by using noncompartmental pharmacokinetic analysis. Mean residence time (MRT) and volume of distribution at steady-state were calculated from data on concentration vs time after dose. We applied this approach to 24 kidney, 12 heart, 8 bone-marrow, 7 liver, and 5 pancreas transplants. Individualized requirements for cyclosporine dose and dosage interval can be predicted from these parameters. MRT is the most useful pharmacokinetic parameter, because it allows prediction of the optimal dosage interval. PMID:3048779

  17. Mitochondrial replacement therapy in reproductive medicine.

    PubMed

    Wolf, Don P; Mitalipov, Nargiz; Mitalipov, Shoukhrat

    2015-02-01

    Mitochondrial dysfunction is implicated in disease and age-related infertility. Mitochondrial replacement therapies (MRT) in oocytes or zygotes, such as pronuclear (PNT), spindle (ST), or polar body (PBT) transfer, could prevent second-generation transmission of mitochondrial DNA (mtDNA) defects. PNT, associated with high levels of mtDNA carryover in mice but low levels in human embryos, carries ethical issues secondary to donor embryo destruction. ST, developed in primates, supports normal development to adults and low mtDNA carryover. PBT in mice, coupled with PN or ST, may increase the yield of reconstructed embryos with low mtDNA carryover. MRT also offers replacement of the deficient cytoplasm in oocytes from older patients, with the expectation of high pregnancy rates following in vitro fertilization. PMID:25573721

  18. 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. PMID:19070022

  19. 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. PMID:18954272

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    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.

  1. 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%.

  2. 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. PMID:24741344

  3. 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

  4. 2D HYDRA Calculations of Magneto-Rayleigh-Taylor Growth and Feedthrough in Cylindrical Liners

    NASA Astrophysics Data System (ADS)

    Weis, Matthew; Zhang, Peng; Lau, Y. Y.; Gilgenbach, Ronald; Peterson, Kyle; Hess, Mark

    2014-10-01

    Cylindrical liner implosions are susceptible to the magneto-Rayleigh-Taylor instability (MRT), along with the azimuthal current-carrying modes (sausage, kink, etc). ``Feedthrough'' of these instabilities has a strong influence on the integrity of the liner/fuel interface in the magnetized liner inertial fusion concept (MagLIF). The linearized ideal MHD equations can be solved to quantify these effects, including the presence of an effective gravity and an axial magnetic field. We investigate the potential of this field to mitigate feedthrough, due to MRT growth from various initial surface finishes (seeded, rough), throughout the implosion using our analytic results and the LLNL code, HYDRA. We will present both low and high convergence cases. Lastly, we illustrate the effect shock compression can have on feedthrough in seeded liners for various fill gases (cold and pre-heated) and magnetic field configurations. M. R. Weis was supported by the Sandia National Laboratories.

  5. Magneto-Rayleigh-Taylor, Sausage And Kink Mode In Cylindrical Liners

    NASA Astrophysics Data System (ADS)

    Lau, Y. Y.; Zhang, Peng; Weis, Matthew; Gilgenbach, Ronald; Hess, Mark; Peterson, Kyle

    2014-10-01

    This paper analyzes the coupling of magneto-Rayleigh-Taylor (MRT), sausage (azimuthal mode number m = 0) and kink mode (m = 1) 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, the feedthrough factor, and the temporal evolution of perturbations were solved exactly, for arbitrary values of g (= gravity), k (= axial wavenumber), m, 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. This analysis might shed lights into some puzzling features in Harris' classic paper, and in the recent cylindrical liner experiments on MRT. M. R. Weis was supported by the Sandia National Laboratories.

  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. Fractionating soils so that others do not have to: radiocarbon informs choice of method for scale, ecosystem, or process

    NASA Astrophysics Data System (ADS)

    Crow, S. E.

    2011-12-01

    Physical separation of soil into various fractions has long been used to address questions concerning mechanisms of soil organic matter stabilization, processes contributing to soil carbon (C) accumulation, and the effects of land use, climate change, and management practice on soil quality and carbon sequestration. However, no published method works well for every soil, ecosystem, or research question. Often a chosen method does not effectively separate soil into C pools that differ in mean residence time (MRT) and sensitivity to change, which can complicate the interpretation of results. Soil C is stabilized by a variety of mechanisms and radiocarbon-based estimates of MRT can reveal the integrated effects of these mechanisms on bulk soil C storage; radiocarbon-based estimates of MRT on isolated soil fractions separated by a carefully chosen method can reveal internal C dynamics invisible to the bulk soil methods. A variety of soils collected around Hawaii (Mollisol, Oxisol, Andisol) were fractionated by several common methods and the radiocarbon-based MRT was estimated for comparison among fractions, soils, and methods. In some cases, depending on the research question of interest, aspects of different methods could be combined to reveal changes in soil C pools on both short and long time frames. For example, for a cultivated, mixed-mineralogy Mollisol, a method that combined a density separation at 1.8 g mL-1 for free light fraction, then calibrated sonication to disrupt aggregates for an occluded fraction, then further sequential fractionation at 2.0 g -1could produce soil C pools with turnover of 3.5 yr (free light fraction), 10 yr (occluded light fraction), 714 yr (1.8-2.0 fraction), and 2090 yr (<2.0 fraction). This method may be ideal for tracking short-term (1-10 year) changes in soil structure due to sustainable agriculture or management practices. For an Andisol, land conversion from old-growth native forest to 80 yr of pasture increased bulk soil C

  8. Mitigation of Electrothermal Instabilities with Thick Insulating Coatings

    NASA Astrophysics Data System (ADS)

    Peterson, Kyle; Awe, Thomas; Yu, Edmund; Sinars, Daniel; Cuneo, Michael

    2013-10-01

    We will show results of recent experiments on Sandia's Z facility that demonstrate a dramatic reduction in instability growth when thick insulating coatings are used to mitigate electrothermal instability growth in magnetically driven imploding liners. These results also provide further evidence that the inherent surface roughness as a result of target fabrication is not the dominant seed for the growth of Magneto-Rayleigh-Taylor (MRT) instabilities in liners with carefully machined smooth surfaces (~100 nm surface RMS or better), but rather electrothermal instabilities that form early in the electrical current pulse as Joule heating melts and vaporizes the liner surface. More importantly, these results suggest a mechanism for possibly reducing the integral MRT instability growth substantially in magnetically driven inertial confinement fusion concepts such as MagLIF. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  9. 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.

  10. Impact of load geometry on plasma formation and radiative properties of Z-pinches at stagnation

    NASA Astrophysics Data System (ADS)

    Kantsyrev, V. L.; Safronova, A. S.; Esaulov, A. A.; Velikovich, A. L.; Rudakov, L. I.; Chuvatin, A. S.; Williamson, K. M.; Yilmaz, M. F.; Osborne, G. C.; Weller, M. E.; Shrestha, I.; Shlyaptseva, V. V.

    2009-11-01

    The double planar wire array (DPWA) is the best x-ray radiator at 1 MA [V. Kantsyrev et al., HEDP 5 (2009), in press]. To improve its radiative performance by reducing the MRT instability growth rate, Al, brass and W DPWAs were skewed to produce initial axial magnetic field Bz. The diagnostics included x-ray devices and laser shadowgraphy. Experiments on 1.6 MA Zebra generator at UNR and MHD modeling have shown that Bz mitigated the MRT instability in the precursor. The stagnation starts in the middle of the A-K gap, and more uniform plasma column with a higher temperature Te is formed compared to a standard DPWA. The yield and power were comparable with standard DPWA. Highest yield and power were for W and brass, respectively. Feasibility of the x-ray pulse shaping was demonstrated in experiments. Research plans are discussed.

  11. Assessing inhibitory control: a revised approach to the stop signal task.

    PubMed

    Carter, J D; Farrow, M; Silberstein, R B; Stough, C; Tucker, A; Pipingas, A

    2003-06-01

    The stop signal task (stop task) is designed to assess inhibitory control and is a frequently used research tool in clinical disorders such as ADHD and schizophrenia. Previous methods of setting stop signal delay and of assessing inhibitory control are problematic. The current study reports two modifications that improve the task as a measure of inhibitory control. The first modification was to set stop signal delays proportional to go mean reaction time (go MRT) to better account for inter-subject variability in go MRT. Twenty-eight normal children were tested, and all standard, stop task dependent measures were obtained when delays were set by this method. The second modification was to calculate a novel dependent measure called the area of inhibition (AOI) which provides a more complete measure of inhibitory control than the slope of the relative finishing time z-scores (ZRFT-slope). Implications for the assessment of inhibitory control in clinical populations are discussed. PMID:12931073

  12. 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

  13. 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.

  14. Effects of high-dose microbeam irradiation on tumor microvascular function and angiogenesis.

    PubMed

    Fontanella, Andrew N; Boss, Mary-Keara; Hadsell, Michael; Zhang, Jian; Schroeder, Thies; Berman, Katherine G; Dewhirst, Mark W; Chang, Sha; Palmer, Gregory M

    2015-02-01

    Microbeam radiation therapy (MRT) is a form of cancer treatment in which a single large dose of radiation is spatially fractionated in-line or grid-like patterns. Preclinical studies have demonstrated that MRT is capable of eliciting high levels of tumor response while sparing normal tissue that is exposed to the same radiation field. Since a large fraction of the MRT-treated tumor is in the dose valley region that is not directly irradiated, tumor response may be driven by radiation bystander effects, which in turn elicit a microvascular response. Differential alterations in hemodynamics between the tumor and normal tissue may explain the therapeutic advantages of MRT. Direct observation of these dynamic responses presents a challenge for conventional ex vivo analysis. Furthermore, knowledge gleaned from in vitro studies of radiation bystander response has not been widely incorporated into in vivo models of tumor radiotherapy, and the biological contribution of the bystander effect within the tumor microenvironment is unknown. In this study, we employed noninvasive, serial observations of the tumor microenvironment to address the question of how tumor vasculature and HIF-1 expression are affected by microbeam radiotherapy. Tumors (approximately 4 mm in diameter) grown in a dorsal window chamber were irradiated in a single fraction using either a single, microplanar beam (300 micron wide swath) or a wide-field setup (whole-window chamber) to a total dose of 50 Gy. The tumors were optically observed daily for seven days postirradiation. Microvascular changes in the tumor and surrounding normal tissue differed greatly between the wide-field and microbeam treatments. We present evidence that these changes may be due to dissimilar spatial and temporal patterns of HIF-1 expression induced through radiation bystander effects. PMID:25574586

  15. The effect of multiple processing and re-use on orthodontic mini-screw torque values

    PubMed Central

    Noorollahian, Saeed; Alavi, Shiva; Rafiei, Elahe

    2015-01-01

    Background: Reusing orthodontic mini-screws would reduce treatment cost and lead to more use of mini-screws and improvement of orthodontic treatments. This study has assessed the effects of reprocessing and reusing the titanium mini-screws on their maximum insertion, removal and fracture torque (FT). Materials and Methods: In this experimental study, 20 titanium mini-screws (1.6-mm × 8-mm) were randomly divided into two equal groups. In the test group, the screws were first sterilized by autoclave and then their FT was assessed. In the control group, FT was assessed after 5 times of insertion, cleaning, processing (37% phosphoric acid for 10 min, 5.25% sodium hypochlorite for 30 min) and sterilizing with autoclave. The maximum insertion and removal torque values were compared using the repeated measure ANOVA and the FT data were analyzed by the t-test. The data were analyzed using the SPSS software (version 13.0) and the significance was set on 0.05. Results: The paired t-test for maximum insertion torque (MIT) showed that MIT1 was significantly lower than other MIT values (P = 0.02) and also MIT2 was significantly higher than MIT5 (P = 0.01), but other MIT values had no significant differences. The paired t-test for maximum removal torque (MRT) showed that only MRT2 was significantly higher than other MRT values (except MRT1) (P = 0.046). Regarding FT, the t-test showed that there was no significant difference between FT0 and FT5 (P = 0.485). Conclusion: Within limitations of this study, five time insertion, cleaning, processing and steam sterilization had no significant negative effect on insertion, removal and FT of the mini-screws. PMID:26005464

  16. 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

  17. 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

    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

  18. 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. PMID:25921796

  19. Effects of High-Dose Microbeam Irradiation on Tumor Microvascular Function and Angiogenesis

    PubMed Central

    Fontanella, Andrew N.; Boss, Mary-Keara; Hadsell, Michael; Zhang, Jian; Schroeder, Thies; Berman, Katherine G.; Dewhirst, Mark W.; Chang, Sha; Palmer, Gregory M.

    2015-01-01

    Microbeam radiation therapy (MRT) is a form of cancer treatment in which a single large dose of radiation is spatially fractionated in-line or grid-like patterns. Preclinical studies have demonstrated that MRT is capable of eliciting high levels of tumor response while sparing normal tissue that is exposed to the same radiation field. Since a large fraction of the MRT-treated tumor is in the dose valley region that is not directly irradiated, tumor response may be driven by radiation bystander effects, which in turn elicit a microvascular response. Differential alterations in hemodynamics between the tumor and normal tissue may explain the therapeutic advantages of MRT. Direct observation of these dynamic responses presents a challenge for conventional ex vivo analysis. Furthermore, knowledge gleaned from in vitro studies of radiation bystander response has not been widely incorporated into in vivo models of tumor radiotherapy, and the biological contribution of the bystander effect within the tumor microenvironment is unknown. In this study, we employed noninvasive, serial observations of the tumor microenvironment to address the question of how tumor vasculature and HIF-1 expression are affected by microbeam radiotherapy. Tumors (approximately 4 mm in diameter) grown in a dorsal window chamber were irradiated in a single fraction using either a single, microplanar beam (300 micron wide swath) or a wide-field setup (whole-window chamber) to a total dose of 50 Gy. The tumors were optically observed daily for seven days postirradiation. Microvascular changes in the tumor and surrounding normal tissue differed greatly between the wide-field and microbeam treatments. We present evidence that these changes may be due to dissimilar spatial and temporal patterns of HIF-1 expression induced through radiation bystander effects. PMID:25574586

  20. Immunodeficiency disorders and treatment

    NASA Astrophysics Data System (ADS)

    Kamenetskaya, O. V.

    1994-08-01

    Chronic diseases result from defects in the immune system. Consideration is being given to the recovery of an immunoreaction in patients treated with quantum medicine methods by Prof. S.P. Sit'ko. The methods are evaluated as to outlook. Method of non-medicamentous non-invasive microwave resonance therapy (MRT) worked out by Prof. S.P. Sit'ko on the basis of quantum medicine has new possibilities for treatment and prophylaxis of different diseases.

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

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    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 (0.10-0.25 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.

  2. Microbeam radiation therapy: A Monte Carlo study of the influence of the source, multislit collimator, and beam divergence on microbeams

    SciTech Connect

    Nettelbeck, H.; Takacs, G. J.; Lerch, M. L. F.; Rosenfeld, A. B.

    2009-02-15

    Microbeam radiation therapy (MRT) is a new oncology method currently under development for the treatment of inoperable pediatric brain tumors. Monte Carlo simulation, or the computational study of radiation transport in matter, is often used in radiotherapy to theoretically estimate the dose required for treatment. However, its potential use in MRT dose planning systems is currently hindered by the significant discrepancies that have been observed between measured and theoretical dose and the PVDR (peak to valley dose ratio). The need to resolve these discrepancies is driven by the desirability of making MRT available to humans in the next few years. This article aims to resolve some of the discrepancies by examining the simplifications adopted in previous MRT Monte Carlo studies, such as the common practice of commencing microbeam transport on the surface of the target which neglects the influence of the distributed synchrotron source, multislit collimator, and the beam divergence between them. This article uses PENELOPE Monte Carlo simulation to investigate the influence of these beamline components upstream of the target on the lateral dose profiles and PVDRs of an array of 25 microbeams. It also compares the dose profiles and PVDRs of a microbeam array produced from a single simulation (full array) to those produced from the superposition of a single microbeam profile (sup array). The effect of modeling the distributed source and the beam divergence was an increase in the absorbed dose in the penumbral and valley regions of the microbeam profiles. Inclusion of the multislit collimator resulted in differences of up to 5 {mu}m in the FWHM of microbeam profiles across the array, which led to minor variations in the corresponding PVDR yields.

  3. 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

  4. 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.

  5. 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. PMID:24763641

  6. Gas puff Z-pinch implosions with external Bz field on COBRA

    NASA Astrophysics Data System (ADS)

    Qi, N.; de Grouchy, P.; Schrafel, P. C.; Atoyan, L.; Potter, W. M.; Cahill, A. D.; Gourdain, P.-A.; Greenly, J. B.; Hammer, D. A.; Hoyt, C. L.; Kusse, B. R.; Pikuz, S. A.; Shelkovenko, T. A.

    2014-12-01

    We present preliminary experimental results on mitigating Magneto-Rayleigh-Taylor (MRT) instabilities by applying an external Bz field. The experiments were conducted on the 1-MA, 200-ns COBRA generator at Cornell University. In the experiments, a triple-nozzle was used to produce z-pinch loads from concentric outer and inner annular gas puffs and a center gas puff column. A single coil was used to produce a Bz field in the pinch region. We have used two 4-frame 2-ns gated EUV cameras to obtain images of the imploding plasmas, in which the MRT instabilities were observed. The MRT instabilities can grow when the plasma accelerates toward the axis. With a triple gas puff (outer, inner and center puff), reduced acceleration or de-acceleration of the imploding plasma occurred when the outer puff plasma imploded onto the inner annular puff plasma resulting a relatively stable implosion. In the absent of the inner annular gas puff, the imploding outer annular plasma continued to accelerate toward the axis. Large turbulent flares at the edge of the implosion or pinch plasma were observed. The implosion was not stable. To stabilize the implosion without the inner gas puff, a Bz field was applied. This external Bz field was compressed by the outer imploding plasma shell. A relatively stable implosion was observed. Increasing the Bz field to 2-kG resulted in a relatively fatter pinch plasma.

  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. The Use of Point-of-Decision Prompts to Increase Stair Climbing in Singapore

    PubMed Central

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

    2013-01-01

    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. PMID:23296208

  9. Effect of telomerase inhibition on preclinical models of malignant rhabdoid tumor.

    PubMed

    Hu, Yafang; Bobb, Daniel; Lu, Yunbiao; He, Jianping; Dome, Jeffrey S

    2014-09-01

    Novel treatment approaches are desperately needed for malignant rhabdoid tumor (MRT). Telomerase is an attractive therapeutic target because it is specific to cancer and critical for cancer cell immortality. We evaluated the effect of the telomerase inhibitor imetelstat in preclinical models of MRT. Three MRT cell lines, BT-12, G401, and RT-peri, were treated with the telomerase inhibitor imetelstat. The effects of imetelstat on telomere length, DNA damage response, and cell proliferation were assessed. The efficacy of imetelstat in vivo was evaluated in subcutaneous xenografts derived from each of the cell lines. Treatment with imetelstat resulted in inhibition of telomerase activity, marked telomere shortening, and activation of the DNA damage response pathway, as measured by formation of γ-H2AX nuclear foci, phosphorylation of ATM, and phosphorylation of TP53. Imetelstat-treated G401 cells underwent complete growth arrest after 16 passages. The other two cell lines exhibited growth inhibition. Imetelstat resulted in 40-50% growth inhibition compared to placebo-treated controls in all three xenograft models. The activity of imetelstat as a single agent suggests that further studies of telomerase inhibitors in combination with other agents may be warranted. PMID:25441685

  10. Creating a three-parent child: an educational paradigm for the responsible conduct of research.

    PubMed

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

    2014-12-01

    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

  11. Mechanical and Histological Effects of Resorbable Blasting Media Surface Treatment on the Initial Stability of Orthodontic Mini-Implants

    PubMed Central

    2016-01-01

    Introduction. This study aimed to evaluate the effects of resorbable blasting media (RBM) treatment on early stability of orthodontic mini-implants by mechanical, histomorphometric, and histological analyses. Methods. Ninety-six (64 for mechanical study and 32 for histological study and histomorphometric analysis) titanium orthodontic mini-implants (OMIs) with machined (machined group) or RBM-treated (CaP) surface (RBM group) were implanted in the tibiae of 24 rabbits. Maximum initial torque (MIT) was measured during insertion, and maximum removal torque (MRT) and removal angular momentum (RAM) were measured at 2 and 4 weeks after implantation. Bone-to-implant contact (BIC) and bone area (BA) were analyzed at 4 weeks after implantation. Results. RBM group exhibited significantly lower MIT and significantly higher MRT and RAM at 2 weeks than machined group. No significant difference in MRT, RAM, and BIC between the two groups was noted at 4 weeks, although BA was significantly higher in RBM group than in machined group. RBM group showed little bone resorption, whereas machined group showed new bone formation after bone resorption. Conclusions. RBM surface treatment can provide early stability of OMIs around 2 weeks after insertion, whereas stability of machined surface OMIs may decrease in early stages because of bone resorption, although it can subsequently recover by new bone apposition. PMID:26942200

  12. 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.

  13. Loss of the tumor suppressor Snf5 leads to aberrant activation of the Hedgehog-Gli pathway

    PubMed Central

    Jagani, Zainab; Mora-Blanco, E Lorena; Sansam, Courtney G; McKenna, Elizabeth S; Wilson, Boris; Chen, Dongshu; Klekota, Justin; Tamayo, Pablo; Nguyen, Phuong T L; Tolstorukov, Michael; Park, Peter J; Cho, Yoon-Jae; Hsiao, Kathy; Buonamici, Silvia; Pomeroy, Scott L; Mesirov, Jill P; Ruffner, Heinz; Bouwmeester, Tewis; Luchansky, Sarah J; Murtie, Joshua; Kelleher, Joseph F; Warmuth, Markus; Sellers, William R; Roberts, Charles W M; Dorsch, Marion

    2013-01-01

    Aberrant activation of the Hedgehog (Hh) pathway can drive tumorigenesis1. To investigate the mechanism by which glioma-associated oncogene family zinc finger-1 (GLI1), a crucial effector of Hh signaling2, regulates Hh pathway activation, we searched for GLI1-interacting proteins. We report that the chromatin remodeling protein SNF5 (encoded by SMARCB1, hereafter called SNF5), which is inactivated in human malignant rhabdoid tumors (MRTs), interacts with GLI1. We show that Snf5 localizes to Gli1-regulated promoters and that loss of Snf5 leads to activation of the Hh-Gli pathway. Conversely, re-expression of SNF5 in MRT cells represses GLI1. Consistent with this, we show the presence of a Hh-Gli–activated gene expression profile in primary MRTs and show that GLI1 drives the growth of SNF5-deficient MRT cells in vitro and in vivo. Therefore, our studies reveal that SNF5 is a key mediator of Hh signaling and that aberrant activation of GLI1 is a previously undescribed targetable mechanism contributing to the growth of MRT cells. PMID:21076395

  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. Revealing the underlying mechanism of microbeam radiation therapy with low energy Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    McNamara, A. L.; Oelfke, U.; Kuncic, Z.

    2014-03-01

    Microbeam radiation therapy (MRT) is a new experimental oncological modality, intended for the treatment of inoperable brain tumours, particularly in difficult cases where conventional radiation therapy can cause irreversible damage. MRT consists of an array of highly collimated, quasi-parallel x-ray microbeams aimed at the tumour tissue, delivering high dose within the beam path and low doses in regions between the beams. For reasons still not fully understood, healthy tissue exposed to the microbeam array is able to regenerate while tumour volumes are significantly reduced. Low energy Monte Carlo radiative transport simulations provide new insight into understanding the underlying mechanisms of MRT. In particular, predicting the ionisation cluster distribution, which is a significant cause of lethal damage to cells, would provide insight into the biological responses. Geant4-DNA was used to model an x-ray microbeam of width 20 μm in liquid water. Secondary electrons, predominately responsible for ionisation clustering, were tracked to predict damage to cells within and adjacent to the beams. We find that higher energy beams (100 keV) produce less secondary electrons in the regions outside the beam than low energy beams (30-50 keV).

  16. Possibility of breakdown of overdamped and narrowing limits in low-frequency Raman spectra: Phenomenological band-shape analysis using the multiple-random-telegraph model

    NASA Astrophysics Data System (ADS)

    Amo, Yuko; Tominaga, Yasunori

    1999-08-01

    Depolarized low-frequency Raman spectra of liquid water and heavy water are investigated from 266 K to 356 K. The reduced Raman spectra below 250 cm-1 are reproduced by a superposition of one relaxation mode and two damped harmonic oscillator modes. The multiple-random-telegraph (MRT) model, which takes into account inertia and memory effects, is applied to analyze the relaxation component. Two damped harmonic oscillators around 50 cm-1 and 180 cm-1 are known as a bendinglike mode and a stretchinglike mode, respectively. It is found that the intensity of the bendinglike mode in water (heavy water) gradually decreases with increasing temperature, and finally vanishes above about 296 K (306 K). The relaxation time of the MRT model is interpreted as representing the averaged lifetime of the vibrating unit. At high temperature, the relaxation time becomes short, that is to say, the vibrating unit is quickly destroyed before the 50 cm-1 mode is oscillating sufficiently. In the present analysis, the strongly disrupted oscillation cannot be distinguished from the relaxation mode which includes the inertia and memory effects. It is found that the low-frequency Raman spectrum of liquid water at high temperature is a good example demonstrating an application of the MRT model.

  17. 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.

    2016-02-01

    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.

  18. Methods for comparing multiple digital PCR experiments.

    PubMed

    Burdukiewicz, Michał; Rödiger, Stefan; Sobczyk, Piotr; Menschikowski, Mario; Schierack, Peter; Mackiewicz, Paweł

    2016-09-01

    The estimated mean copy per partition (λ) is the essential information from a digital PCR (dPCR) experiment because λ can be used to calculate the target concentration in a sample. However, little information is available how to statistically compare dPCR runs of multiple runs or reduplicates. The comparison of λ values from several runs is a multiple comparison problem, which can be solved using the binary structure of dPCR data. We propose and evaluate two novel methods based on Generalized Linear Models (GLM) and Multiple Ratio Tests (MRT) for comparison of digital PCR experiments. We enriched our MRT framework with computation of simultaneous confidence intervals suitable for comparing multiple dPCR runs. The evaluation of both statistical methods support that MRT is faster and more robust for dPCR experiments performed in large scale. Our theoretical results were confirmed by the analysis of dPCR measurements of dilution series. Both methods were implemented in the dpcR package (v. 0.2) for the open source R statistical computing environment. PMID:27551672

  19. Evaluation of the unstructured lattice Boltzmann method in porous flow simulations

    NASA Astrophysics Data System (ADS)

    Misztal, Marek; Matin, Rastin; Hernandez, Anier; Mathiesen, Joachim

    2015-11-01

    Flows in porous media are among the most challenging to simulate using the computational fluid dynamics methods, primarily due to the complex boundaries, often characterized by a very broad distribution of pore sizes. The standard (regular grid based) lattice Boltzmann method with the multi-relaxation time (MRT) collision operator is often used to simulate such flows. However, due to the lack of coupling between the positions of the computational grid nodes and the solid boundaries, the properties of the simulated flow might unnaturally vary with the fluid's viscosity, depending on the parameters of the MRT operator. This is, for instance, the case with the otherwise popular, single-relaxation time Bhatnagar-Gross-Krook (BGK) collision operator. Our focus has been on the unstructured grid based, finite element variant of the LBM. By using such approach, we can place the computational grid nodes precisely at the solid boundary. Since there is no prior work on the accuracy of this method in simulating porous flows, we perform a thorough permeability study using both BGK and MRT operators at a wide range of viscosities. We benchmark these models on artificial samples with known solutions, and further, we demonstrate the findings of our studies in the porous networks of real rocks. Predicting Petrophysical Parameters: A Project Sponsored by HTF and Maersk Oil and Gas.

  20. An exact solution of the linearized Boltzmann transport equation and its application to mobility calculations in graphene bilayers

    NASA Astrophysics Data System (ADS)

    Paussa, A.; Esseni, D.

    2013-03-01

    This paper revisits the problem of the linearized Boltzmann transport equation (BTE), or, equivalently, of the momentum relaxation time, momentum relaxation time (MRT), for the calculation of low field mobility, which in previous works has been almost universally solved in approximated forms. We propose an energy driven discretization method that allows an exact determination of the relaxation time by solving a linear, algebraic problem, where multiple scattering mechanisms are naturally accounted for by adding the corresponding scattering rates before the calculation of the MRT, and without resorting to the semi-empirical Matthiessen's rule for the relaxation times. The application of our rigorous solution of the linearized BTE to a graphene bilayer reveals that, for a non monotonic energy relation, the relaxation time can legitimately take negative values with no unphysical implications. We finally compare the mobility calculations provided by an exact solution of the MRT problem with the results obtained with some of the approximations most frequently employed in the literature and so discuss their accuracy.

