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1

Venus - Ovda Regio  

NASA Technical Reports Server (NTRS)

This Magellan image shows part of the northern boundary of Ovda Regio, one of the large highlands ringing the equator of Venus. The scene consists largely of low-relief, rounded linear ridges. These ridges, 8-15 kilometers (5-9 miles) in width and 30-60 kilometers (20-40 miles) long, lie mostly along a 100-200 kilometer (60-120 mile) wide slope where the elevation drops 3 kilometers (2 miles) from Ovda Regio to the surrounding plains. Some of the ridges have been cut at right angles by extension fractures. Dark material, either lava or windblown dirt, fills the region between the ridges. The curvilinear, banded nature of these ridges suggests that crustal shortening, roughly oriented north-south, is largely responsible for their formation. Such crustal shortening was unexpected by Magellan scientists, who believed that Ovda Region, a likely site of hot upwelling from the interior of Venus, should be dominated by volcanism and crustal extension. This image, centered approximately at 1 degree north, 81 degrees east, measures 300 kilometers (190 miles) by 225 kilometers (140 miles) and was acquired by Magellan in November 1990.

1991-01-01

2

Venus: Geology of beta Regio Rift System.  

National Technical Information Service (NTIS)

Beta Regio is characterized by the existence of rift structures. We compiled new geologic maps of Beta Regio according to Magellan data. There are many large uplifted tesserae on beta upland. These tesserae are partly buried by younger volcanic cover. We ...

A. M. Nikishin V. K. Borozdin N. N. Bobina

1992-01-01

3

Tectonics of the Galileo Regio on Ganymede  

NASA Technical Reports Server (NTRS)

The surface of Ganymede consists of dark cratered terrain, and groved terrain. The dark cratered terrains form polygonal units, the largest of which is Galileo Regio, the surface of which is transected by furrows, smooth floored valleys bounded by relatively sharp parallel ridges. The most apparent of them are grouped together and form an apparently arcuate system of subparallel furrows which was mapped using Voyager pictures and plotted on a map using a stereographic projection. With this kind of projection, the main furrow system is not arcuate, but rectilinear. Observations strongly suggest that the Galileo Regio furrow systems are not of impact origin and appear to be irrelevant to discussions about the basins' morphology or evolution of planetary lithosphere determined from multiring structures.

Thomas, P. G.; Masson, P. L.

1985-01-01

4

Lithospheric modeling over Atla Regio, Venus  

NASA Astrophysics Data System (ADS)

Atla Regio is a broad, rift-dominated volcanic rise on Venus, extending from 10°S-20°N and 170°E-220°E. The lithospheric structure at volcanic rises on Venus are highly unconstrained with models of thermal lithospheric thickness being particularly ambiguous. Estimates of melt generation rates, volcanic volume estimates, the presence of extensional features, elastic lithosphere thicknesses and the resulting thermal gradients, imply a thin thermal lithosphere of ~100-150 km. However, the lack of recent geological activity, stagnant lid convection and thermal thinning models imply a thicker thermal lithosphere of ~200-400 km. Crustal thickness estimates are usually more constrained with thicker estimates at the volcanic rise compared to the surrounding plains regions. This study aims to constrain the lithospheric structure below Atla Regio and to determine the isostatic, dynamic and flexural contribution to the observed topography. From this we aim to constrain the processes shaping topography at volcanic rises on Venus. We use the interactive software package LitMod3D, modified to operate under Venusian conditions. This software simultaneously solves equations for heat transfer, thermodynamical, rheological, geopotential and isostasy for a proposed lithospheric structure and outputs temperature, surface heat flow, gravity anomalies, absolute elevation and geoid anomalies. We used data sets from the Magellan mission to Venus to obtain elevation, free-air, bouguer and geoid anomalies. By simultaneously fitting these observables we obtained a consistent lithospheric model, as well as estimates of surface heat flow and flexural responses for a range of elastic lithosphere thicknesses. Our results show that the lithospheric structure below the volcanic rise is different to the surrounding plains regions. Below the volcanic rise the thermal lithosphere is thin, with thicknesses of 80-110 km, which thicken to values of 85-140 km in the plains, immediately surrounding the rise. These thermal lithospheric thicknesses for the plains regions are thinner than previous estimates of 200-300 km, suggesting the modeled plains are being influenced by their close proximity to the rift-dominated volcanic rise. These plains regions also have a crustal thickness of 10-30 km, with the crust thickening to 30-45 km towards the volcanic rise, due to a mafic crustal root. Similar to previous studies, the thinner thermal lithosphere directly below the volcanic rise suggests Atla Regio has experienced possible lithospheric thinning by the action of a mantle plume or active rifting, which is also consistent with extensive volcanic and extensional activity in this area.

Schinella, E.; Afonso, J. C.; O'Neill, C.

2011-12-01

5

Geologic map of the Themis Regio quadrangle (V-53), Venus  

USGS Publications Warehouse

The Themis Regio quadrangle (V-53), Venus, has been geologically mapped at 1:5,000,000 scale as part of the NASA Planetary Geologic Mapping Program. The quadrangle extends from lat 25° to 50° S. and from long 270° to 300° E. and encompasses the Themis Regio highland, the surrounding plains, and the southernmost extension of Parga Chasmata. Themis Regio is a broad regional topographic high with a diameter of about 2,000 km and a height of about 0.5 km that has been interpreted previously as a hotspot underlain by a mantle plume. The Themis rise is dominated by coronae and lies at the terminus of the Parga Chasmata corona chain. Themis Regio is the only one of the three corona-dominated rises that contains significant extensional deformation. Fractures and grabens are much less common than along the rest of Parga Chasmata and are embayed by corona-related flows in places. Rift and corona formation has overlapped in time at Themis Regio.

Stofan, Ellen R.; Brian, Antony W.

2012-01-01

6

Estimating lithospheric properties at Atla Regio, Venus  

NASA Astrophysics Data System (ADS)

Magellan spehrical harmonic gravity and topography models are used to estimate lithospheric properties at Alta Regio, Venus, a proposed hotspot with dynamic support from mantle plume(s). Global spherical harmonic and local representations of the gravity field share common properties in the Atla region interms of their spectral behavior over a wavelength band from approximately 2100 to approximately 700 km. The estimated free-air admittance spectrum displays a rather featureless long-wavelength portion followed by a sharp rise at wavelengths shorter than about 1000 km. This sharp rise requires significant flexural support of short-wavelength structures. The Bouguer coherence also displays a sharp drop in this wavelength band, indicating a finite flexural rigidity of the lithosphere. A simple model for lithospheric loading from above and below is introduced (D. W. Forsyth, 1985) with four parameters: f, the ratio of bottom loading to top loading; zm, crustal thickness; zl depth to bottom loading source; and Te elastic lithosphere thickness. A dual-mode compensation model is introduced in which the shorter wavelengths (lambda approximately less than 1000 km) might be explained best by a predominance of top loading by the large shield volcanoes Maat Mons, Ozza Mons, and Sapas Mons, and the longer wavelengths (lambda approximately greater than 1500 km) might be explained best by a deep depth of compensation, possibly representing bottom loading by a dynamic source. A Monte Carlo inversion technique is introduced to thoroughly search out the four-space of the model parameters and to examine parameter correlation in the solutions. Venus either is a considerabe deficient in heat sources relative to Earth, or the thermal lithosphere is overthickened in response to an earlier episode of significant heat loss from the planet.

Phillips, Roger J.

1994-11-01

7

Venus - False Color of Eistla Regio  

NASA Technical Reports Server (NTRS)

This false color Magellan image shows a portion of Eistla Regio (region) in the northern hemisphere of Venus, centered at 1 degrees south latitude, 37 degrees east longitude. The area is 440 kilometers (270 miles) wide and 350 kilometers (220 miles) long. This image was produced from Magellan radar data collected in Cycle 2 of the mission. Cycle 2 was completed January 15, 1992. The area was not imaged during the first cycle because of superior conjunction when the sun was between the Earth and Venus, preventing communication with the spacecraft. This image contains examples of several of the major geologic terrains on Venus and illustrates the basic stratigraphy or sequence of geologic events. The oldest terrain appears as bright, highly fractured or chaotic highlands rising out of the plains. This is seen in the right half of the image. The chaotic highlands, sometimes called tessera, may represent older and thicker crustal material and occupy about 15 percent of the surface of Venus. The fractured terrain in this region has a distinctly linear structure with a shear-like pattern. Plains surround and embay the fractured highland tessera. Plains are formed by fluid volcanic flows that may have once formed vast lava seas which covered all the low lying surfaces. Plains comprise more than 80 percent of the surface of Venus. The most recent activity in the region is volcanism that produced the radar bright flows best seen in the upper left quadrant of the image. The flows are similar, in their volcanic origin to the darker plains volcanics, but apparently have more rugged surfaces that more efficiently scatter the radar signal back to the spacecraft. The geologic sequence is early fracturing of the tessera, flooding by extensive plains lavas, and scattered less extensive individual flows on the plains surface. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft.

1992-01-01

8

Galileo Regio Mosaic - Galileo over Voyager Data  

NASA Technical Reports Server (NTRS)

A mosaic of four Galileo images of the Galileo Regio region on Ganymede (Latitude 18 N, Longitude: 149 W) is shown overlayed on the data obtained by the Voyager 2 spacecraft in 1979. North is to the top of the picture, and the sun illuminates the surface from the lower left, about 58 degrees above the horizon. The smallest features that can be discerned are about 80 meters (262 feet) in size in the Galileo images. These Galileo images show fine details of the dark terrain that makes up about half of the surface of the planet-sized moon. Ancient impact craters of various sizes and states of degradation testify to the great age of the terrain, dating back several billion years. The images reveal distinctive variations in albedo from the brighter rims, knobs, and furrow walls to a possible accumulation of dark material on the lower slopes, and crater floors. High photometric activity (large light contrast at high spatial frequencies) of this ice-rich surface was such that the Galileo camera's hardware data compressor was pushed into truncating lines. The north-south running gap between the left and right halves of the mosaic is a result of line truncation from the normal 800 samples per line to about 540. The images were taken on 27 June, 1996 Universal Time at a range of 7,580 kilometers (4,738 miles) through the clear filter of the Galileo spacecraft's imaging system. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

1996-01-01

9

Regio- and diastereoselective Cu-mediated trifluoromethylation of functionalized alkenes.  

PubMed

?- and ?-substituted N,N-diethylacrylamides undergo copper-mediated direct ?-trifluoromethylation. The amide moiety acts as a directing group for the regio- and the stereo-controlled introduction of the trifluoromethyl group. The reaction is carried out under acidic conditions in the presence of Umemoto's reagent. This method does not require prefunctionalized substrates and delivers excellent stereoselectivity. PMID:24279496

Besset, Tatiana; Cahard, Dominique; Pannecoucke, Xavier

2014-01-01

10

Venus - Three-Dimensional Perspective View of Alpha Regio  

NASA Technical Reports Server (NTRS)

A portion of Alpha Regio is displayed in this three-dimensional perspective view of the surface of Venus. Alpha Regio, a topographic upland approximately 1300 kilometers across, is centered on 25 degrees south latitude, 4 degrees east longitude. In 1963, Alpha Regio was the first feature on Venus to be identified from Earth-based radar. The radar-bright area of Alpha Regio is characterized by multiple sets of intersecting trends of structural features such as ridges, troughs, and flat-floored fault valleys that, together, form a polygonal outline. Directly south of the complex ridged terrain is a large ovoid-shaped feature named Eve. The radar-bright spot located centrally within Eve marks the location of the prime meridian of Venus. Magellan synthetic aperture radar data is combined with radar altimetry to develop a three-dimensional map of the surface. Ray tracing is used to generate a perspective view from this map. The vertical scale is exaggerated approximately 23 times. Simulated color and a digital elevation map developed by the U. S. Geological Survey are used to enhance small scale structure. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. The image was produced at the JPL Multimission Image Processing Laboratory by Eric De Jong, Jeff Hall, and Myche McAuley, and is a single frame from the movie released at the March 5, 1991, press conference.

1992-01-01

11

Geologic Mapping of Northern Atla Regio on Venus: Preliminary Data.  

National Technical Information Service (NTIS)

The Northern part of Atla Regio within the frame of C1-formate Magellan photo map 15N197 was mapped geologically at scale 1:8,000,000. This is a part of Russia's contribution into C1 geologic mapping efforts. The map is reproduced here being reduced about...

A. M. Nikishin G. A. Burba

1993-01-01

12

Venus: Preliminary Geologic Mapping of Northern Atla Regio.  

National Technical Information Service (NTIS)

A preliminary geologic map of C1 sheet 15N197 was compiled according to Magellan data. Northern Atla Regio is dominantly a volcanic plain with numerous volcanic features: radar-bright and -dark flows and spots, shield volcanos, volcanic domes and hills wi...

A. M. Nikishin G. A. Burba

1992-01-01

13

Spectroscopic studies of regio-regular and regio-random polythiophene films  

NASA Astrophysics Data System (ADS)

Poly(3 hexyl thiophene) [P3HT] can be synthesized with regio-regular (RR-) order in which the side groups are arranged head to tail, and regio-random (RRa-) order in which the side groups are not arranged in a particular form. It has been recently discovered that films cast from RR-P3HT form two-dimensional (2D) lamellae perpendicular to the substrate, whereas RRa-P3HT forms lamellae to a lesser extend [1,2]. The interchain interplane separation in the lamellae is of order 4 Angstr. causing a strong interchain interaction. This has a profound influence on the charged and neutral photoexcitations in RR-P3HT films compared to those of RRa-P3HT. We have employed a variety of steady state and ps transient spectroscopies to study and compare the photoexcitations in RR- and RRa- P3HT films. In the ps time domain we found [3] in RRa-P3HT films that intrachain excitons with correlated photoinduced absorption (PA) and stimulated emission (SE) bands are the primary excitations; they give rise to a moderately strong photoluminescence (PL) band. In RR-P3HT films, on the contrary the primary excitations are excitons with a much larger interchain component; this results in lack of a SE band, vanishing small intersystem crossing and very weak PL band [3]. We also measured in RR-P3HT films photogenerated polaron pairs with ultrafast dynamics that are precursor to long-lived polaron excitations. In the steady state we measured long-lived polaron excitations in both RR- and RRa- P3HT films, however with different relaxation energies [2]. Whereas the polaron relaxation energy in RRa-P3HT is of the order of 0.5 eV, it is only about 50 meV in RR-P3HT. This shows that the polarons are delocalized in the 2D lamellae, consistent with the carrier relative high mobility [1] and superconductivity [4] found in RR-P3HT films. As a result of the very low relaxation energy in RR-P3HT we found that the polaron optical transition in the mid ir spectral range overlaps with several photoinduced ir active vibrations (IRAV)[2]. This spectral overlap leads to quantum interference between the electronic and vibrational optical transitions that results in sharp dips (Fano resonances) superimposed on the polaron PA band. The Fano resonances can be readily analyzed in terms of the amplitude mode model with non-adiabatic approximation [5] to get the polaron important parameters such as the exact relaxation energy, effective mass, wave-function extent and strength of the e-p coupling and thus understand the factors governing the superconductivity transition temperature. [1] H. Sirringhaus et al., Nature 401, 685 (1999). [2] R. Osterbacka et al., Science 287, 839 (2000). [3] O. J. Korovyanko et al., Phys. Rev. B 64, 235122 (2001). [4] J. H. Schon et al., Nature 410, 189 (2001). [5] R. Osterbacka et al., Phys. Rev. Lett. (at press).

Valy Vardeny, Z.

2002-03-01

14

Regio- and chemoselective immobilization of proteins on gold surfaces.  

PubMed

Protein chips are powerful tools as analytical and diagnostic devices for detection of biomolecular interactions, where the proteins are covalently or noncovalently attached to biosensing surfaces to capture and detect target molecules or biomarkers. Thus, fabrication of biosensing surfaces for regio- and chemoselective immobilization of biomolecules is a crucial step for better biosensor performance. In our previous studies, a regio- and chemoselective immobilization strategy was demonstrated on glass surfaces. This strategy is now used to regioselectively attach proteins to self-assembled monolayers (SAMs) on gold surfaces. Recombinant green fluorescent protein (GFP), glutathione S-transferase (GST), and antibody-binding protein G, bearing a C-terminal CVIA motif, were prepared and a farnesyl analogue with an ?-alkyne moiety was attached to the sulfhydryl moiety in the cysteine side chain by protein farnesyltransferase. The proteins, modified with the bioorthogonal alkyne functional group, were covalently and regioselectively immobilized on thiol or dithiocarbamate (DTC) SAMs on a gold surface by a Huigsen [3 + 2] cycloaddition reaction with minimal nonspecific binding. A concentration-dependent increase of fluorescence intensity was observed in wells treated with GFP on both thiol- and DTC-SAMs. The highly ordered, densely packed layer allowed for a high loading of immobilized protein, with a concomitant increase in substrate binding capacity. The DTC-SAMs were substantially more resistant to displacement of the immobilized proteins from the gold surface by ?-mercaptoethanol than alkane-thiol SAMs. PMID:24437976

Choi, Seoung-Ryoung; Seo, Jin-Soo; Bohaty, Rochelle F H; Poulter, C Dale

2014-02-19

15

Optical and Magnetic Resonance Studies of Regio-Regular and Regio-Random Poly (3-hexylthiophene)/PCBM Blends  

NASA Astrophysics Data System (ADS)

Regio-regular (RR) P3HT has been successfully used as donor polymer in organic bulk heterojunction photovoltaic cells based on blends with fullerene acceptors; with power conversion efficiencies of over 6%. However, when regio-random (RR-a) P3HT is used as donor polymer in the blend, the power conversion efficiency drops to less than 0.5%. We have used various optical and magnetic resonance techniques to elucidate the charge photogeneration in the two polymer/fullerene blends. Using tunneling electron microscopy we conclude that phase separation takes place in blends based on RR P3HT but not in blends based on RR-a P3HT. Photoluminescence spectrum shows a prominent band in RR-a P3HT blend at 1.32 eV, indicating the dominance of charge transfer exciton recombination. Photoinduced absorption shows higher localization of polarons in RRa-P3HT blend, with a distinct PA band due to negative polaron on PCBM molecules. Photoinduced absorption detected magnetic resonance resolves the contributions of RR-a P3HT and PCBM as two resonances indicating positive polarons on the polymer and negative polaron on the fullerene. A model based on our experimental results will be discussed.

Hukic-Markosian, Golda; Zhang, Ye; Singh, Sanjeev; Vardeny, Valy

2010-03-01

16

Structural and Geologic Mapping of Northern Tellus Regio, Venus: Implications for Crustal Plateau Evolution  

NASA Astrophysics Data System (ADS)

Crustal plateaus, one type of large surface feature on Venus, are features that no longer form today, and represent ancient geodynamic processes. Crustal plateaus host distinctive tectonic fabric, referred to as ribbon tesserae terrain. The formation of crustal plateaus is a highly debated topic with the major differences in surface deformation and plateau support. Each hypothesis also has different mechanisms that form the crustal plateau, which leads to slightly different spatial and temporal relationships between structures. Detailed mapping of northern Tellus Regio displays deformational structures across the study area and provides clues for crustal plateau evolution. The study area, divided into domains based on topography and surface roughness, displays structures occurring in specific domains and structures occurring within multiple domains. Spatial and temporal relationships of structures between domains provide insight into crustal plateau evolution and the deformational interactions between crustal plateaus and lowlands. Structural relationships in northern Tellus Regio indicate that short-wavelength structures form early on, and wavelengths of structures increase with time. The mapping of this study displays structural trends and temporal relationships, and provides a way of identifying and defining the northern boundary of Tellus Regio. Geologic mapping shows that Tellus Regio extends north up to 60°N and contains a large area of highly deformed deposited material. The collision between this northern part of Tellus Regio and a separate crustal plateau led to a folded terrain and raises questions regarding the evolution of individual crustal plateaus, as well as interactions of multiple crustal plateaus.

Slonecker, Aaron

17

Hotspots on Venus: Possible recent activity at Themis Regio  

NASA Astrophysics Data System (ADS)

Themis Regio, Venus is a 2300 x 1700 km topographic rise, with an average height of about 0.5 km. It is one of the ~10 hotspots on Venus, thought to be underlain by a mantle plume (e.g., Stofan and Smrekar, 2005). Thirteen coronae are located on the rise, with an additional six in the surrounding region (Stofan and Brian, 2012). In addition, six volcanoes with diameters > 100 km are found on and near the rise, along with numerous intermediate and smaller volcanoes. The Themis rise lies at the western end of the Parga Chasma rift system. Flows associated with Themis coronae, volcanoes and plains both superpose and are cut by Parga fractures and graben. Recent mapping of Themis Regio reveals a complex history of corona, volcano and rift formation that has overlapped in time and space (Stofan and Brian, 2012). Smrekar and Stofan (1999) found that gravity data for Themis was best fit by a bottom-loading model with an elastic thickness estimate of 22 km, a crustal thickness of 10 km, and an apparent depth of compensation of 80-110 km. The observed range in morphologies of the Themis coronae indicating a range in stages of evolution, along with the delamination signal seen in the gravity data, and the broad topographic swell indicate that Themis is likely to be underlain by an active plume with ongoing surface deformation due to delamination. In addition, the complex sequence of corona formation observed at Themis suggests that a series of small-scale upwellings over time are responsible for corona formation, rather than nearly simultaneously from the break-up of a single large-scale mantle plume (Stofan and Smrekar, 2005). VIRTIS data from the Venus Express mission has provided evidence that relatively recent volcanic activity may have occurred in the region (Smrekar et al., 2010). Fifteen locations on or near the Themis rise have elevated values of emissivity in the VIRTIS data. We investigate all of these regions, and find them to be correlated with areas of volcanic activity, associated with either coronae or volcanoes. While a few of the high emissivity spots are associated with steep-sided domes, most are associated with flows that are likely to be basaltic in origin. The anomalies occur on both topographically elevated terrain as well as on relatively low-lying plains. Based on their morphology and stratigraphic relations with surrounding units, we interpret all of the features to provide evidence of volcanic activity that likely occurred within the last 250,000 years (e.g., Smrekar et al., 2010). References: Smrekar, S.E. and E.R. Stofan, Icarus 139, 100, 1999; Smrekar, S.E. et al., Science 328, 305, 2010; Stofan, E.R. and A.W. Brian, U.S.G.S. SIM- 3165, 2012; Stofan, E.R. and S.E. Smrekar, GSA Spec. Paper 388, 841, 2005.

Stofan, E. R.; Smrekar, S. E.; Helbert, J.; Mueller, N. T.

2012-12-01

18

Magellan observations of Alpha Regio - Implications for formation of complex ridged terrains on Venus  

NASA Technical Reports Server (NTRS)

The deformational features that make up the complex ridged terrain (CRT) of Alpha Regio are characterized, and observations of these features and their interpretations are used to evaluate quantitative models for the formation of Alpha Regio. In particular, two models are considered: a hotspot or mantle plume model and a coldspot or mantle downwelling model. Based on an analysis of the observed morphology of structures, their distribution, superposition and crosscutting relationships, and Magellan altimetry, a sequence of deformational events is suggested, and the observed topography, tectonics, and volcanism are compared with the predictions of the hotspot and coldspot models. It is found that a number of observations are more consistent with the downwelling than a hotspot model. This is particularly true of margin-parallel compressional features near the plains-CRT boundary in much of Alpha Regio.

Bindschadler, Duane L.; Decharon, Annette; Beratan, Kathi K.; Smrekear, Suzanne E.; Head, James W.

1992-01-01

19

Mantle and crustal structure in Phoebe Regio and Devana Chasma, Venus  

NASA Technical Reports Server (NTRS)

We use gravity and topography data to study crust and mantle structure in Phoebe Regio and Devana Chasma on Venus. We find that Phoebe is a region of thickened crust and hotter than normal mantle. These results are inconsistent with a cold, downwelling model and may support a mantle plume origin for Phoebe. However, the pattern of thermal anomalies is unusual, with temperature maxima on the periphery of the highland rather than in its center. This may reflect development of thermal boundary layer instabilities as the plume head interacts with the lithosphere. The hot mantle anomaly beneath Devana Chasma is discontinuous near latitude 10 North, coinciding with a 600 km offset in the rift zone trend. Devana should be regarded as two separate rifts, one propagating south from Beta Regio and the other propagating north from Phoebe Regio. Our results support the view that Venus remains a geologically active world.

Kiefer, Walter S.; Peterson, Kelly

2003-01-01

20

Beta Regio Rift System on Venus: Geologic Interpretation of Magellan Images.  

National Technical Information Service (NTIS)

Magellan SAR images and altimetric data were used to produce a new geologic map of the Northern part of Beta Regio within the frames of C1-30N279 mapsheet. It was part of our contributions into C1-formate geologic mapping efforts. The original map is at 1...

A. M. Nikishin N. N. Bobina V. K. Borozdin G. A. Burba

1993-01-01

21

Arylations of substituted enamides by aryl iodides: regio- and stereoselective synthesis of (Z)-?-amido-?-arylacrylates.  

PubMed

Arylations of substituted enamides by aryl iodides were achieved for the first time via an unusual PdCl2(COD)/Ag3PO4 catalytic system. A broad range of (Z)-?-amido-?-arylacrylates were prepared regio- and stereoselectively in a highly efficient manner. PMID:23947658

Gou, Quan; Deng, Bin; Zhang, Hongbin; Qin, Jun

2013-09-01

22

Pd-catalyzed highly regio-, diastereo-, and enantioselective allylic alkylation of ?-fluorophosphonates.  

PubMed

Highly efficient Pd-catalyzed asymmetric allylic alkylation reaction of ethyl-2-fluoro-2-(diethoxyphosphoryl)acetate with monosubstituted allylic substrates has been developed, affording corresponding ?-fluorophosphonates with two chiral centers in high regio-, diastereo- and enantio-selectivities. The usefulness of the products in organic synthesis has been demonstrated. PMID:24831029

Huang, Ying; Zhang, Qing-Song; Fang, Ping; Chen, Tie-Gen; Zhu, Jun; Hou, Xue-Long

2014-05-29

23

Venus - Comparison of gravity and topography in the vicinity of Beta Regio  

NASA Technical Reports Server (NTRS)

The Doppler tracking data obtained from the Pioneer Venus Orbiter when it passed near Beta Regio yielded a peak vertical anomaly of 150 mGal when analyzed by our two stage procedure. A comparison of maps of the gravity and topography at comparable resolution shows a striking correlation. A scatter plot shows that the observed gravity anomaly is approximately 0.4 of that expected from uncompensated topography of half the mean density of Venus. However, the spectral admittance shows that the gravity anomalies can not be explained either by Airy compensation at fixed depth or by a model comprising an elastic plate atop an inviscid fluid. The gravity and topography variations may signify deep compensation or dynamic support for Beta Regio and more shallow compensation for other features.

Reasenberg, R. D.; Goldberg, Z. M.; Shapiro, I. I.

1982-01-01

24

Regio- and stereoselective reactions of gem-difluorinated vinyloxiranes with heteronucleophiles.  

PubMed

[Reaction: see text]. Regio- and stereoselectivity in reactions of gem-difluorinated vinyloxiranes with heteronucleophiles were successfully controlled. Halogen atoms were introduced regioselectively at the allylic epoxide carbon with an inversion in stereochemistry using MgBr2*Et2O or Li2CuCl4 to produce anti-vic-halohydrine. The other diastereomers were obtained selectively using LiBr/AcOH or BCl3, and SN2' type products were formed selectively with excellent E preference by changing the reaction temperature. Moreover, a further investigation led us to find that a regio- and stereoselective SN2' addition of several Brnsted acids was dependent on the pKa values of the acids. Under strong acidic conditions, we exclusively obtained E allylic alcohols. PMID:16268608

Ueki, Hisanori; Kitazume, Tomoya

2005-11-11

25

Regio- and stereo-selective carbon–carbon bond formation in ionic liquids  

Microsoft Academic Search

Ionic liquids, that is molten salts, may represent activating and stabilizing solvents for C–C coupling reactions. In particular, tetrabutylammonium bromide (TBAB) is particularly suitable for Heck reactions as it enhances reaction rates. In the presence of tetrabutylammonium acetate as base, palladium complex with benzothiazolidene as ligands as well palladium acetate are transformed to Pd-nanoparticles which allow regio- and stereo-specific Heck

Vincenzo Calò; Angelo Nacci; Antonio Monopoli

2004-01-01

26

Chemo-, regio-, and stereoselective iron-catalysed hydroboration of alkenes and alkynes.  

PubMed

The highly chemo-, regio-, and stereoselective synthesis of alkyl- and vinyl boronic esters with good functional group tolerance has been developed using in situ activation of a bench-stable iron(II) pre-catalyst and pinacolborane (16 examples, 45-95% yield, TOF up to 30,000 mol h(-1)). The first iron-catalysed alkene hydrogermylation is also reported. PMID:24158267

Greenhalgh, Mark D; Thomas, Stephen P

2013-12-11

27

Copper-catalyzed regio- and stereoselective intermolecular three-component oxyarylation of allenes.  

PubMed

A copper(II)-catalyzed intermolecular three-component oxyarylation of allenes using arylboronic acids as a carbon source and TEMPO as an oxygen source is described. The reaction proceeded under mild conditions with high regio- and stereoselectivity and functional group tolerance. A plausible reaction mechanism is proposed, involving carbocupration of allenes, homolysis of the intervening allylcopper(II), and a radical TEMPO trap. PMID:24766635

Itoh, Taisuke; Shimizu, Yohei; Kanai, Motomu

2014-05-16

28

Tectonic evolution of Bell Regio, Venus: Regional stress, lithospheric flexure, and edifice stresses  

NASA Astrophysics Data System (ADS)

In order to understand the relationship between volcanic and tectonic processes and the stress state in the lithosphere of Venus, we analyzed the stress environments and resulting tectonic features associated with the major volcanic edifices in Bell Regio, using Magellan synthetic aperture radar (SAR) images and altimeter measurements of topography. The major volcanoes of Bell Regio, Tepev Mons and Nyx Mons, exhibit tectonic characteristics that are unique relative to other volcanic edifices on Venus. The most prominent distinction is the lack of large rift zones within the overall highland uplift, which characterize many other highland rises on Venus. Also, previous studies have determined that many large Venus volcanoes exhibit radial tectonic structures on their flanks but generally lack the circumferential graben which surround volcanoes on Earth and Mars. Tepev and Nyx Montes exhibit both the radial tectonic features associated with other Venusian edifices and numerous concentric graben. Nyx Mons implies a more distributed magmatic system by its broad shape, radial chains of pit craters, and expansive flow fields, whereas Tepev Mons is a more centralized volcanic system, with limited associated long flows. We investigate the regional stresses associated with Bell Regio and structural features believed to be a consequence of lithospheric flexure due to volcanic loading, modeling both Nyx Mons and Tepev Mons as axisymmetric loads with Gaussian mass distributions on an elastic plate. The relationship between the tectonic features surrounding Tepev Mons and stresses associated with magma chamber inflation are also examined through finite element analysis. Using topography data to model the shape of the volcano, we determine that a horizontally ellipsoidal or tabular reservoir at a range of depths from approximately 20 to 40 km can satisfy the locations of graben formation observed in Magellan images. These results imply a shift in volcanic style within Bell Regio from an early phase of broad, low shield formation to later steep-sided, more centralized edifice development. Such changes are consistent with an increase in the thickness of the lithosphere over time.

Rogers, Patricia G.; Zuber, Maria T.

1998-07-01

29

Regio- and diastereoselective reduction of nonenolizable alpha-diketones to acyloins mediated by indium metal.  

PubMed

[reaction: see text] Alpha-diketones are efficiently reduced with indium metal in methanol-water in the presence of NH(4)Cl, LiCl, or NaCl to give regio- and diastereoselectively the corresponding acyloins in good to excellent yield. The cleavage of the acyloins under Pb(OAc)(4)/MeOH-PhH condition provides a convenient and regioselective access to highly functionalized cyclopentane carboxaldehydes, potential building blocks in organic syntheses. PMID:11893210

Khan, Faiz Ahmed; Dash, Jyotirmayee; Sahu, Nilam; Gupta, Sharad

2002-03-21

30

Regio- and diastereoselective synthesis of 2-alkylidenetetrahydrofurans by domino SN/SN' and SN/SN reactions of 1,3-dicarbonyl dianions.  

PubMed

The domino C,O-cyclodialkylation reaction of dilithiated 1,3-dicarbonyl compounds with 1,4-dibromo-2-butene resulted in regio- and diastereoselective formation of 2-alkylidene-5-vinyltetrahydrofurans. The cyclization of 1,3-dicarbonyl dianions with 1-bromo-2-chloroethane regio- and diastereoselectively afforded 2-alkylidenetetrahydrofurans under thermodynamic reaction control. PMID:11529731

Langer, P; Holtz, E; Karimé, I; Saleh, N N

2001-09-01

31

Beta Regio rift system on Venus: Geologic interpretation of Magellan images  

NASA Technical Reports Server (NTRS)

Magellan SAR images and altimetric data were used to produce a new geologic map of the Northern part of Beta Regio within the frames of C1-30N279 mapsheet. It was part of our contributions into C1-formate geologic mapping efforts. The original map is at 1:8,000,000 scale. The rift structures are typical for Beta Regio on Venus. There are many large uplifted tessera areas on Beta upland. They occupy areas of higher topography. These tessera are partly burried by younger volcanic cover of plain material. These observations show that Beta upland was formed mainly due to lithospheric tectonical uplifting, and only partly was constructed by volcanic activity. A number of rift valleis traverse Beta upland and spread to the surrounding lowlands. The largest rift crosses Beta N to S. Typical width of rifts is 40 to 160 km. Rift valleis in this region are structurally represented by crustal grabens and half-grabens. There are symmetrical and asymmetrical rifts. A lot of them have shoulder uplifts with the relative high up to 0.5-1 km and width 40 to 60 km. Preliminary analysis of the largest rift valley structural cross-sections leads to the conclusion that it originated due to a 5-10 percent crustal extension. The prominent shield volcano - Theia Mons - is located at the center of Beta rift system. It could be considered as the surface manifestation of the upper mantle hot spot. Most of the rift belts are located radially to Theia Mons. The set of these data leads to conclusion that Beta rift system has an 'active-passive' origin. It was formed due to the regional tectonic lithospheric extension. Rifting was accelerated by the upper mantle hot spot located under the center of passive extension (under Beta Regio).

Nikishin, A. M.; Bobina, N. N.; Borozdin, V. K.; Burba, G. A.

1993-01-01

32

Are the Basins of Tui Regio and Hotei Arcus Sites of Former Titanian Seas?  

NASA Technical Reports Server (NTRS)

Features observed in the basins of Tui Regio and Hotei Arcus on Titan have attracted the attention of the Cassini-era investigators. At both locations, VIMS observed discrete 5-micron bright approx.500-km wide features described as lobate in shape. Several studies have proposed that these materials are cryo-volcanic flows; in the case of the Hotei Arcus feature this inference was buttressed with SAR RADAR images showing bright and dark patches with lobate margins. We propose an alternative explanation. First we note that all landforms on Titan that are unambiguously identifiable can be explained by exogenic processes (aeolian, fluvial, impact cratering, and mass wasting). Suggestions of endogenically produced cryovolcanic constructs and flows have, without exception, lacked conclusive diagnostic evidence. Recently published topographic profiles across Tui Regio and the lobate feature region north of Hotei Arcus indicate these features appear to occur in large regional basins, at least along the direction of the profiles. SAR images show that the terrains surrounding both 5-micron bright features exhibit fluvial networks that appear to converge and debauch into the probable basins. The 5-micron bright features themselves correspond to fields of discrete radar-bright depressions whose bounding edges are commonly rounded and cumulate in planform in SAR images. These fields of discrete radar-bright depressions strongly resemble fields of features seen at Titan s high latitudes usually attributed to be dry lakes. Thus the combination of (1) the resemblance to high-latitude dry lakes, (2) location in the centers of probable regional depressions, and (3) convergence of fluvial networks are inferred by us to best explain the 5-micron bright regions at Tui Regio and Hotei Arcus as sites of dry seas or at least paleolake clusters. Such equatorial seas, if real, may be evidence of substantially larger inventories of liquid alkanes in Titan s past.

Moore, Jeffrey Morgan; Howard, Alan

2012-01-01

33

Regio-Selective 10-Hydroxylation of Patchoulol, a Sesquiterpene, by Pithomyces Species  

PubMed Central

Of some 350 microorganisms screened, four strains of Pithomyces species were found to carry out regio-selective hydroxylation of patchoulol, a sesquiterpene, to 10-hydroxypatchoulol: Pithomyces sp. NRJ201, P. chartarum NRJ210, and, to a lesser extent, P. cynodontis ATCC 26150 and P. atro-olivaceus IFO 6651 were found to catalyze this reaction. A method has been developed by which 10-hydroxypatchoulol was obtained in 25 to 45% yields in 1- to 5-liter fermentation jars at 2 to 4 g of patchoulol per liter and isolated as pure material in 30% yields.

Suhara, Yasuji; Itoh, Sayuri; Ogawa, Mayumi; Yokose, Kazuteru; Sawada, Toyoaki; Sano, Takashi; Ninomiya, Rieko; Maruyama, Hiromi B.

1981-01-01

34

Structural architecture and a new tectonic perspective of Ovda Regio, Venus  

NASA Astrophysics Data System (ADS)

The structural architecture of the Ovda Regio, Venus, derived from regional and detailed structural mapping of several key segments, reveals a new tectonic perspective, for the first time that varies from most of the existing tectonic models. The interpreted structural features include folds of different styles and scales, mega shear zones, ribbon structures, and other kinematic indicators. While concentric folding is predominant in the western Ovda, the eastern Ovda is characterized by shear folding. Two mega shear zones are recognised: dextral NW-SE trending GMSZ and a complimentary sinistral NE-SW trending KKSZ. Two tectonic stages are identified in a coherent and continuous strain history involving initial N-S compression that gave rise to regional east-west folding providing the fundamental tectonic architecture of a mountain fold-thrust belt. Ribbon structures in a broad radial pattern were developed contemporaneously with this folding. The second tectonic stage saw the development of a conjugate pair of mega shear zones and a range of kinematic indicators, consistent with continued N-S compression and the pre-existing fold pattern was modified resulting in the development of new fold structures, particularly in the eastern Ovda. The structural characteristics of Ovda Regio are analogous to those of Himalaya-Tibet collision front and also the Precambrian mobile belts of southern India.

Chetty, T. R. K.; Venkatrayudu, M.; Venkatasivappa, V.

2010-08-01

35

Ruthenium-catalyzed highly regio- and stereoselective hydroarylation of aryl carbamates with alkynes via C-H bond activation.  

PubMed

Chelation-assisted alkenylation of ortho C-H bond of aryl carbamates with alkynes in the presence of a ruthenium catalyst, AgSbF(6) and pivalic acid gives highly substituted alkene derivatives in good to excellent yields in a highly regio- and stereoselective manner. PMID:23192381

Reddy, Mallu Chenna; Jeganmohan, Masilamani

2013-01-18

36

PERDA AUDITIVA INDUZIDA PELO RU?DO EM TRABALHADORES INDUSTRIAIS DA REGIO METROPOLITANA DE SALVADOR, BAHIA  

Microsoft Academic Search

Summary An audiometric evaluation was conducted in 7,925 workers of fourty-four industrial companies in nine different fields of activity. The hearing loss prevalence was 45.9%. The noise-induced hearing loss (NIHL) prevalence was 35.7% considering bilateral and unilateral losses. For each field of activity, the prevalence estimates were: 58.7% in the graphic, 51.7% in the mechanic, 45.9% in the beverage industry,

Carlos R. Miranda; Carlos R. Dias; Paulo G. L. Pena; C. C. Nobre; Rosana Aquino

37

Synthesis of 1-[bis(trifluoromethyl)phosphine]-1'-oxazolinylferrocene ligands and their application in regio- and enantioselective Pd-catalyzed allylic alkylation of monosubstituted allyl substrates  

PubMed Central

Summary A class of novel, easily accessible and air-stable 1-[bis(trifluoromethyl)phosphine]-1’-oxazolinylferrocene ligands has been synthesized from ferrocene. It became apparent that these ligands can be used in the regio- and enantioselective Pd-catalyzed allylic alkylation of monosubstituted allyl substrates in a highly efficient manner. Excellent regio- and enantioselectivity could be obtained for a wide range of substrates.

Lai, Zeng-Wei; Yang, Rong-Fei; Ye, Ke-Yin

2014-01-01

38

Rhodium-catalyzed regio- and stereoselective oxyamination of dienes via tandem aziridination/ring-opening of dienyl carbamates.  

PubMed

The reaction of dienyl carbamates with PhI(OR)2 in the presence of rhodium catalysts affords vinyl aziridines which are in situ regio- and stereoselectively opened to afford oxyamination products resulting from a selective SN2 (Rh2(OAc)4/PhI(OPiv)2) or SN2' (Rh2(OPiv)4/PhI(OAc)2) opening. The scope and limitations of this tandem process are described. PMID:24869654

Guasch, Joan; Díaz, Yolanda; Matheu, M Isabel; Castillón, Sergio

2014-06-12

39

Photoconduction action spectra of regio-regular poly(3-hexylthiopene):TiO2 diodes  

NASA Astrophysics Data System (ADS)

The development of polymer-based photovoltaic devices brings the promise of low-cost and lightweight solar energy conversion systems. This technology requires new materials and device architectures with enhanced efficiency and lifetime, which depends on the understanding of charge-transport mechanisms. Organic films combined with electronegative nanoparticles may form systems with efficient dissociation of the photogenerated excitons, thus increasing the number of carriers to be collected by the electrodes. In this paper we investigate the steady-state photoconductive action spectra of devices formed by a bilayer of regio-regular poly(3-hexylthiophene) (RRP3HT) and TiO2 sandwiched between ITO and aluminum electrodes (ITO/TiO2:RRP3HT/Al). Photocurrents were measured for distinct bias voltages with illumination from either side of the device. Heterojunction structures were prepared by spin coating a RRP3HT film on an already deposited TiO2 layer on ITO. Symbatic and antibatic curves were obtained and a model for photocurrent action spectra was able to fit the symbatic responses. The quantum yield increased with the electric field, indicating that exciton dissociation is a field-assisted process as in an Onsager mechanism. Furthermore, the quantum yield was significantly higher when illumination was carried out through the ITO electrode onto which the TiO2 layer was deposited, as the highly electronegative TiO2 nanoparticles were efficient in exciton dissociation.

deSouza, C. E. Z.; Ibaldo, A. P.; Coutinho, D. J.; Valaski, R.; Oliveira, O. N.; Faria, R. M.

2012-03-01

40

Regio- and Stereospecific Conversion of 4-Alkylphenols by the Covalent Flavoprotein Vanillyl-Alcohol Oxidase  

PubMed Central

The regio- and stereospecific conversion of prochiral 4-alkylphenols by the covalent flavoprotein vanillyl-alcohol oxidase was investigated. The enzyme was active, with 4-alkylphenols bearing aliphatic side chains of up to seven carbon atoms. Optimal catalytic efficiency occurred with 4-ethylphenol and 4-n-propylphenols. These short-chain 4-alkylphenols are stereoselectively hydroxylated to the corresponding (R)-1-(4?-hydroxyphenyl)alcohols (F. P. Drijfhout, M. W. Fraaije, H. Jongejan, W. J. H. van Berkel, and M. C. R. Franssen, Biotechnol. Bioeng. 59:171–177, 1998). (S)-1-(4?-Hydroxyphenyl)ethanol was found to be a far better substrate than (R)-1-(4?-hydroxyphenyl)ethanol, explaining why during the enzymatic conversion of 4-ethylphenol nearly no 4-hydroxyacetophenone is formed. Medium-chain 4-alkylphenols were exclusively converted by vanillyl-alcohol oxidase to the corresponding 1-(4?-hydroxyphenyl)alkenes. The relative cis-trans stereochemistry of these reactions was strongly dependent on the nature of the alkyl side chain. The enzymatic conversion of 4-sec-butylphenol resulted in two (4?-hydroxyphenyl)-sec-butene isomers with identical masses but different fragmentation patterns. We conclude that the water accessibility of the enzyme active site and the orientation of the hydrophobic alkyl side chain of the substrate are of major importance in determining the regiospecific and stereochemical outcome of vanillyl-alcohol oxidase-mediated conversions of 4-alkylphenols.

van den Heuvel, Robert H. H.; Fraaije, Marco W.; Laane, Colja; van Berkel, Willem J. H.

1998-01-01

41

Sequential deformation of plains along Tessera boundaries on Venus: Evidence from Alpha Regio  

NASA Technical Reports Server (NTRS)

Tesserae are regions of elevated terrain characterized by two or more sets of ridges and grooves that intersect orthogonally. Tesserae comprise 15-20 percent of the surface of Venus, but the nature of their formation and evolution is not well understood; processes proposed to account for their characteristics are many and varied. Two types of tessera boundaries have been described: type 1 are generally embayed by plains; and type 2 boundaries are characterized by being linear at the 100-km scale and often associated with steep scarps or tectonic features. Margins such as the western edge of Alpha have been described as type 2. Some of the tessera have boundaries that display deformation of both the edge of the tessera and the adjoining plains. This study focuses on the western edge of Alpha Regio in an effort to characterize on occurrence of this type of boundary and assess the implications of the style in general. Using Magellan SAR imagery, lineament lengths, orientations, and spacing were measured for ten 50 x 60 km areas spanning 500 km of the western boundary. Structural characteristics and orientations were compared to stratigraphic units in order to assess the sequence and style of deformation.

Gilmore, M. S.; Head, James W., III

1992-01-01

42

Hot-spot tectonics of Eistla Regio, Venus: Results from Magellan images and Pioneer Venus gravity  

NASA Technical Reports Server (NTRS)

Eistla Regio (ER) is a broad, low, discontinuous topographic rise striking roughly EW at low northern latitudes of Venus. Some 2000 x 7000 km in dimensions, it is the third largest rise in planform on Venus after Aphrodite Terra and Beta Phoebe Regiones. These rises are the key physiographic elements in a hot spot model of global tectonics including transient plume behavior. Since ER is the first such rise viewed by Magellan and the latitude is very favorable for Pioneer Venus gravity studies, some of the predictions of a time dependent hot spot model are tested. Western ER is defined as the rise including Gula and Sif Mons and central ER as that including Sappho Patera. Superior conjunction prevented Magellan from returning data on eastern ER (Pavlova) during the first mapping cycle. It is concluded that the western and central portions of ER, while part of the same broad topographic rise and tectonic framework, have distinctly different surface ages and gravity signatures. The western rise, including Gula and Sif Mons, is the expression of deep seated uplift with volcanism limited to the individual large shields. The eastern portion has been widely resurfaced more recently by thermal anomalies in the mantle.

Grimm, Robert E.; Phillips, Roger J.

1991-01-01

43

Engineering of p450pyr hydroxylase for the highly regio- and enantioselective subterminal hydroxylation of alkanes.  

PubMed

Terminal-selective cytochrome P450pyr has been successfully engineered through directed evolution for the subterminal hydroxylation of alkanes with excellent regio- and enantioselectivity. A sensitive colorimetric high-throughput screening (HTS) assay was developed for the measurement of both the regioselectivity and the enantioselectivity of a hydroxylation reaction. By using the HTS assay and iterative saturation mutagenesis, sextuple-mutant P450pyrSM1 was created for the hydroxylation of n-octane (1) to give (S)-2-octanol (2) with 98?%?ee and >99?% subterminal selectivity. The engineered P450 is the first enzyme for this type of highly selective alkane hydroxylation, being useful for the C-H activation and functionalization of alkanes and the preparation of enantiopure alcohols. Molecular modeling provided structure-based understanding of the fully altered regioselectivity and the excellent enantioselectivity. Another sextuple-mutant P450pyrSM2 catalyzed the hydroxylation of propylbenzene (3) to afford (S)-1-phenyl-2-propanol (4) with 95?%?ee and 98?% subterminal selectivity. PMID:24554642

Yang, Yi; Liu, Ji; Li, Zhi

2014-03-17

44

Fractal analysis of Venus topography in Tinatin Planitia and Ovda Regio  

NASA Technical Reports Server (NTRS)

A one-dimensional fractal analysis is applied to Magellan altimetry data for two 20 x 20 deg equatorial regions on Venus. For the Ovda Regio, highlands the power spectra of the altimetry data correlate well with power law (fractal) statistics over the full range of wavelengths considered 36-703 km; the mean fractal dimension is D(Ovda) = 1.64. For the Tinatin Planitia lowlands, the power spectra consistently show a rollover at long wavelengths, (greater than 200 km), the long-wavelength topography in this region either never developed or has subsequently relaxed. The mean of the best fit fractal dimension for Tinatin is D(Tinatin) = 1.41. The measure of roughness (RA) correlates well with variations in relief, especially at short wavelengths (about 50 km). The quantitative analysis of Venus topography can be applied on a global scale. The one-dimensional method can be extended to two-dimensional space, yielding two-dimensional maps of regional D and RA, allowing a more complete use of regional two-dimensional altimetry data.

Kucinskas, Algis B.; Turcotte, Donald L.; Huang, Jie; Ford, Peter G.

1992-01-01

45

Comparisons between the rift systems of East Africa, Earth and Beta Regio, Venus  

NASA Astrophysics Data System (ADS)

The rift systems of southern East Africa and Beta Regio, Venus are similar in a number of ways. The rifted East African and Venusian lithospheres have effective elastic thicknesses of ˜ 30 km, suggesting that both lithospheres maintain significant flexural strength during rifting. Both rift systems have maximum fault segment lengths of ˜ 100 km. The effective elastic thickness and maximum fault segment length of both rifts are greater than those seen in many other active extensional regions on Earth, despite the high surface temperatures on Venus. We suggest that the southern East African and Venusian elastic thicknesses and maximum fault segment lengths are due to stronger lithosphere. The rift systems differ in the maximum width of their half graben. East African half grabens are up to ˜ 50 km wide, whilst those on Venus are up to ˜ 150 km wide. To support the topography associated with such half grabens requires shear stresses to act on the bounding faults. In East Africa the greater elastic thickness (compared to most other terrestrial extensional regions) means that wide half grabens can form without requiring the shear stresses acting on the bounding faults to be greater than the ˜ 1-10 MPa (10-100 bars) stress drop typically seen in earthquakes. However, on Venus the absence of sediment infill, greater widths and larger effective topographic steps of the half grabens require shear stresses of up to ˜ 80 MPa (800 bars) to act on the bounding faults. This difference is significant; Venusian faults must be stronger than those on Earth.

Foster, Adrian; Nimmo, Francis

1996-09-01

46

Microwave signatures and surface properties of Ovda Regio and surroundings, Venus  

NASA Technical Reports Server (NTRS)

Magellan observations of horizontally and vertically polarized emissivity and radar specific cross sections are jointly modeled to separate dielectric constants from textural effect for lobate plains, fractured plains, fracture belts, festoon flows, and tessera in Ovda Regio and surroundings. The model assumes surface emission and scattering dominate and that signatures are controlled by a combination of quasi-specular and diffuse-scale mechanisms. Textural parameters are found to correlate with geology whereas dielectric constants are found to depend on elevation. A gradual increase in dielectric constant from rock-like values (4 to 5) to a value of approximately 50 is evident over the interval from 6054 to 6056 km, where elevations are derived from Magellan altimetry observations. Stereo radargrammetric analyses demonstrate that a return to rock-like values occurs over approximately 0.5 km above the terrain with highest dielectric constants. The abrupt return to rock-like values occurs independently of geology and reinforces the hypothesis of elevation control on dielectric constant values. Variations in dielectric constant with elevation are modeled using an 1000-ppm concentration of a ferroelectric mineral with a Curie temperature of 707 K. The model reproduces the abrupt change at highest elevations, as the Curie temperature is reached, and the gradual change as lower elevations are encountered. To our knowledge no other model explains the trends with such simplicity.

Arvidson, R. E.; Brackett, R. A.; Shepard, M. K.; Isenberg, N. R.; Fegley, B., Jr.

1994-01-01

47

A facile chemo-, regio- and stereoselective synthesis and cholinesterase inhibitory activity of spirooxindole-pyrrolizine-piperidine hybrids.  

PubMed

A series of novel hybrid spiro heterocycles comprising pyrrolizine, spiroxindole and piperidine moieties was synthesized chemo-, regio- and stereoselectively in good yields from 1,3-dipolar cycloaddition reaction of a series of 1-acryloyl-3,5-bisarylmethylidenepiperidin-4-ones with azomethine ylides generated in situ from 5-choloroisatin and l-proline in methanol. These cycloadducts displayed significant cholinesterase inhibitory activity. Among the compounds screened, 8g and 8e, showed maximum inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinestrase (BChE) with IC50 values of 3.33 and 3.13?M, respectively. PMID:23570788

Kia, Yalda; Osman, Hasnah; Kumar, Raju Suresh; Murugaiyah, Vikneswaran; Basiri, Alireza; Perumal, Subbu; Razak, Ibrahim Abdul

2013-05-15

48

A regio- and stereoselective entry to (Z)-?-halo alkenyl sulfides and their applications to access stereodefined trisubstituted alkenes.  

PubMed

A mild and efficient preparation of (Z)-?-halo alkenyl sulfides via the K2CO3-promoted hydrothiolation of haloalkynes has been realized, producing (Z)-?-bromo and (Z)-?-chloro vinylic sulfides in high yields with excellent regio- and stereoselectivity. This approach covers a variety of substrates, including both aryl and alkyl haloalkynes. Meaningfully, it allows a facile access to stereodefined (Z)- or (E)-trisubstituted olefins featuring the iterative cross-coupling of carbon-halide and carbon-sulfur bonds of ?-halo alkenyl sulfides. PMID:24589923

Liu, Ge; Kong, Lichun; Shen, Ji; Zhu, Gangguo

2014-04-14

49

Efficient entry to highly functionalized beta-lactams by regio- and stereoselective 1,3-dipolar cycloaddition reaction of 2-azetidinone-tethered nitrones. Synthetic applications.  

