SLAC All Access: Laser Labs

ScienceCinema

Minitti, Mike; Woods, Mike

2018-05-23

From supermarket checkouts to video game consoles, lasers are ubiquitous in our lives. Here at SLAC, high-power lasers are critical to the cutting-edge research conducted at the laboratory. But, despite what you might imagine, SLAC's research lasers bear little resemblance to the blasters and phasers of science fiction. In this edition of All Access we put on our safety goggles for a peek at what goes on inside some of SLAC's many laser labs. LCLS staff scientist Mike Minitti and SLAC laser safety officer Mike Woods detail how these lasers are used to study the behavior of subatomic particles, broaden our understanding of cosmic rays and even unlock the mysteries of photosynthesis.

Exploring the speed and performance of molecular replacement with AMPLE using QUARK ab initio protein models.

PubMed

Keegan, Ronan M; Bibby, Jaclyn; Thomas, Jens; Xu, Dong; Zhang, Yang; Mayans, Olga; Winn, Martyn D; Rigden, Daniel J

2015-02-01

AMPLE clusters and truncates ab initio protein structure predictions, producing search models for molecular replacement. Here, an interesting degree of complementarity is shown between targets solved using the different ab initio modelling programs QUARK and ROSETTA. Search models derived from either program collectively solve almost all of the all-helical targets in the test set. Initial solutions produced by Phaser after only 5 min perform surprisingly well, improving the prospects for in situ structure solution by AMPLE during synchrotron visits. Taken together, the results show the potential for AMPLE to run more quickly and successfully solve more targets than previously suspected.

SLAC All Access: Laser Labs

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

Minitti, Mike; Woods, Mike

2013-03-01

From supermarket checkouts to video game consoles, lasers are ubiquitous in our lives. Here at SLAC, high-power lasers are critical to the cutting-edge research conducted at the laboratory. But, despite what you might imagine, SLAC's research lasers bear little resemblance to the blasters and phasers of science fiction. In this edition of All Access we put on our safety goggles for a peek at what goes on inside some of SLAC's many laser labs. LCLS staff scientist Mike Minitti and SLAC laser safety officer Mike Woods detail how these lasers are used to study the behavior of subatomic particles, broadenmore » our understanding of cosmic rays and even unlock the mysteries of photosynthesis.« less

Exploring the speed and performance of molecular replacement with AMPLE using QUARK ab initio protein models

PubMed Central

Keegan, Ronan M.; Bibby, Jaclyn; Thomas, Jens; Xu, Dong; Zhang, Yang; Mayans, Olga; Winn, Martyn D.; Rigden, Daniel J.

2015-01-01

AMPLE clusters and truncates ab initio protein structure predictions, producing search models for molecular replacement. Here, an interesting degree of complementarity is shown between targets solved using the different ab initio modelling programs QUARK and ROSETTA. Search models derived from either program collectively solve almost all of the all-helical targets in the test set. Initial solutions produced by Phaser after only 5 min perform surprisingly well, improving the prospects for in situ structure solution by AMPLE during synchrotron visits. Taken together, the results show the potential for AMPLE to run more quickly and successfully solve more targets than previously suspected. PMID:25664744

Water diffusion-exchange effect on the paramagnetic relaxation enhancement in off-resonance rotating frame

NASA Astrophysics Data System (ADS)

Zhang, Huiming; Xie, Yang; Ji, Tongyu

2007-06-01

The off-resonance rotating frame technique based on the spin relaxation properties of off-resonance T1 ρ can significantly increase the sensitivity of detecting paramagnetic labeling at high magnetic fields by MRI. However, the in vivo detectable dimension for labeled cell clusters/tissues in T1 ρ-weighted images is limited by the water diffusion-exchange between mesoscopic scale compartments. An experimental investigation of the effect of water diffusion-exchange between compartments on the paramagnetic relaxation enhancement of paramagnetic agent compartment is presented for in vitro/ in vivo models. In these models, the size of paramagnetic agent compartment is comparable to the mean diffusion displacement of water molecules during the long RF pulses that are used to generate the off-resonance rotating frame. The three main objectives of this study were: (1) to qualitatively correlate the effect of water diffusion-exchange with the RF parameters of the long pulse and the rates of water diffusion, (2) to explore the effect of water diffusion-exchange on the paramagnetic relaxation enhancement in vitro, and (3) to demonstrate the paramagnetic relaxation enhancement in vivo. The in vitro models include the water permeable dialysis tubes or water permeable hollow fibers embedded in cross-linked proteins gels. The MWCO of the dialysis tubes was chosen from 0.1 to 15 kDa to control the water diffusion rate. Thin hollow fibers were chosen to provide sub-millimeter scale compartments for the paramagnetic agents. The in vivo model utilized the rat cerebral vasculatures as a paramagnetic agent compartment, and intravascular agents (Gd-DTPA) 30-BSA were administrated into the compartment via bolus injections. Both in vitro and in vivo results demonstrate that the paramagnetic relaxation enhancement is predominant in the T1 ρ-weighted image in the presence of water diffusion-exchange. The T1 ρ contrast has substantially higher sensitivity than the conventional T1 contrast in detecting paramagnetic agents, especially at low paramagnetic agent volumetric fractions, low paramagnetic agent concentrations, and low RF amplitudes. Short pulse duration, short pulse recycle delay and efficient paramagnetic relaxation can reduce the influence of water diffusion-exchange on the paramagnetic enhancement. This study paves the way for the design of off-resonance rotating experiments to detect labeled cell clusters/tissue compartments in vivo at a sub-millimeter scale.

Exploiting distant homologues for phasing through the generation of compact fragments, local fold refinement and partial solution combination.

PubMed

Millán, Claudia; Sammito, Massimo Domenico; McCoy, Airlie J; Nascimento, Andrey F Ziem; Petrillo, Giovanna; Oeffner, Robert D; Domínguez-Gil, Teresa; Hermoso, Juan A; Read, Randy J; Usón, Isabel

2018-04-01

Macromolecular structures can be solved by molecular replacement provided that suitable search models are available. Models from distant homologues may deviate too much from the target structure to succeed, notwithstanding an overall similar fold or even their featuring areas of very close geometry. Successful methods to make the most of such templates usually rely on the degree of conservation to select and improve search models. ARCIMBOLDO_SHREDDER uses fragments derived from distant homologues in a brute-force approach driven by the experimental data, instead of by sequence similarity. The new algorithms implemented in ARCIMBOLDO_SHREDDER are described in detail, illustrating its characteristic aspects in the solution of new and test structures. In an advance from the previously published algorithm, which was based on omitting or extracting contiguous polypeptide spans, model generation now uses three-dimensional volumes respecting structural units. The optimal fragment size is estimated from the expected log-likelihood gain (LLG) values computed assuming that a substructure can be found with a level of accuracy near that required for successful extension of the structure, typically below 0.6 Å root-mean-square deviation (r.m.s.d.) from the target. Better sampling is attempted through model trimming or decomposition into rigid groups and optimization through Phaser's gyre refinement. Also, after model translation, packing filtering and refinement, models are either disassembled into predetermined rigid groups and refined (gimble refinement) or Phaser's LLG-guided pruning is used to trim the model of residues that are not contributing signal to the LLG at the target r.m.s.d. value. Phase combination among consistent partial solutions is performed in reciprocal space with ALIXE. Finally, density modification and main-chain autotracing in SHELXE serve to expand to the full structure and identify successful solutions. The performance on test data and the solution of new structures are described.

Stennis hosts NASA Night in Oxford

NASA Technical Reports Server (NTRS)

2010-01-01

A young visitor to the Powerhouse Community Arts and Cultural Center in Oxford, Miss., enjoys a balloon rocket transportation activity during a NASA Night in the Neighborhood on March 29. NASA's John C. Stennis Space Center near Bay St. Louis visited the center with a variety of space-related displays and educational activities. Events targeted for children included moon phasers and build-your-own rocket transportation exercises, as well as an astronaut ice cream tasting station. Visitors also were able to take photos in the astronaut suit display. Displays focused on the 40th anniversaries of the Apollo 11 and Apollo 13 lunar missions, the International Space Station, and various aspects of Stennis work. The event was sponsored by the NASA Office of External Affairs and Education at Stennis.

Digital phase-lock loop

NASA Technical Reports Server (NTRS)

Thomas, Jr., Jess B. (Inventor)

1991-01-01

An improved digital phase lock loop incorporates several distinctive features that attain better performance at high loop gain and better phase accuracy. These features include: phase feedback to a number-controlled oscillator in addition to phase rate; analytical tracking of phase (both integer and fractional cycles); an amplitude-insensitive phase extractor; a more accurate method for extracting measured phase; a method for changing loop gain during a track without loss of lock; and a method for avoiding loss of sampled data during computation delay, while maintaining excellent tracking performance. The advantages of using phase and phase-rate feedback are demonstrated by comparing performance with that of rate-only feedback. Extraction of phase by the method of modeling provides accurate phase measurements even when the number-controlled oscillator phase is discontinuously updated.

Dynamics of paramagnetic agents by off-resonance rotating frame technique in the presence of magnetization transfer effect

NASA Astrophysics Data System (ADS)

Zhang, Huiming; Xie, Yang

2007-02-01

The simple method for measuring the rotational correlation time of paramagnetic ion chelates via off-resonance rotating frame technique is challenged in vivo by the magnetization transfer effect. A theoretical model for the spin relaxation of water protons in the presence of paramagnetic ion chelates and magnetization transfer effect is described. This model considers the competitive relaxations of water protons by the paramagnetic relaxation pathway and the magnetization transfer pathway. The influence of magnetization transfer on the total residual z-magnetization has been quantitatively evaluated in the context of the magnetization map and various difference magnetization profiles for the macromolecule conjugated Gd-DTPA in cross-linked protein gels. The numerical simulations and experimental validations confirm that the rotational correlation time for the paramagnetic ion chelates can be measured even in the presence of strong magnetization transfer. This spin relaxation model also provides novel approaches to enhance the detection sensitivity for paramagnetic labeling by suppressing the spin relaxations caused by the magnetization transfer. The inclusion of the magnetization transfer effect allows us to use the magnetization map as a simulation tool to design efficient paramagnetic labeling targeting at specific tissues, to design experiments running at low RF power depositions, and to optimize the sensitivity for detecting paramagnetic labeling. Thus, the presented method will be a very useful tool for the in vivo applications such as molecular imaging via paramagnetic labeling.

Demonstrating Paramagnetism Using Liquid Nitrogen.

ERIC Educational Resources Information Center

Simmonds, Ray; And Others

1994-01-01

Describes how liquid nitrogen is attracted to the poles of neodymium magnets. Nitrogen is not paramagnetic, so the attraction suggests that the liquid nitrogen contains a small amount of oxygen, which causes the paramagnetism. (MVL)

Point defects in crystalline zircon (zirconium silicate), ZrSiO4: electron paramagnetic resonance studies

NASA Astrophysics Data System (ADS)

Tennant, W. C.; Claridge, R. F. C.; Walsby, C. J.; Lees, N. S.

This article outlines the present state of knowledge of paramagnetic defects in crystalline zircon as obtained mainly, but not exclusively, from electron paramagnetic resonance (EPR) studies in crystalline zircon (zirconium silicate, ZrSiO4). The emphasis is on single-crystal studies where, in principle, unambiguous analysis is possible. Firstly, the crystallography of zircon is presented. Secondly, the relationships between available crystal-site symmetries and the symmetries of observed paramagnetic species in zircon, and how these observations lead to unambiguous assignments of point-group symmetries for particular paramagnetic species are detailed. Next, spin-Hamiltonian (SH) analysis is discussed with emphasis on the symmetry relationships that necessarily exist amongst the Laue classes of the crystal sites in zircon, the paramagnetic species occupying those sites and the SH itself. The final sections of the article then survey the results of EPR studies on zircon over the period 1960-2002.

Optically driven self-oscillations of a silica nanospike at low gas pressures

NASA Astrophysics Data System (ADS)

Xie, Shangran; Pennetta, Riccardo; Noskov, Roman E.; Russell, Philip St. J.

2016-09-01

We report light-driven instability and optomechanical self-oscillation of a fused silica "nanospike" at low gas pressures. The nanospike (tip diameter 400 nm), fabricated by thermally tapering and HF-etching a single mode fiber (SMF), was set pointing at the endface of a hollow-core photonic crystal fiber (HC-PCF) into the field created by the fundamental optical mode emerging from the HC-PCF. At low pressures, the nanospike became unstable and began to self-oscillate for optical powers above a certain threshold, acting like a phonon laser or "phaser". Because the nanospike is robustly connected to the base, direct measurement of the temporal dynamics of the instability is possible. The experiment sheds light on why particles escape from optical traps at low pressures.

Improving the efficiency of molecular replacement by utilizing a new iterative transform phasing algorithm

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

He, Hongxing; Fang, Hengrui; Miller, Mitchell D.

2016-07-15

An iterative transform algorithm is proposed to improve the conventional molecular-replacement method for solving the phase problem in X-ray crystallography. Several examples of successful trial calculations carried out with real diffraction data are presented. An iterative transform method proposed previously for direct phasing of high-solvent-content protein crystals is employed for enhancing the molecular-replacement (MR) algorithm in protein crystallography. Target structures that are resistant to conventional MR due to insufficient similarity between the template and target structures might be tractable with this modified phasing method. Trial calculations involving three different structures are described to test and illustrate the methodology. The relationshipmore » of the approach to PHENIX Phaser-MR and MR-Rosetta is discussed.« less

Stable and rigid DTPA-like paramagnetic tags suitable for in vitro and in situ protein NMR analysis.

PubMed

Chen, Jia-Liang; Zhao, Yu; Gong, Yan-Jun; Pan, Bin-Bin; Wang, Xiao; Su, Xun-Cheng

2018-02-01

Organic synthesis of a ligand with high binding affinities for paramagnetic lanthanide ions is an effective way of generating paramagnetic effects on proteins. These paramagnetic effects manifested in high-resolution NMR spectroscopy are valuable dynamic and structural restraints of proteins and protein-ligand complexes. A paramagnetic tag generally contains a metal chelating moiety and a reactive group for protein modification. Herein we report two new DTPA-like tags, 4PS-PyDTTA and 4PS-6M-PyDTTA that can be site-specifically attached to a protein with a stable thioether bond. Both protein-tag adducts form stable lanthanide complexes, of which the binding affinities and paramagnetic tensors are tunable with respect to the 6-methyl group in pyridine. Paramagnetic relaxation enhancement (PRE) effects of Gd(III) complex on protein-tag adducts were evaluated in comparison with pseudocontact shift (PCS), and the results indicated that both 4PS-PyDTTA and 4PS-6M-PyDTTA tags are rigid and present high-quality PREs that are crucially important in elucidation of the dynamics and interactions of proteins and protein-ligand complexes. We also show that these two tags are suitable for in-situ protein NMR analysis.

Trispyrazolylborate Complexes: An Advanced Synthesis Experiment Using Paramagnetic NMR, Variable-Temperature NMR, and EPR Spectroscopies

ERIC Educational Resources Information Center

Abell, Timothy N.; McCarrick, Robert M.; Bretz, Stacey Lowery; Tierney, David L.

2017-01-01

A structured inquiry experiment for inorganic synthesis has been developed to introduce undergraduate students to advanced spectroscopic techniques including paramagnetic nuclear magnetic resonance and electron paramagnetic resonance. Students synthesize multiple complexes with unknown first row transition metals and identify the unknown metals by…

Disequilibrium, complexity, the Schottky effect, and q-entropies, in paramagnetism

NASA Astrophysics Data System (ADS)

Pennini, F.; Plastino, A.

2017-12-01

We investigate connections between statistical quantifiers and paramagnetism. More concretely, we apply the notions of (i) disequilibrium and (ii) statistical complexity, to a paramagnetic system of non-coupled dipoles. Interesting insights are thereby obtained. In particular, we encounter a kind of criticality, not associated to the temperature but to the disequilibrium.

Mechanical membrane for the separation of a paramagnetic constituent from a fluid

DOEpatents

Maurice, David

2017-05-02

The disclosure provides an apparatus and method for the separation of a paramagnetic component from a mixture using a mechanical membrane apparatus. The mechanical membrane comprises a supporting material having a plurality of pores where each pore is surrounded by a plurality of magnetic regions. The magnetic regions augment a magnetic field on one side of the supporting material while mitigating the field to near zero on the opposite side. In operation, a flow of fluid such as air comprising a paramagnetic component such as O.sub.2 is directed toward the mechanical membrane, and the paramagnetic component is typically attracted toward a magnetic field surrounding a pore while dimagnetic components such as N.sub.2 are generally repelled. As some portion of the fluid passes through the plurality of magnetic apertures to the opposite side of the mechanical membrane, the mechanical membrane generates a fluid enriched in the paramagnetic component. Alternately, the magnetic field may act to repel the paramagnetic component while diamagnetic components such as N.sub.2 are generally unaffected and pass to the opposite side of the mechanical membrane.

Separation of diamagnetic and paramagnetic anisotropy by high-field, low-temperature torque measurements

NASA Astrophysics Data System (ADS)

Schmidt, Volkmar; Hirt, Ann M.; Rosselli, Pascal; Martín-Hernández, Fátima

2007-01-01

The anisotropy of magnetic susceptibility (AMS) of rocks can be composed of contributions from ferromagnetic, paramagnetic and diamagnetic minerals. However, in general the AMS of only one fraction is of interest. While there are several approaches to isolate the ferromagnetic contribution to the AMS, the separation of the diamagnetic from the paramagnetic contribution is still problematic. A new method for the separation of these two contributions based on high-field torque measurements at room and low-temperature is presented. The paramagnetic anisotropy increases at low temperature according to the Curie-Weiss law, whereas the diamagnetic contribution is temperature independent. If the paramagnetic AMS is due to perfectly oblate or prolate minerals and the ratio of the susceptibility differences at two temperatures is known, paramagnetic and diamagnetic AMS can be separated. When measuring in fields high enough to saturate the ferromagnetic phases all three contributions to the AMS can be separated. The separation of paramagnetic and diamagnetic AMS is demonstrated on natural crystals and synthetic calcite-muscovite aggregates. A high-field torque magnetometer, equipped with a cryostat for measurements at 77 K, allows sensitive measurements at two different temperatures. The sensitivity at 77 K is 3 × 10-7 J and standard-sized (palaeomagnetic) samples of 11.4 cm3 can be measured. This new method is especially suited for the investigation of diamagnetic fabrics of impure carbonate rocks.

Electron paramagnetic resonance of several lunar rock samples

NASA Technical Reports Server (NTRS)

Marov, P. N.; Dubrov, Y. N.; Yermakov, A. N.

1974-01-01

The results are presented of investigating lunar rock samples returned by the Luna 16 automatic station, using electron paramagnetic resonance (EPR). The EPR technique makes it possible to detect paramagnetic centers and investigate their nature, with high sensitivity. Regolith (finely dispersed material) and five particles from it, 0.3 mm in size, consisting mostly of olivine, were investigated with EPR.

Monitoring changes of paramagnetically-shifted 31P signals in phospholipid vesicles

NASA Astrophysics Data System (ADS)

Joyce, Rebecca E.; Williams, Thomas L.; Serpell, Louise C.; Day, Iain J.

2016-03-01

Phospholipid vesicles are commonly used as biomimetics in the investigation of the interaction of various species with cell membranes. In this letter we present a 31P NMR investigation of a simple vesicle system using a paramagnetic shift reagent to probe the inner and outer layers of the lipid bilayer. Time-dependent changes in the 31P NMR signal are observed, which differ whether the paramagnetic species is inside or outside the vesicle, and on the choice of buffer solution used. An interpretation of these results is given in terms of the interaction of the paramagnetic shift reagent with the lipids.

Paramagnetic Spin Seebeck Effect

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

Wu, Stephen M.; Pearson, John E.; Bhattacharya, Anand

2015-05-01

We report the observation of the longitudinal spin Seebeck effect in paramagnetic insulators. By using a microscale on-chip local heater, we generate a large thermal gradient confined to the chip surface without a large increase in the total sample temperature. Using this technique at low temperatures (< 20 K), we resolve the paramagnetic spin Seebeck effect in the insulating paramagnets Gd3Ga5O12 (gadolinium gallium garnet) and DyScO3 (DSO), using either W or Pt as the spin detector layer. By taking advantage of the strong magnetocrystalline anisotropy of DSO, we eliminate contributions from the Nernst effect in W or Pt, which producesmore » a phenomenologically similar signal.« less

Paramagnetic NMR Investigation of Dendrimer-Based Host-Guest Interactions

PubMed Central

Wang, Fei; Shao, Naimin; Cheng, Yiyun

2013-01-01

In this study, the host-guest behavior of poly(amidoamine) (PAMAM) dendrimers bearing amine, hydroxyl, or carboxylate surface functionalities were investigated by paramagnetic NMR studies. 2,2,6,6-Tetramethylpiperidinyloxy (TEMPO) derivatives were used as paramagnetic guest molecules. The results showed that TEMPO-COOH significantly broaden the 1H NMR peaks of amine- and hydroxyl-terminated PAMAM dendrimers. In comparison, no paramagnetic relaxation enhancement (PRE) was observed between TEMPO-NH2, TEMPO-OH and the three types of PAMAM dendrimers. The PRE phenomenon observed is correlated with the encapsulation of TEMPO-COOH within dendrimer pockets. Protonation of the tertiary amine groups within PAMAM dendrimers plays an important role during this process. Interestingly, the absence of TEMPO-COOH encapsulation within carboxylate-terminated PAMAM dendrimer is observed due to the repulsion of TEMPO-COO- anion and anionic dendrimer surface. The combination of paramagnetic probes and 1H NMR linewidth analysis can be used as a powerful tool in the analysis of dendrimer-based host-guest systems. PMID:23762249

Retrospective Reconstruction of Radiation Doses of Chernobyl Liquidators by Electron Paramagnetic Resonance

DTIC Science & Technology

1997-12-01

Armed Forces Rad I Research Institute Retrospective Reconstruction of Radiation Doses of Chernobyl Liquidators by Electron Paramagnetic Resonance A...of Radiation Doses of Chernobyl Liquidators by Electron Paramagnetic Resonance Authored by Scientific Center of Radiation Medicine Academy of Medical...libraries associated with the U.S. Government’s Depository Library System. Preface On April 26, 1986, Reactor #4 at the Chernobyl Nuclear Power Plant near

NARROW LINE ABSORPTION IN CACO3.

DTIC Science & Technology

CARBONATES), (*CALCIUM COMPOUNDS, (*ABSORPTION SPECTRA, CALCITE), (*CALCITE, RADIATION EFFECTS), ELECTRON PARAMAGNETIC RESONANCE, SINGLE CRYSTALS , NEUTRONS, X RAYS, GAMMA RAYS, IONS, CRYSTAL DEFECTS, PARAMAGNETIC RESONANCE.

Stennis hosts Gulf Pine Council's NASA Brownie Day

NASA Image and Video Library

2007-10-13

Tori Williams, of Brownie Girl Scout Troop 313, builds her own `stomp rocket' with the help of adult chaperone Pamela Cottrell. The two, of Gulfport, participated in NASA Brownie Day on Oct. 13 at Stennis Space Center. They were among nearly 200 members of Brownie Girl Scout Troops within the Gulf Pines Council who took part in the day of educational activities at SSC. Brownie Day used NASA curriculum support materials to teach about the sun and its significance in our solar system. In addition to building and launching their own model rockets, the girls toured the center's portable Starlab planetarium; viewed demonstrations about living and working in space; played games of `Moon Phasers' that teach about the rotation of the moon around the earth; made bracelets with ultraviolet-sensitive beads; and other activities that celebrated Earth's very own star. They also toured StenniSphere and were able to earn their Earth and Sky and Space Explorer `Try-Its.'

Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing (PHASERS)

NASA Technical Reports Server (NTRS)

Guerra, David V.; Schwemmer, Geary K.; Wooten, Albert D., Jr.; Chaudhuri, Sandipan S.; Wilkerson, Thomas D.

1995-01-01

A ground-based atmospheric lidar system that utilizes a Holographic Optical Telescope and Scanner has been developed and successfully operated to obtain atmospheric backscatter profiles. The Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing is built around a volume phase reflection Holographic Optical Element. This single optical element both directs and collimates the outgoing laser beam as well as collects, focuses, and filters the atmospheric laser backscatter, while offering significant weight savings over existing telescope mirror technology. Conical scanning is accomplished as the HOE rotates on a turntable sweeping the 1.2 mrad field of view around a 42deg cone. During this technology demonstration, atmospheric aerosol and cloud return signals have been received in both stationary and scanning modes. The success of this program has led to the further development of this technology for integration into airborne and eventually satellite earth observing scanning lidar telescopes.

Stennis hosts Gulf Pine Council's NASA Brownie Day

NASA Technical Reports Server (NTRS)

2007-01-01

Tori Williams, of Brownie Girl Scout Troop 313, builds her own `stomp rocket' with the help of adult chaperone Pamela Cottrell. The two, of Gulfport, participated in NASA Brownie Day on Oct. 13 at Stennis Space Center. They were among nearly 200 members of Brownie Girl Scout Troops within the Gulf Pines Council who took part in the day of educational activities at SSC. Brownie Day used NASA curriculum support materials to teach about the sun and its significance in our solar system. In addition to building and launching their own model rockets, the girls toured the center's portable Starlab planetarium; viewed demonstrations about living and working in space; played games of `Moon Phasers' that teach about the rotation of the moon around the earth; made bracelets with ultraviolet-sensitive beads; and other activities that celebrated Earth's very own star. They also toured StenniSphere and were able to earn their Earth and Sky and Space Explorer `Try-Its.'

Hyperfine Interactions in the Electron Paramagnetic Resonance Spectra of Point Defects in Wide-Band-Gap Semiconductors

DTIC Science & Technology

2014-09-18

compensation) during growth due to their preferred trivalent charge states. The electron paramagnetic resonance spectrum of the singly ionized chromium ...neutral nitrogen acceptor in ZnO . . . . . . . . . . . . . . . . . . 45 16 Spectrum of the singly ionized chromium acceptor in TiO2 . . . . . . . . . 49...is a single crystal of magnesium oxide that has been doped with chromium . Chromium Cr3+ substitutes for magnesium Mg2+ and creates a paramagnetic

Simplifying Logistics and Avoiding the Unnecessary in Patients With Breast Cancer Undergoing Sentinel Node Biopsy. A Prospective Feasibility Trial of the Preoperative Injection of Super Paramagnetic Iron Oxide Nanoparticles.

PubMed

Karakatsanis, A; Olofsson, H; Stålberg, P; Bergkvist, L; Abdsaleh, S; Wärnberg, F

2018-06-01

Sentinel node is routinely localized with the intraoperative use of a radioactive tracer, involving challenging logistics. Super paramagnetic iron oxide nanoparticle is a non-radioactive tracer with comparable performance that could allow for preoperative localization, would simplify the procedure, and possibly be of value in axillary mapping before neoadjuvant treatment. The current trial aimed to determine the a priori hypothesis that the injection of super paramagnetic iron oxide nanoparticles in the preoperative period for the localization of the sentinel node is feasible. This is a prospective feasibility trial, conducted from 9 September 2014 to 22 October 2014 at Uppsala University Hospital. In all, 12 consecutive patients with primary breast cancer planned for resection of the primary and sentinel node biopsy were recruited. Super paramagnetic iron oxide nanoparticles were injected in the preoperative visit in the outpatient clinic. The radioactive tracer ( 99 mTc) and the blue dye were injected perioperatively in standard fashion. A volunteer was injected with super paramagnetic iron oxide nanoparticles to follow the decline in the magnetic signal in the sentinel node over time. The primary outcome was successful sentinel node detection. Super paramagnetic iron oxide nanoparticles' detection after preoperative injection (3-15 days) was successful in all cases (100%). In the volunteer, axillary signal was presented for 4 weeks. No adverse effects were noted. Conclusion and relevance: Preoperative super paramagnetic iron oxide nanoparticles' injection is feasible and leads to successful detection of the sentinel node. That may lead to simplified logistics as well as the identification, sampling, and marking of the sentinel node in patients planned for neoadjuvant treatment.

Optical detection of paramagnetic centres: From crystals to glass-ceramics

NASA Astrophysics Data System (ADS)

Rogulis, Uldis

2016-07-01

An unambiguous attribution of the absorption spectra to definite paramagnetic centres identified by the EPR techniques in the most cases is problematic. This problem may be solved by applying of a direct measurement techniques—the EPR detected via the magnetic circular dichroism, or briefly MCD-EPR. The present survey reports on the advantages and disadvantages applying the MCD-EPR techniques to simple and complex paramagnetic centres in crystals as well as glasses and glass-ceramics.

Application of Electron Paramagnetic Resonance to Study of Gallstones

NASA Astrophysics Data System (ADS)

Kiselev, S. A.; Tsyro, L. V.; Afanasiev, D. A.; Unger, F. G.; Soloviev, M. M.

2014-03-01

We present the results of an electron paramagnetic resonance (EPR) study of mixed cholesterol gallstones. We have established that free radicals are distributed nonuniformly within the interior of the stone. The type and number of paramagnetic centers depend on the pigment content in the selected layer. We show that the parameters of the sextet lines in the EPR spectrum of the pigment are close to the parameters of lines in the spectrum of a brown pigment stone.

CW EPR and 9 GHz EPR imaging investigation of stable paramagnetic species and their antioxidant activities in dry shiitake mushroom (Lentinus edodes).

PubMed

Nakagawa, Kouichi; Hara, Hideyuki

2016-01-01

We investigated the antioxidant activities and locations of stable paramagnetic species in dry (or drying) shiitake mushroom (Lentinus edodes) using continuous wave (CW) electron paramagnetic resonance (EPR) and 9 GHz EPR imaging. CW 9 GHz EPR detected paramagnetic species (peak-to-peak linewidth (ΔHpp) = 0.57 mT) in the mushroom. Two-dimensional imaging of the sharp line using a 9 GHz EPR imager showed that the species were located in the cap and shortened stem portions of the mushroom. No other location of the species was found in the mushroom. However, radical locations and concentrations varied along the cap of the mushroom. The 9 GHz EPR imaging determined the exact location of stable paramagnetic species in the shiitake mushroom. Distilled water extracts of the pigmented cap surface and the inner cap of the mushroom showed similar antioxidant activities that reduced an aqueous solution of 0.1 mM 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl. The present results suggest that the antioxidant activities of the edible mushroom extracts are much weaker than those of ascorbic acid. Thus, CW EPR and EPR imaging revealed the location and distribution of stable paramagnetic species and the antioxidant activities in the shiitake mushroom for the first time.

Physicochemical characterization, and relaxometry studies of micro-graphite oxide, graphene nanoplatelets, and nanoribbons.

PubMed

Paratala, Bhavna S; Jacobson, Barry D; Kanakia, Shruti; Francis, Leonard Deepak; Sitharaman, Balaji

2012-01-01

The chemistry of high-performance magnetic resonance imaging contrast agents remains an active area of research. In this work, we demonstrate that the potassium permanganate-based oxidative chemical procedures used to synthesize graphite oxide or graphene nanoparticles leads to the confinement (intercalation) of trace amounts of Mn(2+) ions between the graphene sheets, and that these manganese intercalated graphitic and graphene structures show disparate structural, chemical and magnetic properties, and high relaxivity (up to 2 order) and distinctly different nuclear magnetic resonance dispersion profiles compared to paramagnetic chelate compounds. The results taken together with other published reports on confinement of paramagnetic metal ions within single-walled carbon nanotubes (a rolled up graphene sheet) show that confinement (encapsulation or intercalation) of paramagnetic metal ions within graphene sheets, and not the size, shape or architecture of the graphitic carbon particles is the key determinant for increasing relaxivity, and thus, identifies nano confinement of paramagnetic ions as novel general strategy to develop paramagnetic metal-ion graphitic-carbon complexes as high relaxivity MRI contrast agents.

Physicochemical Characterization, and Relaxometry Studies of Micro-Graphite Oxide, Graphene Nanoplatelets, and Nanoribbons

PubMed Central

Paratala, Bhavna S.; Jacobson, Barry D.; Kanakia, Shruti; Francis, Leonard Deepak; Sitharaman, Balaji

2012-01-01

The chemistry of high-performance magnetic resonance imaging contrast agents remains an active area of research. In this work, we demonstrate that the potassium permanganate-based oxidative chemical procedures used to synthesize graphite oxide or graphene nanoparticles leads to the confinement (intercalation) of trace amounts of Mn2+ ions between the graphene sheets, and that these manganese intercalated graphitic and graphene structures show disparate structural, chemical and magnetic properties, and high relaxivity (up to 2 order) and distinctly different nuclear magnetic resonance dispersion profiles compared to paramagnetic chelate compounds. The results taken together with other published reports on confinement of paramagnetic metal ions within single-walled carbon nanotubes (a rolled up graphene sheet) show that confinement (encapsulation or intercalation) of paramagnetic metal ions within graphene sheets, and not the size, shape or architecture of the graphitic carbon particles is the key determinant for increasing relaxivity, and thus, identifies nano confinement of paramagnetic ions as novel general strategy to develop paramagnetic metal-ion graphitic-carbon complexes as high relaxivity MRI contrast agents. PMID:22685555

An EPR study on tea: Identification of paramagnetic species, effect of heat and sweeteners

NASA Astrophysics Data System (ADS)

Bıyık, Recep; Tapramaz, Recep

2009-10-01

Tea ( Camellia Sinensis) is the most widely consumed beverage in the world, and is known to be having therapeutic, antioxidant and nutritional effects. Electron paramagnetic resonance (EPR) spectral studies made on the tea cultivated along the shore of Black Sea, Turkey, show Mn 2+ and Fe 3+ centers in green tea leaves and in black tea extract. Dry black tea flakes and dry extract show additional sharp line attributed to semiquinone radical. The origins of the paramagnetic species in black tea are defined and discussed. Effect of humidity and heat are investigated. It is observed that dry extract of black tea melts at 100 °C and the semiquinone radical lives up to 140 °C while Mn 2+ sextet disappears just above 100 °C in tea extract. Natural and synthetics sweeteners have different effects on the paramagnetic centers. White sugar (sucrose) quenches the Mn 2+ and semiquinone lines in black tea EPR spectrum, and glucose, fructose, lactose and maltose quench Fe 3+ line while synthetic sweeteners acesulfam potassium, aspartame and sodium saccharine do not have any effect on paramagnetic species in tea.

An EPR study on tea: identification of paramagnetic species, effect of heat and sweeteners.

PubMed

Biyik, Recep; Tapramaz, Recep

2009-10-15

Tea (Camellia Sinensis) is the most widely consumed beverage in the world, and is known to be having therapeutic, antioxidant and nutritional effects. Electron paramagnetic resonance (EPR) spectral studies made on the tea cultivated along the shore of Black Sea, Turkey, show Mn(2+) and Fe(3+) centers in green tea leaves and in black tea extract. Dry black tea flakes and dry extract show additional sharp line attributed to semiquinone radical. The origins of the paramagnetic species in black tea are defined and discussed. Effect of humidity and heat are investigated. It is observed that dry extract of black tea melts at 100 degrees C and the semiquinone radical lives up to 140 degrees C while Mn(2+) sextet disappears just above 100 degrees C in tea extract. Natural and synthetics sweeteners have different effects on the paramagnetic centers. White sugar (sucrose) quenches the Mn(2+) and semiquinone lines in black tea EPR spectrum, and glucose, fructose, lactose and maltose quench Fe(3+) line while synthetic sweeteners acesulfam potassium, aspartame and sodium saccharine do not have any effect on paramagnetic species in tea.

Electron paramagnetic resonance of natural and gamma-irradiated alunite and kaolin mineral powders

NASA Astrophysics Data System (ADS)

Koksal, F.; Koseoglu, R.; Saka, I.; Basaran, E.; Sener, F.

2004-06-01

Natural alunite and kaolin minerals obtained from West Anatolia were investigated by electron paramagnetic resonance (EPR) in natural and gamma-irradiated states at room temperature and at 113 K. The paramagnetic centres at ambient temperature in natural alunite were attributed to the (C) over dot H 2OH, (C) over dot O-3(-), (S) over dot O-2(-), (C) over dot O-2(-) and [AlO4 ](0) radicals. In natural kaolin, the paramagnetic centres were attributed to the (C) over dot O-3(-), (S) over dot O-2(-) (C) over dot O-2(-) and [AlO4](0) radicals. The gamma-irradiation does not produce any detectable effects on these radicals. At 113 K, the lines for (C) over dot H2OH could not be observed well, probably due to the anisotropic behaviour of the hyperfine interaction of the methylene protons, but the lines for [AlO4](0) centres were found to be perfectly observable at above 20 mW microwave power in both alunite and kaolin powders before and after gamma-irradiation. The EPR parameters of the observed paramagnetic centres were reported.

Quasiclassical Theory on Third-Harmonic Generation in Conventional Superconductors with Paramagnetic Impurities

NASA Astrophysics Data System (ADS)

Jujo, Takanobu

2018-02-01

We investigate the third-harmonic generation (THG) of s-wave superconductors under microwave pulse irradiation. We consider the effect of paramagnetic impurities on the THG intensity of dirty superconductors. The nonlinear response function is calculated using the method of the quasiclassical Green function. It is shown that the amplitude mode is included as the vertex correction and makes a predominant contribution to the THG intensity. When the effect of paramagnetic impurities is weak, the THG intensity shows a peak at the temperature at which the superconducting gap is about the same as the frequency of the incident pulse, similarly to in experiments. As the effect of paramagnetic impurities is strengthened, the peak of the THG intensity disappears. This indicates that time-reversal symmetry breaking due to paramagnetic impurities eliminates the well-defined amplitude mode. The result of our calculation shows that the existence of the amplitude mode can be confirmed through the THG intensity. The result of a semiquantitative calculation is in good agreement with the experimental result, and it also shows that the diamagnetic term is negligible.

EPR Characterization of Dinitrosyl Iron Complexes with Thiol-Containing Ligands as an Approach to Their Identification in Biological Objects: An Overview.

PubMed

Vanin, Anatoly F

2018-06-01

The overview demonstrates how the use of only one physico-chemical approach, viz., the electron paramagnetic resonance method, allowed detection and identification of dinitrosyl iron complexes with thiol-containing ligands in various animal and bacterial cells. These complexes are formed in biological objects in the paramagnetic (electron paramagnetic resonance-active) mononuclear and diamagnetic (electron paramagnetic resonance-silent) binuclear forms and control the activity of nitrogen monoxide, one of the most universal regulators of metabolic processes in the organism. The analysis of electronic and spatial structures of dinitrosyl iron complex sheds additional light on the mechanism whereby dinitrosyl iron complex with thiol-containing ligands function in human and animal cells as donors of nitrogen monoxide and its ionized form, viz., nitrosonium ions (NO + ).

Van vleck paramagnetism in orthorhombic TiO2 (Brookite)

USGS Publications Warehouse

Senftle, F.E.; Thorpe, A.N.

1968-01-01

The magnetic susceptibility of the orthorhombic form of titanium dioxide has been measured from 5 to 300??K. After deducting the temperature-dependent component, which is probably due to defects or impurities, and the free-ion diamagnetic component, the Van Vleck paramagnetism was estimated to be 33??10-6 emu/mole. Comparison is made between this value and the Van Vleck paramagnetism of strontium titanate and the two tetragonal forms of titanium dioxide: rutile and anatase. ?? 1968 The American Physical Society.

Paramagnetic Europium Salen Complex and Sickle-Cell Anemia

NASA Astrophysics Data System (ADS)

Wynter, Clive I.; Ryan, D. H.; May, Leopold; Oliver, F. W.; Brown, Eugene; Hoffman, Eugene J.; Bernstein, David

2005-04-01

A new europium salen complex, Eu(salen)2NH4, was synthesized, and its composition was confirmed by chemical analysis and infrared spectroscopy. Further characterization was carried out by 151 Eu Mössbauer spectroscopy and magnetic susceptibility measurements. Mössbauer spectroscopic measurements were made at varying temperatures between 9 K and room temperature and a value of Debye temperature of 133 ±5 K was computed. Both Mössbauer and magnetic susceptibility measurements confirmed the paramagnetic behavior of this complex and the trivalent state of the europium ion. In view of the fact that the "odd" paramagnetic molecule NO has been shown to reverse sickling of red blood cells in sickle cell anemia, the interaction between the paramagnetic europium salen complex and sickle cells was examined after incubation with this europium complex and shown to have similar effects.

High-gradient permanent magnet apparatus and its use in particle collection

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

Cheng, Mengdawn; Ludtka, Gerard Michael; Avens, Larry R.

A high-gradient permanent magnet apparatus for capturing paramagnetic particles, the apparatus comprising: (i) at least two permanent magnets positioned with like poles facing each other; (ii) a ferromagnetic spacer separating the like poles; and (iii) a magnetizable porous filling material in close proximity to the at least two permanent magnets. Also described is a method for capturing paramagnetic particles in which a gas or liquid sample containing the paramagnetic particles is contacted with the high-gradient permanent magnet apparatus described above; wherein, during the contacting step, the gas or liquid sample contacts the magnetizable porous filling material of the high-gradient permanentmore » magnet apparatus, and at least a portion of the paramagnetic particles in the gas or liquid sample is captured on the magnetizable porous filling material.« less

TRANSFORMER APPARATUS

DOEpatents

Wolfgang, F.; Nicol, J.

1962-11-01

Transformer apparatus is designed for measuring the amount of a paramagnetic substance dissolved or suspended in a diamagnetic liquid. The apparatus consists of a cluster of tubes, some of which are closed and have sealed within the diamagnetic substance without any of the paramagnetic material. The remaining tubes are open to flow of the mix- ture. Primary and secondary conductors are wrapped around the tubes in such a way as to cancel noise components and also to produce a differential signal on the secondaries based upon variations of the content of the paramagnetic material. (AEC)

Measurement of electron paramagnetic resonance using terahertz time-domain spectroscopy.

PubMed

Kozuki, Kohei; Nagashima, Takeshi; Hangyo, Masanori

2011-12-05

We present a frequency-domain electron spin resonance (ESR) measurement system using terahertz time-domain spectroscopy. A crossed polarizer technique is utilized to increase the sensitivity in detecting weak ESR signals of paramagnets caused by magnetic dipole transitions between magnetic sublevels. We demonstrate the measurements of ESR signal of paramagnetic copper(II) sulfate pentahydrate with uniaxial anisotropy of the g-factor under magnetic fields up to 10 T. The lineshape of the obtained ESR signals agrees well with the theoretical predictions for a powder sample with the uniaxial anisotropy.

The EPR of the triplet state of aryl cations in crystals of diazonium salts

NASA Astrophysics Data System (ADS)

Kondratenko, P. A.; Shrubovich, E. V.; Shulga, S. Z.

The spectra of the electron paramagnetic resonance (EPR) of aryl cations possessing a principle triplet ground-state and orientated in a monocrystal of diazonium salts is studied. It is shown that two nonequivalent paramagnetic centers, which differ in orientation are formed within the crystal. A theoretic description of experimental results is possible only when allowing for the effect of low symmetry. This symmetry is invoked by the interactivity of the paramagnetic center of symmetry C(sub 2v) with the crystal field of symmetry C(sub i).

Dynamics of paramagnetic agents by off-resonance rotating frame technique

NASA Astrophysics Data System (ADS)

Zhang, Huiming; Xie, Yang

2006-12-01

Off-resonance rotating frame technique offers a novel tool to explore the dynamics of paramagnetic agents at high magnetic fields ( B0 > 3 T). Based on the effect of paramagnetic relaxation enhancement in the off-resonance rotating frame, a new method is described here for determining the dynamics of paramagnetic ion chelates from the residual z-magnetizations of water protons. In this method, the dynamics of the chelates are identified by the difference magnetization profiles, which are the subtraction of the residual z-magnetization as a function of frequency offset obtained at two sets of RF amplitude ω1 and pulse duration τ. The choices of ω1 and τ are guided by a 2-D magnetization map that is created numerically by plotting the residual z-magnetization as a function of effective field angle θ and off-resonance pulse duration τ. From the region of magnetization map that is the most sensitive to the alteration of the paramagnetic relaxation enhancement efficiency R1 ρ/ R1, the ratio of the off-resonance rotating frame relaxation rate constant R1 ρ verse the laboratory frame relaxation rate constant R1, three types of difference magnetization profiles can be generated. The magnetization map and the difference magnetization profiles are correlated with the rotational correlation time τR of Gd-DTPA through numerical simulations, and further validated by the experimental data for a series of macromolecule conjugated Gd-DTPA in aqueous solutions. Effects of hydration water number q, diffusion coefficient D, magnetic field strength B0 and multiple rotational correlation times are explored with the simulations of the magnetization map. This method not only provides a simple and reliable approach to determine the dynamics of paramagnetic labeling of molecular/cellular events at high magnetic fields, but also a new strategy for spectral editing in NMR/MRI based on the dynamics of paramagnetic labeling in vivo.

Investigating the Distribution of Stable Paramagnetic Species in an Apple Seed Using X-Band EPR and EPR Imaging.

PubMed

Nakagawa, Kouichi; Epel, Boris

2017-03-01

This study investigated the location and distribution of paramagnetic species in apple seeds using electron paramagnetic resonance (EPR) and X-band (9 GHz) EPR imaging (EPRI). EPR primarily detected two paramagnetic species per measured seed. These two different radical species were assigned as stable radicals and Mn 2+ species based on the g values and hyperfine components. The signal from the stable radical was noted at g ≈ 2.00 and was strong and relatively stable. The subsequent noninvasive EPRI of the radical present in each seed revealed that the stable radicals were located primarily in the seed coat, with very few radicals observed in the cotyledon of the seed. These results indicate that the stable radical species were only found within the seed coat, and few radical species were found in other seed parts.

Buckling of paramagnetic chains in soft gels

NASA Astrophysics Data System (ADS)

Huang, Shilin; Pessot, Giorgio; Cremer, Peet; Weeber, Rudolf; Holm, Christian; Nowak, Johannes; Odenbach, Stefan; Menzel, Andreas M.; Auernhammer, Günter K.

We study the magneto-elastic coupling behavior of paramagnetic chains in soft polymer gels exposed to external magnetic fields. To this end, a laser scanning confocal microscope is used to observe the morphology of the paramagnetic chains together with the deformation field of the surrounding gel network. The paramagnetic chains in soft polymer gels show rich morphological shape changes under oblique magnetic fields, in particular a pronounced buckling deformation. The details of the resulting morphological shapes depend on the length of the chain, the strength of the external magnetic field, and the modulus of the gel. Based on the observation that the magnetic chains are strongly coupled to the surrounding polymer network, a simplified model is developed to describe their buckling behavior. A coarse-grained molecular dynamics simulation model featuring an increased matrix stiffness on the surfaces of the particles leads to morphologies in agreement with the experimentally observed buckling effects.

Paramagnetic resonance and susceptibility of ilmenite, FeTiO3 crystal

NASA Technical Reports Server (NTRS)

Mcdonald, P. F.; Parasiris, A.; Pandey, R. K.; Gries, B. L.; Kirk, W. P.

1991-01-01

Large high-purity single crystals of FeTiO3 with ilmenite structure have been grown from a stoichiometric melt of Fe2O3 and TiO2 under an inert atmosphere using the modified Czochralski technique. Susceptibility and X-band paramagnetic resonance studies have been performed. Susceptibility measurements indicate a Neel temperature of about 59 K. The paramagnetic resonance spectrum for magnetic field perpendicular to the crystal c axis consists of a portion of a single, very intense approximately Lorentzian absorption line with its peak at about 600 G and half width at half maximum almost 1200 G. The absorption extends to zero magnetic field. For magnetic field approximately parallel to the c axis, the paramagnetic absorption is much smaller and may be considered a superposition of two approximately Lorentzian line shapes. The magnetic resonance measurements indicate a weak temperature dependence and large angular anisotropy.

[Detection of the lethal process in plankton noctiluca by means of a forbidden transition of ESR of Mn2+ ion].

PubMed

Kamenev, S E; Kopvillem, U Kh; Pasynkov, A S; Sharipov, R Z

1981-01-01

A forbidden ESR line of Mn2+ that is connected with the penetration of Mn into the plancton organism and binding it to a marcomolecule is selected from the experiment. A method for saturating the plancton organism with paramagnetic ions is proposed. It is shown that the constant of the axial electric field in the spin hamiltonian of Mn2+ ion described the dynamics of a selforganizing system. It is tested that the lethal process in the plancton with paramagnetic ion enrichment originated from boson avalanche. Experiments are performed with plancton noctiluca which illustrate the occurrence of avalancheline lethal process in the case of paramagnetic ion enrichment with limiting concentration. The meaning of these results for the problems of oceanology and pollution-ocean inhabitants interaction in the case of paramagnetic ions is discussed.

Effect of the lattice dynamics on the electronic structure of paramagnetic NiO within the disordered local moment picture

NASA Astrophysics Data System (ADS)

Mozafari, Elham; Alling, Björn; Belov, Maxim P.; Abrikosov, Igor A.

2018-01-01

Using the disordered local moments approach in combination with the ab initio molecular dynamics method, we simulate the behavior of a paramagnetic phase of NiO at finite temperatures to investigate the effect of magnetic disorder, thermal expansion, and lattice vibrations on its electronic structure. In addition, we study its lattice dynamics. We verify the reliability of our theoretical scheme via comparison of our results with available experiment and earlier theoretical studies carried out within static approximations. We present the phonon dispersion relations for the paramagnetic rock-salt (B1) phase of NiO and demonstrate that it is dynamically stable. We observe that including the magnetic disorder to simulate the paramagnetic phase has a small yet visible effect on the band gap. The amplitude of the local magnetic moment of Ni ions from our calculations for both antiferromagnetic and paramagnetic phases agree well with other theoretical and experimental values. We demonstrate that the increase of temperature up to 1000 K does not affect the electronic structure strongly. Taking into account the lattice vibrations and thermal expansion at higher temperatures have a major impact on the electronic structure, reducing the band gap from ˜3.5 eV at 600 K to ˜2.5 eV at 2000 K. We conclude that static lattice approximations can be safely employed in simulations of the paramagnetic state of NiO up to relatively high temperatures (˜1000 K), but as we get closer to the melting temperature vibrational effects become quite large and therefore should be included in the calculations.

Exploring medical student decisions regarding attending live lectures and using recorded lectures.

PubMed

Gupta, Anmol; Saks, Norma Susswein

2013-09-01

Student decisions about lecture attendance are based on anticipated effect on learning. Factors involved in decision-making, the use of recorded lectures and their effect on lecture attendance, all warrant investigation. This study was designed to identify factors in student decisions to attend live lectures, ways in which students use recorded lectures, and if their use affects live lecture attendance. A total of 213 first (M1) and second year (M2) medical students completed a survey about lecture attendance, and rated factors related to decisions to attend live lectures and to utilize recorded lectures. Responses were analyzed overall and by class year and gender. M1 attended a higher percentage of live lectures than M2, while both classes used the same percentage of recorded lectures. Females attended more live lectures, and used a smaller percentage of recorded lectures. The lecturer was a key in attendance decisions. Also considered were the subject and availability of other learning materials. Students use recorded lectures as replacement for live lectures and as supplement to them. Lectures, both live and recorded, are important for student learning. Decisions about lecture placement in the curriculum need to be based on course content and lecturer quality.

High field electron paramagnetic resonance spectroscopy under ultrahigh vacuum conditions—A multipurpose machine to study paramagnetic species on well defined single crystal surfaces

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

Rocker, J.; Cornu, D.; Kieseritzky, E.

2014-08-01

A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on a commercial Bruker E600 spectrometer, which is adapted to ultrahigh vacuum conditions using a home made Fabry Perot resonator. The key idea of the resonator is to use the planar metal single crystal required to grow the single crystalline oxide films as one of the mirrors of themore » resonator. EPR spectroscopy is solely sensitive to paramagnetic species, which are typically minority species in such a system. Hence, additional experimental characterization tools are required to allow for a comprehensive investigation of the surface. The apparatus includes a preparation chamber hosting equipment, which is required to prepare supported model catalysts. In addition, surface characterization tools such as low energy electron diffraction (LEED)/Auger spectroscopy, temperature programmed desorption (TPD), and infrared reflection absorption spectroscopy (IRAS) are available to characterize the surfaces. A second chamber used to perform EPR spectroscopy at 94 GHz has a room temperature scanning tunneling microscope attached to it, which allows for real space structural characterization. The heart of the UHV adaptation of the EPR experiment is the sealing of the Fabry-Perot resonator against atmosphere. To this end it is possible to use a thin sapphire window glued to the backside of the coupling orifice of the Fabry Perot resonator. With the help of a variety of stabilization measures reducing vibrations as well as thermal drift it is possible to accumulate data for a time span, which is for low temperature measurements only limited by the amount of liquid helium. Test measurements show that the system can detect paramagnetic species with a density of approximately 5 × 10{sup 11} spins/cm{sup 2}, which is comparable to the limit obtained for the presently available UHV-EPR spectrometer operating at 10 GHz (X-band). Investigation of electron trapped centers in MgO(001) films shows that the increased resolution offered by the experiments at W-band allows to identify new paramagnetic species, that cannot be differentiated with the currently available methodology.« less

Microscale Demonstration of the Paramagnetism of Liquid Oxygen with a Neodymium Magnet

ERIC Educational Resources Information Center

Mattson, Bruce

2007-01-01

A microscale classroom demonstration of the paramagnetic behavior of various samples of liquid oxygen with neodymium magnet is being presented. The experiment should be done with extreme caution, as liquid oxygen reacts violently with organic matters.

Ferromagnetic clusters induced by a nonmagnetic random disorder in diluted magnetic semiconductors

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

Bui, Dinh-Hoi; Physics Department, Hue University’s College of Education, 34 Le Loi, Hue; Phan, Van-Nham, E-mail: phanvannham@dtu.edu.vn

In this work, we analyze the nonmagnetic random disorder leading to a formation of ferromagnetic clusters in diluted magnetic semiconductors. The nonmagnetic random disorder arises from randomness in the host lattice. Including the disorder to the Kondo lattice model with random distribution of magnetic dopants, the ferromagnetic–paramagnetic transition in the system is investigated in the framework of dynamical mean-field theory. At a certain low temperature one finds a fraction of ferromagnetic sites transiting to the paramagnetic state. Enlarging the nonmagnetic random disorder strength, the paramagnetic regimes expand resulting in the formation of the ferromagnetic clusters.

Magnetic resonance force microscopy with a paramagnetic probe

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

Berman, G. P.; Gorshkov, V. N.; Tsifrinovich, V. I.

Here, we consider theoretically extension of magnetic resonance force microscopy (MRFM) replacing a ferromagnetic probe on a cantilever tip (CT) with a paramagnetic one (PMRFM). The dynamics of the interaction between the paramagnetic probe and a local magnetic moment in a sample is analyzed, using a quasi-classical approach. We show that the application of a proper sequence of electromagnetic pulses provides a significant deflection of the CT from the initial equilibrium position. Periodic application of these sequences of pulses results in quasi-periodic CT deflections from the equilibrium, which can be used for detection of the magnetic moment in a sample.

Dedicated Co-deposition System for Metallic Paramagnetic Films

DOE PAGES

Jaeckel, F.; Kotsubo, V.; Hall, J. A.; ...

2012-01-27

Here, we describe a dedicated co-sputtering/ion-mill system developed to study metallic paramagnetic films for use in magnetic microcalorimetry. Small-diameter sputtering guns allow study of several precious-metal-based paramagnetic alloy systems within a reasonable budget. We demonstrated safe operation of a 1" sputtering gun at >5x the rated maximum power, achieving deposition rates up to ~900 Å/min/gun (Cu) in our co-sputtering geometry. Demonstrated co-sputtering deposition ratios up to 100:1 allow accurate tuning of magnetic dopant concentration and eliminate the difficulty of preparing homogeneous alloy targets of extreme dilution.

Magnetic resonance force microscopy with a paramagnetic probe

NASA Astrophysics Data System (ADS)

Berman, G. P.; Gorshkov, V. N.; Tsifrinovich, V. I.

2017-04-01

We consider theoretically extension of magnetic resonance force microscopy (MRFM) replacing a ferromagnetic probe on a cantilever tip (CT) with a paramagnetic one (PMRFM). The dynamics of the interaction between the paramagnetic probe and a local magnetic moment in a sample is analyzed, using a quasi-classical approach. We show that the application of a proper sequence of electromagnetic pulses provides a significant deflection of the CT from the initial equilibrium position. Periodic application of these sequences of pulses results in quasi-periodic CT deflections from the equilibrium, which can be used for detection of the magnetic moment in a sample.