  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. 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

    2015-01-01

    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

  3. Syndromic surveillance in an ICD-10 world.

    PubMed

    Jayatilleke, Achala; Kriseman, Jeffrey; Bastin, Lisa H; Ajani, Umed; Hicks, Peter

    2014-01-01

    The Centers for Disease Control and Prevention's BioSense program is an integrated national public health surveillance system that uses electronic medical record (EMR) data to provide situational awareness for all-hazard health-related events. Because the system leverages International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) coded data from EMRs for syndromic surveillance, the upcoming Health and Human Services-mandated transition from ICD-9-CM to ICD-10-CM will have a significant impact. To translate across the two encoding systems, we developed a Mapping Reference Table (MRT) for the ICD-9/10 transition. We extracted ICD-9-CM codes binned to predefined syndromes and mapped each to its corresponding ICD-10-CM code(s). Then, we translated the output ICD-10-CM codes back to ICD-9-CM through a reverse translation validation process. Throughout the translation process, we examined outputs manually and incorporated annotated results into the MRT. The resulting MRT can be used to refine and update each existing syndromic surveillance definition in BioSense to be compatible with ICD-10-CM and consistently classify or bin any given emergency department visit into the correct syndrome regardless of coding system. PMID:25954453

  4. 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.

  5. 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

  6. 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. PMID:27014142

  7. Increased Systemic Exposure of Methotrexate by a Polyphenol-Rich Herb via Modulation on Efflux Transporters Multidrug Resistance-Associated Protein 2 and Breast Cancer Resistance Protein.

    PubMed

    Yu, Chung-Ping; Hsieh, Yun-Chung; Shia, Chi-Sheng; Hsu, Pei-Wen; Chen, Jen-Yuan; Hou, Yu-Chi; Hsieh, Yo-Wen

    2016-01-01

    Scutellariae radix (SR, roots of Scutellaria baicalensis Georgi), a popular Chinese medicine, contains plenty of flavonoids such as baicalin, wogonoside, baicalein, and wogonin. Methotrexate (MTX), an important immunosuppressant with a narrow therapeutic index, is a substrate of multidrug resistance-associated proteins (MRPs) and breast cancer resistance protein (BCRP). This study investigated the effect of SR on MTX pharmacokinetics and the underlying mechanisms. Rats were orally administered MTX alone and with 1.0 or 2.0 g/kg of SR. The serum concentrations of MTX were determined by a fluorescence polarization immunoassay. Cell models were used to explore the involvement of MRP2 and BCRP in the interaction. The results showed that 1.0 g/kg of SR significantly increased Cmax, AUC(0-30), AUC(0-2880), and mean residence time (MRT) of MTX by 50%, 45%, 501%, and 347%, respectively, and 2.0 g/kg of SR significantly enhanced the AUC(0-2880) and MRT by 242% and 293%, respectively, but decreased AUC(0-30) by 41%. Cell line studies indicated that SR activated the BCRP-mediated efflux transport, whereas the serum metabolites of SR inhibited both the BCRP- and MRP2-mediated efflux transports. In conclusion, SR ingestion increased the systemic exposure and MRT of MTX via modulation on MRP2 and BCRP. PMID:26852865

  8. Plasma superwarfarin levels and vitamin K1 treatment in dogs with anticoagulant rodenticide poisoning.

    PubMed

    Robben, J H; Kuijpers, E A; Mout, H C

    1998-01-01

    The plasma concentration, plasma half-life (t1/2), and mean residence time (MRT) of rodenticide anticoagulants were determined in 21 dogs in which a preliminary diagnosis of anticoagulant rodenticide poisoning had been made. Brodifacoum, difethialone, and difenacoum were detected by high-performance liquid chromatography (HPLC) in the plasma of 13, 3, and 2 dogs, respectively. At presentation the plasma concentration ranged from below the detection limit (10 ng/L) to 851 ng/L. Toxin could not be detected in 3 dogs, despite these animals showing characteristic coagulation disturbances and a positive response to therapy with vitamin K1. In 7 dogs the estimated t1/2 of brodifacoum ranged from 0.9 to 4.7 (median 2.4) days with a MRT of 1.9 to 3.7 (median 2.8) days. In 2 dogs the individual t1/2 of difethialone was 2.2 and 3.2 days and the MRT was 2.3 and 2.8 days, respectively. Two dogs died during emergency treatment. Treatment in the remaining 19 dogs consisted of the administration of vitamin K1 and supportive therapy. The dose of vitamin K1 was reduced in a stepwise manner as long as the prothrombin time remained within physiological limits. The variation in initial plasma concentrations of the anticoagulants combined with the results of treatment support the idea that an individual therapeutic approach is warranted. PMID:9477532

  9. 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.

  10. 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.

  11. Recent Experimental Results at General Fusion

    NASA Astrophysics Data System (ADS)

    Howard, Stephen

    2013-10-01

    Experiments relevant to MTF are underway at General Fusion in which self-confined Compact Toroid (CT) plasmas in a spheromak configuration are rapidly compressed. Plasma Injector 1 (PI-1) is a two stage Marshal gun with a conical accelerator, 5 meters long and 1.9 m diameter in formation where a high aspect ratio (4.4) spheromak is formed with λ = 9 m-1. CTs formed with Bp = 0.2 T, Te = 40 eV, and ne = 0.5×1020 m-3 when compressed (2x radial) reached Bp = 0.8 T, Te = 160 eV, ne = 4×1020 m-3 which is consistent with adiabatic compressional heating. A smaller device, the Magnetized Ring Test (MRT) can form a unity-aspect ratio CT of λ = 35 m-1 directly within an implodable cylindrical liner of aluminum. The MRT electrodes form a bow-tie cavity known for its high- β stability. MRT has begun a set of implosive compression tests to observe the behavior of a high density CT as it experiences increasing beta, possible interactions with the liner wall, and changing profiles as the compression proceeds. Progress is being made to understand losses during compression via analysis of magnetic fluctuations, spectroscopy, and comparison to 3D MHD simulation.

  12. Virtual reality adaptive stimulation of limbic networks in the mental readiness training.

    PubMed

    Cosić, Kresimir; Popović, Sinisa; Kostović, Ivica; Judas, Milos

    2010-01-01

    A significant proportion of severe psychological problems in recent large-scale peacekeeping operations underscores the importance of effective methods for strengthening the stress resilience. Virtual reality (VR) adaptive stimulation, based on the estimation of the participant's emotional state from physiological signals, may enhance the mental readiness training (MRT). Understanding neurobiological mechanisms by which the MRT based on VR adaptive stimulation can affect the resilience to stress is important for practical application in the stress resilience management. After the delivery of a traumatic audio-visual stimulus in the VR, the cascade of events occurs in the brain, which evokes various physiological manifestations. In addition to the "limbic" emotional and visceral brain circuitry, other large-scale sensory, cognitive, and memory brain networks participate with less known impact in this physiological response. The MRT based on VR adaptive stimulation may strengthen the stress resilience through targeted brain-body interactions. Integrated interdisciplinary efforts, which would integrate the brain imaging and the proposed approach, may contribute to clarifying the neurobiological foundation of the resilience to stress. PMID:20543262

  13. 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.

  14. 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.

  15. A new methodology for predicting human pharmacokinetics for inhaled drugs from oratracheal pharmacokinetic data in rats.

    PubMed

    Jones, Rhys M; Harrison, Anthony

    2012-01-01

    Prediction of pharmacokinetic (PK) profile for inhaled drugs in humans provides valuable information to aid toxicology safety assessment, evaluate the potential for systemic accumulation on multiple dosing and enable an estimate for the clinical plasma assay requirements. The accuracy in prediction of inhaled human PK profiles for seven inhaled drugs or drug candidates (salmeterol, salbutamol, formoterol, fluticasone propionate, budesonide, CP-325366 and UK-432097) was assessed using rat oratracheal solution and dry powder PK data. The prediction methodology incorporates allometric scaling and mean residence time (MRT) principles with a two compartmental PK approach. Across the range of compounds tested, the prediction of human inhaled maximum concentration (C(max)) and MRT was within 2-fold for 5 of the 7 compounds, providing an accuracy of prediction similar to the current methodologies used to predict human oral C(max) from preclinical data ( De Buck et al. 2007 ). Administering as a dry powder formulation slowed the rat lung absorption rate of the least soluble compound (fluticasone propionate), impacting the prediction of C(max) and MRT. This flags the potential for preclinical studies with dry powder formulations to positively influence predictive accuracy, although further studies with low solubility inhaled drugs are required to confirm this. This study illustrates the value of preclinical assessment of PKs following administration to the lung, and provides a viable means of predicting the human PK profile for inhaled drugs. PMID:22077102

  16. The Morehead Radio Telescope: Design and Fabrication of a Research Instrument for Undergraduate Faculty and Student Research in Radio Frequency Astrophysics

    NASA Astrophysics Data System (ADS)

    Malphrus, B. K.

    1996-12-01

    Faculty and students of the Departments of Physical Sciences and Industrial Education and Technology at Morehead State University have designed and assembled the Morehead Radio Telescope (MRT) to provide a research instrument for undergraduate astronomy and physics students and an active laboratory for physics, engineering, and computer science undergraduates and faculty. The instrument will function as a research and educational instrument for undergraduate students, faculty, and science teachers throughout Kentucky. The goals of the MRT program are to enhance the curricula in physics, physical science, electronics, and science education programs by serving to provide: 1.) a research instrument for investigations in astronomy and astrophysics; 2.) an active laboratory in astronomy, physics, electrical engineering, and computer science; and 3.) a research instrument and laboratory for science teacher education and inservice programs. The MRT utilizes a 40-foot parabolic reflector, a low-noise hydrogen line receiver and a fully- automated alt-azimuth positioning system. The telescope incorporates a modular design in which components may be easily removed for use in laboratory investigations and for student research and design projects. The performance characteristics of the telescope allow a varied and in-depth scientific program. The sensitivity and versatility of the telescope design facilitate the investigation of a wide variety of astrophysically interesting phenomena.

  17. 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

  18. 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.

  19. Multiple-dose acetaminophen pharmacokinetics.

    PubMed

    Sahajwalla, C G; Ayres, J W

    1991-09-01

    Four different treatments of acetaminophen (Tylenol) were administered in multiple doses to eight healthy volunteers. Each treatment (325, 650, 825, and 1000 mg) was administered five times at 6-h intervals. Saliva acetaminophen concentration versus time profiles were determined. Noncompartmental pharmacokinetic parameters were calculated and compared to determine whether acetaminophen exhibited linear or dose-dependent pharmacokinetics. For doses less than or equal to 18 mg/kg, area under the curve (AUC), half-life (t1/2), mean residence time (MRT), and ratio of AUC to dose for the first dose were compared with the last dose. No statistically significant differences were observed in dose-corrected AUC for the first or last dose among subjects or treatments. Half-lives and MRT were not significantly different among treatments for the first or the last dose. Statistically significant differences in t1/2 and MRT were noted (p less than 0.05) among subjects for the last dose. A plot of AUC versus dose for the first and the last doses exhibited a linear relationship. Dose-corrected saliva concentration versus time curves for the treatments were superimposable. Thus, acetaminophen exhibits linear pharmacokinetics for doses of 18 mg/kg or less. Plots of AUC versus dose for one subject who received doses higher than 18 mg/kg were curved, suggesting nonlinear behavior of acetaminophen in this subject. PMID:1800709

  20. Mechanical and Histological Effects of Resorbable Blasting Media Surface Treatment on the Initial Stability of Orthodontic Mini-Implants.

    PubMed

    Gansukh, Odontuya; Jeong, Jong-Wha; Kim, Jong-Wan; Lee, Jong-Ho; Kim, Tae-Woo

    2016-01-01

    Introduction. This study aimed to evaluate the effects of resorbable blasting media (RBM) treatment on early stability of orthodontic mini-implants by mechanical, histomorphometric, and histological analyses. Methods. Ninety-six (64 for mechanical study and 32 for histological study and histomorphometric analysis) titanium orthodontic mini-implants (OMIs) with machined (machined group) or RBM-treated (CaP) surface (RBM group) were implanted in the tibiae of 24 rabbits. Maximum initial torque (MIT) was measured during insertion, and maximum removal torque (MRT) and removal angular momentum (RAM) were measured at 2 and 4 weeks after implantation. Bone-to-implant contact (BIC) and bone area (BA) were analyzed at 4 weeks after implantation. Results. RBM group exhibited significantly lower MIT and significantly higher MRT and RAM at 2 weeks than machined group. No significant difference in MRT, RAM, and BIC between the two groups was noted at 4 weeks, although BA was significantly higher in RBM group than in machined group. RBM group showed little bone resorption, whereas machined group showed new bone formation after bone resorption. Conclusions. RBM surface treatment can provide early stability of OMIs around 2 weeks after insertion, whereas stability of machined surface OMIs may decrease in early stages because of bone resorption, although it can subsequently recover by new bone apposition. PMID:26942200

  1. Digesta kinetics in gazelles in comparison to other ruminants: Evidence for taxon-specific rumen fluid throughput to adjust digesta washing to the natural diet.

    PubMed

    Dittmann, Marie T; Hummel, Jürgen; Hammer, Sven; Arif, Abdi; Hebel, Christiana; Müller, Dennis W H; Fritz, Julia; Steuer, Patrick; Schwarm, Angela; Kreuzer, Michael; Clauss, Marcus

    2015-07-01

    Digesta flow plays an important role in ruminant digestive physiology. We measured the mean retention time (MRT) of a solute and a particle marker in the gastrointestinal tract (GIT) and the reticulorumen (RR) of five gazelles and one dikdik species. Species-specific differences were independent from body mass (BM) or food intake. Comparative evaluations (including up to 31 other ruminant species) indicate that MRT GIT relate positively to BM, and are less related to feeding type (the percentage of grass in the natural diet, %grass) than MRT RR. The MRTparticleRR is related to BM and (as a trend) %grass, matching a higher RR capacity with increasing BM in grazers compared to browsers. MRTsoluteRR is neither linked to BM nor to %grass but shows a consistent phylogenetic signal. Selectivity factors (SF; MRTparticle/MRTsolute, proxies for the degree of digesta washing) are positively related to %grass, with a threshold effect, where species with >20% grass have higher SF. These findings suggest that in different ruminant taxa, morphophysiological adaptations controlling MRTsoluteRR evolved to achieve a similar SF RR in relation to a %grass threshold. A high SF could facilitate an increased microbial yield from the forestomach. Reasons for variation in SF above the %grass threshold might represent important drivers of ruminant diversification and await closer investigation. PMID:25637787

  2. 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.

  3. Kinetics of respiratory and circulatory responses to step, impulse, sinusoidal and ramp forcings of exercise load in humans.

    PubMed

    Miyamoto, Y

    1992-01-01

    Transient responses of minute ventilation (VE), oxygen consumption (VO2), carbon dioxide output (VCO2), cardiac output (Q) and heart rate (HR) to step, impulse, sinusoidal and ramp changes in exercise load were studied in healthy human subjects at the moderate load range. Exercise was performed in the upright position using a bicycle ergometer. The transient responses to step and impulse forcings fitted essentially to a second-order model consisting of a fast and a slow component, while the responses to sinusoidal and ramp forcings fitted to a first-order model. No significant asymmetry was observed between the on- and off-responses to step forcing. On the contrary, the mean response time (MRT = pure time delay + time constant) of variables to ascending ramp forcing was prolonged, while the MRT to descending ramp was shortened with decreasing ramp slope. The on- and off asymmetry of the MRT was observed in VE, VO2 and VCO2 and, to a lesser extent, also in HR and Q. A non-linear blood flow model, which simulates changes in the wash-in and wash-out time of metabolic substances into and from the chemoreceptor, has been proposed as a likely explanation for the asymmetrical responses. It was concluded that the regulatory system of respiration and circulation might be essentially non-linear in its operation, despite the fact that the cardiorespiratory responses during exercise seemed to fit linear models. PMID:1599881

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

    PubMed

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

    2015-02-01

    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

  5. 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.

  6. 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. PMID:26788666

  7. Methimazole increases the plasma concentrations of the albendazole metabolites of netobimin in sheep.

    PubMed

    Lanusse, C E; Prichard, R K

    1992-03-01

    The influence of methimazole (MTZ) on the pharmacokinetics of netobimin (NTB) and its metabolites was investigated in adult sheep. NTB zwitterion suspension was administered at 20 mg kg-1 by intraruminal injection either alone or with simultaneous administration of MTZ intramuscularly at 1.5 mg kg-1. Blood samples were taken serially over a 120-h period and plasma was analysed by HPLC for NTB, albendazole (ABZ), albendazole sulphoxide (ABZSO), and albendazole sulphone (ABZSO2). NTB parent drug showed fast absorption, low area under the plasma concentration-time curve (AUC) and was rapidly removed from plasma after both treatments. The presence of MTZ did increase significantly the ABZ AUC (138 per cent) and mean residence time (MRT) (86 per cent). Concomitant treatment with MTZ resulted in a notably higher ABZSO plasma profile with significantly longer elimination half-life (t1/2 beta) (390 per cent) and MRT (252 per cent) and with significantly higher AUC (95 per cent). Also, MTZ induced significant increases in ABZSO2 t1/2 beta, AUC, and MRT. We have demonstrated a pharmacokinetic interaction between MTZ and NTB metabolites. MTZ may alter the liver biotransformation of ABZ metabolites which results in pronounced changes in the disposition kinetics of anthelmintically active metabolites. PMID:1550912

  8. 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.

  9. Verbesserung der Prozessbedingungen beim Einlippentiefbohren durch unterschiedliche Formen der Vorschubmodulation

    NASA Astrophysics Data System (ADS)

    Eisseler, Rocco

    Das Tiefbohren mit Einlippenwerkzeugen ist bei vielen Anwendungen das Verfahren der ersten Wahl, vor allem wenn kleine und kleinste Bohrungsdurchmesser, ein sehr großes Verhältnis zwischen Bohrtiefe und Durchmesser (l/D) und eine hohe Bearbeitungsqualität gefordert werden. Der erreichbare Durchmesserbereich des Verfahrens liegt zwischen D = 0,5 mm und 40 mm, wobei die möglichen Bohrtiefen von l = 3 x D bis 250 x D reichen. Diese Werte beziehen sich auf das Vollbohren, beim Aufbohren können noch größere Durchmesser erreicht werden [1]. Die erreichbare Oberflächenqualität ist so hoch, dass in den meisten Fällen auf eine nachfolgende Feinbearbeitung verzichtet werden kann.

  10. Fahrzeugsicherheit: Herausforderungen und Lösungen

    NASA Astrophysics Data System (ADS)

    Franz, Walter

    Ich möchte meinen Vortrag beginnen mit der Frage: Das sichere Fahrzeug, gibt es das überhaupt? Sie merken schon, das ist eine rhetorische Frage. Lassen Sie uns aber diese Frage verwenden, um Fahrzeugsicherheit zu klassifizieren. Wenn wir von Sicherheit reden, kann man zwischen Prozesssicherheit, Sicherheit von ITSystemem oder IT-Sicherheit in Produkten unterscheiden. Ich möchte heute über das Produkt reden.

  11. Verknüpfung von DQ-Indikatoren mit KPIs und Auswirkungen auf das Return on Investment

    NASA Astrophysics Data System (ADS)

    Block, Frank

    Häufig ist nicht klar, welche Beziehungen zwischen Datenqualitätsindikatoren (DQI, Definition folgt weiter unten) und Key Performance Indicators (KPI, s. Abschnitt 1.3 für weitere Details) eines Unternehmens oder einer Organisation bestehen. Dies ist insbesondere deshalb von Bedeutung, da die Kenntnis dieser Beziehungen maßgeblich die Ausprägung eines Datenqualitätsprojekts beeinflusst.

  12. Rayleigh-Taylor instability of a magnetic tangential discontinuity in the presence of flow

    NASA Astrophysics Data System (ADS)

    Ruderman, M. S.

    2015-08-01

    We studied the magnetic Rayleigh-Taylor (MRT) instability of a magnetohydrodynamic tangential discontinuity in an infinitely conducting incompressible plasma in the presence of flow. We assumed that the flow magnitude is small enough to guarantee that there is no Kelvin-Helmholtz (KH) instability. In addition, we assumed that there is the magnetic shear, that is, the magnetic field has different directions at the two side of the discontinuity. In this case, only perturbations whose wavelength is greater than the critical one are unstable. As a consequence, the perturbation growth rate is bounded, and the initial-value problem describing their evolution is well posed. We also studied the absolute and convective nature of the MRT instability using the Briggs method. We obtained the necessary and sufficient condition for a perturbation propagating in a given direction to be only convectively unstable but absolutely stable. We also obtained the condition for perturbations propagating in any direction to be only convectively unstable, but absolutely stable. The results of the general analysis were applied to the MRT instability of prominence threads and the heliopause. Similar to previous research, we assumed that the thread disappearance is related to the MRT instability and the thread lifetime is equal to the inverse instability increment. Using this assumption we estimated the angle between the magnetic field inside the thread and in the surrounding plasma and studied how this estimate depends on the magnitude of the flow inside the thread. We found that this dependence is very weak. To apply this to the heliopause stability, we carried out the local analysis and restricted it to the near flanks of the heliopause only where the plasma flow can be considered incompressible. We showed that, for values of the magnetic field magnitude observed by Voyager 1, there is no KH instability. We then studied the MRT instability that can occur when the heliosheath is accelerated

  13. 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

  14. The Influence of Ball Velocity and Court Illumination on Reaction Time for Tennis Volley

    PubMed Central

    Tu, Jui-hung; Lin, Yaw-feng; Chin, Shu-chen

    2010-01-01

    The he purpose of this study is to examine the effects of ball velocity, court illumination, and volley type on the reaction time (RT) of a tennis athlete for a volley stroke. Eights cases with two different ball velocities (high and low), two volley types (forehand and backhand ) and two court illumination levels (dark and bright) were studied. The 30 participating subjects consisted of 18 male and 12 female college tennis athletes (age: 24 ± 3.2 yr), with a United States Tennis Association (USTA) ranking above 2.5. In order to ensure the validity of real-world correlations, the experiments were designed to simulate real competition situations. Reaction times were measured for volley strokes in response to different approaching ball velocities (high: 25.05 ± 0.37 m/s and low: 17.56 ± 0.92 m·s-1) for several volley types (forehand and backhand) and court illumination levels (55649 ± 4292 lux and 363.24 ± 6.53 lux on the court). During the tests, the signals from an electromyogram sensor and a 3-axis accelerometer (± 50 g) were recorded using an NI DAQ card (NI PXI-6251) and then analyzed to determine reaction time (RT), premotor reaction time (PRT), and motor reaction time (MRT) through the LabVIEW system. Subsequent 3-way ANOVA analysis indicated no RT, PRT, or MRT interaction between ball velocity, volley type and illumination. The ball velocity and illumination parameters did affect RT and PRT values significantly with p < 0.05, no significant variation in MRT was observed across any implemented experimental conditions. All experimental results indicate that ball velocity and illumination levels strongly affect the value of PRT, but have no significant effect on the value of MRT, the changes in RT were dominated by PRT. Key points RT can generally be divided into two components with the help of the electromyogram (EMG) signal - the premotor reaction time (PRT) and the motor reaction time (MRT). The purpose of this study is to examine the effects of ball

  15. 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

  16. Threshold groundwater ages and young water fractions estimated from 3H, 3He, and 14C

    NASA Astrophysics Data System (ADS)

    Kirchner, James; Jasechko, Scott

    2016-04-01

    It is widely recognized that a water sample taken from a running stream is not described by a single age, but rather by a distribution of ages. It is less widely recognized that the same principle holds true for groundwaters, as indicated by the commonly observed discordances between model ages obtained from different tracers (e.g., 3H vs 14C) in the same sample. Water age distributions are often characterized by their mean residence times (MRT's). However, MRT estimates are highly uncertain because they depend on the shape of the assumed residence time distribution (in particular on the thickness of the long-time tail), which is difficult or impossible to constrain with data. Furthermore, because MRT's are typically nonlinear functions of age tracer concentrations, they are subject to aggregation bias. That is, MRT estimates derived from a mixture of waters with different ages (and thus different tracer concentrations) will systematically underestimate the mixture's true mean age. Here, building on recent work with stable isotope tracers in surface waters [1-3], we present a new framework for using 3H, 3He and 14C to characterize groundwater age distributions. Rather than describing groundwater age distributions by their MRT, we characterize them by the fraction of the distribution that is younger or older than a threshold age. The threshold age that separates "young" from "old" water depends on the characteristics of the specific tracer, including its history of atmospheric inputs. Our approach depends only on whether a given slice of the age distribution is younger or older than the threshold age, but not on how much younger or older it is. Thus our approach is insensitive to the tails of the age distribution, and is therefore relatively unaffected by uncertainty in the distribution's shape. Here we show that concentrations of 3H, 3He, and 14C are almost linearly related to the fractions of water that are younger or older than specified threshold ages. These

  17. 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

  18. 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

  19. X-Tream quality assurance in synchrotron X-ray microbeam radiation therapy.

    PubMed

    Fournier, Pauline; Cornelius, Iwan; Donzelli, Mattia; Requardt, Herwig; Nemoz, Christian; Petasecca, Marco; Bräuer-Krisch, Elke; Rosenfeld, Anatoly; Lerch, Michael

    2016-09-01

    Microbeam radiation therapy (MRT) is a novel irradiation technique for brain tumours treatment currently under development at the European Synchrotron Radiation Facility in Grenoble, France. The technique is based on the spatial fractionation of a highly brilliant synchrotron X-ray beam into an array of microbeams using a multi-slit collimator (MSC). After promising pre-clinical results, veterinary trials have recently commenced requiring the need for dedicated quality assurance (QA) procedures. The quality of MRT treatment demands reproducible and precise spatial fractionation of the incoming synchrotron beam. The intensity profile of the microbeams must also be quickly and quantitatively characterized prior to each treatment for comparison with that used for input to the dose-planning calculations. The Centre for Medical Radiation Physics (University of Wollongong, Australia) has developed an X-ray treatment monitoring system (X-Tream) which incorporates a high-spatial-resolution silicon strip detector (SSD) specifically designed for MRT. In-air measurements of the horizontal profile of the intrinsic microbeam X-ray field in order to determine the relative intensity of each microbeam are presented, and the alignment of the MSC is also assessed. The results show that the SSD is able to resolve individual microbeams which therefore provides invaluable QA of the horizontal field size and microbeam number and shape. They also demonstrate that the SSD used in the X-Tream system is very sensitive to any small misalignment of the MSC. In order to allow as rapid QA as possible, a fast alignment procedure of the SSD based on X-ray imaging with a low-intensity low-energy beam has been developed and is presented in this publication. PMID:27577773

  20. Intake, selection, digesta retention, digestion and gut fill of two coprophageous species, rabbits (Oryctolagus cuniculus) and guinea pigs (Cavia porcellus), on a hay-only diet.

    PubMed

    Franz, R; Kreuzer, M; Hummel, J; Hatt, J-M; Clauss, M

    2011-10-01

    A colonic separation mechanism (CSM) is the prerequisite for the digestive strategy of coprophagy. Two different CSM are known in small herbivores, the 'wash-back' CSM of lagomorphs and the 'mucous-trap' CSM of rodents. Differences between these groups in their digestive pattern when fed exclusively hay were investigated in six rabbits (Oryctolagus cuniculus) and six guinea pigs (Cavia porcellus). Intake, digestibility (by total faecal collection), solute and particle mean retention times (MRT, using Co-EDTA and Cr-mordanted fibres) were measured. Rabbits selected less fibrous parts of the hay than guinea pigs, leaving orts with higher content of neutral detergent fibre [NDF; 721 ± 21 vs. 642 ± 31 g/kg dry matter (DM) in guinea pigs]. They also expressed a lower NDF digestibility (0.44 ± 0.10 vs. 0.55 ± 0.05 of total), a similar particle MRT (15 ± 3 vs. 18 ± 6 h), a longer solute MRT (51 ± 9 vs. 16 ± 4 h), and a lower calculated dry matter gut fill (19.6 ± 4.7 vs. 29.7 ± 4.1 g DM/kg body mass) than guinea pigs (p < 0.05 for each variable). These results support the assumption that the 'wash-back' CSM, exhibited in the rabbits, is more efficient in extracting bacterial matter from the colonic digesta plug than the 'mucous-trap' CSM found in the guinea pigs. Related to metabolic body mass, rabbits therefore need a less capacious colon for their CSM where a more efficient bacteria wash-out is reflected in the lower fibre digestibility. A lighter digestive tract could contribute to a peculiarity of lagomorphs: their ability to run faster than other similar-sized mammals. PMID:21091550

  1. 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. PMID:11286372

  2. 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.