PubMed

Racemic as well as optically pure 2-azetidinone-tethered nitrones, both cyclic and acyclic, were smoothly prepared from 4-oxoazetidine-2-carbaldehydes. The regio- and diastereoselectivities of the intermolecular 1,3-dipolar cycloaddition reactions of 2-azetidinone-tethered nitrones with substituted alkenes and alkynes were investigated. 2-Azetidinone-tethered nitrones on reacting with various dipolarophiles yielded isoxazolinyl-, isoxazolidinyl-, or fused polycyclic-beta-lactams, exhibiting good regio- and facial stereoselectivity in the most of the cases. In addition, some interesting transformations of these cycloadducts were performed, yielding aziridinyl beta-lactams or functionalized beta-alkoxycarbonyl gamma-lactams (derivatives of the aza analogue of paraconic acid). PMID:12353993

Alcaide, Benito; Almendros, Pedro; Alonso, Jose M; Aly, Moustafa F; Pardo, Carmen; Sáez, Elena; Torres, M Rosario

2002-10-01

50

Photocycloadditions of substituted oxazoles with isoquinoline-1,3,4-trione--chemo-, regio-, diastereoselectivities and transformation of the photocycloadducts.  

PubMed

Photoreactions of isoquinoline-1,3,4-triones and oxazoles with different substituents were found to give different chemo-, regio- and diastereoselectivities. The substituent at the C5 on the oxazole ring showed great influence on the chemoselectivity of the photoreaction as well as on the transformation of the photocycloadducts. The 2-methyl-5-methoxyoxazoles reacted with isoquinoline-1,3,4-triones rapidly and gave spirooxetanes with high regio- and diastereo-selectivity. Diastereoselectivity in the reaction of 2-phenyl-5-methoxyoxazoles with isoquinoline-1,3,4-triones was relevant to the substituent on the 4-position on the oxazole ring. Replacement of the 5-methoxy group with 5-methyl or 5-phenyl resulted in significant decrease on the reactivity of the oxazole as well as change on the diastereoselectivity in photocycloaddition with isoquinoline-1,3,4-triones. Acid-mediated transformations of the photocycloadduct spirooxetanes was found to give different type of products including ?-hydroxy-?-aminocarbonyl compounds and spiroisoquinolineoxazolines under different reaction conditions. Substituents on the spirooxetanes as well as the type and amount of acid used in the reaction played important roles in determining the type and diastereoselectivity of the products in the transformations. PMID:23801247

Huang, Cheng-mei; Jiang, Heng; Wang, Ru-zhi; Quah, Ching Kheng; Fun, Hoong-Kun; Zhang, Yan

2013-08-14

51

Estimating Regio and Stereoselectivity in [4+2] Cycloadditions of Vinyl-Substituted Cyclic Dienes with Maleic Anhydride  

NASA Astrophysics Data System (ADS)

Density functional theory calculations are performed to examine the regio and stereoselective preferences in [4+2] cycloaddition reactions of vinyl cyclopentadiene (1 and 2) and vinyl heterocyclic (1-N, 1-O, 1-S, 2-N, 2-O and 2-S) systems with maleic anhydride. Stepwise and concerted pathways of model systems 1 and 2 as dienes with ethylene as dienophile reveal that the reactions proceed through asynchronous and concerted pathway. 3-Vinyl systems (2) are predicted to be more reactive compared to 2-vinyl systems (1). The regio and stereoselective preferences are evaluated based on activation energies, reaction energies, density functional based descriptors and atoms in molecules analysis. In all cases, extra-annular cycloadducts are more feasible compared to intra-annular cycloadducts. Stereoselectivity depends on the favorable secondary orbital interactions. Solvents such as water, tetrahydrofuran, acetone, and dimethyl sulphoxide are employed to understand the effects of solvents on the cycloadduct formation. The computational results thus obtained are compared with the earlier experimental observations that are available.

Gayatri, Gaddamanugu; Sastry, G. Narahari

2009-09-01

52

Coupling of chiral 1-bromo-1,2-dienes with zinc-based cuprates: a new procedure for the regio and stereoselective synthesis of functionalized acetylenic compounds  

Microsoft Academic Search

Zinc alkylcyanocuprates (Knochel reagents) are found to be active in the cross-coupling reaction with allenic bromides affording acetylenic products with a high regio and stereoselective 1,3-anti substitution. The coupling process, which has been successfully extended to functionalized cuprates, can also be performed with alkylzinc chlorides in the presence of catalytic amounts of cuprous salts.

Anna Maria Caporusso; Sara Filippi; Federica Barontini; Piero Salvadori

2000-01-01

53

Regio-selective bromination of multiflorine and structures of 3-bromomultiflorine and its molecular complex with succinimide  

NASA Astrophysics Data System (ADS)

The regio-specific bromination of multiflorine, an alkaloid isolated from Lupinus albus is described. The bromomultiflorine and its molecular complex with succinimide have been characterized by IR and NMR spectroscopy, as well as by X-ray diffraction. The conformation in solution and in the solid state has been determined. The molecular complex formation between 3-bromomultiflorine and succinimide molecules is the first case in the class of lupine alkaloids. Both molecules of this complex are held together by an intermolecular hydrogen bond N?H⋯N which leads to a conversion of alkaloid nitrogen atom configuration. As a consequence, ring C adopts a chair conformation, whereas it is in a boat form in 3-bromomultiflorine.

Borowiak, Teresa; Kubicki, Maciej; Wysocka, Waleria; Przyby?, Anna

1998-02-01

54

Regio- and enantiospecific rhodium-catalyzed arylation of unsymmetrical fluorinated acyclic allylic carbonates: inversion of absolute configuration.  

PubMed

The transition metal-catalyzed allylic substitution with unstabilized carbon nucleophiles represents an important cross-coupling reaction for the construction of ternary carbon stereogenic centers. We have developed a new regio- and enantiospecific rhodium-catalyzed allylic alkylation of acyclic unsymmetrical chiral nonracemic allylic alcohol derivatives with aryl zinc bromides. This study demonstrates that the hydrotris(pyrazolyl)borate rhodium catalyst and zinc(II) halide salt are crucial for efficiency, while the addition of lithium bromide to the catalyst is necessary for obtaining optimal regiospecificity. The stereochemical course of this reaction was established through the synthesis of (S)-ibuprofen, which demonstrated that the alkylation proceeds with net inversion of absolute configuration consistent with direct addition of the nucleophile to the metal center followed by reductive elimination. PMID:12797772

Evans, P Andrew; Uraguchi, Daisuke

2003-06-18

55

An artificial cytochrome P450 that hydroxylates unactivated carbons with regio- and stereoselectivity and useful catalytic turnovers  

PubMed Central

A catalyst has been synthesized comprising a manganese porphyrin carrying four beta-cyclodextrin groups. It catalyzes the hydroxylation of substrates of appropriate size carrying tert-butylphenyl groups that can hydrophobically bind into the cyclodextrin cavities. In one example as many as 650 catalytic turnovers are seen before the catalyst is oxidatively destroyed, and with a rate comparable to that of typical cytochrome P450 enzymes. In another example, a steroid derivative is regio- and stereoselectively hydroxylated at a single unactivated carbon atom, but more slowly and with fewer turnovers. The carbon attacked is not the most chemically reactive, and the selectivity is determined by the geometry of the catalyst-substrate complex. Nonbinding substrates are not reactive under the conditions used, and substrates with more flexible binding geometries give more than a single product.

Breslow, Ronald; Huang, Ying; Zhang, Xiaojun; Yang, Jerry

1997-01-01

56

Regio- and Stereoselective Synthesis of Ferrocene-Containing ?-Iodoallylic Esters and Ethers from the Iodofunctionalization of Ferrocenylallene with Carboxylic Acids, Phenols, and Alcohols.  

PubMed

The iodofunctionalization of ferrocenylallene with carboxylic acids, phenols, and alcohols is described. The reaction proceeds smoothly in the presence of molecule iodine as a halonium promoter and using various carboxylic acids, phenols, and alcohols as nucleophiles to give the corresponding ferrocene-containing ?-iodoallylic ester and ether products in moderate to high yields and with high regio- and stereoselectivities. It can be envisaged that the regio- and stereoselectivity of this reaction may be controlled by the steric effect of the bulky ferrocene group. The presence of the C-I bond in the corresponding products makes these molecules highly attractive from a synthetic point of view, as it provides an opportunity for further transformations. Thus, palladium-catalyzed Heck coupling, Suzuki coupling, Sonogashira coupling, and copper-catalyzed click reactions were carried out successfully. PMID:24855998

Chen, Shufeng; Zhang, Hongli; Yan, Qing; Wang, Chenjun; Han, Fei; Zhang, Kaixin; Zhao, Haiying; Li, Baoguo

2014-06-20

57

Copper-mediated regio- and enantio-selective cross-coupling of heterocyclic allyl sulphides with organomagnesium compounds: A case of 1,7-relative stereogenesis  

Microsoft Academic Search

Optically active heterocyclic allyl sulphides 1–7 react with organomagnesium compounds in the presence of CuBr to afford optically active alkenes in good yields and very high ?-selectivity. The regioselectivity depends on the solvent as well on the CuBr: allylic sulphide ratio. The heterocyclic nucleus imparts asymmetric induction in the range of 50–98% ee. The regio- and enantio-selectivity of these reactions

Vincenzo Caló; Angelo Nacci; Vito Fiandanese

1996-01-01

58

Regio- and stereoselectivity of 1,3-dipolar cycloaddition of cyclic aldonitrones of the 3-imidazoline 3-oxide series to monosubstituted alkenes  

Microsoft Academic Search

Regio- and stereoselectivity of 1,3-dipolar cycloaddition of cyclic aldonitrones of the 3-imidazoline 3-oxide series mainly depends on the type of the substituent in the dipolarophile. The configuration of the main cycloadduct has been determined, and a method has been suggested to establish the stereochemistry of the cycloaddition products by1H NMR spectroscopy. An increase in electron-acceptor properties of the substituent in

T. A. Berezina; V. A. Reznikov; V. I. Mamatyuk; P. A. Butakov; Yu. V. Gatilov; I. Yu. Bagryanskaya; L. B. Volodarsky

1994-01-01

59

Regio- and Diastereoselective Construction of ?-Hydroxy-?-amino Ester Derivatives via 1,4-Conjugate Addition of ?,?-Unsaturated N-Sulfonylimines.  

PubMed

A first example of 1,4-conjugate addition of ?,?-unsaturated N-sulfonylimines via the oxonium ylides trapping process was developed. This method afforded a novel and efficient access for the high regio- and diastereoselective construction of ?-hydroxyl-?-amino esters derivatives, which exhibit inhibitory activity on PTP1B and SIRT1 enzymes in vitro. The synthetic potentials and the biological activity of the resulting products were well demonstrated to be promising for drug discovery. PMID:24689439

Qiu, Lin; Gao, Lixin; Tang, Jixing; Wang, Dongwei; Guo, Xin; Liu, Shunying; Yang, Liping; Li, Jia; Hu, Wenhao

2014-05-01

60

Copper-catalyzed aerobic oxidative n?s bond functionalization for c?s bond formation: regio- and stereoselective synthesis of sulfones and thioethers.  

PubMed

A regio- and stereoselective synthesis of sulfones and thioethers by means of Cu(I) -catalyzed aerobic oxidative N?S bond cleavage of sulfonyl hydrazides, followed by cross-coupling reactions with alkenes and aromatic compounds to form the C?sp?2?S bond, is described herein. N2 and H2 O are the byproducts of this transformation, thus offering an environmentally benign process with a wide range of potential applications in organic synthesis and medicinal chemistry. PMID:24860978

Li, Xianwei; Xu, Yanli; Wu, Wanqing; Jiang, Chang; Qi, Chaorong; Jiang, Huanfeng

2014-06-23

61

DFT survey of monoboron and diboron corroles: regio- and stereochemical preferences for a constrained, low-symmetry macrocycle.  

PubMed

The structures of a number of mono- and diboron corrole complexes have been optimized using DFT methods in order to establish regio- and stereochemical preferences for bonding of one or two boron atoms to the corrole macrocycle. The formulations of the complexes were suggested either from preliminary experimental results (to be reported elsewhere) or by analogy with related diboron porphyrin compounds. The computational results suggest for the monoboron corroles BF(2)(H(2)corrole) and BPhH(H(2)corrole) that the regioisomer in which the boron is bound to a dipyrromethene site adjacent to the bipyrrole is preferred over the other possible regioisomers in which boron coordinates either in the bipyrrole or in the dipyrromethene site opposite the bipyrrole. In the N-substituted corrole complexes there are only two possiblities and, for each complex, the regioisomer with boron in the dipyrromethene site adjacent to the bipyrrole is lower in energy. For all four monoboron complexes the stereoisomers in which boron and both its substituents are displaced out of the mean N(4) plane are more stable than the boron in-plane stereoisomers. These regio- and stereochemical preferences are rationalised by an analysis of the deformations to the corrole macrocycle and the geometry at the boron atoms. The lowest energy structures in all cases correspond to the least strained configurations. In addition, all four complexes show significant BFHN hydrogen bonding and BHHN dihydrogen bonding interactions, which are maximised in the lowest energy configurations for each structure, indicating that these are important additional stabilising interactions. Three different regioisomers, each with cisoid or transoid stereochemistry were optimised for the diboron complex PhBOB(corrole) which contains a bridging BOB group. The dipyrromethene/dipyrromethene isomer is more stable than either of the dipyrromethene/bipyrrole isomers and cisoid stereochemistry is preferred over transoid. This contrasts with porphyrin complexes containing BOB groups for which both stereochemical possibilities are observed, and reflects the contracted size of the corrole macrocycle. Three further diboron corroles were investigated, the diboranyl cation [B(2)(corrole)](+) and its one- and two-electron reduced derivatives B(2)(corrole) and [B(2)(corrole)](-). These calculations were undertaken to determine whether the site of reduction of [B(2)(corrole)](+) is likely to be the diboron moiety or the macrocycle. The B-B bond lengths do not shorten upon reduction and an analysis of the molecular orbitals of each species indicates that reduction will be most likely to occur at the macrocycle, offering a potential route to an example of the two-electron reduced corrole ligand, an analogue of the 20-electron isophlorin ligand observed in the corresponding reduced porphyrin complex B(2)(porphine). PMID:18698450

Albrett, Amelia M; Conradie, Jeanet; Ghosh, Abhik; Brothers, Penelope J

2008-09-01

62

Mineralogy and Major Element Abundance of the Dust Particles Recovered from Muses-C Regio on the Asteroid Itokawa  

NASA Technical Reports Server (NTRS)

Remote sensing by the spacecraft Hayabusa suggested that outermost surface particles of Muses-C regio of the asteroid Itokawa consist of centimeter and sub-centimeter size small pebbles. However, particles we found in the sample catcher A stored in the Hayabusa capsule, where Muses-C particles were captured during first touchdown, are much smaller. i.e., most are smaller than 100 microns in size. This suggests that only small fractions of Muses-C particles were stirred up due to the impact of the sampling horn onto the surface, or due to jets from chemical thrusters during the lift off of the spacecraft from the surface. X-ray fluorescence and near-infrared measurements by the Hayabusa spacecraft suggested that Itokawa surface materials have mineral and major element composition roughly similar to LL chondrites. The particles of the Muses-C region are expected to have experienced some effects of space weathering. Both of these prospects can be tested by the direct mineralogical analyses of the returned Itokawa particles in our study and another one. This comparison is most important aspect of the Hayabusa mission, because it finally links chemical analyses of meteorites fallen on the Earth to spectroscopic measurements of the asteroids.

Nakamura, T.; Noguchi, T.; Tanaka, M.; Zolensky, M. E.; Kimura, M.; Nakato, A.; Ogami, T.; Ishida, H.; Tsuchiyama, A.; Yada, T.; Shirai, K.; Okazaki, R.; Fujimura, A.; Ishibashi, Y.; Abe, M.; Okada, T.; Ueno, M.; Mukai, T.

2011-01-01

63

Regio- and Stereoselective Metabolism of 7,12-Dimethylbenz[a]anthracene by Mycobacterium vanbaalenii PYR-1  

PubMed Central

The degradation of 7,12-dimethylbenz[a]anthracene (DMBA), a carcinogenic polycyclic aromatic hydrocarbon, by cultures of Mycobacterium vanbaalenii PYR-1 was studied. When M. vanbaalenii PYR-1 was grown in the presence of DMBA for 136 h, high-pressure liquid chromatography (HPLC) analysis showed the presence of four ethyl acetate-extractable compounds and unutilized substrate. Characterization of the metabolites by mass and nuclear magnetic resonance spectrometry indicated initial attack at the C-5 and C-6 positions and on the methyl group attached to C-7 of DMBA. The metabolites were identified as cis-5,6-dihydro-5,6-dihydroxy-7,12-dimethylbenz[a]anthracene (DMBA cis-5,6-dihydrodiol), trans-5,6-dihydro-5,6-dihydroxy-7,12-dimethylbenz[a]anthracene (DMBA trans-5,6-dihydrodiol), and 7-hydroxymethyl-12-methylbenz[a]anthracene, suggesting dioxygenation and monooxygenation reactions. Chiral stationary-phase HPLC analysis of the dihydrodiols showed that DMBA cis-5,6-dihydrodiol had 95% 5S,6R and 5% 5R,6S absolute stereochemistry. On the other hand, the DMBA trans-5,6-dihydrodiol was a 100% 5S,6S enantiomer. A minor photooxidation product, 7,12-epidioxy-7,12-dimethylbenz[a]anthracene, was also formed. The results demonstrate that M. vanbaalenii PYR-1 is highly regio- and stereoselective in the degradation of DMBA.

Moody, Joanna D.; Fu, Peter P.; Freeman, James P.; Cerniglia, Carl E.

2003-01-01

64

New chiral P-N ligands for the regio- and stereoselective Pd-catalyzed dimerization of styrene.  

PubMed

Two new chiral, enantiomerically pure, hybrid P-N ligands, namely (2R,5S)-2-phenyl-3-(2-pyridyl)-1,3-diaza-2-phosphanicyclo[3,3,0]octan-4-one (1) and (2R,5S)-2-phenyl-3-(2-pyridyl)-1,3-diaza-2-phosphanicyclo[3,3,0]octane (2), have been synthesized starting from L-proline. The two ligands differ in the presence or not of a carbonyl group in the diazaphosphane ring. Their coordination chemistry towards Pd(II) was studied by reacting them with [Pd(CH?)Cl(cod)]. A different behaviour was observed: ligand 2 shows the expected bidentate chelating behaviour leading to the mononuclear Pd-complex, while ligand 1 acts as a terdentate ligand giving a dinuclear species. The corresponding cationic derivatives were obtained from the palladium neutral complexes, both as mono- and dinuclear derivatives, and tested as precatalysts for styrene dimerization, yielding E-1,3-diphenyl-1-butene regio- and stereoselectively as the sole product. A detailed analysis of the catalytic behaviour is reported. PMID:21343886

Fanfoni, Lidia; Meduri, Angelo; Zangrando, Ennio; Castillon, Sergio; Felluga, Fulvia; Milani, Barbara

2011-01-01

65

Photoinduced [4 + 4], [4 + 2], and [2 + 2] cycloadditions of o-quinones with oxazoles: chemo-, regio-, and diastereoselectivity.  

PubMed

Photoinduced reactions of the 1,2-dicarbonyl compounds phenanthrenequinone (PQ), 1-acetylisatin (IS), and benzil (BZ) with the oxazoles 1a-j have been investigated. In photoreactions of PQ with the oxazoles, in addition to the 1,4-dioxins derived from [4 + 2] cycloaddition and the oxetanes from the Paternó-Büchi [2 + 2] reactions, [4 + 4] cycloaddition products are formed in the reactions with 1a, 1c, 1g, 1i, and 1j, with the quinone's dicarbonyl unit (O?C-C?O) and the oxazole's C?N-C?C moiety as two 4? addends. Photoreactions of IS with the oxazoles 1f and 1g give the [4 + 4] cycloaddition products exclusively, while in photoreactions of IS with 1a, 1c, 1e, 1h, and 1i, [4 + 4] products are formed together with the [2 + 2] products. Reaction pathway partitioning in these photocycloaddtions strongly depends on the substitution pattern on the oxazole ring. The presence of a substituent at the oxazole's C2 atom hampers the [4 + 4] pathway by causing steric hindrance to radical pair recombination in the corresponding 1,7-diradical intermediate to form the [4 + 4] cycloaddition products. A substituent at the C4 atom results in steric hindrance for ring closure of the 1,4-diradicals in the [2 + 2] cycloaddition pathway, therefore favoring the [4 + 4] and [4 + 2] cycloaddition pathways. Regio- and diastereoselectivity in the [2 + 2] and [4 + 4] cycloadditions have been discussed based on the thermodynamic stability of the relevant triplet diradical intermediates and the conformations of these diradicals suitable for the intersystem crossing process. Photoreactions of BZ with the oxazoles afford only [2 + 2] cycloaddition products. PMID:21028907

Wang, Lei; Huang, Yu-Cheng; Liu, Yang; Fun, Hoong-Kun; Zhang, Yan; Xu, Jian-Hua

2010-11-19

66

A computational mechanistic study of an unprecedented Heck-type relay reaction: insight into the origins of regio- and enantioselectivities.  

PubMed

Density functional theory (DFT) calculations (B3LYP and M06) have been utilized to study a newly reported Heck-type reaction that uses an allylic or alkenyl alcohol as substrate and palladium as catalyst in the form of a chelate with a chiral pyridine oxazoline (PyrOx) ligand. The reaction not only controls the regio- and enantioselectivities of arylation of the C?C bond, but also forms the carbonyl functionality up to four bonds away from the aryl substituent via tandem C?C bond migration and enol-to-keto conversion. Computations performed on representative reaction systems allow us to propose a detailed mechanism with several key steps. Initial oxidation of palladium(0) by aryldiazonium generates active arylpalladium(II) species that bind the C?C bond of an allylic or alkenyl alcohol. The activated C?C bond inserts into the palladium-aryl moiety to attain aryl substitution and a chiral carbon center, and the resulting complex undergoes ?-hydride elimination to give a new C?C bond that can repeat the insertion/elimination process to move down the carbon chain to form an enol that tautomerizes to a highly stable carbonyl final product. The calculations reveal that the C?C bond migratory insertion step determines both the regioselectivity and the enantioselectivity of arylation, with the former arising mainly from the electronic effect of the hydroxyl group on the charge distribution over the C?C bond and the latter originating from a combination of steric repulsion, trans influence, and C-H/? dispersion interactions. PMID:24380644

Dang, Yanfeng; Qu, Shuanglin; Wang, Zhi-Xiang; Wang, Xiaotai

2014-01-22

67

Regio- and stereospecific oxidation of fluorene, dibenzofuran, and dibenzothiophene by naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.  

PubMed Central

The regio- and stereospecific oxidation of fluorene, dibenzofuran, and dibenzothiophene was examined with mutant and recombinant strains expressing naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4. The initial oxidation products were isolated and identified by gas chromatography-mass spectrometry and nuclear magnetic resonance spectrometry. Salicylate-induced cells of Pseudomonas sp. strain 9816/11 and isopropyl-beta-D-thiogalactopyranoside-induced cells of Escherichia coli JM109(DE3)(pDTG141) oxidized fluorene to (+)-(3S,4R)-cis-3,4-dihydroxy-3,4-dihydrofluorene (80 to 90% relative yield; > 95% enantiomeric excess [ee]) and 9-fluorenol (< 10% yield). The same cells oxidized dibenzofuran to (1R,2S)-cis-1,2-dihydroxy-1, 2-dihydrodibenzofuran (60 to 70% yield; > 95% ee) and (3S,4R)-cis-3, 4-dihydroxy-3,4-dihydrodibenzofuran (30 to 40% yield; > 95% ee). Induced cells of both strains, as well as the purified dioxygenase, also oxidized dibenzothiophene to (+)-(1R,2S)-cis-1,2-dihydroxy-1, 2-dihydrodibenzothiophene (84 to 87% yield; > 95% ee) and dibenzothiophene sulfoxide (< 15% yield). The major reaction catalyzed by naphthalene dioxygenase with each substrate was stereospecific dihydroxylation in which the cis-dihydrodiols were of identical regiochemistry and of R configuration at the benzylic center adjacent to the bridgehead carbon atom. The regiospecific oxidation of dibenzofuran differed from that of the other substrates in that a significant amount of the minor cis-3,4-dihydrodiol regioisomer was formed. The results indicate that although the absolute stereochemistry of the cis-diene diols was the same, the nature of the bridging atom or heteroatom influenced the regiospecificity of the reactions catalyzed by naphthalene dioxygenase.

Resnick, S M; Gibson, D T

1996-01-01

68

Structural and Biochemical Studies of the Hedamycin Type II Polyketide Ketoreductase (HedKR): Molecular Basis of Stereo- and Regio-Specificities  

PubMed Central

Bacterial aromatic polyketides that include many antibiotic and antitumor therapeutics are biosynthesized by the type II polyketide synthase (PKS), which consists of 5 – 10 stand-alone enzymatic domains. Hedamycin, an antitumor antibiotic polyketide, is uniquely primed with a hexadienyl group generated by a type I PKS followed by coupling to a downstream type II PKS to biosynthesize a 24-carbon polyketide, whose C9 position is reduced by hedamycin type II ketoreductase (hedKR). HedKR is homologous to the actinorhodin KR (actKR), for which we have conducted extensive structural studies previously. How hedKR can accommodate a longer polyketide substrate than the actKR, and the molecular basis of its regio- and stereospecificities, is not well understood. Here we present a detailed study of hedKR that sheds light on its specificity. Sequence alignment of KRs predicts that hedKR is less active than actKR, with significant differences in substrate/inhibitor recognition. In vitro and in vivo assays of hedKR confirmed this hypothesis. The hedKR crystal structure further provides the molecular basis for the observed differences between hedKR and actKR in the recognition of substrates and inhibitors. Instead of the 94-PGG-96 motif observed in actKR, hedKR has the 92-NGG-94 motif, leading to S-dominant stereospecificity, whose molecular basis can be explained by the crystal structure. Together with mutations, assay results, docking simulations, and the hedKR crystal structure, a model for the observed regio- and stereospecificities is presented herein that elucidates how different type II KRs recognize substrates with different chain lengths, yet precisely reduce only the C9-carbonyl group. The molecular features of hedKR important for regio- and stereospecificities can potentially be applied to biosynthesize new polyketides via protein engineering that rationally controls polyketide ketoreduction.

Javidpour, Pouya; Das, Abhirup; Khosla, Chaitan; Tsai, Shiou-Chuan

2011-01-01

69

Mineral chemistry of MUSES-C Regio inferred from analysis of dust particles collected from the first- and second-touchdown sites on asteroid Itokawa  

NASA Astrophysics Data System (ADS)

The mineralogy and mineral chemistry of Itokawa dust particles captured during the first and second touchdowns on the MUSES-C Regio were characterized by synchrotron-radiation X-ray diffraction and field-emission electron microprobe analysis. Olivine and low- and high-Ca pyroxene, plagioclase, and merrillite compositions of the first-touchdown particles are similar to those of the second-touchdown particles. The two touchdown sites are separated by approximately 100 meters and therefore the similarity suggests that MUSES-C Regio is covered with dust particles of uniform mineral chemistry of LL chondrites. Quantitative compositional properties of 48 dust particles, including both first- and second-touchdown samples, indicate that dust particles of MUSES-C Regio have experienced prolonged thermal metamorphism, but they are not fully equilibrated in terms of chemical composition. This suggests that MUSES-C particles were heated in a single asteroid at different temperatures. During slow cooling from a peak temperature of approximately 800 °C, chemical compositions of plagioclase and K-feldspar seem to have been modified: Ab and Or contents changed during cooling, but An did not. This compositional modification is reproduced by a numerical simulation that modeled the cooling process of a 50 km sized Itokawa parent asteroid. After cooling, some particles have been heavily impacted and heated, which resulted in heterogeneous distributions of Na and K within plagioclase crystals. Impact-induced chemical modification of plagioclase was verified by a comparison to a shock vein in the Kilabo LL6 ordinary chondrite where Na-K distributions of plagioclase have been disturbed.

Nakamura, Tomoki; Nakato, Aiko; Ishida, Hatsumi; Wakita, Shigeru; Noguchi, Takaaki; Zolensky, Michael E.; Tanaka, Masahiko; Kimura, Makoto; Tshuchiyama, Akira; Ogami, Toshihiro; Hashimoto, Takahito; Konno, Mitsuru; Uesugi, Masayuki; Yada, Toru; Shirai, Kei; Fujimura, Akio; Okazaki, Ryuji; Sandford, Scott. A.; Ishibashi, Yukihiro; Abe, Masanao; Okada, Tatsuaki; Ueno, Munetaka; Kawaguchi, Junichiro

2014-02-01

70

Regio- and diastereoselective synthesis and X-ray structure determination of (+)-2-deoxyoryzalexin S from (+)-podocarpic acid. Structural nonidentity with its nominal natural isolated enantiomer.  

PubMed

(+)-2-Deoxyoryzalexin S (1), the nominal enantiomer of a diterpenoid isolated in Chile from Calceolaria species, was regio- and diastereoselectively synthesized from (+)-podocarpic acid. (+)-2-Deoxyoryzalexin S (1) was characterized also as its acetyl derivative, (+)-2, whose structure was confirmed by X-ray crystallographic analysis. Surprisingly, comparison of the data recorded for (+)-1 and (+)-2 and those reported in the literature for the Calceolaria isolated diterpenoid 1 and its derivative (-)-2 showed some differences, suggesting that the latter do not possess the proposed structures. PMID:23088775

Leonelli, Francesca; Latini, Valentina; Trombetta, Andrea; Bartoli, Gabriele; Ceccacci, Francesca; La Bella, Angela; Sferrazza, Alessio; Lamba, Doriano; Migneco, Luisa M; Bettolo, Rinaldo Marini

2012-11-26

71

Mechanism and Origins of Regio- and Enantioselectivities in RhI-Catalyzed Hydrogenative Couplings of 1,3-Diynes and Activated Carbonyl Partners: Intervention of a Cumulene Intermediate  

PubMed Central

The mechanism of the rhodium-catalyzed reductive coupling of 1,3-diynes and vicinal dicarbonyl compounds employing H2 as reductant was investigated by density functional theory. Oxidative coupling through 1,4-addition of the RhI-bound dicarbonyl to the conjugated diyne via a seven-membered cyclic cumulene transition state leads to exclusive formation of linear adducts. Diyne 1,4-addition is much faster than the 1,2-addition to simple alkynes. The 1,2-dicarbonyl compound is bound to rhodium in a bidentate fashion during the oxidative coupling event. The chemo-, regio-, and enantioselectivities of this reaction were investigated and are attributed to this unique 1,4-addition pathway. The close proximity of the ligand and the alkyne substituent distal to the forming C–C bond controls the regio- and enantioselectivity: coupling occurs at the sterically more demanding alkyne terminus, which minimizes nonbonded interaction with the ligand. A stereochemical model is proposed that accounts for preferential formation of the (R)-configurated coupling product when (R)-biaryl phosphine ligands are used.

Liu, Peng; Krische, Michael J.; Houk, Kendall N.

2011-01-01

72

Pd(0)-catalyzed regio- and stereoselective cyclization of alkynes: selective synthesis of (E)-4-(isobenzofuran-1(3H)-ylidene)-1,2,3,4-tetrahydroisoquinolines and aze/oxepinoindoles.  

PubMed

Palladium-catalyzed highly regio- and stereoselective 6-exo-dig and 7-endo-dig cyclization of functionalized propargylic compounds has been developed for the synthesis of (E)-4-(isobenzofuran-1(3H)-ylidene)-1,2,3,4-tetrahydroisoquinolines and aze/oxepinoindoles. PMID:24357272

Nandakumar, Avanashiappan; Kiruthika, Selvarangam E; Naveen, Kanagaraj; Perumal, Paramasivan Thirumalai

2014-02-14

73

Highly regio- and chemoselective palladium-catalyzed propargylallylation of activated olefins: a novel route to 1,7-enyne derivatives.  

PubMed

An efficient method for the synthesis of 1,7-enyne derivatives via phosphine-palladium-catalyzed three-component assembling of activated olefins, allylic chlorides, and allenylstannanes is described. Substituted arylethylidene malononitriles 1a-g (RCH=C(CN)(2): R = C(6)H(5) (1a), p-ClC(6)H(4) (1b), p-OMeC(6)H(4) (1c), p-NO(2)C(6)H(4) (1d), 1-naphthyl (1e), 2-furyl (1f), and 2-thienyl (1g)) undergo propargylallylation with allylic chlorides 2a-e (allyl chloride (2a), methallyl chloride (2b), 4-chloropent-2-ene (2c), cinnamyl chloride (2d), and 3-chlorocyclohexene (2e)) and n-tributylallenylstannane (n-Bu(3)SnCH=C=CH(2), 3a) in the presence of Pd(PPh(3))(4) in toluene to afford the corresponding 1,7-enyne derivatives 4a-m in good to excellent yields. The catalytic reaction is highly regioselective, with the propargyl group adding to the carbon where the R group is attached and the allyl group adding to the carbon connected to the CN groups of activated olefins 1a-g. The present catalytic reaction is successfully extended to substituted arylethylidene-1,3-indanediones 5a-j (RCH = (1,3-indanedione): R = C(6)H(5) (5a), p-ClC(6)H(4) (5b), p-BrC(6)H(4) (5c), p-OMeC(6)H(4) (5d), p-NO(2)C(6)H(4) (5e), p-CNC(6)H(4) (5f), p-biphenyl (5g), 1-naphthyl (5h), 2-thienyl (5i), and 2-benzo[b]furane-2-yl (5j)) and substituted 2,2-dimethyl-5-(arylethylidene)-1,3-dioxane-4,6-diones 7a,b (RCH = (1,3-dioxane-4,6-dione): R = p-NO(2)C(6)H(4) (7a), p-OMeC(6)H(4) (7b)). The three-component assembling of these substrates with allylic chlorides (2a,b,d,e) and n-tributylallenylstannane (n-Bu(3)SnCH=C=CH(2), 3a) proceeds smoothly to afford the corresponding 1,7-enyne derivatives 6a-m and 8a-d in good to excellent yields. The catalytic propargylallylation can be further applied to the activated dienes, C(6)H(5)CH=CH=CR(2) (R(2) = (CN)(2) (9a), 1,3-indanedione (9b), 2,2-dimethyl-1,3-dioxane-4,6-dione (9c)), with allylic chlorides (2a,b,d) and allenylstannane 3a to give regio- and chemoselective 1,2-addition products 10a-h in good to excellent yields. A plausible mechanism based on an eta(1)-allenyl eta(3)-allyl palladium intermediate is proposed to account for the catalytic three-component reaction. PMID:15176830

Jeganmohan, Masilamani; Shanmugasundaram, Muthian; Cheng, Chien-Hong

2004-06-11

74

The Regio- and Stereospecific Intermolecular Dehydrative Alkoxylation of Allylic Alcohols Catalyzed by a Gold(I) N-Heterocyclic Carbene Complex  

PubMed Central

A 1:1 mixture of (IPr)AuCl [IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidine] and AgClO4 catalyzes the intermolecular dehydrative alkoxylation of primary and secondary allylic alcohols with aliphatic primary and secondary alcohols to form allylic ethers. These transformations are regio- and stereospecific with preferential addition of the alcohol nucleophile at the ?-position of the allylic alcohol syn to the departing hydroxyl group and with predominant formation of the E stereoisomer. The minor ?-regioisomer is formed predominantly through a secondary reaction manifold involving regioselective ?-alkoxylation of the initially formed allylic ether rather than via the direct ?-alkoxylation of the allylic alcohol.

Mukherjee, Paramita

2013-01-01

75

Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions  

PubMed Central

Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17), under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO) calculations.

Flores-Conde, Maria Ines; Reyes, Leonor; Herrera, Rafael; Rios, Hulme; Vazquez, Miguel A.; Miranda, Rene; Tamariz, Joaquin; Delgado, Francisco

2012-01-01

76

A remarkable regiocontrol in the palladium-catalyzed silylstannylation of fluoroalkylated alkynes--highly regio- and stereoselective synthesis of multi-substituted fluorine-containing alkenes.  

PubMed

On treating fluorine-containing internal alkynes with 1.2 equiv. of (trimethylsilyl)tributyltin in the presence of 2.5 mol% of Pd(PPh3)2Cl2 in THF at the reflux temperature for 6 h, the silylstannylation reaction proceeded smoothly to afford the corresponding silylstannylated adducts in high yields in a highly regio- and cis-selective manner. Switching the palladium catalyst from Pd(PPh3)2Cl2 to Pd(t-BuNC)2Cl2 promoted the formation of silylstannylated adducts with opposite regioselectivity. The thus obtained silylstannylated adducts were subjected to Stille cross-coupling reactions to furnish the corresponding fluoroalkylated vinylsilanes whose C-Si bond was converted to a C-C bond by treating with aldehyde in the presence of TBAF and Zn(OTf)2, the corresponding fluoroalkylated tetra-substituted alkenes being afforded in moderate to good yields with a defined stereochemistry. PMID:24469343

Konno, Tsutomu; Kinugawa, Ryoko; Ishihara, Takashi; Yamada, Shigeyuki

2014-03-14

77

Allylindation of cyclopropenes in organic and aqueous media: switching the regio- and stereoselectivity based on the chelation with a hydroxyl group and the crystal structure of the cyclopropylindium product.  

PubMed

Hydroxy-bearing cyclopropenes react with allylindium reagents to undergo clean allylindation both in organic and aqueous media, in which the chelation of the hydroxyl group to indium plays the central role. The regio- and stereoselectivity have been regulated both by the location of the hydroxyl group in the molecules and the reaction solvents. In particular, the allylindation in water shows marked differences from that in organic solvents; the regio- and stereoselectivity have totally been reversed compared with those in organic solvents. Unusually stable cyclopropyl-indium compounds have been isolated from the reaction of 1-(omega-hydroxyalkyl)cyclopropenes and the structure has fully been established by X-ray crystallography. PMID:11486954

Araki, S; Shiraki, F; Tanaka, T; Nakano, H; Subburaj, K; Hirashita, T; Yamamura, H; Kawai, M

2001-07-01

78

Overcoming synthetic challenges of oridonin A-ring structural diversification: regio- and stereoselective installation of azides and 1,2,3-triazoles at the C-1, C-2, or C-3 position.  

PubMed

Efficient and concise synthetic approaches have been developed for the rapid and diverse installation of azide functionalities at the C-1, C-2, or C-3 positions of oridonin (1) with highly controlled regio- and stereoselectivity, while keeping key reactive pharmacophores intact by utilizing unique preactivation strategies based on the common synthon 4. Further functionalization of these azides through click chemistry yielding triazole derivatives successfully provides access to an expanded natural scaffold-based compound library for potential anticancer agents. PMID:23834026

Ding, Chunyong; Zhang, Yusong; Chen, Haijun; Wild, Christopher; Wang, Tianzhi; White, Mark A; Shen, Qiang; Zhou, Jia

2013-07-19

79

Interaction Between Radiating Graben-Fissure Systems and Local Geology, Ulfrun Regio, Venus: A Contribution to the Venus Global Dyke Swarm Map Project.  

NASA Astrophysics Data System (ADS)

This study is part of the larger Venus Global Dyke Swarm Map project, which has the goals of (1) producing a global map of graben-fissure systems, (2) assessing which systems are underlain by dyke swarms, and (3) contributing to the understanding of the tectonic and magmatic history of the planet. Graben-fissure systems on Venus are comprised of extensional lineaments, related to tectonic and/or magmatic activity. We are concentrating on the radiating systems (sometimes termed novae or radial fracture centres) which are of particular interest because they are largely ac-knowledged to be underlain by dyke swarms laterally emplaced from a magmatic centre located at the focus of the system [e.g., 1]. We have mapped the radiating graben fissure-systems in the Ulfrun Regio region of Venus using Magellan Synthetic Aperture Radar (SAR ) data at the highest resolution available (75 m/pixel). This area (200-240° E, 0-25° N) notably contains the western portion of the Hecate Chasma system, two large volcanoes (Ozza Mons and Nazit Mons), and a number of large coronae and novae. It also involves considerable deformation relating to extensional rifting and associated magmatic activity. In the Ulfrun Regio area, our mapping (over an area of 10.7 Mkm2) has identified 69 radiating systems, with diameters ranging from 20 km to greater than 2000 km. Many magmatic centres (at the foci of these radiating systems) are newly recognized, while others correspond to previously known coronae and volcanoes. We have found that it is not unusual for a single magmatic centre to exhibit multiple generations of radiating graben-fissure systems. Our graben-fissure mapping is compared with the new global geological map produced by M. Ivanov [1]. We are studying the manner in which large radiating graben-fissure systems interact with separate geological units. Radiating systems can be extensive; when crossing different geological units their surface expression varies and can manifest itself through changes in fracture density, definition, or fracture width. Radiating systems can be obscured in a geological unit and be visible in another unit, further from the presumed source. We hypothesize that these interactions are primarily a function of the relative ages of the systems with respect to the geological units, and thus that this approach can yield new information about the emplacement of individual systems and the relative ages of different magmatic centres. [1] Grosfils E. B. and Head J. W. (1994) Geophys. Res. Let., 21, 701-704. [2] Ivanov, M. A. (2008) LPSC XXXIX, abstract #1017.

Studd, Duncan; Ernst, Richard; Samson, Claire; Grosfils, Eric B.; Head, James W.; Ivanov, M. A.

80

Regio- and stereoselective anomeric esterification of glucopyranose 1,2-diols and a facile preparation of 2-O-acetylated glucopyranosyl trichloroacetimidates from the corresponding 1,2-diols.  

PubMed

A highly regio- and stereoselective anomeric esterification of 3-O-allyl (or benzyl, or benzoyl)-4,6-O-isopropylidene-alpha,beta-d-glucopyranose with acetyl chloride, or allyl chloroformate, or ethyl chloroformate gave the corresponding 2-OH, 1-beta-acetates or -carbonates in excellent yields. The 2-OH, 1-beta-acetates were readily converted to the corresponding 2-O-acetylated glucopyranosyl trichloroacetimidates by reaction with trichloroacetonitrile via base promoted acetyl migration, while the 2-OH, 1-beta-carbonates were good glycosyl acceptors for the synthesis of (1-->2)-linked oligosaccharides. PMID:17300768

Zhang, Jianjun; Liang, Xiaomei; Wang, Daoquan; Kong, Fanzuo

2007-05-01

81

Regio- and stereoselective indium triflate-mediated nucleophilic ring-opening reactions of 3-aza-2-oxabicyclo[2.2.1]hept-5-ene and -[2.2.2]oct-5-ene systems.  

PubMed

Indium triflate-mediated nucleophilic ring-opening reactions of 3-aza-2-oxabicyclo[2.2.1]hept-5-ene and -[2.2.2]oct-5-ene systems with alcohols and water were investigated. Reactions of [2.2.1] bicyclic systems gave anti-1,2-, anti-1,4- and syn-1,4-ring-opened products with moderate to excellent regio- and stereoselectivity. When [2.2.2] bicyclic systems were subjected to similar reaction conditions, only anti-1,2 and anti-1,4-ring-opened products were obtained. PMID:19754105

Yang, Baiyuan; Miller, Marvin J

2009-10-16

82

Regio- and stereoselective ring opening of 2,3-diaryl oxiranes by LiBr/Amberlyst 15: a new stereocontrolled access to 1,2-diaryl-2-bromo alcohols.  

PubMed

Both symmetrical and nonsymmetrical trans-2,3-diaryloxiranes are regio- and stereoselectively opened by the LiBr/Amberlyst 15 system. In the case of symmetrical trans-stilbene oxide, the syn- versus anti-bromohydrins ratio ranged between 88/12 and 30/70, by varying the reaction temperature from 20 to -30 degrees C. In the case of nonsymmetrical para-substituted trans-2,3-diaryloxiranes, the regioselectivity is determined by electronic effects. If one phenyl bears a strong electron-withdrawing group (as NO2 or CF3), the nucleophilic attack is totally on the beta-carbon with respect to the substituted phenyl ring. With one phenyl bearing a strong electron-releasing group (OCH3), the regioselectivity is reversed. Ab initio calculation at the DFT/B3LYP/6-31G level, run on protonated epoxide structures, supports the formation of a cationic acyclic intermediate. Application of the method on ortho-methoxy and ortho-nitro 2,3-diaryloxiranes afforded the syn-bromohydrins in excellent yield, via regio- and stereoselective opening at either alpha- or beta-carbon, respectively. PMID:15730278

Solladié-Cavallo, Arlette; Lupattelli, Paolo; Bonini, Carlo

2005-03-01

83

Oxygen deprivation inhibits basal keratinocyte proliferation in a model of human skin and induces regio-specific changes in the distribution of epidermal adherens junction proteins, aquaporin-3, and glycogen  

PubMed Central

It is generally accepted that hypoxia and recovery from oxygen deprivation contribute to the breakdown and ulceration of human skin. The effects of these stresses on proliferation, differentiation and expression of cell-cell adhesion molecules were investigated for the first time in an organotypic model of human skin. Fully stratified tissues were exposed to a time course of oxygen deprivation and subsequent reoxygenation. Regional changes in keratinocyte morphology, glycogen stores and cellular junctions were observed, with more differentiated layers of the epidermis exhibiting the first evidence of oxygen deprivation. Cellular swelling within the granular layer was concurrent with aquaporin-3 depletion. The keratinocyte adherens junction proteins E-cadherin and ?-catenin were dramatically decreased in a regio-specific manner throughout the epidermis following oxygen deprivation. In contrast, P-cadherin and the desmosomal proteins desmoplakin and desmoglein-1 were refractory to oxygen deprivation. Relative to normoxic controls, hypoxic tissues exhibited increased mRNA levels of the transcriptional repressor Slug however mRNA levels of the related transcriptional factor Snail were unaffected. All cellular and molecular changes were reversible upon reoxygenation. These results demonstrate that oxygen deprivation and reoxygenation exert differential effects on epidermal adhesion proteins and suggest a novel role for cadherins, ?-catenin, and Slug in hypoxia-induced junctional changes occurring in stratified squamous epithelium.

Straseski, Joely A.; Gibson, Angela L.; Thomas-Virnig, Christina L.; Allen-Hoffmann, B. Lynn

2009-01-01

84

Beta Regio - Phoebe Regio on Venus: Geologic Mapping with the Magellan Data.  

National Technical Information Service (NTIS)

The geologic maps of C1-15N283 and C1-00N283 sheets were produced (preliminary versions) with Magellan SAR images. This work was undertaken as a part of Russia's contribution into C1 geologic mapping efforts. The scale of the original maps is 1:8,000,000,...

A. M. Nikishin V. K. Borozdin N. N. Bobina G. A. Burba

1993-01-01

85

Beta Regio - Phoebe Regio on Venus: Geologic mapping with the Magellan data  

NASA Technical Reports Server (NTRS)

The geologic maps of C1-15N283 and C1-00N283 sheets were produced (preliminary versions) with Magellan SAR images. This work was undertaken as a part of Russia's contribution into C1 geologic mapping efforts. The scale of the original maps is 1:8,000,000, and the maps are reproduced here at a reduced size.

Nikishin, A. M.; Borozdin, V. K.; Bobina, N. N.; Burba, G. A.

1993-01-01

86

Micelles catalyzed chemo- and regio-selective one pot and one step synthesis of 2,3,5,6-tetrakis(alkyl and arylsulfanyl)-1,4-benzoquinones and 2,5-diaminosubstituted-1,4-benzoquinones "In-Water" and their biological evaluation as antibacterial and antifungal agents.  

PubMed

Chemo- and regio-selective one pot and one step synthesis of novel 2,3,5,6-tetrakis (substituted thio)cyclohexa-2,5-diene-1,4-diones (4d-14), 2,5-dichloro-3,6-diaminocyclohexa-2,5-diene-1,4-diones and 2,5-diaminocyclohexa-2,5-diene-1,4-diones (16) by economical green methodology approach using LD (Laundry detergent) as a catalyst "In-Water" by nucleophilic addition and substitution reactions of 1,4-benzoquinone and chloranil with sulfur and nitrogen nucleophiles in high yields has been demonstrated. The antifungal profile of 4 and 16 indicates that compounds 4d and 16f had better antifungal activity compared to clinically prevalent antifungal drugs Fluconazole, 5-Fluorocytosine and Clotrimazole against Sporothrix schenckii and Trichophyton mentagraphytes. 16f had also been found to possess better antibacterial activity compared to Ampicillin in vitro against Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. Compound 16f did not exhibit any toxicity towards mammalian cells L929. PMID:22939606

Tandon, Vishnu K; Kumar, Sandeep; Mishra, Nripendra N; Shukla, Praveen K

2012-10-01

87

EMS System Plan.  

National Technical Information Service (NTIS)

An Emergency Medical Service (EMS) system plan for an eight-county, primarily rural district of south central Oklahoma is presented. Demographic and area characteristics of the district are described. The existing EMS resources such as: manpower (physicia...

G. L. Dahl R. Eidson

1975-01-01

88

EMS Student Handbook.  

ERIC Educational Resources Information Center

This student guide is one of a series of self-contained materials for students enrolled in an emergency medical services (EMS) training program. Discussed in the individual sections of the guide are the following topics: the purpose and history of EMS professionals; EMS training, certification and examinations (national and state certification and…

Ogle, Patrick

89

EM International. Volume 1  

SciTech Connect

It is the intent of EM International to describe the Office of Environmental Restoration and Waste Management`s (EM`s) various roles and responsibilities within the international community. Cooperative agreements and programs, descriptions of projects and technologies, and synopses of visits to international sites are all highlighted in this semiannual journal. Focus on EM programs in this issue is on international collaboration in vitrification projects. Technology highlights covers: in situ sealing for contaminated sites; and remote sensors for toxic pollutants. Section on profiles of countries includes: Arctic contamination by the former Soviet Union, and EM activities with Germany--cooperative arrangements.

Not Available

1993-07-01

90

EM and beyond  

Microsoft Academic Search

The basic theme of the EM algorithm, to repeatedly use complete-data methods to solve incomplete data problems, is also a theme of several more recent statistical techniques. These techniques—multiple imputation, data augmentation, stochastic relaxation, and sampling importance resampling—combine simulation techniques with complete-data methods to attack problems that are difficult or impossible for EM.

Donald B. Rubin

1991-01-01

91

Deterministic annealing EM algorithm.  

PubMed

This paper presents a deterministic annealing EM (DAEM) algorithm for maximum likelihood estimation problems to overcome a local maxima problem associated with the conventional EM algorithm. In our approach, a new posterior parameterized by `temperature' is derived by using the principle of maximum entropy and is used for controlling the annealing process. In the DAEM algorithm, the EM process is reformulated as the problem of minimizing the thermodynamic free energy by using a statistical mechanics analogy. Since this minimization is deterministically performed at each temperature, the total search is executed far more efficiently than in the simulated annealing. Moreover, the derived DAEM algorithm, unlike the conventional EM algorithm, can obtain better estimates free of the initial parameter values. We also apply the DAEM algorithm to the training of probabilistic neural networks using mixture models to estimate the probability density and demonstrate the performance of the DAEM algorithm. PMID:12662837

Ueda, N; Nakano, R

1998-03-01

92

Geologic map of the Bell Regio Quadrangle (V-9), Venus  

USGS Publications Warehouse

The Magellan spacecraft orbited Venus from August 10, 1990, until it plunged into the venusian atmosphere on October 12, 1994. Magellan had the objectives of (1) improving knowledge of the geologic processes, surface properties, and geologic history of Venus by analysis of surface radar characteristics, topography, and morphology and (2) improving knowledge of the geophysics of Venus by analysis of venusian gravity. The Magellan spacecraft carried a 12.6-cm radar system to map the surface of Venus. The transmitter and receiver systems were used to collect three datasets: synthetic aperture radar (SAR) images of the surface, passive microwave thermal emission observations, and measurements of the backscattered power at small angles of incidence, which were processed to yield altimetric data. Radar imaging and altimetric and radiometric mapping of the venusian surface were done in mission cycles 1, 2, and 3, from September 1990 until September 1992. Ninety-eight percent of the surface was mapped with radar resolution of approximately 120 meters. The SAR observations were projected to a 75-m nominal horizontal resolution; these full-resolution data compose the image base used in geologic mapping. The primary polarization mode was horizontal-transmit, horizontal-receive (HH), but additional data for selected areas were collected for the vertical polarization sense. Incidence angles varied from about 20° to 45°. High-resolution Doppler tracking of the spacecraft was done from September 1992 through October 1994 (mission cycles 4, 5, 6). High-resolution gravity observations from about 950 orbits were obtained between September 1992 and May 1993, while Magellan was in an elliptical orbit with a periapsis near 175 kilometers and an apoapsis near 8,000 kilometers. Observations from an additional 1,500 orbits were obtained following orbitcircularization in mid-1993. These data exist as a 75° by 75° harmonic field.

Campbell, Bruce A.; Campbell, Patricia G.

2002-01-01

93

Regio- and stereoselective intermolecular oxidative phenol coupling in Streptomyces.  

PubMed

Intermolecular oxidative phenol coupling is the main process in nature for the formation of atroposelective biaryl compounds. Although well defined in plants and fungi, this type of dimerization reaction in bacteria is poorly understood. Therefore, the biosynthesis of julichromes, spectomycins, and setomimycin was investigated. The monomeric subunits of these biarylic pre-anthraquinones are derived from a common polyketidic precursor, yet the coupling reaction proceeds in a regioselective manner, with the position of attachment of the two subunits depending on the specific streptomycete strain. By using genome analysis and deletion experiments, the biosynthetic gene clusters were identified. Furthermore, it was established that cytochrome P450 enzymes are fundamentally involved during dimerization of the polyketide monomers. PMID:24746278

Präg, Andreas; Grüning, Björn A; Häckh, Matthias; Lüdeke, Steffen; Wilde, Marcel; Luzhetskyy, Andriy; Richter, Michael; Luzhetska, Marta; Günther, Stefan; Müller, Michael

2014-04-30

94

Structural investigations of the regio- and enantioselectivity of lipases  

Microsoft Academic Search

Although lipases are widely applied for the stereospecific resolution of racemic mixtures of esters, the atomic details of the factors that are responsible for their stereospecificity are largely obscure. We determined the X-ray structures of Pseudomonascepacia lipase in complex with two enantiopure triglyceride analogues, that closely mimic natural substrates. This allowed an unambiguous view of how the two wings of

Dietmar A. Lang; Bauke W. Dijkstra

1998-01-01

95

EM Radiation Program  

NSDL National Science Digital Library

The EM Radiation program displays the electric field vectors (in the x-y plane) and magnetic field contours (for the field in the z direction) calculated from the Lienard-Wiechert potentials for a charged particle. The default scenario shows the resulting radiation from a charged particle in simple harmonic motion. Additional particle trajectories can be specified using the Display | Switch GUI menu item. EM Radiation is an Open Source Physics program written for the teaching of electromagnetism. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the em_radiation.jar file will run the program if Java is installed. Other electromagnetism programs are also available. They can be found by searching ComPADRE for Open Source Physics, OSP, or electromagnetism.

