Modeling collective behavior of molecules in nanoscale direct deposition processes

NASA Astrophysics Data System (ADS)

Lee, Nam-Kyung; Hong, Seunghun

2006-03-01

We present a theoretical model describing the collective behavior of molecules in nanoscale direct deposition processes such as dip-pen nanolithography. We show that strong intermolecular interactions combined with nonuniform substrate-molecule interactions can produce various shapes of molecular patterns including fractal-like structures. Computer simulations reveal circular and starlike patterns at low and intermediate densities of preferentially attractive surface sites, respectively. At large density of such surface sites, the molecules form a two-dimensional invasion percolation cluster. Previous experimental results showing anisotropic patterns of various chemical and biological molecules correspond to the starlike regime [P. Manandhar et al., Phys. Rev. Lett. 90, 115505 (2003); J.-H. Lim and C. A. Mirkin, Adv. Mater. (Weinheim, Ger.) 14, 1474 (2002); D. L. Wilson et al., Proc. Natl. Acad. Sci. U.S.A. 98, 13660 (2001); M. Su et al., Appl. Phys. Lett. 84, 4200 (2004); R. McKendry et al., Nano Lett. 2, 713 (2002); H. Zhou et al., Appl. Surf. Sci. 236, 18 (2004); G. Agarwal et al., J. Am. Chem. Soc. 125, 580 (2003)].

Electrospinning Applications in Mechanochemistry and Multi-Functional Hydrogel Materials

DTIC Science & Technology

2012-01-01

Price, G. J., Annu. Rev. Mater. Sci. 1999, 29, 295-326. 11. Koda , S.; Mori, H.; Matsumoto, K.; Nomura, H., Polymer 1994, 35 (1), 30-33. 
13
 12...Polymer Science: Polymer Letters Edition 1980, 18 (12), 757-760. 14. Koda , S.; Mori, H.; Matsumoto, K.; Nomura, H., Polymer 1994, 35 (1), 30-33

Coherent Plasmon-Exciton Coupling in Silver Platelet-J-aggregate Nanocomposites

DTIC Science & Technology

2015-02-27

2011, 11, 1556−1560. (12) Zengin, G.; Johansson, G.; Johansson, P.; Antosiewics, T. J.; Kall , M.; Shegai, T. Sci. Rep. 2013, 3 (3074), 1−8. (13...Mater. 2005, 17, 412−415. (21) Davydov, A. S. Theory of Molecular Excitons; Plenum Press: New York, 1971 . (22) Van Burgel, M.; Wiersma, D. A.; Duppen, K

Embedded-atom-method study of structural, thermodynamic, and atomic-transport properties of liquid Ni-Al alloys

NASA Astrophysics Data System (ADS)

Asta, Mark; Morgan, Dane; Hoyt, J. J.; Sadigh, Babak; Althoff, J. D.; de Fontaine, D.; Foiles, S. M.

1999-06-01

Structural, thermodynamic, and atomic-transport properties of liquid Ni-Al alloys have been studied by Monte Carlo and molecular-dynamics simulations based upon three different embedded-atom method (EAM) interatomic potentials, namely those due to Foiles and Daw (FD) [J. Mater. Res. 2, 5 (1987)], Voter and Chen (VC) [in Characterization of Defects in Materials, edited by R. W. Siegel et al. MRS Symposia Proceedings. No. 82 (Materials Research Society, Pittsburgh, 1987), p.175] and Ludwig and Gumbsch (LG) [Model. Simul. Mater. Sci. Eng. 3, 533 (1995)]. We present detailed comparisons between calculated results and experimental data for structure factors, atomic volumes, enthalpies of mixing, activities, and viscosities. Calculated partial structure factors are found to be in semiquantitative agreement with published neutron scattering measurements for Ni20Al80 alloys, indicating that short-range order in the liquid phase is qualitatively well described. Calculated thermodynamic properties of mixing are found to agree very well with experimental data for Ni compositions greater than 75 atomic %, while for alloys richer in Al the magnitudes of the enthalpies and entropies of mixing are significantly underestimated. The VC and LG potentials give atomic densities and viscosities in good agreement with experiment for Ni-rich compositions, while FD potentials consistently underestimate both properties at all concentrations. The results of this study demonstrate that VC and LG potentials provide a realistic description of the thermodynamic and atomic transport properties for NixAl1-x liquid alloys with x>=0.75, and point to the limitations of EAM potentials for alloys richer in Al.

Particle processing technology

NASA Astrophysics Data System (ADS)

Sakka, Yoshio

2014-02-01

In recent years, there has been strong demand for the development of novel devices and equipment that support advanced industries including IT/semiconductors, the environment, energy and aerospace along with the achievement of higher efficiency and reduced environmental impact. Many studies have been conducted on the fabrication of innovative inorganic materials with novel individual properties and/or multifunctional properties including electrical, dielectric, thermal, optical, chemical and mechanical properties through the development of particle processing. The fundamental technologies that are key to realizing such materials are (i) the synthesis of nanoparticles with uniform composition and controlled crystallite size, (ii) the arrangement/assembly and controlled dispersion of nanoparticles with controlled particle size, (iii) the precise structural control at all levels from micrometer to nanometer order and (iv) the nanostructural design based on theoretical/experimental studies of the correlation between the local structure and the functions of interest. In particular, it is now understood that the application of an external stimulus, such as magnetic energy, electrical energy and/or stress, to a reaction field is effective in realizing advanced particle processing [1-3]. This special issue comprises 12 papers including three review papers. Among them, seven papers are concerned with phosphor particles, such as silicon, metals, Si3N4-related nitrides, rare-earth oxides, garnet oxides, rare-earth sulfur oxides and rare-earth hydroxides. In these papers, the effects of particle size, morphology, dispersion, surface states, dopant concentration and other factors on the optical properties of phosphor particles and their applications are discussed. These nanoparticles are classified as zero-dimensional materials. Carbon nanotubes (CNT) and graphene are well-known one-dimensional (1D) and two-dimensional (2D) materials, respectively. This special issue also includes two papers on the fabrication of mechanically reliable nanocomposites by dispersing graphene into a ceramic matrix, and on supercapacitors with high energy densities in a Co(OH)2 system decorated with graphene and carbon nanotubes. As a novel preparation method of oxide films, the fabrication of alumina films with laminated structures by ac anodization is reviewed. Moreover a new type of nanosheet has been fabricated by the exfoliation of layered, ternary transition-metal carbide and nitride compounds, known as Mn + 1AXn phases (or MAX phases) where M is an early transition metal, such as Ti or Nb, A is an A group element, such as Si or Al, X is carbon and/or nitrogen and n = 1-3 [4]. Among the MAX phases, those containing Mo have been theoretically calculated by first-principles calculations to be a source for obtaining Mo2C nanosheets with potentially unique properties. As an example of improving bulk ceramic properties, texturing by using a high magnetic field [5] and sintering by the electric current activated/assisted sintering (ECAS) technology [6] have been demonstrated for ultra-high temperature ceramics with high-temperature strength. A project on the development of materials and particle processing for the field of environment and energy has been ongoing at the National Institute for Materials Science since April 2011. This project employs various core competence technologies for particle processing such as ion beam irradiation for nanoparticle fabrication [7], fullerene nanomaterial processing using liquid-liquid interface precipitation [8], a gas reduction nitridation process to obtain Si3N4-based phosphor materials [9], advanced phosphors via novel processing [10, 11], ultra-high pressure technology for processing and in situ analysis [12, 13], colloidal processing in a high magnetic field to obtain laminated, textured ceramics [1, 3, 5], the ECAS process for nanostructuring ceramics [6] and so forth. Here, I would like to introduce some research achievements that are not covered in this special issue. (1) The evolution of hydrogen by the reaction of fine metal particles such as Al [14] and Mg [15] with water; the specific surface area and surface modification are important factors.(2) The realization of new carbon related materials with 1D and 2D structures consisting of fullerenes prepared by liquid-liquid interface precipitation: alkaline-doped superconductive nanotubes consisting of fullerenes [16], application to solar cells of fullerene/cobalt porphyrin hybrid nanosheets [17], etc.(3) The fabrication of textured films and bulk materials with excellent functional properties by colloidal processing methods such as slip casting [5], gel casting [18] and electrophoretic deposition [3, 19], in a high magnetic field, and with subsequent heating; examples of such materials include dye-sensitized TiO2 solar cells, thermoelectric materials and cathode materials for solid state Li-ion batteries and dielectric ceramics.(4) The fabrication of high-strength and high-toughness MAX phase ceramics [20, 21] inspired by the nacreous structure [22].(5) The modeling and development of the ECAS process [6]. This involves two-step pressure application [23] and high-pressure application above 400 MPa to fabricate transparent oxides [24-26], and rapid heating to obtain dense nanocomposites of ceramic-CNT [27] and diamonds [28].(6) The contraction of ternary phase diagrams for oxide ion conductor systems such as zirconia [29] and apatite systems [30], leading to an increased understanding of the stability of such systems and assisting the search for high oxygen ion conductors. Acknowledgments I am grateful to the authors who have contributed to this special issue, and sincerely hope that the readers will expand their knowledge of particle processing technology. References [1] Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [2] Badica P, Crisan A, Aldica G, Endo K, Borodianska H, Togano K, Awaji S, Vasylkiv O and Sakka Y 2011 Sci. Technol. Adv. Mater. 12 013001 [3] Sakka Y and Uchikoshi T 2010 KONA Powder Particle J. 28 74 (kona.or.jp/search/28_074.pdf) [4] Naguib M, Mashtalir O, Carle J, Presser V, Lu J, Hultman L, Gogotsi Y and Barsoum M W 2012 ACS Nano 6 1322 [5] Sakka Y and Suzuki T S 2005 J. Ceram. Soc. Japan 113 26 [6] Grasso S, Sakka Y and Maizza G 2009 Sci. Technol. Adv. Mater. 10 053001 [7] Nakao H, Tokonami S, Hamada T, Shiigi H, Nagaoka T, Iwate F and Takeda Y 2012 Nanoscale 4 6814 [8] Miyazawa K and Hotta K 2010 J. Cryst. Growth 312 2764 [9] Suehiro T, Xie R and Hirosaki N 2013 Indust. Eng. Chem. Res. 52 7453 [10] Zhu Q, Li J-G, Li X, Sun X and Sakka Y 2011 Sci. Technol. Adv. Mater. 12 055001 [11] Li J, Li J-G, Zhang Z, Wu X, Liu S, Li X, Sun X and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 035007 [12] Kawamura F, Yusa H and Taniguchi T 2012 Appl. Phys. Lett. 100 251910 [13] Watanabe K and Taniguchi T 2011 Int. J. Appl. Ceram. Technol. 8 977 [14] Deng Z-Y, Ferreira J M F and Sakka Y 2008 J. Am. Ceram. Soc. 91 3825 [15] Uda M, Okuyama H, Suzuki T S and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 025009 [16] Takeya H, Kato R, Wakahara T, Miyazawa K, Yamaguchi T, Ozaki T, Okazaki H and Takano Y 2013 Mater. Res. Bull. 48 343 [17] Wakahara T, D'Angelo P, Miyazawa K, Nemoto Y, Ito O, Tanigaki N, Bradley D D C and Anthopoulos T D 2012 J. Am. Chem. Soc. 134 7204 [18] Wiecinska P, Sakka Y, Suzuki T S, Uchikoshi T, Mizerski T and Szafran M 2013 J. Ceram. Soc. Japan 121 89 [19] Kawakita M, Uchikoshi T, Kawakita J and Sakka Y 2009 J. Am. Ceram. Soc. 92 984 [20] Hu C, Sakka Y, Grasso S, Nishimura T, Guo S and Tanaka H 2011 Scr. Mater. 64 765 [21] Hu C, Sakka Y, Nishimura T, Guo S, Grasso S and Tanaka H 2011 Sci. Technol. Adv. Mater. 12 044603 [22] Kakisawa H and Sumitomo T 2011 Sci. Technol. Adv. Mater. 12 064710 [23] Grasso S, Hu C F, Maizza G, Kim B N and Sakka Y 2011 J. Am. Ceram. Soc. 94 1405 [24] Grasso S, Kim B N, Hu C F, Maizza G and Sakka Y 2010 J. Am. Ceram. Soc. 93 2460 [25] Zhang H B, Kim B N, Morita K, Hiraga K, Yoshida H and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 055003 [26] Kim B-N, Hiraga K, Grasso S, Morita K, Yoshida H, Zhang H and Sakka Y 2012 J. Ceram. Soc. Japan 120 116 [27] Estili M, Kawasaki A and Sakka Y 2012 Adv. Mater. 24 4322 [28] Grasso S, Hu C F, Maizza G and Sakka Y 2012 J. Am. Ceram. Soc. 95 2423 [29] Andrievskaya E R, Kornienko O A, Sayir A, Vasylkiv O and Sakka Y 2011 J. Am. Ceram. Soc. 94 1911 [30] Kobayashi K and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 045006

Direct Observations of Fracture and the Damage Mechanics of Ceramics

DTIC Science & Technology

1988-10-31

microplasticity up to the fracture load. d. It shculd have low enough strength in tension and compression to enable strength measurements at easily accessible...15jm. SEM examination of the grains after large amounts of deformation indicated that the grains are brittle without any evidence of microplasticity . In...and microplasticity in polycrystalline alumina", J.Mater.Sci., 12(1977)791-796. 93. J Lankford, "Compressive microfracture and indentation damage in A1

Ballistic low-temperature magnon heat conduction in the helimagnetic insulator Cu2OSeO3

NASA Astrophysics Data System (ADS)

Prasai, Narayan; Akopyan, Artem; Huang, Sunxiang; Cohn, Joshua L.; Trump, Benjamin; Marcus, Guy G.; McQueen, Tyrel M.

We report on the observation of magnon thermal conductivities κm 80 W/mK near T = 5 K in single crystals of the helimagnetic insulator Cu2OSeO3, exceeding those observed previously in any other ferro- or ferrimagnet by almost two orders of magnitude. Distinguished in applied magnetic field, both magnon and phonon thermal conductivities exhibit ballistic behavior below 1K, with mean free paths limited by specimen boundaries. Changes in κm through the helical-conical and conical-collinear spin-phase transitions with increasing applied field will also be discussed. This material is based on work supported by the U.S. DOE, Off. of BES, Div. of Mater. Sci. and Eng., under Grants No. DEFG02-12ER46888 (Miami), DEFG02-08ER46544 (JHU), and the NSF, Div. of Mater. Res., Sol. St. Chem., CAREER Grant No. DMR-1253562 (JHU).

Low-temperature spin-Seebeck effect in the helimagnetic insulator Cu2OSeO3

NASA Astrophysics Data System (ADS)

Akopyan, Artem; Prasai, Narayan; Huang, Sunxiang; Cohn, Joshua L.; Trump, Benjamin; Marcus, Guy G.; McQueen, Tyrel M.

We report on measurements of the longitudinal spin-Seebeck effect in single crystals of the helimagnetic insulator Cu2OSeO3 in the range 0 . 5 K <= T <= 15 K , using sputtered Pt thin films for spin-current detection. Simultaneous determination of magnon thermal conductivities for each specimen allows for a ``calibration'' of the spin current. The influence on the inverse spin-Hall signal of the helical-conical and conical-collinear magnetic phase transitions as well as different crystallographic orientations for the heat flow and applied magnetic field, will be discussed. This material is based on work supported by the U.S. DOE, Off. of BES, Div. of Mater. Sci. and Eng., under Grants No. DEFG02-12ER46888 (Miami), DEFG02-08ER46544 (JHU), and the NSF, Div. of Mater. Res., Sol. St. Chem., CAREER Grant No. DMR-1253562 (JHU).

Fundamental Concepts Relating Local Atomic Arrangements, Deformation, and Fracture of Intermetallic Alloys

DTIC Science & Technology

1993-06-01

Takahashi and H. Oikawa, J. Mater. Sci., 25 (1990) 629. 1 18. S.C. Huang and D.S. Shih, in Microstructure/Property Relationships in Titanium Aluminides and...driven development of directionally-solidified and single crystal superalloy turbine blades . Comparison of the deformation mechanism map for NiAI...1990) 35-44. 101. Bania, P.J. and Hall, J.A., in Titanium Science and Technology, Lutjering, G., Swicker, V., and Bunk, W. (eds.), Deutche

Imaging Molecular Signatures of Breast Cancer with X-ray-Activated Nanophosphors

DTIC Science & Technology

2012-09-01

REPORT DATE : September 2012 TYPE OF REPORT: Annual PREPARED FOR: U.S. Army Medical Research and Materiel Command Fort...THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2012 2. REPORT TYPE ANNUAL SUMMARY 3. DATES COVERED (From - To) 1 2011 – 2012 4. TITLE AND...Development of nanophosphors - A review,” Mater. Sci. Eng. Rep. 49(5), 113–155 (2005). 10. J. Shen, L.-D. Sun, and C.-H. Yan, “Luminescent rare earth

Precipitation Coating of Monazite on Woven Ceramic Fibers: 1. Feasibility (Postprint)

DTIC Science & Technology

2007-02-01

08 Aug 2006. Paper contains color . 14. ABSTRACT Monazite coatings were deposited on woven cloths and tows of NextelTM 610 fibers by heterogeneous...by dissolving concentrated phosphoric acid ( Fish - er Scientific Co., Pittsburgh, PA) or a combination of lantha- num nitrate (Aldrich Chemical Co...Boccaccini, P. Karapappas, J. M. Marijuan, and C. Kaya, ‘‘ TiO2 Coat- ings on Silicon Carbide Fiber Substrates by Electrophoretic Deposition,’’ J.Mater. Sci

Regeneration and Remodeling of Composite Materials

DTIC Science & Technology

2015-08-27

10.1002/adhm.201400084. [47] K. Jud, H.H. Kausch, J.G. Williams, Fracture mechanics studies of crack healing and welding of polymers, J. Mater. Sci...1.1. Archival publications resulting from the AFOSR Discovery grant 1. H. Jin , K.R. Hart, A.M. Coppola, R.C. Gergely, J.S. Moore, N.R. Sottos, S.R...Discovery grant 1. R.C.R. Gergely, J.S. Moore, N.R. Sottos, S.R. White, Regenerative Coatings, Society for Experimental Mechanics Annual Conference and

Effect of Heat Treatment on Chemical Segregation in CMSX-4 Nickel-Base Superalloy

NASA Astrophysics Data System (ADS)

Szczotok, A.; Chmiela, B.

2014-08-01

Superalloys display a strong tendency toward chemical segregation during solidification. Therefore, it is of great importance to develop appropriate techniques for the melting and casting of superalloys. Elements partitioning between the γ and γ' phases in single crystal superalloys have been investigated by several authors using electron probe microanalysis (Hemmersmeier and Feller-Kniepmeier Mater Sci Eng A 248:87-97, 1998; Kearsey et al. Intermetallics 12:903-910, 2004; Kearsey et al. Superalloys 2004, pp 801-810, 2004; D'Souza et al. Mater Sci Eng A 490:258-265, 2008). We examined the effect of the particular stages of standard heat treatment (solution treatment and ageing) applied to CMSX-4 single crystal superalloy on chemical segregation that occurs between dendrites and interdendritic areas. Dendritic structures were observed using a scanning electron microscope. Analyses of the chemical composition were performed using energy dispersive x-ray spectroscopy. The obtained qualitative and quantitative results for the concentrations of elements enabled us to confirm the dendritic segregation in as-cast CMSX-4 superalloy. The concentrations of some refractory elements (tungsten, rhenium) were much greater in dendrites than in interdendritic areas. However, these differences in chemical composition gradually decreased during heat treatment. The results obtained in this study warrant further examination of the diffusion processes of elements during heat treatment of the investigated superalloy, and of the kinetics of diffusion.

Ion Beam Processing of Diamond

DTIC Science & Technology

1990-05-07

Diamond structure. We can make ohmic contacts to silicon . If we could tailor the structure from Si to Si. C,-, to diamond, we should be able to form a low...func- ricr injection. Refractory metals such as tantalum. tung- tion of contact spacing. Extrapolation of the data to zero sten , or titanium have also...layer of the diamond could be miade n-type gallium nitride. and silicon carbide.- Mater. Sci. Fng.. vol. 91, pp.77-104.1(998. with a five to six orders

Development of a 30 kW Inductively Coupled Plasma Torch Facility for Advanced Aerospace Material Investigations

DTIC Science & Technology

2012-02-21

passive oxidation of zirconium diboride forms zirconia and boron oxide, and the passive oxidation of silicon carbide forms silica and carbon monoxide: ZrB2... silicon carbide composites in the ICP wind tunnels. However, this concept has never been explored as an in situ diagnostic for UHTC materials systems...Process- ing, properties, and arc jet oxidation of hafnium diboride/ silicon carbide ultra high temperature ceramics. J Mater Sci 2004;39:5925–37. 12

A study of Bi-Pb-Sn-Cd-Sb penta-alloys rapidly quenched from melt

NASA Astrophysics Data System (ADS)

Kamal, M.; El-Bediwi, A. B.

2004-11-01

Optical microscopy, X-ray diffractometry, the double bridge method, the Vickers microhardness testing and dynamic resonance techniques have been used to investigate structure, electrical resistivity, hardness, internal friction and elastic modulus of quenched Bi-Pb-Sn-Cd-Sb penta-alloys. The properties of these penta-alloys are greatly affected by rapid quenching. The intermetallic compound chi(Pb-Bi) or Bi3Pb7 is obtained after rapid quenching using the melt-spinning technique, and this is in agreement with reports by other authors [Marshall, T.J., Mott, G. T. and Grieverson, M. H. (1975). Br. J. Radiol., 48, 924, Kamal, M., El-Bediwi, A. B. and Karman, M. B. (1998). Structure, mechanical properties and electrical resistivity of rapidly solidified Pb-Sn-Cd and Pb-Bi-Sn-Cd alloys. J. Mater. Sci.: Mater. Electron., 9, 425, Borromee-Gautier, C., Giessen, B. C. and Grrant, N. J. (1968). J. Chem. Phys., 48,1905, Moon, K.-W., Boettinger, W. J., Kanner, U. R., Handwerker, C. A. and Lee, D.-J. (2001). The effect of Pb contamination on the solidification behavior of Sn-Bi solders. J. Electron. Mater, 30, 45.]. The quenched Bi43.5Pb44.5Cd5Sn2Sb5 alloy has important properties for safety devices in fire detection and extinguishing systems.

Polytype stability and defects in differently doped bulk SiC

NASA Astrophysics Data System (ADS)

Schmitt, Erwin; Straubinger, Thomas; Rasp, Michael; Vogel, Michael; Wohlfart, Andreas

2008-03-01

In this work, we present recent results on development and production of n-type 4 H bulk material. From previous studies it is evident that inclusions of foreign polytypes can act as origin of severe structural imperfections [N. Schulze, D.L. Barret, G. Pensl, S. Rohmfeld, M. Hundhausen, Mater. Sci. Eng. B 61-62 (1999) 44; D. Hofmann, E. Schmitt, M. Bickermann, M. Kölbl, P.J. Wellmann, A. Winnacker, Mater. Sci. Eng. B 61-62 (1999) 48], accompanied by defects like micropipes, stacking faults and dislocations. For that reason, we have carried out investigations to sustain polytype stability throughout the entire process, including nucleation and subsequent growth. Assisted by numerical calculations the influence of growth conditions, especially with respect to thermal field, Si/C ratio and doping, was examined. Several methods for the evaluation of material properties were applied to determine the quality most precisely, e.g. KOH-defect etching, optical microscopy, electron microscopy, X-ray diffraction and resistivity mapping. The key experience we gained was that moderate growth conditions with reduced temperature gradients are only one prerequisite for the reduction of defect density. Also stoichiometry in the gas phase and its modulation by nitrogen doping have to be taken into account and must be adjusted on the prevailing growth regime. We finally identified an optimized process that initiated a considerable improvement of material quality. Best values for 3″ 4 H wafers show that EPD<5×10 3 cm -2 and MPD<0.1 cm -2 can be achieved.

Computer simulation of heterogeneous polymer photovoltaic devices

NASA Astrophysics Data System (ADS)

Kodali, Hari K.; Ganapathysubramanian, Baskar

2012-04-01

Polymer-based photovoltaic devices have the potential for widespread usage due to their low cost per watt and mechanical flexibility. Efficiencies close to 9.0% have been achieved recently in conjugated polymer based organic solar cells (OSCs). These devices were fabricated using solvent-based processing of electron-donating and electron-accepting materials into the so-called bulk heterojunction (BHJ) architecture. Experimental evidence suggests that a key property determining the power-conversion efficiency of such devices is the final morphological distribution of the donor and acceptor constituents. In order to understand the role of morphology on device performance, we develop a scalable computational framework that efficiently interrogates OSCs to investigate relationships between the morphology at the nano-scale with the device performance. In this work, we extend the Buxton and Clarke model (2007 Modelling Simul. Mater. Sci. Eng. 15 13-26) to simulate realistic devices with complex active layer morphologies using a dimensionally independent, scalable, finite-element method. We incorporate all stages involved in current generation, namely (1) exciton generation and diffusion, (2) charge generation and (3) charge transport in a modular fashion. The numerical challenges encountered during interrogation of realistic microstructures are detailed. We compare each stage of the photovoltaic process for two microstructures: a BHJ morphology and an idealized sawtooth morphology. The results are presented for both two- and three-dimensional structures.

Simple intrinsic defects in GaP and InP

NASA Astrophysics Data System (ADS)

Schultz, Peter A.

2012-02-01

To faithfully simulate evolution of defect chemistry and electrical response in irradiated semiconductor devices requires accurate defect reaction energies and energy levels. In III-Vs, good data is scarce, theory hampered by band gap and supercell problems. I apply density functional theory (DFT) to intrinsic defects in GaP and InP, predicting stable charge states, ground state configurations, defect energy levels, and identifying mobile species. The SeqQuest calculations incorporate rigorous charge boundary conditions removing supercell artifacts, demonstrated converged to the infinite limit. Computed defect levels are not limited by a band gap problem, despite Kohn-Sham gaps much smaller than the experimental gap. As in GaAs, [P.A. Schultz and O.A. von Lilienfeld, Modeling Simul. Mater. Sci. Eng. 17, 084007 (2009)], defects in GaP and InP exhibit great complexity---multitudes of charge states, bistabilities, and negative U systems---but show similarities to each other (and to GaAs). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Characterization of Ignition and Combustion Properties of Nanowire-based Energetics

DTIC Science & Technology

2013-07-23

Sannia, A. Cincotti, G. Cao, Chem. Eng. Sci. 54 (15–16) (1999) 3053–3061. [4] C. Rossi, K. Zhang, D. Esteve, P. Alphonse , P. Tailhades, C. Vahlas, J...94 (5) (2003) 2923–2929. [30] K. Zhang, C. Rossi, G.A.A. Rodriguez, C. Tenail- leau, P. Alphonse , Appl. Phys. Lett. 91 (11) (2007) 113117/1–113117/3...Pister, Smart Mater. Struct. 10(6), 1145 (2001). 8C. Rossi, K. Zhang, D. Esteve, P. Alphonse , P. Tailhades, and C. Vahlas, J. Microelectromech. Syst. 16

WITHDRAWN: A novel nano-hydroxyapatite - PMMA hybrid scaffolds adopted by conjugated thermal induced phase separation (TIPS) and wet-chemical approach: Analysis of its mechanical and biological properties.

PubMed

G, Radha; S, Balakumar; Venkatesan, Balaji; Vellaichamy, Elangovan

2017-04-01

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Mater. Sci. Eng.: C, 73 (2017) 164–172, 10.1016/http://dx.doi.org/j.msec.2016.12.133. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal. Copyright © 2016 Elsevier B.V. All rights reserved.

Pulsed Laser Deposition of High Tc Superconducting Thin Films

DTIC Science & Technology

1992-04-15

Torr. This pressure is Mg capture by 02 decreases the desorption , in agreement high compared to pressures employed for the commonly with our...34’/C). Microplasticity ’F. 1. Grunthaner and P. J. Grunthaner, Mater. Sci. Rep 1. 65 (1986) has been observed 7 in Y’SZ at 23 *C, and may be involved...2.72 3.25 ing to Yadavalli er al.,15 thermal desorption of Mg is in- 300 S 162 1.97 2.40 3.10 hibited by lower substrate temperature and Mg oxidation

Proceedings of the Japan - U.S. Conference on Composite Materials (6th) Held in Orlando, Florida on June 22-24, 1992

DTIC Science & Technology

1993-03-01

correlation was determined between the matrix microplastic flow and the global composite tensile stress-strain curve. Based on the knowledge of the...framentation of the elastic matrix to form remnant elastic pockets at Silw tip surrounded y the matrix plastic flow. The matrix microplasticity is also...Deformation of SiC-Al Composites.’ Mater. Sci. Engng., A131:55-68. 11. Hamann, R., P. F. Gobin, and R. Fougeres, 1990. "A Study of the Microplasticity of Some

Simulation of wind-driven dispersion of fire pollutants in a street canyon using FDS.

PubMed

Pesic, Dusica J; Blagojevic, Milan Dj; Zivkovic, Nenad V

2014-01-01

Air quality in urban areas attracts great attention due to increasing pollutant emissions and their negative effects on human health and environment. Numerous studies, such as those by Mouilleau and Champassith (J Loss Prevent Proc 22(3): 316-323, 2009), Xie et al. (J Hydrodyn 21(1): 108-117, 2009), and Yassin (Environ Sci Pollut Res 20(6): 3975-3988, 2013) focus on the air pollutant dispersion with no buoyancy effect or weak buoyancy effect. A few studies, such as those by Hu et al. (J Hazard Mater 166(1): 394-406, 2009; J Hazard Mater 192(3): 940-948, 2011; J Civ Eng Manag (2013)) focus on the fire-induced dispersion of pollutants with heat buoyancy release rate in the range from 0.5 to 20 MW. However, the air pollution source might very often be concentrated and intensive, as a consequence of the hazardous materials fire. Namely, transportation of fuel through urban areas occurs regularly, because it is often impossible to find alternative supply routes. It is accompanied with the risk of fire accident occurrences. Accident prevention strategies require analysis of the worst scenarios in which fire products jeopardize the exposed population and environment. The aim of this article is to analyze the impact of wind flow on air pollution and human vulnerability to fire products in a street canyon. For simulation of the gasoline tanker truck fire as a result of a multivehicle accident, computational fluid dynamics large eddy simulation method has been used. Numerical results show that the fire products flow vertically upward, without touching the walls of the buildings in the absence of wind. However, when the wind velocity reaches the critical value, the products touch the walls of the buildings on both sides of the street canyon. The concentrations of carbon monoxide and soot decrease, whereas carbon dioxide concentration increases with the rise of height above the street canyon ground level. The longitudinal concentration of the pollutants inside the street increases with the rise of the wind velocity at the roof level of the street canyon.

Molecular-dynamics simulations of thin films with a free surface

NASA Astrophysics Data System (ADS)

Peter, Simone; Meyer, Hendrik; Baschnagel, Joerg

2007-03-01

We present results [1,2] from molecular-dynamics simulations for a model of non-entangled short polymer chains in a free standing and a supported film geometry. We investigate the influence of confinement on static and dynamic properties of the melt. We find that the relaxation at the surfaces is faster in comparison to the bulk. We perform a layer-resolved analysis of the dynamics and show that it is possible to associate a gradient in critical temperatures Tc(y) with the gradient in the relaxation dynamics. This finding is in qualitative agreement with experimental results on supported polystyrene (PS) films [Ellison et al, Nat. Mater. 2, 695 (2003)]. Furthermore we show that the y-dependence of Tc(y) can be expressed in terms of the depression of Tc(h), the global Tc for a film of thickness h, if we assume that Tc(h) is the arithmetic mean of Tc(y) and parameterize the depression of Tc(h) by Tc(h)=Tc/(1+h0/h), a formula suggested by Herminghaus et al [Eur. Phys. J E 5, 531 (2001)] for the reduction of the glass transition temperature in supported PS films. We demonstrate the validity of this formula by comparing our simulation results to results from other simulations and experiments. [1] S. Peter, H. Meyer and J. Baschnagel, J. Polym. Sci. B, 44, 2951 (2006) [2] S. Peter, H. Meyer, J. Baschnagel and R, Seemann, J. Phys: Condens. Matter (2007)

Analysis of the application of the generalized monod kinetics model to describe the human corneal oxygen-consumption rate during soft contact lens wear.

PubMed

Compañ, V; Aguilella-Arzo, M; Del Castillo, L F; Hernández, S I; Gonzalez-Meijome, J M

2017-11-01

This work is an analysis of the application of the generalized Monod kinetics model describing human corneal oxygen consumption during soft contact lens wear to models previously used by Chhabra et al. (J Biomed Mater Res B Appl Biomater, 2009a;90:202-209, Optom Vis Sci 2009b;86:454-466) and Larrea and Büchler (Invest Ophthalmol Vis Sci 2009;50:1076-1080). We use oxygen tension from in vivo estimations provided by Bonanno [Bonanno et al., Invest Ophthalmol Vis Sci 2002;43:371-376, and Bonanno et al 2009]. We consider four hydrogel and six silicone hydrogel lenses. The cornea is considered a single homogeneous layer, with constant oxygen permeability regardless of the type of lens worn. Our calculations yield different values for the maximum oxygen consumption rate Q c,max , whith differents oxygen tensions (high and low p c ) at the cornea-tears interface. Surprisingly, for both models, we observe an increase in oxygen consumption near an oxygen tension of 105 mmHg until a maximum is reached, then decreasing for higher levels of oxygen pressure. That is, when lowering the pressure of oxygen, the parameter Q c,max initially increases depending on the intensity of the change in pressure. Which, it could be related with the variation of the pH. Furthermore, it is also noted that to greater reductions in pressure, this parameter decreases, possibly due to changes in the concentration of glucose related to the anaerobic respiration. The averaged in vivo human corneal oxygen consumption rate of 1.47 × 10 -4 cm 3 of O 2 /cm 3 tissue s, with Monod kinetics model, considering all the lenses studied, is smaller than the average oxygen consumption rate value obtained using the Larrea and Büchler model. The impact that these calculations have on the oxygen partial pressure available at different depths in the corneal tissue is presented and discussed, taking into consideration previous models used in this study. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2269-2281, 2017. © 2016 Wiley Periodicals, Inc.

The simulated clinical environment: Cognitive and emotional impact among undergraduates.

PubMed

Tremblay, Marie-Laurence; Lafleur, Alexandre; Leppink, Jimmie; Dolmans, Diana H J M

2017-02-01

Simulated clinical immersion (SCI) is used in undergraduate healthcare programs to expose the learner to real-life situations in authentic simulated clinical environments. For novices, the environment in which the simulation occurs can be distracting and stressful, hence potentially compromising learning. This study aims to determine whether SCI (with environment) imposes greater extraneous cognitive load and stress on undergraduate pharmacy students than simulated patients (SP) (without environment). It also aims to explore how features of the simulated environment influence students' perception of learning. In this mixed-methods study, 143 undergraduate pharmacy students experienced both SCI and SP in a crossover design. After the simulations, participants rated their cognitive load and emotions. Thirty-five students met in focus groups to explore their perception of learning in simulation. Intrinsic and extraneous cognitive load and stress scores in SCI were significantly but modestly higher compared to SP. Qualitative findings reveal that the physical environment in SCI generated more stress and affected students? focus. In SP, students concentrated on clinical reasoning. SCI stimulated a focus on data collection but impeded in-depth problem solving processes. The physical environment in simulation influences what and how students learn. SCI was reported as more cognitively demanding than SP. Our findings emphasize the need for the development of adapted instructional design guidelines in simulation for novices.

A numerical study on the influence of the Portevin Le Chatelier effect on necking in an aluminium alloy

NASA Astrophysics Data System (ADS)

Hopperstad, O. S.; Børvik, T.; Berstad, T.; Lademo, O.-G.; Benallal, A.

2007-10-01

The constitutive relation proposed by McCormick (1988 Acta Metall. 36 3061-7) for materials exhibiting negative steady-state strain-rate sensitivity and the Portevin-Le Chatelier (PLC) effect is incorporated into an elastic-viscoplastic model for metals with plastic anisotropy. The constitutive model is implemented in LS-DYNA for corotational shell elements. Plastic anisotropy is taken into account by use of the yield criterion Yld2000/Yld2003 proposed by Barlat et al (2003 J. Plast. 19 1297-319) and Aretz (2004 Modelling Simul. Mater. Sci. Eng. 12 491-509). The parameters of the constitutive equations are determined for a rolled aluminium alloy (AA5083-H116) exhibiting negative steady-state strain-rate sensitivity and serrated yielding. The parameter identification is based on existing experimental data. A numerical investigation is conducted to determine the influence of the PLC effect on the onset of necking in uniaxial and biaxial tension for different overall strain rates. The numerical simulations show that the PLC effect leads to significant reductions in the strain to necking for both uniaxial and biaxial stress states. Increased surface roughness with plastic deformation is predicted for strain rates giving serrated yielding in uniaxial tension. It is likely that this is an important reason for the reduced critical strains. The characteristics of the deformation bands (orientation, width, velocity and strain rate) are also studied.

Simulated spinal cerebrospinal fluid leak repair: an educational model with didactic and technical components.

PubMed

Ghobrial, George M; Anderson, Paul A; Chitale, Rohan; Campbell, Peter G; Lobel, Darlene A; Harrop, James

2013-10-01

In the era of surgical resident work hour restrictions, the traditional apprenticeship model may provide fewer hours for neurosurgical residents to hone technical skills. Spinal dura mater closure or repair is 1 skill that is infrequently encountered, and persistent cerebrospinal fluid leaks are a potential morbidity. To establish an educational curriculum to train residents in spinal dura mater closure with a novel durotomy repair model. The Congress of Neurological Surgeons has developed a simulation-based model for durotomy closure with the ongoing efforts of their simulation educational committee. The core curriculum consists of didactic training materials and a technical simulation model of dural repair for the lumbar spine. Didactic pretest scores ranged from 4/11 (36%) to 10/11 (91%). Posttest scores ranged from 8/11 (73%) to 11/11 (100%). Overall, didactic improvements were demonstrated by all participants, with a mean improvement between pre- and posttest scores of 1.17 (18.5%; P = .02). The technical component consisted of 11 durotomy closures by 6 participants, where 4 participants performed multiple durotomies. Mean time to closure of the durotomy ranged from 490 to 546 seconds in the first and second closures, respectively (P = .66), whereby the median leak rate improved from 14 to 7 (P = .34). There were also demonstrative technical improvements by all. Simulated spinal dura mater repair appears to be a potentially valuable tool in the education of neurosurgery residents. The combination of a didactic and technical assessment appears to be synergistic in terms of educational development.

Precipitation behavior in a nitride-strengthened martensitic heat resistant steel during hot deformation.

PubMed

Zhang, Wenfeng; Su, Qingyong; Xu, Mi; Yan, Wei

2015-09-01

The stress relaxation curves for three different hot deformation processes in the temperature range of 750-1000 °C were studied to develop an understanding of the precipitation behavior in a nitride-strengthened martensitic heat resistant steel (Zhang et al., Mater. Sci. Eng. A, 2015) [1]. This data article provides supporting data and detailed information on how to accurately analysis the stress relaxation data. The statistical analysis of the stress peak curves, including the number of peaks, the intensity of the peaks and the integral value of the pumps, was carried out. Meanwhile, the XRD energy spectrum data was also calculated in terms of lattice distortion.

Precipitation behavior in a nitride-strengthened martensitic heat resistant steel during hot deformation

PubMed Central

Zhang, Wenfeng; Su, Qingyong; Xu, Mi; Yan, Wei

2015-01-01

The stress relaxation curves for three different hot deformation processes in the temperature range of 750–1000 °C were studied to develop an understanding of the precipitation behavior in a nitride-strengthened martensitic heat resistant steel (Zhang et al., Mater. Sci. Eng. A, 2015) [1]. This data article provides supporting data and detailed information on how to accurately analysis the stress relaxation data. The statistical analysis of the stress peak curves, including the number of peaks, the intensity of the peaks and the integral value of the pumps, was carried out. Meanwhile, the XRD energy spectrum data was also calculated in terms of lattice distortion. PMID:26306310

The Simulation of Read-time Scalable Coherent Interface

NASA Technical Reports Server (NTRS)

Li, Qiang; Grant, Terry; Grover, Radhika S.

1997-01-01

Scalable Coherent Interface (SCI, IEEE/ANSI Std 1596-1992) (SCI1, SCI2) is a high performance interconnect for shared memory multiprocessor systems. In this project we investigate an SCI Real Time Protocols (RTSCI1) using Directed Flow Control Symbols. We studied the issues of efficient generation of control symbols, and created a simulation model of the protocol on a ring-based SCI system. This report presents the results of the study. The project has been implemented using SES/Workbench. The details that follow encompass aspects of both SCI and Flow Control Protocols, as well as the effect of realistic client/server processing delay. The report is organized as follows. Section 2 provides a description of the simulation model. Section 3 describes the protocol implementation details. The next three sections of the report elaborate on the workload, results and conclusions. Appended to the report is a description of the tool, SES/Workbench, used in our simulation, and internal details of our implementation of the protocol.

Cohesion enhancing effect of magnesium in aluminum grain boundary: A first-principles determination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Shengjun; Freeman, Arthur J.; Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208

2012-06-04

The effect of magnesium on grain boundary cohesion in aluminum was investigated by means of first-principles calculations using the Rice-Wang model [Rice and Wang, Mater. Sci. Eng. A 107, 23 (1989)]. It is demonstrated that magnesium is a cohesion enhancer with a potency of -0.11 eV/atom. It is further determined through electronic structure and bonding character analysis that the cohesion enhancing property of magnesium is due to a charge transfer mechanism which is unusually strong and overcomes the negative result of the size effect mechanism. Consistent with experimental results, this work clarifies the controversy and establishes that Mg segregation doesmore » not contribute to stress corrosion cracking in Al alloys.« less

Development and initial evaluation of the SCI-FI/AT

PubMed Central

Jette, Alan M.; Slavin, Mary D.; Ni, Pengsheng; Kisala, Pamela A.; Tulsky, David S.; Heinemann, Allen W.; Charlifue, Susie; Tate, Denise G.; Fyffe, Denise; Morse, Leslie; Marino, Ralph; Smith, Ian; Williams, Steve

2015-01-01

Objectives To describe the domain structure and calibration of the Spinal Cord Injury Functional Index for samples using Assistive Technology (SCI-FI/AT) and report the initial psychometric properties of each domain. Design Cross sectional survey followed by computerized adaptive test (CAT) simulations. Setting Inpatient and community settings. Participants A sample of 460 adults with traumatic spinal cord injury (SCI) stratified by level of injury, completeness of injury, and time since injury. Interventions None Main outcome measure SCI-FI/AT Results Confirmatory factor analysis (CFA) and Item response theory (IRT) analyses identified 4 unidimensional SCI-FI/AT domains: Basic Mobility (41 items) Self-care (71 items), Fine Motor Function (35 items), and Ambulation (29 items). High correlations of full item banks with 10-item simulated CATs indicated high accuracy of each CAT in estimating a person's function, and there was high measurement reliability for the simulated CAT scales compared with the full item bank. SCI-FI/AT item difficulties in the domains of Self-care, Fine Motor Function, and Ambulation were less difficult than the same items in the original SCI-FI item banks. Conclusion With the development of the SCI-FI/AT, clinicians and investigators have available multidimensional assessment scales that evaluate function for users of AT to complement the scales available in the original SCI-FI. PMID:26010975

Development and initial evaluation of the SCI-FI/AT.

PubMed

Jette, Alan M; Slavin, Mary D; Ni, Pengsheng; Kisala, Pamela A; Tulsky, David S; Heinemann, Allen W; Charlifue, Susie; Tate, Denise G; Fyffe, Denise; Morse, Leslie; Marino, Ralph; Smith, Ian; Williams, Steve

2015-05-01

To describe the domain structure and calibration of the Spinal Cord Injury Functional Index for samples using Assistive Technology (SCI-FI/AT) and report the initial psychometric properties of each domain. Cross sectional survey followed by computerized adaptive test (CAT) simulations. Inpatient and community settings. A sample of 460 adults with traumatic spinal cord injury (SCI) stratified by level of injury, completeness of injury, and time since injury. None SCI-FI/AT RESULTS: Confirmatory factor analysis (CFA) and Item response theory (IRT) analyses identified 4 unidimensional SCI-FI/AT domains: Basic Mobility (41 items) Self-care (71 items), Fine Motor Function (35 items), and Ambulation (29 items). High correlations of full item banks with 10-item simulated CATs indicated high accuracy of each CAT in estimating a person's function, and there was high measurement reliability for the simulated CAT scales compared with the full item bank. SCI-FI/AT item difficulties in the domains of Self-care, Fine Motor Function, and Ambulation were less difficult than the same items in the original SCI-FI item banks. With the development of the SCI-FI/AT, clinicians and investigators have available multidimensional assessment scales that evaluate function for users of AT to complement the scales available in the original SCI-FI.

Diagnostic accuracy of evoked potentials for functional impairment after contusive spinal cord injury in adult rats.

PubMed

Thirumala, Parthasarathy; Zhou, James; Krishnan, Rohan; Manem, Nihita; Umredkar, Shreya; Hamilton, D K; Balzer, Jeffrey R; Oudega, Martin

2016-03-01

Iatrogenic spinal cord injury (SCI) is a cause of potentially debilitating post-operative neurologic complications. Currently, intra-operative neurophysiological monitoring (IONM) via somatosensory evoked potentials and motor-evoked potentials is used to detect and prevent impending SCI. However, no empirically validated interventions exist to halt the progression of iatrogenic SCI once it is detected. This is in part due to the lack of a suitable translational model that mimics the circumstances surrounding iatrogenic SCI detected via IONM. Here, we evaluate a model of simulated contusive iatrogenic SCI detected via IONM in adult female Sprague-Dawley rats. We show that transient losses of somatosensory evoked potentials responses are 88.24% sensitive (95% confidence interval [CI] 63.53-98.20) and 80% specific (95% CI 51.91-95.43) for significant functional impairment following simulated iatrogenic SCI. Similarly, we show that transient losses in motor-evoked potentials responses are 70.83% sensitive (95% CI 48.91-87.33) and 100% specific (95% CI 62.91-100.00) for significant functional impairment following simulated iatrogenic SCI. These results indicate that our model is a suitable replica of the circumstances surrounding clinical iatrogenic SCI. Copyright © 2015 Elsevier Ltd. All rights reserved.

Science Classroom Inquiry (SCI) Simulations: A Novel Method to Scaffold Science Learning

PubMed Central

Peffer, Melanie E.; Beckler, Matthew L.; Schunn, Christian; Renken, Maggie; Revak, Amanda

2015-01-01

Science education is progressively more focused on employing inquiry-based learning methods in the classroom and increasing scientific literacy among students. However, due to time and resource constraints, many classroom science activities and laboratory experiments focus on simple inquiry, with a step-by-step approach to reach predetermined outcomes. The science classroom inquiry (SCI) simulations were designed to give students real life, authentic science experiences within the confines of a typical classroom. The SCI simulations allow students to engage with a science problem in a meaningful, inquiry-based manner. Three discrete SCI simulations were created as website applications for use with middle school and high school students. For each simulation, students were tasked with solving a scientific problem through investigation and hypothesis testing. After completion of the simulation, 67% of students reported a change in how they perceived authentic science practices, specifically related to the complex and dynamic nature of scientific research and how scientists approach problems. Moreover, 80% of the students who did not report a change in how they viewed the practice of science indicated that the simulation confirmed or strengthened their prior understanding. Additionally, we found a statistically significant positive correlation between students’ self-reported changes in understanding of authentic science practices and the degree to which each simulation benefitted learning. Since SCI simulations were effective in promoting both student learning and student understanding of authentic science practices with both middle and high school students, we propose that SCI simulations are a valuable and versatile technology that can be used to educate and inspire a wide range of science students on the real-world complexities inherent in scientific study. PMID:25786245

Science classroom inquiry (SCI) simulations: a novel method to scaffold science learning.

PubMed

Peffer, Melanie E; Beckler, Matthew L; Schunn, Christian; Renken, Maggie; Revak, Amanda

2015-01-01

Science education is progressively more focused on employing inquiry-based learning methods in the classroom and increasing scientific literacy among students. However, due to time and resource constraints, many classroom science activities and laboratory experiments focus on simple inquiry, with a step-by-step approach to reach predetermined outcomes. The science classroom inquiry (SCI) simulations were designed to give students real life, authentic science experiences within the confines of a typical classroom. The SCI simulations allow students to engage with a science problem in a meaningful, inquiry-based manner. Three discrete SCI simulations were created as website applications for use with middle school and high school students. For each simulation, students were tasked with solving a scientific problem through investigation and hypothesis testing. After completion of the simulation, 67% of students reported a change in how they perceived authentic science practices, specifically related to the complex and dynamic nature of scientific research and how scientists approach problems. Moreover, 80% of the students who did not report a change in how they viewed the practice of science indicated that the simulation confirmed or strengthened their prior understanding. Additionally, we found a statistically significant positive correlation between students' self-reported changes in understanding of authentic science practices and the degree to which each simulation benefitted learning. Since SCI simulations were effective in promoting both student learning and student understanding of authentic science practices with both middle and high school students, we propose that SCI simulations are a valuable and versatile technology that can be used to educate and inspire a wide range of science students on the real-world complexities inherent in scientific study.

Dynamic mechanical characterization of aluminum: analysis of strain-rate-dependent behavior

NASA Astrophysics Data System (ADS)

Rahmat, Meysam

2018-05-01

A significant number of materials show different mechanical behavior under dynamic loads compared to quasi-static (Salvado et al. in Prog. Mater. Sci. 88:186-231, 2017). Therefore, a comprehensive study of material dynamic behavior is essential for applications in which dynamic loads are dominant (Li et al. in J. Mater. Process. Technol. 255:373-386, 2018). In this work, aluminum 6061-T6, as an example of ductile alloys with numerous applications including in the aerospace industry, has been studied under quasi-static and dynamic tensile tests with strain rates of up to 156 s^{-1}. Dogbone specimens were designed, instrumented and tested with a high speed servo-hydraulic load frame, and the results were validated with the literature. It was observed that at a strain rate of 156 s^{-1} the yield and ultimate strength increased by 31% and 33% from their quasi-static values, respectively. Moreover, the failure elongation and fracture energy per unit volume also increased by 18% and 52%, respectively. A Johnson-Cook model was used to capture the behavior of the material at different strain rates, and a modified version of this model was presented to enhance the capabilities of the original model, especially in predicting material properties close to the failure point. Finally, the fracture surfaces of specimens tested under quasi-static and dynamic loads were compared and conclusions about the differences were drawn.

The spinal cord dura mater reaction to nitinol and titanium alloy particles: a 1-year study in rabbits

PubMed Central

Rhalmi, Souad; Charette, Sylvie; Assad, Michel; Coillard, Christine

2007-01-01

This investigation was undertaken to simulate in an animal model the particles released from a porous nitinol interbody fusion device and to evaluate its consequences on the dura mater, spinal cord and nerve roots, lymph nodes (abdominal para-aortic), and organs (kidneys, spleen, pancreas, liver, and lungs). Our objective was to evaluate the compatibility of the nitinol particles with the dura mater in comparison with titanium alloy. In spite of the great use of metallic devices in spine surgery, the proximity of the spinal cord to the devices raised concerns about the effect of the metal debris that might be released onto the neural tissue. Forty-five New Zealand white female rabbits were divided into three groups: nitinol (treated: N = 4 per implantation period), titanium (treated: N = 4 per implantation period), and sham rabbits (control: N = 1 per observation period). The nitinol and titanium alloy particles were implanted in the spinal canal on the dura mater at the lumbar level L2–L3. The rabbits were sacrificed at 1, 4, 12, 26, and 52 weeks. Histologic sections from the regional lymph nodes, organs, from remote and implantation sites, were analyzed for any abnormalities and inflammation. Regardless of the implantation time, both nitinol and titanium particles remained at the implantation site and clung to the spinal cord lining soft tissue of the dura mater. The inflammation was limited to the epidural space around the particles and then reduced from acute to mild chronic during the follow-up. The dura mater, sub-dural space, nerve roots, and the spinal cord were free of reaction. No particles or abnormalities were found either in the lymph nodes or in the organs. In contact with the dura, the nitinol elicits an inflammatory response similar to that of titanium. The tolerance of nitinol by a sensitive tissue such as the dura mater during the span of 1 year of implantation demonstrated the safety of nitinol and its potential use as an intervertebral fusion device. PMID:17334794

Phonon structures of GaN-based random semiconductor alloys

NASA Astrophysics Data System (ADS)

Zhou, Mei; Chen, Xiaobin; Li, Gang; Zheng, Fawei; Zhang, Ping

2017-12-01

Accurate modeling of thermal properties is strikingly important for developing next-generation electronics with high performance. Many thermal properties are closely related to phonon dispersions, such as sound velocity. However, random substituted semiconductor alloys AxB1-x usually lack translational symmetry, and simulation with periodic boundary conditions often requires large supercells, which makes phonon dispersion highly folded and hardly comparable with experimental results. Here, we adopt a large supercell with randomly distributed A and B atoms to investigate substitution effect on the phonon dispersions of semiconductor alloys systematically by using phonon unfolding method [F. Zheng, P. Zhang, Comput. Mater. Sci. 125, 218 (2016)]. The results reveal the extent to which phonon band characteristics in (In,Ga)N and Ga(N,P) are preserved or lost at different compositions and q points. Generally, most characteristics of phonon dispersions can be preserved with indium substitution of gallium in GaN, while substitution of nitrogen with phosphorus strongly perturbs the phonon dispersion of GaN, showing a rapid disintegration of the Bloch characteristics of optical modes and introducing localized impurity modes. In addition, the sound velocities of both (In,Ga)N and Ga(N,P) display a nearly linear behavior as a function of substitution compositions. Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjb/e2017-80481-0.

Physics of bandgap formation in Cu-Sb-Se based novel thermoelectrics: the role of Sb valency and Cu d levels.

PubMed

Do, Dat; Ozolins, Vidvuds; Mahanti, S D; Lee, Mal-Soon; Zhang, Yongsheng; Wolverton, C

2012-10-17

In this paper we discuss the results of ab initio electronic structure calculations for Cu(3)SbSe(4) (Se4) and Cu(3)SbSe(3) (Se3), two narrow bandgap semiconductors of thermoelectric interest. We find that Sb is trivalent in both the compounds, in contrast to a simple nominal valence (ionic) picture which suggests that Sb should be 5 + in Se4. The gap formation in Se4 is quite subtle, with hybridization between Sb 5s and the neighboring Se 4s, 4p orbitals, position of Cu d states, and non-local exchange interaction, each playing significant roles. Thermopower calculations show that Se4 is a better p-type system. Our theoretical results for Se4 agree very well with recent experimental results obtained by Skoug et al (2011 Sci. Adv. Mater. 3 602).

Experimental invalidation of phase-transition-induced elastic softening in CrN

NASA Astrophysics Data System (ADS)

Wang, Shanmin; Yu, Xiaohui; Zhang, Jianzhong; Chen, Miao; Zhu, Jinlong; Wang, Liping; He, Duanwei; Lin, Zhijun; Zhang, Ruifeng; Leinenweber, Kurt; Zhao, Yusheng

2012-08-01

We report experimental results of phase stability and incompressibility of CrN. The obtained bulk moduli for cubic and orthorhombic CrN are 257 and 262 GPa, respectively. These results invalidate the conclusion of phase-transition-induced elastic softening recently reported based on nonmagnetic simulations for cubic CrN [Nature Mater.NMAACR1476-112210.1038/nmat2549 8, 947 (2009)]. On the other hand, they provide the only experimental evidence to support the computational models involving the local magnetic moment of Cr atoms [Nature Mater.NMAACR1476-112210.1038/nmat2722 9, 283 (2010)], indicating that atomic spin has a profound influence on the material's elastic properties. We also demonstrate that nonstoichiometry in CrNx has strong effects on its structural stability.

Simulated microgravity facilitates cell migration and neuroprotection after bone marrow stromal cell transplantation in spinal cord injury

PubMed Central

2013-01-01

Introduction Recently, cell-based therapy has gained significant attention for the treatment of central nervous system diseases. Although bone marrow stromal cells (BMSCs) are considered to have good engraftment potential, challenges due to in vitro culturing, such as a decline in their functional potency, have been reported. Here, we investigated the efficacy of rat BMSCs (rBMSCs) cultured under simulated microgravity conditions, for transplantation into a rat model of spinal cord injury (SCI). Methods rBMSCs were cultured under two different conditions: standard gravity (1G) and simulated microgravity attained by using the 3D-clinostat. After 7 days of culture, the rBMSCs were analyzed morphologically, with RT-PCR and immunostaining, and were used for grafting. Adult rats were used for constructing SCI models by using a weight-dropping method and were grouped into three experimental groups for comparison. rBMSCs cultured under 1 g and simulated microgravity were transplanted intravenously immediately after SCI. We evaluated the hindlimb functional improvement for 3 weeks. Tissue repair after SCI was examined by calculating the cavity area ratio and immunohistochemistry. Results rBMSCs cultured under simulated microgravity expressed Oct-4 and CXCR4, in contrast to those cultured under 1 g conditions. Therefore, rBMSCs cultured under simulated microgravity were considered to be in an undifferentiated state and thus to possess high migration ability. After transplantation, grafted rBMSCs cultured under microgravity exhibited greater survival at the periphery of the lesion, and the motor functions of the rats that received these grafts improved significantly compared with the rats that received rBMSCs cultured in 1 g. In addition, rBMSCs cultured under microgravity were thought to have greater trophic effects on reestablishment and survival of host spinal neural tissues because cavity formations were reduced, and apoptosis-inhibiting factor expression was high at the periphery of the SCI lesion. Conclusions Here we show that transplantation of rBMSCs cultured under simulated microgravity facilitates functional recovery from SCI rather than those cultured under 1 g conditions. PMID:23548163

Tailoring Mater-Bi properties by the use of a biowaste-derived additive

NASA Astrophysics Data System (ADS)

Cerruti, Pierfrancesco; Santagata, Gabriella; Gomez d'Ayala, Giovanna; Malinconico, Mario; Ambrogi, Veronica; Carfagna, Cosimo; Persico, Paola

2010-06-01

In this work, a polyphenol-containing extract from winery bio-waste (EP) has been used as additive to tailor Mater-Bi properties. EP was able to efficiently modulate both polymer processing and mechanical, thermal and biodegradation properties. EP decreased the melt viscosity, behaved as a Mater-Bi plasticizer and delayed the Mater-Bi crosslinking process occurring upon thermal aging. Finally, the biodisintegration rate of doped Mater-Bi decreased, thus indicating that EP interfered with the microbial digestion of the polymer films.

Effect of quercetin on plasma extravasation in rat CNS and dura mater by ACE and NEP inhibition.

PubMed

Cyrino, Luiz A R; Cardoso, Ronie C F; Hackl, Luciane P N; Nicolau, Mauro

2002-09-01

The effects of quercetin on substance P-induced plasma protein extravasation (PE) in the rat dura mater, cerebellum, olfactory bulb and cortex and also its modulation by endopeptidases, angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) were studied. PE was assessed by photometric measurement of extravasated Evans blue. Substance P (SP) and NEP or ACE inhibitors increased the PE in dura mater. Pretreatment with captopril or phosphoramidon potentiated PE induced by SP in the dura mater and cerebellum, respectively. Quercetin increased the PE in the dura mater, cerebellum and cortex. Further results suggested that the PE induced by SP in the dura mater was enhanced by pretreatment with quercetin, similar to that observed with selective peptidase inhibitors. Quercetin-stimulated extravasation in all tissues was abolished by NK-1 receptor blockade. These results suggest that quercetin increases PE in the dura mater and CNS tissues by inhibiting NEP and/or ACE, showing that the effect induced in the dura mater, cerebellum and cortex occurs through endogenous SP accumulation. Copyright 2002 John Wiley & Sons, Ltd.

Quantification of oxide particle composition in model oxide dispersion strengthened steel alloys.

PubMed

London, A J; Lozano-Perez, S; Moody, M P; Amirthapandian, S; Panigrahi, B K; Sundar, C S; Grovenor, C R M

2015-12-01

Oxide dispersion strengthened ferritic steels (ODS) are being considered for structural components of future designs of fission and fusion reactors because of their impressive high-temperature mechanical properties and resistance to radiation damage, both of which arise from the nanoscale oxide particles they contain. Because of the critical importance of these nanoscale phases, significant research activity has been dedicated to analysing their precise size, shape and composition (Odette et al., Annu. Rev. Mater. Res. 38 (2008) 471-503 [1]; Miller et al., Mater. Sci. Technol. 29(10) (2013) 1174-1178 [2]). As part of a project to develop new fuel cladding alloys in India, model ODS alloys have been produced with the compositions, Fe-0.3Y2O3, Fe-0.2Ti-0.3Y2O3 and Fe-14Cr-0.2Ti-0.3Y2O3. The oxide particles in these three model alloys have been studied by APT in their as-received state and following ion irradiation (as a proxy for neutron irradiation) at various temperatures. In order to adequately quantify the composition of the oxide clusters, several difficulties must be managed, including issues relating to the chemical identification (ranging and variable peak-overlaps); trajectory aberrations and chemical structure; and particle sizing. This paper presents how these issues can be addressed by the application of bespoke data analysis tools and correlative microscopy. A discussion follows concerning the achievable precision in these measurements, with reference to the fundamental limiting factors. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of re-ageing on a novel thermomechanical treatment for improving the mechanical properties of AA2139 aerospace aluminium alloys

NASA Astrophysics Data System (ADS)

Ragkousis, A.; Bakare, F.; Babalola, M. I.

2017-11-01

This study presents the effects of a novel thermomechanical treatment on the mechanical properties of the AA2139 aerospace aluminium alloys. The novel treatment, which is comprised of a combination of under-aging, cold-rolling, and re-aging, was successfully employed by Wang et al (2014 Mater. Sci. Eng. A 607 313-7) to enhance the mechanical and microstructure properties of 6000 series aluminium alloys. The influence of under-ageing and re-aging parameters of the treatment on the AA2139 properties has been examined by tensile and hardness testing, differential scanning calorimetry, and thermoelectric power measurements. It was determined that a higher temperature under-ageing, combined with lower temperature and long duration re-ageing resulted in the most attractive mechanical properties, which significantly exceeded those of other traditional treatments. More specifically, a 175 °C/1.5 h under-ageing treatment, followed by a cold rolling reduction of 75% and a 110 °C/96 h re-ageing resulted in a yield strength of 554 MPa, an ultimate tensile strength of 618 MPa, and an elongation of 7.5%, far exceeding the strength requirements and 5% acceptable elongation for applications in the aerospace industry. These results, in conjunction with the results of the parallel study focusing on the effects of the cold-rolling component of the treatment (Bakare et al 2017 Mater. Res. Express 4) further reinforce the position that the treatment employed is superior to conventional ones for the 2139 alloy.

Forecasting Financial Resources for Future Traumatic Spinal Cord Injury Care Using Simulation Modeling.

PubMed

Ahn, Henry; Lewis, Rachel; Santos, Argelio; Cheng, Christiana L; Noonan, Vanessa K; Dvorak, Marcel F; Singh, Anoushka; Linassi, A Gary; Christie, Sean; Goytan, Michael; Atkins, Derek

2017-10-15

Survivors of traumatic spinal cord injury (tSCI) have intense healthcare needs during acute and rehabilitation care and often through the rest of life. To prepare for a growing and aging population, simulation modeling was used to forecast the change in healthcare financial resources and long-term patient outcomes between 2012 and 2032. The model was developed with data from acute and rehabilitation care facilities across Canada participating in the Access to Care and Timing project. Future population and tSCI incidence for 2012 and 2032 were predicted with data from Statistics Canada and the Canadian Institute for Health Information. The projected tSCI incidence for 2012 was validated with actual data from the Rick Hansen SCI Registry of the participating facilities. Using a medium growth scenario, in 2032, the projected median age of persons with tSCI is 57 and persons 61 and older will account for 46% of injuries. Admissions to acute and rehabilitation facilities in 2032 were projected to increase by 31% and 25%, respectively. Because of the demographic shift to an older population, an increase in total population life expectancy with tSCI of 13% was observed despite a 22% increase in total life years lost to tSCI between 2012 and 2032. Care cost increased 54%, and rest of life cost increased 37% in 2032, translating to an additional CAD $16.4 million. With the demographics and management of tSCI changing with an aging population, accurate projections for the increased demand on resources will be critical for decision makers when planning the delivery of healthcare after tSCI.

Graphene Foam: Uniaxial Tension Behavior and Fracture Mode Based on a Mesoscopic Model.

PubMed

Pan, Douxing; Wang, Chao; Wang, Tzu-Chiang; Yao, Yugui

2017-09-26

Because of the combined advantages of both porous materials and two-dimensional (2D) graphene sheets, superior mechanical properties of three-dimensional (3D) graphene foams have received much attention from material scientists and energy engineers. Here, a 2D mesoscopic graphene model (Modell. Simul. Mater. Sci. Eng. 2011, 19, 054003), was expanded into a 3D bonded graphene foam system by utilizing physical cross-links and van der Waals forces acting among different mesoscopic graphene flakes by considering the debonding behavior, to evaluate the uniaxial tension behavior and fracture mode based on in situ SEM tensile testing (Carbon 2015, 85, 299). We reasonably reproduced a multipeak stress-strain relationship including its obvious yielding plateau and a ductile fracture mode near 45° plane from the tensile direction including the corresponding fracture morphology. Then, a power scaling law of tensile elastic modulus with mass density and an anisotropic strain-dependent Poisson's ratio were both deduced. The mesoscopic physical mechanism of tensile deformation was clearly revealed through the local stress state and evolution of mesostructure. The fracture feature of bonded graphene foam and its thermodynamic state were directly navigated to the tearing pattern of mesoscopic graphene flakes. This study provides an effective way to understand the mesoscopic physical nature of 3D graphene foams, and hence it may contribute to the multiscale computations of micro/meso/macromechanical performances and optimal design of advanced graphene-foam-based materials.

Mesoscale Modeling of Nonlinear Elasticity and Fracture in Ceramic Polycrystals Under Dynamic Shear and Compression

DTIC Science & Technology

2012-08-01

investigation of heterogeneous microplasticity in ceramics deformed under high confining stresses. Mech. Mater. 37, 95–112. Zhang, K., Wu, M., Feng, R., 2005b...Simulation of microplasticity -induced deformation in uniaxially strained ceramics by 3-D Voronoi polycrystal modeling. Int. J. Plasticity 21, 801–834

Equation of state of paramagnetic CrN from ab initio molecular dynamics

NASA Astrophysics Data System (ADS)

Steneteg, Peter; Alling, Björn; Abrikosov, Igor A.

2012-04-01

The equation of state for chromium nitride has been debated in the literature in connection with a proposed collapse of its bulk modulus following the pressure-induced transition from the paramagnetic cubic phase to the antiferromagnetic orthorhombic phase [F. Rivadulla , Nature Mater.1476-112210.1038/nmat2549 8, 947 (2009); B. Alling , Nature Mater.1476-112210.1038/nmat2722 9, 283 (2010)]. Experimentally the measurements are complicated due to the low transition pressure, while theoretically the simulation of magnetic disorder represents a major challenge. Here a first-principles method is suggested for the calculation of thermodynamic properties of magnetic materials in their high-temperature paramagnetic phase. It is based on ab initio molecular dynamics and simultaneous redistributions of the disordered but finite local magnetic moments. We apply this disordered local moments molecular dynamics method to the case of CrN and simulate its equation of state. In particular the debated bulk modulus is calculated in the paramagnetic cubic phase and is shown to be very similar to that of the antiferromagnetic orthorhombic CrN phase for all considered temperatures.

Forecasting Financial Resources for Future Traumatic Spinal Cord Injury Care Using Simulation Modeling

PubMed Central

Ahn, Henry; Lewis, Rachel; Santos, Argelio; Cheng, Christiana L.; Dvorak, Marcel F.; Singh, Anoushka; Linassi, A. Gary; Christie, Sean; Goytan, Michael; Atkins, Derek

2017-01-01

Abstract Survivors of traumatic spinal cord injury (tSCI) have intense healthcare needs during acute and rehabilitation care and often through the rest of life. To prepare for a growing and aging population, simulation modeling was used to forecast the change in healthcare financial resources and long-term patient outcomes between 2012 and 2032. The model was developed with data from acute and rehabilitation care facilities across Canada participating in the Access to Care and Timing project. Future population and tSCI incidence for 2012 and 2032 were predicted with data from Statistics Canada and the Canadian Institute for Health Information. The projected tSCI incidence for 2012 was validated with actual data from the Rick Hansen SCI Registry of the participating facilities. Using a medium growth scenario, in 2032, the projected median age of persons with tSCI is 57 and persons 61 and older will account for 46% of injuries. Admissions to acute and rehabilitation facilities in 2032 were projected to increase by 31% and 25%, respectively. Because of the demographic shift to an older population, an increase in total population life expectancy with tSCI of 13% was observed despite a 22% increase in total life years lost to tSCI between 2012 and 2032. Care cost increased 54%, and rest of life cost increased 37% in 2032, translating to an additional CAD $16.4 million. With the demographics and management of tSCI changing with an aging population, accurate projections for the increased demand on resources will be critical for decision makers when planning the delivery of healthcare after tSCI. PMID:28594315

In silico modeling of axonal reconnection within a discrete fiber tract after spinal cord injury.

PubMed

Woolfe, Franco; Waxman, Stephen G; Hains, Bryan C

2007-02-01

Following spinal cord injury (SCI), descending axons that carry motor commands from the brain to the spinal cord are injured or transected, producing chronic motor dysfunction and paralysis. Reconnection of these axons is a major prerequisite for restoration of function after SCI. Thus far, only modest gains in motor function have been achieved experimentally or in the clinic after SCI, identifying the practical limitations of current treatment approaches. In this paper, we use an ordinary differential equation (ODE) to simulate the relative and synergistic contributions of several experimentally-established biological factors related to inhibition or promotion of axonal repair and restoration of function after SCI. The factors were mathematically modeled by the ODE. The results of our simulation show that in a model system, many factors influenced the achievability of axonal reconnection. Certain factors more strongly affected axonal reconnection in isolation, and some factors interacted in a synergistic fashion to produce further improvements in axonal reconnection. Our data suggest that mathematical modeling may be useful in evaluating the complex interactions of discrete therapeutic factors not possible in experimental preparations, and highlight the benefit of a combinatorial therapeutic approach focused on promoting axonal sprouting, attraction of cut ends, and removal of growth inhibition for achieving axonal reconnection. Predictions of this simulation may be of utility in guiding future experiments aimed at restoring function after SCI.

Quantitative comparisons between experimentally measured 2D carbon radiation and Monte Carlo impurity (MCI) code simulations

NASA Astrophysics Data System (ADS)

Evans, T. E.; Finkenthal, D. F.; Fenstermacher, M. E.; Leonard, A. W.; Porter, G. D.; West, W. P.

Experimentally measured carbon line emissions and total radiated power distributions from the DIII-D divertor and scrape-off layer (SOL) are compared to those calculated with the Monte Carlo impurity (MCI) model. A UEDGE [T.D. Rognlien et al., J. Nucl. Mater. 196-198 (1992) 347] background plasma is used in MCI with the Roth and Garcia-Rosales (RG-R) chemical sputtering model [J. Roth, C. García-Rosales, Nucl. Fusion 36 (1992) 196] and/or one of six physical sputtering models. While results from these simulations do not reproduce all of the features seen in the experimentally measured radiation patterns, the total radiated power calculated in MCI is in relatively good agreement with that measured by the DIII-D bolometric system when the Smith78 [D.L. Smith, J. Nucl. Mater. 75 (1978) 20] physical sputtering model is coupled to RG-R chemical sputtering in an unaltered UEDGE plasma. Alternatively, MCI simulations done with UEDGE background ion temperatures along the divertor target plates adjusted to better match those measured in the experiment resulted in three physical sputtering models which when coupled to the RG-R model gave a total radiated power that was within 10% of measured value.

Systematic investigations of low energy Ar ion beam sputtering of Si and Ag

NASA Astrophysics Data System (ADS)

Feder, R.; Frost, F.; Neumann, H.; Bundesmann, C.; Rauschenbach, B.

2013-12-01

Ion beam sputter deposition (IBD) delivers some intrinsic features influencing the growing film properties, because ion properties and geometrical process conditions generate different energy and spatial distributions of the sputtered and scattered particles. Even though IBD has been used for decades, the full capabilities are not investigated systematically and specifically used yet. Therefore, a systematic and comprehensive analysis of the correlation between the properties of the ion beam, the generated secondary particles and backscattered ions and the deposited films needs to be done.A vacuum deposition chamber has been set up which allows ion beam sputtering of different targets under variation of geometrical parameters (ion incidence angle, position of substrates and analytics in respect to the target) and of ion beam parameters (ion species, ion energy) to perform a systematic and comprehensive analysis of the correlation between the properties of the ion beam, the properties of the sputtered and scattered particles, and the properties of the deposited films. A set of samples was prepared and characterized with respect to selected film properties, such as thickness and surface topography. The experiments indicate a systematic influence of the deposition parameters on the film properties as hypothesized before. Because of this influence, the energy distribution of secondary particles was measured using an energy-selective mass spectrometer. Among others, experiments revealed a high-energetic maximum for backscattered primary ions, which shifts with increasing emission angle to higher energies. Experimental data are compared with Monte Carlo simulations done with the well-known Transport and Range of Ions in Matter, Sputtering version (TRIM.SP) code [J.P. Biersack, W. Eckstein, Appl. Phys. A: Mater. Sci. Process. 34 (1984) 73]. The thicknesses of the films are in good agreement with those calculated from simulated particle fluxes. For the positions of the high-energetic maxima in the energy distribution of the backscattered primary ions, a deviation between simulated and measured data was found, most likely originating in a higher energy loss under experimental conditions than considered in the simulation.

Control of rabbit dura mater optical properties with osmotical liquids

NASA Astrophysics Data System (ADS)

Yao, Lei; Cheng, Haiying; Luo, Qingming; Zhang, Wei; Zeng, Shaoqun; Tuchin, Valery V.

2002-04-01

An experimental study of controlling the optical properties of in vitro and in vivo rabbit dura mater with administration of osmotical agents, 40% glucose solution and glycerol, using video camera and spectrometer was presented. The preliminary results of experimental study of influence of osmotical liquids (glucose solutions, glycerol) on transmittance (in vitro) and reflectance (in vivo) spectra of rabbit dura mater were reported. The significant decreasing of the reflectance and increasing of the transmittance of dura mater under action of osmotical solutions were demonstrated. Experiments showed that administration of osmolytes to dura mater allowed for effective and temporary control of its optical characteristics, which made dura mater more transparent, increased the ability of light penetrating the tissue, and consequently improved the optical imaging depth. It is a significant study, which can improve penetration of optical imaging of cerebral function and acquire more information of the deep brain tissue.

Shallow layer simulation of heavy gas released on a slope in a calm ambient. Part II. Instantaneous releases.

PubMed

Hankin, Robin K S

2003-10-31

This paper assesses the value of shallow layer modelling for instantaneous releases of heavy gas over a slope using the established computer model TWODEE [R.K.S. Hankin, Heavy gas dispersion over complex terrain, Ph.D. thesis, Cambridge University, 1997; J. Hazard. Mater. 66 (1999) 211; J. Hazard. Mater. 66 (1999) 227; J. Hazard. Mater. 66 (1999) 239] and the experimental results of Schatzmann et al. [M. Schatzmann, K. Marotzke, J. Donat, Research on continuous and instantaneous heavy gas clouds, Contribution of sub-project EV 4T-0021-D to the final report of the joint CEC project, Technical report, Meteorological Institute, University of Hamburg, February 1991]. This is the second of a two-part paper; part I considered continuous releases using the same model, using the same entrainment parameters. Schatzmann et al. carried out instantaneous releases of heavy gas over three slopes; each experiment was repeated five times under nominally identical conditions. The goodness-of-fit measures (GFMs) of Hanna et al. [Atmos. Environ. 27A (15) (1993) 2265] are generalized to account for the multiple releases carried out by Schatzmann et al. Using these statistical GFMs, predicted peak concentrations are generally correct to within a factor of two; and cloud arrival times are generally late.

Mechanical Properties of Structural Polymers. Computer Simulations and Key Experiments

DTIC Science & Technology

1992-09-30

Technology", edited by R.W. Cahn, P. Haasen, and E.J. Kramer, (VCH: Weinheim, Germany) (vol. editor H. Mughrabi ) Vol. 6, in the press (1992). 14. A.S. Argon...34, Acta Metall. et Mater., submitted for publication. 5 32. A. Galeski, Z. Bartczak, A.S. Argon and R.E. Cohen, "Morphological Al - terations during

The collagenic architecture of human dura mater.

PubMed

Protasoni, Marina; Sangiorgi, Simone; Cividini, Andrea; Culuvaris, Gloria Tiffany; Tomei, Giustino; Dell'Orbo, Carlo; Raspanti, Mario; Balbi, Sergio; Reguzzoni, Marcella

2011-06-01

Human dura mater is the most external meningeal sheet surrounding the CNS. It provides an efficient protection to intracranial structures and represents the most important site for CSF turnover. Its intrinsic architecture is made up of fibrous tissue including collagenic and elastic fibers that guarantee the maintenance of its biophysical features. The recent technical advances in the repair of dural defects have allowed for the creation of many synthetic and biological grafts. However, no detailed studies on the 3D microscopic disposition of collagenic fibers in dura mater are available. The authors report on the collagenic 3D architecture of normal dura mater highlighting the orientation, disposition in 3 dimensions, and shape of the collagen fibers with respect to the observed layer. Thirty-two dura mater specimens were collected during cranial decompressive surgical procedures, fixed in 2.5% Karnovsky solution, and digested in 1 N NaOH solution. After a routine procedure, the specimens were observed using a scanning electron microscope. The authors distinguished the following 5 layers in the fibrous dura mater of varying thicknesses, orientation, and structures: bone surface, external median, vascular, internal median, and arachnoid layers. The description of the ultrastructural 3D organization of the different layers of dura mater will give us more information for the creation of synthetic grafts that are as similar as possible to normal dura mater. This description will be also related to the study of the neoplastic invasion.

Nascent energy distribution of the Criegee intermediate CH2OO from direct dynamics calculations of primary ozonide dissociation.

PubMed

Pfeifle, Mark; Ma, Yong-Tao; Jasper, Ahren W; Harding, Lawrence B; Hase, William L; Klippenstein, Stephen J

2018-05-07

Ozonolysis produces chemically activated carbonyl oxides (Criegee intermediates, CIs) that are either stabilized or decompose directly. This branching has an important impact on atmospheric chemistry. Prior theoretical studies have employed statistical models for energy partitioning to the CI arising from dissociation of the initially formed primary ozonide (POZ). Here, we used direct dynamics simulations to explore this partitioning for decomposition of c-C 2 H 4 O 3 , the POZ in ethylene ozonolysis. A priori estimates for the overall stabilization probability were then obtained by coupling the direct dynamics results with master equation simulations. Trajectories were initiated at the concerted cycloreversion transition state, as well as the second transition state of a stepwise dissociation pathway, both leading to a CI (H 2 COO) and formaldehyde (H 2 CO). The resulting CI energy distributions were incorporated in master equation simulations of CI decomposition to obtain channel-specific stabilized CI (sCI) yields. Master equation simulations of POZ formation and decomposition, based on new high-level electronic structure calculations, were used to predict yields for the different POZ decomposition channels. A non-negligible contribution of stepwise POZ dissociation was found, and new mechanistic aspects of this pathway were elucidated. By combining the trajectory-based channel-specific sCI yields with the channel branching fractions, an overall sCI yield of (48 ± 5)% was obtained. Non-statistical energy release was shown to measurably affect sCI formation, with statistical models predicting significantly lower overall sCI yields (∼30%). Within the range of experimental literature values (35%-54%), our trajectory-based calculations favor those clustered at the upper end of the spectrum.

Nascent energy distribution of the Criegee intermediate CH2OO from direct dynamics calculations of primary ozonide dissociation

NASA Astrophysics Data System (ADS)

Pfeifle, Mark; Ma, Yong-Tao; Jasper, Ahren W.; Harding, Lawrence B.; Hase, William L.; Klippenstein, Stephen J.

2018-05-01

Ozonolysis produces chemically activated carbonyl oxides (Criegee intermediates, CIs) that are either stabilized or decompose directly. This branching has an important impact on atmospheric chemistry. Prior theoretical studies have employed statistical models for energy partitioning to the CI arising from dissociation of the initially formed primary ozonide (POZ). Here, we used direct dynamics simulations to explore this partitioning for decomposition of c-C2H4O3, the POZ in ethylene ozonolysis. A priori estimates for the overall stabilization probability were then obtained by coupling the direct dynamics results with master equation simulations. Trajectories were initiated at the concerted cycloreversion transition state, as well as the second transition state of a stepwise dissociation pathway, both leading to a CI (H2COO) and formaldehyde (H2CO). The resulting CI energy distributions were incorporated in master equation simulations of CI decomposition to obtain channel-specific stabilized CI (sCI) yields. Master equation simulations of POZ formation and decomposition, based on new high-level electronic structure calculations, were used to predict yields for the different POZ decomposition channels. A non-negligible contribution of stepwise POZ dissociation was found, and new mechanistic aspects of this pathway were elucidated. By combining the trajectory-based channel-specific sCI yields with the channel branching fractions, an overall sCI yield of (48 ± 5)% was obtained. Non-statistical energy release was shown to measurably affect sCI formation, with statistical models predicting significantly lower overall sCI yields (˜30%). Within the range of experimental literature values (35%-54%), our trajectory-based calculations favor those clustered at the upper end of the spectrum.

21 CFR 882.5975 - Human dura mater.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Human dura mater. 882.5975 Section 882.5975 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5975 Human dura mater. (a...

21 CFR 882.5975 - Human dura mater.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Human dura mater. 882.5975 Section 882.5975 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5975 Human dura mater. (a...

21 CFR 882.5975 - Human dura mater.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Human dura mater. 882.5975 Section 882.5975 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5975 Human dura mater. (a...

21 CFR 882.5975 - Human dura mater.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Human dura mater. 882.5975 Section 882.5975 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5975 Human dura mater. (a...

21 CFR 882.5975 - Human dura mater.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Human dura mater. 882.5975 Section 882.5975 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5975 Human dura mater. (a...

Mechanical and thermal properties of bacterial-cellulose-fibre-reinforced Mater-Bi(®) bionanocomposite.

PubMed

Nainggolan, Hamonangan; Gea, Saharman; Bilotti, Emiliano; Peijs, Ton; Hutagalung, Sabar D

2013-01-01

The effects of the addition of fibres of bacterial cellulose (FBC) to commercial starch of Mater-Bi(®) have been investigated. FBC produced by cultivating Acetobacter xylinum for 21 days in glucose-based medium were purified by sodium hydroxide 2.5 wt % and sodium hypochlorite 2.5 wt % overnight, consecutively. To obtain water-free BC nanofibres, the pellicles were freeze dried at a pressure of 130 mbar at a cooling rate of 10 °C min(-1). Both Mater-Bi and FBC were blended by using a mini twin-screw extruder at 160 °C for 10 min at a rotor speed of 50 rpm. Tensile tests were performed according to ASTM D638 to measure the Young's modulus, tensile strength and elongation at break. A field emission scanning electron microscope was used to observe the morphology at an accelerating voltage of 10 kV. The crystallinity (T c) and melting temperature (T m) were measured by DSC. Results showed a significant improvement in mechanical and thermal properties in accordance with the addition of FBC into Mater-Bi. FBC is easily incorporated in Mater-Bi matrix and produces homogeneous Mater-Bi/FBC composite. The crystallinity of the Mater-Bi/FBC composites decrease in relation to the increase in the volume fraction of FBC.

Effect of native oxide layers on copper thin-film tensile properties: A reactive molecular dynamics study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skarlinski, Michael D., E-mail: michael.skarlinski@rochester.edu; Quesnel, David J.; Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627

2015-12-21

Metal-oxide layers are likely to be present on metallic nano-structures due to either environmental exposure during use, or high temperature processing techniques such as annealing. It is well known that nano-structured metals have vastly different mechanical properties from bulk metals; however, difficulties in modeling the transition between metallic and ionic bonding have prevented the computational investigation of the effects of oxide surface layers. Newly developed charge-optimized many body [Liang et al., Mater. Sci. Eng., R 74, 255 (2013)] potentials are used to perform fully reactive molecular dynamics simulations which elucidate the effects that metal-oxide layers have on the mechanical propertiesmore » of a copper thin-film. Simulated tensile tests are performed on thin-films while using different strain-rates, temperatures, and oxide thicknesses to evaluate changes in yield stress, modulus, and failure mechanisms. Findings indicate that copper-thin film mechanical properties are strongly affected by native oxide layers. The formed oxide layers have an amorphous structure with lower Cu-O bond-densities than bulk CuO, and a mixture of Cu{sub 2}O and CuO charge character. It is found that oxidation will cause modifications to the strain response of the elastic modulii, producing a stiffened modulii at low temperatures (<75 K) and low strain values (<5%), and a softened modulii at higher temperatures. While under strain, structural reorganization within the oxide layers facilitates brittle yielding through nucleation of defects across the oxide/metal interface. The oxide-free copper thin-film yielding mechanism is found to be a tensile-axis reorientation and grain creation. The oxide layers change the observed yielding mechanism, allowing for the inner copper thin-film to sustain an FCC-to-BCC transition during yielding. The mechanical properties are fit to a thermodynamic model based on classical nucleation theory. The fit implies that the oxidation of the films reduces the activation volume for yielding.« less

SciDAC Center for Gyrokinetic Particle Simulation of Turbulent Transport in Burning Plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Zhihong

2013-12-18

During the first year of the SciDAC gyrokinetic particle simulation (GPS) project, the GPS team (Zhihong Lin, Liu Chen, Yasutaro Nishimura, and Igor Holod) at the University of California, Irvine (UCI) studied the tokamak electron transport driven by electron temperature gradient (ETG) turbulence, and by trapped electron mode (TEM) turbulence and ion temperature gradient (ITG) turbulence with kinetic electron effects, extended our studies of ITG turbulence spreading to core-edge coupling. We have developed and optimized an elliptic solver using finite element method (FEM), which enables the implementation of advanced kinetic electron models (split-weight scheme and hybrid model) in the SciDACmore » GPS production code GTC. The GTC code has been ported and optimized on both scalar and vector parallel computer architectures, and is being transformed into objected-oriented style to facilitate collaborative code development. During this period, the UCI team members presented 11 invited talks at major national and international conferences, published 22 papers in peer-reviewed journals and 10 papers in conference proceedings. The UCI hosted the annual SciDAC Workshop on Plasma Turbulence sponsored by the GPS Center, 2005-2007. The workshop was attended by about fifties US and foreign researchers and financially sponsored several gradual students from MIT, Princeton University, Germany, Switzerland, and Finland. A new SciDAC postdoc, Igor Holod, has arrived at UCI to initiate global particle simulation of magnetohydrodynamics turbulence driven by energetic particle modes. The PI, Z. Lin, has been promoted to the Associate Professor with tenure at UCI.« less

Games and Simulations for Climate, Weather and Earth Science Education

NASA Astrophysics Data System (ADS)

Russell, R. M.