Improved paramagnetic chelate for molecular imaging with MRI

NASA Astrophysics Data System (ADS)

Winter, Patrick; Athey, Phillip; Kiefer, Garry; Gulyas, Gyongyi; Frank, Keith; Fuhrhop, Ralph; Robertson, David; Wickline, Samuel; Lanza, Gregory

2005-05-01

The relaxivity and transmetallation of two lipophilic paramagnetic chelates incorporated onto perfluorocarbon nanoparticles, i.e., gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid phosphatidylethanolamine (Gd-MeO-DOTA-PE) and gadolinium-methoxy-tetraazacyclododecane-tetraacetic acid triglycine phosphatidylethanolamine (Gd-MeO-DOTA-triglycine-PE (Gd-MeO-DOTA-triglycine-PE)), were compared to a prototypic gadolinium-diethylene-triamine-pentaacetic acid bis-oleate (Gd-DTPA-BOA) paramagnetic formulation. Nanoparticles with MeO-DOTA-based chelates demonstrated higher relaxivity (40% higher for Gd-MeO-DOTA-PE and 55% higher for Gd-MeO-DOTA-triglycine-PE) and less transmetallation than the original Gd-DTPA-BOA-based agent.

Magnetic resonance force microscopy with a paramagnetic probe

DOE PAGES

Berman, G. P.; Gorshkov, V. N.; Tsifrinovich, V. I.

2017-04-01

Here, we consider theoretically extension of magnetic resonance force microscopy (MRFM) replacing a ferromagnetic probe on a cantilever tip (CT) with a paramagnetic one (PMRFM). The dynamics of the interaction between the paramagnetic probe and a local magnetic moment in a sample is analyzed, using a quasi-classical approach. We show that the application of a proper sequence of electromagnetic pulses provides a significant deflection of the CT from the initial equilibrium position. Periodic application of these sequences of pulses results in quasi-periodic CT deflections from the equilibrium, which can be used for detection of the magnetic moment in a sample.

Cancer detection based on Raman spectra super-paramagnetic clustering

NASA Astrophysics Data System (ADS)

González-Solís, José Luis; Guizar-Ruiz, Juan Ignacio; Martínez-Espinosa, Juan Carlos; Martínez-Zerega, Brenda Esmeralda; Juárez-López, Héctor Alfonso; Vargas-Rodríguez, Héctor; Gallegos-Infante, Luis Armando; González-Silva, Ricardo Armando; Espinoza-Padilla, Pedro Basilio; Palomares-Anda, Pascual

2016-08-01

The clustering of Raman spectra of serum sample is analyzed using the super-paramagnetic clustering technique based in the Potts spin model. We investigated the clustering of biochemical networks by using Raman data that define edge lengths in the network, and where the interactions are functions of the Raman spectra's individual band intensities. For this study, we used two groups of 58 and 102 control Raman spectra and the intensities of 160, 150 and 42 Raman spectra of serum samples from breast and cervical cancer and leukemia patients, respectively. The spectra were collected from patients from different hospitals from Mexico. By using super-paramagnetic clustering technique, we identified the most natural and compact clusters allowing us to discriminate the control and cancer patients. A special interest was the leukemia case where its nearly hierarchical observed structure allowed the identification of the patients's leukemia type. The goal of this study is to apply a model of statistical physics, as the super-paramagnetic, to find these natural clusters that allow us to design a cancer detection method. To the best of our knowledge, this is the first report of preliminary results evaluating the usefulness of super-paramagnetic clustering in the discipline of spectroscopy where it is used for classification of spectra.

Apparatus for magnetic separation of paramagnetic and diamagnetic material

DOEpatents

Doctor, Richard D.

1988-01-01

The present invention relates to methods and apparatus for segregating paramagnetic from diamagnetic particles in particulate material and, in particular, to the open gradient magnetic separation of ash producing components and pyritic sulfur from coal. The apparatus includes a vertical cylinder and a rotatable vertical screw positioned within the cylinder, the screw having a helical blade angled downwardly and outwardly from the axis. Rotation of the vertical screw causes denser particles, which in the case of coal include pyritic sulfur and ash, which are paramagnetic, to migrate to the outside of the screw, and less dense particles, such as the low sulfur organic portion of the coal, which are diamagnetic, to migrate towards the center of the screw. A vibration mechanism attached to the screw causes the screw to vibrate during rotation, agitating and thereby accommodating further segregation of the particles. An open gradient magnetic field is applied circumferentially along the entire length of the screw by a superconducting quadropole magnet. The open gradient magnetic field further segregates the paramagnetic particles from the diamagnetic particles. The paramagnetic particles may then be directed from the cylinder into a first storage bin, and the diamagnetic particles, which are suitable for relatively clean combustion, may be directed into a second storage bin.

Apparatus for magnetic separation of paramagnetic and diamagnetic material

DOEpatents

Doctor, R.D.

1988-10-18

The present invention relates to methods and apparatus for segregating paramagnetic from diamagnetic particles in particulate material and, in particular, to the open gradient magnetic separation of ash producing components and pyritic sulfur from coal. The apparatus includes a vertical cylinder and a rotatable vertical screw positioned within the cylinder, the screw having a helical blade angled downwardly and outwardly from the axis. Rotation of the vertical screw causes denser particles, which in the case of coal include pyritic sulfur and ash, which are paramagnetic, to migrate to the outside of the screw, and less dense particles, such as the low sulfur organic portion of the coal, which are diamagnetic, to migrate towards the center of the screw. A vibration mechanism attached to the screw causes the screw to vibrate during rotation, agitating and thereby accommodating further segregation of the particles. An open gradient magnetic field is applied circumferentially along the entire length of the screw by a superconducting quadrupole magnet. The open gradient magnetic field further segregates the paramagnetic particles from the diamagnetic particles. The paramagnetic particles may then be directed from the cylinder into a first storage bin, and the diamagnetic particles, which are suitable for relatively clean combustion, may be directed into a second storage bin. 5 figs.

Apparatus for magnetic separation of paramagnetic and diamagnetic material

DOEpatents

Doctor, R.D.

1986-07-24

The present invention relates to methods and apparatus for segregating paramagnetic from diamagnetic particles in particulate material and, in particular, to the open gradient magnetic separation of ash producing components and pyritic sulfur from coal. The apparatus includes a vertical cylinder and a rotatable vertical screw positioned within the cylinder, the screw having a helical blade angled downwardly and outwardly from the axis. Rotation of the vertical screw causes denser particles, which in the case of coal include pyritic sulfur and ash, which are paramagnetic, to migrate to the outside of the screw, and less dense particles, such as the low sulfur organic portion of the coal, which are diamagnetic, to migrate towards the center of the screw. A vibration mechanism attached to the screw causes the screw to vibrate during rotation, agitating and thereby accommodating further segregation of the particles. An open gradient magnetic field is applied circumferentially along the entire length of the screw by a superconducting quadrupole magnet. The open gradient magnetic field further segregates the paramagnetic-particles from the diamagnetic particles. The paramagnetic particles may then be directed from the cylinder into a first storage bin, and the diamagnetic particles, which are suitable for relatively clean combustion, may be directed into a second storage bin. 5 figs.

Development of a Hybrid EPR/NMR Coimaging System

PubMed Central

Samouilov, Alexandre; Caia, George L.; Kesselring, Eric; Petryakov, Sergey; Wasowicz, Tomasz; Zweier, Jay L.

2010-01-01

Electron paramagnetic resonance imaging (EPRI) is a powerful technique that enables spatial mapping of free radicals or other paramagnetic compounds; however, it does not in itself provide anatomic visualization of the body. Proton magnetic resonance imaging (MRI) is well suited to provide anatomical visualization. A hybrid EPR/NMR coimaging instrument was constructed that utilizes the complementary capabilities of both techniques, superimposing EPR and proton-MR images to provide the distribution of paramagnetic species in the body. A common magnet and field gradient system is utilized along with a dual EPR and proton-NMR resonator assembly, enabling coimaging without the need to move the sample. EPRI is performed at ~1.2 GHz/~40 mT and proton MRI is performed at 16.18 MHz/~380 mT; hence the method is suitable for whole-body coimaging of living mice. The gradient system used is calibrated and controlled in such a manner that the spatial geometry of the two acquired images is matched, enabling their superposition without additional postprocessing or marker registration. The performance of the system was tested in a series of phantoms and in vivo applications by mapping the location of a paramagnetic probe in the gastrointestinal (GI) tract of mice. This hybrid EPR/NMR coimaging instrument enables imaging of paramagnetic molecules along with their anatomic localization in the body. PMID:17659621

Exploring Tablet PC Lectures: Lecturer Experiences and Student Perceptions in Biomedicine

ERIC Educational Resources Information Center

Choate, Julia; Kotsanas, George; Dawson, Phillip

2014-01-01

Lecturers using tablet PCs with specialised pens can utilise real-time changes in lecture delivery via digital inking. We investigated student perceptions and lecturer experiences of tablet PC lectures in large-enrolment biomedicine subjects. Lecturers used PowerPoint or Classroom Presenter software for lecture preparation and in-lecture pen-based…

Educational Effect of Online Lecture using Streaming Technology

NASA Astrophysics Data System (ADS)

Akiyama, Hidenori; Teramoto, Akemi; Kozono, Kazutake

A conventional lecture on Laser Engineering had been done in a lecture room till 1999. A content using on-demand streaming method was made for an online lecture of Laser Engineering in 2000. The figures and equations used on the conventional lecture and the voice recorded for the online lecture were converted to the real media. Then an online lecture has been provided to students by using a Helix Universal Server. The trial of the online lecture was done only for the students who wanted to take the online lecture course in 2000. The online lectures have been recognized as the credits for graduation by the change of a law since 2001. About 100 students have registered the online lecture of Laser Engineering every year since 2001. Here, three years' questionnaire surveys of the online lecture are summarized, and results of examinations on the conventional lecture for two years and on the online lecture for three years are compared. It is recognized for the lecture of Laser Engineering that the educational effect of the online lecture is comparable to or better than that of the conventional lecture.

Upper critical fields in Ba2Ti2Fe2As4O single crystals: Evidence for dominant Pauli paramagnetic effect

NASA Astrophysics Data System (ADS)

Abdel-Hafiez, M.; Brisbois, J.; Zhu, Z.; Adamski, A.; Hassen, A.; Vasiliev, A. N.; Silhanek, A. V.; Krellner, C.

2018-03-01

We report on magneto-optical imaging and the temperature dependency of the upper critical fields Hc2 c(T ) parallel to the c axis and Hc2 a b(T ) parallel to the a b plane in Ba2Ti2Fe2As4O single crystals. These data were inferred from the measurements of the temperature-dependent resistance in static magnetic fields up to 14 T and magnetoresistance in pulsed fields up to 60 T. Hc 2 values are found to be 52 and 50 T for H ∥a b and H ∥c , respectively. These values are 1.2-1.35 times larger than the weak-coupling Pauli paramagnetic limit (Hp˜1.84 Tc ), indicating that enhanced paramagnetic limiting is essential and this superconductor is unconventional. Our observations of strong bending in the Hc2 a b(T ) curves and a nearly isotropic maximum upper critical field Hc2 a b(0 ) ≈Hc2 c(0 ) support the presence of a strong Pauli paramagnetic effect. We show that the Werthamer-Helfand-Hohenberg (WHH) formula that includes the spin-orbit scattering can effectively describe the Hc2 a b(T ) curve, whereas Hc 2 deviates from the conventional WHH theoretical model without considering the spin paramagnetic effect for the H ∥c and H ∥a b directions. For H ∥c , a two-band model is required to fully reproduce the behavior of Hc 2, while for H ∥a b the spin paramagnetic effect is responsible for the behavior of Hc 2. The anisotropy of Hc 2 is close to 3 near Tc and decreases rapidly at lower temperatures.

Separation of Diamagnetic and Paramagnetic Fabrics Reveals Strain Directions in Carbonate Rocks

NASA Astrophysics Data System (ADS)

Issachar, R.; Levi, T.; Marco, S.; Weinberger, R.

2018-03-01

We present a new procedure for separating magnetic fabrics in coccolith-bearing chalk samples, demonstrated in the case studies of three sites located within the Dead Sea Fault (DSF) plate boundary. The separation is achieved by combining measurements of room temperature and low-temperature anisotropy of magnetic susceptibility (RT-AMS and LT-AMS, respectively) with anisotropy of anhysteretic remanence magnetization (AARM). The LT-AMS, measured at 77 K, enhances the fabric of paramagnetic clay minerals. The AARM represents the fabric of ferromagnetic Fe oxides. By subtracting the paramagnetic and ferromagnetic fabrics from the RT-AMS, the diamagnetic fabric is separated. In the studied samples, we found that the ferromagnetic contribution to the bulk magnetic fabric is negligible and could be excluded from the subtraction procedure. Our analysis indicates that in chalks with a negligible ferromagnetic contribution, diamagnetic fabric predominates the rock bulk magnetic fabric, if the mean susceptibility is <-6 × 10-6 SI, whereas with a mean susceptibility >11 × 10-6 SI, paramagnetic fabric predominates. In the studied rocks, the paramagnetic clay minerals preserve the original depositional fabric, whereas the diamagnetic minerals show a tectonic fabric. We propose a mechanism by which coccolith rotation under tectonic strain contributes to the development of the diamagnetic fabric parallel to the shortening direction. We infer that the diamagnetic fabrics of the studied rocks indicate strain regime of approximately N-S horizontal shortening near strands of the DSF system. This suggests a deflection of the regional principal strain axes near the DSF. The diamagnetic fabric is more sensitive to tectonic strain than paramagnetic fabric in chalks and provides a valuable strain indicator near major faults.

The Effect of Electronic Paramagnetism on Nuclear Magnetic Resonance Frequencies in Metals

DOE R&D Accomplishments Database

Townes, C. H.; Herring, C.; Knight, W. D.

1950-09-22

Observations on the shifts of nuclear resonances in metals ( Li{sup 7}, Na{sup 23}, Cu {sup 63}, Be{sup 9}, Pb{sup 207}, Al{sup 27}, and Ca{sup 69} ) due to free electron paramagnetism; comparison with theoretical values.

Complexation of β-cyclodextrin with dual molecular probes bearing fluorescent and paramagnetic moieties linked by short polyether chains.

PubMed

Mocanu, S; Matei, I; Ionescu, S; Tecuceanu, V; Marinescu, G; Ionita, P; Culita, D; Leonties, A; Ionita, Gabriela

2017-10-18

Electron paramagnetic resonance (EPR) and fluorescence spectroscopies provide molecular-level insights on the interaction of paramagnetic and fluorescent species with the microenvironment. A series of dual molecular probes bearing fluorescent and paramagnetic moieties linked by flexible short polyether chains have been synthesized. These new molecular probes open the possibility to investigate various multi-component systems such as host-guest systems, polymeric micelles, gels and protein solutions by using EPR and fluorescence spectroscopies concertedly. The EPR and fluorescence spectra of these compounds show that the dependence of the rotational correlation time and fluorescence quantum yield on the chain length of the linker is not linear, due to the flexibility of the polyether linker. The quenching effect of the nitroxide moiety on the fluorescence intensity of the pyrene group varies with the linker length and flexibility. The interaction of these dual molecular probes with β-cyclodextrin, in solution and in polymeric gels, was evaluated and demonstrated by analysis of EPR and fluorescence spectra.

The dual role of paramagnetic particles for integrated lysis and measurement in a rapid immunoassay for intracellular proteins.

PubMed

Sharif, Elham; Kiely, Janice; Wraith, Patrick; Luxton, Richard

2013-05-01

A novel, integrated lysis and immunoassay methodology and system for intracellular protein measurement are described. The method uses paramagnetic particles both as a lysis agent and assay label resulting in a rapid test requiring minimal operator intervention, the test being homogeneous and completed in less than 10 min. A design study highlights the critical features of the magnetic detection system used to quantify the paramagnetic particles and a novel frequency-locked loop-based magnetometer is presented. A study of paramagnetic particle enhanced lysis demonstrates that the technique is more than twice as efficient at releasing intracellular protein as ultrasonic lysis alone. Results are presented for measurements of intracellular prostate specific antigen in an LNCAP cell line. This model was selected to demonstrate the rapidity and efficiency of intracellular protein quantification. It was shown that, on average, LNCAP cells contained 0.43 fg of prostate specific antigen. This system promises an attractive solution for applications that require a rapid determination of intracellular proteins.

CoAs: The line of 3 d demarcation

NASA Astrophysics Data System (ADS)

Campbell, Daniel J.; Wang, Limin; Eckberg, Chris; Graf, Dave; Hodovanets, Halyna; Paglione, Johnpierre

2018-05-01

Transition metal-pnictide compounds have received attention for their tendency to combine magnetism and unconventional superconductivity. Binary CoAs lies on the border of paramagnetism and the more complex behavior seen in isostructural CrAs, MnP, FeAs, and FeP. Here we report the properties of CoAs single crystals grown with two distinct techniques along with density functional theory calculations of its electronic structure and magnetic ground state. While all indications are that CoAs is paramagnetic, both experiment and theory suggest proximity to a ferromagnetic instability. Quantum oscillations are seen in torque measurements up to 31.5 T and support the calculated paramagnetic Fermiology.

Susceptibility cancellation of a microcoil wound with a paramagnetic-liquid-filled copper capillary

NASA Astrophysics Data System (ADS)

Takeda, Kazuyuki; Takasaki, Tomoya; Takegoshi, K.

2015-09-01

Even though microcoils improve the sensitivity of NMR measurement of tiny samples, magnetic-field inhomogeneity due to the bulk susceptibility effect of the coil material can cause serious resonance-line broadening. Here, we propose to fabricate the microcoil using a thin, hollow copper capillary instead of a wire and fill paramagnetic liquid inside the capillary, so as to cancel the diamagnetic contribution of the copper. Susceptibility cancellation is demonstrated using aqueous solution of NiSO4. In addition, the paramagnetic liquid serves as coolant when it is circulated through the copper capillary, effectively transferring the heat generated by radiofrequency pulses.

Paramagnetic and Diamagnetic Materials

ERIC Educational Resources Information Center

Thompson, Frank

2011-01-01

Paramagnetic and diamagnetic materials are now generally known as the "Cinderella" materials of the magnetic world. However, susceptibility measurements made on these materials in the past have revealed many details about the molecular bonding and the atomic structure of the so-called "transition" elements. Indeed, the magnetic moment of neodymium…

Dual excitation acoustic paramagnetic logging tool

DOEpatents

Vail, III, William B.

1989-01-01

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in gelogical formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleous present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described.

Dual excitation acoustic paramagnetic logging tool

DOEpatents

Vail, W.B. III.

1989-02-14

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be performed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described. 6 figs.

What Type of Lectures Students Want? - A Reaction Evaluation of Dental Students

PubMed Central

Roopa, Srinivasan; Geetha M, Bagavad; Rani, Anitha; Chacko, Thomas

2013-01-01

Introduction: An one hour didactic lecture is the common method of teaching in dental colleges in India. Lengthy lectures are boring and students are passive recipients of the information. Interactive lectures are suggested as a means of overcoming the disadvantages of regular lectures. Aims: The present study was conducted to pilot various methods of making lectures interactive and to find the students’ reactions to interactive lectures as compared to regular lectures. Material and Methods: An entire batch of first year dental students (n = 78) was exposed to both interactive and regular lectures for the cardiovascular system in physiology. Among the total number of 12 lectures, alternate lectures were conducted in an interactive style. At the end of the 12 lecture series, students’ opinions were obtained using a structured feedback evaluation questionnaire, consisting of five statements, on a five point Likert scale. Statistical Analysis was done using SPSS software, version 15. Results: Interactive lectures were found to be more useful than regular lectures by 92% of the students. Significantly more number of students agreed or strongly agreed that interactive lectures kept them attentive, created interest, overcame monotony, motivated them for self learning and provided well defined learning than regular lectures. Among the different techniques which were used, the students preferred use of video clippings (58.1%), followed by each-one-teach-one. Results of the present study support the use of interactive lectures for ensuring increased interest and attention of students during lectures. Conclusion: Interactive lectures were more accepted and considered to be more useful than regular lectures by the students. PMID:24298487

Electronic voting to encourage interactive lectures: a randomised trial

PubMed Central

2007-01-01

Background Electronic Voting Systems have been used for education in a variety of disciplines. Outcomes from these studies have been mixed. Because results from these studies have been mixed, we examined whether an EVS system could enhance a lecture's effect on educational outcomes. Methods A cohort of 127 Year 5 medical students at the University of Adelaide was stratified by gender, residency status and academic record then randomised into 2 groups of 64 and 63 students. Each group received consecutive 40-minute lectures on two clinical topics. One group received the EVS for both topics. The other group received traditional teaching only. Evaluation was undertaken with two, 15-question multiple-choice questionnaires (MCQ) assessing knowledge and problem solving and undertaken as a written paper immediately before and after the lectures and repeated online 8–12 weeks later. Standardised institutional student questionnaires were completed for each lecture and independent observers assessed student behaviour during the lectures. Lecturer's opinions were assessed by a questionnaire developed for this study. Results Two-thirds of students randomised to EVS and 59% of students randomised to traditional lectures attended. One-half of the students in the EVS group and 41% in the traditional group completed all questionnaires. There was no difference in MCQ scores between EVS and traditional lectures (p = 0.785). The cervical cancer lectures showed higher student ranking in favour of EVS in all parameters. The breast cancer lectures showed higher ranking in favour of traditional lectures in 5 of 7 parameters (p < 0.001). The observed higher-order lecturer-students interactions were increased in the EVS lecture for one lecturer and reduced for the other. Both lecturers felt that the EVS lectures were difficult to prepare, that they were able to keep to time in the traditional lectures, that the educational value of both lecture styles was similar, and that they were neutral-to-slightly favourably disposed to continue with the EVS technology. The 2 lecturers disagreed regarding the ease of preparation of the traditional lecture, their ability to keep to time in the EVS lecture, and personal satisfaction with the EVS lecture. The lecturers felt that EVS encouraged student participation and helped identify where students were having difficulty. Conclusion In this setting, EVS technology used in large group lectures did not offer significant advantages over the more traditional lecture format. PMID:17655773

20-Year Status Report on the Human Systems Integration (HSI)/Manpower and Personnel Integration (MANPRINT) Soldier Survivability Domain

DTIC Science & Technology

2015-05-01

ARL/SLAD Electromagnetic Vulnerability Analysis Facility: provides the results of radio frequency detection and jamming susceptibility analysis of the...Lecture 10: Environment/Weather*  Lecture 11 : Habitability*  Lecture 12: Air Composition and Pressure*  Lecture 14: Communications ...Lecture 15: Radio Frequency /Microwave/E3I  Lecture 16: Vibration/Acoustic Noise  Lecture 17: Acceleration/Stabilization  Lecture 18

Do prerecorded lecture VODcasts affect lecture attendance of first-yearpre-clinical Graduate Entry to Medicine students?

PubMed

Rae, Mark G; O'Malley, Dervla

2017-03-01

There is increasing concern amongst educators that the provision of recorded lectures may reduce student attendance of live lectures. We therefore sought to determine if the provision of prerecorded lecture video podcasts (VODcasts) to first-year Graduate Entry to Medicine (GEM) students, affected attendance at 21 Physiology lectures within three separate pre-clinical modules. Data on lecture attendance, utilization of VODcasts, and whether VODcasts should replace live lectures were drawn from three surveys conducted in academic years 2014-2015 and 2015-2016 on all first-year GEM students in two first-year pre-clinical modules where prerecorded Physiology VODcasts were available for viewing or downloading prior to scheduled live lectures. A total of 191/214 (89%) students responded to the three surveys, with 84.3% of students attending all 21 lectures in the study. Only 4% of students missed more than one lecture in each of the three lecture series, with 79% indicating that VODcasts should not replace lectures. Therefore, we conclude that the attendance of pre-clinical GEM students at live lectures is not significantly impacted upon by the provision of lecture VODcasts, with most students viewing them as useful revision tools rather than as a replacement for live lectures.

Goals and design of public physics lectures: perspectives of high-school students, physics teachers and lecturers

NASA Astrophysics Data System (ADS)

Kapon, S.; Ganiel, U.; Eylon, B.

2009-09-01

Many large scientific projects and scientific centres incorporate some kind of outreach programme. Almost all of these outreach programmes include public scientific lectures delivered by practising scientists. In this article, we examine such lectures from the perspectives of: (i) lecturers (7) who are practising scientists acknowledged to be good public lecturers and (ii) audiences composed of high-school students (169) and high-school physics teachers (80) who attended these lectures. We identify and discuss the main goals as expressed by the lecturers and the audiences, and the correspondence between these goals. We also discuss how the lecturers' goals impact on the design of their lectures and examine how the lecture affects audiences with different attitudes towards (and interests in) physics. Our findings suggest that the goals of the participating lecturers and the expectations of their audiences were highly congruent. Both believe that a good public scientific lecture must successfully communicate state-of-the-art scientific knowledge to the public, while inspiring interest in and appreciation of science. Our findings also suggest that exemplary public scientific lectures incorporate content, structure and explanatory means that explicitly adhere to the lecturers' goals. We identify and list several design principles.

A randomized trial comparing digital and live lecture formats [ISRCTN40455708.

PubMed

Solomon, David J; Ferenchick, Gary S; Laird-Fick, Heather S; Kavanaugh, Kevin

2004-11-29

Medical education is increasingly being conducted in community-based teaching sites at diverse locations, making it difficult to provide a consistent curriculum. We conducted a randomized trial to assess whether students who viewed digital lectures would perform as well on a measure of cognitive knowledge as students who viewed live lectures. Students' perceptions of the digital lecture format and their opinion as whether a digital lecture format could serve as an adequate replacement for live lectures was also assessed. Students were randomized to either attend a lecture series at our main campus or view digital versions of the same lectures at community-based teaching sites. Both groups completed the same examination based on the lectures, and the group viewing the digital lectures completed a feedback form on the digital format. There were no differences in performance as measured by means or average rank. Despite technical problems, the students who viewed the digital lectures overwhelmingly felt the digital lectures could replace live lectures. This study provides preliminary evidence digital lectures can be a viable alternative to live lectures as a means of delivering didactic presentations in a community-based setting.

A randomized trial comparing digital and live lecture formats [ISRCTN40455708

PubMed Central

Solomon, David J; Ferenchick, Gary S; Laird-Fick, Heather S; Kavanaugh, Kevin

2004-01-01

Background Medical education is increasingly being conducted in community-based teaching sites at diverse locations, making it difficult to provide a consistent curriculum. We conducted a randomized trial to assess whether students who viewed digital lectures would perform as well on a measure of cognitive knowledge as students who viewed live lectures. Students' perceptions of the digital lecture format and their opinion as whether a digital lecture format could serve as an adequate replacement for live lectures was also assessed. Methods Students were randomized to either attend a lecture series at our main campus or view digital versions of the same lectures at community-based teaching sites. Both groups completed the same examination based on the lectures, and the group viewing the digital lectures completed a feedback form on the digital format. Results There were no differences in performance as measured by means or average rank. Despite technical problems, the students who viewed the digital lectures overwhelmingly felt the digital lectures could replace live lectures. Conclusions This study provides preliminary evidence digital lectures can be a viable alternative to live lectures as a means of delivering didactic presentations in a community-based setting. PMID:15569389

Basic magnetic properties of bituminous coal

USGS Publications Warehouse

Alexander, C.C.; Thorpe, A.N.; Senftle, F.E.

1979-01-01

Magnetic susceptibility and other static magnetic parameters have been measured on a number of bituminous coals from various locations in the United States. The paramagnetic Curie constant correlates negatively with carbon concentration on a moisture-free basis. The major contribution to the total paramagnetism comes from the mineral matter rather than from free radicals or broken bonds. Analysis of the data indicates that the specific paramagnetism is generally lower in the mineral matter found in high-ash compared to low-ash coal. A substantial number of the coal specimens tested also had a ferromagnetic susceptibility which appeared to be associated with magnetite. Magnetite and ??-iron spherules, possibly of meteoritic or volcanic origin, were found in several specimens. ?? 1979.

Excess-Si related defect centers in buried SiO2 thin films

NASA Astrophysics Data System (ADS)

Warren, W. L.; Fleetwood, D. M.; Shaneyfelt, M. R.; Schwank, J. R.; Winokur, P. S.; Devine, R. A. B.

1993-06-01

Using electron paramagnetic resonance (EPR) and capacitance-voltage measurements we have investigated the role of excess-silicon related defect centers as charge traps in separation by the implantation of oxygen materials. Three types of EPR-active centers were investigated: oxygen vacancy Eγ' centers (O3≡Si• +Si≡O3), delocalized Eδ' centers, and D centers (Si3≡Si•). It was found that all of these paramagnetic centers are created by selective hole injection, and are reasonably ascribed as positively charged when paramagnetic. These results provide the first experimental evidence for (1) the charge state of the Eδ' center, and (2) that the D center is an electrically active point defect in these materials.

Single crystal EPR and optical studies of paramagnetic ions doped zinc potassium phosphate hexahydrate—Part I: Cu(II)—a case of orthorhombic symmetry

NASA Astrophysics Data System (ADS)

Sambasiva Rao, P.; Rajendiran, T. M.; Venkatesan, R.; Madhu, N.; Chandrasekhar, A. V.; Reddy, B. J.; Reddy, Y. P.; Ravikumar, R. V. S. S. N.

2001-12-01

Single crystal electron paramagnetic resonance (EPR) studies on Cu(II) doped zinc potassium phosphate hexahydrate (ZPPH) were carried out at room temperature. The angular variation spectra in the three orthogonal planes indicate that the paramagnetic impurity has entered the lattice substitutionally in place of Zn(II) and the spin Hamiltonian parameters calculated from these spectra are gxx=2.188, gyy=2.032, gzz=2.373, Axx=50 G, Ayy=65.0 G and Azz=80 G. The g and A tensors were coincident and these values matched fairly well with the values obtained from powder spectrum. The bonding parameters have also been calculated.

Gigantic magnetoelectric effect caused by magnetic-field-induced canted antiferromagnetic-paramagnetic transition in quasi-two-dimensional Ca2CoSi2O7 crystal

NASA Astrophysics Data System (ADS)

Akaki, M.; Tozawa, J.; Akahoshi, D.; Kuwahara, H.

2009-05-01

We have investigated the magnetic and dielectric properties of Ca2CoSi2O7 crystal. The dielectricity and magnetism of Ca2CoSi2O7 are strongly coupled below a canted antiferromagnetic transition temperature (TN). Magnetic fields induce electric polarization below TN. Interestingly, the magnetic-field-induced electric polarization is detected even without poling electric fields. Below TN, a canted antiferromagnetic-paramagnetic transition is induced by magnetic fields. The large magnetocapacitance is observed around TN. The origin of the large magnetocapacitance is due to the magnetic-field-induced the canted antiferromagnetic-paramagnetic transition.

Bulk magnetic properties of La1-xCaxMnO3 (0⩽x⩽0.14) : Signatures of local ferromagnetic order

NASA Astrophysics Data System (ADS)

Terashita, Hirotoshi; Neumeier, J. J.

2005-04-01

We report the bulk magnetic properties of hole-doped La1-xCaxMnO3 (0⩽x⩽0.14) in the paramagnetic and antiferromagnetic regions; the Mn4+ concentration was determined with chemical analysis. Significant enhancement of the effective paramagnetic moment illustrates the existence of ferromagnetic clusters (polarons). The data reveal a distinct crossover in the paramagnetic region, signifying competition between ferromagnetic clusters and antiferromagnetic correlations associated with the low-temperature magnetically ordered state. The results suggest similarity in the magnetic properties at low temperatures between hole-doped LaMnO3 and electron-doped CaMnO3 .

Ionic liquids and solids with paramagnetic anions.

PubMed

Krieger, Brenna M; Lee, Heather Y; Emge, Thomas J; Wishart, James F; Castner, Edward W

2010-08-21

Four paramagnetic ionic compounds have been prepared and their magnetic, structural and thermal properties have been investigated. The four compounds are methylbutylpyrrolidinium tetrachloroferrate(III) ([Pyrr(14)](+)/[FeCl(4)](-)), methyltributylammonium tetrachloroferrate(III) ([N(1444)](+)/[FeCl(4)](-)), butylmethylimidazolium tetrachloroferrate(III) ([bmim](+)/[FeCl(4)](-)) and tetrabutylammonium bromotrichloroferrate(III) ([N(4444)](+)/[FeBrCl(3)](-)). Temperature-dependent studies of their magnetic behaviors show that all four compounds are paramagnetic at ambient temperatures. Glass transitions are observed for only two of the four compounds, [Pyrr(14)](+)/[FeCl(4)](-) and [bmim](+)/[FeCl(4)](-). Crystal structures for [Pyrr(14)](+)/[FeCl(4)](-) and [N(1444)](+)/[FeCl(4)](-) are compared with the previously reported [N(4444)](+)/[FeBrCl(3)](-).

Undergraduate mathematics students' reasons for attending live lectures when recordings are available

NASA Astrophysics Data System (ADS)

Yoon, Caroline; Oates, Greg; Sneddon, Jamie

2014-02-01

With the proliferation of new affordable recording technologies, many universities have begun offering students recordings of live lectures as a part of the course resources. We conducted a survey to investigate why some students choose to attend lectures in person rather than simply watching the recordings online, and how students view the two types of lectures. Students attending live lectures in five large undergraduate mathematics lecture streams were invited to respond to the survey. A significant number of respondents viewed recorded lecture as superfluous to their needs which were met upon attending live lecture. Surprisingly, however, an equally large number of students described compelling reasons for watching both live and recorded lectures. A number of factors were identified as determining students' perceptions of live and recorded lectures as competing or complementary: personal learning styles, study habits, esteem for the lecturer, and the possibility of interaction in the lecture.

Live lecture versus video-recorded lecture: are students voting with their feet?

PubMed

Cardall, Scott; Krupat, Edward; Ulrich, Michael

2008-12-01

In light of educators' concerns that lecture attendance in medical school has declined, the authors sought to assess students' perceptions, evaluations, and motivations concerning live lectures compared with accelerated, video-recorded lectures viewed online. The authors performed a cross-sectional survey study of all first- and second-year students at Harvard Medical School. Respondents answered questions regarding their lecture attendance; use of class and personal time; use of accelerated, video-recorded lectures; and reasons for viewing video-recorded and live lectures. Other questions asked students to compare how well live and video-recorded lectures satisfied learning goals. Of the 353 students who received questionnaires, 204 (58%) returned responses. Collectively, students indicated watching 57.2% of lectures live, 29.4% recorded, and 3.8% using both methods. All students have watched recorded lectures, and most (88.5%) have used video-accelerating technologies. When using accelerated, video-recorded lecture as opposed to attending lecture, students felt they were more likely to increase their speed of knowledge acquisition (79.3% of students), look up additional information (67.7%), stay focused (64.8%), and learn more (63.7%). Live attendance remains the predominant method for viewing lectures. However, students find accelerated, video-recorded lectures equally or more valuable. Although educators may be uncomfortable with the fundamental change in the learning process represented by video-recorded lecture use, students' responses indicate that their decisions to attend lectures or view recorded lectures are motivated primarily by a desire to satisfy their professional goals. A challenge remains for educators to incorporate technologies students find useful while creating an interactive learning culture.

The impact of lecture attendance and other variables on how medical students evaluate faculty in a preclinical program.

PubMed

Martin, Stanley I; Way, David P; Verbeck, Nicole; Nagel, Rollin; Davis, John A; Vandre, Dale D

2013-07-01

High-quality audiovisual recording technology enables medical students to listen to didactic lectures without actually attending them. The authors wondered whether in-person attendance affects how students evaluate lecturers. This is a retrospective review of faculty evaluations completed by first- and second-year medical students at the Ohio State University College of Medicine during 2009-2010. Lecture-capture technology was used to record all lectures. Attendance at lectures was optional; however, all students were required to complete lecturer evaluation forms. Students rated overall instruction using a five-option response scale. They also reported their attendance. The authors used analysis of variance to compare the lecturer ratings of attendees versus nonattendees. The authors included additional independent variables-year of student, student grade/rank in class, and lecturer degree-in the analysis. The authors analyzed 12,092 evaluations of 220 lecturers received from 358 students. The average number of evaluations per lecturer was 55. Seventy-four percent (n = 8,968 evaluations) of students attended the lectures they evaluated, whereas 26% (n = 3,124 evaluations) viewed them online. Mean lecturer ratings from attendees was 3.85 compared with 3.80 by nonattendees (P ≤ .05; effect size: 0.055). Student's class grade and year, plus lecturer degree, also affected students' evaluations of lecturers (effect sizes: 0.055-0.3). Students' attendance at lectures, year, and class grade, as well as lecturer degree, affect students' evaluation of lecturers. This finding has ramifications on how student evaluations should be collected, interpreted, and used in promotion and tenure decisions in this evolving medical education environment.

Introduction to Spin Label Electron Paramagnetic Resonance Spectroscopy of Proteins

ERIC Educational Resources Information Center

Melanson, Michelle; Sood, Abha; Torok, Fanni; Torok, Marianna

2013-01-01

An undergraduate laboratory exercise is described to demonstrate the biochemical applications of electron paramagnetic resonance (EPR) spectroscopy. The beta93 cysteine residue of hemoglobin is labeled by the covalent binding of 3-maleimido-proxyl (5-MSL) and 2,2,5,5-tetramethyl-1-oxyl-3-methyl methanethiosulfonate (MTSL), respectively. The excess…

Method of manufacturing a high temperature superconductor with improved transport properties

DOEpatents

Balachandran, Uthamalingam; Siegel, Richard W.; Askew, Thomas R.

2001-01-01

A method of preparing a high temperature superconductor. A method of preparing a superconductor includes providing a powdered high temperature superconductor and a nanophase paramagnetic material. These components are combined to form a solid compacted mass with the paramagnetic material disposed on the grain boundaries of the polycrystaline high temperature superconductor.

THE INTERACTION OF PARAMAGNETIC RELAXATION REAGENTS WITH INTRA- AND INTERMOLECULAR HYDROGEN BONDED PHENOLS

EPA Science Inventory

Intermolecular electron-nuclear 13-C relaxation times (T(1)sup e's) from solutions containing the paramagnetic relaxation reagent (PARR), Cr(acac)3, used in conjunction with 13-C T(1)'s in diamagnetic solutions (intramolecular 13-C - (1)H dipolar T(1)'s) provide a significant inc...

Locations of radical species in black pepper seeds investigated by CW EPR and 9 GHz EPR imaging

NASA Astrophysics Data System (ADS)

Nakagawa, Kouichi; Epel, Boris

2014-10-01

In this study, noninvasive 9 GHz electron paramagnetic resonance (EPR)-imaging and continuous wave (CW) EPR were used to investigate the locations of paramagnetic species in black pepper seeds without further irradiation. First, lithium phthalocyanine (LiPC) phantom was used to examine 9 GHz EPR imaging capabilities. The 9 GHz EPR-imager easily resolved the LiPC samples at a distance of ∼2 mm. Then, commercially available black pepper seeds were measured. We observed signatures from three different radical species, which were assigned to stable organic radicals, Fe3+, and Mn2+ complexes. In addition, no EPR spectral change in the seed was observed after it was submerged in distilled H2O for 1 h. The EPR and spectral-spatial EPR imaging results suggested that the three paramagnetic species were mostly located at the seed surface. Fewer radicals were found inside the seed. We demonstrated that the CW EPR and 9 GHz EPR imaging were useful for the determination of the spatial distribution of paramagnetic species in various seeds.

Locations of radical species in black pepper seeds investigated by CW EPR and 9GHz EPR imaging.

PubMed

Nakagawa, Kouichi; Epel, Boris

2014-10-15

In this study, noninvasive 9GHz electron paramagnetic resonance (EPR)-imaging and continuous wave (CW) EPR were used to investigate the locations of paramagnetic species in black pepper seeds without further irradiation. First, lithium phthalocyanine (LiPC) phantom was used to examine 9GHz EPR imaging capabilities. The 9GHz EPR-imager easily resolved the LiPC samples at a distance of ∼2mm. Then, commercially available black pepper seeds were measured. We observed signatures from three different radical species, which were assigned to stable organic radicals, Fe(3+), and Mn(2+) complexes. In addition, no EPR spectral change in the seed was observed after it was submerged in distilled H2O for 1h. The EPR and spectral-spatial EPR imaging results suggested that the three paramagnetic species were mostly located at the seed surface. Fewer radicals were found inside the seed. We demonstrated that the CW EPR and 9GHz EPR imaging were useful for the determination of the spatial distribution of paramagnetic species in various seeds. Copyright © 2014 Elsevier B.V. All rights reserved.

EPR investigation of electronic excitations in rare gas solids (Review Article)

NASA Astrophysics Data System (ADS)

Zhitnikov, R. A.; Dmitriev, Yu. A.

1998-10-01

The methods are described for producing unstable paramagnetic excited states in rare gas cryocrystals Ne, Ar, Kr, and Xe through the trapping, in the cryocrystals growing from the gas phase, the products of the gas discharge taking place in the same or other rare gas. The paper presents a technique and results of an observation and investigation of excited states in rare gas cryocrystals with electron paramagnetic resonance (EPR). The discovered unstable paramagnetic centers are interpreted as being local metastable excited np5(n+1)s atomic-type states in rare gas cryocrystals which are subject to the action of the anisotropic electric field resulted from the crystal surroundings distorted by the center. An account is given of the mechanisms for formation of observed paramagnetic excited states in cryocrystals which arise owing to the excitation energy of the metastable 3P2 atoms of Ne, Ar, Kr, Xe and He 23S1 and 21S0 atoms that form in the discharge in an appropriate gas and trap in the growing cryocrystal.

High-frequency EPR of surface impurities on nanodiamond

NASA Astrophysics Data System (ADS)

Peng, Zaili; Stepanov, Viktor; Takahashi, Susumu

Diamond is a fascinating material, hosting nitrogen-vacancy (NV) defect centers with unique magnetic and optical properties. There have been many reports that suggest the existence of paramagnetic impurities near surface of various kinds of diamonds. Electron paramagnetic resonance (EPR) investigation of mechanically crushed nanodiamonds (NDs) as well as detonation NDs revealed g 2 like signals that are attributed to structural defects and dangling bonds near the diamond surface. In this presentation, we investigate paramagnetic impurities in various sizes of NDs using high-frequency (HF) continuous wave (cw) and pulsed EPR spectroscopy. Strong size dependence on the linewidth of HF cw EPR spectra reveals the existence of paramagnetic impurities in the vicinity of the diamond surface. We also study the size dependence of the spin-lattice and spin-spin relaxation times (T1 and T2) of single substitutional nitrogen defects in NDs Significant deviations from the temperature dependence of the phonon-assisted T1 process were observed in the ND samples, and were attributed to the contribution from the surface impurities. This work was supported by the Searle Scholars Program and the National Science Foundation (DMR-1508661 and CHE-1611134).

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.

Optional Student Use of Online Lecture Resources: Resource Preferences, Performance and Lecture Attendance

ERIC Educational Resources Information Center

Grabe, M.; Christopherson, K.

2008-01-01

One of the most common uses of a course management system in the on-campus environment is to offer lecture resources to students. Few researchers have investigated how students use such resources. This study considers student use of lecture resources that offer a representation of the lecture presented (i.e. lecture outline, lecture summary, audio…

Magnetic anisotropy of some phyllosilicates

NASA Astrophysics Data System (ADS)

Borradaile, Graham J.; Werner, Tomasz

1994-08-01

Magnetic susceptibility, anisotropy of susceptibility and hysteresis of single microcrystals of chlorite, biotite, phlogopite, muscovite, zinnwaldite and fuchsite were measured in low and high magnetic fields with an alternating gradient force magnetometer (Micromag). Their properties are sufficient to account for the low field susceptibility (AMS) of most micaceous rocks. Nearly all samples show some ferromagnetic contribution at low fields due to inclusions of pseudosingle domain and multidomain magnetite. The paramagnetic contribution isolated at high fields usually exceeds the ferromagnetic contribution. The paramagnetic susceptibility is intrinsic to the silicate lattice and agrees with values predicted from chemical composition within the limits of error. The minimum susceptibility is nearly parallel to c, another axis is parallel to b and the third susceptibility (usually the maximum) is close to a. The paramagnetic susceptibility has a disk-shaped magnitude ellipsoid with strong anisotropy ( P' < 2). The ferromagnetic contributions at low fields have more variably shaped ellipsoids with greater eccentricity ( P' < 5). The silicate lattice does not constrain their orientation. Our technique cannot determine the principal axes of the ferromagnetic component. However, its principal values usually correspond with the paramagnetic principal susceptibilities in order of magnitude. Thus, the combined paramagnetic-ferromagnetic anisotropy recognised in routine studies of AMS should faithfully represent the petrofabric of most micaceous rocks. Nevertheless, nearly 10% of our samples have incompatible anisotropy ellipsoids for the silicate host and magnetite inclusions. These yield a net inverse AMS that does not correctly represent the orientation of the silicate lattice. Therefore, some caution is necessary in petrofabric-AMS studies of micaceous rocks.

Diffusional mechanisms augment the fluorine magnetic resonance relaxation in paramagnetic perfluorocarbon nanoparticles that provides a “relaxation switch” for detecting cellular endosomal activation

PubMed Central

Hu, Lingzhi; Zhang, Lei; Chen, Junjie; Lanza, Gregory M.; Wickline, Samuel A.

2011-01-01

Purpose To develop a physical model for the 19F relaxation enhancement in paramagnetic perfluorocarbon nanoparticles (PFC NP) and demonstrate its application in monitoring cellular endosomal functionality through a “19F relaxation switch” phenomenon. Materials and Methods An explicit expression for 19F longitudinal relaxation enhancement was derived analytically. Monte-Carlo simulation was performed to confirm the gadolinium induced magnetic field inhomogenity inside the PFC NP. Field dependent T1 measurements for three types of paramagnetic PFC NPs were carried out to validate the theoretical prediction. Based on the physical model, 19F and 1H relaxation properties of macrophage internalized paramagnetic PFC NPs were measured to evaluate the intracellular process of NPs by macrophages in vitro. Results The theoretical description was confirmed experimentally by field-dependent T1 measurements. The shortening of 19F T1 was found to be attributed to the Brownian motion of PFC molecules inside the NP in conjunction with their ability to permeate into the lipid surfactant coating. A dramatic change of 19F T1 was observed upon endocytosis, revealing the transition from intact bound PFC NP to processed constituents. Conclusion The proposed first-principle analysis of 19F spins in paramagnetic PFC NP relates their structural parameters to the special MR relaxation features. The demonstrated “19F relaxation switch” phenomenon is potentially useful for monitoring cellular endosomal functionality. PMID:21761488

Dynamic nuclear polarization of (1)H, (13)C, and (59)Co in a tris(ethylenediamine)cobalt(III) crystalline lattice doped with Cr(III).

PubMed

Corzilius, Björn; Michaelis, Vladimir K; Penzel, Susanne A; Ravera, Enrico; Smith, Albert A; Luchinat, Claudio; Griffin, Robert G

2014-08-20

The study of inorganic crystalline materials by solid-state NMR spectroscopy is often complicated by the low sensitivity of heavy nuclei. However, these materials often contain or can be prepared with paramagnetic dopants without significantly affecting the structure of the crystalline host. Dynamic nuclear polarization (DNP) is generally capable of enhancing NMR signals by transferring the magnetization of unpaired electrons to the nuclei. Therefore, the NMR sensitivity in these paramagnetically doped crystals might be increased by DNP. In this paper we demonstrate the possibility of efficient DNP transfer in polycrystalline samples of [Co(en)3Cl3]2·NaCl·6H2O (en = ethylenediamine, C2H8N2) doped with Cr(III) in varying concentrations between 0.1 and 3 mol %. We demonstrate that (1)H, (13)C, and (59)Co can be polarized by irradiation of Cr(III) with 140 GHz microwaves at a magnetic field of 5 T. We further explain our findings on the basis of electron paramagnetic resonance spectroscopy of the Cr(III) site and analysis of its temperature-dependent zero-field splitting, as well as the dependence of the DNP enhancement factor on the external magnetic field and microwave power. This first demonstration of DNP transfer from one paramagnetic metal ion to its diamagnetic host metal ion will pave the way for future applications of DNP in paramagnetically doped materials or metalloproteins.

Dynamic Nuclear Polarization of 1H, 13C, and 59Co in a Tris(ethylenediamine)cobalt(III) Crystalline Lattice Doped with Cr(III)

PubMed Central

2015-01-01

The study of inorganic crystalline materials by solid-state NMR spectroscopy is often complicated by the low sensitivity of heavy nuclei. However, these materials often contain or can be prepared with paramagnetic dopants without significantly affecting the structure of the crystalline host. Dynamic nuclear polarization (DNP) is generally capable of enhancing NMR signals by transferring the magnetization of unpaired electrons to the nuclei. Therefore, the NMR sensitivity in these paramagnetically doped crystals might be increased by DNP. In this paper we demonstrate the possibility of efficient DNP transfer in polycrystalline samples of [Co(en)3Cl3]2·NaCl·6H2O (en = ethylenediamine, C2H8N2) doped with Cr(III) in varying concentrations between 0.1 and 3 mol %. We demonstrate that 1H, 13C, and 59Co can be polarized by irradiation of Cr(III) with 140 GHz microwaves at a magnetic field of 5 T. We further explain our findings on the basis of electron paramagnetic resonance spectroscopy of the Cr(III) site and analysis of its temperature-dependent zero-field splitting, as well as the dependence of the DNP enhancement factor on the external magnetic field and microwave power. This first demonstration of DNP transfer from one paramagnetic metal ion to its diamagnetic host metal ion will pave the way for future applications of DNP in paramagnetically doped materials or metalloproteins. PMID:25069794

Impact of various lecture delivery methods in pharmacology

PubMed Central

Seth, Vikas; Upadhyaya, Prerna; Ahmad, Mushtaq; Kumar, Virendra

2010-01-01

The aim of the study was to assess the impact of three common lecture delivery methods viz. the lectures using chalkboard, the lectures using PowerPoint presentations and the lectures utilizing transparencies with an overhead projector. By filling in a questionnaire, the second year MBBS students were asked to assess the impact of three pharmacology lectures given by three different methods of lecture delivery. Also after each lecture an objective test was given to compare the impact of the lecture delivered by different methods. The results of the study show that as per the subjective assessment of the lectures, students preferred PowerPoint teaching the most. As far as the students' performance is concerned the impact of traditional Chalkboard and PowerPoint teaching was much more than the lectures using transparency and overhead projector (OHP). PMID:29255392

A comparison of traditional and engaging lecture methods in a large, professional-level course.

PubMed

Miller, Cynthia J; McNear, Jacquee; Metz, Michael J

2013-12-01

In engaging lectures, also referred to as broken or interactive lectures, students are given short periods of lecture followed by "breaks" that can consist of 1-min papers, problem sets, brainstorming sessions, or open discussion. While many studies have shown positive effects when engaging lectures are used in undergraduate settings, the literature surrounding use of the learning technique for professional students is inconclusive. The novelty of this study design allowed a direct comparison of engaging physiology lectures versus didactic lecture formats in the same cohort of 120 first-year School of Dentistry DMD students. All students were taught five physiological systems using traditional lecture methods and six physiological systems using engaging lecture methods. The use of engaging lectures led to a statistically significant higher average on unit exams compared with traditional didactic lectures (8.6% higher, P < 0.05). Furthermore, students demonstrated an improved long-term retention of information via higher scores on the comprehensive final exam (22.9% higher in engaging lecture sections, P < 0.05). Many qualitative improvements were also indicated via student surveys and evaluations, including an increased perceived effectiveness of lectures, decrease in distractions during lecture, and increased confidence with the material. The development of engaging lecture activities requires a significant amount of instructor preparation and limits the time available to provide traditional lectures. However, the positive results of this study suggest the need for a restructuring of the physiology curriculum to incorporate more engaging lectures to improve both the qualitative experiences and performance levels of professional students.

Models And Experiments Of Laminar Diffusion Flames In Non-Uniform Magnetic Fields

NASA Technical Reports Server (NTRS)

Baker, J.; Varagani, R.; Saito, K.

2003-01-01

Non-uniform magnetic fields affect laminar diffusion flames as a result of the paramagnetic and diamagnetic properties of the products and reactants. Paramagnetism is the weak attraction to a magnetic field a material exhibits as a result of permanent magnetic dipole moments in the atoms of the material. Diamagnetism is the weak repulsion to a magnetic field exhibited by a material due to the lack of permanent magnetic dipole moments in the atoms of a material. The forces associated with paramagnetic and diamagnetism are several orders of magnitude less than the forces associated with the more familiar ferromagnetism. A typical example of a paramagnetic gas is oxygen while hydrocarbon fuels and products of combustion are almost always diamagnetic. The fact that magnets can affect flame behavior has been recognized for more than one hundred years. Early speculation was that such behavior was due to the magnetic interaction with the ionized gases associated with a flame. Using a scaling analysis, it was later shown that for laminar diffusion flames the magnetic field/ionized gas interaction was insignificant to the paramagnetic and diamagnetic influences. In this effort, the focus has been on examining laminar diffusion slot flames in the presence of non-uniform upward decreasing magnetic fields produced using permanent magnets. The principal reason for choosing slot flames was mathematical models of such flames show an explicit dependence on gravitational body forces, in the buoyancy-controlled regime, and an applied magnetic field would also impose a body force. In addition, the behavior of such flames was more easily visualized while maintaining the symmetry of the two-dimensional problem whereas it would have been impossible to obtain a symmetric magnetic field around a circular flame and still visually record the flame height and shape along the burner axis. The motivation for choosing permanent magnets to produce the magnetic fields was the assumption that space-related technologies based on the knowledge gained during this investigation would more likely involve permanent magnets as opposed to electromagnets. While no analysis has been done here to quantify the impact that an electric field, associated with an electromagnetic, would have relative to the paramagnetic and diamagnetic interactions, by using permanent magnets this potential effect was completely eliminated and thus paramagnetic and diamagnetic effects were isolated.

Improving Lecture Quality through Training in Public Speaking

ERIC Educational Resources Information Center

Mowbray, Robert; Perry, Laura B.

2015-01-01

Lecturing is a common instructional format but poor lecturing skills can detract from students' learning experiences and outcomes. As lecturing is essentially a form of public communication, training in public speaking may improve lecture quality. Twelve university lecturers in Malaysia participated in a six-week public speaking skills training…

Lecture attendance improves success in medical physiology.

PubMed

Demir, Enver Ahmet; Tutuk, Okan; Dogan, Hatice; Egeli, Duygu; Tumer, Cemil

2017-12-01

The educators have underlined the importance of lecture attendance for decades. Nowadays, students have ample online educational sources, which began a debate on the necessity of in-class lectures. In the present study, we investigated the influence of lecture attendance on the exam success. To this aim, we adopted a novel approach and matched second-year medicine students' answers in three interim exams with the lectures related to those questions. Thereby, we were able to evaluate if attending lectures increases the chance of giving a correct answer to the exam question generated from the attended lecture. Furthermore, we examined students who had never taken the course before (first-time takers) and students who had failed and repeated the course (repeat takers) separately, since repeat takers may have attended a lecture previously. We found that first-time takers attended more lectures and gained higher total scores than repeat takers. Lecture-matched correct answers were significantly higher for attended lectures than for skipped lectures in all interim exams. Moreover, the correlation analyses revealed that the number of correct answers increases by lecture attendance in both first-time and repeat takers. These results indicate that in-class lectures still should be considered as an essential part of the medical physiology education, even in the internet era. Copyright © 2017 the American Physiological Society.

Hyperfine Structure and Exchange Narrowing of Paramagnetic Resonance

DOE R&D Accomplishments Database

Townes, C. H.; Turkevich, J.

1950-01-01

Discussion of electronic paramagnetic resonance for the free radical ?, ?-diphenyl ?-picryl hydrazyl as observed by its effect on the transmission of microwave through a TE{sub 01} cavity with a small amount of the free radical placed approximately on the axis of the cavity; the half-width of this resonance at half maximum absorption was 1.45 oersteds.