Christian, Wolfgang

2008-05-20

96

emGain: Determination of EM gain of CCD  

NASA Astrophysics Data System (ADS)

The determination of the EM gain of the CCD is best done by fitting the histogram of many low-light frames. Typically, the dark+CIC noise of a 30ms frame itself is a sufficient amount of signal to determine accurately the EM gain with about 200 512x512 frames. The IDL code emGain takes as an input a cube of frames and fit the histogram of all the pixels with the EM stage output probability function. The function returns the EM gain of the frames as well as the read-out noise and the mean signal level of the frames.

Daigle, Olivier; Carignan, Claude; Blais-Ouellette, Sebastien

2012-01-01

97

The EM Earthquake Precursor  

NASA Astrophysics Data System (ADS)

Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After the 1989 Loma Prieta Earthquake, American earthquake investigators predetermined magnetometer use and a minimum earthquake magnitude necessary for EM detection. This action was set in motion, due to the extensive damage incurred and public outrage concerning earthquake forecasting; however, the magnetometers employed, grounded or buried, are completely subject to static and electric fields and have yet to correlate to an identifiable precursor. Secondly, there is neither a networked array for finding any epicentral locations, nor have there been any attempts to find even one. This methodology needs dismissal, because it is overly complicated, subject to continuous change, and provides no response time. As for the minimum magnitude threshold, which was set at M5, this is simply higher than what modern technological advances have gained. Detection can now be achieved at approximately M1, which greatly improves forecasting chances. A propagating precursor has now been detected in both the field and laboratory. Field antenna testing conducted outside the NE Texas town of Timpson in February, 2013, detected three strong EM sources along with numerous weaker signals. The antenna had mobility, and observations were noted for recurrence, duration, and frequency response. Next, two directional techniques were employed, resulting in three mapped, potential epicenters. The remaining, weaker signals presented similar directionality results to more epicentral locations. In addition, the directional results of the Timpson field tests lead to the design and construction of a third prototype antenna. In a laboratory setting, experiments were created to fail igneous rock types within a custom-designed Faraday Cage. An antenna emplaced within the cage detected EM emissions, which were both reproducible and distinct, and the laboratory results paralleled field results. With a viable system and continuous monitoring, a fracture cycle could be established and observed in real-time. Sequentially, field data would be reviewed quickly for assessment; thus, leading to a much improved earthquake forecasting capability. The EM precursor determined by this method may surpass all prior precursor claims, and the general public will finally receive long overdue forecasting.

Jones, K. B., II; Saxton, P. T.

2013-12-01

98

EMS Course Coordinator's Implementation Guide.  

ERIC Educational Resources Information Center

This handbook is intended to clarify the responsibilities of an instructor-coordinator responsible for coordinating an emergency medical services (EMS) training program and to describe many of the materials now available for use in coordinating EMS training. Addressed in the individual chapters of the guide are the nature and scope of the…

Cockrum, Jim

99

Identified EM Earthquake Precursors  

NASA Astrophysics Data System (ADS)

Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After a number of custom rock experiments, two hypotheses were formed which could answer the EM wave model. The first hypothesis concerned a sufficient and continuous electron movement either by surface or penetrative flow, and the second regarded a novel approach to radio transmission. Electron flow along fracture surfaces was determined to be inadequate in creating strong EM fields, because rock has a very high electrical resistance making it a high quality insulator. Penetrative flow could not be corroborated as well, because it was discovered that rock was absorbing and confining electrons to a very thin skin depth. Radio wave transmission and detection worked with every single test administered. This hypothesis was reviewed for propagating, long-wave generation with sufficient amplitude, and the capability of penetrating solid rock. Additionally, fracture spaces, either air or ion-filled, can facilitate this concept from great depths and allow for surficial detection. A few propagating precursor signals have been detected in the field occurring with associated phases using custom-built loop antennae. Field testing was conducted in Southern California from 2006-2011, and outside the NE Texas town of Timpson in February, 2013. The antennae have mobility and observations were noted for recurrence, duration, and frequency response. At the Southern California field sites, one loop antenna was positioned for omni-directional reception and also detected a strong First Schumann Resonance; however, additional Schumann Resonances were absent. At the Timpson, TX field sites, loop antennae were positioned for directional reception, due to earthquake-induced, hydraulic fracturing activity currently conducted by the oil and gas industry. Two strong signals, one moderately strong signal, and approximately 6-8 weaker signals were detected in the immediate vicinity. The three stronger signals were mapped by a biangulation technique, followed by a triangulation technique for confirmation. This was the first antenna mapping technique ever performed for determining possible earthquake epicenters. Six and a half months later, Timpson experienced two M4 (M4.1 and M4.3) earthquakes on September 2, 2013 followed by a M2.4 earthquake three days later, all occurring at a depth of five kilometers. The Timpson earthquake activity now has a cyclical rate and a forecast was given to the proper authorities. As a result, the Southern California and Timpson, TX field results led to an improved design and construction of a third prototype antenna. With a loop antenna array, a viable communication system, and continuous monitoring, a full fracture cycle can be established and observed in real-time. In addition, field data could be reviewed quickly for assessment and lead to a much more improved earthquake forecasting capability. The EM precursors determined by this method appear to surpass all prior precursor claims, and the general public will finally receive long overdue forecasting.

Jones, Kenneth, II; Saxton, Patrick

2014-05-01

100

EPA LABORATORIES IMPLEMENT EMS PROGRAM  

EPA Science Inventory

This paper highlights the breadth and magnitude of carrying out an effective Environmental Management System (EMS) program at the U.S. EPA's research and development laboratories. Federal research laboratories have unique operating challenges compared to more centralized industr...

101

Spatial EM jamming: A countermeasure against EM Analysis?  

Microsoft Academic Search

Electro-Magnetic Analysis has been identified as an efficient technique to retrieve the secret key of cryptographic algorithms. Although similar mathematically speaking, Power or Electro-Magnetic Analysis have different advantages in practice. Among the advantages of EM Analysis, the feasibility of attacking limited and bounded area of integrated systems is the key one. Within this context, the contribution of this paper is

Francois Poucheret; Lyonel Barthe; Pascal Benoit; Lionel Torres; Philippe Maurine; Michel Robert

2010-01-01

102

Alveolar Echinococcosis: Characterization of Diagnostic Antigen Em18 and Serological Evaluation of Recombinant Em18  

PubMed Central

The Echinococcus multilocularis protein Em18 is one of the most promising antigens for use in serodiagnosis of alveolar echinococcosis in human patients. Here we identify an antigenic relationship between Em18 and a 65-kDa immunodominant E. multilocularis surface protein previously identified as either EM10 or EmII/3. The NH2-terminal sequence of native Em18 was determined, revealing it to be a fragment of EM10. Experiments were undertaken to investigate the effect of proteinase inhibitors on the degradation of EM10 in crude extracts of E. multilocularis protoscoleces. Em18 was found to be the product of degradation of EM10 by cysteine proteinase. A recombinant Em18 (RecEm18, derived from 349K to 508K of EM10) was successfully expressed by using Escherichia coli expression system and then evaluated for use in serodiagnosis of alveolar echinococcosis. RecEm18 was recognized by 27 (87.1%) and 28 (90.3%) of 31 serum samples from clinically and/or pathologically confirmed alveolar echinococcosis patients by enzyme-linked immunosorbent assay and immunoblotting, respectively. Of 33 serum samples from cystic echinococcosis patients, 1 was recorded as having a weak positive reaction to RecEm18; however, none of the serum samples which were tested from neurocysticercosis patients (n = 10) or healthy people (n = 15) showed positive reactions. RecEm18 has the potential for use in the differential serodiagnosis of alveolar echinococcosis.

Sako, Yasuhito; Nakao, Minoru; Nakaya, Kazuhiro; Yamasaki, Hiroshi; Gottstein, Bruno; Lightowers, Marshall W.; Schantz, Peter M.; Ito, Akira

2002-01-01

103

Žem?s dangos skaitmenini? vaizd? identifikavimo analiz?  

NASA Astrophysics Data System (ADS)

Straipsnyje nagrin?jamas žem?s dangos skaitmenini? vaizd? identifikavimas taikant kovariacini? funkcij? ir Wavelet (bang?) teorij?. Dviej? skaitmenini? vaizd? arba pavieni? vaizd? autokovariacini? funkcij? ?ver?iai skai?iuojami pagal atsitiktines funkcijas, sudarytas iš skaitmenini? vaizd? pikseli? vektori? pavidalu. Pikseli? vektori? ?ver?iai gaunami skleidžiant skaitmenini? vaizd? pikseli? masyvus viena eilute. Tyrimams panaudoti HJ-DEM Ikonos palydoviniai vaizdai, kai kartografin? projekcija n?ra ortografin?, ir skaitmeninio vaizdo ta\\vsk? masteliai skirtingi. Kei?iant skaitmeninio vaizdo mastel? pavieni? pikseli? spalv? bang? dažniai lieka nekintantys, t. y. const, ir kovariacini? funkcij? skai?iavimo proced?rose mastelio kaitos ?taka nepasirei\\vskia. Vaizdams identifikuoti taikytas RGB formato spalv? spektras. Analizuota RGB spektro dedam?j? bei spalv? tenzoriaus ?taka skaitmenini? vaizd? kovariacini? funkcij? ?ver?iams. Skaitmenini? vaizd? tapatumas ?vertinamas pagal koreliacijos koeficient? reikšmi? kait? atitinkam? reikšmi? diapazone, taikant sudaryt? kompiuterin? program?.

Skeivalas, Jonas; Aleknien?, Edita; Ge?yt?, Silvija

2010-01-01

104

Deterministini? ir geostatistini? interpoliavimo metod? taikymas Žem?s paviršiui modeliuoti  

NASA Astrophysics Data System (ADS)

Analizuojamas Žem?s paviršiaus trimatis modeliavimas pagal geodezinius ir fotogrametrinius matavimo duomenis, taikant tiesin?, svorin? ir Kriging interpoliavimo metodus. Interpoliavimo algoritmai pertvarkyti ir pritaikyti MATLAB paketo vykdomajam kodui. Sudarytoji programa Geo3D skirta erdviniams duomenims vaizduoti pagal geodezinius ir fotogrametrinius duomenis. Geo3D programa sudaryti trima?iai Žem?s paviršiaus modeliai ?vertinti bei palyginti su modeliais, sukurtais reljefo vaizdavimo programa WinSurf.

Nareiko, Viktor; Ruzgien?, Birut?; ?selis, Adomas

2010-01-01

105

Three-wave mixing of volume EM, surface EM and surface acoustic waves  

Microsoft Academic Search

The authors have investigated the diffraction of volume EM waves into surface EM waves (or vice versa) by surface acoustic (SA) waves, i.e. the three-wave mixing of volume EM, surface EM and SA waves, using a Kretschmann (prism\\/Ag film\\/air) configuration with the SA waves propagating in the Ag film. The diffraction intensity was measured as a function of the angle

H. Talaat; W. P. Chen; E. Burstein

1982-01-01

106

DOE/EM Criticality Safety Needs Assessment  

SciTech Connect

The issue of nuclear criticality safety (NCS) in Department of Energy Environmental Management (DOE/EM) fissionable material operations presents challenges because of the large quantities of material present in the facilities and equipment that are committed to storage and/or material conditioning and dispositioning processes. Given the uncertainty associated with the material and conditions for many DOE/EM fissionable material operations, ensuring safety while maintaining operational efficiency requires the application of the most-effective criticality safety practices. In turn, more-efficient implementation of these practices can be achieved if the best NCS technologies are utilized. In 2002, DOE/EM-1 commissioned a survey of criticality safety technical needs at the major EM sites. These needs were documented in the report Analysis of Nuclear Criticality Safety Technology Supporting the Environmental Management Program, issued May 2002. Subsequent to this study, EM safety management personnel made a commitment to applying the best and latest criticality safety technology, as described by the DOE Nuclear Criticality Safety Program (NCSP). Over the past 7 years, this commitment has enabled the transfer of several new technologies to EM operations. In 2008, it was decided to broaden the basis of the EM NCS needs assessment to include not only current needs for technologies but also NCS operational areas with potential for improvements in controls, analysis, and regulations. A series of NCS workshops has been conducted over the past years, and needs have been identified and addressed by EM staff and contractor personnel. These workshops were organized and conducted by the EM Criticality Safety Program Manager with administrative and technical support by staff at Oak Ridge National Laboratory (ORNL). This report records the progress made in identifying the needs, determining the approaches for addressing these needs, and assimilating new NCS technologies into EM fissionable material operations. In addition, the report includes projections of future EM needs and associted recommendations.

Westfall, Robert Michael [ORNL; Hopper, Calvin Mitchell [ORNL

2011-02-01

107

School Budget Hold'em Facilitator's Guide  

ERIC Educational Resources Information Center

"School Budget Hold'em" is a game designed to help school districts rethink their budgeting process. It evolved out of Education Resource Strategies' (ERS) experience working with large urban districts around the country. "School Budget Hold'em" offers a completely new approach--one that can turn the budgeting process into a long-term visioning…

Education Resource Strategies, 2012

2012-01-01

108

Risco no mercado de arroz em casca  

Microsoft Academic Search

O presente trabalho avaliou as características das séries de retornos, normalmente encontradas em séries financeiras, para dados do mercado de arroz em casca ao produtor do Rio Grande do Sul. Um modelo da classe GARCH (1,1) tipo VaR foi utilizado para obter previsões da variância condicional e verificar o risco incorrido pelas posições comprada e vendida no mercado de arroz

Andreia Cristina de Oliveira Adami; Geraldo SantAna de Camargo Barros

2008-01-01

109

Ambiente e formação estelar em galáxias  

NASA Astrophysics Data System (ADS)

Estudamos o ambiente de galáxias com formação estelar inicialmente a partir de uma amostra limitada em volume proveniente do 2dF Galaxy Redshift Survey. Discriminamos as galáxias com formação estelar com base em distintas classes espectrais, utilizando para esta classificação as larguras equivalentes das linhas [OII]l3727 e Hd. O ambiente é caracterizado pela densidade espacial local de galáxias. Mostramos que a fração de galáxias com formação estelar é bastante reduzida em ambientes densos, enquanto a de galáxias passivas aumenta nestas regiões. Por outro lado, quando analisamos a fração de galáxias que apresentam um surto recente de formação estelar, notamos que ela independe do ambiente, sendo que em regiões mais densas alguns destes objetos apresentam distorções em sua morfologia. Estes resultados são confrontados com a análise da dependência ambiental da taxa de formação estelar, estimada pela emissão em Ha, de uma amostra extraída do Sloan Digital Sky Survey. Um declínio gradual da formação estelar também é observado nesta análise, sugerindo que as interações por efeitos de maré sejam responsáveis pela redução da formação estelar em ambientes densos através da remoção do reservatório de gás das galáxias. No entanto, estas interações também podem induzir surtos de formação estelar nas galáxias, além de peculiaridades morfológicas observadas nos objetos que habitam regiões mais densas.

Mateus, A., Jr.; Sodré, L., Jr.

2003-08-01

110

Evolução química em galáxias compactas azuis (BCGs)  

NASA Astrophysics Data System (ADS)

Neste trabalho, a formação estelar e evolução quí mica em galáxias Compactas Azuis (Blue Compact Galaxies - BCGs) foram estudadas através da comparação de previsões de modelos de evolução quí mica a várias razões de abundância quí mica observadas nestas galáxias. Modelos detalhados com recentes dados de nucleossí ntese e que levam em consideração o papel desempenahdo por supernovas de ambos os tipos (II e Ia) na evolução galáctica foram desenvolvidos para as BCGs permitindo seguir a evolução de vários elementos quí micos (H, D, He, C, N, O, Mg, Si, S, Ca, e Fe). O modelo é caracterizado pelas prescrições adotadas para a formação estelar, a qual ocorre em vários surtos de atividade separados por longos perí odos quiescentes. Após ajustar os melhores modelos aos dados observacionais, as previsões destes modelos foram comparadas também a razões de abundância observadas em sistemas Damped Lyman alpha (DLAs) e a origem do N (primária ou secundária) foi discutida. Alguns dos resultados obtidos são: i) as razões de abundância observadas nas BCGs são reproduzidas por modelos com 2 a 7 surtos de formação estelar com eficiência entre n = 0.2-0.9 Gano-1; ii) os baixos valores de N/O observados nestas galáxias são um resultado natural de uma formação estelar em surtos; iii) os modelos para BCGs podem reproduzir os dados dos DLAs, iv) uma quantidade "baixa" de N primário produzido em estrelas de alta massa pode ser uma explicação para os baixos valores de [N/a] observados em DLAs.

Lanfranchi, G. A.; Matteucci, F.

2003-08-01

111

EM International, July 1994, Volume 2  

SciTech Connect

The Office of Environmental Management (EM) at the Department of Energy (DOE) is seeking out and leveraging foreign technology, data, and resources in keeping with EM`s mandate to protect public health and the environment through the safe and cost-effective remediation of the Department`s nuclear weapons sites. EM works closely with foreign governments, industry, and universities to obtain innovative environmental technologies, scientific and engineering expertise, and operations experience that will support EM`s objectives. Where appropriate, these international resources are used to manage the more urgent risks at our sites, secure a safe workplace, help build consensus on critical issues, and strengthen our technology development program. Through international agreements EM engages in cooperative exchange of information, technology, and individuals. Currently, we are managing agreements with a dozen countries in Europe, Latin America, and Asia. These agreements focus on environmental restoration, waste management, transportation of radioactive wastes, and decontamination and decommissioning. This publication contains the following articles: in situ remediation integrated program; in-situ characterization and inspection of tanks; multimedia environmental pollutant assessment system (MEPAS); LLNL wet oxidation -- AEA technology. Besides these articles, this publication covers: EU activities with Russia; technology transfer activities; and international organization activities.

Not Available

1994-10-01

112

Project X RFQ EM Design  

SciTech Connect

Project X is a proposed multi-MW proton facility at Fermi National Accelerator Laboratory (FNAL). The Project X front-end would consist of an H- ion source, a low-energy beam transport (LEBT), a CW 162.5 MHz radio-frequency quadrupole (RFQ) accelerator, and a medium-energy beam transport (MEBT). Lawrence Berkeley National Laboratory (LBNL) and FNAL collaboration is currently developing the designs for various components in the Project X front end. This paper reports the detailed EM design of the CW 162.5 MHz RFQ that provides bunching of the 1-10 mA H- beam with acceleration from 30 keV to 2.1 MeV.

Romanov, Gennady; /Fermilab; Hoff, Matthew; Li, Derun; Staples, John; Virostek, Steve; /LBNL

2012-05-09

113

Manufacturing Methods of Multi-ingredient Compost with EM  

Microsoft Academic Search

This project is performed for increasing the integrated effect of EM by reasonable mixing of EM solution and multi-ingredient compost in agriculture. This compost has been manufactured by treating organic materials with EM and culturing other beneficial bacteria with high density, and by adding some minerals. The organic substrates were fermented by EM. There was a definite difference between organic

H. G. Ryang; M. S. Rim; Y. H. Rim; C. U. Chang; C. G. Kang; D. C. Yang

114

Regio- and chemoselective bromination of 2,3-diarylcyclopent-2-en-1-ones.  

PubMed

The bromination of 2,3-diarylcyclopent-2-en-1-ones under various conditions has been studied. It was found that depending on the brominating reagent and nature of solvent the bromine atom can be introduced at the 4- or 5-position of the ethene "bridge", as well as into the aryl moieties. Aryl group bromination is accomplished with such reagents as molecular bromine, N-bromosuccinimide, or tetrabutylammonium tribromide. 5-Bromocyclopentenones with very high efficiency can be obtained by the reaction with copper(II) bromide in methanol, while 4-bromoketones are prepared in n-propyl acetate. The developed methods can be highly useful for the synthesis of bromo-substituted 2-cyclopenten-1-ones and their close analogues, which are important synthons in organic synthesis and for the preparation of a variety of useful substances. PMID:22924429

Shirinian, Valerii Z; Lonshakov, Dmitry V; Kachala, Vadim V; Zavarzin, Igor V; Shimkin, Alexey A; Lvov, Andrew G; Krayushkin, Mikhail M

2012-09-21

115

Regio- and stereoselectivity in the decatungstate photocatalyzed alkylation of alkenes by alkylcyclohexanes.  

PubMed

Tetrabutylammonium decatungstate (WO) photocatalyzes radical alkylation reactions starting directly from alkanes. When using tert-butylcyclohexane and methylcyclohexane as the radical precursors, the addition to electrophilic alkenes (beta,beta-dialkylmethylenemalononitriles, acrylonitrile, methyl acrylate, methyl vinyl ketone) is regioselective and exclusively gives 3- and 4-substituted cyclohexyl adducts, with no significant functionalization of the other positions. Furthermore, when a beta,beta-disubstituted alkene is used, the reaction is stereoselective (cis stereochemistry for the 1,3-cyclohexane derivatives and trans for the 1,4 isomers). Some of the reactions have also been carried out by using benzophenone as the photocatalyst, giving the same product distribution. However, the decatungstate anion is a superior catalyst from a preparative point of view, because it is efficient at low concentrations (0.002 m, 2 mol %) and allows for a simple work up. From a mechanistic point of view, the role of both the alkyl radicals and the radical adducts has been assessed by trapping experiments in the presence of suitable additives (alpha-phenyl-N-tert-butylnitrone, PBN, and 2-methyl-2-nitrosopropane, MNP) and by EPR spectroscopic detection of the resulting nitroxides in solution. Furthermore, trapping by the nitroxide TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidine N-oxide) gives O-(tert-butylcyclohexyl)hydroxylamines, again as only the 3- and the 4-substituted isomers. We conclude that the observed regioselective activation originates from the initial hydrogen abstraction step (the statistically corrected ratio for positions 3 and 4 ranges from 1.1 to 1.35 for all of the trapping products). The selectivity is mainly due to steric hinderence. PMID:19609992

Dondi, Daniele; Ravelli, Davide; Fagnoni, Maurizio; Mella, Mariella; Molinari, Alessandra; Maldotti, Andrea; Albini, Angelo

2009-08-10

116

A convergent approach to (R)-Tiagabine by a regio- and stereocontrolled hydroiodination of alkynes.  

PubMed

The occurrence of unsaturated systems in natural products combined with the mildness and the wide range of applicability of CeCl(3) promoted methodologies suggest several potential future synthetic applications within the field of total synthesis of biologically active molecules. On this concept, the use of CeCl(3).7H(2)O-NaI system as an efficient heterogeneous promoter has been highlighted in the iodofunctionalization of carbon-carbon triple bonds. The study has shown that this method would be particularly interesting for the stereoselective formation of trisubstituted (Z)- or (E)-iodoalkenes by simply changing the nature of the solvent. The methodology has been successfully applied to the synthesis of (R)-1-[4,4-bis-(3-methyl-2-thienyl)-3-butenyl]-3-piperidinecarboxylic acid , named (R)-Tiagabine, which is a potent and selective gamma-aminobutyric acid (GABA) uptake inhibitor with proven anticonvulsant efficacy in humans. PMID:20532411

Bartoli, Giuseppe; Cipolletti, Roberto; Di Antonio, Giustino; Giovannini, Riccardo; Lanari, Silvia; Marcolini, Mauro; Marcantoni, Enrico

2010-08-01

117

Modeling of biliverdin reduction process: regio-specificity and H-bonding  

NASA Astrophysics Data System (ADS)

Octa ethyl biliverdin (OEBV) has been employed as a model for natural biliverdin and its geometry has been optimized by using semiempirical (AM1, PM3), DFT, and hybrid ONIOM methods. Geometries and energetics of formation of octa ethyl bilirubin (OEBR) formed by reduction from OEBV via three carbon sites ?, ?, and ? have been obtained. It has been shown that ?-OEBR has two configurational isomers (named ? 1 and ? 2), which can convert to each other by internal 1,5-hydrogen shift. The results show that, within the accuracy level of semiempirical methods, all three isomers namely, ?, ? 1, and ?-OEBR are of similar stability whereas, at higher level of theory, ? 1-OEBR is less stable than others. Moreover, ? 2-isomer with one more of its pyrrole rings being aromatic can achieve a higher symmetry, and is the most stable among others by at least 5-6 kcal mol -1 based on various methods employed. It is interesting to note that the ridge-tile conformation, which has been confirmed for natural bilirubin was not observed for calculated geometries of ? 1- and ? 2-isomers. A conformational analysis show that an energy barrier of ˜25 kcal mol -1 must be surmounted for ? 2 to obtain the ridge-tile geometry. OEBV was synthesized and purified from octa ethyl porphyrin iron (III) chloride, and was reduced to OEBR by sodium borohydride (NaBH 4). Chemical reduction of OEBV with NaBH 4 was followed in CDCl 3 and CD 3OD solutions and the product was characterized by 1H NMR and UV-Vis spectroscopy. The results show that ? 2-isomer as the major product, forms along with ? 1 via an equilibrium tautomerization reaction.

Zahedi, Mansour; Ghiasi, Mina; Safari, Nasser

2005-04-01

118

Modeling of biliverdin reduction process: regio-specificity and H-bonding  

Microsoft Academic Search

Octa ethyl biliverdin (OEBV) has been employed as a model for natural biliverdin and its geometry has been optimized by using semiempirical (AM1, PM3), DFT, and hybrid ONIOM methods. Geometries and energetics of formation of octa ethyl bilirubin (OEBR) formed by reduction from OEBV via three carbon sites ?, ?, and ? have been obtained. It has been shown that

Mansour Zahedi; Mina Ghiasi; Nasser Safari

2005-01-01

119

Total Synthesis of Tetrahydrolipstatin and Stereoisomers via a Highly Regio- and Diastereoselective Carbonylation of Epoxyhomoallylic Alcohols.  

PubMed

A concise enantioselective synthesis of tetrahydrolipstatin (THL) and seven stereoisomers has been achieved. The synthesis of THL was accomplished in 10 steps and 31% overall yield from an achiral ynone. Key to the success of the approach is the use of a bimetallic [Lewis acid](+)[Co(CO)4](-) catalyst for a late-stage regioselective carbonylation of an enantiomerically pure cis-epoxide to a trans-?-lactone. The success of this route to THL and its stereoisomers also demonstrated the practicality of the carbonylation catalyst for complex molecule synthesis as well as its functional group compatibility. PMID:25004122

Mulzer, Michael; Tiegs, Brandon J; Wang, Yanping; Coates, Geoffrey W; O'Doherty, George A

2014-07-30

120

On the origin of regio- and stereoselectivity in singlet oxygen addition to enecarbamates.  

PubMed

The reactions of excited state singlet molecular oxygen ((1)?(g),(1)O(2)) continue to witness interesting new developments. In the most recent manifestation, (1)O(2) is tamed to react with enecarbamates in a stereoselective manner, which is remarkable, in view of its inherently high reactivity (Acc. Chem. Res. 2008, 41, 387). Herein, we employed the CAS-MP2(8,7)/6-31G* as well as the CAS-MP2(10,8)/6-31G* computations to unravel the origin of (i) diastereoselectivities in dioxetane or hydroperoxide formation and (ii) regioselectivity leading to a [2 + 2] cycloadduct or an ene product when (1)O(2) reacts with an oxazolidinone tethered 2-phenyl-1-propenyl system. The computed Gibbs free energy profiles for E- and Z-isomers when (1)O(2) approaches through the hindered and nonhindered diastereotopic faces (by virtue of chiral oxazolidinone) of the enecarbamates exhibit distinct differences. In the case of E-isomer, the relative energies of the transition structures responsible for hydroperoxide (ene product) are lower than that for dioxetane formation. On the other hand, the ene pathway is predicted to involve higher barriers as compared to the corresponding dioxetane pathway for Z-isomer. The energy difference between the rate-determining diastereomeric transition structures involved in the most favored ene reaction for E-enecarbamate suggests high diastereoselectivity. In contrast, the corresponding energy difference for Z-enecarbamate in the ene pathway is found to be diminishingly close, implying low diastereoselectivity. However, the dioxetane formation from Z-enecarbamate is predicted to exhibit high diastereoselectivity. The application of activation strain model as well as the differences in stereoelectronic effects in the stereocontrolling transition structures is found to be effective toward rationalizing the origin of selectivities reported herein. These predictions are found to be in excellent agreement with the experimental observations. PMID:22324308

Rajeev, Ramanan; Sunoj, Raghavan B

2012-03-01

121

Application of immobilized lipase to regio-specific interesterification of triglyceride in organic solvent  

Microsoft Academic Search

Lipase from Rhizopus delemar was immobilized by entrapment with photo-crosslinkable resin prepolymers or urethane prepolymers or by binding to various types of porous silica beads. The immobilized lipase preparations thus obtained were examined for their activity in converting olive oil to an interesterified fat (cacao butter-like fat), whose oleic acid moieties at 1- and 3-positions were replaced with stearic acid

Kenzo Yokozeki I; Shigeru Yamanaka; Koichi Takinami I; Yoshio Hirose; Atsuo Tanaka; Kenji Sonomoto; Saburo Fukui

1982-01-01

122

INDIUM MEDIATED HIGHLY REGIO- AND DIASTEREOSELECTIVE ALLENYLATION IN AQUEOUS MEDIUM: TOTAL SYNTHESIS OF (+)-GONIOFUFURONE. (R822668)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

123

Regio-Selective Arene Halogenation Using the FAD-Dependent Halogenase RebH  

PubMed Central

Co-expression of the halogenase RebH with GroEL/ES and fusion of the flavin reductase RebF to MBP enabled production of both enzymes on scales sufficient for preparative regioselective oxidative halogenation of arenes. The activity and selectivity of RebH contrast with those reported for PrnA, a structurally homologous halogenase, which provided a narrower substrate scope and only enabled halogenation of unnatural substrates at their most electronically activated positions.

Payne, James T.; Andorfer, Mary C.

2013-01-01

124

Regio-selective chemical-enzymatic synthesis of pyrimidine nucleotides facilitates RNA structure and dynamics studies.  

PubMed

Isotope labeling has revolutionized NMR studies of small nucleic acids, but to extend this technology to larger RNAs, site-specific labeling tools to expedite NMR structural and dynamics studies are required. Using enzymes from the pentose phosphate pathway, we coupled chemically synthesized uracil nucleobase with specifically (13) C-labeled ribose to synthesize both UTP and CTP in nearly quantitative yields. This chemoenzymatic method affords a cost-effective preparation of labels that are unattainable by current methods. The methodology generates versatile (13) C and (15) N labeling patterns which, when employed with relaxation-optimized NMR spectroscopy, effectively mitigate problems of rapid relaxation that result in low resolution and sensitivity. The methodology is demonstrated with RNAs of various sizes, complexity, and function: the exon splicing silencer 3 (27 nt), iron responsive element (29 nt), Pro-tRNA (76 nt), and HIV-1 core encapsidation signal (155 nt). PMID:24954297

Alvarado, Luigi J; LeBlanc, Regan M; Longhini, Andrew P; Keane, Sarah C; Jain, Niyati; Yildiz, Zehra F; Tolbert, Blanton S; D'Souza, Victoria M; Summers, Michael F; Kreutz, Christoph; Dayie, T Kwaku

2014-07-21

125

Consumo e Fermentação Ruminal de Proteínas em Função de Suplementação Alimentar Energética e Protéica em Novilhos1  

Microsoft Academic Search

RESUMO - Objetivou-se analisar o efeito de suplementação energética sobre o consumo e a fermentação ruminal de proteínas em dois níveis de proteína dietética (6 e 20%). Quatro novilhos mestiços fistulados no rúmen foram utilizados em um quadrado latino e os tratamentos arranjados em um fatorial 2 × 2, em que as dietas testadas constituíram-se de: A. só feno; B.

Natália Guarino; Souza Barbosa; Rogério de Paula Lana; Gulab Newandram Jham; Arnaldo Chaer Borges; Antônio Bento Mâncio; José Carlos Pereira; Juliana Silva Oliveira

126

Fontes de metionina em rações formuladas com base em aminoácidos totais ou digestíveis para frangas de reposição leves e semipesadas  

Microsoft Academic Search

RESUMO - Foram conduzidos dois experimentos com o objetivo de avaliar a utilização de duas fontes de metionina (em pó ou líquida) em rações formuladas com base em aminoácidos digestíveis ou totais para frangas de reposição leves e semipesadas, nas fases inicial (de 1 a 6 semanas de idade) e de crescimento (de 11 a 16 semanas de idade). Em

Luiz Gustavo Rombola; Douglas Emygdio de Faria; Bruno José Deponti; Flávio Henrique Araujo Silva; Daniel Emygdio de Faria Filho; Otto Mack Junqueira

2008-01-01

127

Antibody responses against Em18 and Em16 serodiagnostic markers in alveolar and cystic echinococcosis patients from northwest China.  

PubMed

Western blot analysis was carried out in order to evaluate new serodiagnostic markers, Em18 and Em16, for differentiation of alveolar echinococcosis (AE) from cystic echinococcosis (CE) using 36 serum samples from hydatid patients from Xinjiang, China, where AE and CE are both endemic and one double infection case has been reported. All AE cases except one (5/6) who exhibited a calcified lesion and a single case of double infection showed antibody responses against Em18 and Em16. Some of CE patient sera (6/22) showed antibody response against Em16 except one who showed that against Em18. Analyses of IgG subclass responses against Em18 and Em16 were carried out using all serum samples showing antibody responses against Em18 and/or Em16 (seven CE, five AE, and one AE + CE) and additional samples of three CE and 22 AE from Sichuan, China. IgG4 was the most predominant antibody subclass. Em18 and Em16 were recognized by both IgG4 and IgG1 (in most cases) or by either IgG4 or IgG1 (in minor cases) or by IgG3 (in very rare cases). Neither Em18 nor Em16 was recognized by IgG2 antibodies. The usefulness of Em18 and Em16 as potential new markers for serological differentiation of human AE and CE, respectively, is discussed. PMID:9354966

Ito, A; Wen, H; Craig, P S; Ma, L; Nakao, M; Horii, T; Pang, X L; Okamoto, M; Itoh, M; Osawa, Y; Wang, X G; Liu, Y H

1997-02-01

128

Revisão sistemática sobre obesidade em adolescentes brasileiros  

Microsoft Academic Search

Resumo - O propósito deste estudo foi revisar, de forma sistemática, a literatura nacional sobre a prevalência e fatores associados à obesidade em adolescentes. A busca foi realizada nas bases de dados Pubmed e Bireme, através dos descritores: \\

Rafael Miranda Tassitano; Maria Cecília Marinho Tenório; Pedro C Hallal

129

Naval Electromagnetic (EM) Gun Technology Assessment.  

National Technical Information Service (NTIS)

The Naval Research Advisory Committee was asked in May 2003 to conduct an assessment of the current maturity of electromagnetic (EM) gun technology for the Assistant Secretary of the Navy (Research, Development & Acquisition). Specifically, the Committee ...

J. Bachkosky D. Katz R. Rumpf W. Weldon

2003-01-01

130

Naval Electromagnetic (EM) Gun Technology Assessment.  

National Technical Information Service (NTIS)

The Naval Research Advisory Committee was asked in May 2003 to conduct an assessment of the current maturity of electromagnetic (EM) gun technology for the Assistant Secretary of the Navy (Research, Development & Acquisition). Specifically, the Commit...

J. Bachkosky D. Katz R. Rumpf W. Weldon

2004-01-01

131

Evaluation of Em18-, Em16-, Antigen B-Western blots, Em2 plus-ELISA and four other tests for differential serodiagnosis of alveolar and cystic echinococcosis patients in Poland  

Microsoft Academic Search

Seven alveolar echinococcosis (AE) and 20 cystic echinococcosis (CE) cases in humans, confirmed clinically or pathologically, were analyzed serologically by Em18-, Em16-, Antigen B subunit (8 kDa)-Western blots (Em18-, Em16-, AgB-WBs) and five other serological tests including commercially available Em2plus-ELISA and IHA. Some serologically doubtful AE cases were rechecked parasitologically or histopathologically. In Em18-WB and Em2plus-ELISA, five and four of

Akira Ito; Liang Ma; Malgorzata Paul; Jerzy Stefaniak; Zbigniew S. Pawlowski

1998-01-01

132

EMS adaptation for climate change  

NASA Astrophysics Data System (ADS)

The purpose of this study was to find an appropriate scenario of pre-hospital transportation of an emergency medical service (EMS) system for burdensome casualties resulting from extreme climate events. A case of natural catastrophic events in Taiwan, 88 wind-caused disasters, was reviewed and analyzed. A sequential-conveyance method was designed to shorten the casualty transportation time and to promote the efficiency of ambulance services. A proposed mobile emergency medical center was first constructed in a safe area, but nearby the disaster area. The Center consists of professional medical personnel who process the triage of incoming patients and take care of casualties with minor injuries. Ambulances in the Center were ready to sequentially convey the casualties with severer conditions to an assigned hospital that is distant from the disaster area for further treatment. The study suggests that if we could construct a spacious and well-equipped mobile emergency medical center, only a small portion of casualties would need to be transferred to distant hospitals. This would reduce the over-crowding problem in hospital ERs. First-line ambulances only reciprocated between the mobile emergency medical center and the disaster area, saving time and shortening the working distances. Second-line ambulances were highly regulated between the mobile emergency medical center and requested hospitals. The ambulance service of the sequential-conveyance method was found to be more efficient than the conventional method and was concluded to be more profitable and reasonable on paper in adapting to climate change. Therefore, additional practical work should be launched to collect more precise quantitative data.

Pan, C.; Chang, Y.; Wen, J.; Tsai, M.

2010-12-01

133

de energia elétrica em equipamentos de energia elétrica em equipamentos de energia elétrica em equipamentos de energia elétrica em equipamentos de energia elétrica em equipamentos utilizados em galpão de frangos de corte utilizados em galpão de frangos de corte utilizados em galpão de frangos de corte utilizados em galpão de frangos de corte utilizados em galpão de frangos de corte  

Microsoft Academic Search

2 FCAV\\/UNESP. Fone: (16) 3209-2637 3 FCAV\\/UNESP. Fone: (16) 3209-2654 Resumo: Resumo: Resumo: Resumo: Resumo: Este trabalho teve por objetivo analisar o consumo e o custo da energia elétrica em um galpão comercial de frangos de corte, durante dois ciclos de criação, inverno e verão. Foram realizadas medidas de consumo dos ventiladores, nebulizadores, lâmpadas e comedouros durante o manejo de

José E. P. Turco; Luiz F. S. A. Ferreira; Renato L. Furlan

134

Tour of the Electromagnetic Spectrum (EMS) Videos  

NSDL National Science Digital Library

These videos introduce middle- and high school-age learners to the electromagnetic spectrum. The product consists of 8 animations including an introduction to electromagnetic waves and one animation for each wavelength of the EM spectrum (Radio, Microwave, Infrared, Visible, Ultraviolet, X-Rays and Gamma Rays). Each wavelength of the EM spectrum offers a construct to illustrate and teach about NASA sensors, missions, and science. Emphasis is placed on relevant science, such as lunar exploration, and hot science topics, such as climate change. The examples and narrative for each wavelength animation build on the learnersâ prior knowledge then introduces examples from NASA missions. These examples explore the use of spectral analysis and visualizations that help scientists make discoveries about the world around us using EM waves.

Benesch, Troy

2009-01-01

135

A emissão em 8mm e as bandas de Merrill-Sanford em estrelas carbonadas  

NASA Astrophysics Data System (ADS)

Estrelas carbonadas possuem bandas moleculares em absorção no visível e, no infravermelho (IR) as principais características espectrais se devem a emissão de grãos. Recentemente foi detectada a presença de bandas de SiC2 (Merrill-Sanford, MS) em emissão sendo atribuída à presença de um disco rico em poeira. Neste trabalho analisamos uma amostra de 14 estrelas carbonadas, observadas no telescópio de 1.52 m do ESO em 4 regiões espectrais diferentes, a fim de detectar as bandas de MS em emissão. Nossa amostra é composta de estrelas que apresentam além da emissão em 11.3 mm, outra em 8 mm. Esta última emissão, não usual nestes objetos, tem sido atribuída ou a moléculas de C2H2, ou a um composto sólido ainda indefinido. A detecção de emissões de MS e aquelas no IR, simultaneamente, revelaria um cenário mais complexo que o habitualmente esperado para os ventos destes objetos. No entanto como primeiro resultado, verificamos que as bandas de Merrill-Sanford encontram-se em absorção, não revelando nenhuma conexão com a emissão a 8 mm. Assim, temos duas hipóteses: (a) a emissão a 8 mm se deve à molécula C2H2 ou (b) essa emissão é resultado da emissão térmica de grãos. Testamos a segunda hipótese modelando a amostra com grãos não-homogêneos de SiC e quartzo, o qual emite em aproximadamente 8mm. Este grão seria produzido em uma fase evolutiva anterior a das carbonadas (estrelas S) e por terem uma estrutura cristalina são destruídos apenas na presença de campos de radiação ultravioleta muito intensos. Os modelos para os envoltórios utilizam o método de Monte Carlo para descrever o problema do transporte da radiação. As conclusões deste trabalho são: (1) as bandas de Merrill-Sanford se encontram em absorção, sugerindo um cenário usual para os ventos das estrelas da amostra; (2) neste cenário, a emissão em 8 mm seria resultado de grãos de quartzo com mantos de SiC, indicando que o quartzo poderia sobreviver a fase evolutiva S.

de Mello, A. B.; Lorenz-Martins, S.

2003-08-01

136

Risk Communication Within the EM Program  

SciTech Connect

The U.S. Department of Energy Environmental Management program (EM) conducts the most extensive environmental remediation effort in the world. The annual EM budgets have exceeded $6,000,000,000 for approximately ten years and EM has assumed responsibility for the cleanup of the largest DOE reservations (i.e., at Hanford, Washington, Aiken, South Carolina, and Idaho Falls, Idaho) as well as the facilities at Rocky Flats, Colorado and in Ohio. Each of these sites has areas of extensive radioactive and chemical contamination, numerous surplus facilities that require decontamination and removal, while some have special nuclear material that requires secure storage. The EM program has been criticized for being ineffective (1) and has been repeatedly reorganized to address perceived shortcomings. The most recent reorganization was announced in 2001 to become effective at the beginning of the 2003 Federal Fiscal Year (i.e., October 2002). It was preceded by a ''top to bottom'' review (TTBR) of the program (2) that identified several deficiencies that were to be corrected as a result of the reorganization. One prominent outcome of the TTBR was the identification of ''risk reduction'' as an organizing principle to prioritize the activities of the new EM program. The new program also sought to accelerate progress by identifying a set of critical activities at each site that could be accelerated and result in more rapid site closure, with attendant risk, cost, and schedule benefits. This paper investigates how the new emphasis on risk reduction in the EM program has been communicated to EM stakeholders and regulators. It focuses on the Rocky Flats Environmental Technology Site (RFETS) as a case study and finds that there is little evidence for a new emphasis on risk reduction in EM communications with RFETS stakeholders. Discussions between DOE and RFETS stakeholders often refer to ''risk,'' but the word serves as a placeholder for other concepts. Thus ''risk'' communication at RFETS is lively and involves important issues, but often does not inform participants about true ''risk reduction.''

Edelson, M.

2003-02-26

137

Synthesis, characterization and adsorption capacities of microporous titanosilicate EMS3  

Microsoft Academic Search

A titanosilicate, named EMS-3, has been synthesized using the organic base TMAOH (tetramethylammonium hydroxide) and Na ion, as structure directing agents, under hydrothermal conditions. The XRD pattern of EMS-3 contains sharp and broad reflections typical of a partially disordered structure. EMS-3 has low thermal stability, indeed XRD pattern shows a decreased resolution after thermal treatment at 300°C. An amorphous phase

C. Rizzo; A. Carati; R. Millini; G. Bellussi; W. O. Parker Jr.; S. Zanardi

2006-01-01

138

EM21 Retrieval Knowledge Center: Waste Retrieval Challenges  

Microsoft Academic Search

EM-21 is the Waste Processing Division of the Office of Engineering and Technology, within the U.S. Department of Energys (DOE) Office of Environmental Management (EM). In August of 2008, EM-21 began an initiative to develop a Retrieval Knowledge Center (RKC) to provide the DOE, high level waste retrieval operators, and technology developers with centralized and focused location to share knowledge

Andrew P. Fellinger; Michael W. Rinker; Eric J. Berglin; Richard L. Minichan; Micheal R. Poirier; Phillip A. Gauglitz; Bruce A. Martin; Brian K. Hatchell; Eloy Saldivar; O Dennis Mullen; Noel F. Chapman; Beric E. Wells; Peter W. Gibbons

2009-01-01

139

EMS response to an airliner crash.  

PubMed

This report of an aircraft crash at a major airport in Kingston, Jamaica examines the response of the local Emergency Medical Services (EMS). Factors that impacted the response are discussed, and the need for more disaster simulation exercises is highlighted. The objective of this case report was to document the response of EMS personnel to the crash of American Airlines Flight 331, and to utilize the information to examine and improve the present protocol. While multiple errors can occur during a mass-casualty event, these can be reduced by frequent simulation exercises during which various personnel practice and learn designated roles. Efficient triage, proper communication, and knowledge of the roles are important in ensuring the best possible outcome. While the triage system and response of the EMS personnel were effective for this magnitude of catastrophe, more work is needed in order to meet predetermined standards. Ways in which this can be overcome include: (1) hosting more disaster simulation exercises; (2) encouraging more involvement with first responders; and (3) strengthening the links in the local EMS system. Vigorous public education must be instituted and maintained. PMID:22853919

Dasgupta, Shuvra; French, Simone; Williams-Johnson, Jean; Hutson, Rhonda; Hart, Nicole; Wong, Mark; Williams, Eric; Espinosa, Kurdell; Maycock, Celeste; Edwards, Romayne; McCartney, Trevor; Cawich, Shamir; Crandon, Ivor

2012-06-01

140

Áreas de Risco em Manaus: Inventário preliminar  

Microsoft Academic Search

O presente trabalho pautou-se em mapear as ocorrências registradas pela Defesa Civil Municipal (SEMDEC), nos anos de 2005 a 2008, com a finalidade de identificar as áreas mais afetadas por eventos adversos (alagação e deslizamento). Para tanto, foram utilizadas a base cartográfica Google Earth e QGIS. Uma das principais dificuldades foi a localização precisa dos eventos, pois as bases cartográficas

Denise Rodrigues Cruz; Karla R. Mendes Cassiano; Reinaldo Corrêa Costa

2009-01-01

141

O USO DE ANIMAIS EM PESQUISAS CIENTÍFICAS  

Microsoft Academic Search

Historicamente, atividades didáticas e de pesquisa utilizando animais são realizadas desde a Antigüidade. Inicialmente, muitas destas práticas eram executadas por pessoas interessadas em aprofundar o seu conhecimento sobre um determinado assunto, porém, sem a exigência da aplicação de um método sistematizado de investigação. Com o passar do tempo esta sistematização incorporou-se às práticas didático-científicas, sendo realizadas por pessoas capacitadas para

Marcia Mocellin Raymundo; José Roberto Goldim

142

ESPÉCIES DO GÊNERO Eimeria (APICOMPLEXA: EIMERIIDAE) EM TAMANDUÁS-BANDEIRA (Myrmecophaga tridactyla LINNAEUS, 1758) EM CATIVEIRO  

Microsoft Academic Search

1 ABSTRACT:- FREITAS, F.L. DA C.; ALMEIDA, K. DE S.; ZANETTI, A.S.; NASCIMENTO, A.A. DO; MACHADO, C. R.; MACHADO, R.Z. (Species of the genus Eimeria (Apicomplexa: Eimeriidae) in giant anteaters (Myrmecophaga tridactyla Linnaeus, 1758) in captivity). Espécies do gênero Eimeria (Apicomplexa: Eimeriidae) em Tamanduás-bandeira (Myrmecophaga tridactyla Linnaeus, 1758) em cativeiro. Revista Brasileira de Parasitologia Veterinária, v. 15, n. 1, p.

FAGNER LUIZ DA C. FREITAS; ANDRÉ S. ZANETTI; CÉLIO R. MACHADO; ROSANGELA Z. MACHADO

143

Modelling and design for PM/EM magnetic bearings  

NASA Technical Reports Server (NTRS)

A mathematical model of a permanent magnet/electromagnet (PM/EM) radially active bearing is presented. The bearing is represented by both a reluctance model and a stiffness model. The reluctance model analyzes the magnetic circuit of the PM/EM bearings. By combining the two models, the performance of the bearing can be predicted given geometric dimensions, permanent magnet strength, and the parameters of the EM coils. The overall bearing design including the PM and EM design is subject to the performance requirement and physical constraints. A study of these requirements and constraints is discussed. The PM design is based on the required magnetic flux for proper geometric dimensions and magnet strength. The EM design is based on the stability and force slew rate consideration, and dictates the number of turns for the EM coils and the voltage and current of the power amplifier. An overall PM/EM bearing design methodology is proposed and a case study is also demonstrated.

Pang, D.; Kirk, J. A.; Anand, D. K.; Johnson, R. G.; Zmood, R. B.

1992-01-01

144

The association between EMS workplace safety culture and safety outcomes  

PubMed Central

Objective Prior studies have highlighted wide variation in EMS workplace safety culture across agencies. We sought to determine the association between EMS workplace safety culture scores and patient or provider safety outcomes. Methods We administered a cross-sectional survey to EMS workers affiliated with a convenience sample of agencies. We recruited these agencies from a national EMS management organization. We used the EMS Safety Attitudes Questionnaire (EMS-SAQ) to measure workplace safety culture and the EMS Safety Inventory (EMS-SI), a tool developed to capture self-reported safety outcomes from EMS workers. The EMS-SAQ provides reliable and valid measures of six domains: safety climate, teamwork climate, perceptions of management, perceptions of working conditions, stress recognition, and job satisfaction. A panel of medical directors, paramedics, and occupational epidemiologists developed the EMS-SI to measure self-reported injury, medical errors and adverse events, and safety-compromising behaviors. We used hierarchical linear models to evaluate the association between EMS-SAQ scores and EMS-SI safety outcome measures. Results Sixteen percent of all respondents reported experiencing an injury in the past 3 months, four of every 10 respondents reported an error or adverse event (AE), and 90% reported safety-compromising behaviors. Respondents reporting injury scored lower on 5 of the 6 domains of safety culture. Respondents reporting an error or AE scored lower for 4 of the 6 domains, while respondents reporting safety-compromising behavior had lower safety culture scores for 5 of 6 domains. Conclusions Individual EMS worker perceptions of workplace safety culture are associated with composite measures of patient and provider safety outcomes. This study is preliminary evidence of the association between safety culture and patient or provider safety outcomes.

Weaver, Matthew D.; Wang, Henry E.; Fairbanks, Rollin J.; Patterson, Daniel

2012-01-01

145

Crosshole EM in steel-cased boreholes  

SciTech Connect

The application of crosshole EM methods through steel well-casing was investigated in theoretical, laboratory and field studies. A numerical code was developed that calculates the attenuation and phase delay of an EM dipole signal propagated through a steel well casing lodged in a homogeneous medium. The code was validated with a scale model and used for sensitivity studies of casing and formation properties. Finally, field measurements were made in an oil field undergoing waterflooding. Our most important findings are that (1) crosshole surveys are feasible using a well pair with one metallic and one non-metallic casing. (2) The casing effect seems be localized within the pipe section that includes the sensor. (3) The effects of the casing can be corrected using simple means and (4) crosshole field data that are sensitive to both formation and casing were acquired in a working environment.

Wilt, M.; Lee, K.H.; Becker, A.; Spies, B.; Wang, B.

1996-07-01

146

Simplex EMS users knock company's service support  

Microsoft Academic Search

Simplex Tape Recorder Co. is not responding fast enough to please some of its energy management system (EMS) users who need service or new parts. The users complain that Simplex load-shedding, time-of-day control, and duty-cycling functions do not compare with the quality of its security and fire functions. Company spokesmen claim that service and parts are available on a 24-hour

Cohn

1982-01-01

147

Telescópio de patrulhamento solar em 12 GHz  

NASA Astrophysics Data System (ADS)

O telescópio de patrulhamento solar é um instrumento dedicado à observação de explosões solares com início de suas operações em janeiro de 2002, trabalhando próximo ao pico de emissão do espectro girossincrotrônico (12 GHz). Trata-se de um arranjo de três antenas concebido para a detecção de explosões e determinação em tempo real da localização da região emissora. Porém, desde sua implementação em uma montagem equatorial movimentada por um sistema de rotação constante (15 graus/hora) o rastreio apresentou pequenas variações de velocidade e folgas nas caixas de engrenagens. Assim, tornou-se necessária a construção de um sistema de correção automática do apontamento que era de fundamental importância para os objetivos do projeto. No segundo semestre de 2002 empreendemos uma série de tarefas com o objetivo de automatizar completamente o rastreio, a calibração, a aquisição de dados, controle de ganhos, offsets e transferência dos dados pela internet através de um projeto custeado pela FAPESP. O rastreio automático é realizado através de um inversor que controla a freqüência da rede de alimentação do motor de rastreio podendo fazer micro-correções na direção leste-oeste conforme os radiômetros desta direção detectem uma variação relativa do sinal. Foi adicionado também um motor na direção da declinação para correção automática da variação da direção norte-sul. Após a implementação deste sistema a precisão do rastreio melhorou para um desvio máximo de 30 segundos de arco, o que está muito bom para este projeto. O Telescópio se encontra em funcionamento automático desde março de 2003 e já conta com várias explosões observadas após a conclusão desta fase de automação. Estamos apresentando as explosões mais intensas do período e com as suas respectivas posições no disco solar.

Utsumi, F.; Costa, J. E. R.

2003-08-01

148

TandEM: Titan and Enceladus mission  

Microsoft Academic Search

TandEM was proposed as an L-class (large) mission in response to ESA’s Cosmic Vision 2015–2025 Call, and accepted for further\\u000a studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds\\u000a tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini–Huygens\\u000a mission. These

A. Coustenis; S. K. Atreya; T. Balint; R. H. Brown; M. K. Dougherty; F. Ferri; M. Fulchignoni; D. Gautier; R. A. Gowen; C. A. Griffith; L. I. Gurvits; R. Jaumann; Y. Langevin; M. R. Leese; J. I. Lunine; C. P. McKay; X. Moussas; I. Müller-Wodarg; F. Neubauer; T. C. Owen; F. Raulin; E. C. Sittler; F. Sohl; C. Sotin; G. Tobie; T. Tokano; E. P. Turtle; J.-E. Wahlund; J. H. Waite; K. H. Baines; J. Blamont; A. J. Coates; I. Dandouras; T. Krimigis; E. Lellouch; R. D. Lorenz; A. Morse; C. C. Porco; M. Hirtzig; J. Saur; T. Spilker; J. C. Zarnecki; E. Choi; N. Achilleos; R. Amils; P. Annan; D. H. Atkinson; Y. Bénilan; C. Bertucci; B. Bézard; G. L. Bjoraker; M. Blanc; L. Boireau; J. Bouman; M. T. Capria; E. Chassefière; P. Coll; M. Combes; J. F. Cooper; A. Coradini; F. Crary; T. Cravens; I. A. Daglis; E. de Angelis; C. de Bergh; I. de Pater; C. Dunford; G. Durry; O. Dutuit; D. Fairbrother; F. M. Flasar; A. D. Fortes; R. Frampton; M. Fujimoto; M. Galand; O. Grasset; M. Grott; T. Haltigin; A. Herique; F. Hersant; H. Hussmann; W. Ip; R. Johnson; E. Kallio; S. Kempf; M. Knapmeyer; W. Kofman; R. Koop; T. Kostiuk; N. Krupp; M. Küppers; H. Lammer; L.-M. Lara; P. Lavvas; S. Le Mouélic; S. Lebonnois; S. Ledvina; J. Li; T. A. Livengood; R. M. Lopes; J.-J. Lopez-Moreno; D. Luz; P. R. Mahaffy; U. Mall; J. Martinez-Frias; B. Marty; T. McCord; C. Menor Salvan; A. Milillo; D. G. Mitchell; R. Modolo; O. Mousis; M. Nakamura; C. D. Neish; C. A. Nixon; D. Nna Mvondo; G. Orton; M. Paetzold; J. Pitman; S. Pogrebenko; W. Pollard; O. Prieto-Ballesteros; P. Rannou; K. Reh; L. Richter; F. T. Robb; R. Rodrigo; S. Rodriguez; P. Romani; M. Ruiz Bermejo; E. T. Sarris; P. Schenk; B. Schmitt; N. Schmitz; D. Schulze-Makuch; K. Schwingenschuh; A. Selig; B. Sicardy; L. Soderblom; L. J. Spilker; D. Stam; A. Steele; K. Stephan; D. F. Strobel; K. Szego; C. Szopa; R. Thissen; M. G. Tomasko; D. Toublanc; H. Vali; I. Vardavas; V. Vuitton; R. A. West; R. Yelle; E. F. Young

2009-01-01

149

TandEM: Titan and Enceladus mission  

USGS Publications Warehouse

TandEM was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfi??re) and possibly several landing probes to be delivered through the atmosphere. ?? Springer Science + Business Media B.V. 2008.

Coustenis, A.; Atreya, S. K.; Balint, T.; Brown, R. H.; Dougherty, M. K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R. A.; Griffith, C. A.; Gurvits, L. I.; Jaumann, R.; Langevin, Y.; Leese, M. R.; Lunine, J. I.; McKay, C. P.; Moussas, X.; Muller-Wodarg, I.; Neubauer, F.; Owen, T. C.; Raulin, F.; Sittler, E. C.; Sohl, F.; Sotin, C.; Tobie, G.; Tokano, T.; Turtle, E. P.; Wahlund, J. -E.; Waite, J. H.; Baines, K. H.; Blamont, J.; Coates, A. J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R. D.; Morse, A.; Porco, C. C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J. C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D. H.; Benilan, Y.; Bertucci, C.; Bezard, B.; Bjoraker, G. L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M. T.; Chassefiere, E.; Coll, P.; Combes, M.; Cooper, J. F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I. A.; de Angelis, E.; de Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F. M.; Fortes, A. D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Kuppers, M.; Lammer, H.; Lara, L. -M.; Lavvas, P.; Le, Mouelic, S.; Lebonnois, S.; Ledvina, S.; Li, J.; Livengood, T. A.; Lopes, R. M.; Lopez-Moreno, J. -J.; Luz, D.; Mahaffy, P. R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Salvan, C. M.; Milillo, A.; Mitchell, D. G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, C. D.; Nixon, C. A.; Mvondo, D. N.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F. T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Bermejo, M. R.; Sarris, E. T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L. J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D. F.; Szego, K.; Szopa,

2009-01-01

150

Em18 and Em16, new serologic marker epitopes for alveolar echinococcosis in western blot analysis, are the only two epitopes recognized by commercially available weak positive (cut off) sera for Em2plus-ELISA.  

PubMed

The assay system for antibody responses against Em2, the most specific antigen for serodiagnosis of alveolar echinococcosis (AE), has been established by enzyme-linked immunosorbent assay (ELISA) but not by Western blot assay, since Em2 antigen is not protein but carbohydrate in nature. Recently we reported that previously undescribed protein epitopes, designated Em18 and Em16 due to their molecular weights, were good serologic markers for AE by Western blot analysis. It has been shown that Em18 and Em16 are the only two epitopes recognized by commercially available weak positive (cut off) sera for the Em2plus-ELISA. PMID:8583132

Ito, A; Osawa, Y; Nakao, M; Horii, T; Okamoto, M; Itoh, M; Yamashita, T

1995-12-01

151

Modelling of patient EMS exposure: translating pharmacokinetics of EMS in vitro and in animals into patients.  

PubMed

In order to support the toxicological risk assessment for the ethyl methanesulfonate (EMS) exposure of patients ingesting contaminated Viracept tablets (Müller and Singer, 2009), there was a need to correlate the effects observed in in vivo genotoxicity studies with mice to EMS exposure and to estimate human exposure to EMS at the level of contamination of Viracept tablets. The species differences in volume of distribution of EMS, a key factor for determination of its C(max), were small in the species investigated (mouse, rat, monkey), the species differences in clearance, the key factor involved in AUC assessment, were large (Lavé et al., 2009). Because of this uncertainty in extrapolation of clearance across species we used a conservative approach for human exposure predictions in terms of AUC where clearance was assumed to solely reflect the chemical stability of EMS neglecting additional clearance pathways such as metabolism and exhalation. This approach was compared to the estimates obtained from allometric scaling based on rat clearance, the species leading to the lowest clearance predicted in man. We found that both approaches led to nearly identical predictions of the human AUC. Thus, we predict a human AUC of 13 microM h for patients ingesting the most contaminated Viracept tablets, corresponding to a maximal daily intake of 0.055 mg/kg of EMS. The C(max) of EMS in these patients is predicted to be 0.85 microM. In order to provide a basis for toxicological risk assessment, these maximal human AUC and C(max) values are to be compared to the AUC and C(max) values in mice at the EMS dose of 25mg/kg which was found to be the threshold dose for induction of mutagenic effects, i.e. the dose at which no mutagenic effects were observed (Gocke et al., 2009-a). We calculate AUC and C(max) in mice at the threshold dose to be 350 microM h and 315 microM, respectively. Thus we conclude that a large safety factor can be deduced, whatever the basis of comparison, as is discussed in detail by Müller et al. (2009). PMID:19695316

Lavé, Thierry; Paehler, Axel; Grimm, Hans Peter; Gocke, Elmar; Müller, Lutz

2009-11-12

152

Blind subspace-based channel estimation using the EM algorithm  

Microsoft Academic Search

We propose an application of the Expectation-Maximization (EM) algorithm to the problem of blind estimation of single-input multiple-output (SIMO), finite-impulse-response (FIR) channels. We first assume Gaussian input to formulate an EM-based estimation of the signal subspace of the output covariance matrix. This Gaussian assumption allows us to utilize knowledge from EM-based probabilistic principle component analysis (P-PCA). Next, we show that

Koji Harada; Hideaki Sakai

2009-01-01

153

A New Semi-Supervised EM Algorithm for Image Retrieval  

Microsoft Academic Search

One of the main tasks in content-based image retrieval (CBIR) is to reduce the gap between low-level visual features and high-level human concepts. This paper presents a new semi-supervised EM algorithm (NSS-EM), where the image distribution in feature space is modeled as a mixture of Gaussian densities. Due to the statistical mechanism of accumulating and process-ing meta knowledge, the NSS-EM

Anlei Dong; Bir Bhanu

2003-01-01

154

Immunoblot evaluation of the species-specificity of Em18 and Em16 antigens for serodiagnosis of human alveolar echinococcosis  

Microsoft Academic Search

An immunoblot study to confirm the species-specificity of the diagnostic antigens Em18 and Em16 of Echinococcus multilocularis protoscolex extract showed that both antigens cross-reacted with sera from cystic echinococcosis (CE) patients. The 18 kDa component was detectable by 75% of the sera from active alveolar echinococcosis (AE) patients, while only 31% detected Em16. Western blot analysis also showed that AE

Niroshini Nirmalan; Philip S. Craig

1997-01-01

155

Best Practices for Protecting EMS Responders during Treatment and Transport of Victims of Hazardous Substance Releases.  

National Technical Information Service (NTIS)

OSHA has developed a guide for emergency medical service (EMS) responders who provide medical assistance release. This guide is intended for employers of EMS responders and discusses the measures these employers need to take to protect their EMS responder...

2009-01-01

156

Doenças cerebrovasculares em pacientes entre 15 e 40 anos: achados neuropatológicos em 47 casos  

Microsoft Academic Search

RESUMO - As doenças cerebrovasculares em pacientes entre 15 e 40 anos são pouco estudadas na literatura latino americana, principalmente no que tange aos achados neuropatológicos. Analisamos 47 encéfalos provenientes de necrópsias completas realizadas no período de 1987 a 1997 selecionados com base na faixa etária e alteração neuropatológica básica envolvendo fenômenos vasculares. Destes 47 casos analisados, 26 eram (55,3%)

Everton M. Maggio; Mário R. Montemór-Netto; Emerson L. Gasparetto; Jorge S. Reis-Filho; Fábio A. Tironi; Luiz F. Bleggi Torres

2001-01-01

157

Via de parto em gestações sucessivas em adolescentes: estudo de 714 casos  

Microsoft Academic Search

Objetivo: analisar a associação da via de partos consecutivos de 714 gestantes adolescentes, que pariram na Maternidade do Hospital das Clínicas da Universidade Federal de Pernambuco, no período de janeiro a dezembro de 2001. Pacientes e Métodos: em estudo prospectivo, analítico, transversal, tipo incidência, foi analisada a sucessão das vias de parto da primeira até a quarta gestação de 714

Vamberto Oliveira de Azevedo Maia; Alessandra Costa de Azevedo Maia; Fábio Lima Queiroga; Vamberto Oliveira de Azevedo Maia Filho; Aline Brandão de Araújo; Luís André Marinho Lippo; Rivaldo Mendes de Albuquerque

2004-01-01

158

Communication - An Effective Tool for Implementing ISO 14001/EMS  

SciTech Connect

The Idaho National Engineering and Environmental Laboratory (INEEL) received ISO 14001/EMS certification in June 2002. Communication played an effective role in implementing ISO 14001/EMS at the INEEL. This paper describes communication strategies used during the implementation and certification processes. The INEEL achieved Integrated Safety Management System (ISMS) and Voluntary Protection Program (VPP) Star status in 2001. ISMS implemented a formal process to plan and execute work. VPP facilitated worker involvement by establishing geographic units at various facilities with employee points of contact and management champions. The INEEL Environmental Management System (EMS) was developed to integrate the environmental functional area into its ISMS and VPP. Since the core functions of ISMS, VPP, and EMS are interchangeable, they were easy to integrate. Communication is essential to successfully implement an EMS. (According to ISO 14001 requirements, communication interacts with 12 other elements of the requirements.) We developed communication strategies that integrated ISMS, VPP, and EMS. For example, the ISMS, VPP, and EMS Web sites communicated messages to the work force, such as “VPP emphasizes the people side of doing business, ISMS emphasizes the system side of doing business, and EMS emphasizes the systems to protect the environment; but they all define work, identify and analyze hazards, and mitigate the hazards.” As a result of this integration, the work force supported and implemented the EMS. In addition, the INEEL established a cross-functional communication team to assist with implementing the EMS. The team included members from the Training and Communication organizations, VPP office, Pollution Prevention, Employee and Media Relations, a union representative, facility environmental support, and EMS staff. This crossfunctional team used various communication strategies to promote our EMS to all organization levels and successfully implemented EMS activities through VPP geographic units. In summary, the ISMS and VPP process at the INEEL provided the basic framework of management support and worker involvement to implement our EMS. A cross-functional communication team was established to facilitate the implementation with great success. Communication has been an effective tool for implementing an ISO 14001/EMS at the INEEL.

Rachel Damewood; Bowen Huntsman

2004-04-01

159

EM threat analysis for wireless systems.  

SciTech Connect

Modern digital radio systems are complex and must be carefully designed, especially when expected to operate in harsh propagation environments. The ability to accurately predict the effects of propagation on wireless radio performance could lead to more efficient radio designs as well as the ability to perform vulnerability analyses before and after system deployment. In this report, the authors--experts in electromagnetic (EM) modeling and wireless communication theory--describe the construction of a simulation environment that is capable of quantifying the effects of wireless propagation on the performance of digital communication.

Burkholder, R. J. (Ohio State University Electroscience Laboratory); Mariano, Robert J.; Schniter, P. (Ohio State University Electroscience Laboratory); Gupta, I. J. (Ohio State University Electroscience Laboratory)

2006-06-01

160

10 CFR Appendixes E-M to Part 52 - [Reserved  

10 Energy 2 2014-01-01 2014-01-01 false [Reserved] E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52...

2014-01-01

161

Stochastic EM-based TFBS motif discovery with MITSU  

PubMed Central

Motivation: The Expectation–Maximization (EM) algorithm has been successfully applied to the problem of transcription factor binding site (TFBS) motif discovery and underlies the most widely used motif discovery algorithms. In the wider field of probabilistic modelling, the stochastic EM (sEM) algorithm has been used to overcome some of the limitations of the EM algorithm; however, the application of sEM to motif discovery has not been fully explored. Results: We present MITSU (Motif discovery by ITerative Sampling and Updating), a novel algorithm for motif discovery, which combines sEM with an improved approximation to the likelihood function, which is unconstrained with regard to the distribution of motif occurrences within the input dataset. The algorithm is evaluated quantitatively on realistic synthetic data and several collections of characterized prokaryotic TFBS motifs and shown to outperform EM and an alternative sEM-based algorithm, particularly in terms of site-level positive predictive value. Availability and implementation: Java executable available for download at http://www.sourceforge.net/p/mitsu-motif/, supported on Linux/OS X. Contact: a.m.kilpatrick@sms.ed.ac.uk

Kilpatrick, Alastair M.; Ward, Bruce; Aitken, Stuart

2014-01-01

162

Tactical EMS: An emerging opportunity in graduate medical education  

Microsoft Academic Search

Objectives: Modification of traditional emergency medical services (EMS) principles and procedures for use in the tactical law enforcement setting is emerging as a subspecialty of emergency medicine. Few opportunities exist to train physicians in the principles of tactical medicine, and no studies demonstrate the effectiveness of physician-level training in tactical EMS. Methods: A standardized eight-hour CONTOMS (Counter Terrorism Operations Medical

William P. Bozeman; Edward R. Eastman

2002-01-01

163

Convergence Properties of the EM Algorithm for Gaussian Mixtures.  

National Technical Information Service (NTIS)

Expectation-Maximization(EM) algorithm and gradient-based approaches for maximum likelihood learning of finite Gaussian mixtures. We show that the EM step in parameter space is obtained from the gradient via a projection matrix $P$, and we provide an expl...

M. Jordan L. Xu

1995-01-01

164

Quality Improvement in EMS: A Unique and Challenging Necessity.  

PubMed

Quality Improvement (QI) is required in all aspects of the healthcare field. Emergency Medical Services (EMS) poses unique QI challenges. This article explores some of these challenges and provides some points to consider when performing QI in EMS services. [Full text available at http://rimed.org/rimedicaljournal-2014-08.asp, free with no login]. PMID:25083952

Tsai, Devin; Choi, Bryan; Sullivan, Francis; Williams, Kenneth A

2014-01-01

165

PROTECTIVE LAYERS OF MEMS FOR ELECTRO MAGNETIC (EM) DEVICES  

Microsoft Academic Search

Recent year's electromagnetic (EM) devices are used more frequently in a network by military as well as civilian applications for communications, navigation, sensing and data storage. This trend leads to an increasing use of EM devices which may result in a complex operation in the future. It creates electronic warfare and disturbances. This process can be prevented by imposing a

Himanshu Shekhar; J. Sam; Jeba Kumar; Joselin Retna Kumar

2009-01-01

166

THE DOE EM SCIENCE AND TECHNOLOGY PROGRAM VISION - AN OVERVIEW  

Microsoft Academic Search

The Department of Energy (DOE) Office of Environmental Management (EM) is in an era of shrinking budgets and increasing scrutiny of the budget that is provided. This is occurring at a time when EM has established a new, aggressive approach to environmental restoration and disposition of legacy waste inventory. This approach, as outlined in the guidance for the Accelerating Cleanup:

J. Walker USDOE

167

As implicações do trabalho em cooperativas de trabalhadores rurais  

Microsoft Academic Search

A cooperativa de trabalho é um meio pelo qual os trabalhadores rurais se organizam e gerenciam suas forças com maior poder de barganha no mercado, para alcançar melhores condições de trabalho, particularmente em situações em que se encontram desprovidos total ou parcialmente de direitos trabalhistas. Enquanto trabalhadores autônomos, por meio da assistência social da cooperativa, os associados podem melhor adequar

Geraldo Magela Braga; Leonardo Pinheiro Deboçã; José Mauro Ferraz Andrade; Rosiane Maria Lima Gonçalves

2007-01-01

168

Antibioticoterapia em Crianças com Pneumonia Antibioticoterapia em Crianças com Pneumonia Antibioticoterapia em Crianças com Pneumonia Antibioticoterapia em Crianças com Pneumonia Antibioticoterapia em Crianças com Pneumonia Therapy with Antibiotics in Childhood Pneumonia  

Microsoft Academic Search

Pneumonia é responsável por elevadas taxas de hospitalização e óbito na faixa etária pediátrica, especialmente em crianças menores de cinco anos. Um grande número de microorganismos pode causar pneumonia na infância; no entanto, há nítido predomínio dos agentes bacterianos, principalmente do Streptococcus pneumoniae, entre os casos fatais. A terapia antimicrobiana é, portanto, um importante meio de controle da mortalidade por

Adriana O. Rocha; Delano S. Valois; Jovita S. Araújo; Lívia M. B. Mendes; Lucas C. S. Oliveira; N. Alcântara

2007-01-01

169

The Post-LBV Supernova 2001em  

NASA Astrophysics Data System (ADS)

The supernova (SN) 2001em in UGC 11794 was classified early as Type Ib/c, i.e., as one arising from a hydrogen-stripped star. As part of a radio survey with the Very Large Array of SNe Ib/c at late times (Stockdale et al. 2003, BAAS, 35, 1346), SN 2001em was detected as a highly luminous radio source ˜2 years after explosion. The SN was also subsequently discovered with Chandra to be a very luminous X-ray source. The properties of both the radio and X-ray emission are more characteristic of the Type II-narrow (IIn) SNe, where the SN shock is interacting with dense, massive circumstellar matter, resulting in bright radio synchrotron emission and thermal bremsstrahlung from the interaction region. In fact, SN 2001em has shown to have spectroscopically transformed to a SN IIn. The premise that this might indicate an off-axis gamma-ray burst has been presented (Granot & Ramirez-Ruiz 2004, ApJ, 609, L9) and later, rather convincingly, refuted (e.g., Schinzel et al. 2009, ApJ, 691, 1380). Chugai & Chevalier (2006, ApJ, 641, 1051) have interpreted the spectral transformation and radio/X-ray emission as the SN shock overtaking the detached hydrogen envelope of the progenitor star, which was shed in a superwind episode many years prior to explosion. Chevalier (2007, RMxAC, 30, 41) has further pointed to the required mass-loss rate in the event being equivalent to what would occur in the eruption of a luminous blue variable (LBV). The optical (ground-based and HST) and radio/X-ray data, together with mid-infrared Spitzer observations, tend to support this scenario of a very massive star that experienced a powerful LBV outburst prior to explosion. Such an event may not be unique, with possible parallels in the cases of SNe 2005bf and 2006jc, and may provide valuable new information about massive stellar evolution.

Van Dyk, Schuyler D.; Chornock, R.; Filippenko, A. V.; Foley, R. J.; Lewin, W. H. G.; Li, W.; Panagia, N.; Pooley, D.; Stockdale, C. J.; Weiler, K. W.

2009-12-01

170

Landelijk Meetnet Luchtkwaliteit: Meetresultaten 1993. Deel 2. Regio 4, Zuid-Holland; Regio 5, Noord-Holland (National Air Quality Monitoring Network: Monitoring Results 1993. Part 2. Regions 4 and 5).  

National Technical Information Service (NTIS)

This report presents tabulated monitoring results from the National Air Quality Monitoring Network for the Regions 4 (Zuid Holland) and 5 (Noord Holland) for the calendar year 1993, the summer of 1993, the winter of 1992-1993, and the period 1 April 1992 ...

M. J. van Doesburg E. C. M. Rentinck P. Swaan

1994-01-01

171

Electromagnetic optimization of EMS-MAGLEV systems  

SciTech Connect

In EMS-MAGLEV high-speed transport systems, devices for propulsion, levitation and contactless on-board electric power transfer are combined in a single electromagnetic structure. The strong coupling among the windings affects the performance of each device and requires the utilization of numerical codes. The paper describes an overall optimization procedure, based on a suitable mathematical model of the system, which takes into account several items of the system performance. The parameters of the model are calculated by an automated sequence of FEM analyses of the configuration. Both the linear generator output characteristics and the propulsion force ripple are improved applying the procedure to a reference configuration. The results are compared with the results obtained by a sequence of partial optimizations operating separately on two different subsets of the geometric parameters.

Andriollo, M.; Martinelli, G.; Morini, A.; Tortella, A. [Univ. of Padova (Italy). Dept. of Electrical Engineering] [Univ. of Padova (Italy). Dept. of Electrical Engineering

1998-07-01

172

DOE EM industry programs robotics development  

SciTech Connect

The Office of Science and Technology (OST) manages an aggressive program for RD&D, as well as testing and evaluation for the U.S. Department of Energy`s (DOE) Environmental Management (EM) organization. The goal is to develop new and improved environmental restoration and waste management technologies to clean up the inventory of the DOE weapons complex faster, safer, and cheaper than is possible with currently available technologies. OST has organized technology management activities along focus teams for each major problem area. There are currently five focus areas: decontamination and decommissioning, tanks, subsurface contaminants, mixed waste, and plutonium. In addition, OST is pursuing research and development (R&D) that cuts across these focus areas by having applications in two or more focus areas. Currently, there are three cross-cutting programs: the robotics technology development; characterization, monitoring, and sensor technologies; and efficient separations and processing.

Staubly, R.; Kothari, V. [Dept. of Energy, Morgantown, WV (United States)

1997-12-01

173

Evaluation of Fracture Azimuth by EM Wave and Elastic Wave  

NASA Astrophysics Data System (ADS)

Fracture system plays an important role in the development of underground energy, for example enhanced geothermal system (EGS), oil shale and shale gas, etc. Therefore, it becomes more and more important to detect and evaluate the fracture system. Geophysical prospecting is an useful method to evaluate the characteristics of the subsurface fractures. Currently, micro-seismology, multi-wave seismic exploration, and electromagnetic (EM) survey are reported to be used for the purpose. We are studying a method using both elastic wave and EM wave to detect and evaluate the fracture azimuth in laboratory. First, we build a 3D horizontal transverse isotropy (HTI) model, shown in the figure 1, by dry parallel fractures system, which was constructed by plexiglass plates and papers. Then, we used the ultrasonic system to obtain reflected S-wave data. Depending on the shear wave splitting, we evaluated the fracture azimuth by the algorithm of Pearson correlation coefficient. In addition, we used the full Polarimetric ultra wide band electromagnetic (FP-UWB-EM) wave System, shown in the figure 2, to obtain full polarimetric reflected EM-wave data. Depending on the rotation of the EM wave polarimetry, we evaluated the fracture azimuth by the the ration between maximum amplitude of co-polarimetric EM wave and maximum amplitude of cross-polarimetric EM wave. Finally, we used both EM-wave data and S-wave data to evaluate the fracture azimuth by the method of cross plot and statistical mathematics. To sum up, we found that FP-UWB-EM wave can be used to evaluated the fracture azimuth and is more accurate than ultrasound wave. Also joint evaluation using both data could improve the precision.

Feng, X.; Wang, Q.; Liu, C.; Lu, Q.; Zeng, Z.; Liang, W.; Yu, Y.; Ren, Q.

2013-12-01

174

LAN based data communication in modern energy management systems (EMS)  

SciTech Connect

The use of energy management systems (EMS) demands high reliability, real-time behavior and more and more economical systems. The last demand requires use of inexpensive standard components, whenever possible. The following article discusses realization of EMS, especially system communication, with respect to these constraints. Problems due to conventional use of standardized communication protocols in distributed supervisory systems in general and highly-reliable systems in particular are shown. Multicast communication concepts are presented as solutions, using standardized protocols in a problem specific way. The presented concepts fulfill the necessity of using standard components as well as the specific demands towards EMS.

Dieterle, W.; Kochs, H.D. [Univ. of Duisburg (Germany). Dept. of Computer Science] [Univ. of Duisburg (Germany). Dept. of Computer Science; Dittmar, E. [ABB Netzleittechnik Gmbh, Ladenburg (Germany)] [ABB Netzleittechnik Gmbh, Ladenburg (Germany)

1996-02-01

175

Application of the Chameleon Model to EM Field Momentum  

NASA Astrophysics Data System (ADS)

The Chameleon scalar field model proposed by Khoury and Weltman presents an alternative mechanism for circumventing the constraints from local tests of gravity by mediating a fifth force for cosmological expansion, which could result in experimental signatures detectable through modest improvements of current laboratory set-ups in the vicinity of oscillating matter. In this paper, the oscillation of a dielectric by a crossed EM field is investigated in light of the Chameleon model. An EM excited Chameleon field-force equation is developed and compared to several EM experiments using the Barium Titanate based dielectric material.

Robertson, Glen A.

2008-01-01

176

EMS control chosen instead of refrigeration, HVAC upgrade  

SciTech Connect

A Wisconsin supermarket decided on the basis of costs to install an energy management system (EMS) to improve the store's energy efficiency rather than invest in new refrigerating equipment at this time. When the next remodeling occurs in two years, the store will purchase new equipment using energy savings from the EMS to help defray the costs. The store selected an EMS with distributed processing that can expand to control new equipment. It expects a 22% drop in energy bills and a two-year payback of the $50,000 investment. Details of the system's functions describe some of the 53 control points.

Watson, F.

1984-05-07

177

Catalytic intermolecular hetero-dehydro-Diels-Alder cycloadditions: regio- and diasteroselective synthesis of 5,6-dihydropyridin-2-ones.  

PubMed

A novel catalyzed intermolecular heterodehydro-Diels-Alder reaction between push-pull 1,3-dien-5-ynes and aldimines or silylaldimines is reported. The sequence is promoted both by gold(I) or silver(I) catalysts and leads to the diastereo- and regioselective formation of 5,6-dihydropyridin-2-ones. PMID:21870796

Fernández-García, Jesús Manuel; Fernández-Rodríguez, Manuel Á; Aguilar, Enrique

2011-10-01

178

Regio- and stereocontrolled synthesis of novel steroidal isoxazolines: a new route to the formation of selectively modified steroid side chains.  

PubMed

1,3-Dipolar cycloaddition reaction of acetonitrile oxide to cis- and trans-22-hydroxy-24-alkoxycarbonyl-?(23)-steroids is investigated. An unusual stereochemical course of the cycloaddition, leading to the same set of the isoxazoline adducts for both (Z)- and (E)-disubstituted olefins is revealed. It is shown, the reaction is regioselective and all possible 4',5'-diastereoisomers of resulting isoxazolines can be prepared as major products by cycloaddition to the suitable alkene. The structure of the key compounds is confirmed by X-ray and 2D NMR analysis. PMID:23664846

Zhylitskaya, Halina; Litvinovskaya, Raisa; Baranovsky, Alexander; Eigner, Václav; Kratochvíl, Bohumil; Drašar, Pavel; Khripach, Vladimir

2013-09-01

179

Facile, regio- and diastereoselective synthesis of spiro-pyrrolidine and pyrrolizine derivatives and evaluation of their antiproliferative activities.  

PubMed

A number of novel spiro-pyrrolidines/pyrrolizines derivatives were synthesized through [3+2]-cycloaddition of azomethine ylides with 3,5-bis[(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones 2a-n. Azomethine ylides were generated in situ from the reaction of 1H-indole-2,3-dione (isatin, 3) with N-methylglycine (sarcosine), phenylglycine, or proline. All compounds (50 ?M) were evaluated for their antiproliferative activity against human breast carcinoma (MDA-MB-231), leukemia lymphoblastic (CCRF-CEM), and ovarian carcinoma (SK-OV-3) cells. N-?-Phenyl substituted spiro-pyrrolidine derivatives (5a-n) showed higher antiproliferative activity in MDA-MB-231 than other cancer cell lines. Among spiro-pyrrolizines 6a-n, a number of derivatives including 6a-c and 6i-m showed a comparable activity with doxorubicin in all three cell lines. Among all compounds in three classes, 6a, 6b, and 6m, were found to be the most potent derivatives showing 64%, 87%, and 74% antiproliferative activity in MDA-MB-231, SK-OV-3, and CCRF-CEM cells, respectively. Compound 6b showed an IC50 value of 3.6 mM in CCRF-CEM cells. These data suggest the potential antiproliferative activity of spiro-pyrrolidines/pyrrolizines. PMID:25014532

Almansour, Abdulrahman I; Kumar, Raju Suresh; Beevi, Farzana; Shirazi, Amir Nasrolahi; Osman, Hasnah; Ismail, Rusli; Choon, Tan Soo; Sullivan, Brian; McCaffrey, Kellen; Nahhas, Alaa; Parang, Keykavous; Ali, Mohamed Ashraf

2014-01-01

180

Síndrome Metabólica em Crianças e Adolescentes Síndrome Metabólica em Crianças e Adolescentes Síndrome Metabólica em Crianças e Adolescentes Síndrome Metabólica em Crianças e Adolescentes Síndrome Metabólica em Crianças e Adolescentes Metabolic Syndrome in Children and Adolescents  

Microsoft Academic Search

A Síndrome Metabólica caracteriza-se pela associação de fatores de risco cardiovascular, como obesidade, resistência à insulina, dislipidemia e hipertensão arterial. Sua prevalência geral em crianças e adolescentes norte-americanos é de 3-4%, mas atinge 28,7% naqueles com Índice de Massa Corpórea (IMC) = percentil 95. Observa-se que os fatores predisponentes à síndrome se manifestam desde a vida intra-uterina. Apesar de bem

Cristhine L. Chagas; Diego G. Figuerôa; Ênio H. Rios; Gérson Carvalho; Gustavo Mascarenhas; Ives D. Barbosa; João M. Braghiroli; João N. Tupiná; Mariana F. Miranda; Naiara A. Fraga; Luis F. Adan

2007-01-01

181

E.M. and Hadronic Shower Simulation with FLUKA  

SciTech Connect

A description of the main features of e.m. and hadronic shower simulation models used in the FLUKA code is summarized and some recent applications are discussed. The general status of the FLUKA project is also reported.

Battistoni, G.; Fasso, A.; Ferrari, A.; Ranft, J.; Rubbia, A.; Sala, P.R.; /INFN, Milan /SLAC /CERN /Siegen U. /Zurich, ETH

2005-10-03

182

Truncated and constrained helical analogs of antimicrobial esculentin-2EM.  

PubMed

Esculentin-2EM is a 37-residue, cationic, amphipathic, ?-helical antimicrobial peptide isolated from a Korean frog, Glandirama emeljanovi. Many studies revealed that truncation of this peptide results in substantial decreases in its antimicrobial activity. Lee and his colleagues have recently reported that a 23-residue esculentin-2EM analog containing a tryptophanyl substitution at position 16 showed a significant recovery of the antimicrobial activity of the parent peptide. Here we report a new series of 15-residue esculentin-2EM analogs which are constrained into an ?-helical conformation via an oct-4-enyl cross-link. The resulting 'stapled' derivatives displayed remarkable increases not only in antimicrobial activity but also in helical content and protease resistance compared to Lee's original 23-residue esculentin-2EM analog. The preliminary data obtained in this work strongly supports the potential of our strategy for the development of a new class of peptide antibiotics. PMID:24211019

Pham, Thanh Kim; Kim, Do-Hee; Lee, Bong-Jin; Kim, Young-Woo

2013-12-15

183

Structure of Matter, Forces, EM Waves, Spectroscopy, Doppler Effect  

NSDL National Science Digital Library

These supplemental class notes cover the basic properties of matter, the nature of forces, the electromagnetic spectrum, and how astronomers exploit the properties of the EM spectrum to deduce the physical nature of distant objects.

O'Connell, Robert

2005-06-28

184

Digital C4I Interoperability: The EM Protection Issue.  

National Technical Information Service (NTIS)

In this paper, a unified protection methodology is applied to a digital mobile C4I platform subjected to several human-generated and nature- generated EM environments and effects. The unclassified values for self-induced electromagnetic interference (EMI)...

R. Pfeffer

2000-01-01

185

Superconducting Electromagnetic Suspension (EMS) System for Grumman Maglev Concept.  

National Technical Information Service (NTIS)

The Grumman developed Electromagnetic Suspension (EMS) Maglev system has the following key characteristics: a large operating airgap--40 mm; levitation at all speeds; both high speed and low speed applications; no deleterious effects on SC coils at low ve...

S. S. Kalsi

1994-01-01

186

E.M. and Hadronic Shower Simulation with Fluka.  

National Technical Information Service (NTIS)

A description of the main features of e.m. and hadronic shower simulation models used in the FLUKA code is summarized and some recent applications are discussed. The general status of the FLUKA project is also reported.

G. Battistoni A. Fasso A. Ferrari J. Ranfit A. Rubbia P. R. Sala

2006-01-01

187

NASA EM Followup of LIGO-Virgo Candidate Events  

NASA Technical Reports Server (NTRS)

We present a strategy for a follow-up of LIGO-Virgo candidate events using offline survey data from several NASA high-energy photon instruments aboard RXTE, Swift, and Fermi. Time and sky-location information provided by the GW trigger allows for a targeted search for prompt and afterglow EM signals. In doing so, we expect to be sensitive to signals which are too weak to be publicly reported as astrophysical EM events.

Blackburn, Lindy L.

2011-01-01

188

EM clustering analysis of diabetes patients basic diagnosis index.  

PubMed

Cluster analysis can group similar instances into same group and different instances into different groups. It assigns classes to samples without known the classes in advance. EM clustering algorithm can find number of distributions of generating data and build "mixture models". It identifies groups that are either overlapping or varying sizes and shapes. In this project, by using EM in Weka system, diabetes patient basic diagnosis index data have been analyzed for clustering. PMID:16779444

Wu, Cai; Steinbauer, Jeffrey R; Kuo, Grace M

2005-01-01

189

Preliminary Experiment of EM Technology on Waste Water Treatment  

Microsoft Academic Search

The objective of the experiment was to investigate the effect of EM4 on improving the quality of waste water. The experiment was conducted in two locations of candy factory, viz Nestle and Trebor Companies in Jakarta. The EM4 was treated in laboratory condition to the effluent of waste water of non adjusted pH (pH 4.0) and adjusted pH (pH 7.44)

Gede Ngurah Wididana

190

An LTCC design technique based on FDTD EM simulations  

Microsoft Academic Search

This paper described the Low Technology Co-fired Ceramic (LTCC) design methodology at TMRND based on FDTD EM simulations that are required when designing the RF\\/microwave circuit. In this paper, 3D EM analysis and optimization with Finite Different Time Domain (FDTD) software Empire XcCeltrade from IMST was applied to achieve accurate modeling of the RF\\/microwave circuit using LTCC technology. A multilayer

Zulkifli Ambak; Rosidah Alias; Azmi Ibrahim; Sabrina Mohd Shapee; Samsiah Ahmad; Mohamed Razman Yahya; A. Mat

2007-01-01

191

Elevated ethyl methanesulfonate (EMS) in nelfinavir mesylate (Viracept®, Roche): overview  

Microsoft Academic Search

Roche's protease inhibitor nelfinavir mesylate (Viracept®) produced between March 2007-June 2007 was found to contain elevated levels of ethyl methanesulfonate (EMS), a known mutagen (alkylator) – leading to a global recall of the drug. EMS levels in a daily dose (2,500 mg Viracept\\/day) were predicted not to exceed a dose of ~2.75 mg\\/day (~0.055 mg\\/kg\\/day based on 50 kg patient).

Anton Pozniak; Lutz Müller; Miklos Salgo; Judith K Jones; Peter Larson; David Tweats

2009-01-01

192

Electromagnetic divergence correction for 3D anisotropic EM modeling  

NASA Astrophysics Data System (ADS)

Until now, the application of divergence correction has been focusing on the electromagnetic (EM) isotropic modeling. However, in regions where the earth demonstrates strong electrical anisotropy due to lamina or faults saturated with water, the traditional divergence corrections may not be working for EM modeling. In this paper, based on the divergence-free property of the current density, we propose a divergence correction technique to speed up the EM modeling process for a 3D arbitrarily anisotropic earth. The volume current density weighting method is adopted for the discretization of divergence correction, so it can be applied to non-uniform grid model. By enforcing the constraints associated with the divergence-free property, the quasi-minimal residual (QMR) iterations and the total computational time for the EM modeling are largely reduced. Furthermore, we discuss how to divide the QMR process into sections and the influence of the number of iterations and the normalized residual on the solution process. We take a helicopter-borne EM system over a 3D earth with arbitrarily electrical anisotropy as an example to examine the effectiveness of our anisotropic divergence correction technique on the EM modelings.

Liu, Yun-He; Yin, Chang-Chun

2013-09-01

193

Análise da medição do raio solar em ultravioleta  

NASA Astrophysics Data System (ADS)

A medição acurada do raio solar em qualquer banda do espectro eletromagnético é de relevância na formulação e calibração de modelos da estrutura e atmosfera solar. Esses modelos atribuem emissão do contínuo do Sol calmo em microondas à mesma região da linha Ha do Hell. Apresentamos a medição do raio solar em UV com imagens do EIT (Extreme Ultraviolet Image Telescope) entre 1996 e 2002, no comprimento de onda 30,9 nm (Ha do Hell), que se forma na região de transição/cromosfera solar. A técnica utilizada para o cálculo do raio UV foi baseada na transformada Wavelet B3spline. Fizemos um banco de dados com 1 imagem por dia durante o período citado. Obtivemos como resultado o raio médio da ordem de 975.61" e uma diminuição do mesmo para o período citado variando em média -0,45" /ano. Comparamos estes dados com os valores obtidos pelo ROI (Radio Observatório de Itapetinga) em 22/48 GHz e Nobeyama Radio Heliograph em 17 GHz mostrando que os raios médios são muito próximos o que indica que a região de formação nessas freqüências é a mesma conforme os modelos. Comparamos os resultados também com outros índices de atividade solar.

Saraiva, A. C. V.; Giménez de Castro, C. G.; Costa, J. E. R.; Selhorst, C. L.; Simões, P. J. A.

2003-08-01

194

Evaluation of Use of Recombinant Em18 and Affinity-Purified Em18 for Serological Differentiation of Alveolar Echinococcosis from Cystic Echinococcosis and Other Parasitic Infections  

PubMed Central

To further evaluate recombinant Em18 antigen (rEm18) for immunodiagnosis of human alveolar echinococcosis, 208 serum samples were examined by enzyme-linked immunosorbent assay (ELISA). To comparatively assess the results of rEm18-ELISA, ELISA and immunoblot analysis with two affinity-purified native antigens were also performed with 45 selected serum samples. The results indicate that rEm18 is highly useful for serodiagnosis.

Xiao, Ning; Mamuti, Wulamu; Yamasaki, Hiroshi; Sako, Yasuhito; Nakao, Minoru; Nakaya, Kazuhiro; Gottstein, Bruno; Schantz, Peter M.; Lightowlers, Marshall W.; Craig, Philip S.; Ito, Akira

2003-01-01

195

Evaluation of Use of Recombinant Em18 and Affinity-Purified Em18 for Serological Differentiation of Alveolar Echinococcosis from Cystic Echinococcosis and Other Parasitic Infections  

Microsoft Academic Search

To further evaluate recombinant Em18 antigen (rEm18) for immunodiagnosis of human alveolar echino- coccosis, 208 serum samples were examined by enzyme-linked immunosorbent assay (ELISA). To compara- tively assess the results of rEm18-ELISA, ELISA and immunoblot analysis with two affinity-purified native antigens were also performed with 45 selected serum samples. The results indicate that rEm18 is highly useful for serodiagnosis.

Ning Xiao; Wulamu Mamuti; Hiroshi Yamasaki; Yasuhito Sako; Minoru Nakao; Kazuhiro Nakaya; Bruno Gottstein; Peter M. Schantz; Marshall W. Lightowlers; Philip S. Craig; Akira Ito

2003-01-01

196

Immunoblot evaluation of the species-specificity of Em18 and Em16 antigens for serodiagnosis of human alveolar echinococcosis.  

PubMed

An immunoblot study to confirm the species-specificity of the diagnostic antigens Em18 and Em16 of Echinococcus multilocularis protoscolex extract showed that both antigens cross-reacted with sera from cystic echinococcosis (CE) patients. The 18 kDa component was detectable by 75% of the sera from active alveolar echinococcosis (AE) patients, while only 31% detected Em16. Western blot analysis also showed that AE sera recognized a band in the 18 kDa region of E. granulosus protoscolex extract, which was different from the 16/17 kDa subunit of antigen B. The results suggested that Em18 antigen is present in E. granulosus as well as E. multilocularis, and that some CE patients may have serum antibody against this antigen. PMID:9373662

Nirmalan, N; Craig, P S

1997-01-01

197

A History and Informal Assessment of the <em>Slacker Astronomyem> Podcast  

NASA Astrophysics Data System (ADS)

Slacker Astronomyem> is a weekly podcast that covers a recent astronomical news event or discovery. The show has a unique style consisting of irreverent, over-the-top humor combined with a healthy dose of hard science. According to our demographic analysis, the combination of this style and the unique podcasting distribution mechanism allows the show to reach audiences younger and busier than those reached via traditional channels. We report on the successes and challenges of the first year of the show, and provide an informal assessment of its role as a source for astronomical news and concepts for its approximately 15,500 weekly listeners.

Price, Aaron; Gay, Pamela; Searle, Travis; Brissenden, Gina

198

EM Task 9 - Centrifugal Membrane Filtration  

SciTech Connect

This project is designed to establish the utility of a novel centrifugal membrane filtration technology for the remediation of liquid mixed waste streams at US Department of Energy (DOE) facilities in support of the DOE Environmental Management (EM) program. The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., a small business and owner of the novel centrifugal membrane filtration technology, to establish the applicability of the technology to DOE site remediation and the commercial viability of the technology for liquid mixed waste stream remediation. The technology is a uniquely configured process that makes use of ultrafiltration and centrifugal force to separate suspended and dissolved solids from liquid waste streams, producing a filtered water stream and a low-volume contaminated concentrate stream. This technology has the potential for effective and efficient waste volume minimization, the treatment of liquid tank wastes, the remediation of contaminated groundwater plumes, and the treatment of secondary liquid waste streams from other remediation processes, as well as the liquid waste stream generated during decontamination and decommissioning activities.

Stevens, B.G.; Stepan, D.J.; Hetland, M.D.

1998-11-01

199

DOE EM industry programs robotics development  

SciTech Connect

The Office of Science and Technology (OST) manages an aggressive program for RD and D, as well as testing and evaluation for the Department of Energy`s (DOE`s) Environmental Management (EM) organization. The goal is to develop new and improved environmental restoration and waste management technologies to clean up the inventory of the DOE weapons complex faster, safer, and cheaper than is possible with currently available technologies. Robotic systems reduce worker exposure to the absolute minimum, while providing proven, cost-effective, and, for some applications, the only acceptable technique for addressing challenging problems. Development of robotic systems for remote operations occurs in three main categories: tank waste characterization and retrieval; decontamination and dismantlement; and characterization, mapping, and inspection systems. In addition, the Federal Energy Technology Center (FETC) has some other projects which fall under the heading of supporting R and D. The central objective of all FETC robotic projects is to make robotic systems more attractive by reducing costs and health risks associated with the deployment of robotic technologies in the cleanup of the nuclear weapons complex. This will be accomplished through development of robots that are cheaper, faster, safer, and more reliable, as well as more straightforward to modify/adapt and more intuitive to operate with autonomous capabilities and intelligent controls that prevent accidents and optimize task execution.

Staubly, R.; Kothari, V.

1998-12-31

200

Emergency medical service (EMS): A unique flight environment  

NASA Technical Reports Server (NTRS)

The EMS flight environment is unique in today's aviation. The pilots must respond quickly to emergency events and often fly to landing zones where they have never been before . The time from initially receiving a call to being airborne can be as little as two to three minutes. Often the EMS pilot is the only aviation professional on site, they have no operations people or other pilots to aid them in making decisons. Further, since they are often flying to accident scenes, not airports, there is often complete weather and condition information. Therefore, the initial decision that the pilot must make, accepting or declining a flight, can become very difficult. The accident rate of EMS helicopters has been relatively high over the past years. NASA-Ames research center has taken several steps in an attempt to aid EMS pilots in their decision making and situational awareness. A preflight risk assessment system (SAFE) was developed to aid pilots in their decision making, and was tested at an EMS service. The resutls of the study were promising and a second version incorporating the lessons learned is under development. A second line of research was the development of a low cost electronic chart display (ECD). This is a digital map display to help pilots maintain geographical orientation. Another thrust was undertaken in conjunction with the Aviation Safety Reporting System (ASRS). This involved publicizing the ASRS to EMS pilots and personnel, and calling each of the reporters back to gather additional information. This paper will discuss these efforts and how they may positively impact the safety of EMS operations.

Shively, R. Jay

1993-01-01

201

Degradation of Benzodiazepines after 120 Days of EMS Deployment.  

PubMed

Abstract Introduction. EMS treatment of status epilepticus improves outcomes, but the benzodiazepine best suited for EMS use is unclear, given potential high environmental temperature exposures. Objective. To describe the degradation of diazepam, lorazepam, and midazolam as a function of temperature exposure and time over 120 days of storage on active EMS units. Methods. Study boxes containing vials of diazepam, lorazepam, and midazolam were distributed to 4 active EMS units in each of 2 EMS systems in the southwestern United States during May-August 2011. The boxes logged temperature every minute and were stored in EMS units per local agency policy. Two vials of each drug were removed from each box at 30-day intervals and underwent high-performance liquid chromatography to determine drug concentration. Concentration was analyzed as mean (and 95%CI) percent of initial labeled concentration as a function of time and mean kinetic temperature (MKT). Results. 192 samples were collected (2 samples of each drug from each of 4 units per city at 4 time-points). After 120 days, the mean relative concentration (95%CI) of diazepam was 97.0% (95.7-98.2%) and of midazolam was 99.0% (97.7-100.2%). Lorazepam experienced modest degradation by 60 days (95.6% [91.6-99.5%]) and substantial degradation at 90 days (90.3% [85.2-95.4%]) and 120 days (86.5% [80.7-92.3%]). Mean MKT was 31.6°C (95%CI 27.1-36.1). Increasing MKT was associated with greater degradation of lorazepam, but not midazolam or diazepam. Conclusions. Midazolam and diazepam experienced minimal degradation throughout 120 days of EMS deployment in high-heat environments. Lorazepam experienced significant degradation over 120 days and appeared especially sensitive to higher MKT exposure. PMID:24548058

McMullan, Jason T; Jones, Elizabeth; Barnhart, Bruce; Denninghoff, Kurt; Spaite, Daniel; Zaleski, Erin; Silbergleit, Robert

2014-01-01

202

Astronomia para/com crianças carentes em Limeira  

NASA Astrophysics Data System (ADS)

Em 2001, o Instituto Superior de Ciências Aplicadas (ISCA Faculdades de Limeira) iniciou um projeto pelo qual o Observatório do Morro Azul empreendeu uma parceria com o Centro de Promoção Social Municipal (CEPROSOM), instituição mantida pela Prefeitura Municipal de Limeira para atender crianças e adolescentes carentes. O CEPROSOM contava com dois projetos: Projeto Centro de Convivência Infantil (CCI) e Programa Criança e Adolescente (PCA), que atendiam crianças e adolescentes em Centros Comunitários de diversas áreas da cidade. Esses projetos têm como prioridades estabelecer atividades prazerosas para as crianças no sentido de retirá-las das ruas. Assim sendo, as crianças passaram a ter mais um tipo de atividade - as visitas ao observatório. Este painel descreve as várias fases do projeto, que envolveu: reuniões de planejamento, curso de Astronomia para as orientadoras dos CCIs e PCAs, atividades relacionadas a visitas das crianças ao Observatório, proposta de construção de gnômons e relógios de Sol nos diversos Centros Comunitários de Limeira e divulgação do projeto na imprensa. O painel inclui discussões sobre a aprendizagem de crianças carentes, relatos que mostram a postura das orientadoras sobre a pertinência do ensino de Astronomia, relatos do monitor que fez o atendimento no Observatório e o que o número de crianças atendidas representou para as atividades da instituição desde o início de suas atividades e, em particular, em 2001. Os resultados são baseados na análise de relatos das orientadoras e do monitor do Observatório, registros de visitas e matérias da imprensa local. Conclui com uma avaliação do que tal projeto representou para as Instituições participantes. Para o Observatório, em particular, foi feita uma análise com relação às outras modalidades de atendimentos que envolvem alunos de escolas e público em geral. Também é abordada a questão do compromisso social do Observatório na educação do público em questão.

Bretones, P. S.; Oliveira, V. C.

2003-08-01

203

Thermal Insulation Performance Test with an EM Shielding MLI  

NASA Astrophysics Data System (ADS)

We have conducted a thermal insulation performance test with an EM (electromagnetic) shielding MLI (multi-layer insulator) and have compared its performances with a conventional MLI thermal insulation. The test was done in a vacuum chamber with a liquid nitrogen temperature shroud. The temperatures at various locations in the MLI were measured to obtain their effective emittances. The EM shielding provides an additional layer of copper fabric as an EM shielding layer, inserted in between conventional MLI layers to enhance EM shielding. The shielding MLI will be used for a lunar radar sounder to protect it from noise emitted by other instruments on board of the spacecraft in the SELENE mission, which is a collaboration mission between ISAS and NASDA. The lunar radar sounder has wide-band and highly sensitive radio wave receivers to detect weak signals in a ``noiseless'' environment on the far side of the moon. The desired signals are extremely weak, especially in the range between 1 MHz and 30 MHz. The EM shielding MLI was also tested and confirmed that its shielding effect was desirable in the specified range.

Iida, T.; Iijima, Y.; Nakazawa, S.

2004-06-01

204

International Space Station (ISS) Emergency Mask (EM) Development  

NASA Technical Reports Server (NTRS)

The Emergency Mask (EM) is considered a secondary response emergency Personal Protective Equipment (PPE) designed to provide respiratory protection to the International Space Station (ISS) crewmembers in response to a post-fire event or ammonia leak. The EM is planned to be delivered to ISS in 2012 to replace the current air purifying respirator (APR) onboard ISS called the Ammonia Respirator (AR). The EM is a one ]size ]fits ]all model designed to fit any size crewmember, unlike the APR on ISS, and uses either two Fire Cartridges (FCs) or two Commercial Off-the-Shelf (COTS) 3M(Trademark). Ammonia Cartridges (ACs) to provide the crew with a minimum of 8 hours of respiratory protection with appropriate cartridge swap ]out. The EM is designed for a single exposure event, for either post ]fire or ammonia, and is a passive device that cannot help crewmembers who cannot breathe on their own. The EM fs primary and only seal is around the wearer fs neck to prevent a crewmember from inhaling contaminants. During the development of the ISS Emergency Mask, several design challenges were faced that focused around manufacturing a leak free mask. The description of those challenges are broadly discussed but focuses on one key design challenge area: bonding EPDM gasket material to Gore(Registered Trademark) fabric hood.

Toon, Katherine P.; Hahn, Jeffrey; Fowler, Michael; Young, Kevin

2011-01-01

205

EMS Stretcher "Misadventures" in a Large, Urban EMS System: A Descriptive Analysis of Contributing Factors and Resultant Injuries  

PubMed Central

Purpose. There is a paucity of data regarding EMS stretcher-operation-related injuries. This study describes and analyzes characteristics associated with undesirable stretcher operations, with or without resultant injury in a large, urban EMS agency. Methods. In the study agency, all stretcher-related “misadventures” are required to be documented, regardless of whether injury results. All stretcher-related reports between July 1, 2009 and June 30, 2010 were queried in retrospective analysis, avoiding Hawthorne effect in stretcher operations. Results. During the year studied, 129,110 patients were transported. 23 stretcher incidents were reported (0.16 per 1,000 transports). No patient injury occurred. Four EMS providers sustained minor injuries. Among contributing aspects, the most common involved operations surrounding the stretcher-ambulance safety latch, 14/23 (60.9%). From a personnel injury prevention perspective, there exists a significant relationship between combative patients and crew injury related to stretcher operation, Fisher's exact test 0.048. Conclusions. In this large, urban EMS system, the incidence of injury related to stretcher operations in the one-year study period is markedly low, with few personnel injuries and no patient injuries incurred. Safety for EMS personnel and patients could be advanced by educational initiatives that highlight specific events and conditions contributing to stretcher-related adverse events.

Goodloe, Jeffrey M.; Crowder, Christopher J.; Arthur, Annette O.; Thomas, Stephen H.

2012-01-01

206

Discos de acresção em sistemas Be-X  

NASA Astrophysics Data System (ADS)

Alguns fenômenos de outbursts em Be-X sugerem a existência, mesmo que temporária, de um disco de acresção quando da passagem do objeto compacto pelo periastro orbital. Neste trabalho avaliamos a possibilidade de formação do disco de acresção em sistemas Be+estrela de neutrons e Be+anã branca, e a influência da excentricidade orbital na ocorrência deste fenômeno. Utilizamos a expressão analítica para o momento angular específico da matéria constituinte de um meio em expansão lenta, como é o caso do disco circunstelar das estrelas Be, proposta por Wang(1981), sob a condição básica de que o raio de circularização deva ser maior do que o raio de Alfvén. Concluímos que existe um limite para o período orbital do sistema acima do qual não é possível a formação do disco de acresção, e que este valor aumenta para sistemas com excentricidade orbital maior.

Lopes de Oliveira, R.; Janot-Pacheco, E.

2003-08-01

207

Influence of PCB and Attached Line of Hardware on Electromagnetic (EM) Information Leakage  

NASA Astrophysics Data System (ADS)

Electromagnetic (EM) radiation from information hardware under normal operating conditions can compromise secret information (EM information leakage), for example, operations or processed data contained in the hardware. Methods for analyzing EM radiation with the intention of extracting secret information have been proposed, and EM side-channel attacks on cryptographic hardware are a major concern. This paper investigates how EM information leakage changes with the configuration of information hardware, focusing on the frequency characteristics of the hardware. We assume that frequency characteristics of the EM radiation correspond to physical aspects of the hardware configuration. To address the issue of information leakage, this paper presents a novel analysis of EM radiation from information hardware by using a model circuit board. Through this model we show that the intensity of EM emission can be related to the layout of the hardware.

Hayashi, Yu-Ichi; Ohmura, Kouhei; Mizuki, Takaaki; Sone, Hideaki

208

Analytical Prediction of EM Scattering by Complex Obstacles Within Electrically Large Open Cavities.  

National Technical Information Service (NTIS)

The object of this paper is to describe an analytical technique for predicting the electromagnetic(EM) scattering by complex obstacles within electrically large open waveguide cavities. This topic is of relevance to EM scattering and EMC type applications...

P. H. Pathak

1991-01-01

209

How to migrate a proprietary EMS into an open system  

SciTech Connect

Energy Management Software (EMS) is a proprietary third party product and hence cannot be easily installed. One driving force behind every user`s effort to migrate is the significant need to get away from proprietary systems, including proprietary protocols. Manufacturing message specification (MMS) is an internationally standardized messaging system for exchanging real-time data and supervisory control information between networked devices and/or computer applications. It is independent of the application function being performed and the developer of the device or the application. This paper describes several utility company`s efforts in migrating to MMS-based EMS systems. 4 figs.

Tweedy, J.; McGinnis, D.; Hird, R.; Carr, D.

1996-02-01

210

Waste fuel, EMS may save plant $1M yearly  

SciTech Connect

A mixture of paper trash and coal ash fueling an Erie, Pa. General Electric plant and a Network 90 microprocessor-based energy-management system (EMS) to optimize boiler efficiency will cost about $3 million and have a three-to-four-year payback. Over half the savings will come from the avoided costs of burning plant-generated trash. The EMS system will monitor fuel requirements in the boiler and compensate for changes in steam demand. It will also monitor plant electrical needs and control the steam diverted for cogeneration. (DCK)

Barber, J.

1982-05-24

211

Noninvasive monitoring of CO2 sequestration sites using airborne EM technology  

Microsoft Academic Search

Usage of conventional airborne EM methods for studies related to CO2 sequestration reservoirs have been restricted up to date due to depth and system noise limitations. Recently a family of new EM systems was developed and launched in Canada, allowing superior depth of investigation to that of the conventional EM systems. Depending on the resistivity of the area such systems

V. Kaminski; W. P. Harbert; J. M. Legault

2009-01-01

212

Airborne EM for geothermal and hydrogeological mapping  

NASA Astrophysics Data System (ADS)

Within the "VIGOR" project, aimed at assessing the geothermal potential of four regions in southern Italy, Airborne EM data have been acquired, modeled and interpreted. The system deployed was SkyTEM, a time-domain helicopter electromagnetic system designed for hydrogeophysical, environmental and mineral investigations. The AEM data provide, after data acquisition, analysis, processing, and modeling, a distribution volume of electrical resistivity, spanning an investigation depth from ground surface of few hundred meters, depending on resistivity condition. Resistivity is an important physical parameter for geothermal investigation, since it proved to be very effective in mapping anomalies due to hydrothermal fluid circulation, which usually has high salt content and produces clayey alteration minerals. Since the project required, among other issues, to define geothermal resources at shallow level, it was decided to perform a test with an airborne electromagnetic geophysical survey, to verify the advantages offered by the system in covering large areas in a short time. The geophysical survey was carried out in Sicily, Italy, in late 2011, over two test sites named "Termini" and "Western Sicily". The two areas were chosen on different basis. "Termini" area is covered by extensive geological surveys, and was going to be investigated also by means of electrical tomography in its northern part. Since geological condition of Sicily, even at shallow depth, is very complex, this area provided a good place for defining the resistivity values of the main geological units outcropping in the region. "Termini" survey has been also an occasion to define relations between resistivity distribution, lithological units and thermal conductivity. The "Western Sicily" area cover the main thermal manifestations of western Sicily, and the research target was to establish whether they are characterized by common hydrogeological or tectonic features that could be mapped by resistivity. SkyTEM data have been acquired in a series of flight lines and were then processed and inverted. In the "Termini" area the flight line spacing had 150 m separation. In the "Western Sicily" area two different line spacing were used: the 1 km spacing was used for the regional mapping, whereas for infill areas, around the main hydrothermal springs, the flight lines had 100 m spacing. The total number of flight line was 4580 km, and the explored surface was in excess of 2000 km2. After acquisition, data were processed to eliminate coupling with infrastructures, and noise. Inversions was then carried out using the quasi 3-D Spatially Constrained Inversion. The obtained resistivity volume has then been the base for a detailed lithological and geothermal interpretation. Lithological and geological maps were used to constrain surface condition and to understand the resistivity ranges of the different lithological units. On the base of resistivity values, lithological units were combined to establish the main litho-resistive units, then modeled at depth, down to achievable investigation depth. This detailed interpretative modeling was also the occasion of recognizing resistivity anomalies within carbonate units, which may possibly represent hydrogeological or hydrothermal bodies. The litho-resitive 3D model is now under investigation to verify how it can represent a viable way to image thermal conductivity variations at depth.

Menghini, A.; Manzella, A.; Viezzoli, A.; Montanari, D.; Maggi, S.

2012-12-01

213

An On-Line EM Algorithm Applied to Kernel PCA  

Microsoft Academic Search

Kernel principal component analysis (Pca) is a recent method for non-linear feature extraction. Applying kernel Pca to a data set with N patterns requires storing and nding the eigenvectors of a N N kernel matrix. This paper describes how an Expectation-Maximization (Em) algorithm for standard Pca can be adapted to kernel Pca without having to store the kernel matrix. Experimental

Perry Moerland

2000-01-01

214

Cost-Effectiveness Analysis of Helicopter EMS for Trauma Patients  

Microsoft Academic Search

Study objective: To evaluate the cost-effectiveness of helicopter EMS for trauma patients. Methods: We applied a cost-effectiveness analysis from the service provider's perspective to cost and effectiveness estimates. The cost estimates comprise direct operating costs and additional survivors' hospital costs. The effectiveness estimates were calculated with the TRISS methodology from literature sources and data from a cohort of patients transported

Peter A Gearhart; Richard Wuerz; A. Russell Localio

1997-01-01

215

Communications technology guidelines for EMS\\/SCADA systems  

Microsoft Academic Search

The purpose of this Guideline Technical Paper is to provide a summary of the different communications technologies available for use or application with EMS\\/SCADA system projects. All of the various communication media are addressed with a brief description along with tables of the advantages and disadvantages of each and recommendations for choosing the most appropriate communication technology. The technologies discussed

Donald J. Marihart

2001-01-01

216

Reservoir characterization and steam flood monitoring with crosshole EM  

SciTech Connect

Crosshole electromagnetic (EM) imaging is applied to reservoir characterization and steam flood monitoring in a central California oil field. Steam was injected into three stacked eastward-dipping, unconsolidated oil sands within the upper 200 m. The steam plume is expected to develop as an ellipse aligned with the regional northwest-southeast strike. EM measurements were made from two fiberglass-cased observation wells straddling the steam injector on a northeast-southwest profile using the LLNL frequency domain crosshole EM system. Field data were collected before the initiation of a steam drive to map the distribution of the oil sands and then 6 and 12 months later to monitor the progress of the steam chest. Resistivity images derived from the EM data before steam injection clearly delineate the distribution and dipping structure on the target oil sands. Difference images, from data collected before and after steam flooding, show resistivity changes that indicate that the steam chest has developed only in the deeper oil sands although steam injection occurred in all three sand layers.

Wilt, M. [Lawrence Livermore National Lab., CA (United States); Torres-Verdin, C. [Univ. of California, Berkeley, CA (United States)

1995-06-01

217

Sobre as bases dos procedimentos investigativos em psicanálise  

Microsoft Academic Search

Resumo O presente trabalho examina as bases da pesquisa psicanalítica. Parte das marcas deixadas nas investigações psicanalíticas pelos procedimentos científicos de disciplinas como a neurologia e a neurofisiologia no século XIX. Em seguida, acompanha o surgimento de um novo objeto, o sujeito do inconsciente, o qual, ainda que requeira operações que mantenham o rigor e a precisão característicos do pensamento

Anna Carolina; Lo Bianco

218

A connection between half-quadratic criteria and EM algorithms  

Microsoft Academic Search

Iteratively Reweighted Least Squares (IRLS) and Residual Steepest descent (RSD) algorithms of robust statistics arise as special cases of half-quadratic schemes . Here, we adopt a statistical framework and we show that both algorithms are instances of the EM algorithm. The augmented dataset respectively involves a scale and a location mixture of Gaussians. The sufficient conditions for the construction cover

Frédéric Champagnat; Jérôme Idier

2004-01-01

219

Germinação de Sementes de Forrageiras em Diferentes Profundidades de Semeadura  

Microsoft Academic Search

3 Aluno de graduação em Agronomia - UNIFENAS Abstract: The experiment was conducted at José do Rosário Vellano University - UNIFENAS, in Alfenas, MG, with the purpose of evaluating the germination of forage seeds at different sowing depths. The experimental design was in randomized blocks with three replicates, four forages plants and four sowing depths being utilized, amounting to 20

Adauton Vilela de Rezende; Hélio Henrique Vilela; Geraldo Benedito de Souza Almeida; Paulo Roberto; Correa Landgraf; Gustavo Augusto Andrade; Paulo de Figueiredo Vieira

220

Debris Avalanche Formation at Kick'em Jenny Submarine Volcano  

Microsoft Academic Search

Kick'em Jenny submarine volcano near Grenada is the most active volcanic center in the Lesser Antilles arc. Multibeam surveys of the volcano by NOAA in 2002 revealed an arcuate fault scarp east of the active cone, suggesting flank collapse. More extensive NOAA surveys in 2003 demonstrated the presence of an associated debris avalanche deposit, judging from their surface morphologic expression

H. Sigurdsson; S. N. Carey; D. Wilson

2005-01-01

221

Transparent EMI Shielding for EM Windows and Domes.  

National Technical Information Service (NTIS)

Shielding from electromagnetic interference (EMI) can be provided for EM windows and domes by application of a thin transparent conductive coating. Indium Tin Oxide (ITO) coatings 0.8 microns thick can be reactively sputtered onto many materials such as g...

W. T. Pawlewicz G. L. Brown R. H. Sobieske D. L. Jones B. L. Woodham

1983-01-01

222

Síndrome da cabeça caída em doença do neurônio motor  

Microsoft Academic Search

RESUMO - A síndrome da cabeça caída é causada por diminuição de força nos músculos extensores do pescoço sendo encontrada em diversas doenças neuro m u s c u l a res, bem como, na esclerose lateral amiotrófica. D e s c revemos o caso de três mulheres com diagnóstico de doença do neurônio motor com quadro clínico de disfagia

Paulo José Lorenzoni; Marcos Christiano Lange; Cláudia S. K. Kay; Luiz G. M. P. de Almeida; Hélio A. G. Teive; Rosana H. Scola; Lineu C. Werneck

2006-01-01

223

ML\\/EM Reconstruction Algorithm for Cosmic Ray Muon Tomography  

Microsoft Academic Search

Highly penetrating cosmic ray muons constantly shower the earth at a rate of about 1 muon per cm2 per minute. We have developed a technique which exploits the multiple Coulomb scattering of these particles to perform non-destructive inspection without the use of artificial radiation. In this paper we present a Maximum Likelihood \\/ Expectation Maximization (ML\\/EM) tomographic reconstruction algorithm designed

Larry Schultz; Gary Blanpied; Konstantin Borozdin; Andrew Fraser; Alexei Klimenko; Nicholas Hengartner; Chris Morris; Christopher Orum; Michael Sossong

2006-01-01

224

A Generalized Partial Credit Model: Application of an EM Algorithm  

Microsoft Academic Search

The partial credit model (PCM) with a varying slope parameter is developed and called the generalized partial credit model (GPCM). The item step parameter of this model is decomposed to a location and a threshold parameter, following Andrich's (1978) rating scale formulation. The EM algorithm for estimating the model parameters is derived. The performance of this generalized model is compared

Eiji Muraki

1992-01-01

225

Modified Helical Method for Determining e\\/m  

Microsoft Academic Search

In the helical method a cathode-ray tube is inserted in a solenoid and e\\/m determined from the condition for focusing deflected electrons to a spot on the screen. This has been modified by substituting alternating current in the solenoid and simultaneously supplying a voltage to the deflection plates proportional to the solenoid current. As a result, all electrons move in

Bernard L. Miller

1959-01-01

226

Texas Hold 'em Online Poker: A Further Examination  

ERIC Educational Resources Information Center

Playing Texas Hold 'em Online Poker (THOP) is on the rise. However, there is relatively little research examining factors that contribute to problem gambling in poker players. The aim of this study was to extend the research findings of Hopley and Nicki (2010). The negative mood states of depression, anxiety and stress were found to be linked to…

Hopley, Anthony A. B.; Dempsey, Kevin; Nicki, Richard

2012-01-01

227

Alterações hepáticas em roedores com cisticercos de Taenia taeniformis  

Microsoft Academic Search

RESUMO A Taenia taeniformis é um parasito gastrointestinal, pertencente à classe Cestoda, ordem Cyclophilidea e família Taenidae. Este parasito, infecta roedores e felinos principalmente, embora em circunstância s anormais possa parasitar seres humanos. O objetivo deste trabalho foi relatar alterações nas enzimas hepáticas decorrentes de um surto por cisticercos de Taenia taeniformis no fígado de roedores. Ratos (Rattus norvergicus) e

Aleksandro S. SILVA; Patrícia WOLKMER; Carolina K. TRAESEL

228

Factors associated with the safety of EMS helicopters.  

PubMed

The accident rate for emergency medical service (EMS) helicopters is thought to be approximately twice the rate for other commercial (Part 135) helicopters. This observation has led to numerous news reports and to the publication of conclusions of a National Transportation Safety Board investigation. The data for these reports come from investigations of EMS helicopter accidents and incidents. The authors surveyed all listed civilian EMS helicopter programs to examine both helicopter ambulance mishaps and the number of safely completed missions. Epidemiological methods were then used to compare the safety records of different groups of EMS helicopters. The single most important factor identified was the number of flights made by the program during the study period: busy programs had an eightfold lower accident rate (P less than .0005) and a three-fold lower total mishap (accidents + incidents) rate (P less than .0005) than less active programs. Programs with the ability to fly under instrument flight rules (IFR) at the pilots discretion had no mishaps (P = .044) during the study period. Multivariate analysis shows this IFR capability to be marginally significant as an independent factor (P = .099). PMID:1994933

Low, R B; Dunne, M J; Blumen, I J; Tagney, G

1991-03-01

229

DESENVOLVIMENTO SUSTENTÁVEL E SOJICULTURA EM RORAIMA: TRAJETÓRIAS ANTAGÔNICAS OU CONCILIÁVEIS?  

Microsoft Academic Search

Quando há o entendimento de que crescimento e desenvolvimento são sinônimos, tende-se a prezar uma dimensão do desenvolvimento em detrimento das outras, o que acaba por prejudicar a população por meio de carências nas condições de vida e destruição do meio ambiente principalmente. O ideal do desenvolvimento sustentável surge na tentativa de harmonizar crescimento econômico, igualdade social e preservação ambiental.

Luciana Dal Gianluppi; Paulo Dabdab Waquil

2008-01-01

230

A shape constrained MAP-EM algorithm for colorectal segmentation  

NASA Astrophysics Data System (ADS)

The task of effectively segmenting colon areas in CT images is an important area of interest in medical imaging field. The ability to distinguish the colon wall in an image from the background is a critical step in several approaches for achieving larger goals in automated computer-aided diagnosis (CAD). The related task of polyp detection, the ability to determine which objects or classes of polyps are present in a scene, also relies on colon wall segmentation. When modeling each tissue type as a conditionally independent Gaussian distribution, the tissue mixture fractions in each voxel via the modeled unobservable random processes of the underlying tissue types can be estimated by maximum a posteriori expectation-maximization (MAP-EM) algorithm in an iterative manner. This paper presents, based on the assumption that the partial volume effect (PVE) could be fully described by a tissue mixture model, a theoretical solution to the MAP-EM segmentation algorithm. However, the MAP-EM algorithm may miss some small regions which also belong to the colon wall. Combining with the shape constrained model, we present an improved algorithm which is able to merge similar regions and reserve fine structures. Experiment results show that the new approach can refine the jagged-like boundaries and achieve better results than merely exploited our previously presented MAP-EM algorithm.

Wang, Huafeng; Li, Lihong; Song, Bowen; Han, Fangfang; Liang, Zhengrong

2013-02-01

231

Modelo Conceitual de Segurança para uma Arquitetura Multidomínio em Telemedicina  

Microsoft Academic Search

Resumo - A comunicação e a troca de informações de maneira rápida e segura entre centros hospitalares geograficamente distribuídos tornam-se cada vez mais importantes em um cenário de telemedicina. Nesse contexto, pode-se compartilhar informações clínicas sensíveis, como a história do paciente, a fim de se ob- ter maior qualidade e precisão no atendimento ao paciente, com custos relativos menores. Este

João F. M. Figueiredo; Eduardo P. Serafim; Walber J. A. Silva; Diego S. A. Pizzol; Gustavo H. M. B. Motta

232

Vision: EM-erging Motion-Detecting Circuits.  

PubMed

How does the brain compare visual inputs over space and time to extract motion? Electron microscopic (EM) and molecular analyses reveal a new circuit architecture for motion processing in Drosophila. An offset in the weighting of synaptic connections and differential use of fast and slow nicotinic receptors suggests a mechanism that can implement spatiotemporal comparisons. PMID:24845666

Silies, Marion; Clandinin, Thomas R

2014-05-19

233

Effective Teaching of Photonics E&M Theory Using COMSOL  

NSDL National Science Digital Library

Photonics and optical communications, after the exuberant growth and subsequent down turn in late 1990s and early 2000s, have entered a more mature and stable growth phase. As the technology of choice for long distance, high data rate, and high performance communication systems underlying the now ubiquitous Internet communications, photonics and optical communication professionals are and will continue to be in high demand. Because electromagnetic (E&M) theory is the foundation of photonics and optical communications, mastery of E&M theory is essential for those electrical engineering (EE) students who want to develop a career in this field. Traditionally, rigorous analytic skills in advanced mathematics especially in subjects such as partial differential equations (PDE) and linear algebra are a must to the understanding and applications of E&M theory, as well as photonic device and waveguide designs. However, as practical designs grow in complexity, even the most sophisticated and advanced analytic techniques in these mathematical subject areas can quickly fall short of being a suitable practical design tool. Standard industry practices utilize comprehensive software simulation packages to address these design needs. It is therefore appropriate and advantageous for EE students to learn and more importantly visualize the E&M theory by combining the basic mathematical principles, e.g., the Maxwell equations and wave equations, with practical software tools that they are more likely to use in their professional life. This paper discusses the introduction of COMSOL, a predominant industry PDE solver, to senior EE undergraduates as a learning tool of fundamental concepts in photonics such as transverse electrical (TE) modes and transverse magnetic (TM) modes in planar waveguide designs. This teaching method improves teaching effectiveness of E&M field and wave theory by helping the students better understand mathematical complexities through this readily available and reliable software tool. In addition to the theory, the students also gain the design capability using these industry standard software packages, and therefore bridging the gap between theory and practice.

2009-10-08

234

EM calibration based on Post OPC layout analysis  

NASA Astrophysics Data System (ADS)

Design for Manufacturability (DFM) involves changes to the design and CAD tools to help increase pattern printability and improve process control. Design for Reliability (DFR) performs the same to improve reliability of devices from failures such as Electromigration (EM), gate-oxide break down, hot carrier injection (HCI), Negative Bias Temperature Insatiability (NBTI) and mechanical stress effects. Electromigration (EM) occurs due to migration or displacement of atoms as a result of the movement of electrons through a conducting medium. The rate of migration determines the Mean Time to Failure (MTTF) which is modeled as a function of temperature and current density. The model itself is calibrated through failure analysis (FA) of parts that are deemed to have failed due to EM against design parameters such as linewidth. Reliability Verification (RV) of a design involves verifying that every conducting line in a design meets certain MTTF threshold. In order to perform RV, current density for each wire must be computed. Current itself is a function of the parasitics that are determined through RC extraction. The standard practice is to perform the RC extraction and current density calculation on drawn, pre-OPC layouts. If a wire fails to meet threshold for MTTF, it may be resized. Subsequently, mask preparation steps such as OPC and PSM introduce extra features such as SRAFs, jogs,hammerheads and serifs that change their resistance, capacitance and current density values. Hence, calibrating EM model based on pre-OPC layouts will lead to different results compared to post-OPC layouts. In this work, we compare EM model calibration and reliability check based on drawn layout versus predicted layout, where the drawn layout is pre-OPC layout and predicted layout is based on litho simulation of post-OPC layout. Results show significant divergence between these two approaches, making a case for methodology based on predicted layout.

Sreedhar, Aswin; Kundu, Sandip

2010-03-01

235

A Hybrid EM and Monte Carlo EM Algorithm and Its Application to Analysis of Transmission of Infectious Diseases  

PubMed Central

Summary In epidemics of infectious diseases such as influenza, an individual may have one of four possible final states: prior immune, escaped from infection, infected with symptoms, and infected asymptomatically. The exact state is often not observed. In addition, the unobserved transmission times of asymptomatic infections further complicate analysis. Under the assumption of missing at random, data-augmentation techniques can be used to integrate out such uncertainties. We adapt an importance-sampling-based Monte Carlo EM (MCEM) algorithm to the setting of an infectious disease transmitted in close contact groups. Assuming the independence between close contact groups, we propose a hybrid EM-MCEM algorithm that applies the MCEM or the traditional EM algorithms to each close contact group depending on the dimension of missing data in that group, and discuss the variance estimation for this practice. In addition, we propose a bootstrap approach to assess the total Monte Carlo error and factor that error into the variance estimation. The proposed methods are evaluated using simulation studies. We use the hybrid EM-MCEM algorithm to analyze two influenza epidemics in the late 1970s to assess the effects of age and pre-season antibody levels on the transmissibility and pathogenicity of the viruses.

Yang, Yang; Longini, Ira M.; Halloran, M. Elizabeth; Obenchain, Valerie

2012-01-01

236

ATTRACT-EM: A New Method for the Computational Assembly of Large Molecular Machines Using Cryo-EM Maps  

PubMed Central

Many of the most important functions in the cell are carried out by proteins organized in large molecular machines. Cryo-electron microscopy (cryo-EM) is increasingly being used to obtain low resolution density maps of these large assemblies. A new method, ATTRACT-EM, for the computational assembly of molecular assemblies from their components has been developed. Based on concepts from the protein-protein docking field, it utilizes cryo-EM density maps to assemble molecular subunits at near atomic detail, starting from millions of initial subunit configurations. The search efficiency was further enhanced by recombining partial solutions, the inclusion of symmetry information, and refinement using a molecular force field. The approach was tested on the GroES-GroEL system, using an experimental cryo-EM map at 23.5 Å resolution, and on several smaller complexes. Inclusion of experimental information on the symmetry of the systems and the application of a new gradient vector matching algorithm allowed the efficient identification of docked assemblies in close agreement with experiment. Application to the GroES-GroEL complex resulted in a top ranked model with a deviation of 4.6 Å (and a 2.8 Å model within the top 10) from the GroES-GroEL crystal structure, a significant improvement over existing methods.

de Vries, Sjoerd J.; Zacharias, Martin

2012-01-01

237

Composting of rice straw with effective microorganisms (EM) and its influence on compost quality  

PubMed Central

This study aims to assess the effect of EM application on the composting process of rice straw with goat manure and green waste and to evaluate the quality of both compost treatments. There are two treatment piles in this study, in which one pile was applied with EM and another pile without EM. Each treatment was replicated three times with 90 days of composting duration. The parameters for the temperature, pH, TOC and C/N ratio, show that decomposition of organic matter occurs during the 90-day period. The t-test conducted shows that there is a significant difference between compost with EM and compost without EM. The application of EM in compost increases the macro and micronutrient content. The following parameters support this conclusion: compost applied with EM has more N, P and K content (P?EM. Although the Fe in compost with EM is much higher (P?EM, for Zn and Cu, there is no significant difference between treatments. This study suggests that the application of EM is suitable to increase the mineralization in the composting process. The final resultant compost indicated that it was in the range of the matured level and can be used without any restriction.

2013-01-01

238

Erosão em compósitos à base de fibras de vidro\\/kevlar e resina epóxi de uso aeronáutico  

Microsoft Academic Search

Resumo: Este trabalho tem como objetivo principal o estudo e a análise da eficiência de dois diferentes tipos de recobrimentos usados na proteção contra o processo de desgaste por erosão em substratos fabricados em materiais compósitos poliméricos de uso aeronáutico, dando ênfase às peças fabricadas em fibras de vidro \\/ kevlar impregnadas com resina epóxi. Revestimentos protetores baseados em um

Rogério A. Silva; Mirabel C. Rezende

2003-01-01

239

Avaliação do índice de temperatura de globo negro e umidade e desempenho de suínos nas fases de crescimento e terminação criados em sistemas em camas sobrepostas em condições de verão  

Microsoft Academic Search

RESUMO - Um estudo foi realizado com o objetivo de avaliar o sistema de criação em camas sobrepostas de maravalha e de casca de arroz, em comparação ao piso tradicional de concreto e sua influência no desempenho dos animais com base no ITGU (Índice de Temperatura de Globo negro e Umidade), no ganho de peso, no consumo de ração, na

Ilda de Fátima Ferreira Tinôco; Cecília de Fátima Souza; Paulo Armando Victoria de Oliveira; Robson Mendes de Paulo; Josiane Aparecida Campos; Cinara da Cunha Siqueira Carvalho; Marcelo Bastos Cordeiro

2007-01-01

240

Lysis in the well-fixed shell: "hold 'em" or "fold 'em".  

PubMed

Periacetabular osteolysis is the greatest challenge for longevity of total hip arthroplasty. The generation of wear debris from the bearing surface is inevitably going to cause bone loss around the implants. The challenges for the arthroplasty surgeon in managing this problem are: detection, knowing when to intervene surgically, and choosing the best reconstructive option. From a surgical standpoint, the options for addressing osteolysis are: (1) liner exchange with or without bone grafting of lytic lesions; or (2) complete component revision. The advantages of "holding 'em" include a faster surgery, no bony disruption, a quicker recovery for the patient, and cost. The downside of isolated liner exchange is that there is a high rate of instability, there may be incomplete access to the lytic lesions, and the limitations of the existing component. There have been techniques developed to provide access to the retroacetabular lesions, particularly superolaterally via a trap-door technique. Alternatively, other surgeons have advocated injection of bone graft substitutes in the retroacetabular regions to fill osteolytic defects. However, one may not be able to take advantage of newer bearing materials, larger head sizes, or component reposition to improve stability and wear properties. The advantages of a complete component revision are access to lytic lesions, and the ability to modify component position and take advantage of newer technologies. The disadvantages are cost, a longer recovery, and bony disruption. Each method of addressing acetabular osteolysis has compelling reasons to use it; individual patient factors such as component type, size of lesion, and remaining bone will play a role in selecting the treatment. PMID:20839674

Su, Edwin P

2010-09-01

241

EM susceptibility studies and measurements on electro explosive devices  

NASA Astrophysics Data System (ADS)

Electroexplosive devices (EEDs) are susceptible to stray electromagnetic (EM) fields near high-power communications and radar transmitters. Experiments have been carried out to measure the exact susceptibility of EED resistive squibs in pulsed and continuous EM environments, respectively. The susceptibility test procedure consisted of individual measurements of direct current sensitivity (mA); impulse sensitivity; RF impedance measurements; and safety margin calculations. A stray energy monitor was used to evaluate the safe performance of a hybrid weapons system. It is found that the RF sensitivity of the squib was influenced by the transmission characteristics of the transmission line connected to it. RF absorption peaks were observed above the EED sensitivity threshold of 120 MHz. Methods of EMI control are discussed, including: low-pass pin filters; lossy line filters for all dc power line interconnections; and twisting and shielding of the wires.

Deb, G. K.; Mukherjee, M.

242

Magen David Adom--the EMS in Israel.  

PubMed

Israel is a small country with a population of around 7 million. The sole EMS provider for Israel is Magen David Adom (MDA) (translated as 'Red Shield of David'). MDA also carries out the functions of a National Society (similar to the Red Cross) and provides all the blood and blood product services for the country. Nationwide, the organisation responds to over 1000 emergency calls a day and uses doctors, paramedics, emergency medical technicians and volunteers. Local geopolitics has meant that MDA has to be prepared for anything from everyday emergency calls to suicide bombings and regional wars. MDA also prides itself in being able to rapidly assemble and dispatch mobile aid teams to scenes of international disasters. Such a broad range of activities is unusual for a single EMS organisation. PMID:17767990

Ellis, Daniel Y; Sorene, Eliot

2008-01-01

243

Superconducting Electromagnetic Suspension (EMS) system for Grumman Maglev concept  

NASA Technical Reports Server (NTRS)

The Grumman developed Electromagnetic Suspension (EMS) Maglev system has the following key characteristics: a large operating airgap--40 mm; levitation at all speeds; both high speed and low speed applications; no deleterious effects on SC coils at low vehicle speeds; low magnetic field at the SC coil--less than 0.35 T; no need to use non-magnetic/non-metallic rebar in the guideway structure; low magnetic field in passenger cabin--approximately 1 G; low forces on the SC coil; employs state-of-the-art NbTi wire; no need for an active magnet quench protection system; and lower weight than a magnet system with copper coils. The EMS Maglev described in this paper does not require development of any new technologies. The system could be built with the existing SC magnet technology.

Kalsi, Swarn S.

1994-01-01

244

Evolução temporal de discos circunstelares em estrelas Be  

NASA Astrophysics Data System (ADS)

A pesquisa do mecanismo que leva uma estrela do tipo Be a perder massa e formar um envelope circunstelar, nomeado como fenômeno Be, é uma questão em aberto, intrigante, e que adquire contornos interessantes em face às informações espectroscópicas de alta resolução. Nesta última década, consolida-se a idéia de que a forma destes envelopes é de tipo discóide, obedecendo a uma lei Kepleriana de velocidades, e mais ainda, recentemente há evidências de que a distribuição de matéria nestes discos pode assumir um caráter de anel. Medidas de algumas dimensões de discos circunstelares puderam ser obtidas pela análise de espectros de alta resolução e alta relação sinal-ruído para as estrelas Be: alpha Eri (HD 10144, B3Vpe), omicron And (HD 217675, B6IIIpe), e eta Cen (HD el972, B1.5Vne), no período dos anos de 1991 a 2001. Alguns modelos clássicos de envelope predizem uma distribuição de massa que decresce suavemente a partir da superfície estelar. Entretanto, considerando que a separação de picos de emissão em perfis de linhas do HeI e H-alpha, alargados por efeitos cinemáticos, é função do raio estelar e da velocidade rotacional projetada (vsini); nossos resultados sugerem a presença de um anel de matéria circunstelar, que aparece logo após a ejeção do material fotosférico, imediatamente acima da superfície estelar, e que se expande para raios maiores ao longo do tempo, eventualmente desconectando-se da superfície por uma região de densidade de matéria mínima. Tais interpretações revivem a idéia de que anéis de matéria circunstelar podem ser os responsáveis por algumas variabilidades em perfis de linhas de emissão, como as variações V/R.

Fernandes, M. V. M.; Leister, N. V.; Levenhagen, R. S.

2003-08-01

245

EMS Mutagenesis in the Pea Aphid Acyrthosiphon pisum.  

PubMed

In aphids, clonal individuals can show distinct morphologic traits in response to environmental cues. Such phenotypic plasticity cannot be studied with classical genetic model organisms such as Caenorhabditis elegans or Drosophila melanogaster. The genetic basis of this biological process remain unknown, as mutations affecting this process are not available in aphids. Here, we describe a protocol to treat third-stage larvae with an alkylating mutagen, ethyl methanesulfonate (EMS), to generate random mutations within the Acyrthosiphon pisum genome. We found that even low concentrations of EMS were toxic for two genotypes of A. pisum. Mutagenesis efficiency was nevertheless assessed by estimating the occurrence of mutational events on the X chromosome. Indeed, any lethal mutation on the X-chromosome would kill males that are haploid on the X so that we used the proportion of males as an estimation of mutagenesis efficacy. We could assess a putative mutation rate of 0.4 per X-chromosome at 10 mM of EMS. We then applied this protocol to perform a small-scale mutagenesis on parthenogenetic individuals, which were screened for defects in their ability to produce sexual individuals in response to photoperiod shortening. We found one mutant line showing a reproducible altered photoperiodic response with a reduced production of males and the appearance of aberrant winged males (wing atrophy, alteration of legs morphology). This mutation appeared to be stable because it could be transmitted over several generations of parthenogenetic individuals. To our knowledge, this study represents the first example of an EMS-generated aphid mutant. PMID:24531730

Tagu, Denis; Le Trionnaire, Gaël; Tanguy, Sylvie; Gauthier, Jean-Pierre; Huynh, Jean-René

2014-01-01

246

Integrated EM & Thermal Simulations with Upgraded VORPAL Software  

Microsoft Academic Search

Nuclear physics accelerators are powered by microwaves which must travel in waveguides between room-temperature sources and the cryogenic accelerator structures. The ohmic heat load from the microwaves is affected by the temperature-dependent surface resistance and in turn affects the cryogenic thermal conduction problem. Integrated EM & thermal analysis of this difficult non-linear problem is now possible with the VORPAL finite-difference

D. N. Smithe; D. Karipides; P. Stoltz; G. Cheng; H. Wang

2011-01-01

247

DustEM: Dust extinction and emission modelling  

NASA Astrophysics Data System (ADS)

DustEM computes the extinction and the emission of interstellar dust grains heated by photons. It is written in Fortran 95 and is jointly developed by IAS and CESR. The dust emission is calculated in the optically thin limit (no radiative transfer) and the default spectral range is 40 to 108 nm. The code is designed so dust properties can easily be changed and mixed and to allow for the inclusion of new grain physics.

Compiègne, M.; Verstraete, L.; Jones, A.; Bernard, J.-P.; Boulanger, F.; Flagey, N.; Le Bourlot, J.; Paradis, D.; Ysard, N.

2013-07-01

248

EMS Mutagenesis in the Pea Aphid Acyrthosiphon pisum  

PubMed Central

In aphids, clonal individuals can show distinct morphologic traits in response to environmental cues. Such phenotypic plasticity cannot be studied with classical genetic model organisms such as Caenorhabditis elegans or Drosophila melanogaster. The genetic basis of this biological process remain unknown, as mutations affecting this process are not available in aphids. Here, we describe a protocol to treat third-stage larvae with an alkylating mutagen, ethyl methanesulfonate (EMS), to generate random mutations within the Acyrthosiphon pisum genome. We found that even low concentrations of EMS were toxic for two genotypes of A. pisum. Mutagenesis efficiency was nevertheless assessed by estimating the occurrence of mutational events on the X chromosome. Indeed, any lethal mutation on the X-chromosome would kill males that are haploid on the X so that we used the proportion of males as an estimation of mutagenesis efficacy. We could assess a putative mutation rate of 0.4 per X-chromosome at 10 mM of EMS. We then applied this protocol to perform a small-scale mutagenesis on parthenogenetic individuals, which were screened for defects in their ability to produce sexual individuals in response to photoperiod shortening. We found one mutant line showing a reproducible altered photoperiodic response with a reduced production of males and the appearance of aberrant winged males (wing atrophy, alteration of legs morphology). This mutation appeared to be stable because it could be transmitted over several generations of parthenogenetic individuals. To our knowledge, this study represents the first example of an EMS-generated aphid mutant.

Tagu, Denis; Le Trionnaire, Gael; Tanguy, Sylvie; Gauthier, Jean-Pierre; Huynh, Jean-Rene

2014-01-01

249

Partially supervised learning using an EM-boosting algorithm.  

PubMed

Training data in a supervised learning problem consist of the class label and its potential predictors for a set of observations. Constructing effective classifiers from training data is the goal of supervised learning. In biomedical sciences and other scientific applications, class labels may be subject to errors. We consider a setting where there are two classes but observations with labels corresponding to one of the classes may in fact be mislabeled. The application concerns the use of protein mass-spectrometry data to discriminate between serum samples from cancer and noncancer patients. The patients in the training set are classified on the basis of tissue biopsy. Although biopsy is 100% specific in the sense that a tissue that shows itself to have malignant cells is certainly cancer, it is less than 100% sensitive. Reference gold standards that are subject to this special type of misclassification due to imperfect diagnosis certainty arise in many fields. We consider the development of a supervised learning algorithm under these conditions and refer to it as partially supervised learning. Boosting is a supervised learning algorithm geared toward high-dimensional predictor data, such as those generated in protein mass-spectrometry. We propose a modification of the boosting algorithm for partially supervised learning. The proposal is to view the true class membership of the samples that are labeled with the error-prone class label as missing data, and apply an algorithm related to the EM algorithm for minimization of a loss function. To assess the usefulness of the proposed method, we artificially mislabeled a subset of samples and applied the original and EM-modified boosting (EM-Boost) algorithms for comparison. Notable improvements in misclassification rates are observed with EM-Boost. PMID:15032790

Yasui, Yutaka; Pepe, Margaret; Hsu, Li; Adam, Bao-Ling; Feng, Ziding

2004-03-01

250

Parameter estimation of superimposed signals using the EM algorithm  

Microsoft Academic Search

A computationally efficient algorithm for parameter estimation of superimposed signals based on the two-step iterative EM (estimate-and-maximize, with an E step and an M step) algorithm is developed. The idea is to decompose the observed data into their signal components and then to estimate the parameters of each signal component separately. The algorithm iterates back and forth, using the current

MEIR FEDER; EHUD WEINSTEIN

1988-01-01

251

Swine Waste Management Through Kyusei Nature Farming and EM  

Microsoft Academic Search

Ten swine farms were installed waste management systems. Farm size was different from 200 to 3,000 pigs. Pigs were managed under a fully automated system. Treatments were made with 2 x 3 Latin square arrangements. Two seasonal effects were hot summer (25 - 35 0C) and cold winter (10 - -15 0C). Three EM levels were 1:1,000, 1:5,000, 1:10,000 dilution

Sangsoo Sun; Byungjin Ahn; Kyuho Myung; Kwanghyun Kim

252

A Bayesian View on Cryo-EM Structure Determination  

PubMed Central

Three-dimensional (3D) structure determination by single-particle analysis of cryo-electron microscopy (cryo-EM) images requires many parameters to be determined from extremely noisy data. This makes the method prone to overfitting, that is, when structures describe noise rather than signal, in particular near their resolution limit where noise levels are highest. Cryo-EM structures are typically filtered using ad hoc procedures to prevent overfitting, but the tuning of arbitrary parameters may lead to subjectivity in the results. I describe a Bayesian interpretation of cryo-EM structure determination, where smoothness in the reconstructed density is imposed through a Gaussian prior in the Fourier domain. The statistical framework dictates how data and prior knowledge should be combined, so that the optimal 3D linear filter is obtained without the need for arbitrariness and objective resolution estimates may be obtained. Application to experimental data indicates that the statistical approach yields more reliable structures than existing methods and is capable of detecting smaller classes in data sets that contain multiple different structures.

Scheres, Sjors H.W.

2012-01-01

253

EMS-induced cytomictic variability in safflower (Carthamus tinctorius L.).  

PubMed

Seeds of safflower (Carthamus tinctorius L.) were subjected to three treatment durations (3h, 5h and 7h) of 0.5 % Ethyl Methane Sulphonate (EMS). Microsporogenesis was carried out in the control as well as in the treated materials. EMS treated plants showed interesting feature of partial inter-meiocyte chromatin migration through channel formation, beak formation or direct cell fusion. Another interesting feature noticed during the study was the fusion among tetrads due to wall dissolution. The phenomenon of cytomixis was recorded at nearly all the stages of microsporogenesis connecting from a few to several meiocytes. Other abnormalities such as laggards, precocious movement, bridge and non-disjunction of chromosomes were also recorded but in very low frequencies. The phenomenon of cytomixis increased along with the increase in treatment duration of EMS. Cells with these types of cytomictic disturbances may probably result in uneven formation of gametes or zygote, heterogenous sized pollen grains or even loss of fertility in future. PMID:21950142

Srivastava, P; Kumar, G

2011-01-01

254

Improving EM&V for Energy Efficiency Programs (Fact Sheet)  

SciTech Connect

This fact sheet describes the objectives of the U.S. Department of Energy Uniform Methods Project to bring consistency to energy savings calculations in U.S. energy efficiency programs. The U.S. Department of Energy (DOE) is developing a framework and a set of protocols for determining gross energy savings from energy efficiency measures and programs. The protocols represent a refinement of the body of knowledge supporting energy efficiency evaluation, measurement, and verification (EM&V) activities. They have been written by technical experts within the field and reviewed by industry experts. Current EM&V practice allows for multiple methods for calculating energy savings. These methods were developed to meet the needs of energy efficiency program administrators and regulators. Although they served their original objectives well, they have resulted in inconsistent and incomparable savings results - even for identical measures. The goal of the Uniform Methods Project is to strengthen the credibility of energy savings determinations by improving EM&V, increasing the consistency and transparency of how energy savings are determined.

Not Available

2012-07-01

255

The US DOE-EM International Program - 13004  

SciTech Connect

The U.S. Department of Energy (DOE) Office of Environmental Management (EM) conducts international collaboration activities in support of U.S. policies and objectives regarding the accelerated risk reduction and remediation of environmental legacy of the nations' nuclear weapons program and government sponsored nuclear energy research. The EM International Program supported out of the EM Office of the Associate Principal Deputy Assistant Secretary pursues collaborations with foreign government organizations, educational institutions and private industry to assist in identifying technologies and promote international collaborations that leverage resources and link international experience and expertise. In fiscal year (FY) 2012, the International Program awarded eight international collaborative projects for work scope spanning waste processing, groundwater and soil remediation, deactivation and decommissioning (D and D) and nuclear materials disposition initiatives to seven foreign organizations. Additionally, the International Program's scope and collaboration opportunities were expanded to include technical as well as non-technical areas. This paper will present an overview of the on-going tasks awarded in FY 2012 and an update of upcoming international activities and opportunities for expansion into FY 2013 and beyond. (authors)

Elmetti, Rosa R.; Han, Ana M.; Williams, Alice C. [Department of Energy, Office of Environmental Management, 1000 Independence Ave. SW, Washington, DC 20585 (United States)] [Department of Energy, Office of Environmental Management, 1000 Independence Ave. SW, Washington, DC 20585 (United States)

2013-07-01

256

Generalized EM-type reconstruction algorithms for emission tomography.  

PubMed

We provide a general form for many reconstruction estimators of emission tomography. These estimators include Shepp and Vardi's maximum likelihood (ML) estimator, the quadratic weighted least squares (WLS) estimator, Anderson's WLS estimator, and Liu and Wang's multi-objective estimator, and others. We derive a generic update rule by constructing a surrogate function. This work is inspired by the ML-EM (EM, expectation maximization), where the latter naturally arises as a special case. A regularization with a specific form can also be incorporated by De Pierro's trick. We provide a general and quite different convergence proof compared with the proofs of the ML-EM and De Pierro. Theoretical analysis shows that the proposed algorithm monotonically decreases the cost function and automatically meets nonnegativity constraints. We have introduced a mechanism to provide monotonic, self-constraining, and convergent algorithms, from which some interesting existing and new algorithms can be derived. Simulation results illustrate the behavior of these algorithms in term of image quality and resolution-noise tradeoff. PMID:22665503

Teng, Yueyang; Zhang, Tie

2012-09-01

257

Retrospectively exploring the importance of items in the decision to leave the emergency medical services (EMS) profession and their relationships to life satisfaction after leaving EMS and likelihood of returning to EMS.  

PubMed

An exit survey was returned by a sample of 127 respondents in fully compensated positions who left the EMS profession, most within 12 months prior to filling out the exit survey. A very high percentage continued to work after leaving EMS. Respondents were asked to rate the importance of each of 17 items in affecting their decision to leave EMS. A higher than anticipated response to a "not applicable" response choice affected the usability of 8 of these items. Nine of the 17 items had at least 65 useable responses and were used for further analysis. Within these 9, stress/burnout and lack of job challenges had the highest importance in affecting the decision to leave EMS, while desire for better pay and benefits had the lowest importance. Desire for career change was positively related to life satisfaction after leaving EMS and negatively related to likelihood of returning to EMS. Stress/burnout was positively related to life satisfaction after leaving EMS. Study limitations and future research issues are briefly discussed. PMID:21695362

Blau, Gary; Chapman, Susan

2011-01-01

258

What variables affect public perceptions for EMS meeting general community needs?  

PubMed

In the fall, 2010, a phone survey of 928 respondents examined two research questions: does the general public perceive Emergency Medical Services (EMS) as meeting their community needs? And what factors or correlates help to explain EMS meeting community needs? To maximize geographical representation across the contiguous United States, a clustered stratified sampling strategy was used based upon zip codes across the 48 states. Results showed strong support by the sample for perceiving that EMS was meeting their general community needs. 17 percent of the variance in EMS meeting community needs was collectively explained by the demographic and perceptual variables in the regression model. Of the correlates tested, the strongest relationship was found between greater admiration for EMS professionals and higher perception of EMS meeting community needs. Study limitations included sampling households with only landline (no cell) phones, using a simulated emergency situation, and not collecting gender data. PMID:22735824

Blau, Gary; Hochner, Arthur; Portwood, James

2012-01-01

259

A hybrid EM and Monte Carlo EM algorithm and its application to analysis of transmission of infectious diseases.  

PubMed

In epidemics of infectious diseases such as influenza, an individual may have one of four possible final states: prior immune, escaped from infection, infected with symptoms, and infected asymptomatically. The exact state is often not observed. In addition, the unobserved transmission times of asymptomatic infections further complicate analysis. Under the assumption of missing at random, data-augmentation techniques can be used to integrate out such uncertainties. We adapt an importance-sampling-based Monte Carlo Expectation-Maximization (MCEM) algorithm to the setting of an infectious disease transmitted in close contact groups. Assuming the independence between close contact groups, we propose a hybrid EM-MCEM algorithm that applies the MCEM or the traditional EM algorithms to each close contact group depending on the dimension of missing data in that group, and discuss the variance estimation for this practice. In addition, we propose a bootstrap approach to assess the total Monte Carlo error and factor that error into the variance estimation. The proposed methods are evaluated using simulation studies. We use the hybrid EM-MCEM algorithm to analyze two influenza epidemics in the late 1970s to assess the effects of age and preseason antibody levels on the transmissibility and pathogenicity of the viruses. PMID:22506893

Yang, Yang; Longini, Ira M; Halloran, M Elizabeth; Obenchain, Valerie

2012-12-01

260

EMS-CO2 Welding: A New Approach to Improve Droplet Transfer Characteristics and Welding Formation  

Microsoft Academic Search

In this article, to improve the stability of droplet transfer and reduce the spatter of pure carbon dioxide gas shield welding (CO2 welding), we propose a new welding method called EMS-CO2 welding by applying an additional longitudinal electromagnetic field to a CO2 welding process (abbr. EMS-CO2 welding). The characteristics of droplet transfer, welding formation and microstructure between EMS-CO2 welding and

Jian Luo; Qian Luo; Xiangjie Wang; Xiaochuan Wang

2010-01-01

261

An EM Algorithm for Estimating SPECT Emission and Transmission Parameters from Emission Data Only  

Microsoft Academic Search

A maximum-likelihood (ML) expectation-maximization (EM) algorithm (called EM-IntraSPECT) is presented for simultaneously estimating single photon emission computed tomography (SPECT) emission and attenuation parameters from emission data alone. The algorithm uses the activity within the patient as transmission tomography sources, with which attenuation coefficients can he estimated. For this initial study, EM-IntraSPECT was tested on computer-simulated attenuation and emission maps representing

Andrzej Król; James E. Bowsher; Stephen H. Manglos; David H. Feiglin; Martin P. Tornai; F. Deaver Thomas

2001-01-01

262

Comprehensive regional trauma\\/Emergency Medical Services (EMS) delivery systems: The United States experience  

Microsoft Academic Search

The early 1970's, as an outgrowth of the American military experience, several pioneer regional trauma\\/EMS programs showed the way for better planning, organization, and resource deployment for trauma\\/EMS systems in the civilian community. The experience of the mid and late 1970's has brought an even wider implementation and modeling of trauma\\/EMS care systems with identification of specific patient problems, designation

David R. Boyd; R. Adams Cowley

1983-01-01

263

EM-ANN models for microstrip vias and interconnects in dataset circuits  

Microsoft Academic Search

A novel approach for accurate and efficient modeling of monolithic microwave\\/millimeter wave integrated circuit (MMIC) components by using electromagnetically trained artificial neural network (EM-ANN) software modules is presented. Full-wave EM analysis is employed to characterize MMIC components. Structures for simulation are chosen using design of experiments (DOE) methodology. EM-ANN models are then trained using physical parameters as inputs and S-parameters

Paul M. Watson; Kuldip C. Gupta

1996-01-01

264

Effect of PU.1 Phosphorylation on Interaction with NF-EM5 and Transcriptional Activation  

Microsoft Academic Search

PU.1 recruits the binding of a second B cell-restricted nuclear factor, NF-EM5, to a DNA site in the immunoglobulin kappa 3' enhancer. DNA binding by NF-EM5 requires a protein-protein interaction with PU.1 and specific DNA contacts. Dephosphorylated PU.1 bound to DNA but did not interact with NF-EM5. Analysis of serine-to-alanine mutations in PU.1 indicated that serine 148 (Ser148) is required

Jagan M. R. Pongubala; Charles van Beveren; Sujatha Nagulapalli; Michael J. Klemsz; Scott R. McKercher; Richard A. Maki; Michael L. Atchison

1993-01-01

265

Modeling of MHD edge containment in strip casting with ELEKTRA and CaPS-EM codes  

SciTech Connect

This paper presents modeling studies of magnetohydrodynamics analysis in twin-roll casting. Argonne National Laboratory (ANL) and ISPAT Inland Inc. (Inland), formerly Inland Steel Co., have worked together to develop a three-dimensional (3-D) computer model that can predict eddy currents, fluid flows, and liquid metal containment of an electromagnetic (EM) edge containment device. The model was verified by comparing predictions with experimental results of liquid metal containment and fluid flow in EM edge dams (EMDs) that were designed at Inland for twin-roll casting. This mathematical model can significantly shorten casting research on the use of EM fields for liquid metal containment and control. The model can optimize the EMD design so it is suitable for application, and minimize expensive time-consuming full-scale testing. Numerical simulation was performed by coupling a 3-D finite-element EM code (ELEKTRA) and a 3-D finite-difference fluids code (CaPS-EM) to solve heat transfer, fluid flow, and turbulence transport in a casting process that involves EM fields. ELEKTRA can predict the eddy-current distribution and the EM forces in complex geometries. CaPS-EM can model fluid flows with free surfaces. The computed 3-D magnetic fields and induced eddy currents in ELEKTRA are used as input to temperature- and flow-field computations in CaPS-EM. Results of the numerical simulation compared well with measurements obtained from both static and dynamic tests.

Chang, F. C.

2000-01-12

266

Epidemiology of major incidents: an EMS study from Pakistan  

PubMed Central

Background A major incident is defined as an event that owing to the number of casualties has the potential to overwhelm the available resources. This paper attempts to describe the incidence and epidemiology of major incidents dealt with by a government-run emergency medical service (EMS) in the Punjab province of Pakistan, a developing country in South Asia. A major incident in this EMS is defined as any incident that produces three or more patients, or any incident in which extraordinary resources are needed. Methods All the calls received by an EMS Rescue 1122 were studied over a 6-month period. Calls that were defined as major incidents were identified, and further details were sought from the districts regarding these incidents. Questions specifically asked were the type of incident, time of the incident, response time for the incident, the resources needed, and the number of dead and injured casualties. Retrospective data were collected from the submitted written reports. Results Road traffic crashes (RTCs) emerged as the leading cause of a major incident in the province of Punjab and also led to the greatest number of casualties, followed by fire incidents. The total number of casualties was 3,380, out of which 73.7% were RTC victims. There was a high rate of death on the scene (10.4%). Certain other causes of major incidents also emerged, including violence, gas explosions and drowning. Conclusion Road traffic crashes are the most common cause of a major incident in developing countries such as Pakistan. Injury prevention initiatives need to focus on RTCs.