2014-12-01

We will demonstrate several interactive, computer-based simulations, games, and other interactive multimedia. These resources were developed for weather, climate, atmospheric science, and related Earth system science education. The materials were created by the UCAR Center for Science Education. These materials have been disseminated via our web site (SciEd.ucar.edu), webinars, online courses, teacher workshops, and large touchscreen displays in weather and Sun-Earth connections exhibits in NCAR's Mesa Lab facility in Boulder, Colorado. Our group has also assembled a web-based list of similar resources, especially simulations and games, from other sources that touch upon weather, climate, and atmospheric science topics. We'll briefly demonstrate this directory. More info available at: scied.ucar.edu/events/agu-2014-games-simulations-sessions

76 FR 36993 - Medical Devices; Neurological Devices; Clarification of Classification for Human Dura Mater...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-24

...; Clarification of Classification for Human Dura Mater; Technical Amendment AGENCY: Food and Drug Administration... amending the device regulations to clarify the applicability of the device classification for human dura..., human dura mater is now defined under 21 CFR 1271.3(d) as a HCT/P. As such, it is regulated under...

Autoantibody response against NALP5/MATER in primary ovarian insufficiency and in autoimmune Addison's disease.

PubMed

Brozzetti, Annalisa; Alimohammadi, Mohammad; Morelli, Silvia; Minarelli, Viviana; Hallgren, Åsa; Giordano, Roberta; De Bellis, Annamaria; Perniola, Roberto; Kämpe, Olle; Falorni, Alberto

2015-05-01

NACHT leucine-rich-repeat protein 5 (NALP5)/maternal antigen that embryo requires (MATER) is an autoantigen in hypoparathyroidism associated with autoimmune polyendocrine syndrome type 1 (APS1) but is also expressed in the ovary. Mater is an autoantigen in experimental autoimmune oophoritis. The objectives of the study were to determine the frequency of NALP5/MATER autoantibodies (NALP5/MATER-Ab) in women with premature ovarian insufficiency (POI) and in patients with autoimmune Addison's disease (AAD) and to evaluate whether inhibin chains are a target for autoantibodies in POI. Autoantibodies against NALP5/MATER and inhibin chains-α and -βA were determined by radiobinding assays in 172 patients with AAD without clinical signs of gonadal insufficiency, 41 women with both AAD and autoimmune POI [steroidogenic cell autoimmune POI (SCA-POI)], 119 women with idiopathic POI, 19 patients with APS1, and 211 healthy control subjects. NALP5/MATER-Ab were detected in 11 of 19 (58%) sera from APS1 patients, 12 of 172 (7%) AAD sera, 5 of 41 (12%) SCA-POI sera, 0 of 119 idiopathic POI sera and 1 of 211 healthy control sera (P < .001). None of 160 POI sera, including 41 sera from women with SCA-POI and 119 women with idiopathic POI, and none of 211 healthy control sera were positive for inhibin chain-α/βA autoantibodies. NALP5/MATER-Ab are associated with hypoparathyroidism in APS1 but are present also in patients with AAD and in women with SCA-POI without hypoparathyroidism. Inhibin chains do not appear to be likely candidate targets of autoantibodies in human POI.

Monitoring of tissue modification with optical coherence tomography

NASA Astrophysics Data System (ADS)

Zhang, Wei; Luo, Qingming; Yao, Lei; Cheng, Haiying; Zeng, Shaoqun

2002-04-01

An experimental monitoring of tissue modification of in vitro and in vivo rabbit dura mater with administration of osmotical agents, 40% glucose solution and glycerol, using optical coherence tomography was presented. The preliminary results of experimental study of influence of osmotical liquids (glucose solutions, glycerol) of rabbit dura mater were reported. The significant decreasing of the light from surface and increasing of the light from the deep of dura mater under action of osmotical solutions and the increasing of OCT imaging depth were demonstrated. Experiments showed that administration of osmolytes to dura mater allowed for effective and temporary control of its optical characteristics, which made dura mater more transparent, increased the ability of light penetrating the tissue, and consequently improved the optical imaging depth. It is a significant study, which can improve penetration of optical imaging of cerebral function and acquire more information of the deep brain tissue.

The application of operations research methodologies to the delivery of care model for traumatic spinal cord injury: the access to care and timing project.

PubMed

Noonan, Vanessa K; Soril, Lesley; Atkins, Derek; Lewis, Rachel; Santos, Argelio; Fehlings, Michael G; Burns, Anthony S; Singh, Anoushka; Dvorak, Marcel F

2012-09-01

The long-term impact of spinal cord injury (SCI) on the health care system imposes a need for greater efficiency in the use of resources and the management of care. The Access to Care and Timing (ACT) project was developed to model the health care delivery system in Canada for patients with traumatic SCI. Techniques from Operations Research, such as simulation modeling, were used to predict the impact of best practices and policy initiatives on outcomes related to both the system and patients. These methods have been used to solve similar problems in business and engineering and may offer a unique solution to the complexities encountered in SCI care delivery. Findings from various simulated scenarios, from the patients' point of injury to community re-integration, can be used to inform decisions on optimizing practice across the care continuum. This article describes specifically the methodology and implications of producing such simulations for the care of traumatic SCI in Canada. Future publications will report on specific practices pertaining to the access to specialized services and the timing of interventions evaluated using the ACT model. Results from this type of research will provide the evidence required to support clinical decision making, inform standards of care, and provide an opportunity to engage policymakers.

The Application of Operations Research Methodologies to the Delivery of Care Model for Traumatic Spinal Cord Injury: The Access to Care and Timing Project

PubMed Central

Noonan, Vanessa K.; Soril, Lesley; Atkins, Derek; Lewis, Rachel; Santos, Argelio; Fehlings, Michael G.; Burns, Anthony S.; Singh, Anoushka

2012-01-01

Abstract The long-term impact of spinal cord injury (SCI) on the health care system imposes a need for greater efficiency in the use of resources and the management of care. The Access to Care and Timing (ACT) project was developed to model the health care delivery system in Canada for patients with traumatic SCI. Techniques from Operations Research, such as simulation modeling, were used to predict the impact of best practices and policy initiatives on outcomes related to both the system and patients. These methods have been used to solve similar problems in business and engineering and may offer a unique solution to the complexities encountered in SCI care delivery. Findings from various simulated scenarios, from the patients' point of injury to community re-integration, can be used to inform decisions on optimizing practice across the care continuum. This article describes specifically the methodology and implications of producing such simulations for the care of traumatic SCI in Canada. Future publications will report on specific practices pertaining to the access to specialized services and the timing of interventions evaluated using the ACT model. Results from this type of research will provide the evidence required to support clinical decision making, inform standards of care, and provide an opportunity to engage policymakers. PMID:22800432

SciDAC-Data, A Project to Enabling Data Driven Modeling of Exascale Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mubarak, M.; Ding, P.; Aliaga, L.

The SciDAC-Data project is a DOE funded initiative to analyze and exploit two decades of information and analytics that have been collected by the Fermilab Data Center on the organization, movement, and consumption of High Energy Physics data. The project will analyze the analysis patterns and data organization that have been used by the NOvA, MicroBooNE, MINERvA and other experiments, to develop realistic models of HEP analysis workflows and data processing. The SciDAC-Data project aims to provide both realistic input vectors and corresponding output data that can be used to optimize and validate simulations of HEP analysis. These simulations aremore » designed to address questions of data handling, cache optimization and workflow structures that are the prerequisites for modern HEP analysis chains to be mapped and optimized to run on the next generation of leadership class exascale computing facilities. We will address the use of the SciDAC-Data distributions acquired from Fermilab Data Center’s analysis workflows and corresponding to around 71,000 HEP jobs, as the input to detailed queuing simulations that model the expected data consumption and caching behaviors of the work running in HPC environments. In particular we describe in detail how the Sequential Access via Metadata (SAM) data handling system in combination with the dCache/Enstore based data archive facilities have been analyzed to develop the radically different models of the analysis of HEP data. We present how the simulation may be used to analyze the impact of design choices in archive facilities.« less

Laser range profile of cones

NASA Astrophysics Data System (ADS)

Zhou, Wenzhen; Gong, Yanjun; Wang, Mingjun; Gong, Lei

2016-10-01

technology. Laser one-dimensional range profile can reflect the characteristics of the target shape and surface material. These techniques were motivated by applications of laser radar to target discrimination in ballistic missile defense. The radar equation of pulse laser about cone is given in this paper. This paper demonstrates the analytical model of laser one-dimensional range profile of cone based on the radar equation of the pulse laser. Simulations results of laser one-dimensional range profiles of some cones are given. Laser one-dimensional range profiles of cone, whose surface material with diffuse lambertian reflectance, is given in this paper. Laser one-dimensional range profiles of cone, whose surface mater with diffuse materials whose retroreflectance can be modeled closely with an exponential term that decays with increasing incidence angles, is given in this paper. Laser one-dimensional range profiles of different pulse width of cone is given in this paper. The influences of surface material, pulse width, attitude on the one-dimensional range are analyzed. The laser two-dimensional range profile is two-dimensional scattering imaging of pulse laser of target. The two-dimensional range profile of roughness target can provide range resolved information. An analytical model of two-dimensional laser range profile of cone is proposed. The simulations of two-dimensional laser range profiles of some cones are given. Laser two-dimensional range profiles of cone, whose surface mater with diffuse lambertian reflectance, is given in this paper. Laser two-dimensional range profiles of cone, whose surface mater with diffuse materials whose retroreflectance can be modeled closely with an exponential term that decays with increasing incidence angles, is given in this paper. The influence of pulse width, surface material on laser two-dimensional range profile is analyzed. Laser one-dimensional range profile and laser two-dimensional range profile are called as laser range profile (LRP).

Commnity Petascale Project for Accelerator Science And Simulation: Advancing Computational Science for Future Accelerators And Accelerator Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spentzouris, Panagiotis; /Fermilab; Cary, John

The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessarymore » accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.« less

High resolution transmission electron microscope Imaging and first-principles simulations of atomic-scale features in graphene membrane

NASA Astrophysics Data System (ADS)

Wang, Wei; Bhandari, Sagar; Yi, Wei; Bell, David; Westervelt, Robert; Kaxiras, Efthimios

2012-02-01

Ultra-thin membranes such as graphene[1] are of great importance for basic science and technology applications. Graphene sets the ultimate limit of thinness, demonstrating that a free-standing single atomic layer not only exists but can be extremely stable and strong [2--4]. However, both theory [5, 6] and experiments [3, 7] suggest that the existence of graphene relies on intrinsic ripples that suppress the long-wavelength thermal fluctuations which otherwise spontaneously destroy long range order in a two dimensional system. Here we show direct imaging of the atomic features in graphene including the ripples resolved using monochromatic aberration-corrected transmission electron microscopy (TEM). We compare the images observed in TEM with simulated images based on an accurate first-principles total potential. We show that these atomic scale features can be mapped through accurate first-principles simulations into high resolution TEM contrast. [1] Geim, A. K. & Novoselov, K. S. Nat. Mater. 6, 183-191, (2007). [2] Novoselov, K. S.et al. Science 306, 666-669, (2004). [3] Meyer, J. C. et al. Nature 446, 60-63, (2007). [4] Lee, C., Wei, X. D., Kysar, J. W. & Hone, J. Science 321, 385-388, (2008). [5] Nelson, D. R. & Peliti, L. J Phys-Paris 48, 1085-1092, (1987). [6] Fasolino, A., Los, J. H. & Katsnelson, M. I. Nat. Mater. 6, 858-861, (2007). [7] Meyer, J. C. et al. Solid State Commun. 143, 101-109, (2007).

Spherical nanoindentation stress-strain analysis, Version 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weaver, Jordan S.; Turner, David; Miller, Calvin

Nanoindentation is a tool that allows the mechanical response of a variety of materials at the nano to micron length scale to be measured. Recent advances in spherical nanoindentation techniques have allowed for a more reliable and meaningful characterization of the mechanical response from nanoindentation experiments in the form on an indentation stress-strain curve. This code base, Spin, is written in MATLAB (The Mathworks, Inc.) and based on the analysis protocols developed by S.R. Kalidindi and S. Pathak [1, 2]. The inputs include the displacement, load, harmonic contact stiffness, harmonic displacement, and harmonic load from spherical nanoindentation tests in themore » form of an Excel (Microsoft) spreadsheet. The outputs include indentation stress-strain curves and indentation properties as well their variance due to the uncertainty of the zero-point correction in the form of MATLAB data (.mat) and figures (.png). [1] S. Pathak, S.R. Kalidindi. Spherical nanoindentation stress–strain curves, Mater. Sci. Eng R-Rep 91 (2015). [2] S.R. Kalidindi, S. Pathak. Determination of the effective zero-point and the extraction of spherical nanoindentation stress-strain curves, Acta Materialia 56 (2008) 3523-3532.« less

Reconstructing the microstructure of polyimide-silicalite mixed-matrix membranes and their particle connectivity using FIB-SEM tomography.

PubMed

Diblíková, P; Veselý, M; Sysel, P; Čapek, P

2018-03-01

Properties of a composite material made of a continuous matrix and particles often depend on microscopic details, such as contacts between particles. Focusing on processing raw focused-ion beam scanning electron microscope (FIB-SEM) tomography data, we reconstructed three mixed-matrix membrane samples made of 6FDA-ODA polyimide and silicalite-1 particles. In the first step of image processing, backscattered electron (BSE) and secondary electron (SE) signals were mixed in a ratio that was expected to obtain a segmented 3D image with a realistic volume fraction of silicalite-1. Second, after spatial alignment of the stacked FIB-SEM data, the 3D image was smoothed using adaptive median and anisotropic nonlinear diffusion filters. Third, the image was segmented using the power watershed method coupled with a seeding algorithm based on geodesic reconstruction from the markers. If the resulting volume fraction did not match the target value quantified by chemical analysis of the sample, the BSE and SE signals were mixed in another ratio and the procedure was repeated until the target volume fraction was achieved. Otherwise, the segmented 3D image (replica) was accepted and its microstructure was thoroughly characterized with special attention paid to connectivity of the silicalite phase. In terms of the phase connectivity, Monte Carlo simulations based on the pure-phase permeability values enabled us to calculate the effective permeability tensor, the main diagonal elements of which were compared with the experimental permeability. In line with the hypothesis proposed in our recent paper (Čapek, P. et al. (2014) Comput. Mater. Sci. 89, 142-156), the results confirmed that the existence of particle clusters was a key microstructural feature determining effective permeability. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Sink or Swim: Learning by Doing in a Supply Chain Integration Activity*

ERIC Educational Resources Information Center

Harnowo, Akhadian S.; Calhoun, Mikelle A.; Monteiro, Heather

2016-01-01

Studies show that supply chain integration (SCI) is important to organizations. This article describes an activity that places students in the middle of an SCI scenario. The highly interactive hands-on simulation requires only 50 to 60 minutes of classroom time, may be used with 18 to about 36 students, and involves minimal instructor preparation.…

Secretory expression and surface display of a new and biologically active single-chain insulin (SCI-59) analog by lactic acid bacteria.

PubMed

Mao, Ruifeng; Wu, Dongli; Hu, Shimeng; Zhou, Kangping; Wang, Man; Wang, Yefu

2017-04-01

Insulin plays an important role in drug therapies for diabetes mellitus and as the main route of insulin delivery, subcutaneous injection may cause local discomfort, hypoglycemia, hyperinsulinemia, and patient non-compliance. Therefore, oral delivery of insulin is more preferred. However, there is a low bioavailability due to insulin degradation by proteolytic enzymes and severe pH conditions along the gastrointestinal tract. In order to use the food-grade bacteria lactic acid bacteria (LAB) as oral delivery vehicles, a new and bioactive single-chain insulin (SCI-59) analog, containing the insulin B- and A-chains connected by an eight-residue linker (RSRGLPFR), was secretory expressed in Lactococcus lactis NZ3900 without using an antibiotic resistance gene and displayed onto the surface of various non-viable bacteria (NVBs) without genetic modification. Both the free SCI-59 and SCI-59 displayed on the surface of NVBs are biologically active as assayed by their ability to stimulate Akt signaling in differentiated 3T3-L1 adipocytes. Modification of the pH of the medium by NaOH addition at early time during induction can enhance the bioactivity of SCI-59. The C-terminal fused anchoring domain, three LysM repeats, does not affect the formation of disulfide bonds and/or the folding of SCI-59, and SCI-59 could be exposed properly and fully when SCI-59-3LysM bound to the surface of NVBs. Compared to the free form SCI-59, SCI-59 displayed on the surface of NVBs is more stable in simulate gastric juice. It may open new prospects for possible oral treatments of diabetes using live LAB secreting or NVBs carrying bioactive SCI analogs.

Spinal Cord Injury Clinical Registries: Improving Care across the SCI Care Continuum by Identifying Knowledge Gaps.

PubMed

Dvorak, Marcel F; Cheng, Christiana L; Fallah, Nader; Santos, Argelio; Atkins, Derek; Humphreys, Suzanne; Rivers, Carly S; White, Barry A B; Ho, Chester; Ahn, Henry; Kwon, Brian K; Christie, Sean; Noonan, Vanessa K

2017-10-15

Timely access and ongoing delivery of care and therapeutic interventions is needed to maximize recovery and function after traumatic spinal cord injury (tSCI). To ensure these decisions are evidence-based, access to consistent, reliable, and valid sources of clinical data is required. The Access to Care and Timing Model used data from the Rick Hansen SCI Registry (RHSCIR) to generate a simulation of healthcare delivery for persons after tSCI and to test scenarios aimed at improving outcomes and reducing the economic burden of SCI. Through model development, we identified knowledge gaps and challenges in the literature and current health outcomes data collection throughout the continuum of SCI care. The objectives of this article were to describe these gaps and to provide recommendations for bridging them. Accurate information on injury severity after tSCI was hindered by difficulties in conducting neurological assessments and classifications of SCI (e.g., timing), variations in reporting, and the lack of a validated SCI-specific measure of associated injuries. There was also limited availability of reliable data on patient factors such as multi-morbidity and patient-reported measures. Knowledge gaps related to structures (e.g., protocols) and processes (e.g., costs) at each phase of care have prevented comprehensive evaluation of system performance. Addressing these knowledge gaps will enhance comparative and cost-effectiveness evaluations to inform decision-making and standards of care. Recommendations to do so were: standardize data element collection and facilitate database linkages, validate and adopt more outcome measures for SCI, and increase opportunities for collaborations with stakeholders from diverse backgrounds.

Spinal Cord Injury Clinical Registries: Improving Care across the SCI Care Continuum by Identifying Knowledge Gaps

PubMed Central

Cheng, Christiana L.; Fallah, Nader; Santos, Argelio; Atkins, Derek; Humphreys, Suzanne; Rivers, Carly S.; White, Barry A.B.; Ho, Chester; Ahn, Henry; Kwon, Brian K.; Christie, Sean; Noonan, Vanessa K.

2017-01-01

Abstract Timely access and ongoing delivery of care and therapeutic interventions is needed to maximize recovery and function after traumatic spinal cord injury (tSCI). To ensure these decisions are evidence-based, access to consistent, reliable, and valid sources of clinical data is required. The Access to Care and Timing Model used data from the Rick Hansen SCI Registry (RHSCIR) to generate a simulation of healthcare delivery for persons after tSCI and to test scenarios aimed at improving outcomes and reducing the economic burden of SCI. Through model development, we identified knowledge gaps and challenges in the literature and current health outcomes data collection throughout the continuum of SCI care. The objectives of this article were to describe these gaps and to provide recommendations for bridging them. Accurate information on injury severity after tSCI was hindered by difficulties in conducting neurological assessments and classifications of SCI (e.g., timing), variations in reporting, and the lack of a validated SCI-specific measure of associated injuries. There was also limited availability of reliable data on patient factors such as multi-morbidity and patient-reported measures. Knowledge gaps related to structures (e.g., protocols) and processes (e.g., costs) at each phase of care have prevented comprehensive evaluation of system performance. Addressing these knowledge gaps will enhance comparative and cost-effectiveness evaluations to inform decision-making and standards of care. Recommendations to do so were: standardize data element collection and facilitate database linkages, validate and adopt more outcome measures for SCI, and increase opportunities for collaborations with stakeholders from diverse backgrounds. PMID:28745934

Collagen/heparin sulfate scaffolds fabricated by a 3D bioprinter improved mechanical properties and neurological function after spinal cord injury in rats.

PubMed

Chen, Chong; Zhao, Ming-Liang; Zhang, Ren-Kun; Lu, Gang; Zhao, Chang-Yu; Fu, Feng; Sun, Hong-Tao; Zhang, Sai; Tu, Yue; Li, Xiao-Hong

2017-05-01

Effective treatments promoting axonal regeneration and functional recovery for spinal cord injury (SCI) are still in the early stages of development. Most approaches have been focused on providing supportive substrates for guiding neurons and overcoming the physical and chemical barriers to healing that arise after SCI. Although collagen has become a promising natural substrate with good compatibility, its low mechanical properties restrict its potential applications. The mechanical properties mainly rely on the composition and pore structure of scaffolds. For the composition of a scaffold, we used heparin sulfate to react with collagen by crosslinking. For the structure, we adopted a three-dimensional (3D) printing technology to fabricate a scaffold with a uniform pore distributions. We observed that the internal structure of the scaffold printed with a 3D bioprinter was regular and porous. We also found that both the compression modulus and strengths of the scaffold were significantly enhanced by the collagen/heparin sulfate composition compared to a collagen scaffold. Meanwhile, the collagen/heparin sulfate scaffold presented good biocompatibility when it was co-cultured with neural stem cells in vitro. We also demonstrated that heparin sulfate modification significantly improved bFGF immobilization and absorption to the collagen by examining the release kinetics of bFGF from scaffolds. Two months after implantating the scaffold into transection lesions in T10 of the spinal cord in rats, the collagen/heparin sulfate group demonstrated significant recovery of locomotor function and according to electrophysiological examinations. Parallel to functional recovery, collagen/heparin sulfate treatment further ameliorated the pathological process and markedly increased the number of neurofilament (NF) positive cells compared to collagen treatment alone. These data suggested that a collagen/heparin sulfate scaffold fabricated by a 3D bioprinter could enhance the mechanical properties of collagen and provide continuous guidance channels for axons, which would improve the neurological function after SCI. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1324-1332, 2017. © 2017 Wiley Periodicals, Inc.

Simulation-Based Military Regional Anesthesia Training System

DTIC Science & Technology

2008-12-01

and Zhang, X.Z., 2006 : Development of an MR-brake-based haptic device, Smart Mater. Struct., 15, 1960-66. Meislin, H., Criss, E. A. et al ., 1997...operations were superficial wounds or wounds to the extremities (Trunkey, 1983; Rush et al ., 2007). This was partly due to the advent of body... et al ., 1997). Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to

Atomistic-Dislocation Dynamics Modelling of Fatigue Microstructure and Crack Initiation

DTIC Science & Technology

2013-01-01

experimental) Brown 󈧊 (Upper Limit’) DD Results Mughrabi & Pschenitzka 󈧉 (Lower Limit) y = 50 nm d, = 1.2 |lm M I 4 Simulations of... Mughrabi . Introduction to the viewpoint set on: Surface effects in cyclic deformation and fatigue. Scr. Metall. Mater., 26(10): 1499-1504, 1992. [3] E...associated with dislocation cores. Acta Materialia, 53:13131321, 2005. [13] H. Mughrabi . The long-range internal stress field in the dislocation wall

Simulation of Pores Sealing During Homoepitaxy on Si(111) Surface

DTIC Science & Technology

2000-06-23

Yonehara, Jpn. J. Appi. Phys. 37, P2, N11B, 1354 (1998). [5] T. Ito, T. Yasumatsu and A. Hiraki , Appi. Surf Sci. 44, 97 (1990). [6] Y Yasumatsu, T. Ito...H. Nishizawa and A. Hiraki , Appl. Surf Sci. 48/49, 414 (199 1). [7] A. V. Zverev, 1. G. Neizvestny, N. L. Shwartz and Z. Sh. Yanovitskaya, Izv. RAS (Russian) 63, 356 (2000).

MATER protein expression and intracellular localization throughout folliculogenesis and preimplantation embryo development in the bovine

PubMed Central

Pennetier, Sophie; Perreau, Christine; Uzbekova, Svetlana; Thélie, Aurore; Delaleu, Bernadette; Mermillod, Pascal; Dalbiès-Tran, Rozenn

2006-01-01

Background Mater (Maternal Antigen that Embryos Require), also known as Nalp5 (NACHT, leucine rich repeat and PYD containing 5), is an oocyte-specific maternal effect gene required for early embryonic development beyond the two-cell stage in mouse. We previously characterized the bovine orthologue MATER as an oocyte marker gene in cattle, and this gene was recently assigned to a QTL region for reproductive traits. Results Here we have analyzed gene expression during folliculogenesis and preimplantation embryo development. In situ hybridization and immunohistochemistry on bovine ovarian section revealed that both the transcript and protein are restricted to the oocyte from primary follicles onwards, and accumulate in the oocyte cytoplasm during follicle growth. In immature oocytes, cytoplasmic, and more precisely cytosolic localization of MATER was confirmed by immunohistochemistry coupled with confocal microscopy and immunogold electron microscopy. By real-time PCR, MATER messenger RNA was observed to decrease strongly during maturation, and progressively during the embryo cleavage stages; it was hardly detected in morulae and blastocysts. The protein persisted after fertilization up until the blastocyst stage, and was mostly degraded after hatching. A similar predominantly cytoplasmic localization was observed in blastomeres from embryos up to 8-cells, with an apparent concentration near the nuclear membrane. Conclusion Altogether, these expression patterns are consistent with bovine MATER protein being an oocyte specific maternal effect factor as in mouse. PMID:16753072

Optic Nerve Sheath Mechanics in VIIP Syndrome

NASA Technical Reports Server (NTRS)

Raykin, Julia; Forte, Taylor E.; Wang, Roy; Feola, Andrew; Samuels, Brian; Myers, Jerry; Nelson, Emily; Gleason, Rudy; Ethier, C. Ross

2016-01-01

Visual Impairment Intracranial Pressure (VIIP) syndrome is a major concern in current space medicine research. While the exact pathology of VIIP is not yet known, it is hypothesized that the microgravity-induced cephalad fluid shift increases intracranial pressure (ICP) and drives remodeling of the optic nerve sheath. To investigate this possibility, we are culturing optic nerve sheath dura mater samples under different pressures and investigating changes in tissue composition. To interpret results from this work, it is essential to first understand the biomechanical response of the optic nerve sheath dura mater to loading. Here, we investigated the effects of mechanical loading on the porcine optic nerve sheath.Porcine optic nerves (number: 6) were obtained immediately after death from a local abattoir. The optic nerve sheath (dura mater) was isolated from the optic nerve proper, leaving a hollow cylinder of connective tissue that was used for biomechanical characterization. We developed a custom mechanical testing system that allowed for unconfined lengthening, twisting, and circumferential distension of the dura mater during inflation and under fixed axial loading. To determine the effects of variations in ICP, the sample was inflated (0-60 millimeters Hg) and circumferential distension was simultaneously recorded. These tests were performed under variable axial loads (0.6 grams - 5.6 grams at increments of 1 gram) by attaching different weights to one end of the dura mater. Results and Conclusions: The samples demonstrated nonlinear behavior, similar to other soft connective tissue (Figure 1). Large increases in diameter were observed at lower transmural pressures (approximately 0 to 5 millimeters Hg), whereas only small diameter changes were observed at higher pressures. Particularly interesting was the existence of a cross-over point at a pressure of approximately 11 millimeters Hg. At this pressure, the same diameter is obtained for all axial loads applied to the tissue; i.e., as the axial load is varied, the diameter of the dura mater remains constant. This cross-over in the pressure-diameter curves occurred in all optic nerve sheaths that were tested, and may correspond with in vivo ICP levels for pigs. These data suggest that diameter of the dura mater of the optic nerve remains nearly constant in vivo despite being stretched axially. This may be a homeostatic mechanism aimed at maintaining target stresses/strains on the cells in the dura mater, and deviations from these stresses may play an important role in optic nerve sheath remodeling. Future studies will involve subjecting the dura mater to varying pressures and axial tensions for extended periods of time, while monitoring changes in the biomechanical properties. The data can then be used to study the effects of changes in ICP on the remodeling of the dura mater.

Meninges of the brain (image)

MedlinePlus

... covered by connective tissue layers collectively called the meninges. Consisting of the pia mater (closest to the ... the dura mater (farthest from the CNS), the meninges also support blood vessels and contain cerebrospinal fluid. ...

Meninges of the spine (image)

MedlinePlus

... by 3 connective tissue layers collectively called the meninges. Consisting of the pia mater (closest to the ... the dura mater (farthest from the CNS), the meninges also support blood vessels and contain cerebrospinal fluid. ...

Multiferroic properties of nanocrystalline BaTiO 3

NASA Astrophysics Data System (ADS)

Mangalam, R. V. K.; Ray, Nirat; Waghmare, Umesh V.; Sundaresan, A.; Rao, C. N. R.

2009-01-01

Some of the Multiferroics [H. Schmid, Ferroelectrics 162 (1994) 317] form a rare class of materials that exhibit magneto-electric coupling arising from the coexistence of ferromagnetism and ferroelectricity, with potential for many technological applications [J.F. Scott, Nat. Mater. 6 (2007) 256; N.A. Spaldin, M. Fiebig, Science 309 (2005) 391]. Over the last decade, an active research on multiferroics has resulted in the identification of a few routes that lead to multiferroicity in bulk materials [C. Ederer, N.A. Spaldin, Nat. Mater. 3 (2004) 849; D.V. Efremov, J. van den Brink, D.I. Khomskii, Nat. Mater. 3 (2004) 853; N. Hur, S. Park, P.A. Sharma, J.S. Ahn, S. Guha, S.W. Cheong, Nature 429 (2004) 392]. While ferroelectricity in a classic ferroelectric such as BaTiO 3 is expected to diminish with the reducing particle size, [C.H. Ahn, K.M. Rabe, J.M. Triscone, Science 303 (2004) 488; J. Junquera, P. Ghosez, Nature 422 (2003) 506] ferromagnetism cannot occur in its bulk form [N.A. Hill, J. Phys. Chem. B 104 (2000) 6694]. Here, we use a combination of experiment and first-principles simulations to demonstrate that multiferroic nature emerges in intermediate size nanocrystalline BaTiO 3, ferromagnetism arising from the oxygen vacancies at the surface and ferroelectricity from the core. A strong coupling between a surface polar phonon and spin is shown to result in a magnetocapacitance effect observed at room temperature, which can open up possibilities of new electro-magneto-mechanical devices at the nano-scale.

Simulating the Atmospheric Impact of Criegee Intermediates: Implementation of new understanding in atmospheric chemical mechanisms

NASA Astrophysics Data System (ADS)

Bloss, William; Newland, Mike; Rickard, Andrew; Vereecken, Luc; Evans, Mathew; Munoz, Amalia; Rodenas, Mila

2016-04-01

Unsaturated hydrocarbons - alkenes - account for about 90% of global VOC. Stabilized Criegee Intermediates (SCI) are thought to be formed in the atmosphere mainly from reactions of unsaturated hydrocarbons with ozone. SCI have been shown in laboratory and chamber experiments to rapidly oxidise SO2 and NO2, providing a potentially important gas phase oxidation route for these species in the atmosphere. They have also been implicated in the formation of aerosol and organic acids. However, the importance of SCI reactions with traces gases is critically dependent on the relative ratio of the rate constants for the reactions of the SCI with these and other trace gases, with H2O, and for unimolecular decomposition, which vary between SCIs, and between geometric isomers. The selection of reactions and rate constants is critically important in determining the calculated impact of SCI processes upon atmospheric composition and chemistry. Since the recent resurgence in interest in this chemistry, a number of model studies have been performed, with SCI mechanisms of varying comprehensiveness and accuracy, as the understanding of the community has evolved from new laboratory, theoretical and chamber studies, and field observations. Here we present an assessment of the dependence of modelled SCI abundance, behaviour and impacts upon the Criegee mechanism adopted, in the context of (a) the accepted status quo prior to the laboratory and field studies of Welz et al. and Mauldin et al., (b) changes to the SCI mechanism reflecting new kinetics for key bimolecular reactions, e.g. with SO2 and NO2; (c) emerging understanding of the interactions of SCI with water vapour and their unimolecular decomposition and (d) reactions with other atmospheric trace gases. The modelled SCI behaviour is compared with the results from recent chamber studies, and the resulting calculated SCI abundance and impacts evaluated for urban and forested atmospheric boundary layer scenarios.

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 27: Knowledge diffusion and US government technology policy: Issues and opportunities for sci/tech librarians

NASA Technical Reports Server (NTRS)

Pinelli, Thomas E.; Barclay, Rebecca O.; Hannah, Stan; Lawrence, Barbara; Kennedy, John M.

1992-01-01

Federal involvement in simulating economic growth through the development and application of technology policy is currently the subject of serious debate. A recession and the recognition that an internationally competitive economy is a prerequisite for the attainment of national goals have fostered a number of technology policy initiatives aimed at improving the economic competitiveness of American industry. This paper suggests that the successful implementation of U.S. technology policy will require the adoption of a knowledge diffusion model, the development of user oriented information products and services, and a more 'activist' approach on the part of sci/tech librarians in the provision of scientific and technical information (STI). These changes will have a dramatic impact on the sci/tech library of the future and the preparation of sci/tech librarians.

MICROMECHANICS AND MICROSTRUCTURE EVOLUTION: Modeling, Simulation and Experiments. Held in Madrid, Spain on 12-16 September 2005

DTIC Science & Technology

2006-10-30

acknowledges funding from the ‘‘ Programa Torres Quevedo’’ of the Spanish Ministerio de Educación y Ciencia. References [1] Nix WD. Metall Mater Trans A...University of Madrid E. T. S. de Ingenieros de Caminos Madrid 28040 Spain 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 10. SPONSOR...Rodney * Génie Physique et Mécanique des Matériaux (UMR CNRS 5010), Institut National Polytechnique de Grenoble, 101 rue de la Physique, 38402

Micromechanics and Microstructure Evolution: Modeling, Simulation and Experiments. Conference Held in Madrid, Spain, 12-16 Sep 2005

DTIC Science & Technology

2006-10-30

acknowledges funding from the ‘‘ Programa Torres Quevedo’’ of the Spanish Ministerio de Educación y Ciencia. References [1] Nix WD. Metall Mater Trans A...University of Madrid E. T. S. de Ingenieros de Caminos Madrid 28040 Spain 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 10. SPONSOR...Rodney * Génie Physique et Mécanique des Matériaux (UMR CNRS 5010), Institut National Polytechnique de Grenoble, 101 rue de la Physique, 38402

A Computational, Tissue-Realistic Model of Pressure Ulcer Formation in Individuals with Spinal Cord Injury.

PubMed

Ziraldo, Cordelia; Solovyev, Alexey; Allegretti, Ana; Krishnan, Shilpa; Henzel, M Kristi; Sowa, Gwendolyn A; Brienza, David; An, Gary; Mi, Qi; Vodovotz, Yoram

2015-06-01

People with spinal cord injury (SCI) are predisposed to pressure ulcers (PU). PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM) of ischemia/reperfusion-induced inflammation and PU (the PUABM) was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to "better" vs. "worse" outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs) suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU.

A Computational, Tissue-Realistic Model of Pressure Ulcer Formation in Individuals with Spinal Cord Injury

PubMed Central

Ziraldo, Cordelia; Solovyev, Alexey; Allegretti, Ana; Krishnan, Shilpa; Henzel, M. Kristi; Sowa, Gwendolyn A.; Brienza, David; An, Gary; Mi, Qi; Vodovotz, Yoram

2015-01-01

People with spinal cord injury (SCI) are predisposed to pressure ulcers (PU). PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM) of ischemia/reperfusion-induced inflammation and PU (the PUABM) was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to “better” vs. “worse” outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs) suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU. PMID:26111346

Revealing Grain Boundary Sliding from Textures of a Deformed Nanocrystalline Pd–Au Alloy

PubMed Central

Skrotzki, Werner; Zhao, Yajun; Pukenas, Aurimas; Birringer, Rainer

2018-01-01

Employing a recent modeling scheme for grain boundary sliding [Zhao et al. Adv. Eng. Mater. 2017, doi:10.1002/adem.201700212], crystallographic textures were simulated for nanocrystalline fcc metals deformed in shear compression. It is shown that, as grain boundary sliding increases, the texture strength decreases while the signature of the texture type remains the same. Grain boundary sliding affects the texture components differently with respect to intensity and angular position. A comparison of a simulation and an experiment on a Pd–10 atom % Au alloy with a 15 nm grain size reveals that, at room temperature, the predominant deformation mode is grain boundary sliding contributing to strain by about 60%. PMID:29370130

Comprehensive joint feedback control for standing by functional neuromuscular stimulation-a simulation study.

PubMed

Nataraj, Raviraj; Audu, Musa L; Kirsch, Robert F; Triolo, Ronald J

2010-12-01

Previous investigations of feedback control of standing after spinal cord injury (SCI) using functional neuromuscular stimulation (FNS) have primarily targeted individual joints. This study assesses the potential efficacy of comprehensive (trunk, hips, knees, and ankles) joint feedback control against postural disturbances using a bipedal, 3-D computer model of SCI stance. Proportional-derivative feedback drove an artificial neural network trained to produce muscle excitation patterns consistent with maximal joint stiffness values achievable about neutral stance given typical SCI muscle properties. Feedback gains were optimized to minimize upper extremity (UE) loading required to stabilize against disturbances. Compared to the baseline case of maximum constant muscle excitations used clinically, the controller reduced UE loading by 55% in resisting external force perturbations and by 84% during simulated one-arm functional tasks. Performance was most sensitive to inaccurate measurements of ankle plantar/dorsiflexion position and hip ab/adduction velocity feedback. In conclusion, comprehensive joint feedback demonstrates potential to markedly improve FNS standing function. However, alternative control structures capable of effective performance with fewer sensor-based feedback parameters may better facilitate clinical usage.

Comprehensive Joint Feedback Control for Standing by Functional Neuromuscular Stimulation – a Simulation Study

PubMed Central

Nataraj, Raviraj; Audu, Musa L.; Kirsch, Robert F.; Triolo, Ronald J.

2013-01-01

Previous investigations of feedback control of standing after spinal cord injury (SCI) using functional neuromuscular stimulation (FNS) have primarily targeted individual joints. This study assesses the potential efficacy of comprehensive (trunk, hips, knees, and ankles) joint-feedback control against postural disturbances using a bipedal, three-dimensional computer model of SCI stance. Proportional-derivative feedback drove an artificial neural network trained to produce muscle excitation patterns consistent with maximal joint stiffness values achievable about neutral stance given typical SCI muscle properties. Feedback gains were optimized to minimize upper extremity (UE) loading required to stabilize against disturbances. Compared to the baseline case of maximum constant muscle excitations used clinically, the controller reduced UE loading by 55% in resisting external force perturbations and by 84% during simulated one-arm functional tasks. Performance was most sensitive to inaccurate measurements of ankle plantar/dorsiflexion position and hip ab/adduction velocity feedback. In conclusion, comprehensive joint-feedback demonstrates potential to markedly improve FNS standing function. However, alternative control structures capable of effective performance with fewer sensor-based feedback parameters may better facilitate clinical usage. PMID:20923741

Final Report. Institute for Ultralscale Visualization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Kwan-Liu; Galli, Giulia; Gygi, Francois

The SciDAC Institute for Ultrascale Visualization brought together leading experts from visualization, high-performance computing, and science application areas to make advanced visualization solutions for SciDAC scientists and the broader community. Over the five-year project, the Institute introduced many new enabling visualization techniques, which have significantly enhanced scientists’ ability to validate their simulations, interpret their data, and communicate with others about their work and findings. This Institute project involved a large number of junior and student researchers, who received the opportunities to work on some of the most challenging science applications and gain access to the most powerful high-performance computing facilitiesmore » in the world. They were readily trained and prepared for facing the greater challenges presented by extreme-scale computing. The Institute’s outreach efforts, through publications, workshops and tutorials, successfully disseminated the new knowledge and technologies to the SciDAC and the broader scientific communities. The scientific findings and experience of the Institute team helped plan the SciDAC3 program.« less

Hybrid Equation/Agent-Based Model of Ischemia-Induced Hyperemia and Pressure Ulcer Formation Predicts Greater Propensity to Ulcerate in Subjects with Spinal Cord Injury

PubMed Central

Solovyev, Alexey; Mi, Qi; Tzen, Yi-Ting; Brienza, David; Vodovotz, Yoram

2013-01-01

Pressure ulcers are costly and life-threatening complications for people with spinal cord injury (SCI). People with SCI also exhibit differential blood flow properties in non-ulcerated skin. We hypothesized that a computer simulation of the pressure ulcer formation process, informed by data regarding skin blood flow and reactive hyperemia in response to pressure, could provide insights into the pathogenesis and effective treatment of post-SCI pressure ulcers. Agent-Based Models (ABM) are useful in settings such as pressure ulcers, in which spatial realism is important. Ordinary Differential Equation-based (ODE) models are useful when modeling physiological phenomena such as reactive hyperemia. Accordingly, we constructed a hybrid model that combines ODEs related to blood flow along with an ABM of skin injury, inflammation, and ulcer formation. The relationship between pressure and the course of ulcer formation, as well as several other important characteristic patterns of pressure ulcer formation, was demonstrated in this model. The ODE portion of this model was calibrated to data related to blood flow following experimental pressure responses in non-injured human subjects or to data from people with SCI. This model predicted a higher propensity to form ulcers in response to pressure in people with SCI vs. non-injured control subjects, and thus may serve as novel diagnostic platform for post-SCI ulcer formation. PMID:23696726

Opening Comments: SciDAC 2008

NASA Astrophysics Data System (ADS)

Strayer, Michael

2008-07-01

Welcome to Seattle and the 2008 SciDAC Conference. This conference, the fourth in the series, is a continuation of the PI meetings we first began under SciDAC-1. I would like to start by thanking the organizing committee, and Rick Stevens in particular, for organizing this year's meeting. This morning I would like to look briefly at SciDAC, to give you a brief history of SciDAC and also look ahead to see where we plan to go over the next few years. I think the best description of SciDAC, at least the simulation part, comes from a quote from Dr Ray Orbach, DOE's Under Secretary for Science and Director of the Office of Science. In an interview that appeared in the SciDAC Review magazine, Dr Orbach said, `SciDAC is unique in the world. There isn't any other program like it anywhere else, and it has the remarkable ability to do science by bringing together physical scientists, mathematicians, applied mathematicians, and computer scientists who recognize that computation is not something you do at the end, but rather it needs to be built into the solution of the very problem that one is addressing'. Of course, that is extended not just to physical scientists, but also to biological scientists. This is a theme of computational science, this partnership among disciplines, which goes all the way back to the early 1980s and Ken Wilson. It's a unique thread within the Department of Energy. SciDAC-1, launched around the turn of the millennium, created a new generation of scientific simulation codes. It advocated building out mathematical and computing system software in support of science and a new collaboratory software environment for data. The original concept for SciDAC-1 had topical centers for the execution of the various science codes, but several corrections and adjustments were needed. The ASCR scientific computing infrastructure was also upgraded, providing the hardware facilities for the program. The computing facility that we had at that time was the big 3 teraflop/s center at NERSC and that had to be shared with the programmatic side supporting research across DOE. At the time, ESnet was just slightly over half a gig per sec of bandwidth; and the science being addressed was accelerator science, climate, chemistry, fusion, astrophysics, materials science, and QCD. We built out the national collaboratories from the ASCR office, and in addition we built Integrated Software Infrastructure Centers (ISICs). Of these, three were in applied mathematics, four in computer science (including a performance evaluation research center), and four were collaboratories or Grid projects having to do with data management. For science, there were remarkable breakthroughs in simulation, such as full 3D laboratory scale flame simulation. There were also significant improvements in application codes - from factors of almost 3 to more than 100 - and code improvement as people began to realize they had to integrate mathematics tools and computer science tools into their codes to take advantage of the parallelism of the day. The SciDAC data-mining tool, Sapphire, received a 2006 R&D 100 award. And the community as a whole worked well together and began building a publication record that was substantial. In 2006, we recompeted the program with similar goals - SciDAC-1 was very successful, and we wanted to continue that success and extend what was happening under SciDAC to the broader science community. We opened up the partnership to all of the Offices of Science and the NSF and the NNSA. The goal was to create comprehensive scientific computing software and the infrastructure for the software to enable scientific discovery in the physical, biological, and environmental sciences and take the simulations to an extreme scale, in this case petascale. We would also build out a new generation of data management tools. What we observed during SciDAC-1 was that the data and the data communities - both experimental data from large experimental facilities and observational data, along with simulation data - were expanding at a rate significantly faster than Moore's law. In the past few weeks, the FastBit indexing technology software tool for data analyses and data mining developed under SciDAC's Scientific Data Management project was recognized with an R&D 100 Award, selected by an independent judging panel and editors of R&D Magazine as one of the 100 most technologically significant products introduced into the marketplace over the past year. For SciDAC-2 we had nearly 250 proposals requesting a total of slightly over 1 billion in funding. Of course, we had nowhere near 1 billion. The facilities and the science we ended up with were not significantly different from what we had in SciDAC-1. But we had put in place substantially increased facilities for science. When SciDAC-1 was originally executed with the facilities at NERSC, there was significant impact on the resources at NERSC, because not only did we have an expanding portfolio of programmatic science, but we had the SciDAC projects that also needed to run at NERSC. Suddenly, NERSC was incredibly oversubscribed. With SciDAC-2, we had in place leadership-class computing facilities at Argonne with slightly more than half a petaflop and at Oak Ridge with slightly more than a quarter petaflop with an upgrade planned at the end of this year for a petaflop. And we increased the production computing capacity at NERSC to 104 teraflop/s just so that we would not impact the programmatic research and so that we would have a startup facility for SciDAC. At the end of the summer, NERSC will be at 360 teraflop/s. Both the Oak Ridge system and the principal resource at NERSC are Cray systems; Argonne has a different architecture, an IBM Blue Gene/P. At the same time, ESnet has been built out, and we are on a path where we will have dual rings around the country, from 10 to 40 gigabits per second - a factor of 20 to 80 over what was available during SciDAC-1. The science areas include accelerator science and simulation, astrophysics, climate modeling and simulation, computational biology, fusion science, high-energy physics, petabyte high-energy/ nuclear physics, materials science and chemistry, nuclear physics, QCD, radiation transport, turbulence, and groundwater reactive transport modeling and simulation. They were supported by new enabling technology centers and university-based institutes to develop an educational thread for the SciDAC program. There were four mathematics projects and four computer science projects; and under data management, we see a significant difference in that we are bringing up new visualization projects to support and sustain data-intensive science. When we look at the budgets, we see growth in the budget from just under 60 million for SciDAC-1 to just over 80 for SciDAC-2. Part of the growth is due to bringing in NSF and NNSA as new partners, and some of the growth is due to some program offices increasing their investment in SciDAC, while other program offices are constant or have decreased their investment. This is not a reflection of their priorities per se but, rather, a reflection of the budget process and the difficult times in Washington during the past two years. New activities are under way in SciDAC - the annual PI meeting has turned into what I would describe as the premier interdisciplinary computational science meeting, one of the best in the world. Doing interdisciplinary meetings is difficult because people tend to develop a focus for their particular subject area. But this is the fourth in the series; and since the first meeting in San Francisco, these conferences have been remarkably successful. For SciDAC-2 we also created an outreach magazine, SciDAC Review, which highlights scientific discovery as well as high-performance computing. It's been very successful in telling the non-practitioners what SciDAC and computational science are all about. The other new instrument in SciDAC-2 is an outreach center. As we go from computing at the terascale to computing at the petascale, we face the problem of narrowing our research community. The number of people who are `literate' enough to compute at the terascale is more than the number of those who can compute at the petascale. To address this problem, we established the SciDAC Outreach Center to bring people into the fold and educate them as to how we do SciDAC, how the teams are composed, and what it really means to compute at scale. The resources I have mentioned don't come for free. As part of the HECRTF law of 2005, Congress mandated that the Secretary would ensure that leadership-class facilities would be open to everyone across all agencies. So we took Congress at its word, and INCITE is our instrument for making allocations at the leadership-class facilities at Argonne and Oak Ridge, as well as smaller allocations at NERSC. Therefore, the selected proposals are very large projects that are computationally intensive, that compute at scale, and that have a high science impact. An important feature is that INCITE is completely open to anyone - there is no requirement of DOE Office of Science funding, and proposals are rigorously reviewed for both the science and the computational readiness. In 2008, more than 100 proposals were received, requesting about 600 million processor-hours. We allocated just over a quarter of a billion processor-hours. Astrophysics, materials science, lattice gauge theory, and high energy and nuclear physics were the major areas. These were the teams that were computationally ready for the big machines and that had significant science they could identify. In 2009, there will be a significant increase amount of time to be allocated, over half a billion processor-hours. The deadline is August 11 for new proposals and September 12 for renewals. We anticipate a significant increase in the number of requests this year. We expect you - as successful SciDAC centers, institutes, or partnerships - to compete for and win INCITE program allocation awards. If you have a successful SciDAC proposal, we believe it will make you successful in the INCITE review. We have the expectation that you will among those most prepared and most ready to use the machines and to compute at scale. Over the past 18 months, we have assembled a team to look across our computational science portfolio and to judge what are the 10 most significant science accomplishments. The ASCR office, as it goes forward with OMB, the new administration, and Congress, will be judged by the science we have accomplished. All of our proposals - such as for increasing SciDAC, increasing applied mathematics, and so on - are tied to what have we accomplished in science. And so these 10 big accomplishments are key to establishing credibility for new budget requests. Tony Mezzacappa, who chaired the committee, will also give a presentation on the ranking of these top 10, how they got there, and what the science is all about. Here is the list - numbers 2, 5, 6, 7, 9, and 10 are all SciDAC projects. RankTitle 1Modeling the Molecular Basis of Parkinson's Disease (Tsigelny) 2Discovery of the Standing Accretion Shock Instability and Pulsar Birth Mechanism in a Core-Collapse Supernova Evolution and Explosion (Blondin) 3Prediction and Design of Macromolecular Structures and Functions (Baker) 4Understanding How Lifted Flame Stabilized in a Hot Coflow (Yoo) 5New Insights from LCF-enabled Advanced Kinetic Simulations of Global Turbulence in Fusion Systems (Tang) 6High Transition Temperature Superconductivity: A High-Temperature Superconductive State and a Pairing Mechanism in 2-D Hubbard Model (Scalapino) 7 PETsc: Providing the Solvers for DOE High-Performance Simulations (Smith) 8 Via Lactea II, A Billion Particle Simulation of the Dark Matter Halo of the Milky Way (Madau) 9Probing the Properties of Water through Advanced Computing (Galli) 10First Provably Scalable Maxwell Solver Enables Scalable Electromagnetic Simulations (Kovel) So, what's the future going to look like for us? The office is putting together an initiative with the community, which we call the E3 Initiative. We're looking for a 10-year horizon for what's going to happen. Through the series of town hall meetings, which many of you participated in, we have produced a document on `Transforming Energy, the Environment and Science through simulations at the eXtreme Scale'; it can be found at http://www.science.doe.gov/ascr/ProgramDocuments/TownHall.pdf . We sometimes call it the Exascale initiative. Exascale computing is the gold-ring level of computing that seems just out of reach; but if we work hard and stretch, we just might be able to reach it. We envision that there will be a SciDAC-X, working at the extreme scale, with SciDAC teams that will perform and carry out science in the areas that will have a great societal impact, such as alternative fuels and transportation, combustion, climate, fusion science, high-energy physics, advanced fuel cycles, carbon management, and groundwater. We envision institutes for applied mathematics and computer science that probably will segue into algorithms because, at the extreme scale, we see the distinction between the applied math and the algorithm per se and its implementation in computer science as being inseparable. We envision an INCITE-X with multi-petaflop platforms, perhaps even exaflop computing resources. ESnet will be best in class - our 10-year plan calls for having 400 terabits per second capacity available in dual rings around the country, an enormously fast data communications network for moving large amounts of data. In looking at where we've been and where we are going, we can see that the gigaflops and teraflops era was a regime where we were following Moore's law through advances in clock speed. In the current regime, we're introducing massive parallelism, which I think is exemplified by Intel's announcement of their teraflop chip, where they envision more than a thousand cores on a chip. But in order to reach exascale, extrapolations talk about machines that require 100 megawatts of power in terms of current architectures. It's clearly going to require novel architectures, things we have perhaps not yet envisioned. It is of course an era of challenge. There will be an unpredictable evolution of hardware if we are to reach the exascale; and there will clearly be multilevel heterogeneous parallelism, including multilevel memory hierarchies. We have no idea right now as to the programming models needed to execute at such an extreme scale. We have been incredibly successful at the petascale - we know that already. Managing data and just getting communications to scale is an enormous challenge. And it's not just the extreme scaling. It's the rapid increase in complexity that represents the challenge. Let me end with a metaphor. In previous meetings we have talked about the road to petascale. Indeed, we have seen in hindsight that it was a road well traveled. But perhaps the road to exascale is not a road at all. Perhaps the metaphor will be akin to scaling the south face of K2. That's clearly not something all of us will be able to do, and probably computing at the exascale is not something all of us will do. But if we achieve that goal, perhaps the words of Emily Dickinson will best summarize where we will be. Perhaps in her words, looking backward and down, you will say: I climb the `Hill of Science' I view the landscape o'er; Such transcendental prospect I ne'er beheld before!

1973 Winter Simulation Conference. Sponsored by ACM/AIIE/SHARE/SCi/TIMS.

ERIC Educational Resources Information Center

Hoggatt, Austin Curwood, Ed.

A record of the current state of the art of simulation and the major part it now plays in policy formation in large organizations is provided by these conference proceedings. The 40 papers presented reveal an emphasis on the applications of simulation. In addition, the abstracts of 28 papers submitted to a more informal "paper fair" are also…

[A case of cavernous angioma at the convexity in the dura mater: characteristics of images in the literature].

PubMed

Yonezawa, Ushio; Ikawa, Fusao; Hamasaki, Osamu; Hidaka, Toshikazu; Kurokawa, Yasuharu; Onuma, Hideyuki

2014-08-01

We describe a rare case of cavernous angioma in the dura mater and discuss published MRI findings on similar cases. The patient was a 78-year-old woman who was referred to Shimane Prefectural Central Hospital with complaints of headaches. We were subsequently able to identify a tumor at the convexity in the dura mater. The tumor showed a high intensity on T2-weighted images and was heterogeneously enhanced on contrast-enhanced T1-weighted images. The maximum size of the tumor was 35 mm. Moreover, preoperative angiography showed a slight vascularity in the tumor. We performed surgery with the expectation of finding a meningioma, metastatic brain tumor, or another mesenchymal tumor. The tumor was dark and red, attached to the dura mater, and adhered to the arachnoid. However, we were able to peel the tumor away from the meninges and achieved a total removal of the mass, successfully cutting a fine feeding cortical artery. The patient was discharged without neurological defects 9 days after surgery;the pathological diagnosis was cavernous angioma. In conclusion, it is difficult to discern between meningioma and cavernous angioma in the dura mater. However, the specificity of high intensity on T2-weighted images is relatively high, and preoperative diagnosis can be determined by MRI and angiography findings.

Navigating Tensions Between Conceptual and Metaconceptual Goals in the Use of Models

NASA Astrophysics Data System (ADS)

Delgado, Cesar

2015-04-01

Science education involves learning about phenomena at three levels: concrete (facts and generalizations), conceptual (concepts and theories), and metaconceptual (epistemology) (Snir et al. in J Sci Educ Technol 2(2):373-388, 1993). Models are key components in science, can help build conceptual understanding, and may also build metaconceptual understanding. Technology can transform teaching and learning by turning models into interactive simulations that learners can investigate. This paper identifies four characteristics of models and simulations that support conceptual learning but misconstrue models and science at a metaconceptual level. Ahistorical models combine the characteristics of several historical models; they conveniently compile ideas but misrepresent the history of science (Gilbert in Int J Sci Math Educ 2(2):115-130, 2004). Teleological models explain behavior in terms of a final cause; they can lead to useful heuristics but imply purpose in processes driven by chance and probability (Talanquer in Int J Sci Educ 29(7):853-870, 2007). Epistemological overreach occurs when models or simulations imply greater certainty and knowledge about phenomena than warranted; conceptualizing nature as being well known (e.g., having a mathematical structure) poses the danger of conflating model and reality or data and theory. Finally, models are inevitably ontologically impoverished. Real-world deviations and many variables are left out of models, as models' role is to simplify. Models and simulations also lose much of the sensory data present in phenomena. Teachers, designers, and professional development designers and facilitators must thus navigate the tension between conceptual and metaconceptual learning when using models and simulations. For each characteristic, examples are provided, along with recommendations for instruction and design. Prompts for explicit reflective activities around models are provided for each characteristic

Observation of cosmic ray hadrons at the top of the Sierra Negra volcano in Mexico with the SciCRT prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz, E.; Valdés-Galicia, J. F.; Matsubara, Y.

In this work we report the flux of protons and neutral emission measured at the top of the Sierra Negra volcano at 4600 m.a.s.l. (575 g/cm2), in Eastern Mexico. As an example of the capability of the mini-SciCR as a cosmic ray detector we present the Forbush decrease recorded on March 7, 2012. These data were obtained with a cosmic ray detector prototype called mini-SciCR that was operating from October 2010 to July 2012. Our main aims were to measure the hadronic component flux of the secondary cosmic ray and to show the appropriate performance of all system of themore » detector. To separate the signals of protons from other charged particles we obtained the energy deposition pattern when they cross the detector using a Monte Carlo simulation, and to separate the signals of neutral emission we used an anticoincidence system between the edge bars and the internal bars of the detector. The mini-SciCR is a prototype of a new cosmic ray detector called SciBar Cosmic Ray Telescope (SciCRT) installed in the same place, which is in the process of calibration. The SciCRT will work mainly as a Solar Neutron and Muon Telescope, it is designed to achieve: (1) larger effective area than the current Solar Neutron Telescope, (2) higher energy resolution to determine the energy spectrum of solar neutrons, (3) lower energy threshold, and (4) higher particle identification ability.« less

Observation of cosmic ray hadrons at the top of the Sierra Negra volcano in Mexico with the SciCRT prototype

DOE PAGES

Ortiz, E.; Valdés-Galicia, J. F.; Matsubara, Y.; ...

2016-02-16

In this study we report the flux of protons and neutral emission measured at the top of the Sierra Negra volcano at 4600 m.a.s.l. (575 g/cm 2), in Eastern Mexico. As an example of the capability of the mini-SciCR as a cosmic ray detector we present the Forbush decrease recorded on March 7, 2012. These data were obtained with a cosmic ray detector prototype called mini-SciCR that was operating from October 2010 to July 2012. Our main aims were to measure the hadronic component flux of the secondary cosmic ray and to show the appropriate performance of all system ofmore » the detector. To separate the signals of protons from other charged particles we obtained the energy deposition pattern when they cross the detector using a Monte Carlo simulation, and to separate the signals of neutral emission we used an anticoincidence system between the edge bars and the internal bars of the detector. The mini-SciCR is a prototype of a new cosmic ray detector called SciBar Cosmic Ray Telescope (SciCRT) installed in the same place, which is in the process of calibration. The SciCRT will work mainly as a Solar Neutron and Muon Telescope, it is designed to achieve: (1) larger effective area than the current Solar Neutron Telescope, (2) higher energy resolution to determine the energy spectrum of solar neutrons, (3) lower energy threshold, and (4) higher particle identification ability.« less

Observation of cosmic ray hadrons at the top of the Sierra Negra volcano in Mexico with the SciCRT prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz, E.; Valdés-Galicia, J. F.; Matsubara, Y.

In this study we report the flux of protons and neutral emission measured at the top of the Sierra Negra volcano at 4600 m.a.s.l. (575 g/cm 2), in Eastern Mexico. As an example of the capability of the mini-SciCR as a cosmic ray detector we present the Forbush decrease recorded on March 7, 2012. These data were obtained with a cosmic ray detector prototype called mini-SciCR that was operating from October 2010 to July 2012. Our main aims were to measure the hadronic component flux of the secondary cosmic ray and to show the appropriate performance of all system ofmore » the detector. To separate the signals of protons from other charged particles we obtained the energy deposition pattern when they cross the detector using a Monte Carlo simulation, and to separate the signals of neutral emission we used an anticoincidence system between the edge bars and the internal bars of the detector. The mini-SciCR is a prototype of a new cosmic ray detector called SciBar Cosmic Ray Telescope (SciCRT) installed in the same place, which is in the process of calibration. The SciCRT will work mainly as a Solar Neutron and Muon Telescope, it is designed to achieve: (1) larger effective area than the current Solar Neutron Telescope, (2) higher energy resolution to determine the energy spectrum of solar neutrons, (3) lower energy threshold, and (4) higher particle identification ability.« less

Optimization of low-level light therapy's illumination parameters for spinal cord injury in a rat model

NASA Astrophysics Data System (ADS)

Shuaib, Ali; Bourisly, Ali

2018-02-01

Spinal cord injury (SCI) can result in complete or partial loss of sensation and motor function due to interruption along the severed axonal tract(s). SCI can result in tetraplegia or paraplegia, which can have prohibitive lifetime medical costs and result in shorter life expectancy. A promising therapeutic technique that is currently in experimental phase and that has the potential to be used to treat SCI is Low-level light therapy (LLLT). Preclinical studies have shown that LLLT has reparative and regenerative capabilities on transected spinal cords, and that LLLT can enhance axonal sprouting in animal models. However, despite the promising effects of LLLT as a therapy for SCI, it remains difficult to compare published results due to the use of a wide range of illumination parameters (i.e. different wavelengths, fluences, beam types, and beam diameter), and due to the lack of a standardized experimental protocol(s). Before any clinical applications of LLLT for SCI treatment, it is crucial to standardize illumination parameters and efficacy of light delivery. Therefore, in this study we aim to evaluate the light fluence distribution on a 3D voxelated SCI rat model with different illumination parameters (wavelengths: 660, 810, and 980 nm; beam types: Gaussian and Flat; and beam diameters: 0.1, 0.2, and 0.3 cm) for LLLT using Monte Carlo simulation. This study provides an efficient approach to guide researchers in optimizing the illumination parameters for LLLT spinal cord injury in an experimental model and will aid in quantitative and qualitative standardization of LLLT-SCI treatment.

Preface: SciDAC 2007

NASA Astrophysics Data System (ADS)

Keyes, David E.

2007-09-01

It takes a village to perform a petascale computation—domain scientists, applied mathematicians, computer scientists, computer system vendors, program managers, and support staff—and the village was assembled during 24-28 June 2007 in Boston's Westin Copley Place for the third annual Scientific Discovery through Advanced Computing (SciDAC) 2007 Conference. Over 300 registered participants networked around 76 posters, focused on achievements and challenges in 36 plenary talks, and brainstormed in two panels. In addition, with an eye to spreading the vision for simulation at the petascale and to growing the workforce, 115 participants—mostly doctoral students and post-docs complementary to the conferees—were gathered on 29 June 2007 in classrooms of the Massachusetts Institute of Technology for a full day of tutorials on the use of SciDAC software. Eleven SciDAC-sponsored research groups presented their software at an introductory level, in both lecture and hands-on formats that included live runs on a local BlueGene/L. Computation has always been about garnering insight into the behavior of systems too complex to explore satisfactorily by theoretical means alone. Today, however, computation is about much more: scientists and decision makers expect quantitatively reliable predictions from simulations ranging in scale from that of the Earth's climate, down to quarks, and out to colliding black holes. Predictive simulation lies at the heart of policy choices in energy and environment affecting billions of lives and expenditures of trillions of dollars. It is also at the heart of scientific debates on the nature of matter and the origin of the universe. The petascale is barely adequate for such demands and we are barely established at the levels of resolution and throughput that this new scale of computation affords. However, no scientific agenda worldwide is pushing the petascale frontier on all its fronts as vigorously as SciDAC. The breadth of this conference archive reflects the philosophy of the SciDAC program, which was introduced as a collaboration of all of the program offices in the Office of Science of the U.S. Department of Energy (DOE) in Fall 2001 and was renewed for a second period of five years in Fall 2006, with additional support in certain areas from the DOE's National Nuclear Security Administration (NNSA) and the U.S. National Science Foundation (NSF). All of the projects in the SciDAC portfolio were represented at the conference and most are captured in this volume. In addition, the Organizing Committee incorporated into the technical program a number of computational science highlights from outside of SciDAC, and, indeed, from outside of the United States. As implied by the title, scientific discovery is the driving deliverable of the SciDAC program, spanning the full range of the DOE Office of Science: accelerator design, astrophysics, chemistry and materials science, climate science, combustion, life science, nuclear physics, plasma physics, and subsurface physics. As articulated in the eponymous report that launched SciDAC, the computational challenges of these diverse areas are remarkably common. Each is profoundly multiscale in space and time and therefore continues to benefit at any margin from access to the largest and fastest computers available. Optimality of representation and execution requires adaptive, scalable mathematical algorithms in both continuous (geometrically complex domain) and discrete (mesh and graph) aspects. Programmability and performance optimality require software environments that both manage the intricate details of the underlying hardware and abstract them for scientific users. Running effectively on remote specialized hardware requires transparent workflow systems. Comprehending the petascale data sets generated in such simulations requires automated tools for data exploration and visualization. Archiving and sharing access to this data within the inevitably distributed community of leading scientists requires networked collaborative environments. Each of these elements is a research and development project in its own right. SciDAC does not replace theoretical programs oriented towards long-term basic research, but harvests them for contemporary, complementary state-of-the-art computational campaigns. By clustering researchers from applications and enabling technologies into coordinated, mission-driven projects, SciDAC accomplishes two ends with remarkable effectiveness: (1) it enriches the scientific perspective of both applications and enabling communities through mutual interaction and (2) it leverages between applications solutions and effort encapsulated in software. Though SciDAC is unique, its objective of multiscale science at extreme computational scale is shared and approached through different programmatic mechanisms, notably NNSA's ASC program, NSF's Cyberinfrastructure program, and DoD's CREATE program in the U.S., and RIKEN's computational simulation programs in Japan. Representatives of each of these programs were given the podium at SciDAC 2007 and communication occurred that will be valuable towards the ends of complementarity, leverage, and promulgation of best practices. The 2007 conference was graced with additional welcome program announcements. Michael Strayer announced a new program of postdoctoral research fellowships in the enabling technologies. (The computer science post-docs will be named after the late Professor Ken Kennedy, who briefly led the SciDAC project Center for Scalable Application Development Software (CScADS) until his untimely death in February 2007.) IBM announced its petascale BlueGene/P system on June 26. Meanwhile, at ISC07 in Dresden, the semi-annual posting of a revised Top 500 list on June 27 showed several new Top 10 systems accessible to various SciDAC participants. While SciDAC is dominated in 2007 by the classical scientific pursuit of understanding through reduction to components and isolation of causes and effects, simulation at scale is beginning to offer something even more tantalizing: synthesis and integration of multiple interacting phenomena in complex systems. Indeed, the design-oriented elements of SciDAC, such as accelerator and tokamak modeling, area already emphasizing multiphysics coupling, and climate science has been doing so for years in the coupling of models of the ocean, atmosphere, ice, and land. In one of the panels at SciDAC 2007, leaders of a three-stage `progressive workshop' on exascale simulation for energy and environment (E3), considered prospects for whole-system modeling in a variety of scientific areas within the domain of DOE related to energy, environmental, and global security. Computer vendors were invited to comment on the prospects for delivering exascale computing systems in another panel. The daunting nature of this challenge is summarized with the observation that the peak processing power of the entire Top 500 list of June 2007 is only 0.0052 exaflop/s. It takes the combined power of most of the computers on the internet today worldwide to reach 1 exaflop/s or 1018 floating point operations per second. The program of SciDAC 2007 followed a template honed by its predecessor meetings in San Francisco in 2005 and Denver in 2006. The Boston venue permitted outreach to a number of universities in the immediate region and throughout southern New England, including SciDAC campuses of Boston University, Harvard, and MIT, and a dozen others including most of the Ivy League. Altogether 55 universities, 20 laboratories, 14 private companies, 5 agencies, and 4 countries were represented among the conference and tutorial workshop participants. Approximately 47% of the conference participants were from government laboratories, 37% from universities, 9% from federal program offices, and 7% from industry. Keys to the success of SciDAC 2007 were the informal poster receptions, coffee breaks, working breakfasts and lunches, and even the `Right-brain Night' featuring artistic statements, both reverent and irreverent, by computational scientists, inspired by their work. The organizers thank the sponsors for their generosity in attracting participants to these informal occasions with sumptuous snacks and beverages: AMD, Cray, DataDirect, IBM, SGI, SiCortex, and the Institute of Physics. A conference as logistically complex as SciDAC 2007 cannot possibly and should not be executed primarily by the scientists, themselves. It is a great pleasure to acknowledge the many talented staff that contributed to a productive time for all participants and nearperfect adherence to schedule. Chief among them is Betsy Riley, currently detailed from ORNL to the program office in Germantown, with degrees in mathematics and computer science, but a passion for organizing interdisciplinary scientific programs. Betsy staffed the organizing committee during the year of telecon meetings leading up to the conference and masterminded sponsorship, invitations, and the compilation of the proceedings. Assisting her from ORNL in managing the program were Daniel Pack, Angela Beach, and Angela Fincher. Cynthia Latham of ORNL performed admirably in website and graphic design for all aspects of the online and printed materials of the meeting. John Bui, John Smith, and Missy Smith of ORNL ran their customary tight ship with respect to audio-visual execution and capture, assisted by Eric Ecklund and Keith Quinn of the Westin. Pamelia Nixon-Hartje of Ambassador Services was personally invaluable in getting the most out of the hotel and its staff. We thank Jeff Nichols of ORNL for managing the primary subcontract for the meeting. The SciDAC tutorial program was a joint effort of Professor John Negele of MIT, David Skinner, PI of the SciDAC Outreach Center, and the SciDAC 2007 Chair. Sponsorship from the Outreach Center in the form of travel scholarships for students, and of the local area SciDAC university delegation of BU, Harvard, and MIT for food and facilities is gratefully acknowledged. Of course, the archival success of a scientific meeting rests with the willingness of the presenters to make the extra effort to package their field-leading science in a form suitable for interaction with colleagues from other disciplines rather than fellow specialists. This goal, oft-stated in the run up to the meeting, was achieved to an admirable degree, both in the live presentations and in these proceedings. This effort is its own reward, since it leads to enhanced communication and accelerated scientific progress. Our greatest thanks are reserved for Michael Strayer, Associate Director for OASCR and the Director of SciDAC, for envisioning this celebratory meeting three years ago, and sustaining it with his own enthusiasm, in order to provide a highly visible manifestation of the fruits of SciDAC. He and the other Office of Science program managers in attendance and working in Washington, DC to communicate the opportunities afforded by SciDAC deserve the gratitude of a new virtual scientific village created and cemented under the vision of scientific discovery through advanced computing. David E Keyes Fu Foundation Professor of Applied Mathematics

Simultaneous Evaporation of Cu and Sn from Liquid Steel

NASA Astrophysics Data System (ADS)

Jung, Sung-Hoon; Kang, Youn-Bae

2016-08-01

In order to understand evaporation refining of tramp elements in molten ferrous scrap, Cu and Sn, a series of experiments were carried out using liquid-gas reaction in a levitation melting equipment. Effect of S and C, which are abundant in hot metal from ironmaking process, was examined and analyzed by employing a comprehensive evaporation kinetic model developed by the present authors (Jung et al. in Metall Mater Trans B 46B:250-258, 2014; Jung et al. in Metall Mater Trans B 46B:259-266, 2014; Jung et al. in Metall Mater Trans B 46B:267-277, 2014; Jung and Kang in Metall Mater Trans B 10.1007/s11663-016-0601-5, 2016). Evaporation of Cu and Sn were treated by evaporation of individual species such as Cu(g), CuS(g), Sn(g), and SnS(g), along with CS2(g). Decrease of Cu and Sn content in liquid steel was in good agreement with the model prediction. Optimum conditions of steel composition for the rapid evaporation of Cu and Sn were proposed by utilizing the model predictions.

A THREE-DIMENSIONAL MAP OF THE HINDLIMB MOTOR REPRESENTATION IN THE LUMBAR SPINAL CORD IN SPRAGUE DAWLEY RATS

PubMed Central

Borrell, Jordan A.; Frost, Shawn; Peterson, Jeremy; Nudo, Randolph J.

2016-01-01

Objective Spinal cord injury (SCI) is a devastating neurological trauma with a prevalence of about 282,000 people living with an SCI in the United States in 2016. Advances in neuromodulatory devices hold promise for restoring function by incorporating the delivery of electrical current directly into the spinal cord grey matter via intraspinal microstimulation (ISMS). In such designs, detailed topographic maps of spinal cord outputs are needed to determine ISMS locations for eliciting hindlimb movements. The primary goal of the present study was to derive a topographic map of functional motor outputs in the lumbar spinal cord to hindlimb skeletal muscles as defined by ISMS in a rat model. Approach Experiments were carried out in nine healthy, adult, male, Sprague Dawley rats. After a laminectomy of the T13-L1 vertebrae and removal of the dura mater, a four-shank, 16-channel microelectrode array was inserted along a three-dimensional (200 µm) stimulation grid. Trains of three biphasic current pulses were used to determine evoked movements and EMG activity. Via fine wire electromyographic (EMG) electrodes, Stimulus-Triggered Averaging (StTA) was used on rectified EMG data to determine response latency. Main results Hindlimb movements were elicited at a median current intensity of 6 µA, and thresholds were significantly lower in ventrolateral sites. Movements typically consisted of whole leg, hip, knee, ankle, toe, and trunk movements. Hip movements dominated rostral to the T13 vertebral segment, knee movements were evoked at the T13-L1 vertebral junction, while ankle and digit movements were found near the rostral L1 vertebra. Whole leg movements spanned the entire rostrocaudal region explored, while trunk movements dominated medially. StTAs of EMG activity demonstrated a latency of ~4 ms. Significance The derived motor map provides insight into the parameters needed for future neuromodulatory devices. PMID:27934789

A 3D map of the hindlimb motor representation in the lumbar spinal cord in Sprague Dawley rats

NASA Astrophysics Data System (ADS)

Borrell, Jordan A.; Frost, Shawn B.; Peterson, Jeremy; Nudo, Randolph J.

2017-02-01

Objective. Spinal cord injury (SCI) is a devastating neurological trauma with a prevalence of about 282 000 people living with an SCI in the United States in 2016. Advances in neuromodulatory devices hold promise for restoring function by incorporating the delivery of electrical current directly into the spinal cord grey matter via intraspinal microstimulation (ISMS). In such designs, detailed topographic maps of spinal cord outputs are needed to determine ISMS locations for eliciting hindlimb movements. The primary goal of the present study was to derive a topographic map of functional motor outputs in the lumbar spinal cord to hindlimb skeletal muscles as defined by ISMS in a rat model. Approach. Experiments were carried out in nine healthy, adult, male, Sprague Dawley rats. After a laminectomy of the T13-L1 vertebrae and removal of the dura mater, a four-shank, 16-channel microelectrode array was inserted along a 3D (200 µm) stimulation grid. Trains of three biphasic current pulses were used to determine evoked movements and electromyographic (EMG) activity. Via fine wire EMG electrodes, stimulus-triggered averaging (StTA) was used on rectified EMG data to determine response latency. Main results. Hindlimb movements were elicited at a median current intensity of 6 µA, and thresholds were significantly lower in ventrolateral sites. Movements typically consisted of whole leg, hip, knee, ankle, toe, and trunk movements. Hip movements dominated rostral to the T13 vertebral segment, knee movements were evoked at the T13-L1 vertebral junction, while ankle and digit movements were found near the rostral L1 vertebra. Whole leg movements spanned the entire rostrocaudal region explored, while trunk movements dominated medially. StTAs of EMG activity demonstrated a latency of ~4 ms. Significance. The derived motor map provides insight into the parameters needed for future neuromodulatory devices.

PHOTOCHEMICAL SIMULATIONS OF POINT SOURCE EMISSIONS WITH THE MODELS-3 CMAQ PLUME-IN-GRID APPROACH

EPA Science Inventory

A plume-in-grid (PinG) approach has been designed to provide a realistic treatment for the simulation the dynamic and chemical processes impacting pollutant species in major point source plumes during a subgrid scale phase within an Eulerian grid modeling framework. The PinG sci...

Interaction of micron and nano-sized particles with cells of the dura mater

PubMed Central

Papageorgiou, Iraklis; Marsh, Rainy; Tipper, Joanne L; Hall, Richard M; Fisher, John; Ingham, Eileen

2014-01-01

Intervertebral total disc replacements (TDR) are used in the treatment of degenerative spinal disc disease. There are, however, concerns that they may be subject to long-term failure due to wear. The adverse effects of TDR wear have the potential to manifest in the dura mater and surrounding tissues. The aim of this study was to investigate the physiological structure of the dura mater, isolate the resident dural epithelial and stromal cells and analyse the capacity of these cells to internalise model polymer particles. The porcine dura mater was a collagen-rich structure encompassing regularly arranged fibroblastic cells within an outermost epithelial cell layer. The isolated dural epithelial cells had endothelial cell characteristics (positive for von Willebrand factor, CD31, E-cadherin and desmoplakin) and barrier functionality whereas the fibroblastic cells were positive for collagen I and III, tenascin and actin. The capacity of the dural cells to take up model particles was dependent on particle size. Nanometer sized particles readily penetrated both types of cells. However, dural fibroblasts engulfed micron-sized particles at a much higher rate than dural epithelial cells. The study suggested that dural epithelial cells may offer some barrier to the penetration of micron-sized particles but not nanometer sized particles. © 2014 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1496–1505, 2014. PMID:24604838

Ultrasound-guided evaluation of the lumbar subarachnoid space in lateral and sitting positions in pregnant patients to receive elective cesarean operation.

PubMed

Gulay, Ucarli; Meltem, Turkay; Nadir, Sinikoglu Sitki; Aysin, Alagol

2015-01-01

The aim was to compare visibility of the spinal space in sitting and lateral positions, number of attempts, spinal needle depth, skin-dura mater distance and the possible complications; in application of spinal anesthesia, using ultrasound in pregnant patients scheduled to receive elective cesarean operations. The study was conducted prospective-randomly after receiving approval from the ethics committee and the patients' permission. ASA I-II 50 pregnant patients were divided into two groups. The patients in Group SP were those placed in a sitting position and the patients in Group LP were those placed in a lateral position. In both groups, the skin-dura mater distance was recorded through an out-of plane technique accompanied by ultrasound. The depth of the spinal needle was measured. The number of attempts, the level of attempts recorded. The degree of visibility of the vertebral space was observed through ultrasound and was numerically scored. Intraoperative and postoperative complications were recorded. There was no difference between the number of attempts, Modified Bromage Scale and mean measurements of skin-dura mater distance observed through ultrasound. The mean needle depths of Group LP were statistically found significantly higher than Group SP (p=0.002). Our study supports the notion that access to the skin-dura mater distance is longer in the lateral decubitus position when skin-dura mater distance is evaluated by measuring needle depth.

Longitudinal changes in femur bone mineral density after spinal cord injury: effects of slice placement and peel method

PubMed Central

Dudley-Javoroski, S.

2010-01-01

Summary Surveillance of femur metaphysis bone mineral density (BMD) decline after spinal cord injury (SCI) may be subject to slice placement error of 2.5%. Adaptations to anti-osteoporosis measures should exceed this potential source of error. Image analysis parameters likewise affect BMD output and should be selected strategically in longitudinal studies. Introduction Understanding the longitudinal changes in bone mineral density (BMD) after spinal cord injury (SCI) is important when assessing new interventions. We determined the longitudinal effect of SCI on BMD of the femur metaphysis. To facilitate interpretation of longitudinal outcomes, we (1) determined the BMD difference associated with erroneous peripheral quantitative computed tomography (pQCT) slice placement, and (2) determined the effect of operator-selected pQCT peel algorithms on BMD. Methods pQCT images were obtained from the femur metaphysis (12% of length from distal end) of adult subjects with and without SCI. Slice placement errors were simulated at 3 mm intervals and were processed in two ways (threshold-based vs. concentric peel). Results BMD demonstrated a rapid decline over 2 years post-injury. BMD differences attributable to operator-selected peel methods were large (17.3% for subjects with SCI). Conclusions Femur metaphysis BMD declines after SCI in a manner similar to other anatomic sites. Concentric (percentage-based) peel methods may be most appropriate when special sensitivity is required to detect BMD adaptations. Threshold-based methods may be more appropriate when asymmetric adaptations are observed. PMID:19707702

Borrelia burgdorferi adhere to blood vessels in the dura mater and are associated with increased meningeal T cells during murine disseminated borreliosis

PubMed Central

Divan, Ali; Casselli, Timothy; Narayanan, S. Anand; Mukherjee, Sanjib; Zawieja, David C.; Watt, John A.

2018-01-01

Borrelia burgdorferi, the causative agent of Lyme disease, is a vector-borne bacterial infection that is transmitted through the bite of an infected tick. If not treated with antibiotics during the early stages of infection, disseminated infection can spread to the central nervous system (CNS). In non-human primates (NHPs) it has been demonstrated that the leptomeninges are among the tissues colonized by B. burgdorferi spirochetes. Although the NHP model parallels aspects of human borreliosis, a small rodent model would be ideal to study the trafficking of spirochetes and immune cells into the CNS. Here we show that during early and late disseminated infection, B. burgdorferi infects the meninges of intradermally infected mice, and is associated with concurrent increases in meningeal T cells. We found that the dura mater was consistently culture positive for spirochetes in transcardially perfused mice, independent of the strain of B. burgdorferi used. Within the dura mater, spirochetes were preferentially located in vascular regions, but were also present in perivascular, and extravascular regions, as late as 75 days post-infection. At the same end-point, we observed significant increases in the number of CD3+ T cells within the pia and dura mater, as compared to controls. Flow cytometric analysis of leukocytes isolated from the dura mater revealed that CD3+ cell populations were comprised of both CD4 and CD8 T cells. Overall, our data demonstrate that similarly to infection in peripheral tissues, spirochetes adhere to the dura mater during disseminated infection, and are associated with increases in the number of meningeal T cells. Collectively, our results demonstrate that there are aspects of B. burgdorferi meningeal infection that can be modelled in laboratory mice, suggesting that mice may be useful for elucidating mechanisms of meningeal pathogenesis by B. burgdorferi. PMID:29723263

Chronic adriamycin treatment impairs CGRP-mediated functions of meningeal sensory nerves.

PubMed

Deák, Éva; Rosta, Judit; Boros, Krisztina; Kis, Gyöngyi; Sántha, Péter; Messlinger, Karl; Jancsó, Gábor; Dux, Mária

2018-06-01

Adriamycin is a potent anthracycline-type antitumor agent, but it also exerts potentially serious side effects due to its cardiotoxic and neurotoxic propensity. Multiple impairments in sensory nerve functions have been recently reported in various rat models. The present experiments were initiated in an attempt to reveal adriamycin-induced changes in sensory effector functions of chemosensitive meningeal afferents. Meningeal blood flow was measured with laser Doppler flowmetry in the parietal dura mater of adult male Wistar rats. The dura mater was repeatedly stimulated by topical applications of capsaicin, a transient receptor potential vanilloid 1 (TRPV1) receptor agonist, or acrolein, a transient receptor potential ankyrin 1 (TRPA1) receptor agonist, which induce the release of calcitonin gene-related peptide (CGRP) from meningeal afferents. The blood flow increasing effects of CGRP, histamine, acetylcholine and forskolin were also measured. Capsaicin- and acrolein-induced CGRP release was measured with enzyme-linked immunoassay in an ex vivo dura mater preparation. TRPV1 content of trigeminal ganglia and TRPV1-, CGRP- and CGRP receptor component-immunoreactive structures were examined in dura mater samples obtained from control and adriamycin-treated rats. The vasodilator effects of capsaicin, acrolein and CGRP were significantly reduced in adriamycin-treated animals while histamine-, acetylcholine- and forskolin-induced vasodilatation were unaffected. Measurements of CGRP release in an ex vivo dura mater preparation revealed an altered dynamic upon repeated stimulations of TRPV1 and TRPA1 receptors. In whole-mount dura mater preparations immunohistochemistry revealed altered CGRP receptor component protein (RCP)-immunoreactivity in adriamycin-treated animals, while CGRP receptor activity modifying protein (RAMP1)-, TRPV1- and CGRP-immunostaining were left apparently unaltered. Adriamycin-treatment slightly reduced TRPV1 protein content of trigeminal ganglia. The present findings demonstrate that adriamycin-treatment alters the function of the trigeminovascular system leading to reduced meningeal sensory neurogenic vasodilatation that may affect the local regulatory and protective mechanisms of chemosensitive afferents leading to alterations in tissue integrity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Inheritance of steroid-independent male sexual behavior in male offspring of B6D2F1 mice.

PubMed

McInnis, Christine M; Bonthuis, Paul J; Rissman, Emilie F; Park, Jin Ho

2016-04-01

The importance of gonadal steroids in modulating male sexual behavior is well established. Individual differences in male sexual behavior, independent of gonadal steroids, are prevalent across a wide range of species, including man. However, the genetic mechanisms underlying steroid-independent male sexual behavior are poorly understood. A high proportion of B6D2F1 hybrid male mice demonstrates steroid-independent male sexual behavior (identified as "maters"), providing a mouse model that opens up avenues of investigation into the mechanisms regulating male sexual behavior in the absence of gonadal hormones. Recent studies have revealed several proteins that play a significant factor in regulating steroid-independent male sexual behavior in B6D2F1 male mice, including amyloid precursor protein (APP), tau, and synaptophysin. The specific goals of our study were to determine whether steroid-independent male sexual behavior was a heritable trait by determining if it was dependent upon the behavioral phenotype of the B6D2F1 sire, and whether the differential expression of APP, tau, and synaptophysin in the medial preoptic area found in the B6D2F1 sires that did and did not mate after gonadectomy was similar to those found in their male offspring. After adult B6D2F1 male mice were bred with C57BL/6J female mice, they and their male offspring (BXB1) were orchidectomized and identified as either maters or "non-maters". A significant proportion of the BXB1 maters was sired only from B6D2F1 maters, indicating that the steroid-independent male sexual behavior behavioral phenotype of the B6D2F1 hybrid males, when crossed with C57BL/6J female mice, is inherited by their male offspring. Additionally, APP, tau, and synaptophysin were elevated in in the medial preoptic area in both the B6D2F1 and BXB1 maters relative to the B6D2F1 and BXB1 non-maters, respectively, suggesting a potential genetic mechanism for the inheritance of steroid-independent male sexual behavior. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of spinal cord injury-induced changes in muscle activation on foot drag in a computational rat ankle model

PubMed Central

Hillen, Brian K.; Jindrich, Devin L.; Abbas, James J.; Yamaguchi, Gary T.

2015-01-01

Spinal cord injury (SCI) can lead to changes in muscle activation patterns and atrophy of affected muscles. Moderate levels of SCI are typically associated with foot drag during the swing phase of locomotion. Foot drag is often used to assess locomotor recovery, but the causes remain unclear. We hypothesized that foot drag results from inappropriate muscle coordination preventing flexion at the stance-to-swing transition. To test this hypothesis and to assess the relative contributions of neural and muscular changes on foot drag, we developed a two-dimensional, one degree of freedom ankle musculoskeletal model with gastrocnemius and tibialis anterior muscles. Anatomical data collected from sham-injured and incomplete SCI (iSCI) female Long-Evans rats as well as physiological data from the literature were used to implement an open-loop muscle dynamics model. Muscle insertion point motion was calculated with imposed ankle trajectories from kinematic analysis of treadmill walking in sham-injured and iSCI animals. Relative gastrocnemius deactivation and tibialis anterior activation onset times were varied within physiologically relevant ranges based on simplified locomotor electromyogram profiles. No-atrophy and moderate muscle atrophy as well as normal and injured muscle activation profiles were also simulated. Positive moments coinciding with the transition from stance to swing phase were defined as foot swing and negative moments as foot drag. Whereas decreases in activation delay caused by delayed gastrocnemius deactivation promote foot drag, all other changes associated with iSCI facilitate foot swing. Our results suggest that even small changes in the ability to precisely deactivate the gastrocnemius could result in foot drag after iSCI. PMID:25673734

Effects of spinal cord injury-induced changes in muscle activation on foot drag in a computational rat ankle model.