Electron paramagnetic resonance and FT-IR spectroscopic studies of glycine anhydride and betaine hydrochloride

NASA Astrophysics Data System (ADS)

Halim Başkan, M.; Kartal, Zeki; Aydın, Murat

2015-12-01

Gamma irradiated powders of glycine anhydride and betaine hydrochloride have been investigated at room temperature by electron paramagnetic resonance (EPR). In these compounds, the observed paramagnetic species were attributed to the R1 and R2 radicals, respectively. It was determined that the free electron interacted with environmental protons and 14N nucleus in both radicals. The EPR spectra of gamma irradiated powder samples remained unchanged at room temperature for two weeks after irradiation. Also, the Fourier Transform Infrared (FT-IR), FT-Raman and thermal analyses of both compounds were investigated. The functional groups in the molecular structures of glycine anhydride and betaine hydrochloride were identified by vibrational spectroscopies (FT-IR and FT-Raman).

Single crystal EPR and optical studies of paramagnetic ions doped zinc potassium phosphate hexahydrate--part I: Cu(II)--a case of orthorhombic symmetry.

PubMed

Sambasiva Rao, P; Rajendiran, T M; Venkatesan, R; Madhu, N; Chandrasekhar, A V; Reddy, B J; Reddy, Y P; Ravikumar, R V

2001-12-01

Single crystal electron paramagnetic resonance (EPR) studies on Cu(II) doped zinc potassium phosphate hexahydrate (ZPPH) were carried out at room temperature. The angular variation spectra in the three orthogonal planes indicate that the paramagnetic impurity has entered the lattice substitutionally in place of Zn(II) and the spin Hamiltonian parameters calculated from these spectra are g(xx) = 2.188, g(yy) = 2.032, g(zz) = 2.373, Axx = 50 G, Ayy = 65.0 G and Azz = 80 G. The g and A tensors were coincident and these values matched fairly well with the values obtained from powder spectrum. The bonding parameters have also been calculated.

Explicit constructivism: a missing link in ineffective lectures?

PubMed

Prakash, E S

2010-06-01

This study tested the possibility that interactive lectures explicitly based on activating learners' prior knowledge and driven by a series of logical questions might enhance the effectiveness of lectures. A class of 54 students doing the respiratory system course in the second year of the Bachelor of Medicine and Bachelor of Surgery program in my university was randomized to two groups to receive one of two types of lectures, "typical" lectures (n = 28, 18 women and 10 men) or "constructivist" lectures (n = 26, 19 women and 7 men), on the same topic: the regulation of respiration. Student pretest scores in the two groups were comparable (P > 0.1). Students that received the constructivist lectures did much better in the posttest conducted immediately after the lectures (6.8 +/- 3.4 for constructivist lectures vs. 4.2 +/- 2.3 for typical lectures, means +/- SD, P = 0.004). Although both types of lectures were well received, students that received the constructivist lectures appeared to have been more satisfied with their learning experience. However, on a posttest conducted 4 mo later, scores obtained by students in the two groups were not any different (6.9 +/- 3 for constructivist lectures vs. 6.9 +/- 3.7 for typical lectures, P = 0.94). This study adds to the increasing body of evidence that there is a case for the use of interactive lectures that make the construction of knowledge and understanding explicit, easy, and enjoyable to learners.

Memory for Lectures: How Lecture Format Impacts the Learning Experience

PubMed Central

Varao-Sousa, Trish L.; Kingstone, Alan

2015-01-01

The present study investigated what impact the presentation style of a classroom lecture has on memory, mind wandering, and the subjective factors of interest and motivation. We examined if having a professor lecturing live versus on video alters the learning experience of the students in the classroom. During the lectures, students were asked to report mind wandering and later complete a memory test. The lecture format was manipulated such that all the students received two lectures, one live and one a pre-recorded video. Results indicate that lecture format affected memory performance but not mind wandering, with enhanced memory in the live lectures. Additionally, students reported greater interest and motivation in the live lectures. Given that a single change to the classroom environment, professor presence, impacted memory performance, as well as motivation and interest, the present results have several key implications for technology-based integrations into higher education classrooms. PMID:26561235

Memory for Lectures: How Lecture Format Impacts the Learning Experience.

PubMed

Varao-Sousa, Trish L; Kingstone, Alan

2015-01-01

The present study investigated what impact the presentation style of a classroom lecture has on memory, mind wandering, and the subjective factors of interest and motivation. We examined if having a professor lecturing live versus on video alters the learning experience of the students in the classroom. During the lectures, students were asked to report mind wandering and later complete a memory test. The lecture format was manipulated such that all the students received two lectures, one live and one a pre-recorded video. Results indicate that lecture format affected memory performance but not mind wandering, with enhanced memory in the live lectures. Additionally, students reported greater interest and motivation in the live lectures. Given that a single change to the classroom environment, professor presence, impacted memory performance, as well as motivation and interest, the present results have several key implications for technology-based integrations into higher education classrooms.

Magnetic Ordering in Gold Nanoclusters

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

Agrachev, Mikhail; Antonello, Sabrina; Dainese, Tiziano

Here, several research groups have observed magnetism in monolayer-protected gold-cluster samples, but the results were often contradictory and thus a clear understanding of this phenomenon is still missing. We used Au 25(SCH 2CH 2Ph) 18 0, which is a paramagnetic cluster that can be prepared with atomic precision and whose structure is known precisely. Previous magnetometry studies only detected paramagnetism. We used samples representing a range of crystallographic orders and studied their magnetic behaviors by electron paramagnetic resonance (EPR). As a film, Au 25(SCH 2CH 2Ph) 18 0 displays paramagnetic behavior but, at low temperature, ferromagnetic interactions are detectable. Onemore » or few single crystals undergo physical reorientation with the applied field and display ferromagnetism, as detected through hysteresis experiments. A large collection of microcrystals is magnetic even at room temperature and shows distinct paramagnetic, superparamagnetic, and ferromagnetic behaviors. Simulation of the EPR spectra shows that both spin-orbit coupling and crystal distortion are important to determine the observed magnetic behaviors. DFT calculations carried out on single cluster and periodic models predict values of spin6orbit coupling and crystal6splitting effects in agreement with the EPR derived quantities. Magnetism in gold nanoclusters is thus demonstrated to be the outcome of a very delicate balance of factors. To obtain reproducible results, the samples must be (i) controlled for composition and thus be monodispersed with atomic precision, (ii) of known charge state, and (iii) well defined also in terms of crystallinity and experimental conditions. This study highlights the efficacy of EPR spectroscopy to provide a molecular understanding of these phenomena« less

Magnetic Ordering in Gold Nanoclusters

DOE PAGES

Agrachev, Mikhail; Antonello, Sabrina; Dainese, Tiziano; ...

2017-06-12

Here, several research groups have observed magnetism in monolayer-protected gold-cluster samples, but the results were often contradictory and thus a clear understanding of this phenomenon is still missing. We used Au 25(SCH 2CH 2Ph) 18 0, which is a paramagnetic cluster that can be prepared with atomic precision and whose structure is known precisely. Previous magnetometry studies only detected paramagnetism. We used samples representing a range of crystallographic orders and studied their magnetic behaviors by electron paramagnetic resonance (EPR). As a film, Au 25(SCH 2CH 2Ph) 18 0 displays paramagnetic behavior but, at low temperature, ferromagnetic interactions are detectable. Onemore » or few single crystals undergo physical reorientation with the applied field and display ferromagnetism, as detected through hysteresis experiments. A large collection of microcrystals is magnetic even at room temperature and shows distinct paramagnetic, superparamagnetic, and ferromagnetic behaviors. Simulation of the EPR spectra shows that both spin-orbit coupling and crystal distortion are important to determine the observed magnetic behaviors. DFT calculations carried out on single cluster and periodic models predict values of spin6orbit coupling and crystal6splitting effects in agreement with the EPR derived quantities. Magnetism in gold nanoclusters is thus demonstrated to be the outcome of a very delicate balance of factors. To obtain reproducible results, the samples must be (i) controlled for composition and thus be monodispersed with atomic precision, (ii) of known charge state, and (iii) well defined also in terms of crystallinity and experimental conditions. This study highlights the efficacy of EPR spectroscopy to provide a molecular understanding of these phenomena« less

Uniform magnetic targeting of magnetic particles attracted by a new ferromagnetic biological patch.

PubMed

Pei, Ning; Cai, Lanlan; Yang, Kai; Ma, Jiaqi; Gong, Yongyong; Wang, Qixin; Huang, Zheyong

2018-02-01

A new non-toxic ferromagnetic biological patch (MBP) was designed in this paper. The MBP consisted of two external layers that were made of transparent silicone, and an internal layer that was made of a mixture of pure iron powder and silicon rubber. Finite-element analysis showed that the local inhomogeneous magnetic field (MF) around the MBP was generated when MBP was placed in a uniform MF. The local MF near the MBP varied with the uniform MF and shape of the MBP. Therefore, not only could the accumulation of paramagnetic particles be adjusted by controlling the strength of the uniform MF, but also the distribution of the paramagnetic particles could be improved with the different shape of the MBP. The relationship of the accumulation of paramagnetic particles or cells, magnetic flux density, and fluid velocity were studied through in vitro experiments and theoretical considerations. The accumulation of paramagnetic particles first increased with increment in the magnetic flux density of the uniform MF. But when the magnetic flux density of the uniform MF exceeded a specific value, the magnetic flux density of the MBP reached saturation, causing the accumulation of paramagnetic particles to fall. In addition, the adsorption morphology of magnetic particles or cells could be improved and the uniform distribution of magnetic particles could be achieved by changing the shape of the MBP. Also, MBP may be used as a new implant to attract magnetic drug carrier particles in magnetic drug targeting. Bioelectromagnetics. 39:98-107, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Preparation of a Cobalt(II) Cage: An Undergraduate Laboratory Experiment That Produces a ParaSHIFT Agent for Magnetic Resonance Spectroscopy

ERIC Educational Resources Information Center

Burns, Patrick J.; Tsitovich, Pavel B.; Morrow, Janet R.

2016-01-01

Laboratory experiments that demonstrate the effect of paramagnetic complexes on chemical shifts and relaxation times of protons are a useful way to introduce magnetic resonance spectroscopy (MRS) probes or magnetic resonance imaging (MRI) contrast agents. In this undergraduate inorganic chemistry experiment, a paramagnetic Co(II) cage complex is…

Upcycling: converting waste plastics into paramagnetic, conducting, solid, pure carbon microspheres.

PubMed

Pol, Vilas Ganpat

2010-06-15

The recent tremendous increase in the volume of waste plastics (WP) will have a harmful environmental impact on the health of living beings. Hundreds of years are required to degrade WP in atmospheric conditions. Hence, in coming years, in addition to traditional recycling services, innovative "upcycling" processes are necessary. This article presents an environmentally benign, solvent-free autogenic process that converts various WP [low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate (PET), polystyrene (PS), or their mixtures] into carbon microspheres (CMSs), an industrially significant, value-added product. The thermal dissociation of these individual or mixed WP in a closed reactor under autogenic pressure ( approximately 1000 psi) produced dry, pure powder of CMSs. In this paper, the optimization of process parameters such as the effect of mixing of WP with other materials, and the role of reaction temperature and time are reported. Employing advanced analytical techniques, the atomic structure, composition, and morphology of as-obtained CMSs were analyzed. The room-temperature paramagnetism in CMSs prepared from waste LDPE, HDPE, and PS was further studied by electron paramagnetic resonance (EPR). The conducting and paramagnetic nature of CMSs holds promise for their potential applications in toners, printers, paints, batteries, lubricants, and tires.

Paramagnetic or diamagnetic persistent currents? A topological point of view

NASA Astrophysics Data System (ADS)

Waintal, Xavier

2009-03-01

A persistent current flows at low temperatures in small conducting rings when they are threaded by a magnetic flux. I will discuss the sign of this persistent current (diamagnetic or paramagnetic response) in the special case of N electrons in a one dimensional ring [1]. One dimension is very special in the sense that the sign of the persistent current is entirely controlled by the topology of the system. I will establish lower bounds for the free energy in the presence of arbitrary electron-electron interactions and external potentials. Those bounds are the counterparts of upper bounds derived by Leggett using another topological argument. Rings with odd (even) numbers of polarized electrons are always diamagnetic (paramagnetic). The situation is more interesting with unpolarized electrons where Leggett upper bound breaks down: rings with N=4n exhibit either paramagnetic behavior or a superconductor-like current-phase relation. The topological argument provides a rigorous justification for the phenomenological Huckel rule which states that cyclic molecules with 4n + 2 electrons like benzene are aromatic while those with 4n electrons are not. [4pt] [1] Xavier Waintal, Geneviève Fleury, Kyryl Kazymyrenko, Manuel Houzet, Peter Schmitteckert, and Dietmar Weinmann Phys. Rev. Lett.101, 106804 (2008).

Two-stage magnetic refrigerator for astronomical applications with reservoir temperatures above 4 K

NASA Astrophysics Data System (ADS)

Hagmann, C.; Richards, P. L.

We propose a novel adiabatic demagnetization refrigerator (ADR) to produce temperatures as low as 100 mK starting from a high temperature reservoir between 4 and 8 K. The high temperature reservoir for the ADR can be provided by a mechanical cooler or an unpumped liquid helium bath. This refrigerator can be used to cool bolometric infrared detectors for low background astronomy from mountain tops, balloons or satellites, as well as to cool cryogenic X-ray detectors. The two-stage ADR consists of a single magnet with a paramagnetic chromic caesium alum (CCA) salt pill to produce the low temperature and paramagnetic gadolinium gallium garnet (GGG) as the first stage to intercept heat from the high temperature reservoir. Thermal contact between the paramagnets and the reservoir during magnetization is made with a mechanical heat switch. The ADR is suspended with Kevlar cords under tension for high mechanical stiffness and low parasitic heat leak. In a single cycle, the ADR maintains a temperature of 100 mK for 10-100 h. This time depends strongly on the magnetic field and reservoir temperature but not on the volume of the paramagnetic material as long as the heat leak is dominated by the suspension.

Rapid detection of Bacillus anthracis spores using a super-paramagnetic lateral-flow immunological detection system.

PubMed

Wang, Dian-Bing; Tian, Bo; Zhang, Zhi-Ping; Deng, Jiao-Yu; Cui, Zong-Qiang; Yang, Rui-Fu; Wang, Xu-Ying; Wei, Hong-Ping; Zhang, Xian-En

2013-04-15

There is an urgent need for convenient, sensitive, and specific methods to detect the spores of Bacillus anthracis, the causative agent of anthrax, because of the bioterrorism threat posed by this bacterium. In this study, we firstly develop a super-paramagnetic lateral-flow immunological detection system for B. anthracis spores. This system involves the use of a portable magnetic assay reader, super-paramagnetic iron oxide particles, lateral-flow strips and two different monoclonal antibodies directed against B. anthracis spores. This detection system specifically recognises as few as 400 pure B. anthracis spores in 30 min. This system has a linear range of 4×10³-10⁶ CFU ml⁻¹ and reproducible detection limits of 200 spores mg⁻¹ milk powder and 130 spores mg⁻¹ soil for simulated samples. In addition, this approach shows no obvious cross-reaction with other related Bacillus spores, even at high concentrations, and has no significant dependence on the duration of the storage of the immunological strips. Therefore, this super-paramagnetic lateral-flow immunological detection system is a promising tool for the rapid and sensitive detection of Bacillus anthracis spores under field conditions. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of iodinated contrast agent, xylocaine and gadolinium concentration on the signal emitted in magnetic resonance arthrography: a samples study*

PubMed Central

da Silva, Yvana Lopes Pinheiro; Costa, Rita Zanlorensi Visneck; Pinho, Kátia Elisa Prus; Ferreira, Ricardo Rabello; Schuindt, Sueliton Miyamoto

2015-01-01

Objective To investigate the effects of dilution of paramagnetic contrast agent with iodinated contrast and xylocaine on the signal intensity during magnetic resonance arthrography, and to improve the paramagnetic contrast agent concentration utilized in this imaging modality. Materials and Methods Samples specially prepared for the study with three different concentrations of paramagnetic contrast agent diluted in saline, iodinated contrast agent and xylocaine were imaged with fast spin echo T1-weighted sequences with fat saturation. The samples were placed into flasks and graphical analysis of the signal intensity was performed as a function of the paramagnetic contrast concentration. Results As compared with samples of equal concentrations diluted only with saline, the authors have observed an average signal intensity decrease of 20.67% for iodinated contrast agent, and of 28.34% for xylocaine. However, the increased gadolinium concentration in the samples caused decrease in signal intensity with all the dilutions. Conclusion Minimizing the use of iodinated contrast media and xylocaine and/or the use of a gadolinium concentration of 2.5 mmol/L diluted in saline will improve the sensitivity of magnetic resonance arthrography. PMID:25987746

Different Patterns of University Students' Integration of Lecture Podcasts, Learning Materials, and Lecture Attendance in a Psychology Course

ERIC Educational Resources Information Center

Luttenberger, Silke; Macher, Daniel; Maidl, Verena; Rominger, Christian; Aydin, Nilüfer; Paechter, Manuela

2018-01-01

Lecture podcasts are considered an efficient means for passing on learning contents to students, most notably in lectures with large numbers of students. Here, the lecturer's presentation, combined with lecture slides, is recorded and broadcasted in video form. The present study investigates how students organize learning when they have the choice…

A Study on Perception of Lecturer-Student Interaction in English Medium Science Lectures

ERIC Educational Resources Information Center

Navaz, Abdul Majeed Mohamed

2013-01-01

This paper, which is a part of a thesis, investigates the perception and practice of lecturers and students with regard to lecturer-student interaction in English medium science lectures of a university in Sri Lanka where English is a second language. This paper argues that dialogic lecturer-student interaction, which enables students to take a…

Automatic Camera Control System for a Distant Lecture with Videoing a Normal Classroom.

ERIC Educational Resources Information Center

Suganuma, Akira; Nishigori, Shuichiro

The growth of a communication network technology enables students to take part in a distant lecture. Although many lectures are conducted in universities by using Web contents, normal lectures using a blackboard are still held. The latter style lecture is good for a teacher's dynamic explanation. A way to modify it for a distant lecture is to…

A Blackboard for the 21st Century: An Inexpensive Light Board Projection System for Classroom Use

ERIC Educational Resources Information Center

Skibinski, Erik S.; DeBenedetti, William J. I.; Ortoll-Bloch, Amnon G.; Hines, Melissa A.

2015-01-01

An inexpensive light board projection system that enables lecturers to face the classroom while lecturing is described. The lecturer's writing appears in high contrast in front of the lecturer; it is never blocked by the lecturer, even while writing. The projected image displays both the writing as well as the lecturer's gestures and facial…

The Computer-based Lecture

PubMed Central

Wofford, Marcia M; Spickard, Anderson W; Wofford, James L

2001-01-01

Advancing computer technology, cost-containment pressures, and desire to make innovative improvements in medical education argue for moving learning resources to the computer. A reasonable target for such a strategy is the traditional clinical lecture. The purpose of the lecture, the advantages and disadvantages of “live” versus computer-based lectures, and the technical options in computerizing the lecture deserve attention in developing a cost-effective, complementary learning strategy that preserves the teacher-learner relationship. Based on a literature review of the traditional clinical lecture, we build on the strengths of the lecture format and discuss strategies for converting the lecture to a computer-based learning presentation. PMID:11520384

On magnetic structure of CuFe 2Ge 2: Constrains from the 57Fe Mössbauer spectroscopy

DOE PAGES

Bud’ko, Sergey L.; Jo, Na Hyun; Downing, Savannah S.; ...

2017-09-20

57Fe Mössbauer spectroscopy measurements were performed on a powdered CuFe 2Ge 2 sample that orders antiferromagnetically at ~175 K. Whereas a paramagnetic doublet was observed above the Néel temperature, a superposition of paramagnetic doublet and magnetic sextet (in approximately 0.5:0.5 ratio) was observed in the magnetically ordered state, suggesting a magnetic structure similar to a double-Q spin density wave with half of the Fe paramagnetic and another half bearing static moment of ~0.5–1μ B. Lastly, these results call for a re-evaluation of the recent neutron scattering data and band structure calculations, as well as for deeper examination of details ofmore » sample preparation techniques.« less

Speeding up NMR by in Situ Photo-Induced Reversible Acceleration of T1 -Relaxation (PIRAT).

PubMed

Stadler, Eduard; Dommaschk, Marcel; Frühwirt, Philipp; Herges, Rainer; Gescheidt, Georg

2018-03-05

Increasing the signal-to-noise ratio is one of the major goals in the field of NMR spectroscopy. In this proof of concept, we accelerate relaxation during an NMR pulse sequence using photo-generated paramagnetic states of an inert sensitizer. For the follow-up acquisition period, the system is converted to a diamagnetic state. The reversibility of the photo-induced switching allows extensive repetition required for multidimensional NMR. We thus eliminate the obstacle of line-broadening by the presence of paramagnetic species. In this contribution, we show how cycling of synchronized light/pulse sequences leads to an enhanced efficiency in multidimensional NMR. Our approach utilizes a molecular spin switch reversibly altering between a paramagnetic and diamagnetic state. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Final Report from The University of Texas at Austin for DEGAS: Dynamic Global Address Space programming environments

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

Erez, Mattan; Yelick, Katherine; Sarkar, Vivek

The Dynamic, Exascale Global Address Space programming environment (DEGAS) project will develop the next generation of programming models and runtime systems to meet the challenges of Exascale computing. Our approach is to provide an efficient and scalable programming model that can be adapted to application needs through the use of dynamic runtime features and domain-specific languages for computational kernels. We address the following technical challenges: Programmability: Rich set of programming constructs based on a Hierarchical Partitioned Global Address Space (HPGAS) model, demonstrated in UPC++. Scalability: Hierarchical locality control, lightweight communication (extended GASNet), and ef- ficient synchronization mechanisms (Phasers). Performance Portability:more » Just-in-time specialization (SEJITS) for generating hardware-specific code and scheduling libraries for domain-specific adaptive runtimes (Habanero). Energy Efficiency: Communication-optimal code generation to optimize energy efficiency by re- ducing data movement. Resilience: Containment Domains for flexible, domain-specific resilience, using state capture mechanisms and lightweight, asynchronous recovery mechanisms. Interoperability: Runtime and language interoperability with MPI and OpenMP to encourage broad adoption.« less

Media Richness and Social Norms in the Choice to Attend Lectures or to Watch Them Online

ERIC Educational Resources Information Center

Bassili, John N.

2008-01-01

Lectures in a large psychology course were taped and posted online where they could be viewed by streaming video. All students in the course had the option to attend lectures or watch them online, a choice that could be exercised on a lecture-by-lecture basis. The proportion of lectures watched online revealed that students chose between…

Analysis of Students' Eye Movement in Relation to Contents of Multimedia Lecture

NASA Astrophysics Data System (ADS)

Murakami, Masayuki; Kakusho, Koh; Minoh, Michihiko

In this article, we report our analysis of how the students' eye movement is affected by the content of lecture in order to utilize as standard of selection of image for distance learning and WBT. We classified content of lecture into nine parts: introduction, presentation, explanation, illustration, assertion, query, reply, question, response.We analyzed students' eye movement in the multimedia lecture "Japanese Economics", which was distance lecture between Kyoto University and UCLA. As the result of analysis, we get the following characteristic of eye movement of each course process in practical lecture.Introduction; students gaze at lecturer at first in order to achieve advance organizer, and next look at material.Presentation; they mainly stare at material and sometimes peer at lecturer to complement lack of understanding with information given by lecturer.Explanation; staring time is longer than other course process categories, and students stare at the object which they regard as important.Illustration; students stare at material which offers main information source.Assertion; they gaze at lecturer because of interaction between lecturer and students.Question-and-answer; generally students look at speaker but in the case of "query" about material, they change their focuses on material and lecturer fast and by turns in order to get information of lecturer and material.And our research suggests the practical guide for our choice of image information.

Interpolated testing influences focused attention and improves integration of information during a video-recorded lecture.

PubMed

Jing, Helen G; Szpunar, Karl K; Schacter, Daniel L

2016-09-01

Although learning through a computer interface has become increasingly common, little is known about how to best structure video-recorded lectures to optimize learning. In 2 experiments, we examine changes in focused attention and the ability for students to integrate knowledge learned during a 40-min video-recorded lecture. In Experiment 1, we demonstrate that interpolating a lecture with memory tests (tested group), compared to studying the lecture material for the same amount of time (restudy group), improves overall learning and boosts integration of related information learned both within individual lecture segments and across the entire lecture. Although mind wandering rates between the tested and restudy groups did not differ, mind wandering was more detrimental for final test performance in the restudy group than in the tested group. In Experiment 2, we replicate the findings of Experiment 1, and additionally show that interpolated tests influence the types of thoughts that participants report during the lecture. While the tested group reported more lecture-related thoughts, the restudy group reported more lecture-unrelated thoughts; furthermore, lecture-related thoughts were positively related to final test performance, whereas lecture-unrelated thoughts were negatively related to final test performance. Implications for the use of interpolated testing in video-recorded lectures are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Lectures in medical educaton: what students think?

PubMed

Mustafa, Tajammal; Farooq, Zerwa; Asad, Zunaira; Amjad, Rabbia; Badar, Iffat; Chaudhry, Abdul Majeed; Khan, Mohammad Amer Zaman; Rafique, Farida

2014-01-01

The volume of medical knowledge has increased exponentially and so has the need to improve the efficiency of current teaching practices.With increasing emphasis on interactive and problem based learning, the place of lectures in modern medical education has become a questionable issue. Objectives were to assess the perspective of undergraduate medical students regarding the role and effectiveness of lectures as a mode of instruction as well as the ways and means that can be employed to enhance the effectiveness of lectures. A cross sectional study was carried out among 2nd to final year medical students from five medical colleges including both private and public sector institutions. A total of 347 students participated by completing a structured questionnaire. Data was analyzed using SPSS-17. Sixty seven percent students considered lectures as a useful mode of instruction (47% males and 77% females), whereas 83% of the students reported that clinical sessions were superior to lectures because of small number of students in clinical sessions, active student participation, enhanced clinical orientation, and interaction with patients. About 64% responded that lectures should be replaced by clinical sessions. Majority of the students (92%) reported not being able to concentrate during a lecture beyond 30 minutes, whereas 70% skipped lectures as they were boring. A significantly greater proportion of male respondents, students from clinical years, and those who skipped lectures, considered lectures to be boring, a poor utilization of time and resources, and could not concentrate for the full duration of a lecture compared to females, students from preclinical years, and those who do not skip lectures, respectively. Lecturing techniques need to be improvised. The traditional passive mode of instruction has to be replaced with active learning and inquiry based approach to adequately utilize the time and resources spent on lectures.

[THE DISCUSSION CONCERNING THE PLACE OF LECTURES AND COMPULSORY LECTURE ATTENDANCE IN MEDICAL EDUCATION].

PubMed

Reis, Shmuel

2016-04-01

Luder shows that there is a lack of correlation between lecture attendance in medical school and examination performance, and thus draws attention to a discourse concerning the place of lectures and lecture attendance enforcement in 2015 and beyond. The paper addresses 4 questions: First, what is the current place of the traditional lecture in the education of medical students? Second, are there alternatives to this format of teaching? Third, what are the educational consequences of mandating lecture attendance; and fourth, should there be such enforcement? The author discusses these questions and concludes that lectures should be used sparingly, after a careful evaluation that they have an added value over learning away from the classroom. Furthermore, that there are clear guidelines on how to make the traditional lecture enhanced and educationally effective, as well as alternatives such as the "flipped classroom", e-learning and more to lectures. In addition, that lectures frequently drive learning negatively and enforcing attendance in Israel entails serious unintended consequences such as a need to monitor attendance, and a host of disciplinary adverse reactions. Finally, that besides lecture efficiency and economy (when having added value) one reason to consider compulsory attendance, may be when poor attendance negatively influences teachers morale.

Instructional analysis of lecture video recordings and its application for quality improvement of medical lectures.

PubMed

Baek, Sunyong; Im, Sun Ju; Lee, Sun Hee; Kam, Beesung; Yune, So Joung; Lee, Sang Soo; Lee, Jung A; Lee, Yuna; Lee, Sang Yeoup

2011-12-01

The lecture is a technique for delivering knowledge and information cost-effectively to large medical classes in medical education. The aim of this study was to analyze teaching quality, based on triangle analysis of video recordings of medical lectures, to strengthen teaching competency in medical school. The subjects of this study were 13 medical professors who taught 1st- and 2nd-year medical students and agreed to a triangle analysis of video recordings of their lectures. We first performed triangle analysis, which consisted of a professional analysis of video recordings, self-assessment by teaching professors, and feedback from students, and the data were crosschecked by five school consultants for reliability and consistency. Most of the distress that teachers experienced during the lecture occurred in uniform teaching environments, such as larger lecture classes. Larger lectures that primarily used PowerPoint as a medium to deliver information effected poor interaction with students. Other distressing factors in the lecture were personal characteristics and lack of strategic faculty development. Triangle analysis of video recordings of medical lectures gives teachers an opportunity and motive to improve teaching quality. Faculty development and various improvement strategies, based on this analysis, are expected to help teachers succeed as effective, efficient, and attractive lecturers while improving the quality of larger lecture classes.

Why do students miss lectures? A study of lecture attendance amongst students of health science.

PubMed

Bati, A Hilal; Mandiracioglu, Aliye; Orgun, Fatma; Govsa, Figen

2013-06-01

In the domain of health sciences, attendance by students at lectures is more critical. Lecture attendance is an issue which has been widely neglected. This study aims to determine those factors which affect the lecture attendance. The research data was collected by means of a questionnaire during the second semester of the academic year 2010-2011 from second-year students of the Faculties of Medicine, Pharmacy, Dentistry and Nursing. Together with demographic data, the questionnaire includes a Likert-type scale aiming to determine the factors influencing attendance at lectures. 663 participated in this study on a voluntary basis from Medical, Dentistry, Pharmacy and Nursing Faculties. Raising attainment levels, being able to take their own lecture notes, learning which aspects of the lecture content were being emphasized, and the opportunity to ask questions were amongst the chief reasons for attending lectures. It appears that the factors preventing students from attending lectures are mainly individual. Amongst the most frequently cited causes of non-attendance, sleeplessness, ill health and the inefficiency of lectures in overcrowded halls are emphasized. In the totals and sub-dimensions of the Lecture Attendance Scale, Medical Faculty students have average scores higher than those of students at other faculties. The vital nature of professional expertise and its applications, health sciences students' attendance at lectures carries greater importance. It is important to strengthen the mentoring system with regard to individual and external factors, which have been implicated as having a substantial influence on lecture attendance by students. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mini-Lectures: A Taster to Engage the Audience for the Main Event

ERIC Educational Resources Information Center

Ingram, Matthew J.; Crane, Simeon; Mokree, Alan; Curdy, Marion E.; Patel, Bhavik A.

2017-01-01

This article explores the use of pre-recorded video mini-lectures to support and enhance traditional face-to-face lectures for undergraduate students. Mini-lectures guide students through key concepts so that they can understand and assimilate key content before attending lectures.

Reciprocating magnetic refrigerator employing tandem porous matrices within a reciprocating displacer

NASA Technical Reports Server (NTRS)

Johnson, D. L. (Inventor)

1985-01-01

Disclosed is a method and apparatus for a magnetic refrigeration system. A continuously reciprocating displacer houses at least a pair of paramagnetic substances each of which is alternately driven into and out of a magnetic field. Two separate bidirectional pumping systems flow helium gas through the displacer and through both paramagnetic substances to create heat exchange conditions at two separate temperature extremes.

Learning from Online Video Lectures

ERIC Educational Resources Information Center

Brecht, H. David

2012-01-01

This study empirically examines the instructional value of online video lectures--videos that a course's instructor prepares to supplement classroom or online-broadcast lectures. The study examines data from a classroom course, where the videos have a slower, more step-by-step lecture style than the classroom lectures; student use of videos is…

Factors Shaping Mathematics Lecturers' Service Teaching in Different Departments

ERIC Educational Resources Information Center

Bingolbali, E.; Ozmantar, M. F.

2009-01-01

In this article we focus on university lecturers' approaches to the service teaching and factors that influence their approaches. We present data obtained from the interviews with 19 mathematics and three physics lecturers along with the observations of two mathematics lecturers' calculus courses. The findings show that lecturers' approaches to…

Experiences of using an interactive audience response system in lectures

PubMed Central

Uhari, Matti; Renko, Marjo; Soini, Hannu

2003-01-01

Background Lectures are good for presenting information and providing explanations, but because they lack active participation they have been neglected. Methods Students' experiences were evaluated after exposing them to the use of voting during lectures in their paediatrics course. Questions were delivered to the students taking paediatrics course. Thirty-six students out of the total of 40 (90%) attended the opening lecture, at which the first survey concerning previous experiences of lectures was performed. Thirty-nine students (98%) answered the second series of questions at the end of the paediatrics course. Results Most of the students felt that voting improved their activity during lectures, enhanced their learning, and that it was easier to make questions during lectures than earlier. Conclusions The students gained new, exciting insights much more often during the paediatrics course than before. We as teachers found that voting during lectures could easily overcome some of the obstacles of good lecturing. PMID:14678571

Creation of a web-based lecture series for psychiatry clerkship students: initial findings.

PubMed

Martin, Vicki L; Bennett, David S

2004-01-01

In recent years, the trend in medical education has been to utilize clerkship settings outside the medical school. Subsequently, students rotate at distant sites from the main campus and have lectures of varying quantity and quality. The objective of the present study was to standardize the core didactic experience for students in the Psychiatry clerkship by using web-based lectures and to assess student satisfaction with such lectures. Students completed a brief satisfaction questionnaire after viewing both web-based and live lectures. Students rated both web-based and live lectures positively, although overall satisfaction ratings were higher for live lectures. Shelf-exam scores improved for the current year, suggesting that learning was not negatively affected by the use of web-based lectures. Web-based lectures appear to be a feasible and satisfactory way to ensure didactic comparability across clinical sites.

Mechanism for the occurrence of paramagnetic planes within magnetically ordered cerium systems

NASA Astrophysics Data System (ADS)

Kioussis, Nicholas; Cooper, Bernard R.; Banerjea, Amitava

1988-11-01

Hybridization of moderately delocalized f electrons with band electrons gives rise to a highly anisotropic two-ion interaction. Previously it has been shown that such an interaction explains the experimentally observed unusual magnetic behavior of CeBi, yielding a phase transition from a higher-temperature type-I (↑↓) to a lower-temperature type-IA (↑↑↓↓) antiferromagnetic structure. If the hybridization-mediated interaction is the key to understanding the magnetic behavior of such moderately delocalized f-electron systems, we should expect to be able to understand on this basis the even more unusual magnetic behavior of CeSb. In CeSb, there is a sequence of magnetic structures in which the higher-temperature structures involve a periodic stacking of paramagnetic \\{001\\} planes alternating with magnetically ordered \\{001\\} planes of [001]-moment alignment. In this paper we show that such a coexistence of paramagnetic and magnetically ordered Ce3+ sites can be understood on the basis of the hybridization-mediated interionic interaction when there are cubic crystal-field (CF) interactions of comparable strength. The tendency to form paramagnetic planes is found to increase with increasing CF strength (Γ7 ground state); and the stability of the up-down paramagnetic plane arrangement at high temperatures is shown to arise from the reconciliation of the magnetic ordering with the CF interactions. We also find that for a certain range of parameters a different novel situation occurs, with a fully nonmagnetic (singlet) ground state for the Ce3+ ion. This singlet state is not Kondo-like, and occurs in such a way that the system would be expected to fluctuate between two differently polarized states, one of which is the singlet state.

Paramagnet induced signal quenching in MAS-DNP experiments in frozen homogeneous solutions

NASA Astrophysics Data System (ADS)

Corzilius, Björn; Andreas, Loren B.; Smith, Albert A.; Ni, Qing Zhe; Griffin, Robert G.

2014-03-01

The effects of nuclear signal quenching induced by the presence of a paramagnetic polarizing agent are documented for conditions used in magic angle spinning (MAS)-dynamic nuclear polarization (DNP) experiments on homogeneous solutions. In particular, we present a detailed analysis of three time constants: (1) the longitudinal build-up time constant TB for 1H; (2) the rotating frame relaxation time constant T1ρ for 1H and 13C and (3) T2 of 13C, the transverse relaxation time constant in the laboratory frame. These relaxation times were measured during microwave irradiation at a magnetic field of 5 T (140 GHz) as a function of the concentration of four polarizing agents: TOTAPOL, 4-amino-TEMPO, trityl (OX063), and Gd-DOTA and are compared to those obtained for a sample lacking paramagnetic doping. We also report the EPR relaxation time constants T1S and T2S, the DNP enhancements, ε, and the parameter E, defined below, which measures the sensitivity enhancement for the four polarizing agents as a function of the electron concentration. We observe substantial intensity losses (paramagnetic quenching) with all of the polarizing agents due to broadening mechanisms and cross relaxation during MAS. In particular, the monoradical trityl and biradical TOTAPOL induce ∼40% and 50% loss of signal intensity. In contrast there is little suppression of signal intensity in static samples containing these paramagnetic species. Despite the losses due to quenching, we find that all of the polarizing agents provide substantial gains in signal intensity with DNP, and in particular that the net enhancement is optimal for biradicals that operate with the cross effect. We discuss the possibility that much of this polarization loss can be regained with the development of instrumentation and methods to perform electron decoupling.

Effect of body temperature on the pharmacokinetics of a triarylmethyl-type paramagnetic contrast agent used in EPR oximetry.

PubMed

Matsumoto, Ken-Ichiro; Hyodo, Fuminori; Mitchell, James B; Krishna, Murali C

2018-02-01

Pharmacokinetics of the tri[8-carboxy-2,2,6,6-tetrakis(2-hydroxymethyl)benzo[1,2-d:4,5-d']bis(1,3)dithio-4-yl]methyl radical (Oxo63) after a single bolus and/or continuous intravenous infusion was investigated in tumor-bearing C3H mice with or without body temperature control while under anesthesia. The in vivo time course of Oxo63 in blood was measured using X-band electron paramagnetic resonance spectroscopy. Distribution of Oxo63 in normal muscle and tumor tissues was obtained using a surface coil resonator and a 700-MHz electron paramagnetic resonance spectrometer. The whole-body distribution of Oxo63 was obtained by 300-MHz continuous-wave electron paramagnetic resonance imaging. The high-resolution 300-MHz time-domain electron paramagnetic resonance imaging was also carried out to probe the distribution of Oxo63. Urination of mice was retarded at low body temperature, causing the concentration of Oxo63 in blood to attain high levels. However, the concentration of Oxo63 in tumor tissue was lower with no control of body temperature than active body temperature control. The nonsystemized blood flow in the tumor tissues may pool Oxo63 at lower body temperature. Pharmacokinetics of the contrast agent were found to be significantly affected by body temperature of the experimental animal, and can influence the probe distribution and the image patterns. Magn Reson Med 79:1212-1218, 2018. © Published 2017. This article is a U.S. Government work and is in the public domain in the USA. © Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Lanthanide paramagnetic probes for NMR spectroscopic studies of fast molecular conformational dynamics and temperature control. Effective six-site proton exchange in 18-crown-6 by exchange spectroscopy.

PubMed

Babailov, Sergey P

2012-02-06

(1)H and (13)C NMR measurements are reported for the CDCl(3) and CD(2)Cl(2) solutions of [La(18-crown-6)(NO(3))(3)] (I), [Pr(18-crown-6) (NO(3))(3)] (II), [Ce(18-crown-6)(NO(3))(3)] (III), and [Nd(18-crown-6)(NO(3))(3)] (IV) complexes. Temperature dependencies of the (1)H NMR spectra of paramagnetic II-IV have been analyzed using the dynamic NMR (DNMR) methods for six-site exchange. Two types of conformational dynamic processes were identified (the first one is conditioned by interconversion of complex enantiomeric forms and pseudorotation of a macrocycle molecule upon the C(2) symmetry axis; the second one is conditioned by macrocycle molecule inversion). Application of exchange spectroscopy (2D-EXSY) of DNMR for investigation of this dynamic system (II-IV) simplifies the assignment of the NMR signals and represents the first experimental study of multisite exchange. In the present work, the methodology of paramagnetic 4f (Ce, Pr, and Nd) probe applications for the study of free-energy, enthalpy, and entropy changes in chemical exchange processes, as well as the advantages of this method in a comparison with DNMR studies of diamagnetic substances, is discussed. In particular, as a result of paramagnetic chemical shifts in 4f complexes, the range of measurable rate constants expands considerably compared to the analogous range in diamagnetic compounds. Coordination compounds investigated in the paper represent new types of thermometric NMR sensors and lanthanide paramagnetic probes for in situ temperature control in solution.

Mass and Spin Measurement Techniques (for the Large Hadron Collider):. Lectures Given at TASI 2011, Boulder, Colorado

NASA Astrophysics Data System (ADS)

Lester, Christopher G.

2013-12-01

For TASI 2011, I was asked to give a series of lectures on "Mass and Spin Measurement Techniques" with relevance to the Large Hadron Collider. This document provides a written record of those lectures - or more precisely of what I said while giving the lectures - warts and all. It is provided as my contribution to the proceedings primarily for the benefit of those who heard the lectures first hand and may wish to refer back to them. What it is not is a scientific paper or a teaching resource. Though lecture slides may be prepared in advance, what is actually said in a lecture is usually extemporaneous, may be partial, can be influenced by audience reaction, and may not even make sense without a visual record of the concomitant gesticulations of the lecturer. More worryingly, some of the statements made may be down-right false, if the lecturer's tongue is in a twist. Accordingly, these proceedings are provided without warranty of any kind - not least in respect of accuracy or impartiality. The lectures were intended to engage the audience and get them thinking about a number of topics that they had not seen before. They were not expected to be the sort of sombre or well-balanced overview of the field that one might hope to achive in a review. These proceedings are provided to jog the memory of those who saw the lectures first hand, and for little other purpose. Footnotes, where they appear, indicate text/thoughts I have added during the editing process that were not voiced during the lectures themselves. Copies of the lecture slides are inserted at approximately the locations they would have become visible in the lectures.

Nitrogen-containing species in the structure of the synthesized nano-hydroxyapatite

NASA Astrophysics Data System (ADS)

Gafurov, M.; Biktagirov, T.; Yavkin, B.; Mamin, G.; Filippov, Y.; Klimashina, E.; Putlayev, V.; Orlinskii, S.

2014-04-01

Synthesized by the wet chemical precipitation technique, hydroxyapatite (HAp) powders with the sizes of the crystallites of 20-50 nm and 1 μm were analyzed by different analytical methods. By means of electron paramagnetic resonance (EPR) it is shown that during the synthesis process nitrate anions from the reagents (byproducts) could incorporate into the HAp structure. The relaxation times and EPR parameters of the stable axially symmetric NO{3/2-} paramagnetic centers detected after X-ray irradiation are measured with high accuracy. Analyses of high-frequency (95 GHz) electron-nuclear double resonance spectra from 1H and 31P nuclei and ab initio density functional theory calculations allow suggesting that the paramagnetic centers and nitrate anions as the precursors of NO{3/2-} radicals preferably occupy PO{4/3-} site in the HAp structure.

Electron paramagnetic resonance study of radiation-induced paramagnetic centers in succinic anhydride single crystal

NASA Astrophysics Data System (ADS)

Caliskan, Betul; Caliskan, Ali Cengiz; Er, Emine

2017-09-01

Succinic anhydride single crystals were exposed to 60Co-gamma irradiation at room temperature. The irradiated single crystals were investigated at 125 K by Electron Paramagnetic Resonance (EPR) Spectroscopy. The investigation of EPR spectra of irradiated single crystals of succinic anhydride showed the presence of two succinic anhydride anion radicals. The anion radicals observed in gamma-irradiated succinic anhydride single crystal were created by the scission of the carbon-oxygen double bond. The structure of EPR spectra demonstrated that the hyperfine splittings arise from the same radical species. The reduction of succinic anhydride was identified which is formed by the addition of an electron to oxygen of the Csbnd O bond. The g values, the hyperfine structure constants and direction cosines of the radiation damage centers observed in succinic anhydride single crystal were obtained.

Imaging single spin probes embedded in a conductive diamagnetic layer.

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

Messina, P.; Fradin, F.

2009-01-01

The detection of spin noise by means of scanning tunneling microscopy (STM) has recently been substantially improved by the work presented by Komeda and Manassen (Komeda, T.; Manassen, Y. Appl. Phys. Lett. 2008, 92, 212506). The application of this technique to molecular paramagnets requires the positioning and anchoring of paramagnetic molecules at surfaces. It also requires the possibility of tunneling high current densities into the STM-molecule-substrate tunneling junction. In this letter, we exploit the self-assembly of 1,10-phenantroline on the Au(111) surface to form a diamagnetic matrix that hosts individual molecules and dimers of diphenyl-2-picryl-hydrazyl (DPPH). STM measurements are used tomore » characterize the molecular layer. Electron spin resonance (ESR) measurements elucidate the role of thermal annealing in the preservation of the paramagnetic nature of the DPPH molecules.« less

On the Paramagnetic Inelastic Scattering of Neutrons due to Ions in the Anisotropic Crystalline Field

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

Yamada, Yasusada

1960-03-15

The paramagnetic inelastic scattering of neutrons due to ions of3d transition elements in the anisotropic crystalline field was considered. When the orbital momentum of the paramagnetic tons is not quenched, the spin states are no longer degenerate but split into discrete levels. The transition between these levels can occur by mugnetic dipole interaction of ions with neutrons. In the special case of FeCl/sub 2/, an antiferromagnetic crystal whose Neel temperature is 24 deg K, the calculation of the forward scuttering cross-sections of neutrons at various temperatures and wave lengths was carried out which showed that it is possible, under ordinarymore » conditions, to observe the inelastically scattered neutrons and hence to obtain information about the energy level scheme of the atomic spin in the cry stal. (auth)« less

Spin injection and spin transport in paramagnetic insulators

DOE PAGES

Okamoto, Satoshi

2016-02-22

We investigate the spin injection and the spin transport in paramagnetic insulators described by simple Heisenberg interactions using auxiliary particle methods. Some of these methods allow access to both paramagnetic states above magnetic transition temperatures and magnetic states at low temperatures. It is predicted that the spin injection at an interface with a normal metal is rather insensitive to temperatures above the magnetic transition temperature. On the other hand below the transition temperature, it decreases monotonically and disappears at zero temperature. We also analyze the bulk spin conductance. We show that the conductance becomes zero at zero temperature as predictedmore » by linear spin wave theory but increases with temperature and is maximized around the magnetic transition temperature. These findings suggest that the compromise between the two effects determines the optimal temperature for spintronics applications utilizing magnetic insulators.« less

Determinants of Mobile Wireless Technology for Promoting Interactivity in Lecture Sessions: An Empirical Analysis

ERIC Educational Resources Information Center

Gan, Chin Lay; Balakrishnan, Vimala

2014-01-01

The aim of this paper is to identify adoption factors of mobile wireless technology to increase interactivity between lecturers and students during lectures. A theoretical framework to ascertain lecturers' intentions to use mobile wireless technology during lectures (dependent variable) is proposed with seven independent variables. The…

The Lecture Is Dead Long Live the e-Lecture

ERIC Educational Resources Information Center

Folley, Duncan

2010-01-01

This research paper investigates if the traditional lecture is no longer appropriate for Neomillennial Learning Styles and whether an alternative blended approach could/should be used? Over the past decade the lecture as we know it, has gradually been under attack from constructivists, Twigg (1999) for example argues that the lecture is in the…

The Impact of Online Lecture Recordings on Student Performance

ERIC Educational Resources Information Center

Williams, Andrew; Birch, Elisa; Hancock, Phil

2012-01-01

The use of online lecture recordings as a supplement to physical lectures is an increasingly popular tool at many universities. This paper combines survey data with student record data for students in a "Microeconomics Principles" class to examine the relative effects of lecture attendance and online lecture recordings. The main finding…

Can Australian Universities Take Measures to Increase the Lecture Attendance of Marketing Students?

ERIC Educational Resources Information Center

Dolnicar, Sara; Kaiser, Sebastian; Matus, Katrina; Vialle, Wilma

2009-01-01

Lectures are a central element of traditional university learning, but Australian lecturers increasingly face very low levels of lecture attendance. A significant amount of research exists that investigates the drivers of lecture attendance. However, those studies typically study single factors in an isolated manner, thus overestimating the…

Students and Recorded Lectures: Survey on Current Use and Demands for Higher Education

ERIC Educational Resources Information Center

Gorissen, Pierre; van Bruggen, Jan; Jochems, Wim

2012-01-01

Online recordings of lectures provide students with anytime-anyplace access to lectures. Research shows that students prefer courses accompanied by online recordings and an increasing number of universities provide recorded lectures. This paper presents the results of a study into the use of recorded lectures at two universities in the…

Problem-based learning within endocrine physiology lectures.

PubMed

Walters, M R

2001-12-01

Methods were needed to improve the interest of medical students in the 10-lecture Endocrine Physiology block at the end of the second semester of study. Other incentives for improvement included the possibility of attracting students into endocrine research electives and the pressure to improve teaching approaches that results from the high tuition they pay. The principal approach adopted was that of whole class problem-based learning sessions (PBLS) in which the lecture period begins with a brief overview of one to three simplified cases, followed by the usual didactic lecture. At the end of the lecture, each PBL case is read in detail, with several questions posed to the students. Their answers are then used to reinforce concepts from the lecture material. This method can also provide some continuity between lectures, either by using a case in several lectures to illustrate different points, or by posing a question at the beginning of class that illustrates a point from the prior lecture. The outcome of this approach has been very successful: student evaluations of the lecture block and their attendance have significantly improved.

Impact of online lecture-capture on student outcomes in a therapeutics course.

PubMed

Bollmeier, Suzanne G; Wenger, Philip J; Forinash, Alicia B

2010-09-10

To examine the correlation between students accessing recorded lecture files (audio and slides) online and course grades and class attendance. Second professional year (of 6-year program) students in a therapeutics course had access to recorded online lectures for 72 hours following live lectures. The number and duration of lecture accessions were compared to final course grades and class attendance. Course grades were compared to those of a historical control group. At the end of the semester, students completed a brief survey instrument regarding their use and perceptions of online lectures. No correlation was found between final course grades and the number of lecture accessions (r = 0.0014) or total number of minutes lectures were viewed (r = 0.033), nor between class attendance and minutes viewed (r = 0.2158). Students with access to recorded lectures outperformed the historical control group on the final examination (p < 0.002). Seventy-two percent of students reported no influence of online files on class attendance. Posting lectures online did not affect student outcomes, but students did score higher on the final examination.

Using lecture capture: a qualitative study of nursing faculty's experience.

PubMed

Freed, Patricia E; Bertram, Julie E; McLaughlin, Dorcas E

2014-04-01

As lecture capture technology becomes widely available in schools of nursing, faculty will need to master new technological skills and make decisions about recording their classroom lectures or other activities. This study sought to understand faculty's experience of using a new lecture capture system. This qualitative study used Kruger's systematic approach to explore undergraduate nursing faculty's first-time experience using a lecture capture system purchased by the university. Four focus groups were conducted with a total of fourteen undergraduate faculty using lecture capture for the first-time. The interviews were recorded and transcribed and then analyzed by the researchers. Four themes were identified from the faculty interviews. Two of the themes expressed faculty's concerns about the teaching role, and two themes expressed the faculty's concerns about student learning. Participants experienced stress when learning to use the new lecture capture technology and struggled to resolve it with their own beliefs and teaching values. The impact of lecture capture on student learning, impact on class attendance, and the promotion of a culture of lecturing were revealed as important issues to consider when lecture capture becomes available. © 2013.

Student Perceptions of Online Lectures and WebCT in an Introductory Drug Information Course

PubMed Central

Freeman, Maisha Kelly; Schrimsher, Robert H.; Kendrach, Michael G.

2006-01-01

Objectives To determine student perceptions regarding online lectures and quizzes during an introductory drug information course for first-year professional doctor of pharmacy students. Design Formal and online lectures, online quizzes, written semester projects, a practice-based examination, a careers in pharmacy exercise, and a final examination were used to deliver the course content and assess performance. A multiple-choice survey instrument was used to evaluate student perceptions of WebCT and online lectures. Assessment More than 47% of students reported that online lectures helped them learn the material better, 77% reported that lectures would be used to study for the final examination, and 59% reported that they would use WebCT lectures for future classes. Approximately 40% of students agreed that online lectures should be used in future courses. Conclusion Students reported that WebCT was easy to use; however, the majority of students preferred in-class lectures compared to online lectures. A positive correlation was observed for those students who performed well on the online quizzes and those who performed well on the final examination. PMID:17332852

Audience-response systems for evaluation of pediatric lectures – comparison with a classic end-of-term online-based evaluation

PubMed Central

Bode, Sebastian Felix Nepomuk; Straub, Christine; Giesler, Marianne; Biller, Silke; Forster, Johannes; Krüger, Marcus

2015-01-01

Aim: Course evaluations are often conducted and analyzed well after the course has taken place. By using a digital audience response system (ARS), it is possible to collect, view and discuss feedback during or directly following a course or lecture session. This paper analyzes a student evaluation of a lecture course with ARS to determine if significant differences exist between the results of the ARS lecture evaluation and those of the online evaluation at the end of the semester. In terms of the overall evaluation, consideration is given to the level of students’ prior knowledge, the presentation of the lecture material by the lecturers and the relevance of the lecture topic for students. Method: During the 2011-12 winter semester, the lecture on Pediatrics at the Freiburg Center for Pediatric and Adolescent Medicine (Zentrum für Kinder- und Jugendmedizin (ZKJ) Freiburg) was evaluated using ARS. Thirty-four lectures were evaluated by an average of 22 (range 8-44) students, who responded to four questions each time an evaluation took place. Results: On a 6-point Likert scale (1=very good to 6=deficient), the students rated their level of preparedness with a mean of 3.18, the presentation of the lecture with 2.44, and the relevance of the lecture topic with 2.19. The overall evaluation of the lecture course by means of ARS resulted in 2.31. The online evaluation conducted at the end of the semester yielded a score of 2.45. Highly significant correlations were seen between the results of the ARS for the overall evaluation, assessment of prior knowledge, lecture presentation, and the estimated relevance of the lecture topic. Conclusion: The use of ARS is suitable for immediate evaluation of lectures, in particular regarding timely feedback for the individual lecturerlecturers. In comparison with an end-of-term evaluation, ARS yielded a better assessment. PMID:26038683

Using paper presentation breaks during didactic lectures improves learning of physiology in undergraduate students.

PubMed

Ghorbani, Ahmad; Ghazvini, Kiarash

2016-03-01

Many studies have emphasized the incorporation of active learning into classrooms to reinforce didactic lectures for physiology courses. This work aimed to determine if presenting classic papers during didactic lectures improves the learning of physiology among undergraduate students. Twenty-two students of health information technology were randomly divided into the following two groups: 1) didactic lecture only (control group) and 2) didactic lecture plus paper presentation breaks (DLPP group). In the control group, main topics of gastrointestinal and endocrine physiology were taught using only the didactic lecture technique. In the DLPP group, some topics were presented by the didactic lecture method (similar to the control group) and some topics were taught by the DLPP technique (first, concepts were covered briefly in a didactic format and then reinforced with presentation of a related classic paper). The combination of didactic lecture and paper breaks significantly improved learning so that students in the DLPP group showed higher scores on related topics compared with those in the control group (P < 0.001). Comparison of the scores of topics taught by only the didactic lecture and those using both the didactic lecture and paper breaks showed significant improvement only in the DLPP group (P < 0.001). Data obtained from the final exam showed that in the DLPP group, the mean score of the topics taught by the combination of didactic lecture and paper breaks was significantly higher than those taught by only didactic lecture (P < 0.05). In conclusion, the combination of paper presentation breaks and didactic lectures improves the learning of physiology. Copyright © 2016 The American Physiological Society.

Development of an electron paramagnetic resonance methodology for studying the photo-generation of reactive species in semiconductor nano-particle assembled films

NASA Astrophysics Data System (ADS)

Twardoch, Marek; Messai, Youcef; Vileno, Bertrand; Hoarau, Yannick; Mekki, Djamel E.; Felix, Olivier; Turek, Philippe; Weiss, Jean; Decher, Gero; Martel, David

2018-06-01

An experimental approach involving electron paramagnetic resonance is proposed for studying photo-generated reactive species in semiconductor nano-particle-based films deposited on the internal wall of glass capillaries. This methodology is applied here to nano-TiO2 and allows a semi-quantitative analysis of the kinetic evolutions of radical production using a spin scavenger probe.

Acoustic paramagnetic logging tool

DOEpatents

Vail, III, William B.

1988-01-01

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth3 s magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation . The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores.

