Search Results - (Author, Cooperation:M. R. Freeman)
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1Latest Papers from Table of Contents or Articles in PressT. C. Burdett ; M. R. Freeman
American Association for the Advancement of Science (AAAS)
Published 2014Staff ViewPublication Date: 2014-07-26Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Axons/*physiology ; Mitochondrial Degradation/*physiology ; Optic Disk/*cytology ; Retinal Ganglion Cells/*physiologyPublished by: -
2Latest Papers from Table of Contents or Articles in PressJ. M. Osterloh ; J. Yang ; T. M. Rooney ; A. N. Fox ; R. Adalbert ; E. H. Powell ; A. E. Sheehan ; M. A. Avery ; R. Hackett ; M. A. Logan ; J. M. MacDonald ; J. S. Ziegenfuss ; S. Milde ; Y. J. Hou ; C. Nathan ; A. Ding ; R. H. Brown, Jr. ; L. Conforti ; M. Coleman ; M. Tessier-Lavigne ; S. Zuchner ; M. R. Freeman
American Association for the Advancement of Science (AAAS)
Published 2012Staff ViewPublication Date: 2012-06-09Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Animals, Genetically Modified ; Apoptosis ; Armadillo Domain Proteins/analysis/*genetics/*physiology ; Axons/*physiology/ultrastructure ; Axotomy ; Cell Survival ; Cells, Cultured ; Cytoskeletal Proteins/analysis/*genetics/*physiology ; Denervation ; Drosophila/embryology/genetics/physiology ; Drosophila Proteins/analysis/*genetics/*physiology ; Mice ; Mutation ; Neurons/*physiology ; Sciatic Nerve/injuries/physiology ; Signal Transduction ; Superior Cervical Ganglion/cytology ; Tissue Culture Techniques ; *Wallerian DegenerationPublished by: -
3Latest Papers from Table of Contents or Articles in PressJ. E. Losby ; F. Fani Sani ; D. T. Grandmont ; Z. Diao ; M. Belov ; J. A. Burgess ; S. R. Compton ; W. K. Hiebert ; D. Vick ; K. Mohammad ; E. Salimi ; G. E. Bridges ; D. J. Thomson ; M. R. Freeman
American Association for the Advancement of Science (AAAS)
Published 2015Staff ViewPublication Date: 2015-11-14Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
4Latest Papers from Table of Contents or Articles in PressJ. A. Burgess ; A. E. Fraser ; F. F. Sani ; D. Vick ; B. D. Hauer ; J. P. Davis ; M. R. Freeman
American Association for the Advancement of Science (AAAS)
Published 2013Staff ViewPublication Date: 2013-01-19Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
5Latest Papers from Table of Contents or Articles in PressO. Simakov ; T. Kawashima ; F. Marletaz ; J. Jenkins ; R. Koyanagi ; T. Mitros ; K. Hisata ; J. Bredeson ; E. Shoguchi ; F. Gyoja ; J. X. Yue ; Y. C. Chen ; R. M. Freeman, Jr. ; A. Sasaki ; T. Hikosaka-Katayama ; A. Sato ; M. Fujie ; K. W. Baughman ; J. Levine ; P. Gonzalez ; C. Cameron ; J. H. Fritzenwanker ; A. M. Pani ; H. Goto ; M. Kanda ; N. Arakaki ; S. Yamasaki ; J. Qu ; A. Cree ; Y. Ding ; H. H. Dinh ; S. Dugan ; M. Holder ; S. N. Jhangiani ; C. L. Kovar ; S. L. Lee ; L. R. Lewis ; D. Morton ; L. V. Nazareth ; G. Okwuonu ; J. Santibanez ; R. Chen ; S. Richards ; D. M. Muzny ; A. Gillis ; L. Peshkin ; M. Wu ; T. Humphreys ; Y. H. Su ; N. H. Putnam ; J. Schmutz ; A. Fujiyama ; J. K. Yu ; K. Tagawa ; K. C. Worley ; R. A. Gibbs ; M. W. Kirschner ; C. J. Lowe ; N. Satoh ; D. S. Rokhsar ; J. Gerhart
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-11-19Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Chordata, Nonvertebrate/classification/*genetics ; Conserved Sequence/genetics ; Echinodermata/classification/genetics ; *Evolution, Molecular ; Genome/*genetics ; Multigene Family/genetics ; Phylogeny ; Signal Transduction ; Synteny/genetics ; Transforming Growth Factor betaPublished by: -
6Articles: DFG German National LicensesBallentine, G. E. ; Hiebert, W. K. ; Stankiewicz, A. ; Freeman, M. R.