PubMed

Hillen, Brian K; Jindrich, Devin L; Abbas, James J; Yamaguchi, Gary T; Jung, Ranu

2015-04-01

Spinal cord injury (SCI) can lead to changes in muscle activation patterns and atrophy of affected muscles. Moderate levels of SCI are typically associated with foot drag during the swing phase of locomotion. Foot drag is often used to assess locomotor recovery, but the causes remain unclear. We hypothesized that foot drag results from inappropriate muscle coordination preventing flexion at the stance-to-swing transition. To test this hypothesis and to assess the relative contributions of neural and muscular changes on foot drag, we developed a two-dimensional, one degree of freedom ankle musculoskeletal model with gastrocnemius and tibialis anterior muscles. Anatomical data collected from sham-injured and incomplete SCI (iSCI) female Long-Evans rats as well as physiological data from the literature were used to implement an open-loop muscle dynamics model. Muscle insertion point motion was calculated with imposed ankle trajectories from kinematic analysis of treadmill walking in sham-injured and iSCI animals. Relative gastrocnemius deactivation and tibialis anterior activation onset times were varied within physiologically relevant ranges based on simplified locomotor electromyogram profiles. No-atrophy and moderate muscle atrophy as well as normal and injured muscle activation profiles were also simulated. Positive moments coinciding with the transition from stance to swing phase were defined as foot swing and negative moments as foot drag. Whereas decreases in activation delay caused by delayed gastrocnemius deactivation promote foot drag, all other changes associated with iSCI facilitate foot swing. Our results suggest that even small changes in the ability to precisely deactivate the gastrocnemius could result in foot drag after iSCI. Copyright © 2015 the American Physiological Society.

EDITORIAL: Nanotechnology-based flexible electronics Nanotechnology-based flexible electronics

NASA Astrophysics Data System (ADS)

Subramanian, Vivek; Lee, Takhee

2012-08-01

Research on flexible electronics has grown exponentially over the last decade. Researchers around the globe are developing a wide range of flexible systems, including displays [1, 2], sensors [3-5], RFID tags [6, 7] and other similar devices [8]. Innovations in materials have been key to the increased research success in this field of research in recent years [9]. Transistors, interconnects, memory cells, passive components and other assorted devices all have challenging material demands for flexible electronics to become a reality. Nanomaterials of various kinds have been found to represent a tremendously powerful tool, with nanoparticles [10], nanotubes, nanowires [3, 11] and engineered organic molecules [12, 13] contributing to the realization of high-performance semiconductors, dielectrics and conductors for flexible electronics applications. Nanomaterials offer tunability in terms of performance, solution processability and processing temperature requirements, which makes them very attractive as building blocks for flexible electronic systems. Indeed, such systems represent some of the largest families of commercially produced nanomaterials today, and numerous commercial products based on nanoparticle formulations are widely available. This special issue focuses on the rapidly blossoming field of flexible electronics, with a particular focus on the use of nanotechnology to facilitate flexible electronic materials, processes, devices and systems. Contributions to the issue describe the development of nanomaterials—including nanoparticles, nanotubes, nanowires and carbon-based thin films—for use in conductors, transparent electrodes, semiconductors and dielectrics. The articles feature innovations in nanomanufacturing and novel materials, as well as the application of these technologies to advanced flexible devices and systems. As flexible electronics systems move rapidly towards successful commercial deployment, it is extremely likely that they will exploit nanomaterials as building blocks. Developments in the field will help to leverage the power of these materials to realize novel functionalities in flexible form factors. This special issue provides a view of the state of the art in these technologies, and gives a vision of the coming innovations that will make flexible electronics a reality. References [1] Gelinck G H et al 2004 Flexible active-matrix displays and shift registers based on solution-processed organic transistors Nature Mater. 3 106-10 [2] Zhou L, Wanga A, Wu S C, Sun J, Park S and Jackson T N 2006 All-organic active matrix flexible display Appl. Phys. Lett. 88 083502 [3] Fan Z, Ho J C, Jacobson Z A, Razavi H and Javey A 2008 Large-scale, heterogeneous integration of nanowire arrays for image sensor circuitry Proc. Natl Acad. Sci. 105 11066 [4] Sekitani T et al 2009 Organic nonvolatile memory transistors for flexible sensor arrays Science 326 1516-9 [5] Mannsfeld S C B et al 2010 Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers Nature Mater. 9 859-64 [6]Subramanian V, Frechet J M J, Chang P C, Huang D C, Lee J B, Molesa S E, Murphy A R, Redinger D R and Volkman S K 2005 Progress toward development of all-printed RFID tags: materials, processes, and devices Proc. IEEE 93 1330-8 [7] Jung M et al 2010 All-printed and roll-to-roll-printable 13.56 MHz-operated 1 bit RF tag on plastic foils IEEE Trans. Electron. Devices 57 571-80 [8] Kim D-H et al 2011 Epidermal electronics Science 333 838-43 [9] Wagner S and Bauer S 2012 Materials for stretchable electronics MRS Bull. 37 207 [10] Grouchko M, Kamyshny A and Magdassi S 2009 Formation of air-stable copper-silver core-shell nanoparticles for inkjet printing J. Mater. Chem. 19 3057-62 [11] Takei K et al 2010 Nanowire active-matrix circuitry for low-voltage macroscale artificial skin Nature Mater. 9 821-6 [12] Sekitani T, Zschieschang U, Klauk H and Someya T 2010 Flexible organic transistors and circuits with extreme bending stability Nature Mater. 9 1015-22 [13] Park S, Wang G, Cho B, Kim Y, Song S, Ji Y, Yoon M and Lee T 2012 Flexible molecular-scale electronic devices Nature Nanotechnol. 7 438-42

Cell-level temperature distributions in skeletal muscle post spinal cord injury as related to deep tissue injury.

PubMed

Ruschkewitz, Yael; Gefen, Amit

2010-02-01

Deep tissue injury (DTI) is a severe pressure ulcer, which initiates in skeletal muscle tissue under intact skin. Patients with spinal cord injury (SCI) are especially vulnerable to DTI, due to their impaired motosensory capacities. The underlying mechanisms that lead to DTI are, however, still poorly understood. This study focuses on cell-level temperature distributions in muscles of patients with SCI, which typically contain thinner muscle fibers and fewer capillaries. It has been shown previously by our group that ischemic muscles of rat models of DTI cool down mildly and locally, which is very likely to slow the diffusivity of metabolites in the ischemic regions. However, it is unclear how these temperature decreases affect diffusivity at the scale of individual muscle cells in the microanatomy of SCI patients. We hypothesize that a 2 degrees C drop in the temperature of inflowing capillary blood, as shown in our animal studies, has a substantial effect on lowering the diffusivity of metabolites in skeletal muscle, but the pathological microanatomy in the chronic phase of SCI is less dominant in affecting the local temperatures in and around muscle cells. In order to test this hypothesis, two-dimensional finite element (FE) models of cross sections through the microanatomy of muscle tissue were developed using COMSOL Multiphysics software for normal and SCI muscles. The models included muscle cells, extracellular matrix (ECM), and capillaries, each with its own geometrical, thermal, and heat production properties. The SCI model configuration specifically included reduced cross section of myofibrils in favor of more ECM, less capillaries, and decreased blood inflow rate. After a 20-s heat transfer simulation, it was found that temperatures around the cells of the SCI muscle were approximately 2 degrees C lower than that in the normal muscle, that is, heat production from the muscle cell metabolism did not compensate for the lower inflowing blood temperature in the SCI model. We conclude that the temperature and rate of inflowing capillary blood are the dominant factors determining the localized temperatures in the microarchitecture of an ischemic SCI muscle tissue. The altered SCI microanatomy was shown to be less influential. Taken together with the Stokes-Einstein theory, our results indicate that diffusivity of metabolites would be approximately 50% less around the cells of SCI muscle due to local cooling, which is yet another factor compromising tissue viability in the patients with SCI.

Biomechanical Modeling of the Human Head

DTIC Science & Technology

2017-10-03

between model predictions and experimental data. This report details model calibration for all materials identified in models of a human head and...14 3 Stress-strain data for the pia mater and dura mater (human subject); experimental data orig- inally presented in [28...treated as one material) based on a hyperelastic model and experimental data from [59] ............................................... 20 5 Comparison of

New Methods of Low-Field Magnetic Resonance Imaging for Application to Traumatic Brain Injury

DTIC Science & Technology

2012-02-01

Subdural hemor- rhage (or hematoma ) is a form of traumatic brain injury, in which blood gathers between the du- ra and arachnoid mater (in meningeal...to an hour. Subdural hemorrhage (or hematoma ) is a form of traumatic brain injury, in which blood gathers between the dura and arachnoid mater (in

Visualization of plasmon-enhanced photocarrier generation in ZnO/Ag nanogratings (Conference Presentation)

NASA Astrophysics Data System (ADS)

Gwon, Minji; Sohn, Ahrum; Cho, Yunae; Kim, Dong-Wook

2017-03-01

ZnO has attracted growing research attention as a strong candidate material for various optoelectronic device applications. It is important to understand and control the interactions between surface plasmons (SPs) and charge carriers in metal-ZnO hybrid nanostructures to improve the optical characteristics. In this work, we fabricated ZnO/Ag nanogratings using patterned polymer and Si templates. Excitation of the surface plasmon polaritons (SPPs) well explained the optical reflectance and photoluminescence spectra of the ZnO/Ag nanogratings [1,2]. Nanoscopic mapping of surface photovoltage (SPV), i.e., changes in the surface potential under illumination, obtained by Kelvin probe force microscopy (KPFM) enabled us to investigate the local behaviors of the photo-generated carriers. The magnitude and relaxation time of the measured SPV depended on the wavelength and polarization of the incident light [3]. This showed that the SP excitation in the nanogratings directly affected the creation and recombination processes of the charge carriers. All of these results suggested that SPV measurements using KPFM should be very useful for studying the SP effects in metal/semiconductor hybrid nanostructures. References [1] Gwon et al., Opt. Express 19, 5895 (2011). [2] Gwon et al., ACS Appl. Mater. Interfaces. 6, 8602 (2014). [3] Gwon et al., Sci. Rep. 5, 16727; doi: 10.1038/srep16727 (2015).

Polymer-silicon nanosheet composites: bridging the way to optoelectronic applications

NASA Astrophysics Data System (ADS)

Lyuleeva, Alina; Helbich, Tobias; Rieger, Bernhard; Lugli, Paolo

2017-04-01

The fabrication of electronic devices from sensitive, functional, two-dimensional (2D) nanomaterials with anisotropic structural properties has attracted much attention. Many theoretical and experimental studies have been performed; however, such materials have not been used in applications. In this context, the focus has shifted toward the study and synthesis of new materials. Freestanding hydrogen-terminated silicon nanosheets (SiNSs) are a new class of material with outstanding (opto)electronic properties (e.g. photoluminescence at approximately 510 nm) (Nakano 2014 J. Ceram. Soc. Japan 122 748). SiNSs are promising candidates for use in nanoelectronic devices and flexible electronics. Additional reasons for interest in such nanomaterials are their structural anisotropy and the fact that they are made from silicon. Here, we present examples for the application of functionalized SiNS-based composites as active materials for photonic sensors. The implementation of SiNSs in a covalent nanocomposite not only improves their stability but also facilitates subsequent device fabrication. Thus, SiNSs can be used in a straightforward setup preparation procedure. We show that the modification of novel Si-based 2D nanosheets with selected organic components not only opens a new field of photosensitive applications but also improves the processability of these nanosheets (Niu et al 2014 Sci. Rep. 4 4810, Chimene et al 2015 Adv. Mater. 27 7261).

Operation of a brain-computer interface walking simulator for individuals with spinal cord injury

PubMed Central

2013-01-01

Background Spinal cord injury (SCI) can leave the affected individuals with paraparesis or paraplegia, thus rendering them unable to ambulate. Since there are currently no restorative treatments for this population, novel approaches such as brain-controlled prostheses have been sought. Our recent studies show that a brain-computer interface (BCI) can be used to control ambulation within a virtual reality environment (VRE), suggesting that a BCI-controlled lower extremity prosthesis for ambulation may be feasible. However, the operability of our BCI has not yet been tested in a SCI population. Methods Five participants with paraplegia or tetraplegia due to SCI underwent a 10-min training session in which they alternated between kinesthetic motor imagery (KMI) of idling and walking while their electroencephalogram (EEG) were recorded. Participants then performed a goal-oriented online task, where they utilized KMI to control the linear ambulation of an avatar while making 10 sequential stops at designated points within the VRE. Multiple online trials were performed in a single day, and this procedure was repeated across 5 experimental days. Results Classification accuracy of idling and walking was estimated offline and ranged from 60.5% (p = 0.0176) to 92.3% (p = 1.36×10−20) across participants and days. Offline analysis revealed that the activation of mid-frontal areas mostly in the μ and low β bands was the most consistent feature for differentiating between idling and walking KMI. In the online task, participants achieved an average performance of 7.4±2.3 successful stops in 273±51 sec. These performances were purposeful, i.e. significantly different from the random walk Monte Carlo simulations (p<0.01), and all but one participant achieved purposeful control within the first day of the experiments. Finally, all participants were able to maintain purposeful control throughout the study, and their online performances improved over time. Conclusions The results of this study demonstrate that SCI participants can purposefully operate a self-paced BCI walking simulator to complete a goal-oriented ambulation task. The operation of the proposed BCI system requires short training, is intuitive, and robust against participant-to-participant and day-to-day neurophysiological variations. These findings indicate that BCI-controlled lower extremity prostheses for gait rehabilitation or restoration after SCI may be feasible in the future. PMID:23866985

Scidac-Data: Enabling Data Driven Modeling of Exascale Computing

NASA Astrophysics Data System (ADS)

Mubarak, Misbah; Ding, Pengfei; Aliaga, Leo; Tsaris, Aristeidis; Norman, Andrew; Lyon, Adam; Ross, Robert

2017-10-01

The SciDAC-Data project is a DOE-funded initiative to analyze and exploit two decades of information and analytics that have been collected by the Fermilab data center on the organization, movement, and consumption of high energy physics (HEP) data. The project analyzes the analysis patterns and data organization that have been used by NOvA, MicroBooNE, MINERvA, CDF, D0, and other experiments to develop realistic models of HEP analysis workflows and data processing. The SciDAC-Data project aims to provide both realistic input vectors and corresponding output data that can be used to optimize and validate simulations of HEP analysis. These simulations are designed to address questions of data handling, cache optimization, and workflow structures that are the prerequisites for modern HEP analysis chains to be mapped and optimized to run on the next generation of leadership-class exascale computing facilities. We present the use of a subset of the SciDAC-Data distributions, acquired from analysis of approximately 71,000 HEP workflows run on the Fermilab data center and corresponding to over 9 million individual analysis jobs, as the input to detailed queuing simulations that model the expected data consumption and caching behaviors of the work running in high performance computing (HPC) and high throughput computing (HTC) environments. In particular we describe how the Sequential Access via Metadata (SAM) data-handling system in combination with the dCache/Enstore-based data archive facilities has been used to develop radically different models for analyzing the HEP data. We also show how the simulations may be used to assess the impact of design choices in archive facilities.

Mater Academy Charter Middle School: Consistent Expectations

ERIC Educational Resources Information Center

Principal Leadership, 2010

2010-01-01

Mater Academy Charter Middle/High School is located in what was once a big box store in a commercial and industrial area of Hialeah Gardens, FL. The same energy that transformed a vacant store into a thriving campus for a grades 6-12 school is apparent in every classroom. Even the mayor of Hialeah Gardens credits the school with helping to…

First-principles Calculations of Twin-boundary and Stacking-fault Energies in Magnesium

DTIC Science & Technology

2010-01-01

Vasu KI. Scripta Mater 1969;3:927. [7] Couret A, Caillard D. Acta Metall 1985;33:1455. [8] Fleischer RL . Scripta Mater 1986;20:223. [9] Liu ZK. J...Jackson KA, Pederson MR, Singh DJ, Fiolhais C. Phys Rev B 1992;46:6671. [17] Kresse G, Furthmuller J. Phys Rev B 1996;54:11169. [18] Kresse G, Joubert

Vertical osteoconductivity of sputtered hydroxyapatite-coated mini titanium implants after dura mater elevation: Rabbit calvarial model.

PubMed

Wang, Xin; Zakaria, Osama; Madi, Marwa; Kasugai, Shohei

2015-01-01

This study evaluated the quantity and quality of newly formed vertical bone induced by sputtered hydroxyapatite-coated titanium implants compared with sandblasted acid-etched implants after dura mater elevation. Hydroxyapatite-coated and non-coated implants (n = 20/group) were used and divided equally into two groups. All implants were randomly placed into rabbit calvarial bone (four implants for each animal) emerging from the inferior cortical layer, displacing the dura mater 3 mm below the original bone. Animals were sacrificed at 4 (n = 5) and 8 (n = 5) weeks post-surgery. Vertical bone height and area were analyzed histologically and radiographically below the original bone. Vertical bone formation was observed in both groups. At 4 and 8 weeks, vertical bone height reached a significantly higher level in the hydroxyapatite compared with the non-coated group (p < 0.05). Vertical bone area was significantly larger in the hydroxyapatite compared with the non-coated group at 4 and 8 weeks (p < 0.05). This study indicates that vertical bone formation can be induced by dura mater elevation and sputtered hydroxyapatite coating can enhance vertical bone formation.

ESIM: Edge Similarity for Screen Content Image Quality Assessment.

PubMed

Ni, Zhangkai; Ma, Lin; Zeng, Huanqiang; Chen, Jing; Cai, Canhui; Ma, Kai-Kuang

2017-10-01

In this paper, an accurate full-reference image quality assessment (IQA) model developed for assessing screen content images (SCIs), called the edge similarity (ESIM), is proposed. It is inspired by the fact that the human visual system (HVS) is highly sensitive to edges that are often encountered in SCIs; therefore, essential edge features are extracted and exploited for conducting IQA for the SCIs. The key novelty of the proposed ESIM lies in the extraction and use of three salient edge features-i.e., edge contrast, edge width, and edge direction. The first two attributes are simultaneously generated from the input SCI based on a parametric edge model, while the last one is derived directly from the input SCI. The extraction of these three features will be performed for the reference SCI and the distorted SCI, individually. The degree of similarity measured for each above-mentioned edge attribute is then computed independently, followed by combining them together using our proposed edge-width pooling strategy to generate the final ESIM score. To conduct the performance evaluation of our proposed ESIM model, a new and the largest SCI database (denoted as SCID) is established in our work and made to the public for download. Our database contains 1800 distorted SCIs that are generated from 40 reference SCIs. For each SCI, nine distortion types are investigated, and five degradation levels are produced for each distortion type. Extensive simulation results have clearly shown that the proposed ESIM model is more consistent with the perception of the HVS on the evaluation of distorted SCIs than the multiple state-of-the-art IQA methods.

Complex dynamics of a delayed discrete neural network of two nonidentical neurons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yuanlong; Huang, Tingwen; Huang, Yu, E-mail: stshyu@mail.sysu.edu.cn

2014-03-15

In this paper, we discover that a delayed discrete Hopfield neural network of two nonidentical neurons with self-connections and no self-connections can demonstrate chaotic behaviors. To this end, we first transform the model, by a novel way, into an equivalent system which has some interesting properties. Then, we identify the chaotic invariant set for this system and show that the dynamics of this system within this set is topologically conjugate to the dynamics of the full shift map with two symbols. This confirms chaos in the sense of Devaney. Our main results generalize the relevant results of Huang and Zoumore » [J. Nonlinear Sci. 15, 291–303 (2005)], Kaslik and Balint [J. Nonlinear Sci. 18, 415–432 (2008)] and Chen et al. [Sci. China Math. 56(9), 1869–1878 (2013)]. We also give some numeric simulations to verify our theoretical results.« less

Complex dynamics of a delayed discrete neural network of two nonidentical neurons.

PubMed

Chen, Yuanlong; Huang, Tingwen; Huang, Yu

2014-03-01

In this paper, we discover that a delayed discrete Hopfield neural network of two nonidentical neurons with self-connections and no self-connections can demonstrate chaotic behaviors. To this end, we first transform the model, by a novel way, into an equivalent system which has some interesting properties. Then, we identify the chaotic invariant set for this system and show that the dynamics of this system within this set is topologically conjugate to the dynamics of the full shift map with two symbols. This confirms chaos in the sense of Devaney. Our main results generalize the relevant results of Huang and Zou [J. Nonlinear Sci. 15, 291-303 (2005)], Kaslik and Balint [J. Nonlinear Sci. 18, 415-432 (2008)] and Chen et al. [Sci. China Math. 56(9), 1869-1878 (2013)]. We also give some numeric simulations to verify our theoretical results.

Impact of holmium fibre laser radiation (λ = 2.1 μm) on the spinal cord dura mater and adipose tissue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Filatova, S A; Kamynin, V A; Ryabova, A V

The impact of holmium fibre laser radiation on the samples of biologic tissues (dura mater of spinal cord and adipose tissue with interlayers of muscle) is studied. The experimental results are evaluated by the size of carbonisation and coagulation necrosis zones. The experiment shows that in the case of irradiation of the spinal cord dura mater samples the size of carbonisation and coagulation necrosis zones is insignificant. In the adipose tissue the carbonisation zone is also insignificant, but the region of cellular structure disturbance is large. In the muscle tissue the situation is opposite. The cw laser operation provides clinicallymore » acceptable degree of destruction in tissue samples with a minimal carbonisation zone. (laser applications in medicine)« less

Biocompatibility and mechanical properties of diamond-like coatings on cobalt-chromium-molybdenum steel and titanium-aluminum-vanadium biomedical alloys.

PubMed

Hinüber, C; Kleemann, C; Friederichs, R J; Haubold, L; Scheibe, H J; Schuelke, T; Boehlert, C; Baumann, M J

2010-11-01

Diamond-like carbon (DLC) films are favored for wear components because of diamond-like hardness, low friction, low wear, and high corrosion resistance (Schultz et al., Mat-wiss u Werkstofftech 2004;35:924-928; Lappalainen et al., J Biomed Mater Res B Appl Biomater 2003;66B:410-413; Tiainen, Diam Relat Mater 2001;10:153-160). Several studies have demonstrated their inertness, nontoxicity, and the biocompatibility, which has led to interest among manufacturers of surgical implants (Allen et al., J Biomed Mater Res B Appl Biomater 2001;58:319-328; Uzumaki et al., Diam Relat Mater 2006;15:982-988; Hauert, Diam Relat Mater 2003;12:583-589; Grill, Diam Relat Mater 2003;12:166-170). In this study, hydrogen-free amorphous, tetrahedrally bonded DLC films (ta-C) were deposited at low temperatures by physical vapor deposition on medical grade Co28Cr6Mo steel and the titanium alloy Ti6Al4V (Scheibe et al., Surf Coat Tech 1996;85:209-214). The mechanical performance of the ta-C was characterized by measuring its surface roughness, contact angle, adhesion, and wear behavior, whereas the biocompatibility was assessed by osteoblast (OB) attachment and cell viability via Live/Dead assay. There was no statistical difference found in the wettability as measured by contact angle measurements for the ta-C coated and the uncoated samples of either Co28Cr6Mo or Ti6Al4V. Rockwell C indentation and dynamic scratch testing on 2-10 μm thick ta-C films on Co28Cr6Mo substrates showed excellent adhesion with HF1 grade and up to 48 N for the critical load L(C2) during scratch testing. The ta-C coating reduced the wear from 3.5 × 10(-5) mm(3)/Nm for an uncoated control sample (uncoated Co28Cr6Mo against uncoated stainless steel) to 1.1 × 10(-7) mm(3)/Nm (coated Co28Cr6Mo against uncoated stainless steel) in reciprocating pin-on-disk testing. The lowest wear factor of 3.9 × 10(-10) mm(3)/Nm was measured using a ta-C coated steel ball running against a ta-C coated and polished Co28Cr6Mo disk. Student's t-test found that the ta-C coating had no statistically significant (p < 0.05) effect on OB attachment, when compared with the uncoated control samples. There was no significant difference (p < 0.05) in the Live/Dead assay results in cell death between the ta-C coated Co28Cr6Mo and Ti6Al4V samples and the uncoated controls. Therefore, these ta-C coatings show improved wear and corrosion (Dorner-Reisel et al., Diam Relat Mater 2003;11:823-827; Affato et al., J Biomed Mater Res B Appl Biomater 2000;53:221-226; Dorner-Reisel et al., Surf Coat Tech 2004;177-178:830-837; Kim et al., Diam Relat Mater 2004;14:35-41) performance and excellent in vitro cyto-compatibility, when compared with currently used uncoated Co28Cr6Mo and Ti6Al4V implant materials.

Face-Centred Cubic Iron: Ab Initio Calculations of Sound Velocities in the Lunar Core

NASA Astrophysics Data System (ADS)

Wood, M. C.; Wood, I. G.; Vočadlo, L.

2017-12-01

Studies, such as the reanalysis of the Apollo lunar seismograms [1], have shown that the Moon has undergone differentiation and possesses a small core. The composition of the lunar core is not well constrained, and many compositional models have been suggested including combinations of iron, nickel, and light elements such as sulphur and carbon [e.g. 1, 2, 3, 4], and other more exotic compositions [5]. Additional constraints are crucial to our understanding of the Moon, including its formation, the dynamics of its interior, and a lunar dynamo. We use ab initio molecular dynamics simulations to calculate elastic constants of face-centred cubic (fcc) iron and iron alloys and hence sound velocities at lunar core conditions, at 5-6 GPa and 1,300-1,900 K [3]. The results from these simulations will then be compared with the data from the Apollo seismograms and experimental data to help form a description of the lunar interior. [1] Weber et al. (2011) Science 331, 309-312. [2] Dasgupta et al. (2009) Geochim. Cosmochim. Acta 73, 6678-6692. [3] Antonangeli et al. (2015) Proc. Natl. Acad. Sci. U.S.A. 112, 3916-3919. [4] Righter et al. (2017) Earth Planet. Sci. Lett. 463, 323-332. [5] Wieczorek & Zuber (2002) Lunar Planet. Sci. 33, abstract 1384.

Comparison of predicted pesticide concentrations in groundwater from SCI-GROW and PRZM-GW models with historical monitoring data.

PubMed

Estes, Tammara L; Pai, Naresh; Winchell, Michael F

2016-06-01

A key factor in the human health risk assessment process for the registration of pesticides by the US Environmental Protection Agency (EPA) is an estimate of pesticide concentrations in groundwater used for drinking water. From 1997 to 2011, these estimates were obtained from the EPA empirical model SCI-GROW. Since 2012, these estimates have been obtained from the EPA deterministic model PRZM-GW, which has resulted in a significant increase in estimated groundwater concentrations for many pesticides. Historical groundwater monitoring data from the National Ambient Water Quality Assessment (NAWQA) Program (1991-2014) were compared with predicted groundwater concentrations from both SCI-GROW (v.2.3) and PRZM-GW (v.1.07) for 66 different pesticides of varying environmental fate properties. The pesticide environmental fate parameters associated with over- and underprediction of groundwater concentrations by the two models were evaluated. In general, SCI-GROW2.3 predicted groundwater concentrations were close to maximum historically observed groundwater concentrations. However, for pesticides with soil organic carbon content values below 1000 L kg(-1) and no simulated hydrolysis, PRZM-GW overpredicted, often by greater than 100 ppb. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

UV-light induced fabrication of CdCl2 nanotubes through CdSe/Te nanocrystals based on dimension and configuration control.

PubMed

Zeng, Jie; Liu, Chi; Huang, Jianliu; Wang, Xiaoping; Zhang, Shuyuan; Li, Gongpu; Hou, Jianguo

2008-05-01

Since the discovery of WS2 nanotubes in 1992 ( Nature 1992, 360, 444), there have been significant research efforts to synthesize nanotubes and fullerene-like hollow nanoparticles (HNPs) of inorganic materials ( Nat. Nanotechnol. 2006, 1, 103) due to their potential applications as solid lubrications ( J. Mater. Chem. 2005, 15, 1782), chemical sensing ( Adv. Funct. Mater. 2006, 16, 371), drug delivering ( J. Am. Chem. Soc. 2005, 127, 7316), catalysis ( Adv. Mater. 2006, 18, 2561), or quantum harvesting ( Acc. Chem. Res. 2006, 39, 239). Nanotubes can be produced either by rolling up directly from layer compounds ( Nature 2001, 410, 168) or through other mechanisms ( Adv. Mater. 2004, 16, 1497) such as template growth ( Nature 2003, 422, 599) and decomposition ( J. Am. Chem. Soc. 2001, 123, 4841). The Kirkendall effect, a classical phenomenon in metallurgy ( Trans. AIME 1947, 171, 130), was recently exploited to fabricate hollow 0-D nanocrystals ( Science 2004, 304, 711) as well as 1-D nanotubes ( Nat. Mater. 2006, 5, 627). Although the dimension of resulting hollow nanostructures depends on precursors, the hollow nanomaterials can also be organized into various dimensional nanostructures spontaneously or induced by an external field. In this letter, we report, for the first time, the UV-light induced fabrication of the ends-closed 1-D CdCl2 nanotubes from 0-D CdSe solid nanocrystals through the Kirkendall effect and the head-to-end assembled process. Our results demonstrate the possibility to control the dimension (0-D to 1-D) and the configuration (solid to hollow) of nanostructures simultaneously and have implications in fabricating hollow nano-objects from zero-dimensional to multidimensional.

Effect of electrical stimulation on neural regeneration via the p38-RhoA and ERK1/2-Bcl-2 pathways in spinal cord-injured rats

PubMed Central

Joo, Min Cheol; Jang, Chul Hwan; Park, Jong Tae; Choi, Seung Won; Ro, Seungil; Kim, Min Seob; Lee, Moon Young

2018-01-01

Although electrical stimulation is therapeutically applied for neural regeneration in patients, it remains unclear how electrical stimulation exerts its effects at the molecular level on spinal cord injury (SCI). To identify the signaling pathway involved in electrical stimulation improving the function of injured spinal cord, 21 female Sprague-Dawley rats were randomly assigned to three groups: control (no surgical intervention, n = 6), SCI (SCI only, n = 5), and electrical simulation (ES; SCI induction followed by ES treatment, n = 10). A complete spinal cord transection was performed at the 10th thoracic level. Electrical stimulation of the injured spinal cord region was applied for 4 hours per day for 7 days. On days 2 and 7 post SCI, the Touch-Test Sensory Evaluators and the Basso-Beattie-Bresnahan locomotor scale were used to evaluate rat sensory and motor function. Somatosensory-evoked potentials of the tibial nerve of a hind paw of the rat were measured to evaluate the electrophysiological function of injured spinal cord. Western blot analysis was performed to measure p38-RhoA and ERK1/2-Bcl-2 pathways related protein levels in the injured spinal cord. Rat sensory and motor functions were similar between SCI and ES groups. Compared with the SCI group, in the ES group, the latencies of the somatosensory-evoked potential of the tibial nerve of rats were significantly shortened, the amplitudes were significantly increased, RhoA protein level was significantly decreased, protein gene product 9.5 expression, ERK1/2, p38, and Bcl-2 protein levels in the spinal cord were significantly increased. These data suggest that ES can promote the recovery of electrophysiological function of the injured spinal cord through regulating p38-RhoA and ERK1/2-Bcl-2 pathway-related protein levels in the injured spinal cord. PMID:29557386

Is IQ in Childhood Associated with Suicidal Thoughts and Attempts? Findings from the Mater University Study of Pregnancy and Its Outcomes

ERIC Educational Resources Information Center

Alati, Rosa; Gunnell, David; Najman, Jake; Williams, Gail; Lawlor, Debbie

2009-01-01

This study explores associations of IQ at age 14 with adult symptoms of suicidal thoughts and attempts at age 21. Analysis was based on the Mater University Study of Pregnancy and its outcomes, an Australian prospective birth cohort study started in Brisbane Australia in 1981. We assessed associations with suicide thoughts, plans, and attempts. We…

Comment on papers ``Effect of Ag substitution on the transport property and magnetoresistance of LaMnO3'' [J. Magn. Magn. Mater. 248 (2002) 26] and ``Possible magnetic phase separation in Ru-doped La0.67Ca0.33O3'' [J. Magn. Magn. Mater. 257 (2003) 195

NASA Astrophysics Data System (ADS)

Rozenberg, E.

2004-03-01

In recent papers Ye et al. (J. Magn. Magn. Mater. 248 (2002) 26) and Lakshmi et al. (J. Magn. Magn. Mater. 257 (2003) 195) reported the characteristic features of electrical resistivity ( ρ) versus temperature ( T) dependences of polycrystalline-doped manganites La 1- xAg xMnO 3 and La 0.67Ca 0.33Mn 1- xRu xO 3. Infact, two peaks on ρ( T) curve coexist: broad one at some Tmax below the Curie points ( TC) of these compounds and a sharp peak near TC. Authors interpreted such coexistence as an evidence of electronic/magnetic phase separation in the above-noted systems below its TC. It is shown in this comment that such an interpretation is obviously invalid for La 1- xAg xMnO 3 system and is very questionable for La 0.67Ca 0.33Mn 1- xRu xO 3. The simplest and natural reason for the appearance of considered features on ρ( T) dependences of polycrystalline manganites is the well-known grain-boundary effects.

Self-Replenishing Vascularized Fouling-Release Surfaces

DTIC Science & Technology

2014-01-01

similar results. Surfaces submerged for 12 days in static cultures of B. braunii, a green microalga known for its potential in the algae biofuels...Technol. 2004, 32, 219−222. (12) Kirschner, C. M.; Brennan, A. B. Bio -Inspired Antifouling Strategies. Annu. Rev. Mater. Res. 2012, 42, 211−229. (13...Release from Fouling Release Coatings. Biofouling 2000, 15, 73−81. (25) Liu, K.; Jiang, L. Bio -Inspired Self-Cleaning Surfaces. Annu. Rev. Mater. Res

Final Report for "Tech-X Corporation work for the SciDAC Center for Simulation of RF Wave Interactions with Magnetohydrodynamics (SWIM)"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jenkins, Thomas G.; Kruger, Scott E.

Work carried out by Tech-X Corporation for the DoE SciDAC Center for Simulation of RF Wave Interactions with Magnetohydrodynamics (SWIM; U.S. DoE Office of Science Award Number DE-FC02-06ER54899) is summarized and is shown to fulfil the project objectives. The Tech-X portion of the SWIM work focused on the development of analytic and computational approaches to study neoclassical tearing modes and their interaction with injected electron cyclotron current drive. Using formalism developed by Hegna, Callen, and Ramos [Phys. Plasmas 16, 112501 (2009); Phys. Plasmas 17, 082502 (2010); Phys. Plasmas 18, 102506 (2011)], analytic approximations for the RF interaction were derived andmore » the numerical methods needed to implement these interactions in the NIMROD extended MHD code were developed. Using the SWIM IPS framework, NIMROD has successfully coupled to GENRAY, an RF ray tracing code; additionally, a numerical control system to trigger the RF injection, adjustment, and shutdown in response to tearing mode activity has been developed. We discuss these accomplishments, as well as prospects for ongoing future research that this work has enabled (which continue in a limited fashion under the SciDAC Center for Extended Magnetohydrodynamic Modeling (CEMM) project and under a baseline theory grant). Associated conference presentations, published articles, and publications in progress are also listed.« less

Inheritance of steroid-independent male sexual behavior in male offspring of B6D2F1 mice

PubMed Central

McInnis, Christine M.; Bonthuis, Paul J.; Rissman, Emilie F.; Park, Jin Ho

2016-01-01

The importance of gonadal steroids in modulating male sexual behavior is well established. Individual differences in male sexual behavior, independent of gonadal steroids, are prevalent across a wide range of species, including man. However, the genetic mechanisms underlying steroid-independent male sexual behavior are poorly understood. A high proportion of B6D2F1 hybrid male mice demonstrate steroid-independent male sexual behavior (identified as “maters”), providing a mouse model that opens up avenues of investigation into the mechanisms regulating male sexual behavior in the absence of gonadal hormones. Recent studies have revealed several proteins that play a significant factor in regulating steroid-independent male sexual behavior in B6D2F1 male mice, including amyloid precursor protein (APP), tau, and synaptophysin. The specific goals of our study were to determine whether steroid-independent male sexual behavior was a heritable trait by determining if it was dependent upon the behavioral phenotype of the B6D2F1 sire, and whether the differential expression of APP, tau, and synaptophysin in the medial preoptic area found in the B6D2F1 sires that did and did not mate after gonadectomy was similar to those found in their male offspring. After adult B6D2F1 male mice were bred with C57BL/6J female mice, they and their male offspring (BXB1) were orchidectomized and identified as either maters or “non-maters.” A significant proportion of the BXB1 maters were sired only from B6D2F1 maters, indicating that the steroid-independent male sexual behavior behavioral phenotype of the B6D2F1 hybrid males, when crossed with C57BL/6J female mice, is inherited by their male offspring. Additionally, APP, tau, and synaptophysin were elevated in in the medial preoptic area in both the B6D2F1 and BXB1 maters relative to the B6D2F1 and BXB1 non-maters, respectively, suggesting a potential genetic mechanism for the inheritance of steroid-independent male sexual behavior. PMID:26940434

Tensile Fracture Behavior of 316L Austenitic Stainless Steel Manufactured by Hot Isostatic Pressing

NASA Astrophysics Data System (ADS)

Cooper, A. J.; Brayshaw, W. J.; Sherry, A. H.

2018-02-01

Herein we investigate how the oxygen content in hot isostatically pressed (HIP'd) 316L stainless steel affects the mechanical properties and tensile fracture behavior. This work follows on from previous studies, which aimed to understand the effect of oxygen content on the Charpy impact toughness of HIP'd steel. We expand on the work by performing room-temperature tensile testing on different heats of 316L stainless steel, which contain different levels of interstitial elements (carbon and nitrogen) as well as oxygen in the bulk material. Throughout the work we repeat the experiments on conventionally forged 316L steel as a reference material. The analysis of the work indicates that oxygen does not contribute to a measureable solution strengthening mechanism, as is the case with carbon and nitrogen in austenitic stainless steels (Werner in Mater Sci Eng A 101:93-98, 1988). Neither does oxygen, in the form of oxide inclusions, contribute to precipitation hardening due to the size and spacing of particles. However, the oxide particles do influence fracture behavior; fractography of the failed tension test specimens indicates that the average ductile dimple size is related to the oxygen content in the bulk material, the results of which support an on-going hypothesis relating oxygen content in HIP'd steels to their fracture mechanisms by providing additional sites for the initiation of ductile damage in the form of voids.

Work function and quantum efficiency study of metal oxide thin films on Ag(100)

NASA Astrophysics Data System (ADS)

Chang, V.; Noakes, T. C. Q.; Harrison, N. M.

2018-04-01

Increasing the quantum efficiency (QE) of metal photocathodes is in the design and development of photocathodes for free-electron laser applications. The growth of metal oxide thin films on certain metal surfaces has previously been shown to reduce the work function (WF). Using a photoemission model B. Camino et al. [Comput. Mater. Sci. 122, 331 (2016), 10.1016/j.commatsci.2016.05.025] based on the three-step model combined with density functional theory calculations we predict that the growth of a finite number of MgO(100) or BaO(100) layers on the Ag(100) surface increases significantly the QE compared with the clean Ag(100) surface for a photon energy of 4.7 eV. Different mechanisms for affecting the QE are identified for the different metal oxide thin films. The addition of MgO(100) increases the QE due to the reduction of the WF and the direct excitation of electrons from the Ag surface to the MgO conduction band. For BaO(100) thin films, an additional mechanism is in operation as the oxide film also photoemits at this energy. We also note that a significant increase in the QE for photons with an energy of a few eV above the WF is achieved due to an increase in the inelastic mean-free path of the electrons.

Musculoskeletal Model-Guided, Customizable Selection of Shoulder and Elbow Muscles for a C5 SCI Neuroprosthesis

PubMed Central

Hincapie, Juan Gabriel; Blana, Dimitra; Chadwick, Edward K.; Kirsch, Robert F.

2010-01-01

Individuals with C5/C6 spinal cord injury (SCI) have a number of paralyzed muscles in their upper extremities that can be electrically activated in a coordinated manner to restore function. The selection of a practical subset of paralyzed muscles for stimulation depends on the specific condition of the individual, the functions targeted for restoration, and surgical considerations. This paper presents a musculoskeletal model-based approach for optimizing the muscle set used for functional electrical stimulation (FES) of the shoulder and elbow in this population. Experimentally recorded kinematics from able-bodied subjects served as inputs to a musculoskeletal model of the shoulder and elbow, which was modified to reflect the reduced muscle force capacities of an individual with C5 SCI but also the potential of using FES to activate paralyzed muscles. A large number of inverse dynamic simulations mimicking typical activities of daily living were performed that included 1) muscles with retained voluntary control and 2) many different combinations of stimulated paralyzed muscles. These results indicate that a muscle set consisting of the serratus anterior, infraspinatus and triceps would enable the greatest range of relevant movements. This set will become the initial target in a C5 SCI neuroprosthesis to restore shoulder and elbow function. PMID:18586604

Scidac-Data: Enabling Data Driven Modeling of Exascale Computing

DOE PAGES

Mubarak, Misbah; Ding, Pengfei; Aliaga, Leo; ...

2017-11-23

Here, the SciDAC-Data project is a DOE-funded initiative to analyze and exploit two decades of information and analytics that have been collected by the Fermilab data center on the organization, movement, and consumption of high energy physics (HEP) data. The project analyzes the analysis patterns and data organization that have been used by NOvA, MicroBooNE, MINERvA, CDF, D0, and other experiments to develop realistic models of HEP analysis workflows and data processing. The SciDAC-Data project aims to provide both realistic input vectors and corresponding output data that can be used to optimize and validate simulations of HEP analysis. These simulationsmore » are designed to address questions of data handling, cache optimization, and workflow structures that are the prerequisites for modern HEP analysis chains to be mapped and optimized to run on the next generation of leadership-class exascale computing facilities. We present the use of a subset of the SciDAC-Data distributions, acquired from analysis of approximately 71,000 HEP workflows run on the Fermilab data center and corresponding to over 9 million individual analysis jobs, as the input to detailed queuing simulations that model the expected data consumption and caching behaviors of the work running in high performance computing (HPC) and high throughput computing (HTC) environments. In particular we describe how the Sequential Access via Metadata (SAM) data-handling system in combination with the dCache/Enstore-based data archive facilities has been used to develop radically different models for analyzing the HEP data. We also show how the simulations may be used to assess the impact of design choices in archive facilities.« less

Extraordinary Tools for Extraordinary Science: The Impact ofSciDAC on Accelerator Science&Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryne, Robert D.

2006-08-10

Particle accelerators are among the most complex and versatile instruments of scientific exploration. They have enabled remarkable scientific discoveries and important technological advances that span all programs within the DOE Office of Science (DOE/SC). The importance of accelerators to the DOE/SC mission is evident from an examination of the DOE document, ''Facilities for the Future of Science: A Twenty-Year Outlook''. Of the 28 facilities listed, 13 involve accelerators. Thanks to SciDAC, a powerful suite of parallel simulation tools has been developed that represent a paradigm shift in computational accelerator science. Simulations that used to take weeks or more now takemore » hours, and simulations that were once thought impossible are now performed routinely. These codes have been applied to many important projects of DOE/SC including existing facilities (the Tevatron complex, the Relativistic Heavy Ion Collider), facilities under construction (the Large Hadron Collider, the Spallation Neutron Source, the Linac Coherent Light Source), and to future facilities (the International Linear Collider, the Rare Isotope Accelerator). The new codes have also been used to explore innovative approaches to charged particle acceleration. These approaches, based on the extremely intense fields that can be present in lasers and plasmas, may one day provide a path to the outermost reaches of the energy frontier. Furthermore, they could lead to compact, high-gradient accelerators that would have huge consequences for US science and technology, industry, and medicine. In this talk I will describe the new accelerator modeling capabilities developed under SciDAC, the essential role of multi-disciplinary collaboration with applied mathematicians, computer scientists, and other IT experts in developing these capabilities, and provide examples of how the codes have been used to support DOE/SC accelerator projects.« less

Responses of the Acutely Injured Spinal Cord to Vibration that Simulates Transport in Helicopters or Mine-Resistant Ambush-Protected Vehicles.

PubMed

Streijger, Femke; Lee, Jae H T; Manouchehri, Neda; Melnyk, Angela D; Chak, Jason; Tigchelaar, Seth; So, Kitty; Okon, Elena B; Jiang, Shudong; Kinsler, Rachel; Barazanji, Khalid; Cripton, Peter A; Kwon, Brian K

2016-12-15

In the military environment, injured soldiers undergoing medical evacuation via helicopter or mine-resistant ambush-protected vehicle (MRAP) are subjected to vibration and shock inherent to the transport vehicle. We conducted the present study to assess the consequences of such vibration on the acutely injured spinal cord. We used a porcine model of spinal cord injury (SCI). After a T10 contusion-compression injury, animals were subjected to 1) no vibration (n = 7-8), 2) whole body vibration at frequencies and amplitudes simulating helicopter transport (n = 8), or 3) whole body vibration simulating ground transportation in an MRAP ambulance (n = 7). Hindlimb locomotor function (using Porcine Thoracic Injury Behavior Scale [PTIBS]), Eriochrome Cyanine histochemistry and biochemical analysis of inflammatory and neural damage markers were analyzed. Cerebrospinal fluid (CSF) expression levels for monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-6, IL-8, and glial fibrillary acidic protein (GFAP) were similar between the helicopter or MRAP group and the unvibrated controls. Spared white/gray matter tended to be lower in the MRAP-vibrated animals than in the unvibrated controls, especially rostral to the epicenter. However, spared white/gray matter in the helicopter-vibrated group appeared normal. Although there was a relationship between the extent of sparing and the extent of locomotor recovery, no significant differences were found in PTIBS scores between the groups. In summary, exposures to vibration in the context of ground (MRAP) or aeromedical (helicopter) transportation did not significantly impair functional outcome in our large animal model of SCI. However, MRAP vibration was associated with increased tissue damage around the injury site, warranting caution around exposure to vehicle vibration acutely after SCI.

Extraordinary tools for extraordinary science: the impact of SciDAC on accelerator science and technology

NASA Astrophysics Data System (ADS)

Ryne, Robert D.

2006-09-01

Particle accelerators are among the most complex and versatile instruments of scientific exploration. They have enabled remarkable scientific discoveries and important technological advances that span all programs within the DOE Office of Science (DOE/SC). The importance of accelerators to the DOE/SC mission is evident from an examination of the DOE document, ''Facilities for the Future of Science: A Twenty-Year Outlook.'' Of the 28 facilities listed, 13 involve accelerators. Thanks to SciDAC, a powerful suite of parallel simulation tools has been developed that represent a paradigm shift in computational accelerator science. Simulations that used to take weeks or more now take hours, and simulations that were once thought impossible are now performed routinely. These codes have been applied to many important projects of DOE/SC including existing facilities (the Tevatron complex, the Relativistic Heavy Ion Collider), facilities under construction (the Large Hadron Collider, the Spallation Neutron Source, the Linac Coherent Light Source), and to future facilities (the International Linear Collider, the Rare Isotope Accelerator). The new codes have also been used to explore innovative approaches to charged particle acceleration. These approaches, based on the extremely intense fields that can be present in lasers and plasmas, may one day provide a path to the outermost reaches of the energy frontier. Furthermore, they could lead to compact, high-gradient accelerators that would have huge consequences for US science and technology, industry, and medicine. In this talk I will describe the new accelerator modeling capabilities developed under SciDAC, the essential role of multi-disciplinary collaboration with applied mathematicians, computer scientists, and other IT experts in developing these capabilities, and provide examples of how the codes have been used to support DOE/SC accelerator projects.

Scidac-Data: Enabling Data Driven Modeling of Exascale Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mubarak, Misbah; Ding, Pengfei; Aliaga, Leo

Here, the SciDAC-Data project is a DOE-funded initiative to analyze and exploit two decades of information and analytics that have been collected by the Fermilab data center on the organization, movement, and consumption of high energy physics (HEP) data. The project analyzes the analysis patterns and data organization that have been used by NOvA, MicroBooNE, MINERvA, CDF, D0, and other experiments to develop realistic models of HEP analysis workflows and data processing. The SciDAC-Data project aims to provide both realistic input vectors and corresponding output data that can be used to optimize and validate simulations of HEP analysis. These simulationsmore » are designed to address questions of data handling, cache optimization, and workflow structures that are the prerequisites for modern HEP analysis chains to be mapped and optimized to run on the next generation of leadership-class exascale computing facilities. We present the use of a subset of the SciDAC-Data distributions, acquired from analysis of approximately 71,000 HEP workflows run on the Fermilab data center and corresponding to over 9 million individual analysis jobs, as the input to detailed queuing simulations that model the expected data consumption and caching behaviors of the work running in high performance computing (HPC) and high throughput computing (HTC) environments. In particular we describe how the Sequential Access via Metadata (SAM) data-handling system in combination with the dCache/Enstore-based data archive facilities has been used to develop radically different models for analyzing the HEP data. We also show how the simulations may be used to assess the impact of design choices in archive facilities.« less

Interaction of micron and nano-sized particles with cells of the dura mater.

PubMed

Papageorgiou, Iraklis; Marsh, Rainy; Tipper, Joanne L; Hall, Richard M; Fisher, John; Ingham, Eileen

2014-10-01

Intervertebral total disc replacements (TDR) are used in the treatment of degenerative spinal disc disease. There are, however, concerns that they may be subject to long-term failure due to wear. The adverse effects of TDR wear have the potential to manifest in the dura mater and surrounding tissues. The aim of this study was to investigate the physiological structure of the dura mater, isolate the resident dural epithelial and stromal cells and analyse the capacity of these cells to internalise model polymer particles. The porcine dura mater was a collagen-rich structure encompassing regularly arranged fibroblastic cells within an outermost epithelial cell layer. The isolated dural epithelial cells had endothelial cell characteristics (positive for von Willebrand factor, CD31, E-cadherin and desmoplakin) and barrier functionality whereas the fibroblastic cells were positive for collagen I and III, tenascin and actin. The capacity of the dural cells to take up model particles was dependent on particle size. Nanometer sized particles readily penetrated both types of cells. However, dural fibroblasts engulfed micron-sized particles at a much higher rate than dural epithelial cells. The study suggested that dural epithelial cells may offer some barrier to the penetration of micron-sized particles but not nanometer sized particles. © 2014 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc.

Evidence for novel age-dependent network structures as a putative primo vascular network in the dura mater of the rat brain

PubMed Central

Lee, Ho-Sung; Kang, Dai-In; Yoon, Seung Zhoo; Ryu, Yeon Hee; Lee, Inhyung; Kim, Hoon-Gi; Lee, Byung-Cheon; Lee, Ki Bog

2015-01-01

With chromium-hematoxylin staining, we found evidence for the existence of novel age-dependent network structures in the dura mater of rat brains. Under stereomicroscopy, we noticed that chromium-hematoxylin-stained threadlike structures, which were barely observable in 1-week-old rats, were networked in specific areas of the brain, for example, the lateral lobes and the cerebella, in 4-week-old rats. In 7-week-old rats, those structures were found to have become larger and better networked. With phase contrast microscopy, we found that in 1-week-old rats, chromium-hematoxylin-stained granules were scattered in the same areas of the brain in which the network structures would later be observed in the 4- and 7-week-old rats. Such age-dependent network structures were examined by using optical and transmission electron microscopy, and the following results were obtained. The scattered granules fused into networks with increasing age. Cross-sections of the age-dependent network structures demonstrated heavily-stained basophilic substructures. Transmission electron microscopy revealed the basophilic substructures to be clusters with high electron densities consisting of nanosized particles. We report these data as evidence for the existence of age-dependent network structures in the dura mater, we discuss their putative functions of age-dependent network structures beyond the general concept of the dura mater as a supporting matrix. PMID:26330833

Studies of Turbulence and Transport in Alcator C-Mod H-Mode Plasmas with Phase Contrast Imaging and Comparisons with GYRO

NASA Astrophysics Data System (ADS)

Porkolab, M.; Lin, L.; Edlund, E. M.; Rost, J. C.; Fiore, C. L.; Greenwald, M.; Mikkelsen, D.

2008-11-01

We present recent experimental measurements of turbulence and transport in C-Mod H-Mode plasmas with and without internal transport barriers (ITB) using the phase contrast imaging (PCI) diagnostic and compare the results with GYRO predictions. In plasmas without ITB, the fluctuation above 300 kHz observed by PCI agrees with ITG in GYRO simulation, including the direction of propagation, wavenumber spectrum, and absolute intensity within experimental uncertainly (+/-75%). After transition to ITBs, the observed overall fluctuation intensity increases. GYRO simulation in the core shows that ITG dominates in ITBs but its intensity is lower than the overall experimental measurements which may also include contributions from the plasma edge. These results, as well as the impact of varying ∇Ti, ∇n, and ExB shear on turbulence will be discussed. C.L. Fiore et al., Fusion Sci. Technol., 51, 303 (2007). M. Porkolab et al., IEEE Trans. Plasma Sci. 34, 229 (2006). J. Candy et al., Phys. Rev. Lett., 91, 045001 (2003).

Interfacial Layer Effects in Ba(1-x)Sr(x)TiO3 Thick Films Prepared by Plasma Spray

DTIC Science & Technology

2003-04-01

in Materials Development for Direct Write technologies, edited by D. B. Chrisey, D. R. Gamota, H . Helvajian , and D. P. Taylor, (Mater. Res. Soc. Proc...Direct Write technologies, edited by D. B. Chrisey, D. R. Gamota, H . Helvajian , and D. P. Taylor, (Mater. Res. Soc. Proc. 624, San Francisco, CA, 2000...Research Center at Northwestern University supported by the MRSEC program under a NSF grant (DMR-0076097). REFERENCES 1. K. H . Church, C. Fore, T. Feeley

Targeted Delivery of Carbon Nanotubes to Cancer Cells

DTIC Science & Technology

2009-09-01

Taylor S, Li HP, Fernando KAS, Qu LW, Wang W, Gu LR, Zhou B, Sun YP. Advances toward bioapplications of carbon nanotubes. J Mater Chem. 14: 527...respectively. For car- boxylated-CNTs and RFB4-coupled CNTs, 20 ll of the dispersion was spun cast on to freshly cleaved mica at 3500 rpm for 30 sec...Lin Y, Taylor S, Li HP, Fernando KAS, Qu LW, Wang W, Gu LR, Zhou B, Sun YP. Advances toward bioapplications of carbon nano- tubes. J Mater Chem

Characterization of Residual Stress as a Function of Friction Stir Welding Parameters in ODS Steel MA956

DTIC Science & Technology

2013-06-01

dispersion strengthened - Eurofer steel ,” J. Nucl. Mater., vol. 416 , pp. 2229, Sep 1, 2011. [10] H. J. K. Lemmen and K. J. Sudmeijer, I, “Laser beam...Reynolds and W. Tang, “Structure, properties, and residual stress of 304L stainless steel friction stir welds,” Scr. Mater., vol. 48, pp. 12891294...OF RESIDUAL STRESS AS A FUNCTION OF FRICTION STIR WELDING PARAMETERS IN ODS STEEL MA956 by Martin S. Bennett June 2013 Thesis Advisor

Simulations of Turbulent Flows with Strong Shocks and Density Variations: Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanjiva Lele

2012-10-01

The target of this SciDAC Science Application was to develop a new capability based on high-order and high-resolution schemes to simulate shock-turbulence interactions and multi-material mixing in planar and spherical geometries, and to study Rayleigh-Taylor and Richtmyer-Meshkov turbulent mixing. These fundamental problems have direct application in high-speed engineering flows, such as inertial confinement fusion (ICF) capsule implosions and scramjet combustion, and also in the natural occurrence of supernovae explosions. Another component of this project was the development of subgrid-scale (SGS) models for large-eddy simulations of flows involving shock-turbulence interaction and multi-material mixing, that were to be validated with the DNSmore » databases generated during the program. The numerical codes developed are designed for massively-parallel computer architectures, ensuring good scaling performance. Their algorithms were validated by means of a sequence of benchmark problems. The original multi-stage plan for this five-year project included the following milestones: 1) refinement of numerical algorithms for application to the shock-turbulence interaction problem and multi-material mixing (years 1-2); 2) direct numerical simulations (DNS) of canonical shock-turbulence interaction (years 2-3), targeted at improving our understanding of the physics behind the combined two phenomena and also at guiding the development of SGS models; 3) large-eddy simulations (LES) of shock-turbulence interaction (years 3-5), improving SGS models based on the DNS obtained in the previous phase; 4) DNS of planar/spherical RM multi-material mixing (years 3-5), also with the two-fold objective of gaining insight into the relevant physics of this instability and aiding in devising new modeling strategies for multi-material mixing; 5) LES of planar/spherical RM mixing (years 4-5), integrating the improved SGS and multi-material models developed in stages 3 and 5. This final report is outlined as follows. Section 2 shows an assessment of numerical algorithms that are best suited for the numerical simulation of compressible flows involving turbulence and shock phenomena. Sections 3 and 4 deal with the canonical shock-turbulence interaction problem, from the DNS and LES perspectives, respectively. Section 5 considers the shock-turbulence inter-action in spherical geometry, in particular, the interaction of a converging shock with isotropic turbulence as well as the problem of the blast wave. Section 6 describes the study of shock-accelerated mixing through planar and spherical Richtmyer-Meshkov mixing as well as the shock-curtain interaction problem In section 7 we acknowledge the different interactions between Stanford and other institutions participating in this SciDAC project, as well as several external collaborations made possible through it. Section 8 presents a list of publications and presentations that have been generated during the course of this SciDAC project. Finally, section 9 concludes this report with the list of personnel at Stanford University funded by this SciDAC project.« less

ICPP: Charge and Density Coupling in Nonideal Plasmas

NASA Astrophysics Data System (ADS)

Fortov, V. E.

2000-10-01

Plasmas with Strong Coulomb Interaction (SCI) are found in astrophysics, planetary physics, inertial confinement fusion, advanced energetics and elsewhere[1]. SCI plasmas can be achieved in: I Dusty plasmas, II Shock-compressed plasmas. I. SCI in low-density dusty (colloidal) plasmas arises from the high charge of micron-size macroparticles[2]. Experiments use glow and inductive RF discharges, combustion flames of gas and solid propellant, ultraviolet light beams, and radioactive decay fluxes. Liquid- and solid-like structures are seen, and phase diagrams and transitions investigated by experiment and simulation. Zero-g experiments on space station Mir and in aircraft clarified the gravity effect on plasma crystal formation. II. Plasma SCI can arise in shock compression of solid and porous metals, noble gases, hydrogen, sulphur, and iodine at megabar pressures [3,4], using high explosive drive. Phase diagram regions were examined, where thermal and pressure ionization exist. Multiple-shock-compressed hydrogen can show metal-like conductivity from pressure ionization. The ``metal-to-dielectric" transition in shock-compressed lithium at 0.5 Mbar was detected and analyzed. Thermodynamics, equation of state, plasma composition, electrical and radiative properties show SCI suppression of discrete electron spectra and strong lowering of ionization potentials, evoking the ``confined-atom" model[5] for SCI and other models[6]. [1] V.E.Fortov, I.T.Yakubov, Physics of Nonideal Plasmas, Hemisphere, N.Y.-London (1989). [2] V.E.Fortov, A.P.Nefedov, O.F.Petrov, Soviet Physics-Uspekhy, 167(1997)1215. [3] V.Gryaznov, I.Iosilevsky, V.Fortov, Contrib. Plasma Physics, 39(1999)89. [4] V.Ya.Temovoi, A.S. Filimonov, V.E.Fortov et al. Proc. XXXVI EHPRG Meeting, Catania, Italy (1998). [5] V.K.Gryaznov, M.V.Zhernokletov et al. Zh. Exp. Teor. Fiz. (Soviet JETP) 78(1980) 573. [6] V.Ebeling, A.Foerster, V.Fortov et al. Thermodynamical Properties of Hot Dense Plasmas, Teubner Verlaggeselschaft , Berlin-Stuttgart, 1991.

Mater semper incertus est: who's your mummy?

PubMed

D'alton-Harrison, Rita

2014-01-01

In English law, the legal term for father has been given a broad definition but the definition of mother remains rooted in biology with the Roman law principle mater semper certa est (the mother is always certain) remaining the norm. However, motherhood may be acquired through giving birth to a child, by donation of gametes or by caring and nurturing a child so that the identity of the mother is no longer certain particularly in the case of surrogacy arrangements. While the law in the UK may automatically recognise the parental status of a commissioning father in a traditional surrogacy arrangement, the parental status of the commissioning mother is not automatically recognised in either a traditional or a gestational surrogacy arrangement. Thus the maxim mater est quam gestation demonstrat (meaning the mother is demonstrated by gestation) is also not approached consistently in the legal interpretation of parentage or motherhood in surrogacy as against other assisted reproduction methods. This raises questions about the extent to which motherhood should be affected by the method of reproduction and whether the sociological and philosophical concept of motherhood should, in the case of surrogacy, give rise to a new principle of 'mater semper incertus est' (the mother is uncertain). This article will argue that the time has come to move away from a legal definition of 'mother' that is based on biology to one that recognises the different forms of motherhood. © The Author [2014]. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

Automatic Identification System (AIS) Transmit Testing in Louisville Phase 2

DTIC Science & Technology

2014-08-01

project. Two of the captains were Capt. David Williams and Capt. Spencer Kennedy. After leaving SCI, the team members went to Crounse Inc. and met...team members had a phone conference with Herbert Taylor (VP Operations, Kongsberg Maritime Simulation Inc.) to discuss the integration of AIS data in

Modeling the Northern Adriatic Double-Gyre Response to Intense Bora Wind: A Revist

DTIC Science & Technology

2006-12-27

simulation (Adriatic monthly upstream location-i. Chiggiato , personal communication) climatological values were used instead). Consequently. in the...geofizicheskaVa. chap. 5, pp. 331 352, Joint Yugoslav-Italian Sci. Coop. Program, Signell, R. P., S. Carniel, L. Cavaleri, J. Chiggiato , J. D. Doyle, J

In-World Behaviors and Learning in a Virtual World

ERIC Educational Resources Information Center

Nadolny, Larysa; Childs, Mark

2014-01-01

Educational virtual worlds can give students opportunities that would not otherwise be possible in face-to-face settings. The SciEthics Interactive simulations allow learners to conduct scientific research and practice ethical decision-making within a virtual world. This study examined the in-world behaviors that identify students who perceive…

Simulation of nitrous oxide and nitric oxide emissions from tropical primary forests in the Costa Rican Atlantic Zone

Treesearch

Shuguanga Liu; William A. Reiners; Michael Keller; Davis S. Schimel

2000-01-01

Nitrous oxide (N2O) and nitric oxide (NO) are important atmospheric trace gases participating in the regulation of global climate and environment. Predictive models on the emissions of N2O and NO emissions from soil into the atmosphere are required. We modified the CENTURY model (Soil Sci. Soc. Am. J., 51 (1987) 1173) to simulate the emissions of N2O and NO from...

Determination of the Relationship between Information Capacity and Identification by Simulated Aerial Photography.

DTIC Science & Technology

1978-06-27

experiment by Frank Scott, Peter Hollanda , and Albert Harabedian 7 7Scott, F., Hollanda , P. A., and Harabedian, A., Phot. Sci. Eng., 14 1 pp 21-27...photographs of models of military tanks and trucks. The information capacity of these photos was varied by defocussing the taking camera and the simulated...photographic reconnaissance mission. This was done by photographing models of military targets, I processing and duplicating the resulting images, and

Scientific Objectives of Small Carry-on Impactor (SCI) and Deployable Camera 3 Digital (DCAM3-D): Observation of an Ejecta Curtain and a Crater Formed on the Surface of Ryugu by an Artificial High-Velocity Impact

NASA Astrophysics Data System (ADS)

Arakawa, M.; Wada, K.; Saiki, T.; Kadono, T.; Takagi, Y.; Shirai, K.; Okamoto, C.; Yano, H.; Hayakawa, M.; Nakazawa, S.; Hirata, N.; Kobayashi, M.; Michel, P.; Jutzi, M.; Imamura, H.; Ogawa, K.; Sakatani, N.; Iijima, Y.; Honda, R.; Ishibashi, K.; Hayakawa, H.; Sawada, H.

2017-07-01

The Small Carry-on Impactor (SCI) equipped on Hayabusa2 was developed to produce an artificial impact crater on the primitive Near-Earth Asteroid (NEA) 162173 Ryugu (Ryugu) in order to explore the asteroid subsurface material unaffected by space weathering and thermal alteration by solar radiation. An exposed fresh surface by the impactor and/or the ejecta deposit excavated from the crater will be observed by remote sensing instruments, and a subsurface fresh sample of the asteroid will be collected there. The SCI impact experiment will be observed by a Deployable CAMera 3-D (DCAM3-D) at a distance of ˜1 km from the impact point, and the time evolution of the ejecta curtain will be observed by this camera to confirm the impact point on the asteroid surface. As a result of the observation of the ejecta curtain by DCAM3-D and the crater morphology by onboard cameras, the subsurface structure and the physical properties of the constituting materials will be derived from crater scaling laws. Moreover, the SCI experiment on Ryugu gives us a precious opportunity to clarify effects of microgravity on the cratering process and to validate numerical simulations and models of the cratering process.

SciBox, an end-to-end automated science planning and commanding system

NASA Astrophysics Data System (ADS)

Choo, Teck H.; Murchie, Scott L.; Bedini, Peter D.; Steele, R. Josh; Skura, Joseph P.; Nguyen, Lillian; Nair, Hari; Lucks, Michael; Berman, Alice F.; McGovern, James A.; Turner, F. Scott

2014-01-01

SciBox is a new technology for planning and commanding science operations for Earth-orbital and planetary space missions. It has been incrementally developed since 2001 and demonstrated on several spaceflight projects. The technology has matured to the point that it is now being used to plan and command all orbital science operations for the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission to Mercury. SciBox encompasses the derivation of observing sequences from science objectives, the scheduling of those sequences, the generation of spacecraft and instrument commands, and the validation of those commands prior to uploading to the spacecraft. Although the process is automated, science and observing requirements are incorporated at each step by a series of rules and parameters to optimize observing opportunities, which are tested and validated through simulation and review. Except for limited special operations and tests, there is no manual scheduling of observations or construction of command sequences. SciBox reduces the lead time for operations planning by shortening the time-consuming coordination process, reduces cost by automating the labor-intensive processes of human-in-the-loop adjudication of observing priorities, reduces operations risk by systematically checking constraints, and maximizes science return by fully evaluating the trade space of observing opportunities to meet MESSENGER science priorities within spacecraft recorder, downlink, scheduling, and orbital-geometry constraints.

Further Progress Applying the Generalized Wigner Distribution to Analysis of Vicinal Surfaces

NASA Astrophysics Data System (ADS)

Einstein, T. L.; Richards, Howard L.; Cohen, S. D.

2001-03-01

Terrace width distributions (TWDs) can be well fit by the generalized Wigner distribution (GWD), generally better than by conventional Gaussians, and thus offers a convenient way to estimate the dimensionless elastic repulsion strength tildeA from σ^2, the TWD variance.(T.L. Einstein and O. Pierre-Louis, Surface Sci. 424), L299 (1999) The GWD σ^2 accurately reproduces values for the two exactly soluble cases at small tildeA and in the asymptotic limit. Taxing numerical simulations show that the GWD σ^2 interpolates well between these limits. Extensive applications have been made to experimental data, esp. on Cu.(M. Giesen and T.L. Einstein, Surface Sci. 449), 191 (2000) Recommended analysis procedures are catalogued.(H.L. Richards, S.D. Cohen, TLE, & M. Giesen, Surf Sci 453), 59 (2000) Extensions of the GWD for multistep distributions are tested, with good agreement for second-neighbor distributions, less good for third.(TLE, HLR, SDC, & OP-L, Proc ISSI-PDSC2000, cond-mat/0012xxxxx) Alternatively, step-step correlation functions, about which there is more theoretical information, should be measured.

Preface: SciDAC 2009

NASA Astrophysics Data System (ADS)

Simon, Horst

2009-07-01

By almost any measure, the SciDAC community has come a long way since DOE launched the SciDAC program back in 2001. At the time, we were grappling with how to efficiently run applications on terascale systems (the November 2001 TOP500 list was led by DOE's ASCI White IBM system at Lawrence Livermore achieving 7.2 teraflop/s). And the results stemming from the first round of SciDAC projects were summed up in two-page reports. The scientific results were presented at annual meetings, which were by invitation only and typically were attended by about 75 researchers. Fast forward to 2009 and we now have SciDAC Review, a quarterly magazine showcasing the scientific computing contributions of SciDAC projects and related programs, all focused on presenting a comprehensive look at Scientific Discovery through Advanced Computing. That is also the motivation behind the annual SciDAC conference that in 2009 was held from June 14-18 in San Diego. The annual conference, which can also be described as a celebration of all things SciDAC, grew out those meetings organized in the early days of the program. In 2005, the meeting was held in San Francisco and attendance was opened up to all members of the SciDAC community. The schedule was also expanded to include a keynote address, plenary speakers and other features found in a conference format. This year marks the fifth such SciDAC conference, which now comprises four days of computational science presentations, multiple poster sessions and, since last year, an evening event showcasing simulations and modeling runs resulting from SciDAC projects. The fifth annual SciDAC conference was remarkable on several levels. The primary purpose, of course, is to showcase the research accomplishments resulting from SciDAC programs in particular and computational science in general. It is these accomplishments, represented in 38 papers and 52 posters, that comprise this set of conference proceedings. These proceedings can stand alone as evidence of the success of DOE's innovative SciDAC efforts. But from the outset, a critical driver for the program was to foster increased collaboration among researchers across disciplines and organizations. In particular, SciDAC wanted to engage scientists at universities in the projects, both to expand the community and to develop the next generation of computational scientists. At the meeting in San Diego, the fruits of this emphasis were clearly visible, from the special poster session highlighting the work of the DOE Computational Science Graduate Fellows, to the informal discussions in hotel hallways, to focused side meetings apart from the main presentations. A highlight of the meeting was the keynote address by Dr Ray Orbach, until recently the DOE Under Secretary for Science and head of the Office of Science. It was during his tenure that the first round of projects matured and the second set of SciDAC projects were launched. And complementing these research projects was Dr Orbach's vision for INCITE, DOE's Innovative and Novel Computational Impact on Theory and Experiment program, inaugurated in 2003. This program allocated significant HPC resources to scientists tackling high-impact problems, including some of those addressed by SciDAC teams. Together, SciDAC and INCITE are dramatically accelerating the field of computational science. As has been noted before, the SciDAC conference celebrates progress in advancing science through large-scale modeling and simulation. Over 400 people registered to attend this year's talks, poster sessions and tutorials, all spanning the disciplines supported by DOE. While the principal focus was on SciDAC accomplishments, this year's conference also included invited presentations and posters from colleagues whose research is supported by other agencies. At the 2009 meeting we also formalized a developing synergy with the Department of Defense's HPC Users Group Meeting, which has occasionally met in parallel with the SciDAC meeting. But in San Diego, we took the additional steps of organizing a joint poster session and a joint plenary session, further advancing opportunities for broader networking. Throughout the four-day program, attendees at both meetings had the option of sitting in on sessions at either conference. We also included several of the NSF Petascale applications in the program, and have also extended invitations to our computational colleagues in other federal agencies, including the National Science Foundation, NASA, and the National Oceanographic and Atmospheric Administration, as well as international collaborators to join us in San Diego. In 2009 we also reprised one of the more popular sessions from Seattle in 2008, the Electronic Visualization and Poster Night, during which 29 scientific visualizations were presented on high-resolution large-format displays. The best entries were awarded one of the coveted 'OASCR Awards.' The conference also featured a session about breakthroughs in computational science, based on the 'Breakthrough Report' that was published in 2008, led by Tony Mezzacappa (ORNL). Tony was also the chair of the SciDAC 2005 conference. For the third consecutive year, the conference was followed by a day of tutorials organized by the SciDAC Outreach Center and aimed primarily at students interested in scientific computing. This year, nearly 100 participants attended the tutorials, hosted by the San Diego Supercomputer Center and General Atomics. This outreach to the broader community is really what SciDAC is all about - Scientific Discovery through Advanced Computing. Such discoveries are not confined by organizational lines, but rather are often the result of researchers reaching out and collaborating with others, using their combined expertise to push our boundaries of knowledge. I am happy to see that this vision is shared by so many researchers in computational science, who all decided to join SciDAC 2009. While credit for the excellent presentations and posters goes to the teams of researchers, the success of this year's conference is due to the strong efforts and support from members of the 2009 SciDAC Program Committee and Organizing Committee, and I would like to extend my heartfelt thanks to them for helping to make the 2009 meeting the largest and most successful to date. Program Committee members were: David Bader, LLNL; Pete Beckman, ANL; John Bell, LBNL; John Boisseau, University of Texas; Paul Bonoli, MIT; Hank Childs, LBNL; Bill Collins, LBNL; Jim Davenport, BNL; David Dean, ORNL; Thom Dunning, NCSA; Peg Folta, LLNL; Glenn Hammond, PNNL; Maciej Haranczyk, LBNL; Robert Harrison, ORNL; Paul Hovland, ANL; Paul Kent, ORNL; Aram Kevorkian, SPAWAR; David Keyes, Columbia University; Kwok Ko, SLAC; Felice Lightstone, LLNL; Bob Lucas, ISI/USC; Paul Mackenzie, Fermilab; Tony Mezzacappa, ORNL; John Negele, MIT; Jeff Nichols, ORNL; Mike Norman, UCSD; Joe Oefelein, SNL; Jeanie Osburn, NRL; Peter Ostroumov, ANL; Valerio Pascucci, University of Utah; Ruth Pordes, Fermilab; Rob Ross, ANL; Nagiza Samatova, ORNL; Martin Savage, University of Washington; Tim Scheibe, PNNL; Ed Seidel, NSF; Arie Shoshani, LBNL; Rick Stevens, ANL; Bob Sugar, UCSB; Bill Tang, PPPL; Bob Wilhelmson, NCSA; Kathy Yelick, NERSC/LBNL; Dave Zachmann, Vista Computational Technology LLC. Organizing Committee members were: Communications: Jon Bashor, LBNL. Contracts/Logistics: Mary Spada and Cheryl Zidel, ANL. Posters: David Bailey, LBNL. Proceedings: John Hules, LBNL. Proceedings Database Developer: Beth Cerny Patino, ANL. Program Committee Liaison/Conference Web Site: Yeen Mankin, LBNL. Tutorials: David Skinner, NERSC/LBNL. Visualization Night: Hank Childs, LBNL; Valerio Pascucci, Chems Touati, Nathan Galli, and Erik Jorgensen, University of Utah. Again, my thanks to all. Horst Simon San Diego, California June 18, 2009

Neuroprotective effects of perflurocarbon (oxycyte) after contusive spinal cord injury.

PubMed

Yacoub, Adly; Hajec, Marygrace C; Stanger, Richard; Wan, Wen; Young, Harold; Mathern, Bruce E

2014-02-01

Spinal cord injury (SCI) often results in irreversible and permanent neurological deficits and long-term disability. Vasospasm, hemorrhage, and loss of microvessels create an ischemic environment at the site of contusive or compressive SCI and initiate the secondary injury cascades leading to progressive tissue damage and severely decreased functional outcome. Although the initial mechanical destructive events cannot be reversed, secondary injury damage occurs over several hours to weeks, a time frame during which therapeutic intervention could be achieved. One essential component of secondary injury cascade is the reduction in spinal cord blood flow with resultant decrease in oxygen delivery. Our group has recently shown that administration of fluorocarbon (Oxycyte) significantly increased parenchymal tissue oxygen levels during the usual postinjury hypoxic phase, and fluorocarbon has been shown to be effective in stroke and head injury. In the current study, we assessed the beneficial effects of Oxycyte after a moderate-to-severe contusion SCI was simulated in adult Long-Evans hooded rats. Histopathology and immunohistochemical analysis showed that the administration of 5 mL/kg of Oxycyte perfluorocarbon (60% emulsion) after SCI dramatically reduced destruction of spinal cord anatomy and resulted in a marked decrease of lesion area, less cell death, and greater white matter sparing at 7 and 42 days postinjury. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining showed a significant reduced number of apoptotic cells in Oxycyte-treated animals, compared to the saline group. Collectively, these results demonstrate the potential neuroprotective effect of Oxycyte treatment after SCI, and its beneficial effects may be, in part, a result of reducing apoptotic cell death and tissue sparing. Further studies to determine the most efficacious Oxycyte dose and its mechanisms of protection are warranted.

Ultrastructural characteristics of the cranial dura mater-arachnoid interface layer.

PubMed

Angelov, D N

1990-01-01

The ultrastructural features of the encephalic dura mater-arachnoid borderline (interface) layer (zone) of rats, rabbits, cats and humans were studied. The rat's interface zone included the electron-lucent epithelium-like arranged fibroblasts of the inner dural layer, the rich in filaments cells of the dural neurothelium, a 20 nm wide intercellular cleft filled with electron-dense material and the dark mitochondria-rich cells of the outer arachnoidal layer; in rabbits and cats, this laminar distinction was less prominent, while in man, it was almost absent.

Construction Productivity Advancement Research (CPAR) Program: Improved Materials and Processes for Sealing and Resealing Joints in Portland Cement Concrete Pavements - Field Evaluation

DTIC Science & Technology

1993-10-01

sealant was determined by noting the type and number of defects each sealant incurred. Figure 4 provides a sample evaluation sheet used dur- ing the field...was conducted by visually inspect- ing the mater~al for defects . If any defects were noted, the type of defect was described and the quant~ty of that... defect was measured. The quantity of the defect was dividted by the total quantity of sealant and the result reported as percent defect . Adhesion and

Mesh Dependence on Shear Driven Boundary Layers in Stable Stratification Generated by Large Eddy-Simulation

NASA Astrophysics Data System (ADS)

Berg, Jacob; Patton, Edward G.; Sullivan, Peter S.

2017-11-01

The effect of mesh resolution and size on shear driven atmospheric boundary layers in a stable stratified environment is investigated with the NCAR pseudo-spectral LES model (J. Atmos. Sci. v68, p2395, 2011 and J. Atmos. Sci. v73, p1815, 2016). The model applies FFT in the two horizontal directions and finite differencing in the vertical direction. With vanishing heat flux at the surface and a capping inversion entraining potential temperature into the boundary layer the situation is often called the conditional neutral atmospheric boundary layer (ABL). Due to its relevance in high wind applications such as wind power meteorology, we emphasize on second order statistics important for wind turbines including spectral information. The simulations range from mesh sizes of 643 to 10243 grid points. Due to the non-stationarity of the problem, different simulations are compared at equal eddy-turnover times. Whereas grid convergence is mostly achieved in the middle portion of the ABL, statistics close to the surface of the ABL, where the presence of the ground limits the growth of the energy containing eddies, second order statistics are not converged on the studies meshes. Higher order structure functions also reveal non-Gaussian statistics highly dependent on the resolution.

Delicacy, Imprecision, and Uncertainty of Oceanic Simulations: An Investigation with the Regional Oceanic Modeling System (ROMS)

DTIC Science & Technology

2013-09-30

Geochemistry and Ecosystems: An important community use for ROMS is biogeochemisty: chemical cycles, water quality, blooms , micro-nutrients, larval...Sci., submitted. Colas, F., J.C. McWilliams, X. Capet, and J. Kurian, 2012: Heat balance and eddies in the Peru- Chile Current System. Climate

Simulation of Gas-Surface Dynamical Interactions

DTIC Science & Technology

2007-07-01

the interacting particle on the surface. Trapping probabilities often scale as Ei cosn θi with n < 2. An exponent of n = 0 corresponds to total energy...1996). [85] A. E. Wiskerke, F. H. Geuzebroek, A. W. Kleyn, and B. E. Hayden, Surf. Sci. 272, 256 (1992). [86] J. E. Hurst , L. Wharton, K. C. Janda

Evidence for CGRP re-uptake in rat dura mater encephali

PubMed Central

Gupta, Saurabh; Amrutkar, Dipak Vasantrao; Mataji, Aydin; Salmasi, Hassan; Hay-Schmidt, Anders; Sheykhzade, Majid; Messlinger, Karl; Olesen, Jes; Jansen-Olesen, Inger

2010-01-01

BACKGROUND AND PURPOSE Calcitonin gene-related peptide (CGRP) is widely distributed in the trigeminovascular system and released from sensory fibres of the cranial dura mater upon noxious stimulation. Such release may be a mechanism underlying migraine headache. Based on data from guinea pig basilar artery preparations, we have here studied CGRP release and uptake in an organ preparation of the hemisected rat skull. EXPERIMENTAL APPROACH CGRP release from the cranial dura was quantified by a commercial enzyme-linked immunoassay. CGRP was depleted using repetitive challenges of capsaicin. After incubating the tissue with CGRP for 20 min and extensive washing, another capsaicin challenge was performed. Immunohistochemistry was used to visualize CGRP immunofluorescence in dural nerve fibres. KEY RESULTS Capsaicin-induced CGRP release was attenuated by the transient receptor potential vanilloid receptor type I antagonist capsazepine or by Ca2+-free solutions. After the CGRP-depleted preparation had been exposed to exogenous CGRP, capsaicin-induced CGRP release was increased compared to the challenge just prior to incubation. CGRP uptake was not influenced by Ca2+-free solutions. Olcegepant and CGRP8–37 (CGRP receptor antagonists) did not affect uptake of CGRP. However, a monoclonal CGRP-binding antibody decreased CGRP uptake significantly. Release of CGRP after incubation was attenuated by Ca2+-free solutions and by capsazepine. Immunohistochemical assays indicated a weak trend towards CGRP uptake in rat dura mater. CONCLUSION AND IMPLICATIONS We have presented evidence for CGRP uptake in nerves and its re-release in rat dura mater. This may have implications for the pathophysiology and treatment of migraine. PMID:20804493

Passive hind-limb cycling improves cardiac function and reduces cardiovascular disease risk in experimental spinal cord injury.

PubMed

West, Christopher R; Crawford, Mark A; Poormasjedi-Meibod, Malihe-Sadat; Currie, Katharine D; Fallavollita, Andre; Yuen, Violet; McNeill, John H; Krassioukov, Andrei V

2014-04-15

Spinal cord injury (SCI) causes altered autonomic control and severe physical deconditioning that converge to drive maladaptive cardiac remodelling. We used a clinically relevant experimental model to investigate the cardio-metabolic responses to SCI and to establish whether passive hind-limb cycling elicits a cardio-protective effect. Initially, 21 male Wistar rats were evenly assigned to three groups: uninjured control (CON), T3 complete SCI (SCI) or T3 complete SCI plus passive hind-limb cycling (SCI-EX; 2 × 30 min day(-1), 5 days week(-1) for 4 weeks beginning 6 days post-SCI). On day 32, cardio-metabolic function was assessed using in vivo echocardiography, ex vivo working heart assessments, cardiac histology/molecular biology and blood lipid profiles. Twelve additional rats (n = 6 SCI and n = 6 SCI-EX) underwent in vivo echocardiography and basal haemodynamic assessments pre-SCI and at days 7, 14 and 32 post-SCI to track temporal cardiovascular changes. Compared with CON, SCI exhibited a rapid and sustained reduction in left ventricular dimensions and function that ultimately manifested as reduced contractility, increased myocardial collagen deposition and an up-regulation of transforming growth factor beta-1 (TGFβ1) and mothers against decapentaplegic homolog 3 (Smad3) mRNA. For SCI-EX, the initial reduction in left ventricular dimensions and function at day 7 post-SCI was completely reversed by day 32 post-SCI, and there were no differences in myocardial contractility between SCI-EX and CON. Collagen deposition was similar between SCI-EX and CON. TGFβ1 and Smad3 were down-regulated in SCI-EX. Blood lipid profiles were improved in SCI-EX versus SCI. We provide compelling novel evidence that passive hind-limb cycling prevents cardiac dysfunction and reduces cardiovascular disease risk in experimental SCI.

Extreme nonlinear terahertz electro-optics in diamond for ultrafast pulse switching

NASA Astrophysics Data System (ADS)

Shalaby, Mostafa; Vicario, Carlo; Hauri, Christoph P.

2017-03-01

Polarization switching of picosecond laser pulses is a fundamental concept in signal processing [C. Chen and G. Liu, Annu. Rev. Mater. Sci. 16, 203 (1986); V. R. Almeida et al., Nature 431, 1081 (2004); and A. A. P. Pohl et al., Photonics Sens. 3, 1 (2013)]. Conventional switching devices rely on the electro-optical Pockels effect and work at radio frequencies. The ensuing gating time of several nanoseconds is a bottleneck for faster switches which is set by the performance of state-of-the-art high-voltage electronics. Here we show that by substituting the electric field of several kV/cm provided by modern electronics by the MV/cm field of a single-cycle THz laser pulse, the electro-optical gating process can be driven orders of magnitude faster, at THz frequencies. In this context, we introduce diamond as an exceptional electro-optical material and demonstrate a pulse gating time as fast as 100 fs using sub-cycle THz-induced Kerr nonlinearity. We show that THz-induced switching in the insulator diamond is fully governed by the THz pulse shape. The presented THz-based electro-optical approach overcomes the bandwidth and switching speed limits of conventional MHz/GHz electronics and establishes the ultrafast electro-optical gating technology for the first time in the THz frequency range. We finally show that the presented THz polarization gating technique is applicable for advanced beam diagnostics. As a first example, we demonstrate tomographic reconstruction of a THz pulse in three dimensions.

Spontaneous Polarization in Bio-organic Materials Studied by Scanning Pyroelectric Microscopy (SPEM) and Second Harmonic Generation Microscopy (SHGM)

NASA Astrophysics Data System (ADS)

Putzeys, T.; Wübbenhorst, M.; van der Veen, M. A.

2015-06-01

Bio-organic materials such as bones, teeth, and tendon generally show nonlinear optical (Masters and So in Handbook of Biomedical Nonlinear Optical Microscopy, 2008), pyro- and piezoelectric (Fukada and Yasuda in J Phys Soc Jpn 12:1158, 1957) properties, implying a permanent polarization, the presence of which can be rationalized by describing the growth of the sample and the creation of a polar axis according to Markov's theory of stochastic processes (Hulliger in Biophys J 84:3501, 2003; Batagiannis et al. in Curr Opin Solid State Mater Sci 17:107, 2010). Two proven, versatile techniques for probing spontaneous polarization distributions in solids are scanning pyroelectric microscopy (SPEM) and second harmonic generation microscopy (SHGM). The combination of pyroelectric scanning with SHG-microscopy in a single experimental setup leading to complementary pyroelectric and nonlinear optical data is demonstrated, providing us with a more complete image of the polarization in organic materials. Crystals consisting of a known polar and hyperpolarizable material, CNS (4-chloro-4-nitrostilbene) are used as a reference sample, to verify the functionality of the setup, with both SPEM and SHGM images revealing the same polarization domain information. In contrast, feline and human nails exhibit a pyroelectric response, but a second harmonic response is absent for both keratin containing materials, implying that there may be symmetry-allowed SHG, but with very inefficient second harmonophores. This new approach to polarity detection provides additional information on the polar and hyperpolar nature in a variety of (bio) materials.