A two-stage magnetic refrigerator for astronomical applications with reservoir temperatures above 4 K

NASA Astrophysics Data System (ADS)

Hagmann, C.; Richards, P. L.

1993-02-01

We propose a novel adiabatic demagnetization refrigerator (ADR) to produce temperatures as low as 100 mK starting from a high temperature reservoir between 4 and 8 K. The high temperature reservoir for the ADR can be provided by a mechanical cooler or an unpumped liquid helium bath. This refrigerator can be used to cool bolometric infrared detectors for low background astronomy from mountain tops, balloons or satellites as well as to cool cryogenic x-ray detectors. The two-stage ADR consists of a single magnet with a paramagnetic chromic-cesium-alum (CCA) salt pill to produce the low temperature and paramagnetic gadolinium-gallium-garnet (GGG) as the first stage to intercept heat from the high temperature reservoir. Thermal contact between the paramagnets and the reservoir during magnetization is made with a mechanical heat switch. The ADR is suspended with Kevlar chords under tension for high mechanical stiffness and low parasitic heat leak. In a single cycle, the ADR maintains a temperature of 100 mK for 10 to 100 hours. This time depends strongly on the magnetic field and reservoir temperature but not on the volume of the paramagnetic material as long as the heat leak is dominated by the suspension.

Application of Electron Paramagnetic Resonance Spectroscopy to Comparative Examination of Different Groups of Free Radicals in Thermal Injuries Treated with Propolis and Silver Sulphadiazine

PubMed Central

Olczyk, Pawel; Ramos, Pawel; Bernas, Marcin; Komosinska-Vassev, Katarzyna; Stojko, Jerzy; Pilawa, Barbara

2013-01-01

Different groups of free radicals expressed in burn wounds treated with propolis and silver sulphadiazine were examined. The thermal effect forms major types of free radicals in a wound because of the breaking of chemical bonds. Free radicals, located in the heated skin, were tested after 21 days of treating by these two substances. The aim of this work was to find the method for determination of types and concentrations of different groups of free radicals in wound after high temperature impact during burning. The effects of the therapy by propolis and silver sulphadiazine on free radicals were studied. Since the chemical methods of free radicals studies are destructive, the usefulness of the electron paramagnetic resonance spectroscopy was tested in this work. The electron paramagnetic resonance spectra measured with the microwave power of 2.2 mW were numerically fitted by theoretical curves of Gaussian and Lorentzian shapes. The experimental electron paramagnetic resonance spectra of tissue samples are best fitted by the sum of one Gauss and two Lorentz lines. An innovatory numerical procedure of spectroscopic skin analysis was presented. It is very useful in the alternative medicine studies. PMID:23762162

Upcycling : converting waste plastics into paramagnetic, conducting, solid, pure carbon microspheres.

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

Pol, V.

2010-06-15

The recent tremendous increase in the volume of waste plastics (WP) will have a harmful environmental impact on the health of living beings. Hundreds of years are required to degrade WP in atmospheric conditions. Hence, in coming years, in addition to traditional recycling services, innovative 'upcycling' processes are necessary. This article presents an environmentally benign, solvent-free autogenic process that converts various WP [low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate (PET), polystyrene (PS), or their mixtures] into carbon microspheres (CMSs), an industrially significant, value-added product. The thermal dissociation of these individual or mixed WP in a closed reactormore » under autogenic pressure (1000 psi) produced dry, pure powder of CMSs. In this paper, the optimization of process parameters such as the effect of mixing of WP with other materials, and the role of reaction temperature and time are reported. Employing advanced analytical techniques, the atomic structure, composition, and morphology of as-obtained CMSs were analyzed. The room-temperature paramagnetism in CMSs prepared from waste LDPE, HDPE, and PS was further studied by electron paramagnetic resonance (EPR). The conducting and paramagnetic nature of CMSs holds promise for their potential applications in toners, printers, paints, batteries, lubricants, and tires.« less

Structural, magnetic, and magnetocaloric properties of bilayer manganite La1.38Sr1.62Mn2O7

NASA Astrophysics Data System (ADS)

Yang, Yu-E.; Xie, Yunfei; Xu, Lisha; Hu, Dazhi; Ma, Chunlan; Ling, Langsheng; Tong, Wei; Pi, Li; Zhang, Yuheng; Fan, Jiyu

2018-04-01

In this study, we investigated the structural, magnetic phase transition, and magnetocaloric properties of bilayer perovskite manganite La1.38Sr1.62Mn2O7 based on X-ray diffraction, electron paramagnetic resonance, and temperature-/magnetic field-dependent magnetization measurements. The structural characterization results showed the prepared sample had a tetragonal structure with the space group I4/mmm. The Curie temperature was determined as 114 K in the magnetization studies and a second-order paramagnetic-ferromagnetic transition was confirmed by the Arrott plot, which showed that the slopes were positive for all the curves. According to the variation in the electron paramagnetic resonance spectrum, we detected obvious electronic phase separation across a broad temperature range from 220 to 80 K in this magnetic material, thereby indicating that the paramagnetic and ferromagnetic phases coexist above as well as below the Curie temperature. Based on a plot of the isothermal magnetization versus the magnetic applied field, we deduced the maximum magnetic entropy change, which only reached 1.89 J/kg.K under an applied magnetic field of 7.0 T. These theoretical investigations indicated that in addition to the magnetoelastic couplings and electron interaction, electronic phase separation and anisotropic exchange interactions also affect the magnetic entropy changes in this bilayer manganite.

A two-stage magnetic refrigerator for astronomical applications with reservoir temperatures above 4 K

NASA Technical Reports Server (NTRS)

Hagmann, C.; Richards, P. L.

1993-01-01

We propose a novel adiabatic demagnetization refrigerator (ADR) to produce temperatures as low as 100 mK starting from a high temperature reservoir between 4 and 8 K. The high temperature reservoir for the ADR can be provided by a mechanical cooler or an unpumped liquid helium bath. This refrigerator can be used to cool bolometric infrared detectors for low background astronomy from mountain tops, balloons or satellites as well as to cool cryogenic x-ray detectors. The two-stage ADR consists of a single magnet with a paramagnetic chromic-cesium-alum (CCA) salt pill to produce the low temperature and paramagnetic gadolinium-gallium-garnet (GGG) as the first stage to intercept heat from the high temperature reservoir. Thermal contact between the paramagnets and the reservoir during magnetization is made with a mechanical heat switch. The ADR is suspended with Kevlar chords under tension for high mechanical stiffness and low parasitic heat leak. In a single cycle, the ADR maintains a temperature of 100 mK for 10 to 100 hours. This time depends strongly on the magnetic field and reservoir temperature but not on the volume of the paramagnetic material as long as the heat leak is dominated by the suspension.

Paramagnetic liposomes as innovative contrast agents for magnetic resonance (MR) molecular imaging applications.

PubMed

Terreno, Enzo; Delli Castelli, Daniela; Cabella, Claudia; Dastrù, Walter; Sanino, Alberto; Stancanello, Joseph; Tei, Lorenzo; Aime, Silvio

2008-10-01

This article illustrates some innovative applications of liposomes loaded with paramagnetic lanthanide-based complexes in MR molecular imaging field. When a relatively high amount of a Gd(III) chelate is encapsulated in the vesicle, the nanosystem can simultaneously affect both the longitudinal (R(1)) and the transverse (R(2)) relaxation rate of the bulk H2O H-atoms, and this finding can be exploited to design improved thermosensitive liposomes whose MRI response is not longer dependent on the concentration of the probe. The observation that the liposome compartmentalization of a paramagnetic Ln(III) complex induce a significant R(2) enhancement, primarily caused by magnetic susceptibility effects, prompted us to test the potential of such agents in cell-targeting MR experiments. The results obtained indicated that these nanoprobes may have a great potential for the MR visualization of cellular targets (like the glutamine membrane transporters) overexpressing in tumor cells. Liposomes loaded with paramagnetic complexes acting as NMR shift reagents have been recently proposed as highly sensitive CEST MRI agents. The main peculiarity of CEST probes is to allow the MR visualization of different agents present in the same region of interest, and this article provides an illustrative example of the in vivo potential of liposome-based CEST agents.

The Relationship Between Method of Viewing Lectures, Course Ratings, and Course Timing.

PubMed

Burton, William B; Ma, Terence P; Grayson, Martha S

2017-01-01

In recent years, medical schools have provided students access to video recordings of course lectures, but few studies have investigated the impact of this on ratings of courses and teachers. This study investigated whether the method of viewing lectures was related to student ratings of the course and its components and whether the method used changed over time. Preclinical medical students indicated whether ratings of course lectures were based primarily on lecture attendance, video capture, or both. Students were categorized into Lecture, Video, or Both groups based on their responses to this question. The data consisted of 7584 student evaluations collected over 2 years. Students who attended live lectures rated the course and its components higher than students who only viewed the video or used both methods, although these differences were very small. Students increasingly watched lectures exclusively by video over time: in comparison with first-year students, second-year students were more likely to watch lectures exclusively by video; in comparison with students in the first half of the academic year, students in the second half of the academic year were more likely to watch lectures exclusively by video. With the increase in use of lecture video recordings across medical schools, attention must be paid to student attitudes regarding these methods.

The role of observational research in improving faculty lecturing skills: A qualitative study in an Italian dental school.

PubMed

Visioli, Sonia; Lodi, Giovanni; Carrassi, Antonio; Zannini, Lucia

2009-08-01

This pilot study is based on observational research of lecturing skills during the annual Oral Medicine course at the Milan Dentistry School. Our goals were to explore how teachers exhibited desirable lecturing skills, to observe how their attitudes and lecturing skills affected students' attention and thereby learning, and to provide feedback. We prepared a structured observational grid divided into four categories: explaining, questioning, visual aids, and lecturer attitude. The grid was filled in by a participant, nonactive researcher. Two main types of lecture were observed: "traditional" and "interactive". Both of these can result in a high level of attention among students. Among the categories, only "lecturer attitude" appeared to affect student attention. In particular, the skills of "speaking aloud" and "sustaining verbal communication with vocal inflection" appeared to have the greatest impact on lecturer attitude. The data were then presented blindly to the five lecturers, who were able to identify their own lesson. Our grid proved to be a valid instrument although it was very expensive. When integrated with other strategies for improving lecturing, such as student scoring, peer evaluation, and microteaching, observational research can be a cost-effective method to stimulate guided reflection and to improve the lecturing skills of faculty members.

The Relationship Between Method of Viewing Lectures, Course Ratings, and Course Timing

PubMed Central

Burton, William B; Ma, Terence P; Grayson, Martha S

2017-01-01

Background: In recent years, medical schools have provided students access to video recordings of course lectures, but few studies have investigated the impact of this on ratings of courses and teachers. This study investigated whether the method of viewing lectures was related to student ratings of the course and its components and whether the method used changed over time. Methods: Preclinical medical students indicated whether ratings of course lectures were based primarily on lecture attendance, video capture, or both. Students were categorized into Lecture, Video, or Both groups based on their responses to this question. The data consisted of 7584 student evaluations collected over 2 years. Results: Students who attended live lectures rated the course and its components higher than students who only viewed the video or used both methods, although these differences were very small. Students increasingly watched lectures exclusively by video over time: in comparison with first-year students, second-year students were more likely to watch lectures exclusively by video; in comparison with students in the first half of the academic year, students in the second half of the academic year were more likely to watch lectures exclusively by video. Conclusions: With the increase in use of lecture video recordings across medical schools, attention must be paid to student attitudes regarding these methods. PMID:29349337

A Comparison of Traditional and Engaging Lecture Methods in a Large, Professional-Level Course

ERIC Educational Resources Information Center

Miller, Cynthia J.; McNear, Jacquee; Metz, Michael J.

2013-01-01

In engaging lectures, also referred to as broken or interactive lectures, students are given short periods of lecture followed by "breaks" that can consist of 1-min papers, problem sets, brainstorming sessions, or open discussion. While many studies have shown positive effects when engaging lectures are used in undergraduate settings,…

Issues in Lecturing in a Second Language: Lecturer's Behaviour and Students' Perceptions

ERIC Educational Resources Information Center

Miller, Lindsay

2007-01-01

This article explores how Hong Kong Chinese engineering students with low English language proficiency manage to cope with their lectures given in English. An ethnographic case study approach was used with multiple sources of data triangulated to provide a picture of the lecture event from both the students' and the lecturer's perspectives. One of…

Lecture Attendance and Web Based Lecture Technologies: A Comparison of Student Perceptions and Usage Patterns

ERIC Educational Resources Information Center

von Konsky, Brian R.; Ivins, Jim; Gribble, Susan J.

2009-01-01

This paper investigates the impact of web based lecture recordings on learning and attendance at lectures. Student opinions regarding the perceived value of the recordings were evaluated in the context of usage patterns and final marks, and compared with attendance data and student perceptions regarding the usefulness of lectures. The availability…

How to Present It? On the Rhetoric of an Outstanding Lecturer

ERIC Educational Resources Information Center

Movshovitz-Hadar, Nitsa; Hazzan, Orit

2004-01-01

This paper analyses a lecture by an excellent teaching award winner professor of mathematics, given to high school mathematics teachers. The analysis is based upon two sources: (i) the lecture plan, as expressed in a series of 29 transparencies, prepared by the lecturer in advance; (ii) the actual implementation of the lecture, as transcribed from…

Do Pictures "Tell" a Thousand Words in Lectures? How Lecturers Vocalise Photographs in Their Presentations

ERIC Educational Resources Information Center

Hallewell, Madeline J.; Lackovic, Natasa

2017-01-01

This article explores how 145 photographs collected from 20 PowerPoint lectures in undergraduate psychology at 16 UK universities were integrated with lecturers' speech. Little is currently known about how lecturers refer to the distinct types of photographs included in their presentations. Findings show that only 48 photographs (33%) included in…

Does Tagging Improve the Navigation of Online Recorded Lectures by Students?

ERIC Educational Resources Information Center

Gorissen, Pierre; van Bruggen, Jan; Jochems, Wim

2015-01-01

Students more and more have access to online recordings of the lectures they attend at universities. The volume and length of these recorded lectures however make them difficult to navigate. Research shows that students primarily watch the recorded lectures while preparing for their exams. They do watch the full recorded lectures, but review only…

Should Lecture Recordings Be Mandated in Dental Schools? Two Viewpoints: Viewpoint 1: Lecture Recordings Should Be Mandatory in U.S. Dental Schools and Viewpoint 2: Lecture Recordings Should Not Be Mandatory in U.S. Dental Schools.

PubMed

Zandona, Andrea Ferreira; Kinney, Janet; Seong, WookJin; Kumar, Vandana; Bendayan, Alexander; Hewlett, Edmond

2016-12-01

Transcription or recording of lectures has been in use for many years, and with the availability of high-fidelity recording, the practice is now ubiquitous in higher education. Since technology has permeated education and today's tech-savvy students have expectations for on-demand learning, dental schools are motivated to record lectures, albeit with positive and negative implications. This Point/Counterpoint article addresses the question of whether lecture recording should be mandatory in U.S. dental schools. Viewpoint 1 supports the statement that lecture recording should be mandatory. Proponents of this viewpoint argue that the benefits-notably, student satisfaction and potential for improvement in student performance-outweigh concerns. Viewpoint 2 takes the opposite position, arguing that lecture recording decreases students' classroom attendance and adversely affects the morale of educators. Additional arguments against mandatory lecture recordings involve the expense of incorporating technology that requires ongoing support.

The Web-Lecture - a viable alternative to the traditional lecture format?

NASA Astrophysics Data System (ADS)

Meibom, S.

2004-12-01

Educational research shows that students learn best in an environment with emphasis on teamwork, problem-solving, and hands-on experience. Still professors spend the majority of their time with students in the traditional lecture-hall setting where the combination of large classes and limited time prevents sufficient student-teacher interaction to foster an active learning environment. Can modern computer technology be used to provide "lecture-type" information to students via the World Wide Web? If so, will that help professors make better and/or different use of their scheduled time with the students? Answering these questions was the main motivation for the Extra-Solar Planet Project. The Extra-Solar Planet Project was designed to test the effectiveness of a lecture available to the student on the World Wide Web (Web-Lecture) and to engage the students in an active learning environment were their use the information presented in the Web-Lecture. The topic of the Web-Lecture was detection of extra-solar planets and the project was implemented into an introductory astronomy course at University of Wisconsin Madison in the spring of 2004. The Web-Lecture was designed to give an interactive presentation of synchronized video, audio and lecture notes. It was created using the eTEACH software developed at the University of Wisconsin Madison School of Engineering. In my talk, I will describe the project, show excerpts of the Web-Lecture, and present assessments of student learning and results of student evaluations of the web-lecture format.

Online Lecture Recordings and Lecture Attendance: Investigating Student Preferences in a Large First Year Psychology Course

ERIC Educational Resources Information Center

Yeung, Alexandra; Raju, Sadhana; Sharma, Manjula D.

2016-01-01

While blended learning has been around for some time, the interplay between lecture recordings, lecture attendance and grades needs further examination particularly for large cohorts of over 1,000 students in 500 seat lecture theatres. This paper reports on such an investigation with a cohort of 1,450 first year psychology students' who indicated…

An Observational Study of the Lecture Delivery Style Characteristics of High and Low Rated Lectures.

ERIC Educational Resources Information Center

Albanese, Mark A.; And Others

This study identifies distinguishing differences in lecture delivery styles of lecturers rated by students in a large multi-instructor course: the Introduction to Clinical Medicine Course (ICM). The 20 lowest- and highest-rated lecturers of the 1982 and 1983 ICM courses served as the target group. Non-student raters observing the 1984 lectures…

The Use of Lecture Recordings in Higher Education: A Review of Institutional, Student, and Lecturer Issues

ERIC Educational Resources Information Center

O'Callaghan, Frances V.; Neumann, David L.; Jones, Liz; Creed, Peter A.

2017-01-01

Web-based lecture technologies are being used increasingly in higher education. One widely-used method is the recording of lectures delivered during face-to-face teaching of on-campus courses. The recordings are subsequently made available to students on-line and have been variously referred to as lecture capture, video podcasts, and Lectopia. We…

The Performance of Academic Identity as Pedagogical Model and Guide in/through Lecture Discourse

ERIC Educational Resources Information Center

McInnes, David

2013-01-01

This article argues that lecture discourse has the capacity to support students in their transition into modes of social critique and that the lecturer, through an enactment of an academic identity in lecture discourse, plays a crucial role as both model and guide. Certain crucial phases and sub-phases of lectures are used to model an engagement…

Adult Education between the Wars: The Curious Case of the Selborne Lecture Bureau

ERIC Educational Resources Information Center

Clarke, Richard

2010-01-01

"Independent" lecture agencies are a neglected element in the history of education. Between 1918 and 1939, the Selborne Lecture Bureau was a significant national provider of adult education in Britain, both in its own right and as a supplier of lecture(r)s to Women's Institutes and other bodies, and it pioneered the use of films in…

Confchem Conference on Flipped Classroom: Student Engagement with Flipped Chemistry Lectures

ERIC Educational Resources Information Center

Seery, Michael K.

2015-01-01

This project introduces the idea of "flipped lecturing" to a group of second-year undergraduate students. The aim of flipped lecturing is to provide much of the "content delivery" of the lecture in advance, so that the lecture hour can be devoted to more in-depth discussion, problem solving, and so on. As well as development of…

The Use of Recorded Lectures in Education and the Impact on Lecture Attendance and Exam Performance

ERIC Educational Resources Information Center

Bos, Nynke; Groeneveld, Caspar; van Bruggen, Jan; Brand-Gruwel, Saskia

2016-01-01

Universities increasingly record lectures and make them available online for students. Though the technology to record these lectures is now solidly implemented and embedded in many institutions, the impact of the usage of recorded lectures on exam performance is not clear. The purpose of the current study is to address the use of recorded…

The use of popular movies during lectures to aid the teaching and learning of undergraduate pharmacology.

PubMed

Ventura, Sab; Onsman, Andrys

2009-07-01

The role of the lecturer has changed to one where they must engage and motivate students to learn the subject material. To investigate whether the use of short movie references to pharmacology during lectures could stimulate learning in undergraduate students. One- to two-min film clips from popular movies containing a reference to the subject being covered were incorporated into Powerpoint presentations and shown at different times during pharmacology lectures. At the end of the lecture series, a student survey was conducted to assess the impact of the movies on student motivation, engagement and learning. Three positive effects were noted. First, students related theory to (simulated) practice by recognising that what they had learnt was actually being used. Second, students were motivated to attend lectures to see what clip would be used. Third, the clips provided a sectioning break, which helped to maintain the engagement of students throughout the lecture as well as the organisation of the lecture by the lecturer. The use of short popular movie references was a novel way to motivate and maintain the interest of large classes of undergraduate students throughout lectures.

Characteristics of good mathematics lecturers based on students and lecturers perspectives

NASA Astrophysics Data System (ADS)

Hapsari, Trusti; Putri, Dian Permana; Raharjo, Jajo Firman

2017-05-01

This study aims to determine the characteristics of good mathematics lecturers based on students' and lecturers' perspectivesand compare the characteristics of good lecturers/ teachers which are in accordance with the findings of some previous studies and the theories. This study is survey study. The Data were collected through questionnaires and interview. The population consists of some mathematics students from the first level through the third level and some mathematics education lecturers of a private university in West Java. Qualitative analysis was undertaken to examine the results of questionnaires and interviews. The finding shows that the characteristic of good mathematics lecturers is inspiring. They can inspire other mathematics lecturers and educators in general. Based on the students and lecturers' perspective, some characteristics of good mathematics lecturers are mastering the materials well, being on time, being objective, understanding the students, presenting the materials with clearly, and being disciplined. Some other characteristic mentioned are: teaching eagerly, being unhurried, being friendly, giving exemplary and preparing the lesson well. These characteristics are not much different from the characteristics described by some previous researchers and some theories of experts, i.e. mastering the subject matters well, pedagogic, and work wholeheartedly.

Lecturing and Loving It: Applying the Information-Processing Model.

ERIC Educational Resources Information Center

Parker, Jonathan K.

1993-01-01

Discusses the benefits of lecturing, when done properly, in high schools. Describes the positive attributes of effective lecturers. Provides a human information-processing model applicable to the task of lecturing to students. (HB)

Comparison of the didactic lecture with the simulation/model approach for the teaching of a novel perioperative ultrasound curriculum to anesthesiology residents.

PubMed

Ramsingh, Davinder; Alexander, Brenton; Le, Khanhvan; Williams, Wendell; Canales, Cecilia; Cannesson, Maxime

2014-09-01

To expose residents to two methods of education for point-of-care ultrasound, a traditional didactic lecture and a model/simulation-based lecture, which focus on concepts of cardiopulmonary function, volume status, and evaluation of severe thoracic/abdominal injuries; and to assess which method is more effective. Single-center, prospective, blinded trial. University hospital. Anesthesiology residents who were assigned to an educational day during the two-month research study period. Residents were allocated to two groups to receive either a 90-minute, one-on-one didactic lecture or a 90-minute lecture in a simulation center, during which they practiced on a human model and simulation mannequin (normal pathology). Data points included a pre-lecture multiple-choice test, post-lecture multiple-choice test, and post-lecture, human model-based examination. Post-lecture tests were performed within three weeks of the lecture. An experienced sonographer who was blinded to the education modality graded the model-based skill assessment examinations. Participants completed a follow-up survey to assess the perceptions of the quality of their instruction between the two groups. 20 residents completed the study. No differences were noted between the two groups in pre-lecture test scores (P = 0.97), but significantly higher scores for the model/simulation group occurred on both the post-lecture multiple choice (P = 0.038) and post-lecture model (P = 0.041) examinations. Follow-up resident surveys showed significantly higher scores in the model/simulation group regarding overall interest in perioperative ultrasound (P = 0.047) as well understanding of the physiologic concepts (P = 0.021). A model/simulation-based based lecture series may be more effective in teaching the skills needed to perform a point-of-care ultrasound examination to anesthesiology residents. Copyright © 2014 Elsevier Inc. All rights reserved.

Trends in National Emergency Medicine Conference Didactic Lectures Over a 6-Year Period.

PubMed

Gottlieb, Michael; Riddell, Jeff; Njie, Abdoulie

2017-01-01

National conference didactic lectures have traditionally featured hour-long lecture-based presentations. However, there is evidence that longer lectures can lead to both decreased attention and retention of information. The authors sought to identify trends in lecture duration, lecture types, and number of speakers at four national emergency medicine (EM) conferences over a 6-year period. The authors performed a retrospective analysis of the length, number of speakers, and format of didactic lectures at four different national EM conferences over 6 years. The authors abstracted data from the national academic assemblies for the four largest not-for-profit EM organizations in the United States: American Academy of Emergency Medicine, American College of Emergency Physicians, Council of Emergency Medicine Residency Directors, and Society for Academic Emergency Medicine. There was a significant yearly decrease in the mean lecture lengths for three of the four conferences. There was an increase in the percentage of rapid fire sessions over the preceding 2 years with a corresponding decrease in the percentage of general educational sessions. There was no significant difference in the mean number of speakers per lecture. An analysis of 4210 didactic lecture sessions from the annual meetings of four national EM organizations over a 6-year period showed significant decreases in mean lecture length. These findings can help to guide EM continuing medical education conference planning and research.

The interrupted learner: How distractions during live and video lectures influence learning outcomes.

PubMed

Zureick, Andrew H; Burk-Rafel, Jesse; Purkiss, Joel A; Hortsch, Michael

2017-11-27

New instructional technologies have been increasingly incorporated into the medical school learning environment, including lecture video recordings as a substitute for live lecture attendance. The literature presents varying conclusions regarding how this alternative experience impacts students' academic success. Previously, a multi-year study of the first-year medical histology component at the University of Michigan found that live lecture attendance was positively correlated with learning success, while lecture video use was negatively correlated. Here, three cohorts of first-year medical students (N = 439 respondents, 86.6% response rate) were surveyed in greater detail regarding lecture attendance and video usage, focusing on study behaviors that may influence histology learning outcomes. Students who reported always attending lectures or viewing lecture videos had higher average histology scores than students who employed an inconsistent strategy (i.e., mixing live attendance and video lectures). Several behaviors were negatively associated with histology performance. Students who engaged in "non-lecture activities" (e.g., social media use), students who reported being interrupted while watching the lecture video, or feeling sleepy/losing focus had lower scores than their counterparts not engaging in these behaviors. This study suggests that interruptions and distractions during medical learning activities-whether live or recorded-can have an important impact on learning outcomes. Anat Sci Educ 00: 000-000. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

Detection of Nitric Oxide by Electron Paramagnetic Resonance Spectroscopy

PubMed Central

Hogg, Neil

2010-01-01

Electron paramagnetic resonance (EPR) spectroscopy has been used in a number of ways to study nitric oxide chemistry and biology. As an intrinsically stable and relatively unreactive diatomic free radical, the challenges for detecting this species by EPR are somewhat different than those for transient radical species. This review gives a basic introduction to EPR spectroscopy and discusses its uses to assess and quantify nitric oxide formation in biological systems. PMID:20304044

The Demonstration of the Feasibility of the Tuning and Stimulation of Nuclear Radiation.

DTIC Science & Technology

1988-10-31

line, or the center of a resonance pattern, is called the isomer shift. It is due to the electrostatic interaction of the nucleus with the electron ...magnetic moment due to the presence of unpaired electrons , the material is either paramagnetic or ferromagnetic. In paramagnetic materials these moments...capture and fission.4,5,8 A very fertile interdisciplinary area of nuclear quantum electronics 7 appeared to be developing, encouraged by the

Magnetic properties of point defects in proton irradiated diamond

NASA Astrophysics Data System (ADS)

Makgato, T. N.; Sideras-Haddad, E.; Ramos, M. A.; García-Hernández, M.; Climent-Font, A.; Zucchiatti, A.; Muñoz-Martin, A.; Shrivastava, S.; Erasmus, R.

2016-09-01

We investigate the magnetic properties of ultra-pure type-IIa diamond following irradiation with proton beams of ≈1-2 MeV energy. SQUID magnetometry indicate the formation of Curie type paramagnetism according to the Curie law. Raman and Photoluminescence spectroscopy measurements show that the primary structural features created by proton irradiation are the centers: GR1, ND1, TR12 and 3H. The Stopping and Range of Ions in Matter (SRIM) Monte Carlo simulations together with SQUID observations show a strong correlation between vacancy production, proton fluence and the paramagnetic factor. At an average surface vacancy spacing of ≈1-1.6 nm and bulk (peak) vacancy spacing of ≈0.3-0.5 nm Curie paramagnetism is induced by formation of ND1 centres with an effective magnetic moment μeff~(0.1-0.2)μB. No evidence of long range magnetic ordering is observed in the temperature range 4.2-300 K.

Molecular modeling of biomolecules by paramagnetic NMR and computational hybrid methods.

PubMed

Pilla, Kala Bharath; Gaalswyk, Kari; MacCallum, Justin L

2017-11-01

The 3D atomic structures of biomolecules and their complexes are key to our understanding of biomolecular function, recognition, and mechanism. However, it is often difficult to obtain structures, particularly for systems that are complex, dynamic, disordered, or exist in environments like cell membranes. In such cases sparse data from a variety of paramagnetic NMR experiments offers one possible source of structural information. These restraints can be incorporated in computer modeling algorithms that can accurately translate the sparse experimental data into full 3D atomic structures. In this review, we discuss various types of paramagnetic NMR/computational hybrid modeling techniques that can be applied to successful modeling of not only the atomic structure of proteins but also their interacting partners. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of the oxidized and non- oxidized bitumen modified with additive «Adgezolin» by using electron paramagnetic resonance

NASA Astrophysics Data System (ADS)

Mukhamatdinov, I.; Gafurov, M.; Kemalov, A.; Rodionov, A.; Mamin, G.; Fakhretdinov, P.

2018-05-01

Cationic surfactant (adhesion additive) «Adgezolin» has been developed. It is shown that introduction of «Adgezolin» into the oxidized bitumen increases the relative amount of asphaltenes and monocyclearomatic hydrocarbons. By means of electron paramagnetic resonance (EPR) it is demonstrated that the introduction of additive «Adgezolin» increases the number of paramagnetic «free» carbon radicals (FR) in the oxidized bitumen and decreases that in the unoxidized species. In both types of bitumen shift from the Lorentzian to Gaussian EPR lineshape of FR is obtained that could be connected with as an increase of the samples homogeneity. It is supposed that while in the oxygenated bitumens introduction of additives leads to the disaggregation of asphaltene-resins compounds, in the unoxidized samples the balance is shifted towards formation of di-radicals.

Combined multifrequency EPR and DFT study of dangling bonds in a-Si:H

NASA Astrophysics Data System (ADS)

Fehr, M.; Schnegg, A.; Rech, B.; Lips, K.; Astakhov, O.; Finger, F.; Pfanner, G.; Freysoldt, C.; Neugebauer, J.; Bittl, R.; Teutloff, C.

2011-12-01

Multifrequency pulsed electron paramagnetic resonance (EPR) spectroscopy using S-, X-, Q-, and W-band frequencies (3.6, 9.7, 34, and 94 GHz, respectively) was employed to study paramagnetic coordination defects in undoped hydrogenated amorphous silicon (a-Si:H). The improved spectral resolution at high magnetic field reveals a rhombic splitting of the g tensor with the following principal values: gx=2.0079, gy=2.0061, and gz=2.0034, and shows pronounced g strain, i.e., the principal values are widely distributed. The multifrequency approach furthermore yields precise 29Si hyperfine data. Density functional theory (DFT) calculations on 26 computer-generated a-Si:H dangling-bond models yielded g values close to the experimental data but deviating hyperfine interaction values. We show that paramagnetic coordination defects in a-Si:H are more delocalized than computer-generated dangling-bond defects and discuss models to explain this discrepancy.

Biocompatible Collagen Paramagnetic Scaffold for Controlled Drug Release.

PubMed

Bettini, Simona; Bonfrate, Valentina; Syrgiannis, Zois; Sannino, Alessandro; Salvatore, Luca; Madaghiele, Marta; Valli, Ludovico; Giancane, Gabriele

2015-09-14

A porous collagen-based hydrogel scaffold was prepared in the presence of iron oxide nanoparticles (NPs) and was characterized by means of infrared spectroscopy and scanning electron microscopy. The hybrid scaffold was then loaded with fluorescein sodium salt as a model compound. The release of the hydrosoluble species was triggered and accurately controlled by the application of an external magnetic field, as monitored by fluorescence spectroscopy. The biocompatibility of the proposed matrix was also tested by the MTT assay performed on 3T3 cells. Cell viability was only slightly reduced when the cells were incubated in the presence of the collagen-NP hydrogel, compared to controls. The economicity of the chemical protocol used to obtain the paramagnetic scaffolds as well as their biocompatibility and the safety of the external trigger needed to induce the drug release suggest the proposed collagen paramagnetic matrices for a number of applications including tissue engeneering and drug delivery.

Low-temperature anomalies in the dynamic elastic moduli of cubic AIIBVI crystals with 3d-transition metal impurities

NASA Astrophysics Data System (ADS)

Lonchakov, A. T.

2011-04-01

A negative paramagnetic contribution to the dynamic elastic moduli is identified in AIIBVI:3d wide band-gap compounds for the first time. It appears as a paramagnetic elastic, or, briefly, paraelastic, susceptibility. These compounds are found to have a linear temperature dependence for the inverse paraelastic susceptibility. This is explained by a contribution from the diagonal matrix elements of the orbit-lattice interaction operators in the energy of the spin-orbital states of the 3d-ion as a function of applied stress (by analogy with the Curie contribution to the magnetic susceptibility). The inverse paraelastic susceptibility of AIIBVI crystals containing non-Kramers 3d-ions is found to deviate from linearity with decreasing temperature and reaches saturation. This effect is explained by a contribution from nondiagonal matrix elements (analogous to the well known van Vleck contribution to the magnetic susceptibility of paramagnets).

Dependence of Van-Vleck paramagnetism on the size of nanocrystals in superstoichiometric TiO{sub y}

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

Valeeva, A. A., E-mail: valeeva@ihim.uran.ru; Nazarova, S. Z.; Rempel, A. A.

2016-04-15

In situ measurements of the magnetic susceptibility of titanium monoxide nanocrystals with superstoichiometric composition TiO{sub y} (y > 1) in the 300–1200 K temperature range showed that this value depends not only on the structural state of a sample, but also on the size of crystals. Analysis of data obtained for both ordered and disordered TiO{sub y} showed that the Van-Vleck paramagnetism is inversely proportional to the nanocrystal size because of breakage of the symmetry of local environment of the near-surface atoms of titanium and oxygen. The Van-Vleck paramagnetism contribution due to atomic-vacancy disorder in superstoichiometric titanium monoxide nanocrystals, asmore » well as in the stoichiometric composition, is proportional to a deviation of the degree of long-range order from its maximum value.« less

Time-dependent broken-symmetry density functional theory simulation of the optical response of entangled paramagnetic defects: Color centers in lithium fluoride

NASA Astrophysics Data System (ADS)

Janesko, Benjamin G.

2018-02-01

Parameter-free atomistic simulations of entangled solid-state paramagnetic defects may aid in the rational design of devices for quantum information science. This work applies time-dependent density functional theory (TDDFT) embedded-cluster simulations to a prototype entangled-defect system, namely two adjacent singlet-coupled F color centers in lithium fluoride. TDDFT calculations accurately reproduce the experimental visible absorption of both isolated and coupled F centers. The most accurate results are obtained by combining spin symmetry breaking to simulate strong correlation, a large fraction of exact (Hartree-Fock-like) exchange to minimize the defect electrons' self-interaction error, and a standard semilocal approximation for dynamical correlations between the defect electrons and the surrounding ionic lattice. These results motivate application of two-reference correlated ab initio approximations to the M-center, and application of TDDFT in parameter-free simulations of more complex entangled paramagnetic defect architectures.

Paramagnetic particles and mixing in micro-scale flows.

PubMed

Calhoun, R; Yadav, A; Phelan, P; Vuppu, A; Garcia, A; Hayes, M

2006-02-01

Mixing in microscale flows with rotating chains of paramagnetic particles can be enhanced by adjusting the ratio of viscous to magnetic forces so that chains dynamically break and reform. Lattice Boltzmann (LB) simulations were used to calculate the interaction between the fluid and suspended paramagnetic particles under the influence of a rotating magnetic field. Fluid velocities obtained from the LB simulations are used to solve the advection diffusion equation for massless tracer particles. At relatively high Mason numbers, small chains result in low edge velocities, and hence mixing is slower than at other Mason numbers. At low Mason numbers, long, stable chains form and produce little mixing toward the center of the chains. A peak in mixing rate is observed when chains break and reform. The uniformity of mixing is greater at higher Mason numbers because more small chains result in a larger number of small mixing areas.

Studying the Structure and Dynamics of Biomolecules by Using Soluble Paramagnetic Probes

PubMed Central

Hocking, Henry G; Zangger, Klaus; Madl, Tobias

2013-01-01

Characterisation of the structure and dynamics of large biomolecules and biomolecular complexes by NMR spectroscopy is hampered by increasing overlap and severe broadening of NMR signals. As a consequence, the number of available NMR spectroscopy data is often sparse and new approaches to provide complementary NMR spectroscopy data are needed. Paramagnetic relaxation enhancements (PREs) obtained from inert and soluble paramagnetic probes (solvent PREs) provide detailed quantitative information about the solvent accessibility of NMR-active nuclei. Solvent PREs can be easily measured without modification of the biomolecule; are sensitive to molecular structure and dynamics; and are therefore becoming increasingly powerful for the study of biomolecules, such as proteins, nucleic acids, ligands and their complexes in solution. In this Minireview, we give an overview of the available solvent PRE probes and discuss their applications for structural and dynamic characterisation of biomolecules and biomolecular complexes. PMID:23836693

Pumping Liquid Oxygen by Use of Pulsed Magnetic Fields

NASA Technical Reports Server (NTRS)

Youngquist, Robert; Lane, John; Immer, Christopher; Simpson, James

2004-01-01

An effort is underway to develop a method of pumping small amounts of liquid oxygen by use of pulsed magnetic fields. This development is motivated by a desire to reduce corrosion and hazards of explosion and combustion by eliminating all moving pump parts in contact with the pumped oxygen. The method exploits the known paramagnetism of liquid oxygen. Since they both behave similarly, the existing theory of ferrofluids (liquids with colloidally suspended magnetic particles) is directly applicable to paramagnetic liquid oxygen. In general, the force density of the paramagnetic interaction is proportional to the magnetic susceptibility multiplied by the gradient of the square of the magnitude of the magnetic field. The local force is in the direction of intensifying magnetic field. In the case of liquid oxygen, the magnetic susceptibility is large enough that a strong magnetic-field gradient can lift the liquid in normal Earth gravitation.

Ionic Liquids and Solids with Paramagnetic Anions

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

Castner, Jr., E.W.; Wishart, J.; Krieger, B.M.

2010-06-18

Four paramagnetic ionic compounds have been prepared and their magnetic, structural and thermal properties have been investigated. The four compounds are methylbutylpyrrolidinium tetrachloroferrate(III) ([Pyrr{sub 14}]{sup +}/[FeCl{sub 4}]{sup -}), methyltributylammonium tetrachloroferrate(III) ([N{sub 1444}]{sup +}/[FeCl{sub 4}]{sup -}), butylmethylimidazolium tetrachloroferrate(III) ([bmim]{sup +}/[FeCl{sub 4}]{sup -}) and tetrabutylammonium bromotrichloroferrate(III) ([N{sub 4444}]{sup +}/[FeBrCl{sub 3}]{sup -}). Temperature-dependent studies of their magnetic behaviors show that all four compounds are paramagnetic at ambient temperatures. Glass transitions are observed for only two of the four compounds, [Pyrr{sub 14}]{sup +}/[FeCl{sub 4}]{sup -} and [bmim]{sup +}/[FeCl{sub 4}]{sup -}. Crystal structures for [Pyrr{sub 14}]{sup +}/[FeCl{sub 4}]{sup -} and [N{sub 1444}]{sup +}/[FeCl{sub 4}]{sup -}more » are compared with the previously reported [N{sub 4444}]{sup +}/[FeBrCl{sub 3}]{sup -}.« less

The Evolution of Toxicology and Chemical Regulation ...

EPA Pesticide Factsheets

Presentation for lecture for the 17th Annual Sitlington Lecture in Toxicology at Oklahoma State University Interdisciplinary Toxicology Symposium Presentation for lecture for the 17th Annual Sitlington Lecture in Toxicology at Oklahoma State University Interdisciplinary Toxicology Symposium

Laurance David Hall.

PubMed

Coxon, Bruce

2011-01-01

An account is given of the life, scientific contributions, and passing of Laurance David Hall (1938-2009), including his early history and education at the University of Bristol, UK, and the synthesis and NMR spectroscopy of carbohydrates and other natural products during ∼20 years of research and teaching at the University of British Columbia in Vancouver, Canada. Lists of graduate students, post-doctoral fellows, and sabbatical visitors are provided for this period. Following a generous endowment by Dr. Herchel Smith, Professor Hall built a new Department of Medicinal Chemistry at Cambridge University, UK, and greatly expanded his researches into the technology and applications of magnetic resonance imaging (MRI) and zero quantum NMR. MRI technology was applied both to medical problems such as the characterization of cartilage degeneration in knee joints, the measurement of ventricular function, lipid localization in animal models of atherosclerosis, paramagnetic metal complexes of polysaccharides as contrast agents, and studies of many other anatomical features, but also to several aspects of materials analysis, including food analyses, process control, and the elucidation of such physical phenomena as the flow of liquids through porous media, defects in concrete, and the visualization of fungal damage to wood. Professor Hall's many publications, patents, lectures, and honors and awards are described, and also his successful effort to keep the Asilomar facility in Pacific Grove, California as the alternating venue for the annual Experimental NMR Conference. Two memorial services for Professor Hall are remembered. Copyright © 2011 Elsevier Inc. All rights reserved.

A Survey of First-Year Biology Student Opinions Regarding Live Lectures and Recorded Lectures as Learning Tools

ERIC Educational Resources Information Center

Simcock, D. C.; Chua, W. H.; Hekman, M.; Levin, M. T.; Brown, S.

2017-01-01

A cohort of first-year biology students was surveyed regarding their opinions and viewing habits for live and recorded lectures. Most respondents (87%) attended live lectures as a rule (attenders), with 66% attending more than two-thirds of the lectures. In contrast, only 52% accessed recordings and only 13% viewed more than two-thirds of the…

Forum: The Lecture and Student Learning. Lecture and Active Learning as a Dialectical Tension

ERIC Educational Resources Information Center

Mallin, Irwin

2017-01-01

Lecture remains a valuable tool in the student learning toolbox--one that at its best helps students unpack what they read for class, place course material in context, and see how a subject matter expert solves problems. It may be useful to think of lecture and active learning as a dialectical tension satisfied by the interactive lecture. Just as…

Playing Games during a Lecture Hour: Experience with an Online Blood Grouping Game

ERIC Educational Resources Information Center

Bhaskar, Anand

2014-01-01

Theory lectures are boring and sleep inducing for students, and it is difficult to get their full attention during 1 h of lecture. The ability of students to concentrate diminishes 20-25 min after the start of the lecture. There is also a lack of active participation of students during theory lectures. In an effort to break the monotony of the…

A comparison of interteaching and lecture in the college classroom.

PubMed

Saville, Bryan K; Zinn, Tracy E; Neef, Nancy A; Van Norman, Renee; Ferreri, Summer J

2006-01-01

Interteaching is a new method of classroom instruction that is based on behavioral principles but offers more flexibility than other behaviorally based methods. We examined the effectiveness of interteaching relative to a traditional form of classroom instruction-the lecture. In Study 1, participants in a graduate course in special education took short quizzes after alternating conditions of interteaching and lecture. Quiz scores following interteaching were higher than quiz scores following lecture, although both methods improved performance relative to pretest measures. In Study 2, we also alternated interteaching and lecture but counterbalanced the conditions across two sections of an undergraduate research methods class. After each unit of information, participants from both sections took the same test. Again, test scores following interteaching were higher than test scores following lecture. In addition, students correctly answered more interteaching-based questions than lecture-based questions on a cumulative final test. In both studies, the majority of students reported a preference for interteaching relative to traditional lecture. In sum, the results suggest that interteaching may be an effective alternative to traditional lecture-based methods of instruction.

Flip or flop? Students' perspectives of a flipped lecture in mathematics

NASA Astrophysics Data System (ADS)

Novak, Julia; Kensington-Miller, Barbara; Evans, Tanya

2017-07-01

This paper describes students' perspectives of a one-off flipped lecture in a large undergraduate mathematics service course. The focus was on calculating matrix determinants and was designed specifically to introduce debate and argumentation into a mathematics lecture. The intention was to promote a deeper learning and understanding through engagement with the added hope of instilling some passion for the subject. During the lecture, students were asked to vote with their feet, literally moving around the lecture theatre to form groups according to their shared favourite technique for calculating matrix determinants. Group discussions were then followed by a whole class debate facilitated by the lecturers, before they wrapped up the lecture by resolving the professional disagreements that had come to light during the debate. Following the lecture, data on student perspectives was gathered using both surveys and focus groups. Within this paper, we share the data and reveal the interesting results that emerged from our analysis. Despite remaining unconvinced as to whether flipped lectures are better for learning, students reported greater engagement and increased understanding of the material covered.

The Impact of Online or F2F Lecture Choice on Student Achievement and Engagement in a Large Lecture-Based Science Course: Closing the Gap

ERIC Educational Resources Information Center

Murphy, Cheryl A.; Stewart, John C.

2015-01-01

Blended learning options vary and universities are exploring an assortment of instructional combinations, some involving video lectures as a replacement for face-to-face (f2f) lectures. This methodological study investigates the impact of the provision of lecture choice (online or f2f) on overall student achievement and course engagement. This…

2012 AGU section and focus group awardees and named lecturers

NASA Astrophysics Data System (ADS)

Williams, Danica

2012-11-01

Each year, more than 20 awards are presented by AGU sections and focus groups to recipients at various stages in their careers. In addition, nearly 25 individuals are selected annually to present lectures under the Bowie Lecture Series and the Section and Focus Group Named Lecture Series. The Bowie Lecture Series was inaugurated in 1989 to commemorate the fiftieth presentation of the William Bowie Medal, which is AGU's highest honor and is named for AGU's first president. Named lectures are designated by sections and focus groups to honor and memorialize distinguished scientists in their respective fields of science.

Manpower planning using Markov Chain model

NASA Astrophysics Data System (ADS)

Saad, Syafawati Ab; Adnan, Farah Adibah; Ibrahim, Haslinda; Rahim, Rahela

2014-07-01

Manpower planning is a planning model which understands the flow of manpower based on the policies changes. For such purpose, numerous attempts have been made by researchers to develop a model to investigate the track of movements of lecturers for various universities. As huge number of lecturers in a university, it is difficult to track the movement of lecturers and also there is no quantitative way used in tracking the movement of lecturers. This research is aimed to determine the appropriate manpower model to understand the flow of lecturers in a university in Malaysia by determine the probability and mean time of lecturers remain in the same status rank. In addition, this research also intended to estimate the number of lecturers in different status rank (lecturer, senior lecturer and associate professor). From the previous studies, there are several methods applied in manpower planning model and appropriate method used in this research is Markov Chain model. Results obtained from this study indicate that the appropriate manpower planning model used is validated by compare to the actual data. The smaller margin of error gives a better result which means that the projection is closer to actual data. These results would give some suggestions for the university to plan the hiring lecturers and budgetary for university in future.

Investigations on the Crystal-Chemical Behavior of Transition-Metal-Bearing Aluminosilicate Garnet Solid Solutions Using 27Al and 29Si NMR Spectroscopy

NASA Astrophysics Data System (ADS)

Palke, A. C.; Geiger, C. A.; Stebbins, J. F.

2015-12-01

The petrological importance of silicate garnet is derived from the presence of three distinct cation sites of varying size and coordination number. This allows for a wide range of trace, minor, and major element substitutions. However, a full and precise crystal-chemical understanding of the nature of transition metals in garnet is not at hand. Possible mechanisms of various charge-balanced substitutions (e.g. octahedral Ti4+ or tetrahedral Al3+) and the structural state of solid solutions (i.e. short- to long-range ordering) need study. We report on ongoing efforts in these directions using 27Al and 29Si Magic-Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) spectroscopy. Early work on synthetic and natural Fe- and Mn-bearing pyrope- and grossular-rich garnets focused on the effect these paramagnetic transition metals have in measuring and interpreting NMR spectra. These results have been expanded with NMR measurements on synthetic pyrope-rich garnets containing other paramagnetic transition metals including Cr3+, V3+, Co2+, and Ni2+ as well as diamagnetic Ti4+. NMR peaks are severely broadened in the presence of even small concentrations of Cr3+, Mn2+, and Fe3+ leading to a loss of spectral resolution. On the other hand, the spectra of garnet containing V3+, Fe2+, Co2+, and Ni2+ have better resolution and show separate paramagnetically shifted NMR peaks. In some cases, crystal-chemical information can be obtained because of the large frequency separations between the NMR peaks that can be assigned to various local atomic configurations around Al and Si. Furthermore, the 27Al NMR spectrum of a synthetic pyrope garnet with about 2% diamagnetic Ti4+ on the octahedral site showed the absence of any tetrahedral Al3+, which rules out the substitution mechanism VITi + IVAl = VIAl + IVSi in the solid solution. Our NMR investigations on garnet are now being made at the exploratory level. We think that NMR spectra of diamagnetic garnet can provide information on a number of crystal-chemical properties. Spectra of garnet containing various paramagnetic transition elements can also, in some cases, give local structural information. With a better understanding of paramagnetic effects in NMR spectroscopy, this type of study can possibly be expanded to other geologically important paramagnetic minerals and phases.

Do not Lose Your Students in Large Lectures: A Five-Step Paper-Based Model to Foster Students’ Participation

PubMed Central

Aburahma, Mona Hassan

2015-01-01

Like most of the pharmacy colleges in developing countries with high population growth, public pharmacy colleges in Egypt are experiencing a significant increase in students’ enrollment annually due to the large youth population, accompanied with the keenness of students to join pharmacy colleges as a step to a better future career. In this context, large lectures represent a popular approach for teaching the students as economic and logistic constraints prevent splitting them into smaller groups. Nevertheless, the impact of large lectures in relation to student learning has been widely questioned due to their educational limitations, which are related to the passive role the students maintain in lectures. Despite the reported feebleness underlying large lectures and lecturing in general, large lectures will likely continue to be taught in the same format in these countries. Accordingly, to soften the negative impacts of large lectures, this article describes a simple and feasible 5-step paper-based model to transform lectures from a passive information delivery space into an active learning environment. This model mainly suits educational establishments with financial constraints, nevertheless, it can be applied in lectures presented in any educational environment to improve active participation of students. The components and the expected advantages of employing the 5-step paper-based model in large lectures as well as its limitations and ways to overcome them are presented briefly. The impact of applying this model on students’ engagement and learning is currently being investigated. PMID:28975906

Metal Ion Interactions with Immunoglobulin G (IgG). 1. Preliminary Studies with Electron Paramagnetic Resonance (EPR) Spectroscopy and Ultrafiltration

DTIC Science & Technology

1978-12-12

EPR and ultrafiltration studies are recommceided to conduct luture metal ion- IgG binding research. Using Scatchard plots, bind.ng levels can be...of the binding sites can be best pursued by EPR and ultrafiltration using the fragments of IgG . This report noted some difference in the binding...immunoelectrophoresis, ultrafiltration, UV spectroscopy, atomic absorption spectroscopy, and electron paramagnetic resonance (EPR). IgG used ,- ,is non

Laser Spectroscopy Investigations of Materials for Solid State Laser Systems.

DTIC Science & Technology

1988-02-01

34 ing tools such as electron paramagnetic resonance and ". oc Be11 uniaxial stress. 19 However, the lattice structure of chryso- .,Pt AI3 PAIR 4 beryl... paramagnetic of these new emission bands is not known at the present time. resonance spectrum. 15The other features of the optical spectra cannot be...solution is peak absorption c-iefficient, and E, is the saturation field. The detuning parameter which accounts for the width of the resonant electronic

A comparison of two forms of teaching instruction: video vs. live lecture for education in clinical periodontology.

PubMed

Ramlogan, S; Raman, V; Sweet, J

2014-02-01

This crossover controlled study aimed to compare the knowledge and skill attained by third-year dental students in three clinical exercises in the discipline of periodontology through video and live lecture instruction. Students (n = 35) segregated into two group either viewed a video or attended a live lecture repeated over three clinical teaching sessions. Pre-test and post-test written assessments were completed and comparisons between video and live lecture done (analysis of variance, P < 0.05). Students were assessed on clinic by a simple checklist. A questionnaire was administered after all three sessions to determine preferences and opinions on video and live lecture. For the combined three sessions, both video (n = 48) and live lecture (n = 47) groups attained similar mean pre-test scores. The mean post-test score was statistically significantly greater (P = 0.049) for the live lecture (74.9%, SD 14.9) compared to the video group (68.6%, SD 16.3). All students attained clinical proficiency via the simple checklist. In adding to their clinical skill, more students favoured video (97%) vs. live lecture (78.8%). Most students (97%) favoured a future combination of video and lecture. While students were deemed clinically competent via a simple checklist, the live lecture group performed better than the video group via the in-depth post-test assessment. Students had a preference for video and would like it integrated in the lecture rather than act as a substitute for the lecture. The use of video alone in clinical periodontology training may have limitations unless supplemented by appropriate learning activities. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Charge ordering transition in GdBaCo2O5: Evidence of reentrant behavior

NASA Astrophysics Data System (ADS)

Allieta, M.; Scavini, M.; Lo Presti, L.; Coduri, M.; Loconte, L.; Cappelli, S.; Oliva, C.; Ghigna, P.; Pattison, P.; Scagnoli, V.

2013-12-01

We present a detailed study on the charge ordering transition in a GdBaCo2O5.0 system by combining high-resolution synchrotron powder/single-crystal diffraction with electron paramagnetic resonance experiments as a function of temperature. We found a second-order structural phase transition at TCO = 247 K (Pmmm to Pmma) associated with the onset of long-range charge ordering. At Tmin ≈ 1.2TCO, the electron paramagnetic resonance linewidth rapidly broadens, providing evidence of antiferromagnetic spin fluctuations. This likely indicates that, analogously to manganites, the long-range antiferromagnetic order in GdBaCo2O5.0 sets in at ≈TCO. Pair distribution function analysis of diffraction data revealed signatures of structural inhomogeneities at low temperature. By comparing the average and local bond valences, we found that above TCO the local structure is consistent with a fully random occupation of Co2+ and Co3+ in a 1:1 ratio and with a complete charge ordering below TCO. Below T ≈ 100 K the charge localization is partially melted at the local scale, suggesting a reentrant behavior of charge ordering. This result is supported by the weakening of superstructure reflections and the temperature evolution of electron paramagnetic resonance linewidth that is consistent with paramagnetic reentrant behavior reported in the GdBaCo2O5.5 parent compound.

Magnetic-field-induced effects in the electronic structure of itinerant d- and f-metal systems

NASA Astrophysics Data System (ADS)

Grechnev, G. E.

2009-08-01

A paramagnetic response of transition metals and itinerant d- and f-metal compounds in an external magnetic field is studied by employing ab initio full-potential LMTO method in the framework of the local spin density approximation. Within this method the anisotropy of the magnetic susceptibility in hexagonal close-packed transition metals is evaluated for the first time. This anisotropy is owing to the orbital Van Vleck-like paramagnetic susceptibility, which is revealed to be substantial in transition-metal systems due to hybridization effects in the electronic structure. It is demonstrated that compounds TiCo, Ni3Al, YCo2, CeCo2, YNi5, LaNi5, and CeNi5 are strong paramagnets close to the quantum critical point. For these systems the Stoner approximation underestimates the spin susceptibility, whereas the calculated field-induced spin moments provide a good description of the large paramagnetic susceptibilities and magnetovolume effects. It is revealed that an itinerant description of hybridized f electrons produces magnetic properties of the compounds CeCo2, CeNi5, UAl3, UGa3, USi3, and UGe3 in close agreement with experiment. In the uranium compounds UX3 the strong spin-orbit coupling together with hybridization effects give rise to peculiar magnetic states in which the field-induced spin moments are antiparallel to the external field, and the magnetic response is dominated by the orbital contribution.

Concentration of point defects in 4H-SiC characterized by a magnetic measurement

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

Peng, B.; Jia, R. X., E-mail: rxjia@mail.xidian.edu.cn; Wang, Y. T.