  3. Using stable isotopes to estimate and compare mean residence times in contrasting geologic catchments (Attert River, NW Luxembourg)

    NASA Astrophysics Data System (ADS)

    Martínez-Carreras, N.; Fenicia, F.; Frentress, J.; Wrede, S.; Pfister, L.

    2012-04-01

    In recent years, stable isotopes have been increasingly used to characterize important aspects of catchment hydrological functioning, such as water storage dynamics, flow pathways and water sources. These characteristics are often synthesized by the Mean Residence Time (MRT), which is a simple catchment descriptor that employ the relation of distinct stable isotopic signatures in the rainfall input and streamflow output of a catchment that are significantly dampened through sub-surface propagation. In this preliminary study, MRT was estimated in the Attert River catchment (NW Luxembourg), where previous studies have shown that lithology exerts a major control on runoff generation. The Attert catchment lies at the transition zone of contrasting bedrock lithology: the Northern part is characterized by Devonian schist of the Ardennes massif, while sedimentary deposits of sandstone and marls dominate in the south of the catchment. As a consequence of differing lithologic characteristics, hydrological processes change across scales. The schistose catchments exhibit a delayed shallow groundwater component, sandstone catchments have slow-responding year-round groundwater component, whereas flashy runoff regimes prevails in the marly catchments. Under these circumstances, the MRTs are expected to vary significantly according to lithology, and provide additional understanding in internal catchment processes and their scale dependencies. In order to test this, bi-weekly monitoring of rainfall and discharge stable water isotope composition (oxygen-18 and deuterium) has been carried out since 2007 in 10 nested sub-catchments ranging in size from 0.4 to 247 km2 in the Attert catchment. MRT was estimated using different lumped convolution integral models and sine wave functions with varying transit times distributions (TTDs). TTDs were evaluated through calibration. Further research efforts will deal with the application of conceptual models to simulate and compare TTD, using

  4. 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. PMID:27020346

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

    PubMed

    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. PMID:26657052

  6. Seasonal variations of aerosol residence time in the lower atmospheric boundary layer.

    PubMed

    Ahmed, A A; Mohamed, A; Ali, A E; Barakat, A; Abd El-Hady, M; El-Hussein, A

    2004-01-01

    During a one year period, from Jan. 2002 up to Dec. 2002, approximately 130 air samples were analyzed to determine the atmospheric air activity concentrations of short- and long-lived (222Rn) decay products 214Pb and 210Pb. The samples were taken by using a single-filter technique and gamma-spectrometry was applied to determine the activity concentrations. A seasonal fluctuation in the concentration of 214Pb and 210Pb in surface air was observed. The activity concentrations of both radionuclides were observed to be relatively higher during the winter/autumn season than in spring/summer season. The mean activity concentration of 214Pb and 210Pb within the whole year was found to be 1.4+/-0.27 Bq m(-3) and 1.2+/-0.15 mBq m(-3), respectively. Different 210Pb:214Pb activity ratios during the year varied between 1.78 x 10(-4) and 1.6 x 10(-3) with a mean value of 8.9 x 10(-4) +/- 7.6 x 10(-5). From the ratio between the activity concentrations of the radon decay products 214Pb and 210Pb a mean residence time (MRT) of aerosol particles in the atmosphere of about 10.5+/-0.91 d could be estimated. The seasonal variation pattern shows relatively higher values of MRT in spring/summer season than in winter/autumn season. The MRT data together with relative humidity (RH), air temperature (T) and wind speed (WS), were used for a comprehensive regression analysis of its seasonal variation in the atmospheric air. PMID:15381321

  7. Morphine, pethidine and buprenorphine disposition in the cat.

    PubMed

    Taylor, P M; Robertson, S A; Dixon, M J; Ruprah, M; Sear, J W; Lascelles, B D; Waters, C; Bloomfield, M

    2001-12-01

    Pharmacokinetics of morphine, buprenorphine and pethidine were determined in 10 cats. Six cats received morphine (0.2 mg/kg) intravenously and four intramuscularly. Five received buprenorphine (0.01 mg/kg) intravenously and six intramuscularly. Six received pethidine (5 mg/kg) intramuscularly. Jugular venous blood samples were collected at time points to 24 h, and plasma morphine concentrations were measured by high performance liquid chromatograpy (HPLC), buprenorphine by radioimmunoassay (RIA) and pethidine by gas chromatography. Our data for morphine show elimination half-life (t1/2el) 76.3 min intravenous (i.v.) and 93.6 min intramuscular (i.m.); mean residence time (MRT) 105.0 and 120.5 min; clearance (Clp) 24.1 and 13.9 mL/kg/min; and volume of distribution (V(dss)) 2.6 and 1.7 L/kg, respectively. Comparable data for buprenorphine are t1/2el 416.8 and 380.2 min; MRT 417.6 and 409.8 min; Clp 16.7 and 23.7 mL/kg/min; and V(dss) 7.1 and 8.9 L/kg. For i.m. pethidine, t1/2el 216.4 min; MRT 307.5 min; Clp 20.8 mL/kg/min and V(dss) 5.2 L/kg. For i.m. dosing, the tmax for morphine, buprenorphine and pethidine were 15, 3 and 10 min, respectively. The pharmacokinetics of the three opioids in cats are broadly comparable with those of the dog, although there is a suggestion that the cat may clear morphine more slowly. PMID:11903869

  8. 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. PMID:24823333

  9. Estimation of mean residence times of subsurface waters using seasonal variation in deuterium excess in a small headwater catchment in Japan

    NASA Astrophysics Data System (ADS)

    Kabeya, Naoki; Katsuyama, Masanori; Kawasaki, Masatoshi; Ohte, Nobuhito; Sugimoto, Atsuko

    2007-01-01

    We measured deuterium excess (d = D - 818O) in throughfall, groundwater, soil water, spring water, and stream water for 3 years in a small headwater catchment (Matsuzawa, 0.68 ha) in the Kiryu Experimental Watershed in Japan. The d value represents a kinetic effect produced when water evaporates. The d value of the throughfall showed a sinusoidal change (amplitude: 6.9 relative to Vienna standard mean ocean water (V-SMOW)) derived from seasonal changes in the source of water vapour. The amplitude of this sinusoidal change was attenuated to 1.3-6.9 V-SMOW in soil water, groundwater, spring water, and stream water. It is thought that these attenuations derive from hydrodynamic transport processes in the subsurface and mixing processes at an outflow point (stream or spring) or a well. The mean residence time (MRT) of water was estimated from d value variations using an exponential-piston flow model and a dispersion model. MRTs for soil water were 0-5 months and were not necessarily proportional to the depth. This may imply the existence of bypass flow in the soil. Groundwater in the hillslope zone had short residence times, similar to those of the soil water. For groundwater in the saturated zone near the spring outflow point, the MRTs differed between shallow and deeper groundwater; shallow groundwater had a shorter residence time (5-8 months) than deeper groundwater (more than 9 months). The MRT of stream water (8-9 months) was between that of shallow groundwater near the spring and deeper groundwater near the spring. The seasonal variation in the d value of precipitation arises from changes in isotopic water vapour composition associated with seasonal activity of the Asian monsoon mechanism. The d value is probably an effective tracer for estimating the MRT of subsurface water not only in Japan, but also in other East Asian countries influenced by the Asian monsoon. Copyright

  10. SWI/SNF mediates polycomb eviction and epigenetic reprogramming of the INK4b-ARF-INK4a locus.

    PubMed

    Kia, Sima Kheradmand; Gorski, Marcin M; Giannakopoulos, Stavros; Verrijzer, C Peter

    2008-05-01

    Stable silencing of the INK4b-ARF-INK4a tumor suppressor locus occurs in a variety of human cancers, including malignant rhabdoid tumors (MRTs). MRTs are extremely aggressive cancers caused by the loss of the hSNF5 subunit of the SWI/SNF chromatin-remodeling complex. We found previously that, in MRT cells, hSNF5 is required for p16(INK4a) induction, mitotic checkpoint activation, and cellular senescence. Here, we investigated how the balance between Polycomb group (PcG) silencing and SWI/SNF activation affects epigenetic control of the INK4b-ARF-INK4a locus in MRT cells. hSNF5 reexpression in MRT cells caused SWI/SNF recruitment and activation of p15(INK4b) and p16(INK4a), but not of p14(ARF). Gene activation by hSNF5 is strictly dependent on the SWI/SNF motor subunit BRG1. SWI/SNF mediates eviction of the PRC1 and PRC2 PcG silencers and extensive chromatin reprogramming. Concomitant with PcG complex removal, the mixed lineage leukemia 1 (MLL1) protein is recruited and active histone marks supplant repressive ones. Strikingly, loss of PcG complexes is accompanied by DNA methyltransferase DNMT3B dissociation and reduced DNA methylation. Thus, various chromatin states can be modulated by SWI/SNF action. Collectively, these findings emphasize the close interconnectivity and dynamics of diverse chromatin modifications in cancer and gene control. PMID:18332116

  11. Reduced white matter integrity is related to cognitive instability.

    PubMed

    Fjell, Anders M; Westlye, Lars T; Amlien, Inge K; Walhovd, Kristine B

    2011-12-01

    Increased performance variability has been demonstrated in several groups and conditions, including aging and cognitive decline. Structural brain characteristics underlying this phenomenon have so far been elusive. However, there is reason to expect that disconnectivity in associative pathways, whether caused by immature or degraded white matter (WM) tracts, will increase performance variability by neural noise. The aim of this study was to test whether the quality of WM, measured by diffusion tensor imaging, is related to performance variability in healthy adults. Intraindividual standard deviation of the reaction time (sdRT) across trials and median reaction time (mRT) from 270 participants were obtained from a speeded continuous performance task (Eriksen flanker task) with two conditions (congruent, incongruent). Tract-based spatial statistics was used to test the relationship with diffusion characteristics [fractional anisotropy (FA), mean diffusion (MD), radial diffusion (RD), axial diffusion (AD)]. Robust relationships between sdRT and all diffusion measures were found in most WM areas, independently of mRT, age, and sex. The effects were anatomically more widespread in the congruent than the incongruent condition, covering almost 50% of the voxels for RD and MD, and >25% of the voxels for FA and AD. Partial betas were in the range 0.45-0.55, and the strength of the relationships increased significantly with age. For mRT, the effects were smaller and unstable across condition. We concluded that performance variability is a likely consequence of individual differences in WM integrity, and that it is a promising behavioral correlate of individual differences in WM microstructure. PMID:22159119

  12. Pharmacokinetics of benzydamine in dairy cows following intravenous or intramuscular administration.

    PubMed

    Anfossi, P; Malvisi, J; Catraro, N; Bolognini, M; Tomasi, L; Stracciari, G L

    1993-01-01

    Five lactating cows were given benzydamine hydrochloride by rapid intravenous (0.45 mg/kg) and by intramuscular (0.45 and 1.2 mg/kg) injection in a crossover design. The bioavailability, pharmacokinetic parameters and excretion in milk of benzydamine were evaluated. After intravenous administration, the disposition kinetics of benzydamine was best described using a two-compartment open model. Drug disposition and elimination were fast (t1/2 alpha: 11.13 +/- 3.76 min; t1/2 beta: 71.98 +/- 24.75 min; MRT 70.69 +/- 11.97 min). Benzydamine was widely distributed in the body fluids and tissues (Vd(area): 3.549 +/- 1.301 L/kg) and characterized by a high value for body clearance (33.00 +/- 5.54 ml/kg per min). After intramuscular administration the serum concentration-time curves fitted a one-compartment open model. Following a dose of 0.45 mg/kg, the Cmax value was 38.13 +/- 4.2 ng/ml at a tmax of 67.13 +/- 4.00 min; MAT and MRT were 207.33 +/- 22.64 min and 278.01 +/- 12.22 min, respectively. Benzydamine bioavailability was very high (92.07% +/- 7.08%). An increased intramuscular dose (1.2 mg/kg) resulted in longer serum persistence (MRT 420.34 +/- 86.39 min) of the drug, which was also detectable in milk samples collected from both the first and second milking after treatment. PMID:8146956

  13. Tsunami, post-tsunami malaria situation in Nancowry group of islands, Nicobar district, Andaman and Nicobar Islands

    PubMed Central

    Manimunda, Sathya Prakash; Sugunan, Attayoor Purushottaman; Sha, Wajid Ali; Singh, Shiv Shankar; Shriram, Ananganallur Nagarajan; Vijayachari, Paluru

    2011-01-01

    Background & objectives: Due to tsunami in 2004 a large proportion of population in Nicobar group of Islands become homeless, and in 2006 large scale labour migration took place to construct the houses. In 2008, a significant increase in malaria incidence was observed in this area. Therefore, in March 2008, the situation of malaria was assessed in Nancowry Islands in Nicobar District to study the reasons for the observed upsurge in the number of cases, and to suggest public health measures to control the infection. Methods: The methods included a retrospective analysis of long term trend in the behaviour of malaria over the years from 2001 to 2008, analysis of the acute malaria situation, and rapid fever and malaria parasitemia survey along with environmental component. Mass radical therapy (MRT) and post-intervention parasitemia survey were carried out. The malaria situation in the aftermath of MRT was analysed. Results: During the post tsunami year (2005) there was a large increase in the incidence of malaria and this trend continued till 2008. The percentage of Plasmodium falciparum increased from 23 to 53 per cent from 2006 to 2007 that coincides with the labour influx from mainland. The study showed that Nancowry was highly endemic, with high transmission setting, and high risk area for malaria. Though, more number of migrant labourers suffered fever (75 vs 20%) and sought malaria treatment over past month but parasitemia survey showed higher point prevalence of malaria among native tribes (7.4 vs 6.5%). Post-MRT, there was a decline in the occurrence of malaria, though it did not last long. Interpretation & conclusions: The study findings suggest that the migrant workers hailing from non-endemic or moderately endemic settings became victims of malaria in epidemic proportion in high endemic and high transmission setting. To find out the reasons for deterioration of malaria situation at Nancowry in the aftermath of tsunami requires further research. PMID

  14. A practical approach to genetic screening for influenza virus variants.

    PubMed Central

    Zou, S

    1997-01-01

    This report describes a quick genetic approach to the screening of influenza virus variants. Multiplex reverse transcription (MRT) and multiplex PCR (MPCR) were used to amplify and differentiate the hemagglutinin (HA) genes of different types and subtypes of influenza viruses. Heteroduplex mobility assay (HMA) was then used to differentiate strains within the same type and subtype. Three primers complementary to the consensus 3' termini of viral genomic RNA segments of human influenza virus types A, B, and C were used in a single MRT reaction to prime the synthesis of cDNA of all the viral genome segments. The cDNA was then amplified in an MPCR containing primers for the HA genes of the H1 and H3 subtypes of type A, the HA gene of type B, and the counterpart of type C virus. Amplicons of the different types and subtypes differ in size, thus allowing typing and subtyping. The regions amplified cover most of the HA1 portion of the HA genes and therefore amplicons of variants identified by the described HMA can be sequenced directly. In the HMA, the amplicon of an individual strain was mixed with that of a reference strain and heteroduplexes derived from mismatches migrated more slowly than homoduplexes of the same size in electrophoresis, with the mobility shift pattern indicating the divergence of amplicons. The whole process from viral RNA extraction to HMA can be completed within 2 days and thus provides a quick screening before further analysis by hemagglutination inhibition testing and sequencing. In addition, all segments of the viral genome can be amplified from a single MRT reaction, which can yield valuable sources of products for future genetic analyses. This method should facilitate genetic screening and characterization of influenza virus variants. PMID:9316919

  15. 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.

  16. 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. PMID:19257763

  17. Generalization of the Landau-Lifshitz-Gilbert Equation for Conducting Ferromagnets

    NASA Astrophysics Data System (ADS)

    Zhang, Shufeng; Zhang, Steven S.-L.

    2009-02-01

    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.

  18. Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Anderson, Danielle; Siegbahn, E. Albert; Fallone, B. Gino; Serduc, Raphael; Warkentin, Brad

    2012-05-01

    This work evaluates four dose-volume metrics applied to microbeam radiation therapy (MRT) using simulated dosimetric data as input. We seek to improve upon the most frequently used MRT metric, the peak-to-valley dose ratio (PVDR), by analyzing MRT dose distributions from a more volumetric perspective. Monte Carlo simulations were used to calculate dose distributions in three cubic head phantoms: a 2 cm mouse head, an 8 cm cat head and a 16 cm dog head. The dose distribution was calculated for a 4 × 4 mm2 microbeam array in each phantom, as well as a 16 × 16 mm2 array in the 8 cm cat head, and a 32 × 32 mm2 array in the 16 cm dog head. Microbeam widths of 25, 50 and 75 µm and center-to-center spacings of 100, 200 and 400 µm were considered. The metrics calculated for each simulation were the conventional PVDR, the peak-to-mean valley dose ratio (PMVDR), the mean dose and the percentage volume below a threshold dose. The PVDR ranged between 3 and 230 for the 2 cm mouse phantom, and between 2 and 186 for the 16 cm dog phantom depending on geometry. The corresponding ranges for the PMVDR were much smaller, being 2-49 (mouse) and 2-46 (dog), and showed a slightly weaker dependence on phantom size and array size. The ratio of the PMVDR to the PVDR varied from 0.21 to 0.79 for the different collimation configurations, indicating a difference between the geometric dependence on outcome that would be predicted by these two metrics. For unidirectional irradiation, the mean lesion dose was 102%, 79% and 42% of the mean skin dose for the 2 cm mouse, 8 cm cat and 16 cm dog head phantoms, respectively. However, the mean lesion dose recovered to 83% of the mean skin dose in the 16 cm dog phantom in intersecting cross-firing regions. The percentage volume below a 10% dose threshold was highly dependent on geometry, with ranges for the different collimation configurations of 2-87% and 33-96% for the 2 cm mouse and 16 cm dog heads, respectively. The results of this study

  19. Digesta retention and fibre digestion in maras (Dolichotis patagonum) and guinea-pigs.

    PubMed

    Sakaguchi, E; Nippashi, K; Endoh, G

    1992-04-01

    1. Digestibilities of feed and turnover time (1/k), transit time (TT) and mean retention time (MRT: 1/k+TT) of fluid and particle markers were measured in maras (Dolichotis patagonum) and guinea-pigs (Cavia procellus) fed a diet containing 50% alfalfa. 2. The digestibility of fibre was similar in both animals, however, the digestibilities of crude protein (nitrogen x 6.25) and crude ash were lower in the mara than in the guinea-pig. 3. 1/k of the digesta markers were similar in both animals, suggesting that the two animals possess similar dilution and retention time of digesta in their caecum and proximal colon. PMID:1351463

  20. [Sigmoidoperianal fistula associated with diverticulitis and Cul de Sac situation--diagnostics and therapy].

    PubMed

    Weyand, G; Rinast, E; Englert, A; Houf, M

    2002-07-01

    We report on the case of a 64-year-old female patient who presented herself in our outpatient clinic because of a perianal fistula with recurrent abscesses. We describe the step diagnostics and the surgical treatment of the causal sigmoido-perianal fistula with diverticulitis and Cul de sac situation. Clinical examination, fistulography, colonoscopy and MRT were part of the precise representation and preparation for the high anterior rectosigmoidal resection with simultaneous rectopexy according to Sudeck which were performed without complications. The sigmoidoperianal fistula must be taken into account as a differential diagnosis of a recalcitrant high perianal fistula. PMID:12122593

  1. 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. PMID:26980894

  2. 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

  3. 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

  4. Examination of carbon associated with metal-humus complexes, short-range-order Al and Fe oxides, and crystalline Al and Fe oxides: Differences in carbon abundance and mean residence time

    NASA Astrophysics Data System (ADS)

    Heckman, K. A.; Lawrence, C. R.

    2012-12-01

    Transport of SOM (soil organic matter) between soils and aquatic systems is regulated in part by sorption and desorption reactions happening at mineral surfaces, as well as precipitation and dissolution of metal-humus complexes. Fe and Al hydroxides play a particularly significant role in SOM stabilization in soils due to their ubiquitous distribution and their highly reactive surface properties. Fe and Al hydroxides exist in soils across a wide spectrum of crystallinity, ranging from dissolved Fe and Al cations which combine with organics to form metal-humus precipitates to the more crystalline end members, goethite and gibbsite, which sorb SOM through a variety of molecular interactions. Though the importance of these sorption and precipitation reactions has long been recognized, the distribution of SOM among Fe and Al hydroxides of differing crystallinity has not been well quantified, nor has the timescales over which these stabilization mechanisms operate. In an attempt to measure the distribution of organic C among i) Al- and Fe-humus complexes ii) short-range-order Al and Fe oxide surfaces and iii) crystalline Al and Fe oxide surfaces, a suite of selective dissolutions were applied to soils of four different geneses (a tropical forest andosol, a temperate basaltic mollisol, a grassland alfisol, and a northern pine spodosol. The traditional reactants used in selective dissolutions were replaced with carbon-free analogues so that the carbon released along with the Fe and Al at each stage of the selective dissolution process could be examined. Selective dissolutions were performed sequentially: Na-pyrophosphate (Al- and Fe-humus complexes) followed by hydroxyl-amine (short-range-order Al and Fe hydroxides) followed by dithionite/HCl (crystalline Al and Fe hydroxides). Carbon concentration, δ13C, and Δ14C were measured for the solutions yielded by each stage of the selective dissolution process. Δ14C were used to estimate a MRT (mean residence time) for SOM

  5. Analysis of catchment behavior using residence time distributions with application to the Thuringian Basin

    NASA Astrophysics Data System (ADS)

    Prykhodko, Vladyslav; Heße, Falk; Kumar, Rohini; Samaniego, Luis; Attinger, Sabine

    2014-05-01

    Residence time distribution (RTD), as presented e.g. by Botter et al., are a novel mathematical framework for a quantitative characterization of hydrological systems. These distributions contain information about water storage, flow pathways and water sources and therefore improve the classical hydrograph methods by allowing both nonlinear as well as time-dependent dynamics. In our study we extend this previous works by applying this theoretical framework on real-world heterogeneous catchments. To that end we use a catchment-scale hydrological model (mHM) and apply the approach of Botter et al. to each spatial grid cell of mHM. To facilitate the coupling we amended Botter's approach by introducing additional fluxes (like runoff from unsaturated zone) and specifying the structure of the groundwater zone. By virtue of this coupling we could then make use of the realistic hydrological fluxes and state variables as provided by mHM. This allowed us to use both observed (precipitation, temperature, soil type etc.) and modeled data sets and asses their impact on the behavior of the resulting RTD's. We extended the aforementioned framework to analyze large catchments by including geomorphic effect due to the actual arrangement of subcatchments around the channel network using the flood routing algorithm of mHM. Additionally we study dependencies of the stochastic characteristics of RTD's on the meteorological and hydrological processes as well as on the morphological structure of the catchment. As a result we gained mean residence times (MRT) of base flow and groundwater flow on the mesoscale (4km x 4km). We compare the spatial distribution of MRT's with land cover and soil moisture maps as well as driving forces like precipitation and temperature. Results showed that land cover is a major predictor for MRT's whereas its impact on the mean evapotranspiration time was much lower. Additionally we determined the temporal evolution of mean travel times by using time series of

  6. 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

  7. Status of uncooled infrared imagers

    NASA Astrophysics Data System (ADS)

    Flannery, Robert E.; Miller, James E.

    1992-09-01

    Brassboard infrared imagers containing focal plane arrays of more than 80,000 uncooled detectors sensitive to radiation in the 8- to 14-micrometer wavelength region have been fabricated and tested. These imagers, which have demonstrated noise-equivalent temperature difference (NETD) values of 0.10 degree(s)C, do not require cryogenic cooling or mechanical scanning. Two different types of detector, one ferroelectric and the other bolometric, are used for the focal plane arrays. Measurements of NETD, minimum resolvable temperature (MRT) and modulation transfer function (MTF) are reported. Uncooled sensor technology is being incorporated into prototype security sensors and weapon sights that can also be used as handheld surveillance devices.

  8. 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

  9. 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

  10. 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

  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. New data on diagnosis and medical treatment of retroperitoneal fibrosis.

    PubMed

    Oosterlinck, W; Derie, A

    1997-06-01

    A review of the literature of the last 5 years on retroperitoneal fibrosis is given. MRT seems to add to the exact extend of the disease and galliumscintigraphy can give new information on the activity of the process and the usefulness of medical therapy. The use of corticosteroid or other immunosuppressive drugs such a azathioprine, again is confirmed. Other drugs mentioned in the medical therapy are methotrexate, cyclophosfamide and penicillamine. A few cases responded well to tamoxifen, a drug which was already used in therapy of desmoid tumours. Medical treatment is anyhow superior to surgery alone. PMID:9287431

  13. Effect of chronic ethanol administration on disposition of ethanol and its metabolites in rat.

    PubMed

    Kozawa, Shuji; Yukawa, Nobuhiro; Liu, Jinyao; Shimamoto, Akiko; Kakizaki, Eiji; Fujimiya, Tatsuya

    2007-03-01

    We studied the effects of chronic alcohol intake on the disposition of alcohol and its metabolites in the rat. We used male Wistar rats for all of the experiments in this study. Using a pair-feeding process, rats were fed a liquid diet containing alcohol or without alcohol for 6 weeks. Ethanol solutions (0.5, 1.0, 1.5, and 2.0 g/kg body weight [BW]) were administered as a bolus, intravenously. We then measured blood ethanol and acetate concentrations. Simultaneous multiline fitting was performed using mean blood alcohol concentration (BAC)-time curves fitted to the one-compartment open model with parallel first-order and Michaelis-Menten elimination kinetics. At low doses (0.5, 1.0, and 1.5 g/kgBW), no differences were observed between the alcohol group and the control group with respect to ethanol elimination rate, area under the curve of ethanol (AUC(EtOH)), and mean residence time of ethanol (MRT(EtOH)). At higher doses (2.0 g/kgBW), ethanol elimination rate in the alcohol group was significantly higher than in the control group (P<.5%). These findings were also substantiated by corresponding changes in AUC(EtOH) and MRT(EtOH). At low doses, no differences were observed between the alcohol group and the control group with respect to plateau concentration of acetate (AcT) (concentration of steady state=C(ss)AcT), area under the curve of AcT (AUC(AcT)), and mean residence time of AcT (MRT(AcT)). However, at higher doses, although there were no differences in C(ss)AcT, both AUC(AcT) and MRT(AcT) were significantly lower in the alcohol group when compared to the control group (P<.5%). Chronic alcohol consumption increases ethanol oxidation and AcT metabolism in rats, as observed at high blood alcohol concentrations (BACs). These effects were observed at BACs of 3.5-4.5 mg/ml, and were not observed at lower doses. Thus, with general alcohol consumption, interindividual differences and intra-individual changes in alcohol metabolism may not take into account increased

  14. Magnetic Resonance (MR) rectography in diagnostics of small-size rectal neoplasms

    NASA Astrophysics Data System (ADS)

    Usova, AV; Frolova, IG; Trukhacheva, NG; Cheremisina, OV; Afanas'ev, SG

    2016-02-01

    Purpose was the assessment of diagnostic efficiency of MR-rectography in diagnostics of small-size rectal neoplasms. 12 patients with polyps and small tumors of a rectum are examined, the size of detected neoplasms varied in the range 3-18 mm. Native MRI and MRI with retrograde contrasting by ultrasonic gel was carried out. Results of MRI are compared with results of videocolonoscopy. Sensitivity of native MRT was 24%, MR- rectography was 88%. MR-rectography can be used in diagnostics of small-size rectal neoplasms.

  15. [Acute perilunar dislocations: algorithm for treatment].