Can Creutzfeldt-Jakob disease unravel the mysteries of Alzheimer?

PubMed

Kovacs, Gabor G

2016-09-02

Recent studies on iatrogenic Creutzfeldt-Jakob disease (CJD) raised concerns that one of the hallmark lesions of Alzheimer disease (AD), amyloid-β (Aβ), may be transmitted from human-to-human. The neuropathology of AD-related lesions is complex. Therefore, many aspects need to be considered in deciding on this issue. Observations of recent studies can be summarized as follows: 1) The frequency of iatrogenic CJD cases with parencyhmal and vascular Aβ deposits is statistically higher than expected; 2) The morphology and distribution of Aβ deposition may show distinct features; 3) The pituitary and the dura mater themselves may serve as potential sources of Aβ seeds; 4) Cadaveric dura mater from 2 examined cases shows Aβ deposition; and 5) There is a lack of evidence that the clinical phenotype of AD appears following the application of cadaveric pituitary hormone or dura mater transplantation. These studies support the notion that neurodegenerative diseases have common features regarding propagation of disease-associated proteins as seeds. However, until further evidence emerges, prions of transmissible spongiform encephalopathies are the only neurodegenerative disease-related proteins proven to propagate clinicopathological phenotypes.

Pharmacokinetics of amikacin in serum and in tissue contiguous with pressure sores in humans with spinal cord injury.

PubMed Central

Segal, J L; Brunnemann, S R; Eltorai, I M

1990-01-01

Pressure sores are a common occurrence in immobilized patients. They increase morbidity and mortality and impede rehabilitation. Antibiotics are routinely used to assist in effecting a cure when infection is present. Nevertheless, for patients with spinal cord injuries (SCI), strategies for effective therapy with antibiotics based on measurement of concentrations in tissue and pharmacokinetic behavior in extravascular spaces do not exist. By analyzing the concentration-time profile and protein binding of amikacin in the interstitial fluid (IF) in contact with pressure sores, we found that the disposition of amikacin in the tissue contiguous with pressure sores appears to be governed by simultaneous first-order and capacity-limited pharmacokinetic behavior. Amikacin disposition in IF proceeded without a simple relationship to amikacin concentrations in serum, and the time course in IF was not accurately simulated by linear models of amikacin pharmacokinetic behavior. Total amikacin clearance estimated from a pharmacokinetic model using simultaneous first-order and nonlinear intercompartmental transfer of amikacin was not significantly different from clearance calculated by us in a prior study of amikacin pharmacokinetic behavior in patients with SCI. In patients with SCI, optimal use of amikacin in the treatment of infected pressure sores is contingent upon accurate characterization of the pharmacokinetic behavior of this aminoglycoside in serum and in the IF in contact with these lesions. Only methods which quantitate amikacin concentration and protein binding in IF and incorporate a model that can simultaneously simulate nonlinear and linear disposition processes should be relied upon to influence therapeutic decision making. PMID:2386372

Incorporating root hydraulic redistribution in CLM4.5: Effects on predicted site and global evapotranspiration, soil moisture, and water storage

NASA Astrophysics Data System (ADS)

Tang, Jinyun; Riley, William J.; Niu, Jie

2015-12-01

We implemented the Amenu-Kumar model in the Community Land Model (CLM4.5) to simulate plant Root Hydraulic Redistribution (RHR) and analyzed its influence on CLM hydrology from site to global scales. We evaluated two numerical implementations: the first solved the coupled equations of root and soil water transport concurrently, while the second solved the two equations sequentially. Through sensitivity analysis, we demonstrate that the sequentially coupled implementation (SCI) is numerically incorrect, whereas the tightly coupled implementation (TCI) is numerically robust with numerical time steps varying from 1 to 30 min. At the site-level, we found the SCI approach resulted in better agreement with measured evapotranspiration (ET) at the AmeriFlux Blodgett Forest site, California, whereas the two approaches resulted in equally poor agreement between predicted and measured ET at the LBA Tapajos KM67 Mature Forest site in Amazon, Brazil. Globally, the SCI approach overestimated annual land ET by as much as 3.5 mm d-1 in some grid cells when compared to the TCI estimates. These comparisons demonstrate that TCI is a more robust numerical implementation of RHR. However, we found, even with TCI, that incorporating RHR resulted in worse agreement with measured soil moisture at both the Blodgett Forest and Tapajos sites and degraded the agreement between simulated terrestrial water storage anomaly and Gravity Recovery and Climate Experiment (GRACE) observations. We find including RHR in CLM4.5 improved ET predictions compared with the FLUXNET-MTE estimates north of 20° N but led to poorer predictions in the tropics. The biases in ET were robust and significant regardless of the four different pedotransfer functions or of the two meteorological forcing data sets we applied. We also found that the simulated water table was unrealistically sensitive to RHR. Therefore, we contend that further structural and data improvements are warranted to improve the hydrological dynamics in CLM4.5.

Incorporating root hydraulic redistribution in CLM4.5: Effects on predicted site and global evapotranspiration, soil moisture, and water storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Jinyun; Riley, William J.; Niu, Jie

We implemented the Amenu-Kumar model in the Community Land Model (CLM4.5) to simulate plant Root Hydraulic Redistribution (RHR) and analyzed its influence on CLM hydrology from site to global scales. We evaluated two numerical implementations: the first solved the coupled equations of root and soil water transport concurrently, while the second solved the two equations sequentially. Through sensitivity analysis, we demonstrate that the sequentially coupled implementation (SCI) is numerically incorrect, whereas the tightly coupled implementation (TCI) is numerically robust with numerical time steps varying from 1 to 30 min. At the site-level, we found the SCI approach resulted in bettermore » agreement with measured evapotranspiration (ET) at the AmeriFlux Blodgett Forest site, California, whereas the two approaches resulted in equally poor agreement between predicted and measured ET at the LBA Tapajos KM67 Mature Forest site in Amazon, Brazil. Globally, the SCI approach overestimated annual land ET by as much as 3.5 mm d -1 in some grid cells when compared to the TCI estimates. These comparisons demonstrate that TCI is a more robust numerical implementation of RHR. However, we found, even with TCI, that incorporating RHR resulted in worse agreement with measured soil moisture at both the Blodgett Forest and Tapajos sites and degraded the agreement between simulated terrestrial water storage anomaly and Gravity Recovery and Climate Experiment (GRACE) observations. We find including RHR in CLM4.5 improved ET predictions compared with the FLUXNET-MTE estimates north of 20° N but led to poorer predictions in the tropics. The biases in ET were robust and significant regardless of the four different pedotransfer functions or of the two meteorological forcing data sets we applied. We also found that the simulated water table was unrealistically sensitive to RHR. Therefore, we contend that further structural and data improvements are warranted to improve the hydrological dynamics in CLM4.5.« less

Incorporating root hydraulic redistribution in CLM4.5: Effects on predicted site and global evapotranspiration, soil moisture, and water storage

DOE PAGES

Tang, Jinyun; Riley, William J.; Niu, Jie

2015-11-12

We implemented the Amenu-Kumar model in the Community Land Model (CLM4.5) to simulate plant Root Hydraulic Redistribution (RHR) and analyzed its influence on CLM hydrology from site to global scales. We evaluated two numerical implementations: the first solved the coupled equations of root and soil water transport concurrently, while the second solved the two equations sequentially. Through sensitivity analysis, we demonstrate that the sequentially coupled implementation (SCI) is numerically incorrect, whereas the tightly coupled implementation (TCI) is numerically robust with numerical time steps varying from 1 to 30 min. At the site-level, we found the SCI approach resulted in bettermore » agreement with measured evapotranspiration (ET) at the AmeriFlux Blodgett Forest site, California, whereas the two approaches resulted in equally poor agreement between predicted and measured ET at the LBA Tapajos KM67 Mature Forest site in Amazon, Brazil. Globally, the SCI approach overestimated annual land ET by as much as 3.5 mm d -1 in some grid cells when compared to the TCI estimates. These comparisons demonstrate that TCI is a more robust numerical implementation of RHR. However, we found, even with TCI, that incorporating RHR resulted in worse agreement with measured soil moisture at both the Blodgett Forest and Tapajos sites and degraded the agreement between simulated terrestrial water storage anomaly and Gravity Recovery and Climate Experiment (GRACE) observations. We find including RHR in CLM4.5 improved ET predictions compared with the FLUXNET-MTE estimates north of 20° N but led to poorer predictions in the tropics. The biases in ET were robust and significant regardless of the four different pedotransfer functions or of the two meteorological forcing data sets we applied. We also found that the simulated water table was unrealistically sensitive to RHR. Therefore, we contend that further structural and data improvements are warranted to improve the hydrological dynamics in CLM4.5.« less

Plasma iron levels appraised 15 days after spinal cord injury in a limb movement animal model.

PubMed

Reis, F M; Esteves, A M; Tufik, S; de Mello, M T

2011-03-01

Experimental, controlled trial. The purpose of this study was to evaluate plasma iron and transferrin levels in a limb movement animal model with spinal cord injury (SCI). Universidade Federal de São Paulo, Departamento de Psicobiologia. In all, 72 male Wistar rats aged 90 days were divided into four groups: (1) acute SCI (1 day, SCI1), (2) 3 days post-SCI (SCI3), (3) 7 days post-SCI (SCI7) and (4) 15 days post-SCI (SCI15). Each of these groups had corresponding control (CTRL) and SHAM groups. Plasma iron and transferrin levels of the different groups were analyzed using a one-way analysis of variance (ANOVA) followed by Tukey's test. We found a significant reduction in iron plasma levels after SCI compared with the CTRL group: SCI1 (CTRL: 175±10.58 μg dl(-1); SCI: 108.28±11.7 μg dl(-1)), SCI3 (CTRL: 195.5±11.00 μg dl(-1); SCI: 127.88±12.63 μg dl(-1)), SCI7 (CTRL: 186±2.97 μg dl(-1); SCI: 89.2±15.39 μg dl(-1)) and SCI15 (CTRL: 163±5.48 μg dl(-1); SCI: 124.44±10.30 μg dl(-1)) (P<0.05; ANOVA). The SHAM1 group demonstrated a reduction in iron plasma after acute SCI (CTRL: 175±10.58 μg dl(-1); SHAM: 114.60±7.81 μg dl(-1)) (P<0.05; ANOVA). Reduced iron metabolism after SCI may be one of the mechanisms involved in the pathogenesis of sleep-related movement disorders.

The SDF-1/CXCR4 axis promotes recovery after spinal cord injury by mediating bone marrow-derived from mesenchymal stem cells

PubMed Central

Wang, Xiao; Zhang, Yong-Le; Zhang, Ya-Dong; Xue, Feng

2017-01-01

This study aims to explore the role of the SDF-1/CXCR4 axis in mediating BMSCs and SCI recovery. BMSCs were collected and SCI rat models were established. Wistar rats were assigned into the blank control, sham, SCI, SCI + BMSCs, SCI + BMSCs + SDF-1, SCI + BMSCs + AMD3100 (an inhibitor of SDF-1/CXCR4 axis) and SCI + BMSCs + SDF-1 + AMD3100 groups. Hind limb motor function was measured 7, 14, 21 and 28 days after operation. qRT-PCR, western blotting and ELISA was performed to determine the expressions of SDF-1, CXCR4, NGF, BDNF, GFAP and GAP-43, TNF-α, IL-1β, L-6 and IFN-γ. Hind limb motor function scores 7 days after the operation were reduced in the SCI rats of the blank control and sham groups. Hind limb function was found to be better in the SCI + BMSCs and SCI + BMSCs + SDF-1 groups than in the SCI, SCI + BMSCs + AMD3100 and SCI + BMSCs + SDF-1 + AMD3100 groups 14, 21 and 28 days after operation. Furthermore, the SCI group had lower SDF-1, CXCR4, NGF, BDNF and GAP-43 expressions but higher GFAP, TNF-α, IL-1β, IL-6 and IFN-γ than the blank control and sham groups 28 days after operation. While, the SCI + BMSCs, SCI + BMSCs + SDF-1 and SCI + BMSCs + SDF-1 + AMD3100 groups displayed opposite trends to the SCI and SCI + BMSCs + AMD3100 groups. In conclusion, SDF-1/CXCR4 axis promotes recovery after SCI by mediating BMSCs. PMID:28099928

Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spentzouris, P.; /Fermilab; Cary, J.

The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessarymore » accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors. ComPASS is in the first year of executing its plan to develop the next-generation HPC accelerator modeling tools. ComPASS aims to develop an integrated simulation environment that will utilize existing and new accelerator physics modules with petascale capabilities, by employing modern computing and solver technologies. The ComPASS vision is to deliver to accelerator scientists a virtual accelerator and virtual prototyping modeling environment, with the necessary multiphysics, multiscale capabilities. The plan for this development includes delivering accelerator modeling applications appropriate for each stage of the ComPASS software evolution. Such applications are already being used to address challenging problems in accelerator design and optimization. The ComPASS organization for software development and applications accounts for the natural domain areas (beam dynamics, electromagnetics, and advanced acceleration), and all areas depend on the enabling technologies activities, such as solvers and component technology, to deliver the desired performance and integrated simulation environment. The ComPASS applications focus on computationally challenging problems important for design or performance optimization to all major HEP, NP, and BES accelerator facilities. With the cost and complexity of particle accelerators rising, the use of computation to optimize their designs and find improved operating regimes becomes essential, potentially leading to significant cost savings with modest investment.« less

SciDAC GSEP: Gyrokinetic Simulation of Energetic Particle Turbulence and Transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Zhihong

Energetic particle (EP) confinement is a key physics issue for burning plasma experiment ITER, the crucial next step in the quest for clean and abundant energy, since ignition relies on self-heating by energetic fusion products (α-particles). Due to the strong coupling of EP with burning thermal plasmas, plasma confinement property in the ignition regime is one of the most uncertain factors when extrapolating from existing fusion devices to the ITER tokamak. EP population in current tokamaks are mostly produced by auxiliary heating such as neutral beam injection (NBI) and radio frequency (RF) heating. Remarkable progress in developing comprehensive EP simulationmore » codes and understanding basic EP physics has been made by two concurrent SciDAC EP projects GSEP funded by the Department of Energy (DOE) Office of Fusion Energy Science (OFES), which have successfully established gyrokinetic turbulence simulation as a necessary paradigm shift for studying the EP confinement in burning plasmas. Verification and validation have rapidly advanced through close collaborations between simulation, theory, and experiment. Furthermore, productive collaborations with computational scientists have enabled EP simulation codes to effectively utilize current petascale computers and emerging exascale computers. We review here key physics progress in the GSEP projects regarding verification and validation of gyrokinetic simulations, nonlinear EP physics, EP coupling with thermal plasmas, and reduced EP transport models. Advances in high performance computing through collaborations with computational scientists that enable these large scale electromagnetic simulations are also highlighted. These results have been widely disseminated in numerous peer-reviewed publications including many Phys. Rev. Lett. papers and many invited presentations at prominent fusion conferences such as the biennial International Atomic Energy Agency (IAEA) Fusion Energy Conference and the annual meeting of the American Physics Society, Division of Plasma Physics (APS-DPP).« less

[Pachymeningitis].

PubMed

Fain, O; Mekinian, A

2017-09-01

Pachymeningitis is a fibrosing and inflammatory process, which involves the dura mater. Some pachymeningitis are cranial and induce headaches and cranial nerve palsies. Others are spinal and responsible for nerve roots or spinal cord compression. MRI shows contrast enhancement thickening of the dura mater. Etiologies are infectious (syphilis, tuberculosis, etc.) or inflammatory (sarcoidosis, granulomatosis with polyangiitis, IgG4-related disease, idiopathic). Corticosteroids are the main treatment. The use of immunosuppressive drugs or rituximab is yet to be determined and probably adapted to each etiology. Copyright © 2017 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Passive hind-limb cycling improves cardiac function and reduces cardiovascular disease risk in experimental spinal cord injury

PubMed Central

West, Christopher R; Crawford, Mark A; Poormasjedi-Meibod, Malihe-Sadat; Currie, Katharine D; Fallavollita, Andre; Yuen, Violet; McNeill, John H; Krassioukov, Andrei V

2014-01-01

Spinal cord injury (SCI) causes altered autonomic control and severe physical deconditioning that converge to drive maladaptive cardiac remodelling. We used a clinically relevant experimental model to investigate the cardio-metabolic responses to SCI and to establish whether passive hind-limb cycling elicits a cardio-protective effect. Initially, 21 male Wistar rats were evenly assigned to three groups: uninjured control (CON), T3 complete SCI (SCI) or T3 complete SCI plus passive hind-limb cycling (SCI-EX; 2 × 30 min day−1, 5 days week−1 for 4 weeks beginning 6 days post-SCI). On day 32, cardio-metabolic function was assessed using in vivo echocardiography, ex vivo working heart assessments, cardiac histology/molecular biology and blood lipid profiles. Twelve additional rats (n = 6 SCI and n = 6 SCI-EX) underwent in vivo echocardiography and basal haemodynamic assessments pre-SCI and at days 7, 14 and 32 post-SCI to track temporal cardiovascular changes. Compared with CON, SCI exhibited a rapid and sustained reduction in left ventricular dimensions and function that ultimately manifested as reduced contractility, increased myocardial collagen deposition and an up-regulation of transforming growth factor beta-1 (TGFβ1) and mothers against decapentaplegic homolog 3 (Smad3) mRNA. For SCI-EX, the initial reduction in left ventricular dimensions and function at day 7 post-SCI was completely reversed by day 32 post-SCI, and there were no differences in myocardial contractility between SCI-EX and CON. Collagen deposition was similar between SCI-EX and CON. TGFβ1 and Smad3 were down-regulated in SCI-EX. Blood lipid profiles were improved in SCI-EX versus SCI. We provide compelling novel evidence that passive hind-limb cycling prevents cardiac dysfunction and reduces cardiovascular disease risk in experimental SCI. PMID:24535438

Molecular theory for self assembling mixtures of patchy colloids and colloids with spherically symmetric attractions: The single patch case

NASA Astrophysics Data System (ADS)

Marshall, Bennett D.; Chapman, Walter G.

2013-09-01

In this work we develop a new theory to model self assembling mixtures of single patch colloids and colloids with spherically symmetric attractions. In the development of the theory we restrict the interactions such that there are short ranged attractions between patchy and spherically symmetric colloids, but patchy colloids do not attract patchy colloids and spherically symmetric colloids do not attract spherically symmetric colloids. This results in the temperature, density, and composition dependent reversible self assembly of the mixture into colloidal star molecules. This type of mixture has been recently synthesized by grafting of complimentary single stranded DNA [L. Feng, R. Dreyfus, R. Sha, N. C. Seeman, and P. M. Chaikin, Adv. Mater. 25(20), 2779-2783 (2013)], 10.1002/adma.201204864. As a quantitative test of the theory, we perform new monte carlo simulations to study the self assembly of these mixtures; theory and simulation are found to be in excellent agreement.

DFT study of hydrogen production from formic acid decomposition on Pd-Au alloy nanoclusters

NASA Astrophysics Data System (ADS)

Liu, D.; Gao, Z. Y.; Wang, X. C.; Zeng, J.; Li, Y. M.

2017-12-01

Recently, it has been reported that the hydrogen production rate of formic acid decomposition can be significantly increased using Pd-Au binary alloy nano-catalysts [Wang et al. J. Mater. Chem. A 1 (2013) 12721-12725]. To explain the reaction mechanism of this alloy catalysis method, formic acid decomposition reactions on pure Pd and Pd-Au alloy nanoclusters are studied via density functional theory simulations. The simulation results indicate that the addition of inert element Au would not influence formic acid decomposition on Pd surface sites of Pd-Au alloy nanoclusters. On the other hand, the existence of Au surface sites brings relative weak hydrogen atom adsorption. On Pd-Au alloy nanoclusters, the dissociated hydrogen atoms from formic acid are easier to combine as hydrogen molecules than that on pure Pd clusters. Via the synergetic effect between Pd and Au, both formic acid decomposition and hydrogen production are events with large probability, which eventually results in high hydrogen production rate.

Optimizing Filter-Probe Diffusion Weighting in the Rat Spinal Cord for Human Translation

PubMed Central

Budde, Matthew D.; Skinner, Nathan P.; Muftuler, L. Tugan; Schmit, Brian D.; Kurpad, Shekar N.

2017-01-01

Diffusion tensor imaging (DTI) is a promising biomarker of spinal cord injury (SCI). In the acute aftermath, DTI in SCI animal models consistently demonstrates high sensitivity and prognostic performance, yet translation of DTI to acute human SCI has been limited. In addition to technical challenges, interpretation of the resulting metrics is ambiguous, with contributions in the acute setting from both axonal injury and edema. Novel diffusion MRI acquisition strategies such as double diffusion encoding (DDE) have recently enabled detection of features not available with DTI or similar methods. In this work, we perform a systematic optimization of DDE using simulations and an in vivo rat model of SCI and subsequently implement the protocol to the healthy human spinal cord. First, two complementary DDE approaches were evaluated using an orientationally invariant or a filter-probe diffusion encoding approach. While the two methods were similar in their ability to detect acute SCI, the filter-probe DDE approach had greater predictive power for functional outcomes. Next, the filter-probe DDE was compared to an analogous single diffusion encoding (SDE) approach, with the results indicating that in the spinal cord, SDE provides similar contrast with improved signal to noise. In the SCI rat model, the filter-probe SDE scheme was coupled with a reduced field of view (rFOV) excitation, and the results demonstrate high quality maps of the spinal cord without contamination from edema and cerebrospinal fluid, thereby providing high sensitivity to injury severity. The optimized protocol was demonstrated in the healthy human spinal cord using the commercially-available diffusion MRI sequence with modifications only to the diffusion encoding directions. Maps of axial diffusivity devoid of CSF partial volume effects were obtained in a clinically feasible imaging time with a straightforward analysis and variability comparable to axial diffusivity derived from DTI. Overall, the results and optimizations describe a protocol that mitigates several difficulties with DTI of the spinal cord. Detection of acute axonal damage in the injured or diseased spinal cord will benefit the optimized filter-probe diffusion MRI protocol outlined here. PMID:29311786

Discrepancies between implicit and explicit self-concepts of intelligence: relations to modesty, narcissism, and achievement motivation

PubMed Central

Gerstenberg, Friederike X. R.; Imhoff, Roland; Banse, Rainer; Schmitt, Manfred

2014-01-01

Previous research has shown that different configurations of the implicit self-concept of intelligence (iSCI) and the explicit self-concept of intelligence (eSCI) are consistently related to individuals’ performance on different intelligence tests (Dislich etal., 2012). The results indicated that any discrepant configuration between the iSCI and the eSCI impairs performance. In the present study, how correspondence between the iSCI and the eSCI is related to intelligence test performance as well as personality traits of modesty (low eSCI, high iSCI), narcissism (high eSCI, low iSCI), and achievement motivation was investigated. Furthermore, a moderated mediation analysis showed that the relation between the iSCI–eSCI configurations and intelligence test performance was mediated by achievement motivation for modest individuals. PMID:24575063

Utilization of eucalyptus for bioelectricity production in brazil via fast pyrolysis: a techno-economic analysis

USDA-ARS?s Scientific Manuscript database

In this study, a process model of a 2000 metric ton per day (MTPD) eucalyptus Tail Gas Reactive Pyrolysis (TGRP) and electricity generation plant was developed and simulated in SimSci Pro/II software for the purpose of evaluating its techno-economic viability in Brazil. Two scenarios were compared b...

Length of stay and medical stability for spinal cord-injured patients on admission to an inpatient rehabilitation hospital: a comparison between a model SCI trauma center and non-SCI trauma center.

PubMed

Ploumis, A; Kolli, S; Patrick, M; Owens, M; Beris, A; Marino, R J

2011-03-01

Retrospective database review. To compare lengths of stay (LOS), pressure ulcers and readmissions to the acute care hospital of patients admitted to the inpatient rehabilitation facility (IRF) from a model spinal cord injury (SCI) trauma center or from a non-SCI acute hospital. Only sparse data exist comparing the status of patients admitted to IRF from a model SCI trauma center or from a non-SCI acute hospital. Acute care, IRF and total LOS were compared between patients transferred to IRF from the SCI center (n=78) and from non-SCI centers (n=131). The percentages of pressure ulcers on admission to IRF and transfer back to acute care were also compared. Patients admitted to IRF from the SCI trauma center (SCI TC) had significantly shorter (P=0.01) acute care LOS and total LOS compared with patients admitted from non-SCI TCs. By neurological category, acute-care LOS was less for all groups admitted from the SCI center, but statistically significant only for tetraplegia. There was no significant difference in the incidence of readmissions to acute care from IRF. More patients from non-SCI centers (34%) than SCI centers (12%) had pressure ulcers (P<0.001). Acute care in organized SCI TCs before transfer to IRF can significantly lower acute-care LOS or total LOS and incidence of pressure ulcers compared with non-SCI TCs. Patients admitted to IRF from SCI TCs are no more likely to be sent back to an acute hospital than those from non-SCI TCs.

A case of idiopathic hypertrophic pachymeningitis presenting with chronic headache and multiple cranial nerve palsies: A case report.

PubMed

Huang, Yuanyuan; Chen, Jun; Gui, Li

2017-07-01

Idiopathic hypertrophic pachymeningitis (IHP) is a rare condition, characterized by a chronic fibrosing inflammatory process usually involving either the intracranial or spinal dura mater, but rarely both. Here, we report a rare case of IHP affecting both the intracranial and spinal dura mater. We also discussed the diagnosis, management, and outcome of IHP. We reviewed the case of a 60-year-old woman presenting with chronic headache, multiple cranial nerve palsies and gait disturbance. Magnetic resonance imaging (MRI) of her head revealed thickened and contrast-enhanced dura in the craniocervical region as well as obstructive hydrocephalus and cerebellar tonsillar herniation. The patient had a suboccipital craniectomy and posterior decompression through C1 plus a total laminectomy. The dura was partially resected to the extent of the bony decompression, and a duroplasty was performed. Microscopic examination of the surgically resected sample showed chronic inflammatory changes, lymphoplasmacytic cell infiltration, fibrous tissue hyperplasia, and hyaline degeneration. Blood tests to evaluate the secondary causes of hypertrophic pachymeningitis (HP) were unremarkable. Steroid was used to treat suspected IHP. Postoperatively, the patient showed gradual improvement in her headache, glossolalia, and bucking. Prior to discharge, a follow-up MRI showed improvement of the dura mater thickening. IHP is a chronic inflammatory disorder of the dura mater that usually causes neurological deficits. Clinical manifestations of IHP, MRI findings, and laboratory abnormalities are the essential components for making an accurate diagnosis. When the radiological or laboratory evaluation is uncertain, but neurological deficits are present, a prompt surgical approach should be considered. Postoperative steroid therapy and close observation for recurrence are necessary to ensure a good long-term outcome.

Cation coordination reactions on nanocrystals: surface/interface, doping control and advanced photocatalysis applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhang, Jiatao

2016-10-01

Abstract: Including the shape and size effect, the controllable doping, hetero-composite and surface/interface are the prerequisite of colloidal nanocrystals for exploring their optoelectronic properties, such as fluorescence, plasmon-exciton coupling, efficient electron/hole separation, and enhanced photocatalysis applications. By controlling soft acid-base coordination reactions between cation molecular complexes and colloidal nanocrystals, we showed that chemical thermodynamics could drive nanoscale monocrystalline growth of the semiconductor shell on metal nano-substrates and the substitutional heterovalent doping in semiconductor nanocrystals. We have demonstrated evolution of relative position of Au and II-VI semiconductor in Au-Semi from symmetric to asymmetric configuration, different phosphines initiated morphology engineering, oriented attachment of quantum dots into micrometer nanosheets with synergistic control of surface/interface and doing, which can further lead to fine tuning of plasmon-exciton coupling. Therefore, different hydrogen photocatalytic performance, Plasmon enhanced photocatalysis properties have been achieved further which lead to the fine tuning of plasmon-exciton coupling. Substitutional heterovalent doping here enables the tailoring of optical, electronic properties and photocatalysis applications of semiconductor nanocrystals because of electronic impurities (p-, n-type doping) control. References: (1) J. Gui, J. Zhang*, et al. Angew. Chem. Int. Ed. 2015, 54, 3683. (2) Q. Zhao, J. Zhang*, etc., Adv. Mater. 2014, 26, 1387. (3) J. Liu, Q. Zhao, S. G. Wang*, J. Zhang*, etc., Adv. Mater. 2015, 27-2753-2761. (4) H. Qian, J. Zhang*, etc., NPG Asia Mater. (2015) 7, e152. (5) M. Ji, M. Xu, etc., J. Zhang*, Adv. Mater. 2016, in proof. (6) S. Yu, J. T. Zhang, Y. Tang, M. Ouyang*, Nano Lett. 2015, 15, 6282-6288. (7) J. Zhang, Y. Tang, K. Lee and M. Ouyang*, Science 2010, 327, 1634. (8) J. Zhang, Y. Tang, K. Lee, M. Ouyang*, Nature 2010, 466, 91.

Biological Effects of Clinically Relevant CoCr Nanoparticles in the Dura Mater: An Organ Culture Study

PubMed Central

Papageorgiou, Iraklis; Abberton, Thomas; Fuller, Martin; Tipper, Joanne L.; Fisher, John; Ingham, Eileen

2014-01-01

Medical interventions for the treatment of spinal disc degeneration include total disc replacement and fusion devices. There are, however, concerns regarding the generation of wear particles by these devices, the majority of which are in the nanometre sized range with the potential to cause adverse biological effects in the surrounding tissues. The aims of this study were to develop an organ culture model of the porcine dura mater and to investigate the biological effects of CoCr nanoparticles in this model. A range of histological techniques were used to analyse the structure of the tissue in the organ culture. The biological effects of the CoCr wear particles and the subsequent structural changes were assessed using tissue viability assays, cytokine assays, histology, immunohistochemistry, and TEM imaging. The physiological structure of the dura mater remained unchanged during the seven days of in vitro culture. There was no significant loss of cell viability. After exposure of the organ culture to CoCr nanoparticles, there was significant loosening of the epithelial layer, as well as the underlying collagen matrix. TEM imaging confirmed these structural alterations. These structural alterations were attributed to the production of MMP-1, -3, -9, -13, and TIMP-1. ELISA analysis revealed that there was significant release of cytokines including IL-8, IL-6, TNF-α, ECP and also the matrix protein, tenascin-C. This study suggested that CoCr nanoparticles did not cause cytotoxicity in the dura mater but they caused significant alterations to its structural integrity that could lead to significant secondary effects due to nanoparticle penetration, such as inflammation to the local neural tissue. PMID:28344233

The Implementation Challenge and the Learning Health System for SCI Initiative.

PubMed

Stucki, Gerold; Bickenbach, Jerome

2017-02-01

The paper introduces the special issue by linking the International Spinal Cord Injury (InSCI) Community Survey study to the Learning Health System for SCI Initiative (LHS-SCI). The LHS-SCI was designed to respond to the implementation challenge of bringing about policy reform in light of the targeted policy recommendations of World Health Organization's International Perspectives on SCI report as well as the call for action of WHO's Global Disability Action Plan. The paper reviews the components of LHS-SCI relevant to internationally comparable information, a theory of change to guide for action, and the tools for evidence-informed policy. The interplay between persons, their health needs, and the societal response to those needs provides the foundation for the organization of the LHS-SCI Initiative. Moreover, as the other articles in this special issue describe in detail, the rationale, conceptualization, and study design of the InSCI study are also informed by the rationale, and mission, of the LHS for SCI Initiative. The LHS-SCI, and the implementation challenge that motivates it, is responsible for the design of the InSCI study and the overall mission of LHS-SCI to continuously improve the lived experience of people living with SCI around the world through an international evidence- and rights-informed research and policy reform effort.

Marketing percolation

NASA Astrophysics Data System (ADS)

Goldenberg, J.; Libai, B.; Solomon, S.; Jan, N.; Stauffer, D.

2000-09-01

A percolation model is presented, with computer simulations for illustrations, to show how the sales of a new product may penetrate the consumer market. We review the traditional approach in the marketing literature, which is based on differential or difference equations similar to the logistic equation (Bass, Manage. Sci. 15 (1969) 215). This mean-field approach is contrasted with the discrete percolation on a lattice, with simulations of "social percolation" (Solomon et al., Physica A 277 (2000) 239) in two to five dimensions giving power laws instead of exponential growth, and strong fluctuations right at the percolation threshold.

Mechanical suitability of glycerol-preserved human dura mater for construction of prosthetic cardiac valves.

PubMed

McGarvey, K A; Lee, J M; Boughner, D R

1984-03-01

We have examined the tensile viscoelastic properties of fresh and glycerol-preserved human dura mater, and correlated the results with structural information from the scanning electron microscope. The interwoven laminar structure of dura produces rather high flexural stiffness, while the crossed-fibrillar laminae produce planar mechanical isotropy. Glycerol storage shifts the stress-strain curve to lower strain, reduces stress relaxation and creep, and lowers the ultimate tensile strength and strain at fracture. These changes may be due to glyceraldehyde crosslinking, or to increased interfibrillar friction. The latter hypothesis suggests that glycerol storage may reduce the fatigue lifetime of the tissue.

Chemical Vapor Deposition of Refractory Metals and Ceramics 2. Materials Research Society Symposium Proceedings Held in Boston, Massachusetts on December 4-6, 1991. Volume 250

DTIC Science & Technology

1993-04-01

M.Kamo, Surface and Coatings Technology, 3L40, 183 (1989). 12. J.S. Ma, H. J. Kawarada, T Yonehara, J. Suzuki, J. Wei, Y. Yokota, Y. Mori and A. Hiraki , in...Technology Update on Diamond Films, edited by R.P.H. Chang, D. Nelsson, A. Hiraki (Mater. Res. Soc. Ext. Abs. EA-19.San Diego, CA 1989) pp.6 7 -70...on Diamond Films, edited by R.P H. Chang. D. Nelson and A. Hiraki (Mater. Res. Soc. Ext. Abs. E•. Pittsburg, (1989) p. 9 . 22. S. Komatsu, Y

Ultrastructure of the extracellular matrix of bovine dura mater, optic nerve sheath and sclera.

PubMed

Raspanti, M; Marchini, M; Della Pasqua, V; Strocchi, R; Ruggeri, A

1992-10-01

The sclera, the outermost sheath of the optic nerve and the dura mater have been investigated histologically and ultrastructurally. Although these tissues appear very similar under the light microscope, being dense connective tissues mainly composed of collagen bundles and a limited amount of cells and elastic fibres, they exhibit subtle differences on electron microscopy. In the dura and sclera collagen appears in the form of large, nonuniform fibrils, similar to those commonly found in tendons, while in the optic nerve sheath the fibrils appear smaller and uniform, similar to those commonly observed in reticular tissues, vessel walls and skin. Freeze-fracture also reveals these fibrils to have different subfibrillar architectures, straight or helical, which correspond to 2 distinct forms of collagen fibril previously described (Raspanti et al. 1989). The other extracellular matrix components also vary with the particular collagen fibril structure. Despite their common embryological derivation, the dura mater, optic nerve sheath and sclera exhibit diversification of their extracellular matrix consistent with the mechanical loads to which these tissues are subjected. Our observations indicate that the outermost sheath of the optic nerve resembles the epineurium of peripheral nerves rather than the dura to which it is commonly likened.

Immunohistochemical profile of neurotrophins in human cranial dura mater and meningiomas.

PubMed

Artico, Marco; Bronzetti, Elena; Pompili, Elena; Ionta, Brunella; Alicino, Valentina; D'Ambrosio, Anna; Santoro, Antonio; Pastore, Francesco S; Elenkov, Ilia; Fumagalli, Lorenzo

2009-06-01

The immunohistochemical profile of neurotrophins and their receptors in the human cranial dura mater was studied by examining certain dural zones in specimens harvested from different regions (frontal, temporal, parietal and occipital). Dural specimens were obtained during neurosurgical operations performed in ten patients for surgical treatment of intracranial lesions (meningiomas, traumas, gliomas, vascular malformations). The dural fragments were taken from the area of the craniotomy at least 8 cm from the lesion as well as from the area in which the meningioma had its dural attachment. Immunohistochemical characterization and distribution of neurotrophins, with their receptors, were analyzed. The concrete role played by these neurotrophic factors in general regulation, vascular permeability, algic responsivity and release of locally active substances in the human dura mater is still controversial. Our study revealed a general structural alteration of dural tissue due to the invasivity of meningiomatous lesions, together with an improved expression of brain derived neurotrophic factor (BDNF) in highly proliferating neoplastic cells and an evident production of nerve growth factor (NGF) in inflammatory cells, suggesting that BDNF has a role in supporting the proliferation rate of neoplastic cells, while NGF is involved in the activation of a chronic inflammatory response in neoplastic areas.

Modeling trans-spinal direct current stimulation for the modulation of the lumbar spinal motor pathways

NASA Astrophysics Data System (ADS)

Kuck, A.; Stegeman, D. F.; van Asseldonk, E. H. F.

2017-10-01

Objective. Trans-spinal direct current stimulation (tsDCS) is a potential new technique for the treatment of spinal cord injury (SCI). TsDCS aims to facilitate plastic changes in the neural pathways of the spinal cord with a positive effect on SCI recovery. To establish tsDCS as a possible treatment option for SCI, it is essential to gain a better understanding of its cause and effects. We seek to understand the acute effect of tsDCS, including the generated electric field (EF) and its polarization effect on the spinal circuits, to determine a cellular target. We further ask how these findings can be interpreted to explain published experimental results. Approach. We use a realistic full body finite element volume conductor model to calculate the EF of a 2.5 mA direct current for three different electrode configurations. We apply the calculated electric field to realistic motoneuron models to investigate static changes in membrane resting potential. The results are combined with existing knowledge about the theoretical effect on a neuronal level and implemented into an existing lumbar spinal network model to simulate the resulting changes on a network level. Main results. Across electrode configurations, the maximum EF inside the spinal cord ranged from 0.47 V m-1 to 0.82 V m-1. Axon terminal polarization was identified to be the dominant cellular target. Also, differences in electrode placement have a large influence on axon terminal polarization. Comparison between the simulated acute effects and the electrophysiological long-term changes observed in human tsDCS studies suggest an inverse relationship between the two. Significance. We provide methods and knowledge for better understanding the effects of tsDCS and serve as a basis for a more targeted and optimized application of tsDCS.

Data Container Study for Handling array-based data using Hive, Spark, MongoDB, SciDB and Rasdaman

NASA Astrophysics Data System (ADS)

Xu, M.; Hu, F.; Yang, J.; Yu, M.; Yang, C. P.

2017-12-01

Geoscience communities have come up with various big data storage solutions, such as Rasdaman and Hive, to address the grand challenges for massive Earth observation data management and processing. To examine the readiness of current solutions in supporting big Earth observation, we propose to investigate and compare four popular data container solutions, including Rasdaman, Hive, Spark, SciDB and MongoDB. Using different types of spatial and non-spatial queries, datasets stored in common scientific data formats (e.g., NetCDF and HDF), and two applications (i.e. dust storm simulation data mining and MERRA data analytics), we systematically compare and evaluate the feature and performance of these four data containers in terms of data discover and access. The computing resources (e.g. CPU, memory, hard drive, network) consumed while performing various queries and operations are monitored and recorded for the performance evaluation. The initial results show that 1) the popular data container clusters are able to handle large volume of data, but their performances vary in different situations. Meanwhile, there is a trade-off between data preprocessing, disk saving, query-time saving, and resource consuming. 2) ClimateSpark, MongoDB and SciDB perform the best among all the containers in all the queries tests, and Hive performs the worst. 3) These studied data containers can be applied on other array-based datasets, such as high resolution remote sensing data and model simulation data. 4) Rasdaman clustering configuration is more complex than the others. A comprehensive report will detail the experimental results, and compare their pros and cons regarding system performance, ease of use, accessibility, scalability, compatibility, and flexibility.

QERx- A Faster than Real-Time Emulator for Space Processors

NASA Astrophysics Data System (ADS)

Carvalho, B.; Pidgeon, A.; Robinson, P.

2012-08-01

Developing software for space systems is challenging. Especially because, in order to be sure it can cope with the harshness of the environment and the imperative requirements and constrains imposed by the platform were it will run, it needs to be tested exhaustively. Software Validation Facilities (SVF) are known to the industry and developers, and provide the means to run the On-Board Software (OBSW) in a realistic environment, allowing the development team to debug and test the software.But the challenge is to be able to keep up with the performance of the new processors (LEON2 and LEON3), which need to be emulated within the SVF. Such processor emulators are also used in Operational Simulators, used to support mission preparation and train mission operators. These simulators mimic the satellite and its behaviour, as realistically as possible. For test/operational efficiency reasons and because they will need to interact with external systems, both these uses cases require the processor emulators to provide real-time, or faster, performance.It is known to the industry that the performance of previously available emulators is not enough to cope with the performance of the new processors available in the market. SciSys approached this problem with dynamic translation technology trying to keep costs down by avoiding a hardware solution and keeping the integration flexibility of full software emulation.SciSys presented “QERx: A High Performance Emulator for Software Validation and Simulations” [1], in a previous DASIA event. Since then that idea has evolved and QERx has been successfully validated. SciSys is now presenting QERx as a product that can be tailored to fit different emulation needs. This paper will present QERx latest developments and current status.

Corrigendum to “A new hyperbolic auxiliary function method and exact solutions of the mBBM equation” [Commun Nonlinear Sci Numer Simul 2010;15:135-138

NASA Astrophysics Data System (ADS)

Layeni, Olawanle P.; Akinola, Ade P.

2010-09-01

The symbols w and ω were abused in article [1]. Replacing ξ + ω with ξ throughout the article (that is in Eqs. (5) and (13)-(23)) and afterwards taking w and ω to denote the (same) frequency of the traveling wave(s) set this right.

Biomarkers for PTSD

DTIC Science & Technology

2014-07-01

Molecular evidence of stress- induced acute heart injury in a mouse model simulating posttraumatic stress disorder. Proc Natl Acad Sci U S A. 2014 Feb...obtaining measures aligned with the core neurocognitive domains: IQ, working memory ( auditory /visual), processing speed, verbal memory (immediate...in the test sample and combined sample with a similar pattern for the validation sample. Similarly, performance on tests of auditory and visual

Exploiting magnetic properties of Fe doping in zirconia. From first-principles simulations to the experimental growth and characterization of thin films

NASA Astrophysics Data System (ADS)

Sangalli, Davide; Cianci, Elena; Lamperti, Alessio; Ciprian, Roberta; Albertini, Franca; Casoli, Francesca; Lupo, Pierpaolo; Nasi, Lucia; Campanini, Marco; Debernardi, Alberto

2013-05-01

In this study we explore, both from theoretical and experimental side, the effect of Fe doping in ZrO2 (ZrO2:Fe). By means of first principles simulation, we study the magnetization density and the magnetic interaction between Fe atoms. We also consider how this is affected by the presence of oxygen vacancies and compare our findings with models based on impurity band [J.M.D. Coey, M. Venkatesan, C.B. Fitzgerald, Nat. Mater. 4, 173 (2005)] and carrier mediated magnetic interaction [T. Dietl, H. Ohno, F. Matsukura, J. Cibert, D. Ferrand, Science 287, 1019 (2000)]. Experimentally, thin films (≈20 nm) of ZrO2:Fe at high doping concentration are grown by atomic layer deposition. We provide experimental evidence that Fe is uniformly distributed in the ZrO2 by transmission electron microscopy and energy dispersive X-ray mapping, while X-ray diffraction evidences the presence of the fluorite crystal structure. Alternating gradient force magnetometer measurements show magnetic signal at room temperature, however, with low magnetic moment per atom. Results from experimental measures and theoretical simulations are compared.

Quantification of site-city interaction effects on the response of structure under double resonance condition

NASA Astrophysics Data System (ADS)

Kumar, Neeraj; Narayan, Jay Prakash

2018-01-01

This paper presents the site-city interaction (SCI) effects on the response of closely spaced structures under double resonance condition (F_{02{{D}}}^{{S}} = F_{02{{D}}}^{{B}}), where F_{02{{D}}}^{{S}} and F_{02{{D}}}^{{B}} are fundamental frequencies of 2-D structure and 2-D basin, respectively. This paper also presents the development of empirical relations to predict the F_{02{{D}}}^{{B}} of elliptical and trapezoidal basins for both the polarizations of the S wave. Simulated results revealed that F_{02{{D}}}^{{B}} of a 2-D basin very much depends on its geometry, shape ratio and polarization of the incident S wave. The obtained spectral amplification factor (SAF) at F_{02{{D}}}^{{S}} of a standalone structure in a 2-D basin is greater than that in the 1-D case under double resonance condition. A considerable reduction of the fundamental resonance frequency of structures due to the SCI effects is observed for both the polarizations of the S wave. The SAFs at F_{02{{D}}}^{{S}} of closely spaced structures due to SCI effects is larger in the case of SV than SH waves. A splitting of the fundamental-mode frequency bandwidth along with the drastic decrease of SAF due to the SCI effects is obtained. The findings of this paper raise the question concerning the validity of the predicted response of standalone structure based on soil-structure interaction for the design of structures in a 2-D small basin, in an urban environment.

Increasing specialty care access through use of an innovative home telehealth-based spinal cord injury disease management protocol (SCI DMP)

PubMed Central

Seton, Jacinta M.; Washington, Monique; Tomlinson, Suk C.; Phrasavath, Douangmala; Farrell, Karen R.; Goldstein, Barry

2016-01-01

Background A spinal cord injury disease management protocol (SCI DMP) was developed to address the unique medical, physical, functional, and psychosocial needs of those living with spinal cord injuries and disorders (SCI/D). The SCI DMP was piloted to evaluate DMP clinical content and to identify issues for broader implementation across the Veterans Affairs (VA) SCI System of Care. Methods Thirty-three patients with SCI/D from four VA SCI centers participated in a 6-month pilot. Patients received customized SCI DMP questions through a data messaging device (DMD). Nurse home telehealth care coordinators (HTCC) monitored responses and addressed clinical alerts daily. One site administered the Duke Severity of Illness (DUSOI) Checklist and Short Form-8 (SF-8™) to evaluate the changes in comorbidity severity and health-related quality of life while on the SCI DMP. Results Patients remained enrolled an average of 116 days, with a mean response rate of 56%. The average distance between patient's home and their VA SCI center was 59 miles. Feedback on SCI DMP content and the DMD included requests for additional clinical topics, changes in administration frequency, and adapting the DMD for functional impairments. Improvement in clinical outcomes was seen in a subset of patients enrolled on the SCI DMP. Conclusion SCI HTCCs and patients reported that the program was most beneficial for newly injured patients recently discharged from acute rehabilitation that live far from specialty SCI care facilities. SCI DMP content changes and broader implementation strategies are currently being evaluated based on lessons learned from the pilot. PMID:24617497

Increasing specialty care access through use of an innovative home telehealth-based spinal cord injury disease management protocol (SCI DMP).

PubMed

Woo, Christine; Seton, Jacinta M; Washington, Monique; Tomlinson, Suk C; Phrasavath, Douangmala; Farrell, Karen R; Goldstein, Barry

2016-01-01

A spinal cord injury disease management protocol (SCI DMP) was developed to address the unique medical, physical, functional, and psychosocial needs of those living with spinal cord injuries and disorders (SCI/D). The SCI DMP was piloted to evaluate DMP clinical content and to identify issues for broader implementation across the Veterans Affairs (VA) SCI System of Care. Thirty-three patients with SCI/D from four VA SCI centers participated in a 6-month pilot. Patients received customized SCI DMP questions through a data messaging device (DMD). Nurse home telehealth care coordinators (HTCC) monitored responses and addressed clinical alerts daily. One site administered the Duke Severity of Illness (DUSOI) Checklist and Short Form-8 (SF-8™) to evaluate the changes in comorbidity severity and health-related quality of life while on the SCI DMP. Patients remained enrolled an average of 116 days, with a mean response rate of 56%. The average distance between patient's home and their VA SCI center was 59 miles. Feedback on SCI DMP content and the DMD included requests for additional clinical topics, changes in administration frequency, and adapting the DMD for functional impairments. Improvement in clinical outcomes was seen in a subset of patients enrolled on the SCI DMP. SCI HTCCs and patients reported that the program was most beneficial for newly injured patients recently discharged from acute rehabilitation that live far from specialty SCI care facilities. SCI DMP content changes and broader implementation strategies are currently being evaluated based on lessons learned from the pilot.

Psychometric evaluation of the Spanish version of the MPI-SCI.

PubMed

Soler, M D; Cruz-Almeida, Y; Saurí, J; Widerström-Noga, E G

2013-07-01

Postal surveys. To confirm the factor structure of the Spanish version of the MPI-SCI (MPI-SCI-S, Multidimensional Pain Inventory in the SCI population) and to test its internal consistency and construct validity in a Spanish population. Guttmann Institute, Barcelona, Spain. The MPI-SCI-S along with Spanish measures of pain intensity (Numerical Rating Scale), pain interference (Brief Pain Inventory), functional independence (Functional Independence Measure), depression (Beck Depression Inventory), locus of control (Multidimensional health Locus of Control), support (Functional Social Support Questionnaire (Duke-UNC)), psychological well-being (Psychological Global Well-Being Index) and demographic/injury characteristics were assessed in persons with spinal cord injury (SCI) and chronic pain (n=126). Confirmatory factor analysis suggested an adequate factor structure for the MPI-SCI-S. The internal consistency of the MPI-SCI-S subscales ranged from acceptable (r=0.66, Life Control) to excellent (r=0.94, Life Interference). All MPI-SCI-S subscales showed adequate construct validity, with the exception of the Negative and Solicitous Responses subscales. The Spanish version of the MPI-SCI is adequate for evaluating chronic pain impact following SCI in a Spanish-speaking population. Future studies should include additional measures of pain-related support in the Spanish-speaking SCI population.

Infertility in Men with Spinal Cord Injury: Research and Treatment

PubMed Central

Brackett, Nancy L.

2012-01-01

Spinal cord injury (SCI) occurs most often to young men. Following SCI, most men are infertile due to a combination of erectile dysfunction, ejaculatory dysfunction and semen abnormalities. Erectile dysfunction may be treated by the same therapies that are used in the general population. Similarly, the same treatments that are effective to assist conception in couples with non-SCI male factor patients are effective in assisting conception in SCI male-factor patients. The most apparent differences in male-factor symptoms between SCI and non-SCI patients are the high occurrences of anejaculation and atypical semen profiles in men with SCI. Methods available to assist ejaculation in men with SCI include penile vibratory stimulation and EEJ. Use of surgical sperm retrieval as the first line of treatment for anejaculation in men with SCI is controversial. Most men with SCI have a unique semen profile characterized by normal sperm concentration, but abnormally low sperm motility. Toxic substances in the semen contribute to this problem. Despite impaired sperm parameters, pregnancy outcomes using sperm from men with SCI are similar to pregnancy outcomes using sperm from non-SCI men. Future studies should focus on improving natural ejaculation and improving semen quality in these men. PMID:24278717

Prevalence and Etiology of Hypogonadism in Young Men With Chronic Spinal Cord Injury: A Cross-Sectional Analysis From Two University-Based Rehabilitation Centers.

PubMed

Sullivan, Shannon D; Nash, Mark S; Tefera, Eshetu; Tinsley, Emily; Blackman, Marc R; Groah, Suzanne

2017-08-01

Spinal cord injury (SCI) triggers an "accelerated aging" process that may include development of hypogonadism, even among younger men with SCI; however, few studies have investigated the prevalence or etiology of hypogonadism in men with SCI. Young men with SCI also are at increased risk for developing metabolic dysfunction after injury, which may be exacerbated by concomitant testosterone (T) deficiency, thus identifying the prevalence and risk factors for T deficiency in men with SCI is important for their long-term health. To investigate the prevalence, risk factors, and etiology of T deficiency (hypogonadism) in otherwise-healthy men with chronic, motor complete SCI. Secondary cross-sectional analysis. Rehabilitation research centers in Washington, DC, and Miami, Florida. Men (n = 58) aged 18-45 years with chronic (≥1 year), motor complete SCI without comorbidities or use of testosterone therapy. Plasma concentrations of hormones were measured with standardized assays. Body composition was assessed with dual-energy x-ray absorptiometry scan. Serum total T and calculated free T. T deficiency was more common in men after SCI than in a matched cohort of similarly-aged men without SCI (25%, SCI versus 6.7%, non-SCI, P < .001). The risk of hypogonadism appeared to be increased in men with more extensive injury and with higher percent body fat. The majority of men with SCI with low T had low serum LH levels, suggesting that central suppression of the hypothalamic-pituitary-gonadal axis may be the most common etiology of hypogonadism after SCI. Hypogonadism is more common in young men with SCI than in similarly aged men without SCI, suggesting that SCI should be identified as a risk factor for T deficiency and that routine screening for hypogonadism should be performed in the SCI population. II. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Combined SCI and TBI: Recovery of forelimb function after unilateral cervical spinal cord injury (SCI) is retarded by contralateral traumatic brain injury (TBI), and ipsilateral TBI balances the effects of SCI on paw placement

PubMed Central

Inoue, Tomoo; Lin, Amity; Ma, Xiaokui; McKenna, Stephen L.; Creasey, Graham H.; Manley, Geoffrey T.; Ferguson, Adam R.; Bresnahan, Jacqueline C.; Beattie, Michael S.

2015-01-01

A significant proportion (estimates range from 16–74%) of patients with spinal cord injury (SCI) have concomitant traumatic brain injury (TBI), and the combination often produces difficulties in planning and implementing rehabilitation strategies and drug therapies. For example, many of the drugs used to treat SCI may interfere with cognitive rehabilitation, and conversely drugs that are used to control seizures in TBI patients may undermine locomotor recovery after SCI. The current paper presents an experimental animal model for combined SCI and TBI to help drive mechanistic studies of dual diagnosis. Rats received a unilateral SCI (75 kdyn) at C5 vertebral level, a unilateral TBI (2.0 mm depth, 4.0 m/s velocity impact on the forelimb sensori-motor cortex), or both SCI + TBI. TBI was placed either contralateral or ipsilateral to the SCI. Behavioral recovery was examined using paw placement in a cylinder, grooming, open field locomotion, and the IBB cereal eating test. Over 6 weeks, in the paw placement test, SCI + contralateral TBI produced a profound deficit that failed to recover, but SCI + ipsilateral TBI increased the relative use of the paw on the SCI side. In the grooming test, SCI + contralateral TBI produced worse recovery than either lesion alone even though contralateral TBI alone produced no observable deficit. In the IBB forelimb test, SCI + contralateral TBI revealed a severe deficit that recovered in 3 weeks. For open field locomotion, SCI alone or in combination with TBI resulted in an initial deficit that recovered in 2 weeks. Thus, TBI and SCI affected forelimb function differently depending upon the test, reflecting different neural substrates underlying, for example, exploratory paw placement and stereotyped grooming. Concurrent SCI and TBI had significantly different effects on outcomes and recovery, depending upon laterality of the two lesions. Recovery of function after cervical SCI was retarded by the addition of a moderate TBI in the contralateral hemisphere in all tests, but forepaw placements were relatively increased by an ipsilateral TBI relative to SCI alone, perhaps due to the dual competing injuries influencing the use of both forelimbs. These findings emphasize the complexity of recovery from combined CNS injuries, and the possible role of plasticity and laterality in rehabilitation, and provide a start towards a useful preclinical model for evaluating effective therapies for combine SCI and TBI. PMID:23770071

Combined SCI and TBI: recovery of forelimb function after unilateral cervical spinal cord injury (SCI) is retarded by contralateral traumatic brain injury (TBI), and ipsilateral TBI balances the effects of SCI on paw placement.

PubMed

Inoue, Tomoo; Lin, Amity; Ma, Xiaokui; McKenna, Stephen L; Creasey, Graham H; Manley, Geoffrey T; Ferguson, Adam R; Bresnahan, Jacqueline C; Beattie, Michael S

2013-10-01

A significant proportion (estimates range from 16 to 74%) of patients with spinal cord injury (SCI) have concomitant traumatic brain injury (TBI), and the combination often produces difficulties in planning and implementing rehabilitation strategies and drug therapies. For example, many of the drugs used to treat SCI may interfere with cognitive rehabilitation, and conversely drugs that are used to control seizures in TBI patients may undermine locomotor recovery after SCI. The current paper presents an experimental animal model for combined SCI and TBI to help drive mechanistic studies of dual diagnosis. Rats received a unilateral SCI (75 kdyn) at C5 vertebral level, a unilateral TBI (2.0 mm depth, 4.0 m/s velocity impact on the forelimb sensori-motor cortex), or both SCI+TBI. TBI was placed either contralateral or ipsilateral to the SCI. Behavioral recovery was examined using paw placement in a cylinder, grooming, open field locomotion, and the IBB cereal eating test. Over 6weeks, in the paw placement test, SCI+contralateral TBI produced a profound deficit that failed to recover, but SCI+ipsilateral TBI increased the relative use of the paw on the SCI side. In the grooming test, SCI+contralateral TBI produced worse recovery than either lesion alone even though contralateral TBI alone produced no observable deficit. In the IBB forelimb test, SCI+contralateral TBI revealed a severe deficit that recovered in 3 weeks. For open field locomotion, SCI alone or in combination with TBI resulted in an initial deficit that recovered in 2 weeks. Thus, TBI and SCI affected forelimb function differently depending upon the test, reflecting different neural substrates underlying, for example, exploratory paw placement and stereotyped grooming. Concurrent SCI and TBI had significantly different effects on outcomes and recovery, depending upon laterality of the two lesions. Recovery of function after cervical SCI was retarded by the addition of a moderate TBI in the contralateral hemisphere in all tests, but forepaw placements were relatively increased by an ipsilateral TBI relative to SCI alone, perhaps due to the dual competing injuries influencing the use of both forelimbs. These findings emphasize the complexity of recovery from combined CNS injuries, and the possible role of plasticity and laterality in rehabilitation, and provide a start towards a useful preclinical model for evaluating effective therapies for combine SCI and TBI. Copyright © 2013 Elsevier Inc. All rights reserved.

Neuroprotective effects of lycopene in spinal cord injury in rats via antioxidative and anti-apoptotic pathway.

PubMed

Hu, Wei; Wang, Hongbo; Liu, Zhenfeng; Liu, Yanlu; Wang, Rong; Luo, Xiao; Huang, Yifei

2017-03-06

Oxidative damage induced-mitochondrial dysfunction and apoptosis has been widely studied in spinal cord injury (SCI). Lycopene, a polyunsaturated hydrocarbon, has the highest antioxidant capacity compared to the other carotenoids. However, the role of lycopene in SCI is unknown. In the present study, we evaluated the antioxidant effects of lycopene on mitochondrial dysfunction and apoptosis following T10 contusion SCI in rats. The rats were randomized into 5 groups: the sham group, the SCI group and the SCI pre-treated with lycopene (5, 10, or 20mg/kg) group. The SCI group showed increased malondialdehyde (MDA) content, decreased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) ability, which indicated that SCI could induce oxidative damage. What's more, the SCI group showed decreased mRNA expression of cytochrome b and mitochondrial transcription factor A (Tfam), and decreased mitochondrial membrane potential (ΔYm), which indicated that SCI could induce mitochondrial dysfunction. Besides, the SCI group showed decreased protein expression of bcl-2 and mitochondrial cytochrome C, increased protein expression of cytosolic cytochrome C, cleaved caspase-9, cleaved caspase-3 and bax, and increased TUNEL-positive cell numbers, which indicated that SCI could induce cell apoptosis. Fortunately, the lycopene treatment significantly ameliorated oxidative damage, mitochondrial dysfunction and cell apoptosis via the reversion of those parameters described above in the dose of lycopene of 10 and 20mg/kg. In addition, lycopene significantly ameliorated the hind limb motor disturbances in the SCI+lyco10 group and the SCI+lyco20 group compared with the SCI group. These results suggested that lycopene administration could improve total antioxidant status and might have neuroprotective effects on SCI. Copyright © 2017 Elsevier B.V. All rights reserved.

Games and Simulations for Climate, Weather and Earth Science Education

NASA Astrophysics Data System (ADS)

Russell, R. M.; Clark, S.

2015-12-01

We will demonstrate several interactive, computer-based simulations, games, and other interactive multimedia. These resources were developed for weather, climate, atmospheric science, and related Earth system science education. The materials were created by the UCAR Center for Science Education. These materials have been disseminated via our web site (SciEd.ucar.edu), webinars, online courses, teacher workshops, and large touchscreen displays in weather and Sun-Earth connections exhibits in NCAR's Mesa Lab facility in Boulder, Colorado. Our group has also assembled a web-based list of similar resources, especially simulations and games, from other sources that touch upon weather, climate, and atmospheric science topics. We'll briefly demonstrate this directory.

Effects of Spinal Cord Injury in Heart Rate Variability After Acute and Chronic Exercise: A Systematic Review.

PubMed

Buker, Daniel Bueno; Oyarce, Cristóbal Castillo; Plaza, Raúl Smith

2018-01-01

Background: Spinal cord injury (SCI) above T6 is followed by a loss of sympathetic supraspinal control of the heart, disturbing the autonomic balance and increasing cardiovascular risk. Heart rate variability (HRV) is a widely used tool for assessing the cardiac autonomic nervous system and positive adaptations after regular exercise in able-bodied subjects. However, adaptations in SCI subjects are not well known. Objectives: To compare HRV between able-bodied and SCI subjects and analyze the effects of chronic and acute exercise on HRV in the SCI group. Methods: We searched MEDLINE, Embase, Web of Science, SciELO, and Google Scholar databases to July 2016. We selected English and Spanish observational or experimental studies reporting HRV after training or acute exercise in SCI patients. We also included studies comparing HRV in SCI individuals with able-bodied subjects. Animal studies and nontraumatic SCI studies were excluded. We screened 279 articles by title and abstract; of these, we fully reviewed 29 articles. Eighteen articles fulfilled criteria for inclusion in this study. Results: SCI individuals showed lower HRV values in the low frequency band compared to able-bodied subjects. Regular exercise improved HRV in SCI subjects, however time and intensity data were lacking. HRV decreases after an acute bout of exercise on SCI subjects, but recovery kinetics are unknown. Conclusion: HRV is affected following SCI. Able-bodied subjects and SCI individuals have different values of HRV. Acute bouts of exercise change HRV temporarily, and chronic exercise might improve autonomic balance in SCI.

Overview of the Spinal Cord Injury--Quality of Life (SCI-QOL) measurement system.

PubMed

Tulsky, David S; Kisala, Pamela A; Victorson, David; Tate, Denise G; Heinemann, Allen W; Charlifue, Susan; Kirshblum, Steve C; Fyffe, Denise; Gershon, Richard; Spungen, Ann M; Bombardier, Charles H; Dyson-Hudson, Trevor A; Amtmann, Dagmar; Kalpakjian, Claire Z; Choi, Seung W; Jette, Alan M; Forchheimer, Martin; Cella, David

2015-05-01

The Spinal Cord Injury--Quality of Life (SCI-QOL) measurement system was developed to address the shortage of relevant and psychometrically sound patient reported outcome (PRO) measures available for clinical care and research in spinal cord injury (SCI) rehabilitation. Using a computer adaptive testing (CAT) approach, the SCI-QOL builds on the Patient Reported Outcomes Measurement Information System (PROMIS) and the Quality of Life in Neurological Disorders (Neuro-QOL) initiative. This initial manuscript introduces the background and development of the SCI-QOL measurement system. Greater detail is presented in the additional manuscripts of this special issue. Classical and contemporary test development methodologies were employed. Qualitative input was obtained from individuals with SCI and clinicians through interviews, focus groups, and cognitive debriefing. Item pools were field tested in a multi-site sample (n=877) and calibrated using item response theory methods. Initial reliability and validity testing was performed in a new sample of individuals with traumatic SCI (n=245). Five Model SCI System centers and one Department of Veterans Affairs Medical Center across the United States. Adults with traumatic SCI. n/a n/a The SCI-QOL consists of 19 item banks, including the SCI-Functional Index banks, and 3 fixed-length scales measuring physical, emotional, and social aspects of health-related QOL (HRQOL). The SCI-QOL measurement system consists of psychometrically sound measures for individuals with SCI. The manuscripts in this special issue provide evidence of the reliability and initial validity of this measurement system. The SCI-QOL also links to other measures designed for a general medical population.

Bacterial susceptibility patterns in patients with spinal cord injury and disorder (SCI/D): an opportunity for customized stewardship tools.

PubMed

Suda, K J; Patel, U C; Sabzwari, R; Cao, L; Ramanathan, S; Hill, J N; Evans, C T

2016-11-01

Retrospective observational study of bacterial susceptibilities in Veterans with SCI/D as compared to a general patient population. The purpose of this project was to evaluate the prevalence and susceptibility of bacteria isolated from spinal cord injury and disorder (SCI/D) patients as compared with a general patient population and determine whether a SCI/D-specific antibiogram, a report of bacterial susceptibilities used to guide empiric antibiotic selection, would be a useful stewardship tool. Veterans Affairs Medical Center located in Cook county, IL, USA. Microbiology reports from 1 October 2012 to 30 September 2013 were compiled into a SCI/D-specific antibiogram and compared to a non-SCI/D antibiogram. Persons with positive cultures and SCI/D were younger and had a higher Charlson Index as compared to non-SCI/D patients (P<0.0001 for both). Five thousand one hundred and thirty-one unique isolate cultures were evaluated (SCI/D=23.0%). Frequencies of pathogens isolated in SCI/D and non-SCI/D differed. Methicillin-resistant Staphylococcus aureus occurred more frequently in SCI/D (27.8% vs 55.4%; P<0.0001). Gram-negatives had generally lower susceptibilities in SCI/D and a higher frequency of organisms producing extended-spectrum Beta-lactamases (17.6% vs 5.0%; P<0.0001), carbapenem-resistant Enterobacteriaceae (2.4% vs 0.5%; P<0.0001), carbapenem resistance (7.6% vs 2.4%; P<0.0001) and isolates resistant to ⩾3 antibiotic classes (60.7% vs 28.0%; P=0.0001). Different pathogens with poorer susceptibilities are isolated in SCI/D. Thus an SCI/D-specific antibiogram reflective of resistance patterns in these patients may increase the appropriateness of empiric antibiotic selection. The frequency of multi-drug resistant organisms in cultures obtained from patients with SCI/D is worrisome.

Tracking functional status across the spinal cord injury lifespan: linking pediatric and adult patient-reported outcome scores.

PubMed

Tian, Feng; Ni, Pengsheng; Mulcahey, M J; Hambleton, Ronald K; Tulsky, David; Haley, Stephen M; Jette, Alan M

2014-11-01

To use item response theory (IRT) methods to link scores from 2 recently developed contemporary functional outcome measures, the adult Spinal Cord Injury-Functional Index (SCI-FI) and the Pedi SCI (both the parent version and the child version). Secondary data analysis of the physical functioning items of the adult SCI-FI and the Pedi SCI instruments. We used a nonequivalent group design with items common to both instruments and the Stocking-Lord method for the linking. Linking was conducted so that the adult SCI-FI and Pedi SCI scaled scores could be compared. Community. This study included a total sample of 1558 participants. Pedi SCI items were administered to a sample of children (n=381) with SCI aged 8 to 21 years, and of parents/caregivers (n=322) of children with SCI aged 4 to 21 years. Adult SCI-FI items were administered to a sample of adults (n=855) with SCI aged 18 to 92 years. Not applicable. Five scales common to both instruments were included in the analysis: Wheelchair, Daily Routine/Self-care, Daily Routine/Fine Motor, Ambulation, and General Mobility functioning. Confirmatory factor analysis and exploratory factor analysis results indicated that the 5 scales are unidimensional. A graded response model was used to calibrate the items. Misfitting items were identified and removed from the item banks. Items that function differently between the adult and child samples (ie, exhibit differential item functioning) were identified and removed from the common items used for linking. Domain scores from the Pedi SCI instruments were transformed onto the adult SCI-FI metric. This IRT linking allowed estimation of adult SCI-FI scale scores based on Pedi SCI scale scores and vice versa; therefore, it provides clinicians with a means of tracking long-term functional data for children with an SCI across their entire lifespan. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

An atom probe perspective on phase separation and precipitation in duplex stainless steels

NASA Astrophysics Data System (ADS)

Guo, Wei; Garfinkel, David A.; Tucker, Julie D.; Haley, Daniel; Young, George A.; Poplawsky, Jonathan D.

2016-06-01

Three-dimensional chemical imaging of Fe-Cr alloys showing Fe-rich (α)/Cr-rich (α‧) phase separation is reported using atom probe tomography techniques. The extent of phase separation, i.e., amplitude and wavelength, has been quantitatively assessed using the Langer-Bar-on-Miller, proximity histogram, and autocorrelation function methods for two separate Fe-Cr alloys, designated 2101 and 2205. Although the 2101 alloy possesses a larger wavelength and amplitude after annealing at 427 °C for 100-10 000 h, it exhibits a lower hardness than the 2205 alloy. In addition to this phase separation, ultra-fine Ni-Mn-Si-Cu-rich G-phase precipitates form at the α/α‧ interfaces in both alloys. For the 2101 alloy, Cu clusters act to form a nucleus, around which a Ni-Mn-Si shell develops during the precipitation process. For the 2205 alloy, the Ni and Cu atoms enrich simultaneously and no core-shell chemical distribution was found. This segregation phenomenon may arise from the exact Ni/Cu ratio inside the ferrite. After annealing for 10 000 h, the number density of the G-phase within the 2205 alloy was found to be roughly one order of magnitude higher than in the 2101 alloy. The G-phase precipitates have an additional deleterious effect on the thermal embrittlement, as evaluated by the Ashby-Orowan equation, which explains the discrepancy between the hardness and the rate of phase separation with respect to annealing time (Gladman T 1999 Mater. Sci. Tech. Ser. 15 30-36). ).

An atom probe perspective on phase separation and precipitation in duplex stainless steels

DOE PAGES

Garfinkel, David A.; Tucker, Julie D.; Haley, Daniel A.; ...

2016-05-16

Here, three-dimensional chemical imaging of Fe–Cr alloys showing Fe-rich (α)/Cr-rich (α') phase separation is reported using atom probe tomography techniques. The extent of phase separation, i.e., amplitude and wavelength, has been quantitatively assessed using the Langer-Bar-on-Miller, proximity histogram, and autocorrelation function methods for two separate Fe–Cr alloys, designated 2101 and 2205. Although the 2101 alloy possesses a larger wavelength and amplitude after annealing at 427 °C for 100–10 000 h, it exhibits a lower hardness than the 2205 alloy. In addition to this phase separation, ultra-fine Ni–Mn–Si–Cu-rich G-phase precipitates form at the α/α' interfaces in both alloys. For the 2101more » alloy, Cu clusters act to form a nucleus, around which a Ni–Mn–Si shell develops during the precipitation process. For the 2205 alloy, the Ni and Cu atoms enrich simultaneously and no core–shell chemical distribution was found. This segregation phenomenon may arise from the exact Ni/Cu ratio inside the ferrite. After annealing for 10 000 h, the number density of the G-phase within the 2205 alloy was found to be roughly one order of magnitude higher than in the 2101 alloy. The G-phase precipitates have an additional deleterious effect on the thermal embrittlement, as evaluated by the Ashby–Orowan equation, which explains the discrepancy between the hardness and the rate of phase separation with respect to annealing time (Gladman T 1999 Mater. Sci. Tech. Ser. 15 30–36).« less

Atomic model of anti-phase boundaries in a face-centred icosahedral Zn Mg Dy quasicrystal

NASA Astrophysics Data System (ADS)

Wang, Jianbo; Yang, Wenge; Wang, Renhui

2003-03-01

An atomic model in the physical space for an anti-phase boundary (APB) in the ordered face-centred icosahedral Zn-Mg-Dy quasicrystal phase is presented, based on a six-dimensional model suggested by Ishimasa and Shimizu (2000 Mater. Sci. Eng. A 294-296 232, Ishimasa 2001 private communication). The physical space atomic positions of the defected structure were used for the calculation of the corresponding exit-plane wavefunction and high-resolution transmission electron microscopy images. The analysis of the defect by inverse Fourier transformation reveals that when superstructure reflection spots are used for back-transformation, then at the APB, bright lattice fringes are found to turn into dark ones, and vice versa. When fundamental reflections are used, the APB is not visible. This phenomenon is the same as the corresponding experimental study recently published by Heggen et al(2001a Phys. Rev. B 64 014202). Based on this atomic model it is found that the APB perpendicular to a fivefold axis A5 (APB-A5) is a non-conservative boundary, while the APB perpendicular to a pseudo-twofold axis A2P (APB-A2P) is a conservative one. This fact is consistent with the experimental observation (Heggen et al2002 J. Alloys Compounds 342 330) that the frequency of occurrence of APB-A5 is 90% in the heat-treated samples compared with that in the deformed samples (45%), while the frequency of occurrence of APB-A2P is 34% in the deformed samples compared with that in the heat-treated samples.

Dislocation evolution in 316 L stainless steel during multiaxial ratchetting deformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong Yawei; Kang Guozheng, E-mail: guozhengkang@yahoo.com.cn; Liu Yujie

2012-03-15

Dislocation patterns and their evolutions in 316 L stainless steel during the multiaxial ratchetting deformation were observed by transmission electron microscopy (TEM). The microscopic observations indicate that the dislocation evolution presented during the multiaxial ratchetting with four kinds of multiaxial loading paths is similar to that in the uniaxial case [G. Z. Kang et al., Mater Sci Eng A 527 (2010) 5952]. That is, dislocation networks and dislocation tangles are formed quickly by the multiple-slip and cross-slip of dislocation activated by applied multiaxial stress; and then polarized patterns such as dislocation walls and elongated incipient dislocation cells are formed atmore » the last stage of multiaxial ratchetting. The dislocation patterns evolve more quickly from the modes at low dislocation density to the ones at high density during the multiaxial ratchetting than that in the uniaxial case, and some traces of multiple-slip are observed in the multiaxial ones. The dislocation evolution during the multiaxial ratchetting deformation is summarized by comparing the observed dislocation patterns with those presented in the multiaxial strain-controlled and symmetrical stress-controlled cyclic tests. The multiaxial ratchetting of 316 L stainless steel can be microscopically and qualitatively explained by the observed evolution of dislocation patterns. - Highlights: Black-Right-Pointing-Pointer Dislocation patterns change from lines and nets to tangles, walls and cells. Black-Right-Pointing-Pointer Dislocation patterns evolve quicker in the multiaxial case. Black-Right-Pointing-Pointer Aligned dislocation arrays and some traces of multiple slips are observed. Black-Right-Pointing-Pointer Heterogeneous dislocation patterns result in the multiaxial ratchetting.« less

Critical de Broglie wavelength in superconductors

NASA Astrophysics Data System (ADS)

Talantsev, E. F.

2018-03-01

There are growing numbers of experimental evidences that the self-field critical currents, Jc(sf,T), are a new instructive tool to investigate fundamental properties of superconductors ranging from atomically thin films [M. Liao et al., Nat. Phys. 6 (2018), https://doi.org/10.1038/s41567-017-0031-6; E. F. Talantsev et al., 2D Mater. 4 (2017) 025072; A. Fete et al., Appl. Phys. Lett. 109 (2016) 192601] to millimeter-scale samples [E. F. Talantsev et al., Sci. Rep. 7 (2017) 10010]. The basic empirical equation which quantitatively accurately described experimental Jc(sf,T) was proposed by Talantsev and Tallon [Nat. Commun. 6 (2015) 7820] and it was the relevant critical field (i.e. thermodynamic field, Bc, for type-I and lower critical field, Bc1, for type-II superconductors) divided by the London penetration depth, λL. In this paper, we report new findings relating to this empirical equation. It is that the critical wavelength of the de Broglie wave, λdB,c, of the superconducting charge carrier which within a numerical pre-factor is equal to the largest of two characteristic lengths of Ginzburg-Landau theory, i.e. the coherence length, ξ, for type-I superconductors or the London penetration depth, λL, for type-II superconductors. We also formulate a microscopic criterion for the onset of dissipative transport current flow: ps ṡ 2ṡλL ln(1+2ṡ(λL ξ )) ≥ 1 2 ṡ ( h 2π), where ps is the charge carrier momentum, h is Planck’s constant and the inequality sign “ <” is reserved for the dissipation-free flow.

Helicon antenna radiation patterns in a high-density hydrogen linear plasma device

NASA Astrophysics Data System (ADS)

Caneses, J. F.; Blackwell, B. D.; Piotrowicz, P.

2017-11-01

Antenna radiation patterns in the vicinity of a helicon antenna are investigated in hydrogen plasmas produced in the MAGPIE linear plasma device. Using a uniform cold-plasma full-wave code, we model the wave physics in MAGPIE and find good agreement with experimental wave measurements. We show for the first time which antenna elements in a helicon device couple most strongly to the plasma and discuss the physical mechanism that determines this effect. Helicon wavefields in the near field of the antenna are best described in terms of the group velocity and ray direction, while far from the antenna, helicon wavefields behave like plane waves and are best described in terms of eigen-modes. In addition, we present recent 2D axis-symmetric full-wave simulations of the 120 kW helicon source in ProtoMPEX [Rapp et al., IEEE Trans. Plasma Sci. 44(12), 3456-3464 (2016); Caughman et al., J. Vac. Sci. Technol. Vac. Surf. Films 35, 03E114 (2017); and Goulding et al., Fusion Sci. Technol. 72(4), 588-594 (2017)] ( n e ˜ 5 × 1019 m-3, B 0 ˜ 70 mT, and f = 13.56 MHz) where the antenna radiation patterns are evident, and we provide an interpretation of the numerical results using the ideas developed in this paper.

Preface: SciDAC 2005

NASA Astrophysics Data System (ADS)

Mezzacappa, Anthony

2005-01-01

On 26-30 June 2005 at the Grand Hyatt on Union Square in San Francisco several hundred computational scientists from around the world came together for what can certainly be described as a celebration of computational science. Scientists from the SciDAC Program and scientists from other agencies and nations were joined by applied mathematicians and computer scientists to highlight the many successes in the past year where computation has led to scientific discovery in a variety of fields: lattice quantum chromodynamics, accelerator modeling, chemistry, biology, materials science, Earth and climate science, astrophysics, and combustion and fusion energy science. Also highlighted were the advances in numerical methods and computer science, and the multidisciplinary collaboration cutting across science, mathematics, and computer science that enabled these discoveries. The SciDAC Program was conceived and funded by the US Department of Energy Office of Science. It is the Office of Science's premier computational science program founded on what is arguably the perfect formula: the priority and focus is science and scientific discovery, with the understanding that the full arsenal of `enabling technologies' in applied mathematics and computer science must be brought to bear if we are to have any hope of attacking and ultimately solving today's computational Grand Challenge problems. The SciDAC Program has been in existence for four years, and many of the computational scientists funded by this program will tell you that the program has given them the hope of addressing their scientific problems in full realism for the very first time. Many of these scientists will also tell you that SciDAC has also fundamentally changed the way they do computational science. We begin this volume with one of DOE's great traditions, and core missions: energy research. As we will see, computation has been seminal to the critical advances that have been made in this arena. Of course, to understand our world, whether it is to understand its very nature or to understand it so as to control it for practical application, will require explorations on all of its scales. Computational science has been no less an important tool in this arena than it has been in the arena of energy research. From explorations of quantum chromodynamics, the fundamental theory that describes how quarks make up the protons and neutrons of which we are composed, to explorations of the complex biomolecules that are the building blocks of life, to explorations of some of the most violent phenomena in our universe and of the Universe itself, computation has provided not only significant insight, but often the only means by which we have been able to explore these complex, multicomponent systems and by which we have been able to achieve scientific discovery and understanding. While our ultimate target remains scientific discovery, it certainly can be said that at a fundamental level the world is mathematical. Equations ultimately govern the evolution of the systems of interest to us, be they physical, chemical, or biological systems. The development and choice of discretizations of these underlying equations is often a critical deciding factor in whether or not one is able to model such systems stably, faithfully, and practically, and in turn, the algorithms to solve the resultant discrete equations are the complementary, critical ingredient in the recipe to model the natural world. The use of parallel computing platforms, especially at the TeraScale, and the trend toward even larger numbers of processors, continue to present significant challenges in the development and implementation of these algorithms. Computational scientists often speak of their `workflows'. A workflow, as the name suggests, is the sum total of all complex and interlocking tasks, from simulation set up, execution, and I/O, to visualization and scientific discovery, through which the advancement in our understanding of the natural world is realized. For the computational scientist, enabling such workflows presents myriad, signiflcant challenges, and it is computer scientists that are called upon at such times to address these challenges. Simulations are currently generating data at the staggering rate of tens of TeraBytes per simulation, over the course of days. In the next few years, these data generation rates are expected to climb exponentially to hundreds of TeraBytes per simulation, performed over the course of months. The output, management, movement, analysis, and visualization of these data will be our key to unlocking the scientific discoveries buried within the data. And there is no hope of generating such data to begin with, or of scientific discovery, without stable computing platforms and a sufficiently high and sustained performance of scientific applications codes on them. Thus, scientific discovery in the realm of computational science at the TeraScale and beyond will occur at the intersection of science, applied mathematics, and computer science. The SciDAC Program was constructed to mirror this reality, and the pages that follow are a testament to the efficacy of such an approach. We would like to acknowledge the individuals on whose talents and efforts the success of SciDAC 2005 was based. Special thanks go to Betsy Riley for her work on the SciDAC 2005 Web site and meeting agenda, for lining up our corporate sponsors, for coordinating all media communications, and for her efforts in processing the proceedings contributions, to Sherry Hempfling for coordinating the overall SciDAC 2005 meeting planning, for handling a significant share of its associated communications, and for coordinating with the ORNL Conference Center and Grand Hyatt, to Angela Harris for producing many of the documents and records on which our meeting planning was based and for her efforts in coordinating with ORNL Graphics Services, to Angie Beach of the ORNL Conference Center for her efforts in procurement and setting up and executing the contracts with the hotel, and to John Bui and John Smith for their superb wireless networking and A/V set up and support. We are grateful for the relentless efforts of all of these individuals, their remarkable talents, and for the joy of working with them during this past year. They were the cornerstones of SciDAC 2005. Thanks also go to Kymba A'Hearn and Patty Boyd for on-site registration, Brittany Hagen for administrative support, Bruce Johnston for netcast support, Tim Jones for help with the proceedings and Web site, Sherry Lamb for housing and registration, Cindy Lathum for Web site design, Carolyn Peters for on-site registration, and Dami Rich for graphic design. And we would like to express our appreciation to the Oak Ridge National Laboratory, especially Jeff Nichols, the Argonne National Laboratory, the Lawrence Berkeley National Laboratory, and to our corporate sponsors, Cray, IBM, Intel, and SGI, for their support. We would like to extend special thanks also to our plenary speakers, technical speakers, poster presenters, and panelists for all of their efforts on behalf of SciDAC 2005 and for their remarkable achievements and contributions. We would like to express our deep appreciation to Lali Chatterjee, Graham Douglas and Margaret Smith of Institute of Physics Publishing, who worked tirelessly in order to provide us with this finished volume within two months, which is nothing short of miraculous. Finally, we wish to express our heartfelt thanks to Michael Strayer, SciDAC Director, whose vision it was to focus SciDAC 2005 on scientific discovery, around which all of the excitement we experienced revolved, and to our DOE SciDAC program managers, especially Fred Johnson, for their support, input, and help throughout.

The Role of the Middle Atmosphere in Simulations of the Troposphere during Northern Hemisphere Winter: Differences between High- and Low-Top Models

DTIC Science & Technology

2010-01-01

Perlwitz and Harnik 2004). When SSW events are large, the impact in the lower atmosphere is most evident. An example is given in Fig. 1, which shows the...and troposphere. J. Atmos. Sci., 44, 1775–1800. Perlwitz, J., and N. Harnik , 2004: Downward coupling between the stratosphere and troposphere: The

Electromagnetic Fields Exposure Limits

DTIC Science & Technology

2018-01-01

analysis, synthesis, integration and validation of knowledge derived through the scientific method. In NATO, S&T is addressed using different...Panel • NMSG NATO Modelling and Simulation Group • SAS System Analysis and Studies Panel • SCI Systems Concepts and Integration Panel • SET... integrity or morphology. They later also failed to find a lack of direct DNA damage in human blood (strand breaks, alkali-labile sites, and incomplete

Information Processing, Specificity of Practice, and the Transfer of Learning: Considerations for Reconsidering Fidelity

ERIC Educational Resources Information Center

Grierson, Lawrence E. M.

2014-01-01

Much has been made in the recent medical education literature of the incorrect characterization of simulation along a continuum of low to high fidelity (Cook et al. "JAMA" 306(9): 978-988, 2011; Norman et al. "Med Educ" 46(7): 636-647, 2012; Teteris et al. "Adv Health Sci Educ" 17(1): 137-144, 2012). For the most…

High-Level Connectionist Models

DTIC Science & Technology

1993-10-01

subject of intense research since Axelrod (1984) showed that two agents engaged in a prisoner’s dilemma ( Poundstone , 1992) can evolve into mutually...The various parameter values for the program are set as described above unless otherwise noted. 4.1 Williams ’ Trigger Problem As an initial test...M. P. Vecchi. Optimization by simulated annealing. Sci- ence, 220:671-680, 1983. [39] R. J. Williams . Adaptive State Representation and Estimation

Laboratory Simulations of Space Weathering of Asteroid Surfaces by Solar Wind Ions.