A magnetic method is presented to characterize the concentration of point defects in silicon carbide. In this method, the concentration of common charged point defects, which is related to the density of paramagnetic centers, is determined by fitting the paramagnetic component of the specimen to the Brillouin function. Several parameters in the Brillouin function can be measured such as: the g-factor can be obtained from electron spin resonance spectroscopy, and the magnetic moment of paramagnetic centers can be obtained from positron lifetime spectroscopy combined with a first-principles calculation. To evaluate the characterization method, silicon carbide specimens with different concentrations ofmore » point defects are prepared with aluminum ion implantation. The fitting results of the densities of paramagnetic centers for the implanted doses of 1 × 10{sup 14} cm{sup −2}, 1 × 10{sup 15} cm{sup −2} and 1 × 10{sup 16} cm{sup −2} are 6.52 × 10{sup 14}/g, 1.14 × 10{sup 15}/g and 9.45 × 10{sup 14}/g, respectively. The same trends are also observed for the S-parameters in the Doppler broadening spectra. It is shown that this method is an accurate and convenient way to obtain the concentration of point defects in 4H-SiC.« less

Detectors (5/5)

ScienceCinema

None

2018-02-01

This lecture will serve as an introduction to particle detectors and detection techniques. In the first lecture, a historic overview of particle detector development will be given. In the second lecture, some basic techniques and concepts for particle detection will be discussed. In the third lecture, the interaction of particles with matter, the basis of particle detection, will be presented. The fourth and fifth lectures will discuss different detector types used for particle tracking, energy measurement and particle identification.

Detectors (4/5)

ScienceCinema

None

2018-05-14

This lecture will serve as an introduction to particle detectors and detection techniques. In the first lecture, a historic overview of particle detector development will be given. In the second lecture, some basic techniques and concepts for particle detection will be discussed. In the third lecture, the interaction of particles with matter, the basis of particle detection, will be presented. The fourth and fifth lectures will discuss different detector types used for particle tracking, energy measurement and particle identification.

Stylistic Variations in Science Lectures: Teaching Vocabulary.

ERIC Educational Resources Information Center

Jackson, Jane; Bilton, Linda

1994-01-01

Twenty lectures by native speaker geology lecturers to nonnative speaker students were transcribed, and 921 instances of vocabulary elaboration were coded into a computer database according to 20 linguistic features. Analysis revealed noticeable variation among lecturers in language range/technicality, vocabulary elaboration, signalling, and use…

Comparing Students' and Experts' Understanding of the Content of a Lecture

NASA Astrophysics Data System (ADS)

Hrepic, Zdeslav; Zollman, Dean A.; Sanjay Rebello, N.

2007-06-01

In spite of advances in physics pedagogy, the lecture is by far the most widely used format of instruction. We investigated students' understanding and perceptions of the content delivered during a physics lecture. A group of experts (physics instructors) also participated in the study as a reference for the comparison. During the study, all participants responded to a written conceptual survey on sound propagation. Next, they looked for answers to the survey questions in a videotaped lecture by a nationally known teacher. As they viewed the lecture, they indicated instances, if any, in which the survey questions were answered during the lecture. They also wrote down (and if needed, later explained) the answer, which they perceived was given by the instructor in the video lecture. Students who participated in the study were enrolled in a conceptual physics course and had already covered the topic in class before the study. We discuss and compare students' and experts' responses to the survey questions before and after the lecture.

Course 8: Biological Physics in Silico

NASA Astrophysics Data System (ADS)

Austin, R. H.

1 Why micro/nanofabrication? Lecture 1a: Hydrodynamic Transport 1 Introduction: The need to control flows in 2 1/2 D 2 Somewhat simple hydrodynamics in 2 1/2 D 3 The N-port injector idea 4 Conclusion Lecture 1b: Dielectrophoresis and Microfabrication 1 Introduction 2 Methods 3 Results 4 Data and analysis 5 Origin of the low frequency dielectrophoretic force in DNA 6 Conclusion Lecture 2a: Hex Arrays 1 Introduction 2 Experimental approach 3 Conclusions Lecture 2b: The DNA Prism 1 Introduction 2 Design 3 Results 4 Conclusions Lecture 2c: Bigger is Better in Rachets 1 The problems with insulators in rachets 2 An experimental test 3 Conclusions Lecture 3: Going After Epigenetics 1 Introduction 2 The nearfield scanner 3 The chip 4 Experiments with molecules 5 Conclusions Lecture 4: Fractionating Cells 1 Introduction 2 Blood specifics 3 Magnetic separation 4 Microfabrication 5 Magnetic field gradients 6 Device interface 7 A preliminary blood cell run 8 Conclusions Lecture 5: Protein Folding on a Chip 1 Introduction 2 Technology 3 Experiments 4 Conclusions

Use of questioning during lectures in a dental hygiene didactic course.

PubMed

Hessheimer, Heather M; Rogo, Ellen J; Howlett, Bernadette

2011-08-01

The purposes of this quasi-experimental, one-group crossover study were to determine the effect of questioning during dental hygiene lectures on low-level and high-level learning and to evaluate student perceptions of questioning. Twenty-three dental hygiene students participated in two control lectures using traditional lecturing methods. The students served as their own controls by next participating in two experimental lectures with questions asked throughout the lecture at both low and high cognitive levels. Student performance was measured with an examination containing low- and high-level questions. The interaction between the group and the level of questions was analyzed using ANOVA, and no statistically significant difference was found. Based on a Likert scale (1 to 6), average ratings for student perceptions were as follows: enjoyment of use, 4.5; understanding the lecture material, 4.74; and questioning effectiveness, 4.35. Student perceptions of questioning were positive; however, this strategy was found to be no more effective than the traditional lecture in promoting retention of information.

An Audience Response System Strategy to Improve Student Motivation, Attention, and Feedback

PubMed Central

Black, Esther P.; Rohr, Jürgen

2009-01-01

Objective To implement an audience response system (ARS) to improve student motivation and attention during lectures and provide immediate feedback to the instructor concerning student understanding of lecture content in a Physiological Chemistry/Molecular Biology course. Design Students used ARS devices to respond to strategically placed questions throughout physiological chemistry/molecular biology lectures. The instructor inserted 6 to 7 questions that promoted student/class interactivity into each of several 50-minute lectures to focus students' attention and provide feedback on students' comprehension of material. Assessment Ninety-eight percent of first-year pharmacy (P1) students (n = 109) reported that strategically placed ARS questions throughout lectures helped them maintain attention. Reports from an independent focus group indicated that students favored this strategy. Furthermore, ARS feedback helped the instructor gauge student comprehension and adjust lectures accordingly. Conclusions Focused, strategically placed ARS questions throughout lectures may help students maintain attention and stay motivated to learn. Feedback from these questions also allows instructors to adapt lectures to address areas of deficiency. PMID:19513159

An audience response system strategy to improve student motivation, attention, and feedback.

PubMed

Cain, Jeff; Black, Esther P; Rohr, Jürgen

2009-04-07

To implement an audience response system (ARS) to improve student motivation and attention during lectures and provide immediate feedback to the instructor concerning student understanding of lecture content in a Physiological Chemistry/Molecular Biology course. Students used ARS devices to respond to strategically placed questions throughout physiological chemistry/molecular biology lectures. The instructor inserted 6 to 7 questions that promoted student/class interactivity into each of several 50-minute lectures to focus students' attention and provide feedback on students' comprehension of material. Ninety-eight percent of first-year pharmacy (P1) students (n = 109) reported that strategically placed ARS questions throughout lectures helped them maintain attention. Reports from an independent focus group indicated that students favored this strategy. Furthermore, ARS feedback helped the instructor gauge student comprehension and adjust lectures accordingly. Focused, strategically placed ARS questions throughout lectures may help students maintain attention and stay motivated to learn. Feedback from these questions also allows instructors to adapt lectures to address areas of deficiency.

Resident training for eclampsia and magnesium toxicity management: simulation or traditional lecture?

PubMed

Fisher, Nelli; Bernstein, Peter S; Satin, Andrew; Pardanani, Setul; Heo, Hye; Merkatz, Irwin R; Goffman, Dena

2010-10-01

To compare eclampsia and magnesium toxicity management among residents randomly assigned to lecture or simulation-based education. Statified by year, residents (n = 38) were randomly assigned to 3 educational intervention groups: Simulation→Lecture, Simulation, and Lecture. Postintervention simulations were performed for all and scored using standardized lists. Maternal, fetal, eclampsia management, and magnesium toxcity scores were assigned. Mann-Whitney U, Wilcoxon rank sum and χ(2) tests were used for analysis. Postintervention maternal (16 and 15 vs 12; P < .05) and eclampsia (19 vs 16; P < .05) scores were significantly better in simulation based compared with lecture groups. Postintervention magnesium toxcitiy and fetal scores were not different among groups. Lecture added to simulation did not lead to incremental benefit when eclampsia scores were compared between Simulation→Lecture and Simulation (19 vs 19; P = nonsignificant). Simulation training is superior to traditional lecture alone for teaching crucial skills for the optimal management of both eclampsia and magnesium toxicity, 2 life-threatening obstetric emergencies. Published by Mosby, Inc.

A comparison of two differential methods for nutrition education in elementary school: lecture-and experience-based learning program.

PubMed

Jung, Lan-Hee; Choi, Jeong-Hwa; Bang, Hyun-Mi; Shin, Jun-Ho; Heo, Young-Ran

2015-02-01

This research was conducted to compare lecture-and experience-based methods of nutritional education as well as provide fundamental data for developing an effective nutritional education program in elementary schools. A total of 110 students in three elementary schools in Jeollanam-do were recruited and randomly distributed in lecture-and experience-based groups. The effects of education on students' dietary knowledge, dietary behaviors, and dietary habits were analyzed using a pre/post-test. Lecture-and experience-based methods did not significantly alter total scores for dietary knowledge in any group, although lecture-based method led to improvement for some detailed questions. In the experience-based group, subjects showed significant alteration of dietary behaviors, whereas lecture-based method showed alteration of dietary habits. These outcomes suggest that lecture-and experience-based methods led to differential improvement of students' dietary habits, behaviors, and knowledge. To obtain better nutritional education results, both lectures and experiential activities need to be considered.

Assessment outcome is weakly correlated with lecture attendance: influence of learning style and use of alternative materials.

PubMed

Horton, Dane M; Wiederman, Steven D; Saint, David A

2012-06-01

The relation between lecture attendance and learning is surprisingly weak, and the role of learning styles in this is poorly understood. We hypothesized that 1) academic performance is related to lecture attendance and 2) learning style influences lecture attendance and, consequently, affects performance. We also speculated that the availability of alternative resources would affect this relationship. Second-year Bachelor of Science physiology students (n = 120) self-reported their lecture attendance in a block of 21 lectures (attendance not compulsory) and use of alternative resources. Overall self-reported lecture attendance was 73 ± 2%. Female students (n = 71) attended more lectures (16.4 ± 0.6) than male students (14.3 ± 0.08, n = 49) and achieved a higher composite mark in all assessments (73.6% vs. 69.3%, P < 0.02). Marks in the final exam were not statistically different between the sexes and correlated only weakly with lecture attendance (r = 0.29, n = 49, P < 0.04 for male students; r = 0.10, n = 71, P = not significant for female students; and r =0.21, n = 120, P < 0.02 for the whole class). Of the students who passed the exam, poor attenders (<11 lectures) reported significantly more use of lecture recordings (37 ± 8%, n = 15, vs. 10 ± 1%, n = 85, P < 0.001). In a VARK learning style assessment (where V is visual, A is auditory, R is reading/writing, and K is kinesthetic), students were multimodal, although female students had a slightly higher average percentage of the R learning style (preferred read/write) compared with male students (28.9 ± 0.9%, n = 63, vs. 25.3 ± 1.3%, n = 32, P < 0.03). Lecture attendance was not correlated with measured learning style. We concluded that lecture attendance is only weakly correlated with academic performance and is not related to learning style. The substitution of alternative materials for lecture attendance appears to have a greater role than learning style in determining academic outcomes.

Students' understanding and perceptions of the content of a lecture

NASA Astrophysics Data System (ADS)

Hrepic, Zdeslav; Zollman, Dean; Rebello, Sanjay

2004-09-01

In spite of advances in physics pedagogy, the lecture is by far the most widely used instructional format. We investigated students' understanding and perceptions of the content delivered during a physics lecture. Students participating in our study responded to a written conceptual survey on sound propagation. Next, they looked for answers to the survey questions in a videotaped lecture by a nationally known teacher. As they viewed the lecture, they indicated instances, if any, in which the survey questions were answered during the lecture. A group of experts (physics instructors) also participated in our study. We discuss students' and experts' responses to the survey questions.

Medical student evaluations of lectures attended in person or from rural sites via interactive videoconferencing.

PubMed

Callas, Peter W; Bertsch, Tania F; Caputo, Michael P; Flynn, Brian S; Doheny-Farina, Stephen; Ricci, Michael A

2004-01-01

Interactive videoconferencing may be an effective way for medical students on remote rotations to attend teaching sessions at the main campus. To compare medical student evaluations of lectures for those attending in person and those attending through interactive videoconferencing. Lecture evaluations were completed by medical students on University of Vermont College of Medicine clinical clerkship rotations. Students on clerkships at rural sites attended lectures using our telemedicine network. Responses from in-person and remote attendees were compared. Evaluation forms for 110 lectures were received from 648 in-person and 255 remote attendees. All evaluation items were rated "good" or "excellent" by at least 95% of in-person attendees. Over 90% of remote attendees rated nontelemedicine evaluation items, such as appropriateness of lecture topic for students, as good or excellent. Ratings of telemedicine-specific questions, such as ability to hear the lecturer, were lower. Level of satisfaction was high for most aspects of remote lecture attendance, although not quite as high as for in-person attendance. Improved technical reliability would likely increase remote attendee satisfaction. Overall, lecture attendance using videoconferencing was found to be an acceptable alternative to travel for medical students in rural clerkships.

Should Undergraduate Lectures be Compulsory? The Views of Dental and Medical Students from a UK University

PubMed Central

Daud, Alaa; Bagria, Aaron; Shah, Kushal; Puryer, James

2017-01-01

Formal lectures have been a traditional part of medical and dental education, but there is debate as to their compulsory status. This study was designed to explore dental and medical students’ views on compulsory lectures and the use of Video-Recorded Lectures (VRL). A cross-sectional study of University of Bristol students in Years 2 to 4 was conducted using an online questionnaire. The majority of both dental (76%) and medical (66%) students felt lectures should be non-compulsory. The most common learning resources used by both dental and medical students were live lectures, lecture handouts and VRL. The majority of both dental (84%) and medical (88%) students used VRL. Most students attended lectures all of the time both before and after the introduction of VRL, even though most dental and medical students believe lectures should be non-compulsory. VRL is a popular learning resource. These findings tie-in with General Dental Council and General Medical Council recommendations that encourage self-directed learning. Dental and Medical schools should offer a range of learning resources and make use of current technology, including the use of VRL. PMID:29563421

More Ammunition for the Note-Taking Feud: The "Spaced Lecture."

ERIC Educational Resources Information Center

Bentley, Donna Anderson

1981-01-01

An experiment is discussed that tested a 1975 hypothesis of Aiken, Thomas, and Shennum that a "spaced lecture" might help solve the problem of the negative of concurrently listening and writing. Results indicated that the "spaced lecture" was no better than the traditional lecture. (MLW)

The "Work" of Lecturing in High School Chemistry

ERIC Educational Resources Information Center

Hwang, SungWon; Roth, Wolff-Michael

2013-01-01

Lecturing is an important aspect of the culture of science education. Perhaps because of the negative associations constructivist educators make with lecturing, little research has been done concerning the generally invisible aspects of the (embodied, lived) "work" that is required. Traditional research on science lectures focuses on…

The Lecture

ERIC Educational Resources Information Center

Chaudhury, S. Raj

2011-01-01

Academic lectures for the purpose of instruction maintain an important presence in most colleges and universities worldwide. This chapter examines the current state of the lecture and how learning sciences research can inform the most effective use of this method. The author presents evidence that the lecture can be an effective element of…

Debate preparation/participation: an active, effective learning tool.

PubMed

Koklanaris, Nikki; MacKenzie, Andrew P; Fino, M Elizabeth; Arslan, Alan A; Seubert, David E

2008-01-01

Passive educational techniques (such as lectures) are thought to be less productive than active learning. We examined whether preparing for and participating in a debate would be an effective, active way to learn about a controversial topic. We compared quiz performance in residents who attended a lecture to residents who prepared for/participated in a debate. Twelve residents each participated in one lecture session and one debate session. Learning was evaluated via a quiz. Quizzes were given twice: before the debate/lecture and 1 week after the debate/lecture. Quiz scores were compared using repeated measures analysis of variance, with a p value of < .05 considered significant. A survey evaluating the usefulness of debating was given to all participants. There was a statistically significant difference in the pretest mean quiz score between the debate and lecture groups: 78.3% and 52.5%, respectively (p = .02). Similarly, on posttest quizzes, the average debater scored 85.8%, versus 61.7% for the lecture group (p = .003). Although no one in the debate group scored lower on a follow-up quiz, 3 residents in the lecture group did worse on follow-up. When learning about a controversial topic, residents who prepared for/participated in a debate achieved higher quiz scores and were better at retaining information than those who attended a lecture. When faced with teaching a controversial topic, organizing a debate may be more effective than giving a lecture.

The work of lecturing in high school chemistry

NASA Astrophysics Data System (ADS)

Hwang, SungWon; Roth, Wolff-Michael

2013-09-01

Lecturing is an important aspect of the culture of science education. Perhaps because of the negative associations constructivist educators make with lecturing, little research has been done concerning the generally invisible aspects of the (embodied, lived) work that is required. Traditional research on science lectures focuses on ideas and (mental) concepts that somehow are "gotten across"; and it is interested in identifying verbal content and visual representations science teachers provide. The purpose of this study is to explicitly describe and theorize the living work of lecturing that produces in a societal arena everything from which students can learn. We use two case studies from the chemistry lectures in a tenth-grade Singapore classroom to exemplify the central role of the performative aspects of lecturing. We articulate and exemplify assertions that (a) corporeal performances differentiate and coordinate the contents of lecturing with its pitch, rhythm, and speech volume, and thereby orient students to specific discourse features of chemistry; and (b) corporeal performances differentiate and coordinate layers of talk with prosody, gestures, and body orientation, and thereby make analogies available to students. We conclude that what is visible in lectures (e.g., scientific discourse, analogies) is always the outcome of the (generally unattended to) corporeal labor including gestures, body orientation, and prosodic features (e.g., shifts in pitch) and that this outcome | labor pair constitutes an appropriate unit of understanding lecturing as societal phenomenon.

Lecturing skills as predictors of tutoring skills in a problem-based medical curriculum.

PubMed

Kassab, Salah Eldin; Hassan, Nahla; Abu-Hijleh, Marwan F; Sequeira, Reginald P

2016-01-01

Recruitment of tutors to work in problem-based learning (PBL) programs is challenging, especially in that most of them are graduated from discipline-based programs. Therefore, this study aims at examining whether lecturing skills of faculty could predict their PBL tutoring skills. This study included evaluation of faculty (n=69) who participated in both tutoring and lecturing within particular PBL units at the College of Medicine and Medical Sciences (CMMS), Arabian Gulf University, Bahrain. Each faculty was evaluated by medical students (n=45±8 for lecturing and 8±2 for PBL tutoring) using structured evaluation forms based on a Likert-type scale (poor to excellent). The prediction of tutoring skills using lecturing skills was statistically analyzed using stepwise linear regression. Among the parameters used to judge lecturing skills, the most important predictor for tutoring skills was subject matter mastery in the lecture by explaining difficult concepts and responding effectively to students' questions. Subject matter mastery in the lecture positively predicted five tutoring skills and accounted for 25% of the variance in overall effectiveness of the PBL tutors (F=22.39, P=0.000). Other important predictors for tutoring skills were providing a relaxed class atmosphere and effective use of audiovisual aids in the lecture. Predicting the tutoring skills based on lecturing skills could have implications for recruiting tutors in PBL medical programs and for tutor training initiatives.

Use of lecture recordings in dental education: assessment of status quo and recommendations.

PubMed

Horvath, Zsuzsa; O'Donnell, Jean A; Johnson, Lynn A; Karimbux, Nadeem Y; Shuler, Charles F; Spallek, Heiko

2013-11-01

This research project was part of a planned initiative at the University of Pittsburgh School of Dental Medicine to incorporate lecture recordings as standard educational support technologies. The goal of an institutional survey was 1) to gather current data about how dental educators across the United States and Canada use lecture recordings; 2) determine dental educators' perceived value and outcomes of using lecture recordings; and 3) develop recommendations based on #1 and #2 for the dental education community. Of the sixty-six North American dental schools at the time of the study, forty-five schools responded to the survey, for a 68 percent response rate. Of the respondents, twenty-eight schools were found to currently conduct lecture recording; these comprised the study sample. This study focused on the dental schools' past experiences with lecture recording; thus, those not currently engaged in lecture recording were excluded from further analysis. The survey questions covered a wide range of topics, such as the scope of the lecture recording, logistics, instructional design considerations, outcomes related to student learning, evaluation and reception, barriers to lecture recording, and issues related to copyright and intellectual property. The literature review and results from the survey showed that no common guidelines for best practice were available regarding lecture recordings in dental education. The article concludes with some preliminary recommendations based on this study.

Emergent Interfacial Ferromagnetism in CaMnO3-based Superlattices

NASA Astrophysics Data System (ADS)

Grutter, Alexander

2014-03-01

Interfaces of complex oxide materials provide a rich playground not only for the exploration of properties not found in the bulk constituents but also for the development of functional interfaces to be incorporated in spintronic applications. Emergent interfacial magnetic phenomena have been of great interest but surprisingly there have been few examples of emergent interfacial ferromagnetism. In this talk, I will describe our recent work on the stabilization of ferromagnetism in CaMnO3-based superlattices. We have demonstrated ferromagnetism at the interface between the antiferromagnetic insulator CaMnO3 and a paramagnetic metallic layer, including CaRuO3 and LaNiO3. Theoretically the ferromagnetism has been attributed to an interfacial double exchange interaction among the interfacial Mn ions that is mediated by itinerant electrons from the paramagnetic metallic layer. Through polarized neutron reflectivity and observation of exchange bias, we have demonstrated that the ferromagnetism comes from Mn ions in a single unit cell at the interfaces just as theory has predicted. We have also demonstrated that the metallicity of the paramagnetic layer is critical in stabilizing ferromagnetism at the interface and that the interfacial ferromagnetism can be suppressed by suppressing the metallicity of the paramagnetic layer. Despite the agreement with theory, there remain open questions as to the magnetic interactions among the interfacial ferromagnetic layers. For example, the saturated magnetic moment modulates as a function of the thickness of both the CaMnO3 and paramagnetic metal layers. The origins of this oscillation are not well understood and may stem from either structural effects or long-range oscillatory magnetic coupling interactions reminiscent of RKKY interactions. Evidence of the doubling of the unit cell and long range antiferromagnetic correlations support these speculations. This work was supported by the U.S. Department of Energy, Office of Science, Division of Materials Sciences and Engineering, under Contract # DE-AC05-76RL01830 and DE-SC0008505.

Application of electron paramagnetic resonance imaging to the characterization of the Ultem(R) exposed to 1 MeV electrons. Correlation of radical density data to tiger code calculations

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

Suleman, N.K.

1994-12-01

A major long-term goal of the Materials Division at the NASA Langley Research Center is the characterization of new high-performance materials that have potential applications in the aircraft industry, and in space. The materials used for space applications are often subjected to a harsh and potentially damaging radiation environment. The present study constitutes the application of a novel technique to obtain reliable data for ascertaining the molecular basis for the resilience and durability of materials that have been exposed to simulated space radiations. The radiations of greatest concern are energetic electrons and protons, as well as galactic cosmic rays. Presently,more » the effects of such radiation on matter are not understood in their entirety. It is clear however, that electron radiation causes ionization and homolytic bond rupture, resulting in the formation of paramagnetic spin centers in the polymer matrices of the structural materials. Since the detection and structure elucidation of paramagnetic species are most readily accomplished using Electron Paramagnetic Resonance (EPR) Spectroscopy, the NASA LaRC EPR system was brought back on-line during the 1991 ASEE term. The subsequent 1992 ASEE term was devoted to the adaptation of the EPR core system to meet the requirements for EPR Imaging (EPRI), which provides detailed information on the spatial distribution of paramagnetic species in bulk media. The present (1994) ASEE term was devoted to the calibration of this EPR Imaging system, as well as to the application of this technology to study the effects of electron irradiation on Ultem(exp R), a high performance polymer which is a candidate for applications in aerospace. The Ultem was exposed to a dose of 2.4 x 10(exp 9) Rads (1-MeV energy/electron) at the LaRC electron accelerator facility. Subsequently, the exposed specimens were stored in liquid nitrogen, until immediately prior to analyses by EPRI.« less

Evaluation of a web-based asynchronous pediatric emergency medicine learning tool for residents and medical students.

PubMed

Burnette, Kreg; Ramundo, Maria; Stevenson, Michelle; Beeson, Michael S

2009-12-01

To examine the effectiveness of an asynchronous learning tool consisting of web-based lectures for trainees covering major topics pertinent to pediatric emergency medicine (PEM) and to assess resident and student evaluation of this mode of education. PEM faculty and fellows created a 21-lecture, web-based curriculum. These 20-minute online lectures used Microsoft PowerPoint with the voice-over feature. A 75-question test was created to assess the effectiveness of the web-based learning model, administered online before and after the rotation in the pediatric emergency department (PED). All fourth-year medical students and residents (across all specialties) rotating through the PED were required to complete 10 of the 21 lectures during their 1-month rotation. The main outcome variable was difference in score between pre- and post-rotation tests of participants who viewed no lectures and those who viewed at least one lecture. Evaluation of the program was assessed by anonymous survey using 5-point discrete visual analog scales. Responses of 4 or 5 were considered positive for analysis. One hundred eleven residents and fourth-year medical students participated in the program. An initial 32 completed testing before implementation of the on-line lectures (March 2007-August 2007), and another five did not complete the on-line lectures after implementation (September 2007-February 2008). Seventy-one completed testing and on-line lectures, and all but three completed at least 10 on-line lectures during their rotation. Fourteen of 111 trainees did not complete the pre- or post-test (including two who viewed the lectures). The mean change in score was a 1% improvement from pre-test to post-test for trainees who viewed no lectures and a 6.2% improvement for those who viewed the lectures (mean difference = 5.2%, 95% confidence interval = 2.5% to 7.9%). In the linear regression model, the estimate of the coefficient was 0.43 (p < 0.001), meaning that, for each lecture viewed, post-test score rose by 0.43%. Sixty-nine of 75 test items (92%) had a point biserial correlation greater than 0.15. Thirty of the 72 trainees who completed the online lectures and testing (42%) returned surveys. All were comfortable using the Internet, and 87% (26/30) found the web-site easy to use. All felt that their educational goals were met, and 100% felt that the format would be useful in other areas of education. Although not a replacement for traditional bedside teaching, the use of web-based lectures as an asynchronous learning tool has a positive effect on medical knowledge test scores. Trainees were able to view online lectures on their own schedules, in the location of their choice. This is helpful in a field with shift work, in which trainees rarely work together, making it difficult to synchronously provide lectures to all trainees. (c) 2009 by the Society for Academic Emergency Medicine.

A comparative study of traditional lecture methods and interactive lecture methods in introductory geology courses for non-science majors at the college level

NASA Astrophysics Data System (ADS)

Hundley, Stacey A.

In recent years there has been a national call for reform in undergraduate science education. The goal of this reform movement in science education is to develop ways to improve undergraduate student learning with an emphasis on developing more effective teaching practices. Introductory science courses at the college level are generally taught using a traditional lecture format. Recent studies have shown incorporating active learning strategies within the traditional lecture classroom has positive effects on student outcomes. This study focuses on incorporating interactive teaching methods into the traditional lecture classroom to enhance student learning for non-science majors enrolled in introductory geology courses at a private university. Students' experience and instructional preferences regarding introductory geology courses were identified from survey data analysis. The information gained from responses to the questionnaire was utilized to develop an interactive lecture introductory geology course for non-science majors. Student outcomes were examined in introductory geology courses based on two teaching methods: interactive lecture and traditional lecture. There were no significant statistical differences between the groups based on the student outcomes and teaching methods. Incorporating interactive lecture methods did not statistically improve student outcomes when compared to traditional lecture teaching methods. However, the responses to the survey revealed students have a preference for introductory geology courses taught with lecture and instructor-led discussions and students prefer to work independently or in small groups. The results of this study are useful to individuals who teach introductory geology courses and individuals who teach introductory science courses for non-science majors at the college level.

Web-streamed didactic instruction on substance use disorders compares favorably with live-lecture format.

PubMed

Karam-Hage, M; Maher, Karam-Hage; Brower, Kirk J; Mullan, Patricia B; Gay, Tamara; Gruppen, Larry D

2013-05-01

Education about substance use disorders in medical schools and, subsequently, physicians' identification of and intervention in these diagnoses lag behind that of most other disabling disorders. To reduce barriers and improve access to education about this major public health concern, medical schools are increasingly adopting web-based instruction on substance use and other psychiatric disorders as part of their curricula; however, it is not well known how a web-streamed lecture compares with a traditional one. The authors hypothesized that both these formats would be equally efficacious in terms of knowledge acquisition and student satisfaction. Authors conducted a prospective study to test this hypothesis among third-year medical students who received web-streamed lecture on substance use/addiction versus those who received a traditional live lecture. Of the 243 students, significantly more students completed the on-line lecture series. Of the 216 students in the final study sample, 130 (60%) were assigned to the web-streamed lecture and 86 (40%) to the live lecture. Within-subject comparisons of pre- and post-lecture scores for the entire cohort indicated a significant improvement in the percentage of correct answers (21.0% difference). Although no differences in improved scores between the two groups were found, students in the live-lecture group reported small, but significantly higher levels of satisfaction. This preliminary work supports the hypothesis that a web-streamed lecture can be at least equally efficacious as a traditional lecture in terms of knowledge acquisition. However, attention needs to be paid to the lower satisfaction levels associated with using the web-streamed format.

How We Think and Learn. Lecture Series.

ERIC Educational Resources Information Center

National Learning Center, Washington, DC.

A lecture series was conducted in 1989 to present information on learning theories by learning theorists. This document contains short texts of the lectures; full texts are available on request. In lecture 1, Robert Chase discusses educational reform and Bonnie Guiton examines educational goals from the perspective of White House policy. In…

Lecturers' Experience of Using Social Media in Higher Education Courses

ERIC Educational Resources Information Center

Seechaliao, Thapanee

2015-01-01

This research paper presents lecturers' experience of using social media in higher education courses. The research methodology used a survey approach. The research instrument was a questionnaire about lecturers' experience of using social media in higher education courses. Thirty-one lecturers completed the questionnaire. The data were scored by…

Clickers and Formative Feedback at University Lectures

ERIC Educational Resources Information Center

Egelandsdal, Kjetil; Krumsvik, Rune Johan

2017-01-01

Lecturing is often criticized for being a monological and student passive way of teaching. However, digital technology such as Student Response Systems (SRS) can be used to reconstruct the traditional lecturing format. During a series of five two-hour lectures in "qualitative methods" for first year psychology students, we used SRS to…

The Effect of Instant Messaging on Lecture Retention

ERIC Educational Resources Information Center

McVaugh, Nathan Kant

2012-01-01

The impact of instant message interruptions via computer on immediate lecture retention for college students was examined. While watching a 24-minute video of a classroom lecture, students received various numbers of related-to-lecture ("Is consistent use of the eye contact method necessary for success?") versus not-related-to lecture…

Student Preferences for Online Lecture Formats: Does Prior Experience Matter?

ERIC Educational Resources Information Center

Drouin, Michelle; Hile, Rachel E.; Vartanian, Lesa R.; Webb, Janae

2013-01-01

We examined undergraduate students' quality ratings of and preferences for different types of online lecture formats. Students preferred richer online lecture formats that included both audio and visual components; however, there were no significant differences between students' ratings of PowerPoint lectures with "audio" of the…

In Defence of the Lecture

ERIC Educational Resources Information Center

Webster, R. Scott

2015-01-01

In response to the lecture format coming under "attack" and being replaced by online materials and smaller tutorials, this paper attempts to offer not only a defence but also to assert that the potential value of the lecture is difficult to replicate through other learning formats. Some of the criticisms against lectures will be…

Perceptions of Presentation Capture in Counselor Education

ERIC Educational Resources Information Center

Gibson, Robert; Miller, Ann

2011-01-01

Lecture/presentation capture is a gradually emerging technology at many colleges and universities and will likely increase in use because students prefer courses that offer online lectures over traditional classes that do not. Many capture products also allow faculty to segment and edit lectures, add/exchange notations, view lectures on mobile…

Lecture on Female Masturbation Harassed Him, Male Student Says.

ERIC Educational Resources Information Center

Wilson, Robin

1995-01-01

A male student in a California State University-Sacramento psychology lecture on female masturbation has filed a sexual harassment complaint, claiming the lecture violated institutional policy by creating an intimidating, hostile, and offensive learning environment. He felt the lecture was inappropriately graphic and political in intent. (MSE)

Do-It-Yourself Whiteboard-Style Physics Video Lectures

ERIC Educational Resources Information Center

Douglas, Scott Samuel; Aiken, John Mark; Greco, Edwin; Schatz, Michael; Lin, Shih-Yin

2017-01-01

Video lectures are increasingly being used in physics instruction. For example, video lectures can be used to "flip" the classroom, i.e., to deliver, via the Internet, content that is traditionally transmitted by in-class lectures (e.g., presenting concepts, working examples, etc.), thereby freeing up classroom time for more interactive…

Forum: The Lecture and Student Learning. The Lecture's Absent Audience

ERIC Educational Resources Information Center

Sciullo, Nick J.

2017-01-01

According to the "Oxford English Dictionary" ("OED"), the noun "lecture" dates from the 14th century and means the "action of reading, perusal. Also, that which is read or perused." This definition, while accurate and resonates today in many college classrooms, ignores a key feature of any lecture. The…

45 CFR 73.735-706 - Teaching, lecturing, and speechmaking.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Teaching, lecturing, and speechmaking. 73.735-706... OF CONDUCT Outside Activities § 73.735-706 Teaching, lecturing, and speechmaking. (a) Employees are encouraged to engage in teaching and lecturing activities which are not part of their official duties when...

Spectroscopic and quantum chemical study of the structure of a new paramagnetic dimeric palladium(II,III) complex with creatine

NASA Astrophysics Data System (ADS)

Mitewa, Mariana; Enchev, Venelin; Bakalova, Tatyana

2002-05-01

The structure and coordination mode of the newly synthesized dimeric paramagnetic Pd(II,III) complex are studied using magneto-chemical, EPR and IR spectroscopic methods. In order to perform reliable assignment of the IR bands, the structure and IR spectrum of the free creatine were calculated using ab initio method. For calculation of the configuration of its deprotonated and doubly deprotonated forms the semiempirical AM1 method was used.

Process and apparatus for preparing textured crystalline materials using anisotropy in the paramagnetic susceptibility

DOEpatents

Holloway, Aleksey

1992-01-07

The present invention discloses a process and apparatus for forming textures in materials. The process comprises heating a material having an anisotropy in the paramagnetic or diamagnetic susceptibility within a magnetic field. The material is heated to a temperature approaching its melting point while a magnetic field of at least 10.sup.4 Oe is simultaneously applied. The process and apparatus produce highly textured bulk and elongated materials with high current densities below critical superconducting temperatures.

Process and apparatus for preparing textured crystalline materials using anisotropy in the paramagnetic susceptibility

DOEpatents

Holloway, A.

1992-01-07

The present invention discloses a process and apparatus for forming textures in materials. The process comprises heating a material having an anisotropy in the paramagnetic or diamagnetic susceptibility within a magnetic field. The material is heated to a temperature approaching its melting point while a magnetic field of at least 10[sup 4]Oe is simultaneously applied. The process and apparatus produce highly textured bulk and elongated materials with high current densities below critical superconducting temperatures. 6 figs.

The role of spinning electrons in paramagnetic phenomena

NASA Technical Reports Server (NTRS)

Bose, D. M.

1986-01-01

An attempt is made to explain paramagnetic phenomena without assuming the orientation of a molecule or ion in a magnetic field. Only the spin angular momentum is assumed to be responsible. A derivative of the Gurie-Langevin law and the magnetic moments of ions are given as a function of the number of electrons in an inner, incomplete shell. An explanation of Gerlach's experiments with iron and nickel vapors is attempted. An explanation of magnetomechanical experiments with ferromagne elements is given.

In Vivo Imaging of Tissue Physiological Function using EPR Spectroscopy | NCI Technology Transfer Center | TTC

Cancer.gov

Electron paramagnetic resonance (EPR) is a technique for studying chemical species that have one or more unpaired electrons.  The current invention describes Echo-based Single Point Imaging (ESPI), a novel EPR image formation strategy that allows in vivo imaging of physiological function.  The National Cancer Institute's Radiation Biology Branch is seeking statements of capability or interest from parties interested in in-licensing an in vivo imaging using Electron paramagnetic resonance (EPR) to measure active oxygen species.

[Dr. Michiharu Matsuoka, founder of the Department of Orthopaedic Surgery, Kyoto University, and his achievements. Part 4: Prof. M. Matsuoka's lecture to medical and civic communities].

PubMed

Hirotani, Hayato

2010-03-01

Dr. M. Matsuoka gave many lectures to physicians at the Postdoctoral Course Lectures sponsored by the Kyoto Eisei Kensasho (Kyoto Bacterial and Biochemical Laboratory) run by the Kyoto Medical Association, and the Postdoctoral Course Lectures of the Kyoto Medical School, Kyoto Imperial University. He was also invited to give lectures at several regional medical associations. He also was a speaker at the Kyoto Imperial University Extension course and he lectured at the Enryakuji Temple on Mt. Hiei, sponsored by a newspaper company. It is remarkable that these activities were carried out in addition to his other notable academic work previously reported.

Application of DEN refinement and automated model building to a difficult case of molecular-replacement phasing: the structure of a putative succinyl-diaminopimelate desuccinylase from Corynebacterium glutamicum.

PubMed

Brunger, Axel T; Das, Debanu; Deacon, Ashley M; Grant, Joanna; Terwilliger, Thomas C; Read, Randy J; Adams, Paul D; Levitt, Michael; Schröder, Gunnar F

2012-04-01

Phasing by molecular replacement remains difficult for targets that are far from the search model or in situations where the crystal diffracts only weakly or to low resolution. Here, the process of determining and refining the structure of Cgl1109, a putative succinyl-diaminopimelate desuccinylase from Corynebacterium glutamicum, at ∼3 Å resolution is described using a combination of homology modeling with MODELLER, molecular-replacement phasing with Phaser, deformable elastic network (DEN) refinement and automated model building using AutoBuild in a semi-automated fashion, followed by final refinement cycles with phenix.refine and Coot. This difficult molecular-replacement case illustrates the power of including DEN restraints derived from a starting model to guide the movements of the model during refinement. The resulting improved model phases provide better starting points for automated model building and produce more significant difference peaks in anomalous difference Fourier maps to locate anomalous scatterers than does standard refinement. This example also illustrates a current limitation of automated procedures that require manual adjustment of local sequence misalignments between the homology model and the target sequence.

Application of DEN refinement and automated model building to a difficult case of molecular-replacement phasing: the structure of a putative succinyl-diaminopimelate desuccinylase from Corynebacterium glutamicum

PubMed Central

Brunger, Axel T.; Das, Debanu; Deacon, Ashley M.; Grant, Joanna; Terwilliger, Thomas C.; Read, Randy J.; Adams, Paul D.; Levitt, Michael; Schröder, Gunnar F.

2012-01-01

Phasing by molecular replacement remains difficult for targets that are far from the search model or in situations where the crystal diffracts only weakly or to low resolution. Here, the process of determining and refining the structure of Cgl1109, a putative succinyl-diaminopimelate desuccinylase from Corynebacterium glutamicum, at ∼3 Å resolution is described using a combination of homology modeling with MODELLER, molecular-replacement phasing with Phaser, deformable elastic network (DEN) refinement and automated model building using AutoBuild in a semi-automated fashion, followed by final refinement cycles with phenix.refine and Coot. This difficult molecular-replacement case illustrates the power of including DEN restraints derived from a starting model to guide the movements of the model during refinement. The resulting improved model phases provide better starting points for automated model building and produce more significant difference peaks in anomalous difference Fourier maps to locate anomalous scatterers than does standard refinement. This example also illustrates a current limitation of automated procedures that require manual adjustment of local sequence misalignments between the homology model and the target sequence. PMID:22505259

Effect of impurities and post-experimental purification in SAD phasing with serial femtosecond crystallography data.

PubMed

Zhang, Tao; Gu, Yuanxin; Fan, Haifu

2016-06-01

In serial crystallography (SX) with either an X-ray free-electron laser (XFEL) or synchrotron radiation as the light source, huge numbers of micrometre-sized crystals are used in diffraction data collection. For a SAD experiment using a derivative with introduced heavy atoms, it is difficult to completely exclude crystals of the native protein from the sample. In this paper, simulations were performed to study how the inclusion of native crystals in the derivative sample could affect the result of SAD phasing and how the post-experimental purification proposed by Zhang et al. [(2015), Acta Cryst. D71, 2513-2518] could be used to remove the impurities. A gadolinium derivative of lysozyme and the corresponding native protein were used in the test. Serial femtosecond crystallography (SFX) diffraction snapshots were generated by CrystFEL. SHELXC/D, Phaser, DM, ARP/wARP and REFMAC were used for automatic structure solution. It is shown that a small amount of impurities (snapshots from native crystals) in the set of derivative snapshots can strongly affect the SAD phasing results. On the other hand, post-experimental purification can efficiently remove the impurities, leading to results similar to those from a pure sample.

A Contribution to the Kinetic Study of the Metatectic Reaction U+U$sub 3$Si$sub 2$$Yields$U$sub 3$Si; CONTRIBUTION AL ESTUDIO CINETICO DE LA REACCION METATECTICA U+U$sub 3$Si$sub 2$$Yields$U$sub 3$Si

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

Ruiperez, J.A.; Hernandez, J.A.E.

1962-01-01

An experimental study was made to decide upon the advantages and drawbacks of the different methods and reagents employed in the metallography of U-Si alloys. It has been observed that all samples thermally treated to the epsilon-phase undergo a coalescence of the U/sub 3/Si/sub 2/ particles. The coalescence decreases the surface available for reaction and consequently the reaction rate. The growth of the U/sub 3/Si/sub 2/ phase particles was determined as a function of time and temperature. To obtain samples with nuclei sufficiently isolated so that the U/sub 3/Si rings will not interfere their respective growth, the conditions that regulatemore » coalescence, Si content and thermal treatment, were determined. Data rel1tive to the growth of the U/sub 3/ Si phase-rings were obtained. Curves relating growth, time, and temperature are presented. The parameters that define the diffusion regulated reaction can be deduced from these curves. (auth)« less

Fragon: rapid high-resolution structure determination from ideal protein fragments.

PubMed

Jenkins, Huw T

2018-03-01

Correctly positioning ideal protein fragments by molecular replacement presents an attractive method for obtaining preliminary phases when no template structure for molecular replacement is available. This has been exploited in several existing pipelines. This paper presents a new pipeline, named Fragon, in which fragments (ideal α-helices or β-strands) are placed using Phaser and the phases calculated from these coordinates are then improved by the density-modification methods provided by ACORN. The reliable scoring algorithm provided by ACORN identifies success. In these cases, the resulting phases are usually of sufficient quality to enable automated model building of the entire structure. Fragon was evaluated against two test sets comprising mixed α/β folds and all-β folds at resolutions between 1.0 and 1.7 Å. Success rates of 61% for the mixed α/β test set and 30% for the all-β test set were achieved. In almost 70% of successful runs, fragment placement and density modification took less than 30 min on relatively modest four-core desktop computers. In all successful runs the best set of phases enabled automated model building with ARP/wARP to complete the structure.

Large Aperture Scanning Lidar Based on Holographic Optical Elements

NASA Technical Reports Server (NTRS)

Schwemmer, Geary K.; Miller, David O.; Wilkerson, Thomas D.; Andrus, Ionio; Guerra, David V.; Einaudi, Franco (Technical Monitor)

2001-01-01

Lidar remote sensing instruments can make a significant contribution to satisfying many of the required measurements of atmospheric and surface parameters for future spaceborne platforms, including topographic altimeters, atmospheric profiles of, wind, humidity, temperature, trace molecules, aerosols, and clouds. It is highly desirable to have wide measurement swaths for rapid coverage rather than just the narrow ribbon of data that is obtained with a nadir only observation. For most applications global coverage is required, and for wind measurements scanning or pointing is required in order to retrieve the full 3-D wind vector from multiple line-of-sight Doppler measurements. Conventional lidar receivers make up a substantial portion of the instrument's size and weight. Wide angle scanning typically requires a large scanning mirror in front of the receiver telescope, or pointing the entire telescope and aft optics assembly, Either of these methods entails the use of large bearings, motors, gearing and their associated electronics. Spaceborne instruments also need reaction wheels to counter the torque applied to the spacecraft by these motions. NASA has developed simplified conical scanning telescopes using Holographic Optical Elements (HOEs) to reduce the size, mass, angular momentum, and cost of scanning lidar systems. NASA has developed two operating lidar systems based on 40 cm diameter HOEs. The first such system, named Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing (PHASERS) was a joint development between NASA Goddard Space Flight Center (GSFC) and the University of Maryland College Park. PHASERS is based on a reflection HOE for use at the doubled Nd:YAG laser wavelength of 532 nm and has recently undergone a number of design changes in a collaborative effort between GSFC and Saint Anselm College in New Hampshire. The next step was to develop IR transmission HOEs for use with the Nd:YAG fundamental in the Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE). The HOE spins like a compact disk in a large ring ball bearing. In an aircraft the HOE faces down, looking out through a window at an angle of 45 degrees off-nadir. The HOE diffracts 85% of the incident 532 nm light into a 160 micron spot at a focal length of 1 meter. HARLIE is a field deployable lidar measuring aerosol, cloud, and boundary layer backscatter for atmospheric research. It has flown several times and is also used from a ground-based trailer in an upward-looking mode. The HOE generates a 45 degree conical scan pattern by rotating at speeds up to 30 rpm. Like PHASERS, the HOE in HARLIE serves both as the laser collimating lens as well as the receiver telescope primary optic. The telescope is coupled to the receiver package via fiber optic. The transmitter is a diode pumped Nd:YAG laser operating at 1064 nm, delivering 1 mJ pulses at a 5 KHz rep-rate. The receiver has a 200 microradian field-of-view and a 0.5 nm optical bandpass. The photon counting data system utilizes a single Geiger-mode silicon avalanche photodiode detector, This new technology has also presented us with new data visualization challenges as well as new measurement techniques. The backscatter data obtained from a stationary (i.e. ground-based) scanning HOE lidar is on the surface of a cone, which when viewed over many consecutive scans can reveal atmospheric motions on this surface over time as the atmosphere advects over the site. In a moving platform such as an airplane or satellite, the data from consecutive scans cover different areas under the flight path, revealing atmospheric structure in 3-dimensions. An example of a visualization of HARLIE ground-based data is presented, showing aerosol backscatter on a 90 degree conical surface generated from one 360 degree scan of the lidar during the HOLO-1 field campaign on the afternoon of 10 March 1999. Higher backscatter levels are rendered as lighter signal against a dark background. Breaking Kelvin-Helmholtz waves are evident on the north side of the scan at an altitude of 10-11 km. Time series of successive scans made at regular intervals render unique views of atmospheric motions, from which vertical profiles of atmospheric wind vectors can be obtained using a unique data analysis approach. Wind vectors obtained from the lidar were compared with co-located radiosonde wind profiles during an intensive operating period in September-October 2000 at the Atmospheric Radiation Measurement Program's Southern Great Plains Central Facility.

The effect of podcast lectures on nursing students' knowledge retention and application.

PubMed

Abate, Karen S

2013-01-01

This pilot study sought to evaluate the effectiveness of academic podcasts in promoting knowledge retention and application in nursing students. Nursing education no longer simply occurs in a fixed location or time. Computer-enhanced mobile learning technologies, such as academic podcasts, must be grounded in pedagogically sound characteristics to ensure effective implementation and learning in nursing education. A convenience sample of 35 female undergraduate nursing students was randomized into three groups: a traditional face-to-face lecture group, an unsegmented (non-stop) podcast lecture group, and a segmented podcast lecture group. Retention and application of information were measured through a multiple-choice quiz and a case study based on lecture content. Students in the segmented podcast lecture group demonstrated higher scores on multiple-choice and case-study assessments than those in the other two groups. Nurse educators should be aware of this finding when seeking to employ podcast lectures in nursing education.

[Hospital Doctors Should Receive Lecture for Sedation According to Joint Commission International].

PubMed

Ueshima, Hironobu; Komasawa, Nobuyasu; Kitamura, Akira

2015-08-01

At our hospital, intending to obtaining an approval from the Joint Commission International (JCI), we conducted a workshop on sedation for all staff physicians. A sedation instructor authorized by the Japanese Association for Medical Simulation gave a lecture using the "practice guidelines for sedation and administration of analgesics for non-anesthesiologists", revised in 2002 by the American Society of Anesthesiologists, following which, a test using 10 true-false questions was conducted, while before and after the lecture a questionnaire survey on the sedation lecture was carried out Among 191 physicians attending the lecture, except for one person, 7 or more questions were answered correctly. From the questionnaires, the sedation lectures were also generally accepted favourably. In the test of understanding, the mistakes were mostly in the sections on "sedation evaluation" "intraoperative monitoring" "pharmaceutical knowledge" and "airway management methods". The sedation lecture in the hospital was effective.

Undergraduate Students' Experiences with Recorded Lectures: Towards a Theory of Acculturation

ERIC Educational Resources Information Center

Cilesiz, Sebnem

2015-01-01

The use of recorded lectures--an instructional format that involves recording live lectures and disseminating these recordings to students by means of various technologies--as substitutes for classroom instruction is a growing phenomenon in higher education. Sustained use of recorded lectures has the potential to significantly alter students'…

Psychometric Properties on Lecturers' Beliefs on Teaching Function: Rasch Model Analysis

ERIC Educational Resources Information Center

Mofreh, Samah Ali Mohsen; Ghafar, Mohammed Najib Abdul; Omar, Abdul Hafiz Hj; Mosaku, Monsurat; Ma'ruf, Amar

2014-01-01

This paper focuses on the psychometric analysis of lecturers' beliefs on teaching function (LBTF) survey using Rasch Model analysis. The sample comprised 34 Community Colleges' lecturers. The Rasch Model is applied to produce specific measurements on the lecturers' beliefs on teaching function in order to generalize results and inferential…

Rhetorical Studies: A Reassessment of Adam Smith's Lectures on Rhetoric and Belles Lettres.

ERIC Educational Resources Information Center

Purcell, William M.

1986-01-01

Offers a dissenting interpretation of Adam Smith's Lectures on Rhetoric and Belles Lettres and a more conservative perspective on Smith's significance to the history of rhetorical theory. Views the lectures as an historical commentary on literature and rhetoric from the perspective of an eighteenth-century lecturer. (JD)

431st Brookhaven Lecture. Recombinant Science: The Birth of RHIC, A Drama of Three Acts

ScienceCinema

Crease, Robert

2017-12-22

Crease presents "Recombinant Science: The Birth of the Relativistic Heavy Ion Collider," a lecture that follows on the 429th Brookhaven Lecture, in which Crease talked about the early history of BNL. Both lectures are part of the ongoing celebration of BNL's 60th anniversary year.

The Effects of Lecture Diversity on Germane Load

ERIC Educational Resources Information Center

Costley, Jamie; Lange, Christopher

2017-01-01

An important aspect of MOOCs is the way students interact with video lectures. Instruction provided through video lectures should focus on ways to increase germane cognitive load, which directly contributes to learning. One approach that may lead to an increase of germane load may be to use video lectures with diverse forms of media, including…

Laughter in University Lectures

ERIC Educational Resources Information Center

Nesi, Hilary

2012-01-01

This paper analyses laughter in spoken academic discourse, with the aim of discovering why lecturers provoke laughter in their lectures. A further purpose of the paper is to identify episodes in British data which may differ from those in other cultural contexts where other lecturing practices prevail, and thus to inform the design of study skills…

Who Goes to Lectures (and Does It Matter)?

ERIC Educational Resources Information Center

Birch, Elisa; Williams, Andrew

2015-01-01

Using a combination of survey and student record data from a first year university economics principles class, we look at the characteristics of students who are attending face-to-face lectures, versus those students who choose to view these same lectures via online lecture recordings. The survey includes the Biggs (2001) Revised Study Process…

The Effect on Student Achievement of Increasing Kinetic Structure of Teachers' Lectures.

ERIC Educational Resources Information Center

Lamb, William G.; And Others

1979-01-01

Tests O. R. Anderson's theory of kinetic structure of verbal communications by administering lectures on swine flu to high school biology students and then reteaching the lectures with increased commonality. Results weakly support Anderson's theory. Implications are made for training teachers to increase the commonality of their lectures. (CS)

University Lecturer Publication Output: Qualifications, Time and Confidence Count

ERIC Educational Resources Information Center

Hemmings, Brian; Kay, Russell

2010-01-01

An investigation of factors which differentiate between university lecturers in relation to publication output is reported. The study drew on data from lecturers working full-time at two large Australian universities. Measures of research publication output were used to select two groups of lecturers (N[subscript 1] = 119; N[subscript 2] = 119);…

Lecture-Recording Technology in Higher Education: Exploring Lecturer and Student Views across the Disciplines

ERIC Educational Resources Information Center

Dona, Kulari Lokuge; Gregory, Janet; Pechenkina, Ekaterina

2017-01-01

This paper presents findings of an institutional case study investigating how students and lecturers experienced a new opt-out, fully integrated lecture-recording system which enabled audio and presentation screen capture. The study's focus is on how "traditional" students (generally characterised as young, enrolled full-time and…

Mathematics Lectures as Narratives: Insights from Network Graph Methodology

ERIC Educational Resources Information Center

Weinberg, Aaron; Wiesner, Emilie; Fukawa-Connelly, Tim

2016-01-01

Although lecture is the traditional method of university mathematics instruction, there has been little empirical research that describes the general structure of lectures. In this paper, we adapt ideas from narrative analysis and apply them to an upper-level mathematics lecture. We develop a framework that enables us to conceptualize the lecture…

Engagement of Students with Lectures in Biochemistry and Pharmacology

ERIC Educational Resources Information Center

Davis, Elizabeth Ann; Hodgson, Yvonne; Macaulay, Janet Olwyn

2012-01-01

Academic staff at universities have become concerned about the decrease in student attendance at lectures and the implication of this on student achievement and learning. Few studies have measured actual lecture attendance in a coherent or comprehensive way. The aim of this study was to measure actual lecture attendance of students over two year…

Tips for Teaching.

ERIC Educational Resources Information Center

Langer, Philip

1987-01-01

Suggestions on how to enhance college teaching are provided. Lecturing is stressed as a critical component of teaching, and each lecture's introduction, main body, and conclusion must be correlated prior to any given lecture. Information on how to compose and give a lecture includes: what to put in an introduction; what can be done to help the…

Electronic Delivery of Lectures in the University Environment: An Empirical Comparison of Three Delivery Styles

ERIC Educational Resources Information Center

Stephenson, Julia E.; Brown, Clifford; Griffin, Darren K.

2008-01-01

The purpose of this study was to consider the efficacy and popularity of "Virtual Lectures" (text-based, structured electronic courseware with information presented in manageable "chunks", interaction and multimedia) and "e-Lectures" (on-screen synchrony of PowerPoint slides and recorded voice) as alternatives to traditional lectures. We…

10 Suggestions for Enhancing Lecturing

ERIC Educational Resources Information Center

Heitzmann, Ray

2010-01-01

Criticism of the lecture method remains a staple of discussion and writing in academia--and most of the time it's deserved! Those interested in improving this aspect of their teaching might wish to consider some or all of the following suggestions for enhancing lectures. These include: (1) Lectures must start with a "grabber"; (2)…

22 CFR 63.7 - Grants to United States participants to consult, lecture, teach, engage in research, demonstrate...

Code of Federal Regulations, 2014 CFR

2014-04-01

..., lecture, teach, engage in research, demonstrate special skills, or engage in specialized programs. 63.7... United States participants to consult, lecture, teach, engage in research, demonstrate special skills, or... to consult, lecture, teach, engage in research, demonstrate special skills, or engage in specialized...

22 CFR 63.7 - Grants to United States participants to consult, lecture, teach, engage in research, demonstrate...

Code of Federal Regulations, 2013 CFR

2013-04-01

..., lecture, teach, engage in research, demonstrate special skills, or engage in specialized programs. 63.7... United States participants to consult, lecture, teach, engage in research, demonstrate special skills, or... to consult, lecture, teach, engage in research, demonstrate special skills, or engage in specialized...

22 CFR 63.7 - Grants to United States participants to consult, lecture, teach, engage in research, demonstrate...

Code of Federal Regulations, 2010 CFR

2010-04-01

..., lecture, teach, engage in research, demonstrate special skills, or engage in specialized programs. 63.7... United States participants to consult, lecture, teach, engage in research, demonstrate special skills, or... to consult, lecture, teach, engage in research, demonstrate special skills, or engage in specialized...

22 CFR 63.7 - Grants to United States participants to consult, lecture, teach, engage in research, demonstrate...

Code of Federal Regulations, 2011 CFR

2011-04-01

..., lecture, teach, engage in research, demonstrate special skills, or engage in specialized programs. 63.7... United States participants to consult, lecture, teach, engage in research, demonstrate special skills, or... to consult, lecture, teach, engage in research, demonstrate special skills, or engage in specialized...

22 CFR 63.7 - Grants to United States participants to consult, lecture, teach, engage in research, demonstrate...

Code of Federal Regulations, 2012 CFR

2012-04-01

..., lecture, teach, engage in research, demonstrate special skills, or engage in specialized programs. 63.7... United States participants to consult, lecture, teach, engage in research, demonstrate special skills, or... to consult, lecture, teach, engage in research, demonstrate special skills, or engage in specialized...

Student Use of Mobile Devices in University Lectures

ERIC Educational Resources Information Center

Roberts, Neil; Rees, Michael

2014-01-01

Mobile devices are increasingly used by students in university lectures. This has resulted in controversy and the banning of mobile devices in some lectures. Although there has been some research into how students use laptop computers in lectures, there has been little investigation into the wider use of mobile devices. This study was designed to…

Flipped Statistics Class Results: Better Performance than Lecture over One Year Later

ERIC Educational Resources Information Center

Winquist, Jennifer R.; Carlson, Keith A.

2014-01-01

In this paper, we compare an introductory statistics course taught using a flipped classroom approach to the same course taught using a traditional lecture based approach. In the lecture course, students listened to lecture, took notes, and completed homework assignments. In the flipped course, students read relatively simple chapters and answered…

Use of Lecture Capture in Higher Education--Lessons from the Trenches

ERIC Educational Resources Information Center

Newton, Genevieve; Tucker, Trent; Dawson, John; Currie, Elliott

2014-01-01

Lecture capture, defined here as the capturing of some or all elements of a live lecture in digital format, is becoming increasingly popular in higher education. Despite this increase in popularity, fewer than 10% of institutes of higher education globally have adopted comprehensive lecture capture systems. So, the majority of instructors wanting…

Interactive computer-assisted instruction vs. lecture format in dental education.

PubMed

Howerton, W Bruce; Enrique, Platin R T; Ludlow, John B; Tyndall, Donald A

2004-01-01

The purpose of this study was to compare computer-assisted instruction (CAI) with lecture format using recent hardware and software advances. A pre- and post-test was used to determine student performance and instructional preference. In addition, a post-instruction survey was used to determine student learning preferences. Seventy-five first-year University of North Carolina (UNC) dental students who were registered for the introductory radiology course were asked to participate. All agreed and were randomly placed in one of three groups: interactive CD only, interactive CD and lecture, and lecture only. The content of the multimedia instruction focused on intraoral radiography. A pre- and post-test was administered to determine if there was a significant difference between interactive CD and lecture formats, and an evaluation instrument was used to determine if there was a student learning preference between CAI and lecture format. Analysis of covariance and the sign test were used to determine significance (p<.05). There was no significant difference between pre- and post-test outcomes, indicating that similar learning took place using the interactive CD and/or lecture format. However, students preferred CAI to lecture format.

Proposal for research and education: joint lectures and practicals on central nervous system anatomy and physiology.

PubMed

Kageyama, Ikuo; Yoshimura, Ken; Satoh, Yoshihide; Nanayakkara, Chinthani D; Pallegama, Ranjith W; Iwasaki, Shin-Ichi

2016-07-01

We coordinated anatomy and physiology lectures and practicals to facilitate an integrated understanding of morphology and function in a basic medical science program for dental students and to reduce the time spent on basic science education. This method is a means to provide the essential information and skills in less time. The overall impression was that the practice of joint central nervous system lectures and practicals was an efficient method for students, which suggests that joint lectures might also be useful for clinical subjects. About two-thirds of students felt that the joint anatomy and physiology lecture on the central nervous system was useful and necessary in understanding the relationship between morphology and function, at least for this subject. One-third of students were neutral on the effectiveness of this method. However, the survey results suggest that improvements are needed in the method and timing of joint lectures and practicals. The present teaching approach can be further improved by conducting combined lectures in which the form and function of anatomic structures are presented by the relevant departments during the same lecture. Finally, joint lecturers and practicals offer an opportunity to increase student understanding of the importance of new research findings by the present authors and other researchers.

Lecturing skills as predictors of tutoring skills in a problem-based medical curriculum

PubMed Central

Kassab, Salah Eldin; Hassan, Nahla; Abu-Hijleh, Marwan F; Sequeira, Reginald P

2016-01-01

Purpose Recruitment of tutors to work in problem-based learning (PBL) programs is challenging, especially in that most of them are graduated from discipline-based programs. Therefore, this study aims at examining whether lecturing skills of faculty could predict their PBL tutoring skills. Methods This study included evaluation of faculty (n=69) who participated in both tutoring and lecturing within particular PBL units at the College of Medicine and Medical Sciences (CMMS), Arabian Gulf University, Bahrain. Each faculty was evaluated by medical students (n=45±8 for lecturing and 8±2 for PBL tutoring) using structured evaluation forms based on a Likert-type scale (poor to excellent). The prediction of tutoring skills using lecturing skills was statistically analyzed using stepwise linear regression. Results Among the parameters used to judge lecturing skills, the most important predictor for tutoring skills was subject matter mastery in the lecture by explaining difficult concepts and responding effectively to students’ questions. Subject matter mastery in the lecture positively predicted five tutoring skills and accounted for 25% of the variance in overall effectiveness of the PBL tutors (F=22.39, P=0.000). Other important predictors for tutoring skills were providing a relaxed class atmosphere and effective use of audiovisual aids in the lecture. Conclusion Predicting the tutoring skills based on lecturing skills could have implications for recruiting tutors in PBL medical programs and for tutor training initiatives. PMID:26793014

Multitasking behaviors of osteopathic medical students.

PubMed

Shah, Ankit V; Mullens, Dustin J; Van Duyn, Lindsey J; Januchowski, Ronald P

2014-08-01

To the authors' knowledge, few studies have investigated the relationship between electronic media multitasking by undergraduate and graduate students during lecture and their academic performance, and reports that have looked into this behavior have neglected to investigate factors that may influence students' multitasking during lecture. To determine the extent to which medical students multitask during lecture; the types of multitasking; the frequency of multitasking and factors that influence frequency; and the correlation between multitasking and knowledge acquisition as assessed by a postlecture quiz. A 1-page survey assessing students' multitasking behavior was administered to 125 second-year students at Edward Via College of Osteopathic Medicine and collected at the onset of a standard 50-minute lecture. On completion of the 50-minute lecture, an unannounced 10-question multiple-choice quiz was given to assess knowledge acquisition during those lectures. On a separate date, after a standard 50-minute lecture, a second quiz was administered. The 1-page survey revealed that 98% of students check e-mail, 81% use social media, and 74% study for another class. Students spent the most time studying for another class (23 minutes) followed by using social media (13 minutes) and checking e-mail (7 minutes). The most influential factors behind multitasking were examination schedule (91%), lecturer (90%), and the number of lectures in the day (65%). The mean score for quiz 1 (the day after an examination) was 75%, and the mean score for quiz 2 (the day before an examination) was 60%. Multitasking during lecture is prominent among medical students, and examination schedule is the most influential factor. Although a robust drop in mean score on a lecture-based, unannounced quiz was identified 1 day before a scheduled examination, the effect from multitasking on this process remains unclear. © 2014 The American Osteopathic Association.

An eight-year study of online lecture use in a medical gross anatomy and embryology course.

PubMed

Nieder, Gary L; Borges, Nicole J

2012-01-01

Online lectures have been used in lieu of live lectures in our gross anatomy and embryology course for the past eight years. We examined patterns of online lecture use by our students and related that use to academic entry measures, gender and examination performance. Detailed access records identified by student were available from server logs. Total views per page of lecture material increased over the first six years, then decreased markedly between years seven and eight, possibly due to the recent availability of alternate forms of lecture audio. Lecture use peaked in midafternoon and again in the evening, although some use was seen at all hours. Usage was highest at midweek and lowest on Fridays as might be expected. Individual student's use varied widely from rates equivalent to less than one viewing/page to more than three viewings per page. Overall use by male students was greater than that of females and gender-specific differences in the daily pattern were seen. Lecture use was correlated to the Medical College Admission Test(®) (MCAT(®)) Verbal Reasoning and Physical Sciences scores but not to composite MCAT scores or undergraduate grade point average. Overall use appeared to be driven by scheduled team-based learning (TBL) sessions and major examinations. Specific subsets of lecture material were most often viewed before related TBL sessions and again during review for examinations. A small but significant correlation between lecture use and examination and course performance was seen, specifically in the male student population. These findings, along with earlier observations, suggest that varied use of online lectures is attributable to multiple factors. Copyright © 2012 American Association of Anatomists.

57Fe Mössbauer spectroscopy and electron paramagnetic resonance studies of human liver ferritin, Ferrum Lek and Maltofer®

NASA Astrophysics Data System (ADS)

Alenkina, I. V.; Oshtrakh, M. I.; Klencsár, Z.; Kuzmann, E.; Chukin, A. V.; Semionkin, V. A.

2014-09-01

A human liver ferritin, commercial Ferrum Lek and Maltofer® samples were studied using Mössbauer spectroscopy and electron paramagnetic resonance. Two Mössbauer spectrometers have been used: (i) a high velocity resolution (4096 channels) at 90 and 295 K, (ii) and a low velocity resolution (250 channels) at 20 and 40 K. It is shown that the three studied materials have different superparamagnetic features at various temperatures. This may be caused by different magnetic anisotropy energy barriers, sizes (volume), structures and compositions of the iron cores. The electron paramagnetic resonance spectra of the ferritin, Ferrum Lek and Maltofer® were decomposed into multiple spectral components demonstrating the presence of minor ferro- or ferrimagnetic phases along with revealing marked differences among the studied substances. Mössbauer spectroscopy provides evidences on several components in the measured spectra which could be related to different regions, layers, nanocrystallites, etc. in the iron cores that coincides with heterogeneous and multiphase models for the ferritin iron cores.

Quench of paramagnetic orbital selective Mott phase and appearance of antiferromagnetic orbital selective slater phase in multiorbital correlated systems

NASA Astrophysics Data System (ADS)

Quan, Ya-Min; Liu, Da-Yong; Lin, Hai-Qing; Zou, Liang-Jian

2018-06-01

We present the modulation of magnetic order on the orbital selective Mott phases (OSMP) and the metal-insulator transitions (MIT) of multi-orbital Hubbard models by employing the rotationally invariant slave-boson methods. We show that at half filling, the well-known paramagnetic (PM) OSMP is completely covered by an antiferromagnetic (AFM) Slater insulator, and the PM Mott phase by an AFM Mott insulator when electron correlation strength varies from intermediate to strong both in two- and three-orbitals Hubbard systems. Away from half-filling, we find that a partial-polarized AFM orbital-selective Slater phase appears in the intermediate correlation regime, and an almost full-polarized AFM OSMP fully covers the paramagnetic OSMP. In addition, the ferromagnetic phase in the three-orbital case is more robust than that in the two-orbital case. These results demonstrate that the modulation of magnetic correlation to the quasiparticle spectra leads to much rich and more interesting MIT scenario in multiorbital correlated systems.

How can EPR spectroscopy help to unravel molecular mechanisms of flavin-dependent photoreceptors?

PubMed

Nohr, Daniel; Rodriguez, Ryan; Weber, Stefan; Schleicher, Erik

2015-01-01

Electron paramagnetic resonance (EPR) spectroscopy is a well-established spectroscopic method for the examination of paramagnetic molecules. Proteins can contain paramagnetic moieties in form of stable cofactors, transiently formed intermediates, or spin labels artificially introduced to cysteine sites. The focus of this review is to evaluate potential scopes of application of EPR to the emerging field of optogenetics. The main objective for EPR spectroscopy in this context is to unravel the complex mechanisms of light-active proteins, from their primary photoreaction to downstream signal transduction. An overview of recent results from the family of flavin-containing, blue-light dependent photoreceptors is given. In detail, mechanistic similarities and differences are condensed from the three classes of flavoproteins, the cryptochromes, LOV (Light-oxygen-voltage), and BLUF (blue-light using FAD) domains. Additionally, a concept that includes spin-labeled proteins and examination using modern pulsed EPR is introduced, which allows for a precise mapping of light-induced conformational changes.

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

Gorai, Prashun; Toberer, Eric S.; Stevanović, Vladan

Here, at room temperature and above, most magnetic materials adopt a spin-disordered (paramagnetic) state whose electronic properties can differ significantly from their low-temperature, spin-ordered counterparts. Yet computational searches for new functional materials usually assume some type of magnetic order. In the present work, we demonstrate a methodology to incorporate spin disorder in computational searches and predict the electronic properties of the paramagnetic phase. We implement this method in a high-throughput framework to assess the potential for thermoelectric performance of 1350 transition-metal sulfides and find that all magnetic systems we identify as promising in the spin-ordered ground state cease to bemore » promising in the paramagnetic phase due to disorder-induced deterioration of the charge carrier transport properties. We also identify promising non-magnetic candidates that do not suffer from these spin disorder effects. In addition to identifying promising materials, our results offer insights into the apparent scarcity of magnetic systems among known thermoelectrics and highlight the importance of including spin disorder in computational searches.« less

Enhanced Positive-Contrast Visualization of Paramagnetic Contrast Agents Using Phase Images

PubMed Central

Mills, Parker H.; Ahrens, Eric T.

2009-01-01

Iron oxide–based MRI contrast agents are increasingly being used to noninvasively track cells, target molecular epitopes, and monitor gene expression in vivo. Detecting regions of contrast agent accumulation can be challenging if resulting contrast is subtle relative to endogenous tissue hypointensities. A postprocessing method is presented that yields enhanced positive-contrast images from the phase map associated with T2*-weighted MRI data. As examples, the method was applied to an agarose gel phantom doped with superparamagnetic iron-oxide nanoparticles and in vivo and ex vivo mouse brains inoculated with recombinant viruses delivering transgenes that induce overexpression of paramagnetic ferritin. Overall, this approach generates images that exhibit a 1- to 8-fold improvement in contrast-to-noise ratio in regions where paramagnetic agents are present compared to conventional magnitude images. This approach can be used in conjunction with conventional T2* pulse sequences, requires no prescans or increased scan time, and can be applied retrospectively to previously acquired data. PMID:19780169

Dissociation of O(2-)2 defects into paramagnetic O(-) in wide band-gap insulators - A magnetic susceptibility study of magnesium oxide

NASA Technical Reports Server (NTRS)

Batllo, F.; Leroy, R. C.; Parvin, K.; Freund, F.

1990-01-01

The magnetic susceptibility of single-crystal MgO has been measured in the temperature range 300-1000 K, using a Faraday balance. The high-purity crystal (less than 100 ppm transition metals), grown from the melt in a H2O-containing atmosphere, was found to be paramagnetic due to the presence of defects on the O(2-) sublattice. The defects derive from OH(-) introduced into the MgO matrix by the dissolution of traces of H2O during crystal growth. The OH(-) converts into O(2-)2 and H2. Each O(2-)2 represents two coupled, spin-paired O(-) states. The observed strongly temperature-dependent paramagnetism can be described by three contributions that overlay the intrinsic diamagnetism of MgO and arise from the low level of transition-metal impurities, O(-) generated by 0(2-)2 dissociation, and O(-) states trapped by quenching from high temperatures from previous experiments.

Investigating Pigment Radicals in Black Rice Using HPLC and Multi-EPR.

PubMed

Nakagawa, Kouichi; Maeda, Hayato

2017-01-01

We investigated the location and distribution of paramagnetic species in black and white rice using electron paramagnetic resonance (EPR), X-band (9 GHz) EPR imaging (EPRI), and HPLC. EPR primarily detected two paramagnetic species in black rice, which were identified as a stable radical and Mn 2+ species, based on the g values and hyperfine components of the EPR signals. The signal from the stable radical appeared at g ≈ 2.00 and was relatively strong and stable. Subsequent noninvasive two-dimensional (2D) EPRI revealed that this stable radical was primarily located in the pigmented region of black rice, while very few radicals were observed in the rice interior. Pigments extracted from black rice were analyzed using HPLC; the major compound was found to be cyanidin-3-glucoside. EPR and HPLC results indicate that the stable radical was only found within the pigmented region of the rice, and that it could either be cyanidin-3-glucoside, or one of its oxidative decomposition products.

How can EPR spectroscopy help to unravel molecular mechanisms of flavin-dependent photoreceptors?

PubMed Central

Nohr, Daniel; Rodriguez, Ryan; Weber, Stefan; Schleicher, Erik

2015-01-01

Electron paramagnetic resonance (EPR) spectroscopy is a well-established spectroscopic method for the examination of paramagnetic molecules. Proteins can contain paramagnetic moieties in form of stable cofactors, transiently formed intermediates, or spin labels artificially introduced to cysteine sites. The focus of this review is to evaluate potential scopes of application of EPR to the emerging field of optogenetics. The main objective for EPR spectroscopy in this context is to unravel the complex mechanisms of light-active proteins, from their primary photoreaction to downstream signal transduction. An overview of recent results from the family of flavin-containing, blue-light dependent photoreceptors is given. In detail, mechanistic similarities and differences are condensed from the three classes of flavoproteins, the cryptochromes, LOV (Light-oxygen-voltage), and BLUF (blue-light using FAD) domains. Additionally, a concept that includes spin-labeled proteins and examination using modern pulsed EPR is introduced, which allows for a precise mapping of light-induced conformational changes. PMID:26389123

Is an Apple Magnetic: Magnetic Response of Everyday Materials Supporting Views About the Nature of Science

NASA Astrophysics Data System (ADS)

Laumann, Daniel

2017-03-01

Magnetism and its various applications are essential for our daily life and for many technological developments. The term magnetism is almost always used as a synonym for ferromagnetism. However, the magnetic properties of the elements of the periodic table indicate that the vast majority of elements are not ferromagnetic, but rather, diamagnetic or paramagnetic. Typically, only ferromagnetism is discussed in classrooms, which can create a distorted picture. This article supplies the further development of an experiment demonstrating the dia- and paramagnetic properties with an electronic balance and a neodymium magnet. It focuses on an investigation of ordinary materials that occur in pupils' everyday environment. The experiment is applicable both for a quantitative measurement of the magnetic (volume) susceptibility χV and can serve as a phenomenological approach to dia- and paramagnetism. Moreover, it encourages a discussion about typical beliefs regarding the nature of science, comparing the behavior of common objects in weak and in strong magnetic fields.

Nitroxide paramagnet-induced para-ortho conversion and nuclear spin relaxation of H2 in organic solvents.

PubMed

Sartori, Elena; Ruzzi, Marco; Lawler, Ronald G; Turro, Nicholas J

2008-09-24

The kinetics of para-ortho conversion and nuclear spin relaxation of H 2 in chloroform- d 1 were investigated in the presence of nitroxides as paramagnetic catalysts. The back conversion from para-hydrogen ( p-H 2) to ortho-hydrogen ( o-H 2) was followed by NMR by recording the increase in the intensity of the signal of o-H 2 at regular intervals of time. The nitroxides proved to be hundreds of times more effective at inducing relaxation among the spin levels of o-H 2 than they are in bringing about transitions between p-H 2 and the levels of o-H 2. The value of the encounter distance d between H 2 and the paramagnetic molecule, calculated from the experimental bimolecular conversion rate constant k 0, using the Wigner theory of para-ortho conversion, agrees perfectly with that calculated from the experimental relaxivity R 1 using the force free diffusion theory of spin-lattice relaxation.

Enhanced paramagnetism of mesoscopic graphdiyne by doping with nitrogen.

PubMed

Zhang, Mingjia; Wang, Xiaoxiong; Sun, Huijuan; Wang, Ning; Lv, Qing; Cui, Weiwei; Long, Yunze; Huang, Changshui

2017-09-14

The new two-dimensional graphitic material, graphdiyne, has attracted great interest recently due to the superior intrinsic semiconductor properties. Here we investigate the magnetism of pure graphdiyne material and find it demonstrating a remarkable paramagnetic characteristic, which can be attributed to the appearance of special sp-hybridized carbon atoms. On this basis, we further introduce nitrogen with 5.29% N/C ratio into graphdiyne followed by simply annealing in a dopant source and realize a twofold enhancement of saturation moment at 2 K. Associate with the density of states calculation, we investigate the influence of the nitrogen atom doping sites on paramagnetism, and further reveal the important role of doped nitrogen atom on benzene ring in improving local magnetic moment. These results can not only help us deeply understand the intrinsic magnetism of graphdiyne, but also open an efficient way to improve magnetism of graphdiyne by hetero atom doping, like nitrogen doping, which may promote the potential application of graphdiyne in spintronics.

Origin of negative resistivity slope in U-based ferromagnets

NASA Astrophysics Data System (ADS)

Havela, L.; Paukov, M.; Buturlim, V.; Tkach, I.; Mašková, S.; Dopita, M.

2018-05-01

Ultra-nanocrystalline UH3-based ferromagnets with TC ≈ 200 K exhibit a flat temperature dependence of electrical resistivity with a negative slope both in the ferromagnetic and paramagnetic range. The ordered state with randomness on atomic scale, equivalent to a non-collinear ferromagnetism, can be affected by magnetic field, supressing the static magnetic disorder, which reduces the resistivity and removes the negative slope. It is deduced that the dynamic magnetic disorder in the paramagnetic state can be conceived as continuation of the static disorder in the ordered state. The experiments, performed for (UH3)0.78Mo0.12Ti0.10, demonstrate that the negative resistivity slope, observed for numerous U-based intermetallics in the paramagnetic state, can be due to the strong disorder effect on resistivity. The resulting weak localization, as a quantum interference effect which increases resistivity, is gradually suppressed by enhanced temperature, contributing by electron-phonon scattering, inelastic in nature and removing the quantum coherence.

Alfven seismic vibrations of crustal solid-state plasma in quaking paramagnetic neutron star

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

Bastrukov, S.; Xu, R.-X.; Molodtsova, I.

2010-11-15

Magneto-solid-mechanical model of two-component, core-crust, paramagnetic neutron star responding to quake-induced perturbation by differentially rotational, torsional, oscillations of crustal electron-nuclear solid-state plasma about axis of magnetic field frozen in the immobile paramagnetic core is developed. Particular attention is given to the node-free torsional crust-against-core vibrations under combined action of Lorentz magnetic and Hooke's elastic forces; the damping is attributed to Newtonian force of shear viscose stresses in crustal solid-state plasma. The spectral formulas for the frequency and lifetime of this toroidal mode are derived in analytic form and discussed in the context of quasiperiodic oscillations of the x-ray outburst fluxmore » from quaking magnetars. The application of obtained theoretical spectra to modal analysis of available data on frequencies of oscillating outburst emission suggests that detected variability is the manifestation of crustal Alfven's seismic vibrations restored by Lorentz force of magnetic field stresses.« less

How paramagnetic and diamagnetic LMOCs detect picric acid from surface water and the intracellular environment: a combined experimental and DFT-D3 study.

PubMed

Ghosh, Pritam; Banerjee, Priyabrata

2016-08-17

Diamagnetic and Paramagnetic Luminescent Metal Organic Complexes (LMOCs) have been reported for Explosive and Pollutant Nitro Aromatic (epNAC) recognition. The diamagnetic complex shows a highly intense AIE induced by NEt3H(+), which disappears after picric acid recognition and subsequently RET will quench the emission intensity. Radical stabilized paramagnetic LMOCs seem to be active but show lower sensing efficiency in comparison with diamagnetic LMOCs. Solution and solid state spectroscopy studies along with DFT-D3 have been executed to enlighten the host guest interaction. Limit of PA detection is ∼250 ppb with a binding constant of 1.2 × 10(5) M(-1). Time-stepping, i.e. intervening in the problem of picric acid recognition from surface water collected from several places of West Bengal, India, has been performed. Mutagenic picric acid has been successfully detected in an aqueous medium inside both prokaryotic and eukaryotic cells at a ppm level using fluorescence microscopy.

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

Wolff-Fabris, F.; Lei, Hechang; Wosnitza, J.

We have studied the temperature dependence of the upper critical fields μ 0 H c 2 of K x Fe 2 - y Se 2 - z S z single crystals up to 60 T. The μ 0 H c 2 for H ∥ a b and H ∥ c decrease with increasing sulfur content. The detailed analysis using Werthamer-Helfand-Hohenberg theory including the Pauli spin-paramagnetic effect shows that μ 0 H c 2 for H ∥ a b is dominated by the spin-paramagnetic effect, which diminishes with higher S content, whereas μ 0 H c 2 for H ∥ cmore » shows a linear temperature dependence with an upturn at high fields. The latter observation can be ascribed to multiband effects that become weaker for higher S content. This results in an enhanced anisotropy of μ 0 H c 2 for high S content due to the different trends of the spin-paramagnetic and multiband effect for H ∥ a b and H ∥ c , respectively.« less

Magnetic and thermoelectric properties of electron doped Ca0.85Pr0.15MnO3

NASA Astrophysics Data System (ADS)

Hossain Khan, Momin; Pal, Sudipta; Bose, Esa

2015-10-01

We have investigated temperature-dependent magnetization (M), magnetic susceptibility (χ) and thermoelectric (S) properties of the electron-doped Ca0.85Pr0.15MnO3. With decrease of temperature, paramagnetic (PM) to antiferromagnetic (AFM) phase transition occurs with a well-defined Néel temperature (TN=122 K). Magnetic susceptibility measurements reveal that the paramagnetic state involves modified Curie-Weiss paramagnetism. Field cooled and zero field cooled magnetization measurements indicate a signature of magnetic frustration. Ferromagnetic (FM) double-exchange interactions associated with doped eg electrons are favored over competing AFM interactions below Tirr=112 K. Magnetization data also shows a second-order phase transition. The sign reversal in S(T) has been interpreted in terms of the change in the electronic structure relating to the orbital degrees of freedom of the doped eg electron. Low temperature (5-140 K) thermoelectric power, S (T) signifies the importance of electron-magnon scattering process.

Multiferroic composites for magnetic data storage beyond the super-paramagnetic limit

NASA Astrophysics Data System (ADS)

Vopson, M. M.; Zemaityte, E.; Spreitzer, M.; Namvar, E.

2014-09-01

Ultra high-density magnetic data storage requires magnetic grains of <5 nm diameters. Thermal stability of such small magnetic grain demands materials with very large magneto-crystalline anisotropy, which makes data write process almost impossible, even when Heat Assisted Magnetic Recording (HAMR) technology is deployed. Here, we propose an alternative method of strengthening the thermal stability of the magnetic grains via elasto-mechanical coupling between the magnetic data storage layer and a piezo-ferroelectric substrate. Using Stoner-Wohlfarth single domain model, we show that the correct tuning of this coupling can increase the effective magneto-crystalline anisotropy of the magnetic grains making them stable beyond the super-paramagnetic limit. However, the effective magnetic anisotropy can also be lowered or even switched off during the write process by simply altering the applied voltage to the substrate. Based on these effects, we propose two magnetic data storage protocols, one of which could potentially replace HAMR technology, with both schemes promising unprecedented increases in the data storage areal density beyond the super-paramagnetic size limit.

Isolation of EPR spectra and estimation of spin-states in two-component mixtures of paramagnets.

PubMed

Chabbra, Sonia; Smith, David M; Bode, Bela E

2018-04-26

The presence of multiple paramagnetic species can lead to overlapping electron paramagnetic resonance (EPR) signals. This complication can be a critical obstacle for the use of EPR to unravel mechanisms and aid the understanding of earth abundant metal catalysis. Furthermore, redox or spin-crossover processes can result in the simultaneous presence of metal centres in different oxidation or spin states. In this contribution, pulse EPR experiments on model systems containing discrete mixtures of Cr(i) and Cr(iii) or Cu(ii) and Mn(ii) complexes demonstrate the feasibility of the separation of the EPR spectra of these species by inversion recovery filters and the identification of the relevant spin states by transient nutation experiments. We demonstrate the isolation of component spectra and identification of spin states in a mixture of catalyst precursors. The usefulness of the approach is emphasised by monitoring the fate of the chromium species upon activation of an industrially used precatalyst system.

The Global Health Network and globalization of higher education

PubMed Central

LaPorte, Ron

1999-01-01

The year 2001 and the next millennium will soon be upon us. The major gains in health in the 20th century were primarily the result of improvements in public health including sanitation and immunization. Global health improvements will occur in the 21st century through improvements in information (in particular health training). We will describe a new paradigm for transnational training, the supercourse. In the next century global lecture-shareware training will take place, with Deming based quality control systems on the Internet. Faculty will thus share their best, most passionate lectures on the internet. During the past 100 years there has been a 25-year increase in life expectancy. It has been estimated that 24 of the 25 years were the result of prevention. Most prevention activity is sharing of information. We are working with leaders from WHO, the World Bank, IBM, NASA, PAHO to create a discipline called telepreventive medicine. This is the application of low band with information systems (the Internet) to large numbers of well people to prevent disease. One of the most important aspect of this work is the establishment globalisation of prevention education; the Supercourse. Question: What is the best way to improve health training/research? Answer: Improve the lectures. Question: How do we improve health training/research lectures: Answer: Have academic faculty worldwide share their lectures: Question: Will faculty share lectures? Answer: Yes, The Supercourse has 1107 faculty from 101 countries who created a Library of Lectures with 110 lectures on the Internet with quality control, and cutting edge cognitive design. This is being shared worldwide. We are developing a "Library of Lectures" with passionate lectures in public health from across the world such as seen here from South Africa. We propose to expand this to all areas of research in health. Our program consists of: Shareware: A Global faculty is developing and sharing their best, most passionate lectures. This benefits all. The experienced faculty member can beef up their lectures that are not cutting edge. New instructors reduce preparation time and improve their lectures, as they can employ state of the art lectures from others. Faculty in developing countries have access to current public health information for the first time. The concept is that of a library of lectures for all to use is in many ways similar to that of "shareware" on the computer. Statistical Quality Assurance: We have established a Deming Model of statistical quality control to monitor lectures over time Supporting the teachers: The Library of Lectures consists of exciting lectures by public health experts in the field. The classroom teacher "takes" them out for free like a library book. There is no direct teaching of students from a distance, rather the concept of the system is to provide cutting edge material for all faculty to present. Hypertext comic book: The lectures are icon driven, and the students can go deep into the Internet for more information through hyperlinks. It is based upon PowerPoint for ease of usage Presentation Speed: We have discovered technologies to speed access to lectures world wide Text books: The British Medical Association has put 2 current text books on line for us Multilingual: For global use, this must be multilingual, the first lecture is in 8 languages Voice-Sound Video: We are using state of the art Internet voice-video systems. We soon will be using "clickable" voice video We have published over 68 papers in leading medical journals including the Lancet, British Medical Journal, Nature Medicine among others. We are working with PAHO to put mirrored servers into every medical school in the Americas this year, with 5 years we should reach globally all medical schools. WHO has developed a Supercourse. Initial pilot studies reveal that 2500 individuals will see each lecture each year, which is 50 times that of our classroom teaching. We have beta tested lectures in 2 centers in Japan and one in South Africa with very positive results. We are now developing a Chinese Heritage course.

Can Teacher Self-Disclosure Increase Student Cognitive Learning?

ERIC Educational Resources Information Center

Stoltz, Molly; Young, Raymond W.; Bryant, Kevin L.

2014-01-01

Students (N =102) from communication courses at a Southern regional university was divided into two groups. Each group listened to a 10-minute taped lecture about personality types. One group listened to a lecture that included self-disclosures by the lecturer. The other group listened to a lecture that covered the same material but without the…

Students Pay Attention! Combating the Vigilance Decrement to Improve Learning during Lectures

ERIC Educational Resources Information Center

Young, Mark S.; Robinson, Stephanie; Alberts, Phil

2009-01-01

Maintaining student concentration in lectures has long been a challenge for lecturers. Pedagogical research consistently finds a drop in attention between 10 and 30 minutes into the lecture, which has been associated with the passive nature of the standard format, and has consequences for learning approaches and outcomes. A similar phenomenon has…

Retrieving Essential Material at the End of Lectures Improves Performance on Statistics Exams

ERIC Educational Resources Information Center

Lyle, Keith B.; Crawford, Nicole A.

2011-01-01

At the end of each lecture in a statistics for psychology course, students answered a small set of questions that required them to retrieve information from the same day's lecture. These exercises constituted retrieval practice for lecture material subsequently tested on four exams throughout the course. This technique is called the PUREMEM…

Students' Summaries of Mathematical Lectures: Comparing the Discourse of Students with the Discourse of Lectures

ERIC Educational Resources Information Center

Österholm, Magnus

2012-01-01

This study focuses on a distinction between process- and object-oriented discourses when characterising the discourse of university students' summaries of lectures and examining connections between students' discourse and the discourse of lectures. Results show that students' discourse in general tends to be process-oriented, by their use of…

The Lecture as a Transmedial Pedagogical Form: A Historical Analysis

ERIC Educational Resources Information Center

Friesen, Norm

2011-01-01

The lecture has been much maligned as a pedagogical form, yet it persists and even flourishes today in the form of the podcast, the TED talk, and the "smart" lecture hall. This article examines the lecture as a pedagogical genre, as "a site where differences between media are negotiated" (Franzel) as these media coevolve. This examination shows…

Assessment Outcome Is Weakly Correlated with Lecture Attendance: Influence of Learning Style and Use of Alternative Materials

ERIC Educational Resources Information Center

Horton, Dane M.; Wiederman, Steven D.; Saint, David A.

2012-01-01

The relation between lecture attendance and learning is surprisingly weak, and the role of learning styles in this is poorly understood. We hypothesized that 1) academic performance is related to lecture attendance and 2) learning style influences lecture attendance and, consequently, affects performance. We also speculated that the availability…

Development of a Tool to Evaluate Lecturers' Verbal Repertoire in Action

ERIC Educational Resources Information Center

van der Rijst, R. M.; Visser-Wijnveen, G. J.; Verloop, N.; van Driel, J. H.

2014-01-01

A broad communicative repertoire can help university lecturers to motivate and engage diverse student populations. The aim of this study is to develop and explore the usefulness and validity of a tool to identify patterns in lecturers' verbal repertoire. Speech act theory is presented as a framework to study lecturers' verbal…

Use of the Mid-Lecture Break in Chemistry Teaching: A Survey and Some Suggestions

ERIC Educational Resources Information Center

Smith, David K.

2006-01-01

This article uses student feedback to explore student attitudes towards the use of lecture breaks. The survey illustrates that undergraduates genuinely value such breaks, finding them educationally useful and enhancing their enjoyment of the lecture experience. By comparing and contrasting the perceived value of different types of lecture breaks,…

Web-Based Lecture Technologies and Learning and Teaching: A Study of Change in Four Australian Universities

ERIC Educational Resources Information Center

Gosper, Maree; McNeill, Margot; Woo, Karen; Phillips, Rob; Preston, Greg; Green, David

2011-01-01

The uptake of web-based lecture technologies for recording and delivering live lectures has increased markedly in recent years. Students have responded positively, and for many their use has transformed learning--freeing them up from rigid timetables by providing choice in lecture attendance and supporting learning by extending the lecture…

How Do Students and Lecturers Experience the Interactive Use of Handheld Technology in Large Enrolment Courses?

ERIC Educational Resources Information Center

Van Daele, Tom; Frijns, Carolien; Lievens, Jeroen

2017-01-01

Although constructivist theories have shown learning is accelerated by involvement and meaningful lecturer-student and student-student interaction, these ingredients are mostly absent from large attendance lectures. A number of studies have already focused on more active ways of learning in large lecture classrooms, most often by using student…

Web-Based Lecture Technologies and Learning and Teaching: A Study of Change in Four Australian Universities

ERIC Educational Resources Information Center

Gosper, M.; McNeill, M.; Phillips, R.; Preston, G.; Woo, K.; Green, D.

2010-01-01

The uptake of web-based lecture technologies for recording and delivering live lectures has increased markedly in recent years. Students have responded positively, and for many their use has transformed learning--freeing them up from rigid timetables by providing choice in lecture attendance and supporting learning by extending the lecture…

Pulling My Gut out--Simple Tools for Engaging Students in Gross Anatomy Lectures

ERIC Educational Resources Information Center

Chan, Lap Ki

2010-01-01

A lecture is not necessarily a monologue, promoting only passive learning. If appropriate techniques are used, a lecture can stimulate active learning too. One such method is demonstration, which can engage learners' attention and increase the interaction between the lecturer and the learners. This article describes two simple and useful tools for…

Advice for New and Student Lecturers on Probability and Statistics

ERIC Educational Resources Information Center

Larsen, Michael D.

2006-01-01

Lecture is a common presentation style that gives instructors a lot of control over topics and time allocation, but can limit active student participation and learning. This article presents some ideas to increase the level of student involvement in lecture. The examples and suggestions are based on the author's experience as a senior lecturer for…

Student Perceptions of Effective Use of Tablet PC Recorded Lectures in Undergraduate Mathematics Courses

ERIC Educational Resources Information Center

Yoon, Caroline; Sneddon, Jamie

2011-01-01

Tablet PCs have been increasingly used in undergraduate courses to create recorded lectures that are close copies of the live lectures. Research has shown that students are largely positive about the availability of tablet PC recorded lectures. However, there is some concern that the availability of such faithful recordings may encourage students…

5 CFR 551.423 - Time spent in training or attending a lecture, meeting, or conference.

Code of Federal Regulations, 2013 CFR

2013-01-01

... lecture, meeting, or conference. 551.423 Section 551.423 Administrative Personnel OFFICE OF PERSONNEL... lecture, meeting, or conference. (a) Time spent in training, whether or not it is under the purview of... attending a lecture, meeting, or conference shall be considered hours of work if attendance is: (1) During...

5 CFR 551.423 - Time spent in training or attending a lecture, meeting, or conference.

Code of Federal Regulations, 2012 CFR

2012-01-01

... lecture, meeting, or conference. 551.423 Section 551.423 Administrative Personnel OFFICE OF PERSONNEL... lecture, meeting, or conference. (a) Time spent in training, whether or not it is under the purview of... attending a lecture, meeting, or conference shall be considered hours of work if attendance is: (1) During...

Legends Lecture Series

NASA Image and Video Library

2010-11-09

John C. Stennis Space Center Director Patrick Scheuermann (second from right) stands with Legends Lecture Series presenters George Hopson (l to r), Jerry Hlass and J.R. Thompson. The three former leaders reflected on their experiences in the first of several planned lecture series sessions on Nov. 9, 2010. The lecture series is part of yearlong celebration of the 50th anniversary of Stennis.

Forum: The Lecture and Student Learning. The Lost Art of Lecturing: Cultivating Student Listening and Notetaking

ERIC Educational Resources Information Center

Meyer, Kevin R.; Hunt, Stephen K.

2017-01-01

As this forum's call for papers notes, lecture represents one of the more "controversial forms of instructional communication," yet remains a predominant instructional method in academia. Ironically, instructors face increasing pressure to abandon lecture at a time when these classes are popular and students readily enroll in lecture…

5 CFR 551.423 - Time spent in training or attending a lecture, meeting, or conference.

Code of Federal Regulations, 2014 CFR

2014-01-01

... lecture, meeting, or conference. 551.423 Section 551.423 Administrative Personnel OFFICE OF PERSONNEL... lecture, meeting, or conference. (a) Time spent in training, whether or not it is under the purview of... attending a lecture, meeting, or conference shall be considered hours of work if attendance is: (1) During...

Metaphor Use in Three UK University Lectures

ERIC Educational Resources Information Center

Low, Graham; Littlemore, Jeannette; Koester, Almut

2008-01-01

It has been claimed in recent years that, on the one hand, metaphor occurs in UK university lectures in ways that are likely to confuse ESL learners (Littlemore 2001, 2003) and on the other hand that US lecturers use it in highly structured ways, particularly involving linked clusters, to help organize the lecture and indicate the opinions of the…

Effect of Using Separate Laboratory and Lecture Courses for Introductory Crop Science on Student Performance.

ERIC Educational Resources Information Center

Wiebold, W. J.; Slaughter, Leon

1986-01-01

Reviews a study that examined the effects of laboratories on the grade performance of undergraduates in an introductory crop science course. Results indicated that students enrolled in lecture and laboratory concurrently did not receive higher lecture grades than students enrolled solely in lecture, but did have higher laboratory grades. (ML)

Pinch Hitter: The Effectiveness of Content Summaries Delivered by a Guest Lecturer in Online Course Videos

ERIC Educational Resources Information Center

Fanguy, Mik; Costley, Jamie; Baldwin, Matthew

2017-01-01

Lecture videos have become an increasingly prevalent and important source of learning content. Lecturergenerated summaries may be used during a video lecture to improve student recall. Furthermore, the integration of a guest lecturer into the classroom may be a beneficial educational practice drawing the learner's attention to specific content or…

Does Instructor's Image Size in Video Lectures Affect Learning Outcomes?

ERIC Educational Resources Information Center

Pi, Z.; Hong, J.; Yang, J.

2017-01-01

One of the most commonly used forms of video lectures is a combination of an instructor's image and accompanying lecture slides as a picture-in-picture. As the image size of the instructor varies significantly across video lectures, and so do the learning outcomes associated with this technology, the influence of the instructor's image size should…

An Interactive Mobile Lecturing Model: Enhancing Student Engagement with Face-to-Face Sessions

ERIC Educational Resources Information Center

Boyinbode, Olutayo; Ng'ambi, Dick; Bagula, Antoine

2013-01-01

Although use of podcasts and vodcasts are increasingly becoming popular in higher education, their use is usually unidirectional and therefore replicates the transmission mode of traditional face-to-face lectures. In this paper, the authors propose a tool, MOBILect, a mobile lecturing tool that enables users to comment on lecture vodcasts using…

A lecture on lecturing.

PubMed

Calnan, J

1976-11-01

There are major differences between a lecture and a paper for publication. Often the printed word is spoken at meetings, a kind of compulsive public reading which has robbed the lecturer of the chance of oratory and the audience of a little enjoyment. The simple fact is that although doctors read aloud badly (actors do this far better) most can learn to speak spontaneolsly and with animation; but this requires time and effort, both of which are donated in a miserly way. The successful lecturer is generous and considerate of his audience--a rare being at medical meetings.

Online thesis guidance management information system

NASA Astrophysics Data System (ADS)

Nasution, T. H.; Pratama, F.; Tanjung, K.; Siregar, I.; Amalia, A.

2018-03-01

The development of internet technology in education is still not maximized, especially in the process of thesis guidance between students and lecturers. Difficulties met the lecturers to help students during thesis guidance is the limited communication time and the compatibility of schedule between students and lecturer. To solve this problem, we designed an online thesis guidance management information system that helps students and lecturers to do thesis tutoring process anytime, anywhere. The system consists of a web-based admin app for usage management and an android-based app for students and lecturers.

Using Photo Story Lectures in an Online Astronomy Class

NASA Astrophysics Data System (ADS)

Caffey, James F.

2008-05-01

Photo Story is a free program from Microsoft that was designed to allow people to make videos from photos and add a voice narration to it. I use Photo Story to create video lectures in my online Astronomy class at Drury University in Springfield, Missouri. I take power point slides from my publisher, turn them into JPEG files, and add my voice over them to create the video lecture. Students at a distance say the lectures make them feel like they are back in the classroom. I will present several lectures.

Improving the method of low-temperature anisotropy of magnetic susceptibility (LT-AMS) measurements in air

NASA Astrophysics Data System (ADS)

Issachar, R.; Levi, T.; Lyakhovsky, V.; Marco, S.; Weinberger, R.

2016-07-01

This study examines the limitations of the method of low-temperature anisotropy of magnetic susceptibility (LT-AMS) measurements in air and presents technical improvements that significantly reduce the instrumental drift and measurement errors. We analyzed the temperature profile of porous chalk core after cooling in liquid nitrogen and found that the average temperature of the sample during the LT-AMS measurement in air is higher than 77K and close to 92K. This analysis indicates that the susceptibility of the paramagnetic minerals are amplified by a factor ˜3.2 relative to that of room temperature AMS (RT-AMS). In addition, it was found that liquid nitrogen was absorbed in the samples during immersing and contributed diamagnetic component of ˜-9 × 10-6 SI to the total mean susceptibility. We showed that silicone sheet placed around and at the bottom of the measuring coil is an effective thermal protection, preventing instrument drift by the cold sample. In this way, the measuring errors of LT-AMS reduced to the level of RT-AMS, allowing accurate comparison with standard AMS measurements. We examined the applicability of the LT-AMS measurements on chalk samples that consist <5% (weight) of paramagnetic minerals and showed that it helps to efficiently enhance the paramagnetic fabric. The present study offers a practical approach, which can be applied to various types of rocks to better delineate the paramagnetic phase using conventional equipment.

Emergence of superconductivity and magnetic ordering tuned by Fe-vacancy in alkali-metal Fe chalcogenides RbxFe2-ySe2

NASA Astrophysics Data System (ADS)

Kobayashi, Yoshiaki; Kototani, Shouhei; Itoh, Masayuki; Sato, Masatoshi

2014-12-01

Samples of RbxFe2-ySe2 exhibiting superconductivity [superconducting (SC) samples] undergo a phase-separation into two phases, a Fe-vacancy ordered phase with antiferromagnetic (AFM) transition at TN1~500 K (AFM1 phase) and a phase with little Fe- vacancy and SC transition at Tc~30 K (SC phase). The samples of RbxFe2-ySe2 exhibiting no SC behaviour (non-SC samples) are phase-separated into three phases, the AFM1 phase, another AFM phase with TN2 ~150 K (AFM2 phase), and a paramagnetic phase with no SC transitions (paramagnetic non-SC phase). In this paper, we present the experimental results of magnetic susceptibility, electrical resistivity, and NMR measurements on single crystals of RbxFe2-ySe2 to reveal physical properties of these co-existing phases in the SC and non-SC samples. The 87Rb and 77Se NMR spectra show that the Fe vacancy concentration is very small in the Fe planes of the SC phase, whereas the AFM2 and paramagnetic non-SC phases in non-SC samples have larger amount of Fe vacancies. The randomness induced by the Fe vacancy in the non-SC samples makes the AFM2 and paramagnetic non-SC phases insulating/semiconducting and magnetically active, resulting in the absence of the superconductivity in RbxFe2-ySe2.

Solution 1H NMR characterization of the axial bonding of the two His in oxidized human cytoglobin

PubMed Central

Bondarenko, Vasyl; Dewilde, Sylvia; Moens, Luc; La Mar, Gerd N.

2008-01-01

Solution 1H NMR spectroscopy has been used to determine the relative strengths (covalency) of the two axial His-Fe bonds in paramagnetic, S = 1/2, human met-cytoglobin. The sequence specific assignments of crucial portions of the proximal and distal helices, together with the magnitude of hyperfine shifts and paramagnetic relaxation, establish that His81 and His113, at the canonical positions E7 and F8 in the myoglobin fold, respectively, are ligated to the iron. The characterized complex (~90%) in solution has protohemin oriented as in crystals, with the remaining ~10% exhibiting the hemin orientation rotated 180° about the α-, γ-meso axis. No evidence could be obtained for any five-coordinate complex (<1%) in equilibrium with the six-coordinate complexes. Extensive sequence-specific assignments on other dipolar shifted helical fragments and loops, together with available alternate crystal coordinates for the complex, allowed the robust determination of the orientation and anisotropies of the paramagnetic susceptibility tensor. The tilt of the major axis is controlled by the His-Fe-His vector, and the rhombic axes by the mean of the imidazole orientations for the two His. The anisotropy of the paramagnetic susceptibility tensor allowed the quantitative factoring of the hyperfine shifts for the two axial His to reveal indistinguishable pattern and magnitudes of the contact shifts or π spin densities, and hence, indistinguishable Fe-imidazole covalency for both Fe-His bonds. PMID:17002396

Dynamical arrest with zero complexity: The unusual behavior of the spherical Blume-Emery-Griffiths disordered model

NASA Astrophysics Data System (ADS)

Rainone, Corrado; Ferrari, Ulisse; Paoluzzi, Matteo; Leuzzi, Luca

2015-12-01

The short- and long-time dynamics of model systems undergoing a glass transition with apparent inversion of Kauzmann and dynamical arrest glass transition lines is investigated. These models belong to the class of the spherical mean-field approximation of a spin-1 model with p -body quenched disordered interaction, with p >2 , termed spherical Blume-Emery-Griffiths models. Depending on temperature and chemical potential the system is found in a paramagnetic or in a glassy phase and the transition between these phases can be of a different nature. In specific regions of the phase diagram coexistence of low-density and high-density paramagnets can occur, as well as the coexistence of spin-glass and paramagnetic phases. The exact static solution for the glassy phase is known to be obtained by the one-step replica symmetry breaking ansatz. Different scenarios arise for both the dynamic and the thermodynamic transitions. These include: (i) the usual random first-order transition (Kauzmann-like) for mean-field glasses preceded by a dynamic transition, (ii) a thermodynamic first-order transition with phase coexistence and latent heat, and (iii) a regime of apparent inversion of static transition line and dynamic transition lines, the latter defined as a nonzero complexity line. The latter inversion, though, turns out to be preceded by a dynamical arrest line at higher temperature. Crossover between different regimes is analyzed by solving mode-coupling-theory equations near the boundaries of paramagnetic solutions and the relationship with the underlying statics is discussed.

Towards interpretation of intermolecular paramagnetic relaxation enhancement outside the fast exchange limit.

PubMed

Ceccon, Alberto; Marius Clore, G; Tugarinov, Vitali

2016-09-01

In an exchanging system between major and minor species, the transverse paramagnetic relaxation enhancement rate observed on the resonances of the major species (Γ 2 (app) ) is dependent upon the exchange regime between the species. Quantitative analysis of PRE data in such systems typically assumes that the overall exchange rate k ex between the species is fast on the PRE time scale (k ex ≫ Γ2). Recently, we have characterized the kinetics of binding of the model protein ubiquitin to large (LUV) and small (SUV) unilamellar lipid-based nanoparticles or liposomes (Ceccon A, Tugarinov V, Bax A, Clore GM (2016). J Am Chem Soc 138:5789-5792). Building upon these results and taking advantage of a strong paramagnetic agent with an isotropic g-tensor, Gd(3+), we were able to measure intermolecular methyl carbon and proton PREs between paramagnetically-tagged liposomes and ubiquitin. In the limit of fast exchange (k ex ≫ Γ2) the ratio of the apparent proton to carbon methyl PREs, ((1)Hm-Γ 2 (app) )/((13)Cm-Γ 2 (app) ), is equal to the square of the ratio of the gyromagnetic ratios of the two nuclei, (γΗ/γC)(2). However, outside the fast exchange regime, under intermediate exchange conditions (e.g. when Γ2 is comparable in magnitude to k ex) the ((1)Hm-Γ 2 (app) )/((13)Cm-Γ 2 (app) ) ratio provides a reliable measure of the 'true' methyl PREs.

Interactive Lecture Experiments in Large Introductory Physics Classes

NASA Astrophysics Data System (ADS)

Milner-Bolotin, Marina M.; Kotlicki, A.; Rieger, G.; Bates, F.; Moll, R.; McPhee, K.; Nashon, S.

2006-12-01

We describe Interactive Lecture Experiments (ILE), which build on Interactive Lecture Demonstrations proposed by Sokoloff and Thornton (2004) and extends it by providing students with the opportunity to analyze experiments demonstrated in the lecture outside of the classroom. Real time experimental data is collected, using Logger Pro combined with the digital video technology. This data is uploaded to the Internet and made available to the students for further analysis. Student learning is assessed in the following lecture using conceptual questions (clickers). The goal of this project is to use ILE to make large lectures more interactive and promote student interest in science, critical thinking and data analysis skills. We report on the systematic study conducted using the Colorado Learning Attitudes about Science Survey, Force Concept Inventory, open-ended physics problems and focus group interviews to determine the impact of ILE on student academic achievement, motivation and attitudes towards physics. Three sections of students (750 students) experienced four ILE experiments. The surveys were administered twice and academic results for students who experienced the ILE for a particular topic were compared to the students, from a different section, who did not complete the ILE for that topic. Additional qualitative data on students’ attitudes was collected using open ended survey questions and interviews. We will present preliminary conclusions about the role of ILEs as an effective pedagogy in large introductory physics courses. Sokoloff, D.R. and R.K. Thornton (2004). Interactive Lecture Demonstrations: Active Learning in Introductory Physics, J.Wiley & Sons, INC. Interactive Lecture Experiments: http://www.physics.ubc.ca/ year1lab/p100/LectureLabs/lectureLabs.html

Lecture Evaluations by Medical Students: Concepts That Correlate With Scores.

PubMed

Jen, Aaron; Webb, Emily M; Ahearn, Bren; Naeger, David M

2016-01-01

The didactic lecture remains one of the most popular teaching formats in medical education; yet, factors that most influence lecturing success in radiology education are unknown. The purpose of this study is to identify patterns of narrative student feedback that are associated with relatively higher and lower evaluation scores. All student evaluations from our core radiology elective during 1 year were compiled. All evaluation comments were tagged, to identify discrete descriptive concepts. Correlation coefficients were calculated, for each tag with mean evaluation scores. Tags that were the most strongly associated with the highest- versus lowest-rated (> or < 1 SD) lectures were identified. A total of 3,262 comments, on 273 lectures, rated by 77 senior medical students, were analyzed. The mean lecture score was 8.96 ± 0.62. Three tags were significantly positively correlated with lecture score: "interactive"; "fun/engaging"; and "practical/important content" (r = 0.39, r = 0.34, and r = 0.32, respectively; all P < .001). More tags (n = 12) were significantly negatively correlated with score; the three tags with the strongest such correlation were: "not interactive"; "poorly structured or unevenly paced"; and "content too detailed or abundant" (r = -0.44, r = -0.39, and r = -0.36, respectively; all P < .001). Analysis of only the highest- and lowest-rated lectures yielded similar results. Several factors were identified that were strongly associated with lecture score. Among the actionable characteristics, interactive lectures with appropriately targeted content (ie, practical/useful) were the most highly rated. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Stereoscopic Three-Dimensional Neuroanatomy Lectures Enhance Neurosurgical Training: Prospective Comparison with Traditional Teaching.

PubMed

Clark, Anna D; Guilfoyle, Mathew R; Candy, Nicholas G; Budohoski, Karol P; Hofmann, Riikka; Barone, Damiano G; Santarius, Thomas; Kirollos, Ramez W; Trivedi, Rikin A

2017-12-01

Stereoscopic three-dimensional (3D) imaging is increasingly used in the teaching of neuroanatomy and although this is mainly aimed at undergraduate medical students, it has enormous potential for enhancing the training of neurosurgeons. This study aims to assess whether 3D lecturing is an effective method of enhancing the knowledge and confidence of neurosurgeons and how it compares with traditional two-dimensional (2D) lecturing and cadaveric training. Three separate teaching sessions for neurosurgical trainees were organized: 1) 2D course (2D lecture + cadaveric session), 2) 3D lecture alone, and 3) 3D course (3D lecture + cadaveric session). Before and after each session, delegates were asked to complete questionnaires containing questions relating to surgical experience, anatomic knowledge, confidence in performing procedures, and perceived value of 3D, 2D, and cadaveric teaching. Although both 2D and 3D lectures and courses were similarly effective at improving self-rated knowledge and understanding, the 3D lecture and course were associated with significantly greater gains in confidence reported by the delegates for performing a subfrontal approach and sylvian fissure dissection. Stereoscopic 3D lectures provide neurosurgical trainees with greater confidence for performing standard operative approaches and enhances the benefit of subsequent practical experience in developing technical skills in cadaveric dissection. Copyright © 2017. Published by Elsevier Inc.

Evaluation of doctors’ performance as facilitators in basic medical science lecture classes in a new Malaysian medical school

PubMed Central

Ismail, Salwani; Salam, Abdus; Alattraqchi, Ahmed G; Annamalai, Lakshmi; Chockalingam, Annamalai; Elena, Wan Putri; Rahman, Nor Iza A; Abubakar, Abdullahi Rabiu; Haque, Mainul

2015-01-01

Background Didactic lecture is the oldest and most commonly used method of teaching. In addition, it is considered one of the most efficient ways to disseminate theories, ideas, and facts. Many critics feel that lectures are an obsolete method to use when students need to perform hands-on activities, which is an everyday need in the study of medicine. This study evaluates students’ perceptions regarding lecture quality in a new medical school. Methods This was a cross-sectional study conducted of the medical students of Universiti Sultan Zainal Abidin. The study population was 468 preclinical medical students from years 1 and 2 of academic year 2012–2013. Data were collected using a validated instrument. There were six different sections of questions using a 5-point Likert scale. The data were then compiled and analyzed, using SPSS version 20. Results The response rate was 73%. Among 341 respondents, 30% were male and 70% were female. Eighty-five percent of respondents agree or strongly agree that the lectures had met the criteria with regard to organization of lecture materials. Similarly, 97% of students agree or strongly agree that lecturers maintained adequate voices and gestures. Conclusion Medical students are quite satisfied with the lecture classes and the lectures. However, further research is required to identify student-centered teaching and learning methods to promote active learning. PMID:25878516

An analysis of lecture video utilization in undergraduate medical education: associations with performance in the courses

PubMed Central

McNulty, John A; Hoyt, Amy; Gruener, Gregory; Chandrasekhar, Arcot; Espiritu, Baltazar; Price, Ron; Naheedy, Ross

2009-01-01

Background Increasing numbers of medical schools are providing videos of lectures to their students. This study sought to analyze utilization of lecture videos by medical students in their basic science courses and to determine if student utilization was associated with performance on exams. Methods Streaming videos of lectures (n = 149) to first year and second year medical students (n = 284) were made available through a password-protected server. Server logs were analyzed over a 10-week period for both classes. For each lecture, the logs recorded time and location from which students accessed the file. A survey was administered at the end of the courses to obtain additional information about student use of the videos. Results There was a wide disparity in the level of use of lecture videos by medical students with the majority of students accessing the lecture videos sparingly (60% of the students viewed less than 10% of the available videos. The anonymous student survey revealed that students tended to view the videos by themselves from home during weekends and prior to exams. Students who accessed lecture videos more frequently had significantly (p < 0.002) lower exam scores. Conclusion We conclude that videos of lectures are used by relatively few medical students and that individual use of videos is associated with the degree to which students are having difficulty with the subject matter. PMID:19173725

Evaluation of doctors' performance as facilitators in basic medical science lecture classes in a new Malaysian medical school.

PubMed

Ismail, Salwani; Salam, Abdus; Alattraqchi, Ahmed G; Annamalai, Lakshmi; Chockalingam, Annamalai; Elena, Wan Putri; Rahman, Nor Iza A; Abubakar, Abdullahi Rabiu; Haque, Mainul

2015-01-01

Didactic lecture is the oldest and most commonly used method of teaching. In addition, it is considered one of the most efficient ways to disseminate theories, ideas, and facts. Many critics feel that lectures are an obsolete method to use when students need to perform hands-on activities, which is an everyday need in the study of medicine. This study evaluates students' perceptions regarding lecture quality in a new medical school. This was a cross-sectional study conducted of the medical students of Universiti Sultan Zainal Abidin. The study population was 468 preclinical medical students from years 1 and 2 of academic year 2012-2013. Data were collected using a validated instrument. There were six different sections of questions using a 5-point Likert scale. The data were then compiled and analyzed, using SPSS version 20. The response rate was 73%. Among 341 respondents, 30% were male and 70% were female. Eighty-five percent of respondents agree or strongly agree that the lectures had met the criteria with regard to organization of lecture materials. Similarly, 97% of students agree or strongly agree that lecturers maintained adequate voices and gestures. Medical students are quite satisfied with the lecture classes and the lectures. However, further research is required to identify student-centered teaching and learning methods to promote active learning.

Online Lectures in Undergraduate Medical Education: Scoping Review.

PubMed

Tang, Brandon; Coret, Alon; Qureshi, Aatif; Barron, Henry; Ayala, Ana Patricia; Law, Marcus

2018-04-10

The adoption of the flipped classroom in undergraduate medical education calls on students to learn from various self-paced tools-including online lectures-before attending in-class sessions. Hence, the design of online lectures merits special attention, given that applying multimedia design principles has been shown to enhance learning outcomes. The aim of this study was to understand how online lectures have been integrated into medical school curricula, and whether published literature employs well-accepted principles of multimedia design. This scoping review followed the methodology outlined by Arksey and O'Malley (2005). Databases, including MEDLINE, PsycINFO, Education Source, FRANCIS, ERIC, and ProQuest, were searched to find articles from 2006 to 2016 related to online lecture use in undergraduate medical education. In total, 45 articles met our inclusion criteria. Online lectures were used in preclinical and clinical years, covering basic sciences, clinical medicine, and clinical skills. The use of multimedia design principles was seldom reported. Almost all studies described high student satisfaction and improvement on knowledge tests following online lecture use. Integration of online lectures into undergraduate medical education is well-received by students and appears to improve learning outcomes. Future studies should apply established multimedia design principles to the development of online lectures to maximize their educational potential. ©Brandon Tang, Alon Coret, Aatif Qureshi, Henry Barron, Ana Patricia Ayala, Marcus Law. Originally published in JMIR Medical Education (http://mededu.jmir.org), 10.04.2018.

Annual Advances in Cancer Prevention Lecture | Division of Cancer Prevention

Cancer.gov

2015 Keynote Lecture HPV Vaccination: Preventing More with Less A special keynote lecture became part of the NCI summer Curriculum in Cancer Prevention in 2000. This lecture will be held on Thursday, July 23, 2015 at 3:00pm at Masur Auditorium, Building 10, NIH Main Campus, Bethesda, MD. This year’s keynote speaker is Dr. Douglas Lowy, NCI Acting Director. |

An Understanding Information Management System for a Real-Time Interactive Distance Education Environment

ERIC Educational Resources Information Center

He, Aiguo

2009-01-01

A real-time interactive distance lecture is a joint work that should be accomplished by the effort of the lecturer and his students in remote sites. It is important for the lecturer to get understanding information from the students which cannot be efficiently collected by only using video/audio channels between the lecturer and the students. This…

A Comparison of a Traditional Lecture-Based and Online Supplemental Video and Lecture-Based Approach in an Engineering Statics Class

ERIC Educational Resources Information Center

Halupa, Colleen M.; Caldwell, Benjamin W.

2015-01-01

This quasi-experimental research study evaluated two intact undergraduate engineering statics classes at a private university in Texas. Students in the control group received traditional lecture, readings and homework assignments. Those in the experimental group also were given access to a complete set of online video lectures and videos…

Centre for Advancement of Teaching Education Monograph Series. No. 2. Lessons Not Lectures.

ERIC Educational Resources Information Center

Linacre, E. T.

In view of the well-known disadvantages of lecturing, and the practicability of teaching without them, why does lecturing remain the standard method in universities? To increase the chances of lectures being good, they should be fewer, and to offset their deficiencies they should be regarded as only one component of a combination of methods used…

Taxonomy of Lecture Note-Taking Skills and Subskills

ERIC Educational Resources Information Center

Al-Musalli, Alaa M.

2015-01-01

Note taking (NT) in lectures is as active a skill as listening, which stimulates it, and as challenging as writing, which is the end product. Literature on lecture NT misses an integration of the processes involved in listening with those in NT. In this article, a taxonomy is proposed of lecture NT skills and subskills based on a similar list…

CMSC-130 Introductory Computer Science, Lecture Notes

DTIC Science & Technology

1993-07-01

Introductory Computer Science lecture notes are used in the classroom for teaching CMSC 130, an introductory computer science course , using the ...Unit Testing 2. The Syntax Of Subunits Will Be Studied In The Subsequent Course CMSC130 -5- Lecture 11 TOP-DOWN TESTING Data Processor Procedure...used in the preparation of these lecture notes: Reference Manual For The Ada Prosramming Language, ANSI/MIL-STD

Content Based Lecture Video Retrieval Using Speech and Video Text Information

ERIC Educational Resources Information Center

Yang, Haojin; Meinel, Christoph

2014-01-01

In the last decade e-lecturing has become more and more popular. The amount of lecture video data on the "World Wide Web" (WWW) is growing rapidly. Therefore, a more efficient method for video retrieval in WWW or within large lecture video archives is urgently needed. This paper presents an approach for automated video indexing and video…

Forum: The Lecture and Student Learning. Sound Decision Making about the Lecture's Role in the College Classroom

ERIC Educational Resources Information Center

Waldeck, Jennifer H.; Weimer, Maryellen

2017-01-01

College instructors use lecture and its current counterpoint--active learning--widely and often rely on both strategies, but the question of which best promotes student learning has become a debate that ignores the fact that learning can result from both. Students still listen to and learn from lectures. They pass exams, obtain degrees, and…

Lecturers' Awareness and Utilization of Instructional Media in the State-Owned Colleges of Education, South-West Nigeria

ERIC Educational Resources Information Center

Fakomogbon, Micheal Ayodele; Olanrewaju, Olatayo Solomon; Soetan, Aderonke Kofo

2015-01-01

This paper investigated the awareness and utilization of instructional media (IM) based on gender of the lecturers of tertiary institutions in Nigeria. It was a descriptive type of survey research. All lecturers of Colleges of Education in Southwest geo-political zone of Nigeria formed the population. Some 621 lecturers were randomly selected.…

Reassessing the Value of University Lectures. Issues and Ideas Paper

ERIC Educational Resources Information Center

French, Sarah; Kennedy, Gregor

2016-01-01

Over the past few years the question of whether the lecture is an effective teaching method has been one of the most heatedly debated topics in the field of higher education. While research on the effectiveness of lectures has been carried out since at least the 1960s, the value of the lecture has been increasingly questioned recently for a number…

Annual Advances in Cancer Prevention Lecture | Division of Cancer Prevention

Cancer.gov

2016 Keynote Lecture Polyvalent Vaccines Targeting Oncogenic Driver Pathways A special keynote lecture became part of the NCI Summer Curriculum in Cancer Prevention in 2000. This lecture will be held on Thursday, July 21, 2016 at 1:30pm at Masur Auditorium, Building 10, NIH Main Campus, Bethesda, MD. This year’s keynote speaker is Dr. Mary L. (Nora) Disis, MD. |

Towards Improvement of Student Learning Outcomes: An Assessment of the Professional Development Needs of Lecturers at Kenyan Universities

ERIC Educational Resources Information Center

NaliakaMukhale, Phoebe; Hong, Zhu

2017-01-01

The aim of this study was to explore the professional development needs of lecturers at Kenyan universities. Specifically, the study investigated the challenges that lecturers and their learners face while in class. It also explored the professional development needs of the lecturers, preferred modes of delivery of the professional development…

"But They Won't Come to Lectures..." The Impact of Audio Recorded Lectures on Student Experience and Attendance

ERIC Educational Resources Information Center

Larkin, Helen E.

2010-01-01

The move to increasingly flexible platforms for student learning and experience through provision of online lecture recordings is often interpreted by educators as students viewing attendance at lectures as optional. The trend toward the use of this technology is often met with resistance from some academic staff who argue that student attendance…

If You Record It, Some Won't Come: Using Lecture Capture in Introductory Psychology

ERIC Educational Resources Information Center

Drouin, Michelle A.

2014-01-01

In this study, I examined the effects of offering supplemental video lecture recordings to students in a face-to-face introductory psychology course. I employed a quasi-experimental design, in which one section had lectures recordings available (recordings of the face-to-face lecture) and one section did not, and I examined whether class section…

The Twenty-Third Dudley Allen Sargent Commemorative Lecture 2003: Knowledge and Physical Activity in Higher Education

ERIC Educational Resources Information Center

Estes, Steven G.

2003-01-01

In preparation for this lecture, the author read, among other studies, previous Sargent, Homans, and Hannah lectures. These papers read well, and, they continue to inform people today. Importantly, these lecturers addressed timely issues that confronted physical education in higher education and to some extent shaped the field as one now knows it.…

22 CFR 63.4 - Grants to foreign participants to lecture, teach, and engage in research.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Grants to foreign participants to lecture... EXCHANGE PROGRAM § 63.4 Grants to foreign participants to lecture, teach, and engage in research. A citizen or national of a foreign country who has been awarded a grant to lecture, teach, and engage in...

22 CFR 63.4 - Grants to foreign participants to lecture, teach, and engage in research.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Grants to foreign participants to lecture... EXCHANGE PROGRAM § 63.4 Grants to foreign participants to lecture, teach, and engage in research. A citizen or national of a foreign country who has been awarded a grant to lecture, teach, and engage in...

22 CFR 63.4 - Grants to foreign participants to lecture, teach, and engage in research.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Grants to foreign participants to lecture... EXCHANGE PROGRAM § 63.4 Grants to foreign participants to lecture, teach, and engage in research. A citizen or national of a foreign country who has been awarded a grant to lecture, teach, and engage in...

22 CFR 63.4 - Grants to foreign participants to lecture, teach, and engage in research.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Grants to foreign participants to lecture... EXCHANGE PROGRAM § 63.4 Grants to foreign participants to lecture, teach, and engage in research. A citizen or national of a foreign country who has been awarded a grant to lecture, teach, and engage in...

An Assessment of Teachers' Preference for Lecture Delivery Methods in Medical Education

ERIC Educational Resources Information Center

Seth, Vikas; Upadhyaya, Prerna; Ahmad, Mushtaq; Kumar, Virendra

2010-01-01

The aim of the study was to assess the medical teachers' preference for various lecture delivery methods like the lectures using chalkboard, utilizing transparencies with an overhead projector (OHP) or lectures using a PowerPoint presentation and their frequency of use of teaching aids. The faculty of the medical college was asked to fill in the…

The Effects of Pre-Lecture Quizzes on Test Anxiety and Performance in a Statistics Course

ERIC Educational Resources Information Center

Brown, Michael J.; Tallon, Jennifer

2015-01-01

The purpose of our study was to examine the effects of pre-lecture quizzes in a statistics course. Students (N = 70) from 2 sections of an introductory statistics course served as participants in this study. One section completed pre-lecture quizzes whereas the other section did not. Completing pre-lecture quizzes was associated with improved exam…

Reasons to Rethink the Use of Audio and Video Lectures in Online Courses

ERIC Educational Resources Information Center

Stetz, Thomas A.; Bauman, Antonina A.

2013-01-01

Recent technological developments allow any instructor to create audio and video lectures for the use in online classes. However, it is questionable if it is worth the time and effort that faculty put into preparing those lectures. This paper presents thirteen factors that should be considered before preparing and using audio and video lectures in…

Increasing Students' Attendance at Lecture and Preparation for Lecture by Allowing Students to Use Their Notes during Tests

ERIC Educational Resources Information Center

Messling, Paul A., III; Dermer, Marshall L.

2009-01-01

In an upper-division, college course with a lecture component and two laboratory sections, we experimentally evaluated a treatment package that included this contingency: "only if students attended lecture and submitted notes for each day's reading assignment could they use their notes during a later test," and instructions about the contingency.…

Effectiveness of lectures attended via interactive video conferencing versus in-person in preparing third-year internal medicine clerkship students for Clinical Practice Examinations (CPX).

PubMed

Bertsch, Tania F; Callas, Peter W; Rubin, Alan; Caputo, Michael P; Ricci, Michael A

2007-01-01

The current practice in medical education is to place students at off-site locations. The effectiveness of these students attending remote lectures using interactive videoconferencing needs to be evaluated. To determine whether lecture content covering clinical objectives is learned by medical students located at remote sites. During the University of Vermont medicine clerkship, 52 medical students attended lectures both in person and via 2-way videoconferencing over a telemedicine network. The study used a crossover design, such that all students attended half of the lectures in person and half using videoconferencing. At the end of the clerkship, students were assessed via a Clinical Practice Examination (CPX), with each student completing 1 exam for material learned in person and 1 for material learned over telemedicine. Exam scores did not differ for the 2 lecture modes, with a mean score of 76% for lectures attended in person and a mean score of 78% for lectures attended via telemedicine (p = 0.66). Students learn content focused on clinical learning objectives as well using videoconferencing as they do in the traditional classroom setting.

Comparative use of podcasts vs. lecture transcripts as learning aids for dental students.

PubMed

Allen, Kenneth L; Katz, Ralph V

2011-06-01

The purpose of this project was to describe dental students' use of lecture podcasts versus written lecture transcripts as learning aids under three different circumstances: studying for an exam, reviewing an attended lecture, and reviewing a missed lecture. Additional analyses were performed to see whether demographic differences (e.g., age, gender, language skills, and computer skills) or grade differences were associated with preferences for using podcast versus written lecture transcripts of class notes. Fifty-one percent (n=171) of the second-year dental students at the New York University College of Dentistry voluntarily participated in this survey. The major findings were that 1) a high percentage of students (70-92 percent) used one or both aids in all three utilization circumstances with a consistent preference for podcast use, especially when reviewing a missed lecture; 2) course grades were not associated with the preferred use of either lecture aid; and 3) over half the students listened to the podcasts at speeds that were one and one-half or two times faster than normal speech, especially younger students. Further studies are warranted to delve into the current student generation's preferred learning styles and the resultant learning outcomes associated with those preferences.

Student preparation time for traditional lecture versus team-based learning in a pharmacotherapy course.

PubMed

DeJongh, Beth; Lemoine, Nicia; Buckley, Elizabeth; Traynor, Laura

2018-03-01

Determine how much time students spent preparing for traditional lecture versus team-based learning (TBL) for a pharmacotherapy course and determine if time spent in each pedagogy was within stated expectations for the course. Instructors used a combination of traditional lecture and TBL to deliver material. Before each lecture, instructors recorded the amount of time students spent preparing for each method using a one-question clicker-response survey. Instructors delivered 16 hours of TBL, 32 hours of traditional lecture, and eight hours of a mix of TBL and traditional lecture. The median of students completing the survey each week was 89. A large percentage of the class (40.9%) did not prepare for traditional lecture while only 3.4% did not prepare for TBL. About 61% of students spent between 30 min and two hours preparing for a two-hour TBL session and only 10% spent more than three hours preparing. Results of this project show students spend little time preparing for traditional lectures without in-class accountability, which may give students the perception that TBL requires too much preparation time. Copyright © 2017. Published by Elsevier Inc.

Active Learning in PhysicsTechnology and Research-based Techniques Emphasizing Interactive Lecture Demonstrations

NASA Astrophysics Data System (ADS)

Thornton, Ronald

2010-10-01

Physics education research has shown that learning environments that engage students and allow them to take an active part in their learning can lead to large conceptual gains compared to traditional instruction. Examples of successful curricula and methods include Peer Instruction, Just in Time Teaching, RealTime Physics, Workshop Physics, Scale-Up, and Interactive Lecture Demonstrations (ILDs). An active learning environment is often difficult to achieve in lecture sessions. This presentation will demonstrate the use of sequences of Interactive Lecture Demonstrations (ILDs) that use real experiments often involving real-time data collection and display combined with student interaction to create an active learning environment in large or small lecture classes. Interactive lecture demonstrations will be done in the area of mechanics using real-time motion probes and the Visualizer. A video tape of students involved in interactive lecture demonstrations will be shown. The results of a number of research studies at various institutions (including international) to measure the effectiveness of ILDs and guided inquiry conceptual laboratories will be presented.

Flipped classroom or an active lecture?

PubMed

Pickering, James D; Roberts, David J H

2018-01-01

Recent changes in anatomy education have seen the introduction of flipped classrooms as a replacement to the traditional didactic lecture. This approach utilizes the increasing availability of digital technology to create learning resources that can be accessed prior to attending class, with face-to-face sessions then becoming more student-centered via discussion, collaborative learning, and problem-solving activities. Although this approach may appear intuitive, this viewpoint commentary presents a counter opinion and highlights a simple alternative that utilizes evidence-based active learning approaches as part of the traditional lecture. The active lecture takes the traditional lecture, and (1) ensures the lecture content is relevant and has clear objectives, (2) contains lecture material that is designed according to the latest evidence-base, (3) complements it with additional supplementary material, (4) creates space to check prior understanding and knowledge levels, and (5) utilizes suitable technology to facilitate continual engagement and interaction. Clin. Anat. 31:118-121, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Black Holes and Qubits

NASA Astrophysics Data System (ADS)

Borsten, L.; Duff, M. J.; Rubens, W.

These notes have been compiled to accompany a series of four lectures given at the Kinki University Quantum Computing Series Summer School on Decoherence, Entanglement and Entropy, August 2009 at the Oxford Kobe Institute (Kobe, Japan). Each of the four lectures focuses on a particular topic falling under the broad umbrella of the "black-hole/qubit correspondence". Lecture I introduces the first instance of the black-hole/qubit correspondence, the relationship between the entanglement of three qubits and the entropy of STU black holes. Lecture II develops this correspondence to the case of {N} = 8 black holes and the tripartite entanglement of seven qubits. Lecture III examines the use of Jordan algebras and the Freudenthal triple system, which capture the U-duality symmetries of these black hole systems, in entanglement classification. Lecture IV introduces the superqubit, a natural candidate to represent supersymmetric quantum information. These lectures draw on work done with D. Dahanayake, H. Ebrahim, S. Ferrara and A. Marrani whose efforts are most gratefully acknowledged.

Study of the changes in the magnetic properties of stainless steels under mechanical treatment

NASA Astrophysics Data System (ADS)

Iankov, R.; Rusanov, V.; Paneva, D.; Mitov, I.; Trautwein, A. X.

2016-12-01

Six types of stainless steels (SS) were studied for changes in its structure and magnetic properties under mechanical treatment. Depending on intensity and duration of the process of plastic deformation and the SS type the paramagnetic austenite structure transforms partially to completely into ferrite structure with ferromagnetic behaviour. Some of the SS tested were found slightly modified yet in the process of its manufacturing. Only one SS type with high Ni content preserved its structure and paramagnetic properties even after very intense mechanical treatment.

Low-temperature thermal decomposition of heavy petroleum distillates: interconnection between the electrical properties and concentration of paramagnetic centres

NASA Astrophysics Data System (ADS)

Dolomatov, M.; Gafurov, M.; Rodionov, A.; Mamin, G.; González, L. Miquel; Vakhin, A.; Petrov, A.; Bakhtizin, R.; Khairudinov, I.; Orlinskii, S.

2018-05-01

Changes of paramagnetic centers (PC) concentration in petroleum dispersed systems (PDS) are studied in the process of low-temperature thermolysis. Complex investigation of physicochemical, rheological and electrophysical properties of high-boiling oil fractions is performed. Based on the analysis of the experimental results it can be concluded that the PDS under investigation can be regarded as amorphous broadband organic semiconductors for which PC plays a role of dopant. It shows the perspectives of the asphaltenes usage as a basis for the photovoltaic devices.

Electron paramagnetic resonance of gamma-irradiated single crystals of 3-nitroacetanilide

NASA Astrophysics Data System (ADS)

Aşik, Biray

2008-06-01

The electron paramagnetic resonance of single crystals of 3-nitroacetanilide has been observed and analyzed for different orientations of the crystal in the magnetic field, after being damaged at 300 K by γ-irradiation. The crystals have been investigated between 123 and 300 K. The spectra were found to be temperature independent. The irradiation of 3-nitroacetanilide by γ-rays produces radicals at the nitrogen atoms in the molecule. The principal values of the hyperfine coupling tensor of the unpaired electron and the principal values of the g-tensor were determined.

EPR study of free radical in gamma-irradiated bis(cyclopentadienyl)zirconium dichloride single crystal

NASA Astrophysics Data System (ADS)

Caliskan, Betul; Caliskan, Ali Cengiz

2017-06-01

Bis(cyclopentadienyl)zirconium dichloride (BCZD; zirconocene dichloride) single crystals were exposed to 60Co-γ irradiation at room temperature. The irradiated single crystals were investigated between 125 and 470 K by electron paramagnetic resonance spectroscopy. The spectra of the crystals were found to be temperature independent. The paramagnetic center was attributed to the cyclopentadienyl radical. The g values of the radiation damage center observed in BCZD single crystal and the hyperfine structure constants of the free electron with nearby protons were obtained.

Video Lectures in E-Learning: Effects of Viewership and Media Diversity on Learning, Satisfaction, Engagement, Interest, and Future Behavioral Intention

ERIC Educational Resources Information Center

Costley, Jamie; Lange, Christopher Henry

2017-01-01

Purpose: Because student viewership of video lectures serves as an important aspect of e-learning environments, video lectures should be delivered in a way that enhances the learning experience. The delivery of video lectures through diverse forms of media is a useful approach, which may have an effect on student learning, satisfaction, engagement…

Examine of Mobbing via Humour Styles of Lecturers at Schools of Physical Education and Sport

ERIC Educational Resources Information Center

Cengiz, Recep; Sunay, Hakan; Yasar, Onur Mutlu

2018-01-01

The aim of the study was to examine the mobbing via humour of the lecturers at Schools of Physical Education and Sport. The sample of the study consisted of 470 lecturers dutied at those schools. In order to analyze the lecturers' perception levels about mobbing via humour behaviours, the "Scale of Humour Behaviours" was used. T-test and…

An Eight-Year Study of Online Lecture Use in a Medical Gross Anatomy and Embryology Course

ERIC Educational Resources Information Center

Nieder, Gary L.; Borges, Nicole J.

2012-01-01

Online lectures have been used in lieu of live lectures in our gross anatomy and embryology course for the past eight years. We examined patterns of online lecture use by our students and related that use to academic entry measures, gender and examination performance. Detailed access records identified by student were available from server logs.…

Techniques and methods to guarantee Bologna-conform higher education in GNSS

NASA Astrophysics Data System (ADS)

Mayer, M.

2012-04-01

The Bologna Declaration is aiming for student-centered, outcome-related, and competence-based teaching. In order to fulfill these demands, deep level learning techniques should be used to meet the needs of adult-compatible and self-determined learning. The presentation will summarize selected case studies carried out in the framework of the lecture course "Introduction into GNSS positioning" of the Geodetic Institute of the Karlsruhe Institute of Technology (Karlsruhe, Germany). The lecture course "Introduction into GNSS positioning" is a compulsory part of the Bachelor study course "Geodesy and Geoinformatics" and also a supplementary module of the Bachelor study course "Geophysics". Within the lecture course, basic knowledge and basic principles of Global Navigation Satellite Systems, like GPS, are imparted. The lecture course was migrated starting from a classically designed geodetic lecture course, which consisted of a well-adapted combination of teacher-centered classroom lectures and practical training (e.g., field exercises). The recent Bologna-conform blended learning concepts supports and motivates students to learn more sustainable using online and classroom learning methods. Therefore, an appropriate combination of - classroom lectures: Students and teacher give lectures - practical training: Students select topics individually - online learning: ILIAS (learning management system) is used as data, result, and communication platform. The framing didactical method is based on the so-called anchored instruction approach. Within this approach, an up-to-date scientific GNSS-related paper dealing with the large-scale geodetic project "Fehmarn Belt Fixed Link" is used as anchor. The students have to read the paper individually in the beginning of the semester. This enables them to realize a lot of not-known GNSS-related facts. Therefore, questions can be formulated. The lecture course deals with these questions, in order to answer them. At the end of the lecture course, the author of the scientific paper gave a concluding lecture. Within the presentation, the didactical concept of the enriched blended learning approach is discussed in detail in order to gain insight into the didactical design of the lecture course and the higher education principles taken into account in order to guarantee Bologna-conform teaching and learning.

Factors associated with the success of first-time African American freshmen taking introductory science lecture courses at a private HBCU

NASA Astrophysics Data System (ADS)

Smith, Kendra Leigh

This study had four purposes: (1) to investigate the relationship between performance in introductory biology or introductory chemistry lecture courses and their accompanying laboratory courses, (2) to investigate the relationship between performance in introductory biology or introductory chemistry lecture courses and a student's gender, (3) to investigate the relationship between performance in introductory biology or introductory chemistry lecture courses and a student's major, and (4) to investigate the relationship between performance in introductory biology or introductory chemistry lecture courses and a student's ACT scores. The sample consisted of 195 first--time freshmen who enrolled in and completed an introductory biology or an introductory chemistry lecture and laboratory courses during the fall semesters of 2007-2012. Of the 195 students, 61 were enrolled in introductory chemistry and 134 were enrolled in introductory biology courses. Logistic regression, via the Statistical Package for the Social Sciences (SPSS), was utilized to analyze several variables as they related to success in the lecture courses. Data were extracted from the university's student information system (BANNER), and analyses were conducted on biology and chemistry separately. The dependent variable for this study was a dichotomous variable for success and nonsuccess in introductory biology or introductory chemistry lecture course. The independent variables analyzed were student's gender, major, final grade in an accompanying biology or chemistry laboratory course, and ACT test scores (composite, mathematics, and science). Results indicate that concurrent enrollment in a biology laboratory course increased the likelihood of success by 15.64 times in the lecture course. Gender was found to not be a significant predictor of success for either introductory biology or introductory chemistry lecture courses. STEM majors were 9.6 times more likely to be successful than non-STEM majors in introductory chemistry lecture course. It was also found that the higher the given ACT score (composite, science, mathematics), the higher the rate of success (between a 1.19-1.44 odds increase for every one point increase in ACT score) in both introductory biology and introductory chemistry lecture courses.

The comparison of the efficiency of traditional lectures to video-supported lectures within the training of the Emergency Medicine residents.

PubMed

Sarıhan, Aydın; Oray, Neşe Colak; Güllüpınar, Birdal; Yanturali, Sedat; Atilla, Ridvan; Musal, Berna

2016-09-01

Recent developments in computer and video technology, multimedia resources enter quickest way possible into medical education and have started to gain popularity. The aim of this study is to evaluate the impact of video-supported lectures on leaning, with comparison to traditional lectures. According to lecture techniques, two separate groups; one is the traditional lectures group (TLG) and the other is video-supported lectures group (VSLG), are formed. While the TLG is offered a traditional lecture the VSLG is offered a video-supported lecture with imbedded videos which are related to the topics in the traditional lecture. Both study groups take pretest and posttest with MCQs (multiple choice questions) and OSCEs (objective structured clinical examination). The study includes 30 volunteer residents in Dokuz Eylul University School of Medicine Department of Emergency Medicine. No difference is observed between TGL and VSLG in pretest and posttest scores (p = 0.949, p = 0.580). And additionally, comparing the scores of both groups, we cannot observe any difference between the pretest OSCE scores of each group (p = 0.300), however posttest OSCE scores shows a dramatic odd in-between (p = 0.010). When pretest MCQs and posttest MCQs mean scores are compared, both tests (TLG, VSLG) has not any significant difference (p=0.949, p = 0.580). Nevertheless, after comparing OSCEs pretest and posttest mean scores, we can see significant difference in mean scores of both (TLG, VSLG), (p = 0.011, p = 0.001). Taken into consideration, the findings of this study shows possibility of improving educational techniques to acquire clinical skills by using local resources and low-cost technology.

Health care providers' acceptance of unsedated colonoscopy before and after a state-of-the-art lecture on the feasibility of the option.

PubMed

Leung, Felix W; Aljebreen, Abdulrahman

2012-01-01

The impact of education on acceptance of unsedated colonoscopy by health care providers is unknown. To test the hypothesis that knowledge imparted by a lecture on unsedated colonoscopy is associated with its enhanced acceptance. At the State-of-the-Art Lecture on "Unsedated colonoscopy: Is it feasible?" presented at the 8 th Pan-Arab Conference on Gastroenterology, February, 2011, Riyadh, Saudi Arabia, a questionnaire survey of the audience was undertaken. An expectation questionnaire was administered before and after the lecture. Attendees responded anonymously. The responses of a convenient sample of 49 attendees who provided completed responses to the questionnaire both before and after the lecture were analyzed. Data are expressed as frequency counts and means±SEM. Repeated measures analysis of variance (ANOVA), ANOVA with contrasts and Chi-square analysis (Statview II Program for Macintosh computers) were used to assess the data. A P value of <0.05 is considered significant. The mean±SEM credibility score (maximum possible score=50) was 25.8 ± 1.8 before and 33.3 ± 2.1 after the lecture, with a significant improvement in mean score of 7.5 ± 1.3 (P=0.001, paired t test). Nineteen (39%) respondents were not willing to consider unsedated colonoscopy for themselves before the lecture. This number decreased to 13 (27%) after the lecture. Before the lecture only 4 (8%) respondents were willing to consider unsedated colonoscopy for themselves. After the lecture this number increased to 8 (16%). The data suggest education of healthcare professionals regarding the feasibility of unsedated colonoscopy appears to enhance its acceptance as a credible patient care option at a Pan-Arab Gastroenterology Conference.

Students distracted by electronic devices perform at the same level as those who are focused on the lecture.

PubMed

Nalliah, Romesh P; Allareddy, Veerasathpurush

2014-01-01

Background. Little is known about the characteristics of internet distractions that students may engage in during lecture. The objective of this pilot study is to identify some of the internet-based distractions students engage in during in-person lectures. The findings will help identify what activities most commonly cause students to be distracted from the lecture and if these activities impact student learning. Methods. This study is a quasi-experimental pilot study of 26 students from a single institution. In the current study, one class of third-year students were surveyed after a lecture on special needs dentistry. The survey identified self-reported utilization patterns of "smart" devices during the lecture. Additionally, twelve quiz-type questions were given to assess the students' recall of important points in the lecture material that had just been covered. Results. The sample was comprised of 26 students. Of these, 17 were distracted in some form (either checking email, sending email, checking Facebook, or sending texts). The overall mean score on the test was 9.85 (9.53 for distracted students and 10.44 for non-distracted students). There were no significant differences in test scores between distracted and non-distracted students (p = 0.652). Gender and types of distractions were not significantly associated with test scores (p > 0.05). All students believed that they understood all the important points from the lecture. Conclusions. Every class member felt that they acquired the important learning points during the lecture. Those who were distracted by electronic devices during the lecture performed similarly to those who were not. However, results should be interpreted with caution as this study was a small quasi-experimental design and further research should examine the influence of different types of distraction on different types of learning.

Prospective randomized comparison of standard didactic lecture versus high-fidelity simulation for radiology resident contrast reaction management training.

PubMed

Wang, Carolyn L; Schopp, Jennifer G; Petscavage, Jonelle M; Paladin, Angelisa M; Richardson, Michael L; Bush, William H

2011-06-01

The objective of our study was to assess whether high-fidelity simulation-based training is more effective than traditional didactic lecture to train radiology residents in the management of contrast reactions. This was a prospective study of 44 radiology residents randomized into a simulation group versus a lecture group. All residents attended a contrast reaction didactic lecture. Four months later, baseline knowledge was assessed with a written test, which we refer to as the "pretest." After the pretest, the 21 residents in the lecture group attended a repeat didactic lecture and the 23 residents in the simulation group underwent high-fidelity simulation-based training with five contrast reaction scenarios. Next, all residents took a second written test, which we refer to as the "posttest." Two months after the posttest, both groups took a third written test, which we refer to as the "delayed posttest," and underwent performance testing with a high-fidelity severe contrast reaction scenario graded on predefined critical actions. There was no statistically significant difference between the simulation and lecture group pretest, immediate posttest, or delayed posttest scores. The simulation group performed better than the lecture group on the severe contrast reaction simulation scenario (p = 0.001). The simulation group reported improved comfort in identifying and managing contrast reactions and administering medications after the simulation training (p ≤ 0.04) and was more comfortable than the control group (p = 0.03), which reported no change in comfort level after the repeat didactic lecture. When compared with didactic lecture, high-fidelity simulation-based training of contrast reaction management shows equal results on written test scores but improved performance during a high-fidelity severe contrast reaction simulation scenario.

Studying Behaviors Among Neurosurgery Residents Using Web 2.0 Analytic Tools.

PubMed

Davidson, Benjamin; Alotaibi, Naif M; Guha, Daipayan; Amaral, Sandi; Kulkarni, Abhaya V; Lozano, Andres M

Web 2.0 technologies (e.g., blogs, social networks, and wikis) are increasingly being used by medical schools and postgraduate training programs as tools for information dissemination. These technologies offer the unique opportunity to track metrics of user engagement and interaction. Here, we employ Web 2.0 tools to assess academic behaviors among neurosurgery residents. We performed a retrospective review of all educational lectures, part of the core Neurosurgery Residency curriculum at the University of Toronto, posted on our teaching website (www.TheBrainSchool.net). Our website was developed using publicly available Web 2.0 platforms. Lecture usage was assessed by the number of clicks, and associations were explored with lecturer academic position, timing of examinations, and lecture/subspecialty topic. The overall number of clicks on 77 lectures was 1079. Most of these clicks were occurring during the in-training examination month (43%). Click numbers were significantly higher on lectures presented by faculty (mean = 18.6, standard deviation ± 4.1) compared to those delivered by residents (mean = 8.4, standard deviation ± 2.1) (p = 0.031). Lectures covering topics in functional neurosurgery received the most clicks (47%), followed by pediatric neurosurgery (22%). This study demonstrates the value of Web 2.0 analytic tools in examining resident study behavior. Residents tend to "cram" by downloading lectures in the same month of training examinations and display a preference for faculty-delivered lectures. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Frame-of-Reference Training: Establishing Reliable Assessment of Teaching Effectiveness.

PubMed

Newman, Lori R; Brodsky, Dara; Jones, Richard N; Schwartzstein, Richard M; Atkins, Katharyn Meredith; Roberts, David H

2016-01-01

Frame-of-reference (FOR) training has been used successfully to teach faculty how to produce accurate and reliable workplace-based ratings when assessing a performance. We engaged 21 Harvard Medical School faculty members in our pilot and implementation studies to determine the effectiveness of using FOR training to assess health professionals' teaching performances. All faculty were novices at rating their peers' teaching effectiveness. Before FOR training, we asked participants to evaluate a recorded lecture using a criterion-based peer assessment of medical lecturing instrument. At the start of training, we discussed the instrument and emphasized its precise behavioral standards. During training, participants practiced rating lectures and received immediate feedback on how well they categorized and scored performances as compared with expert-derived scores of the same lectures. At the conclusion of the training, we asked participants to rate a post-training recorded lecture to determine agreement with the experts' scores. Participants and experts had greater rating agreement for the post-training lecture compared with the pretraining lecture. Through this investigation, we determined that FOR training is a feasible method to teach faculty how to accurately and reliably assess medical lectures. Medical school instructors and continuing education presenters should have the opportunity to be observed and receive feedback from trained peer observers. Our results show that it is possible to use FOR rater training to teach peer observers how to accurately rate medical lectures. The process is time efficient and offers the prospect for assessment and feedback beyond traditional learner evaluation of instruction.

Knowledge of the Avalanche Victim Resuscitation Checklist and Utility of a Standardized Lecture in Italy.

PubMed

Strapazzon, Giacomo; Migliaccio, Daniel; Fontana, Diego; Stawinoga, Agnieszka Elzbieta; Milani, Mario; Brugger, Hermann

2018-03-01

To explore baseline knowledge about avalanche guidelines and the Avalanche Victim Resuscitation Checklist (AVReCh) in Italy and the knowledge acquisition from a standardized lecture. Standardized lecture material discussing AVReCh was presented during 8 mountain medicine courses from November 2014 to April 2016 in different regions of Italy. To determine the knowledge acquisition from the lecture, a pre- and postlecture survey was utilized. A total of 193 surveys were analyzed. More than 50% of the participants had never participated in lectures/courses on avalanche guidelines, and less than 50% of the participants knew about the AVReCh before the lecture. The correct temporal sequence of reportable information in the basic life support section of the AVReCh was selected by 40% of the participants before the lecture and by 75% after the lecture (P<0.001). Within subgroups analysis, most groups saw significant improvement in performance (P<0.05). The selection of the correct burial time increased from 36 to 84% (P<0.05). Health care providers and mountain rescue personnel are not widely aware of avalanche guidelines. The standardized lecture significantly improved knowledge of the principles of avalanche management related to core AVReCh elements. However, the effect that this knowledge acquisition has on avalanche victim survival or adherence to the AVReCh in the field is yet to be determined. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Annual Advances in Cancer Prevention Lecture | Division of Cancer Prevention

Cancer.gov

2017 Keynote Lecture Re-visiting the Causes of Cancer A special keynote lecture became part of the NCI Summer Curriculum in Cancer Prevention in 2000. This lecture will be held on Thursday, July 20, 2017 at 1:30pm at Masur Auditorium, Building 10, NIH Main Campus, Bethesda, MD. This year’s keynote speaker is Sir Richard Peto, Fellow of the  Royal Soceity (FRS) of London. |

Lattice gauge theory for QCD

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

DeGrand, T.

1997-06-01

These lectures provide an introduction to lattice methods for nonperturbative studies of Quantum Chromodynamics. Lecture 1: Basic techniques for QCD and results for hadron spectroscopy using the simplest discretizations; lecture 2: Improved actions--what they are and how well they work; lecture 3: SLAC physics from the lattice-structure functions, the mass of the glueball, heavy quarks and {alpha}{sub s} (M{sub z}), and B-{anti B} mixing. 67 refs., 36 figs.

Legends Lecture Series III

NASA Image and Video Library

2011-07-27

Marina Benigno (far right) at Stennis Space Center, welcomes former administrative assistants and secretaries to the third Legends Lecture Series session. Lecture participants spoke about their work experiences with Stennis directors and deputy directors. Panel participants included Janet Austill (l to r), Mary Lou Matthews, Helen Paul, Wanda Howard, Ann Westendorf and Mary Gene Dick. The Legends Lecture Series is part of a yearlong celebration of the 50th anniversary of Stennis Space Center.

Activity-Based Introductory Physics Reform *

NASA Astrophysics Data System (ADS)

Thornton, Ronald

2004-05-01

Physics education research has shown that learning environments that engage students and allow them to take an active part in their learning can lead to large conceptual gains compared to those of good traditional instruction. Examples of successful curricula and methods include Peer Instruction, Just in Time Teaching, RealTime Physics, Workshop Physics, Scale-Up, and Interactive Lecture Demonstrations (ILDs). RealTime Physics promotes interaction among students in a laboratory setting and makes use of powerful real-time data logging tools to teach concepts as well as quantitative relationships. An active learning environment is often difficult to achieve in large lecture sessions and Workshop Physics and Scale-Up largely eliminate lectures in favor of collaborative student activities. Peer Instruction, Just in Time Teaching, and Interactive Lecture Demonstrations (ILDs) make lectures more interactive in complementary ways. This presentation will introduce these reforms and use Interactive Lecture Demonstrations (ILDs) with the audience to illustrate the types of curricula and tools used in the curricula above. ILDs make use real experiments, real-time data logging tools and student interaction to create an active learning environment in large lecture classes. A short video of students involved in interactive lecture demonstrations will be shown. The results of research studies at various institutions to measure the effectiveness of these methods will be presented.

Do-It-Yourself Whiteboard-Style Physics Video Lectures

NASA Astrophysics Data System (ADS)

Douglas, Scott Samuel; Aiken, John Mark; Greco, Edwin; Schatz, Michael; Lin, Shih-Yin

2017-01-01

Video lectures are increasingly being used in physics instruction. For example, video lectures can be used to "flip" the classroom, i.e., to deliver, via the Internet, content that is traditionally transmitted by in-class lectures (e.g., presenting concepts, working examples, etc.), thereby freeing up classroom time for more interactive instruction. To date, most video lectures are live lecture recordings or screencasts. The hand-animated "whiteboard" video is an alternative to these more common styles and affords unique creative opportunities such as stop-motion animation or visual "demonstrations" of phenomena that would be difficult to demo in a classroom. In the spring of 2013, a series of whiteboard-style videos were produced to provide video lecture content for Georgia Tech introductory physics instruction, including flipped courses and a MOOC. This set of videos (which also includes screencasts and live recordings) can be found on the "Your World is Your Lab" YouTube channel. In this article, we describe this method of video production, which is suitable for an instructor working solo or in collaboration with students; we explore students' engagement with these videos in a separate work. A prominent example of whiteboard animation is the "Minute Physics" video series by Henry Reich, whose considerable popularity and accessible, cartoony style were the original inspiration for our own video lectures.

Online Lectures in Undergraduate Medical Education: Scoping Review

PubMed Central

Tang, Brandon; Coret, Alon; Qureshi, Aatif; Barron, Henry; Ayala, Ana Patricia

2018-01-01

Background The adoption of the flipped classroom in undergraduate medical education calls on students to learn from various self-paced tools—including online lectures—before attending in-class sessions. Hence, the design of online lectures merits special attention, given that applying multimedia design principles has been shown to enhance learning outcomes. Objective The aim of this study was to understand how online lectures have been integrated into medical school curricula, and whether published literature employs well-accepted principles of multimedia design. Methods This scoping review followed the methodology outlined by Arksey and O'Malley (2005). Databases, including MEDLINE, PsycINFO, Education Source, FRANCIS, ERIC, and ProQuest, were searched to find articles from 2006 to 2016 related to online lecture use in undergraduate medical education. Results In total, 45 articles met our inclusion criteria. Online lectures were used in preclinical and clinical years, covering basic sciences, clinical medicine, and clinical skills. The use of multimedia design principles was seldom reported. Almost all studies described high student satisfaction and improvement on knowledge tests following online lecture use. Conclusions Integration of online lectures into undergraduate medical education is well-received by students and appears to improve learning outcomes. Future studies should apply established multimedia design principles to the development of online lectures to maximize their educational potential. PMID:29636322

Online activities to optimize in person learning

NASA Astrophysics Data System (ADS)

Stelzer, Tim

Students' unprecedented access to content on the web is providing a unique opportunity to transform the role lectures in education, moving the focus from content delivery to helping students synthesize the content into knowledge. We have introduced a variety of activities to facilitate this transformation at the University of Illinois, including web-based preflight assessments of student understanding before lecture, peer instruction (clickers) to assess and facilitate student understanding during lecture, and web-based multimedia pre-lectures designed to provide students with content before lecture. In this talk I will discuss the pedagogical motivation for introducing these activities, and the impact they have had at the University of Illinois. .

Effects of thermal annealing on the radiation produced electron paramagnetic resonance spectra of bovine and equine tooth enamel: Fossil and modern

NASA Astrophysics Data System (ADS)

Weeks, Robert A.; Bogard, James S.; Elam, J. Michael; Weinand, Daniel C.; Kramer, Andrew

2003-06-01

The concentration of stable radiation-induced paramagnetic states in fossil teeth can be used as a measure of sample age. Temperature excursions >100 °C, however, can cause the paramagnetic state clock to differ from the actual postmortem time. We have heated irradiated enamel from both fossilized bovid and modern equine (MEQ) teeth for 30 min in 50 °C increments from 100 to 300 °C, measuring the electron paramagnetic resonance (EPR) spectrum after each anneal, to investigate such effects. Samples were irradiated again after the last anneal, with doses of 300-1200 Gy from 60Co photons, and measured. Two unirradiated MEQ samples were also annealed for 30 min at 300 °C, one in an evacuated EPR tube and the other in a tube open to the atmosphere, and subsequently irradiated. The data showed that hyperfine components attributed to the alanine radical were not detected in the irradiated MEQ sample until after the anneals. The spectrum of the MEQ sample heated in air and then irradiated was similar to that of the heat treated fossil sample. We conclude that the hyperfine components are due to sample heating to temperatures/times >100 °C/30 min and that similarities between fossil and MEQ spectra after the 300 °C/30 min MEQ anneal are also due to sample heating. We conclude that the presence of the hyperfine components in spectra of fossil tooth enamel indicate that such thermal events occurred either at the time of death, or during the postmortem history.

Observations of Confinement of a Paramagnetic Liquid in Model Propellant Tanks in Microgravity by the Kelvin Force

NASA Technical Reports Server (NTRS)

Kuhlman, John; Gray, Donald D.; Barnard, Austin; Hazelton, Jennifer; Lechliter, Matthew; Starn, Andrew; Battleson, Charles; Glaspell, Shannon; Kreitzer, Paul; Leichliter, Michelle

2002-01-01

The magnetic Kelvin force has been proposed as an artificial gravity to control the orientation of paramagnetic liquid propellants such as liquid oxygen in a microgravity environment. This paper reports experiments performed in the NASA "Weightless Wonder" KC-135 aircraft, through the Reduced Gravity Student Flight Opportunities Program. The aircraft flies through a series of parabolic arcs providing about 25 s of microgravity in each arc. The experiment was conceived, designed, constructed, and performed by the undergraduate student team and their two faculty advisors. Two types of tanks were tested: square-base prismatic tanks 5 cm x 5 cm x 8.6 cm and circular cylinders 5 cm in diameter and 8.6 cm tall. The paramagnetic liquid was a 3.3 molar solution of MnCl2 in water. Tests were performed with each type of tank filled to depths of 1 cm and 4 cm. Each test compared a pair of tanks that were identical except that the base of one was a pole face of a 0.6 Tesla permanent magnet. The Kelvin force attracts paramagnetic materials toward regions of higher magnetic field. It was hypothesized that the Kelvin force would hold the liquid in the bottom of the tanks during the periods of microgravity. The tanks were installed in a housing that could slide on rails transverse to the flight direction. By manually shoving the housing, an identical impulse could be provided to each tank at the beginning of each period of microgravity. The resulting fluid motions were videotaped for later analysis.

Application of Paramagnetically Tagged Molecules for Magnetic Resonance Imaging of Biofilm Mass Transport Processes▿

PubMed Central

Ramanan, B.; Holmes, W. M.; Sloan, W. T.; Phoenix, V. R.

2010-01-01

Molecules become readily visible by magnetic resonance imaging (MRI) when labeled with a paramagnetic tag. Consequently, MRI can be used to image their transport through porous media. In this study, we demonstrated that this method could be applied to image mass transport processes in biofilms. The transport of a complex of gadolinium and diethylenetriamine pentaacetic acid (Gd-DTPA), a commercially available paramagnetic molecule, was imaged both in agar (as a homogeneous test system) and in a phototrophic biofilm. The images collected were T1 weighted, where T1 is an MRI property of the biofilm and is dependent on Gd-DTPA concentration. A calibration protocol was applied to convert T1 parameter maps into concentration maps, thus revealing the spatially resolved concentrations of this tracer at different time intervals. Comparing the data obtained from the agar experiment with data from a one-dimensional diffusion model revealed that transport of Gd-DTPA in agar was purely via diffusion, with a diffusion coefficient of 7.2 × 10−10 m2 s−1. In contrast, comparison of data from the phototrophic biofilm experiment with data from a two-dimensional diffusion model revealed that transport of Gd-DTPA inside the biofilm was by both diffusion and advection, equivalent to a diffusion coefficient of 1.04 × 10−9 m2 s−1. This technology can be used to further explore mass transport processes in biofilms, either by using the wide range of commercially available paramagnetically tagged molecules and nanoparticles or by using bespoke tagged molecules. PMID:20435773

Magnetic properties and electronic structure of manganese-based blue pigments: a high-frequency and -field EPR study.

PubMed

Krzystek, J; Telser, Joshua; Li, Jun; Subramanian, M A

2015-09-21

A variety of new oxide-based materials based on hexagonal phase of YInO3 have been recently described. In some of these materials, the In(III) ions are substituted by Mn(III), which finds itself in a trigonal-bipyramidal (TBP) coordination environment. While YInO3 is colorless and YMnO3 is black, mixed systems YIn1-xMnxO3 (0.02 < x < 0.25) display intense blue color and have been proposed as novel blue pigments. Since the Mn(III) ion is paramagnetic, its presence imparts distinct magnetic properties to the whole class of materials. These properties were investigated by electron paramagnetic resonance (EPR) in its high-frequency and -field version (HFEPR), a technique ideally suited for transition metal ions such as Mn(III) that, in contrast to, for example, Mn(II), are difficult to study by EPR at (conventional) low frequency and field. YIn1-xMnxO3 with 0.02 < x < 0.2 exhibited high-quality HFEPR spectra up to room temperature that could be interpreted as arising from isolated S = 2 paramagnets. A simple ligand-field model, based on the structure and optical spectra, explains the spin Hamiltonian parameters provided by HFEPR, which were D = +3.0 cm(-1), E = 0; g⊥ = 1.99, g∥ = 2.0. This study demonstrates the general applicability of a combined spectroscopic and classical theoretical approach to understanding the electronic structure of novel materials containing paramagnetic dopants. Moreover, HFEPR complements optical and other experimental methods as being a sensitive probe of dopant level.

Effects of three types of lecture notes on medical student achievement.

PubMed

Russell, I J; Caris, T N; Harris, G D; Hendricson, W D

1983-08-01

Two parallel studies were conducted with junior medical students to determine what influence the forms of lecture notes would have on learning. The three types of notes given to the students were: a comprehensive manuscript of the lecture containing text, tables, and figures; a partial handout which included some illustrations but required substantial annotation by the students; and a skeleton outline containing no data from the lecture. The students' knowledge about the subject was measured before the lecture, immediately after the lecture, two to four weeks later, and approximately three months later. The students' responses to questionnaires indicated a strong preference for very detained handouts as essential to preparation for examinations. By contract, the students' performances on tests generally were better for those who had received the partial or skeleton handout formats. This was particularly true for information presented during the last quarter of each lecture, when learning efficiency of the skeleton handout group increased while the other two handout groups exhibited learning fatigue. It was concluded that learning by medical students was improved when they recorded notes in class.

Comparison of Internet versus lecture instructional methods for teaching nursing research.

PubMed

Woo, M A; Kimmick, J V

2000-01-01

Although many higher education programs are using the Internet to teach classes, there are few published reports on the effectiveness of this method on test scores or student satisfaction. The purpose of this study was to compare test and student satisfaction scores of graduate nursing students who take a nursing research course via the Internet with those of students who take the same course via traditional lecture instruction. In addition, student technical support use and Internet student lecture attendance also were examined. A total of 97 students (Internet, 44; lectures, 53) participated. There were no significant differences in test scores and overall course student satisfaction (P > .05). However, the Internet students reported significantly higher (P = .04) stimulation of learning compared with the traditional lecture students. Technical support use by the Internet students was high initially and was related to software problems. Of interest were the large proportion of Internet students (73 percent) who attended at least 3 of the 10 lectures. Use of the Internet to teach graduate-level nursing research can provide comparable learning and student satisfaction to traditional lecture instructional methods.

How is the Inquiry Skills of Biology Preservice Teachers in Biotechnology Lecture?

NASA Astrophysics Data System (ADS)

Hayat, M. S.; Rustaman, N. Y.

2017-09-01

This study was to investigate the inquiry skills of biology pre-service teachers in one teachers college in Central Java in biotechnology lecture. The method used is a case study of 29 biology preservice teacher. Data were collected using observation sheets, questionnaires, and interview guidelines. Research findings collected through questionnaires show that most students are accustomed to asking questions and formulating biotechnology issues; Skilled in conducting experiments; Skilled in obtaining relevant information from various sources; As well as skilled at processing, analyzing and interpreting data. Based on observation: lectures are not dominated by lecturers, students are able to solve problems encountered and conduct investigations. Based on the interview towards lecturers: students are always actively involved in questioning, investigation, inquiry, problem solving and experimenting in lectures. Why do most students show good inquiry skills? Because students are accustomed to invited inquiry in biology lectures. The impact, the students become more ready to be invited to do more advanced inquiry, such as real-world application inquiry, because the skill of inquiry is essentially trained.

Dynamical instability of a spin spiral in an interacting Fermi gas as a probe of the Stoner transition

NASA Astrophysics Data System (ADS)

Conduit, G. J.; Altman, E.