    PubMed

    Towfigh, H

    2001-01-01

    In most cases, perilunar dislocations of the wrist are caused by high speed accidents. Usually these injuries occur by a fall on the dorsiflexed superextension of the hand. The instability caused by injuries of various erticular structures (ligament, bone) show various developmental stages. Clinical symptoms are reduced and painful movement, instability of the carpus, snapping and swelling. The diagnosis is established by X-ray, cinematography, arthrography MRT or CT. Perilunar instability with or without associated fractures and particularly de Quervain must be reduced and treated operatively including suture of the ligament and stabilization of the fracture. PMID:11824286

  16. Vernetzung im Kfz

    NASA Astrophysics Data System (ADS)

    Reif, Konrad

    Elektrische und elektronische Systeme im Kfz sind vielfach nicht voneinander unabhängig, sondern beeinflussen und ergänzen sich gegenseitig. Deshalb wurden schon bei den frühen Einspritz- und Zündsystemen Signalleitungen eingesetzt, um eine einfache Kommunikation zwischen diesen beiden Systemen zu ermöglichen. Die zunehmende Anzahl elektronischer Systeme erhöhte jedoch rasch den Bedarf und die Vielfalt an auszutauschenden Informationen. Die Anzahl der hierzu erforderlichen Signalleitungen und Stecker anschlüsse stiegen gleichermaßen, so dass die bis dahin angewandte Technik an ihre Grenzen stieß.

  17. Unser griechisches Erbe

    NASA Astrophysics Data System (ADS)

    Schöpf, Hans-Georg

    Es wird dargelegt, daß fundamentale Konzeptionen der Physik auf die griechische Naturphilosophie zurückgeführt werden können, speziell auf Pythagoreismus, Platonismus und auf den Atomismus Demokrits. Am Ende des Artikels wird ein kurzer Blick auf den Zusammenhang zwischen Aristotelismus und Physik geworfen.Translated AbstractOur Greek InheritanceIt is shown that fundamental concepts of physics may be traced back to Greek Natural Philosophy, especially to Pythagoreism, Platonism, and to Demokrit's Atomism. At the end of the paper a brief glance is thrown on the relation between Aristotelism and physics.

  18. Keller oder Dach zuerst?

    NASA Astrophysics Data System (ADS)

    Megow, Nicole

    Komplexe Planungsaufgaben entstehen in vielen Bereichen wie z. B. in der Produktion und Logistik, der Bauplanung oder allgemein im Projektmanagement. Typischerweise werden umfangreiche Projekte in viele einzelne Teilaufgaben zerlegt, die dann zeitlich geplant werden. Das heißt, es wird genau bestimmt wann bzw. in welcher Reihenfolge Aufgaben mit welchen Ressourcen durchgeführt warden sollen. Bei der Planung müssen verschiedenste Reihenfolgeabhängigkeiten zwischen den Vorgängen berücksichtigt werden. Diese Abhängigkeiten können technischer Natur sein oder werden aus sicherheitsrelevanten oder wirtschaftlichen Gründen festgelegt.

  19. Elektrotechnik

    NASA Astrophysics Data System (ADS)

    Böge, Gert

    Ursprünglicher Sitz der Elektrizität ist das Atom. Das Wasserstoffatom z.B. besteht aus einem Proton als Kern und einem Elektron, das diesen Kern auf einer bestimmten Bahn umkreist. Das Proton bezeichnet man als elektrisch positiv, - das Elektron als negativ geladen. Zwischen beiden befindet sich die "Elektrizität“ in Form eines besonderen Raumzustandes, der als elektrisches Feld bezeichnet wird. Normalerweise erscheint ein Stoff nach außen hin elektrisch neutral, weil ebenso viele positive wie negative Ladungen in ihm enthalten sind.

  20. „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.

  1. Durch Raum und Zeit reisen - Eine Theorie gibt Antworten auf alte Fragen

    NASA Astrophysics Data System (ADS)

    Sonne, Bernd; Weiß, Reinhard

    2013-07-01

    Im Rahmen der Relativitätstheorie, sei es die spezielle oder auch allgemeine, kommt man zwangsläufig auf die Fragestellung, ob Zeitreisen möglich sind oder nicht. Es gibt darüber sehr viele Veröffentlichungen, da dieses Thema offensichtlich viele Leute beschäftigt: Naturwissenschaftler, Philosophen, Filmautoren. Wir wollen hier nur einige grundlegende Fragestellungen aufgreifen: Kann man in die Zukunft reisen? Gibt es Reisen mit Überlichtgeschwindigkeit? Wie sieht es aus mit Reisen in die Vergangenheit? Wir unterschieden dabei zwischen mathematischen, physikalischen und technischen Lösungen, die Zeitreisen entweder erlauben oder unmöglich machen.

  2. Unfälle mit motorisierten Zweirädern

    NASA Astrophysics Data System (ADS)

    Tschirschwitz, Christian

    Der Fahrer eines Pkw Opel Astra überquerte mit seinem Pkw von einer untergeordneten Einmündung kommend eine außerörtliche Bundesstraße in gerade Richtung. Dabei kam es zur Kollision mit einem sich von rechts vorfahrtsberechtigt annähernden Krad Suzuki RGV250. Der Anprall des Krades erfolgte mit dem Heck an die rechte Pkw-Flanke zwischen vorderem Radausschnitt und Fahrzeugecke. Der Krad-Fahrer, welcher sofort tot war und das Zweirad verklemmten sich am Pkw und verblieben relativ zu selbigem annähernd in Kollisionsstellung.

  3. Verknüpfung von DQ-Indikatoren mit KPIs und Auswirkungen auf das Return on Investment

    NASA Astrophysics Data System (ADS)

    Block, Frank

    Häufig ist nicht klar, welche Beziehungen zwischen Datenqualitätsindikatoren (DQI, Definition folgt weiter unten) und Key Performance Indicators (KPI, s. Abschnitt 1.3 für weitere Details) eines Unternehmens oder einer Organisation bestehen. Dies ist insbesondere deshalb von Bedeutung, da die Kenntnis dieser Beziehungen maßgeblich die Ausprägung eines Datenqualitätsprojekts beeinflusst. Sie ist als Entscheidungsgrundlage unabdingbar und gibt Antworten auf folgende Fragen: Was kostet unserem Unternehmen/unserer Organisation1 schlechte Datenqualität? Können wir uns das leisten?

  4. Absorption and disposition of florfenicol after intravenous, intramuscular and subcutaneous dosing in alpacas.

    PubMed

    Pentecost, Rebecca L; Niehaus, Andrew J; Werle, Nicholas; Lakritz, Jeffrey

    2015-04-01

    The objectives of this study were to define disposition and systemic availability of florfenicol in alpacas. Administration of 20 mg/kg doses to 8 male alpacas by i.v., i.m. and s.c. routes was performed by randomized, 3-way crossover design. Clearance and steady state volumes (Vdss) after i.v. injection were 5 ml/min/kg and 775 ml/kg respectively. Mean residence time (MRT) and terminal phase half-life (T1/2λz) were 2.8 h and 2 h respectively. Maximum serum concentrations (Cmax) after i.m. were higher than s.c. administration (p = 0.034). After s.c. dosing, T1/2λz and MRT were greater than after i.m. injection (p < 0.001; p = 0.006 respectively). Mean absorption time (MAT) after s.c. dosing was also prolonged (p = 0.006). Fractional absorption of florfenicol after i.m. and s.c. was not different (p > 0.05). Serum florfenicol concentrations remained >1.0 µg/ml for 20 h after i.m. dosing. Differences in rate and extent of florfenicol absorption after extravascular dosing could influence therapeutic outcomes. PMID:25744433

  5. Cognitive functions in patients with liver cirrhosis: A tendency to commit more memory errors

    PubMed Central

    Ciećko-Michalska, Irena; Wójcik, Jan; Senderecka, Magdalena; Wyczesany, Mirosław; Binder, Marek; Szewczyk, Jakub; Dziedzic, Tomasz; Słowik, Agnieszka; Mach, Tomasz

    2013-01-01

    Background Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE). For diagnostic purposes, 2 alternative batteries of psychometric screening tests are recommended. They differ from each other in terms of the cognitive domains assessed. The research was designed to provide a profile of cognitive functioning in patients with liver cirrhosis, using an assessment that covers a wider range of cognitive functions than the usual screening battery. Material/Methods We examined 138 persons, including 88 with liver cirrhosis and 50 healthy volunteers. The Mini Mental State Examination (MMSE) was used for screening and excluding advanced cognitive impairment. Then, to assess cognitive functions in more detail, the following tests were used: Auditory Verbal Learning Test (AVLT), Letter and Semantic Fluency Tests (LF and SF), Trail Making Test (TMT A&B), Digit Symbol Test (DST), Block Design Test (BDT), and Mental Rotation Test (MRT). The MRT task has not been used in MHE diagnosis so far. Finally, 57 patients and 48 controls took part in the entire study. Results Patients with liver cirrhosis commit significantly more errors of intrusions in the AVLT during the delayed free recall trial. Results significantly deviating from the norm in at least 2 tests were found only in 7 cirrhosis patients. Conclusions The results do not provide any specific profile of cognitive disturbances in MHE, but suggest that cirrhosis patients have a tendency to commit more memory errors, probably due to subtle impairments of executive function. PMID:23598598

  6. Modified helix-like instability structure on imploding z-pinch liners that are pre-imposed with a uniform axial magnetic field

    SciTech Connect

    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.; Gomez, M. R.; Hansen, S. B.; Herrmann, M. C.; Jones, M. C.; McKenney, J. L.; Robertson, G. K.; Rochau, G. A.; Savage, M. E.; Stygar, W. A.; Tomlinson, K.; and others

    2014-05-15

    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.

  7. Investigation of Abscopal and Bystander Effects in Immunocompromised Mice After Exposure to Pencilbeam and Microbeam Synchrotron Radiation.

    PubMed

    Fernandez-Palomo, Cristian; Schültke, Elisabeth; Bräuer-Krisch, Elke; Laissue, Jean Albert; Blattmann, Hans; Seymour, Colin; Mothersill, Carmel

    2016-08-01

    Out-of-field effects are of considerable interest in radiotherapy. The mechanisms are poorly understood but are thought to involve signaling processes, which induce responses in non-targeted cells and tissues. The immune response is thought to play a role. The goal of this research was to study the induction of abscopal effects in the bladders of NU-Foxn1 mice after irradiating their brains using Pencil Beam (PB) or microbeam (MRT) irradiation at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Athymic nude mice injected with F98 glioma cells into their right cerebral hemisphere 7 d earlier were treated with either MRT or PB. After recovery times of 2, 12, and 48 h, the urinary bladders were extracted and cultured as tissue explants for 24 h. The growth medium containing the potential signaling factors was harvested, filtered, and transferred to HaCaT reporter cells to assess their clonogenic survival and calcium signaling potential. The results show that in the tumor-free mice, both treatment modalities produce strong bystander/abscopal signals using the clonogenic reporter assay; however, the calcium data do not support a calcium channel mediated mechanism. The presence of a tumor reduces or reverses the effect. PB produced significantly stronger effects in the bladders of tumor-bearing animals. The authors conclude that immunocompromised mice produce signals, which can alter the response of unirradiated reporter cells; however, a novel mechanism appears to be involved. PMID:27356059

  8. An adaptive lattice Boltzmann scheme for modeling two-fluid-phase flow in porous medium systems

    NASA Astrophysics Data System (ADS)

    Dye, Amanda L.; McClure, James E.; Adalsteinsson, David; Miller, Cass T.

    2016-04-01

    We formulate a multiple-relaxation-time (MRT) lattice-Boltzmann method (LBM) to simulate two-fluid-phase flow in porous medium systems. The MRT LBM is applied to simulate the displacement of a wetting fluid by a nonwetting fluid in a system corresponding to a microfluidic cell. Analysis of the simulation shows widely varying time scales for the dynamics of fluid pressures, fluid saturations, and interfacial curvatures that are typical characteristics of such systems. Displacement phenomena include Haines jumps, which are relatively short duration isolated events of rapid fluid displacement driven by capillary instability. An adaptive algorithm is advanced using a level-set method to locate interfaces and estimate their rate of advancement. Because the displacement dynamics are confined to the interfacial regions for a majority of the relaxation time, the computational effort is focused on these regions. The proposed algorithm is shown to reduce computational effort by an order of magnitude, while yielding essentially identical solutions to a conventional fully coupled approach. The challenges posed by Haines jumps are also resolved by the adaptive algorithm. Possible extensions to the advanced method are discussed.

  9. 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.

  10. 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. PMID:27453050

  11. [Differential diagnosis of pediatric hip pain in MR tomography].

    PubMed

    Glas, K; Obletter, N; Staudt, F; Scheuerer, K

    1991-01-01

    The efficiency of spin echo tomography in the differential diagnosis of hip joint pain in children in comparison with other imaging methods was tested in 115 spin echo tomography examinations of 68 patients. By means of the different modes available it was possible to determine joint effusion, necrosed areas and the formation of abscesses with great accuracy. In the case of Legg-Calve-Perthes disease the MRT is especially in the early diagnosis superior to the other Methods, already in the early stage a classification in the four Catterall groups was possible. Furthermore the "head at risk" signs, except the gage-sign, were better to describe by BRI than by conventional x-rays. The MRT allows an exacter staging and a better observation of the course of disease, especially the beginning of the revitalisation of the femora epiphysis in earlier and clearer visible than in other imaging methods. Further diseases like epiphysial dysplasie, specific and unspecific coxitis and slipped capital femora epiphysis were also investigated. We regard spin echo examination in the differential diagnosis of hip pain in children indicated by the following criteria: 1. with over six weeks uncertain differential diagnosis of coxitis fugax and Legg-Calve-Perthes disease 2. with Legg-Calve-Perthes disease in the early stage for therapy option 3. with TBC- and non-TBC-coxitis as a therapy attend and diagnostic measure. PMID:1829298

  12. Metronidazole pharmacokinetics during rapid growth in turkeys - relation to changes in haemodynamics and drug metabolism.

    PubMed

    Świtała, M; Poźniak, B; Pasławska, U; Grabowski, T; Motykiewicz-Pers, K; Bobrek, K

    2016-08-01

    Whereas interspecies variation in pharmacokinetics is a commonly investigated issue, variations in drug kinetics within a species are less documented. The aim of the study was to assess the influence of age-related changes in haemodynamics on the pharmacokinetics of metronidazole (MTZ) and its hydroxy metabolite (MTZ-OH) in turkeys. MTZ was administered intravenously and orally at a dose of 25 mg/kg. Plasma drug and metabolite concentrations were assessed by high-performance liquid chromatography, and pharmacokinetic parameters were calculated by noncompartmental analysis. Haemodynamic parameters (heart rate, stroke volume, cardiac output) were assessed by echocardiography and extraction ratio for MTZ was calculated based on total body clearance (ClB ). Between the 5th and 15th week of age, ClB of MTZ decreased from 3.6 to 1.2 mL/min/kg causing a twofold increase in the mean residence time (MRT) and elimination half-life (T1/2el ). The MTZ-OH production decreased threefold and its MRT and T1/2el increased. Although heart rate significantly decreased with age, cardiac output increased. Extraction ratio was low in all age groups. It is concluded that significant age-dependent decrease in ClB of MTZ in turkeys resulted from decreased perfusion of the clearing organs and their reduced metabolic capacity. This phenomenon is probably species specific and may apply to other therapeutic agents. PMID:26813708

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

    PubMed

    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. PMID:27627415

  14. Characterisation and application of ultra-high spin clusters as magnetic resonance relaxation agents.

    PubMed

    Guthausen, Gisela; Machado, Julyana R; Luy, Burkhard; Baniodeh, Amer; Powell, Annie K; Krämer, Steffen; Ranzinger, Florian; Herrling, Maria P; Lackner, Susanne; Horn, Harald

    2015-03-21

    In Magnetic Resonance Tomography (MRT) image contrast can be improved by adding paramagnetic relaxation agents such as lanthanide ions. Here we report on the use of highly paramagnetic isostructural Fe(III)/4f coordination clusters with a [Fe10Ln10] core to enhance relaxation. Measurements were performed over the range of (1)H Larmor frequencies of 10 MHz to 1.4 GHz in order to determine the relevant parameters for longitudinal and transverse relaxivities. Variation of the lanthanide ion allows differentiation of relaxation contributions from electronic states and molecular dynamics. We find that the transverse relaxivities increase with field, whereas the longitudinal relaxivities depend on the nature of the lanthanide. In addition, the Gd(III) analogue was selected in particular to test the interaction with tissue observed using MRT. Studies on biofilms used in waste water treatment reveal that the behaviour of the high-spin clusters is different from what is observed for common relaxation agents with respect to the penetration into the biofilms. The Fe10Gd10 cluster adheres to the surface of the biofilm better than the commercial agent Gadovist. PMID:25670214

  15. Pharmacokinetics and safety of resveratrol derivatives in humans after oral administration of melinjo (Gnetum gnemon L.) seed extract powder.

    PubMed

    Tani, Hiroko; Hikami, Susumu; Iizuna, Sanae; Yoshimatsu, Maiko; Asama, Takashi; Ota, Hidetaka; Kimura, Yuka; Tatefuji, Tomoki; Hashimoto, Ken; Higaki, Kazutaka

    2014-02-26

    Fruits and seeds of melinjo (Gnetum gnemon L.) are resveratrol derivative-rich materials. Pharmacokinetics of resveratrol derivatives in healthy volunteers after oral administration of 1000 mg of melinjo seed extract (MSE) powder were assessed and compared with those after oral dosing of trans-resveratrol (tRV) powder containing 4.8 mg of tRV only, equivalent to the content in 1000 mg MSE powder. Plasma tRV concentrations with enzymatic hydrolysis were maintained over 24 h, with a tmax of 12 h and a mean residence time (MRT) of 14 h, 5 and 2 times higher than those for tRV powder intake, respectively. Gnetin C, a resveratrol dimer, with hydrolysis was maintained in plasma for >96 h with a 36 h MRT. With repeated doses once daily for 28 days, plasma tRV and gnetin C concentrations with hydrolysis were in good agreement with the theoretical curves. MSE powder was well tolerated up to the oral dosing of 5000 mg with no serious adverse events. PMID:24495149

  16. Ruthenium interlayer as diffusion barrier under carbon overcoat in magnetic recording media.

    PubMed

    Wang, Jianhui; Zhang, Sam; Wang, Huili; Xu, Ping; Iha, Dwight; Sawasaki, Steven

    2008-05-01

    A Magnetic film of ternary CoCrTa alloy was deposited onto textured NiP/Al substrate. Then, an atomic (8 A) layer of ruthenium (Ru) film was sputtered before a layer of hydrogenated amorphous carbon (a-C:H) was deposited by hot filament Plasma Enhanced Chemical Vapor Deposition method. Dynamic remanent magnetization and thickness product (MrT) measurement showed that samples without Ru interlayer were susceptible to plasma damage during carbon deposition compared to samples with Ru interlayer. The impact was more obvious as the substrate bias was increased during carbon deposition. Having an intermediate layer of ruthenium film in between magnetic layer and carbon overcoat made magnetic performance of the film more stable. After annealed for 30 minutes under 1 atm of N2 environment, MrT values dropped drastically in samples without Ru interlayer but varied only a little in samples with the interlayer. Water contact angle measurement showed little difference in surface energy with or without the interlayer. XPS studies indicated that Tantalum carbide formed in samples without Ru interlayer. Formation of metal carbide was not found in samples with Ru interlayer. PMID:18572693

  17. 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.

  18. 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 adminstraion 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 commerical product, therefore the new injection may be an alternative choice for sheep to control parasites sensitive to IVM and PZQ. PMID:27084471

  19. Effect of polyethylene glycol conjugation on the circulatory stability of plasma-derived human butyrylcholinesterase in mice.

    PubMed

    Sun, Wei; Luo, Chunyuan; Tipparaju, Prasanthi; Doctor, Bhupendra P; Saxena, Ashima

    2013-03-25

    Exogenously administered human serum butyrylcholinesterase (Hu BChE) was demonstrated to function as a bioscavenger of highly toxic organophosphorus (OP) compounds in several animal species. Since the enzyme is isolated from human serum, it is currently the most suitable pretreatment for human use. A dose of 200-300 mg/70 kg human adult is projected to provide protection from 2 X LD(50) of soman. Due to the limited supply of Hu BChE, strategies aimed at reducing the dose of enzyme are being explored. In this study, we investigated the effect of modification with polyethylene glycol (PEG) on the in vivo stability of Hu BChE. Mice were given two injections of either Hu BChE or Hu BChE modified with PEG-5K or PEG-20K, six weeks apart. Pharmacokinetic parameters, such as mean residence time (MRT), maximal concentration (C(max)), elimination half-life (T(1/2)), and area under the plasma concentration time curve extrapolated to infinity (AUC), were determined. For the first injection, values for MRT, T(1/2), Cmax, and AUC for PEG-5K-Hu BChE and PEG-20K-Hu BChE were similar to those for Hu BChE. These values for the second injection of Hu BChE as well as PEG-Hu BChEs were lower as compared to those for the first injections, likely due to antibody-mediated clearance. PMID:23220586

  20. 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.

  1. 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. PMID:17377292

  2. 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%.

  3. 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. PMID:26239841

  4. Building resilience.

    PubMed

    Seligman, Martin E P

    2011-04-01

    Failure is a familiar trauma in life, but its effects on people differ widely. Some reel, recover, and move on with their lives; others get bogged down by anxiety, depression, and fear of the future. Seligman, who is known as the father of positive psychology, has spent three decades researching failure, helplessness, and optimism. He created a program at the University of Pennsylvania to help young adults and children overcome anxiety and depression, and has worked with colleagues from around the world to develop a program for teaching resilience. That program is being tested by the U.S. Army, an organization of 1.1 million people where trauma is more common and more severe than in any corporate setting. Nevertheless, businesspeo-ple can draw lessons from resilience training, particularly in times of failure and stagnation. The program is called Comprehensive Soldier Fitness, and it has three components: the Global Assessment Tool, a test for psychological fitness (administered to more than 900,000 soldiers to date); self-improvement courses following the test; and "master resilience training" (MRT) for drill sergeants. MRT focuses on enhancing mental toughness, highlighting and honing strengths, and fostering strong relationships-core competencies for any successful manager. PMID:21510522

  5. Thin silicon strip detectors for beam monitoring in Micro-beam Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Povoli, M.; Alagoz, E.; Bravin, A.; Cornelius, I.; Bräuer-Krisch, E.; Fournier, P.; Hansen, T. E.; Kok, A.; Lerch, M.; Monakhov, E.; Morse, J.; Petasecca, M.; Requardt, H.; Rosenfeld, A. B.; Röhrich, D.; Sandaker, H.; Salomé, M.; Stugu, B.

    2015-11-01

    Microbeam Radiation Therapy (MRT) is an emerging cancer treatment that is currently being developed at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. This technique uses a highly collimated and fractionated X-ray beam array with extremely high dose rate and very small divergence, to benefit from the dose-volume effect, thus sparing healthy tissue. In case of any beam anomalies and system malfunctions, special safety measures must be installed, such as an emergency safety shutter that requires continuous monitoring of the beam intensity profile. Within the 3DMiMic project, a novel silicon strip detector that can tackle the special features of MRT, such as the extremely high spatial resolution and dose rate, has been developed to be part of the safety shutter system. The first prototypes have been successfully fabricated, and experiments aimed to demonstrate their suitability for this unique application have been performed. Design, fabrication and the experimental results as well as any identified inadequacies for future optimisation are reported and discussed in this paper.

  6. 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.

  7. Influence of induced axial magnetic field on plasma dynamics and radiative characteristics of Z pinches

    NASA Astrophysics Data System (ADS)

    Kantsyrev, V. L.; Esaulov, A. A.; Safronova, A. S.; Velikovich, A. L.; Rudakov, L. I.; Osborne, G. C.; Shrestha, I.; Weller, M. E.; Williamson, K. M.; Stafford, A.; Shlyaptseva, V. V.

    2011-10-01

    The influence of an induced axial magnetic field on plasma dynamics and radiative characteristics of Z pinches is investigated. An axial magnetic field was induced in a novel Z-pinch load: a double planar wire array with skewed wires (DPWAsk), which represents a planar wire array in an open magnetic configuration. The induced axial magnetic field suppressed magneto-Rayleigh-Taylor (MRT) instabilities (with m = 0 and m = 1 instability modes) in the Z-pinch plasma. The influence of the initial axial magnetic field on the structure of the plasma column at stagnation was manifested through the formation of a more uniform plasma column compared to a standard double planar wire array (DPWA) load [V. L. Kantsyrev , Phys. PlasmasPHPAEN1070-664X10.1063/1.2896577 15, 030704 (2008)]. The DPWAsk load is characterized by suppression of MRT instabilities and by the formation of the sub-keV radiation pulse that occurs before the main x-ray peak. Gradients in plasma parameters along the cathode-anode gap were observed and analyzed for DPWAsk loads made from low atomic number Z (Al) and mid-Z (brass) wires.

  8. Manual landmark identification and tracking during the medial rotation test of the shoulder: an accuracy study using three-dimensional ultrasound and motion analysis measures.

    PubMed

    Morrissey, D; Morrissey, M C; Driver, W; King, J B; Woledge, R C

    2008-12-01

    Palpation of movement is a common clinical tool for assessment of movement in patients with musculoskeletal symptoms. The purpose of this study was to measure the accuracy of palpation of shoulder girdle translation during the medial rotation test (MRT) of the shoulder. The translation of the gleno-humeral and scapulo-thoracic joints was measured using both three-dimensional ultrasound and palpation in order to determine the accuracy of translation tracking during the MRT of the shoulder. Two movements of 11 normal subjects (mean age 24 (SD=4), range 19-47 years) were measured. The agreement between measures was good for scapulo-thoracic translation (r=0.83). Gleno-humeral translation was systematically under estimated (p=0.03) although moderate correlation was found (r=0.65). These results indicate that translation of the measured joints can be tracked by palpation and further tests of the efficacy of palpation tracking during musculoskeletal assessment may be warranted. PMID:18359266

  9. New insight into the clinical pharmacokinetics of cefaclor: tissue penetration.

    PubMed

    Mazzei, T; Novelli, A; Esposito, S; Periti, P

    2000-02-01

    The serum pharmacokinetic data presented are generally in agreement with those obtained by other authors with both the cefaclor IR (immediate release) and AF (advanced formulation) or MR (modified release) formulations. With the new sustained-release formulation, the time of peak (Tmax) and mean residence time (MRT) values are significantly longer than those observed with the standard cefaclor IR. For the first time the penetration of the MR formulation of cefaclor was determined both in suction blister fluid (SBF) and alveolar epithelial lining fluid (ELF). Cefaclor demonstrated a high tissue distribution, with a high penetration index (PI) into blister fluid, which is at least representative of a relatively large volume of fluid-filled spaces and in part of highly vascularized tissues. SBF and ELF concentrations were higher than blood levels starting at the 4th-6th hour after dose, with longer elimination half-lives from the extravascular compartment than from serum. Cefaclor has a favorable pharmacokinetic profile, especially the new sustained-release formulation, which maintains effective concentrations for a longer time than the IR preparation. The MR formulation improves the kinetic properties of the cefaclor molecule with a prolonged MRT which allows a daily dosage of 750 mg every 12 h. PMID:10768516

  10. Verification of micro-beam irradiation

    NASA Astrophysics Data System (ADS)

    Li, Qiongge; Juang, Titania; Beth, Rachel; Chang, Sha; Oldham, Mark

    2015-01-01

    Micro-beam Radiation Therapy (MRT) is an experimental radiation therapy with provocative experimental data indicating potential for improved efficacy in some diseases. Here we demonstrated a comprehensive micro-beam verification method utilizing high resolution (50pm) PRESAGE/Micro-Optical-CT 3D Dosimetry. A small PRESAGE cylindrical dosimeter was irradiated by a novel compact Carbon-Nano-Tube (CNT) field emission based MRT system. The Percentage Depth Dose (PDD), Peak-to-Valley Dose Ratio (PVDR) and beam width (FWHM) data were obtained and analyzed from a three strips radiation experiment. A fast dose drop-off with depth, a preserved beam width with depth (an averaged FWHM across three beams remains constant (405.3um, sigma=13.2um) between depth of 3.0~14.0mm), and a high PVDR value (increases with depth from 6.3 at 3.0mm depth to 8.6 at 14.0mm depth) were discovered during this verification process. Some operating procedures such as precise dosimeter mounting, robust mechanical motions (especially rotation) and stray-light artifact management were optimized and developed to achieve a more accurate and dosimetric verification method.