NASA Astrophysics Data System (ADS)

Miller, Kenneth A.; De Ruette, Nathalie; Harlow, George; Domingue, Deborah L.; Savin, Daniel Wolf

2014-06-01

Studies into the formation of the terrestrial planets rely on the analysis of asteroids and meteorites. Asteroids are solar system remnants from the planetary formation period. By characterizing their mineralogical composition we can better constrain the formation and evolution of the inner planets.Remote sensing is the primary means for studying asteroids. Sample return missions, such as Hayabusa, are complex and expensive, hence we rely on asteroid reflectance spectra to determine chemical composition. Links have been made and debated between meteorite classes and asteroid types [1, 2]. If such relationships can be confirmed, then meteorites would provide a low cost asteroid sample set for study. However, a major issue in establishing this link is the spectral differences between meteorite samples and asteroid surfaces. The most commonly invoked explanation for these differences is that the surfaces of asteroids are space weathered [2, 3]. The dominant mechanism for this weathering is believed to be solar-wind ion irradiation [2, 4, 5]. Laboratory simulations of space weathering have demonstrated changes in the general direction required to alter spectra from unweathered meteorite samples to asteroid observations [3, 6 -10], but many open questions remain and we still lack a comprehensive understanding. We propose to explore the alleged connection of ordinary chondrite (OC) meteorites to S-type asteroids through a series of systematic laboratory simulations of solar-wind space weathering of asteroid surface materials. Here we describe the issue in more detail and describe the proposed apparatus. [1] Chapman C. R. (1996) Meteorit. Planet. Sci., 31, 699-725. [2] Chapman C. R. (2004), Annu. Rev. Earth Planet. Sci., 32, 539-567. [3] Hapke B. (2001) J. Ge-ophys. Res., 106, 10039-10074. [4] Pieters C.M. et al. (2000) Meteorit. Planet. Sci., 35, 1101-1107. [5] Ver-nazza P. et al. (2009) Nature, 458, 993-995. [6] Stra-zulla G. et al. (2005) Icarus, 174, 31-35 (2005). [7] Brunetto R and Strazzulla G (2005) Icarus, 179, 265-273. [8] Marchi S et al. (2005) Astron. Astrophys., 443, 769-775. [9] Loeffler M. J. et al. (2009) J. Geo-phys. Res., 114, E03003. [10] Fu X. et al. (2012) Ica-rus, 219, 630-640

Lipid Peroxidation and Its Role in the Expression of NLRP1a and NLRP3 Genes in Testicular Tissue of Male Rats: a Model of Spinal Cord Injury

PubMed

Bazrafkan, Mahshid; Nikmehr, Banafsheh; Shahverdi, Abdolhossein; Hosseini, Seyed Reza; Hassani, Fatemeh; Poorhassan, Mahnaz; Mokhtari, Tahmineh; Abolhassani, Farid; Choobineh, Hamid; Beyer, Cordian; Hassanzadeh, Gholamreza

2017-10-16

The majority of male patients with spinal cord injury (SCI) suffer from infertility. Nucleotide-binding oligomerization domain-like receptors NOD-like receptors (NLRs) are a kind of receptors that corporate in the inflammasome complex. Recent studies have introduced the inflammasome as the responsible agent for secreting cytokines in semen. Reactive oxygen species (ROS) is one of the elements that trigger inflammasome activation. Genital infections in SCI can lead to ROS generation. We investigated the relation between lipid peroxidation and inflammasome complex activity in testicular tissue of SCI rats. Adult male rats (n=20), weighting 200-250 g, were included and divided into four groups: three experimental groups, including SCI1, SCI3, and SCI7, i.e. the rats were subjected to SCI procedure and sacrificed after one, three, and seven days, respectively and a control group. We performed a moderate, midline spinal contusion injury at thoracic level 10. The animals were anesthetized, and testes were collected for measurement of gene expression by real-time PCR. Caudal parts of epididymis were collected for malondialdehyde (MDA) measurement. No NLRP1a mRNA over expression was seen in the testes of control and SCI groups. After seven days from SCI surgery, NLRP3 mRNA expression was significantly increased in SCI7 animals (P≤0.05). There was a significant difference in MDA level in SCI7 versus control group, as well as SCI1 and SCI3 animals (P≤0.05). NLRP3 overexpression occurs due to the increased ROS production in testicular tissue of SCI rats.

Lipid Peroxidation and Its Role in the Expression of NLRP1a and NLRP3 Genes in Testicular Tissue of Male Rats: A Model of Spinal Cord Injury

PubMed Central

Bazrafkan, Mahshid; Nikmehr, Banafsheh; Shahverdi, Abdolhossein; Hosseini, Seyed Reza; Hassani, Fatemeh; Poorhassan, Mahnaz; Mokhtari, Tahmineh; Abolhassani, Farid; Choobineh, Hamid; Beyer, Cordian; Hassanzadeh, Gholamreza

2018-01-01

Background: The majority of male patients with spinal cord injury (SCI) suffer from infertility. Nucleotide-binding oligomerization domain-like receptors NOD-like receptors (NLRs) are a kind of receptors that corporate in the inflammasome complex. Recent studies have introduced the inflammasome as the responsible agent for secreting cytokines in semen. Reactive oxygen species (ROS) is one of the elements that trigger inflammasome activation. Genital infections in SCI can lead to ROS generation. We investigated the relation between lipid peroxidation and inflammasome complex activity in testicular tissue of SCI rats. Methods: Adult male rats (n=20), weighting 200-250 g, were included and divided into four groups: three experimental groups, including SCI1, SCI3, and SCI7, i.e. the rats were subjected to SCI procedure and sacrificed after one, three, and seven days, respectively and a control group. We performed a moderate, midline spinal contusion injury at thoracic level 10. The animals were anesthetized, and testes were collected for measurement of gene expression by real-time PCR. Caudal parts of epididymis were collected for malondialdehyde (MDA) measurement. Results: No NLRP1a mRNA overexpression was seen in the testes of control and SCI groups. After seven days from SCI surgery, NLRP3 mRNA expression was significantly increased in SCI7 animals (p ≤ 0.05). There was a significant difference in MDA level in SCI7 versus control group, as well as SCI1 and SCI3 animals (p ≤ 0.05). Conclusion: NLRP3 overexpression occurs due to the increased ROS production in testis tissue of SCI rats

Overview of the Spinal Cord Injury – Quality of Life (SCI-QOL) measurement system

PubMed Central

Tulsky, David S.; Kisala, Pamela A.; Victorson, David; Tate, Denise G.; Heinemann, Allen W.; Charlifue, Susan; Kirshblum, Steve C.; Fyffe, Denise; Gershon, Richard; Spungen, Ann M.; Bombardier, Charles H.; Dyson-Hudson, Trevor A.; Amtmann, Dagmar; Z. Kalpakjian, Claire; W. Choi, Seung; Jette, Alan M.; Forchheimer, Martin; Cella, David

2015-01-01

Context/Objective The Spinal Cord Injury – Quality of Life (SCI-QOL) measurement system was developed to address the shortage of relevant and psychometrically sound patient reported outcome (PRO) measures available for clinical care and research in spinal cord injury (SCI) rehabilitation. Using a computer adaptive testing (CAT) approach, the SCI-QOL builds on the Patient Reported Outcomes Measurement Information System (PROMIS) and the Quality of Life in Neurological Disorders (Neuro-QOL) initiative. This initial manuscript introduces the background and development of the SCI-QOL measurement system. Greater detail is presented in the additional manuscripts of this special issue. Design Classical and contemporary test development methodologies were employed. Qualitative input was obtained from individuals with SCI and clinicians through interviews, focus groups, and cognitive debriefing. Item pools were field tested in a multi-site sample (n = 877) and calibrated using item response theory methods. Initial reliability and validity testing was performed in a new sample of individuals with traumatic SCI (n = 245). Setting Five Model SCI System centers and one Department of Veterans Affairs Medical Center across the United States. Participants Adults with traumatic SCI. Interventions n/a Outcome Measures n/a Results The SCI-QOL consists of 19 item banks, including the SCI-Functional Index banks, and 3 fixed-length scales measuring physical, emotional, and social aspects of health-related QOL (HRQOL). Conclusion The SCI-QOL measurement system consists of psychometrically sound measures for individuals with SCI. The manuscripts in this special issue provide evidence of the reliability and initial validity of this measurement system. The SCI-QOL also links to other measures designed for a general medical population. PMID:26010962

Circulating sclerostin is elevated in short-term and reduced in long-term SCI

PubMed Central

Battaglino, Ricardo A.; Sudhakar, Supreetha; Lazzari, Antonio; Garshick, Eric; Zafonte, Ross; Morse, Leslie R.

2012-01-01

Spinal cord injury (SCI) causes profound bone loss due to muscle paralysis resulting in the inability to walk. Sclerostin, a Wnt signaling pathway antagonist produced by osteocytes, is a potent inhibitor of bone formation. Short-term studies in rodent models have demonstrated increased sclerostin in response to mechanical unloading that is reversed with reloading. Although sclerostin inhibition has been proposed as a potential therapy for bone loss, it is not known if sclerostin levels vary with duration of SCI in humans. We analyzed circulating sclerostin in 155 men with varying degrees of SCI who were 1 year or more post-injury. We report that sclerostin levels are greatest in subjects with short-term SCI (≤ 5 years post-injury) and decrease significantly over the first 5 years post-injury. There was no association between sclerostin and injury duration in subjects with long-term SCI (> 5 years post-injury). In subjects with long-term SCI, sclerostin levels were positively associated with lower extremity bone density and bone mineral content. These data suggest that sclerostin levels in SCI are initially increased after SCI in response to mechanical unloading. This response is time-limited and as bone loss progresses, circulating sclerostin is lowest in subjects with severe osteoporosis. These findings support a dual role for sclerostin after SCI: a therapeutic target in acute SCI, and a biomarker of osteoporosis severity in chronic SCI. PMID:22575440

Learning by Creating and Exchanging Objects: The SCY Experience

ERIC Educational Resources Information Center

De Jong, Ton; Van Joolingen, Wouter R.; Giemza, Adam; Girault, Isabelle; Hoppe, Ulrich; Kindermann, Jorg; Kluge, Anders; Lazonder, Ard W.; Vold, Vibeke; Weinberger, Armin; Weinbrenner, Stefan; Wichmann, Astrid; Anjewierden, Anjo; Bodin, Marjolaine; Bollen, Lars; D'Ham, Cedric; Dolonen, Jan; Engler, Jan; Geraedts, Caspar; Grosskreutz, Henrik; Hovardas, Tasos; Julien, Rachel; Lechner, Judith; Ludvigsen, Sten; Matteman, Yuri; Meistadt, Oyvind; Naess, Bjorge; Ney, Muriel; Pedaste, Margus; Perritano, Anthony; Rinket, Marieke; Von Schlanbusch, Henrik; Sarapuu, Tago; Schulz, Florian; Sikken, Jakob; Slotta, Jim; Toussaint, Jeremy; Verkade, Alex; Wajeman, Claire; Wasson, Barbara; Zacharia, Zacharias C.; Van Der Zanden, Martine

2010-01-01

Science Created by You (SCY) is a project on learning in science and technology domains. SCY uses a pedagogical approach that centres around products, called "emerging learning objects" (ELOs) that are created by students. Students work individually and collaboratively in SCY-Lab (the general SCY learning environment) on "missions" that are guided…

75 FR 24747 - SCI, LLC/Zener-Rectifier Operations Division A Wholly Owned Subsidiary of SCI, LLC/ON...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,235] SCI, LLC/Zener-Rectifier... Adjustment Assistance on October 19, 2009, applicable to workers of SCI LLC/Zener-Rectifier, Operations... Technical Resources were employed on-site at the Phoenix Arizona location of SCI LLC/Zener-Rectifier...

Sensitivity of the SCI-FI/AT in Individuals With Traumatic Spinal Cord Injury.

PubMed

Keeney, Tamra; Slavin, Mary; Kisala, Pamela; Ni, Pengsheng; Heinemann, Allen W; Charlifue, Susan; Fyffe, Denise C; Marino, Ralph J; Morse, Leslie R; Worobey, Lynn A; Tate, Denise; Rosenblum, David; Zafonte, Ross; Tulsky, David; Jette, Alan M

2018-03-31

To examine the ability of the Spinal Cord Injury-Functional Index/Assistive Technology (SCI-FI/AT) measure to detect change in persons with spinal cord injury (SCI). Multisite longitudinal (12-mo follow-up) study. Nine SCI Model Systems programs. Adults (N=165) with SCI enrolled in the SCI Model Systems database. Not applicable. SCI-FI/AT computerized adaptive test (CAT) (Basic Mobility, Self-Care, Fine Motor Function, Wheelchair Mobility, and/or Ambulation domains) completed at discharge from rehabilitation and 12 months after SCI. For each domain, effect size estimates and 95% confidence intervals were calculated for subgroups with paraplegia and tetraplegia. The demographic characteristics of the sample were as follows: 46% (n=76) individuals with paraplegia, 76% (n=125) male participants, 57% (n=94) used a manual wheelchair, 38% (n=63) used a power wheelchair, 30% (n=50) were ambulatory. For individuals with paraplegia, the Basic Mobility, Self-Care, and Ambulation domains of the SCI-FI/AT detected a significantly large amount of change; in contrast, the Fine Motor Function and Wheelchair Mobility domains detected only a small amount of change. For those with tetraplegia, the Basic Mobility, Fine Motor Function, and Self-Care domains detected a small amount of change whereas the Ambulation item domain detected a medium amount of change. The Wheelchair Mobility domain for people with tetraplegia was the only SCI-FI/AT domain that did not detect significant change. SCI-FI/AT CAT item banks detected an increase in function from discharge to 12 months after SCI. The effect size estimates for the SCI-FI/AT CAT vary by domain and level of lesion. Findings support the use of the SCI-FI/AT CAT in the population with SCI and highlight the importance of multidimensional functional measures. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Application of COMPONT Medical Adhesive Glue for Tension-Reduced Duraplasty in Decompressive Craniotomy

PubMed Central

Zhou, Yujia; Wang, Gesheng; Liu, Jialin; Du, Yong; Wang, Lei; Wang, Xiaoyong

2016-01-01

Background The aim of this study was to evaluate the application of medical adhesive glue for tension-reduced duraplasty in decompressive craniotomy. Material/Methods A total of 56 cases were enrolled for this study from Jan 2013 to May 2015. All patients underwent decompressive craniotomy and the dura was repaired in all of them with tension-reduced duraplasty using the COMPONT medical adhesive to glue artificial dura together. The postoperative complications and the healing of dura mater were observed and recorded. Results No wound infection, epidural or subdural hematoma, cerebrospinal fluid leakage, or other complications associated with the procedure occurred, and there were no allergic reactions to the COMPONT medical adhesive glue. The second-phase surgery of cranioplasty was performed at 3 to 6 months after the decompressive craniotomy in 32 out of the 56 cases. During the cranioplasty we observed no adherence of the artificial dura mater patch to the skin flap, no residual COMPONT glue, or hydropic or contracture change of tissue at the surgical sites. Additionally, no defect or weakening of the adherence between the artificial dura mater patch and the self dura matter occurred. Conclusions COMPONT medical adhesive glue is a safe and reliable tool for tension-reduced duraplasty in decompressive craniotomy. PMID:27752035

Light emitting diodes as a monitor to study P-type doping of GaN-based heterostructures grown by MOVPE

NASA Astrophysics Data System (ADS)

Schineller, B.; Guttzeit, A.; Vertommen, F.; Schön, O.; Heuken, M.; Heime, K.; Beccard, R.

1998-06-01

The group-III nitrides are an interesting material system for applications in the blue spectral region and for high-power and high-temperature devices. P-type doping in the metalorganic vapour-phase growth process, however, suffers from the material's high-background donor concentration. Hydrogen passivation furthermore decreases the number of activated acceptors [N.M. Johnson, W. Götz, J. Neugebauer, C.G. van de Walle, Mater. Res. Soc. Symp. Proc. 395 (1996) 723; A. Bosin, V. Fiorentini, Mater. Res. Soc. Symp. Proc. 395 (1996) 503] [1, 2]. Thermal treatment was found to increase the amount of activated acceptors [S.J. Pearton, S. Bendi, K.S. Jones, V. Krishnamoorthy, R.G. Wilson, F. Ren, R.F. Karlicek, R.A. Stall, Appl. Phys. Lett. 69 (1996) 1879; Y. Li, Y. Lu, H. Shen, M. Wraback, C.Y. Hwang, M. Schurman, W. Mayo, T. Salagaj, R.A. Stall, Mater. Res. Soc. Symp. Proc. 395 (1996) 369] [3, 4]. We have investigated the influences of thermal treatment process steps on the electrical and optical properties of Mg-doped single layers and used the results to fabricate AlGaN/GaN heterostructure LED layers. A simple test structure was employed to assess the electro-optical properties of the LED structures.

[Headache as a manifestation of SAPHO syndrome with a lesion extending to the dura mater, parietal bone, and temporal muscle].

PubMed

Uematsu, Miho; Tobisawa, Shinsuke; Nagao, Masahiro; Matsubara, Shiro; Mizutani, Toshio; Shibuya, Makoto

2012-01-01

A 50-year-old woman with a history of palmoplantar pustulosis, femur osteomyelitis, and sterno-costo-clavicular hyperostosis presented with a chronic severe left temporal headache that had progressed during the previous year. Her CRP level was elevated. Cranial images showed Gadolinium-enhancement of the left temporal muscle, left parietal bone and dura mater. (99m)Tc-HMDP scintigram showed increased uptake in the left parietal bone, left sterno-costo-clavicular joint, right femoral head and intervertebral joints. Biopsy of the lesion demonstrated 1) proliferation of connective tissue in both perimysium and endomysium of the temporal muscle with mild inflammatory cell infiltration within the interstitium, 2) marked infiltration of granulocytes to the bone marrow of the parietal bone, 3) necrosis and moderate fibrosis in the interstitium with inflammatory cell infiltration in the parietal bone, and 4) moderate fibrosis and slight infiltration of inflammatory cells in the dura mater. The patient was diagnosed with a cranial lesion of synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome. There was a moderate response to treatment with intravenous steroid pulse therapy and subsequent methotrexate. In a case of headache accompanied by inflammatory response, palmoplantar pustulosis and joint lesions such as hyperostosis, the possibility of a rare cranial manifestation of SAPHO syndrome should be considered.

The Relationship of Three-Dimensional Human Skull Motion to Brain Tissue Deformation in Magnetic Resonance Elastography Studies

PubMed Central

Badachhape, Andrew A.; Okamoto, Ruth J.; Durham, Ramona S.; Efron, Brent D.; Nadell, Sam J.; Johnson, Curtis L.; Bayly, Philip V.

2017-01-01

In traumatic brain injury (TBI), membranes such as the dura mater, arachnoid mater, and pia mater play a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is an imaging technique developed for noninvasive estimation of soft tissue material parameters. In MRE, dynamic deformation of brain tissue is induced by skull vibrations during magnetic resonance imaging (MRI); however, skull motion and its mode of transmission to the brain remain largely uncharacterized. In this study, displacements of points in the skull, reconstructed using data from an array of MRI-safe accelerometers, were compared to displacements of neighboring material points in brain tissue, estimated from MRE measurements. Comparison of the relative amplitudes, directions, and temporal phases of harmonic motion in the skulls and brains of six human subjects shows that the skull–brain interface significantly attenuates and delays transmission of motion from skull to brain. In contrast, in a cylindrical gelatin “phantom,” displacements of the rigid case (reconstructed from accelerometer data) were transmitted to the gelatin inside (estimated from MRE data) with little attenuation or phase lag. This quantitative characterization of the skull–brain interface will be valuable in the parameterization and validation of computer models of TBI. PMID:28267188

The Relationship of Three-Dimensional Human Skull Motion to Brain Tissue Deformation in Magnetic Resonance Elastography Studies.

PubMed

Badachhape, Andrew A; Okamoto, Ruth J; Durham, Ramona S; Efron, Brent D; Nadell, Sam J; Johnson, Curtis L; Bayly, Philip V

2017-05-01

In traumatic brain injury (TBI), membranes such as the dura mater, arachnoid mater, and pia mater play a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is an imaging technique developed for noninvasive estimation of soft tissue material parameters. In MRE, dynamic deformation of brain tissue is induced by skull vibrations during magnetic resonance imaging (MRI); however, skull motion and its mode of transmission to the brain remain largely uncharacterized. In this study, displacements of points in the skull, reconstructed using data from an array of MRI-safe accelerometers, were compared to displacements of neighboring material points in brain tissue, estimated from MRE measurements. Comparison of the relative amplitudes, directions, and temporal phases of harmonic motion in the skulls and brains of six human subjects shows that the skull-brain interface significantly attenuates and delays transmission of motion from skull to brain. In contrast, in a cylindrical gelatin "phantom," displacements of the rigid case (reconstructed from accelerometer data) were transmitted to the gelatin inside (estimated from MRE data) with little attenuation or phase lag. This quantitative characterization of the skull-brain interface will be valuable in the parameterization and validation of computer models of TBI.

Acute and Chronic Deficits in the Urinary Bladder after Spinal Contusion Injury in the Adult Rat

PubMed Central

Herrera, Juan J.; Haywood-Watson, Ricky J.L.

2010-01-01

Abstract Traumatic spinal cord injury (SCI) permanently alters bladder function in humans. Hematuria and cystitis occur in both human SCI as well as in rodent models of SCI. Others have reported early SCI-dependent disruption to bladder uroepithelial integrity that results in increased permeability to urine and urine-borne substances. This can result in cystitis, or inflammation of the bladder, an ongoing pathological condition present throughout the chronic phase of SCI in humans. The goals of our study were twofold: (1) to begin to examine the inflammatory and molecular changes that occur within the bladder uroepithelium using a clinically-relevant spinal contusion model of injury, and (2) to assess whether these alterations continue into the chronic phase of SCI. Rats received either moderate SCI or sham surgery. Urine was collected from SCI and sham subjects over 7 days or at 7 months to assess levels of excreted proteins. Inflammation in the bladder wall was assessed via biochemical and immunohistochemical methods. Bladder tight junction proteins, mediators of uroepithelial integrity, were also measured in both the acute and chronic phases of SCI. Urine protein and hemoglobin levels rapidly increase following SCI. An SCI-dependent elevation in numbers of neutrophils within the bladder wall peaked at 48 h. Bladder tight junction proteins demonstrate a rapid but transient decrease as early as 2 h post-SCI. Surprisingly, elevated levels of urine proteins and significant deficits in bladder tight junction proteins could be detected in chronic SCI, suggesting that early pathological changes to the bladder may continue throughout the chronic phase of injury. PMID:19891526

Laser bonding with ICG-infused chitosan patches: preliminary experiences in suine dura mater and vocal folds

NASA Astrophysics Data System (ADS)

Rossi, Francesca; Matteini, Paolo; Ratto, Fulvio; Pini, Roberto; Iacoangeli, Maurizio; Giannoni, Luca; Fortuna, Damiano; Di Cicco, Emiliano; Corbara, Sylwia; Dallari, Stefano

2014-05-01

Laser bonding is a promising minimally invasive approach, emerging as a valid alternative to conventional suturing techniques. It shows widely demonstrated advantages in wound treatment: immediate closuring effect, minimal inflammatory response and scar formation, reduced healing time. This laser based technique can overcome the difficulties in working through narrow surgical corridors (e.g. the modern "key-hole" surgery as well as the endoscopy setting) or in thin tissues that are impossible to treat with staples and/or stitches. We recently proposed the use of chitosan matrices, stained with conventional chromophores, to be used in laser bonding of vascular tissue. In this work we propose the same procedure to perform laser bonding of vocal folds and dura mater repair. Laser bonding of vocal folds is proposed to avoid the development of adhesions (synechiae), after conventional or CO2 laser surgery. Laser bonding application in neurosurgery is proposed for the treatment of dural defects being the Cerebro Spinal Fluid leaks still a major issue. Vocal folds and dura mater were harvested from 9-months old porks and used in the experimental sessions within 4 hours after sacrifice. In vocal folds treatment, an IdocyanineGreen-infused chitosan patch was applied onto the anterior commissure, while the dura mater was previously incised and then bonded. A diode laser emitting at 810 nm, equipped with a 600 μm diameter optical fiber was used to weld the patch onto the tissue, by delivering single laser spots to induce local patch/tissue adhesion. The result is an immediate adhesion of the patch to the tissue. Standard histology was performed, in order to study the induced photothermal effect at the bonding sites. This preliminary experimental activity shows the advantages of the proposed technique in respect to standard surgery: simplification of the procedure; decreased foreign-body reaction; reduced inflammatory response; reduced operating times and better handling in depth.

Analysis of Dislocation Emission during Microvoid Growth in Ductile Metals

NASA Astrophysics Data System (ADS)

Belak, James; Rudd, Robert E.

2001-03-01

Fracture in ductile metals occurs through the nucleation and growth of microscopic voids. This talk focuses on the initial stage when dislocations are first emitted from the void surface. The model system consists of a spherical void in an otherwise perfect crystal under triaxial tension. The stress field is calculated using continuum techniques, both finite element and analytic forms due to Eshelby, and compared with large-scale molecular dynamics (MD) simulation. The stress field is used to derive a criterion for dislocation nucleation on the glide planes intersecting the void surface. The critical resolved shear stress and the unstable stacking fault energy for the strain at the surface are used to compare to the critical stress for void growth in the MD simulations. Acknowledgement: This work was performed under the auspices of the US Dept. of Energy at the University of California/Lawrence Livermore National Laboratory under contract no. W-7405-Eng-48. [1] J. Belak, "On the nucleation and growth of voids at high strain-rates," J. Comp.-Aided Mater. Design 5, 193 (1998).

Follicular progesterone concentrations and messenger RNA expression of MATER and OCT-4 in immature bovine oocytes as predictors of developmental competence.

PubMed

Urrego, R; Herrera-Puerta, E; Chavarria, N A; Camargo, O; Wrenzycki, C; Rodriguez-Osorio, N

2015-04-15

The ability of bovine embryos to develop to the blastocyst stage and to implant and generate healthy offspring depends greatly on the competence of the oocyte. Oocyte competence is attributed to its close communication with the follicular environment and to its capacity to synthesize and store substantial amounts of messenger RNA. Higher developmental competence of bovine oocytes has been associated with both the expression of a cohort of developmental genes and the concentration of sex steroids in the follicular fluid. The aim of this study was to identify differences in the expression of FST in cumulus cells and OCT-4 and MATER in oocytes and the influence of the follicular progesterone and follicular estrogen concentration on the competence of bovine oocytes retrieved 30 minutes or 4 hours after slaughter. Cumulus-oocyte complexes (COCs) were left in postmortem ovaries for 30 minutes (group I) or 4 hours (group II) at 30 °C. Aspirated oocytes were then subjected to IVM, IVF, and IVC or were evaluated for MATER and OCT-4 messenger RNA abundance by quantitative real-time polymerase chain reaction. Total RNA was isolated from pools of 100 oocytes for each experimental replicate. Progesterone and estradiol concentration in follicular fluid was evaluated by immunoassay using an IMMULITE 2000 analyzer. Three repeats of in vitro embryo production were performed with a total of 455 (group I) and 470 (group II) COCs. There were no significant differences between the cleavage rates (72 hours postinsemination [hpi]) between both groups (63.5% vs. 69.1%). However, blastocyst (168 hpi) and hatching (216 hpi) rates were higher (P < 0.05) in group II compared with those of group I (21.3% vs. 30.7% and 27.6% vs. 51.5%, respectively). Group II oocytes exhibited the highest MATER and OCT-4 abundance (P < 0.05). Follicular estradiol concentration was not different between both the groups, whereas the progesterone concentration was lower (P ≤ 0.05) in group II follicles. These results indicate that retrieving COCs 4 hours after slaughter could increase bovine in vitro developmental competence, which is linked to higher levels of oocyte MATER and OCT-4 transcripts and lower follicular progesterone concentration. Moreover, the results of the present study contribute to the identification of factors involved in the developmental competence of immature oocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

Targeting Translational Successes through CANSORT-SCI: Using Pet Dogs To Identify Effective Treatments for Spinal Cord Injury.

PubMed

Moore, Sarah A; Granger, Nicolas; Olby, Natasha J; Spitzbarth, Ingo; Jeffery, Nick D; Tipold, Andrea; Nout-Lomas, Yvette S; da Costa, Ronaldo C; Stein, Veronika M; Noble-Haeusslein, Linda J; Blight, Andrew R; Grossman, Robert G; Basso, D Michele; Levine, Jonathan M

2017-06-15

Translation of therapeutic interventions for spinal cord injury (SCI) from laboratory to clinic has been historically challenging, highlighting the need for robust models of injury that more closely mirror the human condition. The high prevalence of acute, naturally occurring SCI in pet dogs provides a unique opportunity to evaluate expeditiously promising interventions in a population of animals that receive diagnoses and treatment clinically in a manner similar to persons with SCI, while adhering to National Institutes of Health guidelines for scientific rigor and transparent reporting. In addition, pet dogs with chronic paralysis are often maintained long-term by their owners, offering a similarly unique population for study of chronic SCI. Despite this, only a small number of studies have used the clinical dog model of SCI. The Canine Spinal Cord Injury Consortium (CANSORT-SCI) was recently established by a group of veterinarians and basic science researchers to promote the value of the canine clinical model of SCI. The CANSORT-SCI group held an inaugural meeting November 20 and 21, 2015 to evaluate opportunities and challenges to the use of pet dogs in SCI research. Key challenges identified included lack of familiarity with the model among nonveterinary scientists and questions about how and where in the translational process the canine clinical model would be most valuable. In light of these, we review the natural history, outcome, and available assessment tools associated with canine clinical SCI with emphasis on their relevance to human SCI and the translational process.

High Prevalence of Stress and Low Prevalence of Alzheimer Disease CSF Biomarkers in a Clinical Sample with Subjective Cognitive Impairment.

PubMed

Eckerström, Marie; Berg, Anne Ingeborg; Nordlund, Arto; Rolstad, Sindre; Sacuiu, Simona; Wallin, Anders

2016-01-01

Subjective cognitive impairment (SCI) is a trigger for seeking health care in a possible preclinical phase of Alzheimer's disease (AD), although the characteristics of SCI need clarification. We investigated the prevalence of psychosocial stress, depressive symptoms and CSF AD biomarkers in SCI and MCI (mild cognitive impairment). Memory clinic patients (SCI: n = 90; age: 59.8 ± 7.6 years; MCI: n = 160; age: 63.7 ± 7.0 years) included in the Gothenburg MCI study were examined at baseline. Variables were analyzed using logistic regression with SCI as dependent variable. Stress was more prevalent in SCI (51.1%) than MCI (23.1%); p < 0.0005. SCI patients had more previous depressive symptoms (p = 0.006), but showed no difference compared to MCI patients considering current depressive symptoms. A positive CSF AD profile was present in 14.4% of SCI patients and 35.0% of MCI patients (p = 0.001). Stress (p = 0.002), previous stress/depressive symptoms (p = 0.006) and a negative CSF AD profile (p = 0.036) predicted allocation to the SCI group. Psychosocial stress is more prevalent in SCI than previously acknowledged. The high prevalence and long-term occurrence of stress/depressive symptoms in SCI in combination with a low prevalence of altered CSF AD biomarkers strengthens the notion that AD is not the most likely etiology of SCI. © 2016 S. Karger AG, Basel.

MATER - Pianeta Terra-Mare: an interactive and multidisciplinary approach to Geosphere sciences

NASA Astrophysics Data System (ADS)

Piangiamore, Giovanna Lucia; Fanelli, Emanuela; Furia, Stefania; Garau, Daniela; Merlino, Silvia; Musacchio, Gemma; Carla Centineo, Maria

2016-04-01

Recent studies demonstrate that Earth and Marine Sciences are not properly treated in scholastic programs and in textbooks are included in a superficial way. These topics are interdisciplinary and experimental (biology, ecology, oceanography and geology) and the recent advance in these fields is strictly linked to technologic improvement. School cannot keep up with the huge advances of knowledge experimented in the last 20 years, also for the lack of didactic laboratories sufficiently updated to support experimental activities. In this context, in 2014-15 three Italian Research Institutes (INGV, ISMAR-CNR and ENEA-CRAM) have decided to support the Unified School District "ISA 10"of Lerici (Liguria, Italy) - comprehensive of kindergartner, primary and middle schools - to develop the project MATER - Pianeta Terra-Mare (Planet Earth and Sea). The acronym MATER (MARe and TERra) has also a gender value, as people involved in the projects were women, mostly researchers and teachers, which have worked side by side with other women belonging to environmental and cultural associations of the territory. This heterogeneous group has a common objective: to promote the diffusion of a scientific culture and to sensitize students from 3 to 14 years towards problems occurring in marine and terrestrial environments, fostering the settlement of a sustainable attitude to the exploitation of natural resources and consciousness to natural hazards, such as earthquakes and floods, quite common in the Ligurian region. MATER has been considered as one of the best projects funded by MIUR (Italian Ministry of Education, University and Research) inside the Dissemination of Scientific and Technological Culture call for the year 2014. Natural hazards (Planet Earth) and the chemical-physical aspects and resources of the marine environment (Planet Sea) were the two modules of the project. Planet Earth developed through Piovono Idee! (Cloudy with a chance of Ideas!), an interactive exhibition on hydro-geological risk and climate change targeted to students from 8 to 14 years; Planet Sea was articulated in a series of laboratories on the physical-chemical properties ("a sustaining sea") and of the bio-ecological aspects ("a sea of resources") of the sea, engaging students from 4 to 14 years. Scientific conferences, targeted from teenagers and up and open to public, have been organized during the opening and closing weeks of the project, inside the "Week of Planet Earth" 2014 and 2015. The project was also a "peer-education experiment", where students of the High School "Pacinotti" (La Spezia) and of "ISA 10" (Lerici) and "ISA 2" (La Spezia) have played the role of guides in the interactive paths. MATER has reached ca. 1000 students and had excellent feedbacks from teachers and students, supported by questionnaires and press releases. Through the dedicated website, MATER is expected to reach a broader scholastic community, outside its local context. The project was a good example of cooperation of different territorial institutions/associations, working together to promote the culture of prevention and sustainability, involving future citizens to reflect on the values of appropriate behaviors and best practices towards an ethical and sustainable interaction between human activities with the geosphere.

Use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students: Study in six countries in Latin America.

PubMed

Mejia, Christian R; Valladares-Garrido, Mario J; Miñan-Tapia, Armando; Serrano, Felipe T; Tobler-Gómez, Liz E; Pereda-Castro, William; Mendoza-Flores, Cynthia R; Mundaca-Manay, Maria Y; Valladares-Garrido, Danai

2017-01-01

Sci-Hub is a useful web portal for people working in science as it provides access to millions of free scientific articles. Satisfaction and usage should be explored in the Latino student population. The objective of this study was to evaluate the use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students from Latin America. A multicenter, observational, analytical study was conducted in 6632 medical students from 6 countries in Latin America. We surveyed from a previously validated instrument, delving into knowledge, monthly average usage, satisfaction level, and perception of the scientific contributions provided by Sci-Hub. Frequencies and percentages are described, and generalized linear models were used to establish statistical associations. Only 19.2% of study participants knew of Sci-Hub and its function, while the median use was twice a month. 29.9% of Sci-Hub-aware participants claimed they always find the desired scientific information in their Sci-Hub search; 62.5% of participants affirmed that Sci-Hub contributes to scientific investigation; only 2.2% reported that Sci-Hub does not contribute to science. The majority of Latino students are not aware of Sci-Hub.

Recommendations for the National Institute for Neurologic Disorders and Stroke spinal cord injury common data elements for children and youth with SCI.

PubMed

Mulcahey, M J; Vogel, L C; Sheikh, M; Arango-Lasprilla, J C; Augutis, M; Garner, E; Hagen, E M; Jakeman, L B; Kelly, E; Martin, R; Odenkirchen, J; Scheel-Sailer, A; Schottler, J; Taylor, H; Thielen, C C; Zebracki, K

2017-04-01

In 2014, the adult spinal cord injury (SCI) common data element (CDE) recommendations were made available. This project was a review of the adult SCI CDE for relevance to children and youth with SCI. The objective of this study was to review the National Institute of Neurologic Disorders and Stroke (NINDS) adult SCI CDEs for relevance to children and youth with SCI. International. The pediatric working group consisted of international members with varied fields of expertise related to pediatric SCI. The group convened biweekly meetings for 6 months in 2015. All of the adult SCI CDEs were reviewed, evaluated and modified/created for four age groups: 0-5 years, 6-12 years, 13-15 years and 16-18 years. Whenever possible, results of published research studies were used to guide recommendations. In the absence of empirical support, grey literature and international content expert consensus were garnered. Existing pediatric NINDS CDEs and new CDEs were developed in areas where adult recommendations were not appropriate. After internal working group review of domain recommendations, these pediatric CDEs were vetted during a public review from November through December 2015. Version 1.0 of the pediatric SCI CDEs was posted in February 2016. The pediatric SCI CDEs are incorporated directly into the NINDS SCI CDE sets and can be found at https://commondataelements.ninds.nih.gov.

Morphological changes in polycrystalline Fe after compression and release

NASA Astrophysics Data System (ADS)

Gunkelmann, Nina; Tramontina, Diego R.; Bringa, Eduardo M.; Urbassek, Herbert M.

2015-02-01

Despite a number of large-scale molecular dynamics simulations of shock compressed iron, the morphological properties of simulated recovered samples are still unexplored. Key questions remain open in this area, including the role of dislocation motion and deformation twinning in shear stress release. In this study, we present simulations of homogeneous uniaxial compression and recovery of large polycrystalline iron samples. Our results reveal significant recovery of the body-centered cubic grains with some deformation twinning driven by shear stress, in agreement with experimental results by Wang et al. [Sci. Rep. 3, 1086 (2013)]. The twin fraction agrees reasonably well with a semi-analytical model which assumes a critical shear stress for twinning. On reloading, twins disappear and the material reaches a very low strength value.

Verification of sub-grid filtered drag models for gas-particle fluidized beds with immersed cylinder arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, Avik; Sun, Xin; Sundaresan, Sankaran

2014-04-23

The accuracy of coarse-grid multiphase CFD simulations of fluidized beds may be improved via the inclusion of filtered constitutive models. In our previous study (Sarkar et al., Chem. Eng. Sci., 104, 399-412), we developed such a set of filtered drag relationships for beds with immersed arrays of cooling tubes. Verification of these filtered drag models is addressed in this work. Predictions from coarse-grid simulations with the sub-grid filtered corrections are compared against accurate, highly-resolved simulations of full-scale turbulent and bubbling fluidized beds. The filtered drag models offer a computationally efficient yet accurate alternative for obtaining macroscopic predictions, but the spatialmore » resolution of meso-scale clustering heterogeneities is sacrificed.« less

Compiling Planning into Quantum Optimization Problems: A Comparative Study

DTIC Science & Technology

2015-06-07

and Sipser, M. 2000. Quantum computation by adiabatic evolution. arXiv:quant- ph/0001106. Fikes, R. E., and Nilsson, N. J. 1972. STRIPS: A new...become available: quantum annealing. Quantum annealing is one of the most accessible quantum algorithms for a computer sci- ence audience not versed...in quantum computing because of its close ties to classical optimization algorithms such as simulated annealing. While large-scale universal quantum

Comment on “A similarity solution for laminar thermal boundary layer over a flat plate with a convective surface boundary condition” by A. Aziz, Comm. Nonlinear Sci. Numer. Simul. 2009;14:1064-8

NASA Astrophysics Data System (ADS)

Magyari, Eugen

2011-01-01

In a recent paper published in this Journal the title problem has been investigated numerically. In the present paper the exact solution for the temperature boundary layer is given in terms of the solution of the flow problem (the Blasius problem) in a compact integral form.

Effects of Millimeter-Wave Electromagnetic Radiation on the Experimental Model of Migraine.

PubMed

Sivachenko, I B; Medvedev, D S; Molodtsova, I D; Panteleev, S S; Sokolov, A Yu; Lyubashina, O A

2016-02-01

Effects of millimeter-wave electromagnetic radiation (40 GHz frequency, 0.01 mW power) on the spontaneous fi ring of convergent neurons of the spinal trigeminal nucleus and their responses to electrical stimulation of the dura mater were studied in neurophysiological experiments on rats. Irradiation of the area of cutaneous receptive fields of spinal trigeminal nucleus reversibly inhibited both spontaneous discharges and activity induced by electrical stimulation of the dura mater. The second and third exposures to electromagnetic radiation with an interval of 10 min were ineffective. These results suggest that suppression of neuronal excitability in the spinal trigeminal ganglion can be a mechanism of the anti-migraine effects of electromagnetic radiation observed in clinical practice.

Contralateral acute interdural haematoma occurring after burr hole drainage of chronic subdural haematoma.

PubMed

Eom, Ki Seong; Kim, Tae Young; Park, Jong Tae

2009-04-01

We report the case of a 78-year-old man with chronic subdural haematoma (CSDH) who presented with impairment in recent memory and gait disturbance. He underwent burr-hole craniostomy with a closed-drainage system. A computed tomography scan conducted on postoperative day 3 demonstrated an acute epidural haematoma over the contralateral frontoparietal convexity. Craniotomy and haematoma evacuation were immediately performed. The haematoma was located between the outer and inner dura mater that each comprise a single layer. To our knowledge, this is the first reported case of an acute haematoma located between the separated dura mater that occurred following drainage of a contralateral CSDH, and it is the second reported case of interdural haematoma over the cerebral convexity.

Optical properties of animal tissues in the wavelength range from 350 to 2600 nm

NASA Astrophysics Data System (ADS)

Filatova, Serafima A.; Shcherbakov, Ivan A.; Tsvetkov, Vladimir B.

2017-03-01

The optical properties of different cow and pig biological tissues such as skeletal muscle, adipose, spinal cord, and dura mater of the spinal cord were investigated in the spectral range of 350 to 2600 nm. The measurements were carried out by a commercially available spectrophotometer SHIMADZU UV 3101PC. The wavelength dependence on the scattering coefficient has been observed to follow a power-law decay for skeletal muscle and dura mater of spinal cord. The influence of time delay between the sample preparation and measuring of transmittance spectra on the data reasonableness was reviewed. The conclusion about the benefits of 2-μm lasers application in surgery is given for the tissue types listed above.

Spinal cord injury below-level neuropathic pain relief with dorsal root entry zone microcoagulation performed caudal to level of complete spinal cord transection.

PubMed

Falci, Scott; Indeck, Charlotte; Barnkow, Dave

2018-06-01

OBJECTIVE Surgically created lesions of the spinal cord dorsal root entry zone (DREZ) to relieve central pain after spinal cord injury (SCI) have historically been performed at and cephalad to, but not below, the level of SCI. This study was initiated to investigate the validity of 3 proposed concepts regarding the DREZ in SCI central pain: 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through sympathetic nervous system (SNS) pathways. 3) Perceived SCI below-level central pain follows a unique somatotopic map of DREZ pain-generators. METHODS Three unique patients with both intractable SCI below-level central pain and complete spinal cord transection at the level of SCI were identified. All 3 patients had previously undergone surgical intervention to their spinal cords-only cephalad to the level of spinal cord transection-with either DREZ microcoagulation or cyst shunting, in failed attempts to relieve their SCI below-level central pain. Subsequent to these surgeries, DREZ lesioning of the spinal cord solely caudal to the level of complete spinal cord transection was performed using electrical intramedullary guidance. The follow-up period ranged from 1 1/2 to 11 years. RESULTS All 3 patients in this study had complete or near-complete relief of all below-level neuropathic pain. The analyzed electrical data confirmed and enhanced a previously proposed somatotopic map of SCI below-level DREZ pain generators. CONCLUSIONS The results of this study support the following hypotheses. 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through SNS pathways. 3) Perceived SCI below-level central pain follows a unique somatotopic map of DREZ pain generators.

Not just quantity: gluteus maximus muscle characteristics in able-bodied and SCI individuals--implications for tissue viability.

PubMed

Wu, Gary A; Bogie, Kath M

2013-08-01

Some individuals with spinal cord injury (SCI) remain pressure ulcer (PU) free whilst others experience a recurring cycle of tissue breakdown. Detailed analysis of gluteal muscle characteristics may provide insights to local tissue viability variability. The study hypothesis was that SCI individuals have altered muscle composition compared to able-bodied (AB). Ten AB and ten SCI received a supine pelvic CT scan, with contrast. Cross-sectional area (CSA) and overall muscle volume were derived using image analysis. Gluteal muscle tissue type was classified at the S2/S3 sacral vertebrae midpoint, the superior greater trochanters margin (GT) and the inferior ischial tuberosities margin (IT) using the linear transformation Hounsfield Unit scale. SCI gluteal CSA was less than for AB throughout the muscle, with the greatest relative atrophy at the IT (48%). Average AB gluteal volume was nearly double SCI. Eight SCI had over 20% infiltrative adipose tissue, three with over 50%. SCI gluteal CSA and intramuscular fat infiltration were significantly negatively correlated (p < 0.05). SCI IT axial slices showed less lean muscle and higher intramuscular fat infiltration than more proximally (p < 0.05). SCI gluteal muscle characteristics were indicative of impaired tissue viability. SCI disuse muscle atrophy was anticipated; the analytic approach further indicated that intramuscular atrophy was not uniform. SCI muscle composition showed increased proportions of both low density muscle and adipose tissue. CT scan with contrast is effective for gluteal muscle characterization. This assessment technique may contribute to determination of personalized risk for PU development and other secondary complications. Published by Elsevier Ltd.

Targeting Translational Successes through CANSORT-SCI: Using Pet Dogs To Identify Effective Treatments for Spinal Cord Injury

PubMed Central

Granger, Nicolas; Olby, Natasha J.; Spitzbarth, Ingo; Jeffery, Nick D.; Tipold, Andrea; Nout-Lomas, Yvette S.; da Costa, Ronaldo C.; Stein, Veronika M.; Noble-Haeusslein, Linda J.; Blight, Andrew R.; Grossman, Robert G.; Basso, D. Michele; Levine, Jonathan M.

2017-01-01

Abstract Translation of therapeutic interventions for spinal cord injury (SCI) from laboratory to clinic has been historically challenging, highlighting the need for robust models of injury that more closely mirror the human condition. The high prevalence of acute, naturally occurring SCI in pet dogs provides a unique opportunity to evaluate expeditiously promising interventions in a population of animals that receive diagnoses and treatment clinically in a manner similar to persons with SCI, while adhering to National Institutes of Health guidelines for scientific rigor and transparent reporting. In addition, pet dogs with chronic paralysis are often maintained long-term by their owners, offering a similarly unique population for study of chronic SCI. Despite this, only a small number of studies have used the clinical dog model of SCI. The Canine Spinal Cord Injury Consortium (CANSORT-SCI) was recently established by a group of veterinarians and basic science researchers to promote the value of the canine clinical model of SCI. The CANSORT-SCI group held an inaugural meeting November 20 and 21, 2015 to evaluate opportunities and challenges to the use of pet dogs in SCI research. Key challenges identified included lack of familiarity with the model among nonveterinary scientists and questions about how and where in the translational process the canine clinical model would be most valuable. In light of these, we review the natural history, outcome, and available assessment tools associated with canine clinical SCI with emphasis on their relevance to human SCI and the translational process. PMID:28230415

Spinal-Cord-Injured Individual's Experiences of Having a Partner: A Phenomenological-Hermeneutic Study.

PubMed

Angel, Sanne

2015-06-01

Having a partner is a strong factor in adaptation to the new life situation with a spinal cord injury (SCI). Still, more knowledge in detail about the partner's influences according to the experiences of individuals with SCI could contribute to the understanding of the situation after an injury. The aim of this phenomenological-hermeneutic article is to achieve a deeper understanding of nine individuals' experiences the first 2 years after SCI. In rehabilitation after SCI, the partner supported the SCI individual's life spirit by not giving up and by still seeing possibilities in the future. The partner reinforced the SCI individual's commitment to life by sharing experiences; providing love, trust, and hope; and giving priority to the best things in life for the SCI individual. This implied cohabitation providing concrete help and an intimacy that helped to cope with problems and anxieties and allowed SCI individuals the ability to self-realize. This promoted feelings of profound gratitude but also dependency. Thus, the SCI individual benefitted from the partner's support mentally and physically, which enabled a life that would not otherwise be possible.

Global meaning in people with spinal cord injury: Content and changes

PubMed Central

Littooij, Elsbeth; Widdershoven, Guy A.M.; Stolwijk-Swüste, Janneke M.; Doodeman, Suzan; Leget, Carlo J.W.; Dekker, Joost

2016-01-01

Background After spinal cord injury (SCI), people are confronted with abrupt discontinuity in almost all areas of life, leading to questions on how to live a meaningful life again. Global meaning refers to basic ideas and goals that guide people in giving meaning to their lives, in specific situations. Little is known about global meaning relating to SCI and whether global meaning changes after SCI. Purpose The purpose of this study was twofold: (i) to explore the content of global meaning of people with SCI, and (ii) to explore whether or not global meaning changes after SCI. Methods In-depth semi-structured interviews were conducted with 16 people with SCI. Interviews were analyzed according to the method of grounded theory. Results (i) Five aspects of global meaning were found: core values, relationships, worldview, identity and inner posture. (ii) Overall, little change in the content of global meaning was found after SCI; specific aspects of global meaning were foregrounded after SCI. Conclusion Five aspects of global meaning were found in people with SCI. Global meaning seems hardly subject to change. PMID:25615571

Evaluation and Management of SCI-Associated Pain.

PubMed

Saulino, Michael; Averna, Justin F

2016-09-01

Traumatic spinal cord injury (SCI) is a devastating neurological condition. Treatment of SCI-related pain is challenging for the treating physician, as normal neural pathways are disrupted. Patients with SCI consistently rate pain as one of the most difficult problems associated with their injury. SCI-related pain can be refractory and complete relief is often not possible. The multidimensional nature of SCI-related pain affects the neural system including autonomic nervous system deregulation and can alter metabolic and biochemical processes throughout the body. Co-morbid psychological illnesses such as depression and adjustment disorder are seen in a significant percentage of patients. Despite a better understanding of the underlying pain mechanisms and advances in procedural, pharmacologic, and non-pharmacologic therapies, treatment of pain after SCI remains elusive. This manuscript reviews the current evidence-based evaluation and management of the SCI patient with the overarching goal of providing appropriate and effective management of their pain. In particular, additional well-designed studies are needed to help elucidate effective treatments for SCI-related neuropathic pain in an effort to help provide these patients with better management of their pain and improve their quality of life.

Resting-state synchrony between the retrosplenial cortex and anterior medial cortical structures relates to memory complaints in subjective cognitive impairment.

PubMed

Yasuno, Fumihiko; Kazui, Hiroaki; Yamamoto, Akihide; Morita, Naomi; Kajimoto, Katsufumi; Ihara, Masafumi; Taguchi, Akihiko; Matsuoka, Kiwamu; Kosaka, Jun; Tanaka, Toshihisa; Kudo, Takashi; Takeda, Masatoshi; Nagatsuka, Kazuyuki; Iida, Hidehiro; Kishimoto, Toshifumi

2015-06-01

Subjective cognitive impairment (SCI) is a clinical state characterized by subjective cognitive deficits without cognitive impairment. To test the hypothesis that this state might involve dysfunction of self-referential processing mediated by cortical midline structures, we investigated abnormalities of functional connectivity in these structures in individuals with SCI using resting-state functional magnetic resonance imaging. We performed functional connectivity analysis for 23 individuals with SCI and 30 individuals without SCI. To reveal the pathophysiological basis of the functional connectivity change, we performed magnetic resonance-diffusion tensor imaging. Positron emission tomography-amyloid imaging was conducted in 13 SCI and 15 nonSCI subjects. Individuals with SCI showed reduced functional connectivity in cortical midline structures. Reduction in white matter connections was related to reduced functional connectivity, but we found no amyloid deposition in individuals with SCI. The results do not necessarily contradict the possibility that SCI indicates initial cognitive decrements, but imply that reduced functional connectivity in cortical midline structures contributes to overestimation of the experience of forgetfulness. Copyright © 2015 Elsevier Inc. All rights reserved.

32 CFR 154.19 - Reinvestigation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... to Sensitive Compartmented Information (SCI). Each individual having current access to SCI shall be... certain SCI duties may require very special compartmentation and other special security measures. In such... for continued SCI access. (h) Foreign nationals employed by DoD organizations overseas. Foreign...

Measuring stigma after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Stigma item bank and short form.

PubMed

Kisala, Pamela A; Tulsky, David S; Pace, Natalie; Victorson, David; Choi, Seung W; Heinemann, Allen W

2015-05-01

To develop a calibrated item bank and computer adaptive test (CAT) to assess the effects of stigma on health-related quality of life in individuals with spinal cord injury (SCI). Grounded-theory based qualitative item development methods, large-scale item calibration field testing, confirmatory factor analysis, and item response theory (IRT)-based psychometric analyses. Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. SCI-QOL Stigma Item Bank A sample of 611 individuals with traumatic SCI completed 30 items assessing SCI-related stigma. After 7 items were iteratively removed, factor analyses confirmed a unidimensional pool of items. Graded Response Model IRT analyses were used to estimate slopes and thresholds for the final 23 items. The SCI-QOL Stigma item bank is unique not only in the assessment of SCI-related stigma but also in the inclusion of individuals with SCI in all phases of its development. Use of confirmatory factor analytic and IRT methods provide flexibility and precision of measurement. The item bank may be administered as a CAT or as a 10-item fixed-length short form and can be used for research and clinical applications.

Development and psychometric characteristics of the SCI-QOL Pressure Ulcers scale and short form.

PubMed

Kisala, Pamela A; Tulsky, David S; Choi, Seung W; Kirshblum, Steven C

2015-05-01

To develop a self-reported measure of the subjective impact of pressure ulcers on health-related quality of life (HRQOL) in individuals with spinal cord injury (SCI) as part of the SCI quality of life (SCI-QOL) measurement system. Grounded-theory based qualitative item development methods, large-scale item calibration testing, confirmatory factor analysis (CFA), and item response theory-based psychometric analysis. Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. SCI-QOL Pressure Ulcers scale. 189 individuals with traumatic SCI who experienced a pressure ulcer within the past 7 days completed 30 items related to pressure ulcers. CFA confirmed a unidimensional pool of items. IRT analyses were conducted. A constrained Graded Response Model with a constant slope parameter was used to estimate item thresholds for the 12 retained items. The 12-item SCI-QOL Pressure Ulcers scale is unique in that it is specifically targeted to individuals with spinal cord injury and at every stage of development has included input from individuals with SCI. Furthermore, use of CFA and IRT methods provide flexibility and precision of measurement. The scale may be administered in its entirety or as a 7-item "short form" and is available for both research and clinical practice.

Measuring stigma after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Stigma item bank and short form

PubMed Central

Kisala, Pamela A.; Tulsky, David S.; Pace, Natalie; Victorson, David; Choi, Seung W.; Heinemann, Allen W.

2015-01-01

Objective To develop a calibrated item bank and computer adaptive test (CAT) to assess the effects of stigma on health-related quality of life in individuals with spinal cord injury (SCI). Design Grounded-theory based qualitative item development methods, large-scale item calibration field testing, confirmatory factor analysis, and item response theory (IRT)-based psychometric analyses. Setting Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Participants Adults with traumatic SCI. Main Outcome Measures SCI-QOL Stigma Item Bank Results A sample of 611 individuals with traumatic SCI completed 30 items assessing SCI-related stigma. After 7 items were iteratively removed, factor analyses confirmed a unidimensional pool of items. Graded Response Model IRT analyses were used to estimate slopes and thresholds for the final 23 items. Conclusions The SCI-QOL Stigma item bank is unique not only in the assessment of SCI-related stigma but also in the inclusion of individuals with SCI in all phases of its development. Use of confirmatory factor analytic and IRT methods provide flexibility and precision of measurement. The item bank may be administered as a CAT or as a 10-item fixed-length short form and can be used for research and clinical applications. PMID:26010973

Use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students: Study in six countries in Latin America

PubMed Central

Mejia, Christian R.; Valladares-Garrido, Mario J.; Miñan-Tapia, Armando; Serrano, Felipe T.; Tobler-Gómez, Liz E.; Pereda-Castro, William; Mendoza-Flores, Cynthia R.; Mundaca-Manay, Maria Y.; Valladares-Garrido, Danai

2017-01-01

Introduction Sci-Hub is a useful web portal for people working in science as it provides access to millions of free scientific articles. Satisfaction and usage should be explored in the Latino student population. The objective of this study was to evaluate the use, knowledge, and perception of the scientific contribution of Sci-Hub in medical students from Latin America. Methodology A multicenter, observational, analytical study was conducted in 6632 medical students from 6 countries in Latin America. We surveyed from a previously validated instrument, delving into knowledge, monthly average usage, satisfaction level, and perception of the scientific contributions provided by Sci-Hub. Frequencies and percentages are described, and generalized linear models were used to establish statistical associations. Results Only 19.2% of study participants knew of Sci-Hub and its function, while the median use was twice a month. 29.9% of Sci-Hub-aware participants claimed they always find the desired scientific information in their Sci-Hub search; 62.5% of participants affirmed that Sci-Hub contributes to scientific investigation; only 2.2% reported that Sci-Hub does not contribute to science. Conclusion The majority of Latino students are not aware of Sci-Hub. PMID:28982181

Sleep disordered breathing in chronic spinal cord injury.

PubMed

Sankari, Abdulghani; Bascom, Amy; Oomman, Sowmini; Badr, M Safwan

2014-01-15

Spinal cord injury (SCI) is associated with 2-5 times greater prevalence of sleep disordered breathing (SDB) than the general population. The contribution of SCI on sleep and breathing at different levels of injury using two scoring methods has not been assessed. The objectives of this study were to characterize the sleep disturbances in the SCI population and the associated physiological abnormalities using quantitative polysomnography and to determine the contribution of SCI level on the SDB mechanism. We studied 26 consecutive patients with SCI (8 females; age 42.5 ± 15.5 years; BMI 25.9 ± 4.9 kg/m2; 15 cervical and 11 thoracic levels) by spirometry, a battery of questionnaires and by attended polysomnography with flow and pharyngeal pressure measurements. Inclusion criteria for SCI: chronic SCI (> 6 months post injury), level T6 and above and not on mechanical ventilation. Ventilation, end-tidal CO2 (PETCO2), variability in minute ventilation (VI-CV) and upper airway resistance (RUA) were monitored during wakefulness and NREM sleep in all subjects. Each subject completed brief history and exam, Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Berlin questionnaire (BQ) and fatigue severity scale (FSS). Sleep studies were scored twice, first using standard 2007 American Academy of Sleep Medicine (AASM) criteria and second using new 2012 recommended AASM criteria. Mean PSQI was increased to 10.3 ± 3.7 in SCI patients and 92% had poor sleep quality. Mean ESS was increased 10.4 ± 4.4 in SCI patients and excessive daytime sleepiness (ESS ≥ 10) was present in 59% of the patients. Daytime fatigue (FSS > 20) was reported in 96% of SCI, while only 46% had high-risk score of SDB on BQ. Forced vital capacity (FVC) in SCI was reduced to 70.5% predicted in supine compared to 78.5% predicted in upright positions (p < 0.05). Likewise forced expiratory volume in first second (FEV1) was 64.9% predicted in supine compared to 74.7% predicted in upright positions (p < 0.05). Mean AHI in SCI patients was 29.3 ± 25.0 vs. 20.0 ± 22.8 events/h using the new and conventional AASM scoring criteria, respectively (p < 0.001). SCI patients had SDB (AHI > 5 events/h) in 77% of the cases using the new AASM scoring criteria compared to 65% using standard conventional criteria (p < 0.05). In cervical SCI, VI decreased from 7.2 ± 1.6 to 5.5 ± 1.3 L/min, whereas PETCO2 and VI-CV, increased during sleep compared to thoracic SCI. The majority of SCI survivors have symptomatic SDB and poor sleep that may be missed if not carefully assessed. Decreased VI and increased PETCO2 during sleep in patients with cervical SCI relative to thoracic SCI suggests that sleep related hypoventilation may contribute to the pathogenesis SDB in patients with chronic cervical SCI.

Total fluid pressure imbalance in the scrape-off layer of tokamak plasmas

NASA Astrophysics Data System (ADS)

Churchill, R. M.; Canik, J. M.; Chang, C. S.; Hager, R.; Leonard, A. W.; Maingi, R.; Nazikian, R.; Stotler, D. P.

2017-04-01

Simulations using the fully kinetic neoclassical code XGCa (X-point included guiding- center axisymmetric) were undertaken to explore the impact of kinetic effects on scrape-off layer (SOL) physics in DIII-D H-mode plasmas. XGCa is a total-f, gyrokinetic code which self-consistently calculates the axisymmetric electrostatic potential and plasma dynamics, and includes modules for Monte Carlo neutral transport. Previously presented XGCa results showed several noteworthy features, including large variations of ion density and pressure along field lines in the SOL, experimentally relevant levels of SOL parallel ion flow (Mach number  ˜ 0.5), skewed ion distributions near the sheath entrance leading to subsonic flow there, and elevated sheath potentials (Churchill 2016 Nucl. Mater. Energy 1-6). In this paper, we explore in detail the question of pressure balance in the SOL, as it was observed in the simulation that there was a large deviation from a simple total pressure balance (the sum of ion and electron static pressure plus ion inertia). It will be shown that both the contributions from the ion viscosity (driven by ion temperature anisotropy) and neutral source terms can be substantial, and should be retained in the parallel momentum equation in the SOL, but still falls short of accounting for the observed fluid pressure imbalance in the XGCa simulation results.

Vapor phase nucleation of the short-chain n-alkanes (n-pentane, n-hexane and n-heptane): Experiments and Monte Carlo simulations.

PubMed

Ogunronbi, Kehinde E; Sepehri, Aliasghar; Chen, Bin; Wyslouzil, Barbara E

2018-04-14

We measured the nucleation rates of n-pentane through n-heptane in a supersonic nozzle at temperatures ranging from ca. 109 K to 168 K. For n-pentane and n-hexane, these are the first nucleation rate measurements that have been made, and the trends in the current data agree well with those in the earlier work of Ghosh et al. [J. Chem. Phys. 132, 024307 (2010)] for longer chain alkanes. Complementary Monte Carlo simulations, using the transferable potentials for phase equilibria-united atom potentials, suggest that despite the high degree of supercooling, the critical clusters remain liquid like under experimental conditions for n-pentane through n-heptane, but adopt more ordered structures for n-octane and n-nonane. For all three alkanes, the experimental and simulated nucleation rates are offset by ∼3 orders of magnitude when plotted as a function of ln S/(T c /T - 1) 1.5 . Explicitly accounting for the surface tension difference between the real and model substances, or alternatively using the Hale [Phys. Rev. A 33, 4156 (1986); Metall. Mater. Trans. A 23, 1863 (1992)] scaling parameter, Ω, consistent with the model potential, increases the offset to ∼6 orders of magnitude.

Vapor phase nucleation of the short-chain n-alkanes (n-pentane, n-hexane and n-heptane): Experiments and Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Ogunronbi, Kehinde E.; Sepehri, Aliasghar; Chen, Bin; Wyslouzil, Barbara E.

2018-04-01

We measured the nucleation rates of n-pentane through n-heptane in a supersonic nozzle at temperatures ranging from ca. 109 K to 168 K. For n-pentane and n-hexane, these are the first nucleation rate measurements that have been made, and the trends in the current data agree well with those in the earlier work of Ghosh et al. [J. Chem. Phys. 132, 024307 (2010)] for longer chain alkanes. Complementary Monte Carlo simulations, using the transferable potentials for phase equilibria-united atom potentials, suggest that despite the high degree of supercooling, the critical clusters remain liquid like under experimental conditions for n-pentane through n-heptane, but adopt more ordered structures for n-octane and n-nonane. For all three alkanes, the experimental and simulated nucleation rates are offset by ˜3 orders of magnitude when plotted as a function of ln S/(Tc/T - 1)1.5. Explicitly accounting for the surface tension difference between the real and model substances, or alternatively using the Hale [Phys. Rev. A 33, 4156 (1986); Metall. Mater. Trans. A 23, 1863 (1992)] scaling parameter, Ω, consistent with the model potential, increases the offset to ˜6 orders of magnitude.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Churchill, Randy M.; Canik, John M.; Chang, C. S.

Simulations using the fully kinetic neoclassical code XGCa (X-point included guiding-center axisymmetric) were undertaken to explore the impact of kinetic effects on scrape-off layer (SOL) physics in DIII-D H-mode plasmas. XGCa is a total-f, gyrokinetic code which self-consistently calculates the axisymmetric electrostatic potential and plasma dynamics, and includes modules for Monte Carlo neutral transport. Previously presented XGCa results showed several noteworthy features, including large variations of ion density and pressure along field lines in the SOL, experimentally relevant levels of SOL parallel ion flow (Mach number similar to 0.5), skewed ion distributions near the sheath entrance leading to subsonic flowmore » there, and elevated sheath potentials (Churchill 2016 Nucl. Mater. Energy 1-6). In this paper, we explore in detail the question of pressure balance in the SOL, as it was observed in the simulation that there was a large deviation from a simple total pressure balance (the sum of ion and electron static pressure plus ion inertia). It will be shown that both the contributions from the ion viscosity (driven by ion temperature anisotropy) and neutral source terms can be substantial, and should be retained in the parallel momentum equation in the SOL, but still falls short of accounting for the observed fluid pressure imbalance in the XGCa simulation results.« less

Potential of personal health record portals in the care of individuals with spinal cord injuries and disorders: Provider perspectives.

PubMed

Hill, Jennifer N; Smith, Bridget M; Weaver, Frances M; Nazi, Kim M; Thomas, Florian P; Goldstein, Barry; Hogan, Timothy P

2018-05-01

Although personal health record (PHR) portals are designed for patients, healthcare providers are a key influence in how patients use their features and realize benefits from them. A few studies have examined provider attitudes toward PHR portals, but none have focused on those who care for individuals with spinal cord injuries and disorders (SCI/D). We characterize SCI/D provider perspectives of PHR portals, including perceived advantages and disadvantages of PHR portal use in SCI/D care. Cross-sectional; semi-structured interviews. Spinal Cord Injury (SCI) Centers in the Veterans Health Administration. Twenty-six SCI/D healthcare providers. None. Perceived advantages and disadvantages of PHR portals. The complex situations of individuals with SCI/D shaped provider perspectives of PHR portals and their potential role in practice. Perceived advantages of PHR portal use in SCI/D care included the ability to coordinate information and care, monitor and respond to outpatient requests, support patient self-management activities, and provide reliable health information to patients. Perceived disadvantages of PHR portal use in SCI/D care included concerns about the quality of patient-generated health data, other potential liabilities for providers and workload burden, and the ability of individuals with SCI/D to understand clinical information accessed through a portal. Our study highlights advantages and disadvantages that should be considered when promoting engagement of SCI/D healthcare providers in use of PHR portals, and portal features that may have the most utility in SCI/D care.

Circulating sclerostin is elevated in short-term and reduced in long-term SCI.

PubMed

Battaglino, Ricardo A; Sudhakar, Supreetha; Lazzari, Antonio A; Garshick, Eric; Zafonte, Ross; Morse, Leslie R

2012-09-01

Spinal cord injury (SCI) causes profound bone loss due to muscle paralysis resulting in the inability to walk. Sclerostin, a Wnt signaling pathway antagonist produced by osteocytes, is a potent inhibitor of bone formation. Short-term studies in rodent models have demonstrated increased sclerostin in response to mechanical unloading that is reversed with reloading. Although sclerostin inhibition has been proposed as a potential therapy for bone loss, it is not known if sclerostin levels vary with duration of SCI in humans. We analyzed circulating sclerostin in 155 men with varying degrees of SCI who were 1 year or more post-injury. We report that sclerostin levels are greatest in subjects with short-term SCI (≤5 years post-injury) and decrease significantly over the first 5 years post-injury. There was no association between sclerostin and injury duration in subjects with long-term SCI (>5 years post-injury). In subjects with long-term SCI, sclerostin levels were positively associated with lower extremity bone density and bone mineral content. These data suggest that sclerostin levels are initially increased after SCI in response to mechanical unloading. This response is time-limited and as bone loss progresses, circulating sclerostin is lowest in subjects with severe osteoporosis. These findings support a dual role for sclerostin after SCI: a therapeutic target in acute SCI, and a biomarker of osteoporosis severity in chronic SCI. Copyright © 2012 Elsevier Inc. All rights reserved.

Curcumin Increase the Expression of Neural Stem/Progenitor Cells and Improves Functional Recovery after Spinal Cord Injury

PubMed Central

Bang, Woo-Seok; Kim, Kyoung-Tae; Seo, Ye Jin; Cho, Dae-Chul; Sung, Joo-Kyung; Kim, Chi Heon

2018-01-01

Objective To investigates the effect of curcumin on proliferation of spinal cord neural stem/progenitor cells (SC-NSPCs) and functional outcome in a rat spinal cord injury (SCI) model. Methods Sixty adult male Sprague-Dawley rats were randomly and blindly allocated into three groups (sham control group; curcumin treated group after SCI; vehicle treated group after SCI). Functional recovery was evaluated by the Basso, Beattie, and Bresnahan (BBB) scale during 6 weeks after SCI. The expression of SC-NSPC proliferation and astrogliosis were analyzed by nestin/Bromodeoxyuridine (BrdU) and Glial fibrillary acidic protein (GFAP) staining. The injured spinal cord was then examined histologically, including quantification of cavitation. Results The BBB score of the SCI-curcumin group was better than that of SCI-vehicle group up to 14 days (p<0.05). The co-immunoreactivity of nestin/BrdU in the SCI-curcumin group was much higher than that of the SCI-vehicle group 1 week after surgery (p<0.05). The GFAP immunoreactivity of the SCI-curcumin group was remarkably lower than that of the SCI-vehicle group 4 weeks after surgery (p<0.05). The lesion cavity was significantly reduced in the curcumin group as compared to the control group (p<0.05). Conclusion These results indicate that curcumin could increase the expression of SC-NSPCs, and reduce the activity of reactive astrogliosis and lesion cavity. Consequently curcumin could improve the functional recovery after SCI via SC-NSPC properties. PMID:29354231

Spinal Cord Injury Impairs Cardiovascular Capacity in Elite Wheelchair Rugby Athletes.

PubMed

Gee, Cameron M; Currie, Katharine D; Phillips, Aaron A; Squair, Jordan W; Krassioukov, Andrei V

2017-12-19

To examine differences in heart rate (HR) responses during international wheelchair rugby competition between athletes with and without a cervical spinal cord injury (SCI) and across standardized sport classifications. Observational study. The 2015 Parapan American Games wheelchair rugby competition. Forty-three male athletes (31 ± 8 years) with a cervical SCI (n = 32) or tetraequivalent impairment (non-SCI, n = 11). Average and peak HR (HRavg and HRpeak, respectively). To characterize HR responses in accordance with an athletes' International Wheelchair Rugby Federation (IWRF) classification, we separated athletes into 3 groups: group I (IWRF classification 0.5-1.5, n = 15); group II (IWRF classification 2.0, n = 15); and group III (IWRF classification 2.5-3.5, n = 13). Athletes with SCI had lower HRavg (111 ± 14 bpm vs 155 ± 13 bpm) and HRpeak (133 ± 12 bpm vs 178 ± 13 bpm) compared with non-SCI (both P < 0.001). Average HR was higher in group III than in I (136 ± 25 bpm vs 115 ± 20 bpm, P = 0.045); however, SCI athletes showed no difference in HRavg or HRpeak between groups. Within group III, SCI athletes had lower HRavg (115 ± 6 bpm vs 160 ± 8 bpm) and HRpeak (135 ± 11 bpm vs 183 ± 11 bpm) than non-SCI athletes (both P < 0.001). This study is the first to demonstrate attenuated HR responses during competition in SCI compared with non-SCI athletes, likely due to injury to spinal autonomic pathways. Among athletes with SCI, IWRF classification was not related to differences in HR. Specific assessment of autonomic function after SCI may be able to predict HR during competition and consideration of autonomic impairments may improve the classification process.

Understanding Quality of Life in Adults with Spinal Cord Injury Via SCI-Related Needs and Secondary Complications.

PubMed

Sweet, Shane N; Noreau, Luc; Leblond, Jean; Dumont, Frédéric S

2014-01-01

Understanding the factors that can predict greater quality of life (QoL) is important for adults with spinal cord injury (SCI), given that they report lower levels of QoL than the general population. To build a conceptual model linking SCI-related needs, secondary complications, and QoL in adults with SCI. Prior to testing the conceptual model, we aimed to develop and evaluate the factor structure for both SCI-related needs and secondary complications. Individuals with a traumatic SCI (N = 1,137) responded to an online survey measuring 13 SCI-related needs, 13 secondary complications, and the Life Satisfaction Questionnaire to assess QoL. The SCI-related needs and secondary complications were conceptualized into factors, tested with a confirmatory factor analysis, and subsequently evaluated in a structural equation model to predict QoL. The confirmatory factor analysis supported a 2-factor model for SCI related needs, χ(2)(61, N = 1,137) = 250.40, P <.001, comparative fit index (CFI) = .93, root mean square error of approximation (RMSEA) = .05, standardized root mean square residual (SRMR) = .04, and for 11 of the 13 secondary complications, χ(2)(44, N = 1,137) = 305.67, P < .001, CFI = .91, RMSEA = .060, SRMR = .033. The final 2 secondary complications were kept as observed constructs. In the structural model, both vital and personal development unmet SCI-related needs (β = -.22 and -.20, P < .05, respectively) and the neuro-physiological systems factor (β = -.45, P < .05) were negatively related with QoL. Identifying unmet SCI-related needs of individuals with SCI and preventing or managing secondary complications are essential to their QoL.

Methodology for the development and calibration of the SCI-QOL item banks

PubMed Central

Tulsky, David S.; Kisala, Pamela A.; Victorson, David; Choi, Seung W.; Gershon, Richard; Heinemann, Allen W.; Cella, David

2015-01-01

Objective To develop a comprehensive, psychometrically sound, and conceptually grounded patient reported outcomes (PRO) measurement system for individuals with spinal cord injury (SCI). Methods Individual interviews (n = 44) and focus groups (n = 65 individuals with SCI and n = 42 SCI clinicians) were used to select key domains for inclusion and to develop PRO items. Verbatim items from other cutting-edge measurement systems (i.e. PROMIS, Neuro-QOL) were included to facilitate linkage and cross-population comparison. Items were field tested in a large sample of individuals with traumatic SCI (n = 877). Dimensionality was assessed with confirmatory factor analysis. Local item dependence and differential item functioning were assessed, and items were calibrated using the item response theory (IRT) graded response model. Finally, computer adaptive tests (CATs) and short forms were administered in a new sample (n = 245) to assess test-retest reliability and stability. Participants and Procedures A calibration sample of 877 individuals with traumatic SCI across five SCI Model Systems sites and one Department of Veterans Affairs medical center completed SCI-QOL items in interview format. Results We developed 14 unidimensional calibrated item banks and 3 calibrated scales across physical, emotional, and social health domains. When combined with the five Spinal Cord Injury – Functional Index physical function banks, the final SCI-QOL system consists of 22 IRT-calibrated item banks/scales. Item banks may be administered as CATs or short forms. Scales may be administered in a fixed-length format only. Conclusions The SCI-QOL measurement system provides SCI researchers and clinicians with a comprehensive, relevant and psychometrically robust system for measurement of physical-medical, physical-functional, emotional, and social outcomes. All SCI-QOL instruments are freely available on Assessment CenterSM. PMID:26010963

Methodology for the development and calibration of the SCI-QOL item banks.

PubMed

Tulsky, David S; Kisala, Pamela A; Victorson, David; Choi, Seung W; Gershon, Richard; Heinemann, Allen W; Cella, David

2015-05-01

To develop a comprehensive, psychometrically sound, and conceptually grounded patient reported outcomes (PRO) measurement system for individuals with spinal cord injury (SCI). Individual interviews (n=44) and focus groups (n=65 individuals with SCI and n=42 SCI clinicians) were used to select key domains for inclusion and to develop PRO items. Verbatim items from other cutting-edge measurement systems (i.e. PROMIS, Neuro-QOL) were included to facilitate linkage and cross-population comparison. Items were field tested in a large sample of individuals with traumatic SCI (n=877). Dimensionality was assessed with confirmatory factor analysis. Local item dependence and differential item functioning were assessed, and items were calibrated using the item response theory (IRT) graded response model. Finally, computer adaptive tests (CATs) and short forms were administered in a new sample (n=245) to assess test-retest reliability and stability. A calibration sample of 877 individuals with traumatic SCI across five SCI Model Systems sites and one Department of Veterans Affairs medical center completed SCI-QOL items in interview format. We developed 14 unidimensional calibrated item banks and 3 calibrated scales across physical, emotional, and social health domains. When combined with the five Spinal Cord Injury--Functional Index physical function banks, the final SCI-QOL system consists of 22 IRT-calibrated item banks/scales. Item banks may be administered as CATs or short forms. Scales may be administered in a fixed-length format only. The SCI-QOL measurement system provides SCI researchers and clinicians with a comprehensive, relevant and psychometrically robust system for measurement of physical-medical, physical-functional, emotional, and social outcomes. All SCI-QOL instruments are freely available on Assessment CenterSM.

The role of capsaicin-sensitive C-fiber afferent pathways in the control of micturition in spinal-intact and spinal cord-injured mice.

PubMed

Kadekawa, Katsumi; Majima, Tsuyoshi; Shimizu, Takahiro; Wada, Naoki; de Groat, William C; Kanai, Anthony J; Goto, Momokazu; Yoshiyama, Mitsuharu; Sugaya, Kimio; Yoshimura, Naoki

2017-09-01

We examined bladder and urethral sphincter activity in mice with or without spinal cord injury (SCI) after C-fiber afferent desensitization induced by capsaicin pretreatment and changes in electrophysiological properties of mouse bladder afferent neurons 4 wk after SCI. Female C57BL/6N mice were divided into four groups: 1 ) spinal intact (SI)-control, 2 ) SI-capsaicin pretreatment (Cap), 3 ) SCI-control, and 4 ) SCI-Cap groups. Continuous cystometry and external urethral sphincter (EUS)-electromyogram (EMG) were conducted under an awake condition. In the Cap groups, capsaicin (25, 50, or 100 mg/kg) was injected subcutaneously 4 days before the experiments. In the SI-Cap group, 100 mg/kg capsaicin pretreatment significantly increased bladder capacity and decreased the silent period duration of EUS/EMG compared with the SI-control group. In the SCI-Cap group, 50 and 100 mg/kg capsaicin pretreatment decreased the number of nonvoiding contractions (NVCs) and the duration of reduced EUS activity during voiding, respectively, compared with the SCI-control group. In SCI mice, hexamethonium, a ganglionic blocker, almost completely blocked NVCs, suggesting that they are of neurogenic origin. Patch-clamp recordings in capsaicin-sensitive bladder afferent neurons from SCI mice showed hyperexcitability, which was evidenced by decreased spike thresholds and increased firing rate compared with SI mice. These results indicate that capsaicin-sensitive C-fiber afferent pathways, which become hyperexcitable after SCI, can modulate bladder and urethral sphincter activity in awake SI and SCI mice. Detrusor overactivity as shown by NVCs in SCI mice is significantly but partially dependent on capsaicin-sensitive C-fiber afferents, whereas the EUS relaxation during voiding is enhanced by capsaicin-sensitive C-fiber bladder afferents in SI and SCI mice. Copyright © 2017 the American Physiological Society.

Investigation of Microbiota Alterations and Intestinal Inflammation Post-Spinal Cord Injury in Rat Model.

PubMed

O'Connor, Gregory; Jeffrey, Elisabeth; Madorma, Derik; Marcillo, Alexander; Abreu, Maria T; Deo, Sapna K; Dietrich, W Dalton; Daunert, Sylvia

2018-06-07

Although there has been a significant amount of research focused on the pathophysiology of spinal cord injury (SCI), there is limited information on the consequences of SCI on remote organs. SCI can produce significant effects on a variety of organ systems, including the gastrointestinal tract. Patients with SCI often suffer from severe, debilitating bowel dysfunction in addition to their physical disabilities, which is of major concern for these individuals because of the adverse impact on their quality of life. Herein, we report on our investigation into the effects of SCI and subsequent antibiotic treatment on the intestinal tissue and microbiota. For that, we used a thoracic SCI rat model and investigated changes to the microbiota, proinflammatory cytokine levels, and bacterial communication molecule levels post-injury and gentamicin treatment for 7 days. We discovered significant changes, the most interesting being the differences in the gut microbiota beta diversity of 8-week SCI animals compared to control animals at the family, genus, and species level. Specifically, 35 operational taxonomic units were enriched in the SCI animal group and three were identified at species level; Lactobacillus intestinalis, Clostridium disporicum, and Bifidobacterium choerinum. In contrast, Clostridium saccharogumia was identified as depleted in the SCI animal group. Proinflammatory cytokines interleukin (IL)-12, macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor alpha were found to be significantly elevated in intestinal tissue homogenate 4 weeks post-SCI compared to 8-weeks post-injury. Further, levels of IL-1β, IL-12, and MIP-2 significantly correlated with changes in beta diversity 8-weeks post-SCI. Our data provide a greater understanding of the early effects of SCI on the microbiota and gastrointestinal tract, highlighting the need for further investigation to elucidate the mechanism underlying these effects.

The Role of Scientific Communication Skills in Trainees' Intention to Pursue Biomedical Research Careers: A Social Cognitive Analysis.

PubMed

Cameron, Carrie; Lee, Hwa Young; Anderson, Cheryl; Byars-Winston, Angela; Baldwin, Constance D; Chang, Shine

2015-01-01

Scientific communication (SciComm) skills are indispensable for success in biomedical research, but many trainees may not have fully considered the necessity of regular writing and speaking for research career progression. Our purpose was to investigate the relationship between SciComm skill acquisition and research trainees' intentions to remain in research careers. We used social cognitive career theory (SCCT) to test a model of the relationship of SciComm skills to SciComm-related cognitive variables in explaining career intentions. A sample of 510 graduate students and postdoctoral fellows at major academic health science centers in the Texas Medical Center, Houston, Texas, were surveyed online. Results suggested that interest in performing SciComm tasks, SciComm outcome expectations (SCOEs), and SciComm productivity predicted intention to remain in a research career, while SciComm self-efficacy did not directly predict career intention. SCOEs also predicted interest in performing SciComm tasks. As in other SCCT studies, SciComm self-efficacy predicted SCOEs. We conclude that social cognitive factors of SciComm skill acquisition and SciComm productivity significantly predict biomedical trainees' intentions to pursue research careers whether within or outside academia. While further studies are needed, these findings may lead to evidence-based interventions to help trainees remain in their chosen career paths. © 2015 C. Cameron et al. CBE—Life Sciences Education © 2015 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Current practice of methylprednisolone administration for acute spinal cord injury in Germany: a national survey.

PubMed

Druschel, Claudia; Schaser, Klaus-Dieter; Schwab, Jan M

2013-05-15

Written mail-out survey. To determine current practice in high-dose methylprednisolone succinate (MPSS) administration for treatment of acute spinal cord injury (SCI) in Germany. Reanalysis of the National Acute Spinal Cord Injury Studies (NASCIS) resulted in criticism of the use of high-dose MPSS for treatment of acute SCI. Subsequently, SCI treatment guidelines were revised leading to a reduction in MPSS use across North America. The impact of these revisions on SCI treatment in Germany is not known. A questionnaire was sent to all trauma, orthopedic and neurosurgical departments of German university centers, affiliated teaching hospitals, and specialized SCI care centers. Survey included 6 questions about the administration of MPSS after acute SCI. Three hundred seventy-two respondents completed the survey (response rate: 51% overall, 76% university hospitals, 85% specialized SCI care centers). Overall, 55% of departments that treat SCI prescribe MPSS. Among them, 73% are "frequent" users administering MPSS to more than 50% of their patients. Ten percent prescribe according to NASCIS I, 43% NASCIS II, 33% NASCIS III, and 13% "generic protocols." As justification for MPSS treatment, "effectiveness" ranked before "common practice" and "medicolegal reasons." "Specialized" SCI care centers differ in that (1) MPSS is administered less frequently, (2) NASCIS I doses are not used, and (3) during the past several years, practice patterns are more likely to have shifted away from the treatment of SCI with MPSS. About one-half of the institutions continue to prescribe MPSS in the setting of acute SCI. A need for further education in almost one-fourth of German departments treating acute SCI is demonstrated through responses indicating use of the outdated NASCIS I protocol, a "legal need" or "unchanged MPSS application during the last years." "Specialized" SCI centers are more likely to change their practice in accordance with evolving literature. 3.

Persistent Polyuria in a Rat Spinal Contusion Model

PubMed Central

Ward, Patricia J.

2012-01-01

Abstract Polyuria contributes to bladder overdistention, which confounds both lower and upper urinary tract management in individuals having a spinal cord injury (SCI). Bladder overdistention post-SCI is one of the most common triggers for autonomic dysreflexia, a potentially life-threatening condition. Post-SCI polyuria is thought to result from loss of vascular tone in the lower extremities, leading to edema and subsequent excess fluid, resulting in polyuria. Mild SCIs that have near complete recovery would therefore be expected to have little to no polyuria, while severe injuries resulting in flaccid limbs and lower extremity edema would be expected to exhibit severe polyuria. Since interventions that may decrease lower extremity edema are recommended to lessen the severity of polyuria, step training (which promotes vascular circulation) was evaluated as a therapy to reduce post-SCI polyuria. In the present study, polyuria was evaluated in mild, moderate, and severe contusive SCI in adult male rats. The animals were housed in metabolic cages for 24-hour periods pre- and post-SCI (to 6 weeks). Urine, feces, food, water, and body weights were collected. Other assessments included residual expressed urine volumes, locomotor scoring, in-cage activity, and lesion histology. SCI produced an immediate increase in 24-hour urine collection, as early as 3 days post-SCI. Approximately 2.6-fold increases in urine collection occurred from weeks 1–6 post-SCI for all injury severities. Even with substantial gains in locomotor and bladder function following a mild SCI, polyuria remained severe. Step training (30 min/day, 6 days/week) did not alleviate polyuria in the moderate SCI contusion group. These results indicate that (1) mild injuries retaining weight-bearing locomotion that should have mild, if any, edema/loss of vascular tone still exhibit severe polyuria, and (2) step training was unable to reduce post-SCI polyuria. Taken together, these results indicate that the current mechanistic hypothesis of post-SCI polyuria may be incomplete. PMID:22708983

Persistent polyuria in a rat spinal contusion model.

PubMed

Ward, Patricia J; Hubscher, Charles H

2012-10-10

Polyuria contributes to bladder overdistention, which confounds both lower and upper urinary tract management in individuals having a spinal cord injury (SCI). Bladder overdistention post-SCI is one of the most common triggers for autonomic dysreflexia, a potentially life-threatening condition. Post-SCI polyuria is thought to result from loss of vascular tone in the lower extremities, leading to edema and subsequent excess fluid, resulting in polyuria. Mild SCIs that have near complete recovery would therefore be expected to have little to no polyuria, while severe injuries resulting in flaccid limbs and lower extremity edema would be expected to exhibit severe polyuria. Since interventions that may decrease lower extremity edema are recommended to lessen the severity of polyuria, step training (which promotes vascular circulation) was evaluated as a therapy to reduce post-SCI polyuria. In the present study, polyuria was evaluated in mild, moderate, and severe contusive SCI in adult male rats. The animals were housed in metabolic cages for 24-hour periods pre- and post-SCI (to 6 weeks). Urine, feces, food, water, and body weights were collected. Other assessments included residual expressed urine volumes, locomotor scoring, in-cage activity, and lesion histology. SCI produced an immediate increase in 24-hour urine collection, as early as 3 days post-SCI. Approximately 2.6-fold increases in urine collection occurred from weeks 1-6 post-SCI for all injury severities. Even with substantial gains in locomotor and bladder function following a mild SCI, polyuria remained severe. Step training (30 min/day, 6 days/week) did not alleviate polyuria in the moderate SCI contusion group. These results indicate that (1) mild injuries retaining weight-bearing locomotion that should have mild, if any, edema/loss of vascular tone still exhibit severe polyuria, and (2) step training was unable to reduce post-SCI polyuria. Taken together, these results indicate that the current mechanistic hypothesis of post-SCI polyuria may be incomplete.

E2F4 Promotes Neuronal Regeneration and Functional Recovery after Spinal Cord Injury in Zebrafish

PubMed Central

Sasagawa, Shota; Nishimura, Yuhei; Hayakawa, Yuka; Murakami, Soichiro; Ashikawa, Yoshifumi; Yuge, Mizuki; Okabe, Shiko; Kawaguchi, Koki; Kawase, Reiko; Tanaka, Toshio

2016-01-01

Mammals exhibit poor recovery after spinal cord injury (SCI), whereas non-mammalian vertebrates exhibit significant spontaneous recovery after SCI. The mechanisms underlying this difference have not been fully elucidated; therefore, the purpose of this study was to investigate these mechanisms. Using comparative transcriptome analysis, we demonstrated that genes related to cell cycle were significantly enriched in the genes specifically dysregulated in zebrafish SCI. Most of the cell cycle-related genes dysregulated in zebrafish SCI were down-regulated, possibly through activation of e2f4. Using a larval zebrafish model of SCI, we demonstrated that the recovery of locomotive function and neuronal regeneration after SCI were significantly inhibited in zebrafish treated with an E2F4 inhibitor. These results suggest that activation of e2f4 after SCI may be responsible, at least in part, for the significant recovery in zebrafish. This provides novel insight into the lack of recovery after SCI in mammals and informs potential therapeutic strategies. PMID:27242526

Spinal cord injury rehabilitation in Riyadh, Saudi Arabia: Time to rehabilitation admission, length of stay and functional independence

PubMed Central

Mahmoud, Husam; Qannam, Hazem; Mortenson, Ben

2017-01-01

Objectives 1) To describe functional status, length of stay (LOS), and time to rehabilitation admission trends. 2) To identify independent predictors of motor function following rehabilitation for traumatic and nontraumatic spinal cord injury (SCI). Participants Adult patients with SCI discharged from inpatient rehabilitation between 2009–2014. Design Retrospective cohort study. Setting Spinal injury rehabilitation unit at the King Fahad Medical City, Riyadh, Saudi Arabia. Methods From retrospective chart reviews of 312 traumatic and 106 nontraumatic SCI, we extracted information on time from injury to rehabilitation admission, rehabilitation LOS, and Functional Independence Measure (FIM) score (admission and discharge). Additionally we collected information on SCI patients’ demographics and injury characteristics. Hierarchical regression was employed to investigate variables associated with FIM motor score at discharge for traumatic SCI and nontraumatic SCI. Outcome measures FIM motor score measured at discharge. Results Mean and median days from injury to rehabilitation admission were not significantly different for traumatic SCI (377±855, 150) and nontraumatic SCI (288±403, 176). Mean and median days for rehabilitation LOS were significantly longer for traumatic SCI (85±60, 70) compared to nontraumatic SCI (64±59, 49) (p=…..). FIM scores improved significantly from admission to discharge in both groups. For individuals with traumatic SCI, after accounting for admission FIM motor score, tetraplegia and time from injury to rehabilitation, admission had a significant but small negative association with discharge FIM motor score. For individuals with nontraumatic SCI, increasing age and AIS score of A or B had a significant negative association with discharge FIM motor score. LOS in rehabilitation was not a significant contributor for either model. Conclusions Decreasing the time from injury to rehabilitation admission may improve outcomes for those with traumatic SCI. Since time spent in rehabilitation was shorter than most other countries, a change in practice in this area may be warranted. Developing new strategies to improve outcomes for older patients with nontraumatic SCI would also be beneficial. PMID:28139661

Health Information Seeking and Technology Use Among Veterans With Spinal Cord Injuries and Disorders.

PubMed

Hogan, Timothy P; Hill, Jennifer N; Locatelli, Sara M; Weaver, Frances M; Thomas, Florian P; Nazi, Kim M; Goldstein, Barry; Smith, Bridget M

2016-02-01

Access to health information is crucial to persons living with a spinal cord injury or disorder (SCI/D). Although previous research has provided insights on computer and Internet use among persons with SCI/D, as well as how and where persons with SCI/D gather health information, few studies have focused on U.S. veterans with SCI/D. To characterize health information seeking among veterans with SCI/D and to examine the association between technology use and the characteristics of veterans with SCI/D. Cross-sectional. Veterans Health Administration (VHA). Sample of 290 veterans with SCI/D who utilize services at 2 VHA SCI/D Centers. Postal mail survey. Extent of computer, Internet, and text messaging use, information source use, and e-Health literacy rates. The survey response rate was 38%. The majority of respondents were male (97.2%), younger than 65 years (71.0%), and white (71.7%). Of the respondents, 64.8% indicated that they use a computer, 62.9% reported use of the Internet, and 26.2% reported use of text messaging. The mean overall e-Health Literacy Scale score was 27.3 (standard deviation = 7.2). Similar to findings reported in studies focused outside the veteran population, the most frequent source that veterans turned to for information about SCI/D was a health professional (85.1%); this was also the most frequent source that veterans indicated they would turn to first to get information about SCI/D (75.9%). Other frequently reported sources of information included other persons with SCI/D (41.0%), Internet resources (31.0%), and family and friends (27.9%). Fairly high levels of computer and Internet use exist among veterans with SCI/D. Veterans with SCI/D also have a strong preference for people-particularly health professionals, and to a lesser extent peers and family and friends-as sources of information about SCI/D. These findings highlight the importance of combining technology and human interaction to meet the information needs of this population. Published by Elsevier Inc.

Proliferative capacity and osteogenic potential of novel dura mater stem cells on poly-lactic-co-glycolic acid.

PubMed

Petrie, Caren; Tholpady, Sunil; Ogle, Roy; Botchwey, Edward

2008-04-01

The rational design of biomimetic structures for the regeneration of damaged or missing tissue is a fundamental principle of tissue engineering. Multiple variables must be optimized, ranging from the scaffold type to the selection and properties of implanted cell(s). In this study, the osteogenic potential of a novel stem cell was analyzed on biodegradable poly(lactic-co-glycolic acid) (PLGA) biomaterials as a step toward creating new cell-materials constructs for bony regeneration. Dura mater stem cells (DSCs), isolated from rat dura mater, were evaluated and compared to bone marrow stem cells (BMSCs) for proliferative and differentiative properties in vitro. Experiments were carried out on both tissue culture plastic (TCP) and 2D planar films of PLGA. Proliferation of DSCs on both TCP and PLGA films increased over 21 days. Positive fold inductions in all five bone marker genes were observed at days 7, 14, 21 in all experimental samples compared with day 0 controls. DSCs demonstrated greater cell coverage and enhanced matrix staining on 2D PLGA films when compared with BMSCs. These cells can be isolated and expanded in culture and can subsequently attach, proliferate, and differentiate on both TCP and PLGA films to a greater extent than BMSCs. This suggests that DSCs are promising for cell-based bone tissue engineering therapies, particularly those applications involving regeneration of cranial bones. Copyright 2007 Wiley Periodicals, Inc.

[Metastasis of Hepatocellular Carcinoma to the Membrane of Chronic Subdural Hematomas:A Case Report].

PubMed

Oshita, Jumpei; Ohba, Shinji; Itou, Yoko; Yonezawa, Koki; Hosogai, Masahiro

2017-10-01

An 81-year-old man presented with gait disturbance. Two months previously, he suffered from hepatocellular carcinoma and transarterial chemoembolization was performed. A head computed tomography(CT)scan revealed bilateral chronic subdural hematomas. The patient's gait disturbance was improved after achievement of bilateral burr hole drainage. A head CT two months after treatment revealed no recurrence of the hematomas. However, head CT images obtained four months after treatment revealed an abnormal mass in the right parietal region attached to the internal surface of the skull. The mass was located in the same region from where the chronic subdural hematomas were previously removed via burr hole drainage, and was suspected to have originated from the dura mater. We performed craniotomy and total removal of the mass. The dura mater was intact, and macroscopically, the mass originated from the organized membrane of the chronic subdural hematoma. A pathological examination revealed metastasis of hepatocellular carcinoma to the membrane of the chronic subdural hematomas. Head magnetic resonance imaging(MRI)performed 39 days after craniotomy presented a new lesion in the left parietal region attached to the internal surface of the skull. The patient subsequently died 46 days post-operation. When examining chronic subdural hematomas in cancer patients, histological examination of the dura mater, hematoma, and membrane of the hematoma are important. The possibility of metastasis to the capsule of the hematoma should be considered.

Ultrastructure of the extracellular matrix of bovine dura mater, optic nerve sheath and sclera.

PubMed Central

Raspanti, M; Marchini, M; Della Pasqua, V; Strocchi, R; Ruggeri, A

1992-01-01

The sclera, the outermost sheath of the optic nerve and the dura mater have been investigated histologically and ultrastructurally. Although these tissues appear very similar under the light microscope, being dense connective tissues mainly composed of collagen bundles and a limited amount of cells and elastic fibres, they exhibit subtle differences on electron microscopy. In the dura and sclera collagen appears in the form of large, nonuniform fibrils, similar to those commonly found in tendons, while in the optic nerve sheath the fibrils appear smaller and uniform, similar to those commonly observed in reticular tissues, vessel walls and skin. Freeze-fracture also reveals these fibrils to have different subfibrillar architectures, straight or helical, which correspond to 2 distinct forms of collagen fibril previously described (Raspanti et al. 1989). The other extracellular matrix components also vary with the particular collagen fibril structure. Despite their common embryological derivation, the dura mater, optic nerve sheath and sclera exhibit diversification of their extracellular matrix consistent with the mechanical loads to which these tissues are subjected. Our observations indicate that the outermost sheath of the optic nerve resembles the epineurium of peripheral nerves rather than the dura to which it is commonly likened. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:1295858

Investigation of in vitro Hydrophilic and Hydrophobic Dual Drug Release from Polymeric Films Produced by Sodium alginate-MaterBi® Drying Emulsions.

PubMed

Setti, Chiara; Suarato, Giulia; Perotto, Giovanni; Athanassiou, Athanassia; Bayer, Ilker S

2018-06-18

Emulsions are known to be effective carriers of hydrophobic drugs, and particularly injectable emulsions have been successfully implemented for in vivo controlled drug release. Recently, high internal phase emulsions have also been used to produce porous polymeric templates for pharmaceutical applications. However, emulsions containing dissolved biopolymers both in the oil and water phases are very scarce. In this study, we demonstrate such an emulsion, in which the oil phase contains a hydrophobic biodegradable polymer, MaterBi ® , and the water phase is aqueous sodium alginate dispersion. The two phases were emulsified simply by ultrasonic processing without any surfactants. The emulsions were stable for several days and were dried into composite solid films with varying MaterBi ® /alginate fractions. The films were loaded with two model drugs, a hydrophilic eosin-based cutaneous antiseptic and the hydrophobic curcumin. Drug release capacity of the films was investigated in detail, and controlled release of each model drug was achieved either by tuning the polymer fraction in the films during emulsification or by crosslinking sodium alginate fraction of the films by calcium salt solution immersion. The emulsions can be formulated to carry either a single model drug or both drugs depending on the desired application. Films demonstrate excellent cell biocompatibility against human dermal fibroblast, adult cells. Copyright © 2018. Published by Elsevier B.V.

76 FR 10395 - BreconRidge Manufacturing Solutions, Now Known as Sanmina-SCI Corporation, Division...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-24

... Solutions, Now Known as Sanmina-SCI Corporation, Division Optoelectronic and Microelectronic Design and Manufacturing, a Subsidiary of Sanmina-SCI Corporation, Including On- Site Leased Workers From Kelly Services... Manufacturing Solutions, now known as Sanmina-SCI Corporation, Division Optoelectronic and Microelectronic...

A pilot study to evaluate the role of the Spinal Cord Impairment Pressure Ulcer Monitoring Tool (SCI-PUMT) in clinical decisions for pressure ulcer treatment.

PubMed

Thomason, Susan S; Graves, Barbara Ann; Madaris, Linda

2014-12-01

The Spinal Cord Impairment Pressure Ulcer Monitoring Tool (SCI-PUMT) was designed to assess pressure ulcer (PrU) healing in the spinal cord impaired (SCI) population. The tool contains 7 variables: wound surface area, depth, edges, tunneling, undermining, exudate type, and necrotic tissue amount. A 2-phased, quantitative pilot study based on the Theory of Reasoned Action and Theory of Planned Behavior was conducted at a large SCI/Disorders Center in the Department of Veterans Affairs (VA). In the first phase of the study, a convenience sample of 5 physicians, 3 advanced practice registered nurses, and 3 certified wound care nurses (CWCN) was surveyed using a 2-part questionnaire to assess use of the SCI-PUMT instrument, its anticipated improvement in PrU assessment, and intent to use the SCI-PUMT in clinical practice. Attitudes, subjective norms, perceived behavioral controls, and barriers related to the intent to use the SCI-PUMT were evaluated using a 5-point Likert scale (range: 1= extremely likely, 5 = extremely unlikely). In the second phase of the study, the electronic health records (EHR) of 24 veterans (with 30 PrUs) who had at least 2 completed SCI-PUMT scores during a 4-week period were used to evaluate whether an association existed between magnitudes of change of total SCI-PUMT scores and ordered changes in PrU treatment. The overall mean score for intent to use SCI-PUMT was 1.80 (SD 0.75). The least favorable scores were for convenience and motivation to use the SCI-PUMT. Analysis of EHR data showed no significant difference in magnitudes of change in the SCI-PUMT score and changes in PrU treatment recommendations made by the CWCNs. The significance was not affected regardless of an increase or no change in the score (χ2 with 1 degree of freedom = 1.158, P = 0.282) or for a decrease in the score (χ2 with 1 degree of freedom = 0.5, P = 0.478). In this pilot study, the expressed intent to use the SCI-PUMT in making clinical decisions was generally positive but reservations remain. Additional research is being conducted to determine the barriers and facilitators to SCI-PUMT implementation. The SCI-PUMT was the first tool found to be valid, reliable, and sensitive to assess PrU healing in persons with SCI, and studies to examine the prospective validity of using this instrument on ulcer treatment decisions and outcomes are warranted.

Oligomerization reactions for precursors to secondary organic aerosol: Comparison between two formation mechanisms for the oligomeric hydroxyalkyl hydroperoxides

NASA Astrophysics Data System (ADS)

Zhao, Qiangli; Wang, Weina; Liu, Fengyi; Lü, Jian; Wang, Wenliang

2017-10-01

To better understand the formation mechanism of oligomeric hydroxyalkyl hydroperoxides HOROO(SCI)nH composed of stabilized Criegee intermediate (SCI) as a chain unit, the reactions of SCI with hydroxyalkyl hydroperoxides (HOROOH) and hydroxyalkylperoxy radical (HORO2) as well as HO2 radical were investigated. For the reactions of HORO2 + SCI, two preferred pathways involving a SCI insertion in HOROOH hydroperoxide bond can be found, and the formation of HOROO(SCI)H is the dominant pathway in the reaction of HOCH2(CH3)2COOH + (CH3)2COO. The structures of the HORO2, HOROOH as well as the SCIs play a crucial role in determining the reactivity of the oligomerization. Both the reactions of HORO2 + SCI + HO2 and HOROOH + SCI could be the source of the processors to the formation of secondary organic aerosol (SOA). But from the point of free energy barriers, the formation of HOROO(SCI)H prefers to follow the mechanism involving initiation by the reaction of a HORO2 and a SCI, sequential addition of SCIs, and termination by reaction with the HO2 radical. The rate coefficients show negative temperature dependence and vary in different systems depending on the reactants. The reaction process and constituents of the products can be regulated by temperature and reactants.

Abdominal Manual Therapy Repairs Interstitial Cells of Cajal and Increases Colonic c-Kit Expression When Treating Bowel Dysfunction after Spinal Cord Injury

PubMed Central

Zhang, Wenyi; Zhu, Zhaojin; Xie, Bin; Yu, Jun

2017-01-01

Background This study aimed to evaluate the therapeutic effects of abdominal manual therapy (AMT) on bowel dysfunction after spinal cord injury (SCI), investigating interstitial cells of Cajal (ICCs) and related c-kit expression. Methods Model rats were divided as SCI and SCI with drug treatment (intragastric mosapride), low-intensity (SCI + LMT; 50 g, 50 times/min), and high-intensity AMT (SCI + HMT; 100 g, 150 times/min). After 14 days of treatment, weight, improved Basso-Beattie-Bresnahan (BBB) locomotor score, and intestinal movement were evaluated. Morphological structure of spinal cord and colon tissues were examined. Immunostaining, RT-PCR, and western blot were used to assess c-kit expression. Results In SCI rats, AMT could not restore BBB, but it significantly increased weight, shortened time to defecation, increased feces amounts, and improved fecal pellet traits and colon histology. AMT improved the number, distribution, and ultrastructure of colonic ICCs, increasing colonic c-kit mRNA and protein levels. Compared with the SCI + Drug and SCI + LMT groups, the SCI + HMT group showed better therapeutic effect in improving intestinal transmission function and promoting c-kit expression. Conclusions AMT is an effective therapy for recovery of intestinal transmission function. It could repair ICCs and increase c-kit expression in colon tissues after SCI, in a frequency-dependent and pressure-dependent manner. PMID:29349063

Indoxacarb, Metaflumizone, and Other Sodium Channel Inhibitor Insecticides: Mechanism and Site of Action on Mammalian Voltage-Gated Sodium Channels

PubMed Central

von Stein, Richard T.; Silver, Kristopher S.; Soderlund, David M.

2013-01-01

Sodium channel inhibitor (SCI) insecticides were discovered almost four decades ago but have only recently yielded important commercial products (eg., indoxacarb and metaflumizone). SCI insecticides inhibit sodium channel function by binding selectively to slow-inactivated (non-conducting) sodium channel states. Characterization of the action of SCI insecticides on mammalian sodium channels using both biochemical and electrophysiological approaches demonstrates that they bind at or near a drug receptor site, the "local anesthetic (LA) receptor." This mechanism and site of action on sodium channels differentiates SCI insecticides from other insecticidal agents that act on sodium channels. However, SCI insecticides share a common mode of action with drugs currently under investigation as anticonvulsants and treatments for neuropathic pain. In this paper we summarize the development of the SCI insecticide class and the evidence that this structurally diverse group of compounds have a common mode of action on sodium channels. We then review research that has used site-directed mutagenesis and heterologous expression of cloned mammalian sodium channels in Xenopus laevis oocytes to further elucidate the site and mechanism of action of SCI insecticides. The results of these studies provide new insight into the mechanism of action of SCI insecticides on voltage-gated sodium channels, the location of the SCI insecticide receptor, and its relationship to the LA receptor that binds therapeutic SCI agents. PMID:24072940

Development and psychometric characteristics of the SCI-QOL Pressure Ulcers scale and short form

PubMed Central

Kisala, Pamela A.; Tulsky, David S.; Choi, Seung W.; Kirshblum, Steven C.

2015-01-01

Objective To develop a self-reported measure of the subjective impact of pressure ulcers on health-related quality of life (HRQOL) in individuals with spinal cord injury (SCI) as part of the SCI quality of life (SCI-QOL) measurement system. Design Grounded-theory based qualitative item development methods, large-scale item calibration testing, confirmatory factor analysis (CFA), and item response theory-based psychometric analysis. Setting Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Participants Adults with traumatic SCI. Main Outcome Measures SCI-QOL Pressure Ulcers scale. Results 189 individuals with traumatic SCI who experienced a pressure ulcer within the past 7 days completed 30 items related to pressure ulcers. CFA confirmed a unidimensional pool of items. IRT analyses were conducted. A constrained Graded Response Model with a constant slope parameter was used to estimate item thresholds for the 12 retained items. Conclusions The 12-item SCI-QOL Pressure Ulcers scale is unique in that it is specifically targeted to individuals with spinal cord injury and at every stage of development has included input from individuals with SCI. Furthermore, use of CFA and IRT methods provide flexibility and precision of measurement. The scale may be administered in its entirety or as a 7-item “short form” and is available for both research and clinical practice. PMID:26010965

Performance of the SciBar cosmic ray telescope (SciCRT) toward the detection of high-energy solar neutrons in solar cycle 24

NASA Astrophysics Data System (ADS)

Sasai, Yoshinori; Nagai, Yuya; Itow, Yoshitaka; Matsubara, Yutaka; Sako, Takashi; Lopez, Diego; Itow, Tsukasa; Munakata, Kazuoki; Kato, Chihiro; Kozai, Masayoshi; Miyazaki, Takahiro; Shibata, Shoichi; Oshima, Akitoshi; Kojima, Hiroshi; Tsuchiya, Harufumi; Watanabe, Kyoko; Koi, Tatsumi; Valdés-Galicia, Jose Francisco; González, Luis Xavier; Ortiz, Ernesto; Musalem, Octavio; Hurtado, Alejandro; Garcia, Rocio; Anzorena, Marcos

2014-12-01

We plan to observe solar neutrons at Mt. Sierra Negra (4,600 m above sea level) in Mexico using the SciBar detector. This project is named the SciBar Cosmic Ray Telescope (SciCRT). The main aims of the SciCRT project are to observe solar neutrons to study the mechanism of ion acceleration on the surface of the sun and to monitor the anisotropy of galactic cosmic-ray muons. The SciBar detector, a fully active tracker, is composed of 14,848 scintillator bars, whose dimension is 300 cm × 2.5 cm × 1.3 cm. The structure of the detector enables us to obtain the particle trajectory and its total deposited energy. This information is useful for the energy reconstruction of primary neutrons and particle identification. The total volume of the detector is 3.0 m × 3.0 m × 1.7 m. Since this volume is much larger than the solar neutron telescope (SNT) in Mexico, the detection efficiency of the SciCRT for neutrons is highly enhanced. We performed the calibration of the SciCRT at Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) located at 2,150 m above sea level in Mexico in 2012. We installed the SciCRT at Mt. Sierra Negra in April 2013 and calibrated this detector in May and August 2013. We started continuous observation in March 2014. In this paper, we report the detector performance as a solar neutron telescope and the current status of the SciCRT.

Spinal Cord Injury Causes Chronic Liver Pathology in Rats

PubMed Central

Sauerbeck, Andrew D.; Laws, J. Lukas; Bandaru, Veera V.R.; Popovich, Phillip G.; Haughey, Norman J.

2015-01-01

Abstract Traumatic spinal cord injury (SCI) causes major disruption to peripheral organ innervation and regulation. Relatively little work has investigated these post-SCI systemic changes, however, despite considerable evidence that multiple organ system dysfunction contributes to chronic impairments in health. Because metabolic dysfunction is common after SCI and the liver is a pivotal site for metabolic homeostasis, we sought to determine if liver pathology occurs as a result of SCI in a rat spinal contusion model. Histologic evidence showed excess lipid accumulation in the liver for at least 21 days post-injury after cervical or midthoracic SCI. Lipidomic analysis revealed an acute increase in hepatic ceramides as well as chronically elevated lactosylceramide. Post-SCI hepatic changes also included increased proinflammatory gene expression, including interleukin (IL)-1α, IL-1β, chemokine ligand-2, and tumor necrosis factor-α mRNA. These were coincident with increased CD68+ macrophages in the liver through 21 days post-injury. Serum alanine transaminase, used clinically to detect liver damage, was significantly increased at 21 days post-injury, suggesting that early metabolic and inflammatory damage preceded overt liver pathology. Surprisingly, liver inflammation was even detected after lumbar SCI. Collectively, these results suggest that SCI produces chronic liver injury with symptoms strikingly similar to those of nonalcoholic steatohepatitis (fatty liver disease). These clinically significant hepatic changes after SCI are known to contribute to systemic inflammation, cardiovascular disease, and metabolic syndrome, all of which are more prevalent in persons with SCI. Targeting acute and prolonged hepatic pathology may improve recovery and reduce long-term complications after SCI. PMID:25036371

Valproic Acid Increases Expression of Neuronal Stem/Progenitor Cell in Spinal Cord Injury

PubMed Central

Bang, Woo-Seok; Cho, Dae-Chul; Kim, Hye-Jeong; Sung, Joo-Kyung

2013-01-01

Objective This study investigates the effect of valproic acid (VPA) on expression of neural stem/progenitor cells (NSPCs) in a rat spinal cord injury (SCI) model. Methods Adult male rats (n=24) were randomly and blindly allocated into three groups. Laminectomy at T9 was performed in all three groups. In group 1 (sham), only laminectomy was performed. In group 2 (SCI-VPA), the animals received a dose of 200 mg/kg of VPA. In group 3 (SCI-saline), animals received 1.0 mL of the saline vehicle solution. A modified aneurysm clip with a closing force of 30 grams was applied extradurally around the spinal cord at T9, and then rapidly released with cord compression persisting for 2 minutes. The rats were sacrificed and the spinal cord were collected one week after SCI. Immunohistochemistry (IHC) and western blotting sample were obtained from 5 mm rostral region to the lesion and prepared. We analyzed the nestin immunoreactivity from the white matter of ventral cord and the ependyma of central canal. Nestin and SOX2 were used for markers for NSPCs and analyzed by IHC and western blotting, respectively. Results Nestin and SOX2 were expressed significantly in the SCI groups but not in the sham group. Comparing SCI groups, nestin and SOX2 expression were much stronger in SCI-VPA group than in SCI-saline group. Conclusion Nestin and SOX2 as markers for NSPCs showed increased expression in SCI-VPA group in comparison with SCI-saline group. This result suggests VPA increases expression of spinal NSPCs in SCI. PMID:24044073

Effect of lycopene on the blood-spinal cord barrier after spinal cord injury in mice.

PubMed

Zhang, Qian; Wang, Jianbo; Gu, Zhengsong; Zhang, Qing; Zheng, Hong

2016-09-05

The current study aimed to investigate the effect of lycopene on the blood-spinal cord barrier (BSCB) after spinal cord injury (SCI) in a mouse model. Lycopene inhibited lipid peroxidation and oxidative DNA damage as a highly efficient antioxidant and free radical scavenger. Lycopene (4 mg/kg/d) was administrated immediately following SCI. The permeability of the BSCB and water content in the spinal cord tissue were evaluated. Additionally, levels of expression of tight junction proteins and heme oxygenase-1 (HO-1) were determined with Western blotting. An enzyme-linked immunosorbent assay analysis of spinal cord tissue homogenates was performed 48 h after SCI to evaluate the expression of inflammation-related cytokines. In addition, recovery of motor function was assessed 1 d, 2 d, 5 d, 10 d, and 15 d after SCI using the Basso Mouse Scale to score locomotion. Compared to the group with an untreated SCI, mice with an SCI treated with lycopene had significantly reduced spinal cord tissue water content and BSCB permeability. Furthermore, motor function of mice with an SCI was also greatly improved by lycopene administration. The expression of the proinflammatory factors TNF-α and NF-kB increased markedly 48 h after SCI, and their upregulation was significantly attenuated by lycopene treatment. The expression of molecules that protect tight junctions, zonula occluden-1 and claudin-5, was upregulated by lycopene treatment after SCI. Taken together, these results clearly indicate that lycopene attenuated SCI by promoting repair of the damaged BSCB, so lycopene is a novel and promising treatment for SCI in humans.

GeoSciML v3.0 - a significant upgrade of the CGI-IUGS geoscience data model

NASA Astrophysics Data System (ADS)

Raymond, O.; Duclaux, G.; Boisvert, E.; Cipolloni, C.; Cox, S.; Laxton, J.; Letourneau, F.; Richard, S.; Ritchie, A.; Sen, M.; Serrano, J.-J.; Simons, B.; Vuollo, J.

2012-04-01

GeoSciML version 3.0 (http://www.geosciml.org), released in late 2011, is the latest version of the CGI-IUGS* Interoperability Working Group geoscience data interchange standard. The new version is a significant upgrade and refactoring of GeoSciML v2 which was released in 2008. GeoSciML v3 has already been adopted by several major international interoperability initiatives, including OneGeology, the EU INSPIRE program, and the US Geoscience Information Network, as their standard data exchange format for geoscience data. GeoSciML v3 makes use of recently upgraded versions of several Open Geospatial Consortium (OGC) and ISO data transfer standards, including GML v3.2, SWE Common v2.0, and Observations and Measurements v2 (ISO 19156). The GeoSciML v3 data model has been refactored from a single large application schema with many packages, into a number of smaller, but related, application schema modules with individual namespaces. This refactoring allows the use and future development of modules of GeoSciML (eg; GeologicUnit, GeologicStructure, GeologicAge, Borehole) in smaller, more manageable units. As a result of this refactoring and the integration with new OGC and ISO standards, GeoSciML v3 is not backwardly compatible with previous GeoSciML versions. The scope of GeoSciML has been extended in version 3.0 to include new models for geomorphological data (a Geomorphology application schema), and for geological specimens, geochronological interpretations, and metadata for geochemical and geochronological analyses (a LaboratoryAnalysis-Specimen application schema). In addition, there is better support for borehole data, and the PhysicalProperties model now supports a wider range of petrophysical measurements. The previously used CGI_Value data type has been superseded in favour of externally governed data types provided by OGC's SWE Common v2 and GML v3.2 data standards. The GeoSciML v3 release includes worked examples of best practice in delivering geochemical analytical data using the Observations and Measurements (ISO19156) and SWE Common v2 models. The GeoSciML v3 data model does not include vocabularies to support the data model. However, it does provide a standard pattern to reference controlled vocabulary concepts using HTTP-URIs. The international GeoSciML community has developed distributed RDF-based geoscience vocabularies that can be accessed by GeoSciML web services using the standard pattern recommended in GeoSciML v3. GeoSciML v3 is the first version of GeoSciML that will be accompanied by web service validation tools using Schematron rules. For example, these validation tools may check for compliance of a web service to a particular profile of GeoSciML, or for logical consistency of data content that cannot be enforced by the application schemas. This validation process will support accreditation of GeoSciML services and a higher degree of semantic interoperability. * International Union of Geological Sciences Commission for Management and Application of Geoscience Information (CGI-IUGS)

Toward a first-principles integrated simulation of tokamak edge plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, C S; Klasky, Scott A; Cummings, Julian

2008-01-01

Performance of the ITER is anticipated to be highly sensitive to the edge plasma condition. The edge pedestal in ITER needs to be predicted from an integrated simulation of the necessary firstprinciples, multi-scale physics codes. The mission of the SciDAC Fusion Simulation Project (FSP) Prototype Center for Plasma Edge Simulation (CPES) is to deliver such a code integration framework by (1) building new kinetic codes XGC0 and XGC1, which can simulate the edge pedestal buildup; (2) using and improving the existing MHD codes ELITE, M3D-OMP, M3D-MPP and NIMROD, for study of large-scale edge instabilities called Edge Localized Modes (ELMs); andmore » (3) integrating the codes into a framework using cutting-edge computer science technology. Collaborative effort among physics, computer science, and applied mathematics within CPES has created the first working version of the End-to-end Framework for Fusion Integrated Simulation (EFFIS), which can be used to study the pedestal-ELM cycles.« less

Workshop on data acquisition and trigger system simulations for high energy physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1992-12-31

This report discusses the following topics: DAQSIM: A data acquisition system simulation tool; Front end and DCC Simulations for the SDC Straw Tube System; Simulation of Non-Blocklng Data Acquisition Architectures; Simulation Studies of the SDC Data Collection Chip; Correlation Studies of the Data Collection Circuit & The Design of a Queue for this Circuit; Fast Data Compression & Transmission from a Silicon Strip Wafer; Simulation of SCI Protocols in Modsim; Visual Design with vVHDL; Stochastic Simulation of Asynchronous Buffers; SDC Trigger Simulations; Trigger Rates, DAQ & Online Processing at the SSC; Planned Enhancements to MODSEM II & SIMOBJECT -- anmore » Overview -- R.; DAGAR -- A synthesis system; Proposed Silicon Compiler for Physics Applications; Timed -- LOTOS in a PROLOG Environment: an Algebraic language for Simulation; Modeling and Simulation of an Event Builder for High Energy Physics Data Acquisition Systems; A Verilog Simulation for the CDF DAQ; Simulation to Design with Verilog; The DZero Data Acquisition System: Model and Measurements; DZero Trigger Level 1.5 Modeling; Strategies Optimizing Data Load in the DZero Triggers; Simulation of the DZero Level 2 Data Acquisition System; A Fast Method for Calculating DZero Level 1 Jet Trigger Properties and Physics Input to DAQ Studies.« less

Is IQ in childhood associated with suicidal thoughts and attempts? Findings from the Mater University Study of Pregnancy and its outcomes.

PubMed

Alati, Rosa; Gunnell, David; Najman, Jake; Williams, Gail; Lawlor, Debbie

2009-06-01

This study explores associations of IQ at age 14 with adult symptoms of suicidal thoughts and attempts at age 21. Analysis was based on the Mater University Study of Pregnancy and its outcomes, an Australian prospective birth cohort study started in Brisbane Australia in 1981. We assessed associations with suicide thoughts, plans, and attempts. We used two measures of IQ: the Raven's Standard Progressive Matrices and the Wide Range Achievement Test. In multivariable analyses, there was an inverse association between Raven's IQ and suicide thoughts, plans, and attempts, but no strong evidence of an association between the WRAT3 and the three suicidal items. Specific aspects of intelligence may be associated with suicidal thoughts, plans, and attempts.

A Comparison of Zero Mean Strain Rotating Beam Fatigue Test Methods for Nitinol Wire

NASA Astrophysics Data System (ADS)

Norwich, Dennis W.

2014-07-01

Zero mean strain rotating beam fatigue testing has become the standard for comparing the fatigue properties of Nitinol wire. Most commercially available equipment consists of either a two-chuck or a chuck and bushing system, where the wire length and center-to-center axis distance determine the maximum strain on the wire. For the two-chuck system, the samples are constrained at either end of the wire, and both chucks are driven at the same speed. For the chuck and bushing system, the sample is constrained at one end in a chuck and rides freely in a bushing at the other end. These equivalent systems will both be herein referred to as Chuck-to-Chuck systems. An alternate system uses a machined test block with a specific radius to guide the wire at a known strain during testing. In either system, the test parts can be immersed in a temperature-controlled fluid bath to eliminate any heating effect created in the specimen due to dissipative processes during cyclic loading (cyclic stress induced the formation of martensite) Wagner et al. ( Mater. Sci. Eng. A, 378, p 105-109, 1). This study will compare the results of the same starting material tested with each system to determine if the test system differences affect the final results. The advantages and disadvantages of each system will be highlighted and compared. The factors compared will include ease of setup, operator skill level required, consistency of strain measurement, equipment test limits, and data recovery and analysis. Also, the effect of test speed on the test results for each system will be investigated.

Hall mobility in multicrystalline silicon

NASA Astrophysics Data System (ADS)

Schindler, F.; Geilker, J.; Kwapil, W.; Warta, W.; Schubert, M. C.

2011-08-01

Knowledge of the carrier mobility in silicon is of utmost importance for photovoltaic applications, as it directly influences the diffusion length and thereby the cell efficiency. Moreover, its value is needed for a correct quantitative evaluation of a variety of lifetime measurements. However, models that describe the carrier mobility in silicon are based on theoretical calculations or fits to experimental data in monocrystalline silicon. Multicrystalline (mc) silicon features crystal defects such as dislocations and grain boundaries, with the latter possibly leading to potential barriers through the trapping of charge carriers and thereby influencing the mobility, as shown, for example, by Maruska et al. [Appl. Phys. Lett. 36, 381 (1980)]. To quantify the mobilities in multicrystalline silicon, we performed Hall measurements in p-type mc-Si samples of various resistivities and different crystal structures and compared the data to majority carrier Hall mobilities in p-type monocrystalline floatzone (FZ) silicon. For lack of a model that provides reliable values of the Hall mobility in silicon, an empirical fit similar to existing models for conductivity mobilities is proposed based on Hall measurements of monocrystalline p-type FZ silicon. By comparing the measured Hall mobilities obtained from mc silicon with the corresponding Hall mobilities in monocrystalline silicon of the same resistivity, we found that the mobility reduction due to the presence of crystal defects in mc-Si ranges between 0% and 5% only. Mobility decreases of up to 30% as reported by Peter et al. [Proceedings of the 23rd European Photovoltaic Solar Energy Conference, Valencia, Spain, 1-5 September 2008], or even of a factor of 2 to 3 as detected by Palais et al. [Mater. Sci. Eng. B 102, 184 (2003)], in multicrystalline silicon were not observed.

A non-additive repulsive contribution in an equation of state: The development for homonuclear square well chains equation of state validated against Monte Carlo simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trinh, Thi-Kim-Hoang; Laboratoire de Science des Procédés et des Matériaux; Passarello, Jean-Philippe, E-mail: Jean-Philippe.Passarello@lspm.cnrs.fr

This work consists of the adaptation of a non-additive hard sphere theory inspired by Malakhov and Volkov [Polym. Sci., Ser. A 49(6), 745–756 (2007)] to a square-well chain. Using the thermodynamic perturbation theory, an additional term is proposed that describes the effect of perturbing the chain of square well spheres by a non-additive parameter. In order to validate this development, NPT Monte Carlo simulations of thermodynamic and structural properties of the non-additive square well for a pure chain and a binary mixture of chains are performed. Good agreements are observed between the compressibility factors originating from the theory and thosemore » from molecular simulations.« less

Health behavior in persons with spinal cord injury: development and initial validation of an outcome measure.

PubMed

Pruitt, S D; Wahlgren, D R; Epping-Jordan, J E; Rossi, A L

1998-10-01

To describe the development and initial psychometric properties of a new outcome measure for health behaviors that delay or prevent secondary impairments associated with spinal cord injury (SCI). Persons with SCI were surveyed during routine annual physical evaluations. Veterans Affairs Medical Center Spinal Cord Injury Unit, which specializes in primary care for persons with SCI. Forty-nine persons with SCI, aged 19-73 years, 1-50 years post-SCI. The newly developed Spinal Cord Injury Lifestyle Scale (SCILS). Internal consistency is high (alpha = 0.81). Correlations between clinicians' ratings of participants' health behavior and the new SCILS provide preliminary support for construct validity. The SCILS is a brief, self-report measure of health-related behavior in persons with SCI. It is a promising new outcome measure to evaluate the effectiveness of clinical and educational efforts for health maintenance and prevention of secondary impairments associated with SCI.

Clinical interpretation of the Spinal Cord Injury Functional Index (SCI-FI).

PubMed

Fyffe, Denise; Kalpakjian, Claire Z; Slavin, Mary; Kisala, Pamela; Ni, Pengsheng; Kirshblum, Steven C; Tulsky, David S; Jette, Alan M

2016-09-01

To provide validation of functional ability levels for the Spinal Cord Injury - Functional Index (SCI-FI). Cross-sectional. Inpatient rehabilitation hospital and community settings. A sample of 855 individuals with traumatic spinal cord injury enrolled in 6 rehabilitation centers participating in the National Spinal Cord Injury Model Systems Network. Not Applicable. Spinal Cord Injury-Functional Index (SCI-FI). Cluster analyses identified three distinct groups that represent low, mid-range and high SCI-FI functional ability levels. Comparison of clusters on personal and other injury characteristics suggested some significant differences between groups. These results strongly support the use of SCI-FI functional ability levels to document the perceived functional abilities of persons with SCI. Results of the cluster analysis suggest that the SCI-FI functional ability levels capture function by injury characteristics. Clinical implications regarding tracking functional activity trajectories during follow-up visits are discussed.

Measurement of Bone: Diagnosis of SCI-Induced Osteoporosis and Fracture Risk Prediction

PubMed Central

Morse, Leslie R.

2015-01-01

Background: Spinal cord injury (SCI) is associated with a rapid loss of bone mass, resulting in severe osteoporosis and a 5- to 23-fold increase in fracture risk. Despite the seriousness of fractures in SCI, there are multiple barriers to osteoporosis diagnosis and wide variations in treatment practices for SCI-induced osteoporosis. Methods: We review the biological and structural changes that are known to occur in bone after SCI in the context of promoting future research to prevent or reduce risk of fracture in this population. We also review the most commonly used methods for assessing bone after SCI and discuss the strengths, limitations, and clinical applications of each method. Conclusions: Although dual-energy x-ray absorptiometry assessments of bone mineral density may be used clinically to detect changes in bone after SCI, 3-dimensional methods such as quantitative CT analysis are recommended for research applications and are explained in detail. PMID:26689691

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: screening and diagnosis recommendations.

PubMed

Mehta, S; Guy, S D; Bryce, T N; Craven, B C; Finnerup, N B; Hitzig, S L; Orenczuk, S; Siddall, P J; Widerström-Noga, E; Casalino, A; Côté, I; Harvey, D; Kras-Dupuis, A; Lau, B; Middleton, J W; Moulin, D E; O'Connell, C; Parrent, A G; Potter, P; Short, C; Teasell, R; Townson, A; Truchon, C; Wolfe, D; Bradbury, C L; Loh, E

2016-08-01

Clinical practice guidelines. To develop the first Canadian clinical practice guidelines for screening and diagnosis of neuropathic pain in people with spinal cord injury (SCI). The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. The CanPainSCI Working Group reviewed evidence to address clinical questions regarding screening and diagnosis of neuropathic pain after SCI. A consensus process was followed to achieve agreement on recommendations and clinical considerations. Twelve recommendations, based on expert consensus, were developed for the screening and diagnosis of neuropathic pain after SCI. The recommendations address methods for assessment, documentation tools, team member accountability, frequency of screening and considerations for diagnostic investigation. Important clinical considerations accompany each recommendation. The expert Working Group developed recommendations for the screening and diagnosis of neuropathic pain after SCI that should be used to inform practice.

Measurement of Bone: Diagnosis of SCI-Induced Osteoporosis and Fracture Risk Prediction.

PubMed

Troy, Karen L; Morse, Leslie R

2015-01-01

Spinal cord injury (SCI) is associated with a rapid loss of bone mass, resulting in severe osteoporosis and a 5- to 23-fold increase in fracture risk. Despite the seriousness of fractures in SCI, there are multiple barriers to osteoporosis diagnosis and wide variations in treatment practices for SCI-induced osteoporosis. We review the biological and structural changes that are known to occur in bone after SCI in the context of promoting future research to prevent or reduce risk of fracture in this population. We also review the most commonly used methods for assessing bone after SCI and discuss the strengths, limitations, and clinical applications of each method. Although dual-energy x-ray absorptiometry assessments of bone mineral density may be used clinically to detect changes in bone after SCI, 3-dimensional methods such as quantitative CT analysis are recommended for research applications and are explained in detail.

SciLinks

Science.gov Websites

SciLinks Forgot your login? Sign up for FREE access Log In I'm a ... Teacher Student User Name questions and satisfy their curiosity Learn More Sign up for Free Access Sites in the SciLinks program . SciLinks-Targeted, Grade-Specific Web Content for your Books Free web content to extend and expand student

DoD-Wide Intelligence Career Development Program. General Intelligence Personnel

DTIC Science & Technology

1988-07-01

Science ASTRONMY /SPACE SCI Ballistics BALLISTCS Cartography CARTOGRY Cartographic Technician CARTOGR TECH Chemistry/Biochemistry CHEMSTRY/BIOCHEMSTRY...ARCHVST ....................... 4-63 E&E ............................ 4-60 ASTRONMY /SPACE SCI ........... 4-69 ECONMCS ....................... 4-75 AUTO...SPACE SCI-see ASTRONMY / OB-NAV ......................... 4-54 SPACE SCI OCEANOGY ..................... 4-70 SPACE SYS-ENGR ................ 4-48 OFC

The Structured Clinical Interview for DSM-5 Internet Gaming Disorder: Development and Validation for Diagnosing IGD in Adolescents

PubMed Central

Koo, Hoon Jung; Han, Doug Hyun; Park, Sung-Yong

2017-01-01

Objective This study aimed to develop and validate a Structured Clinical Interview for Internet Gaming Disorder (SCI-IGD) in adolescents. Methods First, we generated preliminary items of the SCI-IGD based on the information from the DSM-5 literature reviews and expert consultations. Next, a total of 236 adolescents, from both community and clinical settings, were recruited to evaluate the psychometric properties of the SCI-IGD. Results First, the SCI-IGD was found to be consistent over the time period of about one month. Second, diagnostic concordances between the SCI-IGD and clinician's diagnostic impression were good to excellent. The Likelihood Ratio Positive and the Likelihood Ratio Negative estimates for the diagnosis of SCI-IGD were 10.93 and 0.35, respectively, indicating that SCI-IGD was ‘very useful test’ for identifying the presence of IGD and ‘useful test’ for identifying the absence of IGD. Third, SCI-IGD could identify disordered gamers from non-disordered gamers. Conclusion The implications and limitations of the study are also discussed. PMID:28096871

Physical Activity Inventory for Patients with Spinal Cord Injury

PubMed Central

Butler, Jolene A.; Miller, Terrya; O’Connell, Susan; Jelinek, Christine; Collins, Eileen G.

2010-01-01

Objectives To test the reliability and validity of a physical activity instrument adapted for individuals with spinal cord injuries (SCI), the Physical Activity Instrument-SCI (PAI-SCI). Methods Eligible participants completed the adapted PAI-SCI questionnaire at baseline and 1 week later. At baseline, they were also given an Actical accelerometer to wear on their wrist for 1 week. Results Forty-three male subjects completed the study. There was a moderate relationship between total score on the PAI-SCI and total activity count determined by accelerometry (r = 0.42, P = 0.036). The PAI-SCI was able to differentiate between people with upper and lower level injuries (P = 0.05). Test-retest reliability was supported for the exercise and the general activity/self care subscales and not supported for the light household or the outdoor/gardening subscales. Conclusion The PAI-SCI was able to distinguish between physical activity amongst those with upper level and lower level injuries. More research is needed before the PAI-SCI can be recommended for use in clinical trials. PMID:25190905

The Correlation of Gene Expression of Inflammasome Indicators and Impaired Fertility in Rat Model of Spinal Cord Injury: A Time Course Study.

PubMed

Nikmehr, Banafsheh; Bazrafkan, Mahshid; Hassanzadeh, Gholamreza; Shahverdi, Abdolhossein; Sadighi Gilani, Mohammad Ali; Kiani, Sahar; Mokhtari, Tahmineh; Abolhassani, Farid

2017-11-04

Expression assessment of the inflammasome genes in the acute and the chronic phases of Spinal cord injury (SCI) on adult rat testis and examination of associations between inflammasome complex expression and sperm parameters. In this study, 25 adult male rats were randomly divided into 5 groups. SCI surgery was performed at T10-T11 level of rats' spinal cord in four groups (SCI1, SCI3, SCI7, and SCI56). They were sacrificed after 1day, 3days, 7days and 56 days post SCI, respectively. One group remained intact as control (Co).CASA analysis of sperm parameters and qRT-PCR (ASC and Caspase-1) were made in all cases. Our data showed a severe reduction in sperm count and motility, especially on day 3 and 7. ASC gene expression had a non-significant increase on day 1 and 56 after surgery compared to control group. Caspase-1 expression increased significantly on day 3 post injury versus the control group (P = .009). Moreover, Caspase-1 overexpression, had significant correlations with sperm count (r = -0.555, P = .01) and sperm progressive motility (r = -0.524, P = .02). Inflammasome complex expression increase following SCI induction. This overexpression correlates to low sperm parameters in SCI rats.

Walking in water and on land after an incomplete spinal cord injury.

PubMed

Tamburella, Federica; Scivoletto, Giorgio; Cosentino, Elena; Molinari, Marco

2013-10-01

Although no data are available on the effects of water environment on the gait of subjects with spinal cord injury (SCI), hydrotherapy is used in the rehabilitation protocols of SCI patients. The aim of this study was to characterize gait features of subjects with incomplete SCI walking in water and on land in comparison with healthy controls (CTRLs) to identify the specificity of water environment on influencing gait in SCI subjects. This is a matched case-control study. Kinematic gait parameters and range of motion of joint angles of 15 SCI subjects and 15 CTRLs were analyzed. Compared with gait on land, gait in water of the SCI patients was characterized by speed and stance phase reduction, gait cycle time increment, and invariance of stride length and range of motion values. Comparison with CTRL data remarked that walking in water reduces gait differences between the groups. Furthermore, in water, the SCI subjects presented a reduction in variability of the hip and knee joint angles, whereas in the CTRLs, a larger variability was observed. Gait in water of the SCI subjects is associated with kinematic parameters more similar to those of the CTRLs, particularly regarding speed, stride length, and stance phase, supporting the idea that walking in a water environment may be of rehabilitative significance for SCI subjects.

SCY-635, a Novel Nonimmunosuppressive Analog of Cyclosporine That Exhibits Potent Inhibition of Hepatitis C Virus RNA Replication In Vitro ▿ †

PubMed Central

Hopkins, Sam; Scorneaux, Bernard; Huang, Zhuhui; Murray, Michael G.; Wring, Stephen; Smitley, Craig; Harris, Richard; Erdmann, Frank; Fischer, Gunter; Ribeill, Yves

2010-01-01

SCY-635 is a novel nonimmunosuppressive cyclosporine-based analog that exhibits potent suppression of hepatitis C virus (HCV) replication in vitro. SCY-635 inhibited the peptidyl prolyl isomerase activity of cyclophilin A at nanomolar concentrations but showed no detectable inhibition of calcineurin phosphatase activity at concentrations up to 2 μM. Metabolic studies indicated that SCY-635 did not induce the major cytochrome P450 enzymes 1A2, 2B6, and 3A4. SCY-635 was a weak inhibitor and a poor substrate for P-glycoprotein. Functional assays with stimulated Jurkat cells and stimulated human peripheral blood mononuclear cells indicated that SCY-635 is a weaker inhibitor of interleukin-2 secretion than cyclosporine. A series of two-drug combination studies was performed in vitro. SCY-635 exhibited synergistic antiviral activity with alpha interferon 2b and additive antiviral activity with ribavirin. SCY-635 was shown to be orally bioavailable in multiple animal species and produced blood and liver concentrations of parent drug that exceeded the 50% effective dose determined in the bicistronic con1b-derived replicon assay. These results suggest that SCY-635 warrants further investigation as a novel therapeutic agent for the treatment of individuals who are chronically infected with HCV. PMID:19933795

The Cross-Cultural Societal Response to SCI: Health and Related Systems.

PubMed

Pacheco, Diana; Gross-Hemmi, Mirja H

2017-02-01

The Learning Health System for Spinal Cord Injury (LHS-SCI) is an initiative aligned with the World Health Organization's (WHO) Global Disability Action Plan. Based on the outcomes of this initiative, countries will be able to shape their health systems to better respond to the needs of persons with SCI. This paper describes and compares the macroeconomic situation and societal response to SCI across 27 countries from all 6 WHO regions that will participate in the LHS-SCI initiative. A concurrent mixed-methods study was conducted to identify key indicators that describe the situation of persons with SCI, the general societal response, the health and rehabilitation system, and the experience for a SCI person after discharge from inpatient rehabilitation. A strong correlation was found between the efficiency of a healthcare system and the amount a country invests in health. Higher availability of resources does not necessarily imply that unrestricted access to the healthcare system is warranted. Variations in the health systems were found for various domains of the health and rehabilitation systems. The evaluation and comparative analysis of the societal response to SCI raise the awareness of the need of more standardized data to identify current needs and gaps in the quality and access to SCI-specific health system.

Evaluation of selective control information detection scheme in orthogonal frequency division multiplexing-based radio-over-fiber and visible light communication links

NASA Astrophysics Data System (ADS)

Dalarmelina, Carlos A.; Adegbite, Saheed A.; Pereira, Esequiel da V.; Nunes, Reginaldo B.; Rocha, Helder R. O.; Segatto, Marcelo E. V.; Silva, Jair A. L.

2017-05-01

Block-level detection is required to decode what may be classified as selective control information (SCI) such as control format indicator in 4G-long-term evolution systems. Using optical orthogonal frequency division multiplexing over radio-over-fiber (RoF) links, we report the experimental evaluation of an SCI detection scheme based on a time-domain correlation (TDC) technique in comparison with the conventional maximum likelihood (ML) approach. When compared with the ML method, it is shown that the TDC method improves detection performance over both 20 and 40 km of standard single mode fiber (SSMF) links. We also report a performance analysis of the TDC scheme in noisy visible light communication channel models after propagation through 40 km of SSMF. Experimental and simulation results confirm that the TDC method is attractive for practical orthogonal frequency division multiplexing-based RoF and fiber-wireless systems. Unlike the ML method, another key benefit of the TDC is that it requires no channel estimation.

Heavy-Duty Stoichiometric Compression Ignition Engine with Improved Fuel Economy over Alternative Technologies for Meeting 2010 On-Highway Emission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirby J. Baumgard; Richard E. Winsor

2009-12-31

The objectives of the reported work were: to apply the stoichiometric compression ignition (SCI) concept to a 9.0 liter diesel engine; to obtain engine-out NO{sub x} and PM exhaust emissions so that the engine can meet 2010 on-highway emission standards by applying a three-way catalyst for NO{sub x} control and a particulate filter for PM control; and to simulate an optimize the engine and air system to approach 50% thermal efficiency using variable valve actuation and electric turbo compounding. The work demonstrated that an advanced diesel engine can be operated at stoichiometric conditions with reasonable particulate and NOx emissions atmore » full power and peak torque conditions; calculated that the SCI engine will operate at 42% brake thermal efficiency without advanced hardware, turbocompounding, or waste heat recovery; and determined that EGR is not necessary for this advanced concept engine, and this greatly simplifies the concept.« less

Effect of oxidative stress induced by intracranial iron overload on central pain after spinal cord injury.

PubMed

Meng, Fan Xing; Hou, Jing Ming; Sun, Tian Sheng

2017-02-08

Central pain (CP) is a common clinical problem in patients with spinal cord injury (SCI). Recent studies found the pathogenesis of CP was related to the remodeling of the brain. We investigate the roles of iron overload and subsequent oxidative stress in the remodeling of the brain after SCI. We established a rat model of central pain after SCI. Rats were divided randomly into four groups: SCI, sham operation, SCI plus deferoxamine (DFX) intervention, and SCI plus nitric oxide synthase (NOS) inhibitor treatment. Pain behavior was observed and thermal pain threshold was measured regularly, and brain levels of iron, transferrin receptor 1 (TfR1), ferritin (Fn), and lactoferrin (Lf), were detected in the different groups 12 weeks after establishment of the model. Rats demonstrated self-biting behavior after SCI. Furthermore, the latent period of thermal pain was reduced and iron levels in the hind limb sensory area, hippocampus, and thalamus increased after SCI. Iron-regulatory protein (IRP) 1 levels increased in the hind limb sensory area, while Fn levels decreased. TfR1 mRNA levels were also increased and oxidative stress was activated. Oxidative stress could be inhibited by ferric iron chelators and NOS inhibitors. SCI may cause intracranial iron overload through the NOS-iron-responsive element/IRP pathway, resulting in central pain mediated by the oxidative stress response. Iron chelators and oxidative stress inhibitors can effectively relieve SCI-associated central pain.

Spinal Cord Injury and Migraine Headache: A Population-Based Study

PubMed Central

Warner, Freda M.; Cragg, Jacquelyn J.; Weisskopf, Marc G.; Kramer, John K.

2015-01-01

Migraine headaches are a common neurological condition, negatively impacting health and quality of life. Among potential risk factors for migraine headache, risk of migraine headaches was elevated in individuals with spinal cord injury (SCI). The association between migraines and SCI is intriguing to consider from the perspective that migraine headaches may be acquired in response to damage in the spinal cord. The primary objective of this study was to further examine the association between SCI and migraine headache, controlling for potential confounding variables. A secondary objective was to determine the impact of migraine headaches on self-perceived health. Data from a sample of 61,047 participants were obtained from the cross-sectional Canadian Community Health Survey. Multivariable logistic regression was used to explore the association between SCI and migraine headache using probability weights and adjusting for confounders. The multivariable age- and sex-adjusted model revealed a strong association between SCI and migraine headache, with an adjusted odds ratio for migraine of 4.82 (95% confidence interval [3.02, 7.67]) among those with SCI compared to those without SCI. Further, individuals who experienced both SCI and migraine tended to report poorer perceived general health compared with the other groups (i.e., SCI and no migraine). In conclusion, this study established a strong association between SCI and migraine headache. Further research is needed to explore the possible mechanisms underlying this relationship. Improvements in clinical practice to minimize this issue could result in significant improvements in quality of life. PMID:26308549

Comparison of in vitro fertilization/intracytoplasmic sperm injection outcomes in male factor infertility patients with and without spinal cord injuries.

PubMed

Kathiresan, Anupama S Q; Ibrahim, Emad; Aballa, Teodoro C; Attia, George R; Ory, Steven J; Hoffman, David I; Maxson, Wayne S; Barrionuevo, Marcelo J; Lynne, Charles M; Brackett, Nancy L

2011-09-01

To determine if outcomes after in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) using sperm from men with spinal cord injury (SCI group) differ from those of other etiologies of male factor infertility (non-SCI group). In men with SCI, to determine if IVF/ICSI outcomes differ with sperm obtained by penile vibratory stimulation (PVS group) versus electroejaculation (EEJ group). Retrospective analysis. University medical center and major infertility center. Couples with male factor infertility due to SCI versus other etiologies. PVS, EEJ, surgical sperm retrieval, and IVF/ICSI. Rates of fertilization, pregnancy, and live birth. A total of 31 couples in the SCI group underwent 48 cycles of IVF/ICSI, and a total of 297 couples in the non-SCI group underwent 443 cycles of IVF/ICSI. The SCI group had lower fertilization rates but similar pregnancy and live birth rates compared with the non-SCI group. These rates, however, did not differ significantly when the PVS group was compared with the EEJ group. IVF/ICSI of sperm from men with SCI yield lower fertilization rates but similar pregnancy and live birth outcomes as IVF/ICSI of sperm from men with other etiologies of male factor infertility. Sperm collected by PVS versus EEJ in men with SCI appear to result in similar IVF/ICSI success rates. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Cognitive performance of people with traumatic spinal cord injury: a cross-sectional study comparing people with subacute and chronic injuries.

PubMed

Molina, B; Segura, A; Serrano, J P; Alonso, F J; Molina, L; Pérez-Borrego, Y A; Ugarte, M I; Oliviero, A

2018-02-22

Cross-sectional study. To assess the impact of spinal cord injury (SCI) on cognitive function in individuals with subacute and chronic SCI. National Hospital for SCI patients (Spain). The present investigation was designed to determine the nature, pattern, and extent of cognitive deficits in a group of participants with subacute (n = 32) and chronic (n = 34) SCI, using a comprehensive battery of reliable and validated neuropsychological assessments to study a broad range of cognitive functions. Twenty-seven able-bodied subjects matched to the groups with SCI for age and educational level formed the control group. The neuropsychological assessment showed alterations in the domain of attention, processing speed, memory and learning, executive functions, and in recognition in participants with SCI. The prevalence of cognitive dysfunction in the chronic stage was also confirmed at the individual level. The comparison of the neuropsychological assessment between the groups with subacute and chronic SCI showed a worsening of cognitive functions in those with chronic SCI compared to the group with subacute SCI. In participants with SCI, cognitive dysfunctions are present in the subacute stage and worsen over time. From a clinical point of view, we confirmed the presence of cognitive dysfunction that may interfere with the first stage of rehabilitation which is the most intense and important. Moreover, cognitive dysfunction may be important beyond the end of the first stage of rehabilitation as it can affect an individual's quality of life and possible integration to society.

Correlated lateral phase separations in stacks of lipid membranes

NASA Astrophysics Data System (ADS)

Hoshino, Takuma; Komura, Shigeyuki; Andelman, David

2015-12-01

Motivated by the experimental study of Tayebi et al. [Nat. Mater. 11, 1074 (2012)] on phase separation of stacked multi-component lipid bilayers, we propose a model composed of stacked two-dimensional Ising spins. We study both its static and dynamical features using Monte Carlo simulations with Kawasaki spin exchange dynamics that conserves the order parameter. We show that at thermodynamical equilibrium, due to strong inter-layer correlations, the system forms a continuous columnar structure for any finite interaction across adjacent layers. Furthermore, the phase separation shows a faster dynamics as the inter-layer interaction is increased. This temporal behavior is mainly due to an effective deeper temperature quench because of the larger value of the critical temperature, Tc, for larger inter-layer interaction. When the temperature ratio, T/Tc, is kept fixed, the temporal growth exponent does not increase and even slightly decreases as a function of the increased inter-layer interaction.

Natural Killer (NK) Cell Functionality after human Spinal Cord Injury (SCI): protocol of a prospective, longitudinal study.

PubMed

Laginha, Inês; Kopp, Marcel A; Druschel, Claudia; Schaser, Klaus-Dieter; Brommer, Benedikt; Hellmann, Rick C; Watzlawick, Ralf; Ossami-Saidi, Ramin-Raul; Prüss, Harald; Failli, Vieri; Meisel, Christian; Liebscher, Thomas; Prilipp, Erik; Niedeggen, Andreas; Ekkernkamp, Axel; Grittner, Ulrike; Piper, Sophie K; Dirnagl, Ulrich; Killig, Monica; Romagnani, Chiara; Schwab, Jan M

2016-09-13

Natural killer (NK) cells comprise the main components of lymphocyte-mediated nonspecific immunity. Through their effector function they play a crucial role combating bacterial and viral challenges. They are also thought to be key contributors to the systemic spinal cord injury-induced immune-deficiency syndrome (SCI-IDS). SCI-IDS increases susceptibility to infection and extends to the post-acute and chronic phases after SCI. The prospective study of NK cell function after traumatic SCI was carried out in two centers in Berlin, Germany. SCI patients and control patients with neurologically silent vertebral fracture also undergoing surgical stabilization were enrolled. Furthermore healthy controls were included to provide reference data. The NK cell function was assessed at 7 (5-9) days, 14 days (11-28) days, and 10 (8-12) weeks post-trauma. Clinical documentation included the American Spinal Injury Association (ASIA) impairment scale (AIS), neurological level of injury, infection status, concomitant injury, and medications. The primary endpoint of the study is CD107a expression by NK cells (cytotoxicity marker) 8-12 weeks following SCI. Secondary endpoints are the NK cell's TNF-α and IFN-γ production by the NK cells 8-12 weeks following SCI. The protocol of this study was developed to investigate the hypotheses whether i) SCI impairs NK cell function throughout the post-acute and sub-acute phases after SCI and ii) the degree of impairment relates to lesion height and severity. A deeper understanding of the SCI-IDS is crucial to enable strategies for prevention of infections, which are associated with poor neurological outcome and elevated mortality. DRKS00009855 .

Measuring depression after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Depression item bank and linkage with PHQ-9.

PubMed

Tulsky, David S; Kisala, Pamela A; Kalpakjian, Claire Z; Bombardier, Charles H; Pohlig, Ryan T; Heinemann, Allen W; Carle, Adam; Choi, Seung W

2015-05-01

To develop a calibrated spinal cord injury-quality of life (SCI-QOL) item bank, computer adaptive test (CAT), and short form to assess depressive symptoms experienced by individuals with SCI, transform scores to the Patient Reported Outcomes Measurement Information System (PROMIS) metric, and create a crosswalk to the Patient Health Questionnaire (PHQ)-9. We used grounded-theory based qualitative item development methods, large-scale item calibration field testing, confirmatory factor analysis, item response theory (IRT) analyses, and statistical linking techniques to transform scores to a PROMIS metric and to provide a crosswalk with the PHQ-9. Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. Spinal Cord Injury--Quality of Life (SCI-QOL) Depression Item Bank Individuals with SCI were involved in all phases of SCI-QOL development. A sample of 716 individuals with traumatic SCI completed 35 items assessing depression, 18 of which were PROMIS items. After removing 7 non-PROMIS items, factor analyses confirmed a unidimensional pool of items. We used a graded response IRT model to estimate slopes and thresholds for the 28 retained items. The SCI-QOL Depression measure correlated 0.76 with the PHQ-9. The SCI-QOL Depression item bank provides a reliable and sensitive measure of depressive symptoms with scores reported in terms of general population norms. We provide a crosswalk to the PHQ-9 to facilitate comparisons between measures. The item bank may be administered as a CAT or as a short form and is suitable for research and clinical applications.

B-Cell Maturation Antigen, A Proliferation-Inducing Ligand, and B-Cell Activating Factor Are Candidate Mediators of Spinal Cord Injury-Induced Autoimmunity

PubMed Central

Saltzman, Jonah W.; Battaglino, Ricardo A.; Salles, Loise; Jha, Prateek; Sudhakar, Supreetha; Garshick, Eric; Stott, Helen L.; Zafonte, Ross

2013-01-01

Abstract Autoimmunity is thought to contribute to poor neurological outcomes after spinal cord injury (SCI). There are few mechanism-based therapies, however, designed to reduce tissue damage and neurotoxicity after SCI because the molecular and cellular bases for SCI-induced autoimmunity are not completely understood. Recent groundbreaking studies in rodents indicate that B cells are responsible for SCI-induced autoimmunity. This novel paradigm, if confirmed in humans, could aid in the design of neuroprotective immunotherapies. The aim of this study was to investigate the molecular signaling pathways and mechanisms by which autoimmunity is induced after SCI, with the goal of identifying potential targets in therapies designed to reduce tissue damage and inflammation in the chronic phase of SCI. To that end, we performed an exploratory microarray analysis of peripheral blood mononuclear cells to identify differentially expressed genes in chronic SCI. We identified a gene network associated with lymphoid tissue structure and development that was composed of 29 distinct molecules and five protein complexes, including two cytokines, a proliferation-inducing ligand (APRIL) and B-cell–activating factor (BAFF), and one receptor, B-cell maturation antigen (BMCA) involved in B cell development, proliferation, activation, and survival. Real-time polymerase chain reaction analysis from ribonucleic acid samples confirmed upregulation of these three genes in SCI. To our knowledge, this is the first report that peripheral blood mononuclear cells produce increased levels of BAFF and APRIL in chronic SCI. This finding provides evidence of systemic regulation of SCI-autoimmunity via APRIL and BAFF mediated activation of B cells through BMCA and points toward these molecules as potential targets of therapies designed to reduce neuroinflammation after SCI. PMID:23088438

Characterization of the Antibody Response after Cervical Spinal Cord Injury

PubMed Central

Ulndreaj, Antigona; Tzekou, Apostolia; Mothe, Andrea J.; Siddiqui, Ahad M.; Dragas, Rachel; Tator, Charles H.; Torlakovic, Emina E.

2017-01-01

Abstract The immune system plays a critical and complex role in the pathobiology of spinal cord injury (SCI), exerting both beneficial and detrimental effects. Increasing evidence suggests that there are injury level–dependent differences in the immune response to SCI. Patients with traumatic SCI have elevated levels of circulating autoantibodies against components of the central nervous system, but the role of these antibodies in SCI outcomes remains unknown. In rodent models of mid-thoracic SCI, antibody-mediated autoimmunity appears to be detrimental to recovery. However, whether autoantibodies against the spinal cord are generated following cervical SCI (cSCI), the most common level of injury in humans, remains undetermined. To address this knowledge gap, we investigated the antibody responses following cSCI in a rat model of injury. We found increased immunoglobulin G (IgG) and IgM antibodies in the spinal cord in the subacute phase of injury (2 weeks), but not in more chronic phases (10 and 20 weeks). At 2 weeks post-cSCI, antibodies were detected at the injury epicenter and co-localized with the astroglial scar and neurons of the ventral horn. These increased levels of antibodies corresponded with enhanced activation of immune responses in the spleen. Higher counts of antibody-secreting cells were observed in the spleen of injured rats. Further, increased levels of secreted IgG antibodies and enhanced proliferation of T-cells in splenocyte cultures from injured rats were found. These findings suggest the potential development of autoantibody responses following cSCI in the rat. The impact of the post-traumatic antibody responses on functional outcomes of cSCI is a critical topic that requires further investigation. PMID:27775474

Exercise modulates chloride homeostasis after spinal cord injury.

PubMed

Côté, Marie-Pascale; Gandhi, Sapan; Zambrotta, Marina; Houlé, John D

2014-07-02

Activity-based therapies are routinely integrated in spinal cord injury (SCI) rehabilitation programs because they result in a reduction of hyperreflexia and spasticity. However, the mechanisms by which exercise regulates activity in spinal pathways to reduce spasticity and improve functional recovery are poorly understood. Persisting alterations in the action of GABA on postsynaptic targets is a signature of CNS injuries, including SCI. The action of GABA depends on the intracellular chloride concentration, which is determined largely by the expression of two cation-chloride cotransporters (CCCs), KCC2 and NKCC1, which serve as chloride exporters and importers, respectively. We hypothesized that the reduction in hyperreflexia with exercise after SCI relies on a return to chloride homeostasis. Sprague Dawley rats received a spinal cord transection at T12 and were assigned to SCI-7d, SCI-14d, SCI-14d+exercise, SCI-28d, SCI-28d+exercise, or SCI-56d groups. During a terminal experiment, H-reflexes were recorded from interosseus muscles after stimulation of the tibial nerve and the low-frequency-dependent depression (FDD) was assessed. We provide evidence that exercise returns spinal excitability and levels of KCC2 and NKCC1 toward normal levels in the lumbar spinal cord. Acutely altering chloride extrusion using the KCC2 blocker DIOA masked the effect of exercise on FDD, whereas blocking NKCC1 with bumetanide returned FDD toward intact levels after SCI. Our results indicate that exercise contributes to reflex recovery and restoration of endogenous inhibition through a return to chloride homeostasis after SCI. This lends support for CCCs as part of a pathway that could be manipulated to improve functional recovery when combined with rehabilitation programs. Copyright © 2014 the authors 0270-6474/14/348976-12$15.00/0.

(-)-Epigallocatechin-3-gallate (EGCG) modulates neurological function when intravenously infused in acute and, chronically injured spinal cord of adult rats.

PubMed

Renno, Waleed M; Al-Khaledi, Ghanim; Mousa, Alyaa; Karam, Shaima M; Abul, Habib; Asfar, Sami

2014-02-01

Spinal cord injury (SCI) causes severe and long lasting motor and sensory deficits, chronic pain, and autonomic dysreflexia. (-)-epigallocatechin-3-gallate (EGCG) has shown to produce neuroprotective effect in a broad range of neurodegenerative disease animal models. This study designed to test the efficacy of intravenous infusion of EGCG for 36 h, in acutely injured rats' spinal cord: within first 4 h post-injury and, in chronically SC injured rats: after one year of injury. Functional outcomes measured using standard BBB scale, The Louisville Swim Scale (LSS) and, pain behavior assessment tests. 72 Female adult rats subjected to moderate thoracic SCI using MASCIS Impactor, blindly randomized as the following: (I) Acute SCI + EGCG (II) Acute SCI + saline. (III) Chronic SCI + EGCG. (IV) Chronic SCI + saline and, sham SCI animals. EGCG i.v. treatment of acute and, chronic SCI animals resulted in significantly better recovery of motor and sensory functions, BBB and LSS (P < 0.005) and (P < 0.05) respectively. Tactile allodynia, mechanical nociception (P < 0.05) significantly improved. Paw withdrawal and, tail flick latencies increase significantly (P < 0.05). Moreover, in the EGCG treated acute SCI animals the percentage of lesion size area significantly reduced (P < 0.0001) and, the number of neurons in the spinal cord increased (P < 0.001). Percent areas of GAP-43 and GFAP immunohistochemistry showed significant (P < 0.05) increase. We conclude that the therapeutic window of opportunity for EGCG to depict neurological recovery in SCI animals, is viable up to one year post SCI when intravenously infused for 36 h. Copyright © 2013 Elsevier Ltd. All rights reserved.

Health Care Costs for Patients With Chronic Spinal Cord Injury in the Veterans Health Administration

PubMed Central

French, Dustin D; Campbell, Robert R; Sabharwal, Sunil; Nelson, Audrey L; Palacios, Polly A; Gavin-Dreschnack, Deborah

2007-01-01

Background/Objective: Recurring annual costs of caring for patients with chronic spinal cord injury (SCI) is a large economic burden on health care systems, but information on costs of SCI care beyond the acute and initial postacute phase is sparse. The objective of this study was to establish a frame of reference and estimate of the annual direct medical costs associated with health care for a sample of patients with chronic SCI (ie, >2 years after injury). Methods: Patients were recruited from 3 Veterans Health Administration (VHA) SCI facilities; baseline patient information was cross-referenced to the Decision Support System (DSS) National Data Extracts (NDE) to obtain patient-specific health care costs in VHA. Descriptive statistical analysis of annual DSS-NDE cost of patients with SCI (N = 675) for fiscal year (FY) 2005 by level and completeness of injury was conducted. Results: Total (inpatient and outpatient) annual (FY 2005) direct medical costs for 675 patients with SCI exceeded $14.47 million or $21,450 per patient. Average annual total costs varied from $28,334 for cervical complete SCI to $16,792 for thoracic incomplete SCI. Two hundred thirty-three of the 675 patients with SCI who were hospitalized over the study period accounted for a total of 378 hospital discharges, costing in excess of $7.19 million. This approximated a cost of outpatient care received of $7.28 million for our entire sample. Conclusions: The comprehensive nature of health care delivery and related cost capture for people with chronic SCI in the VHA provided us the opportunity to accurately determine health care costs for this population. Future SCI postacute care cost analyses should consider case-mix adjusting patients at high risk for rehospitalization. PMID:18092564

Prognostic Factors Associated with Recovery of Ambulation and Urinary Continence in Dogs with Acute Lumbosacral Spinal Cord Injury.

PubMed

Shaw, T A; De Risio, L; Laws, E J; Rose, J H; Harcourt-Brown, T R; Granger, N

2017-05-01

Limited information is available about prognostic factors for recovery after spinal cord injury (SCI) to the L4-S3 segments. Previous research suggests that L4-S3 SCI does not have a worse prognosis than T3-L3 SCI. To elucidate prognostic factors for regaining urinary continence and ambulation in dogs with L4-S3 SCI and compare prognosis to T3-L3 SCI. A retrospective study on 61 nonambulatory dogs with L4-S3 SCI, matched to dogs with T3-L3 SCI, compared 3 weeks after onset. Prognostic factors explored using logistic regression and used for matching: nonchondrodystrophic dogs >15 kg versus dogs that were chondrodystrophic or <15 kg; compressive versus noncompressive lesions; presence versus absence of conscious pain perception (CPP); and lower vs upper motor neuron (LMN/UMN) incontinence. Fewer L4-S3 dogs regained continence compared to T3-L3 dogs (64 vs 85%, P = .0033), but no difference existed for regaining ambulation (66 vs 75%, P = .1306). In L4-S3 SCI dogs, fewer dogs regained continence with loss of CPP (P < .001), LMN incontinence (P = .004), and noncompressive lesions (P = .006). Negative prognostic factors for regaining ambulation included absent CPP (P < .001) and large nonchondrodystrophic breed (P = .022). Dogs with L4-S3 SCI have a poorer short-term prognosis than do dogs with T3-L3 SCI. Dogs with L4-S3 SCI had a poor prognosis with loss of CPP, or noncompressive lesions combined with LMN incontinence. Small-breed or chondrodystrophic dogs with retained CPP, compressive lesions, and UMN incontinence had an excellent prognosis. These findings may help guide decision-making in L4-S3 SCI. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Aquaporins in Spinal Cord Injury: The Janus Face of AQP4

PubMed Central

Nesic, Olivera; Guest, James D.; Zivadinovic, Dragoslava; Narayana, Ponnada A.; Herrera, Juan J.; Grill, Raymond J.; Mokkapati, Venkata U.L.; Gelman, Benjamin B.; Lee, Julieann

2010-01-01

Although malfunction of spinal cord water channels (aquaporins, AQP) likely contributes to severe disturbances in ion/water homeostasis after spinal cord injury (SCI), their roles are still poorly understood. Here we report and discuss the potential significance of changes in the AQP4 expression in human SCI that generates GFAP-labeled astrocytes devoid of AQP4, and GFAP-labeled astroglia that overexpress AQP4. We used a rat model of contusion SCI to study observed changes in human SCI. AQP4-negative astrocytes are likely generated during the process of SCI-induced replacement of lost astrocytes, but their origin and role in SCI remains to be investigated. We found that AQP4-overexpression is likely triggered by hypoxia. Our transcriptional profiling of injured rat cords suggests that elevated AQP4-mediated water influx accompanies increased uptake of chloride and potassium ions which represents a protective astrocytic reaction to hypoxia. However, unbalanced water intake also results in astrocytic swelling that can contribute to motor impairment, but likely only in milder injuries. In severe rat SCI, a low abundance of AQP4-overexpressing astrocytes was found during the motor recovery phase. Our results suggest that severe rat contusion SCI is a better model to analyze AQP4 functions after SCI. We found that AQP4 increases in the chronic post-injury phase are associated with the development of pain-like behavior in SCI rats, while possible mechanisms underlying pain development may involve astrocytic swelling-induced glutamate release. In contrast, the formation and size of fluid-filled cavities occurring later after SCI does not appear to be affected by the extent of increased AQP4 levels. Therefore, the effect of therapeutic interventions targeting AQP4 will depend not only on the time interval after SCI or animal models, but also on the balance between protective role of increased AQP4 in hypoxia and deleterious effects of ongoing astrocytic swelling. PMID:20109536

Low-energy extracorporeal shock wave therapy promotes vascular endothelial growth factor expression and improves locomotor recovery after spinal cord injury.

PubMed

Yamaya, Seiji; Ozawa, Hiroshi; Kanno, Haruo; Kishimoto, Koshi N; Sekiguchi, Akira; Tateda, Satoshi; Yahata, Kenichiro; Ito, Kenta; Shimokawa, Hiroaki; Itoi, Eiji

2014-12-01

Extracorporeal shock wave therapy (ESWT) is widely used for the clinical treatment of various human diseases. Recent studies have demonstrated that low-energy ESWT upregulates the expression of vascular endothelial growth factor (VEGF) and promotes angiogenesis and functional recovery in myocardial infarction and peripheral artery disease. Many previous reports suggested that VEGF produces a neuroprotective effect to reduce secondary neural tissue damage after spinal cord injury (SCI). The purpose of the present study was to investigate whether low-energy ESWT promotes VEGF expression and neuroprotection and improves locomotor recovery after SCI. Sixty adult female Sprague-Dawley rats were randomly divided into 4 groups: sham group (laminectomy only), sham-SW group (low-energy ESWT applied after laminectomy), SCI group (SCI only), and SCI-SW group (low-energy ESWT applied after SCI). Thoracic spinal cord contusion injury was inflicted using an impactor. Low-energy ESWT was applied to the injured spinal cord 3 times a week for 3 weeks. Locomotor function was evaluated using the Basso, Beattie, and Bresnahan (BBB) Scale (open field locomotor score) at different time points over 42 days after SCI. Hematoxylin and eosin staining was performed to assess neural tissue damage in the spinal cord. Neuronal loss was investigated by immunostaining for NeuN. The mRNA expressions of VEGF and its receptor, Flt-1, in the spinal cord were assessed using real-time polymerase chain reaction. Immunostaining for VEGF was performed to evaluate VEGF protein expression in the spinal cord. In both the sham and sham-SW groups, no animals showed locomotor impairment on BBB scoring. Histological analysis of H & E and NeuN stainings in the sham-SW group confirmed that no neural tissue damage was induced by the low-energy ESWT. Importantly, animals in the SCI-SW group demonstrated significantly better locomotor improvement than those in the SCI group at 7, 35, and 42 days after injury (p < 0.05). The number of NeuN-positive cells in the SCI-SW group was significantly higher than that in the SCI group at 42 days after injury (p < 0.05). In addition, mRNA expressions of VEGF and Flt-1 were significantly increased in the SCI-SW group compared with the SCI group at 7 days after injury (p < 0.05). The expression of VEGF protein in the SCI-SW group was significantly higher than that in the SCI group at 7 days (p < 0.01). The present study showed that low-energy ESWT significantly increased expressions of VEGF and Flt-1 in the spinal cord without any detrimental effect. Furthermore, it significantly reduced neuronal loss in damaged neural tissue and improved locomotor function after SCI. These results suggested that low-energy ESWT enhances the neuroprotective effect of VEGF in reducing secondary injury and leads to better locomotor recovery following SCI. This study provides the first evidence that low-energy ESWT can be a safe and promising therapeutic strategy for SCI.

Developing Models for Predictive Climate Science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drake, John B; Jones, Philip W

2007-01-01

The Community Climate System Model results from a multi-agency collaboration designed to construct cutting-edge climate science simulation models for a broad research community. Predictive climate simulations are currently being prepared for the petascale computers of the near future. Modeling capabilities are continuously being improved in order to provide better answers to critical questions about Earth's climate. Climate change and its implications are front page news in today's world. Could global warming be responsible for the July 2006 heat waves in Europe and the United States? Should more resources be devoted to preparing for an increase in the frequency of strongmore » tropical storms and hurricanes like Katrina? Will coastal cities be flooded due to a rise in sea level? The National Climatic Data Center (NCDC), which archives all weather data for the nation, reports that global surface temperatures have increased over the last century, and that the rate of increase is three times greater since 1976. Will temperatures continue to climb at this rate, will they decline again, or will the rate of increase become even steeper? To address such a flurry of questions, scientists must adopt a systematic approach and develop a predictive framework. With responsibility for advising on energy and technology strategies, the DOE is dedicated to advancing climate research in order to elucidate the causes of climate change, including the role of carbon loading from fossil fuel use. Thus, climate science--which by nature involves advanced computing technology and methods--has been the focus of a number of DOE's SciDAC research projects. Dr. John Drake (ORNL) and Dr. Philip Jones (LANL) served as principal investigators on the SciDAC project, 'Collaborative Design and Development of the Community Climate System Model for Terascale Computers.' The Community Climate System Model (CCSM) is a fully-coupled global system that provides state-of-the-art computer simulations of the Earth's past, present, and future climate states. The collaborative SciDAC team--including over a dozen researchers at institutions around the country--developed, validated, documented, and optimized the performance of CCSM using the latest software engineering approaches, computational technology, and scientific knowledge. Many of the factors that must be accounted for in a comprehensive model of the climate system are illustrated in figure 1.« less

Birth-related expression of c-fos, c-jun and substance P mRNAs in the rat brainstem and pia mater: possible relationship to changes in central chemosensitivity.

PubMed

Wickström, H R; Holgert, H; Hökfelt, T; Lagercrantz, H

1999-02-05

In situ hybridization was used to characterize respiration-related areas of the brainstem activated around the time of birth as well as their postnatal sensitivity to CO2. Levels of mRNA corresponding to the immediate early genes (IEG), c-fos and c-jun, and of substance P precursor, ppt-A, were determined in rat fetuses (E21) and neonatal pups (1 h, 1 day and 6 days after normal birth) and after exposure to hypercapnia (12% CO2 for 1 h). Transient increases in c-fos mRNA were observed in the central chemoreceptor area of the ventral medullary surface (VMS), in the lateral reticular nucleus (LRN), in the nucleus of the solitary tract (NTS), and in the nucleus raphé pallidus (RPA) 1 h after birth. Increased expression of c-fos mRNA in the VMS could also be evoked by hypercapnia and this response was particularly pronounced 1 day after birth. On the other hand, c-jun mRNA could be detected already at E21 in the hypoglossal nucleus (XII) and LRN and these levels were not significantly altered at 1 h after birth. There was, however, an increase in the expression of c-jun mRNA in the pia mater surrounding the brainstem after birth. At 1 day after birth, c-jun mRNA levels had decreased in the LRN and pia mater, and later on (6 days after birth) in XII. Furthermore, the ppt-A mRNA level in NTS increased immediately after birth and remained high 1 and 6 days later. These results suggest that (a) the central chemoreceptor area of the VMS, as well as the NTS, LRN, RPA and pia mater are activated following birth; (b) the VMS, but not the other structures examined, can be activated immediately after birth by hypercapnia; and (c) increased expression of ppt-A mRNA may be related to the transition of respiratory control at birth. Copyright 1998 Elsevier Science B.V.

A Model for Dissolution of Lime in Steelmaking Slags

NASA Astrophysics Data System (ADS)

Sarkar, Rahul; Roy, Ushasi; Ghosh, Dinabandhu

2016-08-01

In a previous study by Sarkar et al. (Metall. Mater. Trans. B 46B:961 2015), a dynamic model of the LD steelmaking was developed. The prediction of the previous model (Sarkar et al. in Metall. Mater. Trans. B 46B:961 2015) for the bath (metal) composition matched well with the plant data (Cicutti et al. in Proceedings of 6th International Conference on Molten Slags, Fluxes and Salts, Stockholm City, 2000). However, with respect to the slag composition, the prediction was not satisfactory. The current study aims to improve upon the previous model Sarkar et al. (Metall. Mater. Trans. B 46B:961 2015) by incorporating a lime dissolution submodel into the earlier one. From the industrial point of view, the understanding of the lime dissolution kinetics is important to meet the ever-increasing demand of producing low-P steel at a low basicity. In the current study, three-step kinetics for the lime dissolution is hypothesized on the assumption that a solid layer of 2CaO·SiO2 should form around the unreacted core of the lime. From the available experimental data, it seems improbable that the observed kinetics should be controlled singly by any one kinetic step. Accordingly, a general, mixed control model has been proposed to calculate the dissolution rate of the lime under varying slag compositions and temperatures. First, the rate equation for each of the three rate-controlling steps has been derived, for three different lime geometries. Next, the rate equation for the mixed control kinetics has been derived and solved to find the dissolution rate. The model predictions have been validated by means of the experimental data available in the literature. In addition, the effects of the process conditions on the dissolution rate have been studied, and compared with the experimental results wherever possible. Incorporation of this submodel into the earlier global model (Sarkar et al. in Metall. Mater. Trans. B 46B:961 2015) enables the prediction of the lime dissolution rate in the dynamic system of LD steelmaking. In addition, with the inclusion of this submodel, significant improvement in the prediction of the slag composition during the main blow period has been observed.

MadSciNet: The 24-hour exploding laboratory.

Science.gov Websites

Page New! Help Improve The Madsci Network Help Support MadSci MAD Head MAD egg Welcome to the laboratory that never sleeps! MadSci Network represents a collective cranium of scientists providing answers Sunday May 27, 2018. Lynn MadSci Network is a non-profit organization operating in partnership with Third

32 CFR 171.6 - Reutilization and transfer procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., it shall send a written notice of dispute to the owning Military Service and ADUSD(L&MR/SCI) within thirty (30) days of its notice from the Military Service. ADUSD(L&MR/SCI) shall then resolve the dispute... and ADUSD(L&MR/SCI) within thirty (30) days of its notice from the Military Service. ADUSD(L&MR/SCI...

32 CFR 171.6 - Reutilization and transfer procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., it shall send a written notice of dispute to the owning Military Service and ADUSD(L&MR/SCI) within thirty (30) days of its notice from the Military Service. ADUSD(L&MR/SCI) shall then resolve the dispute... and ADUSD(L&MR/SCI) within thirty (30) days of its notice from the Military Service. ADUSD(L&MR/SCI...