2010-10-01

We propose an experiment to probe ferromagnetic phenomena in an ultracold Fermi gas, while alleviating the sensitivity to three-body loss and competing many-body instabilities. The system is initialized in a small pitch spin spiral, which becomes unstable in the presence of repulsive interactions. To linear order the exponentially growing collective modes exhibit critical slowing down close to the Stoner transition point. Also, to this order, the dynamics are identical on the paramagnetic and ferromagnetic sides of the transition. However, we show that scattering off the exponentially growing modes qualitatively alters the collective mode structure. The critical slowing down is eliminated and in its place a new unstable branch develops at large wave vectors. Furthermore, long-wavelength instabilities are quenched on the paramagnetic side of the transition. We study the experimental observation of the instabilities, specifically addressing the trapping geometry and how phase-contrast imaging will reveal the emerging domain structure. These probes of the dynamical phenomena could allow experiments to detect the transition point and distinguish between the paramagnetic and ferromagnetic regimes.

Ferromagnetism observed in silicon-carbide-derived carbon

NASA Astrophysics Data System (ADS)

Peng, Bo; Zhang, Yuming; Wang, Yutian; Guo, Hui; Yuan, Lei; Jia, Renxu

2018-02-01

Carbide-derived carbon (CDC) is prepared by etching high purity 4H-SiC single crystals in a mixed atmosphere of 5% Cl2 and 95% Ar for 120 min and 240 min. The secondary ion mass spectroscopy (SIMS) bulk analysis technique excludes the possibility of ferromagnetic transition metal (TM) contamination arising during the experimental process. The paramagnetic and ferromagnetic components are separated from the measured magnetization-magnetic field curves of the samples. Through the use of the Brillouin function, paramagnetic centers carrying a magnetic moment of ˜1.3 μB are fitted. A resolvable hysteresis loop in the low magnetic field area is preserved at room temperature. The temperature dependence of the relative intensity of the Lorentzian-like electron spin resonance (ESR) line observed by electron spin spectroscopy reveals the existence of exchange interaction between the localized paramagnetic centers. First-principles calculations show the dominant configuration of defects in the graphitic CDC films. By calculating the energy difference between the antiferromagnetic and ferromagnetic phases, we deduce that the ferromagnetic coupling is sensitive to the concentration of defects.

Measurement of Rate Constants for Homodimer Subunit Exchange Using Double Electron-Electron Resonance and Paramagnetic Relaxation Enhancements

PubMed Central

Yang, Yunhuang; Ramelot, Theresa A.; Ni, Shuisong; McCarrick, Robert M.; Kennedy, Michael A.

2013-01-01

Here, we report novel methods to measure rate constants for homodimer subunit exchange using double electron-electron resonance (DEER) electron paramagnetic resonance spectroscopy measurements and nuclear magnetic resonance spectroscopy based paramagnetic relaxation enhancement (PRE) measurements. The techniques were demonstrated using the homodimeric protein Dsy0195 from the strictly anaerobic bacterium Desulfitobacterium hafniense Y51. At specific times following mixing site-specific MTSL-labeled Dsy0195 with uniformly 15N-labeled Dsy0195, the extent of exchange was determined either by monitoring the decrease of MTSL-labeled homodimer from the decay of the DEER modulation depth or by quantifying the increase of MTSL-labeled/15N-labeled heterodimer using PREs. Repeated measurements at several time points following mixing enabled determination of the homodimer subunit dissociation rate constant, k−1;, which was 0.037 ± 0.005 min−1 derived from DEER experiments with a corresponding half-life time of 18.7 minutes. These numbers agreed with independent measurements obtained from PRE experiments. These methods can be broadly applied to protein-protein and protein-DNA complex studies. PMID:23180051

Thermoelectricity in transition metal compounds: The role of spin disorder

DOE PAGES

Gorai, Prashun; Toberer, Eric S.; Stevanović, Vladan

2016-11-01

Here, at room temperature and above, most magnetic materials adopt a spin-disordered (paramagnetic) state whose electronic properties can differ significantly from their low-temperature, spin-ordered counterparts. Yet computational searches for new functional materials usually assume some type of magnetic order. In the present work, we demonstrate a methodology to incorporate spin disorder in computational searches and predict the electronic properties of the paramagnetic phase. We implement this method in a high-throughput framework to assess the potential for thermoelectric performance of 1350 transition-metal sulfides and find that all magnetic systems we identify as promising in the spin-ordered ground state cease to bemore » promising in the paramagnetic phase due to disorder-induced deterioration of the charge carrier transport properties. We also identify promising non-magnetic candidates that do not suffer from these spin disorder effects. In addition to identifying promising materials, our results offer insights into the apparent scarcity of magnetic systems among known thermoelectrics and highlight the importance of including spin disorder in computational searches.« less

EPR imaging and HPLC characterization of the pigment-based organic free radical in black soybean seeds.

PubMed

Nakagawa, Kouichi; Maeda, Hayato

2017-02-01

We investigated the location and distribution of paramagnetic species in dry black, brown, and yellow (normal) soybean seeds using electron paramagnetic resonance (EPR), X-band (9 GHz) EPR imaging (EPRI), and HPLC. EPR primarily detected two paramagnetic species in black soybean. These two different radical species were assigned as stable organic radical and Mn 2+  species based on the g values and hyperfine structures. The signal from the stable radical was noted at g ≈ 2.00 and was relatively strong and stable. Subsequent noninvasive two-dimensional (2D) EPRI of the radical present in black soybean revealed that the stable radical was primarily located in the pigmented region of the soybean coat, with very few radicals observed in the soybean cotyledon (interior). Pigments extracted from black soybean were analyzed using HPLC. The major compound was found to be cyanidin-3-glucoside. Multi-EPR and HPLC results indicate that the stable radical was only found within the pigmented region of the soybean coat, and it could be cyanidin-3-glucoside or an oxidative decomposition product.

Evolution of Triplet Paramagnetic Centers in Diamonds Obtained by Sintering of Detonation Nanodiamonds at High Pressure and Temperature

NASA Astrophysics Data System (ADS)

Osipov, V. Yu.; Shames, A. I.; Efimov, N. N.; Shakhov, F. M.; Kidalov, S. V.; Minin, V. V.; Vul', A. Ya.

2018-04-01

The electron paramagnetic resonance (EPR) spectra of triplet centers in detonation nanodiamonds (DNDs) and diamond single crystals of submicrometer size, synthesized from those DNDs at high pressures and temperatures, are studied. In the EPR spectra of DNDs, signals from negatively charged nitrogen- vacancy centers (NV)/sup(-) with a g factor of g 1 = 4.24 and multivacancies with g 2 = 4.00 are observed. The signals from (NV)/sup(-) centers disappear in the spectra of diamond single crystals, and a quintet signal with g = 4.00 is detected at the position of the signal from multivacancies. Analysis of the shape and position of the quintet' lines showed that this ESR signal is due to the pairs of nitrogen substitution centers in diamond, separated from each other by distances not exceeding 0.7 nm, between which a strong exchange interaction takes place. A comparison of the experimental data and the simulation results allows determining the spin-Hamiltonian parameters of the exchange-coupled pairs of paramagnetic impurity nitrogen atoms.

300 MHz continuous wave electron paramagnetic resonance spectrometer for small animal in vivo imaging

NASA Astrophysics Data System (ADS)

Koscielniak, J.; Devasahayam, N.; Moni, M. S.; Kuppusamy, P.; Yamada, K.; Mitchell, J. B.; Krishna, M. C.; Subramanian, S.

2000-11-01

Design and construction of an electron paramagnetic resonance (EPR) spectrometer, operating in the continuous wave mode in the radio frequency (rf) region, and capable of performing spectroscopy and in vivo imaging of paramagnetic spin probes is described. A resonant frequency of 300 MHz was chosen to provide the required sensitivity at nontoxic levels of commonly used spin probes and penetration of the rf in small animals. Three major components, the magnet, the radio frequency signal detection bridge, and the data acquisition module are described in this article. Integration of a rapid scan capability to reduce imaging time is also described. Two- and three-dimensional EPR images of the spin probe distribution in phantom objects as well as from in vivo experiments are reported. From the EPR images, morphology of some internal organs could be recognized. EPR images of the spin probe distribution in mice suggest differences in perfusion of the spin probe between normal and tumor regions. Addition of a spectral dimension to spatial images should enable differentiation of oxygen status in normal and pathological conditions.

Hierarchical mean-field approach to the J1-J2 Heisenberg model on a square lattice

NASA Astrophysics Data System (ADS)

Isaev, L.; Ortiz, G.; Dukelsky, J.

2009-01-01

We study the quantum phase diagram and excitation spectrum of the frustrated J1-J2 spin-1/2 Heisenberg Hamiltonian. A hierarchical mean-field approach, at the heart of which lies the idea of identifying relevant degrees of freedom, is developed. Thus, by performing educated, manifestly symmetry-preserving mean-field approximations, we unveil fundamental properties of the system. We then compare various coverings of the square lattice with plaquettes, dimers, and other degrees of freedom, and show that only the symmetric plaquette covering, which reproduces the original Bravais lattice, leads to the known phase diagram. The intermediate quantum paramagnetic phase is shown to be a (singlet) plaquette crystal, connected with the neighboring Néel phase by a continuous phase transition. We also introduce fluctuations around the hierarchical mean-field solutions, and demonstrate that in the paramagnetic phase the ground and first excited states are separated by a finite gap, which closes in the Néel and columnar phases. Our results suggest that the quantum phase transition between Néel and paramagnetic phases can be properly described within the Ginzburg-Landau-Wilson paradigm.

Hierarchical mean-field approach to the J1-J2 Heisenberg model on a square lattice

NASA Astrophysics Data System (ADS)

Isaev, Leonid; Ortiz, Gerardo; Dukelsky, Jorge

2009-03-01

We study the quantum phase diagram and excitation spectrum of the frustrated J1-J2 spin-1/2 Heisenberg Hamiltonian. A hierarchical mean-field approach, at the heart of which lies the idea of identifying relevant degrees of freedom, is developed. Thus, by performing educated, manifestly symmetry preserving mean-field approximations, we unveil fundamental properties of the system. We then compare various coverings of the square lattice with plaquettes, dimers and other degrees of freedom, and show that only the symmetric plaquette covering, which reproduces the original Bravais lattice, leads to the known phase diagram. The intermediate quantum paramagnetic phase is shown to be a (singlet) plaquette crystal, connected with the neighbouring N'eel phase by a continuous phase transition. We also introduce fluctuations around the hierarchical mean-field solutions, and demonstrate that in the paramagnetic phase the ground and first excited states are separated by a finite gap, which closes in the N'eel and columnar phases. Our results suggest that the quantum phase transition between N'eel and paramagnetic phases can be properly described within the Ginzburg-Landau-Wilson paradigm.

Electron paramagnetic resonance (EPR) spectroscopy characterization of wheat grains from plants of different water stress tolerance.

PubMed

Łabanowska, Maria; Filek, Maria; Kurdziel, Magdalena; Bednarska, Elżbieta; Dłubacz, Aleksandra; Hartikainen, Helina

2012-09-01

Grains of five genotypes of wheat (four Polish and one Finnish), differing in their tolerance to drought stress were chosen for this investigation. Electron paramagnetic resonance spectroscopy allowed observation of transition metal ions (Mn, Fe, Cu) and different types of stable radicals, including semiquinone centers, present in seed coats, as well as several types of carbohydrate radicals found mainly in the inner parts of grains. The content of paramagnetic metal centers was higher in sensitive genotypes (Radunia, Raweta) than in tolerant ones (Parabola, Nawra), whereas the Finnish genotype (Manu) exhibited intermediate amounts. Similarly, the concentrations of both types of radicals, carbohydrates and semiquinone were significantly higher in the grains originating from more sensitive wheat genotypes. The nature of carbohydrate radicals and their concentrations were confronted with the kinds and amounts of sugars found by the biochemical analyses and microscopy observations. It is suggested that some long lived radicals (semiquinone and starch radicals) occurring in grains could be indicators of stress resistance of wheat plants. Copyright © 2012 Elsevier GmbH. All rights reserved.

Nonlinear magnetoelectric effect and magnetostriction in piezoelectric CsCuCl{sub 3} in paramagnetic and antiferromagnetic states

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

Kharkovskiy, A. I., E-mail: akharkovskiy@inbox.ru; L.F. Vereshchagin Institute for High Pressure Physics RAS, 142190 Troitsk, Moscow; Shaldin, Yu. V.

2016-01-07

The direct nonlinear magnetoelectric (ME) effect and the magnetostriction of piezoelectric CsCuCl{sub 3} single crystals were comprehensively studied over a wide temperature range in stationary magnetic fields of up to 14 T. The direct nonlinear ME effect measurements were also performed in pulsed magnetic fields up to 31 T, at liquid helium temperature in the antiferromagnetic (AF) state for the crystallographic direction in which effect has the maximum value. The nonlinear ME effect was quadratic in the paramagnetic state for the whole range of magnetic fields. In the AF state the phase transition between different configurations of spins manifested itself as plateau-likemore » peculiarity on the nonlinear ME effect. The nonlinear ME effect was saturated by the phase transition to the spin-saturated paramagnetic state. Two contributions to the nonlinear ME effects in CsCuCl{sub 3} were extracted from the experimental data: the intrinsic ME effect originated from the magnetoelectric interactions, and the extrinsic one, which resulted from a magnetostriction-induced piezoelectric effect.« less

[Isolation and culture of bovine choriocapillary endothelial cells using paramagnetic beads coated with Lycopersicon esculentum].

PubMed

Swiech-Zubilewicz, A; Soubrane, G; Mascarelli, F

2000-01-01

To establish a pure culture of choriocapillary endothelial cells as a model of angiogenesis in vitro. Bovine choriocapillary endothelial cells (BCEC) were obtained by the method described by Hoffmann et al. (6) using the polystyrene paramagnetic beads coated with Lycopersicon esculentum, which attach specifically to the rest of fucose on the surface of microvascular endothelial cells. The endothelial characteristic of the cultured cells was evaluated by immunocytochemistry using anti von Willebrand factor and anti-CD 31 antibodies. Proliferation and survival of BCEC were tested using haemacytometer of Mallasez. The purity of obtained BCEC culture was confirmed by positive immunocytochemical staining with anti von Willebrand and anti factor CD 31 antibodies in more than 95% of cells. The proliferation of cells in Endothelial Cell Medium resulted in twofold increase of number of cells during 4-day observation period. After reaching the confluence, the cells continued to proliferate with increase of the cell number by 60% during 4-day observation. The use of paramagnetic beads coated with specific lectine provide a pure isolation of BCEC, which can be maintained in culture with preservation of their characteristic.

Nitrogen-vacancy-assisted magnetometry of paramagnetic centers in an individual diamond nanocrystal.

PubMed

Laraoui, Abdelghani; Hodges, Jonathan S; Meriles, Carlos A

2012-07-11

Semiconductor nanoparticles host a number of paramagnetic point defects and impurities, many of them adjacent to the surface, whose response to external stimuli could help probe the complex dynamics of the particle and its local, nanoscale environment. Here, we use optically detected magnetic resonance in a nitrogen-vacancy (NV) center within an individual diamond nanocrystal to investigate the composition and spin dynamics of the particle-hosted spin bath. For the present sample, a ∼45 nm diamond crystal, NV-assisted dark-spin spectroscopy reveals the presence of nitrogen donors and a second, yet-unidentified class of paramagnetic centers. Both groups share a common spin lifetime considerably shorter than that observed for the NV spin, suggesting some form of spatial clustering, possibly on the nanoparticle surface. Using double spin resonance and dynamical decoupling, we also demonstrate control of the combined NV center-spin bath dynamics and attain NV coherence lifetimes comparable to those reported for bulk, Type Ib samples. Extensions based on the experiments presented herein hold promise for applications in nanoscale magnetic sensing, biomedical labeling, and imaging.

A fluorescent paramagnetic Mn metal–organic framework based on semi-rigid pyrene tetra­carboxylic acid: sensing of solvent polarity and explosive nitroaromatics

PubMed Central

Bajpai, Alankriti; Mukhopadhyay, Arindam; Krishna, Manchugondanahalli Shivakumar; Govardhan, Savitha; Moorthy, Jarugu Narasimha

2015-01-01

An Mn metal–organic framework (Mn-MOF), Mn-L, based on a pyrene-tetraacid linker (H4 L), displays a respectable fluorescence quantum yield of 8.3% in spite of the presence of the paramagnetic metal ions, due presumably to fixation of the metal ions in geometries that do not allow complete energy/charge-transfer quenching. Remarkably, the porous Mn-L MOF with ∼25% solvent-accessible volume exhibits a heretofore unprecedented solvent-dependent fluorescence emission maximum, permitting its use as a probe of solvent polarity; the emission maxima in different solvents correlate excellently with Reichardt’s solvent polarity parameter (E T N). Further, the applicability of Mn-L to the sensing of nitroaromatics via fluorescence quenching is demonstrated; the detection limit for TNT is shown to be 125 p.p.m. The results bring out the fact that MOFs based on paramagnetic metal ions can indeed find application when the quenching mechanisms are attenuated by certain geometries of the organic linkers of the MOF. PMID:26306197

Paramagnetic ionic liquids for measurements of density using magnetic levitation.

PubMed

Bwambok, David K; Thuo, Martin M; Atkinson, Manza B J; Mirica, Katherine A; Shapiro, Nathan D; Whitesides, George M

2013-09-03

Paramagnetic ionic liquids (PILs) provide new capabilities to measurements of density using magnetic levitation (MagLev). In a typical measurement, a diamagnetic object of unknown density is placed in a container containing a PIL. The container is placed between two magnets (typically NdFeB, oriented with like poles facing). The density of the diamagnetic object can be determined by measuring its position in the magnetic field along the vertical axis (levitation height, h), either as an absolute value or relative to internal standards of known density. For density measurements by MagLev, PILs have three advantages over solutions of paramagnetic salts in aqueous or organic solutions: (i) negligible vapor pressures; (ii) low melting points; (iii) high thermal stabilities. In addition, the densities, magnetic susceptibilities, glass transition temperatures, thermal decomposition temperatures, viscosities, and hydrophobicities of PILs can be tuned over broad ranges by choosing the cation-anion pair. The low melting points and high thermal stabilities of PILs provide large liquidus windows for density measurements. This paper demonstrates applications and advantages of PILs in density-based analyses using MagLev.

A fluorescent paramagnetic Mn metal-organic framework based on semi-rigid pyrene tetra-carboxylic acid: sensing of solvent polarity and explosive nitroaromatics.

PubMed

Bajpai, Alankriti; Mukhopadhyay, Arindam; Krishna, Manchugondanahalli Shivakumar; Govardhan, Savitha; Moorthy, Jarugu Narasimha

2015-09-01

An Mn metal-organic framework (Mn-MOF), Mn-L, based on a pyrene-tetraacid linker (H4 L), displays a respectable fluorescence quantum yield of 8.3% in spite of the presence of the paramagnetic metal ions, due presumably to fixation of the metal ions in geometries that do not allow complete energy/charge-transfer quenching. Remarkably, the porous Mn-L MOF with ∼25% solvent-accessible volume exhibits a heretofore unprecedented solvent-dependent fluorescence emission maximum, permitting its use as a probe of solvent polarity; the emission maxima in different solvents correlate excellently with Reichardt's solvent polarity parameter (E T (N)). Further, the applicability of Mn-L to the sensing of nitroaromatics via fluorescence quenching is demonstrated; the detection limit for TNT is shown to be 125 p.p.m. The results bring out the fact that MOFs based on paramagnetic metal ions can indeed find application when the quenching mechanisms are attenuated by certain geometries of the organic linkers of the MOF.

Specific features of the EPR spectra of KTaO3: Mn nanopowders

NASA Astrophysics Data System (ADS)

Golovina, I. S.; Shanina, B. D.; Geifman, I. N.; Andriiko, A. A.; Chernenko, L. V.

2012-03-01

The electron paramagnetic resonance spectra of KTaO3: Mn nanocrystalline powders in the temperature range from 77 to 620 K have been measured and studied for the first time. The change observed in the spectra has been investigated as a function of the doping level. The doping regions in which Mn2+ ions are individual paramagnetic impurities have been established, as well as the regions where the dipole-dipole and exchange interactions of these ions begin to occur. The spin-Hamiltonian constants for the spectrum of non-interacting individual Mn2+ ions have been determined as follows: g = 2.0022, D = 0.0170 cm-1, and A = 85 × 10-4 cm-1. A significant decrease in the axial constant D in the KTaO3: Mn nanopowder, as compared to the single crystal, has been explained by the remoteness of the charge compensator from the paramagnetic ion and by the influence of the surface of the nanoparticle. It has been assumed that the Mn2+ ions are located near the surface and do not penetrate deep into the crystallites.

Anisotropy reversal of the upper critical field at low temperatures and spin-locked superconductivity in K 2 Cr 3 As 3

DOE PAGES

Balakirev, F. F.; Kong, T.; Jaime, M.; ...

2015-06-23

We report measurements of the anisotropic upper critical field H c2(T) for K 2Cr 3As 3 single crystals up to 60 T and T>0.6K. Our results show that the upper critical field parallel to the Cr chains, H ∥ c2(T), exhibits a paramagnetically limited behavior, whereas the shape of the H ⊥ c2(T) curve (perpendicular to the Cr chains) has no evidence of paramagnetic effects. As a result, the curves H ⊥ c2(T) and H ∥ c2(T) cross at T≈4K, so that the anisotropy parameter γ H(T)=H ⊥ c2/H ∥ c2(T) increases from γ H(T c)≈0.35 near T c tomore » γ H(0)≈1.7 at 0.6 K. The paramagnetically limited behavior of H ∥ c2(T) is inconsistent with triplet superconductivity but suggests a form of singlet superconductivity with the electron spins locked onto the direction of Cr chains.« less

The Microscopic Magnetic Properties of W-type Hexaferrite Powder Prepared by A Sol-Gel Route

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

Jotania, Rajshree; Chauhan, Chetna; Sharma, Pooja

2010-12-01

Magnetic particles of W-type barium-calcium hexaferrite (BaCa{sub 2}Fe{sub 16}O{sub 27}) have been synthesized using a Stearic acid gel route. The gel precursors were dried at 100 deg. C for 2 hrs and then calcinated at 650 deg. C, 750 deg. C, 850 deg. C and 950 deg. C for 4 hrs in a furnace and slowly cooled to room temperature in order to obtain barium-calcium hexaferrite particles. The microscopic magnetic properties of prepared samples studying using Moessbauer spectroscopy. Moessbauer spectra of all samples were recorded at room temperature. Mossbauer parameters like Isomer shift, Quadruple splitting etc. were calculated with respectmore » to iron foil. Barium calcium hexaferrite samples heated at 650 deg. C, 750 deg. C, 850 deg. C show relaxation type Moessbauer spectra along with paramagnetic doublet. The intensity of paramagnetic doublet increases with temperature confirm the presence of ferrous ions in the samples, where as sample calcinated at 950 deg. C confirm the presence of ferrimagnetic phase with partial super paramagnetic nature of prepared hexaferrite sample.« less

Electron Paramagnetic Resonance of a Single NV Nanodiamond Attached to an Individual Biomolecule

NASA Astrophysics Data System (ADS)

Teeling-Smith, Richelle M.; Jung, Young Woo; Scozzaro, Nicolas; Cardellino, Jeremy; Rampersaud, Isaac; North, Justin A.; Šimon, Marek; Bhallamudi, Vidya P.; Rampersaud, Arfaan; Johnston-Halperin, Ezekiel; Poirier, Michael G.; Hammel, P. Chris

2016-05-01

A key limitation of electron paramagnetic resonance (EPR), an established and powerful tool for studying atomic-scale biomolecular structure and dynamics is its poor sensitivity, samples containing in excess of 10^12 labeled biomolecules are required in typical experiments. In contrast, single molecule measurements provide improved insights into heterogeneous behaviors that can be masked by ensemble measurements and are often essential for illuminating the molecular mechanisms behind the function of a biomolecule. We report EPR measurements of a single labeled biomolecule that merge these two powerful techniques. We selectively label an individual double-stranded DNA molecule with a single nanodiamond containing nitrogen-vacancy (NV) centers, and optically detect the paramagnetic resonance of NV spins in the nanodiamond probe. Analysis of the spectrum reveals that the nanodiamond probe has complete rotational freedom and that the characteristic time scale for reorientation of the nanodiamond probe is slow compared to the transverse spin relaxation time. This demonstration of EPR spectroscopy of a single nanodiamond labeled DNA provides the foundation for the development of single molecule magnetic resonance studies of complex biomolecular systems.

Novel Synthesis of Slightly Fluorinated Graphene Quantum Dots with Luminescent and Paramagnetic Properties through Thermal Cutting of Fluorinated Graphene

PubMed Central

Feng, Qian; Xiao, Wenqing; Zheng, Yongping; Lin, Yuda; Li, Jiaxin; Ye, Qingying; Huang, Zhigao

2018-01-01

A novel approach has been developed to synthesize slightly fluorinated graphene quantum dots (GQDs-F) through thermal cutting of highly fluorinated graphene. The fluorinated graphene with substantial structure defects is fragile and is readily attacked. The direct evaporation of abundant CFn (n = 2, 3) groups near structure defects lead to the loss of adjacent skelton C atoms, and the fluorinated graphene can be thermally cut into GQDs-F with a relatively uniform nanosize in pyrolysis at 810 K. The GQDs-F with a low F/C atomic ratio of ca. 0.03 exhibit excitation wavelength-dependent properties with multicolor photoluminescence (PL) from blue to green. At the same time, F adatoms that are most likely located at the edges of GQDs-F have a high efficiency of introducing paramagnetic centres, and GQDs-F show a strong paramagnetism because of sp3-type defects and magnetic zigzag edges. The graphene quantum dots with such multimodal capabilities should have great applied value in material science. PMID:29316730

Electron Spin Polarization Transfer to ortho-H2 by Interaction of para-H2 with Paramagnetic Species: A Key to a Novel para → ortho Conversion Mechanism.

PubMed

Terenzi, Camilla; Bouguet-Bonnet, Sabine; Canet, Daniel

2015-05-07

We report that at ambient temperature and with 100% enriched para-hydrogen (p-H2) dissolved in organic solvents, paramagnetic spin catalysis of para → ortho hydrogen conversion is accompanied at the onset by a negative ortho-hydrogen (o-H2) proton NMR signal. This novel finding indicates an electron spin polarization transfer, and we show here that this can only occur if the H2 molecule is dissociated upon its transient adsorption by the paramagnetic catalyst. Following desorption, o-H2 is created until the thermodynamic equilibrium is reached. A simple theory confirms that in the presence of a static magnetic field, the hyperfine coupling between unpaired electrons and nuclear spins is responsible for the observed polarization transfer. Owing to the negative electron gyromagnetic ratio, this explains the experimental results and ascertains an as yet unexplored mechanism for para → ortho conversion. Finally, we show that the recovery of o-H2 magnetization toward equilibrium can be simply modeled, leading to the para → ortho conversion rate.

X-band Electron Paramagnetic Resonance Investigation of Stable Organic Radicals Present under Cold Stratification in 'Fuji' Apple Seeds.

PubMed

Nakagawa, Kouichi; Matsumoto, Kazuhiro; Chaiserm, Nattakan; Priprem, Aroonsri

2017-01-01

We investigated stable organic radicals formed in response to cold stratification in 'Fuji' apple seeds using X-band (9 GHz) electron paramagnetic resonance (EPR) technique. This technique primarily detected two paramagnetic species in each seed. These two different radical species were assigned as a stable organic radical and Mn 2+ species based on the g values and hyperfine components. Signal from the stable radicals was noted at a g value of about 2.00 and was strong and relatively stable. Significant radical intensity changes were observed in apple seeds on refrigeration along with water supplementation. The strongest radical intensity and a very weak Mn 2+ signal were also observed for the seeds kept in moisture-containing sand in a refrigerator. Noninvasive EPR of the radicals present in each seed revealed that the stable radicals were located primarily in the seed coat. These results indicate that the significant radical intensity changes in apple seeds under refrigeration for at least 90 days followed by water supplementation for one week, can be related to cold stratification of the seeds.

Thin chitosan films containing super-paramagnetic nanoparticles with contrasting capability in magnetic resonance imaging.

PubMed

Farjadian, Fatemeh; Moradi, Sahar; Hosseini, Majid

2017-03-01

Magnetic nanoparticles have found application as MRI contrasting agents. Herein, chitosan thin films containing super-paramagnetic iron oxide nanoparticles (SPIONs) are evaluated in magnetic resonance imaging (MRI). To determine their contrasting capability, super-paramagnetic nanoparticles coated with citrate (SPIONs-cit) were synthesized. Then, chitosan thin films with different concentrations of SPIONs-cit were prepared and their MRI data (i.e., r 2 and r 2 *) was evaluated in an aqueous medium. The synthesized SPIONs-cit and chitosan/SPIONs-cit films were characterized by FTIR, EDX, XRD as well as VSM with the morphology evaluated by SEM and AFM. The nanoparticle sizes and distribution confirmed well-defined nanoparticles and thin films formation along with high contrasting capability in MRI. Images revealed well-dispersed uniform nanoparticles, averaging 10 nm in size. SPIONs-cit's hydrodynamic size averaged 23 nm in diameter. The crystallinity obeyed a chitosan and SPIONs pattern. The in vitro cellular assay of thin films with a novel route was performed within Hek293 cell lines showing that thin films can be biocompatible.

Observation of superconductivity in BaNb2S5

NASA Astrophysics Data System (ADS)

Smith, M. G.; Neumeier, J. J.

2018-06-01

Bulk superconductivity is reported in BaNb2S5 at the transition temperature Tc = 0.85(1) K. The electrical resistivity ρ versus T is metallic with ρ(2 K) = 42.4 μΩ cm. The magnetic susceptibility is paramagnetic, with temperature-independent contributions due to diamagnetism, Pauli paramagnetism, and Van Vleck paramagnetism; a Curie-Weiss contribution appears to be impurity related. Hall effect measurements show that the majority charge carriers are electrons with charge-carrier concentration n(3 K) = 2.40(2) × 1021 cm-3. Specific heat measurements reveal an electronic specific heat coefficient γ = 11.2(1) mJ/mol K2, a Debye temperature ΘD = 126.4(8) K, and an energy gap associated with the superconducting state of Eg = 0.184(4) meV. Measurements of ρ(T) in magnetic field provide the upper critical magnetic field of about 3055(74) Oe as T → 0 K, which was used to estimate the coherence length ξ = 6.21(15) nm. The results allow classification of BaNb2S5 as a Type II, BCS superconductor in the dirty limit.

Demetalation of Fe, Mn, and Cu chelates and complexes: application to the NMR analysis of micronutrient fertilizers.

PubMed

López-Rayo, Sandra; Lucena, Juan J; Laghi, Luca; Cremonini, Mauro A

2011-12-28

The application of nuclear magnetic resonance (NMR) for the quality control of fertilizers based on Fe(3+), Mn(2+), and Cu(2+) chelates and complexes is precluded by the strong paramagnetism of metals. Recently, a method based on the use of ferrocyanide has been described to remove iron from commercial iron chelates based on the o,o-EDDHA [ethylenediamine-N,N'bis(2-hydroxyphenylacetic)acid] chelating agent for their analysis and quantification by NMR. The present work extended that procedure to other paramagnetic ions, manganese and copper, and other chelating, EDTA (ethylenediaminetetraacetic acid), IDHA [N-(1,2-dicarboxyethyl)-d,l-aspartic acid], and complexing agents, gluconate and heptagluconate. Results showed that the removal of the paramagnetic ions was complete, allowing us to obtain (1)H NMR spectra characterized by narrow peaks. The quantification of the ligands by NMR and high-performance liquid chromatography showed that their complete recovery was granted. The NMR analysis enabled detection and quantification of unknown impurities without the need of pure compounds as internal standards.

Blended versus lecture learning: outcomes for staff development.

PubMed

Sherman, Heidi; Comer, Linda; Putnam, Lorene; Freeman, Helen

2012-07-01

Critical care pharmacology education is crucial to safe patient care for nurses orienting to specialized areas. Although traditionally taught as a classroom lecture, it is important to consider effectiveness of alternative methods for education. This study provided experimentally derived evidence regarding effectiveness of blended versus traditional lecture for critical care pharmacology education. Regardless of learner demographics, the findings determined no significant differences in cognitive learning outcomes or learner satisfaction between blended versus lecture formats.

Comparison between Effects in Two Blended Classes Which E-Learning Is Used inside and outside Classroom

ERIC Educational Resources Information Center

Miyaji, Isao

2011-01-01

In cases where e-learning is used mainly outside the class, a lecture is given by lecture slide and a small test is given at the end of the class. Students fill out a problem in a structured notebook by viewing lecture slide materials in the e-learning after a lecture. In cases where e-learning is used during school hours, the outline of class on…

High-Fidelity Simulation for Advanced Cardiac Life Support Training

PubMed Central

Davis, Lindsay E.; Storjohann, Tara D.; Spiegel, Jacqueline J.; Beiber, Kellie M.

2013-01-01

Objective. To determine whether a high-fidelity simulation technique compared with lecture would produce greater improvement in advanced cardiac life support (ACLS) knowledge, confidence, and overall satisfaction with the training method. Design. This sequential, parallel-group, crossover trial randomized students into 2 groups distinguished by the sequence of teaching technique delivered for ACLS instruction (ie, classroom lecture vs high-fidelity simulation exercise). Assessment. Test scores on a written examination administered at baseline and after each teaching technique improved significantly from baseline in all groups but were highest when lecture was followed by simulation. Simulation was associated with a greater degree of overall student satisfaction compared with lecture. Participation in a simulation exercise did not improve pharmacy students’ knowledge of ACLS more than attending a lecture, but it was associated with improved student confidence in skills and satisfaction with learning and application. Conclusions. College curricula should incorporate simulation to complement but not replace lecture for ACLS education. PMID:23610477

Management of hypothermia: impact of lecture-based interactive workshops on training of pediatric nurses.

PubMed

Altun, Insaf; Karakoç, Ali

2012-05-01

This study aimed to determine the efficacy of interactive workshop on the management of hypothermia and its impact on pediatric nurses' training. This is a pretest-to-posttest quasi-experimental descriptive study. Thirty pediatric nurses attended an interactive lecture-based interactive workshop on the management of hypothermia. Participants had to accept an invitation to the presentation before the training event. They completed the lecture, and a multiple-choice question test before and after the lecture was given. There was a significant improvement in mean test scores after the lecture when compared with those before the lecture (mean [SD], 15.5 [1.3] vs 5.0 [1.7], P < 0.001). The information gained in this study will be valuable as a baseline for further research and help guide improvements in the management of hypothermia with the ultimate goal of enhancing safe and quality patient care.

Link lecturers' views on supporting student nurses who have a learning difficulty in clinical placement.

PubMed

King, Liz

2018-02-08

literature that reports the experiences of facilitating reasonable adjustments for student nurses who have a learning difficulty (LD) in clinical placement from the viewpoint of link lecturers is limited and warrants further exploration. Research aim: to explore link lecturers' views on reasonable adjustments in clinical placement and whether they are confident with their own knowledge of the processes involved. data were collected using interviews with three link lecturers from three fields of nursing (adult, child and mental health). Audio-recorded interviews were transcribed, coded and thematically analysed. three main themes were identified: student engagement, clarity of link lecturer role and external barriers. findings demonstrate that link lecturers have some confidence with their own knowledge of the processes involved with supporting student nurses with an LD in clinical placement, but these processes are complex with many barriers preventing successful facilitation of available reasonable adjustments.

High-fidelity simulation for advanced cardiac life support training.

PubMed

Davis, Lindsay E; Storjohann, Tara D; Spiegel, Jacqueline J; Beiber, Kellie M; Barletta, Jeffrey F

2013-04-12

OBJECTIVE. To determine whether a high-fidelity simulation technique compared with lecture would produce greater improvement in advanced cardiac life support (ACLS) knowledge, confidence, and overall satisfaction with the training method. DESIGN. This sequential, parallel-group, crossover trial randomized students into 2 groups distinguished by the sequence of teaching technique delivered for ACLS instruction (ie, classroom lecture vs high-fidelity simulation exercise). ASSESSMENT. Test scores on a written examination administered at baseline and after each teaching technique improved significantly from baseline in all groups but were highest when lecture was followed by simulation. Simulation was associated with a greater degree of overall student satisfaction compared with lecture. Participation in a simulation exercise did not improve pharmacy students' knowledge of ACLS more than attending a lecture, but it was associated with improved student confidence in skills and satisfaction with learning and application. CONCLUSIONS. College curricula should incorporate simulation to complement but not replace lecture for ACLS education.

Student and faculty perceptions of lecture recording in a doctor of pharmacy curriculum.

PubMed

Maynor, Lena M; Barrickman, Ashleigh Landis; Stamatakis, Mary K; Elliott, David P

2013-10-14

To describe students' and faculty members' perceptions of the impact of lecture recording in a doctor of pharmacy (PharmD) curriculum. Second- and third-year pharmacy students and faculty members completed an anonymous survey instrument regarding their perceptions of lecture recording with 2 classroom lecture capture software programs, Camtasia Studio and Wimba Classroom. Most students (82%) responded that Camtasia was very helpful and almost half (49%) responded that Wimba Classroom was helpful (p<0.001). Forty-six percent of the students reported being more likely to miss a class that was recorded; however, few students (10%) reported using recordings as a substitute for attending class. The most common concern of faculty members was decreased student attendance (27%). Pharmacy students consider lecture recordings beneficial, and they use the recordings primarily to review the lecture. While faculty members reported concerns with decreased attendance, few students reported using recordings as an alternative to class attendance.

[Discussion of the Application of Micro-lecture in the Clinical Training 
of Thoracic Surgery].

PubMed

Li, Xiaofei; Lei, Jie

2018-04-20

Today, with the rapid development of network information technology, the micro-lecture plays a role in the teaching activities is becoming more and more important. The short and efficient teaching content of micro-lecture can be downloaded rapidly, expediently, and repeatedly, which improve the learning efficiency and independent learning capability. The clinical training of thoracic surgery elementarily remains at the scrabble stage. We require continuous reform and introduce new modes of teaching, which compatible with the development of society and the study habits of novice, to enhance the effectiveness of clinical training. In this paper, the concept, characteristic and advantage of micro-lecture was discussed, and the feasibility of application of micro-lecture in thoracic surgery teaching was also discussed. Our aim was to promote the application of micro-lecture in the clinical training of thoracic surgery reasonable and extensive.
.

Changing Children’s Understanding of the Brain: A Longitudinal Study of the Royal Institution Christmas Lectures as a Measure of Public Engagement

PubMed Central

Gjersoe, Nathalia L.; Hood, Bruce

2013-01-01

Demonstrating the impact of public engagement is an increasingly important activity for today’s academics and researchers. The difficulty is that many areas of interest do not lend themselves well to evaluation because the impact of each single intervention can be hard to trace and take time to become manifest. With this in mind, we evaluated a lecture based around the 2011 Royal Institution Christmas Lectures, ”Meet Your Brain,” delivered to school children from low performing schools. We compared knowledge about four neuroscience facts one week before, one week after and six weeks after the lecture. Analysis revealed significant knowledge transfer one week after the lecture that was retained five weeks later. We conclude that public engagement through tailored lectures can have significant impact in the moderate term with the potential to leave a lasting impression over a longer period. PMID:24260513

Departing from PowerPoint default mode: Applying Mayer's multimedia principles for enhanced learning of parasitology.

PubMed

Nagmoti, Jyoti Mahantesh

2017-01-01

PowerPoint (PPT™) presentation has become an integral part of day-to-day teaching in medicine. Most often, PPT™ is used in its default mode which in fact, is known to cause boredom and ineffective learning. Research has shown improved short-term memory by applying multimedia principles for designing and delivering lectures. However, such evidence in medical education is scarce. Therefore, we attempted to evaluate the effect of multimedia principles on enhanced learning of parasitology. Second-year medical students received a series of lectures, half of the lectures used traditionally designed PPT™ and the rest used slides designed by Mayer's multimedia principles. Students answered pre and post-tests at the end of each lecture (test-I) and an essay test after six months (test-II) which assessed their short and long term knowledge retention respectively. Students' feedback on quality and content of lectures were collected. Statistically significant difference was found between post test scores of traditional and modified lectures (P = 0.019) indicating, improved short-term memory after modified lectures. Similarly, students scored better in test II on the contents learnt through modified lectures indicating, enhanced comprehension and improved long-term memory (P < 0.001). Many students appreciated learning through multimedia designed PPT™ and suggested for their continued use. It is time to depart from default PPT™ and adopt multimedia principles to enhance comprehension and improve short and long term knowledge retention. Further, medical educators may be trained and encouraged to apply multimedia principles for designing and delivering effective lectures.

Impact of utilisation of uncompleted handouts on power point presentations (PPT) in rural Indian medical institute.

PubMed

Bhaisare, Roshan; Kamble, Bhavna

2016-07-01

Note taking while attending a PPT requires high activity of memory and writing process which ultimately leads to what is called "death by power point" referring to boredom and fatigue.  To overcome this we planned to evaluate the impact of utilisation of uncompleted handouts given prior to PPT presentations. Final year MBBS students were divided in 2 batches, batch A and batch B.  For a set of lectures one batch was provided with handouts before lecture while the other batch was given lectures only. Crossover was done to avoid bias, all the lectures being given by the same presenter.  At the end of each lecture, a short questionnaire of 10 Multiple Choice Question (MCQ) was provided to the students. Mean scores were calculated for lectures with handouts and without handouts. For a set of lectures, when batch A was provided with handouts, the mean score was 28.2; for batch B to which no handouts were given the mean score was 23.4. Similarly, for batch B when provided with handouts the mean score was 29.1, for batch A which was not provided with handouts the mean score was 24. There was an average increase of 4.2 marks. Actual gain when handouts were provided was 1.2 marks per lecture.  It was more for the batch comprising of repeater students as compared to the batch of fresher students. Increase in attendance was also noted. Providing uncompleted handouts before a didactic lecture definitely results in increase in knowledge gain; repeater students benefit more with uncompleted handouts.

Encouraging Participation in Face-to-Face Lectures: The Index Card Technique

ERIC Educational Resources Information Center

Daws, Laura Beth

2018-01-01

Courses: This activity will work in any face-to-face communication lecture course. Objectives: By the end of the semester in a face-to-face lecture class, every student will have engaged in verbal discussion.

Stars in Nutrition and Cancer Lecture Series | Division of Cancer Prevention

Cancer.gov

This lecture series features extraordinary contributors or "stars" in the field of cancer and nutrition research. Speakers highlight the important role that nutrition plays in modifying cancer development. Past lectures are videotaped and available for viewing. |

Programmed Multi-Image Lectures for College Biology Instruction.

ERIC Educational Resources Information Center

Jensen, William A.; Knauft, Robert L.

1977-01-01

Discusses the use of a programed multi-image lecture approach for teaching a botany course to nonmajor students at the University of California, Berkeley. Also considers the advantages, production, method of presentation, and design of the multimedia lectures. (HM)

Embedding a Virtual Patient Simulator in an Interactive Surgical lecture.

PubMed

Kleinert, Robert; Plum, Patrick; Heiermann, Nadine; Wahba, Roger; Chang, De-Huan; Hölscher, Arnulf H; Stippel, Dirk L

2016-01-01

Lectures are traditionally used for teaching declarative knowledge. One established tool for clinical education is the demonstration of a real patient. The use of real patients in the daily clinical environment is increasingly difficult. The use of a virtual patient simulator (VPS) can potentially circumvent these problems. Unlimited availability and the opportunity of an electronic feedback system could possibly enrich traditional lectures by enabling more interactivity that meets the expectations of the current student generation. As students face the consequences of their own decisions they take a more active role in the lecture. VPS links declarative knowledge with visual perception that is known to influence students' motivation. Until now, there have been no reports covering the usage and validation of interactive VPS for supporting traditional lectures. In this study, we (1) described the development of a custom-made three-dimensional (3D) VPS for supporting the traditional lecture and (2) performed a feasibility study including an initial assessment of this novel educational concept. Conceptualization included definition of curricular content, technical realization and validation. A custom-made simulator was validated with 68 students. The degree of student acceptance was evaluated. Furthermore, the effect on knowledge gain was determined by testing prelecture and postlecture performance. A custom-made simulator prototype that displays a 3D virtual clinic environment was developed and linked to a PowerPoint presentation. Students were able to connect to the simulator via electronic devices (smartphones and tablets) and to control the simulator via majority vote. The simulator was used in 6 lectures and validated in 2 lectures with 68 students each. Student acceptance and their opinion about effectiveness and applicability were determined. Students showed a high level of motivation when using the simulator as most of them had fun using it. Effect on knowledge gain was proven by comparison of chosen therapeutic workflow before and after the lecture. Students showed significantly (p < 0.05) more correct answers in determination of the therapeutic workflow after the lecture. We successfully developed and evaluated a custom-made 3D VPS for supporting the traditional lecture. VPS is probably an effective instrument that might replace real patients in selected lectures and prepare students for bedside teaching. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

A marriage of continuance: professional development for mathematics lecturers

NASA Astrophysics Data System (ADS)

Barton, Bill; Oates, Greg; Paterson, Judy; Thomas, Mike

2015-06-01

In a 2-year project, we developed and trialled a mode of lecturing professional development amongst staff in our department of mathematics. Theoretically grounded in Schoenfeld's resources, orientations, and goals (ROG) model of teacher action, a group met regularly to discuss both the video excerpts of themselves lecturing along with written pre- and post-lecture statements of their "ROGs". We found evidence of improved teaching performance but more interestingly, identified key aspects of our practice and of undergraduate mathematics that received repeated attention and developed further theoretical insight into lecturer behaviour in mathematics. The trial has been successful enough to be expanded into further groups that now constitute a professional development culture within our department.

The 2008 Charles H. Thompson Lecture-Colloquium Presentation: From Du Bois to Obama--The Education of Peoples of African Descent in the United States in the 21st Century

ERIC Educational Resources Information Center

Lee, Carol D.

2009-01-01

This article presents the text of a lecture delivered by American Educational Research Association President Carol D. Lee at the 29th Annual Charles H. Thompson Lecture-Colloquium Series which was held on November 5, 2008. In her lecture, Lee discussed several points of similarities between W. E. B. Du Bois and President Barack Obama. These…

Everyday attention and lecture retention: the effects of time, fidgeting, and mind wandering.

PubMed

Farley, James; Risko, Evan F; Kingstone, Alan

2013-01-01

We have all had our thoughts wander from the immediate task at hand. The emerging embodied cognition literature emphasizes the role that the body plays in human thought, and raises the possibility that changes in attentional focus may be associated with changes in body behavior. Recent research has found that when individuals view a lecture, mind wandering increases as a function of time. In the present study we asked whether this decline in attention during lecture viewing was associated with fidgeting. Participants were filmed while they watched a 40-min lecture video, and at regular 5-min intervals provided ratings of their attentiveness. Following the lecture, participant's memory for the material was assessed. Fidgeting behavior was coded from video recordings of each session. Results indicated that attention to, and retention of, lecture material declined as a function of time on task. Critically, and as predicted, fidgeting also increased with time on task. We also found that the relation between fidgeting and retention was significant even when the role of attention was factored into the equation, suggesting that fidgeting makes a unique contribution to retention of lecture material over and above that contributed by an individual's attention. We propose a novel non-attentional stress-based account of fidgeting and how this impacts retention for lecture material over and above changes in levels in mind wandering vis-a-vis changes in attention.

Interactive instruction in otolaryngology resident education.

PubMed

Schweinfurth, John M

2007-12-01

Today's academic faculty was typically trained under an education system based entirely on didactic lectures. However, if the aim is to teach thinking or change attitudes beyond the simple transmission of factual knowledge, then lectures alone, without active involvement of the students, are not the most effective method of teaching. If the goals of teaching are to arouse and keep students' interest, give facts and details, to make students think critically about the subject, and to prepare for independent studies by demonstration of problem solving and professional reasoning, then only two of these purposes are suited to didactic lectures. The problem then is how to organize lecture material so that individual student's learning needs are better addressed. The education literature suggests that instruction include a variety of activities designed to stimulate individual thought. These activities include small group discussion, working problems during lecture time, questions included in the lecture, and quizzes at the end of lecture, among others. The current study was undertaken to examine the feasibility of using these types of interactive learning techniques in an otolaryngology residency program. Possibilities considered in the current study include standard interactive lecturing, facilitated discussion, brainstorming, small group activities, problem solving, competitive large group exercises, and the use of illustrative cliff hanger and incident cases. The feasibility of these methodologies being effectively incorporated into a residency curriculum is discussed.

Combination of didactic lectures and review sessions in endocrinology leads to improvement in student performance as measured by assessments.

PubMed

Qureshi, Ayisha; Cozine, Cassy; Rizvi, Farwa

2013-03-01

There can be no single best way of learning, and each teaching mode has its own merits and demerits. Didactic lectures in and of themselves are insufficient, whereas a problem-based tutorial alone can be as ineffective. This study was conducted to determine if a problem-based review after didactic lectures would lead to better student performance. To compare performance, the same student group was taught three units of endocrinology (growth hormone, thyroid hormone, and diabetes). Students were divided into the following three groups: diabetes didactic lectures only, growth hormone didactic lectures plus review, and thyroid hormone didactic lectures plus review. All three topics were covered in the didactic lectures, but only growth hormone and thyroid hormone topics were covered in the review session. At the end of the course, all students were given formative assessments in the form of multiple-choice questions. A highly significant increase (P < 0.000) in the percentage of correct responses on the questions covering growth hormone (mean: 0.838, SD: 0.158) and thyroid hormone (mean: 0.686, SD: 0.232) compared with diabetes (mean: 0.478, SD: 0.259) was observed. In conclusion, this study provides further evidence that the combination of didactic lectures and an active review session leads to an improvement in student performance.

Utilizing public scientific web lectures to teach contemporary physics at the high school level: A case study of learning

NASA Astrophysics Data System (ADS)

Kapon, Shulamit; Ganiel, Uri; Eylon, Bat Sheva

2011-12-01

This paper describes a teaching experiment designed to examine the learning (i.e., retention of content and conceptual development) that takes place when public scientific web lectures delivered by scientists are utilized to present advanced ideas in physics to students with a high school background in physics. The students watched an exemplary public physics web lecture that was followed by a collaborative generic activity session. The collaborative session involved a guided critical reconstruction of the main arguments in the lecture, and a processing of the key analogical explanations. Then the students watched another exemplary web lecture on a different topic. The participants (N=14) were divided into two groups differing only in the order in which the lectures were presented. The students’ discussions during the activities show that they were able to reason and demonstrate conceptual progress, although the physics ideas in the lectures were far beyond their level in physics. The discussions during the collaborative session contributed significantly to the students’ understanding. We illustrate this point through an analysis of one of these discussions between two students on an analogical explanation of the Aharonov-Bohm effect that was presented in one of the lectures. The results from the tests that were administered to the participants several times during the intervention further support this contention.

Brief, cooperative peer-instruction sessions during lectures enhance student recall and comprehension*

PubMed Central

Zhang, Niu; Henderson, Charles N.R.

2016-01-01

Objective: The objective of this study was to evaluate the academic impact of cooperative peer instruction during lecture pauses in an immunology/endocrinology course. Methods: Third-quarter students participated across iterations of the course. Each class offered 20 lectures of 50 minutes each. Classes were divided into a peer-instruction group incorporating cooperative peer instruction and a control group receiving traditional lectures. Peer-instruction group lectures were divided into 2–3 short presentations followed by a multiple-choice question (MCQ). Students recorded an initial answer and then had 1 minute to discuss answers with group peers. Following this, students could submit a revised answer. The control group received the same lecture material, but without MCQs or peer discussions. Final-exam scores were compared across study groups. A mixed-design analysis of covariance was used to analyze the data. Results: There was a statistically significant main effect for the peer-instruction activity (F(1, 93) = 6.573, p = .012, r = .257), with recall scores higher for MCQs asked after peer-instruction activities than for those asked before peer instruction. Final-exam scores at the end of term were greater in the peer-instruction group than the control group (F(1, 193) = 9.264, p = .003, r = .214; question type, F(1, 193) = 26.671, p = .000, r = .348). Conclusion: Lectures with peer-instruction pauses increase student recall and comprehension compared with traditional lectures. PMID:26967766

Medical biochemistry: Is it time to change the teaching style?

PubMed

Palocaren, Jeeji; Pillai, Lekha S; Celine, T M

2016-01-01

The Medical Council of India (MCI) recommendations on medical education suggest a shift from didactic lectures to more interactive lectures. This study assessed the effectiveness of different pedagogical methods in biochemistry and the perceptions of students and teachers about the shift from didactic to interactive lectures. An interventional crossover study was done with the topic divided into three biochemical modules and one clinical module. The students were divided into two batches, one of which was given didactic and the other, interactive lectures. They were assessed immediately after the lecture and four months later. Anonymous feedback was obtained to gauge the students' perceptions regarding the mode of teaching. The teachers' feedback on the use of both pedagogical styles was also obtained. There was no significant difference between the performance of the two groups in either examination in three of the modules. However, there was a statistically significant difference between the two groups' performance in the module that had clinical applications, with students from the interactive lecture group performing better. All students preferred interactive classes, irrespective of the topic taught. The teachers indicated that, although at the outset the interactive lectures were difficult to manage, both in terms of content and time, these drawbacks could be overcome with time and practice. Interactive lectures are an effective teaching method in biochemistry, especially in topics involving clinical application.

Moving Knowledge Acquisition From the Lecture Hall to the Student Home: A Prospective Intervention Study.

PubMed

Raupach, Tobias; Grefe, Clemens; Brown, Jamie; Meyer, Katharina; Schuelper, Nikolai; Anders, Sven

2015-09-28

Podcasts are popular with medical students, but the impact of podcast use on learning outcomes in undergraduate medical education has not been studied in detail. Our aim was to assess the impact of podcasts accompanied by quiz questions and lecture attendance on short- and medium-term knowledge retention. Students enrolled for a cardio-respiratory teaching module were asked to prepare for 10 specific lectures by watching podcasts and submitting answers to related quiz questions before attending live lectures. Performance on the same questions was assessed in a surprise test and a retention test. Watching podcasts and submitting answers to quiz questions (versus no podcast/quiz use) was associated with significantly better test performance in all items in the surprise test and 7 items in the retention test. Lecture attendance (versus no attendance) was associated with higher test performance in 3 items and 1 item, respectively. In a linear regression analysis adjusted for age, gender, and overall performance levels, both podcast/quiz use and lecture attendance were significant predictors of student performance. However, the variance explained by podcast/quiz use was greater than the variance explained by lecture attendance in the surprise test (38.7% vs. 2.2%) and retention test (19.1% vs. 4.0%). When used in conjunction with quiz questions, podcasts have the potential to foster knowledge acquisition and retention over and above the effect of live lectures.

Everyday attention and lecture retention: the effects of time, fidgeting, and mind wandering

PubMed Central

Farley, James; Risko, Evan F.; Kingstone, Alan

2013-01-01

We have all had our thoughts wander from the immediate task at hand. The emerging embodied cognition literature emphasizes the role that the body plays in human thought, and raises the possibility that changes in attentional focus may be associated with changes in body behavior. Recent research has found that when individuals view a lecture, mind wandering increases as a function of time. In the present study we asked whether this decline in attention during lecture viewing was associated with fidgeting. Participants were filmed while they watched a 40-min lecture video, and at regular 5-min intervals provided ratings of their attentiveness. Following the lecture, participant's memory for the material was assessed. Fidgeting behavior was coded from video recordings of each session. Results indicated that attention to, and retention of, lecture material declined as a function of time on task. Critically, and as predicted, fidgeting also increased with time on task. We also found that the relation between fidgeting and retention was significant even when the role of attention was factored into the equation, suggesting that fidgeting makes a unique contribution to retention of lecture material over and above that contributed by an individual's attention. We propose a novel non-attentional stress-based account of fidgeting and how this impacts retention for lecture material over and above changes in levels in mind wandering vis-a-vis changes in attention. PMID:24065933

Probing the Dipolar Coupling in a Heterospin Endohedral Fullerene-Phthalocyanine Dyad.

PubMed

Zhou, Shen; Yamamoto, Masanori; Briggs, G Andrew D; Imahori, Hiroshi; Porfyrakis, Kyriakos

2016-02-03

Paramagnetic endohedral fullerenes and phthalocyanine (Pc) complexes are promising building blocks for molecular quantum information processing, for which tunable dipolar coupling is required. We have linked these two spin qubit candidates together and characterized the resulting electron paramagnetic resonance properties, including the spin dipolar coupling between the fullerene spin and the copper spin. Having interpreted the distance-dependent coupling strength quantitatively and further discussed the antiferromagnetic aggregation effect of the CuPc moieties, we demonstrate two ways of tuning the dipolar coupling in such dyad systems: changing the spacer group and adjusting the solution concentration.