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    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.

  12. 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

    2015-01-01

    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

  13. A white-beam fast-shutter for microbeam radiation therapy at the ESRF

    NASA Astrophysics Data System (ADS)

    Renier, M.; Brochard, T.; Nemoz, C.; Thomlinson, W.

    2002-03-01

    The ID17 Medical Beamline port at the European Synchrotron Radiation Facility (ESRF) delivers white beam generated by a 1.4 T wiggler. It is devoted to medical applications of synchrotron radiation. One major program of the beamline is called Microbeam Radiation Therapy (MRT). In this radiotherapy technique, still under development, the white beam fan is divided into several microbeams before reaching the target which is a tumoral brain. The maximum skin-entrance absorbed dose can reach extremely high values (over 1000 Gy) before causing tissue necrosis, while causing tumor necrosis. One of the key parameters for the success of the MRT is the accurate control of the radiation dose delivered to the target, as well as its location with respect to the tumor, to prevent unnecessary damage to normal tissues. Therefore, the opening and closing positions of the shutter while the target is moving vertically at a constant speed reaching 150 mm/s must be carefully controlled. Shutter opening times as short as 5±0.5 ms must be achieved. The total power of the white beam generated by the wiggler may reach 14.5 kW. It is essential to maintain vacuum continuity in the entire beamline and therefore the shutter had to be built to be vacuum compatible to a level of 10 -8 mbar. This paper describes the fast shutter mechanics and its associated electronics.

  14. Numerical study on the fluid flow pass a square cylinder: The temperature-viscosity dependence

    NASA Astrophysics Data System (ADS)

    Lu, Jianhua; Li, Sheng; Guo, Zhaoli; Shi, Baochang

    2014-10-01

    In this paper, the 2D fluid flow pass a heated/cooled square cylinder exposed to a constant free-stream upward velocity is simulated via a multiple relaxation time (MRT) lattice-Boltzmann (LB) method. The buoyancy effect on the drag and lift coefficients as well as Nusselt number related is compared with the results in the existing literatures to validate the code used. The effect of temperature-viscosity dependence is then investigated to test whether the effect can be neglected or not for the mixed convection case. It is shown that the effect cannot be ignored when |Ri| > 0.15. Fortunately, the effect can be captured by using an effective temperature formula [J. M. Shi, D. Ferlach, M. Breuer, G. Biswas and F. Durst, Phys. Fluids16, 4331 (2004)] in a rather large range of Ri. All the numerical results, from another angle, also demonstrate that the MRT method is an efficient tool in simulating the problems such as the present one.

  15. Sex and cultural differences in spatial performance between Japanese and North Americans.

    PubMed

    Sakamoto, Maiko; Spiers, Mary V

    2014-04-01

    Previous studies have suggested that Asians perform better than North Americans on spatial tasks but show smaller sex differences. In this study, we evaluated the relationship between long-term experience with a pictorial written language and spatial performance. It was hypothesized that native Japanese Kanji (a complex pictorial written language) educated adults would show smaller sex differences on spatial tasks than Japanese Americans or North Americans without Kanji education. A total of 80 young healthy participants (20 native Japanese speakers, 20 Japanese Americans-non Japanese speaking, and 40 North Americans-non Japanese speaking) completed the Rey Complex Figure Test (RCFT), the Mental Rotations Test (MRT), and customized 2D and 3D spatial object location memory tests. As predicted, main effects revealed men performed better on the MRT and RCFT and women performed better on the spatial object location memory tests. Also, as predicted, native Japanese performed better on all tests than the other groups. In contrast to the other groups, native Japanese showed a decreased magnitude of sex differences on aspects of the RCFT (immediate and delayed recall) and no significant sex difference on the efficiency of the strategy used to copy and encode the RCFT figure. This study lends support to the idea that intensive experience over time with a pictorial written language (i.e., Japanese Kanji) may contribute to increased spatial performance on some spatial tasks as well as diminish sex differences in performance on tasks that most resemble Kanji. PMID:24356949

  16. 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.

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

    NASA Astrophysics Data System (ADS)

    McBride, R.; Slutz, S.; Jennings, C.; Sinars, D.; Lemke, R.; Martin, M.; Vesey, R.; Cuneo, M.; Herrmann, M.

    2010-11-01

    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.

  18. Analgesic and thermic responses to intravenously administered morphine in 8- and 24-week-old rats.

    PubMed

    Bhargava, H N; Villar, V M

    1991-01-01

    The analgesic and thermic responses to morphine (5 and 10 mg/kg) injected intravenously to 8- and 24-week-old male Sprague-Dawley rats were determined. Greater analgesic and lower hyperthermic responses to morphine in 24-week-old rats in comparison to 8-week-old rats were observed. The pharmacokinetic parameters of morphine administered intravenously were also determined. Cmax for 5 and 10 mg/kg doses of morphine were smaller in 24-week-old rats in comparison to 8-week-old rats; however, AUC0----infinity was smaller only for 5 mg/kg dose. For 10 mg/kg dose, mean residence time (MRT) and the apparent steady state volume of distribution (Vss) for the older rats were higher than for the younger ones, but for 5 mg/kg dose the values did not differ. The enhanced responses to morphine in older age group of rats for 5 mg/kg dose cannot be explained solely on the basis of pharmacokinetics. However, for 10 mg/kg dose of morphine, the greater responses in 24-week-old rats could probably be related to increases in MRT and Vss. Factors other than serum kinetics, like kinetics of morphine in the brain as well as the brain opiate receptors, may also be involved in the differential effects of morphine in rats of different ages. PMID:1784625

  19. Comparative pharmacokinetic study of paeoniflorin after oral administration of pure paeoniflorin, extract of Cortex Moutan and Shuang-Dan prescription to rats.

    PubMed

    Wu, Hao; Zhu, Zhenyu; Zhang, Guoqing; Zhao, Liang; Zhang, Hai; Zhu, Dongliang; Chai, Yifeng

    2009-09-25

    Shuang-Dan (SD) is a traditional Chinese prescription containing Cortex Moutan and Radix Salviae miltiorrhizae and commonly used for treating cardiovascular disease. Paeoniflorin is a main effective ingredient of Cortex Moutan and the pharmacokinetic differences of paeoniflorin following oral administration of pure paeoniflorin, Cortex Moutan extract and SD decoction to rats were studied with approximately the same dose of 30mg/kg paeoniflorin. At different time points (5, 10, 15, 30, 45, 60, 90, 120, 150, 210, 270, 360, 450min), plasma concentration of paeoniflorin was determined using a simple and rapid HPLC-MS method. Unpaired student's t-test was used for the statistical comparison. A bimodal phenomenon was observed in the plasma profile after oral administration of Cortex Moutan extract. Statistically significant increase (P<0.05) in pharmacokinetic parameters of paeoniflorin including AUC(0-t), AUC(0-infinity) and MRT were obtained after oral administration of Cortex Moutan or SD decoction comparing with pure paeoniflorin. The investigation showed that among all calculated parameters, AUC(0-t), AUC(0-infinity), MRT, k(e) and T(1/2), there were no significant differences between the two decoctions. The results indicated that the reason which delay the elimination of paeoniflorin and enhance its bioavailability might be some ingredients in Cortex Moutan extract. PMID:19635542

  20. 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.

  1. Growth and nitrogen use in Xanthium canadense grown in an open or in a dense stand.

    PubMed

    Watari, Ryoji; Nagashima, Hisae; Hirose, Tadaki

    2012-04-01

    Plants develop branches profusely when grown solitarily, while less so when grown in a dense stand. Such changes in architecture are associated with changes in dry mass allocation and nitrogen use. Here, we studied what traits in plant growth and nitrogen use were influenced by different light climates in the stand. Annual plants (Xanthium canadense) were grown solitarily or in a dense stand. Dry mass growth was analyzed as the product of the net assimilation rate (NAR) and leaf area (LA). Nitrogen use efficiency (NUE) was analyzed as the product of nitrogen productivity (NP) and the mean residence time (MRT) of nitrogen. These growth variables were further factorized into their components. Solitary plants maintained a high NAR, whereas plants in the dense stand decreased the NAR due to mutual shading. Plants in the dense stand developed a larger LA with a higher specific leaf area than solitary plants. Solitary plants had higher NUE due to higher NP. A temporal increase in NUE was attributed to the increase in MRT of nitrogen. Light climate was different between solitary and dense-stand plants, but they took up a comparable amount of nitrogen and used it differently in response to the given light climate. NUE was thus demonstrated to be a useful tool for analyzing the mechanism leading to different N use in plant growth. PMID:22211925

  2. 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.

  3. Sex Differences in Parietal Lobe Morphology: Relationship to Mental Rotation Performance

    PubMed Central

    Koscik, Tim; O’Leary, Dan; Moser, David J.; Andreasen, Nancy C.; Nopoulos, Peg

    2009-01-01

    Structural magnetic resonance imaging (MRI) studies of the human brain have reported evidence for sexual dimorphism. In addition to sex differences in overall cerebral volume, differences in the proportion of gray matter (GM) to white matter (WM) volume have been observed, particularly in the parietal lobe. To our knowledge there have been no studies examining the relationship between the sex differences in parietal lobe structure and function. The parietal lobe is thought to be involved in spatial ability, and particularly involved in mental rotation. The purpose of this study is to examine whether sex differences in parietal lobe structure are present, and if present to relate these differences to performance on the Mental Rotations Test (MRT). We found that women had proportionately greater gray matter volume in the parietal lobe compared to men, and this morphologic difference was disadvantageous for women in terms of performance on the MRT. In contrast, we found that men compared to women had proportionately greater parietal lobe surface area, and this morphologic difference was associated with a performance advantage for men on mental rotation. These findings support the possibility that the sexual dimorphism in the structure of the parietal lobe is a neurobiological substrate for the sex difference in performance on the Mental Rotations Test. PMID:18980790

  4. 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.

  5. Influence of induced axial magnetic field on plasma dynamics and radiative characteristics of Z pinches

    SciTech Connect

    Kantsyrev, V. L.; Esaulov, A. A.; Safronova, A. S.; Osborne, G. C.; Shrestha, I.; Weller, M. E.; Stafford, A.; Shlyaptseva, V. V.; Velikovich, A. L.; Rudakov, L. I.; Williamson, K. M.

    2011-10-15

    The influence of an induced axial magnetic field on plasma dynamics and radiative characteristics of Z pinches is investigated. An axial magnetic field was induced in a novel Z-pinch load: a double planar wire array with skewed wires (DPWAsk), which represents a planar wire array in an open magnetic configuration. The induced axial magnetic field suppressed magneto-Rayleigh-Taylor (MRT) instabilities (with m = 0 and m = 1 instability modes) in the Z-pinch plasma. The influence of the initial axial magnetic field on the structure of the plasma column at stagnation was manifested through the formation of a more uniform plasma column compared to a standard double planar wire array (DPWA) load [V. L. Kantsyrev et al., Phys. Plasmas 15, 030704 (2008)]. The DPWAsk load is characterized by suppression of MRT instabilities and by the formation of the sub-keV radiation pulse that occurs before the main x-ray peak. Gradients in plasma parameters along the cathode-anode gap were observed and analyzed for DPWAsk loads made from low atomic number Z (Al) and mid-Z (brass) wires.

  6. 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

  7. Study the effect of formulation variables on drug release from hydrophilic matrix tablets of milnacipran and prediction of in-vivo plasma profile.

    PubMed

    Singhvi, Gautam; Shah, Abhishek; Yadav, Nilesh; Saha, Ranendra N

    2014-09-01

    The objective of this study was to design oral controlled release (CR) matrix tablets of Milnacipran using hydroxypropyl methylcellulose (HPMC) as the retardant polymer and to study the effect of various formulation factors such as polymer proportion, polymer viscosity, compression force and also the pH of dissolution medium on the in-vitro release of drug. Two viscosity grade of HPMC (15 K and 100 K) were used in the proportion of 50, 100, 150 and 200 mg per CR tablet. In-vitro release rate was characterized using various model dependent approaches and model independent dissolution parameters [T50% and T80% dissolution time, mean dissolution time (MDT), mean residence time (MRT), dissolution efficiency (DE)]. The statistical analysis was performed on all the model independent approaches using student t test and ANOVA. Results were found that as polymer concentration (50 mg to 200 mg) and viscosity (15 K to 100 K) increases, the MDT, MRT, T50% and T80% extended significantly. Drug release rate was found to be significantly different at different hardness. In-vivo human plasma concentration--time profile was predicted from in-vitro release data using convolution method. Predicted human pharmacokinetic parameters shows that the design CR formulation has capability to sustained the plasma drug level of milnacipran. PMID:23931031

  8. Training spatial skills in men and women.

    PubMed

    Cherney, Isabelle D; Bersted, Kyle; Smetter, Joseph

    2014-08-01

    Recent studies suggest that even short-term video game training may transfer to other cognitive tasks. With the popularity of the Nintendo Wii with women, more of them might be exposed to the games that will increase their mental rotation skills. Because performance on mental rotation tests (MRT) has been linked to math performance in women, and thus may ultimately contribute to the under representation of women in STEM fields, it is important to continue to explore ways to decrease or eliminate the robust sex difference in mental rotation. The present study of 30 men and 30 women provides additional evidence that women may benefit from short-term (1 hour) training on either a Nintendo Wii™ or GameCube console to increase their mental rotation skills. One hour of video game training not only increased women's MRT scores to a level similar to men's scores, but also produced greater average improvement for women, even when controlling for experiential factors such as spatial and masculine childhood activities that could contribute to the sex difference in spatial ability. PMID:25153741

  9. Single dose pharmacokinetics of manidipine in hepatic impaired patients and healthy controls.

    PubMed

    Deroubaix, X; Lins, R L; Lens, S; Allemon, A; Jeanbaptiste, B; Poli, G; Acerbi, D; Stockis, A; Ventura, P

    1998-07-01

    The pharmacokinetics and safety of a single oral dose of 20 mg manidipine dihydrochloride have been studied in 8 patients with mild to moderate hepatic impairment (grade A or B in Child's classification, or score < or = 7 in Pugh's modification of Child's classification), and in 12 healthy subjects. They received one 20 mg manidipine dihydrochloride tablet with 100 ml of tap water after a standard breakfast. Manidipine was determined using HPLC with electrochemical detection from plasma samples taken up to 24 or 36 h after dosing. The medication was well tolerated. A trend toward higher Cmax, AUC, and MRT was observed in patients with a more severe hepatic impairment, as a consequence of reduction in the liver metabolic function. Patients with grade A hepatic impairment did not exhibit significantly altered pharmacokinetics with respect to healthy subjects, while grade B impairment patients had significantly higher AUC and MRT. Tmax values pointed to reduced absorption rate in patients compared to healthy subjects; the changes were more evident in grade B than grade A patients, although statistical significance was not reached. The reduction in absorption rate in grade B patients is probably related to their higher mean age, since this effect has been reported for manidipine. The pharmacokinetics of manidipine seem only modified in patients with a certain degree of hepatic impairment (at least Pugh grade 6 and Child grade B); therefore, adaptation of the dosing regimen does not seem to be generally recommendable, but should be modulated according to the liver status of the patient. PMID:9707354

  10. 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.

  11. 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.

  12. Thermal human biometeorological conditions and subjective thermal sensation in pedestrian streets in Chengdu, China

    NASA Astrophysics Data System (ADS)

    Zeng, YuLang; Dong, Liang

    2015-01-01

    The outdoor thermal environment of a public space is highly relevant to the thermal perception of individuals, thereby affecting the use of space. This study aims to connect thermal human biometeorological conditions and subjective thermal sensation in hot and humid regions and to find its influence on street use. We performed a thermal comfort survey at three locations in a pedestrian precinct of Chengdu, China. Meteorological measurements and questionnaire surveys were used to assess the thermal sensation of respondents. The number of people visiting the streets was counted. Meanwhile, mean radiant temperature ( T mrt) and the physiological equivalent temperature (PET) index were used to evaluate the thermal environment. Analytical results reveal that weather and street design drive the trend of diurnal micrometeorological conditions of the street. With the same geometry and orientation, a street with no trees had wider ranges of meteorological parameters and a longer period of discomfort. The neutral temperature in Chengdu (24.4 °C PET) is similar to that in Taiwan, demonstrating substantial human tolerance to hot conditions in hot and humid regions. Visitors' thermal sensation votes showed the strongest positive relationships with air temperature. Overall comfort level was strongly related to every corresponding meteorological parameter, indicating the complexity of people's comfort in outdoor environments. In major alleys with multiple functions, the number of people in the street decreased as thermal indices increased; T mrt and PET had significant negative correlations with the number of people. This study aids in understanding pedestrian street use in hot and humid regions.

  13. Embryonic Stem Cell Specific “Master” Replication Origins at the Heart of the Loss of Pluripotency

    PubMed Central

    Julienne, Hanna; Audit, Benjamin; Arneodo, Alain

    2015-01-01

    Epigenetic regulation of the replication program during mammalian cell differentiation remains poorly understood. We performed an integrative analysis of eleven genome-wide epigenetic profiles at 100 kb resolution of Mean Replication Timing (MRT) data in six human cell lines. Compared to the organization in four chromatin states shared by the five somatic cell lines, embryonic stem cell (ESC) line H1 displays (i) a gene-poor but highly dynamic chromatin state (EC4) associated to histone variant H2AZ rather than a HP1-associated heterochromatin state (C4) and (ii) a mid-S accessible chromatin state with bivalent gene marks instead of a polycomb-repressed heterochromatin state. Plastic MRT regions (≲ 20% of the genome) are predominantly localized at the borders of U-shaped timing domains. Whereas somatic-specific U-domain borders are gene-dense GC-rich regions, 31.6% of H1-specific U-domain borders are early EC4 regions enriched in pluripotency transcription factors NANOG and OCT4 despite being GC poor and gene deserts. Silencing of these ESC-specific “master” replication initiation zones during differentiation corresponds to a loss of H2AZ and an enrichment in H3K9me3 mark characteristic of late replicating C4 heterochromatin. These results shed a new light on the epigenetically regulated global chromatin reorganization that underlies the loss of pluripotency and lineage commitment. PMID:25658386

  14. 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.

  15. New techniques for trapping antiprotons, positrons, and antihydrogen atoms

    SciTech Connect

    Yamazaki, Y.

    2005-10-26

    A large number of antiprotons have been accumulated, cooled, compressed, and extracted for the first time. This was accomplished combining the AD(Antiproton Decelerator), the RFQD (Radio Frequency Quadrupole Decelerator) and an MRT (Multi-Ring Trap) installed in a 2.5T solenoid. Some 1.2 x 106 antiprotons were stably stored per one AD shot, which was {approx}50 times better in the accumulation efficiency than conventional methods with thick degrader foils. The trapped antiprotons were then cooled by a preloaded electron plasma({approx} 108/cm3), radially compressed by a rotating electric field, and then extracted from the MRT as mono-energetic DC beams of 10-500eV. A similar system with much higher electron density({approx} 1011/cm3) has enabled a new positron accumulation, the efficiency of which is 360e+/s/mCi, some {approx}30 times better than previous UHV compatible schemes. With these ingredients, a cusp trap is under development, which could synthesize and at the same time trap spin-polarized antihydrogen atoms in their ground states.

  16. 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.

  17. 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.

  18. 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

  19. Tracer (18O, 3H, 3H/3He, CFC and SF6) and hydrochemistry to elucidate processes and mean residence times in porous aquifers in the South-East of Austria (Grazer and Leibnitzer Feld)

    NASA Astrophysics Data System (ADS)

    Kralik, M.; Humer, F.; Darling, G.; Sültenfuß, J.; Wyhlidal, S.

    2012-04-01

    The European Water Framework Directive requires the surface and groundwater bodies in the EU to be back to good quality conditions by 2015. To elucidate the mean residence time (MRT), the recharge area and the potential source of contaminations in particular monitoring wells a combination of several tracers has to be applied at least over one year to answer these questions with confidence. For the implementation of this goal it is necessary that any measures to improve groundwater quality show an impact depending on the MRT. The two groundwater bodies "Grazer Feld" and "Leibnitzer Feld" in the southern part of Styria, Austria stretch out along the river Mur in the N - S direction and covers an area of 166 and 103 km2. The porous aquifer of 10 - 20 m (Grazer Feld) of 6 - 10 m (Leibnitzer Feld) thickness consists of sandy gravel and boulders. In both groundwater bodies are about 2/3 of the aquifer is covered by loam of variable thickness. The depth to water varies between 2 - 20 and 2 - 8 m, respectively. The mean precipitation rate is 900 mm/a. The groundwater runs more or less along the river Mur with a small gradient. The northern part of the Grazer Feld groundwater body is dominated by the urban structure of the city of Graz. The southern part and the groundwater body Leibnitzer Feld is impacted intensively by agricultural use. Due to the extensive agricultural use it contains high concentrations of nitrate and pesticides and shows other hydrochemical changes caused by urbanisation and industrial use. In 33 monitoring wells delta oxygen-18 was analysed four times during one year within the framework of the Austrian hydrochemical groundwater monitoring system. During one campaign 3H, 3H/3He, CFCs and SF6 was analysed in all wells. In addition, the same methods were applied on depth-resolved groundwater samples at selected wells (Kralik et al. 2011). The results of the 3H-input and 3H/3He-models support in both groundwater bodies the rapid water circulation (<5

  20. 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

  1. Oxygen uptake kinetics during low level exercise in patients with heart failure: relation to neurohormones, peak oxygen consumption, and clinical findings

    PubMed Central

    Rocca, H; Weilenmann, D; Follath, F; Schlumpf, M; Rickli, H; Schalcher, C; Maly, F; Candinas, R; Kiowski, W

    1999-01-01

    Objective—To investigate whether oxygen uptake (V̇O2) kinetics during low intensity exercise are related to clinical signs, symptoms, and neurohumoral activation independently of peak oxygen consumption in chronic heart failure.
Design—Comparison of V̇O2 kinetics with peak V̇O2, neurohormones, and clinical signs of chronic heart failure.
Setting—Tertiary care centre.
Patients—48 patients with mild to moderate chronic heart failure.
Interventions—Treadmill exercise testing with "breath by breath" gas exchange monitoring. Measurement of atrial natriuretic factor (ANF), brain natriuretic peptide (BNP), and noradrenaline. Assessment of clinical findings by questionnaire.
Main outcome measures—O2 kinetics were defined as O2 deficit (time [rest to steady state] × ΔV̇O2 − ∑V̇O2 [rest to steady state]; normalised to body weight) and mean response time of oxygen consumption (MRT; O2 deficit/ΔV̇O2).
Results—V̇O2 kinetics were weakly to moderately correlated to the peak V̇O2 (O2 deficit, r = −0.37, p < 0.05; MRT, r = −0.49, p < 0.001). Natriuretic peptides were more closely correlated with MRT (ANF, r = 0.58; BNP, r = 0.53, p < 0.001) than with O2 deficit (ANF, r = 0.48, p = 0.001; BNP, r = 0.37, p < 0.01) or peak V̇O2 (ANF, r = −0.40; BNP, r = −0.31, p < 0.05). Noradrenaline was correlated with MRT (r = 0.33, p < 0.05) and O2 deficit (r = 0.39, p < 0.01) but not with peak V̇O2 (r = −0.20, NS). Symptoms of chronic heart failure were correlated with all indices of oxygen consumption (MRT, r = 0.47, p < 0.01; O2 deficit, r = 0.39, p < 0.01; peak V̇O2, r = −0.48, p < 0.01). Multivariate analysis showed that the correlation of V̇O2 kinetics with neurohormones and symptoms of chronic heart failure was independent of peak V̇O2 and other variables.
Conclusions—Oxygen kinetics during low intensity exercise may provide additional information over peak V̇O2 in patients

  2. Physiologically gated microbeam radiation using a field emission x-ray source array

    PubMed Central

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

    2014-01-01

    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© 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

  3. Kappa Opioid Receptor-Mediated Dysregulation of GABAergic Transmission in the Central Amygdala in Cocaine Addiction

    PubMed Central

    Kallupi, Marsida; Wee, Sunmee; Edwards, Scott; Whitfield, Tim W.; Oleata, Christopher S.; Luu, George; Schmeichel, Brooke E.; Koob, George F.; Roberto, Marisa

    2013-01-01

    Background Studies have demonstrated an enhanced dynorphin/kappa-opioid receptor (KOR) system following repeated cocaine exposure, but few reports have focused on neuroadaptations within the central amygdala (CeA). Methods We identified KOR-related physiological changes in the CeA following escalation of cocaine self-administration in rats. We used in vitro slice electrophysiological (intracellular and whole-cell recordings) methods to assess whether differential cocaine access in either 1h (short access, ShA) or 6h (long access, LgA) sessions induced plasticity at CeA GABAergic synapses, or altered the sensitivity of these synapses to KOR agonism (U50488) or antagonism (nor-BNI). We then determined the functional effects of CeA KOR blockade in cocaine-related behaviors. Results Baseline evoked GABAergic transmission was enhanced in the CeA from ShA and LgA rats compared to cocaine-naïve rats. Acute cocaine (1 uM) application significantly decreased GABA release in all groups (naïve, ShA, and LgA rats). Application of U50488 (1 uM) significantly decreased GABAergic transmission in the CeA from naïve rats, but increased it in LgA rats. Conversely, nor-BNI (200 nM) significantly increased GABAergic transmission in the CeA from naïve rats, but decreased it in LgA rats. Nor-BNI did not alter the acute cocaine-induced inhibition of GABAergic responses. Finally, CeA microinfusion of nor-BNI blocked cocaine-induced locomotor sensitization and attenuated the heightened anxiety-like behavior observed during withdrawal from chronic cocaine exposure in the defensive burying paradigm. Conclusion Together these data demonstrate that CeA dynorphin/KOR systems are dysregulated following excessive cocaine exposure and suggest KOR antagonism as a viable therapeutic strategy for cocaine addiction. PMID:23751206

  4. 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.

  5. Gestresste Haut? - Aktueller Stand molekularer psychosomatischer Zusammenhänge und ihr Beitrag zu Ursachen und Folgen dermatologischer Erkrankungen.

    PubMed

    Peters, Eva M J

    2016-03-01

    In den 70er Jahren des vergangenen Jahrhunderts wurde zum ersten Mal ein pathogenetisch relevanter Zusammenhang zwischen Stress, im Sinne von psychosozialem Stress, und Krankheit am Beispiel von viralen Erkrankungen der Schleimhäute (wie Rhinovirus-, Coxsackie-Infektion) nachgewiesen. Seither nehmen Publikationen, die diese Zusammenhänge bis auf die molekulare Ebene erforschen, jährlich zu. Dennoch sind die Evidenzen für einen Einfluss von psychosozialer Belastung auf chronisch-entzündliche Hauterkrankungen und auf Hauttumoren wenig bekannt. In diesem Beitrag fassen wir die aktuellen Erkenntnisse aus Epidemiologie, Psychoneuroimmunologie und molekularer Psychosomatik narrativ zusammen. Sie belegen die vielfältigen krankheitsrelevanten Interaktionen zwischen endokrinem System, Nervensystem und Immunsystem. Im Fokus stehen stressinduzierte Verschiebungen in der Immunbalance bei ausgewählten Erkrankungen wie Neurodermitis, Psoriasis oder malignem Melanom. Ziel dieses Beitrages ist die Vermittlung psychosomatischen Grundlagenwissens bei chronischen Dermatosen. Dies reicht von der Ätiologie über die Symptomatik bis zu den therapeutischen Optionen. Besonderes Augenmerk liegt dabei auf den zugrunde liegenden molekularen Zusammenhängen sowohl aus der somatopsychischen als auch aus der psychosomatischen Perspektive. PMID:26972186

  6. 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.