Future Defence Budget Constraints: Challenges and Opportunities (Contraintes futures sur les budgets de defense: Defis et opportunites)

DTIC Science & Technology

2016-12-01

collaborative effort is addressed by six Technical Panels who manage a wide range of scientific research activities, a Group specialising in modelling and...HFM Human Factors and Medicine Panel • IST Information Systems Technology Panel • NMSG NATO Modelling and Simulation Group • SAS System Analysis...and Studies Panel • SCI Systems Concepts and Integration Panel • SET Sensors and Electronics Technology Panel These Panels and Group are the

Statistical Moments in Variable Density Incompressible Mixing Flows

DTIC Science & Technology

2015-08-28

front tracking method: Verification and application to simulation of the primary breakup of a liquid jet . SIAM J. Sci. Comput., 33:1505–1524, 2011. [15... elliptic problem. In case of failure, Generalized Minimal Residual (GMRES) method [78] is used instead. Then update face velocities as follows: u n+1...of the ACM Solid and Physical Modeling Symposium, pages 159–170, 2008. [51] D. D. Joseph. Fluid dynamics of two miscible liquids with diffusion and

3D Modelling of Urban Terrain (Modelisation 3D de milieu urbain)

DTIC Science & Technology

2011-09-01

Panel • IST Information Systems Technology Panel • NMSG NATO Modelling and Simulation Group • SAS System Analysis and Studies Panel • SCI... Systems Concepts and Integration Panel • SET Sensors and Electronics Technology Panel These bodies are made up of national representatives as well as...of a part of it may be made for individual use only. The approval of the RTA Information Management Systems Branch is required for more than one

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arnold H. Kritz

PTRANSP, which is the predictive version of the TRANSP code, was developed in a collaborative effort involving the Princeton Plasma Physics Laboratory, General Atomics Corporation, Lawrence Livermore National Laboratory, and Lehigh University. The PTRANSP/TRANSP suite of codes is the premier integrated tokamak modeling software in the United States. A production service for PTRANSP/TRANSP simulations is maintained at the Princeton Plasma Physics Laboratory; the server has a simple command line client interface and is subscribed to by about 100 researchers from tokamak projects in the US, Europe, and Asia. This service produced nearly 13000 PTRANSP/TRANSP simulations in the four year periodmore » FY 2005 through FY 2008. Major archives of TRANSP results are maintained at PPPL, MIT, General Atomics, and JET. Recent utilization, counting experimental analysis simulations as well as predictive simulations, more than doubled from slightly over 2000 simulations per year in FY 2005 and FY 2006 to over 4300 simulations per year in FY 2007 and FY 2008. PTRANSP predictive simulations applied to ITER increased eight fold from 30 simulations per year in FY 2005 and FY 2006 to 240 simulations per year in FY 2007 and FY 2008, accounting for more than half of combined PTRANSP/TRANSP service CPU resource utilization in FY 2008. PTRANSP studies focused on ITER played a key role in journal articles. Examples of validation studies carried out for momentum transport in PTRANSP simulations were presented at the 2008 IAEA conference. The increase in number of PTRANSP simulations has continued (more than 7000 TRANSP/PTRANSP simulations in 2010) and results of PTRANSP simulations appear in conference proceedings, for example the 2010 IAEA conference, and in peer reviewed papers. PTRANSP provides a bridge to the Fusion Simulation Program (FSP) and to the future of integrated modeling. Through years of widespread usage, each of the many parts of the PTRANSP suite of codes has been thoroughly validated against experimental data and benchmarked against other codes. At the same time, architectural modernizations are improving the modularity of the PTRANSP code base. The NUBEAM neutral beam and fusion products fast ion model, the Plasma State data repository (developed originally in the SWIM SciDAC project and adapted for use in PTRANSP), and other components are already shared with the SWIM, FACETS, and CPES SciDAC FSP prototype projects. Thus, the PTRANSP code is already serving as a bridge between our present integrated modeling capability and future capability. As the Fusion Simulation Program builds toward the facility currently available in the PTRANSP suite of codes, early versions of the FSP core plasma model will need to be benchmarked against the PTRANSP simulations. This will be necessary to build user confidence in FSP, but this benchmarking can only be done if PTRANSP itself is maintained and developed.« less

Enhanced etching of tin-doped indium oxide due to surface modification by hydrogen ion injection

NASA Astrophysics Data System (ADS)

Li, Hu; Karahashi, Kazuhiro; Friederich, Pascal; Fink, Karin; Fukasawa, Masanaga; Hirata, Akiko; Nagahata, Kazunori; Tatsumi, Tetsuya; Wenzel, Wolfgang; Hamaguchi, Satoshi

2018-06-01

It is known that the etching yield (i.e., sputtering yield) of tin-doped indium oxide (ITO) by hydrocarbon ions (CH x +) is higher than its corresponding physical sputtering yield [H. Li et al., J. Vac. Sci. Technol. A 33, 060606 (2015)]. In this study, the effects of hydrogen in the incident hydrocarbon ion beam on the etching yield of ITO have been examined experimentally and theoretically with the use of a mass-selected ion beam system and by first-principles quantum mechanical (QM) simulation. As in the case of ZnO [H. Li et al., J. Vac. Sci. Technol. A 35, 05C303 (2017)], mass-selected ion beam experiments have shown that the physical sputtering yield of ITO by chemically inert Ne ions increases after a pretreatment of the ITO film by energetic hydrogen ion injection. First-principles QM simulation of the interaction of In2O3 with hydrogen atoms shows that hydrogen atoms embedded in In2O3 readily form hydroxyl (OH) groups and weaken or break In–O bonds around the hydrogen atoms, making the In2O3 film less resistant to physical sputtering. This is consistent with experimental observation of the enhanced etching yields of ITO by CH x + ions, considering the fact that hydrogen atoms of the incident CH x + ions are embedded into ITO during the etching process.

Measuring pain phenomena after spinal cord injury: Development and psychometric properties of the SCI-QOL Pain Interference and Pain Behavior assessment tools.

PubMed

Cohen, Matthew L; Kisala, Pamela A; Dyson-Hudson, Trevor A; Tulsky, David S

2018-05-01

To develop modern patient-reported outcome measures that assess pain interference and pain behavior after spinal cord injury (SCI). Grounded-theory based qualitative item development; large-scale item calibration field-testing; confirmatory factor analyses; graded response model item response theory analyses; statistical linking techniques to transform scores to the Patient Reported Outcome Measurement Information System (PROMIS) metric. Five SCI Model Systems centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. N/A. Spinal Cord Injury - Quality of Life (SCI-QOL) Pain Interference item bank, SCI-QOL Pain Interference short form, and SCI-QOL Pain Behavior scale. Seven hundred fifty-seven individuals with traumatic SCI completed 58 items addressing various aspects of pain. Items were then separated by whether they assessed pain interference or pain behavior, and poorly functioning items were removed. Confirmatory factor analyses confirmed that each set of items was unidimensional, and item response theory analyses were used to estimate slopes and thresholds for the items. Ultimately, 7 items (4 from PROMIS) comprised the Pain Behavior scale and 25 items (18 from PROMIS) comprised the Pain Interference item bank. Ten of these 25 items were selected to form the Pain Interference short form. The SCI-QOL Pain Interference item bank and the SCI-QOL Pain Behavior scale demonstrated robust psychometric properties. The Pain Interference item bank is available as a computer adaptive test or short form for research and clinical applications, and scores are transformed to the PROMIS metric.

Measuring anxiety after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Anxiety item bank and linkage with GAD-7.

PubMed

Kisala, Pamela A; Tulsky, David S; Kalpakjian, Claire Z; Heinemann, Allen W; Pohlig, Ryan T; Carle, Adam; Choi, Seung W

2015-05-01

To develop a calibrated item bank and computer adaptive test to assess anxiety symptoms in individuals with spinal cord injury (SCI), transform scores to the Patient Reported Outcomes Measurement Information System (PROMIS) metric, and create a statistical linkage with the Generalized Anxiety Disorder (GAD)-7, a widely used anxiety measure. Grounded-theory based qualitative item development methods; large-scale item calibration field testing; confirmatory factor analysis; graded response model item response theory analyses; statistical linking techniques to transform scores to a PROMIS metric; and linkage with the GAD-7. Setting Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Participants Adults with traumatic SCI. Spinal Cord Injury-Quality of Life (SCI-QOL) Anxiety Item Bank Seven hundred sixteen individuals with traumatic SCI completed 38 items assessing anxiety, 17 of which were PROMIS items. After 13 items (including 2 PROMIS items) were removed, factor analyses confirmed unidimensionality. Item response theory analyses were used to estimate slopes and thresholds for the final 25 items (15 from PROMIS). The observed Pearson correlation between the SCI-QOL Anxiety and GAD-7 scores was 0.67. The SCI-QOL Anxiety item bank demonstrates excellent psychometric properties and is available as a computer adaptive test or short form for research and clinical applications. SCI-QOL Anxiety scores have been transformed to the PROMIS metric and we provide a method to link SCI-QOL Anxiety scores with those of the GAD-7.

Differences in the use of everyday technology among persons with MCI, SCI and older adults without known cognitive impairment.

PubMed

Malinowsky, Camilla; Kottorp, Anders; Wallin, Anders; Nordlund, Arto; Björklund, Eva; Melin, Ilse; Pernevik, Anette; Rosenberg, Lena; Nygård, Louise

2017-07-01

To use valid subjective reports sensible to cognitive decline is vital to identify very early signs of dementia development. Use of everyday technology (ET) has been shown to be sensitive to differentiate adults with mild cognitive impairment (MCI) from controls, but the group with subjective cognitive impairment (SCI) has not yet been examined. This study aims to investigate and compare self-perceived ability in ET use and number of ETs reported as actually used in a sample of older adults with SCI, MCI, and older adults with no known cognitive impairment, i.e. Older adults with MCI (n = 29), SCI ( n = 26), and controls (n = 30) were interviewed with the short version of the Everyday Technology Use Questionnaire (S-ETUQ) to capture self-perceived ability in ET use and number of ETs used. To generate individual measures of ability to use ET, Rasch analysis was used. The measures were then compared group-wise using ANCOVA. The numbers of ETs used were compared group-wise with ANOVA. Controls versus SCI and MCI differed significantly regarding ETs reported as used, but not SCI versus MCI. Similarly, in ability to use ET, controls versus SCI and MCI differed significantly but not SCI versus MCI. The significantly lower numbers of ETs reported as actually used and the lower ability in SCI and MCI groups compared to controls suggest that ET use is affected already in very minor cognitive decline. This indicates that self-reported ET use based on the S-ETUQ is sensitive to detect changes already in SCI.

Incidence of acute spinal cord injury in the Czech Republic: a prospective epidemiological study 2006-2015.

PubMed

Kriz, J; Kulakovska, M; Davidova, H; Silova, M; Kobesova, A

2017-09-01

A prospective study. Analysis of epidemiological data about acute spinal cord injury (SCI) in the Czech Republic over a period of 10 years (2006-2015). A data collection system was implemented in the rehabilitation centres which provides care to patients with acute SCI in the Czech Republic. The recorded variables are as follows: age at time of SCI; gender; cause of injury; neurological level of injury (NLI); and its severity (ASIA Impairment Scale (AIS)). Data from 2006 to 2015 were analysed and trends were determined. The overall number of acute SCI ranges between 250 and 300 cases annually. Two-third of the affected population are males. The average age at time of SCI is 49.1 years. The average incidence of traumatic SCI is 15.5 cases per year and is gradually decreasing. The leading cause of SCI are falls (44.5%), followed by traffic accidents (28.2%) and sports injuries including diving into water (19.7%). The incidence of non-traumatic SCI is 8.6 cases per year on average and has an upward trend. Inflammatory lesions account for 26.7% of cases, tumours account for 20.9%, and vascular related injuries make up 17.7%. The NLI occurs most often in the cervical segments (45.3%). The most frequently occurring lesions are motor incomplete: AIS D (33.3%). This study shows a stable occurrence of SCI in the Czech Republic, with cervical and motor incomplete cases being the leading ones. Epidemiological data are needed to improve the care of SCI patients and to promote an active life following it.

Return to work following spinal cord injury: a review.

PubMed

Lidal, Ingeborg Beate; Huynh, Tuan Khai; Biering-Sørensen, Fin

2007-09-15

To review literature on return to work (RTW) and employment in persons with spinal cord injury (SCI), and present employment rates, factors influencing employment, and interventions aimed at helping people with SCI to obtain and sustain productive work. A systematic review for 2000 - 2006 was carried out in PubMed/Medline, AMED, (ISI) Web of Science, EMBASE, CINAHL, PsycInfo and Sociological abstracts database. The keywords 'spinal cord injuries', 'spinal cord disorder', 'spinal cord lesion' or 'spinal cord disease' were cross-indexed with 'employment', 'return to work', 'occupation' or 'vocational'. Out of approximately 270 hits, 110 references were used, plus 13 more found elsewhere. Among individuals with SCI working at the time of injury 21 - 67% returned to work after injury. RTW was higher in persons injured at a younger age, had less severe injuries and higher functional independence. Employment rate improved with time after SCI. Persons with SCI employed ranged from 11.5% to 74%. Individuals who sustained SCI during childhood or adolescence had higher adult employment rates. Most common reported barriers to employment were problems with transportation, health and physical limitations, lack of work experience, education or training, physical or architectural barriers, discrimination by employers, and loss of benefits. Individuals with SCI discontinue working at younger age. This review confirmed low employment rates after SCI. Future research should explore interventions aimed at helping people with SCI to obtain and sustain productive work.

32 CFR 154.77 - Reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Secret, Secret, and Confidential clearances revoked; (4) Number of SCI access determinations issued; (5) Number of SCI access determinations denied; (6) Number of SCI access determinations revoked; and (7...

Effects of melatonin on spinal cord injury-induced oxidative damage in mice testis.

PubMed

Yuan, X-C; Wang, P; Li, H-W; Wu, Q-B; Zhang, X-Y; Li, B-W; Xiu, R-J

2017-09-01

This study evaluated the effects of melatonin on spinal cord injury (SCI)-induced oxidative damage in testes. Adult male C57BL/6 mice were randomly divided into sham-, SCI- or melatonin (10 mg/kg, i.p.)-treated SCI groups. To induce SCI, a standard weight-drop method that induced a contusion injury at T10 was used. After 1 week, testicular blood flow velocity was measured using the Laser Doppler Line Scanner. Malondialdehyde (MDA), glutathione (GSH), oxidised glutathione (GSSG) and myeloperoxidase (MPO) were measured in testis homogenates. Microvascular permeability of the testes to Evan's Blue was examined by spectrophotometric and fluorescence microscopic quantitation. The tight junction protein zonula occludens-1 (ZO-1) and occludin in testes were assessed by immunoblot analysis. Melatonin increased the reduced blood flow and decreased SCI-induced permeability of capillaries. MDA levels and MPO activity were elevated in the SCI group compared with shams, which was reversed by melatonin. In contrast, SCI-induced reductions in GSH/GSSG ratio were restored by melatonin. Decreased expression of ZO-1 and occludin was observed, which was attenuated by melatonin. Overall, melatonin treatment protects the testes against oxidative stress damage caused by SCI. © 2016 Blackwell Verlag GmbH.

Geraniol promotes functional recovery and attenuates neuropathic pain in rats with spinal cord injury.

PubMed

Lv, Yan; Zhang, Liang; Li, Na; Mai, Naiken; Zhang, Yu; Pan, Shuyi

2017-12-01

Geraniol, a plant-derived monoterpene, has been extensively studied and showed a wide variety of beneficial effects. The aim of this study was to investigate the therapeutic effect of geraniol on functional recovery and neuropathic pain in rats with spinal cord injury (SCI). Rats received a clip-compression SCI and were treated with geraniol 6 h following SCI. Treatment of SCI rats with geraniol markedly improved locomotor function, and reduced sensitivity to the mechanical allodynia and thermal hyperalgesia. Treatment of SCI rats with geraniol increased NeuN-positive cells, suppressed expression of glial fibrillary acidic protein, and reduced activity of caspase-3 in the injured region. Treatment of SCI rats with geraniol reduced levels of malondialdehyde and 3-nitrotyrosine, upregulated protein expression of nuclear factor-erythroid 2-related factor 2 and heme oxygenase 1, and suppressed expression of inducible nitric oxide synthase in the injured region. In addition, treatment of SCI rats with geraniol downregulated protein expression of N-methyl-d-aspartate receptor 1 and reduced the number of CD68-positive cells and protein levels of TNF-α in the injured region. In conclusion, geraniol significantly promoted the recovery of neuronal function and attenuated neuropathic pain after SCI.

Kinetic Monte Carlo simulation of the efficiency roll-off, emission color, and degradation of organic light-emitting diodes (Presentation Recording)

NASA Astrophysics Data System (ADS)

Coehoorn, Reinder; van Eersel, Harm; Bobbert, Peter A.; Janssen, Rene A. J.

2015-10-01

The performance of Organic Light Emitting Diodes (OLEDs) is determined by a complex interplay of the charge transport and excitonic processes in the active layer stack. We have developed a three-dimensional kinetic Monte Carlo (kMC) OLED simulation method which includes all these processes in an integral manner. The method employs a physically transparent mechanistic approach, and is based on measurable parameters. All processes can be followed with molecular-scale spatial resolution and with sub-nanosecond time resolution, for any layer structure and any mixture of materials. In the talk, applications to the efficiency roll-off, emission color and lifetime of white and monochrome phosphorescent OLEDs [1,2] are demonstrated, and a comparison with experimental results is given. The simulations show to which extent the triplet-polaron quenching (TPQ) and triplet-triplet-annihilation (TTA) contribute to the roll-off, and how the microscopic parameters describing these processes can be deduced properly from dedicated experiments. Degradation is treated as a result of the (accelerated) conversion of emitter molecules to non-emissive sites upon a triplet-polaron quenching (TPQ) process. The degradation rate, and hence the device lifetime, is shown to depend on the emitter concentration and on the precise type of TPQ process. Results for both single-doped and co-doped OLEDs are presented, revealing that the kMC simulations enable efficient simulation-assisted layer stack development. [1] H. van Eersel et al., Appl. Phys. Lett. 105, 143303 (2014). [2] R. Coehoorn et al., Adv. Funct. Mater. (2015), publ. online (DOI: 10.1002/adfm.201402532)

Clinical interpretation of the Spinal Cord Injury Functional Index (SCI-FI)

PubMed Central

Fyffe, Denise; Kalpakjian, Claire Z.; Slavin, Mary; Kisala, Pamela; Ni, Pengsheng; Kirshblum, Steven C.; Tulsky, David S.; Jette, Alan M.

2016-01-01

Objective: To provide validation of functional ability levels for the Spinal Cord Injury – Functional Index (SCI-FI). Design: Cross-sectional. Setting: Inpatient rehabilitation hospital and community settings. Participants: A sample of 855 individuals with traumatic spinal cord injury enrolled in 6 rehabilitation centers participating in the National Spinal Cord Injury Model Systems Network. Interventions: Not Applicable. Main Outcome Measures: Spinal Cord Injury-Functional Index (SCI-FI). Results: Cluster analyses identified three distinct groups that represent low, mid-range and high SCI-FI functional ability levels. Comparison of clusters on personal and other injury characteristics suggested some significant differences between groups. Conclusions: These results strongly support the use of SCI-FI functional ability levels to document the perceived functional abilities of persons with SCI. Results of the cluster analysis suggest that the SCI-FI functional ability levels capture function by injury characteristics. Clinical implications regarding tracking functional activity trajectories during follow-up visits are discussed. PMID:26781769

Spinal cord injury-induced immunodeficiency is mediated by a sympathetic-neuroendocrine adrenal reflex.

PubMed

Prüss, Harald; Tedeschi, Andrea; Thiriot, Aude; Lynch, Lydia; Loughhead, Scott M; Stutte, Susanne; Mazo, Irina B; Kopp, Marcel A; Brommer, Benedikt; Blex, Christian; Geurtz, Laura-Christin; Liebscher, Thomas; Niedeggen, Andreas; Dirnagl, Ulrich; Bradke, Frank; Volz, Magdalena S; DeVivo, Michael J; Chen, Yuying; von Andrian, Ulrich H; Schwab, Jan M

2017-11-01

Acute spinal cord injury (SCI) causes systemic immunosuppression and life-threatening infections, thought to result from noradrenergic overactivation and excess glucocorticoid release via hypothalamus-pituitary-adrenal axis stimulation. Instead of consecutive hypothalamus-pituitary-adrenal axis activation, we report that acute SCI in mice induced suppression of serum norepinephrine and concomitant increase in cortisol, despite suppressed adrenocorticotropic hormone, indicating primary (adrenal) hypercortisolism. This neurogenic effect was more pronounced after high-thoracic level (Th1) SCI disconnecting adrenal gland innervation, compared with low-thoracic level (Th9) SCI. Prophylactic adrenalectomy completely prevented SCI-induced glucocorticoid excess and lymphocyte depletion but did not prevent pneumonia. When adrenalectomized mice were transplanted with denervated adrenal glands to restore physiologic glucocorticoid levels, the animals were completely protected from pneumonia. These findings identify a maladaptive sympathetic-neuroendocrine adrenal reflex mediating immunosuppression after SCI, implying that therapeutic normalization of the glucocorticoid and catecholamine imbalance in SCI patients could be a strategy to prevent detrimental infections.

Online support for individuals with spinal cord injuries: An ethnographic investigation

PubMed Central

O'Riley, Alisa A.; Rose, Jon; Dalal, Brinda

2014-01-01

Background Although social support is an important protective factor for individuals with spinal cord injuries (SCIs), individuals often encounter significant barriers to obtaining support after experiencing a SCI. It has been suggested that the Internet may serve to help individuals with disabilities overcome common barriers in obtaining support, yet research examining the efficacy of Internet-based support for individuals with SCI has been mixed. Objective To develop a more nuanced understanding of how individuals with SCI can or might use the Internet for support. Design Using an ethnographic approach, we conducted semi-structured interviews with nine individuals with SCI to explore perceived needs and barriers to information-seeking and online support. Setting Participants were recruited from Veterans Administration medical center outpatient and inpatient units providing specialty care to individuals with SCIs and from a community SCI Center of Excellence. Results Individuals with SCI gain emotional, problem-focused, and reciprocal support from online sources. Conclusions Online resources can provide important opportunities for social support for individuals with SCI. PMID:24090378

Role of the Charge-Transfer State in Reduced Langevin Recombination in Organic Solar Cells: A Theoretical Study

PubMed Central

2015-01-01

Reduced Langevin recombination has been observed in organic solar cells (OSCs) for many years, but its origin is still unclear. A recent work by Burke et al. (Adv. Energy Mater.2015, 5, 1500123-1) was inspired by this reduced Langevin recombination, and they proposed an equilibrium model of charge-transfer (CT) states that correlates the open-circuit voltage of OSCs with experimentally available device parameters. In this work, we extend Burke et al.’s CT model further and for the first time directly correlate the reduced Langevin recombination with the energetic and dynamic behavior of the CT state. Recombination through CT states leads in a straightforward manner to a decrease in the Langevin reduction factor with increasing temperature, without explicit consideration of the temperature dependence of the mobility. To verify the correlation between the CT states and reduced Langevin recombination, we incorporated this CT model and the reduced Langevin model into drift-diffusion simulations of a bilayer OSC. The simulations not only successfully reproduced realistic current–voltage (J–V) characteristics of the bilayer OSC, but also demonstrate that the two models consistently lead to same value of the apparent Langevin reduction factor. PMID:26640611

Against the odds: what to expect in rehabilitation of chronic spinal cord injury with a neurologically controlled Hybrid Assistive Limb exoskeleton. A subgroup analysis of 55 patients according to age and lesion level.

PubMed

Grasmücke, Dennis; Zieriacks, Amrei; Jansen, Oliver; Fisahn, Christian; Sczesny-Kaiser, Matthias; Wessling, Martin; Meindl, Renate C; Schildhauer, Thomas A; Aach, Mirko

2017-05-01

Objective Age and lesion level are believed to represent outcome predictors in rehabilitation of patients with chronic spinal cord injury (SCI). The Hybrid Assistive Limb (HAL) exoskeleton enables patients to perform a voluntary controlled gait pattern via an electromyography-triggered neuromuscular feedback system, and has been introduced as a temporary gait training tool in patients with SCI. The aim of this prospective pre- and postintervention study was to examine functional outcomes as a function of age and lesion level in patients with chronic incomplete SCI (iSCI) or chronic complete SCI (cSCI) with zones of partial preservation (ZPP) by using the HAL as a temporary training tool. Methods Fifty-five participants with chronic iSCI or cSCI (mean time since injury 6.85 ± 5.12 years) were classified according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS) and divided by age (< 50 or ≥ 50 years), independent of lesion level, and also into 4 homogeneous groups according to lesion level. The subgroups were as follows: Subgroup 1, tetraplegic iSCI (n = 13) (C2-8, AIS C [n = 8] and AIS D [n = 5]); Subgroup 2, paraplegic iSCI with spastic motor behavior (n = 15) (T2-12, AIS C [n = 8] and AIS D [n = 7]); Subgroup 3, paraplegic cSCI with complete motor paraplegia and absence of spastic motor behavior (n = 18) (T11-L4 [AIS A], and ZPP from L-3 to S-1); and Subgroup 4, paraplegic iSCI with absence of spastic motor behavior (n = 9) (T12-L3, AIS C [n = 8] and AIS D [n = 1]). The training paradigm consisted of 12 weeks of HAL-assisted treadmill training (5 times/week). Baseline status was documented prior to intervention by using the AIS grade, Walking Index for SCI II (WISCI II) score, the 10-meter walk test (10MWT), and the 6-minute walk test (6MinWT). Training effects were assessed after 6 and 12 weeks of therapy, without HAL assistance. Results Overall, a time reduction of 47% in the 10MWT, self-selected speed (10MWTsss) (< 50 years = 56% vs ≥ 50 years = 37%) and an increase of 50% in the 6MinWT were documented. The WISCI II scores showed a mean gain of 1.69 levels. At the end of the study, 24 of 55 patients (43.6%) were less dependent on walking aids. Age had a nonsignificant negative influence on the 10MWTsss. Despite a few nonsignificant subgroup differences, participants improved across all tests. Namely, patients with iSCI who had spastic motor behavior improved to a nonsignificant, lesser extent in the 6MinWT. Conclusions The HAL-assisted treadmill training leads to functional improvements in chronic iSCI or cSCI, both in and out of the exoskeleton. An improvement of approximately 50% in the 10MWTsss and in gait endurance (6MinWT) can be expected from such training. The influences of SCI lesion level and age on functional outcome were nonsignificant in the present study. Older age (≥ 50 years) may be associated with smaller improvements in the 10MWTsss. An iSCI in paraplegic patients with spastic motor behavior may be a nonsignificant negative predictor in gait endurance improvements. Clinical trial registration no.: DRKS00010250 ( https://drks-neu.uniklinik-freiburg.de/drks_web/setLocale_DE.do ).

Clinical image and pathology of hypertrophic cranial pachymeningitis.

PubMed

Shi, C H; Niu, S T; Zhang, Z Q

2014-12-12

The objective of this study was to examine the clinical findings, magnetic resonance imaging (MRI), pathological features, and treatment experiments of patients with hypertrophic cranial pachymeningitis (HCP). The clinical findings, MRI, and pathological appearances of 9 patients with HCP were analyzed retrospectively. The thickened dura mater was markedly enhanced after contrast media injection. The lesion near the brain hemisphere presented long regions of T1- and T2-weighted abnormal signal intensities. The abnormal signal intensities of the brain tissue were decreased significantly. Pathological examination demonstrated chronic inflammation changes, with cerebral dura mater fibrous tissue showing obvious hyperplasia, and the periphery of the blood vessel showing a great quantity of infiltrating phlegmonosis cells. HCP mainly presents headache and paralysis of multiple cranial nerves. The distinctive signs on brain MRIs involve strengthening the signal in the cerebral dura.

Low-energy extracorporeal shock wave therapy for promotion of vascular endothelial growth factor expression and angiogenesis and improvement of locomotor and sensory functions after spinal cord injury.

PubMed

Yahata, Kenichiro; Kanno, Haruo; Ozawa, Hiroshi; Yamaya, Seiji; Tateda, Satoshi; Ito, Kenta; Shimokawa, Hiroaki; Itoi, Eiji

2016-12-01

OBJECTIVE Extracorporeal shock wave therapy (ESWT) is widely used to treat various human diseases. Low-energy ESWT increases expression of vascular endothelial growth factor (VEGF) in cultured endothelial cells. The VEGF stimulates not only endothelial cells to promote angiogenesis but also neural cells to induce neuroprotective effects. A previous study by these authors demonstrated that low-energy ESWT promoted expression of VEGF in damaged neural tissue and improved locomotor function after spinal cord injury (SCI). However, the neuroprotective mechanisms in the injured spinal cord produced by low-energy ESWT are still unknown. In the present study, the authors investigated the cell specificity of VEGF expression in injured spinal cords and angiogenesis induced by low-energy ESWT. They also examined the neuroprotective effects of low-energy ESWT on cell death, axonal damage, and white matter sparing as well as the therapeutic effect for improvement of sensory function following SCI. METHODS Adult female Sprague-Dawley rats were divided into the SCI group (SCI only) and SCI-SW group (low-energy ESWT applied after SCI). Thoracic SCI was produced using a New York University Impactor. Low-energy ESWT was applied to the injured spinal cord 3 times a week for 3 weeks after SCI. Locomotor function was evaluated using the Basso, Beattie, and Bresnahan open-field locomotor score for 42 days after SCI. Mechanical and thermal allodynia in the hindpaw were evaluated for 42 days. Double staining for VEGF and various cell-type markers (NeuN, GFAP, and Olig2) was performed at Day 7; TUNEL staining was also performed at Day 7. Immunohistochemical staining for CD31, α-SMA, and 5-HT was performed on spinal cord sections taken 42 days after SCI. Luxol fast blue staining was performed at Day 42. RESULTS Low-energy ESWT significantly improved not only locomotion but also mechanical and thermal allodynia following SCI. In the double staining, expression of VEGF was observed in NeuN-, GFAP-, and Olig2-labeled cells. Low-energy ESWT significantly promoted CD31 and α-SMA expressions in the injured spinal cords. In addition, low-energy ESWT significantly reduced the TUNEL-positive cells in the injured spinal cords. Furthermore, the immunodensity of 5-HT-positive axons was significantly higher in the animals treated by low-energy ESWT. The areas of spared white matter were obviously larger in the SCI-SW group than in the SCI group, as indicated by Luxol fast blue staining. CONCLUSIONS The results of this study suggested that low-energy ESWT promotes VEGF expression in various neural cells and enhances angiogenesis in damaged neural tissue after SCI. Furthermore, the neuroprotective effect of VEGF induced by low-energy ESWT can suppress cell death and axonal damage and consequently improve locomotor and sensory functions after SCI. Thus, low-energy ESWT can be a novel therapeutic strategy for treatment of SCI.

ScienceDirect through SciVerse: a new way to approach Elsevier.

PubMed

Bengtson, Jason

2011-01-01

SciVerse is the new combined portal from Elsevier that services their ScienceDirect collection, SciTopics, and their Scopus database. Using SciVerse to access ScienceDirect is the specific focus of this review. Along with advanced keyword searching and citation searching options, SciVerse also incorporates a very useful image search feature. The aim seems to be not only to create an interface that provides broad functionality on par with other database search tools that many searchers use regularly but also to create an open platform that could be changed to respond effectively to the needs of customers.

Evaluating implementation of methicillin-resistant Staphylococcus aureus (MRSA) prevention guidelines in spinal cord injury centers using the PARIHS framework: a mixed methods study.

PubMed

Balbale, Salva N; Hill, Jennifer N; Guihan, Marylou; Hogan, Timothy P; Cameron, Kenzie A; Goldstein, Barry; Evans, Charlesnika T

2015-09-09

To prevent methicillin-resistant Staphylococcus aureus (MRSA) in Spinal Cord Injury and Disorder (SCI/D) Centers, the "Guidelines for Implementation of MRSA Prevention Initiative in the Spinal Cord Injury Centers" were released in July 2008 in the Veterans Affairs (VA) Health Care System. The purpose of this study was to use the Promoting Action on Research Implementation in Health Systems (PARiHS) framework to evaluate the experiences of implementation of SCI/D MRSA prevention guidelines in VA SCI/D Centers approximately 2-3 years after the guidelines were released. Mixed methods were used across two phases in this study. The first phase included an anonymous, web-based cross-sectional survey administered to providers at all 24 VA SCI/D Centers. The second phase included semi-structured telephone interviews with providers at 9 SCI/D Centers. The PARiHS framework was used as the foundation of both the survey questions and semi-structured interview guide. The survey was completed by 295 SCI/D providers (43.8 % response rate) from 22 of the 24 SCI/D Centers (91.7 % participation rate). Respondents included nurses (57.3 %), therapists (24.4 %), physicians (11.1 %), physician assistants (3.4 %), and other health care professionals (3.8 %). Approximately 36 % of the SCI/D providers surveyed had not seen, did not remember seeing, or had never heard of the MRSA SCI/D guidelines, whereas 42.3 % of providers reported that the MRSA SCI/D guidelines were fully implemented in their SCI/D Center. Data revealed numerous barriers and facilitators to guideline implementation. Facilitators included enhanced leadership support and provider education, focused guideline dissemination to reach SCI/D providers, and strong perceived evidence supporting the guidelines. Barriers included lack of awareness of the guidelines among physical therapists and physician assistants and challenges in cohorting/isolating MRSA-positive patients and following contact precautions. Successful implementation of MRSA infection prevention guidelines in SCI/D settings requires (1) guideline dissemination that reaches the full range of SCI/D providers working in inpatient, outpatient, and other care settings, (2) provider education that is frequent and systematic, (3) strong leadership support, and (4) that barriers unique to the recommendations are addressed. These findings may be used to inform selection of implementation strategies and optimize infection prevention beyond MRSA as well as in other specialty care populations.

Costs and Length of Stay for the Acute Care of Patients with Motor-Complete Spinal Cord Injury Following Cervical Trauma: The Impact of Early Transfer to Specialized Acute SCI Center.

PubMed

Richard-Denis, Andréane; Ehrmann Feldman, Debbie; Thompson, Cynthia; Bourassa-Moreau, Étienne; Mac-Thiong, Jean-Marc

2017-07-01

Acute spinal cord injury (SCI) centers aim to optimize outcome following SCI. However, there is no timeframe to transfer patients from regional to SCI centers in order to promote cost-efficiency of acute care. Our objective was to compare costs and length of stay (LOS) following early and late transfer to the SCI center. A retrospective cohort study involving 116 individuals was conducted. Group 1 (n = 87) was managed in an SCI center promptly after the trauma, whereas group 2 (n = 29) was transferred to the SCI center only after surgery. Direct comparison and multivariate linear regression analyses were used to assess the relationship between costs, LOS, and timing to transfer to the SCI center. Length of stay was significantly longer for group 2 (median, 93.0 days) as compared with group 1 (median, 40.0 days; P < 10), and average costs were also higher (median, Canadian $17,920.0 vs. $10,521.6; P = 0.004) for group 2, despite similar characteristics. Late transfer to the SCI center was the main predictive factor of longer LOS and increased costs. Early admission to the SCI center was associated with shorter LOS and lower costs for patients sustaining tetraplegia. Early referral to an SCI center before surgery could lower the financial burden for the health care system. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Determine the optimal timing for transfer of individuals with cervical traumatic spinal cord injury (SCI) in order to decrease acute care resource utilization; (2) Determine benefits of a complete perioperative management in a specialized SCI center; and (3) Identify factors that may influence resource utilization for acute care following motor-complete tetraplegia. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Assessment of Neuroprotective Properties of Melissa officinalis in Combination With Human Umbilical Cord Blood Stem Cells After Spinal Cord Injury

PubMed Central

Hosseini, Seyed Ruhollah; Joghataei, Mohammad Taghi; Hooshmandi, Mehdi; Sadraie, Seyed Homayoon; Yaghoobi, Kayvan; Mohammadi, Alireza

2016-01-01

Introduction The pathophysiology of spinal cord injury (SCI) has a classically bad prognosis. It has been demonstrated that human umbilical cord blood stem cells (hUCBSCs) and Melissa officinalis (MO) are useful for the prevention of neurological disease. Methods Thirty-six adult male rats were randomly divided into intact, sham, control (SCI), MO, hUCBSC, and MO-hUCBSC groups. Intraperitoneal injection of MO (150 mg/kg) was commenced 24 hr post-SCI and continued once a day for 14 days. Intraspinal grafting of hUCBSCs was commenced immediately in the next day. The motor and sensory functions of all animals were evaluated once a week after the commencement of SCI. Electromyography (EMG) was performed in the last day in order to measure the recruitment index. Immunohistochemistry, reverse transcription-polymerase chain reaction, and transmission electron microscopy evaluations were performed to determine the level of astrogliosis and myelination. Results The results revealed that motor function (MO-hUCBSC: 15 ± 0.3, SCI: 8.2 ± 0.37, p < .001), sensory function (MO-hUCBSC: 3.57 ± 0.19, SCI: 6.38 ± 0.23, p < .001), and EMG recruitment index (MO-hUCBSC: 3.71 ± 0.18, SCI: 1.6 ± 0.1, p < .001) were significantly improved in the MO-hUCBSC group compared with SCI group. Mean cavity area (MO-hUCBSC: 0.03 ± 0.03, SCI: 0.07 ± 0.004, p < .001) was reduced and loss of lower motor neurons (MO-hUCBSC: 7.6 ± 0.43, SCI: 3 ± 0.12, p < .001) and astrogliosis density (MO-hUCBSC: 3.1 ± 0.15, SCI: 6.25 ± 1.42, p < 0.001) in the ventral horn of spinal cord were prevented in MO-hUCBSC group compared with SCI group. Conclusion The results revealed that the combination of MO and hUCBSCs in comparison with the control group has neuroprotective effects in SCI. PMID:27815336

Lack of Impact by SCY-078, a First-in-Class Oral Fungicidal Glucan Synthase Inhibitor, on the Pharmacokinetics of Rosiglitazone, a Substrate for CYP450 2C8, Supports the Low Risk for Clinically Relevant Metabolic Drug-Drug Interactions.

PubMed

Wring, Stephen; Murphy, Gail; Atiee, George; Corr, Christy; Hyman, Michele; Willett, Michael; Angulo, David

2018-05-10

SCY-078, the first in a new class of β 1,3-glucan synthesis inhibitors, is being developed as an oral and intravenous antifungal treatment for Candida and Aspergillus species fungal infections. In vitro, studies indicated SCY-078 is an inhibitor of cytochrome P450 (CYP) 2C8 with markedly lower effect over other CYP isozymes. To examine clinically relevant effects of the potential interaction with SCY-078, this phase 1, open-label, 2-period crossover study evaluated the pharmacokinetic parameters of rosiglitazone, a sensitive substrate of CYP2C8 metabolism, in the absence and presence of SCY-078 dosed to therapeutically relevant SCY-078 concentration exposure after repeat dosing. Healthy adult subjects were randomized to 2 treatment sequences: a single oral 4-mg rosiglitazone dose alone on day 1 or a 1250-mg SCY-078 loading dose on day 1 followed by a once-daily 750-mg SCY-078 dose for an additional 7 days (reflecting the clinical regimen evaluated during phase 2 studies for infections by Candida species) and concurrent administration of a single oral 4-mg rosiglitazone dose on day 3, before alternating following a ≥10-day washout. The exposure to SCY-078 observed in this study was in line with the intended exposure for treatment of invasive fungal infections. The 90% confidence intervals for rosiglitazone exposure geometric mean ratios were within the prespecified no effect interval of 0.70-1.43. Additionally, maximum concentration values for rosiglitazone and its metabolite, N-desmethylrosiglitazone, were not significantly affected by co-administration with SCY-078. Overall, rosiglitazone exposure was not impacted to a clinically meaningful extent with co-administration of therapeutically relevant SCY-078 concentration exposure after repeat dosing. The results are indicative of low risk for interaction of SCY-078 with drugs metabolized via the CYP family of enzymes. © 2018, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

Mechanical ventilation weaning and extubation after spinal cord injury: a Western Trauma Association multicenter study.

PubMed

Kornblith, Lucy Z; Kutcher, Matthew E; Callcut, Rachael A; Redick, Brittney J; Hu, Charles K; Cogbill, Thomas H; Baker, Christopher C; Shapiro, Mark L; Burlew, Clay C; Kaups, Krista L; DeMoya, Marc A; Haan, James M; Koontz, Christopher H; Zolin, Samuel J; Gordy, Stephanie D; Shatz, David V; Paul, Doug B; Cohen, Mitchell J

2013-12-01

Respiratory failure after acute spinal cord injury (SCI) is well recognized, but data defining which patients need long-term ventilator support and criteria for weaning and extubation are lacking. We hypothesized that many patients with SCI, even those with cervical SCI, can be successfully managed without long-term mechanical ventilation and its associated morbidity. Under the auspices of the Western Trauma Association Multi-Center Trials Group, a retrospective study of patients with SCI at 14 major trauma centers was conducted. Comprehensive injury, demographic, and outcome data on patients with acute SCI were compiled. The primary outcome variable was the need for mechanical ventilation at discharge. Secondary outcomes included the use of tracheostomy and development of acute lung injury and ventilator-associated pneumonia. A total of 360 patients had SCI requiring mechanical ventilation. Sixteen patients were excluded for death within the first 2 days of hospitalization. Of the 344 patients included, 222 (64.5%) had cervical SCI. Notably, 62.6% of the patients with cervical SCI were ventilator free by discharge. One hundred forty-nine patients (43.3%) underwent tracheostomy, and 53.7% of them were successfully weaned from the ventilator, compared with an 85.6% success rate among those with no tracheostomy (p < 0.05). Patients who underwent tracheostomy had significantly higher rates of ventilator-associated pneumonia (61.1% vs. 20.5%, p < 0.05) and acute lung injury (12.8% vs. 3.6%, p < 0.05) and fewer ventilator-free days (1 vs. 24 p < 0.05). When controlled for injury severity, thoracic injury, and respiratory comorbidities, tracheostomy after cervical SCI was an independent predictor of ventilator dependence with an associated 14-fold higher likelihood of prolonged mechanical ventilation (odds ratio, 14.1; 95% confidence interval, 2.78-71.67; p < 0.05). While many patients with SCI require short-term mechanical ventilation, the majority can be successfully weaned before discharge. In patients with SCI, tracheostomy is associated with major morbidity, and its use, especially among patients with cervical SCI, deserves further study. Prognostic study, level III.

SciServer Compute brings Analysis to Big Data in the Cloud

NASA Astrophysics Data System (ADS)

Raddick, Jordan; Medvedev, Dmitry; Lemson, Gerard; Souter, Barbara

2016-06-01

SciServer Compute uses Jupyter Notebooks running within server-side Docker containers attached to big data collections to bring advanced analysis to big data "in the cloud." SciServer Compute is a component in the SciServer Big-Data ecosystem under development at JHU, which will provide a stable, reproducible, sharable virtual research environment.SciServer builds on the popular CasJobs and SkyServer systems that made the Sloan Digital Sky Survey (SDSS) archive one of the most-used astronomical instruments. SciServer extends those systems with server-side computational capabilities and very large scratch storage space, and further extends their functions to a range of other scientific disciplines.Although big datasets like SDSS have revolutionized astronomy research, for further analysis, users are still restricted to downloading the selected data sets locally - but increasing data sizes make this local approach impractical. Instead, researchers need online tools that are co-located with data in a virtual research environment, enabling them to bring their analysis to the data.SciServer supports this using the popular Jupyter notebooks, which allow users to write their own Python and R scripts and execute them on the server with the data (extensions to Matlab and other languages are planned). We have written special-purpose libraries that enable querying the databases and other persistent datasets. Intermediate results can be stored in large scratch space (hundreds of TBs) and analyzed directly from within Python or R with state-of-the-art visualization and machine learning libraries. Users can store science-ready results in their permanent allocation on SciDrive, a Dropbox-like system for sharing and publishing files. Communication between the various components of the SciServer system is managed through SciServer‘s new Single Sign-on Portal.We have created a number of demos to illustrate the capabilities of SciServer Compute, including Python and R scripts accessing a range of datasets and showing the data flow between storage and compute components.Demos, documentation, and more information can be found at www.sciserver.org.SciServer is funded by the National Science Foundation Award ACI-1261715.

Impact of Blood Pressure Dysregulation on Health-Related Quality of Life in Persons With Spinal Cord Injury: Development of a Conceptual Model

PubMed Central

Carlozzi, Noelle E.; Fyffe, Denise; Morin, Kel G.; Byrne, Rachel; Tulsky, David S.; Victorson, David; Lai, Jin-Shei; Wecht, Jill M.

2015-01-01

Objectives To identify medically relevant aspects of blood pressure dysregulation (BPD) related to quality of life in individuals with spinal cord injury (SCI), and to propose an integrated conceptual framework based on input from both individuals with SCI and their clinical providers. This framework will serve as a guide for the development of a patient-reported outcome (PRO) measure specifically related to BPD. Design Three focus groups with individuals with SCI and 3 groups with SCI providers were analyzed using grounded-theory based qualitative analysis to ascertain how blood pressure impacts health-related quality of life (HRQOL) in individuals with SCI. Setting Focus groups were conducted at 2 Veterans Affairs medical centers and a research center. Participants Individuals with SCI (n=27) in 3 focus groups and clinical providers (n=25) in 3 focus groups. Interventions Not applicable. Main Outcome Measures Not applicable. Results Qualitative analysis indicated that all focus groups spent the highest percentage of time discussing symptoms of BPD (39%), followed by precipitators/causes of BPD (16%), preventative actions (15%), corrective actions (12%), and the impact that BPD has on social or emotional functioning (8%). While patient/consumer focus groups and provider focus groups raised similar issues, providers spent more time discussing precipitators/causes of BPD and preventative actions (38%) than patient/consumer groups (24%). Conclusions These results suggest that BPD uniquely and adversely impacts HRQOL in persons with SCI. While both individuals with SCI and their providers highlighted the relevant symptoms of BPD, the SCI providers offered additional detailed information regarding the precipitators/causes and what can be done to prevent/treat BPD. Further, the results suggest that persons with SCI are aware of how BPD impacts their HRQOL and are able to distinguish between subtle signs and symptoms. These findings exemplify the need for a validated and sensitive clinical measurement tool that can assess the extent to which BPD impacts HRQOL in patients with SCI. PMID:23499779

Epidemiology of pediatric spinal cord injury in the United States: years 1997 and 2000.

PubMed

Vitale, Michael G; Goss, Jordan M; Matsumoto, Hiroko; Roye, David P

2006-01-01

The purpose of this study is to report the current incidence rates of pediatric spinal cord injury (SCI) in the United States and identify specific high-risk populations as a knowledge basis for improving the prevention and treatment of this traumatic injury. The Kids' Inpatient Database (KID) and the National Trauma Data Bank (NTDB) were used to investigate the etiology of pediatric SCI. Significant differences in the annual incidence rate of pediatric SCI were found to exist between patient populations stratified by race and sex. African Americans (1.53 cases/100,000 children) exhibit a significantly higher rate of pediatric SCI than native Americans (1.00), Hispanics (0.87), and Asians (0.36), whereas Asians show a significantly lower incidence than all other races. Also, boys (2.79) are more than twice as likely to experience SCI as girls (1.15). The overall incidence of pediatric SCI in the United States is 1.99 cases per 100,000 children. From these data, it is estimated that 1455 children are admitted to US hospitals each year for treatment of SCI. The etiology of pediatric SCI was also investigated, and the major causative factors were identified: motor vehicle accident (56%), accidental fall (14%), firearm injury (9%), and sports injury (7%). Of those children injured in a motor vehicle accident, 67.7% (n = 107) were reported as not wearing a seatbelt. The role of alcohol and drugs was also investigated and found to be involved in 30% (n = 82) of all pediatric SCI cases. Using discharge records from a public database, it is possible to identify high-risk demographic groups and activities that predispose a child to SCI. With a more thorough understanding of the etiology of pediatric SCI, clinicians and parents are better equipped to devise measures for prevention and treatment of this injury.

The role of cation-dependent chloride transporters in neuropathic pain following spinal cord injury

PubMed Central

Cramer, Samuel W; Baggott, Christopher; Cain, John; Tilghman, Jessica; Allcock, Bradley; Miranpuri, Gurwattan; Rajpal, Sharad; Sun, Dandan; Resnick, Daniel

2008-01-01

Background Altered Cl- homeostasis and GABAergic function are associated with nociceptive input hypersensitivity. This study investigated the role of two major intracellular Cl- regulatory proteins, Na+-K+-Cl- cotransporter 1 (NKCC1) and K+-Cl- cotransporter 2 (KCC2), in neuropathic pain following spinal cord injury (SCI). Results Sprague-Dawley rats underwent a contusive SCI at T9 using the MASCIS impactor. The rats developed hyperalgesia between days 21 and 42 post-SCI. Thermal hyperalgesia (TH) was determined by a decrease in hindpaw thermal withdrawal latency time (WLT) between days 21 and 42 post-SCI. Rats with TH were then treated with either vehicle (saline containing 0.25% NaOH) or NKCC1 inhibitor bumetanide (BU, 30 mg/kg, i.p.) in vehicle. TH was then re-measured at 1 h post-injection. Administration of BU significantly increased the mean WLT in rats (p < 0.05). The group administered with the vehicle alone showed no anti-hyperalgesic effects. Moreover, an increase in NKCC1 protein expression occurred in the lesion epicenter of the spinal cord during day 2–14 post-SCI and peaked on day 14 post-SCI (p < 0.05). Concurrently, a down-regulation of KCC2 protein was detected during day 2–14 post-SCI. The rats with TH exhibited a sustained loss of KCC2 protein during post-SCI days 21–42. No significant changes of these proteins were detected in the rostral region of the spinal cord. Conclusion Taken together, expression of NKCC1 and KCC2 proteins was differentially altered following SCI. The anti-hyperalgesic effect of NKCC1 inhibition suggests that normal or elevated NKCC1 function and loss of KCC2 function play a role in the development and maintenance of SCI-induced neuropathic pain. PMID:18799000

Can FES-rowing mediate bone mineral density in SCI: a pilot study.

PubMed

Gibbons, R S; McCarthy, I D; Gall, A; Stock, C G; Shippen, J; Andrews, B J

2014-11-01

A single case study. To compare proximal tibia trabecular bone mineral density (BMD) of a participant with complete spinal cord injury (SCI), long-termed functional electrical stimulation-rowing (FES-R) trained, with previously reported SCI and non-SCI group norms. To estimate lower limb joint contact forces (JCFs) in the FES-R trained participant. UK University and orthopaedic hospital research centre. Bilateral proximal tibial trabecular BMD of the FES-R trained participant was measured using peripheral quantitative computerised tomography, and the data were compared with SCI and non-SCI groups. An instrumented four-channel FES-R system was used to measure the lower limb JCFs in the FES-R trained participant. Structurally, proximal tibial trabecular BMD was higher in the FES-R trained participant compared with the SCI group, but was less than the non-SCI group. Furthermore, left (184.7 mg cm(-3)) and right (160.7 mg cm(-3)) BMD were well above the threshold associated with non-traumatic fracture. The knee JCFs were above the threshold known to mediate BMD in SCI, but below threshold at the hip and ankle. As pathological fractures predominate in the distal femur and proximal tibia in chronic SCI patients, the fact that the FES-R trained participant's knee JCFs were above those known to partially prevent bone loss, suggests that FES-R training may provide therapeutic benefit. Although the elevated bilateral proximal tibial BMD of the FES-R participant provides circumstantial evidence of osteogenesis, this single case precludes any statement on the clinical significance. Further investigations are required involving larger numbers and additional channels of FES to increase loading at the hip and ankle.

A randomized controlled trial to test the efficacy of the SCI Get Fit Toolkit on leisure-time physical activity behaviour and social-cognitive processes in adults with spinal cord injury.

PubMed

Arbour-Nicitopoulos, Kelly P; Sweet, Shane N; Lamontagne, Marie-Eve; Ginis, Kathleen A Martin; Jeske, Samantha; Routhier, François; Latimer-Cheung, Amy E

2017-01-01

Single blind, two-group randomized controlled trial. To evaluate the efficacy of the SCI Get Fit Toolkit delivered online on theoretical constructs and moderate-to-vigorous physical activity (MVPA) among adults with SCI. Ontario and Quebec, Canada. Inactive, English- and French-speaking Canadian adults with traumatic SCI with Internet access, and no self-reported cognitive or memory impairments. Participants ( N =90 M age =48.12±11.29 years; 79% male) were randomized to view the SCI Get Fit Toolkit or the Physical Activity Guidelines for adults with SCI (PAG-SCI) online. Primary (intentions) and secondary (outcome expectancies, self-efficacy, planning and MVPA behaviour) outcomes were assessed over a 1-month period. Of the 90 participants randomized, 77 were included in the analyses. Participants viewed the experimental stimuli only briefly, reading the 4-page toolkit for approximately 2.5 min longer than the 1-page guideline document. No condition effects were found for intentions, outcome expectancies, self-efficacy, and planning (ΔR 2 ⩽0.03). Individuals in the toolkit condition were more likely to participate in at least one bout of 20 min of MVPA behaviour at 1-week post-intervention compared to individuals in the guidelines condition (OR=3.54, 95% CI=0.95, 13.17). However, no differences were found when examining change in weekly minutes of MVPA or comparing whether participants met the PAG-SCI. No firm conclusions can be made regarding the impact of the SCI Get Fit Toolkit in comparison to the PAG-SCI on social cognitions and MVPA behaviour. The limited online access to this resource may partially explain these null findings.

Activation of KCNQ Channels Suppresses Spontaneous Activity in Dorsal Root Ganglion Neurons and Reduces Chronic Pain after Spinal Cord Injury

PubMed Central

Wu, Zizhen; Li, Lin; Xie, Fuhua; Du, Junhui; Zuo, Yan; Frost, Jeffrey A.; Carlton, Susan M.; Walters, Edgar T.

2017-01-01

Abstract A majority of people who have sustained spinal cord injury (SCI) experience chronic pain after injury, and this pain is highly resistant to available treatments. Contusive SCI in rats at T10 results in hyperexcitability of primary sensory neurons, which contributes to chronic pain. KCNQ channels are widely expressed in nociceptive dorsal root ganglion (DRG) neurons, are important for controlling their excitability, and their activation has proven effective in reducing pain in peripheral nerve injury and inflammation models. The possibility that activators of KCNQ channels could be useful for treating SCI-induced chronic pain is strongly supported by the following findings. First, SCI, unlike peripheral nerve injury, failed to decrease the functional or biochemical expression of KCNQ channels in DRG as revealed by electrophysiology, real-time quantitative polymerase chain reaction, and Western blot; therefore, these channels remain available for pharmacological targeting of SCI pain. Second, treatment with retigabine, a specific KCNQ channel opener, profoundly decreased spontaneous activity in primary sensory neurons of SCI animals both in vitro and in vivo without changing the peripheral mechanical threshold. Third, retigabine reversed SCI-induced reflex hypersensitivity, adding to our previous demonstration that retigabine supports the conditioning of place preference after SCI (an operant measure of spontaneous pain). In contrast to SCI animals, naïve animals showed no effects of retigabine on reflex sensitivity or conditioned place preference by pairing with retigabine, indicating that a dose that blocks chronic pain-related behavior has no effect on normal pain sensitivity or motivational state. These results encourage the further exploration of U.S. Food and Drug Administration–approved KCNQ activators for treating SCI pain, as well as efforts to develop a new generation of KCNQ activators that lack central side effects. PMID:28073317

Activation of KCNQ Channels Suppresses Spontaneous Activity in Dorsal Root Ganglion Neurons and Reduces Chronic Pain after Spinal Cord Injury.

PubMed

Wu, Zizhen; Li, Lin; Xie, Fuhua; Du, Junhui; Zuo, Yan; Frost, Jeffrey A; Carlton, Susan M; Walters, Edgar T; Yang, Qing

2017-03-15

A majority of people who have sustained spinal cord injury (SCI) experience chronic pain after injury, and this pain is highly resistant to available treatments. Contusive SCI in rats at T10 results in hyperexcitability of primary sensory neurons, which contributes to chronic pain. KCNQ channels are widely expressed in nociceptive dorsal root ganglion (DRG) neurons, are important for controlling their excitability, and their activation has proven effective in reducing pain in peripheral nerve injury and inflammation models. The possibility that activators of KCNQ channels could be useful for treating SCI-induced chronic pain is strongly supported by the following findings. First, SCI, unlike peripheral nerve injury, failed to decrease the functional or biochemical expression of KCNQ channels in DRG as revealed by electrophysiology, real-time quantitative polymerase chain reaction, and Western blot; therefore, these channels remain available for pharmacological targeting of SCI pain. Second, treatment with retigabine, a specific KCNQ channel opener, profoundly decreased spontaneous activity in primary sensory neurons of SCI animals both in vitro and in vivo without changing the peripheral mechanical threshold. Third, retigabine reversed SCI-induced reflex hypersensitivity, adding to our previous demonstration that retigabine supports the conditioning of place preference after SCI (an operant measure of spontaneous pain). In contrast to SCI animals, naïve animals showed no effects of retigabine on reflex sensitivity or conditioned place preference by pairing with retigabine, indicating that a dose that blocks chronic pain-related behavior has no effect on normal pain sensitivity or motivational state. These results encourage the further exploration of U.S. Food and Drug Administration-approved KCNQ activators for treating SCI pain, as well as efforts to develop a new generation of KCNQ activators that lack central side effects.

Patients with Spinal Cord Injuries Favor Administration of Methylprednisolone

PubMed Central

Bowers, Christian A.; Kundu, Bornali; Rosenbluth, Jeffrey; Hawryluk, Gregory W. J.

2016-01-01

Methylprednisolone sodium succinate (MPSS) for treatment of acute spinal cord injury (SCI) has been associated with both benefits and adverse events. MPSS administration was the standard of care for acute SCI until recently when its use has become controversial. Patients with SCI have had little input in the debate, thus we sought to learn their opinions regarding administration of MPSS. A summary of the published literature to date on MPSS use for acute SCI was created and adjudicated by 28 SCI experts. This summary was then emailed to 384 chronic SCI patients along with a survey that interrogated the patients’ neurological deficits, communication with physicians and their views on MPSS administration. 77 out of 384 patients completed the survey. 28 respondents indicated being able to speak early after injury and of these 24 reported arriving at the hospital within 8 hours of injury. One recalled a physician speaking to them about MPSS and one patient reported choosing whether or not to receive MPSS. 59.4% felt that the small neurological benefits associated with MPSS were ‘very important’ to them (p<0.0001). Patients had ‘little concern’ for potential side-effects of MPSS (p = 0.001). Only 1.4% felt that MPSS should not be given to SCI patients regardless of degree of injury (p<0.0001). This is the first study to report SCI patients’ preferences regarding MPSS treatment for acute SCI. Patients favor the administration of MPSS for acute SCI, however few had input into whether or not it was administered. Conscious patients should be given greater opportunity to decide their treatment. These results also provide some guidance regarding MPSS administration in patients unable to communicate. PMID:26789007

The Economic Burden of Urinary Tract Infection and Pressure Ulceration in Acute Traumatic Spinal Cord Injury Admissions: Evidence for Comparative Economics and Decision Analytics from a Matched Case-Control Study.

PubMed

White, Barry A B; Dea, Nicolas; Street, John T; Cheng, Christiana L; Rivers, Carly S; Attabib, Najmedden; Kwon, Brian K; Fisher, Charles G; Dvorak, Marcel F

2017-10-15

Secondary complications of spinal cord injury (SCI) are a burden to affected individuals and the rest of society. There is limited evidence of the economic burden or cost of complications in SCI populations in Canada, however, which is necessary for comparative economic analyses and decision analytic modeling of possible solutions to these common health problems. Comparative economic analyses can inform resource allocation decisions, but the outputs are only as good as the inputs. In this article, new evidence of the excess or incremental costs of urinary tract infection (UTI) and pressure ulceration (PU) in acute traumatic SCI from an exploratory case series analysis of admissions to a Level I specialized Canadian spine facility (2008-2013) is presented. Participants in a national SCI registry were case-control matched (1:1) on the predicted probability of experiencing UTI or PU during initial acute SCI admission. The excess costs of UTI and PU are estimated as the mean of the differences in total direct acute SCI admission costs (length of stay, accommodation, nursing, pharmacy) from the perspective of the admitting facility between participants matched or paired on demographic and SCI characteristics. Even relatively minor UTI and PU, respectively, added an average of $7,790 (standard deviation [SD] $6,267) and $18,758 (SD $27,574) to the direct cost of acute SCI admission in 2013 Canadian dollars (CAD). This case series analysis established evidence of the excess costs of UTI and PU in acute SCI admissions, which will support decision-informing analyses in SCI.

Cardiac dysfunctions following spinal cord injury

PubMed Central

Sandu, AM; Popescu, M; Iacobini, MA; Stoian, R; Neascu, C; Popa, F

2009-01-01

The aim of this article is to analyze cardiac dysfunctions occurring after spinal cord injury (SCI). Cardiac dysfunctions are common complications following SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. We reviewed epidemiology of cardiac disturbances after SCI, and neuroanatomy and pathophysiology of autonomic nervous system, sympathetic and parasympathetic. SCI causes disruption of descendent pathways from central control centers to spinal sympathetic neurons, originating into intermediolateral nuclei of T1–L2 spinal cord segments. Loss of supraspinal control over sympathetic nervous system results in reduced overall sympathetic activity below the level of injury and unopposed parasympathetic outflow through intact vagal nerve. SCI associates significant cardiac dysfunction. Impairment of autonomic nervous control system, mostly in patients with cervical or high thoracic SCI, causes cardiac dysrrhythmias, especially bradycardia and, rarely, cardiac arrest, or tachyarrhytmias and hypotension. Specific complication dependent on the period of time after trauma like spinal shock and autonomic dysreflexia are also reviewed. Spinal shock occurs during the acute phase following SCI and is a transitory suspension of function and reflexes below the level of the injury. Neurogenic shock, part of spinal shock, consists of severe bradycardia and hypotension. Autonomic dysreflexia appears during the chronic phase, after spinal shock resolution, and it is a life–threatening syndrome of massive imbalanced reflex sympathetic discharge occurring in patients with SCI above the splanchnic sympathetic outflow (T5–T6). Besides all this, additional cardiac complications, such as cardiac deconditioning and coronary heart disease may also occur. Proper prophylaxis, including nonpharmacologic and pharmacological strategies and cardiac rehabilitation diminish occurrence of the cardiac dysfunction following SCI. Each type of cardiac disturbance requires specific treatment. PMID:20108532

Anabolic steroids reduce spinal cord injury-related bone loss in rats associated with increased Wnt signaling

PubMed Central

Sun, Li; Pan, Jiangping; Peng, Yuanzhen; Wu, Yong; Li, Jianghua; Liu, Xuan; Qin, Yiwen; Bauman, William A.; Cardozo, Christopher; Zaidi, Mone; Qin, Weiping

2013-01-01

Background Spinal cord injury (SCI) causes severe bone loss. At present, there is no practical treatment to delay or prevent bone loss in individuals with motor-complete SCI. Hypogonadism is common in men after SCI and may exacerbate bone loss. The anabolic steroid nandrolone reduces bone loss due to microgravity or nerve transection. Objective To determine whether nandrolone reduced bone loss after SCI and, if so, to explore the mechanisms of nandrolone action. Methods Male rats with complete transection of the spinal cord were administered nandrolone combined with a physiological replacement dose of testosterone, or vehicle, beginning on day 29 after SCI and continued for 28 days. Results SCI reduced distal femoral and proximal tibial bone mineral density (BMD) by 25 and 16%, respectively, at 56 days. This bone loss was attenuated by nandrolone. In ex vivo osteoclasts cultures, SCI increased mRNA levels for tartrate-resistant acid phosphatase (TRAP) and calcitonin receptor; nandrolone-normalized expression levels of these transcripts. In ex vivo osteoblast cultures, SCI increased receptor activator of NF-kB ligand (RANKL) mRNA levels but did not alter osteoprotegerin (OPG) mRNA expression; nandrolone-increased expression of OPG and OPG/RANKL ratio. SCI reduced mRNA levels of Wnt signaling-related genes Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5), Fzd5, Tcf7, and ectodermal-neural cortex 1 (ENC1) in osteoblasts, whereas nandrolone increased expression of each of these genes. Conclusions The results demonstrate that nandrolone reduces bone loss after SCI. A potential mechanism is suggested by our findings wherein nandrolone modulates genes for differentiation and activity of osteoclasts and osteoblasts, at least in part, through the activation of Wnt signaling. PMID:24090150

Semen quality in ejaculates produced by masturbation in men with spinal cord injury.

PubMed

Kathiresan, A S Q; Ibrahim, E; Modh, R; Aballa, T C; Lynne, C M; Brackett, N L

2012-12-01

Retrospective study. Most men with spinal cord injury are anejaculatory. Much has been reported about their semen quality collected by penile vibratory stimulation and electroejaculation (EEJ). What is not well-described is the nature of semen quality in SCI patients who can ejaculate by masturbation. This study was performed to understand the degree to which their semen quality differed from that of anejaculatory SCI patients versus that of healthy non-SCI control subjects. University of Miami. Retrospective chart review of Male Fertility Research Program participants from 1991 to 2011. Of 528 SCI subjects, 444 met inclusion criteria of completing an algorithm in which ejaculation occurred by masturbation (n=43), PVS (n=243), or EEJ (n=158). Sperm motility was higher in the SCI-masturbation group (36.9%) than the PVS group (25.9%, P<0.001) or EEJ group (15.0%, P<0.001), but lower compared with a control group of 61 non-SCI healthy men who collected their semen by masturbation (58.0%, P<0.001). The SCI-masturbation group had similar antegrade sperm concentration (83.3×10(6) cc(-1)) as the PVS group (77.4×10(6) cc(-1)) and control group (82.0×10(6) cc(-1)), but higher than the EEJ group (49.8×10(6) cc(-1), P<0.001). The SCI-masturbation group had significantly more men with incomplete injuries (84%) than the PVS group (54%, P<0.01) or EEJ group (41%, P<0.001). This is the first report focusing on semen quality obtained by masturbation in men with SCI. Sperm motility was higher in men with SCI who could, versus could not, ejaculate by masturbation. Completeness of injury may contribute to this difference.

The effects of using the Internet on the health-related quality of life in people with spinal cord injury: a controlled study.

PubMed

Celik, B; Ones, K; Celik, E C; Bugdayci, D S; Paker, N; Avci, C; Ince, N

2014-05-01

Prospective cohort study. To compare the health-related quality of life (HRQoL) in people with spinal cord injury (SCI) who use the Internet versus those who don't and with a control group of able-bodied individuals. To investigate the frequency of Internet usage before and after injury. To evaluate the differences in terms of demographic features of both groups, analyze the variation in the Internet usage pattern of people with SCI before and after the injury. Istanbul, Turkey. A total of 60 people with SCI (38 Internet users, 22 nonusers) were included in the study. The control group consisted of 33 healthy persons of similar age and sex. The HRQoL was evaluated with the SF-36 Health Survey. The scores of all the subscales of the SF-36, except vitality, were significantly lower in people with SCI than those of the controls'. The bodily pain subscale and physical component scores were found to be significantly higher in people with SCI using the Internet than the nonuser group with SCI (P<0.05). The Internet usage frequency increased significantly in people with SCI after injury (P<0.05). A significant correlation was found between time since injury and Internet use (r=0.365, P=0.007). Although HRQoL scores were lower in people with an SCI, the physical status component score was better in the Internet user SCI group. As there is a significant increase in the time spent online after injury, the Internet could be an effective modality to contact and educate people with an SCI.

RNA-Seq Analysis of Microglia Reveals Time-Dependent Activation of Specific Genetic Programs following Spinal Cord Injury

PubMed Central

Noristani, Harun N.; Gerber, Yannick N.; Sabourin, Jean-Charles; Le Corre, Marine; Lonjon, Nicolas; Mestre-Frances, Nadine; Hirbec, Hélène E.; Perrin, Florence E.

2017-01-01

Neurons have inherent competence to regrow following injury, although not spontaneously. Spinal cord injury (SCI) induces a pronounced neuroinflammation driven by resident microglia and infiltrating peripheral macrophages. Microglia are the first reactive glial population after SCI and participate in recruitment of monocyte-derived macrophages to the lesion site. Both positive and negative influence of microglia and macrophages on axonal regeneration had been reported after SCI, raising the issue whether their response depends on time post-lesion or different lesion severity. We analyzed molecular alterations in microglia at several time-points after different SCI severities using RNA-sequencing. We demonstrate that activation of microglia is time-dependent post-injury but is independent of lesion severity. Early transcriptomic response of microglia after SCI involves proliferation and neuroprotection, which is then switched to neuroinflammation at later stages. Moreover, SCI induces an autologous microglial expression of astrocytic markers with over 6% of microglia expressing glial fibrillary acidic protein and vimentin from as early as 72 h post-lesion and up to 6 weeks after injury. We also identified the potential involvement of DNA damage and in particular tumor suppressor gene breast cancer susceptibility gene 1 (Brca1) in microglia after SCI. Finally, we established that BRCA1 protein is specifically expressed in non-human primate spinal microglia and is upregulated after SCI. Our data provide the first transcriptomic analysis of microglia at multiple stages after different SCI severities. Injury-induced microglia expression of astrocytic markers at RNA and protein levels demonstrates novel insights into microglia plasticity. Finally, increased microglia expression of BRCA1 in rodents and non-human primate model of SCI, suggests the involvement of oncogenic proteins after CNS lesion. PMID:28420963

Delayed Influence of Spinal Cord Injury on the Amino Acids of NO• Metabolism in Rat Cerebral Cortex Is Attenuated by Thiamine

PubMed Central

Boyko, Alexandra; Ksenofontov, Alexander; Ryabov, Sergey; Baratova, Lyudmila; Graf, Anastasia; Bunik, Victoria

2018-01-01

Severe spinal cord injuries (SCIs) result in chronic neuroinflammation in the brain, associated with the development of cognitive and behavioral impairments. Nitric oxide (NO•) is a gaseous messenger involved in neuronal signaling and inflammation, contributing to nitrosative stress under dysregulated production of reactive nitrogen species. In this work, biochemical changes induced in the cerebral cortex of rats 8 weeks after SCI are assessed by quantification of the levels of amino acids participating in the NO• and glutathione metabolism. The contribution of the injury-induced neurodegeneration is revealed by comparison of the SCI- and laminectomy (LE)-subjected animals. Effects of the operative interventions are assessed by comparison of the operated (LE/SCI) and non-operated animals. Lower ratios of citrulline (Cit) to arginine (Arg) or Cit to ornithine and a more profound decrease in the ratio of lysine to glycine distinguish SCI animals from those after LE. The data suggest decreased NO• production from both Arg and homoarginine in the cortex 8 weeks after SCI. Both LE and SCI groups show a strong decrease in the level of cortex glutathione. The neurotropic, anti-inflammatory, and antioxidant actions of thiamine (vitamin B1) prompted us to study the thiamine effects on the SCI-induced changes in the NO• and glutathione metabolism. A thiamine injection (400 mg/kg intraperitoneally) within 24 h after SCI abrogates the changes in the cerebral cortex amino acids related to NO•. Thiamine-induced normalization of the brain glutathione levels after LE and SCI may involve increased supply of glutamate for glutathione biosynthesis. Thus, thiamine protects from sequelae of SCI on NO•-related amino acids and glutathione in cerebral cortex. PMID:29379782

Neuro magnetic resonance spectroscopy using wavelet decomposition and statistical testing identifies biochemical changes in people with spinal cord injury and pain.

PubMed

Stanwell, Peter; Siddall, Philip; Keshava, Nirmal; Cocuzzo, Daniel; Ramadan, Saadallah; Lin, Alexander; Herbert, David; Craig, Ashley; Tran, Yvonne; Middleton, James; Gautam, Shiva; Cousins, Michael; Mountford, Carolyn

2010-11-01

Spinal cord injury (SCI) can be accompanied by chronic pain, the mechanisms for which are poorly understood. Here we report that magnetic resonance spectroscopy measurements from the brain, collected at 3T, and processed using wavelet-based feature extraction and classification algorithms, can identify biochemical changes that distinguish control subjects from subjects with SCI as well as subdividing the SCI group into those with and without chronic pain. The results from control subjects (n=10) were compared to those with SCI (n=10). The SCI cohort was made up of subjects with chronic neuropathic pain (n=5) and those without chronic pain (n=5). The wavelet-based decomposition of frequency domain MRS signals employs statistical significance testing to identify features best suited to discriminate different classes. Moreover, the features benefit from careful attention to the post-processing of the spectroscopy data prior to the comparison of the three cohorts. The spectroscopy data, from the thalamus, best distinguished control subjects without SCI from those with SCI with a sensitivity and specificity of 0.9 (Percentage of Correct Classification). The spectroscopy data obtained from the prefrontal cortex and anterior cingulate cortex both distinguished between SCI subjects with chronic neuropathic pain and those without pain with a sensitivity and specificity of 1.0. In this study, where two underlying mechanisms co-exist (i.e. SCI and pain), the thalamic changes appear to be linked more strongly to SCI, while the anterior cingulate cortex and prefrontal cortex changes appear to be specifically linked to the presence of pain. Copyright 2010 Elsevier Inc. All rights reserved.

Mental health and life satisfaction of individuals with spinal cord injury and their partners 5 years after discharge from first inpatient rehabilitation.

PubMed

Scholten, Eline W M; Tromp, Maria E H; Hillebregt, Chantal F; de Groot, Sonja; Ketelaar, Marjolijn; Visser-Meily, Johanna M A; Post, Marcel W M

2018-06-01

Cross-sectional study. To describe and compare mental health and life satisfaction between individuals with spinal cord injury (SCI) and their partners 5 years after discharge from first inpatient rehabilitation; and to examine if injury severity moderates the association between individuals' with SCI and their partners' mental health and life satisfaction. Dutch community. Sixty-five individuals with SCI and their partners completed a self-report questionnaire. Main outcome measures were the mental health subscale of the Short-Form Health Survey and the Life Satisfaction Questionnaire. Levels of mental health and life satisfaction of individuals with SCI and partners were similar, with median scores of 76 and 4.8 versus 76 and 4.6, respectively. Moderate to strong correlations between individuals with SCI and their partners were found for the mental health (r S  = 0.35) and life satisfaction scores (r S  = 0.51). These associations were generally stronger in the subgroup of individuals with less severe SCI. Associations between scores on separate life domains ranged from negligible (0.05) to moderate (0.53). Individuals with SCI and their partners were least satisfied with their 'sexual life'. Compared with their partners, individuals with SCI were significantly more satisfied in the domains 'leisure situation', 'partnership relation' and 'family life', and less satisfied in 'self-care ability'. This study showed similarities but also differences in mental health and life satisfaction between individuals with SCI and their partners. In clinical practice, attention on mental health and life satisfaction should, therefore, focus on different domains for individuals with SCI and partners.

An Adaptive Neuromuscular Controller for Assistive Lower-Limb Exoskeletons: A Preliminary Study on Subjects with Spinal Cord Injury

PubMed Central

Wu, Amy R.; Dzeladini, Florin; Brug, Tycho J. H.; Tamburella, Federica; Tagliamonte, Nevio L.; van Asseldonk, Edwin H. F.; van der Kooij, Herman; Ijspeert, Auke J.

2017-01-01

Versatility is important for a wearable exoskeleton controller to be responsive to both the user and the environment. These characteristics are especially important for subjects with spinal cord injury (SCI), where active recruitment of their own neuromuscular system could promote motor recovery. Here we demonstrate the capability of a novel, biologically-inspired neuromuscular controller (NMC) which uses dynamical models of lower limb muscles to assist the gait of SCI subjects. Advantages of this controller include robustness, modularity, and adaptability. The controller requires very few inputs (i.e., joint angles, stance, and swing detection), can be decomposed into relevant control modules (e.g., only knee or hip control), and can generate walking at different speeds and terrains in simulation. We performed a preliminary evaluation of this controller on a lower-limb knee and hip robotic gait trainer with seven subjects (N = 7, four with complete paraplegia, two incomplete, one healthy) to determine if the NMC could enable normal-like walking. During the experiment, SCI subjects walked with body weight support on a treadmill and could use the handrails. With controller assistance, subjects were able to walk at fast walking speeds for ambulatory SCI subjects—from 0.6 to 1.4 m/s. Measured joint angles and NMC-provided joint torques agreed reasonably well with kinematics and biological joint torques of a healthy subject in shod walking. Some differences were found between the torques, such as the lack of knee flexion near mid-stance, but joint angle trajectories did not seem greatly affected. The NMC also adjusted its torque output to provide more joint work at faster speeds and thus greater joint angles and step length. We also found that the optimal speed-step length curve observed in healthy humans emerged for most of the subjects, albeit with relatively longer step length at faster speeds. Therefore, with very few sensors and no predefined settings for multiple walking speeds or adjustments for subjects of differing anthropometry and walking ability, NMC enabled SCI subjects to walk at several speeds, including near healthy speeds, in a healthy-like manner. These preliminary results are promising for future implementation of neuromuscular controllers on wearable prototypes for real-world walking conditions. PMID:28676752

An Adaptive Neuromuscular Controller for Assistive Lower-Limb Exoskeletons: A Preliminary Study on Subjects with Spinal Cord Injury.

PubMed

Wu, Amy R; Dzeladini, Florin; Brug, Tycho J H; Tamburella, Federica; Tagliamonte, Nevio L; van Asseldonk, Edwin H F; van der Kooij, Herman; Ijspeert, Auke J

2017-01-01

Versatility is important for a wearable exoskeleton controller to be responsive to both the user and the environment. These characteristics are especially important for subjects with spinal cord injury (SCI), where active recruitment of their own neuromuscular system could promote motor recovery. Here we demonstrate the capability of a novel, biologically-inspired neuromuscular controller (NMC) which uses dynamical models of lower limb muscles to assist the gait of SCI subjects. Advantages of this controller include robustness, modularity, and adaptability. The controller requires very few inputs (i.e., joint angles, stance, and swing detection), can be decomposed into relevant control modules (e.g., only knee or hip control), and can generate walking at different speeds and terrains in simulation. We performed a preliminary evaluation of this controller on a lower-limb knee and hip robotic gait trainer with seven subjects ( N = 7, four with complete paraplegia, two incomplete, one healthy) to determine if the NMC could enable normal-like walking. During the experiment, SCI subjects walked with body weight support on a treadmill and could use the handrails. With controller assistance, subjects were able to walk at fast walking speeds for ambulatory SCI subjects-from 0.6 to 1.4 m/s. Measured joint angles and NMC-provided joint torques agreed reasonably well with kinematics and biological joint torques of a healthy subject in shod walking. Some differences were found between the torques, such as the lack of knee flexion near mid-stance, but joint angle trajectories did not seem greatly affected. The NMC also adjusted its torque output to provide more joint work at faster speeds and thus greater joint angles and step length. We also found that the optimal speed-step length curve observed in healthy humans emerged for most of the subjects, albeit with relatively longer step length at faster speeds. Therefore, with very few sensors and no predefined settings for multiple walking speeds or adjustments for subjects of differing anthropometry and walking ability, NMC enabled SCI subjects to walk at several speeds, including near healthy speeds, in a healthy-like manner. These preliminary results are promising for future implementation of neuromuscular controllers on wearable prototypes for real-world walking conditions.

Nonlinear electromagnetic gyrokinetic particle simulations with the electron hybrid model

NASA Astrophysics Data System (ADS)

Nishimura, Y.; Lin, Z.; Chen, L.; Hahm, T.; Wang, W.; Lee, W.

2006-10-01

The electromagnetic model with fluid electrons is successfully implemented into the global gyrokinetic code GTC. In the ideal MHD limit, shear Alfven wave oscillation and continuum damping is demonstrated. Nonlinear electromagnetic simulation is further pursued in the presence of finite ηi. Turbulence transport in the AITG unstable β regime is studied. This work is supported by Department of Energy (DOE) Grant DE-FG02-03ER54724, Cooperative Agreement No. DE-FC02-04ER54796 (UCI), DOE Contract No. DE-AC02-76CH03073 (PPPL), and in part by SciDAC Center for Gyrokinetic Particle Simulation of Turbulent Transport in Burning Plasmas. Z. Lin, et al., Science 281, 1835 (1998). F. Zonca and L. Chen, Plasma Phys. Controlled Fusion 30, 2240 (1998); G. Zhao and L. Chen, Phys. Plasmas 9, 861 (2002).

Studying Spacecraft Charging via Numerical Simulations

NASA Astrophysics Data System (ADS)

Delzanno, G. L.; Moulton, D.; Meierbachtol, C.; Svyatskiy, D.; Vernon, L.

2015-12-01

The electrical charging of spacecraft due to bombarding charged particles can affect their performance and operation. We study this charging using CPIC; a particle-in-cell code specifically designed for studying plasma-material interactions [1]. CPIC is based on multi-block curvilinear meshes, resulting in near-optimal computational performance while maintaining geometric accuracy. Relevant plasma parameters are imported from the SHIELDS framework (currently under development at LANL), which simulates geomagnetic storms and substorms in the Earth's magnetosphere. Simulated spacecraft charging results of representative Van Allen Probe geometries using these plasma parameters will be presented, along with an overview of the code. [1] G.L. Delzanno, E. Camporeale, J.D. Moulton, J.E. Borovsky, E.A. MacDonald, and M.F. Thomsen, "CPIC: A Curvilinear Particle-In-Cell Code for Plasma-Material Interaction Studies," IEEE Trans. Plas. Sci., 41 (12), 3577 (2013).

How Do Iranian People with Spinal Cord Injury Understand Marriage?

PubMed Central

Merghati-Khoei, Effat; Maasoumi, Raziyeh; Zarei, Fatemeh; Laleh, Leila; Pasha, Yousofreza Yousofnia; Korte, Jeffrey E.

2017-01-01

Background: Spinal cord injury (SCI) is a life-altering experience. There is little information about the perspectives of people with SCI toward marriage. Purpose: To explore the understandings of Iranian adults with SCI about marriage. Methods: In this qualitative inquiry, using a semi-structured interview guide, we collected data from 53 single adults with SCI (41 men and 12 women) who were referred to the Brain and Spinal Cord Injury Research Center, Tehran University of Medical Sciences in Tehran. Barun and Clarke's thematic analysis approach was applied for data analysis. Results: “Marriage” was thematized in outer and inner scenarios. The outer scenario was explored in terms of physical disability identified as a seminal determinant in successful marriage. “Attractiveness,” “able body for breadwinning,” “sexually active,” and “reproduction” were dominant concepts extracted from the participants' narratives. The participants' inner scenarios revealed that marriage would be welcomed if a potential partner accepted them as a “whole person” regardless of their SCI condition. Conclusion: The findings suggest that adults with SCI do not ignore or reject marriage, however it was not their life priority due to major concerns that they had internalized. Considering the quality of care, people with SCI must be reassured about their potential to get married. SCI-based sexuality education and premarital counseling support the patients in their postmarital lives. Our findings will provide decision makers and health providers with significant insight for utilizing culturally appropriate services for people with SCI. PMID:29339879

Effects of melatonin on severe crush spinal cord injury-induced reactive astrocyte and scar formation.

PubMed

Krityakiarana, Warin; Sompup, Kamonrapat; Jongkamonwiwat, Nopporn; Mukda, Sujira; Pinilla, Fernando Gomez; Govitrapong, Piyarat; Phansuwan-Pujito, Pansiri

2016-12-01

The present work aimed at analyzing the effects of melatonin on scar formation after spinal cord injury (SCI). Upregulation of reactive astrocyte under SCI pathological conditions has been presented in several studies. It has been proved that the crucial factor in triggering this upregulation is proinflammatory cytokines. Moreover, scar formation is an important barrier to axonal regeneration through the lesion area. Melatonin plays an important role in reducing inflammation, but its effects on scar formation in the injured spinal cord remain unknown. Hence, we used the model of severe crush injury in mice to investigate the effects of melatonin on scar formation. Mice were randomly separated into four groups; SCI, SCI+Melatonin 1 (single dose), SCI+Melatonin 14 (14 daily doses), and control. Melatonin was administered by intraperitoneal injection (10 mg/kg) after injury. Immunohistochemical analysis, Western blot, and behavioral evaluation were used to explore the effects of melatonin after SCI for 14 days. The melatonin-treated mice presented higher expression of neuronal markers (P < 0.001). Remarkably, the inflammatory response appeared to be greatly reduced in the SCI+Melatonin 14 group (P < 0.001), which also displayed less scar formation (P < 0.05). These findings suggest that melatonin inhibits scar formation by acting on inflammatory cytokines after SCI. Overall, our results suggest that melatonin is a promising treatment strategy after SCI that deserves further investigation. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Pathological activity in mediodorsal thalamus of rats with spinal cord injury pain.

PubMed

Whitt, Jessica L; Masri, Radi; Pulimood, Nisha S; Keller, Asaf

2013-02-27

Spinal cord injury (SCI) results not only in motor deficits, but produces, in many patients, excruciating chronic pain (SCI pain). We have previously shown, in a rodent model, that SCI causes suppression of activity in the GABAergic nucleus, the zona incerta (ZI), and concomitant increased activity in one of its main targets, the posterior nucleus of the thalamus (PO); the increased PO activity is correlated with the maintenance and expression of hyperalgesia after SCI. Here, we test the hypothesis that SCI causes a similar pathological increase in other thalamic nuclei regulated by the ZI, specifically the mediodorsal thalamus (MD), which is involved in the emotional-affective aspects of pain. We recorded single and multiunit activity from MD of either anesthetized or awake rats, and compared data from rats with SCI with data from sham-operated controls (anesthetized experiments) or with data from the same animals prelesion (awake experiments). Consistent with our hypothesis, MD neurons from rats with SCI show significant increases in spontaneous firing rates and in the magnitude and duration of responses to noxious stimuli. In a subset of anesthetized animals, similar changes in activity of MD neurons were produced by pharmacologically inactivating ZI in naive rats, suggesting that the changes in the MD after SCI are related to suppressed inhibition from the ZI. These data support our hypothesis that SCI pain results, at least in part, from a loss of inhibition to thalamic nuclei associated with both the sensory-discriminative and emotional-affective components of pain.

Earnings among people with spinal cord injury.

PubMed

Ramakrishnan, K; Loh, S Y; Omar, Z

2011-09-01

Secondary analysis of cross-sectional data. To identify differences in earnings among participants with spinal cord injury (SCI) and their relation to demographic, injury, educational and employment-related factors. People living with SCI in the community who were members of a disability support organization. A total of 76 members who have had traumatic SCI for at least 2 years, between 15 and 64 years of age at time of study and were working before SCI were interviewed over the phone. The earnings were categorized as more, same or less than before SCI or no income for those unemployed. Of the 76 participants (who averaged about 15.1 years post SCI), only 13 participants (17.1%) were earning more than before injury, whereas majority were in the category of having no income, being unemployed at time of study, n=36 (47.4%). Factors positively related to earnings were having more years in education, both at time of injury and at time of survey. As anticipated, those currently in full time and paid employments were earning more while receipt of financial compensation was negatively related to earnings. Despite a lengthy period of time post SCI, only a minority were earning more, reflecting poorly on the quality of post SCI employment experience. The rehabilitation team should therefore focus on improving both educational and vocational opportunities for persons with SCI and aim for full time, paid employments. The current workers' compensation scheme renders the recipient at a static income and may need to be revised.

Total fluid pressure imbalance in the scrape-off layer of tokamak plasmas

DOE PAGES

Churchill, Randy M.; Canik, John M.; Chang, C. S.; ...

2017-03-10

Simulations using the fully kinetic neoclassical code XGCa (X-point included guiding-center axisymmetric) were undertaken to explore the impact of kinetic effects on scrape-off layer (SOL) physics in DIII-D H-mode plasmas. XGCa is a total-f, gyrokinetic code which self-consistently calculates the axisymmetric electrostatic potential and plasma dynamics, and includes modules for Monte Carlo neutral transport. Previously presented XGCa results showed several noteworthy features, including large variations of ion density and pressure along field lines in the SOL, experimentally relevant levels of SOL parallel ion flow (Mach number similar to 0.5), skewed ion distributions near the sheath entrance leading to subsonic flowmore » there, and elevated sheath potentials (Churchill 2016 Nucl. Mater. Energy 1-6). In this paper, we explore in detail the question of pressure balance in the SOL, as it was observed in the simulation that there was a large deviation from a simple total pressure balance (the sum of ion and electron static pressure plus ion inertia). It will be shown that both the contributions from the ion viscosity (driven by ion temperature anisotropy) and neutral source terms can be substantial, and should be retained in the parallel momentum equation in the SOL, but still falls short of accounting for the observed fluid pressure imbalance in the XGCa simulation results.« less

Validation, Optimization and Simulation of a Solar Thermoelectric Generator Model

NASA Astrophysics Data System (ADS)

Madkhali, Hadi Ali; Hamil, Ali; Lee, HoSung

2017-12-01

This study explores thermoelectrics as a viable option for small-scale solar thermal applications. Thermoelectric technology is based on the Seebeck effect, which states that a voltage is induced when a temperature gradient is applied to the junctions of two differing materials. This research proposes to analyze, validate, simulate, and optimize a prototype solar thermoelectric generator (STEG) model in order to increase efficiency. The intent is to further develop STEGs as a viable and productive energy source that limits pollution and reduces the cost of energy production. An empirical study (Kraemer et al. in Nat Mater 10:532, 2011) on the solar thermoelectric generator reported a high efficiency performance of 4.6%. The system had a vacuum glass enclosure, a flat panel (absorber), thermoelectric generator and water circulation for the cold side. The theoretical and numerical approach of this current study validated the experimental results from Kraemer's study to a high degree. The numerical simulation process utilizes a two-stage approach in ANSYS software for Fluent and Thermal-Electric Systems. The solar load model technique uses solar radiation under AM 1.5G conditions in Fluent. This analytical model applies Dr. Ho Sung Lee's theory of optimal design to improve the performance of the STEG system by using dimensionless parameters. Applying this theory, using two cover glasses and radiation shields, the STEG model can achieve a highest efficiency of 7%.

Phase field models for heterogeneous nucleation: Application to inoculation in alpha-solidifying Ti-Al-B alloys

NASA Astrophysics Data System (ADS)

Apel, M.; Eiken, J.; Hecht, U.

2014-02-01

This paper aims at briefly reviewing phase field models applied to the simulation of heterogeneous nucleation and subsequent growth, with special emphasis on grain refinement by inoculation. The spherical cap and free growth model (e.g. A.L. Greer, et al., Acta Mater. 48, 2823 (2000)) has proven its applicability for different metallic systems, e.g. Al or Mg based alloys, by computing the grain refinement effect achieved by inoculation of the melt with inert seeding particles. However, recent experiments with peritectic Ti-Al-B alloys revealed that the grain refinement by TiB2 is less effective than predicted by the model. Phase field simulations can be applied to validate the approximations of the spherical cap and free growth model, e.g. by computing explicitly the latent heat release associated with different nucleation and growth scenarios. Here, simulation results for point-shaped nucleation, as well as for partially and completely wetted plate-like seed particles will be discussed with respect to recalescence and impact on grain refinement. It will be shown that particularly for large seeding particles (up to 30 μm), the free growth morphology clearly deviates from the assumed spherical cap and the initial growth - until the free growth barrier is reached - significantly contributes to the latent heat release and determines the recalescence temperature.

Full-dispersion Monte Carlo simulation of phonon transport in micron-sized graphene nanoribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mei, S., E-mail: smei4@wisc.edu; Knezevic, I., E-mail: knezevic@engr.wisc.edu; Maurer, L. N.

2014-10-28

We simulate phonon transport in suspended graphene nanoribbons (GNRs) with real-space edges and experimentally relevant widths and lengths (from submicron to hundreds of microns). The full-dispersion phonon Monte Carlo simulation technique, which we describe in detail, involves a stochastic solution to the phonon Boltzmann transport equation with the relevant scattering mechanisms (edge, three-phonon, isotope, and grain boundary scattering) while accounting for the dispersion of all three acoustic phonon branches, calculated from the fourth-nearest-neighbor dynamical matrix. We accurately reproduce the results of several experimental measurements on pure and isotopically modified samples [S. Chen et al., ACS Nano 5, 321 (2011);S. Chenmore » et al., Nature Mater. 11, 203 (2012); X. Xu et al., Nat. Commun. 5, 3689 (2014)]. We capture the ballistic-to-diffusive crossover in wide GNRs: room-temperature thermal conductivity increases with increasing length up to roughly 100 μm, where it saturates at a value of 5800 W/m K. This finding indicates that most experiments are carried out in the quasiballistic rather than the diffusive regime, and we calculate the diffusive upper-limit thermal conductivities up to 600 K. Furthermore, we demonstrate that calculations with isotropic dispersions overestimate the GNR thermal conductivity. Zigzag GNRs have higher thermal conductivity than same-size armchair GNRs, in agreement with atomistic calculations.« less

Type A polymer concrete overlay field trials : final report.

DOT National Transportation Integrated Search

1984-12-01

This report describes placement and subsequent performance of two methyl methacrylate polymer concrete overlays. Performance is evaluated as to: 1) the mixing and placement characteristics of the methyl methacrylate polymer concretes as overlay mater...

76 FR 17135 - Clarifying Edits to Existing Special Controls Guidance Documents; Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-28

... Virus, 29. Endotoxin Assay, 30. Dental Sonography and Jaw Tracking Devices, 31. Human Dura Mater... for the Topical Approximation of Skin, 78. Bone Sonometers, 79. Tissue Expander, 80. Cord Blood...

Physical activity is related to lower levels of pain, fatigue and depression in individuals with spinal-cord injury: a correlational study.

PubMed

Tawashy, A E; Eng, J J; Lin, K H; Tang, P F; Hung, C

2009-04-01

This was a prospective cross-sectional study for people with chronic spinal cord injury (SCI). To (1) evaluate the intensity level and nature of physical activity in community-dwelling individuals living with SCI, and (2) explore the relation between descriptive individual variables (for example, lesion level), secondary complications and participation in physical activity. Urban community setting. A total of 49 subjects with SCI who used a manual wheelchair for primary mode of mobility (mean years since injury, 11.8; mean age, 43.7 years; 67% paraplegia) completed the physical activity recall assessment for people with SCI (PARA-SCI). Approximately 50% of reported physical activity among individuals with SCI is due to activities of daily living. The amount of physical activity was not related to lesion level, age, body mass index or waistline size. Greater heavy-intensity activity was related to lower levels of pain and fatigue and higher levels of self-efficacy, whereas higher amounts of mild-intensity activity and total activity were related to less depressive symptoms. Activities of daily living are a large component for physical activity among individuals with SCI. It appears that greater physical activity is associated with less secondary complications (pain, fatigue and depression) in individuals with SCI.

[Subjective cognitive impairment and Alzheimer's disease: a two year follow up of 51 subjects during two years].

PubMed

Sambuchi, Nathalie; Muraccioli, Isabelle; Alescio-Lautier, Béatrice; Paban, Véronique; Sambuc, Roland; Jouve, Élisabeth; Geda, Yonas Endale; Petersen, Ronald Karl; Michel, Bernard François

2015-12-01

Subjective cognitive impairment (SCI) is defined by a state of subjective complaint, without objective cognitive deterioration. Amnestic mild cognitive impairment (A-MCI), which characterizes a syndrome between normal cognitive aging and early Alzheimer's disease (E-AD), is preceded by A-MCI from many years. SCI expresses a metacognitive impairment. A cohort of 51 subjects [7 normal controls (NC), 28 SCI, 12 A-MCI and 5 E-AD] was followed up during 24 months, with a neuropsychological evaluation each 6 months during 1 year (V1, V2, V3), then 1 year later (V4). Among the 28 SCI, 6 converted to A-MCI at V4 (21.42%), 1 to A-MCI-A at V3, then to E-AD at V4. These results suggest a continuum from SCI to A-MCI, and E-AD. Progressive SCI differed from non-progressive SCI on verbal episodic memory and executive functions tests at the initial examination. MRI showed anterior cingular atrophy in all SCI patients but hippocampal atrophy was only observed in 20 patients. Our results suggest that metacognition impairment is the expression of a dysfunction in the anterior pre-frontal cortex, in correlation with a syndrome of hyper-attention.

From basics to clinical: a comprehensive review on spinal cord injury.

PubMed

Silva, Nuno A; Sousa, Nuno; Reis, Rui L; Salgado, António J

2014-03-01

Spinal cord injury (SCI) is a devastating neurological disorder that affects thousands of individuals each year. Over the past decades an enormous progress has been made in our understanding of the molecular and cellular events generated by SCI, providing insights into crucial mechanisms that contribute to tissue damage and regenerative failure of injured neurons. Current treatment options for SCI include the use of high dose methylprednisolone, surgical interventions to stabilize and decompress the spinal cord, and rehabilitative care. Nonetheless, SCI is still a harmful condition for which there is yet no cure. Cellular, molecular, rehabilitative training and combinatorial therapies have shown promising results in animal models. Nevertheless, work remains to be done to ascertain whether any of these therapies can safely improve patient's condition after human SCI. This review provides an extensive overview of SCI research, as well as its clinical component. It starts covering areas from physiology and anatomy of the spinal cord, neuropathology of the SCI, current clinical options, neuronal plasticity after SCI, animal models and techniques to assess recovery, focusing the subsequent discussion on a variety of promising neuroprotective, cell-based and combinatorial therapeutic approaches that have recently moved, or are close, to clinical testing. Copyright © 2013 Elsevier Ltd. All rights reserved.

ComSciCon: The Communicating Science Workshop for Graduate Students

NASA Astrophysics Data System (ADS)

Sanders, Nathan; Drout, Maria; Kohler, Susanna; Cook, Ben; ComSciCon Leadership Team

2018-01-01

ComSciCon (comscicon.com) is a national workshop series organized by graduate students, for graduate students, focused on leadership and training in science communication. Our goal is to empower young scientists to become leaders in their field, propagating appreciation and understanding of research results to broad and diverse audiences. ComSciCon attendees meet and interact with professional communicators, build lasting networks with graduate students in all fields of science and engineering from around the country, and write and publish original works. ComSciCon consists of both a flagship national conference series run annually for future leaders in science communication, and a series of regional and specialized workshops organized by ComSciCon alumni nationwide. We routinely receive over 1000 applications for 50 spots in our national workshop. Since its founding in 2012, over 300 STEM graduate students have participated in the national workshop, and 23 local spin-off workshops have been organized in 10 different locations throughout the country. This year, ComSciCon is working to grow as a self-sustaining organization by launching as an independent 501(c)(3) non-profit. In this poster we will discuss the ComSciCon program and methods, our results to date, potential future collaborations between ComSciCon and AAS, and how you can become involved.

Melatonin Inhibits Neural Cell Apoptosis and Promotes Locomotor Recovery via Activation of the Wnt/β-Catenin Signaling Pathway After Spinal Cord Injury.

PubMed

Shen, Zhaoliang; Zhou, Zipeng; Gao, Shuang; Guo, Yue; Gao, Kai; Wang, Haoyu; Dang, Xiaoqian

2017-08-01

The spinal cord is highly sensitive to spinal cord injury (SCI) by external mechanical damage, resulting in irreversible neurological damage. Activation of the Wnt/β-catenin signaling pathway can effectively reduce apoptosis and protect against SCI. Melatonin, an indoleamine originally isolated from bovine pineal tissue, exerts neuroprotective effects after SCI through activation of the Wnt/β-catenin signaling pathway. In this study, we demonstrated that melatonin exhibited neuroprotective effects on neuronal apoptosis and supported functional recovery in a rat SCI model by activating the Wnt/β-catenin signaling pathway. We found that melatonin administration after SCI significantly upregulated the expression of low-density lipoprotein receptor related protein 6 phosphorylation (p-LRP-6), lymphoid enhancer factor-1 (LEF-1) and β-catenin protein in the spinal cord. Melatonin enhanced motor neuronal survival in the spinal cord ventral horn and improved the locomotor functions of rats after SCI. Melatonin administration after SCI also reduced the expression levels of Bax and cleaved caspase-3 in the spinal cord and the proportion of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) positive cells, but increased the expression level of Bcl-2. These results suggest that melatonin attenuated SCI by activating the Wnt/β-catenin signaling pathway.

Developing a spinal cord injury research strategy using a structured process of evidence review and stakeholder dialogue. Part III: outcomes.

PubMed

Middleton, J W; Piccenna, L; Lindsay Gruen, R; Williams, S; Creasey, G; Dunlop, S; Brown, D; Batchelor, P E; Berlowitz, D J; Coates, S; Dunn, J A; Furness, J B; Galea, M P; Geraghty, T; Kwon, B K; Urquhart, S; Yates, D; Bragge, P

2015-10-01

Focus Group. To develop a unified, regional spinal cord injury (SCI) research strategy for Australia and New Zealand. Australia. A 1-day structured stakeholder dialogue was convened in 2013 in Melbourne, Australia, by the National Trauma Research Institute in collaboration with the SCI Network of Australia and New Zealand. Twenty-three experts participated, representing local and international research, clinical, consumer, advocacy, government policy and funding perspectives. Preparatory work synthesised evidence and articulated draft principles and options as a starting point for discussion. A regional SCI research strategy was proposed, whose objectives can be summarised under four themes. (1) Collaborative networks and strategic partnerships to increase efficiency, reduce duplication, build capacity and optimise research funding. (2) Research priority setting and coordination to manage competing studies. (3) Mechanisms for greater consumer engagement in research. (4) Resources and infrastructure to further develop SCI data registries, evaluate research translation and assess alignment of research strategy with stakeholder interests. These are consistent with contemporary international SCI research strategy development activities. This first step in a regional SCI research strategy has articulated objectives for further development by the wider SCI research community. The initiative has also reinforced the importance of coordinated, collective action in optimising outcomes following SCI.

[Analysis of the citation of the articles published in National Journal of Andrology by SCI periodicals from 2002 to 2008].

PubMed

Huang, Hai

2009-03-01

Science Citation Index (SCI) is one of the world's most important and influential information retrieval systems. Today Web of Science covers over 9000 international and regional journals and book series in every field of natural sciences, social sciences, and arts and humanities. More and more Chinese periodicals have been cited by SCI. This paper briefly introduces the SCI database and its selection process and analyzes the citation of the articles published in National Journal of Andrology (NJA) by SCI journals from 2002 to 2008, aiming to provide some information for the internationalization of NJA.

A Computer Simulation for Predicting the Time Course of Thermal and Cardiovascular Responses to Various Combinations of Heat Stress, Clothing and Exercise

DTIC Science & Technology

1991-06-01

Anderson and A. Keys, Densitometric analysis of body composition : revision of some quantitative assumptions. Ann. N.Y. Acad. Sci. 110: 113-140, 1963. 6...cylinder at midpoint between adjacent compartments [cm] A, = effective radiating area of the body surface [M’] BF,, n rate of blood flow through...Sutalation for Predicting the Time Cou~rse of ’Thermal and Cardiovrascular Responses to varicus Cmtinations of Heat Stresso Clothing and Excercise 6. AUTHOR

Plasma Detachment Mechanisms in Propulsive Magnetic Nozzles

DTIC Science & Technology

2013-03-07

distribution is unlimited. 41A. Fruchtman, Phys. Rev. Lett. 96, 065002 (2006). 42M. Merino and E. Ahedo, IEEE Trans. Plasma Sci. 39, 2938 (2011). 43J...Ahedo, E., “Simulation of plasma flows in divergent magnetic nozzles,” IEEE Transactions on Plasma Science, Vol. 39, No. 11, 2011, pp. 2938 –2939...Plasma Science, Vol. 39, No. 11, 2011, pp. 2938 –2939. 14Zucrow, M. and Hoffman, J., Gas dynamics, Wiley, New York, 1976. 15Ahedo, E., “Parametric analysis

Final Technical Report - Center for Technology for Advanced Scientific Component Software (TASCS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sussman, Alan

2014-10-21

This is a final technical report for the University of Maryland work in the SciDAC Center for Technology for Advanced Scientific Component Software (TASCS). The Maryland work focused on software tools for coupling parallel software components built using the Common Component Architecture (CCA) APIs. Those tools are based on the Maryland InterComm software framework that has been used in multiple computational science applications to build large-scale simulations of complex physical systems that employ multiple separately developed codes.

Secondary Electron Emission Measurements on Materials Under Stress

DTIC Science & Technology

2004-10-01

2) low rf reflection, and (3) a vacuum-tight seal. Pillbox rf windows are used for the output of S - band (2856MHz) pulsed klystrons (3.5 us, 30MW peak...of Multipactoring Electrons in an S - band Pillbox RF Window", IEEE Trans. on Nucl. Sci., Vol.39, pp.278-282, 1992. [101 Research on Microwave Window...Simulation of Multipactoring Electrons in S - Band Pillbox RF Window", IEEE Transaction on Nuclear Science, Vol. 39, No. 2, 1992. [41 R. V. Latham: "High

Institutional profile: the national Swedish academic drug discovery & development platform at SciLifeLab

PubMed Central

Arvidsson, Per I; Sandberg, Kristian; Sakariassen, Kjell S

2017-01-01

The Science for Life Laboratory Drug Discovery and Development Platform (SciLifeLab DDD) was established in Stockholm and Uppsala, Sweden, in 2014. It is one of ten platforms of the Swedish national SciLifeLab which support projects run by Swedish academic researchers with large-scale technologies for molecular biosciences with a focus on health and environment. SciLifeLab was created by the coordinated effort of four universities in Stockholm and Uppsala: Stockholm University, Karolinska Institutet, KTH Royal Institute of Technology and Uppsala University, and has recently expanded to other Swedish university locations. The primary goal of the SciLifeLab DDD is to support selected academic discovery and development research projects with tools and resources to discover novel lead therapeutics, either molecules or human antibodies. Intellectual property developed with the help of SciLifeLab DDD is wholly owned by the academic research group. The bulk of SciLifeLab DDD's research and service activities are funded from the Swedish state, with only consumables paid by the academic research group through individual grants. PMID:28670468

Chronic Spinal Injury Repair by Olfactory Bulb Ensheathing Glia and Feasibility for Autologous Therapy

PubMed Central

Muñoz-Quiles, Cintia; Santos-Benito, Fernando F.; Llamusí, M. Beatriz; Ramón-Cueto, Almudena

2009-01-01

Olfactory bulb ensheathing glia (OB-OEG) promote repair of spinal cord injury (SCI) in rats after transplantation at acute or subacute (up to 45 days) stages. The most relevant clinical scenario in humans, however, is chronic SCI, in which no more major cellular or molecular changes occur at the injury site; this occurs after the third month in rodents. Whether adult OB-OEG grafts promote repair of severe chronic SCI has not been previously addressed. Rats with complete SCI that were transplanted with OB-OEG 4 months after injury exhibited progressive improvement in motor function and axonal regeneration from different brainstem nuclei across and beyond the SCI site. A positive correlation between motor outcome and axonal regeneration suggested a role for brainstem neurons in the recovery. Functional and histological outcomes did not differ at subacute or chronic stages. Thus, autologous transplantation is a feasible approach as there is time for patient stabilization and OEG preparation in human chronic SCI; the healing effects of OB-OEG on established injuries may offer new therapeutic opportunities for chronic SCI patients. PMID:19915486

Subjective cognitive impairment: functional MRI during a divided attention task.

PubMed

Rodda, J; Dannhauser, T; Cutinha, D J; Shergill, S S; Walker, Z

2011-10-01

Individuals with subjective cognitive impairment (SCI) have persistent memory complaints but normal neurocognitive performance. For some, this may represent a pre-mild cognitive impairment (MCI) stage of Alzheimer's disease (AD). Given that attentional deficits and associated brain activation changes are present early in the course of AD, we aimed to determine whether SCI is associated with brain activation changes during attentional processing. Eleven SCI subjects and 10 controls completed a divided attention task during functional magnetic resonance imaging. SCI and control groups did not differ in sociodemographic, neurocognitive or behavioural measures. When group activation during the divided attention task was compared, the SCI group demonstrated increased activation in left medial temporal lobe, bilateral thalamus, posterior cingulate and caudate. This pattern of increased activation is similar to the pattern of decreased activation reported during divided attention in AD and may indicate compensatory changes. These findings suggest the presence of early functional changes in SCI; longitudinal studies will help to further elucidate the relationship between SCI and AD. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Combined polymer-curcumin conjugate and ependymal progenitor/stem cell treatment enhances spinal cord injury functional recovery.

PubMed

Requejo-Aguilar, Raquel; Alastrue-Agudo, Ana; Cases-Villar, Marta; Lopez-Mocholi, Eric; England, Richard; Vicent, María J; Moreno-Manzano, Victoria

2017-01-01

Spinal cord injury (SCI) suffers from a lack of effective therapeutic strategies. Animal models of acute SCI have provided evidence that transplantation of ependymal stem/progenitor cells of the spinal cord (epSPCs) induces functional recovery, while systemic administration of the anti-inflammatory curcumin provides neuroprotection. However, functional recovery from chronic stage SCI requires additional enhancements in available therapeutic strategies. Herein, we report on a combination treatment for SCI using epSPCs and a pH-responsive polymer-curcumin conjugate. The incorporation of curcumin in a pH-responsive polymeric carrier mainchain, a polyacetal (PA), enhances blood bioavailability, stability, and provides a means for highly localized delivery. We find that PA-curcumin enhances neuroprotection, increases axonal growth, and can improve functional recovery in acute SCI. However, when combined with epSPCs, PA-curcumin also enhances functional recovery in a rodent model of chronic SCI. This suggests that combination therapy may be an exciting new therapeutic option for the treatment of chronic SCI in humans. Copyright © 2016 Elsevier Ltd. All rights reserved.

Institutional profile: the national Swedish academic drug discovery & development platform at SciLifeLab.

PubMed

Arvidsson, Per I; Sandberg, Kristian; Sakariassen, Kjell S

2017-06-01

The Science for Life Laboratory Drug Discovery and Development Platform (SciLifeLab DDD) was established in Stockholm and Uppsala, Sweden, in 2014. It is one of ten platforms of the Swedish national SciLifeLab which support projects run by Swedish academic researchers with large-scale technologies for molecular biosciences with a focus on health and environment. SciLifeLab was created by the coordinated effort of four universities in Stockholm and Uppsala: Stockholm University, Karolinska Institutet, KTH Royal Institute of Technology and Uppsala University, and has recently expanded to other Swedish university locations. The primary goal of the SciLifeLab DDD is to support selected academic discovery and development research projects with tools and resources to discover novel lead therapeutics, either molecules or human antibodies. Intellectual property developed with the help of SciLifeLab DDD is wholly owned by the academic research group. The bulk of SciLifeLab DDD's research and service activities are funded from the Swedish state, with only consumables paid by the academic research group through individual grants.

Fate of patients with spinal cord ischemia complicating thoracic endovascular aortic repair.

PubMed

DeSart, Kenneth; Scali, Salvatore T; Feezor, Robert J; Hong, Michael; Hess, Philip J; Beaver, Thomas M; Huber, Thomas S; Beck, Adam W

2013-09-01

Spinal cord ischemia (SCI) is a potentially devastating complication of thoracic endovascular aortic repair (TEVAR) that can result in varying degrees of short-term and permanent disability. This study was undertaken to describe the clinical outcomes, long-term functional impact, and influence on survival of SCI after TEVAR. A retrospective review of all TEVAR patients at the University of Florida from 2000 to 2011 was performed to identify individuals experiencing SCI, defined by any new lower extremity neurologic deficit not attributable to another cause. SCI was dichotomized into immediate or delayed onset, with immediate onset defined as SCI noted upon awakening from anesthesia, and delayed characterized as a period of normal function, followed by development of neurologic injury. Ambulatory status was determined using database query, record review, and phone interviews with patients and/or family. Mortality was estimated using life-table analysis. A total of 607 TEVARs were performed for various indications, with 57 patients (9.4%) noted to have postoperative SCI (4.3% permanent). SCI patients were more likely to be older (63.9 ± 15.6 vs 70.5 ± 11.2 years; P = .002) and have a number of comorbidities, including chronic obstructive pulmonary disease, hypertension, dyslipidemia, and cerebrovascular disease (P < .0001). At some point in their care, a cerebrospinal fluid drain was placed in 54 patients (95%), with 54% placed postoperatively. In-hospital mortality was 8.8% for the entire cohort (SCI vs no SCI; P = .45). SCI developed immediately in 12 patients, delayed onset in 40, and indeterminate in five patients due to indiscriminate timing from postoperative sedation. Three patients (25%) with immediate SCI had measurable functional improvement (FI), whereas 28 (70%) of the delayed-onset patients experienced some degree of neurologic recovery (P = .04). Of the 34 patients with complete data available, 26 (76%) reported quantifiable FI, but only 13 (38%) experienced return to their preoperative baseline. Estimated mean (± standard error) survival for patients with and without SCI was 37.2 ± 4.5 and 71.6 ± 3.9 months (P < .0006), respectively. Patients with FI had a mean survival of 53.9 ± 5.9 months compared with 9.6 ± 3.6 months for those without improvement (P < .0001). Survival and return of neurologic function were not significantly different when patients with preoperative and postoperative cerebrospinal fluid drains were compared. The minority of patients experience complete return to baseline function after SCI with TEVAR, and outcomes in patients without early functional recovery are particularly dismal. Patients experiencing delayed SCI are more likely to have FI and may anticipate similar life-expectancy with neurologic recovery compared with patients without SCI. Timing of drain placement does not appear to have an impact on postdischarge FI or long-term mortality. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Folic Acid Modulates Matrix Metalloproteinase-2 Expression, Alleviates Neuropathic Pain, and Improves Functional Recovery in Spinal Cord-Injured Rats

PubMed Central

Miranpuri, Gurwattan S.; Meethal, Sivan Vadakkadath; Sampene, Emmanuel; Chopra, Abhishek; Buttar, Seah; Nacht, Carrie; Moreno, Neydis; Patel, Kush; Liu, Lisa; Singh, Anupama; Singh, Chandra K.; Hariharan, Nithya; Iskandar, Bermans; Resnick, Daniel K.

2017-01-01

Background The molecular underpinnings of spinal cord injury (SCI) associated with neuropathic pain (NP) are unknown. Recent studies have demonstrated that matrix metalloproteinases (MMPs) such as MMP2 play a critical role in inducing NP following SCI. Promoter methylation of MMPs is known to suppress their transcription and reduce NP. In this context, it has been shown in rodents that folic acid (FA), an FDA approved dietary supplement and key methyl donor in the central nervous system (CNS), increases axonal regeneration and repair of injured CNS in part via methylation. Purpose Based on above observations, in this study, we test whether FA could decrease MMP2 expression and thereby decrease SCI-induced NP. Methods Sprague-Dawley male rats weighing 250–270 g received contusion spinal cord injuries (cSCIs) with a custom spinal cord impactor device that drops a 10 g weight from a height of 12.5 mm. The injured rats received either i.p. injections of FA (80 µg/kg) or water (control) 3 days prior and 17 days post-cSCI (mid phase) or for 3 days pre-cSCI and 14 days post-cSCI ending on the 42nd day of cSCI (late phase). The functional neurological deficits due to cSCI were then assessed by Basso, Beattie, and Bresnahan (BBB) scores either on post-impaction days 0 through 18 post-cSCI (mid phase) or on days 0, 2, 7, 14, 21, 28, 35, and 42 (late phase). Baseline measurements were taken the day before starting treatments. Thermal hyperalgesia (TH) testing for pain was performed on 4 days pre-cSCI (baseline data) and on days 18, 21, 28, 35, and 42 post-cSCI. Following TH testing, animals were euthanized and spinal cords harvested for MMP-2 expression analysis. Result The FA-treated groups showed higher BBB scores during mid phase (day 18) and in late phase (day 42) of injury compared to controls, suggesting enhanced functional recovery. There is a transient decline in TH in animals from the FA-treated group compared to controls when tested on days 18, 21, 28, and 35, indicative of a decrease in NP. However, when tested 25 days after stopping FA administration on day 42 of cSCI, no significant difference in TH was observed between FA-treated and control animals. Western blot analysis of the injured spinal cord from FA-treated animals showed significant decline in MMP2 expression compared to spinal cord samples from water-treated controls. Conclusion Together, these data suggest that FA could alleviate NP and improve functional recovery post-SCI, possibly by reducing the expression of MMP2. Further studies will open up a novel and easy natural therapy, ideal for clinical translation with minimal side effects, for managing SCI-induced NP. Such studies might also throw light on a possible epigenetic mechanism in FA-induced recovery after SCI. PMID:28588362

The effects of the TRPV1 receptor antagonist SB-705498 on trigeminovascular sensitisation and neurotransmission.

PubMed

Lambert, G A; Davis, J B; Appleby, J M; Chizh, B A; Hoskin, K L; Zagami, A S

2009-10-01

This report examines the effect of the transient receptor potential vanilloid 1 receptor antagonist SB-705498 on neurotransmission and inflammation-induced sensitisation in the trigeminovascular sensory system. A single-neuron electrophysiological animal model for neurovascular head pain was used to evaluate dural and facial noxious inputs and the effects of SB-705498 administered by intravenous (i.v.) injection. Electrical and mechanical stimulation of the dura mater and the facial skin activated second-order neurons in the trigeminal nucleus caudalis of cats, with A-delta latencies. Intravenous injection of SB-705498 (2 mg kg(-1)) produced a slowly developing and long-lasting suppression of responses to dural and skin stimulation. Maximum suppression occurred by 1 h and reached 41% for dura and 24% for skin. Intravenous injection of drug vehicle did not produce significant suppression of responses to stimulation of either dura or skin. Intravenous injection of SB-705498 produced a brief and small rise in blood pressure and dural blood flow, which both returned to normal before suppression of the responses to stimulation became manifest. Application of "inflammatory soup" to the dura mater produced a pronounced increase in dural blood flow and induced a slowly developing increase in the responses of neurons to both electrical and mechanical stimulations of their facial and dural receptive fields. This sensitisation reached a maximum in 60-90 min, at which time responses had risen to approximately twice that of control levels seen before the application of inflammatory soup. Intravenous injection of SB-705498 subsequent to the development of sensitisation produced a slowly developing, prolonged and statistically significant reversal of the sensitisation induced by inflammatory soup. Maximum reversal of sensitisation to electrical stimulation occurred by 150-180 min, when responses had fallen to, or below, control levels. At 70-85 min following injection of SB-705498, the responses of previously sensitised neurons to mechanical stimulation of dura mater and facial receptive field had also returned to near control levels. SB-705498 was also able to prevent the development of sensitisation; application of inflammatory soup to the dura mater induced a slowly developing increase in the responses of neurons to electrical stimulation of the skin and dura mater in cats which had received an i.v. injection of vehicle for SB-705498 but not in cats which had received the active drug. Blood levels of SB-705498 were maximal immediately following i.v. injection and declined over the following 2 h. Significant brain levels of SB-705498 were maintained for up to 9 h. These results suggest that SB-705498 may be an effective suppressant and reversal agent of the sensitisation to sensory input which follows inflammation in the trigeminovascular sensory distribution but may not be particularly useful in blocking primary pain processes such as migraine headache. SB-705498 could thus potentially prevent, modify or reverse the cutaneous trigeminal allodynia seen in certain migraine conditions, especially "transformed" migraine.

Pressure Relief Behaviors and Weight-Shifting Activities to Prevent Pressure Ulcers in Persons with SCI

DTIC Science & Technology

2014-10-01

Prevent Pressure Ulcers in Persons with SCI PRINCIPAL INVESTIGATOR: Stephen Sprigle, PhD CONTRACTING ORGANIZATION: Georgia Tech Research...Pressure Ulcers in Persons with SCI 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-13-1-0387 5c. PROGRAM ELEMENT NUMBER...SUPPLEMENTARY NOTES 14. ABSTRACT Pressure ulcers (PU) are the most costly secondary complication following an SCI. In addition to the medical costs

a Study on the Document Information Service of the National Agricultural Library for Agricultural Sci-Tech Innovation in China

NASA Astrophysics Data System (ADS)

Xu, Qian; Meng, Xianxue

This paper presents the significant function of the Chinese National Agricultural Library (CNAL) in the agricultural sci-tech innovation system in China, analyses the development of collection and service in the CNAL, explores the challenge towards sustain and develop information services for the agricultural sci-tech research and innovation, at last proposes the strategy for sci-tech document information service development.

Experience of sleep in individuals with spinal cord injury

PubMed Central

Fogelberg, Donald J.; Leland, Natalie E.; Blanchard, Jeanine; Rich, Timothy J.; Clark, Florence A.

2017-01-01

Background Poor sleep contributes to adverse health outcomes making it important to understand sleep in medically vulnerable populations, including those with spinal cord injury (SCI). However, little attention has been paid to circumstances specific to SCI that may negatively impact sleep, or to consequences of poor sleep in this population. Objectives To examine the experience of sleep among individuals with SCI. Methodology Secondary analysis using thematic coding of qualitative data from an ethnographic study of community-dwelling adults with SCI. Results Sleep-related data were found in transcripts for 90% of the sample. Participants described diminished sleep duration and irregular sleep patterns. Several factors contributing to poor sleep were identified, including SCI-related circumstances and sleep environment. Participants also discussed how poor sleep affected occupational engagement. Conclusion This study highlights the extent of sleep disturbance experienced after SCI, the subsequent impact on occupational performance, and provides direction for clinical practice. PMID:28196449

Functional Electrical Stimulation and Spinal Cord Injury

PubMed Central

Ho, Chester H.; Triolo, Ronald J.; Elias, Anastasia L.; Kilgore, Kevin L.; DiMarco, Anthony F.; Bogie, Kath; Vette, Albert H.; Audu, Musa; Kobetic, Rudi; Chang, Sarah R.; Chan, K. Ming; Dukelow, Sean; Bourbeau, Dennis J.; Brose, Steven W.; Gustafson, Kenneth J.; Kiss, Zelma; Mushahwar, Vivian K.

2015-01-01

Synopsis Spinal cord injuries (SCI) can disrupt communications between the brain and the body, leading to a loss of control over otherwise intact neuromuscular systems. The use of electrical stimulation (ES) of the central and peripheral nervous system can take advantage of these intact neuromuscular systems to provide therapeutic exercise options, to allow functional restoration, and even to manage or prevent many medical complications following SCI. The use of ES for the restoration of upper extremity, lower extremity and truncal functions can make many activities of daily living a potential reality for individuals with SCI. Restoring bladder and respiratory functions and preventing pressure ulcers may significantly decrease the morbidity and mortality following SCI. Many of the ES devices are already commercially available and should be considered by all SCI clinicians routinely as part of the lifelong rehabilitation care plan for all eligible individuals with SCI. PMID:25064792

“Don’t Think Paralysis Takes Away Your Womanhood”: Sexual Intimacy After Spinal Cord Injury

PubMed Central

Dillaway, Heather; Lysack, Cathy L.

2015-01-01

Sexuality and intimacy are important components of health and well-being. Issues surrounding sexuality and intimacy are equally important for men and women living with physical disabilities, including spinal cord injury (SCI). Yet, women’s sexuality after SCI remains largely unexamined. This article presents the findings from an in-depth qualitative investigation of the sexual and reproductive health experiences of 20 women with SCI in or around Detroit, MI. Findings echo existing literature documenting the sexual consequences of life after SCI and suggest new areas of inquiry important for better addressing sexual concerns across the lifespan. Specifically, findings suggest a need to consider the variable effects of SCI on sexual intimacy in relation to a person’s developmental trajectory, the appropriate timing of sexual education, the need to expand conceptualizations of sexual intimacy, and the ways SCI may affect sexuality in later life. PMID:26122683

Comparison of two psycho-educational family group interventions for improving psycho-social outcomes in persons with spinal cord injury and their caregivers: a randomized-controlled trial of multi-family group intervention versus an active education control condition.

PubMed

Dyck, Dennis G; Weeks, Douglas L; Gross, Sarah; Lederhos Smith, Crystal; Lott, Hilary A; Wallace, Aimee J; Wood, Sonya M

2016-07-26

Over 12,000 individuals suffer a spinal cord injury (SCI) annually in the United States, necessitating long-term, complex adjustments and responsibilities for patients and their caregivers. Despite growing evidence that family education and support improves the management of chronic conditions for care recipients as well as caregiver outcomes, few systematic efforts have been made to involve caregivers in psycho-educational interventions for SCI. As a result, a serious gap exists in accumulated knowledge regarding effective, family-based treatment strategies for improving outcomes for individuals with SCI and their caregivers. The proposed research aims to fill this gap by evaluating the efficacy of a structured adaptation of an evidence-based psychosocial group treatment called Multi-Family Group (MFG) intervention. The objective of this study is to test, in a randomized-controlled design, an MFG intervention for the treatment of individuals with SCI and their primary caregivers. Our central hypothesis is that by providing support in an MFG format, we will improve coping skills of persons with SCI and their caregivers as well as supportive strategies employed by caregivers. We will recruit 32 individuals with SCI who have been discharged from inpatient rehabilitation within the previous 3 years and their primary caregivers. Patient/caregiver pairs will be randomized to the MFG intervention or an active SCI education control (SCIEC) condition in a two-armed randomized trial design. Participants will be assessed pre- and post-program and 6 months post-program. Intent to treat analyses will test two a priori hypotheses: (1) MFG-SCI will be superior to SCIEC for SCI patient activation, health status, and emotion regulation, caregiver burden and health status, and relationship functioning, and (2) MFG will be more effective for individuals with SCI and their caregivers when the person with SCI is within 18 months of discharge from inpatient rehabilitation compared to when the person is between 19 and 36 months post discharge. Support for our hypotheses will indicate that MFG-SCI is superior to specific education for assisting patients and their caregivers in the management of difficult, long-term, life adjustments in the months and years after SCI, with increased efficacy closer in time to the injury. ClinicalTrials.gov NCT02161913 . Registered 10 June 2014.

Multiscale Materials Modeling Workshop Summary

DOT National Transportation Integrated Search

2013-12-01

This report summarizes a 2-day workshop held to share information on multiscale material modeling. The aim was to gain expert feedback on the state of the art and identify Exploratory Advanced Research (EAR) Program opportunities for multiscale mater...

19 CFR 103.5 - Specific requests for records.

Code of Federal Regulations, 2010 CFR

2010-04-01

... requirement for a reasonably description is not a device for improperly withholding records from the public... materal. The latest of those dates is the date of receipt of the request. As soon as the date of receipt...

Development of an International Canine Spinal Cord Injury observational registry: a collaborative data-sharing network to optimize translational studies of SCI.

PubMed

Moore, Sarah A; Zidan, Natalia; Spitzbarth, Ingo; Nout-Lomas, Yvette S; Granger, Nicolas; da Costa, Ronaldo C; Levine, Jonathan M; Jeffery, Nick D; Stein, Veronika M; Tipold, Andrea; Olby, Natasha J

2018-05-23

Prospective cross-sectional cohort study. The canine spontaneous model of spinal cord injury (SCI) is as an important pre-clinical platform as it recapitulates key facets of human injury in a naturally occurring context. The establishment of an observational canine SCI registry constitutes a key step in performing epidemiologic studies and assessing the impact of therapeutic strategies to enhance translational research. Further, accumulating information on dogs with SCI may contribute to current "big data" approaches to enhance understanding of the disease using heterogeneous multi-institutional, multi-species datasets from both pre-clinical and human studies. Multiple veterinary academic institutions across the United States and Europe. Common data elements recommended for experimental and human SCI studies were reviewed and adapted for use in a web-based registry, to which all dogs presenting to member veterinary tertiary care facilities were prospectively entered over ~1 year. Analysis of data accumulated during the first year of the registry suggests that 16% of dogs with SCI present with severe, sensorimotor-complete injury and that 15% of cases are seen by a tertiary care facility within 8 h of injury. Similar to the human SCI population, 34% were either overweight or obese. Severity of injury and timing of presentation suggests that neuroprotective studies using the canine clinical model could be conducted efficiently using a multi-institutional approach. Additionally, pet dogs with SCI experience similar comorbidities to people with SCI, in particular obesity, and could serve as an important model to evaluate the effects of this condition.

Role of Caspase-8 and Fas in Cell Death After Spinal Cord Injury

PubMed Central

Sobrido-Cameán, Daniel; Barreiro-Iglesias, Antón

2018-01-01

Spinal cord injury (SCI) causes the death of neurons and glial cells due to the initial mechanical forces (i.e., primary injury) and through a cascade of secondary molecular events (e.g., inflammation or excitotoxicity) that exacerbate cell death. The loss of neurons and glial cells that are not replaced after the injury is one of the main causes of disability after SCI. Evidence accumulated in last decades has shown that the activation of apoptotic mechanisms is one of the factors causing the death of intrinsic spinal cord (SC) cells following SCI. Although this is not as clear for brain descending neurons, some studies have also shown that apoptosis can be activated in the brain following SCI. There are two main apoptotic pathways, the extrinsic and the intrinsic pathways. Activation of caspase-8 is an important step in the initiation of the extrinsic pathway. Studies in rodents have shown that caspase-8 is activated in SC glial cells and neurons and that the Fas receptor plays a key role in its activation following a traumatic SCI. Recent work in the lamprey model of SCI has also shown the retrograde activation of caspase-8 in brain descending neurons following SCI. Here, we review our current knowledge on the role of caspase-8 and the Fas pathway in cell death following SCI. We also provide a perspective for future work on this process, like the importance of studying the possible contribution of Fas/caspase-8 signaling in the degeneration of brain neurons after SCI in mammals. PMID:29666570

Psychometric properties of the Sleep Condition Indicator and Insomnia Severity Index in the evaluation of insomnia disorder.

PubMed

Wong, Mark Lawrence; Lau, Kristy Nga Ting; Espie, Colin A; Luik, Annemarie I; Kyle, Simon D; Lau, Esther Yuet Ying

2017-05-01

The Sleep Condition Indicator (SCI) and Insomnia Severity Index (ISI) are commonly used instruments to assess insomnia. We evaluated their psychometric properties, particularly their discriminant validity against structured clinical interview (according to DSM-5 and ICSD-3), and their concurrent validity with measures of sleep and daytime functioning. A total of 158 young adults, 16% of whom were diagnosed with DSM-5 insomnia disorder and 13% with ICSD-3 Chronic Insomnia by structured interview, completed the ISI and SCI twice in 7-14 days, in addition to measures of sleep and daytime function. The Chinese version of the SCI was validated with good psychometric properties (ICC = 0.882). A cutoff of ≥8 on the ISI, ≤5 on the SCI short form, and ≤21 on the SCI achieved high discriminant validity (AUC > 0.85) in identifying individuals with insomnia based on both DSM-5 and ICSD-3 criteria. The SCI and ISI had comparable associations with subjective (0.18 < r < 0.51) and actigraphic sleep (0.31 < r < 0.43) and daytime functioning (0.34 < r < 0.53). The SCI, SCI short form, and ISI were found to correctly identify individuals with DSM-5- and ICSD-3-defined insomnia disorder. Moreover, they showed good concordance with measures of daytime dysfunction, as well as subjective and objective sleep. The SCI and ISI are recommended for use in clinical and research settings. Copyright © 2016 Elsevier B.V. All rights reserved.

Isolated spinal cord contusion in rats induces chronic brain neuroinflammation, neurodegeneration, and cognitive impairment. Involvement of cell cycle activation.

PubMed

Wu, Junfang; Stoica, Bogdan A; Luo, Tao; Sabirzhanov, Boris; Zhao, Zaorui; Guanciale, Kelsey; Nayar, Suresh K; Foss, Catherine A; Pomper, Martin G; Faden, Alan I

2014-01-01

Cognitive dysfunction has been reported in patients with spinal cord injury (SCI), but it has been questioned whether such changes may reflect concurrent head injury, and the issue has not been addressed mechanistically or in a well-controlled experimental model. Our recent rodent studies examining SCI-induced hyperesthesia revealed neuroinflammatory changes not only in supratentorial pain-regulatory sites, but also in other brain regions, suggesting that additional brain functions may be impacted following SCI. Here we examined effects of isolated thoracic SCI in rats on cognition, brain inflammation, and neurodegeneration. We show for the first time that SCI causes widespread microglial activation in the brain, with increased expression of markers for activated microglia/macrophages, including translocator protein and chemokine ligand 21 (C-C motif). Stereological analysis demonstrated significant neuronal loss in the cortex, thalamus, and hippocampus. SCI caused chronic impairment in spatial, retention, contextual, and fear-related emotional memory-evidenced by poor performance in the Morris water maze, novel objective recognition, and passive avoidance tests. Based on our prior work implicating cell cycle activation (CCA) in chronic neuroinflammation after SCI or traumatic brain injury, we evaluated whether CCA contributed to the observed changes. Increased expression of cell cycle-related genes and proteins was found in hippocampus and cortex after SCI. Posttraumatic brain inflammation, neuronal loss, and cognitive changes were attenuated by systemic post-injury administration of a selective cyclin-dependent kinase inhibitor. These studies demonstrate that chronic brain neurodegeneration occurs after isolated SCI, likely related to sustained microglial activation mediated by cell cycle activation.

Developing a spinal cord injury research strategy using a structured process of evidence review and stakeholder dialogue. Part I: rapid review of SCI prioritisation literature.

PubMed

Bragge, P; Piccenna, L; Middleton, J W; Williams, S; Creasey, G; Dunlop, S; Brown, D; Gruen, R L

2015-10-01

This is a rapid evidence review. The objective of this study was to gain an overview of the volume, nature and findings of studies regarding priorities for spinal cord injury (SCI) research. A worldwide literature search was conducted. Six medical literature databases and Google Scholar were searched for reviews in which the primary aim was to identify SCI research priorities. Two systematic reviews were identified-one of quantitative and one of qualitative studies. The quality of the reviews was variable. Collectively, the reviews identified 31 primary studies; 24 quantitative studies totalling 5262 participants and 7 qualitative studies totalling 120 participants. Despite the difference in research paradigms, there was convergence in review findings in the areas of body impairments and relationships. The vast majority of literature within the reviews focused on the SCI patient perspective. The reviews inform specific research topics and highlight other important research considerations, most notably those pertaining to SCI patients' perspectives on quality of life, which may be of use in determining meaningful research outcome measures. The views of other SCI research stakeholders such as researchers, clinicians, policymakers, funders and carers would help shape a bigger picture of SCI research priorities, ultimately optimising research outputs and translation into clinical practice and health policy change. Review findings informed subsequent activities in developing a regional SCI research strategy, as described in two companion papers. This project was funded by the Victorian Transport Accident Commission and the Australian and New Zealand SCI Network.

An international age- and gender-controlled model for the Spinal Cord Injury Ability Realization Measurement Index (SCI-ARMI).

PubMed

Scivoletto, Giorgio; Glass, Clive; Anderson, Kim D; Galili, Tal; Benjamin, Yoav; Front, Lilach; Aidinoff, Elena; Bluvshtein, Vadim; Itzkovich, Malka; Aito, Sergio; Baroncini, Ilaria; Benito-Penalva, Jesùs; Castellano, Simona; Osman, Aheed; Silva, Pedro; Catz, Amiram

2015-01-01

Background. A quadratic formula of the Spinal Cord Injury Ability Realization Measurement Index (SCI-ARMI) has previously been published. This formula was based on a model of Spinal Cord Independence Measure (SCIM95), the 95th percentile of the SCIM III values, which correspond with the American Spinal Injury Association Motor Scores (AMS) of SCI patients. Objective. To further develop the original formula. Setting. Spinal cord injury centers from 6 countries and the Statistical Laboratory, Tel-Aviv University, Israel. Methods. SCIM95 of 661 SCI patients was modeled, using a quantile regression with or without adjustment for age and gender, to calculate SCI-ARMI values. SCI-ARMI gain during rehabilitation and its correlations were examined. Results. A new quadratic SCIM95 model was created. This resembled the previously published model, which yielded similar SCIM95 values in all the countries, after adjustment for age and gender. Without this adjustment, however, only 86% of the non-Israeli SCIM III observations were lower than those SCIM95 values (P < .0001). Adding the variables age and gender to the new model affected the SCIM95 value significantly (P < .04). Adding country information did not add a significant effect (P > .1). SCI-ARMI gain was positive (38.8 ± 22 points, P < .0001) and correlated weakly with admission age and AMS. Conclusions. The original quadratic SCI-ARMI formula is valid for an international population after adjustment for age and gender. The new formula considers more factors that affect functional ability following SCI. © The Author(s) 2014.

Spinal Cord Injury Disrupts Resting-State Networks in the Human Brain.

PubMed

Hawasli, Ammar H; Rutlin, Jerrel; Roland, Jarod L; Murphy, Rory K J; Song, Sheng-Kwei; Leuthardt, Eric C; Shimony, Joshua S; Ray, Wilson Z

2018-03-15

Despite 253,000 spinal cord injury (SCI) patients in the United States, little is known about how SCI affects brain networks. Spinal MRI provides only structural information with no insight into functional connectivity. Resting-state functional MRI (RS-fMRI) quantifies network connectivity through the identification of resting-state networks (RSNs) and allows detection of functionally relevant changes during disease. Given the robust network of spinal cord afferents to the brain, we hypothesized that SCI produces meaningful changes in brain RSNs. RS-fMRIs and functional assessments were performed on 10 SCI subjects. Blood oxygen-dependent RS-fMRI sequences were acquired. Seed-based correlation mapping was performed using five RSNs: default-mode (DMN), dorsal-attention (DAN), salience (SAL), control (CON), and somatomotor (SMN). RSNs were compared with normal control subjects using false-discovery rate-corrected two way t tests. SCI reduced brain network connectivity within the SAL, SMN, and DMN and disrupted anti-correlated connectivity between CON and SMN. When divided into separate cohorts, complete but not incomplete SCI disrupted connectivity within SAL, DAN, SMN and DMN and between CON and SMN. Finally, connectivity changed over time after SCI: the primary motor cortex decreased connectivity with the primary somatosensory cortex, the visual cortex decreased connectivity with the primary motor cortex, and the visual cortex decreased connectivity with the sensory parietal cortex. These unique findings demonstrate the functional network plasticity that occurs in the brain as a result of injury to the spinal cord. Connectivity changes after SCI may serve as biomarkers to predict functional recovery following an SCI and guide future therapy.

Isolated spinal cord contusion in rats induces chronic brain neuroinflammation, neurodegeneration, and cognitive impairment

PubMed Central

Wu, Junfang; Stoica, Bogdan A; Luo, Tao; Sabirzhanov, Boris; Zhao, Zaorui; Guanciale, Kelsey; Nayar, Suresh K; Foss, Catherine A; Pomper, Martin G; Faden, Alan I

2014-01-01

Cognitive dysfunction has been reported in patients with spinal cord injury (SCI), but it has been questioned whether such changes may reflect concurrent head injury, and the issue has not been addressed mechanistically or in a well-controlled experimental model. Our recent rodent studies examining SCI-induced hyperesthesia revealed neuroinflammatory changes not only in supratentorial pain-regulatory sites, but also in other brain regions, suggesting that additional brain functions may be impacted following SCI. Here we examined effects of isolated thoracic SCI in rats on cognition, brain inflammation, and neurodegeneration. We show for the first time that SCI causes widespread microglial activation in the brain, with increased expression of markers for activated microglia/macrophages, including translocator protein and chemokine ligand 21 (C–C motif). Stereological analysis demonstrated significant neuronal loss in the cortex, thalamus, and hippocampus. SCI caused chronic impairment in spatial, retention, contextual, and fear-related emotional memory—evidenced by poor performance in the Morris water maze, novel objective recognition, and passive avoidance tests. Based on our prior work implicating cell cycle activation (CCA) in chronic neuroinflammation after SCI or traumatic brain injury, we evaluated whether CCA contributed to the observed changes. Increased expression of cell cycle-related genes and proteins was found in hippocampus and cortex after SCI. Posttraumatic brain inflammation, neuronal loss, and cognitive changes were attenuated by systemic post-injury administration of a selective cyclin-dependent kinase inhibitor. These studies demonstrate that chronic brain neurodegeneration occurs after isolated SCI, likely related to sustained microglial activation mediated by cell cycle activation. PMID:25483194

The swimming test is effective for evaluating spasticity after contusive spinal cord injury

PubMed Central

Ryu, Youngjae; Ogata, Toru; Nagao, Motoshi; Kitamura, Taku; Morioka, Kazuhito; Ichihara, Yoshinori; Doi, Toru; Sawada, Yasuhiro; Akai, Masami; Nishimura, Ryohei; Fujita, Naoki

2017-01-01

Spasticity is a frequent chronic complication in individuals with spinal cord injury (SCI). However, the severity of spasticity varies in patients with SCI. Therefore, an evaluation method is needed to determine the severity of spasticity. We used a contusive SCI model that is suitable for clinical translation. In this study, we examined the feasibility of the swimming test and an EMG for evaluating spasticity in a contusive SCI rat model. Sprague-Dawley rats received an injury at the 8th thoracic vertebra. Swimming tests were performed 3 to 6 weeks after SCI induction. We placed the SCI rats into spasticity-strong or spasticity-weak groups based on the frequency of spastic behavior during the swimming test. Subsequently, we recorded the Hoffman reflex (H-reflex) and examined the immunoreactivity of serotonin (5-HT) and its receptor (5-HT2A) in the spinal tissues of the SCI rats. The spasticity-strong group had significantly decreased rate-dependent depression of the H-reflex compared to the spasticity-weak group. The area of 5-HT2A receptor immunoreactivity was significantly increased in the spasticity-strong group. Thus, both electrophysiological and histological evaluations indicate that the spasticity-strong group presented with a more severe upper motor neuron syndrome. We also observed the groups in their cages for 20 hours. Our results suggest that the swimming test provides an accurate evaluation of spasticity in this contusive SCI model. We believe that the swimming test is an effective method for evaluating spastic behaviors and developing treatments targeting spasticity after SCI. PMID:28182676

International comparison of the organisation of rehabilitation services and systems of care for patients with spinal cord injury.

PubMed

New, P W; Townson, A; Scivoletto, G; Post, M W M; Eriks-Hoogland, I; Gupta, A; Smith, E; Reeves, R K; Gill, Z A

2013-01-01

Survey. Describe and compare the organisation and delivery of rehabilitation services and systems of care for patients with spinal cord injury (SCI). International. Nine spinal rehabilitation units that manage traumatic SCI and non-traumatic SCI (NTSCI) patients. Survey based on clinical expertise and literature review. Completed between November 2010 and April 2011. All units reported public/government funding. Additional funding sources included compensation schemes, private insurance and self funding. Six units had formal attachment to an acute SCI unit. Five units (Italy, Ireland, India, Pakistan and Switzerland) provided a national service; two units (the Netherlands and USA) provided regional and two units (Australia and Canada) provided state/provincial services. The median number of SCI rehabilitation beds was 23 (interquartile range=16-30). All units admitted both traumatic SCI and NTSCI patients. The median proportion of patients admitted who had traumatic SCI was 45% (IQR 20-48%) and 40% (IQR 30-42%) had NTSCI. The rehabilitation team in all centres determined patient readiness for discharge. There was great variability between units in the availability of SCI speciality services, ancillary services and staff/patient ratios. There was a wide range of differences in the organisation, systems of care and services available for patients with SCI in rehabilitation units in different countries. Understanding these differences is important when comparing patient outcomes from different settings. A standardised collection of these system variables should be considered as part of future studies and could be included in the ISCoS data set project.

SCI peer health coach influence on self-management with peers: a qualitative analysis.

PubMed

Skeels, S E; Pernigotti, D; Houlihan, B V; Belliveau, T; Brody, M; Zazula, J; Hasiotis, S; Seetharama, S; Rosenblum, D; Jette, A

2017-11-01

A process evaluation of a clinical trial. To describe the roles fulfilled by peer health coaches (PHCs) with spinal cord injury (SCI) during a randomized controlled trial research study called 'My Care My Call', a novel telephone-based, peer-led self-management intervention for adults with chronic SCI 1+ years after injury. Connecticut and Greater Boston Area, MA, USA. Directed content analysis was used to qualitatively examine information from 504 tele-coaching calls, conducted with 42 participants with SCI, by two trained SCI PHCs. Self-management was the focus of each 6-month PHC-peer relationship. PHCs documented how and when they used the communication tools (CTs) and information delivery strategies (IDSs) they developed for the intervention. Interaction data were coded and analyzed to determine PHC roles in relation to CT and IDS utilization and application. PHCs performed three principal roles: Role Model, Supporter, and Advisor. Role Model interactions included CTs and IDSs that allowed PHCs to share personal experiences of managing and living with an SCI, including sharing their opinions and advice when appropriate. As Supporters, PHCs used CTs and IDSs to build credible relationships based on dependability and reassuring encouragement. PHCs fulfilled the unique role of Advisor using CTs and IDSs to teach and strategize with peers about SCI self-management. The SCI PHC performs a powerful, flexible role in promoting SCI self-management among peers. Analysis of PHC roles can inform the design of peer-led interventions and highlights the importance for the provision of peer mentor training.

The swimming test is effective for evaluating spasticity after contusive spinal cord injury.

PubMed

Ryu, Youngjae; Ogata, Toru; Nagao, Motoshi; Kitamura, Taku; Morioka, Kazuhito; Ichihara, Yoshinori; Doi, Toru; Sawada, Yasuhiro; Akai, Masami; Nishimura, Ryohei; Fujita, Naoki

2017-01-01

Spasticity is a frequent chronic complication in individuals with spinal cord injury (SCI). However, the severity of spasticity varies in patients with SCI. Therefore, an evaluation method is needed to determine the severity of spasticity. We used a contusive SCI model that is suitable for clinical translation. In this study, we examined the feasibility of the swimming test and an EMG for evaluating spasticity in a contusive SCI rat model. Sprague-Dawley rats received an injury at the 8th thoracic vertebra. Swimming tests were performed 3 to 6 weeks after SCI induction. We placed the SCI rats into spasticity-strong or spasticity-weak groups based on the frequency of spastic behavior during the swimming test. Subsequently, we recorded the Hoffman reflex (H-reflex) and examined the immunoreactivity of serotonin (5-HT) and its receptor (5-HT2A) in the spinal tissues of the SCI rats. The spasticity-strong group had significantly decreased rate-dependent depression of the H-reflex compared to the spasticity-weak group. The area of 5-HT2A receptor immunoreactivity was significantly increased in the spasticity-strong group. Thus, both electrophysiological and histological evaluations indicate that the spasticity-strong group presented with a more severe upper motor neuron syndrome. We also observed the groups in their cages for 20 hours. Our results suggest that the swimming test provides an accurate evaluation of spasticity in this contusive SCI model. We believe that the swimming test is an effective method for evaluating spastic behaviors and developing treatments targeting spasticity after SCI.

Durability of filament-wound composite flywheel rotors

NASA Astrophysics Data System (ADS)

Koyanagi, Jun

2012-02-01

This paper predicts the durability of two types of flywheels, one assumes to fail in the radial direction and the other assumes to fail in the circumferential direction. The flywheel failing in the radial direction is a conventional filament-wound composite flywheel and the one failing in the circumferential direction is a tailor-made type. The durability of the former is predicted by Micromechanics of Failure (MMF) (Ha et al. in J. Compos. Mater. 42:1873-1875, 2008), employing time-dependent matrix strength, and that of the latter is predicted by Simultaneous Fiber Failure (SFF) (Koyanagi et al. in J. Compos. Mater. 43:1901-1914, 2009), employing identical time-dependent matrix strength. The predicted durability of the latter is much greater than that of the former, depending on the interface strength. This study suggests that a relatively weak interface is necessary for high-durability composite flywheel fabrication.

Finite Element Analysis of the Effect of Epidural Adhesions.

PubMed

Lee, Nam; Ji, Gyu Yeul; Yi, Seong; Yoon, Do Heum; Shin, Dong Ah; Kim, Keung Nyun; Ha, Yoon; Oh, Chang Hyun

2016-07-01

It is well documented that epidural adhesion is associated with spinal pain. However, the underlying mechanism of spinal pain generation by epidural adhesion has not yet been elucidated. To elucidate the underlying mechanism of spinal pain generation by epidural adhesion using a two-dimensional (2D) non-linear finite element (FE) analysis. A finite element analysis. A two-dimensional nonlinear FE model of the herniated lumbar disc on L4/5 with epidural adhesion. A two-dimensional nonlinear FE model of the lumbar spine was developed, consisting of intervertebral discs, dura, spinal nerve, and lamina. The annulus fibrosus and nucleus pulpous were modeled as hyperelastic using the Mooney-Rivlin equation. The FE mesh was generated and analyzed using Abaqus (ABAQUS 6.13.; Hibbitt, Karlsson & Sorenson, Inc., Providence, RI, USA). Epidural adhesion was simulated as rough contact, in which no slip occurred once two surfaces were in contact, between the dura mater and posterior annulus fibrosus. The FE model of adhesion showed significant stress concentration in the spinal nerves, especially on the dorsal root ganglion (DRG). The stress concentration was caused by the lack of adaptive displacement between the dura mater and posterior annulus fibrosus. The peak von Mises stress was higher in the epidural adhesion model (Adhesion, 0.67 vs. Control, 0.46). In the control model, adaptive displacement was observed with decreased stress in the spinal nerve and DRG (with adhesion, 2.59 vs. without adhesion, 3.58, P < 0.00). This study used a 2D non-linear FE model, which simplifies the 3D nature of the human intervertebral disc. In addition, this 2D non-linear FE model has not yet been validated. The current study clearly demonstrated that epidural adhesion causes significantly increased stress in the spinal nerves, especially at the DRG. We believe that the increased stress on the spinal nerve might elicit more pain under similar magnitudes of lumbar disc protrusion.

Sleep-Disordered Breathing in Chronic SCI: A Randomized Controlled Trial of Treatment Impact on Cognition, Quality of Life, and Cardiovascular Disease

DTIC Science & Technology

2014-10-01

SCI. In this prospective randomized controlled trial, we will objectively measure sleep disordered breathing ( SDB ) in chronic SCI patients using...portable sleep studies, and systematically evaluate the association between SDB , cognitive performance, mood, pain, and CV measures. We will randomize...randomized shortly. 15. SUBJECT TERMS SDB , SCI, PAP, CV 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a

Treatment of Nueropathic Pain after SCI with a Catalytic Oxidoreductant

DTIC Science & Technology

2016-10-01

reducing inflammation and ROS activation acutely post-SCI in rats and mice. On-going experiments will evaluate additional outcome measures and...NF-kB signaling, and inflammation in the spinal cord acutely post-SCI We have completed approximately 100% of the animal experiments in support of this...in the spinal cord acutely post-SCI. These data are in the final analysis stages. Please see the data to date as described in the task section

Establishing ¹H nuclear magnetic resonance based metabonomics fingerprinting profile for spinal cord injury: a pilot study.

PubMed

Jiang, Hua; Peng, Jin; Zhou, Zhi-yuan; Duan, Yu; Chen, Wei; Cai, Bin; Yang, Hao; Zhang, Wei

2010-09-01

Spinal cord injury (SCI) is a complex trauma that consists of multiple pathological mechanisms involving cytotoxic, oxidation stress and immune-endocrine. This study aimed to establish plasma metabonomics fingerprinting atlas for SCI using (1)H nuclear magnetic resonance (NMR) based metabonomics methodology and principal component analysis techniques. Nine Sprague-Dawley (SD) male rats were randomly divided into SCI, normal and sham-operation control groups. Plasma samples were collected for (1)H NMR spectroscopy 3 days after operation. The NMR data were analyzed using principal component analysis technique with Matlab software. Metabonomics analysis was able to distinguish the three groups (SCI, normal control, sham-operation). The fingerprinting atlas indicated that, compared with those without SCI, the SCI group demonstrated the following characteristics with regard to second principal component: it is made up of fatty acids, myc-inositol, arginine, very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), triglyceride (TG), glucose, and 3-methyl-histamine. The data indicated that SCI results in several significant changes in plasma metabolism early on and that a metabonomics approach based on (1)H NMR spectroscopy can provide a metabolic profile comprising several metabolite classes and allow for relative quantification of such changes. The results also provided support for further development and application of metabonomics technologies for studying SCI and for the utilization of multivariate models for classifying the extent of trauma within an individual.

Detection of abnormal muscle activations during walking following spinal cord injury (SCI).

PubMed

Wang, Ping; Low, K H; McGregor, Alison H; Tow, Adela

2013-04-01

In order to identify optimal rehabilitation strategies for spinal cord injury (SCI) participants, assessment of impaired walking is required to detect, monitor and quantify movement disorders. In the proposed assessment, ten healthy and seven SCI participants were recruited to perform an over-ground walking test at slow walking speeds. SCI participants were given assistance from physiotherapists, if required, while they were walking. In agreement with other research, larger cadence and smaller step length and swing phase of SCI gait were observed as a result of muscle weakness and resultant gait instability. Muscle activation patterns of seven major leg muscles were collected. The EMG signal was processed by the RMS in frequency domain to represent the muscle activation power, and the distribution of muscle activation was compared between healthy and SCI participants. The alternations of muscle activation within the phases of the gait cycle are highlighted to facilitate our understanding of the underlying muscular activation following SCI. Key differences were observed (p-value=0.0006) in the reduced activation of tibialis anterior (TA) in single stance phase and rectus femoris (RF) in swing phase (p-value=0.0011). We can then conclude that the proposed assessment approach of gait provides valuable information that can be used to target and define therapeutic interventions and their evaluation; hence impacting the functional outcome of SCI individuals. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fibronectin EDA forms the chronic fibrotic scar after contusive spinal cord injury.

PubMed

Cooper, John G; Jeong, Su Ji; McGuire, Tammy L; Sharma, Sripadh; Wang, Wenxia; Bhattacharyya, Swati; Varga, John; Kessler, John A

2018-04-27

Gliosis and fibrosis after spinal cord injury (SCI) lead to formation of a scar that is an impediment to axonal regeneration. Fibrotic scarring is characterized by the accumulation of fibronectin, collagen, and fibroblasts at the lesion site. The mechanisms regulating fibrotic scarring after SCI and its effects on axonal elongation and functional recovery are not well understood. In this study, we examined the effects of eliminating an isoform of fibronectin containing the Extra Domain A domain (FnEDA) on both fibrosis and on functional recovery after contusion SCI using male and female FnEDA-null mice. Eliminating FnEDA did not reduce the acute fibrotic response but markedly diminished chronic fibrotic scarring after SCI. Glial scarring was unchanged after SCI in FnEDA-null mice. We found that FnEDA was important for the long-term stability of the assembled fibronectin matrix during both the subacute and chronic phases of SCI. Motor functional recovery was significantly improved, and there were increased numbers of axons in the lesion site compared to wildtype mice, suggesting that the chronic fibrotic response is detrimental to recovery. Our data provide insight into the mechanisms of fibrosis after SCI and suggest that disruption of fibronectin matrix stability by targeting FnEDA represents a potential therapeutic strategy for promoting recovery after SCI. Copyright © 2018 Elsevier Inc. All rights reserved.

Spanish adaptation of the Quality of Life Index-Spinal Cord Injury version.

PubMed

Kovacs, F M; Barriga, A; Royuela, A; Seco, J; Zamora, J

2016-10-01

A cross-sectional, validation study. To (a) develop the Spanish version of the Quality of Life Index-Spinal Cord Injury version (SV-QLI/SCI) and (b) assess its psychometric characteristics among permanent wheelchair users and specifically among those with SCI. Associations of wheelchair users in Mallorca (Spain). Two forward and backward translations of the QLI/SCI into Spanish were carried out separately. Seventy-seven subjects were randomly selected among the members of the associations. They completed the SV-QLI/SCI and validated instruments to measure depression and spinal pain upon recruitment and 14 days later. Assessments included comprehensibility, reproducibility, floor and ceiling effects and correlations between quality of life, pain and depression (Spearman's correlation coefficient). Analyses were repeated excluding data from subjects without SCI. Three items of the SV-QLI/SCI required rephrasing. Reproducibility was 'almost perfect' for the entire questionnaire and its 'Health and functioning' subscale, 'substantial' for the 'Social and economic' and 'Family' subscales and 'moderate' for the 'Psychological/spiritual' subscale. Floor effect was not observed, and only for the 'Family' subscale >3% of the subjects reached the maximum possible score. The correlation between quality of life and depression was the strongest (r=-0.628). Results were virtually identical in the subsample with SCI. These results support the use of the SV-QLI/SCI among Spanish-speaking wheelchair users.

Lavandula angustifolia Extract Improves the Result of Human Umbilical Mesenchymal Wharton's Jelly Stem Cell Transplantation after Contusive Spinal Cord Injury in Wistar Rats

PubMed Central

Yaghoobi, Kayvan; Kaka, Gholamreza; Mansouri, Korosh; Davoodi, Shaghayegh; Sadraie, Seyed Homayoon; Hosseini, Seyed Ruhollah

2016-01-01

Introduction. The primary trauma of spinal cord injury (SCI) results in severe damage to nervous functions. At the cellular level, SCI causes astrogliosis. Human umbilical mesenchymal stem cells (HUMSCs), isolated from Wharton's jelly of the umbilical cord, can be easily obtained. Previously, we showed that the neuroprotective effects of Lavandula angustifolia can lead to improvement in a contusive SCI model in rats. Objective. The aim of this study was to investigate the effect of L. angustifolia (Lav) on HUMSC transplantation after acute SCI. Materials and Methods. Sixty adult female rats were randomly divided into eight groups. Every week after SCI onset, all animals were evaluated for behavior outcomes. H&E staining was performed to examine the lesions after injury. GFAP expression was assessed for astrogliosis. Somatosensory evoked potential (SEP) testing was performed to detect the recovery of neural conduction. Results. Behavioral tests showed that the HUMSC group improved in comparison with the SCI group, but HUMSC + Lav 400 was very effective, resulting in a significant increase in locomotion activity. Sensory tests and histomorphological and immunohistochemistry analyses verified the potentiation effects of Lav extract on HUMSC treatment. Conclusion. Transplantation of HUMSCs is beneficial for SCI in rats, and Lav extract can potentiate the functional and cellular recovery with HUMSC treatment in rats after SCI. PMID:27057171

Preface: SciDAC 2006

NASA Astrophysics Data System (ADS)

Tang, William M., Dr.

2006-01-01

The second annual Scientific Discovery through Advanced Computing (SciDAC) Conference was held from June 25-29, 2006 at the new Hyatt Regency Hotel in Denver, Colorado. This conference showcased outstanding SciDAC-sponsored computational science results achieved during the past year across many scientific domains, with an emphasis on science at scale. Exciting computational science that has been accomplished outside of the SciDAC program both nationally and internationally was also featured to help foster communication between SciDAC computational scientists and those funded by other agencies. This was illustrated by many compelling examples of how domain scientists collaborated productively with applied mathematicians and computer scientists to effectively take advantage of terascale computers (capable of performing trillions of calculations per second) not only to accelerate progress in scientific discovery in a variety of fields but also to show great promise for being able to utilize the exciting petascale capabilities in the near future. The SciDAC program was originally conceived as an interdisciplinary computational science program based on the guiding principle that strong collaborative alliances between domain scientists, applied mathematicians, and computer scientists are vital to accelerated progress and associated discovery on the world's most challenging scientific problems. Associated verification and validation are essential in this successful program, which was funded by the US Department of Energy Office of Science (DOE OS) five years ago. As is made clear in many of the papers in these proceedings, SciDAC has fundamentally changed the way that computational science is now carried out in response to the exciting challenge of making the best use of the rapid progress in the emergence of more and more powerful computational platforms. In this regard, Dr. Raymond Orbach, Energy Undersecretary for Science at the DOE and Director of the OS has stated: `SciDAC has strengthened the role of high-end computing in furthering science. It is defining whole new fields for discovery.' (SciDAC Review, Spring 2006, p8). Application domains within the SciDAC 2006 conference agenda encompassed a broad range of science including: (i) the DOE core mission of energy research involving combustion studies relevant to fuel efficiency and pollution issues faced today and magnetic fusion investigations impacting prospects for future energy sources; (ii) fundamental explorations into the building blocks of matter, ranging from quantum chromodynamics - the basic theory that describes how quarks make up the protons and neutrons of all matter - to the design of modern high-energy accelerators; (iii) the formidable challenges of predicting and controlling the behavior of molecules in quantum chemistry and the complex biomolecules determining the evolution of biological systems; (iv) studies of exploding stars for insights into the nature of the universe; and (v) integrated climate modeling to enable realistic analysis of earth's changing climate. Associated research has made it quite clear that advanced computation is often the only means by which timely progress is feasible when dealing with these complex, multi-component physical, chemical, and biological systems operating over huge ranges of temporal and spatial scales. Working with the domain scientists, applied mathematicians and computer scientists have continued to develop the discretizations of the underlying equations and the complementary algorithms to enable improvements in solutions on modern parallel computing platforms as they evolve from the terascale toward the petascale regime. Moreover, the associated tremendous growth of data generated from the terabyte to the petabyte range demands not only the advanced data analysis and visualization methods to harvest the scientific information but also the development of efficient workflow strategies which can deal with the data input/output, management, movement, and storage challenges. If scientific discovery is expected to keep apace with the continuing progression from tera- to petascale platforms, the vital alliance between domain scientists, applied mathematicians, and computer scientists will be even more crucial. During the SciDAC 2006 Conference, some of the future challenges and opportunities in interdisciplinary computational science were emphasized in the Advanced Architectures Panel and by Dr. Victor Reis, Senior Advisor to the Secretary of Energy, who gave a featured presentation on `Simulation, Computation, and the Global Nuclear Energy Partnership.' Overall, the conference provided an excellent opportunity to highlight the rising importance of computational science in the scientific enterprise and to motivate future investment in this area. As Michael Strayer, SciDAC Program Director, has noted: `While SciDAC may have started out as a specific program, Scientific Discovery through Advanced Computing has become a powerful concept for addressing some of the biggest challenges facing our nation and our world.' Looking forward to next year, the SciDAC 2007 Conference will be held from June 24-28 at the Westin Copley Plaza in Boston, Massachusetts. Chairman: David Keyes, Columbia University. The Organizing Committee for the SciDAC 2006 Conference would like to acknowledge the individuals whose talents and efforts were essential to the success of the meeting. Special thanks go to Betsy Riley for her leadership in building the infrastructure support for the conference, for identifying and then obtaining contributions from our corporate sponsors, for coordinating all media communications, and for her efforts in organizing and preparing the conference proceedings for publication; to Tim Jones for handling the hotel scouting, subcontracts, and exhibits and stage production; to Angela Harris for handling supplies, shipping, and tracking, poster sessions set-up, and for her efforts in coordinating and scheduling the promotional activities that took place during the conference; to John Bui and John Smith for their superb wireless networking and A/V set-up and support; to Cindy Latham for Web site design, graphic design, and quality control of proceedings submissions; and to Pamelia Nixon-Hartje of Ambassador for budget and quality control of catering. We are grateful for the highly professional dedicated efforts of all of these individuals, who were the cornerstones of the SciDAC 2006 Conference. Thanks also go to Angela Beach of the ORNL Conference Center for her efforts in executing the contracts with the hotel, Carolyn James of Colorado State for on-site registration supervision, Lora Wolfe and Brittany Hagen for administrative support at ORNL, and Dami Rich and Andrew Sproles for graphic design and production. We are also most grateful to the Oak Ridge National Laboratory, especially Jeff Nichols, and to our corporate sponsors, Data Direct Networks, Cray, IBM, SGI, and Institute of Physics Publishing for their support. We especially express our gratitude to the featured speakers, invited oral speakers, invited poster presenters, session chairs, and advanced architecture panelists and chair for their excellent contributions on behalf of SciDAC 2006. We would like to express our deep appreciation to Lali Chatterjee, Graham Douglas, Margaret Smith, and the production team of Institute of Physics Publishing, who worked tirelessly to publish the final conference proceedings in a timely manner. Finally, heartfelt thanks are extended to Michael Strayer, Associate Director for OASCR and SciDAC Director, and to the DOE program managers associated with SciDAC for their continuing enthusiasm and strong support for the annual SciDAC Conferences as a special venue to showcase the exciting scientific discovery achievements enabled by the interdisciplinary collaborations championed by the SciDAC program.

Comparing Time-Dependent Geomagnetic and Atmospheric Effects on Cosmogenic Nuclide Production Rate Scaling

NASA Astrophysics Data System (ADS)

Lifton, N. A.

2014-12-01

A recently published cosmogenic nuclide production rate scaling model based on analytical fits to Monte Carlo simulations of atmospheric cosmic ray flux spectra (both of which agree well with measured spectra) (Lifton et al., 2014, Earth Planet. Sci. Lett. 386, 149-160: termed the LSD model) provides two main advantages over previous scaling models: identification and quantification of potential sources of bias in the earlier models, and the ability to generate nuclide-specific scaling factors easily for a wide range of input parameters. The new model also provides a flexible framework for exploring the implications of advances in model inputs. In this work, the scaling implications of two recent time-dependent spherical harmonic geomagnetic models spanning the Holocene will be explored. Korte and Constable (2011, Phys. Earth Planet. Int. 188, 247-259) and Korte et al. (2011, Earth Planet. Sci. Lett. 312, 497-505) recently updated earlier spherical harmonic paleomagnetic models used by Lifton et al. (2014) with paleomagnetic measurements from sediment cores in addition to archeomagnetic and volcanic data. These updated models offer improved accuracy over the previous versions, in part to due to increased temporal and spatial data coverage. With the new models as input, trajectory-traced estimates of effective vertical cutoff rigidity (RC- the standard method for ordering cosmic ray data) yield significantly different time-integrated scaling predictions when compared to the earlier models. These results will be compared to scaling predictions using another recent time-dependent spherical harmonic model of the Holocene geomagnetic field by Pavón-Carrasco et al. (2014, Earth Planet. Sci. Lett. 388, 98-109), based solely on archeomagnetic and volcanic paleomagnetic data, but extending to 14 ka. In addition, the potential effects of time-dependent atmospheric models on LSD scaling predictions will be presented. Given the typical dominance of altitudinal over latitudinal scaling effects on cosmogenic nuclide production, incorporating transient global simulations of atmospheric structure (e.g., Liu et al., 2009, Science 325, 310-314) into scaling frameworks may contribute to improved understanding of long-term production rate variations.

Human lamina cribrosa insertion and age.

PubMed

Sigal, Ian A; Flanagan, John G; Lathrop, Kira L; Tertinegg, Inka; Bilonick, Richard

2012-10-03

To test the hypothesis that in healthy human eyes the lamina cribrosa (LC) insertion into the pia mater increases with age. The optic nerve heads (ONHs) of donor eyes fixed at either 5 or 50 mm Hg of IOP were sectioned, stained, and imaged under bright- and dark-field conditions. A 3-dimensional (3D) model of each ONH was reconstructed. From the 3D models we measured the area of LC insertion into the peripapillary scleral flange and into the pia, and computed the total area of insertion and fraction of LC inserting into the pia. Linear mixed effect models were used to determine if the measurements were associated with age or IOP. We analyzed 21 eyes from 11 individuals between 47 and 91 years old. The LC inserted into the pia in all eyes. The fraction of LC inserting into the pia (2.2%-29.6%) had a significant decrease with age (P = 0.049), which resulted from a nonsignificant increase in the total area of LC insertion (P = 0.41) and a nonsignificant decrease in the area of LC insertion into the pia (P = 0.55). None of the measures was associated with fixation IOP (P values 0.44-0.81). Differences between fellow eyes were smaller than differences between unrelated eyes. The LC insertion into the pia mater is common in middle-aged and older eyes, and does not increase with age. The biomechanical and vascular implications of the LC insertion into the pia mater are not well understood and should be investigated further.

Human Lamina Cribrosa Insertion and Age

PubMed Central

Sigal, Ian A.; Flanagan, John G.; Lathrop, Kira L.; Tertinegg, Inka; Bilonick, Richard

2012-01-01

Purpose. To test the hypothesis that in healthy human eyes the lamina cribrosa (LC) insertion into the pia mater increases with age. Methods. The optic nerve heads (ONHs) of donor eyes fixed at either 5 or 50 mm Hg of IOP were sectioned, stained, and imaged under bright- and dark-field conditions. A 3-dimensional (3D) model of each ONH was reconstructed. From the 3D models we measured the area of LC insertion into the peripapillary scleral flange and into the pia, and computed the total area of insertion and fraction of LC inserting into the pia. Linear mixed effect models were used to determine if the measurements were associated with age or IOP. Results. We analyzed 21 eyes from 11 individuals between 47 and 91 years old. The LC inserted into the pia in all eyes. The fraction of LC inserting into the pia (2.2%–29.6%) had a significant decrease with age (P = 0.049), which resulted from a nonsignificant increase in the total area of LC insertion (P = 0.41) and a nonsignificant decrease in the area of LC insertion into the pia (P = 0.55). None of the measures was associated with fixation IOP (P values 0.44–0.81). Differences between fellow eyes were smaller than differences between unrelated eyes. Conclusions. The LC insertion into the pia mater is common in middle-aged and older eyes, and does not increase with age. The biomechanical and vascular implications of the LC insertion into the pia mater are not well understood and should be investigated further. PMID:22956611

Dura mater graft-associated Creutzfeldt-Jakob disease with 30-year incubation period.

PubMed

Shijo, Masahiro; Honda, Hiroyuki; Koyama, Sachiko; Ishitsuka, Koji; Maeda, Koichiro; Kuroda, Junya; Tanii, Mitsugu; Kitazono, Takanari; Iwaki, Toru

2017-06-01

Over 60% of all patients with dura mater graft-associated Creutzfeldt-Jakob disease (dCJD) have been diagnosed in Japan. The incubation period has ranged from 1 to 30 years and the age at onset from 15 to 80 years. Here, we report a 77-year-old male Japanese autopsied dCJD case with the longest incubation period so far in Japan. He received a cadaveric dural graft at the right cranial convexity following a craniotomy for meningioma at the age of 46. At 30 years post-dural graft placement, disorientation was observed as an initial symptom of dCJD. He rapidly began to present with inconsistent speech, cognitive impairment and tremor of the left upper extremity. Occasional myoclonic jerks were predominantly observed on the left side. Brain MRI presented hyperintense signals on diffusion-weighted and T2-weighted images, at the right cerebral cortex. The most hyperintense lesion was located at the right parietal lobe, where the dura mater graft had been transplanted. Single-photon emission CT scan showed markedly decreased cerebral blood flow at the right parietal lobe. EEG revealed diffuse and slow activities with periodic sharp-wave complex discharges seen in the right parietal, temporal and occipital lobes. He died of pneumonia 9 months after onset. Brain pathology revealed non-plaque-type dCJD. Laterality of neuropathological changes, including spongiform change, neuronal loss, gliosis or PrP deposits, was not evident. Western blot analysis showed type 1 PrP CJD . Alzheimer-type pathology and PSP-like pathology were also observed. © 2016 Japanese Society of Neuropathology.

Novel characterization of monocyte-derived cell populations in the meninges and choroid plexus and their rates of replenishment in bone marrow chimeric mice.

PubMed

Chinnery, Holly R; Ruitenberg, Marc J; McMenamin, Paul G

2010-09-01

The mouse dura mater, pia mater, and choroid plexus contain resident macrophages and dendritic cells (DCs). These cells participate in immune surveillance, phagocytosis of cellular debris, uptake of antigens from the surrounding cerebrospinal fluid and immune regulation in many pathologic processes. We used Cx3cr1 knock-in, CD11c-eYFP transgenic and bone marrow chimeric mice to characterize the phenotype, density and replenishment rate of monocyte-derived cells in the meninges and choroid plexus and to assess the role of the chemokine receptor CX3CR1 on their number and tissue distribution. Iba-1 major histocompatibility complex (MHC) Class II CD169 CD68 macrophages and CD11c putative DCs were identified in meningeal and choroid plexus whole mounts. Comparison of homozygous and heterozygous Cx3cr1 mice did not reveal CX3CR1-dependancy on density, distribution or phenotype of monocyte-derived cells. In turnover studies, wild type lethally irradiated mice were reconstituted with Cx3cr1/-positive bone marrow and were analyzed at 3 days, 1, 2, 4 and 8 weeks after transplantation. There was a rapid replenishment of CX3CR1-positive cells in the dura mater (at 4 weeks) and the choroid plexus was fully reconstituted by 8 weeks. These data provide the foundation for future studies on the role of resident macrophages and DCs in conditions such as meningitis, autoimmune inflammatory disease and in therapies involving irradiation and hematopoietic or stem cell transplantation.

Automating Embedded Analysis Capabilities and Managing Software Complexity in Multiphysics Simulation, Part II: Application to Partial Differential Equations

DOE PAGES

Pawlowski, Roger P.; Phipps, Eric T.; Salinger, Andrew G.; ...

2012-01-01

A template-based generic programming approach was presented in Part I of this series of papers [Sci. Program. 20 (2012), 197–219] that separates the development effort of programming a physical model from that of computing additional quantities, such as derivatives, needed for embedded analysis algorithms. In this paper, we describe the implementation details for using the template-based generic programming approach for simulation and analysis of partial differential equations (PDEs). We detail several of the hurdles that we have encountered, and some of the software infrastructure developed to overcome them. We end with a demonstration where we present shape optimization and uncertaintymore » quantification results for a 3D PDE application.« less

Integrating the perspectives of individuals with spinal cord injuries, their family caregivers and healthcare professionals from the time of rehabilitation admission to community reintegration: protocol for a scoping study on SCI needs

PubMed Central

Moreno, Alexander; Zidarov, Diana; Raju, Chandhana; Boruff, Jill; Ahmed, Sara

2017-01-01

Introduction There is fragmented information about the different needs following a spinal cord injury (SCI). Expressed SCI needs can be met or unmet, they change along the rehabilitation continuum (eg, acute, rehabilitation and reintegration into the community) and can be different for traumatic and non traumatic SCI. The general objective of this scoping study is to evaluate and integrate the needs of individuals with traumatic and non-traumatic SCI, their family caregivers and those reported by rehabilitation professionals from the time of rehabilitation admission to community reintegration. The specific objectives are to: (A) synthesise the needs of individuals with SCI as perceived by themselves, their family caregivers and rehabilitation professionals using two theoretical models, (B) classify needs as met and unmet, (C) explore the evolution of met/unmet needs from the time of rehabilitation admission to community reintegration and (D) provide recommendations to improve SCI care. Methods and analysis (A) identifying the most frequent met and unmet needs reported by adults with traumatic and non-traumatic SCI, their family caregivers and their rehabilitation professionals from the time of rehabilitation admission to community reintegration; (B) identifying relevant studies with a search in electronic databases; (C) charting the data based on categories refined and adjusted with a stakeholder group; (D) collating, summarising and reporting the results using two analytical frameworks (Maslow’s hierarchical model of human needs and the Ferrans et al’s model of health-related quality of life) and (E) a stakeholder consultation phase. Ethics and dissemination The results of this scoping study will allow understanding SCI needs from the time of rehabilitation admission to community reintegration from the perspective of different stakeholders. An integrated master report combining the needs of individuals with SCI from the perspectives of different stakeholders from the time of rehabilitation admission to community reintegration will follow the consultation meetings. PMID:28780539

Vascular dysfunctions following spinal cord injury

PubMed Central

Popa, F; Grigorean, VT; Onose, G; Sandu, AM; Popescu, M; Burnei, G; Strambu, V; Sinescu, C

2010-01-01

The aim of this article is to analyze the vascular dysfunctions occurring after spinal cord injury (SCI). Vascular dysfunctions are common complications of SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. Neuroanatomy and physiology of autonomic nervous system, sympathetic and parasympathetic, is reviewed. SCI implies disruption of descendent pathways from central centers to spinal sympathetic neurons, originating in intermediolateral nuclei of T1–L2 cord segments. Loss of supraspinal control over sympathetic nervous system results in reduced overall sympathetic activity below the level of injury and unopposed parasympathetic outflow through intact vagal nerve. SCI associates significant vascular dysfunction. Spinal shock occurs during the acute phase following SCI and it is a transitory suspension of function and reflexes below the level of the injury. Neurogenic shock, part of spinal shock, consists of severe arterial hypotension and bradycardia. Autonomic dysreflexia appears during the chronic phase, after spinal shock resolution, and it is a life–threatening syndrome of massive imbalanced reflex sympathetic discharge occurring in patients with SCI above the splanchnic sympathetic outflow (T5–T6). Arterial hypotension with orthostatic hypotension occurs in both acute and chronic phases. The etiology is multifactorial. We described a few factors influencing the orthostatic hypotension occurrence in SCI: sympathetic nervous system dysfunction, low plasma catecholamine levels, rennin–angiotensin–aldosterone activity, peripheral alpha–adrenoceptor hyperresponsiveness, impaired function of baroreceptors, hyponatremia and low plasmatic volume, cardiovascular deconditioning, morphologic changes in sympathetic neurons, plasticity within spinal circuits, and motor deficit leading to loss of skeletal muscle pumping activity. Additional associated cardiovascular concerns in SCI, such as deep vein thrombosis and long–term risk for coronary heart disease and systemic atherosclerosis are also described. Proper prophylaxis, including non–pharmacologic and pharmacological strategies, diminishes the occurrence of the vascular dysfunction following SCI. Each vascular disturbance requires a specific treatment. PMID:20945818