[S.l.] : American Institute of Physics (AIP)
Published 2000Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: We have measured and simulated dynamics of magnetization reversal in a micrometer scale Ni80Fe20 polycrystalline thin film element in the time domain. The sample is probed experimentally using time-resolved scanning Kerr microscopy. This allows for spatially resolved images of the dynamical magnetization states. We have simulated these magnetic reversals micromagnetically for the case of an ideal rectangular element. The reversal rates agree semiqualitatively, and gross spatial features such as a stripe instability in the directions perpendicular to the applied field are reproduced. © 2000 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesChoi, B. C. ; Ballentine, G. E. ; Belov, M. ; Hiebert, W. K. ; Freeman, M. R.
[S.l.] : American Institute of Physics (AIP)
Published 2001Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Ultrafast magnetization reversal dynamics in a 15-nm-thick Ni80Fe20 microstructure (10 μm×2 μm) is studied using both time-resolved scanning Kerr microscopy and numerical simulation. The time dependence of the magnetization component along the magnetic easy axis reveals a dramatic reduction in switching time, when the magnetization vector is pulsed by a longitudinal switching field while a steady transverse biasing field is applied. According to the time domain images, the abrupt change of the switching time is due to the change in the magnetization reversal mode; i.e., the nucleation dominant reversal process is replaced by domain wall motion if a transverse biasing field is applied. © 2001 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The application of picosecond magneto-optic sampling techniques to studies of the magnetization dynamics of thin-film recording heads is described. Time-resolved magnetization measurements are performed using picosecond stroboscopic scanning Kerr microscopy. A Faraday probe is used to monitor the coil excitation current with the same optical setup, yielding a direct measure of the magnetic propagation delay through the head. This delay is found to have a marked spatial dependence across the face of the pole tips. As an aid to visualization of the spatial dependence, scanned images of the polar Kerr rotation at fixed time delays are acquired. © 1996 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Time-resolved methods using picosecond scale transient magnetic fields have been developed for investigations of ultrafast magnetic phenomena in a broad variety of systems. When combined with synchronous magneto-optic detection, the approach yields stroboscopic observations of magnetic dynamics with a time resolution of order 1 ps, and a corresponding spatial resolution down to the diffraction limit of optics. Results are presented from experiments on europium chalcogenide films at low temperatures. A continuum of behavior from paramagnetic relaxation to ferromagnetic resonance is observed. Electron-beam deposited EuS films are found to have surprisingly fast spin-lattice relaxation rates, of order (100 ps)−1, and the influence of spin-orbit interactions on the spin dynamics is studied through rare-earth alloying. Results are presented from experiments utilizing the magneto-optic sampling method for direct time-resolved screening measurements of normal and superconducting metal films.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: We have measured the magnetostrictive response of small nickel and Tb0.3Dy0.7Fe1.95 cylinders to sudden step changes in applied magnetic field with a time-resolved scanning fiber interferometer. Spatially resolved measurements reveal the nonuniform distortion of the face of the rod as the induced magnetization propagates in toward the center. A crossover is observed, as a function of decreasing cylinder diameter, from eddy current- to longitudinal phonon-limited response times. The ability to characterize dynamic magnetostriction in small samples has also enabled us to perform time-resolved measurements of fast transient signals with a scanning tunneling microscope. Modulation of the tip-sample separation on short time scales is provided by the use of a nickel magnetostrictive tip driven by a local magnetic field coil. The technique offers a broadly applicable means of obtaining fast dynamical information in tunneling microscopy, and is demonstrated here on nanosecond time scales. These experiments illustrate, in the context of magnetics, the general promise of time-resolved scanning probe methods.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesFreeman, M. R. ; Elezzabi, A. Y. ; Stotz, J. A. H.
[S.l.] : American Institute of Physics (AIP)
Published 1997Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Time-domain optical measurements of magnetization dynamics can now be performed with sufficient resolution to reveal the intrinsic speed of many structures relevant to magnetic recording. Here we describe the behavior of the magnetization rise time at the air-bearing surface of a thin film recording head, as a function of the amplitude of current pulses in the write coil. The spatial profile of the magnetization on both sides of the gap is also examined through time-resolved, current dependent measurements. Spatial resolution enhancement via a solid immersion lens allows domain features to be discerned in the data. © 1997 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesFreeman, M. R. ; Awschalom, D. D. ; Hong, J. M.
Woodbury, NY : American Institute of Physics (AIP)
Published 1990Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: A synchronous pair of pulsed dye lasers is used to obtain continuous photoexcitation energy spectra of quantum well luminescence at fixed time delays following carrier generation, with picosecond time resolution. A measurement of the energy-dependent initial luminescence polarization of photoexcited carriers in GaAs/AlGaAs quantum wells, from a pulsed optical pumping experiment, is presented as an illustration of the technique.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesFreeman, M. R. ; Hiebert, W. K. ; Stankiewicz, A.