  7. Einleitung

    NASA Astrophysics Data System (ADS)

    Lange, Kurt

    Das Fließpressen zählt neben dem Stauchen und Gleitziehen zu den Kernverfahren des Kaltmassivumformens. In beschränktem Maße wird es auch im halbwarmen Bereich zwischen 600ºC und 800°C werkstoff- oder verfahrensbedingt angewandt. Besondere technisch-wirtschaftliche Bedeutung hat das Kaltfließpressen von Stahl erlangt, nachdem 1934 durch Phosphatieren der Rohteile nach dem Singer-Patent die sichere Umformung von Stahlwerkstoffen in Stahlwerkzeugen ohne Kaltverschweißen möglich geworden war. Die Werkstückmassen liegen beim Kaltfließpressen zwischen wenigen Gramm und einigen Kilogramm, seltener auch darüber. Grenzen sind die Werkzeugbelastung einerseits und die hohen Umformkräfte andererseits. Grundsätzlich lassen sich fast alle knetbaren Metalle durch Fließpressen umformen. Heute ist diese Verfahrensgruppe eine leistungsfähige Technologie, die die Fertigung präziser, geometrisch komplexer, hochbeanspruchbarer Werkstücke aus hochfesten Stählen für weite Einsatzbereiche mit geringstem Werkstoffeinsatz ermöglicht.

  8. In vitro-in vivo evaluation of in situ gelling and thermosensitive ketoprofen liquid suppositories.

    PubMed

    Ozgüney, Işık; Kardhiqi, Anita; Yıldız, Gülbeyaz; Ertan, Gökhan

    2014-12-01

    The main objective of this study was to investigate the release and pharmacokinetic profiles of ketoprofen (KP) from developed thermosensitive and mucoadhesive liquid suppositories. Thermosensitive liquid suppositories were prepared using KP, poloxamer 407 (P 407), poloxamer 188 (P 188) and various amounts of different mucoadhesive polymers. In vitro release studies was monitored by the USP XXVI paddle method. The results thus obtained were evaluated kinetically and mechanism of release was analyzed. Identification of poloxamer gel localization in vivo was conducted using white male rabbits by adding 1 % methylene blue. For in vivo studies, twenty-four white male rabbits were randomly divided into three groups. The rabbits in each group were administered with liquid suppository F1 [P407/P188/KP (4/20/2.5 %)], F5 [P407/P188/KP/C (4/20/2.5/0.8 %)] or conventional suppository (F-C) into the rectum. The plasma concentration of KP was analyzed by high performance liquid chromatography (HPLC). C max, AUC, MRT and T max were evaluated. The release of KP was variously affected by the mucoadhesive polymers. In vitro release studies showed that Carbopol 934 P(C) has significant effect on release rate among the mucoadhesive polymers. When the formulations were evaluated kinetically, different kinetic models were obtained. Formulation F6 [P407/P188/KP/C (4/20/2.5/1.6 %)] which contains the highest C concentration and very high viscosity, shows a significantly better fit with Higuchi kinetic model. n value of this formulation was also found approximately 0.5. n exponent results of the other formulations showed that KP might be released from the suppositories by non-Fickian diffusion. Identification of poloxamer gel localization in vivo showed that the suppositories remain in the rectum without leakage after administration. With regard to the results of in vivo studies, the AUC6→14 values of KP in liquid suppository containing C are significantly higher than those in

  9. 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.

  10. Plasma and milk kinetics of eprinomectin following topical or oral administration to lactating Chinese Holstein cows.

    PubMed

    Wen, Huiqiang; Pan, Baoliang; Wang, Yuwan; Wang, Fangfei; Yang, Zhenzhong; Wang, Ming

    2010-11-24

    Chinese Holstein, bred by mating the Holstein-Friesian to Chinese Yellow Cattle, is a major dairy cattle breed in China. Eprinomectin is widely used in the treatment of nematode and ectoparasite infections in lactating cattle. The pharmacokinetics of eprinomectin in the plasma and milk were determined in Chinese Holstein cows following topical (at 0.5 mg kg(-1)) or oral (at 0.2 mg kg(-1)) administration. For topical administration, the concentrations of eprinomectin in plasma reached peak values (C(max)) of 16.16 ± 6.02 ng ml(-1) at 3.20 ± 1.30 days (T(max)). In milk, the C(max) values of 2.28 ± 0.85 ng ml(-1) were obtained at 3.48 ± 0.65 days. The MRT values were 5.00 ± 0.96 days for plasma and 4.65 ± 0.60 days for milk. The AUC values were 91.00 ± 25.32 ng d ml(-1) for plasma and 10.53 ± 1.55 ng d ml(-1) for milk. The ratio of AUC milk/plasma was 0.124 ± 0.041. Significant differences were found in C(max) and AUC of eprinomectin in plasma between Chinese Holstein and Prim Holstein following topical administration. It was probably due to the lower storage of body fat in Chinese Holstein than in Prim Holstein. For oral administration, the concentrations of eprinomectin reach peak values of 30.02 ± 5.73 ng ml(-1) at 1.60 ± 0.55 days in plasma and 3.14 ± 0.88 ng ml(-1) at 1.40 ± 0.27 days in milk. The MRT values for plasma and milk were 3.00 ± 0.46 and 3.18 ± 0.55 days, respectively. The AUC values were 98.46 ± 24.75 ng d ml(-1) for plasma and 10.42 ± 4.22 ng d ml(-1) for milk. The ratio of AUC milk/plasma was 0.104 ± 0.022. Compared with the topical administration, a significantly shorter MRT of eprinomectin in plasma was obtained following oral administration, which would shorten residue time of this compound in faeces and reduce its ecotoxicological effect. The low exposure of eprinomectin in milk would favor the use of eprinomectin in lactating Chinese Holstein for topical or oral administration. PMID:20851527

  11. 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

  12. 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

  13. 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. PMID:26122705

  14. 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

  15. Pulmonary Oxygen Uptake Kinetics During Exercise in Subclinical Hypothyroidism

    PubMed Central

    Coelho, Emerson Filipino; de Lima, Jorge Roberto Perrout; Laterza, Mateus Camaroti; Barral, Marselha Marques; Teixeira, Patrícia de Fátima dos Santos; Vaisman, Mário

    2014-01-01

    Background: Patients with subclinical hypothyroidism (SCH) have lower exercise tolerance, but the impact on oxygen uptake (VO2) kinetics is unknown. This study evaluated VO2 kinetics during and after a constant load submaximal exercise in SCH. Methods: The study included 19 women with SCH (thyrotropin (TSH)=6.87±2.88 μIU/mL, free thyroxine (fT4)=0.97±0.15 ng/dL) and 19 controls (TSH=2.29±0.86 μIU/mL, T4=0.99±0.11 ng/dL) aged between 20 and 55 years. Ergospirometry exercise testing was performed for six minutes with a constant load of 50 W, followed by six minutes of passive recovery. The VO2 kinetics was quantified by the mean response time (MRT), which is the exponential time constant and approximates the time needed to reach 63% of change in VO2 (ΔVO2). The O2 deficit—energy supplied by anaerobic metabolism at the onset of exercise—and O2 debit—extra energy demand during the recovery period—were calculated by the formula MRT×ΔVO2. Values are mean±standard deviation. Results: In the rest-exercise transition, patients with SCH showed slower VO2 kinetics (MRT=47±8 sec vs. 40±6 sec, p=0.004) and a higher oxygen deficit (580±102 mL vs. 477±95 mL, p=0.003) than controls respectively. In the exercise-recovery transition, patients with SCH also showed slower VO2 kinetics (MRT=54±6 sec vs. 44±6 sec, p=0.001) and a higher oxygen debit (679±105 mL vs. 572±104 mL, p=0.003). The VO2 kinetics showed a significant correlation with TSH (p<0.05). Conclusions: This study demonstrates that women with SCH have the slowest VO2 kinetics in the onset and recovery of a constant-load submaximal exercise and highlights that this impairment is already manifest in the early stage of the disease. PMID:24512502

  16. 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

  17. Mineral control of soil carbon storage with reforestation of abandoned pastures

    NASA Astrophysics Data System (ADS)

    Marín-Spiotta, E.; Silver, W. L.; Swanston, C. W.; Torn, M. S.; Burton, S. D.

    2006-12-01

    We applied CP MAS 13C-NMR spectroscopy and radiocarbon modeling to soil C density fractions to track changes in the quality and turnover of C with forest regrowth on former pasturelands. Our results showed that inter-aggregate, unattached particulate organic C (free light fraction) and C located inside soil aggregates (occluded light fraction) represent distinct soil C pools. The signal intensity of the O-alkyl region, representing cellulose, decreased with mineral-association, while alkyl C, attributed to waxy compounds and microbially resynthesized lipids, increased from the free to the occluded light fractions. The alkyl/O-alkyl ratio changed consistently with changes in C-to-N and δ15N across different land cover types, and thus appears to be a reliable index of humification. In contrast to cellulose, proteins, lipids and lignin did not show any consistent trends, suggesting different controls on their decomposition. Greater variability in the chemical makeup of the occluded light fraction suggests that it represents material in different stages of decay. Mean residence times (MRT) of the free light C were significantly shorter (4.3 ± 0.5 yrs) than for the occluded fraction (7.3 ± 0.8 yrs). The occluded fraction in active pastures and secondary forests in the earliest stage of succession had shorter MRT than in primary forests and older secondary forests, which would be explained by lower aggregate stability and faster cycling rates in disturbed versus undisturbed soils. The mineral associated C in the disturbed soils had slower cycling C (MRT = 98.9 ± 10.6 yrs) than the undisturbed sites (65.8 ± 2.1 yrs), most likely due to a preferential loss of labile C in the first. Incorporation of C into soil aggregates afforded some protection from decomposition, but the main mechanism of stabilization was direct mineral association. As the sorptive capacity of a soil is dependent on its mineral composition, it appears that the Oxisols at our sites have reached

  18. 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

  19. Human Genome Replication Proceeds through Four Chromatin States

    PubMed Central

    Julienne, Hanna; Zoufir, Azedine; Audit, Benjamin; Arneodo, Alain

    2013-01-01

    Advances in genomic studies have led to significant progress in understanding the epigenetically controlled interplay between chromatin structure and nuclear functions. Epigenetic modifications were shown to play a key role in transcription regulation and genome activity during development and differentiation or in response to the environment. Paradoxically, the molecular mechanisms that regulate the initiation and the maintenance of the spatio-temporal replication program in higher eukaryotes, and in particular their links to epigenetic modifications, still remain elusive. By integrative analysis of the genome-wide distributions of thirteen epigenetic marks in the human cell line K562, at the 100 kb resolution of corresponding mean replication timing (MRT) data, we identify four major groups of chromatin marks with shared features. These states have different MRT, namely from early to late replicating, replication proceeds though a transcriptionally active euchromatin state (C1), a repressive type of chromatin (C2) associated with polycomb complexes, a silent state (C3) not enriched in any available marks, and a gene poor HP1-associated heterochromatin state (C4). When mapping these chromatin states inside the megabase-sized U-domains (U-shaped MRT profile) covering about 50% of the human genome, we reveal that the associated replication fork polarity gradient corresponds to a directional path across the four chromatin states, from C1 at U-domains borders followed by C2, C3 and C4 at centers. Analysis of the other genome half is consistent with early and late replication loci occurring in separate compartments, the former correspond to gene-rich, high-GC domains of intermingled chromatin states C1 and C2, whereas the latter correspond to gene-poor, low-GC domains of alternating chromatin states C3 and C4 or long C4 domains. This new segmentation sheds a new light on the epigenetic regulation of the spatio-temporal replication program in human and provides a

  20. In Situ Persistence and Migration of Biochar Carbon and Its Impact on Native Carbon Emission in Contrasting Soils under Managed Temperate Pastures.

    PubMed

    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 important to

  1. The Morehead State University 18 Meter Radio Telescope Project: Involving Undergraduates in Observational Astrophysics

    NASA Astrophysics Data System (ADS)

    Malphrus, B. K.; Combs, M. S.; Kruth, J.

    2002-12-01

    The Space Science Center at Morehead State University is in the process of developing a large aperture (18-21 meter) cm-wave radio telescope, the Morehead Radio Telescope (MRT). The telescope will be located in the mountainous region of Eastern Kentucky. The instrument will serve as a research instrument and active laboratory for undergraduate astronomy, physics, pre-engineering, and computer science students. The antenna system will be engaged in science programs (in astrophysics) and in satellite mission support services (telemetry, tracking, and control). The benefits to students are based upon a hands-on approach to learning concepts in astrophysics and engineering. Additionally, there are still research contributions that small aperture centimeter-wave instruments can make including long-term observations of microvariability in AGNs, observations of transient events, and surveys. The MRT will operate three receiver systems including an L-band receiver (1.4-1.7 GHz) covering the "water hole", an S-band receiver (2.2-2.4 GHz) and a Ku-band receiver (11.2- 12.7 GHz) for continuum observations and satellite telemetry. The technical specifications for the instrument have been developed and an RFP has been issued inviting antenna vendors to submit proposals. The reflector will have a surface accuracy of 0.020 inches RMS over the entire surface, which will support relatively high frequency (Ku-band) observations. The antenna system will be full-motion and have a slew speed of 2 deg per second and an acceleration of 2 deg per second2. The HI and OH spatial distribution associated with cosmic phenomena will be investigated as well as dynamics and kinematics (particularly in HI) by observing over a range of frequencies (up to 2.5 MHz) with a 2048-channel back-end spectrometer, providing up to 1 KHz frequency resolution. The sensitivity and versatility of the telescope design will facilitate investigation of a wide variety of cosmic phenomena. The MRT is funded by

  2. 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

  3. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Lattice Boltzmann Simulation of the Cross Flow Over a Cantilevered and Longitudinally Vibrating Circular Cylinder

    NASA Astrophysics Data System (ADS)

    Xia, Yong; Lu, De-Tang; Liu, Yang; Xu, You-Sheng

    2009-03-01

    The multiple-relaxation-time lattice Boltzmann method (MRT-LBM) is implemented to numerically simulate the cross flow over a longitudinal vibrating circular cylinder. This research is carried out on a three-dimensional (3D) finite cantilevered cylinder to investigate the effect of forced vibration on the wake characteristics and the 3D effect of a cantilevered cylinder. To meet the accuracy of this method, the present calculation is carried out at a low Reynolds number Re = 100, as well as to make the vibration obvious, we make the vibration strong enough. The calculation results indicate that the vibration has significant influence on the wake characteristics. When the vibrating is big enough, our early works show that the 2D vortex shedding would be locked up by vibration. Contrarily, this phenomenon would not appear in the present 3D case because of the end effect of the cantilevered cylinder.

  4. 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. PMID:26481204

  5. 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%.

  6. 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

  7. 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

  8. Human safety and pharmacokinetics of the CFC alternative propellants HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3, 3-heptafluoropropane) following whole-body exposure.

    PubMed

    Emmen, H H; Hoogendijk, E M; Klöpping-Ketelaars, W A; Muijser, H; Duistermaat, E; Ravensberg, J C; Alexander, D J; Borkhataria, D; Rusch, G M; Schmit, B

    2000-08-01

    /2)beta (beta elimination half-life) across all exposure concentrations was a mean of 36 and 42 min for CFC 12 and HFC 134a, respectively. Mean residence time (MRT) was an overall mean of 42 and 44 min for CFC 12 and HFC 134a, respectively. In the HFC 227 study, t(1/2)alpha for both CFC 12 and HFC 227, at each exposure level, was short (<9 min) and tended to be lower in males than females. For CFC 12 mean t(1/2)beta ranged from 23 to 43 min and for HFC 227 the mean range was 19-92 min. The values tended to be lower for females than males for HFC 227. For both CFC 12 and HFC 227, MRT was statistically significantly lower (P < 0.05) in males than females and independent of exposure concentration. For CFC 12, MRT was a mean of 37 and 45 min for males and females, respectively, and for HFC 227 MRT was a mean of 36 and 42 min, respectively. Exposure of healthy volunteers to exposure levels up to 8000 ppm HFC 134a, 8000 ppm HFC 227, and 4000 ppm CFC 12 did not result in any adverse effects on pulse, blood pressure, electrocardiogram, or lung function. PMID:11029265

  9. Emission of CO, CI, and CII in the spiral arms of M83 and M51

    NASA Astrophysics Data System (ADS)

    Kramer, C.; Mookerjea, B.; Garcia-Burillo, S.; Bayet, E.; Gerin, M.; Israel, F.; Stutzki, J.; Wouterloot, J.

    2005-01-01

    We present a detailed study of photon dominated regions at several spiral arm positions and the centers of the nearby spiral galaxies M51 and M83. For this, we combine all important cooling lines: [CI] 609μm taken at the JCMT with 12CO and 13CO 1-0 and 2-1 lines taken at the IRAM 30m MRT. These transitions are combined with data taken from the literature: ISO/LWS [CII] 158μm, [OI] 63μm, 146μm, and [NII] (122μm) data (Brauher, J., et al. 2004) and mid-J CO lines from (Bayet, E., et al., Dumke, M., et al. 2003, Israel, F., Baas, F., 2002).

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Two relaxation time lattice Boltzmann model for rarefied gas flows

    NASA Astrophysics Data System (ADS)

    Esfahani, Javad Abolfazli; Norouzi, Ali

    2014-01-01

    In this paper, the lattice Boltzmann equation (LBE) with two relaxation times (TRT) is implemented in order to study gaseous flow through a long micro/nano-channel. A new relation is introduced for the reflection factor in the bounce-back/specular reflection (BSR) boundary condition based on the analytical solution of the Navier-Stokes equations. The focus of the present study is on comparing TRT with the other LBE models called multiple relaxation times (MRT) and single relaxation time (SRT) in simulation of rarefied gas flows. After a stability analysis for the TRT and SRT models, the numerical results are presented and validated by the analytical solution of the Navier-Stokes equations with slip boundary condition, direct simulation of Monte Carlo (DSMC) and information preservation (IP) method. The effect of various gases on flow behavior is also investigated by using the variable hard sphere (VHS) model through the symmetrical relaxation time.

  15. 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. PMID:26830535

  16. Zoom athermal telescope having 18.5 magnification range for 8 to 12-u range FLIR systems

    NASA Astrophysics Data System (ADS)

    Shechterman, Mark S.

    1995-10-01

    This paper describes the specific design considerations and performance evaluation for ELOP's MLZFS (modular lightweight zoom FLIR system) utilizing a new athermal wide magnification range IR zoom telescope. The following aspects of the development work are discussed in this paper: MTF and MRT characteristics of the FLIR for different temperatures; comparison with existing zoom systems and with systems of discrete magnification change; calculation of lens group positions as a function of magnification and temperature, including interpolation analyses of these dependencies; implemented methods for narcissus effect reduction at the lowest magnification mode, including development of a new AR coating; critical tolerance analyses; mechanical and electro-mechanical design, answering high accuracy requirements; adjustment and calibration of the zoom system by use of an IR interferometer.

  17. [Absolute bioavailability of the adenine derivative VMA-99-82 possessing antiviral activity].

    PubMed

    Smirnova, L A; Suchkov, E A; Riabukha, A F; Kuznetsov, K A; Ozerov, A A

    2013-01-01

    Investigation of the main pharmacokinetic parameters of adenine derivative VMA-99-82 in rats showed large values of the half-life (T1/2 = 11.03 h) and the mean retention time of drug molecules in the organism (MRT = 9.53 h). A high rate of the drug concentration decrease in the plasma determines a small value of the area under the pharmacokinetic curve (AUC = 74.96 mg h/ml). The total distribution volume (V(d) = 10.61 l/kg) is 15.8 times greater than the volume of extracellular fluid in the body of rat, which is indicative of a high ability of VMA-99-82 to be distributed and accumulated in the organs and tissues. The absolute bioavailability of VMA-99-82 is 66%. PMID:24605425

  18. 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.

  19. 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

  20. [Magnetic resonance tomography in ophthalmology. I. Choroid melanoma].

    PubMed

    Seiler, T; Bende, T; Schilling, A; Wollensak, J

    1987-09-01

    The value of magnetic resonance tomography (MRT) for the diagnosis of choroidal melanomas is illustrated with reference to 26 cases. The geometric dimensions of the tumors are in good agreement with findings obtained by ultrasonography. The relaxation time T2 varies between 85 and 120 msec in contrast to 145-210 msec in subretinal hemorrhages and 190-400 msec in secondary retinal detachments. In contrast to A-scan a differential diagnosis is possible even with lesions less than 1.5 mm in prominence. In solutions of melanin the relaxation time T2 decreases with increasing melanin concentration. This leads to an interpretation that the pigment content of the melanoma is responsible for the relatively short relaxation times. Thus, the relaxation time T2 is a useful factor in predicting metastasis. PMID:3316814

  1. Hourly predictive artificial neural network and multivariate regression trees models of Ganoderma spore concentrations in Rzeszów and Szczecin (Poland).

    PubMed

    Kasprzyk, Idalia; Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka; Wolski, Tomasz

    2011-02-01

    Ganoderma spores are one of the most airspora abundant taxa in many regions of the world, and are considered to be important allergens. The aerobiology of Ganoderma basidiospores in two cities in Poland was examined using the volumetric method, (Burkard and Lanzonii Spore Traps), from selected days in 2004, 2005 and 2006. Spores of Ganoderma were present in the atmosphere from June to November, with peak concentrations generally occurring from late July to mid-October. ANN (artificial neural network) and MRT (multivariate regression trees), models indicated that atmospheric phenomenon, hour and relative humidity were the most important variables influencing spore content. The remaining variables (air temperature, dew point, air pressure, wind speed and wind direction), also contributed to the high network performance, (ratio above 1), but their impact was less distinct. Those results are consistent with the Spearman's rank correlation analysis. PMID:21183203

  2. A peptide & peptide nucleic acid synthesis technology for transporter molecules and theranostics--the SPPS.

    PubMed

    Pipkorn, Ruediger; Braun, Klaus; Wiessler, Manfred; Waldeck, Waldemar; Schrenk, Hans-Hermann; Koch, Mario; Semmler, Wolfhard; Komljenovic, Dorde

    2014-01-01

    Advances in imaging diagnostics using magnetic resonance tomography (MRT), positron emission tomography (PET) and fluorescence imaging including near infrared (NIR) imaging methods are facilitated by constant improvement of the concepts of peptide synthesis. Feasible patient-specific theranostic platforms in the personalized medicine are particularly dependent on efficient and clinically applicable peptide constructs. The role of peptides in the interrelations between the structure and function of proteins is widely investigated, especially by using computer-assisted methods. Nowadays the solid phase synthesis (SPPS) chemistry emerges as a key technology and is considered as a promising methodology to design peptides for the investigation of molecular pharmacological processes at the transcriptional level. SPPS syntheses could be carried out in core facilities producing peptides for large-scale scientific implementations as presented here. PMID:24843319

  3. A Peptide & Peptide Nucleic Acid Synthesis Technology for Transporter Molecules and Theranostics - The SPPS

    PubMed Central

    Pipkorn, Ruediger; Braun, Klaus; Wiessler, Manfred; Waldeck, Waldemar; Schrenk, Hans-Hermann; Koch, Mario; Semmler, Wolfhard; Komljenovic, Dorde

    2014-01-01

    Advances in imaging diagnostics using magnetic resonance tomography (MRT), positron emission tomography (PET) and fluorescence imaging including near infrared (NIR) imaging methods are facilitated by constant improvement of the concepts of peptide synthesis. Feasible patient-specific theranostic platforms in the personalized medicine are particularly dependent on efficient and clinically applicable peptide constructs. The role of peptides in the interrelations between the structure and function of proteins is widely investigated, especially by using computer-assisted methods. Nowadays the solid phase synthesis (SPPS) chemistry emerges as a key technology and is considered as a promising methodology to design peptides for the investigation of molecular pharmacological processes at the transcriptional level. SPPS syntheses could be carried out in core facilities producing peptides for large-scale scientific implementations as presented here. PMID:24843319

  4. A modified multiple-relaxation-time lattice Boltzmann model for convection-diffusion equation

    NASA Astrophysics Data System (ADS)

    Huang, Rongzong; Wu, Huiying

    2014-10-01

    A modified lattice Boltzmann model with multiple relaxation times (MRT) for the convection-diffusion equation (CDE) is proposed. By modifying the relaxation matrix, as well as choosing the corresponding equilibrium distribution function properly, the present model can recover the CDE with anisotropic diffusion coefficient with no deviation term even when the velocity vector varies generally with space or time through the Chapman-Enskog analysis. This model is firstly validated by simulating the diffusion of a Gaussian hill, which demonstrates it can handle the anisotropic diffusion problem correctly. Then it is adopted to calculate the longitudinal dispersion coefficient of the Taylo-Aris dispersion. Numerical results show that the present model can further reduce the numerical error under the condition of non-zero velocity vector, especially when the dimensionless relaxation time is relatively large.

  5. [Imaging and therapy of hamulus-ossis-hamati fracture].

    PubMed

    Andresen, R; Radmer, S; Scheufler, O; Banzer, D

    2001-01-01

    The relatively rare fractures of the hamate bone are the most common osseous injuries of the distal carpal row, whereby fractures of both the body and the hook of the hamate occur. We present a hamulus ossis hamate fracture that was caused by direct trauma in a high-level game of underwater rugby. Although this was diagnosed by conventional x-ray, the precise position of the fracture was clearly imaged using thin-layer CT, while additional multiplanar MRT revealed further sequelae of the trauma. A CT follow-up after 10 weeks of conservative therapy did not show any osseous consolidation, which indicated the need for surgical revision with extirpation of the hamulus. PMID:11799868

  6. 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

  7. 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.

  8. Lattice Boltzmann Simulation of Mixed Convection Heat Transfer in a Driven Cavity with Non-uniform Heating of the Bottom Wall

    NASA Astrophysics Data System (ADS)

    Soufiene, Bettaibi; Ezeddine, Sediki; Frédéric, Kuznik; Sauro, Succi

    2015-01-01

    The goal of this article is to study numerically the mixed convection in a differentially heated lid-driven cavity with non-uniform heating of the bottom wall. The velocity field is solved by a hybrid scheme with multiple relaxation time Lattice Boltzmann (MRT-LBM) model, while the temperature field is obtained by resolution of the energy balance equation using the finite difference method (FDM). First, the model is checked and validated using data from the literature. Validation of the present results with those available in the literature shows a good agreement. A good efficiency in time simulation is confirmed. Thereafter, the model has been applied to mixed convection in a driven cavity with non-uniform heating wall at the fixed Grashof number Gr = 106. It is found that, the heat transfer is weakened as the Richardson number is augmented. For Gr = 106, we note the appearance of secondary vortices at different positions of the cavity corners.

  9. 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.

  10. A review of imaging techniques for plant phenotyping.

    PubMed

    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

  11. 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.

  12. Preparation and passive target of 5-fluorouracil solid lipid nanoparticles.

    PubMed

    Du, Bin; Yan, Ying; Li, Ying; Wang, Shuyu; Zhang, ZhenZhong

    2010-01-01

    This work studied the intravenous injection formulation of solid lipid nanoparticles (SLNs) loaded with 5-fluorouracil (5-FU). The goal was to design longer drug residence in vivo and passive targeting nanoparticles which could improve therapeutic efficacy and reduce side-effects. Based on the optimized results of uniform design experiment, 5-FU-SLNs were prepared by multiple emulsion-ultrasonication (w/o/w). The SLNs were found to be relatively uniform in size (182.1 +/- 25.8 nm) with a negative zeta potential (-27.89 +/- 5.1 mV). The average drug entrapment efficiency and loading were 74% and 10%, respectively. Compared with the 5-FU solution (t(1/2beta), 0.593h; MRT, 0.358h) after intravenous injection to rats, the pharmacokinetic parameters of 5-FU-SLNs exhibited a longer retention time. (t(1/2beta), 4.0628h; MRT, 3.5321h). The area under curve of plasma concentration-time (AUC) of 5-FU-SLNs was 1.48 times greater than that of free drugs. The overall targeting efficiency (TE(C)) of the 5-FU-SLNs was enhanced from 13.25-20.45% in the lung and from 11.48-23.16% in kidney while the spleen distribution of 5-FU was significantly reduced as compared with that of the 5-FU solution. These results indicated that 5-FU-SLNs were promising passive targeting therapeutic agents for curing primary lung carcinoma. PMID:19769532

  13. Genetics of Bladder Malignant Tumors in Childhood.

    PubMed

    Zangari, Andrea; Zaini, Johan; Gulìa, Caterina

    2016-02-01

    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

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

  19. Modulating mitochondrial quality in disease transmission: towards enabling mitochondrial DNA disease carriers to have healthy children.

    PubMed

    Diot, Alan; Dombi, Eszter; Lodge, Tiffany; Liao, Chunyan; Morten, Karl; Carver, Janet; Wells, Dagan; Child, Tim; Johnston, Iain G; Williams, Suzannah; Poulton, Joanna

    2016-08-15

    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

  20. Characterization of a thromboembolic photochemical model of repeated stroke in mice.

    PubMed

    Lozano, J Diego; Abulafia, Denise P; Danton, Gary H; Watson, Brant D; Dietrich, W Dalton

    2007-05-15

    Many stroke research groups utilize the model of middle cerebral artery occlusion induced by insertion of an intraluminal thread, owing to its pragmatism and reliability of cerebral infarct generation. However, 75% of stroke cases result from a thromboembolic event and 10% from occlusive atherothrombosis in situ. Here, we characterize a mouse model of repeated thromboembolic stroke, which closely mimics the intravascular pathophysiology of arterial thrombus generation from an atherosclerotic plaque, and subsequent release of a thrombus into the cerebral circulation as an embolus. Common carotid artery thrombosis (CCAT) was induced photochemically leading to non-occlusive platelet aggregation in C57/BL6 male mice (n=35), and was followed by mechanical assistance to facilitate release of the thrombus (MRT) and thus promote embolism. Six experimental groups, differing by changes in the surgical protocol, were used for the purpose of determining which such procedure yielded the most reliable and consistent brain infarct volumes with the lowest mortality at 3 days after surgery. The group which best satisfied these conditions was a double insult group which consisted of animals that underwent CCAT for 2 min by means of argon laser irradiation (514.5 nm) at an intensity of ca. 130 W/cm(2), with concomitant injection of erythrosin B (EB) (35 mg/kg infused over those same 2 min), followed by MRT 1 min later; the entire procedure was repeated 24h later. This group showed a percent of brain lesion volume of 15+/-4% (mean+/-S.D.) with no associated 3-day mortality. Compared to a single insult group which sustained a percent brain lesion volume of 7+/-3%, there was a statistically significant (p<0.05) increase in the volume of infarction in the double-insult group. PMID:17363066

  1. 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. PMID:22869718

  2. 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.

  3. 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.

  4. MOSFET dosimetry with high spatial resolution in intense synchrotron-generated x-ray microbeams

    SciTech Connect

    Siegbahn, E. A.; Braeuer-Krisch, E.; Bravin, A.; Nettelbeck, H.; Lerch, M. L. F.; Rosenfeld, A. B.

    2009-04-15

    Various dosimeters have been tested for assessing absorbed doses with microscopic spatial resolution in targets irradiated by high-flux, synchrotron-generated, low-energy ({approx}30-300 keV) x-ray microbeams. A MOSFET detector has been used for this study since its radio sensitive element, which is extraordinarily narrow ({approx}1 {mu}m), suits the main applications of interest, microbeam radiation biology and microbeam radiation therapy (MRT). In MRT, micrometer-wide, centimeter-high, and vertically oriented swaths of tissue are irradiated by arrays of rectangular x-ray microbeams produced by a multislit collimator (MSC). We used MOSFETs to measure the dose distribution, produced by arrays of x-ray microbeams shaped by two different MSCs, in a tissue-equivalent phantom. Doses were measured near the center of the arrays and maximum/minimum (peak/valley) dose ratios (PVDRs) were calculated to determine how variations in heights and in widths of the microbeams influenced this for the therapy, potentially important parameter. Monte Carlo (MC) simulations of the absorbed dose distribution in the phantom were also performed. The results show that when the heights of the irradiated swaths were below those applicable to clinical therapy (<1 mm) the MC simulations produce estimates of PVDRs that are up to a factor of 3 higher than the measured values. For arrays of higher microbeams (i.e., 25 {mu}mx1 cm instead of 25x500 {mu}m{sup 2}), this difference between measured and simulated PVDRs becomes less than 50%. Closer agreement was observed between the measured and simulated PVDRs for the Tecomet MSC (current collimator design) than for the Archer MSC. Sources of discrepancies between measured and simulated doses are discussed, of which the energy dependent response of the MOSFET was shown to be among the most important.

  5. Pharmacokinetic interaction of flecainide and paroxetine in relation to the CYP2D6*10 allele in healthy Korean subjects

    PubMed Central

    Lim, Kyoung Soo; Cho, Joo-Youn; Jang, In-Jin; Kim, Bo-Hyung; Kim, JaeWoo; Jeon, Ji-Young; Tae, Yu-Mi; Yi, SoJeong; Eum, SoYoung; Shin, Sang-Goo; Yu, Kyung-Sang

    2008-01-01

    WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT The only existing study of CYP2D6*10-associated alterations in flecainide pharmacokinetics was retrospective. Paroxetine has been known as a strong inhibitor of CYP2D6. WHAT THIS STUDY ADDS This study reports that the extent of drug interaction between flecainide and paroxetine is influenced by the CYP2D6*10 allele in healthy subjects, which is frequent in Asians. AIMS The objectives were to evaluate the effect of CYP2D6 genetic polymorphism on the pharmacokinetics of flecainide, and also on the extent of drug interaction with paroxetine as a CYP2D6 inhibitor after a single oral administration in healthy subjects. METHODS An open-label, two-period, single-sequence, cross-over study was performed in 21 healthy Korean male volunteers (seven for CYP2D6*1/*1 or *1/*2, group 1; seven for CYP2D6*1/*10, group 2; seven for CYP2D6*10/*10 or *10/*36, group 3). Subjects were administered 200 mg of flecainide on day 1. After a 7-day wash-out period, subjects were administered 20 mg of paroxetine from day 8 to 14, and 200 mg of flecainide on day 15. Blood sampling was performed up to 72 h after flecainide administration. RESULTS Terminal elimination half-life and mean residence time (MRT) were significantly different among three genotype groups after a single oral administration of flecainide (P = 0.021, 0.011, respectively). Area under the concentration–time curve, terminal elimination half-life and MRT increased significantly after paroxetine co-administration only in groups 1 and 2. CONCLUSIONS This study reports that the extent of drug interaction between flecainide and paroxetine is influenced by the CYP2D6*10 allele in healthy subjects, which is frequent in Asians. PMID:18754843

  6. Bioactive Markers Based Pharmacokinetic Evaluation of Extracts of a Traditional Medicinal Plant, Piper sarmentosum

    PubMed Central

    Hussain, Khalid; Ismail, Zhari; Sadikun, Amirin; Ibrahim, Pazillah

    2011-01-01

    In vitro assays are economical and easy to perform but to establish relevance of their results to real clinical outcome in animals or human, pharmacokinetics is prerequisite. Despite various in vitro pharmacological activities of extracts of Piper sarmentosum, there is no report of pharmacokinetics. Therefore, the present study aimed to evaluate ethanol extract of fruit of the plant in dose of 500 mg kg−1 orally for pharmacokinetics. Sprague-Dawley rats were randomly divided into groups 1, 2, and 3 (each n = 6) to study absorption, distribution and excretion, respectively. High performance liquid chromatography (HPLC) with ultraviolet detection was applied to quantify pellitorine, sarmentine and sarmentosine in plasma, tissues, feces and urine to calculate pharmacokinetic parameters. Pellitorine exhibited maximum plasma concentration (Cmax) 34.77 ng mL−1 ± 1.040, time to achieve Cmax (Tmax) 8 h, mean resident time (MRT) 26.00 ± 0.149 h and half life (t1/2) 18.64 ± 1.65 h. Sarmentine showed Cmax 191.50 ± 12.69 ng mL−1, Tmax 6 h, MRT 11.12 ± 0.44 h and t1/2 10.30 ± 1.98 h. Sarmentosine exhibited zero oral bioavailability because it was neither detected in plasma nor in tissues, and in urine. Pellitorine was found to be distributed in intestinal wall, liver, lungs, kidney, and heart, whereas sarmentine was found only in intestinal wall and heart. The cumulative excretion of pellitorine, sarmentine and sarmentosine in feces in 72 h was 0.0773, 0.976, and 0.438 μg, respectively. This study shows that pellitorine and sarmentine have good oral bioavailability while sarmentosine is not absorbed from the gastrointestinal tract. PMID:19770264

  7. 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

  8. MODIS Data and Services at the National Snow and Ice Data Center (NSIDC)

    NASA Astrophysics Data System (ADS)

    McAllister, M.; Booker, L.; Fowler, D. K.; Haran, T. M.

    2014-12-01

    For close to 15 years, the National Snow and Ice Data Center (NSIDC) NASA Distributed Active Archive Center (NDAAC) has archived and distributed snow and sea ice products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on the NASA Earth Observing System (EOS) Aqua and Terra satellites. The archive contains a wide selection of snow and sea ice data products relevant to cryospheric science. NSIDC offers a variety of methods for obtaining these data. Users can ftp data directly from an online archive which allows for a very quick download. The Reverb Search & Order Tool contains a complete set of metadata for all products which can be searched for and ordered. Reverb allows a user to order spatial, temporal, and parameter subsets of the data. Users can also request that they be added to our subscription list which makes it possible to have new MODIS data automatically ftp'd or staged on a local server as it is archived at NSIDC. Since MODIS products are in HDF-EOS format, a number of tools have been developed to assist with browsing, editing, reprojection, resampling, and format conversion. One such service, Data Access, can be accessed through Reverb and performs subsetting, reformatting, and reprojection. This service can also be accessed via an Application Programming Interface (API) from a user-written client. Other tools include the MODIS Swath-to-Grid Toolbox (MS2GT) and the MODIS Interactive Subsetting Tool (MIST). MS2GT was created to produce a seamless output grid from multiple input files corresponding to successively acquired, 5-minute MODIS scenes. NSIDC also created the MIST to provide subsets of certain Version 5 MODIS products, over the Greenland Climate Network (GC-Net) and the International Arctic Systems for Observing the Atmosphere (IASOA) stations. Tools from other sources include HDFView from the National Center for Supercomputing Applications (NCSA), and the MODIS Reprojection Tool (MRT) and MRT Swath developed

  9. 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.

  10. 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

  11. The influence of triple energy window scatter correction on activity quantification for (1 7 7)Lu molecular radiotherapy.

    PubMed

    Robinson, Andrew P; Tipping, Jill; Cullen, David M; Hamilton, David

    2016-07-21

    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 [Formula: see text]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 ([Formula: see text]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. PMID:27351914

  12. 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. PMID:25042570

  13. Pharmacokinetics of digoxin cross-reacting substances in patients with acute yellow oleander (Thevetia peruviana) poisoning, including the effect of activated charcoal.

    PubMed Central

    Roberts, Darren M; Southcott, Emma; Potter, Julia M; Roberts, Michael S; Eddleston, Michael; Buckley, Nick A

    2008-01-01

    Intentional self-poisonings with seeds from the yellow oleander tree (Thevetia peruviana) are widely reported. Activated charcoal has been suggested to benefit patients with yellow oleander poisoning by reducing absorption and/or facilitating elimination. Two recent randomised controlled trials (RCTs) assessing the efficacy of activated charcoal reported conflicting outcomes in terms of mortality. The effect of activated charcoal on the pharmacokinetics of Thevetia cardenolides has not been assessed. This information may be useful for determining whether further studies are necessary. Serial blood samples were obtained from patients enrolled in a RCT assessing the relative efficacy of single dose (SDAC) and multiple doses (MDAC) of activated charcoal compared to no activated charcoal (NoAC). The concentration of Thevetia cardenolides was estimated using a digoxin immunoassay. The effect of activated charcoal on cardenolide pharmacokinetics was compared between treatment groups using the AUC24, the 24h Mean Residence Time (MRT24), and regression lines obtained from serial concentration points adjusted for exposure. Erratic and prolonged absorption patterns were noted in each patient group. The apparent terminal half-life was highly variable, with a median time of 42.9h. There was a reduction in MRT24 and the apparent terminal half-life estimated from linear regression in patients administered activated charcoal compared to the control group (NoAC). This effect was approximately equal in patients administered MDAC or SDAC. Activated charcoal appears to favourably influence the pharmacokinetic profile of Thevetia cardenolides in patients with acute self-poisoning, which may have clinical benefits. Given the conflicting clinical outcomes noted in previous RCTs, this mechanistic data supports the need for further studies to determine whether a subgroup of patients (eg. those presenting soon after poisoning) will benefit from activated charcoal. PMID:17164695

  14. γ-H2AX as a Marker for Dose Deposition in the Brain of Wistar Rats after Synchrotron Microbeam Radiation

    PubMed Central

    Fernandez-Palomo, Cristian; Mothersill, Carmel; Bräuer-Krisch, Elke; Laissue, Jean; Seymour, Colin; Schültke, Elisabeth

    2015-01-01

    Objective Synchrotron radiation has shown high therapeutic potential in small animal models of malignant brain tumours. However, more studies are needed to understand the radiobiological effects caused by the delivery of high doses of spatially fractionated x-rays in tissue. The purpose of this study was to explore the use of the γ-H2AX antibody as a marker for dose deposition in the brain of rats after synchrotron microbeam radiation therapy (MRT). Methods Normal and tumour-bearing Wistar rats were exposed to 35, 70 or 350 Gy of MRT to their right cerebral hemisphere. The brains were extracted either at 4 or 8 hours after irradiation and immediately placed in formalin. Sections of paraffin-embedded tissue were incubated with anti γ-H2AX primary antibody. Results While the presence of the C6 glioma does not seem to modulate the formation of γ-H2AX in normal tissue, the irradiation dose and the recovery versus time are the most important factors affecting the development of γ-H2AX foci. Our results also suggest that doses of 350 Gy can trigger the release of bystander signals that significantly amplify the DNA damage caused by radiation and that the γ-H2AX biomarker does not only represent DNA damage produced by radiation, but also damage caused by bystander effects. Conclusion In conclusion, we suggest that the γ-H2AX foci should be used as biomarker for targeted and non-targeted DNA damage after synchrotron radiation rather than a tool to measure the actual physical doses. PMID:25799425

  15. Autosomal recessive mental retardation: homozygosity mapping identifies 27 single linkage intervals, at least 14 novel loci and several mutation hotspots.

    PubMed

    Kuss, Andreas Walter; Garshasbi, Masoud; Kahrizi, Kimia; Tzschach, Andreas; Behjati, Farkhondeh; Darvish, Hossein; Abbasi-Moheb, Lia; Puettmann, Lucia; Zecha, Agnes; Weissmann, Robert; Hu, Hao; Mohseni, Marzieh; Abedini, Seyedeh Sedigheh; Rajab, Anna; Hertzberg, Christoph; Wieczorek, Dagmar; Ullmann, Reinhard; Ghasemi-Firouzabadi, Saghar; Banihashemi, Susan; Arzhangi, Sanaz; Hadavi, Valeh; Bahrami-Monajemi, Gholamreza; Kasiri, Mahboubeh; Falah, Masoumeh; Nikuei, Pooneh; Dehghan, Atefeh; Sobhani, Masoumeh; Jamali, Payman; Ropers, Hans Hilger; Najmabadi, Hossein

    2011-02-01

    Mental retardation (MR) has a worldwide prevalence of around 2% and is a frequent cause of severe disability. Significant excess of MR in the progeny of consanguineous matings as well as functional considerations suggest that autosomal recessive forms of MR (ARMR) must be relatively common. To shed more light on the causes of autosomal recessive MR (ARMR), we have set out in 2003 to perform systematic clinical studies and autozygosity mapping in large consanguineous Iranian families with non-syndromic ARMR (NS-ARMR). As previously reported (Najmabadi et al. in Hum Genet 121:43-48, 2007), this led us to the identification of 12 novel ARMR loci, 8 of which had a significant LOD score (OMIM: MRT5-12). In the meantime, we and others have found causative gene defects in two of these intervals. Moreover, as reported here, tripling the size of our cohort has enabled us to identify 27 additional unrelated families with NS-ARMR and single-linkage intervals; 14 of these define novel loci for non-syndromic ARMR. Altogether, 13 out of 39 single linkage intervals observed in our cohort were found to cluster at 6 different loci on chromosomes, i.e., 1p34, 4q27, 5p15, 9q34, 11p11-q13 and 19q13, respectively. Five of these clusters consist of two significantly overlapping linkage intervals, and on chr 1p34, three single linkage intervals coincide, including the previously described MRT12 locus. The probability for this distribution to be due to chance is only 1.14 × 10(-5), as shown by Monte Carlo simulation. Thus, in contrast to our previous conclusions, these novel data indicate that common molecular causes of NS-ARMR do exist, and in the Iranian population, the most frequent ones may well account for several percent of the patients. These findings will be instrumental in the identification of the underlying genes. PMID:21063731

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Injectable actarit-loaded solid lipid nanoparticles as passive targeting therapeutic agents for rheumatoid arthritis.

    PubMed

    Ye, Jiesheng; Wang, Qun; Zhou, Xuefeng; Zhang, Na

    2008-03-20

    This work systematically studied the intravenous injection formulation of solid lipid nanoparticles (SLNs) loaded with actarit, a poor water soluble anti-rheumatic drug. The goal of this study was to design passive targeting nanoparticles which could improve therapeutic efficacy and reduce side-effects such as nephrotoxicity and gastrointestinal disorders commonly associated with oral formulations of actarit. Based on the optimized results of single-factor and orthogonal design, actarit-loaded SLNs were prepared by a modified solvent diffusion-evaporation method. The formulated SLNs were found to be relatively uniform in size (241+/-23 nm) with a negative zeta potential (-17.14+/-1.6 mV). The average drug entrapment efficiency and loading were (50.87+/-0.25)% and (8.48+/-0.14)%, respectively. The actarit-loaded SLNs exhibited a longer mean retention time in vivo (t(1/2(beta)), 9.373 h; MRT, 13.53 h) compared with the actarit 50% propylene glycol solution (t(1/2(ke)), 0.917 h; MRT, 1.323 h) after intravenous injection to New Zealand rabbits. The area under curve of plasma concentration-time (AUC) of actarit-loaded SLNs was 1.88 times greater than that of the actarit in 50% propylene glycol solution. The overall targeting efficiency (TE(C)) of the actarit-loaded SLNs was enhanced from 6.31% to 16.29% in spleen while the renal distribution of actarit was significantly reduced as compared to that of the actarit solution after intravenous administration to mice. These results indicated that injectable actarit-loaded solid lipid nanoparticles were promising passive targeting therapeutic agents for rheumatoid arthritis. PMID:18054182

  4. 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. PMID:25961808

  5. Pharmacokinetics of tramadol in horses after intravenous, intramuscular and oral administration.

    PubMed

    Shilo, Y; Britzi, M; Eytan, B; Lifschitz, T; Soback, S; Steinman, A

    2008-02-01

    Tramadol is a centrally acting analgesic drug that has been used clinically for the last two decades to treat moderate to moderately severe pain in humans. The present study investigated tramadol administration in horses by intravenous, intramuscular, oral as immediate-release and oral as sustained-release dosage-form routes. Seven horses were used in a four-way crossover study design in which racemic tramadol was administered at 2 mg/kg by each route of administration. Altogether, 23 blood samples were collected between 0 and 2880 min. The concentration of tramadol and its M1 metabolite were determined in the obtained plasma samples by use of an LC/MS/MS method and were used for pharmacokinetic calculations. Tramadol clearance, apparent volume of distribution at steady-state, mean residence time (MRT) and half-life after intravenous administration were 26+/-3 mL/min/kg, 2.17+/-0.52 L/kg, 83+/-10 min, and 82+/-10 min, respectively. The MRT and half-life after intramuscular administration were 155+/-23 and 92+/-14 min. The mean absorption time was 72+/-22 min and the bioavailability 111+/-39%. Tramadol was poorly absorbed after oral administration and only 3% of the administered dose was found in systemic circulation. The fate of the tramadol M1 metabolite was also investigated. M1 appeared to be a minor metabolite in horses, which could hardly be detected in plasma samples. The poor bioavailability after oral administration and the short half-life of tramadol may restrict its usefulness in clinical applications. PMID:18177320

  6. Microrobotic navigable entities for Magnetic Resonance Targeting.

    PubMed

    Martel, Sylvain

    2010-01-01

    Magnetic Resonance Targeting (MRT) uses MRI for gathering tracking data to determine the position of microscale entities with the goal of guiding them towards a specific target in the body accessible through the vascular network. At full capabilities, a MRT platform designed to treat a human would consist of a clinical MRI scanner running special algorithms and upgraded to provide propulsion gradient up to approximately 400mT/m to enable entities as small as a few tens of micrometers in diameter and containing magnetic nanoparticles (MNP) to be steered at vessel bifurcations based on tracking information. Indeed, using a clinical MRI system, we showed that such single entity with a diameter as small as 15microm is detectable in gradient-echo scans. Among many potential interventions, targeted cancer therapy is a good initial application for such new microrobotic approach since secondary toxicity for the patient could be reduced while increasing therapeutic efficacy using lower dosages. Although many types of such entities are needed to provide a larger set of tools, here, only three initial types designed with different functionalities and for different types of cancer are briefly described. Initially designed for targeted chemo-embolization of liver tumors, the first type known as Therapeutic Magnetic Micro-Carriers (TMMC) consists in its present form of approximately 50 microm PLGA microparticles containing therapeutics and approximately 180 nm FeCo MNP. For the second type, MNP are not only used for propulsion and tracking, but also actuation based on a local elevation of the temperature. In its simplest form, it consists of approxiamtely 20 nm MNP embedded in a thermo-sensitive hydrogel known as PNIPA, allowing additional functionalities such as computer triggered drug release and targeted hyperthermia. The third type initially considered to target colorectal tumors, consists of 1-2 microm MR-trackable and controllable MC-1 Magnetotactic Bacteria (MTB) with

  7. Microanalysis, Pharmacokinetics and Tissue Distribution of Polysaccharide-Protein Complexes from Longan Pulp in Mice

    PubMed Central

    Min, Ting; Sun, Jie; Yi, Yang; Wang, Hong-Xun; Hang, Fei; Ai, You-Wei; Wang, Li-Mei

    2015-01-01

    A high performance size exclusion-fluorescence detection (HPSEC-FD) method combined with fluorescein isothiocyanate (FITC) prelabeling was established for the microanalysis of polysaccharide–protein complexes from longan pulp (LPP). FITC-labeled LPP (LPPF) was fractionated by gel filtration chromatography. The weight-average molecular weight and FITC substitution degree of LPPF were 39.01 kDa and 0.20%, respectively. The HPSEC-FD calibration curves linear over the range of 1–200 µg/mL in mouse plasma, spleen and lung samples with correlation coefficients greater than 0.995. The inter-day and intra-day precisions of the method were not more than 6.9%, and the relative recovery ranged from 93.7% to 106.4%. The concentration–time curve of LPPF in plasma following intravenous (i.v.) administration at 40 mg/kg body weight well fitted to a two-compartment model. LPPF rapidly eliminated from plasma according to the short half-lives (t1/2α = 2.23 min, t1/2β = 39.11 min) and mean retention times (MRT0–t = 1.15 h, MRT0–∞ = 1.39 h). After administration over 5 to 360 min, the concentration of LPPF in spleen homogenate decreased from 7.41 to 3.68 µg/mL; the concentration in lung homogenate decreased from 9.08 to 3.40 µg/mL. On the other hand, the increasing concentration of LPPF fraction with low molecular weight in heart homogenate was observed. PMID:26501257

  8. Comparative in vitro and in vivo evaluation of three tablet formulations of amiodarone in healthy subjects

    PubMed Central

    2010-01-01

    Background and the purpose of the study The relative in vivo bioavailability and in vitro dissolution studies of three chemically equivalent amiodarone generic products in healthy volunteers was evaluated in three separate occasions. The possibility of a correlation between in vitro and in vivo performances of these tablet formulations was also evaluated. Methods The bioequivalence studies were conducted based on a single dose, two-sequence, cross over randomized design. The bioavailability was compared using AUC0–72, AUC0–8, Cmax and Tmax. Similarity factor, dissolution efficiency (DE), and mean dissolution time (MDT) was used to compare the dissolution profiles. Polynomial linear correlation models were tested using either MDT vs mean residence time (MRT) or fraction of the drug dissolved (FRD) vs fraction of the drug absorbed (FRA). Results Significant differences were found in the dissolution performances of the tested formulations and therefore they were included in the development of the correlation. The 90% confidence intervals of the log-transformed AUC0-72, AUC0–8, and Cmax of each two formulations in each bioequivalence studies were within the acceptable range of 80–125%. Differences were not observed between the untransformed Tmax values. Poor correlation was found between MRT and MDT of the products. A point-to-point correlation which is essential for a reliable correlation was not obtained between pooled FRD and FRA. The dissolution condition which was used for amiodarone tablets failed for formulations which were bioequivalent in vivo and significant difference between the dissolution characteristics of products (f2<50) did not reflect their in vivo properties. Major conclusions Bioequivalence studies should be considered as the only acceptable way to ensure the interchangeability and in vivo equivalence of amiodarone generic drug products. The dissolution conditions used of the present study could be used for routine and in-process quality

  9. 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

  10. [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. PMID:26710615

  11. Implicit-correction-based immersed boundary-lattice Boltzmann method with two relaxation times.

    PubMed

    Seta, Takeshi; Rojas, Roberto; Hayashi, Kosuke; Tomiyama, Akio

    2014-02-01

    In the present paper, we verify the effectiveness of the two-relaxation-time (TRT) collision operator in reducing boundary slip computed by the immersed boundary-lattice Boltzmann method (IB-LBM). In the linear collision operator of the TRT, we decompose the distribution function into symmetric and antisymmetric components and define the relaxation parameters for each part. The Chapman-Enskog expansion indicates that one relaxation time for the symmetric component is related to the kinematic viscosity. Rigorous analysis of the symmetric shear flows reveals that the relaxation time for the antisymmetric part controls the velocity gradient, the boundary velocity, and the boundary slip velocity computed by the IB-LBM. Simulation of the symmetric shear flows, the symmetric Poiseuille flows, and the cylindrical Couette flows indicates that the profiles of the numerical velocity calculated by the TRT collision operator under the IB-LBM framework exactly agree with those of the multirelaxation time (MRT). The TRT is as effective in removing the boundary slip as the MRT. We demonstrate analytically and numerically that the error of the boundary velocity is caused by the smoothing technique using the δ function used in the interpolation method. In the simulation of the flow past a circular cylinder, the IB-LBM based on the implicit correction method with the TRT succeeds in preventing the flow penetration through the solid surface as well as unphysical velocity distortion. The drag coefficient, the wake length, and the separation points calculated by the present IB-LBM agree well with previous studies at Re = 10, 20, and 40. PMID:25353605

  12. 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.

  13. 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.

  14. 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

  15. 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

    2014-03-01

    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

  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. PMID:27336334

  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. Microanalysis, Pharmacokinetics and Tissue Distribution of Polysaccharide-Protein Complexes from Longan Pulp in Mice.

    PubMed

    Min, Ting; Sun, Jie; Yi, Yang; Wang, Hong-Xun; Hang, Fei; Ai, You-Wei; Wang, Li-Mei

    2015-01-01

    A high performance size exclusion-fluorescence detection (HPSEC-FD) method combined with fluorescein isothiocyanate (FITC) prelabeling was established for the microanalysis of polysaccharide-protein complexes from longan pulp (LPP). FITC-labeled LPP (LPPF) was fractionated by gel filtration chromatography. The weight-average molecular weight and FITC substitution degree of LPPF were 39.01 kDa and 0.20%, respectively. The HPSEC-FD calibration curves linear over the range of 1-200 µg/mL in mouse plasma, spleen and lung samples with correlation coefficients greater than 0.995. The inter-day and intra-day precisions of the method were not more than 6.9%, and the relative recovery ranged from 93.7% to 106.4%. The concentration-time curve of LPPF in plasma following intravenous (i.v.) administration at 40 mg/kg body weight well fitted to a two-compartment model. LPPF rapidly eliminated from plasma according to the short half-lives (t1/2α=2.23 min, t1/2β=39.11 min) and mean retention times (MRT0-t=1.15 h, MRT0-∞=1.39 h). After administration over 5 to 360 min, the concentration of LPPF in spleen homogenate decreased from 7.41 to 3.68 µg/mL; the concentration in lung homogenate decreased from 9.08 to 3.40 µg/mL. On the other hand, the increasing concentration of LPPF fraction with low molecular weight in heart homogenate was observed. PMID:26501257

  19. MOSFET dosimetry with high spatial resolution in intense synchrotron-generated x-ray microbeams.

    PubMed

    Siegbahn, E A; Bräuer-Krisch, E; Bravin, A; Nettelbeck, H; Lerch, M L F; Rosenfeld, A B

    2009-04-01

    Various dosimeters have been tested for assessing absorbed doses with microscopic spatial resolution in targets irradiated by high-flux, synchrotron-generated, low-energy (approximately 30-300 keV) x-ray microbeams. A MOSFET detector has been used for this study since its radio sensitive element, which is extraordinarily narrow (approximately 1 microm), suits the main applications of interest, microbeam radiation biology and microbeam radiation therapy (MRT). In MRT, micrometer-wide, centimeter-high, and vertically oriented swaths of tissue are irradiated by arrays of rectangular x-ray microbeams produced by a multislit collimator (MSC). We used MOSFETs to measure the dose distribution, produced by arrays of x-ray microbeams shaped by two different MSCs, in a tissue-equivalent phantom. Doses were measured near the center of the arrays and maximum/minimum (peak/valley) dose ratios (PVDRs) were calculated to determine how variations in heights and in widths of the microbeams influenced this for the therapy, potentially important parameter. Monte Carlo (MC) simulations of the absorbed dose distribution in the phantom were also performed. The results show that when the heights of the irradiated swaths were below those applicable to clinical therapy (< 1 mm) the MC simulations produce estimates of PVDRs that are up to a factor of 3 higher than the measured values. For arrays of higher microbeams (i.e., 25 microm x 1 cm instead of 25 x 500 microm2), this difference between measured and simulated PVDRs becomes less than 50%. Closer agreement was observed between the measured and simulated PVDRs for the Tecomet MSC (current collimator design) than for the Archer MSC. Sources of discrepancies between measured and simulated doses are discussed, of which the energy dependent response of the MOSFET was shown to be among the most important. PMID:19472618

  20. Cyber-Physical Systems - Wissenschaftliche Herausforderungen Bei Der Entwicklung

    NASA Astrophysics Data System (ADS)

    Broy, Manfred

    Cyber-Physical Systems adressieren die enge Verbindung eingebetteter Systeme zur Überwachung und Steuerung physikalischer Vorgänge mittels Sensoren und Aktuatoren über Kommunikationseinrichtungen mit den globalen digitalen Netzen (dem Cyberspace"). Dieser Typus von Systemen ermöglicht über Wirkketten eine Verbindung zwischen Vorgängen der physischen Realität und den heute verfügbaren digitalen Netzinfrastrukturen. Dies erlaubt vielfältige Applikationen mit hohem wirtschaftlichen Potential, und mit starker Innovationskraft. Die vollständige Ausschöpfung des Potentials erfordert aber gezielte wissenschaftliche Anstrengungen bei der Entwicklung solcher Systeme im Hinblick auf Methodik, Technologie, Kostenbeherrschung und funktionale Angemessenheit.

  1. Minimalinvasive endovaskuläre Stent-Therapie bei Erkrankungen in der thorakalen Aorta

    NASA Astrophysics Data System (ADS)

    Voss, Bernhard; Bauernschmitt, Robert; Brockmann, Gernot; Lange, Rüdiger

    Die Inzidenz der Aortenerkrankungen nimmt aufgrund der Überalterung der Bevölkerung stetig zu und hat sich innerhalb der letzten 20 Jahre von 2,9 auf 10,9 pro 100.000 Einwohner mehr als verdreifacht [1]. Bei Aortenerkrankungen muss zwischen Aneurysmen und Dissektionen unterschieden werden. Der Begriff Aneurysma (Abb. 62.1) bezeichnet die Ausweitung eines arteriellen Blutgefäßes. Sind dabei alle Wandschichten, also innere Schicht (Intima), mittlere Schicht (Media) und äußere Schicht (Adventitia) betroffen, so spricht man von einem echten Aneurysma (Aneurysma verum). Besteht die Aneurysmawand nur aus adventitiellem Gewebe, spricht man von einem falschen Aneurysma. Ursache für ein Aneurysma ist eine Schwächung der elastischen Kräfte der Media, die dann dem intravaskulären Druck nicht mehr standhalten kann.

  2. Heideggerian dynamics and the monadological role of the 'between': A crossing with quantum brain dynamics.

    PubMed

    Globus, Gordon

    2015-12-01

    Heideggerian theory is retrieved as a dynamics, the "Godly event" of das Ereignis ("enowning"), which is unexpectedly compatible with a version of quantum brain dynamics. In both the "between" (das Zwischen) has the fundamental role of the dis-closure that is Existenz. Heidegger's harsh critique of technology and science does not apply to revolutionary quantum brain dynamics. The crossing between Heidegger and quantum brain dynamics, as well as one fundamental ontological difference, illuminates both. To our surprise this difference turns out, contra Heidegger, to be monadological. The monadological conception is applied to long-standing problematics of measurement in quantum physics and consciousness in philosophy. Heideggerian Existenz is affirmed as fundamentally non-computational but is reformulated as a dynamical process of monadological dis-closure that radically deconstructs transcendent world. PMID:26193172

  3. 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).

  4. Anwendung von Methoden der Logistik und Netzplantechnik zur präzedenz- und ressourcenbeschränkten Ablaufplanung von Echtzeitsystemen

    NASA Astrophysics Data System (ADS)

    Gumzej, Roman; Lipičnik, Martin

    Grundlegende Zusammenhänge zwischen Logistik, Netzplantechnik und Echtzeit sowie den zugehörigen Arten der Ablaufplanung und ihrer Nutzung werden dargestellt. Das Echtzeitprinzip beinhaltet Rechtzeitigkeit von Abläufen, wobei es für eine frühzeitige Beendigung eines Ablaufs keinen Bonus gibt; im Gegensatz zum verspäteten Ablauf, dessen Konsequenzen in der Regel negativ und unabschätzbar sind. Das Just-in-Time-Prinzip gleicht dem der Echtzeit und wird vor allem in der Logistik zur Bezeichnung reibungsloser Abläufe in Beschaffungsketten verwendet. In der Netzplantechnik werden die kritischen Aktivitäten binnen eines Projektes bestimmt, die nicht verzögert werden dürfen, um das Projekt rechtzeitig zu beenden. Außerdem haben die drei Bereiche noch eine Gemeinsamkeit: um realistische Ablaufszenarien darzustellen, müssen in den Analysen auch begrenzte Ressourcen angemessen berücksichtigt werden.

  5. Notizen zur Wissenschaftsentwicklung

    NASA Astrophysics Data System (ADS)

    Schmellenmeier, Heinz

    Wissenschaft und Technik sind eine Einheit. Heute läßt sich eine Grenze zwischen den Bereichen schwer finden. Es wird versucht, zu zeigen, wie moderne sozialistische Formen der Wissenschaftsorganisation den Fortschritt fördern. Unter den heutigen Bedingungen der Klassenauseinandersetzung der beiden Weltsysteme auf dem Gebiet der Wissenschaft kann es eine echte Internationalität der Wissenschaft nicht geben.Translated AbstractNotes on the Development of ScienceScience and Technology are a unity. There is no frontier between them. It will be shown, that modern socialist forms of organisation of science further its development. In our time, with its class-struggle between the two social systems in the world, a real internationality of science is impossible.

  6. Eine Beziehung seit 650 Jahren: Universität Wien und Kloster Melk - Katalog zur Sonderausstellung

    NASA Astrophysics Data System (ADS)

    Bruckmüller, Ernst; Niederkorn-Bruck, Meta; Beck, Paul G.; Deibl, Jakob; Deibl, Johannes; Denk, Ulrike; Ellegast, Burkard; Floßmann, Gerhard; Glaßner, Gottfried; Kalteis, Bernadette; Kowarik, Wilfried; Rotheneder, Martin

    2015-04-01

    University of Vienna was founded in 1365 and celebrates its 650 anniversary in 2015. Due to the university's anniversary, the Benedictine abbey of Melk, Austria presents an exhibition, depicting six and half centuries of university history and collaboration between the university as well as the abbey in all disciplines present at medieval universities. The publication describes the historic frame work as well as case-by-case descriptions of displayed manuscripts, prints and artifacts. Die Universität Wien wurde 1365 gegründet und feiert 2015 ihr 650jähriges Bestehen. Aus Anlass dieses Jubiläums präsentiert das Benediktiner Stift Melk eine Ausstellung, in der sechseinhalb Jahrhunderte Universistaetsgeschichte aufgearbeitet werden, sowie die Zusammenarbeit zwischen Universität und Abtei auf allen Themenbereichen, die an mittelalterlichen Universitäten angeboten wurden. Die Publikation bietet eine historische Zusammenfassung sowie eine Detailbeschreibung der ausgestellten Handschriften, Drucke sowie Gegenstände.

  7. Biegen und Brechen im Supercomputer: Duktile Verformungen und spröde Brüche von Kristallen

    NASA Astrophysics Data System (ADS)

    Buehler, Markus J.; Gao, Huajian

    2004-01-01

    Ob sich ein Material unter Krafteinwirkung duktil verformt oder spröde bricht, hängt davon ab, wie sich in ihm Defekte ausbreiten. Um das zu untersuchen, zerstören wir in Supercomputer-Simulationen Nanokristalle, die bis zu einer Milliarde virtueller Atome enthalten. Die Simulationen zeigen zum Beispiel, wie sich Risse an der Grenzfläche zwischen einem härteren und einem weicheren Material ausbreiten. Sie erlauben auch nie zuvor gesehene Einblicke in die mikroskopischen Prozesse während der duktilen Verformung eines Metalls: Das kollektive Verhalten von vielen tausend Versetzungen führt zu einer Kaltverfestigung des Kristalls. Er wird spröde und bricht.

  8. Herausforderungen und Best Practices bei der Speicherung von multi-valued Attributen in LDAP-basierten Verzeichnisdiensten

    NASA Astrophysics Data System (ADS)

    Hommel, Wolfgang; Pluta, Daniel

    LDAP-basierte Verzeichnisdienste unterscheiden sich von relationalen Datenbankmanagementsystemen unter anderem stark bezüglich der Datenmodellierung. Dieser Artikel vertieft eingangs die Herausforderungen bei der LDAP-spezifischen Abbildung von Relationen zwischen mehreren multivalued Attributen. Die Diskussion erfolgt vor dem Hintergrund, dass einerseits Verzeichnisdienste generell nur bedingt zur Speicherung von Relationen geeignet sind und dass andererseits multi-valued Attribute ein mächtiges LDAP-Instrument sind, zu dem es in relationalen Datenbanksystemen keine direkte Entsprechung gibt. Anschließend werden Lösungskonzepte vorgestellt und mögliche Weiterentwicklungen des IntegraTUM-LDAP-Schemas zu deren Umsetzung skizziert, eine exemplarische Implementierung präsentiert und die Ergebnisse der bisherigen Entwicklung des IntegraTUM-Schemas gegenübergestellt.

  9. Simulation und virtuelle Realität

    NASA Astrophysics Data System (ADS)

    von Estorff, Otto; Markiewicz, Marian; Özkan, Ali; Zaleski, Olgierd; Blumrich, Reinhard; Genuit, Klaus; Fiebig, André

    Mit Hilfe akustischer Berechnungen ist es möglich, aufwendige Messungen an Fahrzeugprototypen deutlich zu reduzieren. Dieses Kapitel gibt einen kurzen Überblick über die wichtigsten derzeit verfügbaren Methoden. Dabei wird zunächst auf Elementverfahren, wie die Finite-Elemente-Methode (FEM) und die Boundary-Elemente-Methode (BEM), näher eingegangen. Während diese vor allem im tieffrequenten Bereich eingesetzt werden, kommen bei höheren Frequenzen vermehrt Verfahren zum Einsatz, die auf Energieformulierungen beruhen. Exemplarisch wird hier die Funktionsweise und der Einsatz der Statistischen-Energie-Analyse (SEA) erläutert. Anhand von repräsentativen Beispielen werden die Einsatzmöglichkeiten und Grenzen der verschiedenen Verfahren aufgezeigt, wobei vor allem auch auf Vergleiche zwischen Rechnung und Messung eingegangen wird.

  10. 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].

  11. 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.

  12. 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.

  13. Biochar carbon sequestration and downward translocation in contrasting soils under field conditions in Australia

    NASA Astrophysics Data System (ADS)

    Pal Singh, Bhupinder; Fang, Yunying; Boersma, Mark; Matta, Pushpinder; Van Zwieten, Lukas; Macdonald, Lynne

    2014-05-01

    Carbon (C) sequestration potential of biochar depends on its stability and stabilisation of native or added organic C in soil. However, the processes of biochar degradation, fate in soil organic matter pools, and downward translocation in the soil profile, and the influence of biochar on emissions or stabilisation of native organic C sources are poorly understood under field conditions. An Eucalyptus saligna green-waste biochar (δ13C -36.6o; total C 66.8%) produced by slow pyrolysis at 450° C was applied at 29.2 t ha-1 to 10-cm depth in circular (0.66-m diameter) micro-plots, encompassing three soils [Tenosol, Dermosol and Ferrosol (Australian Soil Classification); Arenosol, Planosol, Ferralsol (approximate WRB Classification] under contrasting pasture systems across New South Wales and Tasmania (Australia). The aims of this study were to (i) monitor the fate of biochar C in respired CO2 and quantify biochar stability and stabilisation under field conditions, (ii) determine the influence of biochar on native soil C emissions, and (iii) track downward migration of the surface (0-10 cm) applied biochar over a 1-year period. We also periodically monitored the impact of biochar on microbial biomass carbon (MBC) and aboveground biomass production. The soils were separated into light and heavy C fractions and the C recovery of applied biochar C was calculated at 0-8, 8-12, 12-20 and 20-30 cm depths. Biochar C mineralisation rates were generally higher, albeit fluctuated widely, in the first 3 to 4 months. Over the first 7 months, the proportion of added biochar C mineralised in soils ranged between 1.4 and 5.5% and followed the sequence: Tenosol < Dermosol < Ferrosol. The mean residence time (MRT) of biochar ranged from 29 and 70 years. These values of MRT should be treated as highly conservative values, as they mainly reflect the MRT of relatively labile C components in biochar. The cumulative CO2-C emission over the 7-month period from native soil and plant sources

  14. [Determination of plasma concentration of quercetin, kaempferid and isorhamnetin in Hippophae rhamnoides extract by HPLC-MS/MS and pharmacokinetics in rats].

    PubMed

    Liu, Yu; Yang, Juan; Tuo, Yang-ling; Wei, Ting; Zeng, Yong; Wang, Ping; Meng, Xian-li

    2015-10-01

    To establish an HPLC-MS/MS method for the analysis of quercetin, kaempferid and isorhamnetin in rats plasma and study its pharmamacokinetics after an intragastrical administration of Hippophae rhamnoides extracts. Five healthy male Sprague-Dawley (SD) rats were given single doses of H. rhamnoides extracts (quercetin 26.35 mg x kg(-1), kaempferid 4.040 mg x kg(-1), isorhamnetin 31.37 mg x kg(-1)), and then their orbital sinus blood samples were collected at different time points. The drug plasma concentration of the three flavonoids was determined by HPLC-MS/MS method. After that, the main pharmacokinetics parameters were calculated by using Kinetica 5. 0. 11 software. The methodological test showed that the linear concentration ranges of quercetin, kaempferid and isorhamnetin were 7.500-600.0 μg x L(-1) (R2 = 0.998 5), 1.000-80.00 μg x L(-1) (R2 = 0.998 5 ) and 10.00-800.0 μg x L(-1) (R2 = 0.998 0), respectively. The inner and inter-days precisions were both less than 14.0%. The plasma samples showed a good stability and consistency with the requirement of biological sample analysis after the samples were frozen once and placed at - 20 degrees C for 15 d and room temperature for 6 h and the treated analytes were placed at -20 degrees C for 24 h. For quercetin, the pharmacokinetic parameter t(½β), AUC(0-∞), MRT(0.∞), C.(max) and T(max) were (113.3 ± 19.37) min, (12 542.14 ± 3 504.05) μg x h x L(-1), (119.6 ± 13.29) h, (164.6 ± 27.33) μg x L(-1) and (5.199 ± 0.840 3) h, respectively. For kaempferid, the pharmacokinetic parameters t(½β), AUC(0-t), MRT(0-∞), C(max) and T(max) were (79.85 ± 17.15) min, (934.51 ± 94.59) μg x h x L(-1), (81.50 ± 13.75) h, (80.15 ± 14.24) μg x L(-1) and (3.827 ± 0.902 7) h, respectively. For isorhamnetin, the pharmacokinetic parameters t1,2,, AUC(0-t), MRT(0-∞), C(max) and T(max) were (118.3 ± 20.73) min, (26 067.77 ± 4 124.60) μg x h x L(-1), (129.0 ± 16.30) h, (269.6 ± 29.32) μg x L(-1) and (6.513 ± 1

  15. Cyclosporine pharmacokinetics in pancreas transplant recipients.

    PubMed

    Munda, R; Schroeder, T J; Pedersen, S A; Clardy, C W; Wadhwa, N K; Myre, S A; Stephens, G W; Pesce, A J; Alexander, J W; First, M R

    1988-04-01

    Ten CsA pharmacokinetic studies were performed on five pancreas transplant recipients to determine proper doses and dosing intervals. These cadaver pancreas transplants were performed with exocrine ductal drainage into the urinary tract through a bladder anastomosis in four cases and into the bowel in one case. Four CsA pharmacokinetic studies were performed on diabetic renal transplant recipients and an additional six studies were performed while with pancreas transplant patients taking metoclopramide in an effort to enhance absorption of CsA. Mean CsA dose was 3.7 mg/kg/dose (range 2.1 to 7.5 mg/kg/dose). All patients but one were on twice daily dosing intervals yielding an average daily dose of 7.4 mg/kg/d. Noncompartmental pharmacokinetic analyses were used. The adequacy of a 1-, 2-, or 3-exponential model was determined by breakpoint analysis of the log concentration v time curve using the F statistic. The terminal rate constant was calculated by nonlinear regression analysis. The AUC and AUMC were calculated by the trapezoidal method with exponential extrapolation and these were used to calculate the MRT and Vdss. The unknown fractional absorption, F, was used to correct the oral data. The average CsA concentration maximum (Cmax) was 528 ng/mL with an average time to maximum concentration (Tmax) of 4.7 hours, a mean residence time of 7.75 hours, with a Vdss/%F of 9.61 L/kg in the pancreas transplant recipients. Additional studies of six patients receiving metoclopramide with CsA revealed an average Cmax of 723 ng/mL, an average Tmax of 2.3 hours, an average MRT of 6.08 hours, and an average Vdss/%F of 5.7% L/kg. These results indicate that coexistent gastroparesis in diabetic recipients of either pancreatic or renal transplants may result in reduced bioavailability of CsA. PMID:3284095

  16. High-Precision Radiosurgical Dose Delivery by Interlaced Microbeam Arrays of High-Flux Low-Energy Synchrotron X-Rays

    PubMed Central

    Serduc, Raphaël; Bräuer-Krisch, Elke; Siegbahn, Erik A.; Bouchet, Audrey; Pouyatos, Benoit; Carron, Romain; Pannetier, Nicolas; Renaud, Luc; Berruyer, Gilles; Nemoz, Christian; Brochard, Thierry; Rémy, Chantal; Barbier, Emmanuel L.; Bravin, Alberto; Le Duc, Géraldine; Depaulis, Antoine; Estève, François; Laissue, Jean A.

    2010-01-01

    Microbeam Radiation Therapy (MRT) is a preclinical form of radiosurgery dedicated to brain tumor treatment. It uses micrometer-wide synchrotron-generated X-ray beams on the basis of spatial beam fractionation. Due to the radioresistance of normal brain vasculature to MRT, a continuous blood supply can be maintained which would in part explain the surprising tolerance of normal tissues to very high radiation doses (hundreds of Gy). Based on this well described normal tissue sparing effect of microplanar beams, we developed a new irradiation geometry which allows the delivery of a high uniform dose deposition at a given brain target whereas surrounding normal tissues are irradiated by well tolerated parallel microbeams only. Normal rat brains were exposed to 4 focally interlaced arrays of 10 microplanar beams (52 µm wide, spaced 200 µm on-center, 50 to 350 keV in energy range), targeted from 4 different ports, with a peak entrance dose of 200Gy each, to deliver an homogenous dose to a target volume of 7 mm3 in the caudate nucleus. Magnetic resonance imaging follow-up of rats showed a highly localized increase in blood vessel permeability, starting 1 week after irradiation. Contrast agent diffusion was confined to the target volume and was still observed 1 month after irradiation, along with histopathological changes, including damaged blood vessels. No changes in vessel permeability were detected in the normal brain tissue surrounding the target. The interlacing radiation-induced reduction of spontaneous seizures of epileptic rats illustrated the potential pre-clinical applications of this new irradiation geometry. Finally, Monte Carlo simulations performed on a human-sized head phantom suggested that synchrotron photons can be used for human radiosurgical applications. Our data show that interlaced microbeam irradiation allows a high homogeneous dose deposition in a brain target and leads to a confined tissue necrosis while sparing surrounding tissues. The use of

  17. Recent advances in theoretical and numerical studies of wire array Z-pinch in the IAPCM

    SciTech Connect

    Ding, Ning Zhang, Yang Xiao, Delong Wu, Jiming Huang, Jun Yin, Li Sun, Shunkai Xue, Chuang Dai, Zihuan Ning, Cheng Shu, Xiaojian Wang, Jianguo Li, Hua

    2014-12-15

    Fast Z-pinch has produced the most powerful X-ray radiation source in laboratory and also shows the possibility to drive inertial confinement fusion (ICF). Recent advances in wire-array Z-pinch researches at the Institute of Applied Physics and Computational Mathematics are presented in this paper. A typical wire array Z-pinch process has three phases: wire plasma formation and ablation, implosion and the MRT instability development, stagnation and radiation. A mass injection model with azimuthal modulation coefficient is used to describe the wire initiation, and the dynamics of ablated plasmas of wire-array Z-pinches in (r, θ) geometry is numerically studied. In the implosion phase, a two-dimensional(r, z) three temperature radiation MHD code MARED has been developed to investigate the development of the Magneto-Rayleigh-Taylor(MRT) instability. We also analyze the implosion modes of nested wire-array and find that the inner wire-array is hardly affected before the impaction of the outer wire-array. While the plasma accelerated to high speed in the implosion stage stagnates on the axis, abundant x-ray radiation is produced. The energy spectrum of the radiation and the production mechanism are investigated. The computational x-ray pulse shows a reasonable agreement with the experimental result. We also suggest that using alloyed wire-arrays can increase multi-keV K-shell yield by decreasing the opacity of K-shell lines. In addition, we use a detailed circuit model to study the energy coupling between the generator and the Z-pinch implosion. Recently, we are concentrating on the problems of Z-pinch driven ICF, such as dynamic hohlraum and capsule implosions. Our numerical investigations on the interaction of wire-array Z-pinches on foam convertors show qualitative agreements with experimental results on the “Qiangguang I” facility. An integrated two-dimensional simulation of dynamic hohlraum driven capsule implosion provides us the physical insights of wire

  18. A mass-conserving lattice Boltzmann method with dynamic grid refinement for immiscible two-phase flows

    NASA Astrophysics Data System (ADS)

    Fakhari, Abbas; Geier, Martin; Lee, Taehun

    2016-06-01

    A mass-conserving lattice Boltzmann method (LBM) for multiphase flows is presented in this paper. The proposed LBM improves a previous model (Lee and Liu, 2010 [21]) in terms of mass conservation, speed-up, and efficiency, and also extends its capabilities for implementation on non-uniform grids. The presented model consists of a phase-field lattice Boltzmann equation (LBE) for tracking the interface between different fluids and a pressure-evolution LBM for recovering the hydrodynamic properties. In addition to the mass conservation property and the simplicity of the algorithm, the advantages of the current phase-field LBE are that it is an order of magnitude faster than the previous interface tracking LBE proposed by Lee and Liu (2010) [21] and it requires less memory resources for data storage. Meanwhile, the pressure-evolution LBM is equipped with a multi-relaxation-time (MRT) collision operator to facilitate attainability of small relaxation rates thereby allowing simulation of multiphase flows at higher Reynolds numbers. Additionally, we reformulate the presented MRT-LBM on nonuniform grids within an adaptive mesh refinement (AMR) framework. Various benchmark studies such as a rising bubble and a falling drop under buoyancy, droplet splashing on a wet surface, and droplet coalescence onto a fluid interface are conducted to examine the accuracy and versatility of the proposed AMR-LBM. The proposed model is further validated by comparing the results with other LB models on uniform grids. A factor of about 20 in savings of computational resources is achieved by using the proposed AMR-LBM. As a more demanding application, the Kelvin-Helmholtz instability (KHI) of a shear-layer flow is investigated for both density-matched and density-stratified binary fluids. The KHI results of the density-matched fluids are shown to be in good agreement with the benchmark AMR results based on the sharp-interface approach. When a density contrast between the two fluids exists, a

  19. Fate of recently fixed carbon in European beech (Fagus sylvatica) saplings during drought and subsequent recovery.

    PubMed

    Zang, Ulrich; Goisser, Michael; Grams, Thorsten E E; Häberle, Karl-Heinz; Matyssek, Rainer; Matzner, Egbert; Borken, Werner

    2014-01-01

    Drought reduces the carbon (C) assimilation of trees and decouples aboveground from belowground carbon fluxes, but little is known about the response of drought-stressed trees to rewetting. This study aims to assess dynamics and patterns of C allocation in beech saplings under dry and rewetted soil conditions. In October 2010, 5-year-old beech saplings from a forest site were transplanted into 20 l pots. In 2011, the saplings were subjected to different levels of soil drought ranging from non-limiting water supply (control) to severe water limitation with soil water potentials of less than -1.5 MPa. As a physiologically relevant measure of drought, the cumulated soil water potential (i.e., drought stress dose (DSD)) was calculated for the growing season. In late August, the saplings were transferred into a climate chamber and pulse-labeled with (13)C-depleted CO2 (δ(13)C of -47‰). Isotopic signatures in leaf and soil respiration were repeatedly measured. Five days after soil rewetting, a second label was applied using 99 atom% (13)CO2. After another 12 days, the fate of assimilated C in each sapling was assessed by calculating the (13)C mass balance. Photosynthesis decreased by 60% in saplings under severe drought. The mean residence time (MRT) of recent assimilates in leaf respiration was more than three times longer than under non-limited conditions and was positively correlated to DSD. Also, the appearance of the label in soil respiration was delayed. Within 5 days after rewetting, photosynthesis, MRT of recent assimilates in leaf respiration and appearance of the label in soil respiration recovered fully. Despite the fast recovery, less label was recovered in the biomass of the previously drought-stressed plants, which also allocated less C to the root compartment (45 vs 64% in the control). We conclude that beech saplings quickly recover from extreme soil drought, although transitional after-effects prevail in C allocation, possibly due to repair

  20. Effect of carbamazepine on the pharmacokinetic parameters of CDRI-97/78 following coadministration to rats.

    PubMed

    Kushwaha, H N; Misra, A; Gautam, N; Singh, Y; Kumar, H; Siddiqui, H H; Singh, S K

    2013-06-01

    Coadministration of 2 or more drugs may result in unexpected toxicity. This study aimed to evaluate the effect of carbamazepine coadministration on the pharmacokinetics of CDRI-97/78, an 1,2,4-trioxane antimalarial agent. Firstly, 97/78 was administered alone and then 97/78 and carbamazepine were coadministered to male and female rats. An revalidated LC-MS/MS method was used for quantitation of 97/63 since 97/78 is instantly and completely converted to 97/63 (an in-vivo active metabolite). The Tmax and Cmax values of 97/63 were 1.75±0.77 h and 862±306 ng/mL in male rats whereas in female rats they were 5.45±0.76 h and 662.75±95.09 ng/mL after a single dose of 97/78 alone. However, following coadministration of 97/78 and carbamazepine, the values for Tmax and Cmax were 1.06±0.16 h and 533±153 ng/mL in male rats and 2.23±1.93 h and 636.5±112.4 ng/mL in female rats. The half life of 97/63 following a single oral dose of 97/78 or coadministration with carbamazepine to male rats was 6.98±0.63 h and 6.64±0.54 h, respectively; the values in female rats were 7.5±0.5 h and 5.48±0.37 h. A statistically insignificant difference (P>0.05) was observed with the student t-test for the pharmacokinetic parameters of 97/63 following oral administration of 97/78 alone or coadministration of 97/78 and carbamazepine except for MRT in female rats. Intersex statistical comparison also showed an insignificant difference for 97/63 following oral administration of 97/78 alone or in combination with carbamazepine except for MRT, which supports coadministration of 97/78 and carbamazepine. PMID:23558601