2011-01-01

267

EM-21 Retrieval Knowledge Center: Waste Retrieval Challenges  

SciTech Connect

EM-21 is the Waste Processing Division of the Office of Engineering and Technology, within the U.S. Department of Energy’s (DOE) Office of Environmental Management (EM). In August of 2008, EM-21 began an initiative to develop a Retrieval Knowledge Center (RKC) to provide the DOE, high level waste retrieval operators, and technology developers with centralized and focused location to share knowledge and expertise that will be used to address retrieval challenges across the DOE complex. The RKC is also designed to facilitate information sharing across the DOE Waste Site Complex through workshops, and a searchable database of waste retrieval technology information. The database may be used to research effective technology approaches for specific retrieval tasks and to take advantage of the lessons learned from previous operations. It is also expected to be effective for remaining current with state-of-the-art of retrieval technologies and ongoing development within the DOE Complex. To encourage collaboration of DOE sites with waste retrieval issues, the RKC team is co-led by the Savannah River National Laboratory (SRNL) and the Pacific Northwest National Laboratory (PNNL). Two RKC workshops were held in the Fall of 2008. The purpose of these workshops was to define top level waste retrieval functional areas, exchange lessons learned, and develop a path forward to support a strategic business plan focused on technology needs for retrieval. The primary participants involved in these workshops included retrieval personnel and laboratory staff that are associated with Hanford and Savannah River Sites since the majority of remaining DOE waste tanks are located at these sites. This report summarizes and documents the results of the initial RKC workshops. Technology challenges identified from these workshops and presented here are expected to be a key component to defining future RKC-directed tasks designed to facilitate tank waste retrieval solutions.

Fellinger, Andrew P.; Rinker, Michael W.; Berglin, Eric J.; Minichan, Richard L.; Poirier, Micheal R.; Gauglitz, Phillip A.; Martin, Bruce A.; Hatchell, Brian K.; Saldivar, Eloy; Mullen, O Dennis; Chapman, Noel F.; Wells, Beric E.; Gibbons, Peter W.

2009-04-10

268

SEI: Junior E&M Course Materials - Electrostatics  

NSDL National Science Digital Library

This is a collection of resources for teaching electrostatics constructed over the course of four semesters of a transformed junior-level Electricity and Magnetism course. Included are homework questions, concept tests, student tutorials, lecture notes, and information about common student difficulties in the topic and ways to address these difficulties. This material was developed as part of a education research-based course transformation for junior level E&M. All of the resources developed for this course are available, sorted by individual topic and type, at http://www.compadre.org/psrc/items/Relations.cfm?ID=7891.

Pollock, Steven J.; Chasteen, Stephanie V.

2010-06-29

269

SEI: Junior E&M I Course Materials - Math Fundamentals  

NSDL National Science Digital Library

This is a collection of resources for teaching mathematical fundamentals of electro- and magnetostatics constructed over the course of four semesters of a transformed junior-level Electricity and Magnetism course. Included are homework questions, concept tests, and information about common student difficulties in the topic and ways to address these difficulties. This material was developed as part of a education research-based course transformation for junior level E&M. All of the resources developed for this course are available, sorted by individual topic and type, at http://www.compadre.org/psrc/items/Relations.cfm?ID=7891.

Pollock, Steven J.; Chasteen, Stephanie V.

2010-06-29

270

Testing For EM Upsets In Aircraft Control Computers  

NASA Technical Reports Server (NTRS)

Effects of transient electrical signals evaluated in laboratory tests. Method of evaluating nominally fault-tolerant, aircraft-type digital-computer-based control system devised. Provides for evaluation of susceptibility of system to upset and evaluation of integrity of control when system subjected to transient electrical signals like those induced by electromagnetic (EM) source, in this case lightning. Beyond aerospace applications, fault-tolerant control systems becoming more wide-spread in industry; such as in automobiles. Method supports practical, systematic tests for evaluation of designs of fault-tolerant control systems.

Belcastro, Celeste M.

1994-01-01

271

A compulsator driven rapid-fire EM gun  

NASA Astrophysics Data System (ADS)

A computator-driven railgun is an attractive alternative to the homopolar generator-inductor-switch configuration, especially for repetitive duty. A conceptual design of rapid-fire EM-gun system is presented. The generator is sized to accelerate a 0.08-kg projectile to 2 to 3 km/s at a 60 pulse-per-second repetition rate. Initial design parameters are discussed, and example current and velocity waveforms are given. The generator is discharged at the proper phase angle to provide a current zero just as the projectile exits the muzzle of the railgun.

Pratap, S. B.; Bird, W. L.; Godwin, G. L.; Weldon, W. F.

1984-03-01

272

Caucasicosides E-M, furostanol glycosides from Helleborus caucasicus.  

PubMed

Nine furostanol glycosides, namely caucasicosides E-M, were isolated from the MeOH extract of the leaves of Helleborus caucasicus, along with 11 known compounds including nine furostanol glycosides, a bufadienolide and an ecdysteroid. Their structures were established by the extensive use of 1D and 2D NMR experiments along with ESIMS(n) analyses. The steroidal composition of leaves of H. caucasicus shows as particular feature the occurrence of steroidal compounds belonging to the 5? series, unusual for Helleborus species, and in particular, caucasicosides F-H are based on a 5?-polyhydroxylated steroidal aglycon never reported before. PMID:21893324

Muzashvili, Tamar; Perrone, Angela; Napolitano, Assunta; Kemertelidze, Ether; Pizza, Cosimo; Piacente, Sonia

2011-12-01

273

SEI: Junior E&M Course Materials - Electrodynamics  

NSDL National Science Digital Library

This is a collection of resources for teaching electrodynamics. Included are homework questions, concept tests, student tutorials, and information about common student difficulties in the topic and ways to address these difficulties. This material was developed as part of a education research-based course transformation for junior level E&M. All of the resources developed for this course are available, sorted by individual topic and type, at http://www.compadre.org/psrc/items/Relations.cfm?ID=7891. Because this topic is not typically taught in depth in the courses used in developing these course materials, these materials are less complete than the other sections.

Pollock, Steven J.; Chasteen, Stephanie V.

2010-09-24

274

Method for evaluating compatibility of commercial electromagnetic (EM) microsensor tracking systems with surgical and imaging tables  

NASA Astrophysics Data System (ADS)

Electromagnetic (EM) tracking systems have been successfully used for Surgical Navigation in ENT, cranial, and spine applications for several years. Catheter sized micro EM sensors have also been used in tightly controlled cardiac mapping and pulmonary applications. EM systems have the benefit over optical navigation systems of not requiring a line-of-sight between devices. Ferrous metals or conductive materials that are transient within the EM working volume may impact tracking performance. Effective methods for detecting and reporting EM field distortions are generally well known. Distortion compensation can be achieved for objects that have a static spatial relationship to a tracking sensor. New commercially available micro EM tracking systems offer opportunities for expanded image-guided navigation procedures. It is important to know and understand how well these systems perform with different surgical tables and ancillary equipment. By their design and intended use, micro EM sensors will be located at the distal tip of tracked devices and therefore be in closer proximity to the tables. Our goal was to define a simple and portable process that could be used to estimate the EM tracker accuracy, and to vet a large number of popular general surgery and imaging tables that are used in the United States and abroad.

Nafis, Christopher; Jensen, Vern; von Jako, Ron

2008-04-01

275

Developing State and National Evaluation Infrastructures- Guidance for the Challenges and Opportunities of EM&V  

SciTech Connect

Evaluating the impacts and effectiveness of energy efficiency programs is likely to become increasingly important for state policymakers and program administrators given legislative mandates and regulatory goals and increasing reliance on energy efficiency as a resource. In this paper, we summarize three activities that the authors have conducted that highlight the expanded role of evaluation, measurement and verification (EM&V): a study that identified and analyzed challenges in improving and scaling up EM&V activities; a scoping study that identified issues involved in developing a national efficiency EM&V standard; and lessons learned from providing technical assistance on EM&V issues to states that are ramping up energy efficiency programs. The lessons learned are summarized in 13 EM&V issues that policy makers should address in each jurisdiction and which are listed and briefly described. The paper also discusses how improving the effectiveness and reliability of EM&V will require additional capacity building, better access to existing EM&V resources, new methods to address emerging issues and technologies, and perhaps foundational documents and approaches to improving the credibility and cross jurisdictional comparability of efficiency investments. Two of the potential foundational documents discussed are a national EM&V standard or resource guide and regional deemed savings and algorithm databases.

Schiller, Steven R.; Goldman, Charles A.

2011-06-24

276

An evaluation of success factors using the AHP to implement ISO 14001-based EMS  

Microsoft Academic Search

Today’s growing concern in environment awareness forces manufacturers to strive for implementing competitive strategies in environmental management. With the introduction of ISO 14001 Environmental Management System (EMS) standard in 1996, many manufacturing companies are facing a decision problem of whether or not to implement the ISO 14001 based EMS. The authors have studied the critical success factors to be considered

Kwai-Sang Chin; Simon Chiu; V. M. Rao Tummala

1999-01-01

277

Influência do veículo na eficácia da reposição de potássio em ratos hipocalêmicos  

Microsoft Academic Search

Resumo Introdução: Pacientes após cirurgia cardíaca são comumente tratados com diuréticos para controle de volume plasmático. A preocupação de distúrbios hipocalêmicos em adultos antes, durante ou após a cirurgia já foi ressaltada anteriormente, visto o risco de arritmias cardíacas. Clinicamente, a diluição da solução de potássio (K+) para administração por via intravenosa, em situações que requerem a sua reposição é

Márcio Petenusso; Vitor Engrácia Valenti; Luiz Carlos de Abreu; Eduardo Colombari; Fernando Luiz Affonso Fonseca; Monica Akemi Sato

2009-01-01

278

Estimation of Item Response Models Using the EM Algorithm for Finite Mixtures.  

ERIC Educational Resources Information Center

This paper presents a detailed description of maximum parameter estimation for item response models using the general EM algorithm. In this paper the models are specified using a univariate discrete latent ability variable. When the latent ability variable is discrete the distribution of the observed item responses is a finite mixture, and the EM…

Woodruff, David J.; Hanson, Bradley A.

279

Theoretical and experimental investigations of gravity modification by specially conditioned EM radiation  

Microsoft Academic Search

Ordinary electromagnetic (em) fields do not couple significantly with those that underlie gravitation and give rise to inertia, and it is suggested that this is because they are of different field essence and form. It is also suggested that a much stronger electro-gravitic coupling might be accomplished for effective propulsion by conditioning ordinary em fields into configurations that are similar

H. D. Froning; T. W. Barrett

2000-01-01

280

EmBOINC: An emulator for performance analysis of BOINC projects  

Microsoft Academic Search

BOINC is a platform for volunteer computing. The server component of BOINC embodies a number of schedul- ing policies and parameters that have a large impact on the projects throughput and other performance metrics. We have developed a system, EmBOINC, for studying these policies and parameters. EmBOINC uses a hybrid ap- proach: it simulates a population of volunteered clients (in-

Trilce Estrada; Michela Taufer; Kevin Reed; David P. Anderson

2009-01-01

281

DIFERENCIAÇÃO OU NECESSIDADE NA CERTIFICAÇÃO ISO 9001: UMA ANÁLISE EM DUAS EMPRESAS AGROINDUSTRIAIS  

Microsoft Academic Search

O presente estudo de caso foi realizado em duas organizações agroindustriais, a AGCO do Brasil Comércio e Indústria Ltda. e a Tecno Moageira S\\/A, tratando-se de um estudo de caso de natureza exploratória e descritiva, que objetivou analisar os motivos pelos quais essas organizações implementaram a certificação ISO 9001, em torno da seguinte problemática: Qual o real interesse da certificação

Alexandre Melo Abicht; Alessandra Carla Ceolin; Augusto Faria Correa; Paulo Rodrigo Pereira; Tania Nunes da Silva

2008-01-01

282

neuromuscular sobre o consumo máximo de oxigênio e salto vertical em atletas iniciantes de voleibol  

Microsoft Academic Search

RESUMO As alterações ocorridas na performance motora de jovens en- volvidos em treinamentos especializados ainda não são muito cla- ras. Este é um conhecimento de suma importância para a correta prescrição desses treinos. O objetivo deste estudo foi verificar a influência do treinamento nas variáveis neuromotoras e orgânicas de jovens atletas na modalidade voleibol em diferentes momen- tos do programa.

Alexandre Altini Neto; Ídico Luiz Pellegrinotti; Maria Imaculada; L. Montebelo

283

Evidence-based performance measures for emergency medical services systems: a model for expanded EMS benchmarking.  

PubMed

There are few evidence-based measures of emergency medical services (EMS) system performance. In many jurisdictions, response-time intervals for advanced life support units and resuscitation rates for victims of cardiac arrest are the primary measures of EMS system performance. The association of the former with patient outcomes is not supported explicitly by the medical literature, while the latter focuses on a very small proportion of the EMS patient population and thus does not represent a sufficiently broad selection of patients. While these metrics have their place in performance measurement, a more robust method to measure and benchmark EMS performance is needed. The 2007 U.S. Metropolitan Municipalities' EMS Medical Directors' Consortium has developed the following model that encompasses a broader range of clinical situations, including myocardial infarction, pulmonary edema, bronchospasm, status epilepticus, and trauma. Where possible, the benefit conferred by EMS interventions is presented in the number needed to treat format. It is hoped that utilization of this model will serve to improve EMS system design and deployment strategies while enhancing the benchmarking and sharing of best practices among EMS systems. PMID:18379908

Myers, J Brent; Slovis, Corey M; Eckstein, Marc; Goodloe, Jeffrey M; Isaacs, S Marshal; Loflin, James R; Mechem, C Crawford; Richmond, Neal J; Pepe, Paul E

2008-01-01

284

EMS Agenda for the Future: Where We Are … Where We Want to Be  

Microsoft Academic Search

During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering

Theodore R Delbridge; Bob Bailey; John L Chew; Alasdair KT Conn; Jack J Krakeel; Dan Manz; David R Miller; Patricia J O'Malley; Susan D Ryan; Daniel W Spaite; Ronald D Stewart; Robert E Suter; E. Marie Wilson

1998-01-01

285

Bayesian reconstructions from emission tomography data using a modified EM algorithm  

Microsoft Academic Search

A novel method of reconstruction from single-photon emission computerized tomography data is proposed. This method builds on the expectation-maximization (EM) approach to maximum likelihood reconstruction from emission tomography data, but aims instead at maximum posterior probability estimation, which takes account of prior belief about smoothness in the isotope concentration. A novel modification to the EM algorithm yields a practical method.

PETER J. GREEN

1990-01-01

286

Multipurpose design optimization of EMS-type magnetically levitated vehicle based on genetic algorithm  

Microsoft Academic Search

A type of the magnetically levitated railway system with the electromagnetic suspension system (EMS), which is named HSST system, will be put into revenue service as an urban transport in Nagoya, Japan at the beginning of April 2005. To extend its operational velocity higher than 200 km\\/h for applications in other cities, the design of its EMS system is reexamined

Shinichi Kusagawa; Jumpei Baba; Katsuhiko Shutoh; Eisuke Masada

2004-01-01

287

Competência social e empatia: um estudo sobre resiliência com crianças em situação de pobreza  

Microsoft Academic Search

Social competence and empathy: Study about resilience with children in poverty Resumo O objetivo desse estudo foi avaliar a competência social e a empatia em crianças escolares que vivem em situação de po- breza. Participaram da pesquisa 100 crianças, de ambos os sexos, com idades entre seis e nove anos. Os instrumentos utilizados foram o Teste das Histórias Incompletas (THI)

Alessandra Marques Cecconello; Sílvia Helena Koller

2000-01-01

288

Programa em Educação a Distância para a Melhoria das Condições de Aprendizagem da Matemática  

Microsoft Academic Search

Resumo - A fim de fundamentar uma ação pedagógica diferenciada, frente ao elevado número de reprovações e desistências que ocorrem em disciplinas iniciais de Matemática na Universidade de Caxias do Sul, apresentamos um programa através do qual investigamos as reais possibilidades de constituir nova opção para alunos reprovados em Cálculo Diferencial e Integral I. Num ambiente virtual de aprendizagem os

Isolda G. De Lima; Laurete Z. Sauer

289

Influência da irrigação e do genótipo na produção de castanha em cajueiro-anão-precoce  

Microsoft Academic Search

(2) Resumo - Avaliou-se a influência da irrigação e do genótipo na produção de castanha em cajueiro-anão- precoce (Anacardium occidentale L.) durante três anos. Foram estudados três clones (CP 09, CP 76 e CP 1001) e quatro regimes hídricos (testemunha sem irrigação e intervalos de irrigação de um, três e cinco dias). O delineamento experimental foi em blocos ao acaso,

Vitor Hugo de Oliveira; Levi de Moura Barros; Raimundo Nonato de Lima

2003-01-01

290

Prevalência de sobrepeso\\/obesidade em crianças e adolescentes com constipação crônica funcional  

Microsoft Academic Search

RESUmO Objetivo: Avaliar a prevalência do sobrepeso\\/obesidade em um grupo de crianças com constipação crônica funcional. Métodos: Estudo retrospectivo com 257 crianças de dois a 15 anos com constipação crônica funcional diag- nosticada segundo critérios de Roma II, atendidas con- secutivamente em clínica terciária de gastroenterologia pediátrica. Informações demográficas, clínicas, diagnós - ticas e antropométricas foram obtidas de prontuários. O

Francisca Teresa V. Faleiros; Cristiane Camargo Omae; Cristiane Yoshie Nakazawa; Mary de Assis Carvalho; Nilton Carlos Machado

2008-01-01

291

NEW ISOTOPES OF EMANATION AND FRANCIUM: ²²³Em, ²²⁴Em, AND ²²⁴Fr  

Microsoft Academic Search

An examination of the products of the interaction of thorium with 230 ; Mev protons revealed evidence for the existence of the neutron-excess isotopes: ; Em²²³, Em²²⁴, and Fr²²⁴. The existence of these three new ; isotopes was confirmed by identification of their decay products: Ra²²³ and ; Ra²²⁴. (auth);

Bellido

1961-01-01

292

The simulated online EM algorithm for latent factor models  

NASA Astrophysics Data System (ADS)

The estimation of latent factor models are treated in an integrated maximum likelihood context where one parameter is marginalized and another is estimated. An extension to the online Expectation Maximization (EM) algorithm is employed the simulated online Expectation Maximization algorithm. Both these algorithms apply to exponential family models, but the simulated version of the algorithm can make use of Monte Carlo simulation to compute the stochastic E-steps while maintaining the convergence properties of the original online EM algorithm. A class of important latent factor models are identified that can be expressed in complete data exponential family form, the algorithm is applied to one of these models Itakura-Saito Non-negative Matrix Factorisation. An additional parameter is introduced into this model and it is conjectured if this is set to a high value the posterior variance of the parameters is reduced and estimation becomes easier. Simulations are provided that support this conjecture, although online estimation for models with even a modest number of components continues to be hampered by the presence of local minima.

Rohde, D.; Cappé, O.; Dikmen, O.

2012-10-01

293

Fabrication and EM shielding properties of electrospining PANi/MWCNT/PEO fibrous membrane and its composite  

NASA Astrophysics Data System (ADS)

In this paper, Polyaniline-based fibrous membranes were fabricated with multi-walled carbon nanotubes and polyethylene oxide (PEO) by the electrospinning method. And then PANi/PEO/MWCNT fibrous membranes reinforced epoxy based nanocomposite was then fabricated. The morphology and electrical properties of PANi /MWCNT /PEO fibrous membrane was characterized by scanning electron microscope (SEM). The morphologies of the membranes indicate that the electrospining method can fabricate well nano structures fibrous membrane. The EM properties of the composite reinforced with the electrospining fibrous membrane were measured by vector network analyzer. The results show that the permittivity real, image parts and permeability real part of the composite increase by filling with PANI/PEO and PANI/CNT/PEO membrane. The EM shielding and absorb performance is base on the dielectric dissipation. And different membranes made of different materials show different EM parameter, and different EM shielding performance, which can be used to the EM shielding and stealth material design and fabrication.

Zhang, Zhichun; Jiang, Xueyong; Liu, Yanju; Leng, Jinsong

2012-03-01

294

Qualidade de frutos de cinco híbridos de melão rendilhado em função do número de frutos por planta  

Microsoft Academic Search

RESUMO-Este trabalho teve por objetivo avaliar a qualidade de cinco híbridos de melão rendilhado, com dois e três frutos por planta, utilizando fibra da casca de coco e fertirrigação. Para tanto, foi instalado um experimento em casa de vegetação na UNESP-FCAV, Câmpus de Jaboticabal, com delineamento experimental em blocos ao acaso, em esquema fatorial 5 x 2, com quatro repetições.

Renata Castoldi; Hamilton César de Oliveira Charlo; Pablo Forlan Vargas; Leila Trevizan Braz

2008-01-01

295

Hybrid BEM\\/FEM Calculation of Thermal Rise in the Human Eye Exposed to Time Harmonic EM Waves  

Microsoft Academic Search

Human eye being unprotected by the layer of skin and bones is one of the most sensitive organs to EM radiation. The absorption of EM radiation is quantified in terms of SAR and to calculate the SAR the knowledge of complete electric field distribution inside the eye is necessary. In this paper the problem of distribution of near EM field

Hrvoje Dodig

2005-01-01

296

ON SPEEDING UP THE EM ALGORITHM IN PATTERN RECOGNITION: A COMPARISON OF INCREMENTAL AND MULTIRESOLUTION KD-TREE-BASED APPROACHES  

Microsoft Academic Search

Finite mixture models implemented via the EM algo- rithm are being increasingly used in a wide range of problems in the context of unsupervised statistical pattern recognition. As each E-step visits each feature vector on a given iteration, the EM algorithm requires considerable computation time in its application to large data sets. We consider two approaches, an incremental EM (IEM)

Shu Kay Ng; Geoffrey John McLachlan

2002-01-01

297

The EM SSAB Annual Work Plan Process: Focusing Board Efforts and Resources - 13667  

SciTech Connect

One of the most daunting tasks for any new member of a local board of the Environmental Management Site Specific Advisory Board (EM SSAB) is to try to understand the scope of the clean-up activities going on at the site. In most cases, there are at least two or three major cleanup activities in progress as well as monitoring of past projects. When planning for future projects is added to the mix, the list of projects can be long. With the clean-up activities involving all major environmental media - air, water, soils, and groundwater, new EM SSAB members can find themselves totally overwhelmed and ineffective. Helping new members get over this initial hurdle is a major objective of EM and all local boards of the EM SSAB. Even as members start to understand the size and scope of the projects at a site, they can still be frustrated at the length of time it takes to see results and get projects completed. Many project and clean-up timelines for most of the sites go beyond 10 years, so it's not unusual for an EM SSAB member to see the completion of only 1 or 2 projects over the course of their 6-year term on the board. This paper explores the annual work planning process of the EM SSAB local boards, one tool that can be used to educate EM SSAB members into seeing the broader picture for the site. EM SSAB local work plans divide the site into projects focused on a specific environmental issue or media such as groundwater and/or waste disposal options. Projects are further broken down into smaller segments by highlighting major milestones. Using these metrics, local boards of the EM SSAB can start to quantify the effectiveness of the project in achieving the ultimate goal of site clean-up. These metrics can also trigger board advice and recommendations for EM. At the beginning of each fiscal year, the EM SSAB work plan provides a road map with quantifiable checkpoints for activities throughout the year. When the work plans are integrated with site-specific, enforceable regulatory milestones, they can provide a comprehensive work plan for not only the board, but also regulators, site contractors, and DOE. Because the work plans are reviewed and approved by DOE, they carry some weight in holding local boards of the EM SSAB accountable. This structure provides the basis for local boards to achieve their primary function, to provide DOE with information, advice, and recommendations concerning issues affecting the EM program at the site. (authors)

Young, Ralph [Paducah Citizens Advisory Board (United States)] [Paducah Citizens Advisory Board (United States)

2013-07-01

298

Linear array implementation of the EM algorithm for PET image reconstruction  

SciTech Connect

The PET image reconstruction based on the EM algorithm has several attractive advantages over the conventional convolution back projection algorithms. However, the PET image reconstruction based on the EM algorithm is computationally burdensome for today`s single processor systems. In addition, a large memory is required for the storage of the image, projection data, and the probability matrix. Since the computations are easily divided into tasks executable in parallel, multiprocessor configurations are the ideal choice for fast execution of the EM algorithms. In tis study, the authors attempt to overcome these two problems by parallelizing the EM algorithm on a multiprocessor systems. The parallel EM algorithm on a linear array topology using the commercially available fast floating point digital signal processor (DSP) chips as the processing elements (PE`s) has been implemented. The performance of the EM algorithm on a 386/387 machine, IBM 6000 RISC workstation, and on the linear array system is discussed and compared. The results show that the computational speed performance of a linear array using 8 DSP chips as PE`s executing the EM image reconstruction algorithm is about 15.5 times better than that of the IBM 6000 RISC workstation. The novelty of the scheme is its simplicity. The linear array topology is expandable with a larger number of PE`s. The architecture is not dependant on the DSP chip chosen, and the substitution of the latest DSP chip is straightforward and could yield better speed performance.

Rajan, K.; Patnaik, L.M.; Ramakrishna, J. [Indian Institute of Science, Bangalore (India)] [Indian Institute of Science, Bangalore (India)

1995-08-01

299

PREFACE: EmQM13: Emergent Quantum Mechanics 2013  

NASA Astrophysics Data System (ADS)

These proceedings comprise the invited lectures of the second international symposium on Emergent Quantum Mechanics (EmQM13), which was held at the premises of the Austrian Academy of Sciences in Vienna, Austria, 3–6 October 2013. The symposium was held at the ''Theatersaal'' of the Academy of Sciences, and was devoted to the open exploration of emergent quantum mechanics, a possible ''deeper level theory'' that interconnects three fields of knowledge: emergence, the quantum, and information. Could there appear a revised image of physical reality from recognizing new links between emergence, the quantum, and information? Could a novel synthesis pave the way towards a 21st century, ''superclassical'' physics? The symposium provided a forum for discussing (i) important obstacles which need to be overcome as well as (ii) promising developments and research opportunities on the way towards emergent quantum mechanics. Contributions were invited that presented current advances in both standard as well as unconventional approaches to quantum mechanics. The EmQM13 symposium was co–organized by Gerhard Grössing (Austrian Institute for Nonlinear Studies (AINS), Vienna), and by Jan Walleczek (Fetzer Franklin Fund, USA, and Phenoscience Laboratories, Berlin). After a very successful first conference on the same topic in 2011, the new partnership between AINS and the Fetzer Franklin Fund in producing the EmQM13 symposium was able to further expand interest in the promise of emergent quantum mechanics. The symposium consisted of two parts, an opening evening addressing the general public, and the scientific program of the conference proper. The opening evening took place at the Great Ceremonial Hall (Grosser Festsaal) of the Austrian Academy of Sciences, and it presented talks and a panel discussion on ''The Future of Quantum Mechanics'' with three distinguished speakers: Stephen Adler (Princeton), Gerard 't Hooft (Utrecht) and Masanao Ozawa (Nagoya). The articles contained in these proceedings represent the talks of the invited speakers as written immediately after the symposium. The volume starts with a contribution by organizers Jan Walleczek and Gerhard Grössing, essentially explaining why emergent quantum mechanics, and other deterministic approaches to quantum theory, must be considered viable approaches in quantum foundations today. This is followed by the exposition of Stephen Adler's talk who introduced to a general audience key questions at the current frontiers of quantum mechanics during the opening evening (with the contents of his conference talk appearing elsewhere). The conference proceedings then continues with the presentations as given in their chronological order i.e. starting with the opening talk of the scientific program by Gerard 't Hooft. While the page number was restricted for all invited speakers, the paper by Jeff Tollaksen was given more space, as his invited collaborator Yakir Aharonov was unable to deliver a separate talk, in order to represent both contributions in one paper. Note that the talks of all speakers, including the talks of those who could not be represented in this volume (M. Arndt, B. Braverman, C. Brukner, S. Colin, Y. Couder, B. Poirier, A. Steinberg, G. Weihs and H. Wiseman) are freely available on the conference website as video presentations (http://www.emqm13.org). The organizers wish to express their gratitude to Siegfried Fussy and Herbert Schwabl from AINS for the organizational support. The organizers also wish to thank Bruce Fetzer, President and CEO, John E. Fetzer Memorial Trust, and the Members of the Board of Trustees, for their strong support and for funding this symposium. We also wish to thank the Austrian Academy of Sciences for allowing the symposium to be held on their premises, and Anton Zeilinger, President of the Austrian Academy of Sciences, for his welcome address. The expertise of the Members of the Scientific Advisory Board of the EmQM13 symposium, Ana Maria Cetto (Mexico), Lajos Diósi (Budapest), Maurice de Gosson (Vienna), Edward Nelson (Princeton), The

2014-04-01

300

SEI: Junior E&M I Course Materials - Homework  

NSDL National Science Digital Library

This homework question collection was constructed over the course of four semesters of a transformed junior-level Electricity and Magnetism course on electro- and magneto-statics. Many questions are related to textbook problems, but with added elements of explanation, sense-making, estimation or approximation, real-world connections, and multiple-representations. Not all these homework questions were used in the course design project. Some problems used include detailed instructor notes, including statistics on student performance on each homework problem assigned. The homework solutions are only available to instructors by writing the authors, Steven.Pollock@colorado.edu This material was developed as part of a education research-based course transformation for junior level E&M. All of the resources developed for this course are available, sorted by individual topic and type, at http://www.compadre.org/psrc/items/Relations.cfm?ID=7891.

Pollock, Steven J.; Chasteen, Stephanie V.

2010-06-10

301

Integrated EM & Thermal Simulations with Upgraded VORPAL Software  

SciTech Connect

Nuclear physics accelerators are powered by microwaves which must travel in waveguides between room-temperature sources and the cryogenic accelerator structures. The ohmic heat load from the microwaves is affected by the temperature-dependent surface resistance and in turn affects the cryogenic thermal conduction problem. Integrated EM & thermal analysis of this difficult non-linear problem is now possible with the VORPAL finite-difference time-domain simulation tool. We highlight thermal benchmarking work with a complex HOM feed-through geometry, done in collaboration with researchers at the Thomas Jefferson National Accelerator Laboratory, and discuss upcoming design studies with this emerging tool. This work is part of an effort to generalize the VORPAL framework to include generalized PDE capabilities, for wider multi-physics capabilities in the accelerator, vacuum electronics, plasma processing and fusion R&D fields, and we will also discuss user interface and algorithmic upgrades which facilitate this emerging multiphysics capability.

D.N. Smithe, D. Karipides, P. Stoltz, G. Cheng, H. Wang

2011-03-01

302

TrakEM2 Software for Neural Circuit Reconstruction  

PubMed Central

A key challenge in neuroscience is the expeditious reconstruction of neuronal circuits. For model systems such as Drosophila and C. elegans, the limiting step is no longer the acquisition of imagery but the extraction of the circuit from images. For this purpose, we designed a software application, TrakEM2, that addresses the systematic reconstruction of neuronal circuits from large electron microscopical and optical image volumes. We address the challenges of image volume composition from individual, deformed images; of the reconstruction of neuronal arbors and annotation of synapses with fast manual and semi-automatic methods; and the management of large collections of both images and annotations. The output is a neural circuit of 3d arbors and synapses, encoded in NeuroML and other formats, ready for analysis.

Cardona, Albert; Saalfeld, Stephan; Schindelin, Johannes; Arganda-Carreras, Ignacio; Preibisch, Stephan; Longair, Mark; Tomancak, Pavel; Hartenstein, Volker; Douglas, Rodney J.

2012-01-01

303

Speech articulator measurements using low power EM-wave sensors  

SciTech Connect

Very low power electromagnetic (EM) wave sensors are being used to measure speech articulator motions as speech is produced. Glottal tissue oscillations, jaw, tongue, soft palate, and other organs have been measured. Previously, microwave imaging (e.g., using radar sensors) appears not to have been considered for such monitoring. Glottal tissue movements detected by radar sensors correlate well with those obtained by established laboratory techniques, and have been used to estimate a voiced excitation function for speech processing applications. The noninvasive access, coupled with the small size, low power, and high resolution of these new sensors, permit promising research and development applications in speech production, communication disorders, speech recognition and related topics. {copyright} {ital 1998 Acoustical Society of America.}

Holzrichter, J.F.; Burnett, G.C.; Ng, L.C. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)] [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States); Lea, W.A. [Speech Science Institute, P.O. Box 240428, Apple Valley, Minnesota 55124 (United States)] [Speech Science Institute, P.O. Box 240428, Apple Valley, Minnesota 55124 (United States)

1998-01-01

304

Imaging protein three-dimensional nanocrystals with cryo-EM.  

PubMed

Flash-cooled three-dimensional crystals of the small protein lysozyme with a thickness of the order of 100 nm were imaged by 300 kV cryo-EM on a Falcon direct electron detector. The images were taken close to focus and to the eye appeared devoid of contrast. Fourier transforms of the images revealed the reciprocal lattice up to 3 Å resolution in favourable cases and up to 4 Å resolution for about half the crystals. The reciprocal-lattice spots showed structure, indicating that the ordering of the crystals was not uniform. Data processing revealed details at higher than 2 Å resolution and indicated the presence of multiple mosaic blocks within the crystal which could be separately processed. The prospects for full three-dimensional structure determination by electron imaging of protein three-dimensional nanocrystals are discussed. PMID:23633595

Nederlof, Igor; Li, Yao Wang; van Heel, Marin; Abrahams, Jan Pieter

2013-05-01

305

Risk Factors for Hypothermia in EMS-treated Burn Patients.  

PubMed

Abstract Objective. Hypothermia has been associated with increased mortality in burn patients. We sought to characterize the body temperature of burn patients transported directly to a burn center by emergency medical services (EMS) personnel and identify the factors independently associated with hypothermia. Methods. We utilized prospective data collected by a statewide trauma registry to carry out a nested case-control study of burn patients transported by EMS directly to an accredited burn center between 2000 and 2011. Temperature at hospital admission ?36.5°C was defined as hypothermia. We utilized registry data abstracted from prehospital care reports and hospital records in building a multivariable regression model to identify the factors associated with hypothermia. Results. Forty-two percent of the sample was hypothermic. Burns of 20-39% total body surface area (TBSA) (OR 1.44; 1.17-1.79) and ?40% TBSA (OR 2.39; 1.57-3.64) were associated with hypothermia. Hypothermia was also associated with age > 60 (OR 1.50; 1.30-1.74), polytrauma (OR 1.58; 1.19-2.09), prehospital Glasgow Coma Scale <8 (OR 2.01; 1.46-2.78), and extrication (OR 1.49; 1.30-1.71). Hypothermia was also more common in the winter months (OR 1.54; 1.33-1.79) and less prevalent in patients weighing over 90 kg (OR 0.63; 0.46-0.88). Conclusions. A substantial proportion of burn patients demonstrate hypothermia at hospital arrival. Risk factors for hypothermia are readily identifiable by prehospital providers. Maintenance of normothermia should be stressed during prehospital care. PMID:24460465

Weaver, Matthew D; Rittenberger, Jon C; Patterson, P Daniel; McEntire, Serina J; Corcos, Alain C; Ziembicki, Jenny A; Hostler, David

2014-01-01

306

Ondas de choque em jatos de quasares e objetos BL Lacertae  

NASA Astrophysics Data System (ADS)

Este trabalho é parte de um projeto que vem sendo realizado há dois anos no CRAAM, cujos objetivos principais são analisar e aplicar um modelo generalizado de ondas de choque em jatos relativísticos de plasma, presentes em quasares e objetos BL Lacertae, para explicar a variabilidade observada nestes objetos. O método consiste em uma decomposição de curvas de luz em séries de explosões similares, em várias freqüências, baseando-se em uma evolução espectro-temporal média das explosões. A partir da evolução média, um ajuste de cada explosão é feito com base em equações empíricas, modificando-se apenas parâmetros específicos de cada explosão. Inicialmente o modelo foi aplicado ajustando-se as curvas de luz a explosões delineadas por uma evolução do choque em três estágios, segundo a predominância do processo de emissão: síncrotron, Compton e adiabático. Entretanto, nesta nova fase de projeto, visando uma parametrização mais concisa, uma otimização do algoritmo de ajuste e uma convergência mais rápida, a formulação para cada evento foi assumida com uma evolução em apenas dois estágios: subida e descida. Isto possibilitou uma ótima delineação das curvas de luz das fontes OV236, OJ287, 3C273 e BL Lac, entre 1980 e 2000, nas freqüências 4.8, 8.0, 14.5 e 22 GHz, utilizando-se dados do Observatório da Universidade de Michigan, do Observatório do Itapetinga (Atibaia SP) e do Observatório Metsähovi. Como conclusões importantes, verificou-se que: os parâmetros ajustados descrevem o comportamento do jato; os valores do índice que descreve a expansão do jato sugerem que o mesmo se expande de uma forma não-cônica; o campo magnético é turbulento atrás da frente de choque; e as peculiaridades das explosões são devidas à influência de grandezas tais como o coeficiente da distribuição espectral de energia dos elétrons, a intensidade de campo magnético e o fator de feixe Doppler, no início do choque.

Melo, F. E.; Botti, L. C. L.

2003-08-01

307

Abscesso pulmonar de aspiração: dados diagnósticos e resultados terapêuticos em 241 casos Primary lung abscess: diagnostic findings and results of the treatment in 241 cases  

Microsoft Academic Search

SINOPSE São mostrados aspectos diagnósticos e terapêuticos do abscesso pulmonar de aspiração. No período de 1968 a 2002 foram reunidos e estudados 241 casos da doença - 199 em homens e 42 em mulheres, com média de idade de 41,3 anos. Em 69% dos pacientes esteve presente a ingestão de álcool e em 64% o hábito tabágico. Tosse, expectoração, febre

ÂNGELA P. ZIEGLER; José S. Moreira; Rua Carlos Von Koseritz

308

SEM and TEM Observation of the Surfaces of the Fine-Grained Particles Retrieved from the Muses-C Regio on the Asteroid 25413 Itokawa  

NASA Technical Reports Server (NTRS)

Surface materials on airless solar system bodies exposed to interplanetary space are gradually changed their visible to near-infrared reflectance spectra by the process called "space weathering", which makes the spectra darker and redder. Hapke et al. proposed a model of space weathering: vapor deposition of nanophase reduced iron (npFe(sup 0)) on the surfaces of the grains within the very surface of lunar regolith. This model has been proved by detailed observation of the surfaces of the lunar soil grains by transmission electron microscope (TEM). They demonstrated that npFe(sup 0) was formed by a combination of vapor deposition and irradiation effects. In other words, both micrometeorite impacts and irradiation by solar wind and galactic cosmic ray play roles on the space weathering on the Moon. Because there is a continuum of reflectance spectra from those of Q-type asteroids (almost the same as those of ordinary chondrites) to those of S-type asteroids, it is strongly suggested that reflectance spectra of asteroids composed of ordinary chondrite-like materials were modified over time to those of S-type asteroids due to space weathering. It is predicted that a small amount of npFe(sup 0) on the surface of grains in the asteroidal regolith composed of ordinary chondrite-like materials is the main agent of asteroidal space weathering.

Noguchi, T.; Nakamura, T.; Zolensky, Michael E.; Tanaka, M.; Hashimoto, T.; Konno, M.; Nakato, A.; Ogami, T.; Fujimura, A.; Abe, M.; Yada, T.; Mukai, T.; Ueno, M.; Okada, T.; Shirai, K.; Ishibashi, Y.; Okazaki, R.

2011-01-01

309

Highly Regio- and Enantioselective Synthesis of Polysubstituted 2H-Pyrroles via Pd-Catalyzed Intermolecular Asymmetric Allylic Dearomatization of Pyrroles.  

PubMed

A highly efficient synthesis of chiral polysubstituted 2H-pyrrole derivatives via a Pd-catalyzed intermolecular asymmetric allylic dearomatization reaction of pyrroles is presented. With the commercially available palladium precursor and chiral ligand, the polysubstituted 2H-pyrrole products containing a chiral quaternary carbon center were obtained with up to 97% ee and >95/5 regioselectivity. PMID:24758260

Zhuo, Chun-Xiang; Zhou, Yong; You, Shu-Li

2014-05-01

310

Regio- and chemoselective reduction of nitroarenes and carbonyl compounds over recyclable magnetic ferrite-nickel nanoparticles (Fe(3)O(4)-Ni) by using glycerol as a hydrogen source.  

PubMed

Reduction by magnetic nano-Fe(3)O(4)-Ni: a facile, simple and environmentally friendly hydrogen-transfer reaction that takes place over recyclable ferrite-nickel magnetic nanoparticles (Fe(3)O(4)-Ni) by using glycerol as hydrogen source allows aromatic amines and alcohols to be synthesized from the precursor nitroarenes and carbonyl compounds. PMID:22933355

Gawande, Manoj B; Rathi, Anuj K; Branco, Paula S; Nogueira, Isabel D; Velhinho, Alexandre; Shrikhande, Janhavi J; Indulkar, Utkarsha U; Jayaram, Radha V; Ghumman, C Amjad A; Bundaleski, Nenad; Teodoro, Orlando M N D

2012-10-01

311

Regio- and Stereospecificity in the Oxygenation of Arachidonic Acid Catalyzed by Leu597 Mutants of Rabbit 15-Lipoxygenase: A QM/MM Study.  

PubMed

We combined quantum mechanics/molecular mechanics calculations with molecular dynamics simulations to study the addition of O2 to the pentadienyl radical of arachidonic acid (AA) catalyzed by the Leu597Val and Leu597Ala mutants of rabbit 15-lipoxygenase (15-rLO). In the Leu597Val mutant, the addition of O2 to C15 of AA is the predominant path, although it reduces the C15/C11 product ratio by almost ten times with respect to the wildtype enzyme. The S stereochemistry is kept. Mutation to Ala causes just the opposite effect: regiospecificity favoring addition to C15 is somewhat sharper than that in the wildtype, but the stereochemistry is R. This is because the extra space created by the mutation to Ala is big enough for AA to move so that it can adopt an alternative binding mode, and this opens new feasible paths for the attack of O2 . So, we showed that the Leu597Ala mutant of 15r-LO works as an aspirin-acetylated cyclooxygenase-2, which makes 15-(R)- hydroperoxyeicosatetraenoic acid. PMID:24753045

Suardíaz, Reynier; Masgrau, Laura; Lluch, José M; González-Lafont, Angels

2014-08-01

312

Origins of Regio- and Stereochemistry in Type 2 Intramolecular N-Acylnitroso Diels-Alder Reactions: A Computational Study of Tether Length and Substituent Effects  

PubMed Central

Quantum mechanical calculations have been used to investigate type 2 intramolecular Nacylnitroso Diels–Alder reactions. Experimentally observed regioselectivities and diastereoselectivities of these reactions have been reproduced using B3LYP/6-31+G(d) DFT calculations. The factors that govern selectivity (i.e. tether length, tether substitution and diene substitution) were systematically investigated. Tethers less than 6 carbon atoms lead to 1,3 regioisomers due to conformational restrictions. Substituents on the tether lead to diastereoselective outcomes dictated by transannular interactions in the transition states. The modest diastereoselectivity of diene-substituted substrates is rationalized as arising from reduction of eclipsing interactions in the flattened diene transition states. This method should prove valuable for planning syntheses involving type 2 intramolecular Diels–Alder reactions.

Cleary, Leah; Mak, Victor W.; Rychnovsky, Scott D.; Shea, Kenneth J.; Sizemore, Nicholas

2013-01-01

313

New reagent system for attaining high regio- and stereoselectivities in allylic displacement of 4-cyclopentene-1,3-diol monoacetate with aryl- and alkenylmagnesium bromides.  

PubMed

[Reaction: see text] Low regioselectivity of RMgBr (R = aryl, alkenyl) in the CuCN-catalyzed reaction with 4-cyclopentene-1,3-diol monoacetate is improved by addition of LiCl or MgCl2 to a similar extent as previously obtained with RMgCl (>90:10). The limitation encountered in the preparation of RMgCl no longer exists in the present method using RMgBr. The method is utilized in the synthesis of AH-13205, a selective EP2-receptor agonist. PMID:15646953

Kobayashi, Yuichi; Nakata, Kenya; Ainai, Takayuki

2005-01-20

314

Lettuce Costunolide Synthase (CYP71BL2) and Its Homolog (CYP71BL1) from Sunflower Catalyze Distinct Regio- and Stereoselective Hydroxylations in Sesquiterpene Lactone Metabolism*  

PubMed Central

Sesquiterpene lactones (STLs) are terpenoid natural products possessing the ?-lactone, well known for their diverse biological and medicinal activities. The occurrence of STLs is sporadic in nature, but most STLs have been isolated from plants in the Asteraceae family. Despite the implication of the ?-lactone group in many reported bioactivities of STLs, the biosynthetic origins of the ?-lactone ring remains elusive. Germacrene A acid (GAA) has been suggested as a central precursor of diverse STLs. The regioselective (C6 or C8) and stereoselective (? or ?) hydroxylation on a carbon of GAA adjacent to its carboxylic acid at C12 is responsible for the ?-lactone formation. Here, we report two cytochrome P450 monooxygenases (P450s) capable of catalyzing 6?- and 8?-hydroxylation of GAA from lettuce and sunflower, respectively. To identify these P450s, sunflower trichomes were isolated to generate a trichome-specific transcript library, from which 10 P450 clones were retrieved. Expression of these clones in a yeast strain metabolically engineered to synthesize substrate GAA identified a P450 catalyzing 8?-hydroxylation of GAA, but the STL was not formed by spontaneous lactonization. Subsequently, we identified the closest homolog of the GAA 8?-hydroxylase from lettuce and discovered 6?-hydroxylation of GAA by the recombinant enzyme. The resulting 6?-hydroxy-GAA spontaneously undergoes a lactonization to yield the simplest form of STL, costunolide. Furthermore, we demonstrate the milligram per liter scale de novo synthesis of costunolide using the lettuce P450 in an engineered yeast strain, an important advance that will enable exploitation of STLs. Evolution and homology models of these two P450s are discussed.

Ikezawa, Nobuhiro; Gopfert, Jens Christian; Nguyen, Don Trinh; Kim, Soo-Un; O'Maille, Paul E.; Spring, Otmar; Ro, Dae-Kyun

2011-01-01

315

Regio- and stereospecific oxidation of 9,10-dihydroanthracene and 9,10-dihydrophenanthrene by naphthalene dioxygenase: structure and absolute stereochemistry of metabolites.  

PubMed Central

The oxidation of 9,10-dihydroanthracene and 9,10-dihydrophenanthrene was examined with mutant and recombinant strains expressing naphthalene dioxygenase from Pseudomonas putida (NCIB 9816.4. Salicylate-induced cells of P. putida strain 9816/11 and isopropylthiogalactopyranoside-induced cells of Escherichia coli JM109(DE3)(pDTG141) oxidized 9,10-dihydroanthracene to (+)-cis-1R,2S)-1,2-dihydroxy-1,2,9,10-tetrahydroanthracene (> 95% relative yield; > 95% enantiomeric excess) as the major product. 9-Hydroxy-9,10-dihydroanthracene (< 5% relative yield) was a minor product formed by both organisms. The same cells oxidized 9,10-dihydrophenanthrene to (+)-cis-(3S,4R)-3,4-dihydroxy-3,4,9,10-tetrahydrophenanthrene (70% relative yield; > 95% enantiomeric excess) and (+)-(S)-9-hydroxy-9,10-dihydrophenanthrene (30% relative yield). The major reaction catalyzed by naphthalene dioxygenase with 9,10-dihydroanthracene and 9,10-dihydrophenanthrene was stereospecific dihydroxylation in which both of the previously undescribed cis-diene diols were of R configuration at the benzylic center adjacent to the bridgehead carbon atom. The results suggest that for benzocylic substrates, the location of benzylic carbons influences the type of reaction(s) catalyzed by naphthalene dioxygenase.

Resnick, S M; Gibson, D T

1996-01-01

316

The regio- and stereochemical course of reductive cross-coupling reactions between 1,3-disubstituted allenes and vinylsilanes: Synthesis of (Z)-dienes  

PubMed Central

In investigations aimed at exploring the potential of disubstituted allenes in stereoselective synthesis, we report studies that explore the reductive cross-coupling reaction of vinylsilanes with a range of substituted allenes. Regiochemical control is attained by employing allenic alkoxides, where the proximal heteroatom dictates the site-selectivity in a process that proceeds by net formal metallo-[3,3] rearrangement (directed carbometalation/elimination). Stereoselectivity in these reactions is complex, with both the nature of allene substitution and relative stereochemistry of the substrate impacting the stereoselective generation of each alkene of a substituted 1,3-diene. 2009 Elsevier Ltd. All rights reserved.

Barlan, Allan U.

2013-01-01

317

Regio- and stereoselective synthesis of a library of bioactive dispiro-oxindolo/acenaphthoquino andrographolides via 1,3-dipolar cycloaddition reaction under microwave irradiation.  

PubMed

Dispiro-pyrrolidino/pyrrolizidino fused oxindoles/acenaphthoquinones have been derived from andrographolide via azomethine ylide cycloaddition to the conjugated double-bond under microwave (MW) irradiation. The reactions are chemo-, stereo-, and regioselective in nature. Change in amino acid from sarcosine/N-benzyl glycine to l-proline changes the regiochemistry. A representative library of 40 compounds along with in vitro anticancer evaluation is reported. PMID:23167870

Hazra, Abhijit; Bharitkar, Yogesh P; Chakraborty, Debanjana; Mondal, Susanta Kumar; Singal, Nupur; Mondal, Shyamal; Maity, Arindam; Paira, Rupankar; Banerjee, Sukdeb; Mondal, Nirup B

2013-01-14

318

An Ems-Sensitivity Factor in Maize Conditioning Albino Leaf Stripes  

PubMed Central

A description is given for a recessive EMS-sensitivity factor conditioning albino leaf stripes. In the homozygous condition, there is low frequency of spontaneous leaf stripes. EMS, depending on the concentration, increases markedly the frequency of the stripes in 100% of the treated plants. The effects of EMS, given to the seeds, starts to appear from the 6th to 7th leaf and persists in all the leaves throughout the life cycle of the M1 plants. Only about 20–25% of the M2 plants showed some variegation. These variegated M2 plants were not distributed at random among the different ear-to-row M2 rows.

Efron, Y.

1974-01-01

319

Integration of artificial intelligence applications in the EMS: Issues and solutions  

SciTech Connect

This paper discusses the issues which must be addressed when integrating Artificial Intelligence (AI) and, in particular, expert system applications in an Energy Management System (EMS) environment. It is argued that these issues can be resolved by creating an environment which supports all the interfaces between the Artificial Intelligence (AI) applications and the EMS. This environment should also be responsible for maintaining a model of the power system common to all the AI applications. Once this environment has been created, AI applications can be easily plugged into the EMS. The design of such an environment is described and case studies of its implementation are provided to illustrate its flexibility.

Bann, J.; Irisarri, G.; Kirschen, D.; Miller, B.; Mokhtari, S. [Empros Power Systems Control, Plymouth, MN (United States)] [Empros Power Systems Control, Plymouth, MN (United States)

1996-02-01

320

Reservoir characterization and process monitoring with EM methods. 1994 Annual report.  

National Technical Information Service (NTIS)

During the past five years at Lawrence Livermore National Laboratory (LLNL) the authors have applied the EM induction method to the problem of petroleum reservoir characterization and enhanced oil recovery (EOR) monitoring. The goal is to develop practica...

M. Wilt

1995-01-01

321

Use of low power EM radar sensors for speech articulator measurements.  

National Technical Information Service (NTIS)

Very low power electromagnetic (EM) wave sensors are being used to measure speech articulator motions such as the vocal fold oscillations, jaw, tongue, and the soft palate. Data on vocal fold motions, that correlate well with established laboratory techni...

J. F. Holzrichter G. C. Burnett

1997-01-01

322

Synthesis and formation of an EMS correlated contaminant in biotechnologically manufactured L-tryptophan.  

PubMed

Contaminants in biotechnologically manufactured L-Tryptophan (Trp) are suspected to be responsible for the outbreak of an unknown autoimmune disease in 1989. The contaminants, found in Trp-lots of a Japanese manufacturer, are classified in EMS-correlated and non EMS-correlated substances. Up to now six EMS-correlated substances are known. One of these compounds is 2-(3'-indolylmethyl)-indole (IMT). IMT was detected as a major contaminant in two investigated EMS-associated trp-samples. In a seven step chemical synthesis IMT was obtained for use as a reference substance. A model system to investigate the formation of IMT was created using Trp and 3-indolylmethanol (IM). IMT formation was observed at acidic and alkaline pH-values and the optimal molar ratio of Trp to IM is 100:1. In addition an IMT formation was observed from indole, formaldehyde and Trp as well as from Trp and 3-indolylacetaldehyde. PMID:10721091

Müller, B; Pacholski, C; Simat, T; Steinhart, H

1999-01-01

323

Applications of the EM Algorithm to the Estimation of Bayesian Hyperparameters.  

National Technical Information Service (NTIS)

Applications of the EM algorithm to the estimation of Bayesian hyperparameters are discussed and reviewed in the context of the author's philosophy involving the inductive and pragmatic modelling of sampling distributions and prior structures. Frequently ...

T. Leonard

1982-01-01

324

A Zernike-moment-based non-local denoising filter for cryo-EM images.  

PubMed

Cryo-electron microscopy (cryo-EM) plays an important role in determining the structure of proteins, viruses, and even the whole cell. It can capture dynamic structural changes of large protein complexes, which other methods such as X-ray crystallography and nuclear magnetic resonance analysis find difficult. The signal-to-noise ratio of cryo-EM images is low and the contrast is very weak, and therefore, the images are very noisy and require filtering. In this paper, a filtering method based on non-local means and Zernike moments is proposed. The method takes into account the rotational symmetry of some biological molecules to enhance the signal-to-noise ratio of cryo-EM images. The method may be useful in cryo-EM image processing such as the automatic selection of particles, orientation determination, and the building of initial models. PMID:23564187

Wang, Jia; Yin, Changcheng

2013-04-01

325

Observações simultâneas no óptico e infravermelho próximo dos BL Lacs PKS 2005-489 e PKS 2155-304 em diversas escalas de tempo  

NASA Astrophysics Data System (ADS)

A existência de variações rápidas de brilho em alguns blazares é um fenômeno bem comprovado, mas até agora não sabemos ao certo quais são os mecanismos físicos envolvidos. A maior dificuldade é a ausência de observações multibanda simultâneas que poderiam fornecer vínculos aos modelos. Buscando colaborar com a discussão estudamos o comportamento de dois BL Lacs, PKS 2005-489 e PKS 2155-304, em relação à variabilidade em diversas escalas de tempo, de poucos minutos até vários meses, com observações simultâneas em seis bandas espectrais (óptico e infravermelho próximo). Para tanto dois telescópios do LNA foram utilizados em conjunto nas campanhas observacionais realizadas em 2001 e 2002, cujos resultados são apresentados aqui. As duas fontes apresentaram características bastante diferentes, inclusive em relação à existência de variabilidade nos índices espectrais. Particularmente, registramos a primeira detecção de variações em escalas de tempo da ordem de poucos minutos em PKS 2005-489, com evidências da presença de um atraso entre as curvas de luz nas bandas V e R e a variação em R ocorrendo antes (o contrário do esperado no modelo de shock-in-jet). Em PKS 2155-304 detectamos pela primeira vez variabilidade em escalas de tempo de poucos minutos no infravermelho em um AGN. As observações indicam que as variações de brilho em blazares são o resultado da ação de mais de um fenômeno, especialmente em escalas de tempo muito curtas. Alguns cenários físicos são sugeridos para explicar os resultados observacionais.

Dominici, T. P.; Abraham, Z.; Galo, A. L.

2003-08-01

326

Experimental study of the E(m, ?)/E(m, 1064) ratio as a function of wavelength, fuel type, height above the burner and temperature  

NASA Astrophysics Data System (ADS)

The optical properties of soot have been studied for many years with a particular attention focused on refractive index. In the present study, the two-excitation wavelength laser-induced incandescence technique has been applied to determine the ratio of the soot absorption function as a function of the wavelength. The advantage of this technique is to provide the determination of the E(m) ratio using a non-intrusive laser-based method without being disturbed by scattering. Measurements have been carried out in a methane premixed flat flame and in a diesel turbulent spray one. Four pairs of wavelength have been used to evaluate the spectral behavior of E(m) ratios from ultraviolet (UV) to near infrared (NIR). The two-excitation wavelength LII method implies heating soot the same way using two different laser excitations. Particular operating conditions must be selected to insure the equality of the LII signals, such an equality being necessary to derive the E(m) ratio. A laser excitation at 1064 nm has been chosen as a reference, and the obtained results have been compared with those issued from the use of UV and visible wavelengths of 266, 355, 532 and 660 nm. Results show a significant decrease of the E(m) ratio from UV to visible while it tends to become constant from 532 nm to NIR. The use of different experimental conditions allows to analyze the dependence of the E(m) ratios with the height above the burner, the fuel type and the soot temperature. No significant influence of these parameters has been pointed out on the relative E(m) values determined in the flame conditions investigated here.

Bejaoui, S.; Lemaire, R.; Desgroux, P.; Therssen, E.

2013-10-01

327

Fully EM algorithms for the quasi-neutral, zero-electron-inertia model  

Microsoft Academic Search

An algorithm has been developed to compute the electromagnetic signature of impulsive currents in quasi-neutral, collisionless plasmas. Such plasmas are common in laser target chambers, space physics, and EMP generating events. Traditional models[1] used in this regime make the Darwin assumption that neglects purely EM waves. Computing electro-magnetic pulse behavior (EMP) requires the solution of the EM wave equations. Other

Dennis Hewett

2009-01-01

328

Parallel Electromagnetic Simulation for Electric Large Target by EMS-FMM  

Microsoft Academic Search

The development framework of parallel electromagnetic simulation software EMS-FMM based on multilevel fast multipole method (MLFMM) is present in this paper. EMS-FMM can solve large-scale scattering problem of 10 million scale with a complexity of O (Nlog N), so it's efficient for electric large target. It's implemented by C and Fortran with MPI communication on cluster DeepComp 7000. Implementation of

Wu Wang; Yangde Feng; Xuebin Chi

2010-01-01

329

Using EM to Obtain Asymptotic Variance-Covariance Matrices: The SEM Algorithm  

Microsoft Academic Search

The expectation maximization (EM) algorithm is a popular, and often remarkably simple, method for maximum likelihood estimation in incomplete-data problems. One criticism of EM in practice is that asymptotic variance–covariance matrices for parameters (e.g., standard errors) are not automatic byproducts, as they are when using some other methods, such as Newton–Raphson. In this article we define and illustrate a procedure

Xiao-Li Meng; Donald B. Rubin

1991-01-01

330

SELETIVIDADE E CONTROLE POR MISTURAS DE HERBICIDAS EM ALGODOEIRO HERBÁCEO1  

Microsoft Academic Search

RESUMO: Utilizam-se misturas de herbicidas para evitar a resistência de plantas daninhas a herbicidas e obter melhor eficiência de controle das plantas daninhas. Conduziu-se, no Campo Experimental da Embrapa Algodão, Barbalha, CE, experimento objetivando avaliar o efeito de misturas duplas, triplas e quádruplas de herbicidas, envolvendo Diuron, pendimethalin, metolachlor e oxadiazon, aplicadas em pré-emergência, no controle de plantas daninhas em

ANTONIA ELIENE DUARTE; JOSÉ RODRIGUES PEREIRA; JOÃO BOSCO PITOMBEIRA; MARIA ARLENE PESSOA DA SILVA; FANUEL PEREIRA DA SILVA

331

Direct EM based optimization of advanced waffle-iron and rectangular combline filters  

Microsoft Academic Search

A fast hybrid mode-matching (MM)\\/finite-element (FE) method is applied for the direct EM based optimization of advanced waffle-iron filters and coax-fed rectangular combline filters. The proposed technique, which combines the efficiency of the MM with the flexibility of the FE technique, achieves the direct EM based optimization of these components within typically an overnight run on a PC. The CAD

F. Arndt; Joem Brandt

2002-01-01

332

Crosshole EM for oil field characterization and EOR monitoring: Field examples  

Microsoft Academic Search

Crosshole and surface-to-borehole electromagnetic (EM) imaging is applied to reservoir characterization and steam flood monitoring in a central California oil field. Steam was injected into three stacked, eastward-dipping, unconsolidated oil sands within the upper 200 in. The steam plume is expected to develop as an ellipse aligned with the regional northwest-southeast strike. EM measurements were made from two flberglass-cased observation

M. Wilt; C. Schenkel; C. Torres-Verdin; Ki Ha Lee; Hung-Wen Tseng

1994-01-01

333

The Distance to SN 1999em in NGC 1637 from the Expanding Photosphere Method  

Microsoft Academic Search

We present 30 optical spectra and 49 photometric epochs sampling the first 517 days after discovery of supernova (SN) 1999em and derive its distance through the expanding photosphere method (EPM). SN 1999em is shown to be a Type II-plateau (II-P) event, with a photometric plateau lasting until about 100 days after explosion. We identify the dominant ions responsible for most

Douglas C. Leonard; Alexei V. Filippenko; Elinor L. Gates; Weidong Li; Ronald G. Eastman; Aaron J. Barth; Schelte J. Bus; Ryan Chornock; Alison L. Coil; Sabine Frink; Carol A. Grady; Alan W. Harris; Matthew A. Malkan; Thomas Matheson; Andreas Quirrenbach; Richard R. Treffers

2002-01-01

334

X-ray, Optical, and Radio Observations of SN 1999em and SN 1998S  

Microsoft Academic Search

Observations of the Type II-P (plateau) Supernova (SN) 1999em and Type IIn (narrow emission line) SN 1998S have enabled estimation of the profile of the SN ejecta, the structure of the circumstellar medium (CSM) established by the pre-SN stellar wind, and the nature of the shock interaction. SN 1999em is the first and only Type II-P detected at both X-ray

D. Pooley; W. H. G. Lewin; D. W. Fox; J. M. Miller; C. K. Lacey; S. D. Van Dyk; K. W. Weiler; R. A. Sramek; A. V. Filippenko; D. C. Leonard; S. Immler; R. A. Chevalier; A. C. Fabian; C. Fransson; K. Nomoto

2001-01-01

335

Pre-flight risk assessment in emergency medical service (EMS) helicopters  

NASA Technical Reports Server (NTRS)

A preflight risk assessment system (SAFE) was developed at NASA-Ames Research Center for civil EMS operations to assist pilots in making a decision objectively to accept or decline a mission. The ability of the SAFE system to predict risk profiles was examined at an EMS operator. Results of this field study showed that the usefulness of SAFE was largely dependent on the type of mission flown.

Shively, Robert J.

1990-01-01

336

Helicopter-borne measurements of sea ice thickness, using a small and lightweight, digital EM system  

Microsoft Academic Search

Sea ice is an important climate variable and is also an obstacle for marine operations in polar regions. We have developed a small and lightweight, digitally operated frequency-domain electromagnetic-induction (EM) system, a so-called EM bird, dedicated for measurements of sea ice thickness. It is 3.5 m long and weighs only 105 kg, and can therefore easily be shipped to remote places and

Christian Haas; John Lobach; Stefan Hendricks; Lasse Rabenstein; Andreas Pfaffling

2009-01-01

337

Fast, simultaneous and robust VLF-EM data denoising and reconstruction via multivariate empirical mode decomposition  

NASA Astrophysics Data System (ADS)

The measurement of Very Low Frequency Electromagnetic (VLF-EM) is important in many different applications, i.e, environmental, archeological, geotechnical studies, etc. In recent years, improving and enhancing VLF-EM data containing complex numbers (bivariate) was presented by several authors in order to produce reliable models, generally using univariate empirical mode decomposition (EMD). Applying univariate EMD separately on each data is problematic. This results in a different number of misaligned Intrinsic Mode Functions (IMFs) which can complicate the selection of some IMFs for denoising process. Thus, a filtering method based on the multivariate empirical mode decomposition (MEMD) approach to decompose simultaneously bivariate data is proposed. In this paper we address two issues by employing the recently introduced noise assisted MEMD (N-A MEMD) for improving bivariate VLF-EM data. Firstly, the N-A MEMD to decompose bivariate measurement of the VLF-EM data into IMFs and a residue is defined as VLF-EM signal or unwanted noise. Secondly, the proposed method is used to enhance VLF-EM data and to reject unwanted noise. Finally, the proposed method is applied to a synthetic data with two added sinusoids. To demonstrate the robustness of the N-A MEMD method, the method was tested on added-noise synthetic data sets and the results were compared to the Ensemble EMD (EEMD) and Bivariate EMD (BEMD). The N-A MEMD gave more robust and accurate results than the EEMD and BEMD methods and the method required less CPU time to obtain the IMFs compared to EEMD. The method was also tested on several field data sets. The results indicate that the filtered VLF-EM data based on the N-A MEMD make the data easier to interpret and to be analyzed further. In addition, the 2D resistivity profile estimated from the inversion of filtered VLF-EM data results was appropriate to the geological condition.

Sungkono; Bahri, Ayi S.; Warnana, Dwa D.; Monteiro Santos, Fernando A.; Santosa, Bagus J.

2014-06-01

338

Two EM-type channel estimation algorithms for OFDM with transmitter diversity  

Microsoft Academic Search

We study channel estimation for orthogonal frequency-division multiplexing (OFDM) systems utilizing transmitter diversity and operating over multipath fading channels. Two expectation-maximization (EM)-type algorithms are introduced and compared with each other in terms of convergence rate. At each iteration and for every OFDM link, the EM-type algorithms partition the problem of estimating a multi-input channel into independent channel estimations for each

Yongzhe Xie; Costas N. Georghiades

2003-01-01

339

The Soils and Groundwater – EM-20 S&T Roadmap Quality Assurance Project Plan  

SciTech Connect

The Soils and Groundwater – EM-20 Science and Technology Roadmap Project is a U.S. Department of Energy, Office of Environmental Management-funded initiative designed to develop new methods, strategies and technology for characterizing, modeling, remediating, and monitoring soils and groundwater contaminated with metals, radionuclides, and chlorinated organics. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by EM-20 Roadmap Project staff.

Fix, N. J.

2008-02-11

340

Very Fast EM-Based Mixture Model Clustering Using Multiresolution Kd-Trees  

Microsoft Academic Search

Clustering is important in many fields including manufacturing, biology,finance, and astronomy. Mixture models are a popular approachdue to their statistical foundations, and EM is a very popular methodfor finding mixture models. EM, however, requires many accesses ofthe data, and thus has been dismissed as impractical (e.g. (Zhang, Ramakrishnan,& Livny, 1996)) for data mining of enormous datasets.We present a new algorithm,

Andrew W. Moore

1998-01-01

341

Visualizing Proteins and Macromolecular Complexes by Negative Stain EM: from Grid Preparation to Image Acquisition  

PubMed Central

Single particle electron microscopy (EM), of both negative stained or frozen hydrated biological samples, has become a versatile tool in structural biology 1. In recent years, this method has achieved great success in studying structures of proteins and macromolecular complexes 2, 3. Compared with electron cryomicroscopy (cryoEM), in which frozen hydrated protein samples are embedded in a thin layer of vitreous ice 4, negative staining is a simpler sample preparation method in which protein samples are embedded in a thin layer of dried heavy metal salt to increase specimen contrast 5. The enhanced contrast of negative stain EM allows examination of relatively small biological samples. In addition to determining three-dimensional (3D) structure of purified proteins or protein complexes 6, this method can be used for much broader purposes. For example, negative stain EM can be easily used to visualize purified protein samples, obtaining information such as homogeneity/heterogeneity of the sample, formation of protein complexes or large assemblies, or simply to evaluate the quality of a protein preparation. In this video article, we present a complete protocol for using an EM to observe negatively stained protein sample, from preparing carbon coated grids for negative stain EM to acquiring images of negatively stained sample in an electron microscope operated at 120kV accelerating voltage. These protocols have been used in our laboratory routinely and can be easily followed by novice users.

Booth, David S.; Avila-Sakar, Agustin; Cheng, Yifan

2011-01-01

342

Method for estimating dynamic EM tracking accuracy of surgical navigation tools  

NASA Astrophysics Data System (ADS)

Optical tracking systems have been used for several years in image guided medical procedures. Vendors often state static accuracies of a single retro-reflective sphere or LED. Expensive coordinate measurement machines (CMM) are used to validate the positional accuracy over the specified working volume. Users are interested in the dynamic accuracy of their tools. The configuration of individual sensors into a unique tool, the calibration of the tool tip, and the motion of the tool contribute additional errors. Electromagnetic (EM) tracking systems are considered an enabling technology for many image guided procedures because they are not limited by line-of-sight restrictions, take minimum space in the operating room, and the sensors can be very small. It is often difficult to quantify the accuracy of EM trackers because they can be affected by field distortion from certain metal objects. Many high-accuracy measurement devices can affect the EM measurements being validated. EM Tracker accuracy tends to vary over the working volume and orientation of the sensors. We present several simple methods for estimating the dynamic accuracy of EM tracked tools. We discuss the characteristics of the EM Tracker used in the GE Healthcare family of surgical navigation systems. Results for other tracking systems are included.

Nafis, Christopher; Jensen, Vern; Beauregard, Lee; Anderson, Peter

2006-03-01

343

High-speed computation of the EM algorithm for PET image reconstruction  

SciTech Connect

The PET image reconstruction based on the EM algorithm has several attractive advantages over the conventional convolution backprojection algorithms. However, two major drawbacks have impeded the routine use of the EM algorithm, namely, the long computational time due to slow convergence and the large memory required for the storage of the image, projection data and the probability matrix. In this study, the authors attempts to solve these two problems by parallelizing the EM algorithm on a multiprocessor system. The authors have implemented an extended hypercube (EH) architecture for the high-speed computation of the EM algorithm using the commercially available fast floating point digital signal processor (DSP) chips as the processing elements (PEs). The authors discuss and compare the performance of the EM algorithm on a 386/387 machine, CD 4360 mainframe, and on the EH system. The results show that the computational speed performance of an EH using DSP chips as PEs executing the EM image reconstruction algorithm is about 130 times better than that of the CD 4360 mainframe. The EH topology is expandable with more number of PEs.

Rajan, K.; Patnaik, L.M.; Ramakrishna, J. (Indian Inst. of Science, Bangalore (India))

1994-10-01

344

Anisotropic 3D inversion of towed streamer EM data from the Troll West oil province (Invited)  

NASA Astrophysics Data System (ADS)

Obviating the need for ocean bottom receivers, the towed streamer EM system enables CSEM data to be acquired simultaneously with seismic over very large areas in frontier and mature basins for higher production rates and more cost effective than conventional marine CSEM. The towed streamer EM data are currently processed and delivered as a spectrum of frequency-domain responses. We apply a 3D anisotropic inversion methodology for towed streamer EM data that includes a moving sensitivity domain. Our implementation is based on the 3D contraction integral equation method for computing the EM responses and Fréchet derivatives, and uses the re-weighted regularized conjugate gradient method for minimizing the objective functional with focusing regularization. We present an actual case study for the 3D anisotropic inversion of towed streamer EM data from the Troll West oil province in the North Sea, and demonstrate our ability to image the Troll West Oil and Gas Provinces. We conclude that 3D anisotropic inversion of the data from the current generation of towed streamer EM system can adequately recover both the vertical and horizontal resistivities in anisotropic hydrocarbon-bearing formations.

Mattsson, J.; Midgley, J.; Zhdanov, M. S.; ENDO, M.

2013-12-01

345

Visualizing proteins and macromolecular complexes by negative stain EM: from grid preparation to image acquisition.  

PubMed

Single particle electron microscopy (EM), of both negative stained or frozen hydrated biological samples, has become a versatile tool in structural biology. In recent years, this method has achieved great success in studying structures of proteins and macromolecular complexes. Compared with electron cryomicroscopy (cryoEM), in which frozen hydrated protein samples are embedded in a thin layer of vitreous ice, negative staining is a simpler sample preparation method in which protein samples are embedded in a thin layer of dried heavy metal salt to increase specimen contrast. The enhanced contrast of negative stain EM allows examination of relatively small biological samples. In addition to determining three-dimensional (3D) structure of purified proteins or protein complexes, this method can be used for much broader purposes. For example, negative stain EM can be easily used to visualize purified protein samples, obtaining information such as homogeneity/heterogeneity of the sample, formation of protein complexes or large assemblies, or simply to evaluate the quality of a protein preparation. In this video article, we present a complete protocol for using an EM to observe negatively stained protein sample, from preparing carbon coated grids for negative stain EM to acquiring images of negatively stained sample in an electron microscope operated at 120kV accelerating voltage. These protocols have been used in our laboratory routinely and can be easily followed by novice users. PMID:22215030

Booth, David S; Avila-Sakar, Agustin; Cheng, Yifan

2011-01-01

346

New Developments in the Technology Readiness Assessment Process in US DOE-EM - 13247  

SciTech Connect

A Technology Readiness Assessment (TRA) is a systematic, metric-based process and accompanying report that evaluates the maturity of the technologies used in systems; it is designed to measure technology maturity using the Technology Readiness Level (TRL) scale pioneered by the National Aeronautics and Space Administration (NASA) in the 1980's. More recently, DoD has adopted and provided systematic guidance for performing TRAs and determining TRLs. In 2007 the GAO recommended that the DOE adopt the NASA/DoD methodology for evaluating technology maturity. Earlier, in 2006-2007, DOE-EM had conducted pilot TRAs on a number of projects at Hanford and Savannah River. In March 2008, DOE-EM issued a process guide, which established TRAs as an integral part of DOE-EM's Project Management Critical Decision Process. Since the development of its detailed TRA guidance in 2008, DOE-EM has continued to accumulate experience in the conduct of TRAs and the process for evaluating technology maturity. DOE has developed guidance on TRAs applicable department-wide. DOE-EM's experience with the TRA process, the evaluations that led to recently developed proposed revisions to the DOE-EM TRA/TMP Guide; the content of the proposed changes that incorporate the above lessons learned and insights are described. (authors)

Krahn, Steven [Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN, 37235 (United States)] [Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN, 37235 (United States); Sutter, Herbert [Consultant, 910 Laurel Green Dr., North Canton, OH, 44720 (United States)] [Consultant, 910 Laurel Green Dr., North Canton, OH, 44720 (United States); Johnson, Hoyt [DOE-EM, 1000 Independence Ave., Washington, DC, 20585 (United States)] [DOE-EM, 1000 Independence Ave., Washington, DC, 20585 (United States)

2013-07-01

347

Tide-driven fluid mud transport in the Ems estuary  

NASA Astrophysics Data System (ADS)

The Ems estuary, located at the border between The Netherlands and Germany, experienced a significant change of the hydrodynamic regime during the past decades, as a result of extensive river engineering. With the net sediment transport now being flood-oriented, suspended sediment concentrations have increased dramatically, inducing siltation and formation of fluid mud layers, which, in turn, influence hydraulic flow properties, such as turbulence and the apparent bed roughness. Here, the process-based understanding of fluid mud is essential to model and predict mud accumulation, not only regarding the anthropogenic impact, but also in view of the expected changes of environmental boundary conditions, i.e., sea level rise. In the recent past, substantial progress has been made concerning the understanding of estuarine circulation and influence of tidal asymmetry on upstream sediment accumulation. While associated sediment transport formulations have been implemented in the framework of numerical modelling systems, in-situ data of fluid mud are scarce. This study presents results on tide-driven fluid mud dynamics, measured during four tidal cycles aside the navigation channel in the Ems estuary. Lutoclines, i.e., strong vertical density gradients, were detected by sediment echo sounder (SES). Acoustic Doppler current profiles (ADCP) of different acoustic frequencies were used to determine hydrodynamic parameters and the vertical distribution of suspended sediment concentrations in the upper part of the water column. These continuous profiling measurements were complemented by CTD, ADV, and OBS casts. SES and ADCP profiles show cycles of fluid mud entrainment during accelerating flow, and subsequent settling, and the reformation of a lutocline during decelerating flow and slack water. Significant differences are revealed between flood and ebb phase. Highest entrainment rates are measured at the beginning of the flood phase, associated with strong current shear and rapid vertical mixing, inducing the highest instantaneous suspended sediment flux measured during the tidal cycle. During decelerating flood currents a lutocline is again established at a certain distance above the consolidated river bed. During slack water after the flood phase the concentration gradient increases and the thickness of the fluid mud layer below is constant, also during a significant part of the ebb phase. As water depth decreases during ebb, entrainment occurs only at the upper part of the fluid mud layer. The suspended sediment flux is low compared to the flood phase. These observations are further elaborated using turbulence parameters obtained from ADV and ADCP, explaining the difference between ebb and flood concerning the vertical location of the maximum concentration gradient. This study is funded through DFG-Research Center / Excellence Cluster "The Ocean in the Earth System". The Senckenberg Institute and the Federal Waterways Engineering and Research Institute are acknowledged for technical support.

Becker, Marius; Maushake, Christian; Winter, Christian

2014-05-01

348

Electromagnetic (EM) wave attachment to femtosecond laser plasma filaments  

NASA Astrophysics Data System (ADS)

This thesis outlines a theoretical and experimental analysis of utilizing plasma filaments generated by a femtosecond class laser system as a means for transmission of Radio Frequency (RF) electro-magnetic waves. Theoretically, the plasma filaments are modeled as complex cylindrical wires in space for single and dual wire configurations. Attenuation as a function of distance is calculated for single wire TE mode propagation and dual wire TEM mode propagation. Minimum attenuation is shown to be dependant on filament diameter, electron density and filament separation (for the dual wire case). Initial experimental validation of theoretical models is performed with copper wire filament surrogates. RF/plasma filament interaction is then demonstrated in a rectangular waveguide fixture. Filament electron density enhancement is demonstrated in cylindrical resonant RF cavities (2.6 GHz and 0.9 GHz) where an increase in pulse width of attached EM waves beyond lifetimes of typical ultra-fast laser generated plasma filaments is observed. Transmission of RF energy out of resonant cavities along a filament is demonstrated further validating transmission theory.

Friedman, Daniel Clint

349

EM modeling for GPIR using 3D FDTD modeling codes  

SciTech Connect

An analysis of the one-, two-, and three-dimensional electrical characteristics of structural cement and concrete is presented. This work connects experimental efforts in characterizing cement and concrete in the frequency and time domains with the Finite Difference Time Domain (FDTD) modeling efforts of these substances. These efforts include Electromagnetic (EM) modeling of simple lossless homogeneous materials with aggregate and targets and the modeling dispersive and lossy materials with aggregate and complex target geometries for Ground Penetrating Imaging Radar (GPIR). Two- and three-dimensional FDTD codes (developed at LLNL) where used for the modeling efforts. Purpose of the experimental and modeling efforts is to gain knowledge about the electrical properties of concrete typically used in the construction industry for bridges and other load bearing structures. The goal is to optimize the performance of a high-sample-rate impulse radar and data acquisition system and to design an antenna system to match the characteristics of this material. Results show agreement to within 2 dB of the amplitudes of the experimental and modeled data while the frequency peaks correlate to within 10% the differences being due to the unknown exact nature of the aggregate placement.

Nelson, S.D.

1994-10-01

350

SEI: Junior E&M I Course Materials - Student Difficulties  

NSDL National Science Digital Library

This is a collection of student difficulties identified in a junior-level Electricity and Magnetism course during four semesters of a curriculum transformation project. These resource documents present the research findings of this project that resulted from: interviews with students using âthink-aloudâ protocol as they worked through problems or diagrammed their understanding using concept maps; observations during help sessions and tutorials; student questions during lecture; student performance on concept tests / clicker questions; student performance on homework and exams; and student performance on the conceptual assessment developed for the course. In addition to student difficulties, these documents include the learning goals associated with each topic and class activities developed by other institutions to address that topic. Those who wish to learn more about these activities activities should steven.pollock@colorado.edu. This material was developed as part of a education research-based course transformation for junior level E&M. All of the resources developed for this course are available, sorted by individual topic and type, at http://www.compadre.org/psrc/items/Relations.cfm?ID=7891.

Pollock, Steven J.; Chasteen, Stephanie V.; Kinney, Edward; Dubson, Michael

2010-06-10

351

Estuarine nitrite maxima and nitrifying bacteria (Ems-Dollard estuary)  

NASA Astrophysics Data System (ADS)

Nitrifying bacteria were isolated from the Ems-Dollard estuary and cultured in batch as well as in continuous cultures. It was shown that the ammonia oxidizing bacteria of the genus Nitrosomonas are able to adapt to the whole estuarine salinity range, though they react to salinity changes initially with an increased lag phase. At the culture conditions (25°C, salinity 15) the ammonia as well as the nitrite oxidizer ( Nitrobacter) had specific maxium growth rates (? m) and half saturation values ( Ks) that are similar to those reported for non-marine conditions. For Nitrosomonas from the Dollard ? m and Ks at 25°C are 0.036 h -1 and 55.4 ?mol · 1 -1 ammonia for Nitrobacter 0.064 h -1 and 267.2 ?mol · 1 -1 nitrite respectively. From a mixed continuous culture of both organisms it is concluded that below 95 ?mol · 1 -1 O 2 oxidation of nitrite and below 32.5 ?mol · 1 -1 O 2 also the oxidation of ammonia is inhibited. It is argued that oxygen limitation in the top sediments of the Dollard is responsible for development of a nitrite maximum in sediment pore water and for a relative high ratio of ammonia oxidizers to nitrite oxidizers. By resuspension of bacteria associated with suspended particles their anomalous ratio is contributing to nitrite development in the water phase also.

Helder, W.; De Vries, R. T. P.

352

If EM waves don't interfere, what causes interferograms?  

NASA Astrophysics Data System (ADS)

Photonics engineers involved in designing and operating Fourier transform spectrometers (FTS) often rely on Maxwell's wave equations and time-frequency (distance-wavenumber) Fourier theory as models to understand and predict the conversion of optical energy to electrical signals in their instruments. Dr. Chandrasekhar Roychoudhuri and his colleagues, at last year's conference, presented three significant concepts that might completely change the way we comprehend the interaction of light and matter and the way interference information is generated. The first concept is his non-interaction of waves (NIW) formulation, which puts in place an optical wave description that more accurately describe the properties of the finite time and spatial signals of an optical system. The second is a new description for the cosmic EM environment that recognizes that space is really filled with the ether of classical electromagnetics. The third concept is a new metaphysics or metaphotonics that compares the photon as a particle in a void against the photon as a wave in a medium to see which best explain the twelve different aspects of light. Dr. Henry Lindner presents a compelling case that photons are waves in a medium and particles (electrons, protons, atoms) are wave-structures embedded in the new ether. Discussion of the three new principles is intended to increase the curiosity of photonics engineers to investigate these changes in the nature of light and matter.

Wellard, Stanley J.

2012-10-01

353

EM703 improves bleomycin-induced pulmonary fibrosis in mice by the inhibition of TGF-? signaling in lung fibroblasts  

Microsoft Academic Search

BACKGROUND: Fourteen-membered ring macrolides have been effective in reducing chronic airway inflammation and also preventing lung injury and fibrosis in bleomycin-challenged mice via anti-inflammatory effects. EM703 is a new derivative of erythromycin (EM) without the bactericidal effects. We investigated the anti-inflammatory and antifibrotic effects of EM703 in an experimental model of bleomycin-induced lung injury and subsequent fibrosis in mice. METHODS:

Ying Ji Li; Arata Azuma; Jiro Usuki; Shinji Abe; Kuniko Matsuda; Toshiaki Sunazuka; Takako Shimizu; Yukiyo Hirata; Hirofumi Inagaki; Tomoyuki Kawada; Satoru Takahashi; Shoji Kudoh; Satoshi Omura

2006-01-01

354

Evolução da morfologia de fases de blendas PA6\\/AES em extrusora de dupla rosca e moldagem por injeção  

Microsoft Academic Search

Resumo: A evolução da morfologia de fases em blendas não reativas e reativas de poliamida-6 com copolímero de acrilonitrila\\/EPDM\\/estireno (AES) em uma extrusora de rosca dupla co-rotacional foi investigada. A evolução da morfologia de fases ao longo da extrusora de rosca dupla foi monitorada através da coleta de pequenas amostras em válvulas no barril da extrusora e caracterização por microscopia

Adriane Bassani; Elias Hage Jr; Luiz A. Pessan; Ana V. Machado; José A. Covas

2005-01-01

355

Investigation of EMS based on fuzzy logic controller for an ICE\\/battery\\/UC hybrid electric vehicle  

Microsoft Academic Search

The EMS(energy management strategy) based on fuzzy logic is presented in this paper ,which is designed in MATLAB and Simulink to control the torque of the engine. The required torque and the SOC(state of charge) of the battery and UC (ultracapacitor) are used as the inputs of the EMS. The EMS is mainly consisted of two FLCs(fuzzy logic controller) ,which

Shijing Xu

2011-01-01

356

Mapping Coastal Wetlands Using EM and Airborne Lidar: a Texas Example  

NASA Astrophysics Data System (ADS)

We combined EM induction and airborne lidar measurements with vegetation surveys along two transects across Mustang Island, a Texas barrier island, to examine whether EM and lidar can be used to map coastal wetlands and associated geomorphic environments. Lidar-derived elevations correlate well with National Wetland Inventory (NWI) upland, palustrine, estuarine, and marine units. Lidar can be used to map wetland habitat more accurately and in greater detail than is feasible from aerial photographs and limited field checks, approaching that achievable on the ground. Where vegetation is dense, lidar-derived elevations may represent the top of massed vegetation rather than the ground surface, leading to potential habitat misclassification. Measurements of shallow electrical conductivity using a ground-based EM instrument range over three orders of magnitude and also correlate well with NWI habitat and geomorphic unit. High conductivities are measured within marine and estuarine NWI units and in salt marsh, wind-tidal flat, and forebeach environments. Low conductivities are measured within upland and palustrine NWI habitats and in dune, VBF, and fresh marsh environments. Conductivity profiles possess more mappable detail than is present on NWI maps. Tests of an airborne EM sensor towed 30 m above the ground yielded insufficient resolution. Elevation and conductivity are inversely correlated along the transects. EM and lidar readily discern saline- and fresh-water environments and complement traditional wetland classification by helping distinguish environments that have similar signatures on aerial photographs. There is some overlap in elevation and conductivity among similar habitats and environments, but a statistical classification based on integrated data from lidar, EM, and aerial photographs can achieve greater resolution and accuracy than current remote-sensing methods. Future work should include evaluating the effect of vegetation density on lidar-beam penetration, quantifying seasonal change in ground conductivity in fresh and saline environments, examining the geographic variability of elevation and conductivity, and further evaluating the use of airborne EM sensors to measure conductivity at multiple exploration depths simultaneously.

Paine, J. G.; White, W. A.; Smyth, R. C.; Andrews, J. R.; Gibeaut, J. C.

2005-12-01

357

Noninvasive monitoring of CO2 sequestration sites using airborne EM technology  

NASA Astrophysics Data System (ADS)

Usage of conventional airborne EM methods for studies related to CO2 sequestration reservoirs have been restricted up to date due to depth and system noise limitations. Recently a family of new EM systems was developed and launched in Canada, allowing superior depth of investigation to that of the conventional EM systems. Depending on the resistivity of the area such systems are capable of recording response from targets emplaced at the depths of up to 2 kilometers below surface. These systems are powered by natural (telluric and storm lightning) EM fields and are particularly sensitive to contrast in electrical properties of the subsurface, rather than absolute values of the conductivities, which make these systems suitable for usage in both resistive and conductive environments, including the subsurface identification and mapping of gas, hydrocarbons, liquid CO2 and supercritical CO2. Based on the well log data collected at one of the proposed sequestration sites, forward modeling has been carried out in order to study which changes in electrical properties of reservoir rocks before and after the introduction of CO2 to the sequestration reservoir are sufficient to provide enough contrast so they become detectable by EM systems. The results of the modeling showed that under favourable conditions it is possible to differentiate between brine-filled reservoirs versus CO2-filled reservoir at a depth of more than 1 kilometer with the main controlling parameters being reservoir effective porosity, thickness, Total Dissolved Solids (TDS) content of the pore-filling fluid and CO2 saturation after the injection. EM surveying can play a crucial role in studies of moderately deep-seated reservoirs, specifically can assist in monitoring CO2 injection and migration and can provide some additional data regarding the CO2 saturation level. The benefits of application of these new EM systems compared with 3D reflection seismic, VSP, gravity, and other geophysical methods will also be discussed.

Kaminski, V.; Harbert, W. P.; Legault, J. M.

2009-12-01

358

EM-54 Technology Development In Situ Remediation Integrated Program. Annual report  

SciTech Connect

The Department of Energy (DOE) established the Office of Technology Development (EM-50) as an element of Environmental Restoration and Waste Management (EM) in November 1989. EM manages remediation of all DOE sites as well as wastes from current operations. The goal of the EM program is to minimize risks to human health, safety and the environment, and to bring all DOE sites into compliance with Federal, state, and local regulations by 2019. EM-50 is charged with developing new technologies that are safer, more effective and less expensive than current methods. The In Situ Remediation Integrated Program (the subject of this report) is part of EM-541, the Environmental Restoration Research and Development Division of EM-54. The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: Significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces; in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP tends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years.

Not Available

1993-08-01

359

The wheat Em promoter drives reporter gene expression in embryo and aleurone tissue of transgenic barley and rice.  

PubMed

The early methionine (Em) proteins are members of the late embryogenesis abundant (LEA) group of proteins that have been considered to be embryo specific. The ability of a 646-bp wheat Em promoter to control green fluorescent protein (gfp) expression was investigated in transgenic barley and rice. Seeds of transgenic plants expressed gfp in the developing embryo but also in the aleurone layer. The 646-bp Em promoter also directed strong gfp expression in cells comprising the junction between the endosperm transfer cells and cells of the aleurone layer. Em-gfp expression in transgenic barley showed differences in spatial and temporal control when compared with that observed in transgenic rice. Em-gfp expression was also detected in mature aleurone cells of transgenic barley and rice with and without abscisic acid (ABA) treatment. Reverse transcriptase-polymerase chain reaction (RT-PCR) results indicated the presence of Em and Em-homologous transcript in embryo, aleurone and endosperm tissues of wheat and of barley and rice, respectively. These results suggest that Em proteins may be expressed in both the embryo and aleurone during seed development, possibly providing protection against desiccation in these two tissues that survive seed drying. They may also have a similar role in these tissues during germination. The Em promoter from wheat may be useful in the expression of novel genes in cereal grains, as an embryo- and aleurone-specific promoter complementing other available endosperm- and pericarp-specific promoters to collectively increase the expression of transgenes in seeds. PMID:17173630

Furtado, Agnelo; Henry, Robert James

2005-07-01

360

Rock 'Em, Sock 'Em!  

ERIC Educational Resources Information Center

K-12-level competitive robotics is growing in popularity around the country and worldwide. According to one of the leading organizers of these events, FIRST--For Inspiration and Recognition of Science and Technology--250,000 students from 56 countries take part in its competitions. FIRST Tech Challenge (FTC) is a yearly event the organization puts…

Waters, John K.

2011-01-01

361

Elimination of error factors, affecting EM and seismic inversions  

NASA Astrophysics Data System (ADS)

EM or seismic data inversions are affected by many factors, which may conceal the responses from target objects. We address here the contributions from the following effects: 1) Pre-survey spectral sensitivity factor. Preliminary information about a target layer can be used for a pre-survey estimation of the required frequency domain and signal level. A universal approach allows making such estimations in real time, helping the survey crew to optimize an acquisition process. 2) Preliminary velocities' identification and their dispersions for all the seismic waves, arising in a stratified media became a fast working tool, based on the exact analytical solution. 3) Vertical gradients effect. For most layers the log data scatter, requiring an averaging pattern. A linear gradient within each representative layer is a reasonable compromise between required inversion accuracy and forward modeling complexity. 4) An effect from the seismic source's radial component becomes comparable with vertical part for explosive sources. If this effect is not taken into account, a serious modeling error takes place. This problem has an algorithmic solution. 5) Seismic modeling is often based on different representations for a source formulated either for a force or to a potential. The wave amplitudes depend on the formulation, making an inversion result sensitive to it. 6) Asymmetrical seismic waves (modified Rayleigh) in symmetrical geometry around liquid fracture come from S-wave and merge with the modified Krauklis wave at high frequencies. A detail analysis of this feature allows a spectral range optimization for the proper wave's extraction. 7) An ultrasonic experiment was conducted to show different waves appearance for a super-thin water-saturated fracture between two Plexiglas plates, being confirmed by comparison with theoretical computations. 8) A 'sandwich effect' was detected by comparison with averaged layer's effect. This opens an opportunity of the shale gas direct identification from the surface measurements.

Magomedov, M.; Zuev, M. A.; Korneev, V. A.; Goloshubin, G.; Zuev, J.; Brovman, Y.

2013-12-01

362

Pre-flight risk assessment in Emergency Medical Service (EMS) helicopters  

NASA Technical Reports Server (NTRS)

The Emergency Medical Service (EMS) industry has been the subject of several television and newspaper articles (Harvey and Jensen, 1987) which emphasized the negative aspects, (e.g., fatalities and high accident rates), rather than the life saving services performed. Until recently, the accident rate of the EMS industry has been five times as high as that of other civil helicopters. This high accident rate has been coupled with the dramatic rise in the number of programs. The industry has built from a single service at its inception in 1972, to over 180 in 1987 (Spray, 1987), to the point that 93 percent of the contiguous U.S. is now covered by some type of EMS service. These factors prompted the National Transportation Safety Board (NTSB) to study the accidents that occurred between May 11, 1978 and December 3, 1986 (NTSB, 1988). The NTSB report concluded that 'Sound pilot judgment is central to safe flight operations.' They further stated that '... factors unique to EMS helicopter operations--such as the influence of the mission itself, program competition, and EMS program management perspectives--can drastically influence pilot judgment during the EMS mission.' One of the most difficult decisions that a pilot must make is whether to accept or decline a mission. A pre-flight risk assessment system (SAFE) was developed at NASA-Ames Research Center for civil EMS operations to aid pilots in making this decision objectively. The ability of the SAFE system to predict mission risk profiles was tested at an EMS facility. The results of this field study demonstrated that the usefulness of SAFE was highly dependent on the type of mission flown. SAFE is now being modified so that it can 'learn' with each mission flown. For example, after flying a mission to a particular site, an EMS pilot would input information about this mission into the system, such as new buildings, wires, or approach procedures. Then, the next time a pilot flew a similar mission or one to the same area, this additional information would be taken into account in computing a risk assessment.

Shively, R. J.

1992-01-01

363

New Advances for a joint 3D inversion of multiple EM methods  

NASA Astrophysics Data System (ADS)

Electromagnetic (EM) methods are routinely applied to image the subsurface from shallow to regional structures. Individual EM methods differ in their sensitivities towards resistive and conductive structures as well as in their exploration depths. Joint 3D inversion of multiple EM data sets can result in significantly better resolution of subsurface structures than the individual inversions. Proper weighting between different EM data is essential, however. We present a recently developed weighting algorithm to combine magnetotelluric (MT), controlled source EM (CSEM) and DC-geoelectric (DC) data. It is well known that MT data are mostly sensible to regional conductive structures, whereas, CSEM and DC data are more suitable to recover more shallow and resistive structures. Our new scheme is based on weighting individual components of the total data gradient after each model update. Norms of each data residual are used to assess how much weight individual components of the total data gradient must have to achieve an equal contribution of all data sets in the inverse model. A numerically efficient way to search for appropriate weighting factors could be established by applying a bi-diagonalization procedure to the sensitivity matrix. Thereby, the original inverse problem can be projected onto a smaller dimension in which the search of weighting factors is numerically cheap. We demonstrate the efficiency of the proposed weighting schemes and explore the model domain with synthetic data sets.

Meqbel, N. M.; Ritter, O.

2013-12-01

364

PWR loss-of-coolant accident analysis capability of the WRAP-EM system  

SciTech Connect

The modular computational system known as the Water Reactor Analysis Package (WRAP) has been extended to provide the computational tools required to perform a complete analysis of loss-of-coolant accidents (LOCAs) in pressurized water reactors (PWR). The new system is known as the WRAP-EM (Evaluation Model) system and will be used by NRC to interpret and evaluate reactor vendor EM methods and computed results. The system for PWR-EM analysis is comprised of several computer codes which have been developed to analyze a particular phase of a LOCA. These codes include GAPCON for calculation of initial fuel conditions, WRAP (the previously developd SRL analog of RELAP4/MOD5) for analysis of the system blowdown and refill, the FLOOD option in WRAP for analysis of the reflood phase, and FRAP for the calculation of the behavior of the hot fuel pin. In addition, a PWR steady-state initialization procedure has been developed to provide the initial operating state of the reactor system. The PWR-EM system is operational and is being evaluated to determine the adequacy and consistency of the physical models employed for EM analysis.

Gregory, M.V.; Beranek, F.

1980-08-01

365

Association of Disomic Chromosome Loss with Ems-Induced Conversion in Yeast  

PubMed Central

Experimental tests with the yeast Saccharomyces cerevisiae of a previously proposed model suggesting a causal relationship between disomic chromosome loss (n + 1 ? n) and centromere-adjacent mitotic gene conversion were performed. Disomic haploid cells heteroallelic at two loci on the left arm of chromosome III were exposed to ethyl methanesulfonate (EMS) under nonlethal conditions; EMS-induced prototrophic gene convertants were selected and tested for coincident chromosome loss. The principal results are: (1) The frequency of chromosome loss among EMS-induced gene convertants selected to arise near the centromere is markedly enhanced over basal levels and remains constant, independent of EMS exposure. There is little such enhancement among EMS-induced convertants selected to arise far from the centromere. (2) Chromosome loss is almost completely associated with induced conversion of the centromere-proximal allele at the centromere-adjacent heteroallelic locus. This result is identical to (and confirms) results found previously for spontaneous loss-associated conversion. (3) The conversion polarity at the centromere-adjacent locus among unselected (nonloss-associated) induced or spontaneous mitotic convertants is identical to that among meiotic convertants and markedly favors the contromere-distal allele. These findings are wholly consistent with, and strengthen, the hypothesis that structural involvement of centromeric regions in nearby recombinational events may interfere with proper segregational function and lead to mitotic chromosome loss.

Campbell, Douglas

1980-01-01

366

Boson Model of Quantized EM-Field and Nature of Photons  

NASA Astrophysics Data System (ADS)

The fundamental result, obtained by Dirac, that the dynamical system, which consists of the ensemble of identical bosons is equivalent to the dynamical system, which consists of the ensemble of oscillators, was used to show, that the presence of scalar charge function ?(vec r, t) to be peer force characteristic of electromagnetic (EM) field along with vector force characteristics vec E(vec r,t), vec H(vec r,t), that was established earlier, agrees with charge neutrality of photons. The simplest analogue in its mathematical description in the physics of condensed matter is the chain of bosonic (spin S = 1) carbon atoms in trans-polyacetylene. It has been shown, that neutral photons are topological relativistic solitons with nonzero spin value, which is equal to ½ instead of prevalent viewpoint, that the photons possess by spin S = 1. Naturally, they have nonzero size, that is, they cannot be considered to be point objects. At the same time, the main excitations in so called "doped" rest massless "boson-atomic" structure of EM-field will be charged spinless EM-solitons. It seems to be reasonable to suggest, that "doping" can be effective by propagation of EM-field in the medium like to rain-clouds, although detailed mechanism has to be additionally studied. The representation of photons to be the result of spin-charge separation effect in rest massless "boson-atomic" structure of EM-field makes substantially more clear the nature of corpuscular-wave dualism.

Yerchuck, Dmitri; Dovlatova, Alia; Alexandrov, Andrey

2014-03-01

367

VLSI implementation of uterus image segmentation using multi-feature EM algorithm based on Gabor filter: FPGA implementation of uterus image segmentation using multi-feature EM algorithm based on Gabor filter  

Microsoft Academic Search

In this work the image is segmented effectively based on texture feature by reducing the noise. For effective image segmentation Expectation-Maximization (EM) algorithm based on Gabor filter is used. The EM algorithm is applied on 2D Ultrasonic image of uterus and tested. The Gabor function has been recognized by its multiresolution properties and the precision of locating the texture features

S. Malarkhodi; R. S. D. W. Banu; M. Malarvizhi

2010-01-01

368

Fully EM algorithms for the quasi-neutral, zero-electron-inertia model  

NASA Astrophysics Data System (ADS)

An algorithm has been developed to compute the electromagnetic signature of impulsive currents in quasi-neutral, collisionless plasmas. Such plasmas are common in laser target chambers, space physics, and EMP generating events. Traditional models[1] used in this regime make the Darwin assumption that neglects purely EM waves. Computing electro-magnetic pulse behavior (EMP) requires the solution of the EM wave equations. Other algorithms designed to treat this problem [2] are susceptible to round-off problems in our applications. The current algorithm, based on the same physics model, is to be much more forgiving in regions of low density or low magnetic field. Results and initial V&V analysis will be presented.[4pt] [1] ``Low-frequency EM (Darwin) applications in plasma simulations'', Hewett, CPC, 84, pg 243, May 1994[0pt] [2] ``A fully electromagnetic model for high density plasma simulations'' Jones, Thomas, Mason, and Winske, 13^th Conference on the Numerical Simulations of Plasmas, 1983.

Hewett, Dennis

2009-11-01

369

Diffusion-based EM algorithm for distributed estimation of Gaussian mixtures in wireless sensor networks.  

PubMed

Distributed estimation of Gaussian mixtures has many applications in wireless sensor network (WSN), and its energy-efficient solution is still challenging. This paper presents a novel diffusion-based EM algorithm for this problem. A diffusion strategy is introduced for acquiring the global statistics in EM algorithm in which each sensor node only needs to communicate its local statistics to its neighboring nodes at each iteration. This improves the existing consensus-based distributed EM algorithm which may need much more communication overhead for consensus, especially in large scale networks. The robustness and scalability of the proposed approach can be achieved by distributed processing in the networks. In addition, we show that the proposed approach can be considered as a stochastic approximation method to find the maximum likelihood estimation for Gaussian mixtures. Simulation results show the efficiency of this approach. PMID:22163956

Weng, Yang; Xiao, Wendong; Xie, Lihua

2011-01-01

370

Direct and indirect measures of speech articulator motions using low power EM sensors  

SciTech Connect

Low power Electromagnetic (EM) Wave sensors can measure general properties of human speech articulator motions, as speech is produced. See Holzrichter, Burnett, Ng, and Lea, J.Acoust.Soc.Am. 103 (1) 622 (1998). Experiments have demonstrated extremely accurate pitch measurements (< 1 Hz per pitch cycle) and accurate onset of voiced speech. Recent measurements of pressure-induced tracheal motions enable very good spectra and amplitude estimates of a voiced excitation function. The use of the measured excitation functions and pitch synchronous processing enable the determination of each pitch cycle of an accurate transfer function and, indirectly, of the corresponding articulator motions. In addition, direct measurements have been made of EM wave reflections from articulator interfaces, including jaw, tongue, and palate, simultaneously with acoustic and glottal open/close signals. While several types of EM sensors are suitable for speech articulator measurements, the homodyne sensor has been found to provide good spatial and temporal resolution for several applications.

Barnes, T; Burnett, G; Gable, T; Holzrichter, J F; Ng, L

1999-05-12

371

Physics-based simulation of EM and SM in TSV-based 3D IC structures  

NASA Astrophysics Data System (ADS)

Evolution of stresses in through-silicon-vias (TSVs) and in the TSV landing pad due to the stress migration (SM) and electromigration (EM) phenomena are considered. It is shown that an initial stress distribution existing in a TSV depends on its architecture and copper fill technology. We demonstrate that in the case of proper copper annealing the SM-induced redistribution of atoms results in uniform distributions of the hydrostatic stress and concentration of vacancies along each segment. In this case, applied EM stressing generates atom migration that is characterized by kinetics depending on the preexisting equilibrium concentration of vacancies. Stress-induced voiding in TSV is considered. EM induced voiding in TSV landing pad is analyzed in details.

Kteyan, Armen; Sukharev, Valeriy; Zschech, Ehrenfried

2014-06-01

372

OsLEA1a, a new Em-like protein of cereal plants.  

PubMed

Proteins abundant in seeds during the late stages of development, late embryogenesis abundant (LEA) proteins, are associated with desiccation tolerance. More than 100 of the group I LEA genes, also termed Em genes, have been identified from plants, bacteria and animals. The wide distribution indicates the functional importance of these genes. In the present study, we characterized a novel Em-like gene, OsLEA1a of rice (Oryza sativa). The encoded OsLEA1a protein has an N-terminal sequence similar to that of other plant Em proteins but lacks a 20-mer motif that is the most significant feature of typical Em proteins. The location of the sole intron indicates that the second exon of OsLEA1a is the mutated product of a typical Em gene. Transcriptome analysis revealed OsLEA1a mainly expressed in embryos, with no or only a few transcripts in osmotic stress-treated vegetative tissues. Structural analysis revealed that the OsLEA1a protein adopts high amounts of disordered conformations in solution and undergoes desiccation-induced conformational changes. Macromolecular interaction studies revealed that OsLEA1a protein interacts with non-reducing sugars and phospholipids but not poly-l-lysine. Thus, although the OsLEA1a protein lost its 20-mer motif, it is still involved in the formation of bioglasses with non-reducing sugars or plasma membrane. However, the protein does not function as a chaperone as do other groups of hydrophilic LEA proteins. The orthologs of the OsLEA1a gene had been identified from various grasses but not in dicot plants. Genetic analysis indicated that rice OsLEA1a locates at a 193 kb segment in chromosome 1 and is conserved in several published cereal genomes. Thus, the ancestor of Em-like genes might have evolved after the divergence of monocot plants. PMID:21097897

Shih, Ming-Der; Huang, Lin-Tzu; Wei, Fu-Jin; Wu, Ming-Tsung; Hoekstra, Folkert A; Hsing, Yue-Ie C

2010-12-01

373

Consensus among flexible fitting approaches improves the interpretation of cryo-EM data  

PubMed Central

Cryo-elecron microscopy (Cryo-EM) can provide important structural information of large macromolecular assemblies in different conformational states. Recent years have seen an increase in structures deposited in the Protein Data Bank (PDB) by fitting a high-resolution structure into its low-resolution cryo-EM map. A commonly used protocol for accommodating the conformational changes between the X-ray structure and the cryo-EM map is rigid body fitting of individual domains. With the emergence of different flexible fitting approaches, there is a need to compare and revise these different protocols for the fitting. We have applied three diverse automated flexible fitting approaches on a protein dataset for which rigid domain fitting (RDF) models have been deposited in the PDB. In general, a consensus is observed in the conformations, which indicates a convergence from these theoretically different approaches to the most probable solution corresponding to the cryo-EM map. However, the result shows that the convergence might not be observed for proteins with complex conformational changes or with missing densities in cryo-EM map. In contrast, RDF structures deposited in the PDB can represent conformations that not only differ from the consensus obtained by flexible fitting but also from X-ray crystallography. Thus, this study emphasizes that a “consensus” achieved by the use of several automated flexible fitting approaches can provide a higher level of confidence in the modeled configurations. Following this protocol not only increases the confidence level of fitting, but also highlights protein regions with uncertain fitting. Hence, this protocol can lead to better interpretation of cryo-EM data.

Ahmed, Aqeel; Whitford, Paul C.; Sanbonmatsu, Karissa Y.; Tama, Florence

2011-01-01

374

The EMS response to the Oklahoma City bombing.  

PubMed

This is a descriptive study of the Emergency Medical Services response to a bombing of a United States Federal Building in Oklahoma City, Oklahoma on 19 April 1995. The explosion emanated from a rented truck parked in the front of the building. The force of the explosion destroyed three of the four support columns in the front of the building and resulted in a pancaking effect of the upper floors onto the lower floors. There were three distinct phases of the medical response: 1) Immediately available local EMS ambulances and staff; 2) Additional ambulances staffed by recalled, off-duty personnel; and 3) mutual-aid ambulances and personnel from the surrounding communities. There were 361 persons in the building at the time of the explosion, 163 of these perished. Within the first hour of the explosion, 139 patients were transported to area hospitals. Of these, 32% were in critical condition. During the day of the explosion, 444 persons were treated for physical injuries: 410 of these were related to the explosion and 14, including one with fatal injuries, were sustained during search and rescue attempts. A total of 354 (80%) were treated and released from emergency departments, and 90 (20%) were admitted to hospitals. Six of the transported victims either were dead on arrival to the emergency department or died after admission to the hospital. Of those who died, 95% of the deaths were related to blunt trauma associated with the collapse of the structure. Only three persons were extricated alive after the first five hours following the explosion. The scene became flooded with volunteers who, although their intentions were to provide help and aid to those injured, created a substantial logistical problem for Incident Command. Several other lessons were learned: 1) Telephone lines and cells became overloaded, but the Hospital Emergency Administrative Radio system was operational only in three of the 15 hospitals; 2) Volunteer personnel should have responded to the hospitals and not to the scene; and 3) Training was an essential for the success of such a response. Thus, the success of this operation was a function of the intense training, practice, and coordination between multiple agencies. PMID:10187007

Maningas, P A; Robison, M; Mallonee, S

1997-01-01

375

EMT Defibrillation Does Not Increase Survival From Sudden Cardiac Death in a Two-Tiered Urban-Suburban EMS System  

Microsoft Academic Search

Objective: The use of automatic external defibrillators (AEDs) by EMS initial responders is widely advocated. Evidence supporting the use of AEDs is based largely on the experience of one metropolitan area, with effect on survival in many systems not yet proved. We conducted this study to determine whether the addition of AEDs to an EMS system with a response time

Thomas A Sweeney; Jeffrey W Runge; Michael A Gibbs; Janet M Raymond; Robert W Schafermeyer; H. James Norton; Madeline J Boyle-Whitesel

1998-01-01

376

Intervenções em consciência fonológica e aprendizagem da linguagem escrita 1 Interventions in phonological conscience and learning of the written language  

Microsoft Academic Search

Resumo: Vários estudos evidenciam alta associação entre a consciência fonológica e as habilidades de ler e escrever. Este trabalho tem como objetivo identificar e analisar pesquisas de intervenção em consciência fonológica e seus efeitos sobre a aprendizagem da linguagem escrita. São identificados três tipos de pesquisas: com adultos analfabetos, com crianças em dificuldade na aprendizagem da escrita e com pré-escolares.

Maria José dos Santos

377

Guidance for establishment and implementation of field sample management programs in support of EM environmental sampling and analysis activities.  

National Technical Information Service (NTIS)

The role of the National Sample Management Program (NSMP) proposed by the Department of Energy's Office of Environmental Management (EM) is to be a resource for EM programs and for local Field Sample Management Programs (FSMPs). It will be a source of inf...

1994-01-01

378

Effect of EM on Soil Quality, Fruit Quality and Yield of Orange Trees in a Brazilian Citrus Orchard  

Microsoft Academic Search

A field investigation was conducted during 1993-94 on citrus in the State of São Paulo, Brazil, to evaluate the interactions of EM with soil, leaves, mite populations, fruit quality and yield of orange trees. The study was designed to test the ability of Effective Microorganisms (EM) to significantly change a number of soil parameters in the citrus agroecosystem. Climate of

A. D. Paschoal; S. K. Homma; A. B. Sanches; M. C. S. Nogueira

379

Discrimination Using the Geonics EM63 in a Cued Interrogation Mode at Fort McClellan, AL.  

National Technical Information Service (NTIS)

Data were collected at the former Fort McClellan to test the Geonics EM63 deployed in a cued interrogation mode. Except for one 37mm and several 60mm seed items, all munitions encountered were 75mm or 3.8 inch shrapnel rounds. The EM63 surveys were cued o...

S. Billings

2009-01-01

380

Quality assurance guidance for laboratory assessment plates in support of EM environmental sampling and analysis activities  

SciTech Connect

This document is one of several guidance documents developed to support the EM (DOE Environmental Restoration and Waste Management) Analytical Services program. Its purpose is to introduce assessment plates that can be used to conduct performance assessments of an organization`s or project`s ability to meet quality goals for analytical laboratory activities. These assessment plates are provided as non-prescriptive guidance to EM-support organizations responsible for collection of environmental data for remediation and waste management programs at DOE facilities. The assessments evaluate objectively all components of the analytical laboratory process to determine their proper selection and use.

Not Available

1994-05-01

381

A laboratory experiment on EM backscatter from Farley-Buneman and gradient drift waves  

NASA Technical Reports Server (NTRS)

Results of laboratory experiment on Bragg backscatter of 3-cm microwaves by turbulent waves driven by the Farley-Buneman and gradient drift instabilities are reported. It is noted that the study is the third in a series of laboratory experiments performed to test, under controlled conditions, prevalent ideas on EM scattering by equatorial and high-latitude ionospheric waves and irregularities. It is shown through separate backscattering from fast and slow ion beam modes that a beam of EM radiation actually provides, in backscatter, information on the spectral content of the scattering medium.

Alport, M. J.; Dangelo, N.; Pecseli, H. L.

1981-01-01

382

ModEM: A modular system for inversion of electromagnetic geophysical data  

NASA Astrophysics Data System (ADS)

We describe implementation of a modular system of computer codes for inversion of electromagnetic geophysical data, referred to as ModEM. The system is constructed with a fine level of modular granularity, with basic components of the inversion – forward modeling, sensitivity computations, inversion search algorithms, model parametrization and regularization, data functionals – interchangeable, reusable and readily extensible. Modular sensitivity computations and generic interfaces to parallelized inversion algorithms provide a ready framework for rapid implementation of new applications or inversion algorithms. We illustrate the code?s versatility and capabilities for code reuse through implementation of 3D magnetotelluric (MT) and controlled-source EM (CSEM) inversions, using essentially the same components.

Kelbert, Anna; Meqbel, Naser; Egbert, Gary D.; Tandon, Kush

2014-05-01

383

Rotating-bed reactor as a power source for EM gun applications  

SciTech Connect

Electromagnetic gun applications of the Rotating Bed Reactor (RBR) are examined. The RBR is a compact (approx. 1 m/sup 3/), (up to several thousand MW(th)), high-power reactor concept, capable of producing a high-temperature (up to approx. 300/sup 0/K) gas stream with a MHD generator coupled to it, the RBR can generate electric power (up to approx. 1000 MW(e)) in the pulsed or cw modes. Three EM gun applications are investigated: a rail gun thruster for orbit transfer, a rapid-fire EM gun for point defense, and a direct ground-to-space launch. The RBR appears suitable for all applications.

Powell, J.; Botts, T.; Stickley, C.M.; Meth, S.

1980-01-01

384

LEC1, FUS3, ABI3 and Em expression reveals no correlation with dormancy in Arabidopsis.  

PubMed

Dormant Arabidopsis seeds require stratification and light for germination. To study gene expression during establishment, maintenance and release of dormancy, various Arabidopsis ecotypes that are different in their degree of dormancy were investigated; three nsm mutants that lack the stratification-dependency, and the precocious germination and reduced dormancy of the abi3-1 mutant (insensitive to ABA). Genes examined by mRNA abundance include LEC1, FUS3 and ABI3, transcription factors that are major regulators of embryo development and, at least indirectly, play some role in the control of dormancy. Moreover, the late embryogenesis marker genes, AtEm1 and AtEm6, were examined in relation to the state of dormancy. The expression of LEC1, FUS3 and ABI3 mRNA is only marginally different during seed development in various strong or moderate dormancy wild types, nsm mutants and abi3-1. Therefore, it is unlikely that these transcription factors directly control the establishment of dormancy in Arabidopsis. Sole and various combina tions of light, temperature, and after-ripening regimes that alter germination behaviour were examined to determine if the expression of ABI3, AtEm1 and AtEm6 mRNAs were correlated with dormancy-breaking processes. ABI3 expression is influenced by cold and light, in a similar way in both dormant and non-dormant wild-type seeds. ABI3 transcript abundance in the nsm1 and nsm2 mutants is higher and in the nsm5-1 mutant is marginally lower than in wild-type seeds, but changes due to temperature and light factors are very similar to those that occur in wild-type seeds. The abundances of AtEm1 and AtEm6 mRNAs are equally affected by imbibition and cold temperature in mature and after-ripened seeds. The LEA transcript abundances for AtEm1 and AtEm6 are reduced in nsm mutants in a common, ABI3-independent pathway. PMID:14676287

Baumbusch, Lars O; Hughes, D Wayne; Galau, Glenn A; Jakobsen, Kjetill S

2004-01-01

385

The longitudinal study of turnover and the cost of turnover in EMS  

PubMed Central

Purpose Few studies have examined employee turnover and associated costs in emergency medical services (EMS). The purpose of this study was to quantify the mean annual rate of turnover, total median cost of turnover, and median cost per termination in a diverse sample of EMS agencies. Methods A convenience sample of 40 EMS agencies was followed over a 6 month period. Internet, telephone, and on-site data collection methods were used to document terminations, new hires, open positions, and costs associated with turnover. The cost associated with turnover was calculated based on a modified version of the Nursing Turnover Cost Calculation Methodology (NTCCM). The NTCCM identified direct and indirect costs through a series of questions that agency administrators answered monthly during the study period. A previously tested measure of turnover to calculate the mean annual rate of turnover was used. All calculations were weighted by the size of the EMS agency roster. The mean annual rate of turnover, total median cost of turnover, and median cost per termination were determined for 3 categories of agency staff mix: all paid staff, mix of paid and volunteer (mixed), and all-volunteer. Results The overall weighted mean annual rate of turnover was 10.7%. This rate varied slightly across agency staffing mix: (all-paid=10.2%, mixed=12.3%, all-volunteer=12.4%). Among agencies that experienced turnover (n=25), the weighted median cost of turnover was $71,613.75, which varied across agency staffing mix: (all-paid=$86,452.05, mixed=$9,766.65, and all-volunteer=$0). The weighted median cost per termination was $6,871.51 and varied across agency staffing mix: (all-paid=$7,161.38, mixed=$1,409.64, and all-volunteer=$0). Conclusions Annual rates of turnover and costs associated with turnover vary widely across types of EMS agencies. The study’s mean annual rate of turnover was lower than expected based on information appearing in the news media and EMS trade magazines. Findings provide estimates of two key workforce measures – turnover rates and costs – where previously none have existed. Local EMS directors and policymakers at all levels of government may find the results and study methodology useful towards designing and evaluating programs targeting the EMS workforce.

Patterson, P. Daniel; Jones, Cheryl B.; Hubble, Michael W.; Carr, Matthew; Weaver, Matthew D.; Engberg, John; Castle, Nicholas

2010-01-01

386

Theoretical and FEM analysis of suspension and propulsion system with HTS hybrid electromagnets in an EMS Maglev model  

NASA Astrophysics Data System (ADS)

We have been constructed a proto-type electromagnetic suspension (EMS) based maglev vehicle system. The maglev concept utilizes magnetic forces for noncontact suspension, guidance and propulsion. The suspension system with high temperature superconducting (HTS) hybrid electromagnet (EM) is composed of HTS coils and normal coils, which consume little power to keep large suspension gap. The magnetic forces realize to guide the vehicle, propel the vehicle along the guide-way and assist in braking action. The proto-type EMS-based Maglev model is designed to keep the suspension gap of 20 mm. This paper presents the theoretical analysis of the maglev vehicle based on the EMS model to obtain the designing parameters for levitation and propulsion forces. The magnetic field distributions of the electromagnetic forces with hybrid EM and propulsion stator coils are analyzed based on three dimension (3D) finite element method (FEM) analysis. From the simulation results, appropriately design parameters of the suspension, guidance and propulsion were obtained.

Chung, Y. D.; Lee, C. Y.; Jang, J. Y.; Yoon, Y. S.; Ko, T. K.

2011-11-01

387

Variação da independência funcional em idosos hospitalizados relacionada a variáveis sociais e de saúde Variation in functional independence in hospitalized elderly related to social and health variables  

Microsoft Academic Search

O processo de envelhecimento, as doenças crônicas não transmissíveis e as hospitalizações podem causar declínio funcional em idosos. Alguns fatores podem potencializar esse comprometimento funcional como gênero, número de internações, presença de acompanhante e medicações em uso. Objetivo: Identificar a variação da capacidade funcional em idosos no decorrer da hospitalização e relacionar a diferença com variáveis sociais e de saúde.

Kozue Kawasaki; Maria José D'Elboux Diogo

2007-01-01

388

Composição florística da vegetação arbórea de um trecho de floresta estacional semidecídua em Viçosa, Minas Gerais, e espécies de maior ocorrência na região  

Microsoft Academic Search

RESUMO - É grande a demanda por estudos ecológicos em florestas que possam embasar trabalhos de recuperação, conservação da biodiversidade e apoio à legislação ambiental. Entre esses estudos, primordialmente está o levantamento da flora. Nesse sentido, este trabalho teve como objetivo determinar a composição florística de um trecho da Reserva da Biologia, em Viçosa, MG, em regeneração natural há 80

Walnir Gomes Ferreira Júnior; Alexandre Francisco da Silva; João Augusto Alves Meira Neto; Carlos Ernesto Gonçalves Reynaud Schaefer; Arildo de Souza Dias; Maíra Ignácio; Maria Cláudia Melo Pacheco de Medeiros

2007-01-01

389

Bacteria of the genus Aeromonas in different locations throughout the process line of beef slaughtering Bactérias do gênero Aeromonas em diferentes pontos do fluxograma de abate bovino  

Microsoft Academic Search

Resumo: Com o objetivo de verificar a ocorrência e a população de bactérias do género Aeromonas em diferentes pontos do fluxo- grama de abate bovino, em estabelecimento de alto nível higiéni- co-sanitário, foram investigados produtos e locais do fluxograma de abate, desde a chegada dos animais até a carne desossada e pronta para comercialização. Das 30 amostras colhidas em cada

CIÊNCIAS VETERINÁRIAS; O. D. Rossi Júnior; L. A. Amaral; A. Nader Filho; R. P. Schocken-Iturrino

390

ADAPTABILIDADE E ESTABILIDADE DE REAÇÃO DE GENÓTIPOS DE SOJA AO OÍDIO, EM CASA DE VEGETAÇÃO ADAPTABILITY AND STABILITY OF REACTION OF SOYBEAN GENOTYPES TO POWDERY MILDEW, IN GREENHOUSE  

Microsoft Academic Search

RESUMO: O objetivo deste trabalho foi estudar o comportamento de genótipos de soja em relação ao oídio, por meio de estudos de adaptabilidade e de estabilidade, em casa de vegetação, durante cinco épocas de avaliação. O delineamento experimental foi inteiramente casualizado, disposto em parcelas subdivididas, com 15 tratamentos e três tipos de controle (parcial, total e sem controle) representando as

Derval Gomes PEREIRA; Tuneo SEDIYAMA; Cosme Damião CRUZ; Múcio Silva REIS

391

In Situ Data Processing With Workflow-based Embedded Cyberinfrastructure (emCI)  

NASA Astrophysics Data System (ADS)

The decreasing cost of sensors and sensor networks has led to the wide scale adoption of this technology by large numbers of scientists for the collection of data in the field. At the same time, advances in both hardware and software have resulted in increased processing power at the sensor, enabling sensors in the field to do more than just data collection. With an increase in the number of sensors and deployments, scientists need tools for the configuration, operation, and debugging problems on their sensor networks. Furthermore, as the amount of data increases, scientists need a way to quickly and easily tag, process, archive, and share their datasets. Without proper tools, it is common for data processing to happen weeks or sometimes months after it is collected. This leads to important events being missed and makes real-time data analysis impossible. Additionally, because data is often manually processed through a series of repetitive steps, the analysis is susceptible to errors that are hard to track after data is combined and shared among researchers. Our emCI (embedded cyberinfrastructure) toolkit enables researchers to easily collect, analyze, and share their data. emCI provides a web-portal with upload/download capabilities that accept data in a number of different formats and ultimately can be used to archive data and share datasets among scientists. emCI uses an embedded general-purpose computer in the field for interfacing with sensors, coordinating data collection, and providing reliable data transfer to the emCI web portal. emCI relies on workflow technologies to automate data processing pipelines and to provide provenance information. In particular, emCI uses the Pegasus Workflow Management System as a core component, adapting it to the embedded computation environment. emCI allows scientists to distribute tasks among sensors in field and servers in the lab. In-situ processing using embedded workflows enable data reduction and validation in the field. Scientists can also create embedded workflows for data analysis and sensor retasking, allowing for much faster response to events in the field as well as disconnected operation from the emCI portal. Workflows executed at the emCI portal can include heavier computations, and combine data from multiple sensors by performing data analysis on data from multiple sources. The emCI portal also supports workflows for data transfers, visualization, and the automatic monitoring of the embedded infrastructure. We have prototyped the emCI toolkit in a project that uses automated digital cameras and weather stations for observing climate change based on plant phenology observations. In this application, embedded workflows are being used to coordinate the field data collection, reduce and analyze image data in the field, and retask cameras based on embedded triggers. We are currently in the process of moving our deployment from prototype to production stage at the Stunt Ranch UC Reserve in the Santa Monica Mountains.

Mehta, G.; Silva, F.; Graham, E. A.; Vahi, K.; Deelman, E.; Rundel, P.

2011-12-01

392

Evaluation of an Enzyme-Linked Immunosorbent Assay (ELISA) with Affinity-Purified Em18 and an ELISA with Recombinant Em18 for Differential Diagnosis of Alveolar Echinococcosis: Results of a Blind Test  

PubMed Central

Alveolar echinococcosis (AE) is the most potentially lethal parasitic zoonosis of the nontropical areas in the northern hemisphere, where cystic echinococcosis (CE) is also endemic. Both AE and CE are highly endemic in China, and both serologic detection of echinococcosis, either AE or CE, and differentiation of AE from CE are crucial problems. Evaluation of Western blot analysis (WB) and enzyme-linked immunosorbent assay (ELISA) for the Em18 antigen, using affinity-purified and recombinant Em18, was carried out “blindly” using 60 human sera from patients diagnosed in France. The results were compared with those obtained using a commercially available Echinococcus WB immunoglobulin G (IgG) kit developed in France. The Em18 WB and Echinococcus WB IgG showed very similar results for detection of AE. Both affinity-purified Em18 or a recombinant Em18 WB and Echinococcus WB IgG seem useful for identification of AE, and the latter seems appropriate for both AE and CE, whereas affinity-purified Em18 ELISA and the newly developed recombinant Em18 ELISA appear to be suitable for detection of AE, especially for epidemiological surveys.

Ito, Akira; Xiao, Ning; Liance, Martine; Sato, Marcello O.; Sako, Yasuhito; Mamuti, Wulamu; Ishikawa, Yuji; Nakao, Minoru; Yamasaki, Hiroshi; Nakaya, Kazuhiro; Bardonnet, Karine; Bresson-Hadni, Solange; Vuitton, Dominique A.

2002-01-01

393

Estimation of elliptical basis function parameters by the EM algorithm with application to speaker verification  

Microsoft Academic Search

This paper proposes to incorporate full covariance matrices into the radial basis function (RBF) networks and to use the expectation-maximization (EM) algorithm to estimate the basis function parameters. The resulting networks, referred to as elliptical basis function (EBF) networks, are evaluated through a series of text-independent speaker verification experiments involving 258 speakers from a phonetically balanced, continuous speech corpus (TIMIT).

Man-Wai Mak; Sun-Yuan Kung

2000-01-01

394

Identificação dos vegetais destinados a ornamentação de praças, parques e creches em Campina Grande, PB  

Microsoft Academic Search

RESUMO O Horto Florestal Lauro Pires Xavier, situado às margens do açude de Bodocongó, em Campina Grande-PB é uma importante unidade mantida pela prefeitura no sentido de preservação e conservação de espécies. Através do viveiro, o município tem condição de aumentar as áreas verdes, proporcionando lazer e bem estar à população. Esse trabalho tem como tema à identificação dos vegetais

Mário Luiz Farias Cavalcanti; Ivan Coelho Dantas; Giselle Medeiros da Costa Silva; Luciana de Luna Costa; Maria José Benício Barros; Ronny Soffiantini Lira

395

SAR reduction for mobile phones based on analysis of EM absorbing material characteristics  

Microsoft Academic Search

With the recent explosive increase of the use of mobile communication handsets, there has been a growing concern about possible hazard to a human body, especially head part, exposed to the EM fields radiated from handsets. The specific absorption rate (SAR) is normally used for one of the important criteria to evaluate the degree of the hazard. The SAR is

Minseok Jung; Bomson Lee

2003-01-01

396

Sintomas Depressivos e Qualidade de Vida em Indivíduos com Epilepsia por Esclerose Mesial Temporal  

Microsoft Academic Search

RESUMO Introdução: Dificuldades no trabalho, em relacionamentos interpessoais, familiares e sociais, a percepção do estigma, da discriminação dentre outros têm sido associados aos estados depressivos interictais, influen- ciando negativamente a qualidade de vida (QV) das pessoas com epilepsia. A depressão tem alta prevalência (20 a 55%) nas epilepsias, sendo vista como o fator mais importante no julgamento do paciente sobre

Neide Barreira Alonso; Tatiana Indelicato da Silva; Ana Carolina Westphal; Auro Mauro Azevedo

397

An EM Algorithm for Fitting a 4-Parameter Logistic Model to Binary Dose-Response Data  

PubMed Central

This article is motivated by the need of biological and environmental scientists to fit a popular nonlinear model to binary dose-response data. The 4-parameter logistic model, also known as the Hill model, generalizes the usual logistic regression model to allow the lower and upper response asymptotes to be greater than zero and less than one, respectively. This article develops an EM algorithm, which is naturally suited for maximum likelihood estimation under the Hill model after conceptualizing the problem as a mixture of subpopulations in which some subjects respond regardless of dose, some fail to respond regardless of dose, and some respond with a probability that depends on dose. The EM algorithm leads to a pair of functionally independent 2-parameter optimizations and is easy to program. Not only can this approach be computationally appealing compared to simultaneous optimization with respect to all four parameters, but it also facilitates estimating covariances, incorporating predictors, and imposing constraints. This article is motivated by, and the EM algorithm is illustrated with, data from a toxicology study of the dose effects of selenium on the death rates of flies. Other biological and environmental applications, as well as medical and agricultural applications, are also described briefly. Computer code for implementing the EM algorithm is available as supplemental material online.

Dinse, Gregg E.

2010-01-01

398

A geographic information system simulation model of EMS: reducing ambulance response time  

Microsoft Academic Search

Response time is a very important factor in determining the quality of prehospital EMS. Our objective was to model the response by Israeli ambulances and to offer model-derived strategies for improved deployment of ambulances to reduce response time. Using a geographic information system (GIS), a retrospective review of computerized ambulance call and dispatch logs was performed in two different regional

Kobi Peleg; Joseph S. Pliskin

2004-01-01

399

A spectral domain approach to modelling of EM scattering for Synthetic Aperture Radar target recognition  

Microsoft Academic Search

A Fourier-based technique for electromagnetic (EM) wave reconstruction with application to polarimetric airborne and spaceborne radar data exploitation is presented. The method is different from conventional modelling techniques for Synthetic Aperture Radar (SAR) applications as a result of the full electromagnetic treatment of field interactions with the scatterer, the possibility of introducing new and controllable feature classes for target classification,

R. Sabry; P. W. Vachon

2005-01-01

400

Miocene basalts in northwestern Taiwan: Evidence for EM-type mantle sources in the continental lithosphere  

NASA Astrophysics Data System (ADS)

Cenozoic extension around the Taiwan Strait resulted in intraplate basalt volcanism in the Fujian-Taiwan region of the southeastern China continental margin. In northwestern Taiwan, the basalt volcanism took place in two distinct periods: the early Miocene (23-20 Ma), with the eruption of alkali basalt only, and the late Miocene (13-9 Ma), marked by the emplacement of various basalt types. The early Miocene basalts have uniform Sr?Nd?Pb isotope compositions comparable with those of the other Fujian-Taiwan basalts, which are believed to have originated from a "plum-pudding" type convecting mantle. These basalts display EM2-type lead isotope signature like that observed in seamount basalts from the South China Sea. By contrast, the late Miocene basalts show distinctive isotope characteristics indicating additional involvement of an EM1-type mantle source that has never been identified before for any volcanics in southern China. We propose that the "enriched mantle" components (EMI and EM2) reside in different levels of the continental lithospheric mantle. Reactivation of the unique EM1 source may be ascribed to the arc-continent collision in Taiwan during the last 12 million years which terminated the intraplate volcanism around this region.

Chung, Sun-Lin; Jahn, Bor-Ming; Chen, Shu-Jen; Lee, Typhoon; Chen, Cheng-Hong

1995-02-01

401

Crosshole EM for oil field characterization and EOR monitoring: Field examples from Lost Hills, California.  

National Technical Information Service (NTIS)

A steamflood recently initiated by Mobil Development and Production U.S. at the Lost Hills No 3 oil field in California is notable for its shallow depth and the application of electromagnetic (EM) geophysical techniques to monitor the subsurface steam flo...

M. Wilt C. Schenkel M. Wratcher I. Lambert C. Torres-Verdin

1996-01-01

402

A Note on Parameter Estimation for Lazarsfeld's Latent Class Model Using the EM Algorithm.  

ERIC Educational Resources Information Center

Latent class analysis is formulated as a problem of estimating parameters in a finite mixture distribution. The EM algorithm is used to find the maximum likelihood estimates, and the case of categorical variables with more than two categories is considered. (Author)

Everitt, B. S.

1984-01-01

403

Environmental Cost Analysis System (ECAS) Status and Compliance Requirements for EM Consolidated Business Center Contracts - 13204  

SciTech Connect

The Department of Energy (DOE) Office of Environmental Management (EM) has developed a web-accessible database to collect actual cost data from completed EM projects to support cost estimating and analysis. This Environmental Cost Analysis System (ECAS) database was initially deployed in early 2009 containing the cost and parametric data from 77 decommissioning, restoration, and waste management projects completed under the Rocky Flats Closure Project. In subsequent years we have added many more projects to ECAS and now have a total of 280 projects from 8 major DOE sites. This data is now accessible to DOE users through a web-based reporting tool that allows users to tailor report outputs to meet their specific needs. We are using it as a principal resource supporting the EM Consolidated Business Center (EMCBC) and the EM Applied Cost Engineering (ACE) team cost estimating and analysis efforts across the country. The database has received Government Accountability Office review as supporting its recommended improvements in DOE's cost estimating process, as well as review from the DOE Office of Acquisition and Project Management (APM). Moving forward, the EMCBC has developed a Special Contract Requirement clause or 'H-Clause' to be included in all current and future EMCBC procurements identifying the process that contractors will follow to provide DOE their historical project data in a format compatible with ECAS. Changes to DOE O 413.3B implementation are also in progress to capture historical costs as part of the Critical Decision project closeout process. (authors)

Sanford, P.C. [Consultant, 11221 E. Cimmarron Dr., Englewood, CO 80111 (United States)] [Consultant, 11221 E. Cimmarron Dr., Englewood, CO 80111 (United States); Moe, M.A. [EMCBC Office of Cost Estimating and Analysis, United States Department of Energy, 250 E. 5th Street, Suite 500, Cincinnati, OH 45202 (United States)] [EMCBC Office of Cost Estimating and Analysis, United States Department of Energy, 250 E. 5th Street, Suite 500, Cincinnati, OH 45202 (United States); Hombach, W.G. [Team Analysis, Inc., 2 Cardinal Park Drive, Suite 105A, Leesburg, VA 20175 (United States)] [Team Analysis, Inc., 2 Cardinal Park Drive, Suite 105A, Leesburg, VA 20175 (United States); Urdangaray, R. [Project Performance Corporation, 1760 Old Meadow Road, McLean, VA 22102 (United States)] [Project Performance Corporation, 1760 Old Meadow Road, McLean, VA 22102 (United States)

2013-07-01

404

Determining the Properties and Capabilities of an Existing Experimental Large Loop EM61 Underwater UXO Detector.  

National Technical Information Service (NTIS)

In response to UXSON-04-03, Dillon Consulting Ltd (DCL) investigated the response of a prototype Large Loop EM61 Marine System. The system was originally conceived in 2002 for a marine UXO survey of Wright's Cove near Halifax, Nova Scotia, to detect accum...

2006-01-01

405

Maximum Likelihood Computations with Repeated Measures: Application of the EM Algorithm  

Microsoft Academic Search

The purpose of this article is to consider the use of the EM algorithm (Dempster, Laird, and Rubin 1977) for both maximum likelihood (ML) and restricted maximum likelihood (REML) estimation in a general repeated measures setting using a multivariate normal data model with linear mean and covariance structure (Anderson 1973). Several models and methods of analysis have been proposed in

Nan Laird; Nicholas Lange; Daniel Stram

1987-01-01

406

A tailored ML-EM algorithm for reconstruction of truncated projection data using few view angles  

NASA Astrophysics Data System (ADS)

Dedicated cardiac single photon emission computed tomography (SPECT) systems have the advantage of high speed and sensitivity at no loss, or even a gain, in resolution. The potential drawbacks of these dedicated systems are data truncation by the small field of view (FOV) and the lack of view angles. Serious artifacts, including streaks outside the FOV and distortion in the FOV, are introduced to the reconstruction when using the traditional emission data maximum-likelihood expectation-maximization (ML-EM) algorithm to reconstruct images from the truncated data with a small number of views. In this note, we propose a tailored ML-EM algorithm to suppress the artifacts caused by data truncation and insufficient angular sampling by reducing the image updating step sizes for the pixels outside the FOV. As a consequence, the convergence speed for the pixels outside the FOV is decelerated. We applied the proposed algorithm to truncated analytical data, Monte Carlo simulation data and real emission data with different numbers of views. The computer simulation results show that the tailored ML-EM algorithm outperforms the conventional ML-EM algorithm in terms of streak artifacts and distortion suppression for reconstruction from truncated projection data with a small number of views.

Mao, Yanfei; Zeng, Gengsheng L.

2013-06-01

407

Incidence of EMS-treated out-of-hospital cardiac arrest in Europe  

Microsoft Academic Search

Background:The potential impact of efforts in Europe to improve survival from out-of-hospital cardiac arrest is unclear, in part, because estimates of incidence and survival are uncertain. The aim of the investigation was to determine a representative European incidence and survival from cardiac arrest in all-rhythms and in ventricular fibrillation treated by the emergency medical services (EMS).

Christie Atwood; Mickey S. Eisenberg; Johan Herlitz; Thomas D. Rea

2005-01-01

408

EM, MCMC, and Chain Flipping for Structure from Motion with Unknown Correspondence  

Microsoft Academic Search

Abstract. Learning spatial models from sensor data often raises a challenging data association problem,of relating parameters in the model to individual measurements. This paper proposes an algorithm based on EM, which simultaneously solves the model learning and the data association problem. The algorithm is developed,in the context of the the structure from motion problem, which is the problem of learning

Frank Dellaert; Steven M. Seitz; Charles E. Thorpe; Sebastian Thrun

2003-01-01

409

Hybrid analysis (MM-UTD) of EM scattering from finned convex objects  

Microsoft Academic Search

It is a formidable task to analyze the electromagnetic (EM) scattering from complex structures containing both electrically large and small parts because, in general, neither low nor high frequency techniques alone can provide a tractable solution to this problem. The method of moments (MM) is a very accurate mathematical technique which is commonly used to solve the governing integral equation

M. Hsu; P. H. Pathak

1995-01-01

410

Is It Round? Spectropolarimetry of the Type IIp Supernova 1999EM  

Microsoft Academic Search

We present the first multiepoch spectropolarimetry of a Type II plateau supernova (SN II-P), with optical observations of SN 1999em on days 7, 40, 49, 159, and 163 after discovery. These data are used to probe the geometry of the electron scattering atmosphere before, during, and after the plateau phase, which ended roughly 90 days after discovery. Weak continuum polarization

Douglas C. Leonard; Alexei V. Filippenko; David R. Ardila; Michael S. Brotherton

2001-01-01

411

Dynamic partnership: A new approach to EM technology commercialization and deployment  

SciTech Connect

The task of restoring nuclear defense complex sites under the U.S. Department of Energy (DOE) Environmental Management (EM) Program presents an unprecedented challenge to the environmental restoration community. Effective and efficient cleanup requires the timely development or modification of novel cleanup technologies applicable to radioactive wastes. Fostering the commercialization of these innovative technologies is the mission of EM-50, the EM Program Office of Science and Technology. However, efforts are often arrested at the {open_quotes}valley of death,{close_quotes} the general term for barriers to demonstration, commercialization, and deployment. The Energy & Environmental Research Center (EERC), a not-for-profit, contract-supported organization focused on research, development, demonstration, and commercialization (RDD&C) of energy and environmental technologies, is in the second year of a cooperative agreement with the U.S. Department of Energy (DOE) Morgantown Energy Technology Center (METC) designed to deliver EM technologies into the commercial marketplace through a unique combination of technical support, real-world demonstration, and brokering. This paper profiles this novel approach, termed {open_quotes}Dynamic Partnership,{close_quotes} and reviews the application of this concept to the ongoing commercialization and deployment of four innovative cleanup technologies. 2 tabs.

Daly, D.J.; Erickson, T.A.; Groenewold, G.H. [and others

1996-12-31

412

A Monte Carlo EM Algorithm for De Novo Motif Discovery in Biomolecular Sequences  

Microsoft Academic Search

Motif discovery methods play pivotal roles in deciphering the genetic regulatory codes (i.e., motifs) in genomes as well as in locating conserved domains in protein sequences. The Expectation Maximization (EM) algorithm is one of the most popular methods used in de novo motif discovery. Based on the position weight matrix (PWM) updating technique, this paper presents a Monte Carlo version

Chengpeng Bi

2009-01-01

413

Medicina Baseada em Evidências: a arte de aplicar o conhecimento científico na prática clínica  

Microsoft Academic Search

RESUMO - Este artigo foi escrito com o objetivo de descrever o conceito de Medicina Baseada em Evidências (MBE) e as competências necessárias para a sua prática. MBE deve ser vista como a integração da experiência clínica com a capacida- de de analisar e aplicar racionalmente a informa- ção científica ao cuidar de pacientes. A aplicação de métodos e estratégias

A. A. Lopes

2000-01-01

414

Shashlyk EM calorimeter prototype readout by MAPD with superhigh pixel density for COMPASS II  

NASA Astrophysics Data System (ADS)

The new-generation high-granularity Shashlyk EM calorimeter readout by micropixel avalanche photodiodes (MAPD) with precision thermostabilization based on the Peltier element is designed, constructed end tested. MAPD-3N with superhigh pixel density 1.5×104 mm-2 and area 3×3 mm2 manufactured by the Zecotek Company were used in the photodetector unit.

Anfimov, N.; Anosov, V.; Chirikov-Zorin, I.; Fedoseev, D.; Gavrishchuk, O.; Khovanskiy, N.; Krumshtein, Z.; Leitner, R.; Meshcheryakov, G.; Nagaytsev, A.; Olchevski, A.; Rezinko, T.; Selyunin, A.; Rybnikov, A.; Sadygov, Z.; Savin, I.; Tchalyshev, V.; Zhmurin, P.

2013-08-01

415

Influência da Proximidade Geográfica na Dinâmica Inovativa de Firmas Localizadas em Sistemas Locais de Inovação  

Microsoft Academic Search

Propõe-se uma discussão a respeito da compreensão da dinâmica inovativa de firmas pertencentes a Sistemas Locais de Produção (SLPs). O objetivo é compreender a dinâmica inovativa de firmas localizadas em SLPs por meio das características dos fluxos de informação e conhecimento estabelecidos pelas firmas. Para tanto, foi realizada uma investigação de campo comparativa entre dois aglomerados do segmento produtor de

Janaína Ruffoni; Wilson Suzigan

2012-01-01

416

Solução Paralela em Agregado de PCs de um Código de Elementos Finitos Aplicado à Elasticidade Linear  

Microsoft Academic Search

Resumo. Este trabalho apresenta os resultados comparativos de desempenho de códigos paralelos, baseados no método dos elementos finitos aplicado à elasticidade linear para problemas estruturais, que utilizam o método dos gradientes conjugados para solução do sistema de equações. Os programas foram executados em um agregado de PCs, por ser uma opção economicamente viável, já que utiliza tecnologia depurada de alta

Flávia R. Villa Verde; Roberta R. Ferreira; Gerson H. Pfitscher

417

Recursive estimate-maximize (EM) algorithms for time varying parameters with applications to multiple target tracking  

Microsoft Academic Search

We investigate the application of EM algorithm to the classical problem of multiple target tracking (MTT) for a known number of targets. Conventional algorithms, have a computational complexity that depends exponentially on the targets' number, and usually divide the problem into a localization stage and a tracking stage. The new algorithms achieve a linear dependency, and integrate those hire stages.

L. Frenkel; M. Feder

1995-01-01

418

De-centralized and centralized control for realistic EMS Maglev systems  

NASA Astrophysics Data System (ADS)

A comparative study of de-centralized and centralized controllers when used with real EMS Maglev Systems is introduced. This comparison is divided into two parts. Part I is concerned with numerical simulation and experimental testing on a two ton six-magnet EMS Maglev vehicle. Levitation and lateral control with these controllers individually and when including flux feedback control in combination with these controllers to enhance stability are introduced. The centralized controller is better than the de-centralized one when the system is exposed to a lateral disturbing force such as wind gusts. The flux feedback control when combined with de-centralized or centralized controllers does improve the stability and is more resistant and robust with respect to the air gap variations. Part II is concerned with the study of Maglev vehicle-girder dynamic interaction system and the comparison between these two controllers on this typical system based on performance and ride quality achieved. Numerical simulations of the ODU EMS Maglev vehicle interacting with girder are conducted with these two different controllers. The de-centralized and centralized control for EMS Maglev systems that interact with a flexible girder provides similar ride quality. Centralized control with flux feedback could be the best controller for the ODU Maglev system when operating on girder. The centralized control will guarantee the suppression of the undesired lateral displacements; hence it will provide smoother ride quality. Flux feedback will suppress air gap variations due to the track discontinuities.

Moawad, Mohamed M. Aly M.

419

Características estruturais e índice de tombamento de Brachiaria decumbens cv. Basilisk em pastagens diferidas  

Microsoft Academic Search

RESUMO - Objetivou-se avaliar o efeito dos períodos de diferimento e de pastejo sobre a densidade populacional de perfilhos, a massa dos componentes morfológicos da forragem e o índice de tombamento em pastagens de Brachiaria decumbens cv. Basilisk. Dois ensaios foram conduzidos: o primeiro denominado ano 1 e, o segundo, ano 2. Adotou-se o esquema de parcelas subdivididas, segundo o

Manoel Eduardo Rozalino Santos; Dilermando Miranda da Fonseca; Valéria Pacheco Batista Euclides; Domicio do Nascimento Júnior; Augusto César de Queiroz; José Ivo Ribeiro Júnior

2009-01-01

420

Tailored ML-EM Algorithm for Reconstruction of Truncated Projection Data using Few View-Angles  

PubMed Central

Dedicated cardiac Single Photon Emission Computed Tomography (SPECT) systems have the advantage of high speed and sensitivity at no loss, or even a gain, in resolution. The potential drawbacks of these dedicated systems are data truncation by the small field of view (FOV) and the lack of view-angles. Serious artifacts, including streaks outside the FOV and distortion in the FOV, are introduced to the reconstruction when using the traditional emission data Maximum-Likelihood Expectation-Maximization (ML-EM) algorithm to reconstruct images from the truncated data at small number of views. In this paper, we propose a tailored ML-EM algorithm to suppress the artifacts caused by data truncation and insufficient angular sampling by reducing the image updating step sizes for the pixels outside the FOV. As a consequence, the convergence speed for the pixels outside the FOV is decelerated. We applied the proposed algorithm to truncated analytical data, Monte Carlo simulation data and real emission data at different numbers of views. The computer simulation results show that the tailored ML-EM algorithm outperforms the conventional ML-EM algorithm in terms of streak artifacts and distortion suppression for reconstruction from truncated projection data with a small number of views.

Mao, Yanfei; Zeng, Gengsheng L.

2013-01-01

421

The Statistical Analysis of General Processing Tree Models with the EM Algorithm.  

ERIC Educational Resources Information Center

The statistical analysis of processing tree models is advanced by showing how the parameters of estimation and hypothesis testing, based on the likelihood functions, can be accomplished by adapting the expectation-maximization (EM) algorithm. The adaptation makes it easy to program a personal computer to accomplish the stages of statistical…

Hu, Xiangen; Batchelder, William H.

1994-01-01

422

Lessons in Generative Design, Publishing, and Circulation: What EM-Journal's First Year Has Taught Us  

ERIC Educational Resources Information Center

"EM-Journal" is a flexibly refereed online journal featuring writing produced by students of Eastern Michigan University. The journal showcases a variety of documents (articles, essays, reports, etc.) written and designed by students enrolled in EMU's First-Year Writing (FYW) program, in selected Writing Intensive (WI) courses affiliated with the…

Rosinski, Jana; Lonsdale, Chelsea; Morrison, Becky; Mueller, Derek; Nannini, Adam

2013-01-01

423

COMPORTAMENTO DE ÓLEOS VEGETAIS EM FRITURAS DESCONTÍNUAS DE PRODUTOS PRÉ-FRITOS CONGELADOS1  

Microsoft Academic Search

-1 e tempo total de aquecimento de 12 h. Nas amostras dos óleos procederam-se as determinações analíticas: compostos polares totais, dienos conjugados, índice de ácido tiobarbitúrico (TBA) e medida da estabilidade oxidativa. Os resultados, em duplicata, obtidos das determinações analíticas foram submetidos às análises de variância, empregando um esquema fatorial, no delineamento inteiramente casual, de modo a determinar a influência

Patrícia Vieira DEL RÉ; Neuza JORGE

424

Longer term impacts of transformed courses on student conceptual understanding of E&M  

NASA Astrophysics Data System (ADS)

We have measured upper-division physics majors' performance using two research-based conceptual instruments in E&M, the BEMA [1] and the CUE (Colorado Upper Division Electrostatics assessment[2].) The BEMA has been given pre/post in freshman E&M (Physics II) courses, and the BEMA and CUE have been given pre/post in several upper-division E&M courses. Some of these data extend over 10 semesters. We used PER-based techniques to transform the introductory and upper-division courses starting in Fall 2004 and 2007, respectively [2, 3]. Our longitudinal data allow us to measure ``fade'' on BEMA performance between freshman and junior year. We investigate the effects of curricula on students by comparing juniors who were enrolled in traditional vs. transformed physics as freshmen, as well as those who were enrolled in traditional or transformed upper-division E&M I, using both BEMA and CUE measures. We find that while freshman reforms significantly impact BEMA scores, junior-level reforms affect CUE but not BEMA outcomes.

Pollock, Steven J.; Chasteen, Stephanie V.

2009-11-01

425

LINFANGITE CRÔNICA EM POTRO: RELATO DE CASO CHRONIC LYMPHANGITIS IN A FOAL: CASE REPORT  

Microsoft Academic Search

RESUMO: Este trabalho relata um caso de linfangite crônica em membro posterior de um potro, o qual se originou a partir de um abcesso mal tratado. Diferentes terapias foram realizadas buscando-se redução de edema de tecidos moles, aumento da circulação vascular sangüínea e linfática e eliminação da infecção. Porém, os sinais clínicos foram apenas parcialmente resolvidos com as terapias e

G. RIBEIRO; DI FILIPPO

426

EM algorithm-based hyperparameters estimator for bayesian image denoising using BKF prior  

Microsoft Academic Search

This paper is devoted to a novel hyperparameters estimator for bayesian denoising of images using the Bessel K Forms prior which we recently developed. More precisely, this approach is based on the EM algorithm. The simulation results show that this estimator offers good performances and is slightly better compared to the cumulant-based estimator suggested in. A comparative study is carried

Larbi Boubchir; Bruno Durning; Eric Petit

2011-01-01

427

Artificial neural networks for fast and accurate EM-CAD of microwave circuits  

Microsoft Academic Search

A novel approach for achieving fast and accurate computer-aided design (CAD) of microwave circuits is described. The proposed approach enhances the ability to utilize electromagnetic (EM) analysis techniques in an interactive CAD environment through the application of neurocomputing technology. Specifically, a multilayer perceptron neural network (MLPNN) is implemented to model monolithic microwave integrated circuit (MMIC) passive elements using the element's

Gregory L. Creech; Bradley J. Paul; Christopher D. Lesniak; Thomas J. Jenkins; Mark C. Calcatera

1997-01-01

428

A comparison between the simulated annealing and the EM algorithms in normal mixture decompositions  

Microsoft Academic Search

We compare the performances of the simulated annealing and the EM algorithms in problems of decomposition of normal mixtures according to the likelihood approach. In this case the likelihood function has multiple maxima and singularities, and we consider a suitable reformulation of the problem which yields an optimization problem having a global solution and at least a smaller number of

Salvatore Ingrassia; Corso Italia

1992-01-01

429

A row-action alternative to the EM algorithm for maximizing likelihood in emission tomography  

Microsoft Academic Search

The maximum likelihood (ML) approach to estimating the radioactive distribution in the body cross section has become very popular among researchers in emission computed tomography (ECT) since it has been shown to provide very good images compared to those produced with the conventional filtered backprojection (FBP) algorithm. The expectation maximization (EM) algorithm is an often-used iterative approach for maximizing the

Jolyon Browne; Alvaro R. De Pierro

1996-01-01

430

Innovation on Energy Power Technology (17)Development of EMS\\/SCADA in TEPCO  

Microsoft Academic Search

Effective Load Dispatching Automatic Controller (ELDAC) is an EMS\\/SCADA system for Central Load Dispatching Office in Tokyo Electric Power Company Inc. This paper introduces the progress of development of ELDAC, which forecasts demand, sets up the most efficient generation schedule, and controls total power from generators.

Mamoru Suzuki

2009-01-01

431

Innovation on Energy Power Technology (17)Development of EMS/SCADA in TEPCO  

NASA Astrophysics Data System (ADS)

Effective Load Dispatching Automatic Controller (ELDAC) is an EMS/SCADA system for Central Load Dispatching Office in Tokyo Electric Power Company Inc. This paper introduces the progress of development of ELDAC, which forecasts demand, sets up the most efficient generation schedule, and controls total power from generators.

Suzuki, Mamoru

432

Are you under stress in EMS. Understanding the slippery slope of burnout and PTSD.  

PubMed

Burnout and PTSD are closely linked and often underreported in EMS. EMS classrooms do little or nothing to prepare providers for the inherent emotional stresses of emergency response and the "thick skin" culture of EMS may make many providers apprehensive about sharing their true feelings. Burnout is triggered by many of the same stresses that lead to the symptoms of PTSD and providers experiencing burnout that doesn't resolve within a few weeks may actually be experiencing PTSD. Be mindful of yourself and your fellow coworkers, particularly after a very traumatic response. And remember traumatic responses don't need to be as dramatic as Sept. 11, New Orleans after Hurricane Katrina or the Aurora, CO shootings to bother an EMS worker. In contrast, these are the calls where providers often receive the most attention. Instead, watch for the new father who just performed CPR on an infant the same age as his own, or the provider who just watched his or her friend die following a motor vehicle collision. Pay attention to yourself and colleagues, and be responsible and honest with yourself and others about when coping strategies are enough, and when they aren't. Finally, don't ever be afraid to seek help. PMID:23097838

Collopy, Kevin T; Kivlehan, Sean M; Snyder, Scott R

2012-10-01

433

MERCADO DE TRABALHO EM EDUCAÇÃO FÍSICA: REESTRUTURAÇÃO PRODUTIVA, RELAÇÕES DE TRABALHO E INTERVENÇÃO PROFISSIONAL  

Microsoft Academic Search

Resumo: No processo de preparação profissional, as discussões sobre mercado de trabalho quase sempre se concentram em apresentar os possíveis locais de intervenção, deixando de analisar a complexidade das relações de trabalho e a reestruturação produtiva. Desta forma, desejando despertar para o interesse dessa temática no universo da Educação Física, os objetivos deste artigo são: a) caracterizar a estruturação e

Rita de Cássia; Garcia Verenguer

434

A New View of the EM Algorithm that Justifies Incremental and Other Variants  

Microsoft Academic Search

We present a new view of the EM algorithm for maximum likelihood estimationin situations with unobserved variables. In this view, both the E and the M stepsof the algorithm are seen as maximizing a joint function of the model parametersand of the distribution over unobserved variables. From this perspective, it iseasy to justify an incremental variant of the algorithm in

Radford M. Neal; Geoffrey E. Hinton

1993-01-01

435

Integrated models for the analysis of biological effects of EM fields used for mobile communications  

Microsoft Academic Search

The understanding of the modalities of interaction of electromagnetic (EM) fields with biological material is a key point in the identification of possible induced effects. Since the beginnings of bioelectromagnetic research studies, most of the attention has been focused on the effects on nervous systems and neuronal cells. The importance of this target has recently increased due to the wide

Francesca Apollonio; Micaela Liberti; G. D'Inzeo; L. Tarricone

2000-01-01

436

Estimation of variance components: what is missing in the EM algorithm  

Microsoft Academic Search

The EM algorithm is a frequently advocated algorithm for the estimation of variance components. A faster converging algorithm is developed using alternative parameter-izations based on the analysis of variance. The procedure is exemplified using designs with two and three variance components and with multivariate designs using parameter values relevant to animal breeding data.

R. Thompson; K. Meyer

1986-01-01

437

EMS runs for suspected opioid overdose: Implications for surveillance and prevention  

PubMed Central

Objective Opioid (including prescription opiate) abuse and overdose rates in the US have surged in the past decade. The dearth and limitations of opioid abuse and overdose surveillance systems impede the development of interventions to address this epidemic. We explored evidence to support the validity of emergency medical services (EMS) data on naloxone administration as a possible proxy for estimating incidence of opioid overdose. Methods We reviewed data from Baltimore City Fire Department EMS patient records matched with dispatch records over a thirteen month time period (2008-2009), and census 2008 data. We calculated incidence rates and patient demographic and temporal patterns of naloxone administration, and examined patient evaluation data associated with naloxone administration. Results were compared to the demographic distributions of the EMS patient and city population and to prior study findings. Results Of 116,910 EMS incidents during the study period for patients 15 years and older, EMS providers administered naloxone 1,297 times (1.1% of incidents), an average of 100 administrations per month. Overall incidence was 1.87 administrations per 1,000 population per year. Findings indicated naloxone administration peaked in summer months (31% of administrations), weekends (32%), and late afternoon (4-5:00pm [8%]); and there was a trend toward peaking in the first week of the month. The incidence of suspected opioid overdose was highest among males, whites, and those in the 45-54 year age group. Findings on temporal patterns were comparable to findings from prior studies. Demographic patterns of suspected opioid overdose were similar to medical examiner reports of demographic patterns of fatal drug or alcohol related overdoses in Baltimore in 2008-9 (88% of which involved opioids). The findings on patient evaluation data suggest some inconsistencies with previously recommended clinical indications of opioid overdose. Conclusions While our findings suggest limitations of EMS naloxone administration data as a proxy indicator of opioid overdose, the results provide partial support of the data for estimating opioid overdose incidence and suggest ways to improve such data. The study findings have implications for an EMS role in conducting real-time surveillance and treatment and prevention of opioid abuse and overdose.

Knowlton, Amy; Weir, Brian; Hazzard, Frank; Olsen, Yngvild; McWilliams, Junette; Fields, Julie; Gaasch, Wade

2013-01-01

438

Determining and Prioritizing the Organizational Determinants of Emergency Medical Services (EMS) in Iran  

PubMed Central

Background Improving the organization of pre-hospital emergency to provide emergency medical services (EMS), as a part of health system, plays an important role in timely and properly response to incidents, as well as, reducing mortalities and disabilities. Objective This study was conducted to determine the organizational determinants of emergency medical services in Iran and analyze their relationship and prioritize them. Materials and Methods The present study is kind of descriptive and cross-sectional study that has been conducted on the first half of 2010 using DEMATEL method (a group decision-making technique). Required data were collected using a questionnaire from a sample of 30 Iranian experts in pre-hospital emergency, who were selected using available sampling method. Results The determinants of establishing an independent EMS organization as a policy maker and observer organization, providing services through public organizations such as Emergency 115, private organizations partnership in pre-hospital emergency system, and integrating pre-hospital and hospital emergency under single supervision and management were determined as organizational determinants. Also, establishing an independent EMS organization and integrating pre-hospital and hospital emergency under single supervision and management were determined as the most affecting and affected organizational determinants, respectively, with the coordinates (1.01 and 1.01) and (0.85 and - 0.85) in the pre-hospital emergency organizational determinants graph. Conclusions Emergency medical services should be considered as a system with its independent components. Establishing an independent EMS organization, integrating pre-hospital and hospital emergency under single supervision and management, as well as, extending the possibility of providing EMS through private sector are essential in order to make fundamental reforms in providing emergency medical services in Iran.

Bahadori, Mohammadkarim; Ravangard, Ramin

2013-01-01

439

Investigating metal removal potential by Effective Microorganisms (EM) in alginate-immobilized and free-cell forms.  

PubMed

Metal removal potential of both alginate-immobilized and free-cells of Effective Microorganisms (EM-1™ Inoculant) was investigated in this study. Results revealed that removal of Cr(III), Cu(II) and Pb(II) followed a similar trend where alginate-immobilized EM were more efficient compared to free-cells of EM. For these metals, 0.940, 2.695 and 4.011 mg g(-1) of Cr(III), Cu(II) and Pb(II) were removed compared to only 0.160, 0.859 and 0.755 mg ml(-1) removed by free-cells, respectively. The higher efficiency of alginate-immobilized EM was primarily attributed to the alginate matrix. This was evident when both alginate-immobilized EM and plain alginate beads (without EM), were not significantly different in their removal efficacies. Presence of alginate also enhanced the use of the biosorbents as maximum metal sorption was achieved after 120 min as opposed to only 60 min for free-cells. EM per se in immobilized or free-cell forms did not enhance metal removal efficacy. PMID:24001691

Ting, Adeline Su Yien; Rahman, Nurul Hidayah Abdul; Isa, Mohamed Ikmal Hafiz Mahamad; Tan, Wei Shang

2013-11-01

440

Drug-resistant T-lymphoid tumors undergo apoptosis selectively in response to an antimicrotubule agent, EM011  

PubMed Central

We have shown previously that EM011, a synthetic compound, binds tubulin with a higher affinity than the founding compound, noscapine, without changing total microtubule polymer mass. Now we show that EM011 is potently effective against vinblastine-resistant human lymphoblastoid line CEM/VLB100 and its parental vinblastine-sensitive line CEM. The cytotoxicity is mediated by cell cycle arrest at G2/M phase and subsequent apoptosis, as indicated by altered plasma membrane asymmetry, loss of mitochondrial transmembrane potential, activation of caspa