[S.l.] : American Institute of Physics (AIP)
Published 1998Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Time-resolved microscopy enables valuable new measurements of the dynamics of resonance and relaxation in a range of magnetic systems. An overview of the scope of applications to ferromagnetic microstructures is presented. These include observations of ferromagnetic resonance and spatially nonuniform modes of oscillation, studies of magnetization reversal, and characterizations of the speed of magnetic recording devices. © 1998 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 1089-7623Source: AIP Digital ArchiveTopics: PhysicsElectrical Engineering, Measurement and Control TechnologyNotes: A high resolution scanning optical microscope for stroboscopic time-resolved studies is presented. High optical efficiency is the prime motivation in selecting a solid immersion lens to surpass conventional diffraction limited resolution. A microscope design including details concerning the fabrication, mounting, and operation of both the hemispherical and the truncated-sphere solid immersion lenses is discussed. A thin-film magnetic recording head is used as a convenient, planar test specimen with well-defined optically reflective and magnetic features on a submicrometer length scale that allows characterization of the lateral spatial resolution of the instrument. In addition, the versatility of the microscope is demonstrated through examples of time-resolved magneto-optic imaging of the head. Further enhancement of the spatial resolution through the incorporation of confocal imaging is also described. The tradeoffs governing the selection of a particular style of microscope for specific circumstances are outlined. © 1997 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: Measurements of the magnetostrictive response of nickel cylinders to sudden step changes in applied magnetic field are performed with a time-resolved scanning fiber interferometer. A crossover is observed, as a function of decreasing cylinder diameter, from eddy current- to longitudinal phonon-limited response times. Spatially resolved measurements reveal the nonuniform distortion of the face of the rod as the induced magnetization propagates in toward the center. The results demonstrate, here in the context of magnetics, the general promise of time-resolved scanning probe methods.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesStaff View
ISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: The ability to perform time-resolved measurements of fast transient signals with a scanning tunneling microscope has been achieved through direct control of the tunneling distance on short time scales. Modulation of the tip-sample separation is provided by the use of a magnetostrictive tip driven by a local magnetic field coil. The technique offers a broadly applicable means of obtaining fast dynamical information in tunneling microscopy, and is demonstrated here on nanosecond time scales.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesFreeman, M. R. ; Brady, M. J. ; Smyth, J.
Woodbury, NY : American Institute of Physics (AIP)
Published 1992Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: An exceptionally broadband method for pulse magnetic resonance detection is described which enables measurements over a broad range of applied magnetic fields and affords excellent coupling to microscopic specimens. Employing a picosecond magneto-optic sampling technique with high temporal and spatial resolution, the precessing magnetization of a spin system is directly observed as a function of time following a photoconductively triggered spin tipping pulse. Free induction decays from 200 MHz to 200 GHz have been measured using a single device, for which the frequency limit in principle is of order 1 THz. Examples are presented for ferromagnetic resonance in yttrium iron garnet films at room temperature.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesSteeves, G. M. ; Elezzabi, A. Y. ; Freeman, M. R.
Woodbury, NY : American Institute of Physics (AIP)
Published 1998Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We present experimental data demonstrating the spatial resolution of an ultrafast junction mixing scanning tunneling microscope (JM-STM). The experiment uses a patterned metal-on-metal (Ti/Au) surface to establish electronic structure contrast on a short length scale. Our measurements achieve a spatio-temporal resolution of 20 nm–20 ps, limited only by the sample properties. The fine spatial resolution proves that the time-resolved signal is generated in the tunnel junction, indicating that atomic resolution should be possible in the JM-STM mode of operation. © 1998 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesSteeves, G. M. ; Elezzabi, A. Y. ; Freeman, M. R.
Woodbury, NY : American Institute of Physics (AIP)
Published 1997Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: Ten picosecond resolution in stroboscopic scanning tunneling microscopy of repetitive phenomena has been demonstrated using tunnel junction mixing. This represents an order-of-magnitude improvement over earlier work. Through relative timing of the tunneling current signal as a function of tip position along a transmission line, additional confirmation of time-resolved signal generation at the tunnel junction has also been established. © 1997 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesStaff View
ISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We report the demonstration of a magneto-optic sampling technique that allows for the detection of picosecond electrical pulses propagating down a microstrip transmission line. A unique feature of the method is that it directly measures the current in ultrashort electrical pulses. The technique is based on time-resolved detection of the magneto-optic Faraday effect in a Bi-substituted yttrium-iron-garnet (Bi-YIG) film. The detailed magnetic response is found to be in excellent agreement with the Bloch-Bloembergen equations. The bandwidth of the sampling system has been demonstrated to scale with the ferromagnetic resonance frequency up to 82.3 GHz, with a potential for increase towards 1 THz. © 1996 American Institute of Physics.Type of Medium: Electronic ResourceURL: