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Sample records for central kurile segment

  1. The Great 2006 and 2007 Kuril Earthquakes, Forearc Segmentation and Seismic Activity of the Central Kuril Islands Region

    NASA Astrophysics Data System (ADS)

    Baranov, B. V.; Ivashchenko, A. I.; Dozorova, K. A.

    2015-12-01

    We present a structural study of the Central Kuril Islands forearc region, where the great megathrust tsunamigenic earthquake ( M w 8.3) occurred on November 15, 2006. Based on new bathymetry and seismic profiles obtained during two research cruises of R/V Akademik Lavrentiev in 2005 and 2006, ten crustal segments with along-arc length ranging from 30 to 100 km, separated by NS- and NW-trending transcurrent faults were identified within the forearc region. The transcurrent faults may serve as barriers impeding stress transfer between the neighboring segments, so that stress accumulated within separate forearc segments is usually released by earthquakes of moderate-to-strong magnitudes. However, the great November 15, 2006 earthquake ruptured seven of the crustal segments probably following a 226-year gap since the last great earthquake in 1780. The geographic extent of earthquake rupture zones, aftershock areas and earthquake clusters correlate well with forearc crustal segments identified using the geophysical data. Based on segmented structure of the Central Kuril Islands forearc region, we consider and discuss three scenarios of a great earthquake occurrence within this area. Although the margin is segmented, we suggest that a rupture could occupy the entire seismic gap with a total length of about 500 km. In such a case, the earthquake magnitude M w might exceed 8.5, and such an event might generate tsunami waves significantly exceeding in height to those produced by the great 2006-2007 Kuril earthquakes.

  2. A great earthquake doublet and seismic stress transfer cycle in the central Kuril islands.

    PubMed

    Ammon, Charles J; Kanamori, Hiroo; Lay, Thorne

    2008-01-31

    Temporal variations of the frictional resistance on subduction-zone plate boundary faults associated with the stick-slip cycle of large interplate earthquakes are thought to modulate the stress regime and earthquake activity within the subducting oceanic plate. Here we report on two great earthquakes that occurred near the Kuril islands, which shed light on this process and demonstrate the enhanced seismic hazard accompanying triggered faulting. On 15 November 2006, an event of moment magnitude 8.3 ruptured the shallow-dipping plate boundary along which the Pacific plate descends beneath the central Kuril arc. The thrust ruptured a seismic gap that previously had uncertain seismogenic potential, although the earlier occurrence of outer-rise compressional events had suggested the presence of frictional resistance. Within minutes of this large underthrusting event, intraplate extensional earthquakes commenced in the outer rise region seaward of the Kuril trench, and on 13 January 2007, an event of moment magnitude 8.1 ruptured a normal fault extending through the upper portion of the Pacific plate, producing one of the largest recorded shallow extensional earthquakes. This energetic earthquake sequence demonstrates the stress transfer process within the subducting lithosphere, and the distinct rupture characteristics of these great earthquakes illuminate differences in seismogenic properties and seismic hazard of such interplate and intraplate faults.

  3. The forearc extension in the Central Kuril Islands and the trench rollback

    NASA Astrophysics Data System (ADS)

    Baranov, B. V.; Lobkovsky, L. I.; Dozorova, K. A.

    2016-07-01

    On the basis of bathymetric and seismic data, obtained during cruises 37 (2005) and 41 (2006) of R/V Akademik M.A. Lavrentiev, a new structural scheme of transverse faults in the forearc of the Central Kuril Islands was compiled, the fault kinematics was studied, and a model of the extension zone in the structural pattern of the study area was proposed. According to this model, the trench rollback and development of back-arc basins resulted from the continuous supply of material into the upper mantle convection cell owing to subduction and an increase in the dynamic pressure that pushes the subducting plate, causing it to migrate toward the ocean.

  4. Satellite and ground observations of the June 2009 eruption of Sarychev Peak volcano, Matua Island, Central Kuriles

    USGS Publications Warehouse

    Rybin, A.; Chibisova, M.; Webley, P.; Steensen, T.; Izbekov, P.; Neal, C.; Realmuto, V.

    2011-01-01

    After 33 years of repose, one of the most active volcanoes of the Kurile island arc-Sarychev Peak on Matua Island in the Central Kuriles-erupted violently on June 11, 2009. The eruption lasted 9 days and stands among the largest of recent historical eruptions in the Kurile Island chain. Satellite monitoring of the eruption, using Moderate Resolution Imaging Spectroradiometer, Meteorological Agency Multifunctional Transport Satellite, and Advanced Very High Resolution Radiometer data, indicated at least 23 separate explosions between 11 and 16 June 2009. Eruptive clouds reached altitudes of generally 8-16 km above sea level (ASL) and in some cases up to 21 km asl. Clouds of volcanic ash and gas stretched to the north and northwest up to 1,500 km and to the southeast for more than 3,000 km. For the first time in recorded history, ash fall occurred on Sakhalin Island and in the northeast sector of the Khabarovsky Region, Russia. Based on satellite image analysis and reconnaissance field studies in the summer of 2009, the eruption produced explosive tephra deposits with an estimated bulk volume of 0. 4 km3. The eruption is considered to have a Volcanic Explosivity Index of 4. Because the volcano is remote, there was minimal risk to people or infrastructure on the ground. Aviation transport, however, was significantly disrupted because of the proximity of air routes to the volcano. ?? 2011 Springer-Verlag.

  5. Shallow-water Ascidians from Matua Island (central Kuril Islands, NW Pacific).

    PubMed

    Sanamyan, Karen; Sanamyan, Nadya

    2017-02-16

    Fifteen species of ascidians were identified in the material collected at Matua Island. Two species are new, Botryllus flavus n. sp. and Distaplia matua n. sp. The first species occurs also at Kamchatka waters, while the second is probably an endemic of Kuril Islands. The genus Macrenteron Redikorzev, 1927 is synonymized with Aplidium Savigny, 1816 and a new name Aplidium macrenteron nom. nov. is proposed for its type species.

  6. Satellite and ground observations of the June 2009 eruption of Sarychev Peak volcano, Matua Island, Central Kuriles

    NASA Astrophysics Data System (ADS)

    Rybin, Alexander; Chibisova, Marina; Webley, Peter; Steensen, Torge; Izbekov, Pavel; Neal, Christina; Realmuto, Vince

    2011-11-01

    After 33 years of repose, one of the most active volcanoes of the Kurile island arc—Sarychev Peak on Matua Island in the Central Kuriles—erupted violently on June 11, 2009. The eruption lasted 9 days and stands among the largest of recent historical eruptions in the Kurile Island chain. Satellite monitoring of the eruption, using Moderate Resolution Imaging Spectroradiometer, Meteorological Agency Multifunctional Transport Satellite, and Advanced Very High Resolution Radiometer data, indicated at least 23 separate explosions between 11 and 16 June 2009. Eruptive clouds reached altitudes of generally 8-16 km above sea level (ASL) and in some cases up to 21 km asl. Clouds of volcanic ash and gas stretched to the north and northwest up to 1,500 km and to the southeast for more than 3,000 km. For the first time in recorded history, ash fall occurred on Sakhalin Island and in the northeast sector of the Khabarovsky Region, Russia. Based on satellite image analysis and reconnaissance field studies in the summer of 2009, the eruption produced explosive tephra deposits with an estimated bulk volume of 0.4 km3. The eruption is considered to have a Volcanic Explosivity Index of 4. Because the volcano is remote, there was minimal risk to people or infrastructure on the ground. Aviation transport, however, was significantly disrupted because of the proximity of air routes to the volcano.

  7. Postseismic Gravity Change After the 2006-2007 Great Earthquake Doublet and Constraints on the Asthenosphere Structure in the Central Kuril Islands

    NASA Technical Reports Server (NTRS)

    Shin-Chan, Han; Sauber, Jeanne; Pollitz, Fred

    2016-01-01

    Large earthquakes often trigger viscoelastic adjustment for years to decades depending on the rheological properties and the nature and spatial extent of coseismic stress. The 2006 Mw8.3 thrust and 2007 Mw8.1 normal fault earthquakes of the central Kuril Islands resulted in significant postseismic gravity change in GRACE but without a discernible coseismic gravity change. The gravity increase of approximately 4 micro-Gal, observed consistently from various GRACE solutions around the epicentral area during 2007-2015, is interpreted as resulting from gradual seafloor uplift by (is) approximately 6 cm produced by postseismic relaxation. The GRACE data are best fit with a model of 25-35 km for the elastic thickness and approximately 10(exp 18) Pa s for the Maxwell viscosity of the asthenosphere. The large measurable postseismic gravity change (greater than coseismic change) emphasizes the importance of viscoelastic relaxation in understanding tectonic deformation and fault-locking scenarios in the Kuril subduction zone.

  8. Postseismic gravity change after the 2006-2007 great earthquake doublet and constraints on the asthenosphere structure in the central Kuril Islands.

    PubMed

    Han, Shin-Chan; Sauber, Jeanne; Pollitz, Fred

    2016-04-16

    Large earthquakes often trigger viscoelastic adjustment for years to decades depending on the rheological properties and the nature and spatial extent of coseismic stress. The 2006 Mw8.3 thrust and 2007 Mw8.1 normal fault earthquakes of the central Kuril Islands resulted in significant postseismic gravity change in GRACE but without a discernible coseismic gravity change. The gravity increase of ~4 µGal, observed consistently from various GRACE solutions around the epicentral area during 2007-2015, is interpreted as resulting from gradual seafloor uplift by ~6 cm produced by postseismic relaxation. The GRACE data are best fit with a model of 25-35 km for the elastic thickness and ~10(18) Pa s for the Maxwell viscosity of the asthenosphere. The large measurable postseismic gravity change (greater than coseismic change) emphasizes the importance of viscoelastic relaxation in understanding tectonic deformation and fault-locking scenarios in the Kuril subduction zone.

  9. Interseismic plate coupling, seismic rupture, and postseismic slip at the 2003 Tokachi-oki segment of Kuril Trench

    NASA Astrophysics Data System (ADS)

    Miyazaki, S.; Segall, P.; Johnson, K. M.; Larson, K. M.; McGuire, J. J.; Choi, K.; Fukuda, J.; Hori, T.; Baba, T.

    2007-05-01

    We investigate interseismic plate coupling, the 2003 Tokachi-oki rupture and its afterslip using Japanese nationwide GPS network. The 2003 Tokachi-oki earthquake (M ~ 8) occurred at the western end of the Kuril Trench on September 25, 2003 (UT). We processed 1-Hz GPS for this earthquake, and inverted GPS displacement waveform to infer the coseismic slip distribution. Then we used daily GPS time series after the quake to infer the space-time distribution of the afterslip following this earthquake. We found that the high-speed rupture and afterslip are not overlapping, and this result support the idea that the frictional property of the plate boundary is significantly different between those two regions. Because we have cumulative slip at every epoch, we are able to calculate shear stress change using dislocation theory. We investigated the slip velocity dependence of the shear stress change, and found that the frictional property of the afterslip area would be steady-state velocity strengthening. On the other hand, it is widely believed that high speed rupture occurs at the steady-state velocity weakening region. Hence we suggest that the spatial inhomogeneity of the frictional properties caused the difference between slip styles in rupture region and afterslip reagion. Interseismic coupling inferred from GPS data also support this hypothesis.

  10. Volcano-Hydrothermal Systems of the Central and Northern Kuril Island Arc - a Review

    NASA Astrophysics Data System (ADS)

    Kalacheva, E.; Taran, Y.; Voloshina, E.; Ptashinsky, L.

    2015-12-01

    More than 20 active volcanoes with historical eruptions are known on 17 islands composing the Central and Northern part of the Kurilian Arc. Six islands - Paramushir, Shiashkotan, Rasshua, Ushishir, Ketoy and Simushir - are characterized by hydrothermal activity, complementary to the fumarolic activity in their craters. There are several types of volcano-hydrothermal systems on the islands. At Paramushir, Shiashkotan and Ketoy the thermal manifestations are acidic to ultra-acidic water discharges associated with hydrothermal aquifers inside volcano edifices and formed as the result of the absorption of magmatic gases by ground waters. A closest known analogue of such activity is Satsuma-Iwojima volcano-island at the Ryukyu Arc. Another type of hydrothermal activity are wide spread coastal hot springs (Shiashkotan, Rasshua), situated as a rule within tide zones and formed by mixing of the heated seawater with cold groundwater or, in opposite, by mixing of the steam- or conductively heated groundwater with seawater. This type of thermal manifestation is similar to that reported for other volcanic islands of the world (Satsuma Iwojima, Monserrat, Ischia, Socorro). Ushishir volcano-hydrothermal system is formed by the absorption of magmatic gases by seawater. Only Ketoy Island hosts a permanent acidic crater lake. At Ebeko volcano (Paramushir) rapidly disappearing small acidic lakes (formed after phreatic eruptions) have been reported. The main hydrothermal manifestation of Simushir is the Zavaritsky caldera lake with numerous coastal thermal springs and weak steam vents. The last time measured temperatures of fumaroles at the islands are: >500ºC at Pallas Peak (Ketoy), 480ºC at Kuntamintar volcano (Shiashkotan), variable and fast changing temperatures from 120º C to 500ºC at Ebeko volcano (Paramushir), 150ºC in the Rasshua crater, and > 300ºC in the Chirpoy crater (Black Brothers islands). The magmatic and rock-forming solute output by the Kurilian volcano

  11. Postseismic gravity change after the 2006–2007 great earthquake doublet and constraints on the asthenosphere structure in the central Kuril Islands

    USGS Publications Warehouse

    Han, Shin-Chan; Sauber, Jeanne; Pollitz, Fred

    2016-01-01

    Large earthquakes often trigger viscoelastic adjustment for years to decades depending on the rheological properties and the nature and spatial extent of coseismic stress. The 2006 Mw8.3 thrust and 2007 Mw8.1 normal fault earthquakes of the central Kuril Islands resulted in significant postseismic gravity change in Gravity Recovery and Climate Experiment (GRACE) but without a discernible coseismic gravity change. The gravity increase of ~4 μGal, observed consistently from various GRACE solutions around the epicentral area during 2007–2015, is interpreted as resulting from gradual seafloor uplift by ~6 cm produced by postseismic relaxation. The GRACE data are best fit with a model of 25–35 km for the elastic thickness and ~1018 Pa s for the Maxwell viscosity of the asthenosphere. The large measurable postseismic gravity change (greater than coseismic change) emphasizes the importance of viscoelastic relaxation in understanding tectonic deformation and fault-locking scenarios in the Kuril subduction zone.

  12. Transformation of tsunami waves passing through the Straits of the Kuril Islands

    NASA Astrophysics Data System (ADS)

    Kostenko, Irina; Kurkin, Andrey; Pelinovsky, Efim; Zaytsev, Andrey

    2015-04-01

    Pacific ocean and themselves Kuril Islands are located in the zone of high seismic activity, where underwater earthquakes cause tsunamis. They propagate across Pacific ocean and penetrates into the Okhotsk sea. It is natural to expect that the Kuril Islands reflect the Okhotsk sea from the Pacific tsunami waves. It has long been noted that the historical tsunami appeared less intense in the sea of Okhotsk in comparison with the Pacific coast of the Kuril Islands. Despite the fact that in the area of the Kuril Islands and in the Pacific ocean earthquakes with magnitude more than 8 occur, in the entire history of observations on the Okhotsk sea coast catastrophic tsunami was not registered. The study of the peculiarities of the propagation of historical and hypothetical tsunami in the North-Eastern part of the Pacific ocean was carried out in order to identify level of effect of the Kuril Islands and Straits on them. Tsunami sources were located in the Okhotsk sea and in the Pacific ocean. For this purpose, we performed a series of computational experiments using two bathymetries: 1) with use Kuril Islands; 2) without Kuril Islands. Magnitude and intensity of the tsunami, obtained during numerical simulation of height, were analyzed. The simulation results are compared with the observations. Numerical experiments have shown that in the simulation without the Kuril Islands tsunamis in the Okhotsk sea have higher waves, and in the Central part of the sea relatively quickly damped than in fact. Based on shallow-water equation tsunami numerical code NAMI DANCE was used for numerical simulations. This work was supported by ASTARTE project.

  13. Active Volcanoes of the Kurile Islands: A Reference Guide for Aviation Users

    USGS Publications Warehouse

    Neal, Christina A.; Rybin, Alexander; Chibisova, Marina; Miller, Edward

    2008-01-01

    Introduction: The many volcanoes of the remote and mostly uninhabited Kurile Island arc (fig. 1; table 1) pose a serious hazard for air traffic in the North Pacific. Ash clouds from Kurile eruptions can impact some of the busiest air travel routes in the world and drift quickly into airspace managed by three countries: Russia, Japan, and the United States. Prevailing westerly winds throughout the region will most commonly send ash from any Kurile eruption directly across the parallel North Pacific airways between North America and Asia (Kristine A. Nelson, National Weather Service, oral commun., 2006; fig. 1). This report presents maps showing locations of the 36 most active Kurile volcanoes plotted on Operational Navigational Charts published by the Defense Mapping Agency (map sheets ONC F-10, F-11, and E-10; figs. 1, 2, 3, 4). These maps are intended to assist aviation and other users in the identification of restless Kurile volcanoes. A regional map is followed by three subsections of the Kurile volcanic arc (North, Central, South). Volcanoes and selected primary geographic features are labeled. All maps contain schematic versions of the principal air routes and selected air navigational fixes in this region.

  14. Recurrence of postseismic coastal uplift, Kuril subduction zone, Japan

    USGS Publications Warehouse

    Kelsey, H.; Satake, K.; Sawai, Y.; Sherrod, B.; Shimokawa, K.; Shishikura, M.

    2006-01-01

    Coastal stratigraphy of eastern Hokkaido indicates that decimeters of coastal uplitt occurred repeatedly m the late Holocene. Employing radiocarbon dating and tephrochronology, we identify along a 100 km length of the Kuril subduction zone six uplift events since ???2,800 years B.P. Uplift events occur at the same frequency as unusually high tsunamis. Each coastal uplift event, which occurs on average every 500 years, is the product of decade-long post seismic deep slip on the down dip extension of the seismogenic plate boundary following an offshore multi-segment earthquake that generates unusually high tsunamis. Copyright 2006 by the American Geophysical Union.

  15. Unusually large earthquakes inferred from tsunami deposits along the Kuril trench

    USGS Publications Warehouse

    Nanayama, F.; Satake, K.; Furukawa, R.; Shimokawa, K.; Atwater, B.F.; Shigeno, K.; Yamaki, S.

    2003-01-01

    The Pacific plate converges with northeastern Eurasia at a rate of 8-9 m per century along the Kamchatka, Kuril and Japan trenches. Along the southern Kuril trench, which faces the Japanese island of Hokkaido, this fast subduction has recurrently generated earthquakes with magnitudes of up to ???8 over the past two centuries. These historical events, on rupture segments 100-200 km long, have been considered characteristic of Hokkaido's plate-boundary earthquakes. But here we use deposits of prehistoric tsunamis to infer the infrequent occurrence of larger earthquakes generated from longer ruptures. Many of these tsunami deposits form sheets of sand that extend kilometres inland from the deposits of historical tsunamis. Stratigraphic series of extensive sand sheets, intercalated with dated volcanic-ash layers, show that such unusually large tsunamis occurred about every 500 years on average over the past 2,000-7,000 years, most recently ???350 years ago. Numerical simulations of these tsunamis are best explained by earthquakes that individually rupture multiple segments along the southern Kuril trench. We infer that such multi-segment earthquakes persistently recur among a larger number of single-segment events.

  16. Interplate coupling along segments of the Central America Subduction zone

    NASA Astrophysics Data System (ADS)

    Zarifi, Zoya; Raeesi, Mohammad; Atakan, Kuvvet

    2013-04-01

    We analyzed 5 major earthquakes that occurred during 1992 to 2012 in a segment of the Central America subduction zone along the coasts of Guatemala and El Salvador. These events include 1992/09/02 (Mw 7.7), 1993/09/10 (Mw 7.2), 2001/01/13 (Mw 7.7), 2012/08/27 (Mw 7.3) and 2012/11/07 (Mw 7.3). We derived the asperities of these earthquakes using two completely independent methods of body-waveform inversion and a gravity-derived measure, Trench Parallel Bouguer Anomaly (TPBA). Using TPBA we discuss the status of interplate coupling along the segment and interpret each of the major earthquakes as a piece of the governing rupture process. We delineate the critical unbroken asperities along the segment that will likely generate great earthquake(s) in the future.

  17. Estimation of Extreme Sea Levels for the Russian Coasts of the Kuril Islands and the Sea of Okhotsk

    NASA Astrophysics Data System (ADS)

    Shevchenko, Georgy; Ivelskaya, Tatiana

    2015-12-01

    Extreme sea levels arising from the combination of tides, storm surges, seasonal oscillations and tsunamis were estimated by the joint probability method for the coast of the Sea of Okhotsk and the Pacific coast of the Kuril Islands. The sea-level observations at 10 coastal tide gauges were examined. The tidal heights at most stations are about 1.5-2 m, and only at Magadan are they much larger (about 5 m). Storm surges have the largest heights for the central Kuril Islands (Matua and Iturup islands), while at the North and South Kuril Islands the surge heights are the smallest. The recurrence of tsunami heights of various probabilities was estimated for each station. The influence of tides and storm surges on the tsunami risk assessment for the Pacific coast of the Kurile Islands was found to be relatively small. For the coast of the Sea of Okhotsk, the contribution of tides and surges is the primary influence, especially for return periods less than 100 years. For longer return periods, tsunamis play the major role in forming the extreme levels (similar to the Russian coast of the Sea of Japan, e.g., R abinovich et al. 1992).

  18. Oblique convergence and deformation along the Kuril and Japan trenches

    NASA Technical Reports Server (NTRS)

    Demets, Charles

    1992-01-01

    The hypothesis that present-day deformation within the southern Kuril forearc is driven by oblique subduction of the Pacific plate is tested using 397 horizontal slip directions derived from shallow-thrust earthquakes from the Kuril and Japan trenches for the period 1963-1991. A simple two-plate model fits the 397 slip vectors significantly worse than a model that permits strike-slip motion of the southern Kuril forearc relative to the overlying plate. Weighted, mean slip directions along the southern Kuril trench are systematically rotated toward the direction orthogonal to the trench, which implies that the net convergence is partitioned into less oblique subduction and trench-parallel displacement of the southern Kuril forearc. The angular discrepancy between the observed slip direction and the direction predicted by the NUVEL-1 Pacific-North America Euler vector implies that the southern Kuril forearc translates 6-11 mm/yr to the southwest relative to the overlying North American plate. These results are consistent with geologically, geodetically, and seismologically observed convergence at the leading edge of the forearc sliver in southern Kokkaido and with previously inferred extension at the trailing edge of the sliver, which is located at the Bussol Strait at 46 deg N.

  19. Fault plane orientations of intermediate-depth and deep-focus earthquakes in the Japan-Kuril-Kamchatka subduction zone

    NASA Astrophysics Data System (ADS)

    Warren, Linda M.; Baluyut, Elena C.; Osburg, Timothy; Lisac, Kristen; Kokkinen, Siiri

    2015-12-01

    In the northwestern Pacific, the Pacific plate subducts to the west at the Japan, Kuril, and Kamchatka trenches. Throughout most of the subduction zone, the subducting slab is planar and dipping at an angle of 30°-60°, with the exception of a fold in the southern Kuril segment. To investigate how the slab deforms in response to the applied forces and which mechanism generates the earthquakes, we analyze the rupture properties of 111 large (MW≥5.7) intermediate-depth and deep-focus earthquakes (60-656 km depth) from 1990 to 2014 in the Japan-Kuril-Kamchatka subduction zone. For each earthquake, we use rupture directivity to estimate rupture direction and rupture speed and to distinguish the fault plane from the auxiliary plane of the focal mechanism. Seventy six percent of the earthquakes with sufficient station coverage are well modeled by unilateral rupture propagation. The estimated rupture speeds range from zero to supershear. The estimated rupture directions allow identification of the fault plane as the more horizontal nodal plane for 30 earthquakes, while an additional 11 earthquakes rupture toward the intersection of the nodal planes, so the fault plane cannot be identified. Combining our newly identified fault planes with previously identified fault planes in the region, we observe that in planar slab segments, most earthquakes slip along a dominant fault orientation. For a steeply dipping slab, this orientation is subhorizontal. In more sharply bent slab segments, such as the Kuril fold, deformation is accommodated along more variable fault orientations, including subvertical faults. The correlation of slab geometry with fault orientation suggests that the local stress field controls fault orientations.

  20. The 2006-2007 Kuril Islands great earthquake sequence

    USGS Publications Warehouse

    Lay, T.; Kanamori, H.; Ammon, C.J.; Hutko, Alexander R.; Furlong, K.; Rivera, L.

    2009-01-01

    The southwestern half of a ???500 km long seismic gap in the central Kuril Island arc subduction zone experienced two great earthquakes with extensive preshock and aftershock sequences in late 2006 to early 2007. The nature of seismic coupling in the gap had been uncertain due to the limited historical record of prior large events and the presence of distinctive upper plate, trench and outer rise structures relative to adjacent regions along the arc that have experienced repeated great interplate earthquakes in the last few centuries. The intraplate region seaward of the seismic gap had several shallow compressional events during the preceding decades (notably an MS 7.2 event on 16 March 1963), leading to speculation that the interplate fault was seismically coupled. This issue was partly resolved by failure of the shallow portion of the interplate megathrust in an MW = 8.3 thrust event on 15 November 2006. This event ruptured ???250 km along the seismic gap, just northeast of the great 1963 Kuril Island (Mw = 8.5) earthquake rupture zone. Within minutes of the thrust event, intense earthquake activity commenced beneath the outer wall of the trench seaward of the interplate rupture, with the larger events having normal-faulting mechanisms. An unusual double band of interplate and intraplate aftershocks developed. On 13 January 2007, an MW = 8.1 extensional earthquake ruptured within the Pacific plate beneath the seaward edge of the Kuril trench. This event is the third largest normal-faulting earthquake seaward of a subduction zone on record, and its rupture zone extended to at least 33 km depth and paralleled most of the length of the 2006 rupture. The 13 January 2007 event produced stronger shaking in Japan than the larger thrust event, as a consequence of higher short-period energy radiation from the source. The great event aftershock sequences were dominated by the expected faulting geometries; thrust faulting for the 2006 rupture zone, and normal faulting for

  1. Body segment inertial parameters and low back load in individuals with central adiposity.

    PubMed

    Pryce, Robert; Kriellaars, Dean

    2014-09-22

    There is a paucity of information regarding the impact of central adiposity on the inertial characteristics of body segments. Deriving low back loads during lifting requires accurate estimate of inertial parameters. The purpose was to determine the body segment inertial parameters of people with central adiposity using a photogrammetric technique, and then to evaluate the impact on lumbar spine loading. Five participants with central adiposity (waist:hip ratio>0.9, waist circumference>102 cm) were compared to a normal BMI group. A 3D wireframe model of the surface topography was constructed, partitioned into 8 body segments and then body segment inertial parameters were calculated using volumetric integration assuming uniform segment densities for the segments. Central adiposity dependent increases in body segment parameters ranged from 12 to 400%, varying across segments (greatest for trunk) and parameters. The increase in mass distribution to the trunk was accompanied by an anterior and inferior shift of the centre of mass. A proximal shift in centre of mass was detected for the extremities, along with a reduction in mass distribution to the lower extremity. L5/S1 torques (392 vs 263 Nm) and compressive forces (5918 vs 3986 N) were substantially elevated in comparison to the normal BMI group, as well as in comparison to torques and forces predicted using published BSIP equations. Central adiposity resulted in substantial but non-uniform increases in inertial parameters resulting in task specific increases in torque and compressive loads arising from different inertial and physical components.

  2. First data on the volatile fluxes from passively degassing volcanoes of the Kuril Island arc

    NASA Astrophysics Data System (ADS)

    Melnikov, Dmitry; Malik, Nataliya; Chaplygin, Ilya; Zelenski, Mikhail

    2017-04-01

    We report the first data on the volatile fluxes from passively degassing volcanoes of Kuril Island arc in the North-Western Pacific measured in 2015-2016. Four volcanoes: Ebeko on the northern Paramushir Island, Kuntomintar and Pallace on the Central Shiashkotan and Ketoy islands, and Kudryavy on the southern Iturup island are representative for the whole Kuril arc as having the largest and strongest fumarolic fields among 40 of the active volcanoes of the arc. The fluxes were measured using scanning DOAS, remote miniDOAS, plume MultiGas and direct sampling techniques using the SO2 flux from the DOAS data and ratios measured by MultiGas (SO2/CO2, SO2/H2S, SO2/H2O) and direct sampling (SO2/HCl). For Kudryavy volcano the ratios were applied that have been measured by Taran et al. (1995) and Fischer et al. (1998) using direct sampling. Until now, for Kuril arc only the SO2 flux from Kudryavy was measured by the COSPEC technique in 1995 by Fischer et al. (1998) with an average SO2 flux of 75 t/d. Our data give for Kudryavy in October 2016 a value of 340 t/d. The total measured SO2 flux in 2015-2016 from the passively degassing volcanoes of the Kuril arc is near 1000 t/d. This value is an excellent agreement with the estimation made in Taran (2009) using a comparative plume height technique based on visual observations. Averaged fluxes (in ton/day) of mayor (Range of vent temperatures °C, SO2, CO2, H2O, HCl, total flux) components of volcanic emissions from Kurilian volcanoes in 2016: Ebeko - 97-490 °C, 100 (SO2), 81 (CO2), 1120 (H2O), 17 (HCl), 1319; Kuntomintar - 130-260 °C, 54 (SO2), 157 (CO2), 1064 (H2O), 8 (HCl), 1283; Pallas - 140-720 °C, 450 (SO2), 78 (CO2), 3800 (H2O), 120 (HCl), 4448; Kudryavy - 130-920 °C, 340 (SO2), 131 (CO2), 4445 (H2O), 85 (HCl), 5001. Total (± 20%): 930 (SO2), 450 (CO2), 10400 (H2O), 230 (HCl), 12050 (total flux). This work was supported by grant from the Russian Science Foundation # 15-17-20011. References: Taran et al. (1995) GCA

  3. Coseismic Slip Distributions of Great or Large Earthquakes in the Northern Japan to Kurile Subduction Zone

    NASA Astrophysics Data System (ADS)

    Harada, T.; Satake, K.; Ishibashi, K.

    2011-12-01

    Slip distributions of great and large earthquakes since 1963 along the northern Japan and Kuril trenches are examined to study the recurrence of interplate, intraslab and outer-rise earthquakes. The main findings are that the large earthquakes in 1991 and 1995 reruptured the 1963 great Urup earthquake source, and the 2006, 2007 and 2009 Simshir earthquakes were all different types. We also identify three seismic gaps. The northern Japan to southern Kurile trenches have been regarded as a typical subduction zone with spatially and temporally regular recurrence of great (M>8) interplate earthquakes. The source regions were grouped into six segments by Utsu (1972; 1984). The Headquarters for Earthquake Research Promotion of the Japanese government (2004) divided the southern Kurile subduction zone into four regions and evaluated future probabilities of great interplate earthquakes. Besides great interplate events, however, many large (M>7) interplate, intraslab, outer-rise and tsunami earthquakes have also occurred in this region. Harada, Ishibashi, and Satake (2010, 2011) depicted the space-time pattern of M>7 earthquakes along the northern Japan to Kuril trench, based on the relocated mainshock-aftershock distributions of all types of earthquakes occurred since 1913. The space-time pattern is more complex than that had been considered conventionally. Each region has been ruptured by a M8-class interplate earthquake or by multiple M7-class events. In this study, in order to examine more detail space pattern, or rupture areas, of M>7 earthquakes since 1963 (WWSSN waveform data have been available since this year), we estimated cosiesmic slip distributions by the Kikuchi and Kanamori's (2003) teleseismic body wave inversion method. The WWSSN waveform data were used for earthquakes before 1990, and digital teleseismic waveform data compiled by the IRIS were used for events after 1990. Main-shock hypocenters that had been relocated by our previous study were used as

  4. Along-strike segmentation of the Abanico Basin, central Chile: New chronological, geochemical and structural constraints

    NASA Astrophysics Data System (ADS)

    Piquer, Jose; Hollings, Pete; Rivera, Orlando; Cooke, David R.; Baker, Michael; Testa, Francisco

    2017-01-01

    The Andes of central Chile are composed mostly of Cenozoic volcanic rocks, erupted during the opening and subsequent inversion of the intra-arc volcano-tectonic Abanico Basin. Until recently, the internal segmentation of this inverted basin was poorly understood. Based on a combination of U-Pb geochronology, (U-Th)/He thermochronology, whole rock geochemistry and structural data, we propose that the Abanico Basin can be divided into two main segments, separated by the NW-striking Piuquencillo fault and conjugate, NE-striking faults. Stratigraphic units defined in the northern segment (Abanico and Farellones formations) cannot be correlated with the rocks of the southern segment (Coya-Machali Formation and Teniente Volcanic Complex) in terms of lithofacies, depositional ages and geochemistry. The northern and southern segments also show temporal differences in their tectonic evolution. An early deformation event beginning at 22 Ma affected only the northern segment and is associated with the formation of progressive unconformities between the Abanico and Farellones formations, and also with crustal thickening as reflected in the geochemistry of the Farellones Formation. A second stage of crustal thickening and exhumation began at 12 Ma, as suggested by a sharp increase of the La/Yb ratios in the northern segment. In the southern segment, this event is reflected by only a moderate increase of La/Yb ratios, and by the transition between the Coya-Machali Formation and the Teniente Volcanic Complex. Finally, a third stage of exhumation and crustal thickening beginning at 7 Ma affected both the northern and southern segments. This last stage was the main exhumation event affecting the rocks of the Andes of central Chile, and is recorded in the geochemistry of igneous rocks by a sharp increase in the La/Yb ratios in the southern segment.

  5. Geochemistry of volcanic and hydrothermal fluids and volatile budget of the Kamchatka Kuril subduction zone

    NASA Astrophysics Data System (ADS)

    Taran, Yuri A.

    2009-02-01

    A data base for the composition and emission rates of more than 100 thermal manifestations including boiling geothermal systems and 23 volcanoes along the 1900 km long Kamchatka-Kuril (KK) arc is presented. These results were used to estimate mean fluxes of volatiles from the KK arc. The fluxes from the KK arc are compared with the fluxes from the best studied Central American (CA) arc and with the compiled literature data on global fluxes. The error ranges and the OUT/IN (in)balance calculations are also discussed. The estimated fluxes of volatiles from volcanic fumaroles and the observed, normalized to the Cl content, fluxes from hydrothermal systems are very close, with the higher hydrothermal flux from Kuril Islands due to a larger number of the acidic Cl-SO 4 springs on the Islands and their outflow rates. The total volcanic SO 2 flux from the whole KK arc is estimated to be higher than 3000 t/d. The measured S and C fluxes from hydrothermal systems are much lower than the volcanic output due to the loss of these components in the upper crust (mineral precipitation). The Cl/ 3He ratio is inferred to be a stable indicator of the arc setting for hydrothermal and volcanic fluids with a mean value of (2 ± 4) × 10 9. Comparison of the obtained volcano-hydrothermal fluxes with fluxes calculated from the erupted solid volcanic products at Kamchatka and Kurils during Holocene time reveals that the total estimated volatile output from the KK arc is compatible with the total magmatic output if the intruded to erupted ratio is close to 7, i.e. almost the same as assumed for the Central American arc. Calculated fluxes as well as the ratios for OUT/IN fluxes (volcanic + hydrothermal output/slab + mantle input) for CO 2, S, H 2O, Cl, N 2, 4He and 3He from the KK arc normalized to the arc length are in general close to the global estimates. The fractions of CO 2 and S in the total volatile output at KK arc derived directly from the mantle wedge are 18% and 16% (mole basis

  6. Tsunami range long wave measurements near the South Kurils Islands

    NASA Astrophysics Data System (ADS)

    Levin, B. V.; Chernov, A. G.; Shevchenko, G. V.; Kovalev, P. D.; Kovalev, D. P.; Kurkin, A. A.; Likhacheva, O. N.; Shishkin, A. A.

    2009-04-01

    The results of long wave measurements data analysis are provided. Autonomous bottom pressure gauges were installed in the Tsrekovnaya bay (Shikotan Island), near the Lovtscova cape (Kunashir Island), Van-Der-Linda cape and Kastrikum cape (Urup Island). The results of three month observations show complicated and ambiguous type of long waves changeability in the different points of the Kuril's islands affected by meteorological and seismological sources. Essential distinctions in the spectral characteristics of long waves `on the different gauges under influence of cyclone and weak tsunami of September 11, 2008 were exposed. It happens because of frequency-selective properties of the ocean area.

  7. Segmentation of the central-chest lymph nodes in 3D MDCT images.

    PubMed

    Lu, Kongkuo; Higgins, William E

    2011-09-01

    Central-chest lymph nodes play a vital role in lung-cancer staging. The definition of lymph nodes from three-dimensional (3D) multidetector computed-tomography (MDCT) images, however, remains an open problem. We propose two methods for computer-based segmentation of the central-chest lymph nodes from a 3D MDCT scan: the single-section live wire and the single-click live wire. For the single-section live wire, the user first applies the standard live wire to a single two-dimensional (2D) section after which automated analysis completes the segmentation process. The single-click live wire is similar but is almost completely automatic. Ground-truth studies involving human 3D MDCT scans demonstrate the robustness, efficiency, and intra-observer and inter-observer reproducibility of the methods.

  8. Capsaicin-induced central sensitization evokes segmental increases in trigger point sensitivity in humans.

    PubMed

    Srbely, John Z; Dickey, James P; Bent, Leah R; Lee, David; Lowerison, Mark

    2010-07-01

    This study investigated whether inducing central sensitization evokes segmental increases in trigger point pressure sensitivity. We evoked central sensitization at the C(5) segment and validated its presence via mechanical cutaneous sensitivity (brush allodynia) testing. Trigger point pressure sensitivity was quantified using the pain pressure threshold (PPT) value. A 50 cm(2) area of the C(5) dermatome at the right lateral elbow was pretreated with 45 degrees heat for 10 minutes. Test subjects (n = 20) then received topical capsaicin cream (0.075%; Medicis, Toronto, Canada) to the C(5) dermatome, whereas control subjects (n = 20) received a topical placebo cream (Biotherm Massage, Montreal, Canada). PPT readings were recorded from the infraspinatus (C(5,6)) and gluteus medius (L(4,5)S(1)) trigger points at zero (pre-intervention), 10, 20, and 30 minutes after intervention; all PPT readings were normalized to pre-intervention (baseline) values. The difference between the PPT readings at the 2 trigger point sites represents the direct influence of segmental mechanisms on the trigger point sensitivity at the infraspinatus site (PPT(seg)). Test subjects demonstrated statistically significant increases in Total Allodynia scores and significant decreases in PPT(seg) at 10, 20, and 30 minutes after application, when compared with control subjects. These results demonstrate that increases in central sensitization evoke increases in trigger point pressure sensitivity in segmentally related muscles. Myofascial pain is the most common form of musculoskeletal pain. Myofascial trigger points play an important role in the clinical manifestation of myofascial pain syndrome. Elucidating the role of central sensitization in the pathophysiology of trigger points is fundamental to developing optimal strategies in the management of myofascial pain syndrome.

  9. Holocene vertical displacement on the central segments of the Wasatch fault zone, Utah

    USGS Publications Warehouse

    DuRoss, C.B.

    2008-01-01

    Compiled per-event vertical-displacement observations from 17 paleoseismic sites along the six central segments of the Wasatch fault zone (WFZ) highlight possible biases and trends in displacement along the fault. The displacement data are consistent with a model of characteristic-type slip, but anomalous and variable displacements indicate that significant natural variability in displacement occurs. When combined into a composite distribution of displacement, 79% of the data fit within a displacement envelope that shows displacement decreasing in a half-ellipse shape from 1.4-3.5 m near the segment centers to 0.6-2.5 m near the ends. Additionally, displacements normalized by the distance from the segment centers to ends decrease from means of 2.0-3.0 m near the segment centers to 1.3-1.9 m near the ends, consistent with characteristic-type slip termination. Although several paleoseismic sites exhibit repeated, similar displacements, the data are sparse and both low-valued (0.5-0.8 m) and high-valued (4.2-4.7 m) outliers suggest complex strain release, possibly resulting from segment interaction and/or noncharacteristic events. Although a global, normal-fault-type surface-rupture-length (SRL) average-displacement regression underpredicts observed WFZ displacements, the largest displacements per segment correspond well with a SRL maximum-displacement regression. This correlation, as well as moderate variability in SRL- and displacement-based moment magnitude, suggests that the anomalous displacements represent the intrinsic variability in characteristic displacement per segment. Thus, minor variations to the characteristic slip model to account for exceptional upper- and lower-bound displacements, e.g., a hybrid characteristic-variable slip model, may be appropriate for the WFZ. Additional paleoseismic data are necessary to address data gaps and biases, to facilitate more robust tests of earthquake-slip models, and to reduce uncertainty in SRL, displacement, and

  10. Segments.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Presents a market taxonomy for higher education, including what it reveals about the structure of the market, the model's technical attributes, and its capacity to explain pricing behavior. Details the identification of the principle seams separating one market segment from another and how student aspirations help to organize the market, making…

  11. Central focused convolutional neural networks: Developing a data-driven model for lung nodule segmentation.

    PubMed

    Wang, Shuo; Zhou, Mu; Liu, Zaiyi; Liu, Zhenyu; Gu, Dongsheng; Zang, Yali; Dong, Di; Gevaert, Olivier; Tian, Jie

    2017-08-01

    Accurate lung nodule segmentation from computed tomography (CT) images is of great importance for image-driven lung cancer analysis. However, the heterogeneity of lung nodules and the presence of similar visual characteristics between nodules and their surroundings make it difficult for robust nodule segmentation. In this study, we propose a data-driven model, termed the Central Focused Convolutional Neural Networks (CF-CNN), to segment lung nodules from heterogeneous CT images. Our approach combines two key insights: 1) the proposed model captures a diverse set of nodule-sensitive features from both 3-D and 2-D CT images simultaneously; 2) when classifying an image voxel, the effects of its neighbor voxels can vary according to their spatial locations. We describe this phenomenon by proposing a novel central pooling layer retaining much information on voxel patch center, followed by a multi-scale patch learning strategy. Moreover, we design a weighted sampling to facilitate the model training, where training samples are selected according to their degree of segmentation difficulty. The proposed method has been extensively evaluated on the public LIDC dataset including 893 nodules and an independent dataset with 74 nodules from Guangdong General Hospital (GDGH). We showed that CF-CNN achieved superior segmentation performance with average dice scores of 82.15% and 80.02% for the two datasets respectively. Moreover, we compared our results with the inter-radiologists consistency on LIDC dataset, showing a difference in average dice score of only 1.98%. Copyright © 2017. Published by Elsevier B.V.

  12. The Central Lake Malawi (Nyasa) Rift: single or multiple rift segments?

    NASA Astrophysics Data System (ADS)

    McCartney, T.; Scholz, C. A.; Shillington, D. J.; Accardo, N. J.; Chindandali, P. R. N.; Kamihanda, G.

    2015-12-01

    Accommodation zones connect rift segments, which are fundamental elements of continental rift architecture. The sedimentary record aids our assessment of the evolution of this linkage. The central basin of Lake Malawi is one of the most structurally complex regions of the Malawi Rift. Border fault margins have been interpreted on both shorelines; three structures within the basin have been interpreted as segments of a corresponding accommodation zone. We investigate these structures by integrating single- and multi-channel reflection seismic data, including new MCS acquired in 2015 for the SEGMeNT project. The stratigraphic record in the central basin, inferred from seismic reflection profiles, provides compelling evidence that most fault-related subsidence is accommodated by the western border fault. Strata on both sides of all three structures dip to the west. The pre-rift basement in the sub-basin west of the central structure is considerably deeper (~ 4 s TWTT sub-bottom) than that in the broader eastern sub-basin (~ 2.5 s TWTT sub-bottom). A syncline in the eastern sub-basin shows little variation in seismic facies, particularly over the last 1.3 m.y. In contrast, the western sub-basin exhibits seismic facies indicative of fluvial input from two major rivers, siliciclastic input from the border fault footwall rising > 1000 m above lake level, and mud diapirs in the deepest part of the sub-basin. Horizons pierced by these diapirs onlap the central structure, suggesting diapir rise postdates relative uplift of the structure. Correlations with the age model from a 2005 scientific drilling project will better constrain this timing. The structural high helps focus siliciclastic sediments into the sub-basin, resulting in the overpressure conditions required for mud diapirism. We hypothesize that the diapirs are the result of sediment loading in the deep main depocenter of the central basin rather than fault mechanisms. The basement highs in the central basin control

  13. Two new species of fungus gnats (Diptera: Mycetophilidae) from Kunashir Island, Kuril Islands.

    PubMed

    Zaitzev, Alexander

    2017-04-05

    Two new species of Mycetophilidae (Diptera), Clastobasis subalternans sp. n. and Phthinia kurilensis sp. n. are described from Kunashir I. (South Kuril Is.). Their relationships with other species of Clastobasis Skuse and Phthinia Winnertz are briefly discussed.

  14. Seismicity of the Earth 1900-2007, Kuril-Kamchatka Arc and Vicinity

    USGS Publications Warehouse

    Rhea, Susan; Tarr, Arthur C.; Hayes, Gavin P.; Villaseñor, Antonio; Furlong, Kevin P.; Benz, Harley

    2010-01-01

    This map shows details of the Kuril-Kamchatka arc not visible in an earlier publication, U.S. Geological Survey Scientific Investigations Map 3064. The arc extends about 2,100 km from Hokkaido, Japan, along the Kuril Islands and the pacific coast of the Kamchatka, Russia, peninsula to its intersection with the Aleutian arc near the Commander Islands, Russia. It marks the region where the Pacific plate subducts into the mantle beneath the Okhotsk microplate, a part of the larger North America plate. This subduction is responsible for the generation of the Kuril Islands chain and the deep offshore Kuril-Kamchatka trench. Relative to a fixed North America plate, the Pacific plate is moving northwest at a rate that decreases from 83 mm per year at the arc's southern end to 75 mm per year near its northern edge.

  15. Rodriguez Segment of the Central Indian Ridge: Hotspot-ridge interaction and hydrothermal activity

    NASA Astrophysics Data System (ADS)

    Tamaki, K.; Ura, T.

    2008-12-01

    We conducted R/V Hakuho-maru KH-06-04 Research Cruise (2006/2007) at the Rodriguez Segment of the Central Indian Ridge with geophysical mapping by SeaBeam, magnetics, and gravity, AUV (Autonomous Underwater Vehicle) dives, CTD hydrocasts, and rock samplings. The principal results of the cruise are summarized as follows. (1) Success of the dives by AUV at the axis of mid-oceanic ridge AUV, r2D4, developed by the Institute of Industrial Sciences, University of Tokyo, successfully dived at the axial part of the IR at its 2800 m water depth and collected high- resolution side scan sonar images, interferometric bathymetry, anomalies of manganese components in the sea water, geomagnetic data, and others. The diving at the Segment 16 of CIR was especially successful with complete sidescan sonar mapping of a large lava plain at the axial rift zone that was named as Great Dodo Lava Plain and the finding of possible hydrothermal site by a realtime manganese analyzer (GAMOS) installed on the AUV. (2) Findings of two hydrothermal sites. Two possible active hydrothermal sites are newly found during the cruise by the CTD operation and AUV operation. One is in the Segment 15 and the other is in the Segment 16. Although further surveys by ROV or submersible are necessary, the intensive signals of manganese anomaly in the deepsea water suggest strong possibility of existence of active hydrothermal sites. (3) High resolution mapping of the axial rift of CIR High resolution bathymetric mapping of the axial rift zones of Segments 15 , 16 , 17 and 18 was achieved by high frequency multi narrow beam bathymetric mapping system with a sonic frequency of 20kHz and beam width of 1 degree. The resultant mapping of 50 m grid may be one the best quality mapping of the mid-oceanic ridges in the world. (4) Pinpoint identification of the contact the Reunion Hotspot plume and CIR spreading axis Very contact of the eastern extension of the Gastiao Ridge and the axial volcanic chain of the Segment

  16. Sedimentation in the central segment of the Aleutian Trench: Sources, transport, and depositional style

    SciTech Connect

    Stevenson, A.J.; Scholl, D.W.; Vallier, T.L. ); Underwood, M.B. )

    1990-05-01

    The central segment of the Aleutian Trench (162{degree}W to 175{degree}E) is an intraoceanic subduction zone that contains an anomalously thick sedimentary fill (4 km maximum). The fill is an arcward-thickening and slightly tilted wedge of sediment characterized acoustically by laterally continuous, closely spaced, parallel reflectors. These relations are indicative of turbidite deposition. The trench floor and reflection horizons are planar, showing no evidence of an axial channel or any transverse fan bodies. Cores of surface sediment recover turbidite layers, implying that sediment transport and deposition occur via diffuse, sheetlike, fine-grained turbidite flows that occupy the full width of the trench. The mineralogy of Holocene trench sediments document a mixture of island-arc (dominant) and continental source terranes. GLORIA side-scan sonar images reveal a westward-flowing axial trench channel that conducts sediment to the eastern margin of the central segment, where channelized flow cases. Much of the sediment transported in this channel is derived from glaciated drainages surrounding the Gulf of Alaska which empty into the eastern trench segment via deep-sea channel systems (Surveyor and others) and submarine canyons (Hinchinbrook and others). Insular sediment transport is more difficult to define. GLORIA images show the efficiency with which the actively growing accretionary wedge impounds sediment that manages to cross a broad fore-arc terrace. It is likely that island-arc sediment reaches the trench either directly via air fall, via recycling of the accretionary prism, or via overtopping of the accretionary ridges by the upper parts of thick turbidite flows.

  17. Evaluation of the Central Corneal Thickness with Anterior Segment Optical Coherence Tomogram after Penetrating Keratoplasty

    PubMed Central

    Dhasmana, Renu; Bahadur, Harsh; Nagpal, Ramesh Chander

    2016-01-01

    Introduction Graft central thickness evaluates the graft quality which affects the outcome of Penetrating Keratoplasty (PK). It varies at different point of time after PK. Anterior Segment Optical Coherence Tomography (ASOCT) can measure graft’s central thickness with quite high precision. Aim The purpose of the study was to monitor the Central Corneal thickness (CCT) with ASOCT after PK and to evaluate its relationship with the pre-operative diagnosis. Materials and Methods This is an observational retrospective study where records of optical PK done in December 2012 and June 2015 were reviewed. Graft central thickness were analysed by ASOCT for all the patients post-operatively at first post-operative day, 3 and 6 months post PK by pachymetry scan and the images captured were analysed for CCT with inbuilt calipers. Results Fifty one eyes of 50 patients with age range of 17-80years (mean 51.64years ±SD 18.45 years) with clear grafts were reviewed in the present study. All subjects recruited were analysed for the indications of PK. Adherent leucoma 20(39.21%) was most common indication for PK. Mean CCT were 647.31±90.40, 605.31±75.08,564.66±66.26 and 537.37±64.09 respectively on first post-operative day, 1, 3 and 6 months. Graft CCT significantly decreased between first post-operative day and 1 month and it showed further decrease at 3 to 6 months post PK. The CCT at 6 month post-surgery showed a strongly positive correlation with the Intraocular Pressure (IOP) (r=0.66) and weakly positive correlation with Best Corrected Visual Acuity (BCVA) (r=0.28). Conclusion Graft central thickness is considered to be quantitative method for evaluating corneal oedema post PK. CCT decreases in post-operative period irrespective of indications of PK. PMID:27891366

  18. Fundamental segmentation of the central and northern Wassuk Range, Nevada: implications for seismic hazard

    NASA Astrophysics Data System (ADS)

    Surpless, B.; Bentz, J. M.

    2011-12-01

    The Wassuk Range fault, within the actively-deforming Walker Lane, is among the most active normal faults in the Basin and Range. Data presented here support a model of fundamental long-term segmentation of the central and northern Wassuk Range fault system. We propose that two cross-range fault systems, the pre-Quaternary Penrod Canyon and Buck Brush Spring fault zones, have acted as seismic barriers during the propagation of slip during earthquakes, thus creating significant variations in range morphology. The Penrod Canyon fault separates the Hussman Spring block (HSB) to the north from the Bald Mountain block (BMB), and further south, the Buck Brush Spring fault separates the BMB from the Dry Creek block (DCB) to the south. Both inactive dextral fault systems strike approximate N35W and are separated by ~8 km, measured normal to the faults. Right en echelon steps of the active range-front normal fault system occur where intersected by these cross-range faults. The three blocks display significant differences in range crest elevations, cross-range ridge profiles, and stream profiles. While the HSB and DCB display similar average range crest elevations of 2315 m and 2359 m, respectively, the BMB displays an average elevation of 2641 m. The range crests lose definition and are offset across segment boundaries, where the two cross faults disrupt the range. The cross-range ridge profiles reveal similar slopes proximal to the active range front, where all blocks display gradients of 0.34 - 0.35, but the BMB and DCB display these gradients for more than 2 km relative to the range front fault, while the HSB profile displays these gradients for only 1 km before becoming significantly shallower. In addition, the distances between range crest and range front are nearly identical for the BMB and the DCB (~6 km), while the HSB displays a smaller value (~4 km). The BMB and DCB display similar stream profiles, measured from range crest to range front, with stream gradients

  19. Hydration of the incoming plate in the Kuril subduction zone

    NASA Astrophysics Data System (ADS)

    Fujie, G.; Kodaira, S.; Yamashita, M.; Sato, T.; Takahashi, T.; Takahashi, N.; Noguchi, N.

    2010-12-01

    Water supplied from the subducting oceanic plate by dehydration is inferred to cause seismicity and magmatism in subduction zones. It is important, therefore, to reveal the distribution of water within the incoming plate for understanding seismic and volcanic activities in subduction zones. In 2009 and 2010, to reveal the detailed seismic structure and hydration process within the incoming plate, we conducted a wide-angle seismic survey in the Kuril subduction zone, where the old Pacific plate formed in the eastern Pacific ridge is subducting from south to north beneath the island arc of Japan. We designed a north-south 500km-long seismic experimental line to be perpendicular to the Kuril trench. The northern end of our line is located at about 30km south of the trench axis and well-developed horst and graben structure is observed around the northern end. We deployed 80 Ocean Bottom Seismometers (OBSs) at intervals of 6km and shot a large tuned airgun array towed by R/V Kairei. In addition, we obtained MCS reflection data using a 444-channel hydrophone streamer (6km long) along the same line. We modelled both P-wave and S-wave velocity structures by the traveltime inversion using refraction, reflection and PS-conversion traveltimes. Our results show that P-wave velocity beneath the well-developed horst and graben structure is about 5% lower than that in the south of outer rise. This is consistent with a previous structure study in the Chili subduction zone that shows the P-wave velocity in the vicinity of the trench axis is lower than that of normal oceanic plate. More notable feature of our results is the regional variations of Vp/Vs. The S-wave velocity, as well as P-wave velocity, gradually decreases toward the trench axis. However Vp/Vs is not uniform; Vp/Vs immediately beneath the sediments is remarkably high beneath the well-developed horst and graben structure, and Vp/Vs decreases with depth (high Vp/Vs is confined to the top of the oceanic plate). Since the

  20. Segmentation pattern and structural complexities in seismogenic extensional settings: The North Matese Fault System (Central Italy)

    NASA Astrophysics Data System (ADS)

    Ferrarini, Federica; Boncio, Paolo; de Nardis, Rita; Pappone, Gerardo; Cesarano, Massimo; Aucelli, Pietro P. C.; Lavecchia, Giusy

    2017-02-01

    We investigated the northern slope of the Matese Mts. (Molise, Central Italy) with the aim of characterizing the N- to NE-dipping active normal fault system in the Bojano basin, a sector of primary importance from a seismic hazard perspective. We collected field data to define the geometry and segmentation pattern of two sub-systems (Patalecchia-Colle di Mezzo and Bojano-Campochiaro). New evidence of late Quaternary faulting was obtained by exploiting well log interpretations. Kinematic analysis revealed the interaction of pre-Quaternary inherited (mainly E-W-striking) and newly formed (NW-SE-striking) normal faults. Slip accommodation through linkage was clearly noted in the case of the Patalecchia-Colle di Mezzo sub-system. Detailed topographic profiles across the active fault segments provided post-LGM (15 ± 3 kyr) slip rates up to ∼2 mm/yr which agree with the high deformation rates based on different approaches in the literature. Finally, the instrumental seismicity analysis constrained the bottom of the seismogenic layer to depths of 13-14 km, and the gathered information allowed us to reconstruct the North Matese seismogenic source. Its 3D geometry and dimensions agree with both the dimension-magnitude relationships and macroseismic information available for the 1805 earthquake (Mw 6.6), the main historical earthquake to have struck the Bojano basin.

  1. Generation of cell diversity and segmental pattern in the embryonic central nervous system of Drosophila.

    PubMed

    Technau, Gerhard M; Berger, Christian; Urbach, Rolf

    2006-04-01

    Development of the central nervous system (CNS) involves the transformation of a two-dimensional epithelial sheet of uniform ectodermal cells, the neuroectoderm, into a highly complex three-dimensional structure consisting of a huge variety of different neural cell types. Characteristic numbers of each cell type become arranged in reproducible spatial patterns, which is a prerequisite for the establishment of specific functional contacts. The fruitfly Drosophila is a suitable model to approach the mechanisms controlling the generation of cell diversity and pattern in the developing CNS, as it allows linking of gene function to individually identifiable cells. This review addresses aspects of the formation and specification of neural stem cells (neuroblasts) in Drosophila in the light of recent studies on their segmental diversification.

  2. Helix and hairpin nucleation in short peptides using centrally positioned conformationally constrained dipeptide segments.

    PubMed

    Chandrappa, Siddappa; Aravinda, Subrayashastry; Raghothama, Srinivasarao; Sonti, Rajesh; Rai, Rajkishor; Harini, Veldore V; Shamala, Narayanaswamy; Balaram, Padmanabhan

    2012-04-14

    The effect of incorporation of a centrally positioned Ac(6)c-Xxx segment where Xxx = (L)Val/(D)Val into a host oligopeptide composed of l-amino acid residues has been investigated. Studies of four designed octapeptides Boc-Leu-Phe-Val-Ac(6)c-Xxx-Leu-Phe-Val-OMe (Xxx = (D)Val 1, (L)Val 2) Boc-Leu-Val-Val-Ac(6)c-Xxx-Leu-Val-Val-OMe (Xxx = (D)Val 3, (L)Val 4) are reported. Diagnostic nuclear Overhouse effects characteristic of hairpin conformations are observed for Xxx = (D)Val peptides (1 and 3) while continuous helical conformation characterized by sequential N(i)H ↔ N(i+1)H NOEs are favored for Xxx = (L)Val peptides (2 and 4) in methanol solutions. Temperature co-efficient of NH chemical shifts are in agreement with distinctly different conformational preferences upon changing the configuration of the residue at position 5. Crystal structures of peptides 2 and 4 (Xxx = (L)Val) establish helical conformations in the solid state, in agreement with the structures deduced from NMR data. The results support the design principle that centrally positioned type I β-turns may be used to nucleate helices in short peptides, while type I'β-turns can facilitate folding into β-hairpins. This journal is © The Royal Society of Chemistry 2012

  3. [Interregional differentiation of chum salmon from Sakhalin and South Kurils infered from microsatellite markers].

    PubMed

    Afanas'ev, K I; Rubtsova, G A; Shitova, M V; Malinina, T V; Zhivotovskiĭ, L A

    2008-07-01

    Variability at ten microsatellite loci was examined in wild and hatchery populations of chum salmon from the Sakhalin Island and Southern Kuril Islands, Iturup and Kunashir. Substantial genetic differences between Sakhalin and South Kurils chum salmon (the differentiation theta reached 6.0%) were revealed. Statistically significant differences between chum salmon from Iturup and that from Kunashir were demonstrated, as well as between the chum salmon populations from different rivers within the islands. It was shown that in different types of population comparisons, required different marker sets most informative were.

  4. Alkaline volcanisms in the Proto-Kuril forearc

    NASA Astrophysics Data System (ADS)

    Yutani, T.; Hirano, N.

    2015-12-01

    The Nemuro Group in the northeasternmost part of Japan represents forearc basin deposits of the Proto-Kuril arc that consist of Upper Cretaceous-Paleocene sedimentary rocks with andesitic volcaniclastics and alkaline lavas. Their occurrence in this setting is unusual because such alkaline lavas and intrusions are not commonly found in forearc environments. Here, we report new petrological and geological data to discuss the nature of magmatic process involved in their petrogenesis. Pillow and massive lava flows represent subaqueous volcanic activity, and the occurrence of inter-pillow sedimentary units indicates their eruption on unconsolidated sediments of the lower Nemuro Group. Sill intrusions with layered structures and thicknesses ranging from 10 to 130 m are also common widely distributed in the Nemuro Group. Major and trace element chemistry and mineralogical data distinguish the analyzed samples as K-rich alkaline rocks with low TiO2 or Nb contents, analogous to island arc-like tholeiites. These K-rich alkaline rocks can be classified into two groups of shoshonites: shoshonites containing olivine phenocrysts and intruding into the lower Nemuro Group (Group 1), and shoshonites with no olivine and making up the middle part of the Nemuro Group (Group 2). Group 1 shoshonites have higher MgO, Cr and Ni contents than those of Group 2. The bulk-rock composition of Group 2, which has lower MgO contents, shows higher SiO2 than that of Group 1. Such compositional differences possibly represent fractional crystallization of magmas between Groups 1 and 2. Based on the limited available data, we conclude that these alkaline rocks intruding into the Nemuro Group represent arc-shoshonites, and that the Group 1 magmas underwent fractional crystallization to produce the Group 2 magmas.

  5. Strong hydrothermal eruption 600 BP inside Golovnin caldera, Kunashir Island, Kurile arc

    NASA Astrophysics Data System (ADS)

    Belousov, Alexander; Belousova, Marina; Kozlov, Dmitry

    2017-04-01

    Hydrothermal explosions are difficult to predict and thus they pose serious hazard to visitors of hydrothermal areas. Here we present results of mapping of airfall deposit of strong prehistoric hydrothermal eruption that was the latest eruptive event in the limits of Golovnin caldera in the southern part of Kunashir Island, Kurile arc. This caldera was formed 30 Ka BP (Razhigaeva et al. 1998) that was followed by extrusion of two dacitic lava domes in the central part of the caldera. The studied hydrothermal eruption occurred at active hydrothermal area located at the southern foot of the Vostochny (Eastern) lava dome. This eruption formed a 350-m wide and 40 m deep crater surrounded by low-profile ring of the ejected material. Part of the crater is occupied by 17-m-deep Kipiashee Lake having intensive hydrothermal discharge on its bottom. The ejected material is represented by yellow-white and yellow-brown poorly sorted sandy gravels and sands with admixture of clay. This clastic material was formed by fragmentation of hydrothermally altered pumice tuffs (former sediments of the intracaldera lake). The airfall deposit has nearly circular distribution around the crater. The deposit thickness decreases from 5-7 m at the crater rim to 5 cm on the distances 2-3 km; thickness half-distance (bt) is estimated as 4.1. Volume of the deposit calculated by the method of Fierstein and Nathenson (1992) is 0.007 cub.km. Radiocarbon dating of soil buried directly under the deposit provided calibrated age 1300-1420 AD. This eruption can be considered as a model for future hydrothermal explosions inside the Golovnin caldera. This study was supported by grant of Russian Science Foundation #15-17-20011.

  6. Palaeozoic - Mesozoic tectonics of the western Transbaikalian segment of the Central Asian Orogenic Belt

    NASA Astrophysics Data System (ADS)

    Gladkochub, Dmitry; Donskaya, Tatiana; Mazukabzov, Anatoly

    2014-05-01

    The western Transbaikalian segment of the Central Asian Orogenic Belt (CAOB) is a key to understand a scenario of gradual growth of continental crust in this part of the Northern Eurasia. In general this growth was directly controlled by long-living processes related to interaction of the southern margin of the Siberian craton with different units of the Palaeo-Asian and Mongol-Okhotsk oceans. The Neoproterozoic activity within this area was related to opening and development of the Palaeo-Asian Ocean. The early Palaeozoic stage was characterized by collision of numerous terranes (microcontinents, relicts of island arcs and back-arc basins, etc.) with the southern flank of the Siberian craton. These events reflect an early stage of Palaeo-Asian Ocean closure and the beginning of CAOB building. Since the late Palaeozoic the development of the Transbaikalian segment of the CAOB was related to the evolution of the Mongol-Okhotsk Ocean. Late Silurian - middle Devonian clastic and carbonate sediments were deposited along a passive margin of the Mongol-Okhotsk Ocean. The low-angle subduction of oceanic lithosphere of the Mongol-Okhotsk Ocean beneath the Siberian continent started in the middle Devonian. In the early to late Carboniferous, a steeper dip of subduction led to tectonic switching from extension to compression. This period was characterized by compression, metamorphism, deformations and thickening of continental crust. Autochthonous biotite granites of the Angara-Vitim batholith (ca. 320-300 Ma) were emplaced during this phase. Destruction of the subducted slab and roll-back toward the ocean in the late Carboniferous - early Permian caused extension of continental lithosphere and magmatic input from the mantle into the continental crust. These processes were responsible for voluminous magmatism that is spectacularly represented by allochthonous granitoids of the Angara-Vitim batholith and magmatic rocks of the western Transbaikalian belt (ca. 300-270 Ma). In

  7. Rupture Process of the 1969 and 1975 Kurile Earthquakes Estimated from Tsunami Waveform Analyses

    NASA Astrophysics Data System (ADS)

    Ioki, Kei; Tanioka, Yuichiro

    2016-12-01

    The 1969 and 1975 great Kurile earthquakes occurred along the Kurile trench. Tsunamis generated by these earthquakes were observed at tide gauge stations around the coasts of the Okhotsk Sea and Pacific Ocean. To understand rupture process of the 1969 and 1975 earthquakes, slip distributions of the 1969 and 1975 events were estimated using tsunami waveform inversion technique. Seismic moments estimated from slip distributions of the 1969 and 1975 earthquakes were 1.1 × 1021 Nm ( M w 8.0) and 0.6 × 1021 Nm ( M w 7.8), respectively. The 1973 Nemuro-Oki earthquake occurred at the plate interface adjacent to that ruptured by the 1969 Kurile earthquake. The 1975 Shikotan earthquake occurred in a shallow region of the plate interface where was not ruptured by the 1969 Kurile earthquake. Further, like a sequence of the 1969 and 1975 earthquakes, it is possible that a great earthquake may occur in a shallow part of the plate interface a few years after a great earthquake that occurs in a deeper part of the same region along the trench.

  8. Epimeria abyssalis sp. n. from the Kuril-Kamchatka Trench (Crustacea, Amphipoda, Epimeriidae).

    PubMed

    Shimomura, Michitaka; Tomikawa, Ko

    2016-01-01

    A new deep-sea epimeriid, Epimeria abyssalis is described from the Kuril-Kamchatka Trench, in the northwestern Pacific. This species differs from its congeners in having a short rostrum and a telson with deep and narrow Y-shaped excavation. Epimeria abyssalis is the deepest recorded Epimeria species. A key to the north Pacific species of Epimeria is provided.

  9. Epimeria abyssalis sp. n. from the Kuril-Kamchatka Trench (Crustacea, Amphipoda, Epimeriidae)

    PubMed Central

    Shimomura, Michitaka; Tomikawa, Ko

    2016-01-01

    Abstract A new deep-sea epimeriid, Epimeria abyssalis is described from the Kuril-Kamchatka Trench, in the northwestern Pacific. This species differs from its congeners in having a short rostrum and a telson with deep and narrow Y-shaped excavation. Epimeria abyssalis is the deepest recorded Epimeria species. A key to the north Pacific species of Epimeria is provided. PMID:28174500

  10. Plastic pollution of the Kuril-Kamchatka Trench area (NW pacific)

    NASA Astrophysics Data System (ADS)

    Fischer, Viola; Elsner, Nikolaus O.; Brenke, Nils; Schwabe, Enrico; Brandt, Angelika

    2015-01-01

    During the German-Russian expedition KuramBio (Kuril-Kamchatka Biodiversity Studies) to the northwest Pacific Kuril-Kamchatka Trench and its adjacent abyssal plain, we found several kinds and sizes of plastic debris ranging from fishing nets and packaging to microplastic in the sediment of the deep-sea floor. Microplastics were ubiquitous in the smaller fractions of the box corer samples from every station from depths between 4869 and 5766 m. They were found on the abyssal plain and in the sediments of the trench slope on both sides. The amount of microplastics differed between the stations, with lowest concentration of 60 pieces per m2 and highest concentrations of more than 2000 pieces per m2. Around 75% of the microplastics (defined here as particles <1 mm) we isolated from the sediment samples were fibers. Other particles were paint chips or small cracked pieces of unknown origin. The Kuril-Kamchatka Trench area is known for its very rich marine fauna (Zenkevich, 1963). Yet we can only guess how these microplastics accumulated in the deep sea of the Kuril-Kamchatka Trench area and what consequences the microplastic itself and its adsorbed chemicals will have on this very special and rich deep-sea fauna. But we herewith present an evaluation of the different kinds of plastic debris we found, as a documentation of human impact into the deep sea of this region of the Northwest Pacific.

  11. Hydrothermal Solute Flux from Ebeko Volcanic Center, Paramushir, Kuril Islands

    NASA Astrophysics Data System (ADS)

    Taran, Y.; Kalacheva, E.; Kotenko, T.; Chaplygin, I.

    2014-12-01

    Ebeko volcano on the northern part of Paramushir Island, Northern Kurils, is characterized by frequent phreatic eruptions, a strong low-temperature fumarolic activity at the summit and was the object of comprehensive volcanological and geochemical studies during the last half a century. The volcanic center is composed of several Pleistocene volcanic structures aadjacent to Ebeko and hosts a hydrothermal system with a high outflow rate of hot SO4-Cl acidic water (Upper Yurieva springs) with the current maximum temperature of ~85oC, pH 1.3 and TDS ~ 10 g/L. All discharging thermal waters are drained by the Yurieva River to the Sea of Okhotsk. The hot springs have been changing in time, generally decreasing their activity from near boiling in 1960s, with TDS ~ 20 g/L and the presence of a small steaming field at the upper part of the ~ 700 m long discharging area, to a much lower discharge rate of main vents, lower temperature and the absence of the steaming ground. The spring chemistry did not react to the Ebeko volcanic activity (14 strong phreato-magmatic events during the last 60 years).The total measured outputs of chloride and sulfur from the system last time (2006-2010) were estimated on average as 730 g/s and 980 g/s, respectively, which corresponds to the equivalent fluxes of 64 t/d of HCl and 169 t/d of SO2. These values are higher than the fumarolic volatile output from Ebeko. The estimated discharge rate of hot (85oC) water from the system with ~ 3500 ppm of chloride is about 0.3 m3/s which is much higher than the thermal water discharge from El Chichon or Copahue volcano-hydrothermal systems and among the highest hot water natural outputs ever measured for a volcano-hydrothermal system. We also report the chemical composition (major and ~ 60 trace elements including REE) of water from the main hot spring vents and the Yurieva river mouth.

  12. Management of ST-segment elevation myocardial infarction in predominantly rural central China

    PubMed Central

    Zhang, You; Yang, Shuyan; Liu, Xinyun; Li, Muwei; Zhang, Weidong; Yang, Haiyan; Hu, Dayi; Gao, Chuanyu; Duan, Guangcai

    2016-01-01

    Abstract The degree of adherence to current guidelines for clinical management of ST-segment elevation myocardial infarction (STEMI) is known in developed countries and large Chinese cities, but in predominantly rural areas information is lacking. We assessed the application of early reperfusion therapy for STEMI in secondary and tertiary hospitals in Henan province in central China. Data were retrospectively collected from 5 secondary and 4 tertiary hospitals in Henan concerning STEMI patients treated from January 2011 to January 2012, including management strategy, delay time, and inhospital mortality. Among 1311 STEMI patients, 613 and 698 were treated at secondary and tertiary hospitals, respectively. Overall, 460 (35.1%) patients received early reperfusion therapy including thrombolysis in 383 patients and primary percutaneous coronary intervention in 77. Compared with secondary centers, early (37.2% vs 32.6%) and successful reperfusion (34.5% vs 25.1%) was significantly higher, whereas thrombolysis was lower in the tertiary hospitals (26.4% vs 32.5%). Median symptom onset-to-first medical contact, and door-to-needle and door-to-balloon time was 168, 18, and 60 minutes, respectively. Delay times closely approached recommended guidelines, especially in secondary centers. Use of recommended pharmacotherapy was low, particularly in secondary hospitals. Inhospital mortality was 5.8%, and similar between secondary and tertiary hospitals (6.0% vs 5.6%; P = 0.183). Two-thirds of STEMI patients did not receive early reperfusion, and tertiary hospitals mostly failed to take advantage of around-the-clock primary percutaneous coronary intervention. Actions such as referrals are warranted to shorten prehospital delay, and the concerns of patients and doctors regarding reperfusion risk should be addressed. PMID:27930573

  13. The opening of central segment of the South Atlantic: symmetry and the extension discrepancy

    NASA Astrophysics Data System (ADS)

    Reston, Timothy

    2010-05-01

    The rifted margins of the central segment of the South Atlantic are considered in terms of magmatism, symmetry and the amount and timing of extension, in comparison to the margins of the North Atlantic. I set out to explain the apparent lack of significant faulting in the pre-salt "sag basins" observed on these margins and the inferred transition from terrestrial to lacustrine to evaporitic to open marine sedimentation. It is suggested that the South Atlantic margins are probably moderately magmatic, with most of the magmatism occurring in the Hauterivian-Barremian, after the onset of rifting in the Berriasian. Most of the crustal extension also took place between the Berriasian and Hauterivian, before focusing along a narrow line of breakup in the Aptian that cut obliquely across the earlier rift structures. The changing locus of the rifting with time led to the development of considerable asymmetry, and the stranding of the large part of the salt basins on variously the African and South American margin. The amount of Berriasian-Hauterivian extension may have been underestimated and may be sufficient to explain the majority of the observed crustal thinning. An apparent subsidence deficit by the time of the deposition of the Aptian evaporites is a likely consequence of either delayed thermal subsidence due to the influx of hot asthenosphere or the effect of a local water level in the isolated early Cretaceous basin well below global sealevel throughout both lacustrine and evaporitic deposition. No erosional unconformity resulting from drawdown is observed as no drawdown occurred: the basin developed with the subdued topography of a subaerial rift before being gradually invaded by seawater during the Aptian (leading to the evaporite sequences), with the transgression leading to open marine conditions in the Albian.

  14. A dipping, thick segment of the Farallon Slab beneath central U.S.

    NASA Astrophysics Data System (ADS)

    Sun, Daoyuan; Gurnis, Michael; Saleeby, Jason; Helmberger, Don

    2017-04-01

    It has been hypothesized that much of the crustal deformation attributed to the Laramide orogeny of the southwest North American Cordillera was caused by dynamic effects induced by the flat subduction of a large oceanic plateau that was embedded within the Farallon Plate. Previous studies have identified within the North American mantle a seismic velocity anomaly that plausibly represents the remnants of the subducted plateau. Coupled plate kinematic and dynamic modeling of the anomaly, as well as surface geological findings, identify this anomaly as the subducted conjugate to the Shatsky Rise. Here we find clear evidence for a northeastward dipping (35° dip), thick (up to 400 km thick) slab-like seismic velocity anomaly within the top of the lower mantle below the central United States. Using a deep focus earthquake below Spain, we find that the observed seismic waveforms recorded with the dense USArray display multipathing indicative of sharp surfaces. Plate tectonic reconstructions in which the anomaly is migrated back in time suggest strong coupling of the plateau-thickened slab segment to the overriding North America Plate as it was subducted. In combination with the reconstructions, we interpret the structure as arising from eastward dipping Farallon subduction at the western margin of North America during the Cretaceous, in contrast with some recent interpretations. It appears that the plateau area of the slab has been further thickened, which might undergo a combination of pure shear bulk shortening during flat-slab subduction and/or by a folding instability during penetration into the lower mantle.

  15. Segmentation and millennium recurrence interval of morphogenic earthquakes of the Longmen Shan Thrust Belt, central China (Invited)

    NASA Astrophysics Data System (ADS)

    Lin, A.

    2013-12-01

    The magnitude (Mw) 7.9 Wenchuan earthquake occurred on 12 May 2008 in the Longmen Shan region of China, the transition zone between the Tibetan Plateau and the Sichuan Basin, rupturing ~285-300 km segment along the active fault zone of the Longmen Shan Thrust Belt (LSTB), which resulted in widespread damage throughout central and western China. Although many studies undertaken since the 2008 Wenchuan earthquake have made substantial progress in terms of understanding the co-seismic ground deformation features along the major active faults of the southwestern and central segments of the LSTB, and the current activity, only a few studies have examined northeast- and southwest-most segments and the paleoseismicity along the 500-km-long LSTB. The structural features, therefore, including its slip sense and paleoseismicity, are still unclear due to a lack of geologic data. In this study, based on the geological structures, tectonic landforms, slip sense and paleoseismic data, co-seismic surface deformation features of the 2008 Wenchuan earthquake, the active fault zone of the LSTB can be divided into four segments: Qingchuan, (the northeast-most), Beichuan (northeast-central), Dujiangyan (southwest-central) and Lingguan (the southwest-most). The northeast-most Qingchuan segment is dominated by right-lateral strike-slip with a little thrust component. The slip rate of this segment is estimated to be ca.4-8 mm/yr with an average rate of 6 mm/yr. In contrast, the central Beichuan and Dujiangyan segments are dominated by folding and thrusting with a little right-lateral and left-lateral displacement component, respectively. The vertical slip rate of these two segments is estimated to be ca.1-3 mm/yr with an average amount of 2 mm/yr. While the southwest-most Lingguan segment is dominated by folding and thrusting with a distinct left-lateral displacement component. Recently, the Mw 6.6 Ya-An earthquake occurred on 20 April 2013, which ruptured ~60 km along this segment

  16. Strain Localisation at Rift Segment Boundaries: An Example from the Bocana Transfer Zone in Central Baja California, Mexico

    NASA Astrophysics Data System (ADS)

    Seiler, C.; Gleadow, A. J.; Kohn, B. P.

    2012-12-01

    Rifts are commonly segmented into several hundred kilometre long zones of opposing upper-plate transport direction with boundaries defined by accommodation and transfer zones. A number of such rift segments have been recognized in the northern Gulf of California, a youthful oceanic basin that is currently undergoing the rift-drift transition. However, detailed field studies have so far failed to identify suitable structures that could accommodate the obvious deformation gradients between different rift segments, and the nature of strain transfer at segment boundaries remains enigmatic. The situation is even less clear in central and southern Baja California, where a number of rift segments have been hypothesized but it is unknown whether the intervening segment boundaries facilitate true reversals in the upper-plate transport direction, or whether they simply accommodate differences in the timing, style or magnitude of deformation. The Bocana transfer zone (BTZ) in central Baja California is a linear, WNW-ESE striking structural discontinuity separating two rift segments with different magnitudes and styles of extensional deformation. North of the BTZ, the Libertad fault is part of the Main Gulf Escarpment, which represents the breakaway fault that separates the Gulf of California rift to the east from the relatively stable western portion of the Baja peninsula. The N-striking Libertad escarpment developed during the Late Miocene (~10-8Ma) and exhibits a topographic relief of ca. 1,000m along a strike-length of ca. 50km. Finite displacement decreases from ~1000m in the central fault segment to ~500m further south, where the fault bends SE and merges with the BTZ. In the hanging wall of the Libertad fault, a series of W-tilted horsts are bound along their eastern margins by two moderate-displacement E-dipping normal faults. South of the BTZ, extension was much less than further north, which explains the comparatively subdued relief and generally shallower tilt of

  17. The Kuril Islands as a potential region for aquaculture: Trace elements in chum salmon.

    PubMed

    Khristoforova, Nadezhda K; Tsygankov, Vasiliy Yu; Lukyanova, Olga N; Boyarova, Margarita D

    2016-06-01

    The Kuril Islands region is considered promising for development of salmon aquaculture. There are 41 salmon fish hatcheries in the Sakhalin Island and the Kuril Islands, 34 of them are hatcheries of the chum. Therefore, concentrations of six elements (Zn, Cu, Cd, Pb, As, and Hg) were determined in chum salmon were caught in this region. The contents of toxic elements (Cd, Pb, As, and Hg) don't exceed their maximum permissible concentrations (MPC) according to the Russian sanitary standards, but concentration of Pb are closely to MPC. Increased concentrations of Pb in wild chum have the natural origin. The unusual conditions of the Western Pacific are formed under the influence such factors as volcanism and upwelling.

  18. Deep-sea sipunculans from the Kuril-Kamchatka Trench and adjacent abyssal plain

    NASA Astrophysics Data System (ADS)

    Maiorova, Anastassya S.; Adrianov, Andrey V.

    2015-01-01

    Deep-sea sipunculans collected during the expedition to the Kuril-Kamchatka Trench and adjacent abyssal plain are described and illustrated using differential interference contrast microscopy (DIC) and scanning electron microscopy (SEM). Specimens were sorted from brown silt collected by giant boxcorer (GKG), epibenthic sledge (EBS) and Agassiz trawl (AGT) from the depths 4830-5780 m. Within about 150 valid species of sipunculans only 15 have been known to be abyssal and six of them were found and identified in this KURAMBIO expedition. Eight species of sipunculans have been previously recorded from the Kuril-Kamchatka region but all of them were described based on preserved museum's material collected by bottom dredge and these descriptions are far from to be complete and comparable with other samplings. All KURAMBIO species are described according to a unified protocol to illustrate the most important taxonomic characters. This is the first description and illustrating of abyssal sipunculans in live condition with natural coloration of non-preserved specimens. Abyssal species were for a first time described with SEM facilities and according to a standardized protocol. For a first time for abyssal sipunculans, species accounts also include quantitative characteristics, distribution and specific biotope data. Nephasoma abyssorum is reported for the Kuril-Kamchatka Trench and adjacent abyssal plain for a first time.

  19. Earthquake Scenarios of a Multi-Segment Fault Systems along the Itoigawa-Shizuoka Tectonic Line, Central Japan

    NASA Astrophysics Data System (ADS)

    Ishise, M.; Miyake, H.; Koketsu, K.; Iwasaki, T.

    2009-12-01

    The Itoigawa-Shizuoka Tectonic Line (ISTL) is a major active fault system with about 250 km length, which divides the Japan islands into northeast and southwest. The Headquarters for Earthquake Research Promotion reports that the central part of the ISTL with the Gofukuji fault, will cause a M8-class earthquake with 14% in the next 30 years. It is particularly perilous area in Japan which has been suffered from a number of earthquake disasters. Thus, it is important to assess the strong ground motions for the forthcoming earthquake along the ISTL. In this study, we have constructed four source fault models for the earthquake scenarios along the ISTL based on the seismic profiling and the geomorphological observations obtained from the Integrated Research Project for Active Fault System along the ISTL (2005-2009). Since the results of the surveys offer multiple possibilities for the fault shape, we prepared two sets of outer fault parameters; one is based on the seismic profiles, and the other is based on the geomorphology and structural geology data. Both of them show the existence of segment boundary around the Suwa lake. The former consists of six segments with three east-dipping and three west-dipping faults, where the dips are turned over at the Suwa lake. Most segments are characterized by low-angle reverse faulting. On the other hand, the latter has different fault system around the Suwa lake where strike slip faults are defined. We assumed four earthquake scenarios for the seismic hazard assessment around the ISTL. (1) all the fault segments ruptured with the source model based on the seismic profiling with Mw 7.7, (2) all the fault segments ruptured with the source model based on the geomorphological observations with Mw 7.6, (3) three northern east-dipping fault segments ruptured with the source model based on the seismic profiling with Mw 7.1, (4) three southern west-dipping fault segments ruptured with the source model based on the seismic profiling with

  20. Determination of shower central position in laterally segmented lead-fluoride electromagnetic calorimeters

    NASA Astrophysics Data System (ADS)

    Mazouz, M.; Ghedira, L.; Voutier, E.

    2016-07-01

    The spatial resolution of laterally segmented electromagnetic calorimeters, built of lead fluoride material, is studied on the basis of Monte-Carlo simulations. Parametrization of the relative resolution on the shower position is proposed and optimized in terms of the energy of incoming particles and the elementary size of the calorimeter blocks. A new fit algorithm method is proposed that improves spatial resolution at high energies (> 5 GeV), and provides guidance for the design optimization of electromagnetic calorimeters.

  1. Interactions between segmental leg central pattern generators during fictive rhythms in the locust.

    PubMed

    Ryckebusch, S; Laurent, G

    1994-12-01

    1. Rhythmic activity of leg motor neurons could be evoked in isolated locust thoracic ganglia as well as in preparations of two or three connected thoracic ganglia superfused with the muscarinic agonist pilocarpine. Rhythms were always more regular and reliably elicited in single isolated ganglia. When the ganglia were connected, rhythmic activity of leg motor neurons was not usually simultaneously evoked in all six hemiganglia. Typically, some of the hemiganglia were rhythmically active, whereas others showed tonic or highly irregular activity. 2. Action potentials from leg motor neuron pools were recorded extracellularly from motor nerves and cross-correlated with the use of standard algorithms. The following correlations were observed between activities of motor neurons in different hemisegments. 1) Within a segment, trochanteral levators were coactive with contralateral trochanteral depressors. This correlation was strong in the metathoracic ganglion, and weaker in the pro- and mesothoracic ganglia. 2) Coupling between levators on opposite sides of the same segment was variable in the pro- and mesothoracic ganglia, because phase relationships between levators were different in each preparation and could also change during the course of an experiment. In the metathoracic ganglion, levators on opposite sides were never coactive. 3) Trochanteral levators were often active within a short latency of levator bursts in an ipsilateral adjacent hemiganglion. In addition, levators in one segment were often inhibited during levators bursts in the ipsilateral adjacent segment. 4) Trochanteral levators were strongly coupled to ipsilateral adjacent trochanteral depressors, for all three thoracic ganglia. 3. The phase relationships between motor neuron activities revealed by cross-correlation are discussed in the context of what is known about the mechanisms involved in the control of intersegmental coupling during legged locomotion.

  2. The relationship between speech segment duration and vowel centralization in a group of older speakers.

    PubMed

    Fletcher, Annalise R; McAuliffe, Megan J; Lansford, Kaitlin L; Liss, Julie M

    2015-10-01

    This study examined the relationship between average vowel duration and spectral vowel quality across a group of 149 New Zealand English speakers aged 65 to 90 yr. The primary intent was to determine whether participants who had a natural tendency to speak slowly would also produce more spectrally distinct vowel segments. As a secondary aim, this study investigated whether advancing age exhibited a measurable effect on vowel quality and vowel durations within the group. In examining vowel quality, both flexible and static formant extraction points were compared. Two formant measurements, from selected [ɐ:], [ i:], and [ o:] vowels, were extracted from a standard passage and used to calculate two measurements of vowel space area (VSA) for each speaker. Average vowel duration was calculated from segments across the passage. The study found a statistically significant relationship between speakers' average vowel durations and VSA measurements indicating that, on average, speakers with slower speech rates produced more acoustically distinct speech segments. As expected, increases in average vowel duration were found with advancing age. However, speakers' formant values remained unchanged. It is suggested that the use of a habitually slower speaking rate may assist speakers in maintaining acoustically distinct vowels.

  3. Using Paleoseismic Trenching and LiDAR Analysis to Evaluate Rupture Propagation Through Segment Boundaries of the Central Wasatch Fault Zone, Utah

    NASA Astrophysics Data System (ADS)

    Bennett, S. E. K.; DuRoss, C. B.; Reitman, N. G.; Devore, J. R.; Hiscock, A.; Gold, R. D.; Briggs, R. W.; Personius, S. F.

    2014-12-01

    Paleoseismic data near fault segment boundaries constrain the extent of past surface ruptures and the persistence of rupture termination at segment boundaries. Paleoseismic evidence for large (M≥7.0) earthquakes on the central Holocene-active fault segments of the 350-km-long Wasatch fault zone (WFZ) generally supports single-segment ruptures but also permits multi-segment rupture scenarios. The extent and frequency of ruptures that span segment boundaries remains poorly known, adding uncertainty to seismic hazard models for this populated region of Utah. To address these uncertainties we conducted four paleoseismic investigations near the Salt Lake City-Provo and Provo-Nephi segment boundaries of the WFZ. We examined an exposure of the WFZ at Maple Canyon (Woodland Hills, UT) and excavated the Flat Canyon trench (Salem, UT), 7 and 11 km, respectively, from the southern tip of the Provo segment. We document evidence for at least five earthquakes at Maple Canyon and four to seven earthquakes that post-date mid-Holocene fan deposits at Flat Canyon. These earthquake chronologies will be compared to seven earthquakes observed in previous trenches on the northern Nephi segment to assess rupture correlation across the Provo-Nephi segment boundary. To assess rupture correlation across the Salt Lake City-Provo segment boundary we excavated the Alpine trench (Alpine, UT), 1 km from the northern tip of the Provo segment, and the Corner Canyon trench (Draper, UT) 1 km from the southern tip of the Salt Lake City segment. We document evidence for six earthquakes at both sites. Ongoing geochronologic analysis (14C, optically stimulated luminescence) will constrain earthquake chronologies and help identify through-going ruptures across these segment boundaries. Analysis of new high-resolution (0.5m) airborne LiDAR along the entire WFZ will quantify latest Quaternary displacements and slip rates and document spatial and temporal slip patterns near fault segment boundaries.

  4. Inferred Tectonic Segmentation in the Eastern Central Atlantic Ocean and the African Margin From Mantle Bouguer Anomalies

    NASA Astrophysics Data System (ADS)

    Llanes Estrada, P.; ten Brink, U.; Canales, J.; Carbo Gorosabel, A.; Munoz Martin, A.

    2008-12-01

    The distribution, wavelength and amplitude of the Mantle Bouguer Anomalies (MBA) in the Eastern Central Atlantic Ocean reveal regional variations in crust and-or upper mantle structure. The MBA variations of such anomalies define four corridors, limited by the Oceanographer, D, Kane, South Cape Verde and Vema fracture zones. Within these corridors second order variations are sometimes present, also limited by facture zones. There is no significant change in the MBA across the Atlantis fracture zone, in contrast to observations from the conjugate Western Atlantic Ocean, which we hypothesize, are related to asymmetry in Mid-Atlantic Ridge processes. The MBA segmentation appears to follow flowlines up to the very old oceanic lithosphere adjacent to the continental margin. However, this segmentation does not mimic the MBA segmentation found along the African continental margin, which is characterized by a narrow and intermittent band of high amplitude mantle Bouguer anomalies. The location and shape of the gravity highs and lows along the margin follow the coastal morphology, with gravity lows located in front of capes and highs in front of gulfs. We conclude that the deep structure of the continental margin has been inherited from the first stages of the rifting processes and differs from the general segmentation later produced by sea-floor spreading along the Mid-Atlantic Ridge. Intraplate volcanism, such as the Canary Islands, Cape Verde Islands and Madeira Island is not responsible for the existence of the MBA corridors or their boundaries in the eastern Atlantic Ocean, but instead generates broad areas of large negative MBA that modify the pre- existing gravity signature of the ocean floor.

  5. Segmentation and the coseismic behavior of Basin and Range normal faults: examples from east-central Idaho and southwestern Montana, U.S.A.

    USGS Publications Warehouse

    Crone, A.J.; Haller, K.M.

    1991-01-01

    The range-front normal faults of the Lost River and Lemhi Ranges, and the Beaverhead and Tendoy Mountains in east-central Idaho and southwestern Montana have well-preserved fault scarps on Quaternary deposits along much of their lengths. Fault-scarp morphology, the age of deposits displaced by the faults, and the morphology of the range fronts provide a basis for dividing the faults into segments that are typically 20-25 km long. The Lost River, Lemhi and Beaverhead fault zones are 141-151 km long, and each has six segments. The 60-km-long Red Rock fault (the range-front fault of the Tendoy Mountains) has two central segments that have been active in late Quaternary time; these two segments span the central 27 km of the fault. We recognize four characteristics that help to identify segment boundaries: (1) major en e??chelon offsets or pronounced gaps in the continuity of fault scarps; (2) distinct, persistent, along-strike changes in fault-scarp morphology that indicate different ages of faulting; (3) major salients in the range front; and (4) transverse bedrock ridges where the cumulative throw is low compared to other places along the fault zone. Only features whose size is measured on the scale of kilometers are regarded as significant enough to represent a segment boundary that could inhibit or halt a propagating rupture. The ability to identify segments of faults that are likely to behave as independent structural entities will improve seismic-hazard assessment. However, one should not assume that the barriers at segment boundaries will completely stop all propagating ruptures. The topographic expression of mountain ranges is evidence that, at times during their history, all barriers fail. Some barriers apparently create 'leaky' segment boundaries that impede propagating ruptures but do not completely prevent faulting on adjacent segments. ?? 1991.

  6. A New View on the Space-Time Pattern of M>7 Earthquakes in the Northern Japan to Kurile Subduction Zones

    NASA Astrophysics Data System (ADS)

    Harada, T.; Satake, K.

    2012-04-01

    The northern Japan to southern Kurile trenches have been regarded as a typical subduction zone with spatially and temporally regular recurrence of great (M>8) interplate earthquakes. The source regions were grouped into six segments by Utsu (1972; 1984). The Headquarters for Earthquake Research Promotion of the Japanese government (2004) divided the southern Kurile subduction zone into four regions and evaluated future probabilities of great interplate earthquakes. Besides great interplate events, however, many large (M>7) interplate, intraslab, outer-rise and tsunami earthquakes have also occurred in this region. First, we depicted the space-time pattern of M>7 earthquakes along the northern Japan to Kuril trench, based on the relocated mainshock-aftershock distributions of all types of earthquakes occurred since 1913. We relocated the hypocenters reported in the ISC, ISS, and BCIS bulletins by using the HYPOSAT (Schweitzer, 2003) and the Modified JHD method (Hurukawa, 1995). Then, in order to examine more detail space pattern, or rupture areas, of M>7 earthquakes since 1963, we estimated coseismic slip distributions by the Kikuchi and Kanamori's (2003) teleseismic body wave inversion method. The WWSSN waveform data were used for earthquakes between 1963 and 1990, and digital teleseismic waveform data compiled by the IRIS were used for events after 1990. Mainshock hypocenters relocated by us were used as initial rupture points. As a result, we found that the more complex feature of earthquake occurrence. Each region has been ruptured by a M8-class interplate earthquake or by multiple M7-class events. Offshore Urup Is. is source region of the 1963 Urup earthquake (M 8.5). Large interplate earthquakes occurred in the eastern and western part of the 1963 source region in 1991 (M 7.6) and 1995 (M 7.9), respectively. Their aftershock areas almost re-occupied the 1963 aftershock area. The 1963, 1991, and 1995 coseismic slip distributions show that the southwestern

  7. Lagrangian analysis of formation, structure, evolution and splitting of anticyclonic Kuril eddies

    NASA Astrophysics Data System (ADS)

    Prants, S. V.; Lobanov, V. B.; Budyansky, M. V.; Uleysky, M. Yu.

    2016-03-01

    We studied in detail a mesoscale anticylonic eddy that has been sampled in the R/V Professor Gagarinskiy cruise (June-July 2012) in the area east of the Kuril Islands in the northwestern subarctic Pacific. Lagrangian approach was applied to study formation, structure and evolution of this feature called the eddy A and of its parent eddy B using a simulation with synthetic tracers advected by the AVISO velocity field. We used different Lagrangian methods and techniques to identify those eddies and their boundaries, to know their structure and to document their deformation, metamorphoses and splitting. It has been found that the eddy A was born as a result of splitting of the eddy B with the core water to be borrowed from the eddy B which, in turn, was influenced by the Okhotsk Sea water flowing into the ocean through the Kuril straits. The periphery of the eddy A was formed mainly by East Kamchatka Current water in the process of its winding onto the eddy A core by portions. All these processes have been documented in detail with the help of drift and tracking Lagrangian maps computed forward and backward in time with a large number of synthetic tracers distributed over the studied area. We have found a Lagrangian structure of those eddies and the ways how they have gained and released water. Simulated and measured locations of the center of the eddy A and its boundary have been be estimated to coincide with the accuracy of ≈ 7-10 and ≈ 15-20 km, respectively. Our simulations were validated in part by tracks of available surface drifters and Argo floats. We presented CTD hydrographic observations of the Kuril eddy A from the surface to deep waters and compared observed and simulated results in order to establish origin and properties of water masses constituting that eddy.

  8. Modeling of influence from remote tsunami at the coast of Sakhalin and Kuriles islands.

    NASA Astrophysics Data System (ADS)

    Zaytsev, Andrey; Pelinovsky, Efim; Yalciner, Ahmet; Chernov, Anton; Kostenko, Irina

    2010-05-01

    The Far East coast of Russia (Kuriles islands, Sakhalin, Kamchatka) is the area where the dangerous natural phenomena as tsunami is located. A lot of works are established for decreasing of tsunami's influence. Tsunami mapping and mitigation strategy are given for some regions. The centers of Tsunami Warning System are opened, enough plenty of records of a tsunami are collected. The properties of local tsunami are studied well. At the same time, the catastrophic event of the Indonesian tsunami, which had happened in December, 2004, when the sufficient waves have reached the coasts of Africa and South America, it is necessary to note, that the coats, which was far from the epicenter of earthquakes can be effected by catastrophic influence. Moreover, it is practically unique case, when using Tsunami Warning System can reduce the number of human victims to zero. Development of the computer technologies, numerical methods for the solution of systems of the nonlinear differential equations makes computer modeling real and hypothetical tsunamis is the basic method of studying features of distribution of waves in water areas and their influence at coast. Numerical modeling of distribution of historical tsunami from the seismic sources in the Pacific Ocean was observed. The events with an epicenter, remote from Far East coast of Russia were considered. The estimation of the remote tsunami waves propagation was developed. Impact force of tsunamis was estimated. The features of passage of tsunami through Kuril Straits were considered. The spectral analysis of records in settlements of Sakhalin and Kuriles is lead. NAMI-DANCE program was used for tsunami propagation numerical modeling. It is used finite element numerical schemes for Shallow Water Equations and Nonlinear-Dispersive Equations, with use Nested Grid.

  9. Recurrence of seismic migrations along the central California segment of the San Andreas fault system

    USGS Publications Warehouse

    Wood, M.D.; Allen, S.S.

    1973-01-01

    VERIFICATIONS of tectonic concepts1 concerning seafloor spreading are emerging in a manner that has direct bearing on earthquake prediction. Although the gross pattern of worldwide seismicity contributed to the formulation of the plate tectonic hypothesis, it is the space-time characteristics of this seismicity that may contribute more toward understanding the kinematics and dynamics of the driving mechanism long speculated to originate in the mantle. If the lithosphere is composed of plates that move essentially as rigid bodies, then there should be seismic edge effects associated with this movement. It is these interplate effects, especially seismic migration patterns, that we discuss here. The unidirectional propagation at constant velocity (80 km yr-1 east to west) for earthquakes (M???7.2) on the Antblian fault for the period 1939 to 1956 (ref. 2) is one of the earliest observations of such a phenomenon. Similar studies3,4 of the Alaska Aleutian seismic zone and certain regions of the west coast of South America suggest unidirectional and recurring migrations of earthquakes (M???7.7) occur in these areas. Between these two regions along the great transform faults of the west coast of North America, there is some evidence 5 for unidirectional, constant velocity and recurrent migration of great earthquakes. The small population of earthquakes (M>7.2) in Savage's investigation5 indicates a large spatial gap along the San Andreas system in central California from 1830 to 1970. Previous work on the seismicity of this gap in central California indicates that the recurrence curves remain relatively constant, independent of large earthquakes, for periods up to a century6. Recurrence intervals for earthquakes along the San Andreas Fault have been calculated empirically by Wallace7 on the basis of geological evidence, surface measurements and assumptions restricted to the surficial seismic layer. Here we examine the evidence for recurrence of seismic migrations along

  10. Geologic map of the Simcoe Mountains Volcanic Field, main central segment, Yakama Nation, Washington

    USGS Publications Warehouse

    Hildreth, Wes; Fierstein, Judy

    2015-01-01

    Lava compositions other than various types of basalt are uncommon here. Andesite is abundant on and around Mount Adams but is very rare east of the Klickitat River. The only important nonbasaltic composition in the map area is rhyolite, which crops out in several patches around the central highland of the volcanic field, mainly in the upper canyons of Satus and Kusshi Creeks and Wilson Charley canyon. Because the rhyolites were some of the earliest lavas erupted here, they are widely concealed by later basalts and therefore crop out only in local windows eroded by canyons that cut through the overlying basalts.

  11. Transient uplift after a 17th-century earthquake along the kuril subduction zone

    USGS Publications Warehouse

    Sawai, Y.; Satake, K.; Kamataki, T.; Nasu, H.; Shishikura, M.; Atwater, B.F.; Horton, B.P.; Kelsey, H.M.; Nagumo, T.; Yamaguchi, M.

    2004-01-01

    In eastern Hokkaido, 60 to 80 kilometers above a subducting oceanic plate, tidal mudflats changed into freshwater forests during the first decades after a 17th-century tsunami. The mudflats gradually rose by a meter, as judged from fossil diatom assemblages. Both the tsunami and the ensuing uplift exceeded any in the region's 200 years of written history, and both resulted from a shallow plate-boundary earthquake of unusually large size along the Kuril subduction zone. This earthquake probably induced more creep farther down the plate boundary than did any of the region's historical events.

  12. Serotonin spillover onto the axon initial segment of motoneurons induces central fatigue by inhibiting action potential initiation.

    PubMed

    Cotel, Florence; Exley, Richard; Cragg, Stephanie J; Perrier, Jean-François

    2013-03-19

    Motor fatigue induced by physical activity is an everyday experience characterized by a decreased capacity to generate motor force. Factors in both muscles and the central nervous system are involved. The central component of fatigue modulates the ability of motoneurons to activate muscle adequately independently of the muscle physiology. Indirect evidence indicates that central fatigue is caused by serotonin (5-HT), but the cellular mechanisms are unknown. In a slice preparation from the spinal cord of the adult turtle, we found that prolonged stimulation of the raphe-spinal pathway--as during motor exercise--activated 5-HT1A receptors that decreased motoneuronal excitability. Electrophysiological tests combined with pharmacology showed that focal activation of 5-HT1A receptors at the axon initial segment (AIS), but not on other motoneuronal compartments, inhibited the action potential initiation by modulating a Na(+) current. Immunohistochemical staining against 5-HT revealed a high-density innervation of 5-HT terminals on the somatodendritic membrane and a complete absence on the AIS. This observation raised the hypothesis that a 5-HT spillover activates receptors at this latter compartment. We tested it by measuring the level of extracellular 5-HT with cyclic voltammetry and found that prolonged stimulations of the raphe-spinal pathway increased the level of 5-HT to a concentration sufficient to activate 5-HT1A receptors. Together our results demonstrate that prolonged release of 5-HT during motor activity spills over from its release sites to the AIS of motoneurons. Here, activated 5-HT1A receptors inhibit firing and, thereby, muscle contraction. Hence, this is a cellular mechanism for central fatigue.

  13. Serotonin spillover onto the axon initial segment of motoneurons induces central fatigue by inhibiting action potential initiation

    PubMed Central

    Cotel, Florence; Exley, Richard; Cragg, Stephanie J.; Perrier, Jean-François

    2013-01-01

    Motor fatigue induced by physical activity is an everyday experience characterized by a decreased capacity to generate motor force. Factors in both muscles and the central nervous system are involved. The central component of fatigue modulates the ability of motoneurons to activate muscle adequately independently of the muscle physiology. Indirect evidence indicates that central fatigue is caused by serotonin (5-HT), but the cellular mechanisms are unknown. In a slice preparation from the spinal cord of the adult turtle, we found that prolonged stimulation of the raphe-spinal pathway—as during motor exercise—activated 5-HT1A receptors that decreased motoneuronal excitability. Electrophysiological tests combined with pharmacology showed that focal activation of 5-HT1A receptors at the axon initial segment (AIS), but not on other motoneuronal compartments, inhibited the action potential initiation by modulating a Na+ current. Immunohistochemical staining against 5-HT revealed a high-density innervation of 5-HT terminals on the somatodendritic membrane and a complete absence on the AIS. This observation raised the hypothesis that a 5-HT spillover activates receptors at this latter compartment. We tested it by measuring the level of extracellular 5-HT with cyclic voltammetry and found that prolonged stimulations of the raphe-spinal pathway increased the level of 5-HT to a concentration sufficient to activate 5-HT1A receptors. Together our results demonstrate that prolonged release of 5-HT during motor activity spills over from its release sites to the AIS of motoneurons. Here, activated 5-HT1A receptors inhibit firing and, thereby, muscle contraction. Hence, this is a cellular mechanism for central fatigue. PMID:23487756

  14. Controlling for Landform Age When Determining the Settlement History of the Kuril Islands

    PubMed Central

    MacInnes, Breanyn; Fitzhugh, Ben; Holman, Darryl

    2014-01-01

    Archaeological investigations of settlement patterns in dynamic landscapes can be strongly biased by the evolution of the Earth’s surface. The Kuril Island volcanic arc exemplifies such a dynamic landscape, where landscape-modifying geological forces were active during settlement, including sea-level changes, tectonic emergence, volcanic eruptive processes, coastal aggradation, and dune formation. With all these ongoing processes, in this paper we seek to understand how new landscape formation in the Holocene might bias archaeological interpretations of human settlement in the Kurils. Resolving this issue is fundamental to any interpretation of human settlement history derived from the distribution and age of archaeological sites from the region. On the basis of a comparison of landform ages and earliest archaeological occupation ages on those landforms, we conclude that landform creation did not significantly bias our aggregate archaeological evidence for earliest settlement. Some sections of the archipelago have larger proportions of landform creation dates closer to archaeological evidence of settlement and undoubtedly some archaeological sites have been lost to geomorphic processes. However, comparisons between regions reveal comparable archaeological establishment patterns irrespective of geomorphic antiquity. PMID:25684855

  15. Controlling for Landform Age When Determining the Settlement History of the Kuril Islands.

    PubMed

    MacInnes, Breanyn; Fitzhugh, Ben; Holman, Darryl

    2014-01-01

    Archaeological investigations of settlement patterns in dynamic landscapes can be strongly biased by the evolution of the Earth's surface. The Kuril Island volcanic arc exemplifies such a dynamic landscape, where landscape-modifying geological forces were active during settlement, including sea-level changes, tectonic emergence, volcanic eruptive processes, coastal aggradation, and dune formation. With all these ongoing processes, in this paper we seek to understand how new landscape formation in the Holocene might bias archaeological interpretations of human settlement in the Kurils. Resolving this issue is fundamental to any interpretation of human settlement history derived from the distribution and age of archaeological sites from the region. On the basis of a comparison of landform ages and earliest archaeological occupation ages on those landforms, we conclude that landform creation did not significantly bias our aggregate archaeological evidence for earliest settlement. Some sections of the archipelago have larger proportions of landform creation dates closer to archaeological evidence of settlement and undoubtedly some archaeological sites have been lost to geomorphic processes. However, comparisons between regions reveal comparable archaeological establishment patterns irrespective of geomorphic antiquity.

  16. The Chako antiform: A folded segment of the Greater Himalayan sequence, Nar valley, Central Nepal Himalaya

    NASA Astrophysics Data System (ADS)

    Gleeson, Thomas P.; Godin, Laurent

    2006-09-01

    Recent and previously published mapping in the Nar valley, north of the Annapurna massif in central Nepal, recognised an enigmatic metamorphic culmination of the Greater Himalayan sequence, surrounded by rocks correlated with the Tethyan sedimentary sequence. The map area is re-interpreted as two structural levels within the Greater Himalayan sequence. The Lower Level is correlated to the well-studied Greater Himalayan sequence of the Annapurna region, based on characteristic rock types, high-strain zones with south-verging shear-sense indicators, and high-grade metamorphism. The rocks of the Upper Level, previously mapped as the sub-greenschist or zeolite facies Tethyan sedimentary sequence, are garnet-bearing schists. Petrography and garnet-biotite thermometry suggest the Upper Level equilibrated at amphibolite facies (500-650 °C). These results support the recent contention that the Upper Level rocks are a component of the Greater Himalayan sequence, and thus indicate that components of the Himalayan metamorphic core vary considerably along strike. Structural, metamorphic and age constraints are integrated into a cohesive regional tectonometamorphic model. The Lower and Upper Levels both experienced D 1 deformation and peak metamorphism before ˜20 Ma. The Lower and Upper Levels were juxtaposed along the synmetamorphic Chame detachment after 20 Ma during retrograde metamorphism. After ˜19 Ma, the Phu detachment placed the unmetamorphosed Tethyan sedimentary sequence above the Lower and Upper Levels. The entire package was then subsequently folded, after 19 Ma, by a non-cylindrical antiform-synform pair with a ˜25 km wavelength creating an apparent dome. The proposed tectonometamorphic model reconciles previously contradictory interpretations of the transition between metamorphic core and overlying sediments in the Nar valley.

  17. Resilience and the population history of the Kuril Islands, Northwest Pacific: A study in complex human ecodynamics.

    PubMed

    Fitzhugh, Ben; Gjesfjeld, Erik; Brown, William; Hudson, Mark J; Shaw, Jennie D

    2016-10-17

    Living in remote places can strain the adaptive capacities of human settlers. It can also protect communities from external social, political and economic forces. In this paper, we present an archaeological population history of the Kuril Islands. This string of small volcanic islands on the margins of the Northwest Pacific was occupied by maritime hunting, fishing and gathering communities from the mid-Holocene to recent centuries. We bring together (1) 380 new and previously published archaeological radiocarbon dates, (2) a new paleodemographic model based on a radiocarbon-timestamped temporal frequency distribution of archaeological deposits, (3) recently published paleoclimate trends, and (4) recently published archaeological proxy evidence for changes in the extent of social networks. We demonstrate that, over the last two millennia, inhabitants of the Kuril Islands underwent dramatic demographic fluctuations. Explanations of these fluctuations are considered in the context of environmental hazards, social networks and the emergence of an East Asian "World System", elucidating the tension between local and external adaptive strategies to social and ecological uncertainty. Results suggest that population resilience to local climate and environmental variability was achieved by virtue of social networks that maintained non-local support in times of crisis. Conversely, the expansion of the East Asian political economy into neighboring regions of the southern margin of the Kuril Islands perhaps in conjunction with exposure to epidemic diseases appears to have undermined the adaptive strategies, resulting in an increase in the vulnerability of Kuril populations to environmental fluctuations.

  18. The influence of the Kuril Islands on the penetration of tsunamis into the Sea of Okhotsk (on the example of the Japan tsunami on March 11, 2011)

    NASA Astrophysics Data System (ADS)

    Kostenko, I. S.; Kurkin, A. A.; Pelinovsky, E. N.; Yalciner, A.

    2016-01-01

    The features of the propagation of the tsunami of March 11, 2011 in the northeastern Pacific have been studied with the aim of revealing the degree of influence of the Kuril Islands on the penetration of the tsunami in the Sea of Okhotsk. For this, a series of computational experiments have been performed within the shallow water theory using bathymetry (1) with and (2) without the Kuril Islands. The wave heights calculated have been analyzed, and the tsunami's magnitude and intensity in the Sea of Okhotsk have been estimated. The computational experiments performed allow assessment of a decrease in the tsunami intensity while passing the Kuril Islands.

  19. Initiation and development of the Kivu rift segment in Central Africa by reactivating un-favorably oriented structural weaknesses

    NASA Astrophysics Data System (ADS)

    Delvaux, Damien; Smets, Benoît

    2015-04-01

    The Kivu rift region forms the central segment of the western branch of the East African rift system, between the northern termination of the Tanganyika rift and the southern extension of the Edward-George rift. Its structure and geological evolution has been revised in the light of a compilation of existing data on earthquake epicenters, focal depth, focal mechanisms, thermal springs and neotectonic faults. It has long been shown that the link between the Kivu rift basin and the Northern termination of the Tanganyika rift basin forms an accommodation zone in which the Rusizi tectonic depression occupies a central place (Ebinger, 1989). In addition, our compilation suggests that the NNE-trending Kivu rift basin and the N-S northern half of the Tanganyika rift basin initiated as separated, partly overlapping and differently oriented basins. The orientation and development of the Kivu rift basin was controlled by an inferred Mid-Proterozoic crustal shear zone and a Pan-African reverse fault front. It was not optimally oriented with the general (first-order) stress field characterized by roughly E-W extension. In a later stage, the more optimally N-S oriented North Tanganyika basin progressed towards the North and connected to Kivu rift in its middle in a region now occupied by the town of Bukavu. This accommodation zone is marked by Quaternary volcanism, warm thermal springs, frequent and relatively shallow seismicity. The southwestern part of the Kivu rift became progressively abandoned but it is still seismically active and hosts a number of warm thermal springs. This particular architecture influences the present-day stress field. This work is a contribution to the Belgian GeoRisCA project. Ebinger, C.J. 1989. Geometric and kinematic development of border faults and accommodation zones, Kivu-Rusizi Rift, Africa. Tectonics, 8, 117-133

  20. Along-Strike Tectonic Segmentation of the Mesozoic Central Orogenic Belt, China: Insights from the Eastern Qinling Magmatic Syntaxis

    NASA Astrophysics Data System (ADS)

    Ma, C.; Sun, Y.; Li, J.; Xu, W.; magmatism; mineralization

    2011-12-01

    Along-strike tectonic segmentation is an important feature of the active continental margin. However, the tectonic segmentation of collisional orogenic belts is yet not to be well constrained. The Triassic Central Orogenic belt in China extends nearly 5,000 km, and is a collisional belt between the North China and Yangtze cratons. Influenced by the subduction of the paleo-Pacific plate, and the lithospheric thinning of the North China craton, this Orogenic belt is superimposed on multi-stage magmatism and mineralization, showing a typical along-strike segmentation. This paper takes the Eastern Qinling magmatic syntaxis as an example, and attempts to understand the manifestation of the structural segmentation and its formation mechanism. The Eastern Qinling magmatic syntaxis can be divided into two parts bounded by a line extending from the Xiaoqinling - Xiong'ershan region in the southern North China craton to Ankang region in the southern Qinling zone(hereafter referred to Xiao-an line). Both sides of the line have distinct geological and geophysical characteristics. (1) Middle-Late Triassic intrusive rocks are widespread in the west of the Xiao-an line, and their rock types include adakitic and shoshonite-series granitoids, rapakivi granites and a small volume of lamprophyre dykes. Triassic igneous rocks are lack in the east of the Xiao-an line, but the late Jurassic (~153Ma) monzogranites and granodiorite, and early Cretaceous (130-108 Ma) alkali-feldspar granites and syenites are widely distributed in the east, probably in response to the subduction of the paleo-Pacific plate and the lithosphere thinning of the North China craton. (2) In the east of the Xiao-an line, the gold mineralization of quartz-veins and altered-rock took place in the late Mesozoic, while in the west, the carlin-like gold deposits formed in the early Mesozoic.In the east of the line there is late Mesozoic molybdenum ore belt, the largest molybdenum ore belt in China. However, in the west

  1. Thrust segment from the Antler orogeny identified north of the Snake River Plain, south-central Idaho

    SciTech Connect

    Skipp, B. )

    1993-04-01

    A small segment of folded thrust fault places silicified, cleaved, folded, graptolite-bearing black mudstone, sandstone, and minor granule conglomerate of the Ordovician Phi Kappa Formation over unnamed cleaved, yellow, calcareous siltstone and silty limestone of Devonian to Silurian age in the Long Canyon area near Fish Creek Reservoir, within a kilometer of the north-central margin of the Snake River Plain. The thrust fault and rocks of both hanging wall and footwall are overlain by sandy limestone and pebble conglomerate of the Middle Pennsylvanian Hailey Member of the Wood River Formation along a locally faulted unconformable contact. Thus, the age of the thrust is bracketed as post-Devonian and pre-Middle Pennsylvanian, a period that encompasses the Antler orogeny. The Long Canyon thrust fault is the first direct evidence of contraction within rocks of the postulated Mississippian Antler highland in western Idaho. Indirect evidence such as penetrative axial plane cleavage in Devonian argillites of the Milligen Formation, not present in younger argillites, has been recognized for several years. The entire sequence of Ordovician through Pennsylvanian rocks constitutes the southernmost exposure of the hanging wall of the Mesozoic Pioneer thrust fault system. In this area, the footwall of the Pioneer thrust comprises Silurian through Devonian platform carbonate rocks overlain unconformably by Mississippian orogenic detritus derived from the western Antler highland.

  2. Interplate locking condition derived from seafloor geodetic observation in the shallowest subduction segment at the Central Nankai Trough, Japan

    NASA Astrophysics Data System (ADS)

    Yasuda, Kenji; Tadokoro, Keiichi; Taniguchi, Sota; Kimura, Hiroshi; Matsuhiro, Kenjiro

    2017-04-01

    We monitored seafloor crustal deformation at two observation stations on opposite sides of the Nankai Trough from 2013 to 2016 in order to investigate the interplate locking condition along the Central Nankai Trough. We estimated the seafloor crustal deformation with respect to the Amurian Plate based on five observations. The results for two stations, TCA and TOA, were 38±25 mm/yr toward N78°W and 57±21 mm/yr toward N69°W (1σ), respectively. The displacement rate at TOA is consistent with the motion of the Philippine Sea Plate with respect to the Amurian Plate using the Euler vector of the REVEL model. The displacement rate at TCA is similar to that at other seafloor geodetic stations, e.g., 48±10 mm/yr at KUM2 station, on the Kumano Basin. The interplate coupling rate was estimated to be roughly 70±40% (1σ) in the shallowest segment of the Nankai Trough.

  3. Unexpectedly higher metazoan meiofauna abundances in the Kuril-Kamchatka Trench compared to the adjacent abyssal plains

    NASA Astrophysics Data System (ADS)

    Schmidt, Christina; Martínez Arbizu, Pedro

    2015-01-01

    We studied meiofauna standing stocks and community structure in the Kuril-Kamchatka Trench and its adjacent abyssal plains in the northwestern Pacific Ocean. In general, the Nematoda were dominant (93%) followed by the Copepoda (4%). Nematode abundances ranged from 87% to 96%; those of copepods from 2% to 7%. The most diverse deployment yielded 17 taxa: Acari, Amphipoda, Annelida, Bivalvia, Coelenterata, Copepoda, Cumacea, Gastrotricha, Isopoda, Kinorhyncha, Loricifera, Nematoda, Ostracoda, Priapulida, Tanaidacea, Tantulocarida, and Tardigrada. Nauplii were also present. Generally, the trench slope and the southernmost deployments had the highest abundances (850-1392 individuals/cm2). The results of non-metric multidimensional scaling indicated that these deployments were similar to each other in meiofauna community structure. The southernmost deployments were located in a zone of higher particulate organic carbon (POC) flux (g Corg m-2 yr-1), whereas the trench slope should have low POC flux due to depth attenuation. Also, POC and abundance were significantly correlated in the abyssal plains. This correlation may explain the higher abundances at the southernmost deployments. Lateral transport was also assumed to explain high meiofauna abundances on the trench slope. Abundances were generally higher than expected from model results. ANOSIM revealed significant differences between the trench slope and the northern abyssal plains, between the central abyssal plains and the trench slope, between the trench slope and the southern abyssal plains, between the central and the southern abyssal plains, and between the central and northern deployments. The northern and southern abyssal plains did not differ significantly. In addition, a U-test revealed highly significant differences between the trench-slope and abyssal deployments. The taxa inhabited mostly the upper 0-3 cm of the sediment layer (Nematoda 80-90%; Copepoda 88-100%). The trench-slope and abyssal did not differ

  4. Tsunami Runup in the Middle Kuril Islands from the Great Earthquake of 15 Nov 2006

    NASA Astrophysics Data System (ADS)

    Bourgeois, J.; Pinegina, T.; Razhegaeva, N.; Kaistrenko, V.; Levin, B.; Macinnes, B.; Kravchunovskaya, E.

    2007-12-01

    Two expeditions to the middle Kuril Islands [IMGG FED RAS, NSF Kurils Biocomplexity Project] in the summer of 2007 yielded tsunami runup and inundation measurements from the 15 Nov 2006 Mw 8.3 subduction-zone earthquake, and possibly from the 13 Jan 2007 Mw 8.1 earthquake seaward of the subduction zone. Both earthquakes produced measurable tsunamis in the far field, the 13 Jan tsunami significantly smaller; the 15 Nov tsunami did some damage in the harbor of Crescent City, CA. Ours are the first near-source measurements because no one lives in the middle Kurils. Moreover, because KBP visited many of the same sites in summer of 2006, we have numerous before-and-after comparisons, including quantified erosion. We measured 120 profiles and made more than 300 runup measurements. We found dramatic tsunami effects of erosion and deposition, with widespread runup of 8-12 m, up to about 20 m, between and including Simushir and Matua islands. In most cases, we measured runup with a transit and surveying rod, producing a topographic profile from sea level to the slope above runup indicators; in some cases, we used a hand level and tape. Runup/inundation criteria were generally subhorizontal lines of floatable debris, typically wood, plastic, glass floats, and styrofoam. Single occurrences, e.g., of a plastic bottle were not considered adequate. Corroborative evidence, not used independently, included limits of consistently oriented stems of tall grasses and flowers, limit of sand and gravel deposits above turf and dead vegetation, and elevation of fresh erosion of turf from slopes landward of the beach plain. Currently we are compiling, correcting and vetting our measurements, which will be submitted to online databases. Topographic profiles obviously had an effect on the data, with short, steep profiles generating high runup and short inundation; most beach-ridge profiles had longer inundation and shorter runup. However, at Ainu Bay on Matua Island, we found as much as 18

  5. Significant foreshock activities of M>7.5 earthquakes in the Kuril subduction zone

    NASA Astrophysics Data System (ADS)

    Harada, T.; Yokoi, S.; Satake, K.

    2014-12-01

    In the Kuril subduction zone, some M>7.5 earthquakes are accompanied by significant foreshock activities, providing a good opportunity to understand the characteristics of foreshocks for large interplate events such as occur along the Japan Trench and Nankai Trough etc. Some preliminary results from our examination of the foreshock sequences are as follows. Relocated foreshocks tend to migrate with time toward the trench axis. Foreshock distributions of the interplate earthquakes do not overlap with the large coseismic slips (asperities) of the mainshocks. Foreshocks of the 2007 northern Kuril outer-rise event, however, were distributed on the entire rupture area. Foreshock sequences seem to be limited in the regions where the background seismicity rates are relatively high. The foreshock activities were found in the examination of the space-time pattern of M>7 events along the northern Japan to Kuril trench since 1913 (e.g. Harada, Satake, and Ishibashi, 2011:AGU, 2012:AOGS). The large earthquakes preceded by active foreshock sequences are: the 2006 (M8.3), 2007 (M8.1) offshore Simushir earthquakes, the 1963 (M8.5), 1991 (M7.6), 1995 (M7.9) offshore Urup events, the 1978 (M7.8) offshore Iturup events, the 1969 (M8.2) offshore Shikotan event. In contrast, M>7.5 interplate earthquakes offshore Hokkaido (1952 (M8.1), 1973 (M7.8), 2003 (M8.1)) and intraslab earthquakes (1958 (M8.3), 1978 (M7.8), 1993 (M7.6), 1994 (M8.3)) had few or no foreshocks. In the examination of the active foreshocks, we relocated foreshocks by the Modified JHD method (Hurukawa, 1995), compared relocated foreshock areas with mainshock coseismic slip distributions estimated by the teleseismic body-wave inversion (Kikuchi and Kanamori, 2003), and examined the relation between active foreshock sequences and regional background seismicity. This study was supported by the MEXT's "New disaster mitigation research project on Mega thrust earthquakes around Nankai/Ryukyu subduction zones".

  6. Insight on fault segmentation, linkage and hazard from the 2016 Mw6.2 Amatrice earthquake (central Italy)

    NASA Astrophysics Data System (ADS)

    Walters, R. J.; Gregory, L. C.; Wedmore, L. N. J.; Craig, T. J.; Elliott, J. R.; Wilkinson, M. W.; McCaffrey, K. J. W.; Michetti, A.; Vittori, E.; Livio, F.; Iezzi, F.; Chen, J.; Li, Z.; Roberts, G.

    2016-12-01

    We investigate the 2016 Mw6.2 Amatrice earthquake (central Italy) with a combination of bodywave seismology, field measurements and satellite geodesy, and show that the earthquake ruptured across two normal faults that had previously been identified as separate structures. Our coseismic source model, obtained from GPS and InSAR data, shows slip in two major patches, taking place over a total length of 20 km, and mainly constrained to shallow (2-7 km) depths. Our model shows that the highest slip was focussed on the unknown linking section between the mapped Laga and Vettore faults. Our model predicts primary surface rupture to be present only on the Vettore fault, in agreement with our field observations. Our seismological model has a simple source-time function, implying that within the resolution of the data, the rupture proceeded without pause across the linking section between the Vettore and Laga faults. Both faults were previously identified as active, but field mapping, remote sensing data, geomorphology, and Holocene slip rates had all been used to support the idea that the faults were separate structures. Each had been thought capable of producing an earthquake with MW<6.5. However, our study suggests that these faults appear to be better linked at depth than previously thought, allowing through-going rupture. Although the Amatrice earthquake did not rupture the full extent of the Laga and Vettore faults, we suggest that if such a scenario did happen with 1 m average slip, the two faults are capable of producing a MW7.1 earthquake. This type of fault behaviour has precedent in Italy; the destructive 1980 MW6.9 Irpinia earthquake in southern Italy was composed of multiple MW6.2-6.5 sub-events on four separate segments. Each of the MW6.7-7 largest known events in central Italy; the 1703 Norcia and L'Aquila earthquakes and the 1915 Avezzano earthquake, are also thought to have involved multi-fault rupture. MW>7 earthquakes are not reported in the long and

  7. Description of two ubiquitous species of Desmosomatidae (Isopoda: Asellota) from the Northwest Pacific Basin east of the Kuril-Kamchatka Trench.

    PubMed

    Golovan, Olga A

    2015-11-05

    Two new species of Desmosomatidae, Eugerdella kurabyssalis sp. nov. and Parvochelus serricaudis sp. nov., are described from the Northwest Pacific open abyssal plain to the east of the Kuril-Kamchatka Trench. These species constituted about one fourth of all collected desmosomatid specimens of the KuramBio expedition (2012), indicating it may be the most abundant species of the family in this area. E. kurabyssalis sp. nov. is rather similar to E. minutula Mezhov, 1986 and E. theodori Brix, 2007, resembling them in the shape of its body segments and appendages, including the absence of the mandibular palp and morphology of the pereopod I. The new species can be distinguished from the mentioned species by the number of cusps of the mandibular incisor process and lacinia mobilis, the relatively stouter pereopods and different setation of the pereopod I ischium. P. serricaudis sp. nov. is the second species of the genus Parvochelus Brix & Kihara, 2015 (see Brix et al. 2015) and the first record of the genus from the Pacific Ocean and from the Northern Hemisphere. P. serricaudis sp. nov. can be distinguished from P. russus Brix & Kihara, 2015 by its relatively stouter pereopod I, presence of the mandibular palp and the shape of the maxilliped palp articles and female operculum. A discussion of the taxonomic characters and the modified diagnosis of the genus Parvochelus are presented.

  8. Sediment dynamics and the changing nature of the subduction component beneath the Kurile volcanic Arc

    NASA Astrophysics Data System (ADS)

    Dreyer, B.; Morris, J.; Tera, F.; Gill, J.

    2006-12-01

    Strong slab signatures in the lavas of the of the Kurile volcanic arc and their systematic changes across this unusually wide (~120-200km above the downgoing slab) arc provide excellent leverage for investigating the changing nature of subduction components and mixing processes across volcanic arcs. Results of new and published geochemical transects of the Kurile arc indicate a waning fluid subduction component across the arc (Bailey et al., Contrib. Mineral. Petrol., 1987; Zhuralev et al., Chem. Geol., 1987; Ryan et al., Science, 1995; Noll, et al., Geochimica et Cosmochimica Acta, 1996; Ishikawa and Tera, Earth Planet. Sci. Lett., 1997; Morris and Ryan, Treatise on Geochemistry, 2003); little geochemical change is observed along the arc. Boron, Sb, As, Pb, Cs, Ba, and Be, are progressively distilled from the slab in approximately decreasing efficiency. When the effects of decreasing degree of partial melting towards the rear-arc are minimized, Cs, Ba, and Be do not return to Pacific MORB values, indicating that they are still being added to the mantle wedge beneath the rear-arc. Despite the longer transit times, and hence additional decay of cosmogenic 10Be (t1/2=1.5Ma), 10Be/9Be ratios in the rear arc are frequently greater than or comparable to those measured at the front and requires (young, <10Ma) sediment contribution across the width of the arc, which likely reflects a greater proportion of sediment Be in rear-arc lavas, possibly as a melt or supercritical fluid (Johnson and Plank, G3, 1999). To characterize the incoming sediment and clarify the sediment dynamics beneath the Kurile arc and, new trace element, radiogenic isotope, and 10Be concentration data have been measured for a 250 meter section of marine sediments from ODP Site 1179 ~550 km outboard of the trench; these data are integrated with those of the Kurile arc lavas. Initial calculations suggest a maximum 10Be inventory of ~1.5x1013 atoms/cm2 in the incoming sediment column, which translates to

  9. Systematic changes in the incoming plate structure at the Kuril trench

    NASA Astrophysics Data System (ADS)

    Fujie, Gou; Kodaira, Shuichi; Yamashita, Mikiya; Sato, Takeshi; Takahashi, Tsutomu; Takahashi, Narumi

    2013-01-01

    Recent seismic structural studies in trench-outer rise regions have shown that Vp within the incoming oceanic plate systematically decreases toward the trench, probably owing to bending and fracturing of the plate. To understand the mechanisms acting to reduce Vp, Vs is critical because the Vp/Vs ratio is a sensitive indicator of lithology, porosity, and the presence of fluid. In the outer rise region of the Kuril trench, we conducted an extensive seismic refraction and reflection survey that revealed systematic changes in Vp, Vs, and Vp/Vs. Our results suggest that water content within the incoming oceanic plate increases toward the trench accompanied by the development of bending-related fractures at the top of the oceanic crust, consistent with the seawater percolation. Our results support the idea that plate bending and fracturing during the bending in the outer rise of the trench play an important role in the water cycle of subduction zones.

  10. Ages of calderas, large explosive craters and active volcanoes in the Kuril-Kamchatka region, Russia

    NASA Astrophysics Data System (ADS)

    Braitseva, O. A.; Melekestsev, I. V.; Ponomareva, V. V.; Sulerzhitsky, L. D.

    1995-12-01

    The ages of most of calderas, large explosive craters and active volcanoes in the Kuril-Kamchatka region have been determined by extensive geological, geomorphological, tephrochronological and isotopic geochronological studies, including more than 600 14C dates. Eight ‘Krakatoa-type’ and three ‘Hawaiian-type’ calderas and no less than three large explosive craters formed here during the Holocene. Most of the Late Pleistocene Krakatoa-type calderas were established around 30 000 40 000 years ago. The active volcanoes are geologically very young, with maximum ages of about 40 000 50 000 years. The overwhelming majority of recently active volcanic cones originated at the very end of the Late Pleistocene or in the Holocene. These studies show that all Holocene stratovolcanoes in Kamchatka were emplaced in the Holocene only in the Eastern volcanic belt. Periods of synchronous, intensified Holocene volcanic activity occurred within the time intervals of 7500 7800 and 1300 1800 14C years BP.

  11. Review of the millipede genus Yasudatyla Shear & Tsurusaki, 1995 new to the fauna of Russia, with description of new species from the Kurile Islands (Diplopoda, Chordeumatida, Conotylidae).

    PubMed

    Mikhaljova, Elena V

    2015-06-03

    The diplopod genus Yasudatyla Shear & Tsurusaki, 1995 is new to the fauna of Russia, due to the discovery of Y. kurilensis sp. nov. from Kurile Islands. The genus is currently represented by four species, i.e. Y. yasudai Shear & Tsurusaki, 1995, Y. hidakaensis Shear & Tsurusaki, 1995, Y. shariensis Shear & Tsurusaki, 1995, all from Japan, and Y. kurilensis sp. nov. from the Kurile Islands, Russia, described here. All known species of the genus are keyed, including the new species.

  12. [Allozyme diversity and genetic divergence of the dolly varden Salvelinus malma Walbaum from the Kuril islands].

    PubMed

    Omel'chenko, V T; Salmenkova, E A; Shed'ko, S V

    2002-09-01

    Genetic variation was studied in the southern subspecies of the Asian Dolly Varden Salvelinus malma krascheninnikovi from the Kuril Islands. Thirty-six genetic loci controlling 19 enzyme systems were analyzed in 13 Dolly Varden populations from the Shumshu, Paramushir, Onekotan, Rasshua, Simushir, Urup, Iturup, and Kunashir islands. In the studied populations, the proportion of polymorphic loci was 35 to 85% and the mean heterozygosity was 0.104 to 0.173; populations from the Kunashir Island were characterized by maximum heterozygosity. In the island populations examined, significant inter-population heterogeneity of allele frequencies was found for all studied population pairs. For the total population of all islands, the inter-population diversity (GST = 0.188) was comparable to this parameter for the total population from the Kunashir Island (GST = 0.170). Genetic distances between populations did not correlate with the corresponding geographical distances, which indicates the lack of a pronounced gene exchange between the island populations. Cluster analysis and multidimensional scaling based on genetic distances did not reveal clear groups among the studied populations but indicated greater similarity within the Iturup-Simushir-Urup-Paramushir group and a greater genetic divergence of the Kunashir, Onekotan, Rasshua, and especially Shumshu populations. In the Shumshu population, allele frequencies indicate the admixture of genes of the northern Dolly Varden. The observed pattern of genetic differentiation was probably caused largely by genetic drift under the conditions of a limited gene flow because of homing (which is typical of the Dolly Varden) and the presence of isolated nonanadromous populations. The population-genetic analysis of the Dolly Varden from the Kuril Islands does not give grounds to distinguish any other isolated Dolly Varden species in this region than S. malma, which is represented by the southern form S. m. krascheninnikovi with an

  13. Vesicomyinae (Bivalvia: Vesicomyidae) of the Kuril-Kamchatka Trench and adjacent abyssal regions

    NASA Astrophysics Data System (ADS)

    Krylova, Elena M.; Kamenev, Gennady M.; Vladychenskaya, Irina P.; Petrov, Nikolai B.

    2015-01-01

    Representatives of the subfamily Vesicomyinae (Bivalvia, Vesicomyidae) are tiny deep-sea molluscs distributed worldwide and reaching huge abundances of hundreds and thousands of specimens in trawl catches. During the German-Russian deep-sea expedition KuramBio (R/V Sonne, 2012) for the first time two vesicomyin species were collected from the abyssal plain adjacent to the Kuril-Kamchatka Trench from the depths of 4861-5787 m, Vesicomya pacifica (Smith, 1885) and "Vesicomya" filatovae sp.n. Two species of vesicomyins, V. sergeeviFilatova, 1971 and V. profundiFilatova, 1971, which were previously reported from the hadal of the Kuril-Kamchatka Trench, were not collected at the abyssal depth despite of the close geographical proximity of the sampling area to their distribution ranges. Altogether nine species of vesicomyins are recorded now from the West and Indo-West Pacific; data on distribution and morpho-anatomical characters of these species are provided. Taxonomic description of V. pacifica is revised including information on its soft part anatomy, new localities and COI sequences. For the first time for a vesicomyin bivalve molecular data is given for a species with an explicit morphological description and unambiguous taxonomic affiliation. Molecular analysis of 160 published COI sequences of vesicomyids and newly obtained molecular data on V. pacifica showed that V. pacifica and two undescribed vesicomyin species forming a monophyletic clade which exhibits sister relationships with the Pliocardiinae, the group of chemosymbiotic vesicomyids. "Vesicomya" filatovae sp.n. is provisionally assigned to the genus Vesicomya (s.l.) until additional morphological and molecular data are obtained. It differs from Vesicomya s.s. by a broader hinge margin with more radiating teeth and the presence of only one pair of demibranchs.

  14. New insights into the abyssal sponge fauna of the Kurile-Kamchatka plain and Trench region (Northwest Pacific)

    NASA Astrophysics Data System (ADS)

    Downey, Rachel V.; Janussen, Dorte

    2015-01-01

    The under-explored abyssal depths of the Kurile-Kamchatka region have been re-examined during the KuramBio (Kurile-Kamchatka Biodiversity Study) expedition. Combining new KuramBio data with previous expedition data in this region has enhanced our understanding abyssal sponge fauna, in particular, the patchiness, rarity, and exceptional richness of the Cladorhizidae family. In total, 14 sponge species, from 7 genera, in 5 families, within two classes (Demospongiae and Hexactinellida) were collected. Of the 14 species, 29% (4 spp.) have been found previously in this region, 36% (5 spp.) were new to the regional abyssal fauna, and 21% (3 spp.) were new to science. The number of abyssal species in this region has now been increased by 26% (8 spp.) and genera by nearly 15% (2 genera). Rarity is a prominent feature of this abyssal fauna, with more than half of species only found at one station, and 83% (19 spp.) of species found previously in this region were not re-found during KuramBio. Cladorhizid sponges dominate demosponge species and genera richness in the abyssal Kurile-Kamchatka region; accounting for 87% (20 spp.) of all demosponge species, and accounting for over 60% (5 genera) of all demosponge genera. Sponge richness in this region is potentially aided by the productivity of the ocean waters, the geological age of the Pacific Ocean, low population densities, and the varied topographic features (ridges, trenches, and seamounts) found in this region. Unusually, the dominance of demosponges in the Kurile-Kamchatka sponge faunal composition is not replicated in other well-sampled abyssal regions, which tend to be richer in deep-sea hexactinellid fauna. Broad depth, latitudinal and longitudinal ranges in Kurile-Kamchatka abyssal fauna are a key characteristic of this faunal assemblage. Strong abyssal faunal connectivity is found between the Kurile-Kamchatka region and North Pacific abyssal fauna, with weaker faunal connections found with the adjacent semi

  15. Management of ST-segment elevation myocardial infarction in predominantly rural central China: A retrospective observational study.

    PubMed

    Zhang, You; Yang, Shuyan; Liu, Xinyun; Li, Muwei; Zhang, Weidong; Yang, Haiyan; Hu, Dayi; Gao, Chuanyu; Duan, Guangcai

    2016-12-01

    The degree of adherence to current guidelines for clinical management of ST-segment elevation myocardial infarction (STEMI) is known in developed countries and large Chinese cities, but in predominantly rural areas information is lacking. We assessed the application of early reperfusion therapy for STEMI in secondary and tertiary hospitals in Henan province in central China.Data were retrospectively collected from 5 secondary and 4 tertiary hospitals in Henan concerning STEMI patients treated from January 2011 to January 2012, including management strategy, delay time, and inhospital mortality.Among 1311 STEMI patients, 613 and 698 were treated at secondary and tertiary hospitals, respectively. Overall, 460 (35.1%) patients received early reperfusion therapy including thrombolysis in 383 patients and primary percutaneous coronary intervention in 77. Compared with secondary centers, early (37.2% vs 32.6%) and successful reperfusion (34.5% vs 25.1%) was significantly higher, whereas thrombolysis was lower in the tertiary hospitals (26.4% vs 32.5%). Median symptom onset-to-first medical contact, and door-to-needle and door-to-balloon time was 168, 18, and 60 minutes, respectively. Delay times closely approached recommended guidelines, especially in secondary centers. Use of recommended pharmacotherapy was low, particularly in secondary hospitals. Inhospital mortality was 5.8%, and similar between secondary and tertiary hospitals (6.0% vs 5.6%; P = 0.183).Two-thirds of STEMI patients did not receive early reperfusion, and tertiary hospitals mostly failed to take advantage of around-the-clock primary percutaneous coronary intervention. Actions such as referrals are warranted to shorten prehospital delay, and the concerns of patients and doctors regarding reperfusion risk should be addressed.

  16. Gravity anomalies over the Central Indian Ridge between 3∘S and 11∘S, Indian Ocean: Segmentation and crustal structure

    NASA Astrophysics Data System (ADS)

    Samudrala, Kiranmai; Kamesh Raju, K. A.; Rao, P. Rama

    2016-12-01

    High-resolution shipboard geophysical investigations along the Indian Ocean ridge system are sparse especially over the Carlsberg and Central Indian ridges. In the present study, the shipboard gravity and multibeam bathymetry data acquired over a 750 km long section of the Central Indian Ridge between 3 ∘S and 11 ∘S have been analysed to understand the crustal structure and the ridge segmentation pattern. The mantle Bouguer anomalies (MBA) and the residual mantle Bouguer anomalies (RMBA) computed in the study area have shown significant variations along the ridge segments that are separated by transform and non-transform discontinuities. The MBA lows observed over the linear ridge segments bounded by well-defined transform faults are attributed to the thickening of the crust at the middle portions of the ridge segments. The estimates of crustal thickness from the RMBA shows an average of 5.2 km thick crust in the axial part of the ridge segments. The MBA and relative RMBA highs along the two non-transform discontinuities suggests a thinner crust of up to 4.0 km. The most significant MBA and RMBA highs were observed over the Vema transform fault suggesting thin crust of 4 km in the deepest part of the transform fault where bathymetry is more than 6000 m. The identified megamullion structures have relative MBA highs suggesting thinner crust. Besides MBA lows along the ridge axis, significant off-axis MBA lows have been noticed, suggesting off-axis mantle upwelling zones indicative of thickening of the crust. The rift valley morphology varies from the typical V-shaped valley to the shallow valley floor with undulations on the inner valley floor. Segments with shallow rift valley floor have depicted well-defined circular MBA lows with persistent RMBA low, suggesting modulation of the valley floor morphology due to the variations in crustal thickness and the mantle temperature. These are supported by thicker crust and weaker lithospheric mantle.

  17. Segmentation and the coseismic behavior of basin and range normal faults. Examples from east-central Idaho and southwestern Montana, USA

    USGS Publications Warehouse

    Crone, Anthony J.; Haller, Kathleen M.

    1991-01-01

    The range-front normal faults of the Lost River and Lemhi Ranges, and the Beaverhead and Tendoy Mountains in east-central Idaho and southwestern Montana have well-preserved fault scarps on Quaternary deposits along much of their lengths. Fault-scarp morphology, the age of deposits displaced by the faults, and the morphology of the range fronts provide a basis for dividing the faults into segments that are typically 20-25 km long. Four characteristics are recognized that help to identify segment boundaries: (1) major en echelon offsets or pronounced gaps in the continuity of fault scarps; (2) distinct, persistent, along-strike changes in fault-scarp morphology that indicate different ages of faulting; (3) major salients in the range front; and (4) transverse bedrock ridges where the cumulative throw is low compared to other places along the fault zone. Only features whose size is measured on the scale of kilometers are regarded as significant enough to represent a segment boundary that could inhibit or halt a propagating rupture. The ability to identify segments of faults that are likely to behave as independent structural entities will improve seismic-hazard assessment. However, one should not assume that the barriers at segment boundaries will completely stop all propagating ruptures.

  18. Three new species and one new genus of abyssal Cumacea (Crustacea, Malacostraca, Peracarida) from the Kuril-Kamchatka Trench area

    NASA Astrophysics Data System (ADS)

    Lavrenteva, Anna V.; Mühlenhardt-Siegel, Ute

    2015-01-01

    Only two species of crustacean Cumacea have been reported in publications for the Kuril-Kamchatka Trench area after nine expeditions on board of the RV "Vityaz". During the KuramBio expedition 2012 to the Kuril-Kamchatka Trench and the adjacent abyssal plain at depths 4830-5780 m no less than 72 species of cumaceans from 23 genera and 6 families were sampled. Five genera were recorded for the first time in the studied region: the genera Pseudoleptostyloides and Platycuma were detected for the first time for the Pacific Ocean; Cyclaspoides, Bathylamprops and Styloptocuma were firstly sampled in North Pacific. About 90% of the sampled species appear to be new to science. Three new deep-sea cumacean species and one new genus from the Kurile Kamchatka area are described in the present paper: Abyssoleucon tzarevae gen. n., sp. n. belonging to the family Leuconidae, Cyclaspoides borisovetsi sp. n. and Bathycuma sonne sp. n. of the family Bodotriidae. A distribution map for the species of the genus Cyclaspoides is provided.

  19. Waist belt and central obesity cause partial hiatus hernia and short-segment acid reflux in asymptomatic volunteers.

    PubMed

    Lee, Yeong Yeh; Wirz, Angela A; Whiting, James G H; Robertson, Elaine V; Smith, Donald; Weir, Alexander; Kelman, Andrew W; Derakhshan, Mohammad H; McColl, Kenneth E L

    2014-07-01

    There is a high incidence of inflammation and metaplasia at the gastro-oesophageal junction (GOJ) in asymptomatic volunteers. Additionally, the majority of patients with GOJ adenocarcinomas have no history of reflux symptoms. We report the effects of waist belt and increased waist circumference (WC) on the physiology of the GOJ in asymptomatic volunteers. 12 subjects with normal and 12 with increased WC, matched for age and gender were examined fasted and following a meal and with waist belts on and off. A magnet was clipped to the squamo-columnar junction (SCJ). Combined assembly of magnet-locator probe, 12-channel pH catheter and 36-channel manometer was passed. The waist belt and increased WC were each associated with proximal displacement of SCJ within the diaphragmatic hiatus (relative to upper border of lower oesophageal sphincter (LOS), peak LOS pressure point and pressure inversion point, and PIP (all p<0.05). The magnitude of proximal migration of SCJ during transient LOS relaxations was reduced by 1.6-2.6 cm with belt on versus off (p=0.01) and in obese versus non-obese (p=0.04), consistent with its resting position being already proximally displaced. The waist belt, but not increased WC, was associated with increased LOS pressure (vs intragastric pressure) and movement of pH transition point closer to SCJ. At 5 cm above upper border LOS, the mean % time pH <4 was <4% in all studied groups. Acid exposure 0.5-1.5 cm above SCJ was increased, with versus without, belt (p=0.02) and was most marked in obese subjects with belt. Our findings indicate that in asymptomatic volunteers, waist belt and central obesity cause partial hiatus herniation and short-segment acid reflux. This provides a plausible explanation for the high incidence of inflammation and metaplasia and occurrence of neoplasia at the GOJ in subjects without a history of reflux symptoms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a

  20. New petrological and age data from the eclogite province in the central segment of the Greenlandic Caledonides

    NASA Astrophysics Data System (ADS)

    Nagel, Thorsten; Fassmer, Kathrin; Froitzheim, Niko; Fonseca, Raul; Sprung, Peter

    2017-04-01

    The Caledonian orogen in northeastern Greenland is a 1200 km long, west-vergent nappe pile mirroring the much better explored Caledonides in Scandinavia. The Greenlandic orogen has traditionally been viewed as the retro-wedge of the Scandinavian Caledonides, which is generally accepted to be the result of west-directed subduction of the Iapetus oceanic realm and the Baltic continental margin. This concept, however, is challenged by the finding of widely distributed high-pressure metamorphism as well as the large amount of horizontal shortening accommodated in the Greenlandic nappe pile (Gasser 2014, and references therein). While eclogites in Liverpool Land in the very south have been interpreted to belong to a window into Baltica, the vast domains of eclogite-bearing basement in the central segment of the orogen are attributed to the Lauretian continental margin. Existing ages for high-pressure metamorphism in this area using U-Pb-zircon and Sm-Nd-garnet dating scatter at 420-390 Ma with an exceptionally young age of 370-330 Ma found for the so far only ultrahigh-pressure location in a very internal position of the orogen (e.g. Gilotti et al. 2004). Eclogite-facies metamorphism in Greenland seems thus coeval to or even younger than the main Scandian orogeny in Scandinavia. However, the relatively high temperatures of metamorphism leave room for the interpretation of the Sm-Nd ages as cooling ages. We present petrologic and Lu-Hf-garnet-age data from three locations in the central eclogite province in Greenland and discuss the implications for tectonic scenarios. Investigated rocks are high-temperature eclogites/high-pressure mafic granulites, and garnet pyroxenites. Samples from the well-known location Danmarkshavn record ultra-high-pressure metamorphic conditions by means of SiO2-exsolutions in clinopyroxene and thermobarometric results. An eclogite yielded a Lu-Hf garnet-whole-rock age of 360 Ma thus confirming the existing young age for ultrahigh

  1. A Novel Two-Step Technique for Retrieving Fractured Peripherally Inserted Central Catheter Segments Migrating into the Heart or the Pulmonary Artery

    PubMed Central

    Peng, Juan; Zhang, Xiao-Ming; Xu, Hao; Miao, Nan-Dong; Ren, Yong-Jun; Liu, Kang; Min, Xu-Li; Yang, Ke; Yang, Shi; Yang, Cheng

    2016-01-01

    Objective. To report the experience of a percutaneous technique for retrieving fractured peripherally inserted central catheter (PICC) segments migrating into the heart or the pulmonary artery. Method. From April 2013 to July 2015, we performed percutaneous retrieval of fractured PICC segments migrating into the heart or the pulmonary artery in five cancer patients who had undergone chemotherapy via PICC. The fractures were diagnosed with chest plain radiography. The patients included three cases of breast cancer, one case of rectal cancer, and one case of lower limb Ewing's tumor. The fractures were retained in the vessels of the patients for 1 to 3 days. All the fractures were retrieved by using a novel two-step technique in the digital subtraction angiography (DSA) suite. This two-step technique involves inserting a pigtail catheter to the heart or the pulmonary artery to grasp the fractured catheter fragment and bring it to the lower segment of the inferior vena cava, followed by grasping and removing the catheter fragment with a retrieval loop system of the vena cava filter retrieval set. Result. The fractured PICC segments were removed successfully in all five patients via unilateral (four patients) or bilateral (one patient) femoral vein access. No complications occurred during the interventional procedure. Conclusion. Percutaneous retrieval can be a safe, convenient, and minimally invasive method for the removal of fractured PICC segments. The technique reported in this paper will be applicable for the retrieval of fractured PICC segments and other catheter fragments migrating into the heart or the pulmonary artery. PMID:27642604

  2. Three-dimensional continuous max flow optimization-based serous retinal detachment segmentation in SD-OCT for central serous chorioretinopathy.

    PubMed

    Wu, Menglin; Fan, Wen; Chen, Qiang; Du, Zhenlong; Li, Xiaoli; Yuan, Songtao; Park, Hyunjin

    2017-09-01

    Assessment of serous retinal detachment plays an important role in the diagnosis of central serous chorioretinopathy (CSC). In this paper, we propose an automatic, three-dimensional segmentation method to detect both neurosensory retinal detachment (NRD) and pigment epithelial detachment (PED) in spectral domain optical coherence tomography (SD-OCT) images. The proposed method involves constructing a probability map from training samples using random forest classification. The probability map is constructed from a linear combination of structural texture, intensity, and layer thickness information. Then, a continuous max flow optimization algorithm is applied to the probability map to segment the retinal detachment-associated fluid regions. Experimental results from 37 retinal SD-OCT volumes from cases of CSC demonstrate the proposed method can achieve a true positive volume fraction (TPVF), false positive volume fraction (FPVF), positive predicative value (PPV), and dice similarity coefficient (DSC) of 92.1%, 0.53%, 94.7%, and 93.3%, respectively, for NRD segmentation and 92.5%, 0.14%, 80.9%, and 84.6%, respectively, for PED segmentation. The proposed method can be an automatic tool to evaluate serous retinal detachment and has the potential to improve the clinical evaluation of CSC.

  3. Foraminifera of the Kuril-Kamchatka Trench area: The prospects of molecular study

    NASA Astrophysics Data System (ADS)

    Lejzerowicz, Franck; Voltski, Ivan; Pawlowski, Jan

    2015-01-01

    Foraminifera remain poorly studied from deep-sea sediment settings, although they often dominate meiofaunal communities and represent an important part of the functional deep-sea diversity. Moreover, there is a striking gap in our knowledge of deep-sea Foraminifera since most of the foraminiferal diversity corresponds to single-chambered monothalamids displaying inconspicuous morphologies. The previous expeditions suggest that the foraminiferal biomass is large in the Kuril-Kamchatka Trench area, including many macrofaunal-size xenophyophoreans and komokiaceans. However, the on-site foraminiferal diversity remains poorly described and was never genetically examined. During the KuramBio expedition, we collected over 1400 specimens representing all major foraminiferal groups, focusing on monothalamids and particularly komokiaceans. From the deep-sea sediments, using four different sampling gears, we sorted, identified and photographed single specimens for DNA (or RNA) extraction. The material we report here will be used in our ongoing research on estimation and visualisation of the diversity of deep-sea monothalamous foraminifera and enigmatic taxa such as the komokiaceans, the origin of which is yet to be determined.

  4. A new species of Abyssobrotula (Ophidiiformes, Ophidiidae) from the Kuril-Kamchatka Trench.

    PubMed

    Ohashi, Shinpei; Nielsen, Jørgen G

    2016-07-01

    A new abyssal ophidiid fish, Abyssobrotula hadropercularis, is described on the basis of two specimens caught at two stations at ca. 5000 meters of depth in the Kuril-Kamchatka Trench. The genus Abyssobrotula Nielsen, 1977 was previously known from the type species, A. galatheae Nielsen, 1977 of which 40-50 specimens now are reported from all oceans at depths greater than 2000 m. One of the specimens from the Puerto Rico Trench captured at 8370 m is still the deepest record for fishes. The new species differs from A. galatheae in having great number of pectoral-fin rays 14-15 (vs 10-11); greater eye diameter (1.2-1.3% SL vs 0.7-0.9% SL); larger prepelvic 14.0-14.5% SL (vs 10.5-12.5% SL) and preanal lengths 42.5% SL (vs 33.0-41.5% SL); opercular spine strongly developed (vs poorly developed); gill rakers on anterior arch robust and close-set (vs rakers thin and well separated). The description of A. hadropercularis makes it necessary to slightly modify the generic diagnosis.

  5. Composition of the abyssal infauna of the Kuril-Kamchatka area (NW Pacific) collected with a box corer

    NASA Astrophysics Data System (ADS)

    Fischer, Viola; Brandt, Angelika

    2015-01-01

    During the German-Russian KuramBio (Kuril-Kamchatka Biodiversity Studies) expedition with the RV Sonne from July to September 2012, a 0.25 m2 box corer was used to sample the benthic fauna of the Kuril-Kamchatka area. 23 cores were deployed at 12 stations, and in total 36,648 individuals could be identified from a combined surface area of 5.75 m2. Total faunal densities ranged from 1024 to 16,592 ind. m-2, respectively, for the macrofauna from 436 to 3520 ind. m-2. The fauna was dominated by Nematoda (65%), even though this group and other meiofaunal taxa were only partially retained by the 300 μm screen that was used as the smallest screen for this study. The remaining part of the fauna was dominated by polychaetes (23%), followed by peracarid crustaceans (6%) and molluscs (3%). Most of the collected taxa occurred very patchily. Over 80% of the animals were extracted from the upper 2 centimeters of the sediment. Compared to other regions of the Pacific the density of the benthic fauna was unusually high. At the upper slope of the continental margin of the trench and at the southern part of the area the benthic fauna was most taxon rich. Station 3 from the continental slope of the trench was also most rich in terms of faunal density (total numbers of ind. m-2), followed by the station 11 and 12 from that the southernmost part of the abyss. Although the Kuril-Kamchatka area has been sampled on several expeditions during the last century, and some studies on the biomass of the benthic fauna have been published, this study offers the first quantitative community analysis of the benthic fauna in terms of abundance and taxon richness.

  6. Detailed Segmentation and Episodic Propagation of the 2014 Bárðarbunga Dike Intrusion and Seismicity Accompanying the Sustained Holuhraun Eruption, Central Icleand

    NASA Astrophysics Data System (ADS)

    Ágústsdóttir, T.; Woods, J.; Greenfield, T. S.; Green, R. G.; White, R. S.; Brandsdottir, B.

    2015-12-01

    An intense swarm of seismicity on 16 August 2014 marked the intrusion of a large dike from the subglacial Bárðarbunga volcano, central Iceland. Melt propagated laterally from the central volcano at the brittle-ductile boundary at ~6 km b.s.l. and created over 30,000 earthquakes along a 46 km path heading NE from Bárðarbunga. On 31 August a fissure eruption began at Holuhraun and the seismicity rate within the dike dropped instantaneously to a much lower level suggesting that once a pathway to the surface had formed, magma was able to flow freely and largely aseismically. Melt was fed from the subsiding Bárðarbunga volcano to Holuhraun for 6 months, until the eruption ceased on 27 February 2015. We discuss the relationship between bursts of seismicity in the feeder volcano and periods of rapid dike propagation. We use a dense seismic network and relative earthquake relocations to map in detail the segmentation of the dike on all scales. New dike segments were initiated with a rapid advance of the dike tip at typically 1 km/h, separated by pauses of up to 78 h. During the stalled periods the magma pressure built until it was sufficient to fracture a new segment, which then propagated rapidly forward. Large segments became seismically quiet once a new segment had intruded beyond it as extensional stresses had been relieved and melt was able to flow freely. Each rapid propagation phase was accompanied by a drop in the seismicity rate directly behind the dike tip, most likely due to a stress shadow being formed behind the dike tip. Moment tensor solutions show that the dominant failure mechanism is left-lateral strike slip faulting at the leading edge, orientated parallel to the dike, with a combination of right-lateral, left-lateral and normal faulting behind the dike tip, contradicting many widely used models. Much of the seismicity behind the tip may represent fracture of frozen melt as the dike inflated and propagated forward

  7. Seismic noise investigation in Kuril-Kamchatka-Japan region: tidal modulation and connection with regional seismicity

    NASA Astrophysics Data System (ADS)

    Saltykov, Vadim

    2010-05-01

    Tidal modulation of seismic noise proves that it's structure includes the endogenous component (seismic emission). This fact presumes the seismic noise self-descriptiveness and allows us to consider it as the self-dependent informational geophysical field. The high-frequency seismic noise (HFSN) is the seismic radiation in the range of the first tens of Hz with amplitude of 10^-9-10^-12 m. The HFSN is a complicated superposition of endogenous and exogenous microseismic signals. The factors affecting the intensity of the HFSN are human activity, wind, warming of the earth's surface, earth tides, and tectonic processes. At present, the observation of the highly sensitive geophysical field is complicated by industrial noise of large territories, which made it impossible to separate the natural signals from the obtained records in many cases. In Kuril-Kamchatka-Japan region the investigation of the HFSN are carrying out more then 20 years. During this time, four points of long-term observation were established in the areas with low level of anthropogenic cativity: «Nachiki» (1987, Southern Kamchatka), «Karymshina» (1999, Southern Kamchatka), «Erimo» (1993, Hokkaido) and «Shikotan» (2003, Lesser Kuriles). A resonance narrow-band vertical seismometer with a sensitive piezoceramic element was used as a sensor of the HFSN signals. Similar detectors are used at all four points of HFSN recording (the sensitivity with consideration for the preliminary amplification is not worse than 5×109 V/m, the frequency of the characteristic oscillation is f = 30 Hz, Q-factor=100). The most interesting object for investigation is the response of the HFSN to long-period deformation processes, in particular, to the Earth tides. The recorded data were processed using different time-windows. High-resolution coherent signal stacking clearly singled out the noise intensity variations with periodicity of tidal waves: O1 (main lunar, period T=25.82 h), K1 (lunar-solar declination, T=23

  8. The Japan Trench and its juncture with the Kuril Trench: cruise results of the Kaiko project, Leg 3

    USGS Publications Warehouse

    Cadet, J.-P.; Kobayashi, K.; Aubouin, J.; Boulegue, J.; Deplus, C.; Dubois, J.; von, Huene R.; Jolivet, L.; Kanazawa, T.; Kasahara, J.; Koizumi, K.; Lallemand, S.; Nakamura, Y.; Pautot, G.; Suyehiro, K.; Tani, S.; Tokuyama, H.; Yamazaki, T.

    1987-01-01

    This paper presents the results of a detailed survey combining Seabeam mapping, gravity and geomagnetic measurements as well as single-channel seismic reflection observations in the Japan Trench and the juncture with the Kuril Trench during the French-Japanese Kaiko project (northern sector of the Leg 3) on the R/V "Jean Charcot". The main data acquired during the cruise, such as the Seabeam maps, magnetic anomalies pattern, and preliminary interpretations are discussed. These new data cover an area of 18,000 km2 and provide for the first time a detailed three-dimensional image of the Japan Trench. Combined with the previous results, the data indicate new structural interpretations. A comparative study of Seabeam morphology, single-channel and reprocessed multichannel records lead to the conclusion that along the northern Japan Trench there is little evidence of accretion but, instead, a tectonic erosion of the overriding plate. The tectonic pattern on the oceanic side of the trench is controlled by the creation of new normal faults parallel to the Japan Trench axis, which is a direct consequence of the downward flexure of the Pacific plate. In addition to these new faults, ancient normal faults trending parallel to the N65?? oceanic magnetic anomalies and oblique to the Japan trench axis are reactivated, so that two directions of normal faulting are observed seaward of the Japan Trench. Only one direction of faulting is observed seaward of the Kuril Trench because of the parallelism between the trench axis and the magnetic anomalies. The convergent front of the Kuril Trench is offset left-laterally by 20 km relative to those of the Japan Trench. This transform fault and the lower slope of the southernmost Kuril Trench are represented by very steep scarps more than 2 km high. Slightly south of the juncture, the Erimo Seamount riding on the Pacific plate, is now entering the subduction zone. It has been preceded by at least another seamount as revealed by magnetic

  9. Bembidion (?Nipponobembidion) ruruy sp. n., a new brachypterous ground beetle (Coleoptera, Carabidae) from Kunashir Island, Kuriles, Russia

    PubMed Central

    Makarov, Kirill V.; Sundukov, Yuri N.

    2014-01-01

    Abstract A new species, Bembidion (?Nipponobembidion) ruruy sp. n., is described from the foot of Ruruy Volcano, Kunashir Island, Kuril Archipelago, Russia. It is only the second consubgener, being characterized by the reduced wings, the rounded elytral shoulders, and the backward position of the posterior supra-orbital pore. In this connection, the subgenus Nipponobembidion Habu & Baba, 1968 is rediagnosed and both of its species are keyed. It might have originated from Plataphodes Ganglbauer, 1891, possibly in relation to volcanic activities in the region. PMID:25589863

  10. Hydrothermal fluxes of magmatic chlorine and sulfur from volcano-hydrothermal systems of the Kuril Islands (Russia).

    NASA Astrophysics Data System (ADS)

    Kalacheva, Elena; Taran, Yuri

    2017-04-01

    The hydrothermal flux may be provided by the discharge of fluids formed at depth over the magma body and/or by acid waters, which are formed by the absorption of the ascending volcanic vapor by shallow groundwater. Thus, the anion composition (Cl and SO4) of the discharging thermal waters from a volcano-hydrothermal system in many cases originates from the volcanic vapor and should be taken into account in estimations of the magmatic volatile output and volatile recycling in subduction zones. Here we report the chemical composition of thermal waters and the measured solute fluxes from volcano-hydrothermal systems of Kuril Islands including Paramushir (Ebeko volcanic centre), Shiashkotan (volcanoes Sinarka and Kuntomintar), Ketoy (Pallas volcano), Kunashir (volcanoes Mendeleev and Golovnin). The fluxes were estimated after measuring flow rates and water composition of streams that drain thermal fields of islands. The maximal hydrothermal flux of Cl and S within the Kuril Chain was measured for Ebeko volcano, Paramushir (drained by Yurieva River) as 82 t/d and 222 t/d of chloride and sulfate, respectively. This is comparable with output by fumaroles of Ebeko. The total discharge of Cl and SO4 from Shiashkotan Island to the Sea of Okhotsk and Pacific Ocean associated with magmatic activity of two volcanoes is estimated as 20 t/d and 102 t/d, respectively, which is significantly lower than the fumarolic output. The hydrothermal flux of Ketoy Island is also low, 8.5 t/d of Cl and 30 t/d of SO4, much lower than the fumarolic flux. There are two volcano-hydrothermal systems at the Kunashir, the southern island of Kurils. The Ozernaya River drains all thermal fields inside of the Golovnin caldera into the Sea of Okhotsk. The Lesnaya River drains two main thermal fields and thermal springs on the Mendeleev volcano slopes into Pacific Ocean. The volcano-hydrothermal output of chloride and sulfate from Mendeleev volcano was measured as 7.8 t/d of Cl and 11.6 of SO4, and from

  11. The Japan Trench and its juncture with the Kuril Trench: cruise results of the Kaiko project, Leg 3

    NASA Astrophysics Data System (ADS)

    Cadet, Jean-Paul; Kobayashi, Kazuo; Aubouin, Jean; Boulègue, Jacques; Deplus, Christine; Dubois, Jacques; von Huene, Roland; Jolivet, Laurent; Kanazawa, Toshihiko; Kasahara, Junzo; Koizumi, Kinichiro; Lallemand, Serge; Nakamura, Yasuo; Pautot, Guy; Suyehiro, Kiyoshi; Tani, Shin; Tokuyama, Hidekazu; Yamazaki, Toshitsugu

    1987-05-01

    This paper presents the results of a detailed survey combining Seabeam mapping, gravity and geomagnetic measurements as well as single-channel seismic reflection observations in the Japan Trench and the juncture with the Kuril Trench during the French-Japanese Kaiko project (northern sector of the Leg 3) on the R/V "Jean Charcot". The main data acquired during the cruise, such as the Seabeam maps, magnetic anomalies pattern, and preliminary interpretations are discussed. These new data cover an area of 18,000 km 2 and provide for the first time a detailed three-dimensional image of the Japan Trench. Combined with the previous results, the data indicate new structural interpretations. A comparative study of Seabeam morphology, single-channel and reprocessed multichannel records lead to the conclusion that along the northern Japan Trench there is little evidence of accretion but, instead, a tectonic erosion of the overriding plate. The tectonic pattern on the oceanic side of the trench is controlled by the creation of new normal faults parallel to the Japan Trench axis, which is a direct consequence of the downward flexure of the Pacific plate. In addition to these new faults, ancient normal faults trending parallel to the N65° oceanic magnetic anomalies and oblique to the Japan trench axis are reactivated, so that two directions of normal faulting are observed seaward of the Japan Trench. Only one direction of faulting is observed seaward of the Kuril Trench because of the parallelism between the trench axis and the magnetic anomalies. The convergent front of the Kuril Trench is offset left-laterally by 20 km relative to those of the Japan Trench. This transform fault and the lower slope of the southernmost Kuril Trench are represented by very steep scarps more than 2 km high. Slightly south of the juncture, the Erimo Seamount riding on the Pacific plate, is now entering the subduction zone. It has been preceded by at least another seamount as revealed by magnetic

  12. Geochemistry and solute fluxes from volcano-hydrothermal system of Ketoy, Kuril Island arc

    NASA Astrophysics Data System (ADS)

    Kalacheva, Elena; Taran, Yuri; Voloshina, Ekaterina; Tarasov, Kirill; Kotenko, Tatiana

    2017-04-01

    Ketoy is a volcanic island in the middle of the Kuril Island arc. With an area of ˜70 km2 it consists of two volcanic structures of different ages. The younger Pallas cone (960 m asl) is characterized by a strong fumarolic activity with maximum temperature of 720˚ C (August 2016) and hosts a cold acid crater lake in the summit crater. The older Ketoy cone (1172 m) at the NE of the island is cut by the erosion crater that open to the east and known as a canyon of Gorchichny Stream. There is a strong hydrothermal activity within the canyon with boiling springs and steam vents. We present our data obtained during the fieldwork in August 2016 on the chemical (major and trace elements including REE) and isotopic (H, O, C, S) composition of thermal fluids from both Gorchichny canyon and thermal fields on the slopes of the Pallas cone. Thermal field of the Gorchichny Stream discharges acid Ca-SO4 and near neutral unusual, Cl-poor, Na-Ca-SO4 hot-to-boiling waters with TDS 2-3 g/L. Thermal field of the summit plateau at the base of the Pallas cone discharges acid Ca-SO4 warm water that can be the seepage from the crater lake. Isotopic compositions of thermal waters are close to the meteoric water line but with a clear positive shift in both δ18O and δD with a trend directed to the isotopic composition of condensates of fumarolic gases of the Pallas cone. For the first time the outflow rates of the draining streams have been measured and hydrothermal solute fluxes from the volcano-hydrothermal system have been estimated. The total hydrothermal flux of chloride and sulfate from Ketoy Island is estimated as 8.5 t/d of Cl and 30 t/d of SO4. This work was supported by the RSF grant #15-17-20011.

  13. Eastern segment of the Azores-Gibraltar line (central-eastern Atlantic) : An oceanic plate boundary with diffuse compressional deformation

    NASA Astrophysics Data System (ADS)

    Sartori, R.; Torelli, L.; Zitellini, N.; Peis, D.; Lodolo, E.

    1994-06-01

    New seismic-reflection images across the eastern segment of the Azores-Gibraltar line west of the collisional area between the African and Iberian plates have revealed a complex pattern of compressional deformation involving the Mesozoic oceanic lithosphere. The compressional deformation developed in a region of slow plate convergence and is diffused, at different lithospheric levels, across an area spanning ˜200 km from the Gorringe Ridge to the Seine Plain. The convergence between the African and Iberian plates has been active since Tertiary time, and our results indicate that no subduction zone exists across this part of the plate boundary.

  14. N-terminal and central segments of the type 1 ryanodine receptor mediate its interaction with FK506-binding proteins.

    PubMed

    Girgenrath, Tanya; Mahalingam, Mohana; Svensson, Bengt; Nitu, Florentin R; Cornea, Razvan L; Fessenden, James D

    2013-05-31

    We used site-directed labeling of the type 1 ryanodine receptor (RyR1) and fluorescence resonance energy transfer (FRET) measurements to map RyR1 sequence elements forming the binding site of the 12-kDa binding protein for the immunosuppressant drug, FK506. This protein, FKBP12, promotes the RyR1 closed state, thereby inhibiting Ca(2+) leakage in resting muscle. Although FKBP12 function is well established, its binding determinants within the RyR1 protein sequence remain unresolved. To identify these sequence determinants using FRET, we created five single-Cys FKBP variants labeled with Alexa Fluor 488 (denoted D-FKBP) and then targeted these D-FKBPs to full-length RyR1 constructs containing decahistidine (His10) "tags" placed within N-terminal (amino acid residues 76-619) or central (residues 2157-2777) regions of RyR1. The FRET acceptor Cy3NTA bound specifically and saturably to these His tags, allowing distance analysis of FRET measured from each D-FKBP variant to Cy3NTA bound to each His tag. Results indicate that D-FKBP binds proximal to both N-terminal and central domains of RyR1, thus suggesting that the FKBP binding site is composed of determinants from both regions. These findings further imply that the RyR1 N-terminal and central domains are proximal to one another, a core premise of the domain-switch hypothesis of RyR function. We observed FRET from GFP fused at position 620 within the N-terminal domain to central domain His-tagged sites, thus further supporting this hypothesis. Taken together, these results support the conclusion that N-terminal and central domain elements are closely apposed near the FKBP binding site within the RyR1 three-dimensional structure.

  15. N-terminal and Central Segments of the Type 1 Ryanodine Receptor Mediate Its Interaction with FK506-binding Proteins*

    PubMed Central

    Girgenrath, Tanya; Mahalingam, Mohana; Svensson, Bengt; Nitu, Florentin R.; Cornea, Razvan L.; Fessenden, James D.

    2013-01-01

    We used site-directed labeling of the type 1 ryanodine receptor (RyR1) and fluorescence resonance energy transfer (FRET) measurements to map RyR1 sequence elements forming the binding site of the 12-kDa binding protein for the immunosuppressant drug, FK506. This protein, FKBP12, promotes the RyR1 closed state, thereby inhibiting Ca2+ leakage in resting muscle. Although FKBP12 function is well established, its binding determinants within the RyR1 protein sequence remain unresolved. To identify these sequence determinants using FRET, we created five single-Cys FKBP variants labeled with Alexa Fluor 488 (denoted D-FKBP) and then targeted these D-FKBPs to full-length RyR1 constructs containing decahistidine (His10) “tags” placed within N-terminal (amino acid residues 76–619) or central (residues 2157–2777) regions of RyR1. The FRET acceptor Cy3NTA bound specifically and saturably to these His tags, allowing distance analysis of FRET measured from each D-FKBP variant to Cy3NTA bound to each His tag. Results indicate that D-FKBP binds proximal to both N-terminal and central domains of RyR1, thus suggesting that the FKBP binding site is composed of determinants from both regions. These findings further imply that the RyR1 N-terminal and central domains are proximal to one another, a core premise of the domain-switch hypothesis of RyR function. We observed FRET from GFP fused at position 620 within the N-terminal domain to central domain His-tagged sites, thus further supporting this hypothesis. Taken together, these results support the conclusion that N-terminal and central domain elements are closely apposed near the FKBP binding site within the RyR1 three-dimensional structure. PMID:23585572

  16. 2005 Volcanic Activity in Alaska, Kamchatka, and the Kurile Islands: Summary of Events and Response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, R.G.; Neal, C.A.; Dixon, J.P.; Ushakov, Sergey

    2008-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptive activity or suspected volcanic activity at or near 16 volcanoes in Alaska during 2005, including the high profile precursory activity associated with the 2005?06 eruption of Augustine Volcano. AVO continues to participate in distributing information about eruptive activity on the Kamchatka Peninsula, Russia, and in the Kurile Islands of the Russian Far East, in conjunction with the Kamchatkan Volcanic Eruption Response Team (KVERT) and the Sakhalin Volcanic Eruption Response Team (SVERT), respectively. In 2005, AVO helped broadcast alerts about activity at 8 Russian volcanoes. The most serious hazard posed from volcanic eruptions in Alaska, Kamchatka, or the Kurile Islands is the placement of ash into the atmosphere at altitudes traversed by jet aircraft along the North Pacific and Russian Trans East air routes. AVO, KVERT, and SVERT work collaboratively with the National Weather Service, Federal Aviation Administration, and the Volcanic Ash Advisory Centers to provide timely warnings of volcanic eruptions and the production and movement of ash clouds.

  17. Expanding extension, subsidence and lateral segmentation within the Santorini - Amorgos basins (central - south Aegean Sea, Greece) during Quaternary.

    NASA Astrophysics Data System (ADS)

    Nomikou, Paraskevi; Hübscher, Christian; Papanikolaou, Dimitris; Farangitakis, Georgios-Pavlos; Ruhnau, Marcel; Lampridou, Danai

    2017-04-01

    New bathymetric and seismic reflection data from the Santorini-Amorgos Tectonic Zone in the southern Cyclades have been analysed and a description of the morphology and tectonic structure of the area has been presented. The basins of Anhydros, Amorgos and Santorini-Anafi have been distinguished together with the intermediate Anhydros Horst within the NE-SW oriented Santorini-Amorgos Tectonic Zone which has a length of 60-70km and a width of 20-25km. The basins represent tectonic grabens or semigrabens bordered by the active marginal normal faults of Santorini-Anafi, Amorgos, Ios, Anhydros and Astypalaea. The Santorini-Anafi, Amorgos and Ios marginal faults have their footwall towards the NW where Alpine basement occurs in the submarine scarps and their hangingwall towards the southeast, where the Quaternary sediments have been deposited with maximum thickness of 700m. Six sedimentary units 1-6 have been distinguished in the stratigraphic successions of the Santorini-Anafi and the westerrn Anhydros Basin whereas in the rest area only the upper four units 3-6 have been deposited. This shows the expansion of the basin with subsidence during the Quaternary due to ongoing extension in a northwest-southeast direction. Growth structures are characterised by different periods of maximum deformation as this is indicated by the different sedimentary units with maximum thickness next to each fault. Transverse structures of northwest-southeast direction have been identified along the Santorini-Amorgos Tectonic Zone with distinction of the blocks/segments of Santorini, Anhydros/Kolumbo, Anhydros islet and Amorgos. Our study shows that the active geodynamic regime is an ongoing process evolved during the last 2-3myears with well-defined periods of expanding, extension and subsidence of a rift zone which however has been segmented by transverse structures separating different geodynamic processes of faulting, tilting, volcanism and morphogenesis.

  18. 3D Variations in Sediment Architecture in the Central Basin of Lake Malawi from the SEGMeNT Active-Source Experiment

    NASA Astrophysics Data System (ADS)

    Eatmon, A.; Accardo, N. J.; Shillington, D. J.; Onyango, E. A.; Scholz, C. A.; McCartney, T.; Ebinger, C. J.; Gaherty, J. B.; Nyblade, A.; Chindandali, P. R. N.; Kamihanda, G.; Ferdinand, R.; Salima, J.; Mruma, A. H.

    2016-12-01

    A fundamental question in geophysics is how continental rifts evolve from initiation to breakup. Our study aims to elucidate the controls on early-stage rifting utilizing recently collected active-source wide-angle refraction data from the weakly extended Malawi Rift, which is composed of a series of border-fault bound basins whose polarity reverses along strike. Our study focuses on the Central Basin of Lake Malawi. The Central Basin is bounded to the west by the 1,000 m high Central Basin border fault and contains a series of enigmatic structures within the basin. To constrain the thickness of synrift and pre-rift sediments and upper crustal structure associated with intrabasinal structure, we have undertaken 3D velocity modeling of the Central Basin using new active-source data acquired in Lake Malawi (Nyasa) as a part of the SEGMeNT project. We picked first arrivals on shots recorded on 12 "lake" bottom seismometers resulting in over 38,000 unique picks with maximum offsets of 90 km. We then inverted these picks using the First Arrival Seismic Tomography (FAST) package for the 3D structure. The resulting model spans 80 km north to south, 50 km east to west, and 10 km in depth. We also apply strict quality control measures to ensure only robust picks are utilized in the inversion. Starting models are built from smoothed inversion of picks at close offsets to ensure that shallow structure is not mapped to depth. Our results indicate a marked transition in the character of sedimentary basins within the Central Basin. Sediments thicken to the west at the southern end of the Central Basin reaching a maximum thickness of 4.5 km and in contrast, sediments thicken to the east at the northern end near Manda, Tanzania and reach a maximum thickness of 4.0 km. This may indicate that the west dipping border fault that bounds the eastern side of the basin to the north influences the Central Basin at its northern end. We image a linear, high-velocity feature that extends from

  19. Satellite observations of the ice cover of the Kuril Basin region of the Okhotsk Sea and its relation to the regional oceanography

    NASA Technical Reports Server (NTRS)

    Wakatsuchi, Masaaki; Martin, Seelye

    1990-01-01

    For the period 1978-1982, this paper examines the nature of the sea ice which forms over the Kuril Basin of the Okhotsk Sea and describes the impact of this ice on the regional oceanography. The oceanographic behavior during the heavy ice season associated with the cold 1979 winter is compared with the behavior during the lighter ice years of 1980 and 1982. Examination of the oceanography in the Okhotsk and the adjacent Pacific shows that the early summer water column structure depends on the heat loss from the Okhotsk during the preceding ice season, the total amount of Okhotsk ice formation, and, specifically, the amount of the ice formation in the Kuril Basin. Following the 1979 ice season, the upper 200-300 m of the Kuril Basin waters were cooler, less saline, and richer in oxygen than for the other years. This modification appears to be a process local to the Kuril Basin, driven by eddy-induced mixing, local cooling, and ice melting.

  20. Satellite observations of the ice cover of the Kuril Basin region of the Okhotsk Sea and its relation to the regional oceanography

    NASA Technical Reports Server (NTRS)

    Wakatsuchi, Masaaki; Martin, Seelye

    1990-01-01

    For the period 1978-1982, this paper examines the nature of the sea ice which forms over the Kuril Basin of the Okhotsk Sea and describes the impact of this ice on the regional oceanography. The oceanographic behavior during the heavy ice season associated with the cold 1979 winter is compared with the behavior during the lighter ice years of 1980 and 1982. Examination of the oceanography in the Okhotsk and the adjacent Pacific shows that the early summer water column structure depends on the heat loss from the Okhotsk during the preceding ice season, the total amount of Okhotsk ice formation, and, specifically, the amount of the ice formation in the Kuril Basin. Following the 1979 ice season, the upper 200-300 m of the Kuril Basin waters were cooler, less saline, and richer in oxygen than for the other years. This modification appears to be a process local to the Kuril Basin, driven by eddy-induced mixing, local cooling, and ice melting.

  1. Eclogites in the central part of the Sveconorwegian Parautochthonous Eastern Segment of the Baltic Shield: support for a subduction-extrusion model.

    NASA Astrophysics Data System (ADS)

    Austin Hegardt, E.; Claesson, L.; Cornell, D. H.; Simakov, S. K.

    2003-04-01

    Mafic boudins found at Viared in the central Eastern Segment display mineralogical and textural features which show that these rocks have been eclogites. This discovery together with occurrences of relict eclogites along the Mylonite Zone suggests that the whole of the Eastern Segment was subjected to eclogite facies. The mafic boudins found are hornblende-plagioclase amphibolite, but the interiors show evidence of retrogression from eclogite: a grid-like pattern of clinopyroxene grains containing exolved plagioclase grains from former omphacite, and garnets frequently surrounded by plagioclase coronas. Geothermobarometry was carried out on two samples and the peak pressure conditions were estimated by re-integrating the original clinopyroxene composition giving 18.7-19.6 kbar and temperatures of 680 to 715 deg C. Calculations using the retrogressed assemblage of clinopyroxene-garnet-plagioclase-quartz gave values of 10.5-12.5 kbar and temperature of 700-750 deg C. Ion-probe dating of inter boudin granite gave a minimum age for eclogite formation at 936 +/- 39 Ma from zircon and 961 +/- 26 Ma from titanite. Pre-Sveconorwegian regional veining is reflected by well developed CL-dark rims, dated at 1426 +/- 18 Ma. The host orthogneiss give a protolith age of 1701 +/- 10 Ma from zircon cores. The recognized textural and mineralogical features, together with the calculated P-T conditions show that the mafic boudins at Viared were subjected to eclogite facies conditions during subduction. A tectonic model which envisages that the Mylonite Zone formed as a Sveconorwegian crustal suture is suggested. In this model the western margin of the Fennoscandian Shield, comprising Trans-Scandinavian Igneous Belt rocks, was subducted and exposed to high-pressure conditions and subsequently exhumed by buoyancy-driven processes to form the Eastern Segment.

  2. Geochemistry and solute fluxes of volcano-hydrothermal systems of Shiashkotan, Kuril Islands

    NASA Astrophysics Data System (ADS)

    Kalacheva, Elena; Taran, Yuri; Kotenko, Tatiana

    2015-04-01

    Shiashkotan Island belongs to the Northern Kuril island arc and consists of two joined volcanoes, Sinarka and Kuntomintar, with about 18 km of distance between the summits. Both volcanoes are active, with historic eruptions, and both emit fumarolic gases. Sinarka volcano is degassing through the extrusive dome with inaccessible strong and hot (> 400 °C) fumaroles. A large fumarolic field of the Kuntomintar volcano situated in a wide eroded caldera-like crater hosts many fumarolic vents with temperatures from boiling point to 480 °C. Both volcanoes are characterized by intense hydrothermal activity discharging acid SO4-Cl waters, which are drained to the Sea of Okhotsk by streams. At least 4 groups of near-neutral Na-Mg-Ca-Cl-SO4 springs with temperatures in the range of 50-80 °C are located at the sea level, within tide zones and discharge slightly altered diluted seawater. Volcanic gas of Kuntomintar as well as all types of hydrothermal manifestations of both volcanoes were collected and analyzed for major and trace elements and water isotopes. Volcanic gases are typical for arc volcanoes with 3He/4He corrected for air contamination up to 6.4 Ra (Ra = 1.4 × 10- 6, the air ratio) and δ13C (CO2) within - 10‰ to - 8 ‰ VPDB. Using a saturation indices approach it is shown that acid volcanic waters are formed at a shallow level, whereas waters of the coastal springs are partially equilibrated with rocks at ~ 180 °C. Trace element distribution and concentrations and the total REE depend on the water type, acidity and Al + Fe concentration. The REE pattern for acidic waters is unusual but similar to that found in some acidic crater lake waters. The total hydrothermal discharge of Cl and S from the island associated with volcanic activity is estimated at ca. 20 t/d and 40 t/d, respectively, based on the measurements of flow rates of the draining streams and their chemistry. The chemical erosion of the island by surface and thermal waters is estimated at 27 and

  3. On the cost of approximating and recognizing a noise perturbed straight line or a quadratic curve segment in the plane. [central processing units

    NASA Technical Reports Server (NTRS)

    Cooper, D. B.; Yalabik, N.

    1975-01-01

    Approximation of noisy data in the plane by straight lines or elliptic or single-branch hyperbolic curve segments arises in pattern recognition, data compaction, and other problems. The efficient search for and approximation of data by such curves were examined. Recursive least-squares linear curve-fitting was used, and ellipses and hyperbolas are parameterized as quadratic functions in x and y. The error minimized by the algorithm is interpreted, and central processing unit (CPU) times for estimating parameters for fitting straight lines and quadratic curves were determined and compared. CPU time for data search was also determined for the case of straight line fitting. Quadratic curve fitting is shown to require about six times as much CPU time as does straight line fitting, and curves relating CPU time and fitting error were determined for straight line fitting. Results are derived on early sequential determination of whether or not the underlying curve is a straight line.

  4. Kamchatka and North Kurile Volcano Explosive Eruptions in 2015 and Danger to Aviation

    NASA Astrophysics Data System (ADS)

    Girina, Olga; Melnikov, Dmitry; Manevich, Alexander; Demyanchuk, Yury; Nuzhdaev, Anton; Petrova, Elena

    2016-04-01

    There are 36 active volcanoes in the Kamchatka and North Kurile, and several of them are continuously active. In 2015, four of the Kamchatkan volcanoes (Sheveluch, Klyuchevskoy, Karymsky and Zhupanovsky) and two volcanoes of North Kurile (Alaid and Chikurachki) had strong and moderate explosive eruptions. Moderate gas-steam activity was observing of Bezymianny, Kizimen, Avachinsky, Koryaksky, Gorely, Mutnovsky and other volcanoes. Strong explosive eruptions of volcanoes are the most dangerous for aircraft because they can produce in a few hours or days to the atmosphere and the stratosphere till several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines. The eruptive activity of Sheveluch volcano began since 1980 (growth of the lava dome) and is continuing at present. Strong explosive events of the volcano occurred in 2015: on 07, 12, and 15 January, 01, 17, and 28 February, 04, 08, 16, 21-22, and 26 March, 07 and 12 April: ash plumes rose up to 7-12 km a.s.l. and extended more 900 km to the different directions of the volcano. Ashfalls occurred at Ust'-Kamchatsk on 16 March, and Klyuchi on 30 October. Strong and moderate hot avalanches from the lava dome were observing more often in the second half of the year. Aviation color code of Sheveluch was Orange during the year. Activity of the volcano was dangerous to international and local aviation. Explosive-effusive eruption of Klyuchevskoy volcano lasted from 01 January till 24 March. Strombolian explosive volcanic activity began from 01 January, and on 08-09 January a lava flow was detected at the Apakhonchich chute on the southeastern flank of the volcano. Vulcanian activity of the volcano began from 10 January. Ashfalls

  5. Multi-parameter analysis of seismoturbidites in the Kumburgaz Basin of Sea of Marmara: Implications for creeping versus locked Central High segment of the North Anatolian Fault

    NASA Astrophysics Data System (ADS)

    Yakupoǧlu, Nurettin; Uçarkuş, Gülsen; Eriş, K. Kadir; Çaǧatay, M. Namık; Henry, Pierre; Yalamaz, Burak; Sabuncu, Asen; Acar, Dursun

    2016-04-01

    Sediment sequences deposited in active transform basins provide valuable archives of earthquake-triggered co-seismic sedimentation. A better understanding of the relationship between offshore fault ruptures and Seismoturbidites would have direct implications for earthquake hazard assessment. Submerged section of the North Anatolian Fault in the northern Sea of Marmara basin, which experienced more than 55 (Ms>6.8) earthquakes in the last 2000 years, poses a unique laboratory to study such kind of sync-tectonic history. Following the devastating 1999 Izmit and Duzce earthquakes (Mw = 7.4/7.2 respectively), a major seismic gap is now along the offshore branch of the NAF in the Sea of Marmara. The segments that control the Cinarcik and Kumburgaz basins in the Sea of Marmara have not ruptured during the 20th century. This study focusses on the Kumburgaz basin, which is located along the central segment of the NAF, and its less-known linkage to historical earthquakes, particularly to Ms>7 1509 and 1766 earthquakes. The main objective of this study is to test the two alternative hypotheses of a creeping versus locked central High segment by determining the frequency and timing of earthquake triggered turbidite units in the Kumburgaz basin. A 21-m-long piston core recovered in Kumburgaz basin during the Marsite cruise in 2014 is analysed at high resolution in order to identify the discrete turbidite-homogenite units (T-H units). The piston core reveals 22 T-H units where several packages consist of a sharp basal contact and multiple fining upward beds of sand to coarse silt as characteristically seen in most Seismoturbidite units. We initiated a systematic study of T-H units with the objectives of establishing criteria for identification of Seismoturbidites by analysing the physical, mineralogical and chemical composition of the piston core. The density and magnetic susceptibility changes along the core are analysed by Multi-Sensor Core Logger (MSCL). High detrital input

  6. The Ionian and Alfeo-Etna fault zones: New segments of an evolving plate boundary in the central Mediterranean Sea?

    NASA Astrophysics Data System (ADS)

    Polonia, A.; Torelli, L.; Artoni, A.; Carlini, M.; Faccenna, C.; Ferranti, L.; Gasperini, L.; Govers, R.; Klaeschen, D.; Monaco, C.; Neri, G.; Nijholt, N.; Orecchio, B.; Wortel, R.

    2016-04-01

    The Calabrian Arc is a narrow subduction-rollback system resulting from Africa/Eurasia plate convergence. While crustal shortening is taken up in the accretionary wedge, transtensive deformation accounts for margin segmentation along transverse lithospheric faults. One of these structures is the NNW-SSE transtensive fault system connecting the Alfeo seamount and the Etna volcano (Alfeo-Etna Fault, AEF). A second, NW-SE crustal discontinuity, the Ionian Fault (IF), separates two lobes of the CA subduction complex (Western and Eastern Lobes) and impinges on the Sicilian coasts south of the Messina Straits. Analysis of multichannel seismic reflection profiles shows that: 1) the IF and the AEF are transfer crustal tectonic features bounding a complex deformation zone, which produces the downthrown of the Western lobe along a set of transtensive fault strands; 2) during Pleistocene times, transtensive faulting reactivated structural boundaries inherited from the Mesozoic Tethyan domain which acted as thrust faults during the Messinian and Pliocene; and 3) the IF and the AEF, and locally the Malta escarpment, accommodate a recent tectonic event coeval and possibly linked to the Mt. Etna formation. Regional geodynamic models show that, whereas AEF and IF are neighboring fault systems, their individual roles are different. Faulting primarily resulting from the ESE retreat of the Ionian slab is expressed in the northwestern part of the IF. The AEF, on the other hand, is part of the overall dextral shear deformation, resulting from differences in Africa-Eurasia motion between the western and eastern sectors of the Tyrrhenian margin of northern Sicily, and accommodating diverging motions in the adjacent compartments, which results in rifting processes within the Western Lobe of the Calabrian Arc accretionary wedge. As such, it is primarily associated with Africa-Eurasia relative motion.

  7. Quaternary Tectonic Tilting Governed by Rupture Segments Controls Surface Morphology and Drainage Evolution along the South-Central Coast of Chile

    NASA Astrophysics Data System (ADS)

    Echtler, H. P.; Bookhagen, B.; Melnick, D.; Strecker, M.

    2004-12-01

    The Chilean coast represents one of the most active convergent margins in the Pacific rim, where major earthquakes (M>8) have repeatedly ruptured the surface, involving vertical offsets of several meters. Deformation along this coast takes place in large-scale, semi-independent seismotectonic segments with partially overlapping transient boundaries. They are possibly related to reactivated inherited crustal anisotropies; internal seismogenic deformation may be accommodated by structures that have developed during accretionary wedge evolution. Seismotectonic segmentation and the identification of large-scale rupture zones, however, are based on limited seismologic und geodetic observations over short timespans. In order to better define the long-term behavior and deformation rates of these segments and to survey the tectonic impact on the landscape on various temporal and spatial scales, we investigated the south-central coast of Chile (37-38S). There, two highly active, competing seismotectonic compartments influence the coastal and fluvial morphology. A rigorous analysis of the geomorphic features is a key for an assessment of the tectonic evolution during the Quaternary and beyond. We studied the N-S oriented Santa María Island (SMI), 20 km off the coast and only ~70km off the trench, in the transition between the two major Valdivia (46-37S) and Concepción (38-35S) rupture segments. The SMI has been tectonically deformed throughout the Quaternary and comprises two tilt domains with two topographic highs in the north and south that are being tilted eastward. The low-lying and flat eastern part of the island is characterized by a set of emergent Holocene strandlines related to coseismic uplift. We measured detailed surface morphology of these strandlines and E-W traversing ephemeral stream channels with a laser-total station and used these data to calibrate and validate high-resolution, digital imagery. In addition, crucial geomorphic markers were dated by the

  8. Development and analysis of control methods of the International Space Station ``ALPHA'' Russian Segment Central Two-Phase Thermal Control System parameters

    NASA Astrophysics Data System (ADS)

    Cykhotsky, V. M.; Sementsov, A. N.; Grigoriev, Y. I.; Prokhorov, Y. M.; Gorbenko, G. A.; Malukhin, C. A.; Ganja, E. P.

    1999-01-01

    Central Two-Phase Thermal Control System (TPS) of the International Space Station ``ALPHA'' Russian Segment (ISSA RS) is a complex thermalhydraulic system aimed to collect heat from the station modules and transport it to Central Heat Exchanger-Radiator (RAD). The TPS is based on a two-phase ammonia heat transfer loop. Proper work of the TPS Parameters Control System is an important factor for ISSA reliability to be maintained. The Control System is mainly intended to provide the following characteristics of the Station: rated values of the Station thermal condition parameters, high tolerance of the Station thermal condition to instabilities caused by selfspontained deviations of the parameters, ability of the system to regain its rated operation parameters in case of failures or accidents. In particular, the Control System should provide stable ammonia evaporative temperature and pressure in Evaporative Heat Exchanger (EHEX), stable liquid coolant (antifreeze) temperature, high vapor quality and prevent the TPS elements from low temperatures. Heat Controlled Accumulator (HCA) maintains nearly constant pressure in vapor line. To control the TPS elements functioning some control methods have been suggested. Namely, how to control HCA electric heater operation, FCV operation, RAD panel rotation, turning on/off Electric Heater and bypass valves operation. Results of mathematical modeling of the TPS operation during ISSA orbital flight and experimental investigations carried out in the Center of Technical Physics of Kharkov Aviation Institute (CEP KhAI) (Ukraine) are presented. It is proved the TPS Parameters Control System designed to be reliable.

  9. NW-SE structural segmentation of the south-central Chilean offshore fore-arc (35S-40S)

    NASA Astrophysics Data System (ADS)

    Block, M.; Kus, J.; Ladage, S.; Diaz-Naveas, J.; Gaedicke, C.; Urbina, O.

    2003-04-01

    One of the targets of RV SONNE cruise 161, as part of the German-Chilean joint venture to study Subduction Processes Off Chile (SPOC), was the Central Chilean margin between Concepcion and Valdivia. Structural analysis of the slope and trench has been conducted from high resolution bathymetric data, aided by GIS and statistical procedures, as well as multichannel reflection seismic profiles. Geological features such as the subduction front, major thrust units in the accretionary prism, the westernmost seismic signature of the Paleozoic metamorphic rocks and the shelf edge were mapped. Structurally, the slope is dominated by NW-SE striking sinistral strike-slip faults and conjugate NE-SW and NNE-SSW oriented lineaments. Sinistral 120 o strike-slip faults are well known from on-shore Chile. The geometrical arrangement of these fault sets dissects the slope into rhomb shaped, tilted fault blocks. Simultaneous block rotation leads to development of graben and half-grabens. The lower slope is built up of a relatively small accretionary prism. Here NE-SW and NNE-SSW striking features correspond to the boundaries of major thrust units and anticlines. Lateral displacement of the thrust units along the NW trending strike slip lineaments ranges in general from about 10 km to 20 km south and from 2 km to 5 km north of 37 o30textquoteright S. Strike-slip faulting of even the youngest folds at the deformation front demonstrates recent mutual frontal accretion and strike-slip movement of the deforming backstop. The observed brittle deformation of the fore-arc fits well with structures encountered on-shore. The complex structural pattern can be explained by a model of margin-parallel shear, driven by oblique subduction.

  10. Health literacy on tuberculosis amongst vulnerable segment of population: special reference to Saharia tribe in central India.

    PubMed

    Muniyandi, M; Rao, V G; Bhat, J; Yadav, R; Sharma, R K; Bhondeley, M K

    2015-05-01

    Health literacy on tuberculosis (TB) is an understanding about TB to perform activities with regard to prevention, diagnosis and treatment. We undertook a study to assess the health literacy on TB among one of the vulnerable tribal groups (Saharia) in central India. In this cross-sectional study, 2721 individuals aged >15 yr from two districts of Madhya Pradesh State of India were interviewed at their residence during December 2012-July 2013. By using a short-form questionnaire, health literacy on cause, symptoms, mode of transmission, diagnosis, treatment and prevention of TB was assessed. Of the 2721 (Gwalior 1381; Shivpuri 1340) individuals interviewed; 76 per cent were aged <45 yr. Living condition was very poor (62% living in huts/katcha houses, 84 per cent with single room, 89 per cent no separate kitchen, 97 per cent used wood/crop as a fuel). Overall literacy rate was 19 per cent, and 22 per cent had >7 members in a house. Of the 2721 respondents participated, 52 per cent had never heard of TB; among them 8 per cent mentioned cough as a symptom, 64 per cent mentioned coughing up blood, and 91 per cent knew that TB diagnosis, and treatment facilities were available in both government and private hospitals. Health literacy score among participants who had heard of TB was <40 per cent among 36 per cent of respondents, 41-60 per cent among 54 per cent and >60 per cent among 8 per cent of respondents. The finding that nearly half of the respondents had not heard of TB indicated an important gap in education regarding TB in this vulnerable population. There is an urgent need to implement targeted interventions to educate this group for better TB control.

  11. Coastal Sedimentation Associated with the Tohoku Tsunami of 11 March 2011 in South Kuril Islands, NW Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Razjigaeva, N. G.; Ganzey, L. A.; Grebennikova, T. A.; Ivanova, E. D.; Kharlamov, A. A.; Kaistrenko, V. M.; Shishkin, A. A.

    2013-06-01

    Sediment deposited by the Tohoku tsunami of March 11, 2011 in the Southern Kurils (Kunashir, Shikotan, Zeleniy, Yuri, Tanfiliev islands) was radically different from sedimentation during local strong storms and from tsunamis with larger runup at the same location. Sediments from the 2011 Tohoku tsunami were surveyed in the field, immediately and 6 months after the event, and analyzed in the laboratory for sediment granulometry, benthos Foraminifa assemblages, and diatom algae. Run-up elevation and inundation distance were calculated from the wrackline (accumulations of driftwood, woody debris, grass, and seaweed) marking the distal edge of tsunami inundation. Run-up of the tsunami was 5 m at maximum, and 3-4 m on average. Maximum distance of inundation was recorded in river mouths (up to 630 m), but was generally in the range of 50-80 m. Although similar to the local strong storms in runup height, the tsunami generally did not erode the coast, nor leave a deposit. However, deposits uncharacteristic of tsunami, described as brown aleuropelitic (silty and clayey) mud rich in organic matter, were found in closed bays facing the South Kuril Strait. These closed bays were covered with sea ice at the time of tsunami. As the tsunami waves broke the ice, the ice floes enhanced the bottom erosion on shoals and destruction of low-lying coastal peatland even at modest ranges of runup. In the muddy tsunami deposits, silt comprised up to 64 % and clay up to 41.5 %. The Foraminifera assemblages displayed features characteristic of benthic microfauna in the near-shore zone. Deep-sea diatoms recovered from tsunami deposits in two closely situated bays, namely Krabovaya and Otradnaya bays, had different requirements for environmental temperature, suggesting these different diatoms were brought to the bays by the tsunami wave entraining various water masses when skirting the island from the north and from the south.

  12. Infrasonic observations of the June 2009 Sarychev Peak eruption, Kuril Islands: Implications for infrasonic monitoring of remote explosive volcanism

    NASA Astrophysics Data System (ADS)

    Matoza, Robin S.; Le Pichon, Alexis; Vergoz, Julien; Herry, Pascal; Lalande, Jean-Marie; Lee, Hee-il; Che, Il-Young; Rybin, Alexander

    2011-02-01

    Sarychev Peak (SP), located on Ostrov Matua, Kurils, erupted explosively during 11-16 June 2009. Whereas remote seismic stations did not record the eruption, we report atmospheric infrasound (acoustic wave ~ 0.01-20 Hz) observations of the eruption at seven infrasound arrays located at ranges of ~ 640-6400 km from SP. The infrasound arrays consist of stations of the International Monitoring System global infrasound network and additional stations operated by the Korea Institute of Geoscience and Mineral Resources. Signals at the three closest recording stations IS44 (643 km, Petropavlovsk-Kamchatskiy, Kamchatka Krai, Russia), IS45 (1690 km, Ussuriysk, Russia), and IS30 (1774 km, Isumi, Japan) represent a detailed record of the explosion chronology that correlates well with an eruption chronology based on satellite data (TERRA, NOAA, MTSAT). The eruption chronology inferred from infrasound data has a higher temporal resolution than that obtained with satellite data. Atmosphere-corrected infrasonic source locations determined from backazimuth cross-bearings of first-arrivals have a mean centroid ~ 15 km from the true location of SP. Scatter in source locations of up to ~ 100 km result from currently unresolved details of atmospheric propagation and source complexity. We observe systematic time-variations in trace-velocity, backazimuth deviation, and signal frequency content at IS44. Preliminary investigation of atmospheric propagation from SP to IS44 indicates that these variations can be attributed to solar tide variability in the thermosphere. It is well known that additional information about active volcanic processes can be learned by deploying infrasonic sensors with seismometers at erupting volcanoes. This study further highlights the significant potential of infrasound arrays for monitoring volcanic regions such as the Kurils that have only sparse seismic network coverage.

  13. New Seismic and Magmatic Constraints on the Geometry and Timing of Shallowing of the Central Andean Chilean-Pampean Flatslab Segment

    NASA Astrophysics Data System (ADS)

    Kay, S. M.; Mulcahy, P.; Chen, C.; Vervoort, J. D.

    2013-05-01

    The shape and evolution of the Central Andean Chilean-Pampean flatslab segment provide modern analogues in numerous studies of flatslab segments of subducting oceanic plates. A revised geometry for the Wadati-Benioff Zone of the Chilean-Pampean flatslab that incorporates 271 well-constrained mantle earthquakes recorded during the 2007-2009 southern Puna seismic experiment (25°-28°S; 70°-65°W) shows that the northern boundary of the flatslab shoals more abruptly southward giving a more symmetric form with a more northerly bend to the flatslab than seen in previous models. The prime evidence for a sharper bend to the north comes from the three distinctive earthquake hypocenter clusters at 110 to 160 km, which form the so-called Pipanaco earthquake nest under the region at 27.5° to 29°S and 68° to 66°W, and whose origins can be attributed to local bending stresses in the subducting plate. This northern bend also passes under the Incapillo Caldera arc volcanic complex near 28°S, which is the southernmost center in the Central Volcanic Zone with post-Pliocene activity until reaching the Tupungato in the Southern Volcanic Zone on the southern side of the flat-slab at 33°S. Support for this northern bend forming largely after near normal subduction of the Juan Fernandez ridge began on the Nazca plate in the middle of the shallowing flatslab at ~10 Ma comes from the ~9-3 Ma Pircas Negras glassy andesites and related lavas at 27° to 28°S, whose chemistry and locations have been suggested to reflect the bending. Further support for the flatslab principally forming at this time comes from the ~45-50 km eastward displacements of the volcanic arcs on both the northern and southern margins of the present flat-slab at ~ 9-3 Ma and the magmatic and deformational history recorded above the area of the flat-slab region. At the same time, the Albarracín region ignimbrites in the central Argentine Precordillera above the main part of the flatslab have recently confirmed

  14. Late Cenozoic thrusting of major faults along the central segment of Longmen Shan, eastern Tibet: Evidence from low-temperature thermochronology

    NASA Astrophysics Data System (ADS)

    Tan, Xi-Bin; Xu, Xi-Wei; Lee, Yuan-Hsi; Lu, Ren-Qi; Liu, Yiduo; Xu, Chong; Li, Kang; Yu, Gui-Hua; Kang, Wen-Jun

    2017-08-01

    The Cenozoic orogenic process of the Longmen Shan (LMS) and the kinematics of major faults along the LMS are crucial for understanding the growth history and mechanism of the eastern Tibetan Plateau. Three major faults, from west to east, are present in the central segment of the LMS: the Wenchuan-Maoxian Fault (WMF), the Beichuan-Yingxiu Fault (BYF), and the Jiangyou-Guanxian Fault (JGF). Previous researchers have placed great impetus on the Pengguan Massif, between the WMF and BYF. However, limited low-temperature thermochronology data coverage in other areas prevents us from fully delineating the tectonic history of the LMS. In this study, we collect 22 samples from vertical profiles in the Xuelongbao Massif and the range frontal area located at the hanging walls of the WMF and JGF respectively, and conduct apatite and zircon fission track analyses. New fission track data reveal that the Xuelongbao Massif has been undergoing rapid exhumation with an average rate of 0.7-0.9 mm/yr since 11 Ma, and the range frontal area began rapid exhumation at 7.5 Ma with total exhumation of 2.5-4.5 km. The exhumation histories indicate that the three major faults (WMF, BYF and JGF) in the central LMS are all reverse faults, and show a basinward in-sequence propagation from middle Miocene to present-day. Such a pattern further implies that upper crustal shortening is the primary driver for the LMS' uplift during the Late Cenozoic. Nevertheless, middle-lower crustal deformation is difficult to be constrained by the exhumation histories, and its contribution to LMS' uplift cannot be ruled out.

  15. Structural Characterization of Fibrils from Recombinant Human Islet Amyloid Polypeptide by Solid-State NMR: The Central FGAILS Segment Is Part of the β-Sheet Core

    PubMed Central

    Weirich, Franziska; Gremer, Lothar; Mirecka, Ewa A.; Schiefer, Stephanie; Hoyer, Wolfgang; Heise, Henrike

    2016-01-01

    Amyloid deposits formed from islet amyloid polypeptide (IAPP) are a hallmark of type 2 diabetes mellitus and are known to be cytotoxic to pancreatic β-cells. The molecular structure of the fibrillar form of IAPP is subject of intense research, and to date, different models exist. We present results of solid-state NMR experiments on fibrils of recombinantly expressed and uniformly 13C, 15N-labeled human IAPP in the non-amidated, free acid form. Complete sequential resonance assignments and resulting constraints on secondary structure are shown. A single set of chemical shifts is found for most residues, which is indicative of a high degree of homogeneity. The core region comprises three to four β-sheets. We find that the central 23-FGAILS-28 segment, which is of critical importance for amyloid formation, is part of the core region and forms a β-strand in our sample preparation. The eight N-terminal amino acid residues of IAPP, forming a ring-like structure due to a disulfide bridge between residues C2 and C7, appear to be well defined but with an increased degree of flexibility. This study supports the elucidation of the structural basis of IAPP amyloid formation and highlights the extent of amyloid fibril polymorphism. PMID:27607147

  16. Sensory feedback induced by front-leg stepping entrains the activity of central pattern generators in caudal segments of the stick insect walking system.

    PubMed

    Borgmann, Anke; Hooper, Scott L; Büschges, Ansgar

    2009-03-04

    Legged locomotion results from a combination of central pattern generating network (CPG) activity and intralimb and interlimb sensory feedback. Data on the neural basis of interlimb coordination are very limited. We investigated here the influence of stepping in one leg on the activities of neighboring-leg thorax-coxa (TC) joint CPGs in the stick insect (Carausius morosus). We used a new approach combining single-leg stepping with pharmacological activation of segmental CPGs, sensory stimulation, and additional stepping legs. Stepping of a single front leg could activate the ipsilateral mesothoracic TC CPG. Activation of the metathoracic TC CPG required that both ipsilateral front and middle legs were present and that one of these legs was stepping. Unlike the situation in real walking, ipsilateral mesothoracic and metathoracic TC CPGs activated by front-leg stepping fired in phase with the front-leg stepping. Local (intralimb) sensory feedback from load sensors could override this intersegmental influence of front-leg stepping, shifting retractor motoneuron activity relative to the front-leg step cycle and thereby uncoupling them from front-leg stepping. These data suggest that front-leg stepping in isolation would result in in-phase activity of all ipsilateral legs, and functional stepping gaits (in which the three ipsilateral legs do not step in synchrony) emerge because of local load sensory feedback overriding this in-phase influence.

  17. Structural Characterization of Fibrils from Recombinant Human Islet Amyloid Polypeptide by Solid-State NMR: The Central FGAILS Segment Is Part of the β-Sheet Core.

    PubMed

    Weirich, Franziska; Gremer, Lothar; Mirecka, Ewa A; Schiefer, Stephanie; Hoyer, Wolfgang; Heise, Henrike

    2016-01-01

    Amyloid deposits formed from islet amyloid polypeptide (IAPP) are a hallmark of type 2 diabetes mellitus and are known to be cytotoxic to pancreatic β-cells. The molecular structure of the fibrillar form of IAPP is subject of intense research, and to date, different models exist. We present results of solid-state NMR experiments on fibrils of recombinantly expressed and uniformly 13C, 15N-labeled human IAPP in the non-amidated, free acid form. Complete sequential resonance assignments and resulting constraints on secondary structure are shown. A single set of chemical shifts is found for most residues, which is indicative of a high degree of homogeneity. The core region comprises three to four β-sheets. We find that the central 23-FGAILS-28 segment, which is of critical importance for amyloid formation, is part of the core region and forms a β-strand in our sample preparation. The eight N-terminal amino acid residues of IAPP, forming a ring-like structure due to a disulfide bridge between residues C2 and C7, appear to be well defined but with an increased degree of flexibility. This study supports the elucidation of the structural basis of IAPP amyloid formation and highlights the extent of amyloid fibril polymorphism.

  18. Observation and modelling of turbulent mixing in the Kuril and Aleutian Straits and impact of its 18.6-year period tidal cycle on ocean and climate

    NASA Astrophysics Data System (ADS)

    Yasuda, I.; Tanaka, Y.; Itoh, S.; Hasumi, H.; Komatsu, K.; Osafune, S.; Yagi, M.; Tanaka, T.; Kaneko, H.; Ikeya, T.; Konda, S.; Nishioka, J.; Nakatsuka, T.; Katsumata, K.; Tatebe, H.; Watanabe, Y.; Hiroe, Y.; Nakamura, T.

    2012-12-01

    Direct turbulent observations in the Kuril Straits and Aleutian Straits reveal that tide-induced strong vertical mixing corresponds to strong shear of combined diurnal tidal and/or mean currents and significantly modifies the water-mass and potential vorticity distribution. Bi-decadal variability synchronized with 18.6-year period moon-tidal cycle were found in various parts of the ocean and climate indices: water-mass variability in the subarctic North Pacific, especially near the strong diurnal tide regions as Kuril Straits and Aleutian Islands, and in long-term climate indices as Pacific Decadal Oscillation (PDO) and El-Nino and Southern Oscillation (ENSO) in proxy-reconstructed records. In low-frequency part of the PDO and SOI records, negative (positive)-PDO and positive (negative)-SOI tend to occur in the 4-6-th (10-12-th) year after the maximum diurnal tide, which is consistent with the climate model experiments with locally enhanced vertical mixing around Kuril Straits showing that tidal mixing and its variability could generate bi-decadal variability in ocean and climate. Ocean and climate model experiments with parameterized tidal mixing explain some of the water-mass modifications and bi-decadal variability of water-masses and climate.

  19. An account of the Ischnomesidae (Peracarida, Isopoda) from the Kuril-Kamchatka Trench and abyssal plain (Northwest Pacific) with the description of two new species

    NASA Astrophysics Data System (ADS)

    Brandt, Angelika; Kristin Stüven, Jana; Caurant, Cyril; Oskar Elsner, Nikolaus

    2015-01-01

    During the German-Russian expedition KuramBio (Kuril-Kamchatka Biodiversity Studies) from board of the RV Sonne to the Kuril-Kamchatka Trench and adjacent abyssal plain, benthic samples were taken by means of a camera-epibenthic sledge. Amongst one of the most diverse macrobenthic taxa, the Isopoda (Crustacea, Malacostraca), Ischnomesidae were the fifth most abundant isopod family in the Kuril-Kamchatka area and were sampled with 24 species from 5 genera in 21 hauls at 12 stations. Fortimesus occurs most frequently in the samples (36% of all Ischnomesidae sampled), followed by Stylomesus (26%), Heteromesus (23%), Ischnomesus (10%) and Gracilimesus (4%). Number of ischnomesid individuals is highest at station 10-12 with 35 specimens, followed by station 12-4 (30 ind.), station 6-12 (29 ind.), station 9-9 (28), and station 1-11 (24). At station 4-3 only 1 specimen was found. A key to all genera of Ischnomesidae is provided. Two new species from two genera: StylomesusWolff, 1956 and FortimesusKavanagh and Wilson, 2007 are described from the KuramBio material. Stylomesus malyutinae sp. nov. is distinguished by the smooth body surface, the shape of pleotelson and the length of uropods from other species of the genus from the Northwest Pacific Ocean. Fortimesus trispiculum sp. nov. is characterised by anterolateral projections of pereonites 1-3 which are forming an angle of about 45° with the longitudinal body axis decreasing in length from anterior to posterior.

  20. Provenance analysis of Permian sandstones in the central and southern Da Xing'an Mountains, China: Constraints on the evolution of the eastern segment of the Central Asian Orogenic Belt

    NASA Astrophysics Data System (ADS)

    Han, Guoqing; Liu, Yongjiang; Neubauer, Franz; Genser, Johann; Zhao, Yingli; Wen, Quanbo; Li, Wei; Wu, Linna; Jiang, Xiaoyan; Zhao, Limin

    2012-12-01

    Modal, chemical and U-Pb zircon data from Permian sandstones in the central and southern Da Xing'an Mountains (eastern Inner Mongolia, China) constrain, for the first time, plate collision processes between the northern margin of the North China craton and the composite Erguna-Xing'an-Songliao block. The study area is located between the Ondor Sum-Xar Moron and Hegenshan suture zones of the eastern segment of the Central Asian Orogenic Belt. Modal and geochemical analyses of Permian sandstones suggest derivation from dissected continental arc and recycled orogenic sources. LA-ICP-MS U-Pb detrital zircon data from sandstones indicate Early Permian to earliest Triassic maximum depositional ages (278 ± 4 Ma to 249 ± 3 Ma). These data also show two uniform age groups of 270-280 Ma and 310-320 Ma, and we interpret their source to be mainly the Sonidzuoqi-Xilinhot-southern Xi Ujimqin magmatic arc in the north (the southern margin of the Xing'an-Erguna block). The sample from the Upper Permian to lowermost Triassic Linxi Formation in the Linxi area also contains zircons with age groups of ~ 1800 Ma and ~ 2500 Ma, consistent with derivation from the northern margin of the North China craton, which lies to the south. Therefore, the collision between the North China craton and the Xing'an-Erguna block began during the deposition of the Linxi Formation, and the final closure of the intervening oceanic basin occurred during ca. Late Permian-earliest Triassic times, forming the Ondor Sum-Xar Moron suture zone.

  1. Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth

    PubMed Central

    Huang, Jinhai; Lu, Weicong; Savini, Giacomo; Chen, Hao; Wang, Chengfang; Yu, Xinxin; Bao, Fangjun; Wang, Qinmei

    2016-01-01

    Purpose. To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan) and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA) for measuring central corneal thickness (CCT), anterior chamber depth (ACD), and aqueous depth (AD). Methods. Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using paired t-tests, Bland-Altman plots, and 95% limits of agreement (LoA). Results. The mean CCT, ACD, and AD measured by AL-Scan were 538.59 ± 27.37 μm, 3.70 ± 0.30 mm, and 3.16 ± 0.30 mm, respectively. The mean values obtained by the Visante OCT were 536.14 ± 26.61 μm for CCT, 3.71 ± 0.29 mm for ACD, and 3.17 ± 0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference = 2.45 ± 6.07 μm, P < 0.05). The differences in ACD and AD measurements were not statistically significant. The 95% LoA of CCT, ACD, and AD were between −9.44 and 14.35 μm, −0.15 and 0.12 mm, and −0.15 and 0.12 mm, respectively. Conclusions. Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic. PMID:27403339

  2. Oceanic Sub-Moho Reflectors in and Around the Segmentation Boundary Between the Tonankai-Nankai Earthquake Area, the Central Nankai Trough

    NASA Astrophysics Data System (ADS)

    Nakanishi, A.; Kodaira, S.; Miura, S.; Ito, A.; Sato, T.; Park, J.; Obana, K.; Kaneda, Y.

    2006-12-01

    The Nankai Trough is a unique subduction zone because the recurrence intervals of M8 class earthquakes and the segmentation of rupture zones are well documented on the basis of geophysical, geological and historic data. In 2004, large intraslab earthquake (Mw7.5) occurred southeast off the Kii Peninsula, the central Nankai Trough. Recent ocean bottom seismograph observation off the Kii Peninsula shows seismicity concentrated in the oceanic crust and the uppermost mantle. To understand the genesis of such intraslab earthquakes and its relation to large interplate earthquakes as well as to obtain an entire structural image of Nankai Trough subduction seismogenic zone, a wide-angle reflection/refraction survey across the coseismic rupture zone of the Tonankai earthquake was conducted in 2004. This research is part of "Structure research on plate dynamics of the presumed rupture zone of the Tonankai-Nankai Earthquakes" funded by Ministry of Education, Culture, Sports, Science and Technology. The result of structural image shows a bit thicker oceanic crust (>8km) subducting landward, and the existence of oceanic sub-Moho reflectors in the uppermost mantle. The aftershocks of the 2004 off Kii Peninsula earthquake are distributed within the oceanic crust and the uppermantle, which is not consistent with the estimated fault plane of main shock. Comparing the structural image with this aftershock distribution and usual seismicity in the uppermost mantle, the depth of the oceanic sub-Moho reflectors and the intraslab events within the uppermantle are both distributed around 20km. We consider that such sub-Moho reflectors may become a seismic fault of intraslab earthquakes.

  3. Arc-arc Collision Structure in the Southernmost Part of the Kuril Trench Region -Results from Integrated Analyses of the 1998-2000 Hokkaido Transect Seismic Data-

    NASA Astrophysics Data System (ADS)

    Iwasaki, Takaya; Tsumura, Noriko; Ito, Tanio; Sato, Hiroshi; Kurashimo, Eiji; Hirata, Naoshi; Arita, Kazunori; Noda, Katsuya; Fujiwara, Akira; Abe, Susumu; Kikkuchi, Shunsuke; Suzuki, Kazuko

    2015-04-01

    The Hokkaido Island, located in the southernmost part of the Kuril trench region, has been under a unique tectonic environment of arc-arc collision. Due to the oblique subduction of the Pacific (PAC) plate, the Kuril forearc sliver started to collide against Northeast (NE) Japan arc from the east at the time of middle Miocene to form complicated structures in the Hidaka collision zone (HCZ), as characterized by the westward obduction of the crustal rocks of the Kuril arc (the Hidaka metamorphic belt (HMB)) along the Hidaka main thrust (HMT) and a thick foreland fold-and-thrust belt. In and around the HCZ, a series of seismic reflection/refraction experiments were undertaken from 1994 to 2000, which provided important structural features including crustal delamination in the southern HCZ and a thick fold-and-thrust belt with velocity reversals (low velocity layers) in the northern HCZ. Reprocessing/reinterpretation for these data sets, which started in 2012, is aimed to construct a more detailed collision model through new processing and interpretation techniques. A multi-disciplinary project of the 1998-2000 Hokkaido Transect, crossing the northern part of the HCZ in EW direction, collected high-quality seismic data on a 227-km seismic refraction/wide-angle reflection profile and three seismic reflection lines. Our reanalyses revealed interesting collision structure ongoing in the northern part of the HCZ. The westward obduction of the Kuril arc crust was clearly imaged along the HMT. This obduction occurs at a depth of 27-30 km, much deeper than in the southern HCZ (23-25 km). The CRS/MDRS processing to the reflection data firstly succeeded in imaging clear reflection events at a 30-45 km depth below the obducted Kuril arc crust. These events show an eastward dip, probably corresponding to the lower crust/Moho within the NE Japan arc descending down to the east under the collision zone. Gently eastward dipping structures above these events (in a depth range of 5

  4. Triticella minini - a new ctenostome bryozoan from the abyssal plain adjacent to the Kuril-Kamchatka Trench

    NASA Astrophysics Data System (ADS)

    Grischenko, Andrei V.; Chernyshev, Alexei V.

    2015-01-01

    A new species of ctenostome bryozoan, Triticella minini sp. nov., is described from the abyssal plain adjacent to the Kuril-Kamchatka Trench, based on material collected by the Russian-German deep-sea expedition KuramBio 2012. Colonies of T. minini sp. nov. were found attached to the oral spines of irregular sea urchin Echinosigra (Echinogutta) amphoraMironov, 1974 by means of rhizoid fibers that penetrated the substratum through circular borings. The specimens were examined by light microscopy, scanning electron microscopy, and confocal laser scanning microscopy with phalloidin and nuclear labeling. The description of T. minini sp. nov. combines a general taxonomic description with a description of the anatomy of the muscular system. The new species differs from congeners in lacking a stolon. It has an intertentacular organ. T. minini sp. nov. is the eleventh species described in the genus TriticellaDalyell, 1848, and the first record for this genus from the northwestern Pacific. The new species is the fifth ctenostome bryozoan known to occur in 5001-5500 m depth interval worldwide, and the deepest record reported for Triticella.

  5. Tanaidacean fauna of the Kuril-Kamchatka Trench and adjacent abyssal plain - abundance, diversity and rare species

    NASA Astrophysics Data System (ADS)

    Błażewicz-Paszkowycz, Magdalena; Pabis, Krzysztof; Jóźwiak, Piotr

    2015-01-01

    Here we examine the distribution patterns, abundance, and species richness of tanaidacean peracarids in the abyssal-hadal transition zone. Material was collected in the region of Kuril-Kamchatka Trench during the German-Russian KuramBio Expedition with use of a giant boxcorer (GKG) of sampling area 0.25 m2. In the 23 samples collected from depths 4900 to 5800 m 48 species of Tanaidacea belonging to 11 families have been identified; most of the species (80%) are new to science. There was no evidence of a distribution pattern associated with depth or geographic location of stations in the nMDS analysis. Frequency of occurrence of twelve species was high (at 34-78% of stations) although the stations were distributed along a distance of about 1000 km. This observation is rationalized by the uniform environmental conditions of temperature, hydrostatic pressure, salinity, conductivity, and character of bottom deposits in the investigated area. Mean tanaidacean densities were 25.0±18.0 ind./0.25 m2, with mean values of species richness (number of species per sample) and diversity (Shannon Index) as high as 9.7±4.6 and 1.9±0.3 respectively. Singletons constituted about 20% of all species and more than one third of the species occurred as low counts per sample. The species accumulation curve did not reach the asymptotic level suggesting under-sampling of the studied area.

  6. Polychaete-parasitizing copepods from the deep-sea Kuril-Kamchatka Trench (Pacific Ocean), with the description of a new Ophelicola species and comments on the currently known annelidicolous copepods

    NASA Astrophysics Data System (ADS)

    Conradi, Mercedes; Bandera, M. Eugenia; Marin, Ivan; Martin, Daniel

    2015-01-01

    The annelid associated copepods, collectively called annelidicolous, were placed in 21 families. Some genera, such as Ophelicola, are considered phylogenetically isolated and are placed into the order Cyclopoida as incertae sedis. In this paper, we describe Ophelicola kurambia, the second species recorded for the genus and the first for the Pacific Ocean. The single known specimen, a female, was found during the German-Russian deep-sea expedition KuramBio at the deep-sea Kuril-Kamchatka Trench. The new species differs from Ophelicola drachi (known from the Gulf of Biscay, Atlantic Ocean) in being attached to the host through the mandibles instead of maxillae and, specially, in the formula of the antennular armature. The study of the new species contributes to clarify the diagnosis of the genus, which clearly differs from Notomasticola (another incertae sedis genus), and resembles both the most modified clausiids (in the mandibular shape and antennular segmentation) and the clausidiids (in the shape of maxilla). However, it does not contribute to clarify the position of Ophelicola within the order Cyclopoida. The paper includes a list of the known annelidicolous copepods (excluding Monstrilloidae) and summarises the main trends shown in terms of diversity, distribution and relationships. Currently, 168 species of copepods from to 74 genera and 22 families and 7 incertae sedis (excluding Monstrilloida) are known to be involved in 235 parasitic relationships (mostly ectoparasitic) with polychaetes. Host polychaetes include 156 species belonging to 104 genera from 22 families (plus 14 unknown). About 50% of these relationships are known from European waters, mainly from shallow depths.

  7. Active Segmentation

    PubMed Central

    Mishra, Ajay; Aloimonos, Yiannis

    2009-01-01

    The human visual system observes and understands a scene/image by making a series of fixations. Every fixation point lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the fixation point. Segmenting the region containing the fixation is equivalent to finding the enclosing contour- a connected set of boundary edge fragments in the edge map of the scene - around the fixation. This enclosing contour should be a depth boundary. We present here a novel algorithm that finds this bounding contour and achieves the segmentation of one object, given the fixation. The proposed segmentation framework combines monocular cues (color/intensity/texture) with stereo and/or motion, in a cue independent manner. The semantic robots of the immediate future will be able to use this algorithm to automatically find objects in any environment. The capability of automatically segmenting objects in their visual field can bring the visual processing to the next level. Our approach is different from current approaches. While existing work attempts to segment the whole scene at once into many areas, we segment only one image region, specifically the one containing the fixation point. Experiments with real imagery collected by our active robot and from the known databases 1 demonstrate the promise of the approach. PMID:20686671

  8. EVENT SEGMENTATION

    PubMed Central

    Zacks, Jeffrey M.; Swallow, Khena M.

    2012-01-01

    One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of ongoing perception, with consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and sub-parts. This segmentation depends on the bottom-up processing of sensory features such as movement, and on the top-down processing of conceptual features such as actors’ goals. How people segment activity affects what they remember later; as a result, those who identify appropriate event boundaries during perception tend to remember more and learn more proficiently. PMID:22468032

  9. Evidence for Cenozoic extensional basin development and tectonic inversion south of the flat-slab segment, southern Central Andes, Chile (33° 36°S.L.)

    NASA Astrophysics Data System (ADS)

    Charrier, R.; Baeza, O.; Elgueta, S.; Flynn, J. J.; Gans, P.; Kay, S. M.; Muñoz, N.; Wyss, A. R.; Zurita, E.

    2002-04-01

    , respectively. Tectonic and volcanic events on the east versant of the Andes [Journal of South American Earth Sciences 15 (2002)], which are coeval with the basin inversion and crustal thickening episodes presented herein and, therefore, with the previously mentioned period of increasing convergence rate, are assumed to correspond with the same episode of major tectonic accommodation of the crust in this Andean region. It is not yet possible to determine if the collisional event of the Juan Fernández ridge at approximately 15 Ma in the flat-slab segment region had a local or a more regional effect on the late Cenozoic tectonic evolution of the continental margin in the Central Andes.

  10. Deep-sea epibiotic hydroids from the abyssal plain adjacent to the Kuril-Kamchatka Trench with description of Garveia belyaevi sp. nov. (Hydrozoa, Bougainvilliidae)

    NASA Astrophysics Data System (ADS)

    Stepanjants, Sofia D.; Chernyshev, Alexey V.

    2015-01-01

    Examination of material collected by the German-Russian KuramBio Deep-Sea Expedition to the abyssal plain adjacent to the Kuril-Kamchatka Trench revealed about 17 hydroid species, including two species presumably new to science. Before the KuramBio Expedition only fragments of the unidentified hydroids and Cryptolaria sp. were collected in the Kuril-Kamchatka Trench from depths exceeding 3000 m. Descriptions of three species of epibiotic hydroids (including one new species, Garveia belyaevi sp. nov.) are presented herein. A colony of G. belyaevi sp. nov. (the third deep-sea and deepest species of the wide distributed genus Garveia) was attached to the spines of unidentified irregular sea urchins from depths 5217 to 5229 m. Нalitholus (?) sp. (Hydrozoa, Anthoathecata) colonized the skin of spoon worms (Echiura) but could not be identified to species level because the mature medusa stage was absent in the material. An unidentified juvenile polyp (Pandeidae) was found on the bryozoan Tricitella minini attached to spines of irregular sea urchins Echinosigra amphora. Colonial sedentary organisms inhabiting abyssal plains with soft bottoms may colonize invertebrates which are seldom used as substrates for epibiota in shallow waters. Epibiosis among abyssal colonial invertebrates, though extremely poorly studied, appears to be rather frequent.

  11. The 2000 Nemuro-Hanto-Oki earthquake, off eastern Hokkaido, Japan, and the high intraslab seismic activity in the southwestern Kuril Trench

    USGS Publications Warehouse

    Takahashi, H.; Hirata, K.

    2003-01-01

    The 2000 Nemuro-Hanto-Oki earthquake (Mw6.8) occurred in the southwestern part of the Kuril Trench. The hypocenter was located close to the aftershock region of the great 1994 Kuril earthquake (Mw8.3), named "the 1994 Hokkaido-Toho-Oki earthquake" by the Japan Meteorological Agency, for which the fault plane is still in debate. Analysis of the 2000 event provides a clue to resolve the fault plane issue for the 1994 event. The hypocenters of the 2000 main shock and aftershocks are determined using arrival times from a combination of nearby inland and submarine seismic networks with an improved azimuthal coverage. They clearly show that the 2000 event was an intraslab event occurring on a shallow-dipping fault plane between 55 and 65 km in depth. The well-focused aftershock distribution of the 2000 event, the relative location of the 1994 event with respect to the 2000 event, and the similarity between their focal mechanisms strongly suggest that the faulting of the great 1994 earthquake also occurred on a shallow-dipping fault plane in the subducting slab. The recent hypocenter distribution around the 1994 aftershock region also supports this result. Large intraslab earthquakes occuring to the southeast of Hokkaido may occur due to a strong coupling on the plate boundary, which generates relatively large stress field within the subducting Pacific plate.

  12. Deep down: Isopod biodiversity of the Kuril-Kamchatka abyssal area including a comparison with data of previous expeditions of the RV Vityaz

    NASA Astrophysics Data System (ADS)

    Elsner, Nikolaus O.; Malyutina, Marina V.; Golovan, Olga A.; Brenke, Nils; Riehl, Torben; Brandt, Angelika

    2015-01-01

    This study focusses on the isopod biodiversity in the abyssal area southeast of the Kuril-Kamchatka Trench. The KuramBio (Kuril-Kamchatka Biodiversity Studies) expedition in summer 2012 collected altogether 10,169 isopods from 21 C-EBS hauls at 12 stations, belonging to 19 families, 73 genera and 207 species from the depth range between 4830 and 5780 m. Munnopsidae and Desmosomatidae were the most abundant and species-rich families, Eurycope (Munnopsidae) and Macrostylis (Macrostylidae) the most abundant genera. An nMDS plot on the basis of the Cosine similarity index reveals no clear pattern and all hauls to be different from each other. We compared our data with 12 stations from the same depth range sampled by the Russian RV Vityaz about 50 years ago and were able to identify several species collected by the RV Vityaz. The identified isopod species belonged to the families Munnopsidae, Macrostylidae, Haploniscidae, Desmosomatidae, Ischnomesidae and Nannoniscidae. Of the 333 individuals collected by the RV Vityaz, Haploniscidae and Munnopsidae were the most abundant families. Desmosomatidae were only represented by <1% of the isopod individuals. However, the rarefaction curves of both the KuramBio and the Vityaz samples are not approaching an asymptote, indicating that even after repeated sampling just a part of the local fauna has been recorded so far.

  13. Abyssal macrofauna of the Kuril-Kamchatka Trench area (Northwest Pacific) collected by means of a camera-epibenthic sledge

    NASA Astrophysics Data System (ADS)

    Brandt, A.; Elsner, N. O.; Malyutina, M. V.; Brenke, N.; Golovan, O. A.; Lavrenteva, A. V.; Riehl, T.

    2015-01-01

    Abyssal macrofaunal composition of 21 epibenthic sledge hauls from twelve stations taken in the Kuril-Kamchatka Trench (KKT) and at the adjacent abyssal plain, Northwest Pacific, is presented. Sampling with the fine meshed epibenthic sledge yielded higher abundances and species richness than was reported from previous expeditions from board of RV Vityaz. In total 84,651 invertebrates were sampled with RV Sonne between July and September of 2012 (31,854 invertebrates if standardised for 1000 m2 trawled distances) from 41 taxa of different taxonomic ranks (15 phyla, 28 classes, 7 orders) were sampled from a trawled area of 53,708 m² and have been analyzed. Few taxa were frequent and most taxa were rare in the samples, twelve taxa occurred with more than 1% frequency. Of these, the Polychaeta were most abundant followed by the benthic Copepoda and Isopoda. Total numbers of individuals varied between stations and were highest with 4238 individuals at station 2-10 close to the KKT in 4865 m depth and lowest with 374 individuals at station 6-11 in 5305 m depth. At this station also the lowest number of taxa occurred (18 taxa) while the highest number occurred with 31 taxa at station 3-9 in 4991 m depth. Numbers of individuals decreased with increasing depth between 4830 and 5780 m. Crustaceans of the superorder Peracarida were one of the dominating taxa with four orders occurring frequently in most samples. In total, Isopoda were most important and occurred with 59% of all peracarid orders sampled, followed by Amphipoda with 21%, Tanaidacea with 11%, Cumacea with 9%, and Mysidacea with <1%. The communities of the stations (and hauls) of the KKT abyssal area differ in terms of taxon composition from each other. A cluster analysis (nMDS) performed for all sampled stations revealed no clear pattern of community similarity between stations or hauls. All hauls close to the trench (2-9 and 2-10 close to the eastern slope of the KKT; and 3-9 and 4-3 at the western slope) were

  14. Fatty acid compositions and trophic relationships of shelled molluscs from the Kuril-Kamchatka Trench and the adjacent abyssal plain

    NASA Astrophysics Data System (ADS)

    Kharlamenko, Vladimir I.; Würzberg, Laura; Peters, Janna; Borisovets, Evgeny E.

    2015-01-01

    Fatty acid (FA) compositions of 12 species of shelled molluscs (gastropods, bivalves, and scaphopods) from the Kuril-Kamchatka Trench and the adjacent abyssal plain were studied. According to the results of multivariate statistical analysis, molluscs were divided into three groups. Group I consisted of three scaphopod species, the bivalve Nucula profundorum and the gastropod Solariella delicata. FA compositions of this group were characterized by high levels of 20:4(n-6). We suggest that the FA pattern found in scaphopods with high values of 20:4(n-6) is most likely typical for that of benthic organisms feeding preferentially on foraminiferans. Group II included the bivalves Neilonella politissima, Bentharca asperula, and Rhinoclama filatovae. Bivalves from the second group had elevated concentrations of 22:6(n-3), and the ratio of 20:4(n-6) to 20:5(n-3) was lower than 1. Bivalves from the second group had elevated concentrations of 22:6(n-3). We propose that high concentrations of this FA can be used as a specific marker for a carnivorous feeding mode of deep-sea benthic invertebrates. The bivalve Bathyspinula calcarella as well as the scaphopod Polyschides sakuraii could not unambiguously be assigned to one group. Within the similarity analysis they rather clustered together with the foraminiferans feeders (group I), but forming an own subgroup. In the PCA on the other hand, P. sakuraii showed a position close to the other bivalves, while B. calcarella had an intermediate position between all three groups. Group III consisted of the gastropods Tacita holoserica and Paracteocina sp., which contained high concentrations of 20:5(n-3) and 22:5(n-3). Both are known to exhibit a carnivorous/scavenging feeding strategy. The very low content of DHA in both species is on first sight not consistent with the suggested carnivorous feeding behavior. A characteristic feature of Paracteocina sp. and T. holoserica was a high level of 22:5(n-3), and HUFA ratios indicate that DHA

  15. Volcano-hydrothermal system of Ebeko volcano, Paramushir, Kuril Islands: Geochemistry and solute fluxes of magmatic chlorine and sulfur

    NASA Astrophysics Data System (ADS)

    Kalacheva, Elena; Taran, Yuri; Kotenko, Tatiana; Hattori, Keiko; Kotenko, Leonid; Solis-Pichardo, Gabriela

    2016-01-01

    Ebeko volcano at the northern part of Paramushir Island in the Kuril island arc produces frequent phreatic eruptions and relatively strong fumarolic activity at the summit area ~ 1000 m above sea level (asl). The fumaroles are characterized by low-temperature, HCl- and S-rich gas and numerous hyper-acid pools (pH < 1) without drains. At ~ 550 m asl, in the Yurieva stream canyon, many hot (up to 87 °C) springs discharge ultra-acidic (pH 1-2) SO4-Cl water into the stream and finally into the Sea of Okhotsk. During quiescent stages of degassing, these fumaroles emit 1000-2000 t/d of water vapor, < 20 t/d of SO2 and < 5 t/d of HCl. The measurement of acidic hot Yurieva springs shows that the flux of Cl and S, 60-80 t/d each, is independent on the volcanic activity in the last two decades. Such high flux of Cl is among the highest ever measured in a volcano-hydrothermal system. Oxygen and hydrogen isotopic composition of water and Cl concentration for Yurieva springs show an excellent positive correlation, indicating a mixing between meteoric water and magmatic vapor. In contrast, volcanic gas condensates of Ebeko fumaroles do not show a simple mixing trend but rather a complicated data suggesting evaporation of the acidic brine. Temperatures calculated from gas compositions and isotope data are similar, ranging from 150 to 250 °C, which is consistent with the presence of a liquid aquifer below the Ebeko fumarolic fields. Saturation indices of non-silicate minerals suggest temperatures ranging from 150 to 200 °C for Yurieva springs. Trace elements (including REE) and Sr isotope composition suggest congruent dissolution of the Ebeko volcanic rocks by acidic waters. Waters of Yurieva springs and waters of the summit thermal fields (including volcanic gas condensates) are different in Cl/SO4 ratios and isotopic compositions, suggesting complicated boiling-condensation-mixing processes.

  16. Building the Record of late Miocene to Pleistocene Explosive Activity in the Kurile-Kamchatka Volcanic Arc: Initial Results and Challenges

    NASA Astrophysics Data System (ADS)

    Ponomareva, V.; Portnyagin, M.; Derkachev, A.; Bazanova, L.; Bubenshchikova, N.; Garbe-Schönberg, D.; Leonov, V.; Plechova, A.; Rogozin, A.; Zelenin, E.

    2016-12-01

    Large explosive eruptions are among the most extreme natural events and can produce hemispheric or even global catastrophic effects. One of the prerequisites of predicting future giant eruptions is the understanding of sizes and recurrence times of past similar events. Volcanism of the North Pacific arcs is highly explosive, which is attested by large nested calderas and numerous tephra layers in marine and terrestrial sediments. At the same time regional record of large eruptions for the pre-Holocene times is still fragmentary. Our ongoing research, now funded by the Russian Science Foundation grant #16-17-10035, is aimed at the compilation of the late Miocene-Pleistocene record of large explosive eruptions from the Kurile-Kamchatka volcanic arc and analysis of the long-term variations in the composition of erupted products. Our studies are based on (1) tephra and cryptotephra sequences from the sediments of northwest Pacific seas; (2) tephra findings in the northeast Asian mainland; and (3) proximal pyroclastic deposits in Kamchatka and Kurile Islands. Geochemical characterization of tephra is based on the analysis of volcanic glass, minerals, and enclosed melt inclusions by electron microprobe, laser ablation-inductively coupled plasma-mass spectrometry, and secondary ion mass spectrometry. Tephra ages are provided by age-depth models for sediment cores and correlations to 14C or Ar-Ar dated proximal deposits. Up to date we have identified ten major middle to late Pleistocene tephras correlating between marine and terrestrial sites over distances of 600-1800 km and likely presenting M>6 eruptions from Kamchatka. Forty more tephras presented by one finding each were found at distances of 400-1500 km from volcanoes and also correspond to large eruptions. Correlation of distal tephras to proximal deposits appeared to be a major challenge because the latter are poorly studied and often have altered glass compositions. We suggest that melt inclusions in minerals

  17. Tsunami-induced electromagnetic fields at the seafloor caused by earthquakes on both sides of the Kuril trench

    NASA Astrophysics Data System (ADS)

    Toh, H.; Hamano, Y.; Goto, T.

    2009-12-01

    It is generally known that electromagnetic (EM) fields can be generated by ocean currents moving through the Earth’s magnetic field. Theory of motional induction in the ocean (Longuet-Higgins, 1949; Sanford, 1971; Chave and Luther, 1991) indicates that observations of the induced EM fields by oceanic dynamo effect can reveal large scale oceanic flows, which is usually difficult by other methods. Especially, detection of tsunami propagation in off-shore areas is very important to predict accurate arrival times and tsunami heights at the sea shore. Unlike conventional tsunami sensors such as ocean bottom pressure gauges, simultaneous measurements of seafloor electric and magnetic fields are superior in detecting arrival directions and particle motions of tsunami flows by a single station, since EM measurements are essentially vector measurements. Recently, it was found, for the first time, that EM time-series from seafloor observatories in the northwest Pacific captured clear signals of the tsunami-induced EM variations. We have been operating one long-term seafloor electromagnetic station at a site called NWP in the northwest Pacific basin since August, 2001 and the other (WPB) in the west Philippine basin since June, 2006 (Toh et al., 2004; 2006). Both stations have successfully provided seafloor EM time-series for slightly less than 2000 days at NWP and more than 900 days at WPB so far. On the other hand, the three years from the end of 2004 were found seismically so active in the Pacific region that the time period covered large tsunami-generating earthquakes such as off the west coast of northern Sumatra earthquake occurred on December 26, 2004. Among the tsunami-generated earthquakes, we focused our analysis to a pair of earthquakes occurred successively on both sides of the Kuril Trench in November, 2006 and January, 2007. It turned out the seafloor EM station at NWP succeeded in capturing the tsunami-induced EM fields. The most dominant periods of the

  18. Crustal structure around the asperity regions of large earthquakes along the southernmost Kuril trench revealed by two Airgun-OBS seismic profilings

    NASA Astrophysics Data System (ADS)

    Machida, Y.; Takanami, T.; Murai, Y.; Amamiya, S.; Nishimura, Y.; Shinohara, M.; McHizuki, K.; Yamada, T.; Nakahigashi, K.; Kuwano, A.; Kanazawa, T.; Hino, R.; Azuma, R.

    2007-12-01

    In the southeast off Hokkaido, Japan, large earthquakes have occurred repeatedly with temporal and spatial regularities along the Kuril trench due to the subduction of Pacific plate at a rate of 80 mm/year (DeMets et al., 1990) [e.g. the 1952 Tokachi-oki earthquake (Mw=8.2), the 1973 Nemuro-oki earthquake (Mw=7.8) and the 2003 Tokachi-oki earthquake (Mw=8.2)]. It is considered that the next large earthquake will occur at the source region of the 1973 Nemuro-oki earthquake in the near future because a low seismic activity has been found in the off shore region of the Nemuro peninsula. In order to clarify the relation between asperity and the recurrence of large earthquake, it is necessary to determine a detailed crustal structure running across the two asperities of the 2003 Tokachi-oki earthquake and 1973 Nemuro-oki earthquake. Therefore we conducted a wide-angle survey across the coseismic rupture areas of the 2003 Tokachi-oki and 1973 Nemuro-oki earthquakes and the afterslip area of the 2003 Tokachi-oki earthquake parallel (profile-A) and perpendicular (profile-B) to the Kuril trench using Ocean Bottom Seismometers (OBSs). In profile-A, 19 OBSs were deployed at a spacing of about 10km and three 25 liter air-guns were fired every 90 seconds which corresponds to a shot interval of about 230m. In profile-B, 11 OBSs were deployed at a spacing of about 11km and two 25 liter airguns were fired every 60 seconds which corresponds to a shot interval of about 150m. In this presentation, we report on the crustal structure using the data obtained in the profile A and B and compare our results with past researches around this region. This study is founded by the Ministry of Education, Culture, Sports, Science and Technology, Japan.

  19. New deep-sea large free-living nematodes from macrobenthos in the Kuril-Kamchatka Trench (the North-Western Pacific)

    NASA Astrophysics Data System (ADS)

    Fadeeva, Natalia; Mordukhovich, Vladimir; Zograf, Julia

    2015-01-01

    The composition of deep-sea nematode assemblages of the North-Western (NW) Pacific is poorly-studied. According to the available literature data more than 700 valid species of nematodes were reported from the depth of 400 m and deeper, out of that only 6 species were registered in the NW Pacific: 2 species from the coast of the Japanese Islands and 4 from the Sea of Japan. Ecological studies of the deep-sea nematode communities of this region are scanty and represent very scarce and fragmentary information. The first recent study of free-living nematodes collected from the abyssal plain adjacent to the Kuril-Kamchatka Trench has revealed more than 50 species of nematodes in macrobenthic samples. Families Anticomidae, Comesomatidae, Desmodoridae, Leptosomatidae, Oncholaimidae, Oxystominidae, Phanodermatidae, Siphonolaimidae and Thoracostomopsidae were the most abundant and diverse. Such taxonomic composition differs greatly from previously described meiobenthical nematode communities of NW Pacific and even World Ocean and similar to macrofaunal nematode assemblages of the Atlantic and Arctic regions. Several genera of nematodes can be considered as new records for the NW Pacific region. Micoletzkyia kamchatika sp. nov., Metaphanoderma improvisa sp. nov., and Phylloncholaimus palmaris sp. nov. are described from the Kuril-Kamchatka Trench. Micoletzkyia kamchatika sp. nov. is particularly characterized by a developed cuticular cephalic capsule underlying amphids, relatively small amphids, and the shape of the gubernaculum. Metaphanoderma improvisa sp. nov. is particularly characterized by a developed cuticular cephalic capsule, relatively large amphids, and the absence of pigmented eye spots. Phylloncholaimus palmaris sp. nov. is similar to the type species in many measurements but may be differentiated from that by the smaller amphid, shape of spicules and gubernaculums and by large precloacal papillae with four setae.

  20. Borehole geophysical, fluid, and hydraulic properties within and near the freshwater/saline-water transition zone, San Antonio segment of the Edwards aquifer, south-central Texas, 2010-11

    USGS Publications Warehouse

    Thomas, Jonathan V.; Stanton, Gregory P.

    2013-01-01

    The freshwater zone of the San Antonio segment of the Edwards aquifer is used by residents of San Antonio and numerous other rapidly growing communities in south-central Texas as their primary water supply source. This freshwater zone is bounded to the south and southeast by a saline-water zone with an intermediate zone transitioning from freshwater to saline water (transition zone). As demands on this water supply increase, there is concern that the transition zone could potentially move, resulting in more saline water in current freshwater supply wells. Since 1985, the U.S. Geological Survey, San Antonio Water System, and other Federal and State agencies have conducted studies to better understand the transition zone.

  1. TPH and PAH concentrations in the subsoil of polyduct segments, oil pipeline pumping stations, and right-of-way pipelines from Central Mexico

    NASA Astrophysics Data System (ADS)

    Iturbe, Rosario; Castro, Alejandrina; Perez, Guillermina; Flores, Carlos; Torres, Luis G.

    2008-10-01

    For the year 1996, 366 incidents related with clandestine poaching of oil-products were reported in Mexico, 159 in 1997, and 240 in 1998. For the year 2003 (the most recently reported figure), there were 136 events. Petroleos Mexicanos (PEMEX), very concerned with the environmental agenda, has developed programs oriented to diminish contamination levels in all of its oil facilities. This work was aimed at characterizing zones around polyduct segments, pipelines, pumping stations, and right-of-way pipelines located in the center of Mexico. The TPH contaminated sites were, in decreasing order, polyduct km 39 + 150 > polyduct km 25 + 020 > Zoquital > Tepetitlan > Catalina > Venta Prieta > Ceiba. Most of the sampled points showed the presence of more than one of the 16 PAHs considered by USEPA as priority pollutants. Except point TEPE 2A, where no PAHs were detected, all the sampled points showed values from low to medium concentrations; however, values found at the sites did not exceed the limits according to the Mexican or the American legislation. The place with the largest contaminated area corresponded to the polyduct km 39 + 150, with 130 m2 and 260 m3 to be treated. The least contaminated area was that around the JUAN 4 point at Juandho station, with 20 m2 and 22 m3 of contaminated soil. The total area to be treated is about 230 m2 and 497 m3.

  2. Thermoluminescence dating of fault-scarp-derived colluvium: Deciphering the timing of paleoearthquakes on the Weber segment of the Wasatch fault zone, north central Utah

    SciTech Connect

    Forman, S.L. ); Nelson, A.R. ); McCalpin J.P. )

    1991-01-10

    The timing of middle to late Holocene faulting on the Weber segment of the Wasatch fault zone, Utah, is constrained by thermoluminescence (TL) and radiocarbon age estimates on fine-grained, fault-related colluvial sediments. The stratigraphy in two trenches excavated across fault scarps is characterized by a stack of three colluvial wedges, deposited in response to three separate faulting events, the oldest of which buried a soil developed on a middle Holocene debris flow. Thermoluminescence age estimates by the partial and total bleach methods and the regeneration method on fine-grained colluvium from the trenches agree within 1 sigma and are concordant with the radiocarbon chronology. A synthesis of the TL and {sup 14}C age estimates indicate that these three faulting events occurred sometime between 4,500 and 3,500, between 3,200 and 2,500, and between 1,400 and 1,000 years ago. Detailed investigation of a sequence of fine-grained, scarp-derived distal colluvium shows that much of the sediment was deposited during <600-year intervals immediately after faulting. The sedimentation rate of colluvium is inferred to increase shortly after faulting, and TL dating of these sediments provides additional information to constrain the timing of faulting events.

  3. Rigid shape matching by segmentation averaging.

    PubMed

    Wang, Hongzhi; Oliensis, John

    2010-04-01

    We use segmentations to match images by shape. The new matching technique does not require point-to-point edge correspondence and is robust to small shape variations and spatial shifts. To address the unreliability of segmentations computed bottom-up, we give a closed form approximation to an average over all segmentations. Our method has many extensions, yielding new algorithms for tracking, object detection, segmentation, and edge-preserving smoothing. For segmentation, instead of a maximum a posteriori approach, we compute the "central" segmentation minimizing the average distance to all segmentations of an image. For smoothing, instead of smoothing images based on local structures, we smooth based on the global optimal image structures. Our methods for segmentation, smoothing, and object detection perform competitively, and we also show promising results in shape-based tracking.

  4. New evidence suggesting segmentation of Cocos Plate

    SciTech Connect

    Lew, L.R.; Sauermann, R.P.; De Boer, J.

    1985-02-01

    Compilation and analysis of geophysical and geological data indicate that the Cocos plate consists of three segments that have individual poles of rotation and independent motion vectors. Contoured heat-flow and gravity maps of the region delineate the boundaries of the segments within the Cocos plate. These segments have different focal-plane solutions along the Middle America Trench and different sedimentary-basin configurations within the Central America-Mexico island arc. Recent studies of seismic data from the region also have suggested that the subducted Cocos plate consists of three segments. The proposed northern and central segments are separated by the northeast-trending Siqueros-Tehuantepec Ridge fracture zone. The proposed central and southern segments are separated by the northeast-trending Costa Rica fracture zone that is located just northwest of the Cocos Ridge and extends from the Galapagos rift to the central valley of Costa Rica. Poles of rotation and relative motion vectors have been calculated with respect to the Caribbean plate for each segment. The northern segment is moving N75/sup 0/E, oblique to the trench; the central segment is moving N50/sup 0/E, perpendicular to the trench; the southern segment is moving north, perpendicular to the trench. The Siqueros-Tehuantepec and Costa Rice fracture zones appear to join with tectonized zones that dissect the Central America-Mexico island arc and extend across the Caribbean plate, suggesting that it too is segmented. Structural and stratigraphic data from the sedimentary basins on the island arc suggest that these fracture zones have existed throughout the Tertiary history of the region.

  5. Calcareous nannoplankton and foraminiferal response to global Oligocene and Miocene climatic oscillations: a case study from the Western Carpathian segment of the Central Paratethys

    NASA Astrophysics Data System (ADS)

    Holcová, Katarína

    2017-06-01

    The reactions of foraminiferal and calcareous nannoplankton assemblages to global warming and cooling events in the time intervals of ca. 27 to 19 Ma and 13.5 to 15 Ma (Oligocene and Miocene) were studied in subtropical epicontinental seas influenced by local tectonic and palaeogeographic events (the Central Paratethys). Regardless of these local events, global climatic processes significantly influenced the palaeoenvironment within the marine basin. Warm intervals are characterized by a stable, humid climate and a high-nutrient regime, due primarily to increased continental input of phytodetritus and also locally due to seasonal upwelling. Coarse clastics deposited in a hyposaline environment characterize the marginal part of the basin. Aridification events causing decreased riverine input and consequent nutrient decreases, characterized cold intervals. Apparent seasonality, as well as catastrophic climatic events, induced stress conditions and the expansion of opportunistic taxa. Carbonate production and hypersaline facies characterize the marginal part of the basins. Hypersaline surface water triggered downwelling circulation and mixing of water masses. Decreased abundance or extinction of K-specialists during each cold interval accelerated their speciation in the subsequent warm interval. Local tectonic events led to discordances between local and global sea-level changes (tectonically triggered uplift or subsidence) or to local salt formation (in the rain shadows of newly-created mountains).

  6. Compartmentalization of central neurons in Drosophila: a new strategy of mosaic analysis reveals localization of presynaptic sites to specific segments of neurites.

    PubMed

    Löhr, Robert; Godenschwege, Tanja; Buchner, Erich; Prokop, Andreas

    2002-12-01

    Synaptogenesis in the CNS has received far less attention than the development of neuromuscular synapses, although only central synapses allow the study of neuronal postsynaptic mechanisms and display a greater variety of structural and functional features. This neglect is attributable mainly to the enormous complexity of the CNS, which makes the visualization of individual synapses on defined neuronal processes very difficult. We overcome this obstacle and demonstrate by confocal microscopy the specific arrangement of output synapses on individual neurites. These studies are performed via genetic mosaic strategies in the CNS of the fruitfly Drosophila melanogaster. First, we use targeted expression of synaptic proteins by the UAS/Gal4 system. Second, we apply a newly developed transplantation-based mosaic strategy that takes advantage of the intrinsic regulation and localization of synaptic proteins in single-cell clones. We propose the existence of three distinct neuritic compartments: (1) primary neurites that appear to form the main transport pathways and are mostly void of output synapses, (2) neuritic compartments that contain output synapses, and (3) neuritic compartments that are postsynaptic in nature. In addition we show that mutations of the kakapo gene have no obvious effect on the distribution of output synapses in the CNS, whereas neuromuscular synapses are severely reduced. This suggests that synaptogenic mechanisms in the CNS might differ from those at neuromuscular junctions.

  7. Reduplication facilitates early word segmentation.

    PubMed

    Ota, Mitsuhiko; Skarabela, Barbora

    2017-02-06

    This study explores the possibility that early word segmentation is aided by infants' tendency to segment words with repeated syllables ('reduplication'). Twenty-four nine-month-olds were familiarized with passages containing one novel reduplicated word and one novel non-reduplicated word. Their central fixation times in response to these as well as new reduplicated and non-reduplicated words introduced at test showed that familiarized reduplicated words were segmented better than familiarized non-reduplicated words. These results demonstrate that infants are predisposed to segment words with repeated phonological elements, and suggest that register-specific words in infant-directed speech may have evolved in response to this learning bias.

  8. Chlorine Stable Isotopes to reveal contribution of magmatic chlorine in subduction zones: the case of the Kamchatka-Kuril and the Lesser Antilles Volcanic Arcs

    NASA Astrophysics Data System (ADS)

    Agrinier, Pierre; Shilobreeva, Svetlana; Bardoux, Gerard; Michel, Agnes; Maximov, Alexandr; Kalatcheva, Elena; Ryabinin, Gennady; Bonifacie, Magali

    2015-04-01

    By using the stable isotopes of chlorine (δ 37Cl), we have shown that magmatic chlorine (δ 37Cl ≤ -0.6 ‰ [1]) is different from surface chlorine (δ 37Cl ≈ 0 ‰ [1]) in hydrothermal system of Soufrière and Montagne Pelé from the young arc volcanic system of Lesser Antilles. First measurements on condensed chlorides from volcanic gases (e.g. [2], [3]) did not permitted to get sensible δ 37Cl values on degassed chlorine likely because chlorine isotopes are fractionated during the HClgas - chloride equilibrium in the fumaroles or during sampling artifacts. Therefore we have developed an alternative strategy based on the analysis of chloride in thermal springs, streams, sout{f}lowing on the flanks of the volcanoes. Due to the highly hydrophilic behavior of Cl, we hypothesize that thermal springs incorporate chlorine without fractionation of chlorine isotopes and might reflect the chlorine isotopic composition degassed by magmas [1]. Indeed Thermal spring with low δ 37Cl chlorides (≤ -0.6 perthousand{}) are linked with magmatic volatiles characters (3He ratio at 5 Ra at and δ 13C CO2 quad ≈ -3 perthousand{}). To go further in the potentiality of using the Chlorine isotopes to reveal contribution of magmatic chlorine in volcanic systems, we have started the survey of thermal springs and wells waters in the Kamchatka-Kuril volcanic mature Arc (on sites Mutnovsky, Paratunka, Nalychevsky, Khodutkinsky, Paramushir Island, identified by Taran, 2009 [4] for concentrations of chloride). Preliminary results show δ 37Cl values ranging from 0.5 to -0.2 ‰ and generally higher chloride concentrations. The δ 37Cl values are higher than the value recorded for the young arc volcanic system of lesser Antilles. At present moment very few negative δ 37Cl have been measured in the Kamchatka-Kuril volcanic mature Arc. [1] Li et al., 2015 EPSL in press. [2] Sharp et al. 2010 GCA. [3] Rizzo et al., 2013, EPSL, 371, 134. [4] Taran, 2009, GCA, 73, 1067

  9. The Tohoku Tsunami of 11 March 2011: The Key Event to Understanding Tsunami Sedimentation on the Coasts of Closed Bays of the Lesser Kuril Islands

    NASA Astrophysics Data System (ADS)

    Razjigaeva, N. G.; Ganzey, L. A.; Grebennikova, T. A.; Ivanova, E. D.; Kharlamov, A. A.; Kaistrenko, V. M.; Arslanov, Kh. A.; Chernov, S. B.

    2014-12-01

    The Tohoku tsunami of 11 March 2011 manifested in the region of the South Kuril Islands, although, as a rule, the run-up heights in this region did not exceed 3 m. In closed bays that were covered with ice before the tsunami, the eroding capacity of tsunami waves was aggravated by the ice fragments they carried. Here, mud sheets formed, reaching up to 106 m inland. The 2012 studies have shown well-preserved tsunami deposits, evident 1.5 years after the event. A comparative analysis of tsunami deposits from the periphery and from the near-field area close to the tsunami source was performed; this was important for understanding the deposition mechanism during the event, as it had different strengths on different shores. The difference in run-up heights determined the considerable differences in erosion, sedimentation, distribution of tsunami deposits, the formation of sedimentary structures, grain-size composition, and diatom and foraminifera assemblages. The sources of the material also varied significantly from each other: the material came from offshore in closed bays located in the tsunami source periphery, while in the near-field region close to the epicenter, the most active erosion occurred in the inundation area. In the latter area, the main sources of sand were beaches and dunes, while soil erosion was the source of mud. Studies of the Tohoku tsunami on the coasts of the Lesser Kuril Islands demonstrated that mud layers in the sections of coastal lowlands in closed bays could contain preserved detailed geological records of paleotsunamis, even those with a small-height run-up. In the sections of coastal peatlands of closed bays on Shikotan Island, up to 7-9 layers of mud and silty sands were found, these can easily be traced for more than 500 m inland. The grain-size composition of the mud is similar to the deposits of the 2011 Tohoku tsunami. The marine origin of these deposits is confirmed by the diatom analysis data.

  10. Automated lung segmentation in digital chest tomosynthesis

    PubMed Central

    Wang, Jiahui; Dobbins, James T.; Li, Qiang

    2012-01-01

    Purpose: The purpose of this study was to develop an automated lung segmentation method for computerized detection of lung nodules in digital chest tomosynthesis. Methods: The authors collected 45 digital tomosynthesis scans and manually segmented reference lung regions in each scan to assess the performance of the method. The authors automated the technique by calculating the edge gradient in an original image for enhancing lung outline and transforming the edge gradient image to polar coordinate space. The authors then employed a dynamic programming technique to delineate outlines of the unobscured lungs in the transformed edge gradient image. The lung outlines were converted back to the original image to provide the final segmentation result. The above lung segmentation algorithm was first applied to the central reconstructed tomosynthesis slice because of the absence of ribs overlapping lung structures. The segmented lung in the central slice was then used to guide lung segmentation in noncentral slices. The authors evaluated the segmentation method by using (1) an overlap rate of lung regions, (2) a mean absolute distance (MAD) of lung borders, (3) a Hausdorff distance of lung borders between the automatically segmented lungs and manually segmented reference lungs, and (4) the fraction of nodules included in the automatically segmented lungs. Results: The segmentation method achieved mean overlap rates of 85.7%, 88.3%, and 87.0% for left lungs, right lungs, and entire lungs, respectively; mean MAD of 4.8, 3.9, and 4.4 mm for left lungs, right lungs, and entire lungs, respectively; and mean Hausdorrf distance of 25.0 mm, 25.5 mm, and 30.1 mm for left lungs, right lungs, and entire lungs, respectively. All of the nodules inside the reference lungs were correctly included in the segmented lungs obtained with the lung segmentation method. Conclusions: The method achieved relatively high accuracy for lung segmentation and will be useful for computer-aided detection

  11. Aftershock distribution of the October 4, 1994 Mw8.3 Kurile Islands Earthquake determined by a local seismic network in Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Katsumata, K.; Ichiyanagi, M.; Miwa, M.; Kasahara, M.; Miyamachi, H.

    On October 4, 1994, an earthquake with magnitude Mw8.3 occurred in the western part of Kurile Islands at 43.42°N, 146.81°E and 33 km in depth. The hypocenter parameters were determined by Hokkaido University in Japan. Aftershocks following this remarkable event were located using data from a local seismic network operated by Hokkaido University. We found that most of the aftershocks occurred (1) on the fault plane of the mainshock, (2) in the subducting plate around the fault plane of the mainshock, and (3) in the focal area of the largest aftershock, which occurred on October 9 with Mw7.3. Both (2) and (3) were not active immediately after the mainshock. Considering the time sequence of the aftershock activity, we identified one of the nodal planes of the Harvard quick CMT solutions as the fault plane of the mainshock; the strike is almost parallel to the trench axis and the dip angle is near vertical. It is obvious that this event is different from a low-angle thrust-type interplate earthquake. The distribution of aftershocks strongly suggests that it is an intraplate event.

  12. Evaluation of velocity-related approximations in the nonlinear shallow water equations for the Kuril Islands, 2006 tsunami event at Honolulu, Hawaii

    NASA Astrophysics Data System (ADS)

    Arcas, Diego; Wei, Yong

    2011-06-01

    The Nonlinear Shallow Water Equations (NSWE) provide a model for long wave behavior commonly used in tsunami modeling problems in which the scale associated with the surface wavelength is much greater than the ocean depth. This approximation allows for the derivation of the NSWE under the assumptions that the pressure is hydrostatic and the horizontal velocity components uniform along the water column. The present study uses current velocity data acquired by the Kilo Nalu Near-Shore Reef Observatory Acoustic Doppler Current Profiler (ADCP) on the south shore of Oahu (21.288°N, 157.865°W) in the aftermath of the 2006 Kuril tsunami to assess the validity of the NSWE assumptions on the velocity components. ADCP measurements provide information on all three velocity components along the water column, allowing the calculation of terms discarded in the NSWE approximation, containing temporal or vertical derivatives. Comparison of the relative magnitude of terms retained and neglected in the NSWE reveals that in shallow waters (10 m) the size of discarded terms remains smaller, but approaches the order of magnitude of retained terms in the momentum equations. Not all terms present in the equations can be evaluated from the available data, so verification of the assumptions investigated here represents a necessary but not sufficient condition for the validity of the NSWE approximation to model tsunami waves in shallow coastal waters.

  13. Description and phylogenetic position of the first abyssal solitary kamptozoan species from the Kuril-Kamchatka Trench area: Loxosomella profundorum sp. nov. (Kamptozoa: Loxosomatidae)

    NASA Astrophysics Data System (ADS)

    Borisanova, Anastasia O.; Chernyshev, Alexei V.; Neretina, Tatyana V.; Stupnikova, Alexandra N.

    2015-01-01

    One of two orders of a small phylum Kamptozoa, Solitaria, consisting of one family Loxosomatidae of about 140 species, has never been recorded deeper than 700 m. All known for the north-western Pacific loxosomatids (about 17 species) occur in shallow waters. The first abyssal solitary kamptozoan, Loxosomella profundorum sp. nov. is described herein. It was collected during the German-Russian deep-sea expedition KuramBio aboard RV Sonne in the summer of 2012 in the abyssal plain adjacent to the Kuril-Kamchatka Trench. It is the deepest finding of Kamptozoa to date. The new species was found living on the anthozoan polyp Corallimorpharia. L. profundorum sp. nov. is a largest solitary kamptozoan species, up to 4 mm in length, with a stalk of up to 3.5 mm, with 10-12 tentacles, with two conspicuous lateral papillae, and a row of glandular cells in its stalk. A preliminary molecular phylogenetic analysis based on partial 18S rDNA indicated that L. profundorum sp. nov. is a sister clade to the clade, which includes other Loxosomella and two species of Loxomitra.

  14. Manifestation of carbonate-barite mineralization around methane seeps in the Sea of Okhotsk (the western slope of the Kuril Basin)

    NASA Astrophysics Data System (ADS)

    Derkachev, A. N.; Nikolaeva, N. A.; Baranov, B. V.; Barinov, N. N.; Mozherovskiy, A. V.; Minami, H.; Hachikubo, A.; Shoji, H.

    2015-05-01

    First data are reported on a new manifestation of carbonate-barite mineralization found at a site of methane emanations on the western slope of the Kuril Basin, Sea of Okhotsk. Morphological types of barite, aragonite, and low-magnesian calcite are considered in detail; the results of carbon and oxygen isotope study of carbonate concretions and crusts are presented. It is shown that the barite was formed in sediments owing to the diffusion infiltration of the barium-rich fluids through sedimentary succession. The component and isotope compositions of gases are determined and the relatively elevated content of heavy hydrocarbons is revealed. It was assumed that the relatively heavy isotope composition of carbonates is caused by the influence of fluid released from deep sedimentary horizons owing to the dehydration of clay minerals during post- sedimentation transformations. Obtained data show that the origin of carbonate-barite mineralization is related to the migration of hydrocarbons (mainly methane) and barium-bearing cold gas-fluid flows, which were derived not only from near-surface reservoirs but also from deeper-seated sources.

  15. Event segmentation ability uniquely predicts event memory.

    PubMed

    Sargent, Jesse Q; Zacks, Jeffrey M; Hambrick, David Z; Zacks, Rose T; Kurby, Christopher A; Bailey, Heather R; Eisenberg, Michelle L; Beck, Taylor M

    2013-11-01

    Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segment activity into meaningful events a unique predictor of subsequent memory, or is the relationship between event perception and memory accounted for by general cognitive abilities? Two hundred and eight adults ranging from 20 to 79years old segmented movies of everyday events and attempted to remember the events afterwards. They also completed psychometric ability tests and tests measuring script knowledge for everyday events. Event segmentation and script knowledge both explained unique variance in event memory above and beyond the psychometric measures, and did so as strongly in older as in younger adults. These results suggest that event segmentation is a basic cognitive mechanism, important for memory across the lifespan.

  16. Segmentation and segment connection of obstructed colon

    NASA Astrophysics Data System (ADS)

    Medved, Mario; Truyen, Roel; Likar, Bostjan; Pernus, Franjo

    2004-05-01

    Segmentation of colon CT images is the main factor that inhibits automation of virtual colonoscopy. There are two main reasons that make efficient colon segmentation difficult. First, besides the colon, the small bowel, lungs, and stomach are also gas-filled organs in the abdomen. Second, peristalsis or residual feces often obstruct the colon, so that it consists of multiple gas-filled segments. In virtual colonoscopy, it is very useful to automatically connect the centerlines of these segments into a single colon centerline. Unfortunately, in some cases this is a difficult task. In this study a novel method for automated colon segmentation and connection of colon segments' centerlines is proposed. The method successfully combines features of segments, such as centerline and thickness, with information on main colon segments. The results on twenty colon cases show that the method performs well in cases of small obstructions of the colon. Larger obstructions are mostly also resolved properly, especially if they do not appear in the sigmoid part of the colon. Obstructions in the sigmoid part of the colon sometimes cause improper classification of the small bowel segments. If a segment is too small, it is classified as the small bowel segment. However, such misclassifications have little impact on colon analysis.

  17. Water-level, borehole geophysical log, and water-quality data from wells transecting the freshwater/saline-water interface of the San Antonio segment of the Edwards Aquifer, South-Central Texas, 1999-2007

    USGS Publications Warehouse

    Lambert, Rebecca B.; Hunt, Andrew G.; Stanton, Gregory P.; Nyman, Michael B.

    2009-01-01

    As a part of a 9-year (1999-2007) study done by the U.S. Geological Survey in cooperation with the San Antonio Water System to improve understanding of the San Antonio segment of the Edwards aquifer, south-central Texas, in and near the freshwater/saline-water transition zone of the aquifer, the U.S. Geological Survey collected water-level, borehole geophysical, and water-quality data during 1999-2007 from 37 wells arranged in nine transects (except for two wells) across the freshwater/saline-water interface of the aquifer. This report presents the data collected and also describes the data-collection, analytical, and quality-assurance methods used. The wells, constructed with casing from land surface into the upper part of the aquifer and completed as open hole in the aquifer, are in Uvalde County (East Uvalde transect), in Medina County (South Medina and Devine wells), in Bexar County (Pitluk, Mission, and San Antonio transects), in Comal and Guadalupe Counties (Tri-County transect), in Comal County (New Braunfels transect), and in Hays County (Fish Hatchery, San Marcos, and Kyle transects). Data collected included continuous water level at 18 wells; fluid electrical conductivity and temperature with depth (fluid profiles) obtained by borehole geophysical logging of 15 wells; discrete (periodic) samples for major ions and trace elements at 36 wells; stable isotopes or stable isotopes and tritium at 27 wells; dissolved gases obtained by pumping (or collecting flow) of 19 wells; and continuous specific conductance and temperature at three of the wells equipped with continuous water-level sensors.

  18. Composition and distribution of Munnopsidae (Crustacea, Isopoda, Asellota), collected during the KuramBio expedition 2012 from the Kuril-Kamchatka Trench area

    NASA Astrophysics Data System (ADS)

    Malyutina, Marina V.; Brandt, Angelika

    2015-01-01

    The abyssal macrobenthos of the Kuril-Kamchatka Trench (KKT) area was sampled for the first time using a fine-meshed camera-epibenthic sledge (C-EBS) during the German-Russian KuramBio expedition 2012 (RV Sonne, 223 cruise). Crustaceans of the order Isopoda were one of the dominant macrobenthic taxa, and the family Munnopsidae was the most abundant and diverse among 17 collected asellotan families, comprising about 48% of all isopods. During the KuramBio expedition no less than 80 species of 28 genera and eight subfamilies of Munnopsidae were collected with 21 EBS hauls at 12 stations. About 80% species are new to science and half of the genera and the subfamily Lipomerinae are recorded for the first time in the Northwest Pacific. The most abundant and speciose subfamily was Eurycopinae (58% of all specimens and 29 % of species), followed by Ilyarachninae (12% and 16%). Most species are rare and occur with low abundance at one or few stations. Ten most numerous species belonging to the genera Eurycope (5 species), Microcope (2), Disconectes (1), Ilyarachna (1) and Aspidarachna (1) comprised 68% of all munnopsids. The species Eurycope sp.1 and Microcope ovata (Birstein, 1970) were the most abundant and frequent species, occurring at all stations. The highest abundance of Munnopsidae and high diversity, with 32 species, occurred at station 3-9 on the western slope of the KKT. The cluster analysis of the Bray-Curtis similarity shows a low similarity between stations. The least similar was station 1-10, with only 26% similarity with other stations. Low similarity also characterized station 3-9 (34%). The comparison with known data revealed differences in species composition of Munnopsidae of the abyssal plain of the KKT area and the fauna of adjacent bathyal and hadal zones. Similar ratios of the munnopsid subfamilies and genera and some similar species have been revealed for the KuramBio and ANDEEP areas.

  19. Sonnenemertes cantelli gen. et sp. nov. (Heteronemertea)-A new Oxypolella-like nemertean from the abyssal plain adjacent to the Kuril-Kamchatka Trench

    NASA Astrophysics Data System (ADS)

    Chernyshev, Alexei V.; Abukawa, Shushi; Kajihara, Hiroshi

    2015-01-01

    Approximately 129 nemertean specimens were obtained in the material collected by the Russian-German KuramBio expedition 2012 to the abyssal plain adjacent to the Kuril-Kamchatka Trench (KKT). Due to deformed, fragmentary condition of most of the collected nemerteans they were identified to the order level only. Both archi- and heteronemerteans were very rare, and tubulanid palaeonemerteans and hoplonemerteans were predominant in the KuramBio epibenthic sledge (EBS) samples. Before the KuramBio expedition, only three species of the World fauna of benthic nemerteans had been known from depths exceeding 3000 m; according to data of Vityaz expedition in the KKT, published in 1955, unidentified nemerteans were found in all trawl samples from depths 1000 to 4640 m, but only one specimen of unidentified nemertean was collected from depths exceeding 5000 m. A reliable estimation of the actual species diversity of the present KuramBio samples could have been made primarily based on molecular genetic analyses; almost all the collected specimens are likely to represent undescribed species. In this study, a new species of the heteronemertean, Sonnenemertes cantelli gen. et sp. nov., from a depth of approximately 4870 m is described. This is the deepest record for an identified benthic nemertean, as well as the first species of the subfamily Oxypolellinae from the North Pacific. A single specimen was examined by light microscopy, scanning electron microscopy, and confocal laser scanning microscopy with phalloidin and antibody labeling. Morphologically, this species is similar to those in the genus Oxypolella. A preliminary molecular phylogenetic analysis based on partial 16S rDNA among the selected heteronemertean species indicated that S. cantelli formed a monophyletic group with Oxypolella alba Bergendal, 1903 together as a sister to the genus Baseodiscus. Systematic positioning of Oxypolella, Sonnenemertes, and related genera is discussed.

  20. A New Approach to Study the Upper-Mantle Seismic Discontinuities Based on Triplication Data: Application to the Kuril Subduction Zone Using Hi-net Array

    NASA Astrophysics Data System (ADS)

    Park, S.; Okeler, A.; Ishii, M.

    2015-12-01

    Constraining seismic properties of the 410- and 660-km discontinuities is crucial for understanding the mantle composition and dynamics. One approach to study the transition zone is to use the "triplicated" arrivals of seismic data. When a wavefield encounters an abrupt increase in wave speed with depth, three different phases, direct, reflected, and transmitted phases, result, and they can arrive at the same distance, producing the triplicated arrivals. Properties of the triplication pattern provide constraints on the depth and velocity jump of the discontinuities. One of the challenging aspects of using the triplication data, however, is to identify the three individual phases, since they arrive close in time and the waveforms often overlap. In order to separate the phases, we apply Radon transform to the data. Based on the transformed data, the caustics are identified, and the depth and the velocity jump of the discontinuities are obtained. This method is applied to study the Kuril subduction zone, beneath a region northeast of Japan. We take advantage of the High-Sensitivity Seismograph Network in Japan that consists of more than 700 stations, to capture the triplication pattern with dense sampling in distance. Given the distribution of the stations, deep and intermediate earthquakes in the Sea of Okhotsk region that are located within the triplication distance range are considered. We constrain the percentage velocity jump and depth of the 410- and 660-km discontinuities. The discontinuity depth estimates show significant deviations from the global average, but are, in general, comparable to the SS precursors and tomographic studies of the region.

  1. 2009 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, Robert G.; Neal, Christina A.; Girina, Olga A.; Chibisova, Marina; Rybin, Alexander

    2014-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest, and reports of unusual activity at or near eight separate volcanic centers in Alaska during 2009. The year was highlighted by the eruption of Redoubt Volcano, one of three active volcanoes on the western side of Cook Inlet and near south-central Alaska's population and commerce centers, which comprise about 62 percent of the State's population of 710,213 (2010 census). AVO staff also participated in hazard communication and monitoring of multiple eruptions at ten volcanoes in Russia as part of its collaborative role in the Kamchatka and Sakhalin Volcanic Eruption Response Teams.

  2. Recent (2008-10) water quality in the Barton Springs segment of the Edwards aquifer and its contributing zone, central Texas, with emphasis on factors affecting nutrients and bacteria

    USGS Publications Warehouse

    Mahler, Barbara J.; Musgrove, MaryLynn; Sample, Thomas L.; Wong, Corinne I.

    2011-01-01

    The Barton Springs zone, which comprises the Barton Springs segment of the Edwards aquifer and the watersheds to the west that contribute to its recharge, is in south-central Texas, an area with rapid growth in population and increasing amounts of land area affected by development. During November 2008-March 2010, an investigation of factors affecting the fate and transport of nutrients and bacteria in the Barton Springs zone was conducted by the U.S. Geological Survey (USGS), in cooperation with the Texas Commission on Environmental Quality. The primary objectives of the study were to characterize occurrence of nutrients and bacteria in the Barton Springs zone under a range of flow conditions; to improve understanding of the interaction between surface-water quality and groundwater quality; and to evaluate how factors such as streamflow variability and dilution affect the fate and transport of nutrients and bacteria in the Barton Springs zone. The USGS collected and analyzed water samples from five streams (Barton, Williamson, Slaughter, Bear, and Onion Creeks), two groundwater wells (Marbridge and Buda), and the main orifice of Barton Springs in Austin, Texas. During the period of the study, during which the hydrologic conditions transitioned from exceptional drought to wetter than normal, water samples were collected routinely (every 3 to 4 weeks) from the streams, wells, and spring and, in response to storms, from the streams and spring. All samples were analyzed for major ions, nutrients, the bacterium Escherichia coli, and suspended sediment. During the dry period, the geochemistry of groundwater at the two wells and at Barton Springs was dominated by flow from the aquifer matrix and was relatively similar and unchanging at the three sites. At the onset of the wet period, when the streams began to flow, the geochemistry of groundwater samples from the Marbridge well and Barton Springs changed rapidly, and concentrations of most major ions and nutrients and

  3. Late Paleozoic tectono-metamorphic evolution of the Altai segment of the Central Asian Orogenic Belt: Constraints from metamorphic P-T pseudosection and zircon U-Pb dating of ultra-high-temperature granulite

    NASA Astrophysics Data System (ADS)

    Li, Zilong; Yang, Xiaoqiang; Li, Yinqi; Santosh, M.; Chen, Hanlin; Xiao, Wenjiao

    2014-09-01

    Ultra-high-temperature (UHT) granulite-facies rocks offer important constraints on crustal evolution processes and tectonic history of orogens. UHT granulites are generally rare in Phanerozoic orogens. In this study, we investigate the late Paleozoic pelitic UHT granulites from Altai in the western segment of the Central Asian Orogenic Belt (CAOB). The diagnostic minerals in these rocks include high alumina orthopyroxene (Al2O3 up to 9.76 wt.%, and y(opx) = AlVI in orthopyroxene up to 0.21) coexisting with sillimanite and quartz, and low Zn spinel (ZnO = 1.85-2.50 wt.%) overgrowth with quartz. Cordierite corona separates sillimanite from orthopyroxene. The high alumina orthopyroxene is replaced by symplectites of low-alumina orthopyroxene (~ 5.80 wt.% Al2O3) and cordierite. These textural observations are consistent with a significant decompression following the peak UHT metamorphism. Phase equilibrium modeling using pseudosections and the y(opx) isopleths indicate an anti-clockwise P-T path for the exhumation of the Altai orogenic belt. The pre-peak assemblage of spinel + quartz in garnet is stable at high- to ultra-high-temperature and low-pressure conditions (P < 5.8 kbar at T ~ 900 °C). The peak P-T values recorded by high aluminium orthopyroxene is > 940 °C and 7.8 to 10 kbar. Subsequent near-isothermal decompression occurred at 890 to 940 °C and 5 to 6 kbar. The final-stage cooling is recorded at 750 and 800 °C and 4 to 5 kbar accompanied by a decrease in the y(opx) values (0.11-0.12). In the UHT granulite, zircon grains are commonly enclosed within cordierite. The overgrowth rims of the zircon grains yield a weighted mean 206Pb/238U age of 277 ± 2 Ma using LA-ICP-MS zircon dating, which is interpreted to mark the timing of decompression and cooling. We propose that the anti-clockwise P-T path of the UHT granulite in the Altai orogenic belt could be related to an extensional event related to the sinistral strike-slip along the Irtish tectonic belt after

  4. Intensive hydration of the wedge mantle at the Kuril arc - NE Japan arc junction: implications from mafic lavas from Usu Volcano, northern Japan

    NASA Astrophysics Data System (ADS)

    Kuritani, T.; Tanaka, M.; Yokoyama, T.; Nakagawa, M.; Matsumoto, A.

    2015-12-01

    The southwestern part of Hokkaido, northern Japan, is located at the junction of the NE Japan arc and the Kuril arc. The subducting Pacific plate under this region shows a hinge-like shape due to the dip change of the subducting plate along the trench. Because of the interest in this unique tectonic setting, this arc-arc junction has been the focus of extensive geophysical studies (e.g. Kita et al., 2010, Morishige and van Keken, 2014; Wada et al., 2015). This region is also known as an area in which magmatism has been intense; there are many active volcanoes such as Usu, Tarumae, and Komagatake, and large calderas including Toya, Shikotsu, and Kuttara. In this region, the temporal and spatial evolution of the volcanism and the chemical compositions of the volcanic rocks are well characterized (e.g. Nakagawa, 1992). However, the generation conditions of magmas have not been estimated for these volcanoes, probably because of the scarcity of basaltic products. Therefore, a possible link between the tectonic setting and the intense magmatism is still unclear. In this study, we carried out a petrological and geochemical study on mafic lavas (49.6-51.3 wt.% SiO2) from Usu Volcano, and estimated the conditions under which the magmas were generated. By application of a plagioclase-melt hygrometer to the plagioclase and the host magma, the water content of ~6.5 wt.% was obtained for the basaltic magma. Using this information, as well as the olivine maximum fractionation model (Tatsumi et al., 1983), the composition of the primary magma is estimated to be 47.9 wt.% SiO2, 15.1 wt.% MgO, and 4.1 wt.% H2O. Analyses using the multi-component thermodynamics suggest that the primary magma was generated in the source mantle with 0.9 wt.% H2O at 1310ºC and at 1.6 GPa. The water content of 0.9 wt.% of the source mantle is significantly higher than the estimates for the source mantle in the main NE Japan arc (<0.7 wt.% H2O); this implies that the flux of slab-derived fluids is

  5. Segmented trapped vortex cavity

    NASA Technical Reports Server (NTRS)

    Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

    2010-01-01

    An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

  6. Station Tour: Russian Segment

    NASA Image and Video Library

    Expedition 33 Commander Suni Williams concludes her tour of the International Space Station with a visit to the Russian segment, which includes Zarya, the first segment of the station launched in 1...

  7. XRA image segmentation using regression

    NASA Astrophysics Data System (ADS)

    Jin, Jesse S.

    1996-04-01

    Segmentation is an important step in image analysis. Thresholding is one of the most important approaches. There are several difficulties in segmentation, such as automatic selecting threshold, dealing with intensity distortion and noise removal. We have developed an adaptive segmentation scheme by applying the Central Limit Theorem in regression. A Gaussian regression is used to separate the distribution of background from foreground in a single peak histogram. The separation will help to automatically determine the threshold. A small 3 by 3 widow is applied and the modal of the local histogram is used to overcome noise. Thresholding is based on local weighting, where regression is used again for parameter estimation. A connectivity test is applied to the final results to remove impulse noise. We have applied the algorithm to x-ray angiogram images to extract brain arteries. The algorithm works well for single peak distribution where there is no valley in the histogram. The regression provides a method to apply knowledge in clustering. Extending regression for multiple-level segmentation needs further investigation.

  8. [Population genetic structure of the char species of the Northern Kuril Islands and the rank of the Dolly Varden Char in the system of the genus Salvelinus (Salmonidae: Teleostei)].

    PubMed

    Shubina, E A; Ponomareva, E V; Gritsenko, O F

    2006-01-01

    Analysis of the taxonomic position of most species and forms of the char (genus Salvelinus, Salmonidae: Teleostei) was made based on RAPD-PCR. The material was represented by samples from 29 populations from the Kuril Islands, coast of the Sea of Okhotsk, Kamchatka, Chukotka, Taymyr, Transbaikalia, the Kola Peninsula, Svalbard, Finland, and North America. It was shown that the genus Salvelinus splits into three well-justified clusters: (1) all the forms assigned to the Salvelinus alpinus--S. malma complex; (2) two samples of the White-Spotted Char from the Southern Kuril Islands and from Kamchatka; (3) two North American species, S. fontinalis and S. namaycush (samples of the North American species S. confluentis were absent from the collection). Analysis of the absolute values of genetic disctances of the S. alpinus--S. malma forms relative to S. leucomaenis, S. fontinalis, and S. namaycush revealed distances approaching the species rank between the following isolates: Frolikh Char, Mountain Char, Black Lake Char, Goggle-Eyed Char, and Neyva Char. Samples of Dolly Varden currently considered as "S. malma", do not constitute a separate cluster, falling within the group of the Arctic char S. alpinus. This conclusion is supported by the analysis of the results of three series of experiments by R. Phillips on ITS1 ribosome genes (Pleute et al., 1992; Phillips et al., 1995; Phillips et al., 1999). This indicates the infraspecific rank of malma within S. alpinus. Isolated populations of "Salvethymus svetovidovi" from the lake Elgygytgyn (Chukotka Peninsula) and of the char from the lake Chyornoye (Onekotan Island), recently described as S. gritzenkoi (Vasil'eva, Stygar, 2000), fell withing the S. alpinus--S. malma complex, the Onekotan char grouped together with another isolate from the same island. Comparison of genetic distances between the samples showed that the differences between the two isolated of Onekotan and migratory forms of the Kuril Islands are

  9. Color image segmentation

    NASA Astrophysics Data System (ADS)

    McCrae, Kimberley A.; Ruck, Dennis W.; Rogers, Steven K.; Oxley, Mark E.

    1994-03-01

    The most difficult stage of automated target recognition is segmentation. Current segmentation problems include faces and tactical targets; previous efforts to segment these objects have used intensity and motion cues. This paper develops a color preprocessing scheme to be used with the other segmentation techniques. A neural network is trained to identify the color of a desired object, eliminating all but that color from the scene. Gabor correlations and 2D wavelet transformations will be performed on stationary images; and 3D wavelet transforms on multispectral data will incorporate color and motion detection into the machine visual system. The paper will demonstrate that color and motion cues can enhance a computer segmentation system. Results from segmenting faces both from the AFIT data base and from video taped television are presented; results from tactical targets such as tanks and airplanes are also given. Color preprocessing is shown to greatly improve the segmentation in most cases.

  10. Rock magnetic and petrographical-mineralogical studies of the dredged rocks from the submarine volcanoes of the Sea-of-Okhotsk slope within the northern part of the Kuril Island Arc

    NASA Astrophysics Data System (ADS)

    Rashidov, V. A.; Pilipenko, O. V.; Petrova, V. V.

    2016-07-01

    The rock magnetic properties of the samples of dredged rocks composing the submarine volcanic edifices within the Sea-of-Okhotsk slope of the northern part of the Kuril Island Arc are studied. The measurements of the standard rock magnetic parameters, thermomagnetic analysis, petrographical studies, and microprobe investigations have been carried out. The magnetization of the studied rocks is mainly carried by the pseudo-single domain and multidomain titanomagnetite and low-Ti titanomagnetite grains. The high values of the natural remanent magnetization are due to the pseudo-single-domain structure of the titanomagnetite grains, whereas the high values of magnetic susceptibility are associated with the high concentration of ferrimagnetic grains. The highest Curie points are observed in the titanomagnetite grains of the igneous rocks composing the edifices of the Smirnov, Edelshtein, and 1.4 submarine volcanoes.

  11. A multi-sensor analysis of the 2009 eruption of Sarychev Peak, Kuril Islands: A case study for hazards to aviation

    NASA Astrophysics Data System (ADS)

    Williams, D.; Thomas, H. E.; Watson, M. I.

    2010-12-01

    The eruption of Sarychev Peak Volcano (48°N,153°E), Kuril Islands, occurred between June 12 and 18 2009 emplacing large volumes of sulphur dioxide and volcanic ash into the atmosphere and severely disrupting air traffic in the region. The eruption was observed by several satellite-borne sensors, including the Ozone Monitoring Instrument (OMI), the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS). This work uses these three sensors concurrently, as the use of several instruments provides more frequent datasets enabling improvements in accurately locating volcanic clouds and the subsequent validation of dispersion models. The North Pacific region sees a large amount of air traffic and the clouds from Sarychev Peak intersected many major air routes. Volcanic ash poses a threat to the operation of aircraft by abrading the engines which can result in failure, as well as “sand blasting” of the cockpit windows. It is also important to detect and map any sulphur dioxide clouds created, as this can also be hazardous for aircraft. Volcanic aerosol can cause corrosion on the aircraft exterior and sulphur based minerals may be deposited within the engines, blocking cooling holes over time. SO2 can also enter the aircraft cabin through the ventilation system, which can cause respiratory problems for the passengers and crew. In addition, SO2 is often associated with volcanic ash as the two species are frequently collocated. When ash retrievals are limited by high concentrations of water vapour and ice in the atmosphere, the presence of SO2 can be used to infer the location of a potential ash cloud, so that aircraft encounters may be avoided. A collection of images from the three sensors, ranging from June 10 to 24 were acquired to determine the mass and location of the SO2 cloud. This data, along with ash cloud data collected from the two MODIS sensors for dates between June 11 and 20, was then used to create a chronology of

  12. KALMAR - "Kurile-Kamchatka and Aleutean Marginal Sea-Island Arc Systems: Geodynamic and Climate Interaction in Space and Time" - an integrated science approach between Russia and Germany

    NASA Astrophysics Data System (ADS)

    Dullo, Wolf-Christian; Baranov, Boris; van den Bogaard, Christel

    2010-05-01

    The exploration of the arctic seas require an integrated approach applying different infrastructures. In Fall 2009 German and Russian scientists performed a geo marine cruise off Kamchatka and in the western Bering Sea within the frame of the KALMAR-Project. Two main research subjects formed the scientific backbone of the cruise: The first objective focuses on the geodynamic and volcanological-magmatic development of the Kuril-Kamchatka island arc system and the Kamchatka Aleutean Islands Triple-Junction. Very little is known about the composition of the mantle and the oceanic crust as well as of the seamounts including their ages. The best studied site is the Volcanologist's Massif located between the Bering- and the Alpha Fracture Zone (Tsvetkov 1990, Volynets et al. 1992, Yogodzinsky et al. 1994), which structurally belongs to the Komandorsky Basin. The oldest rocks of the Volcanologist's Massif show very similar trace element and isotope signatures like those rocks cropping out in the volcanoes on Kamchatka in the prolongation of the Alpha Fracture Zone (Portnyagin et al. 2005a), indicating similar conditions of magma formation. The top of the Volcanologist's Massif is characterized by the young (< 0.5 Ma) and hydrothermally active Piip volcano, which consists of special magnesium rich andesites ("Piip type"). Another hot site was the Meiji-Seamount which is the northernmost Seamount of the hotspot spur of the Hawaii-Emperor-Seamount chain, having an age of probably > 85 Ma. The only existing basement rocks from this seamount were gained during DSDP Leg 19. These are basalts with MORB like trace element and isotope signatures (Keller et al. 2000, Regelous et al. 2003). These data indicate that the Hawaii-Hotspot was at a MOR in Cretaceous time and that large volumes of depleted mantle material played a role during the magma formation. The second objective focuses on paleo-oceanographic investigations concentrating on the sediments along the eastern continental

  13. Impact assisted segmented cutterhead

    DOEpatents

    Morrell, Roger J.; Larson, David A.; Ruzzi, Peter L.

    1992-01-01

    An impact assisted segmented cutterhead device is provided for cutting various surfaces from coal to granite. The device comprises a plurality of cutting bit segments deployed in side by side relationship to form a continuous cutting face and a plurality of impactors individually associated with respective cutting bit segments. An impactor rod of each impactor connects that impactor to the corresponding cutting bit segment. A plurality of shock mounts dampening the vibration from the associated impactor. Mounting brackets are used in mounting the cutterhead to a base machine.

  14. 19. Interior view of eastern segment of Roundhouse showing clerestory ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Interior view of eastern segment of Roundhouse showing clerestory lighting and locomotive smoke flues. - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Roundhouse, Site Bounded by West Broad, Jones, West Boundary & Hull, Savannah, Chatham County, GA

  15. 20. Interior view of eastern segment of Roundhouse looking straight ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Interior view of eastern segment of Roundhouse looking straight on locomotive smoke flue - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Roundhouse, Site Bounded by West Broad, Jones, West Boundary & Hull, Savannah, Chatham County, GA

  16. Hospital benefit segmentation.

    PubMed

    Finn, D W; Lamb, C W

    1986-12-01

    Market segmentation is an important topic to both health care practitioners and researchers. The authors explore the relative importance that health care consumers attach to various benefits available in a major metropolitan area hospital. The purposes of the study are to test, and provide data to illustrate, the efficacy of one approach to hospital benefit segmentation analysis.

  17. Pancreas and cyst segmentation

    NASA Astrophysics Data System (ADS)

    Dmitriev, Konstantin; Gutenko, Ievgeniia; Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Accurate segmentation of abdominal organs from medical images is an essential part of surgical planning and computer-aided disease diagnosis. Many existing algorithms are specialized for the segmentation of healthy organs. Cystic pancreas segmentation is especially challenging due to its low contrast boundaries, variability in shape, location and the stage of the pancreatic cancer. We present a semi-automatic segmentation algorithm for pancreata with cysts. In contrast to existing automatic segmentation approaches for healthy pancreas segmentation which are amenable to atlas/statistical shape approaches, a pancreas with cysts can have even higher variability with respect to the shape of the pancreas due to the size and shape of the cyst(s). Hence, fine results are better attained with semi-automatic steerable approaches. We use a novel combination of random walker and region growing approaches to delineate the boundaries of the pancreas and cysts with respective best Dice coefficients of 85.1% and 86.7%, and respective best volumetric overlap errors of 26.0% and 23.5%. Results show that the proposed algorithm for pancreas and pancreatic cyst segmentation is accurate and stable.

  18. Keypoint Transfer Segmentation

    PubMed Central

    Toews, M.; Langs, G.; Wells, W.; Golland, P.

    2015-01-01

    We present an image segmentation method that transfers label maps of entire organs from the training images to the novel image to be segmented. The transfer is based on sparse correspondences between keypoints that represent automatically identified distinctive image locations. Our segmentation algorithm consists of three steps: (i) keypoint matching, (ii) voting-based keypoint labeling, and (iii) keypoint-based probabilistic transfer of organ label maps. We introduce generative models for the inference of keypoint labels and for image segmentation, where keypoint matches are treated as a latent random variable and are marginalized out as part of the algorithm. We report segmentation results for abdominal organs in whole-body CT and in contrast-enhanced CT images. The accuracy of our method compares favorably to common multi-atlas segmentation while offering a speed-up of about three orders of magnitude. Furthermore, keypoint transfer requires no training phase or registration to an atlas. The algorithm’s robustness enables the segmentation of scans with highly variable field-of-view. PMID:26221677

  19. Keypoint Transfer Segmentation.

    PubMed

    Wachinger, C; Toews, M; Langs, G; Wells, W; Golland, P

    2015-01-01

    We present an image segmentation method that transfers label maps of entire organs from the training images to the novel image to be segmented. The transfer is based on sparse correspondences between keypoints that represent automatically identified distinctive image locations. Our segmentation algorithm consists of three steps: (i) keypoint matching, (ii) voting-based keypoint labeling, and (iii) keypoint-based probabilistic transfer of organ label maps. We introduce generative models for the inference of keypoint labels and for image segmentation, where keypoint matches are treated as a latent random variable and are marginalized out as part of the algorithm. We report segmentation results for abdominal organs in whole-body CT and in contrast-enhanced CT images. The accuracy of our method compares favorably to common multi-atlas segmentation while offering a speed-up of about three orders of magnitude. Furthermore, keypoint transfer requires no training phase or registration to an atlas. The algorithm's robustness enables the segmentation of scans with highly variable field-of-view.

  20. Event Segmentation Ability Uniquely Predicts Event Memory

    PubMed Central

    Sargent, Jesse Q.; Zacks, Jeffrey M.; Hambrick, David Z.; Zacks, Rose T.; Kurby, Christopher A.; Bailey, Heather R.; Eisenberg, Michelle L.; Beck, Taylor M.

    2013-01-01

    Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segment activity into meaningful events a unique predictor of subsequent memory, or is the relationship between event perception and memory accounted for by general cognitive abilities? Two hundred and eight adults ranging from 20 to 79 years old segmented movies of everyday events and attempted to remember the events afterwards. They also completed psychometric ability tests and tests measuring script knowledge for everyday events. Event segmentation and script knowledge both explained unique variance in event memory above and beyond the psychometric measures, and did so as strongly in older as in younger adults. These results suggest that event segmentation is a basic cognitive mechanism, important for memory across the lifespan. PMID:23942350

  1. Actinic Granuloma with Focal Segmental Glomerulosclerosis

    PubMed Central

    Phasukthaworn, Ruedee; Chanprapaph, Kumutnart; Vachiramon, Vasanop

    2016-01-01

    Actinic granuloma is an uncommon granulomatous disease, characterized by annular erythematous plaque with central clearing predominately located on sun-damaged skin. The pathogenesis is not well understood, ultraviolet radiation is recognized as precipitating factor. We report a case of a 52-year-old woman who presented with asymptomatic annular erythematous plaques on the forehead and both cheeks persisting for 2 years. The clinical presentation and histopathologic findings support the diagnosis of actinic granuloma. During that period of time, she also developed focal segmental glomerulosclerosis. The association between actinic granuloma and focal segmental glomerulosclerosis needs to be clarified by further studies. PMID:27293392

  2. Segmented ion thruster

    NASA Technical Reports Server (NTRS)

    Brophy, John R. (Inventor)

    1993-01-01

    Apparatus and methods for large-area, high-power ion engines comprise dividing a single engine into a combination of smaller discharge chambers (or segments) configured to operate as a single large-area engine. This segmented ion thruster (SIT) approach enables the development of 100-kW class argon ion engines for operation at a specific impulse of 10,000 s. A combination of six 30-cm diameter ion chambers operating as a single engine can process over 100 kW. Such a segmented ion engine can be operated from a single power processor unit.

  3. Image segmentation survey

    NASA Technical Reports Server (NTRS)

    Haralick, R. M.

    1982-01-01

    The methodologies and capabilities of image segmentation techniques are reviewed. Single linkage schemes, hybrid linkage schemes, centroid linkage schemes, histogram mode seeking, spatial clustering, and split and merge schemes are addressed.

  4. CPCs with segmented absorbers

    SciTech Connect

    Keita, M.; Robertson, H.S. )

    1991-01-01

    One of the most promising means of improving the performance of solar thermal collectors is to reduce the energy lost by the hot absorber. One way to do this, not currently part of the technology, is to recognize that since the absorber is usually not irradiated uniformly, it is therefore possible to construct an absorber of thermally isolated segments, circulate the fluid in sequence from low to high irradiance segments, and reduce loss by improving effective concentration. This procedure works even for ideal concentrators, without violating Winston's theorem. Two equivalent CPC collectors with single and segmented absorber were constructed and compared under actual operating conditions. The results showed that the daily thermal efficiency of the collector with segmented absorber is higher (about 13%) than that of the collector with nonsegmented absorber.

  5. GPS Control Segment Improvements

    DTIC Science & Technology

    2015-04-29

    Systems Center GPS Control Segment Improvements Mr. Tim McIntyre GPS Product Support Manager GPS Ops Support and Sustainment Division Peterson...hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...DATE 29 APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE GPS Control Segment Improvements 5a. CONTRACT

  6. Squaring a Circular Segment

    ERIC Educational Resources Information Center

    Gordon, Russell

    2008-01-01

    Consider a circular segment (the smaller portion of a circle cut off by one of its chords) with chord length c and height h (the greatest distance from a point on the arc of the circle to the chord). Is there a simple formula involving c and h that can be used to closely approximate the area of this circular segment? Ancient Chinese and Egyptian…

  7. Squaring a Circular Segment

    ERIC Educational Resources Information Center

    Gordon, Russell

    2008-01-01

    Consider a circular segment (the smaller portion of a circle cut off by one of its chords) with chord length c and height h (the greatest distance from a point on the arc of the circle to the chord). Is there a simple formula involving c and h that can be used to closely approximate the area of this circular segment? Ancient Chinese and Egyptian…

  8. Segmented pyroelector detector

    DOEpatents

    Stotlar, S.C.; McLellan, E.J.

    1981-01-21

    A pyroelectric detector is described which has increased voltage output and improved responsivity over equivalent size detectors. The device comprises a plurality of edge-type pyroelectric detectors which have a length which is much greater than the width of the segments between the edge-type electrodes. External circuitry connects the pyroelectric detector segments in parallel to provide a single output which maintains 50 ohm impedance characteristics.

  9. Mesp-family genes are required for segmental patterning and segmental border formation.

    PubMed

    Saga, Yumiko; Takahashi, Yu

    2008-01-01

    Elaborate somite patterning is based on the dynamic gene regulation within the presomitic mesoderm (PSM) derived from the primitive streak and tailbud in the later stage embryo. Notch signaling and the regulators are major players involved in the all events required for the temporally and spatially coordinated somite formation. PSM can be subdivided at least two domains based on the regulation and maybe the function of genes expressed. In the posterior PSM, a basic-HLH protein Hes7 plays a central role to generate traveling wave of gene expression by negatively regulating the transcription of the target genes, which may lead defining soimte spacing and future segmental unit. In the anterior PSM, cells start to prepare segmental pattering by acquiring rostral or caudal identity of somite primordia and defining segmental border. In this process, Mesp2, another basic HLH protein plays a critical role. Genetic evidence is provided how Mesp2 regulates Notch signaling to establish segmental identity in the anterior PSM.

  10. Geometry Guided Segmentation

    NASA Astrophysics Data System (ADS)

    Dunn, Stanley M.; Liang, Tajen

    1989-03-01

    Our overall goal is to develop an image understanding system for automatically interpreting dental radiographs. This paper describes the module that integrates the intrinsic image data to form the region adjacency graph that represents the image. The specific problem is to develop a robust method for segmenting the image into small regions that do not overlap anatomical boundaries. Classical algorithms for finding homogeneous regions (i.e., 2 class segmentation or connected components) will not always yield correct results since blurred edges can cause adjacent anatomical regions to be labeled as one region. This defect is a problem in this and other applications where an object count is necessary. Our solution to the problem is to guide the segmentation by intrinsic properties of the constituent objects. The module takes a set of intrinsic images as arguments. A connected components-like algorithm is performed, but the connectivity relation is not 4- or 8-neighbor connectivity in binary images; the connectivity is defined in terms of the intrinsic image data. We shall describe both the classical method and the modified segmentation procedures, and present experiments using both algorithms. Our experiments show that for the dental radiographs a segmentation using gray level data in conjunction with edges of the surfaces of teeth give a robust and reliable segmentation.

  11. A new piston control strategy for segmented mirrors

    NASA Technical Reports Server (NTRS)

    Olivier, Philip D.

    1994-01-01

    One approach to the adaptive control of large segmented mirrors involves sending tilt commands to each segment and allowing each segment to minimize the distance between its edges and those of (all or some of) its neighbors. This approach has been adopted in the Phased Array Mirror, Extendible Large Aperture (PAMELA) testbed now located at NASA's Marshall Space Flight Center, Huntsville, AL. This approach minimizes (1) the communication between the sensors and the segment actuators and (2) computations required by the central controlling computer. This report discusses issues that large segmented mirrors built around the PAMELA concept (such as SELENE) will face when they migrate to integrated, and presumably to digital, on-segment computational ability and high bandwidth response.

  12. Semi-automatic knee cartilage segmentation

    NASA Astrophysics Data System (ADS)

    Dam, Erik B.; Folkesson, Jenny; Pettersen, Paola C.; Christiansen, Claus

    2006-03-01

    Osteo-Arthritis (OA) is a very common age-related cause of pain and reduced range of motion. A central effect of OA is wear-down of the articular cartilage that otherwise ensures smooth joint motion. Quantification of the cartilage breakdown is central in monitoring disease progression and therefore cartilage segmentation is required. Recent advances allow automatic cartilage segmentation with high accuracy in most cases. However, the automatic methods still fail in some problematic cases. For clinical studies, even if a few failing cases will be averaged out in the overall results, this reduces the mean accuracy and precision and thereby necessitates larger/longer studies. Since the severe OA cases are often most problematic for the automatic methods, there is even a risk that the quantification will introduce a bias in the results. Therefore, interactive inspection and correction of these problematic cases is desirable. For diagnosis on individuals, this is even more crucial since the diagnosis will otherwise simply fail. We introduce and evaluate a semi-automatic cartilage segmentation method combining an automatic pre-segmentation with an interactive step that allows inspection and correction. The automatic step consists of voxel classification based on supervised learning. The interactive step combines a watershed transformation of the original scan with the posterior probability map from the classification step at sub-voxel precision. We evaluate the method for the task of segmenting the tibial cartilage sheet from low-field magnetic resonance imaging (MRI) of knees. The evaluation shows that the combined method allows accurate and highly reproducible correction of the segmentation of even the worst cases in approximately ten minutes of interaction.

  13. Rediscovering market segmentation.

    PubMed

    Yankelovich, Daniel; Meer, David

    2006-02-01

    In 1964, Daniel Yankelovich introduced in the pages of HBR the concept of nondemographic segmentation, by which he meant the classification of consumers according to criteria other than age, residence, income, and such. The predictive power of marketing studies based on demographics was no longer strong enough to serve as a basis for marketing strategy, he argued. Buying patterns had become far better guides to consumers' future purchases. In addition, properly constructed nondemographic segmentations could help companies determine which products to develop, which distribution channels to sell them in, how much to charge for them, and how to advertise them. But more than 40 years later, nondemographic segmentation has become just as unenlightening as demographic segmentation had been. Today, the technique is used almost exclusively to fulfill the needs of advertising, which it serves mainly by populating commercials with characters that viewers can identify with. It is true that psychographic types like "High-Tech Harry" and "Joe Six-Pack" may capture some truth about real people's lifestyles, attitudes, self-image, and aspirations. But they are no better than demographics at predicting purchase behavior. Thus they give corporate decision makers very little idea of how to keep customers or capture new ones. Now, Daniel Yankelovich returns to these pages, with consultant David Meer, to argue the case for a broad view of nondemographic segmentation. They describe the elements of a smart segmentation strategy, explaining how segmentations meant to strengthen brand identity differ from those capable of telling a company which markets it should enter and what goods to make. And they introduce their "gravity of decision spectrum", a tool that focuses on the form of consumer behavior that should be of the greatest interest to marketers--the importance that consumers place on a product or product category.

  14. Fast tip-tilt segment alignment for segmented mirrors

    NASA Astrophysics Data System (ADS)

    Skvarč, Jure

    2016-07-01

    A method for fast identification of segments and alignment of the segmented mirrors has been developed and applied for the deformable mirror of the WHT AO system (NAOMI) and for the GTC 36-segment primary mirror. By moving each segment by a known but different amount and in a different direction it is possible to identify many segments simultaneously using a pattern-matching algorithm which finds spots that have moved by a segment-specific vector from one image to another. The method does not need any special optical setup. The applicability of the method for the segmented primary mirrors of future telescopes is discussed.

  15. Segmented lasing tube for high temperature laser assembly

    DOEpatents

    Sawicki, Richard H.; Alger, Terry W.; Finucane, Raymond G.; Hall, Jerome P.

    1996-01-01

    A high temperature laser assembly capable of withstanding operating temperatures in excess of 1500.degree. C. is described comprising a segmented cylindrical ceramic lasing tube having a plurality of cylindrical ceramic lasing tube segments of the same inner and outer diameters non-rigidly joined together in axial alignment; insulation of uniform thickness surround the walls of the ceramic lasing tube; a ceramic casing, preferably of quartz, surrounding the insulation; and a fluid cooled metal jacket surrounds the ceramic casing. In a preferred embodiment, the inner surface of each of the ceramic lasing tube segments are provided with a pair of oppositely spaced grooves in the wall thereof parallel to the center axis of the segmented cylindrical ceramic lasing tube, and both of the grooves and the center axis of the segmented cylindrical ceramic lasing tube lie in a common plane, with the grooves in each ceramic lasing tube segment in circumferential alignment with the grooves in the adjoining ceramic lasing tube segments; and one or more ceramic plates, all lying in a common plane to one another and with the central axis of the segmented ceramic lasing tube, are received in the grooves to provide additional wall area in the segmented ceramic lasing tube for collision and return to ground state of metastable metal atoms within the segmented ceramic lasing tube.

  16. Improving Cerebellar Segmentation with Statistical Fusion.

    PubMed

    Plassard, Andrew J; Yang, Zhen; Prince, Jerry L; Claassen, Daniel O; Landman, Bennett A

    2016-02-27

    The cerebellum is a somatotopically organized central component of the central nervous system well known to be involved with motor coordination and increasingly recognized roles in cognition and planning. Recent work in multi-atlas labeling has created methods that offer the potential for fully automated 3-D parcellation of the cerebellar lobules and vermis (which are organizationally equivalent to cortical gray matter areas). This work explores the trade offs of using different statistical fusion techniques and post hoc optimizations in two datasets with distinct imaging protocols. We offer a novel fusion technique by extending the ideas of the Selective and Iterative Method for Performance Level Estimation (SIMPLE) to a patch-based performance model. We demonstrate the effectiveness of our algorithm, Non-Local SIMPLE, for segmentation of a mixed population of healthy subjects and patients with severe cerebellar anatomy. Under the first imaging protocol, we show that Non-Local SIMPLE outperforms previous gold-standard segmentation techniques. In the second imaging protocol, we show that Non-Local SIMPLE outperforms previous gold standard techniques but is outperformed by a non-locally weighted vote with the deeper population of atlases available. This work advances the state of the art in open source cerebellar segmentation algorithms and offers the opportunity for routinely including cerebellar segmentation in magnetic resonance imaging studies that acquire whole brain T1-weighted volumes with approximately 1 mm isotropic resolution.

  17. Improving cerebellar segmentation with statistical fusion

    NASA Astrophysics Data System (ADS)

    Plassard, Andrew J.; Yang, Zhen; Prince, Jerry L.; Claassen, Daniel O.; Landman, Bennett A.

    2016-03-01

    The cerebellum is a somatotopically organized central component of the central nervous system well known to be involved with motor coordination and increasingly recognized roles in cognition and planning. Recent work in multiatlas labeling has created methods that offer the potential for fully automated 3-D parcellation of the cerebellar lobules and vermis (which are organizationally equivalent to cortical gray matter areas). This work explores the trade offs of using different statistical fusion techniques and post hoc optimizations in two datasets with distinct imaging protocols. We offer a novel fusion technique by extending the ideas of the Selective and Iterative Method for Performance Level Estimation (SIMPLE) to a patch-based performance model. We demonstrate the effectiveness of our algorithm, Non- Local SIMPLE, for segmentation of a mixed population of healthy subjects and patients with severe cerebellar anatomy. Under the first imaging protocol, we show that Non-Local SIMPLE outperforms previous gold-standard segmentation techniques. In the second imaging protocol, we show that Non-Local SIMPLE outperforms previous gold standard techniques but is outperformed by a non-locally weighted vote with the deeper population of atlases available. This work advances the state of the art in open source cerebellar segmentation algorithms and offers the opportunity for routinely including cerebellar segmentation in magnetic resonance imaging studies that acquire whole brain T1-weighted volumes with approximately 1 mm isotropic resolution.

  18. Improving Cerebellar Segmentation with Statistical Fusion

    PubMed Central

    Plassard, Andrew J.; Yang, Zhen; Prince, Jerry L.; Claassen, Daniel O.; Landman, Bennett A.

    2016-01-01

    The cerebellum is a somatotopically organized central component of the central nervous system well known to be involved with motor coordination and increasingly recognized roles in cognition and planning. Recent work in multi-atlas labeling has created methods that offer the potential for fully automated 3-D parcellation of the cerebellar lobules and vermis (which are organizationally equivalent to cortical gray matter areas). This work explores the trade offs of using different statistical fusion techniques and post hoc optimizations in two datasets with distinct imaging protocols. We offer a novel fusion technique by extending the ideas of the Selective and Iterative Method for Performance Level Estimation (SIMPLE) to a patch-based performance model. We demonstrate the effectiveness of our algorithm, Non-Local SIMPLE, for segmentation of a mixed population of healthy subjects and patients with severe cerebellar anatomy. Under the first imaging protocol, we show that Non-Local SIMPLE outperforms previous gold-standard segmentation techniques. In the second imaging protocol, we show that Non-Local SIMPLE outperforms previous gold standard techniques but is outperformed by a non-locally weighted vote with the deeper population of atlases available. This work advances the state of the art in open source cerebellar segmentation algorithms and offers the opportunity for routinely including cerebellar segmentation in magnetic resonance imaging studies that acquire whole brain T1-weighted volumes with approximately 1 mm isotropic resolution. PMID:27127334

  19. Scorpion image segmentation system

    NASA Astrophysics Data System (ADS)

    Joseph, E.; Aibinu, A. M.; Sadiq, B. A.; Bello Salau, H.; Salami, M. J. E.

    2013-12-01

    Death as a result of scorpion sting has been a major public health problem in developing countries. Despite the high rate of death as a result of scorpion sting, little report exists in literature of intelligent device and system for automatic detection of scorpion. This paper proposed a digital image processing approach based on the floresencing characteristics of Scorpion under Ultra-violet (UV) light for automatic detection and identification of scorpion. The acquired UV-based images undergo pre-processing to equalize uneven illumination and colour space channel separation. The extracted channels are then segmented into two non-overlapping classes. It has been observed that simple thresholding of the green channel of the acquired RGB UV-based image is sufficient for segmenting Scorpion from other background components in the acquired image. Two approaches to image segmentation have also been proposed in this work, namely, the simple average segmentation technique and K-means image segmentation. The proposed algorithm has been tested on over 40 UV scorpion images obtained from different part of the world and results obtained show an average accuracy of 97.7% in correctly classifying the pixel into two non-overlapping clusters. The proposed 1system will eliminate the problem associated with some of the existing manual approaches presently in use for scorpion detection.

  20. Robust vessel segmentation

    NASA Astrophysics Data System (ADS)

    Bock, Susanne; Kühnel, Caroline; Boskamp, Tobias; Peitgen, Heinz-Otto

    2008-03-01

    In the context of cardiac applications, the primary goal of coronary vessel analysis often consists in supporting the diagnosis of vessel wall anomalies, such as coronary plaque and stenosis. Therefore, a fast and robust segmentation of the coronary tree is a very important but challenging task. We propose a new approach for coronary artery segmentation. Our method is based on an earlier proposed progressive region growing. A new growth front monitoring technique controls the segmentation and corrects local leakage by retrospective detection and removal of leakage artifacts. While progressively reducing the region growing threshold for the whole image, the growing process is locally analyzed using criteria based on the assumption of tubular, gradually narrowing vessels. If a voxel volume limit or a certain shape constraint is exceeded, the growing process is interrupted. Voxels affected by a failed segmentation are detected and deleted from the result. To avoid further processing at these positions, a large neighborhood is blocked for growing. Compared to a global region growing without local correction, our new local growth control and the adapted correction can deal with contrast decrease even in very small coronary arteries. Furthermore, our algorithm can efficiently handle noise artifacts and partial volume effects near the myocardium. The enhanced segmentation of more distal vessel parts was tested on 150 CT datasets. Furthermore, a comparison between the pure progressive region growing and our new approach was conducted.

  1. Cooperative processes in image segmentation

    NASA Technical Reports Server (NTRS)

    Davis, L. S.

    1982-01-01

    Research into the role of cooperative, or relaxation, processes in image segmentation is surveyed. Cooperative processes can be employed at several levels of the segmentation process as a preprocessing enhancement step, during supervised or unsupervised pixel classification and, finally, for the interpretation of image segments based on segment properties and relations.

  2. Segmented heterochromia in scalp hair.

    PubMed

    Yoon, Kyeong Han; Kim, Daehwan; Sohn, Seonghyang; Lee, Won Soo

    2003-12-01

    Segmented heterochromia of scalp hair is characterized by the irregularly alternating segmentation of hair into dark and light bands and is known to be associated with iron deficiency anemia. The authors report the case of an 11-year-old boy with segmented heterochromia associated with iron deficiency anemia. After 11 months of iron replacement, the boy's segmented heterochromic hair recovered completely.

  3. Cooperative processes in image segmentation

    NASA Technical Reports Server (NTRS)

    Davis, L. S.

    1982-01-01

    Research into the role of cooperative, or relaxation, processes in image segmentation is surveyed. Cooperative processes can be employed at several levels of the segmentation process as a preprocessing enhancement step, during supervised or unsupervised pixel classification and, finally, for the interpretation of image segments based on segment properties and relations.

  4. Head segmentation in vertebrates

    PubMed Central

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Here again, a basic segmental plan for the head has been sought among chordates. We convened a symposium that brought together leading researchers dealing with this problem, in a number of different evolutionary and developmental contexts. Here we give an overview of the outcome and the status of the field in this modern era of Evo-Devo. We emphasize the fact that the head segmentation problem is not fully resolved, and we discuss new directions in the search for hints for a way out of this maze. PMID:20607135

  5. Segmented annular combustor

    DOEpatents

    Reider, Samuel B.

    1979-01-01

    An industrial gas turbine engine includes an inclined annular combustor made up of a plurality of support segments each including inner and outer walls of trapezoidally configured planar configuration extents and including side flanges thereon interconnected by means of air cooled connector bolt assemblies to form a continuous annular combustion chamber therebetween and wherein an air fuel mixing chamber is formed at one end of the support segments including means for directing and mixing fuel within a plenum and a perforated header plate for directing streams of air and fuel mixture into the combustion chamber; each of the outer and inner walls of each of the support segments having a ribbed lattice with tracks slidably supporting porous laminated replaceable panels and including pores therein for distributing combustion air into the combustion chamber while cooling the inner surface of each of the panels by transpiration cooling thereof.

  6. [Pulmonary segmental mediolytic arteriopathy].

    PubMed

    Müller, A M; Kullmann, H J

    2006-03-01

    Segmental mediolytic arteriopathy (SMA) is defined as non-inflammatory arteriopathy with mediolysis due to segmental loss of media and consecutive formation of vascular gaps. Up to now, less than 40 cases of visceral and cerebral SMA and, to our knowledge, only one case of pulmonary SMA have been reported. We present the history of a 21 year old female patient, admitted to hospital with hemoptysis, but without other symptoms. Apart from two lesions in the sixth and tenth pulmonary segment, documented by CT and interpreted as colliquations, there were no other clinical and laboratory findings. Repeated bronchoscopy supplied no further information. Histomorphology of the resected lesion revealed SMA without evidence of vasculitis. Wegener's disease could be excluded. The aetiology of the disease is still unknown. Acute vasospasm (due to inappropriate reactions to catecholamine or endothelial dysfunction), as well as SMA as a precursor or subtype of fibromuscular dysplasia, are two theories still under discussion.

  7. Segmental curvilinear distraction osteogenesis.

    PubMed

    Zhou, Libin; Shang, Hongtao; Feng, Zhihong; Liu, Chen; Ye, Wenmin; Ma, Qin; Wu, Wei; Liu, Yanpu

    2012-10-01

    Curvilinear distraction is currently under investigation to reconstruct curved maxillofacial bone defects. However, previous studies have revealed the discrepancy between the contour of the regenerated bone in the distraction gap and the curvilinear pathway of the transport disc. We hypothesize that the discrepancy is because of the conflict of the distraction vector and the strain vector during the consolidation. In curvilinear distraction osteogenesis, the distraction vector varies, while the strain vector during the consolidation phase is fixed-linear, from the beginning to the end of the distraction pathway. Here we bring forward a solution of segmental curvilinear distraction osteogenesis to divide the curvilinear distraction into several segments, with respective consolidation for each distraction gap. If this hypothesis is verified, the segmental distraction curvilinear distraction will benefit the reconstruction of complicated long-range maxillofacial bone defects. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. U-Pb geochronology of modern river sands from the flat-slab segment of the southern central Andes, Argentina, 29-31°S: Implications for Neogene foreland and hinterland basin evolution

    NASA Astrophysics Data System (ADS)

    Capaldi, T.; Horton, B. K.; McKenzie, R.; Stockli, D. F.

    2015-12-01

    This study investigates how Andean river sediments in the flat-slab segment of western Argentina record active mixing of lithologically and geochemically distinct source regions comprising the Principal Cordillera, Frontal Cordillera, Precordillera fold-thrust belt, Sierras Pampeanas basement uplifts, and recycled Neogene basin fill. Detrital zircon U-Pb geochronological results for modern river sands discriminate variations from hinterland source regions, through river tributaries and main trunks of the Bermejo, Jachal, San Juan, and Mendoza rivers, and their respective fluvial megafans within the active foreland basin. Proportions of proximal zircon populations in the hinterland trunk rivers (with extensive Permian-Triassic and Cenozoic igneous exposures) diminish downstream with progressive contributions from the frontal Precordillera fold-thrust belt (dominantly Paleozoic sedimentary rocks) and Pampean basement uplifts. However, this systematic downstream dilution is perturbed in several catchments by significant recycling of older foreland basin fill. The degree of recycling depends on the position and extent of Oligocene-Pliocene exposures within the catchments. To discern the effects of the variable detrital zircon sources, multiple statistical methods are utilized. Quantitative comparisons suggest that variations in detrital zircon age distributions among the modern sands, and with older foreland basin fill and exposed bedrock, are dependent on spatial and temporal variations in exhumation and drainage network evolution within their respective Andean catchments. The present surface area of competing source regions and the configuration of hinterland tributary rivers largely dictate the degree of downstream dilution and/or recycling. This study provides a modern analogue and baseline for reconstructing Neogene shifts in foreland basin provenance, depositional systems, and drainage configurations during a critical transition to flat-slab subduction.

  9. Combined apatite fission-track and single grain apatite (U Th)/He ages from basement rocks of central Dronning Maud Land (East Antarctica) — Possible identification of thermally overprinted crustal segments?

    NASA Astrophysics Data System (ADS)

    Emmel, B.; Jacobs, J.; Crowhurst, P.; Daszinnies, M. C.

    2007-12-01

    Apatite fission-track (FT) and single grain (U-Th)/He ages from four vertical profiles in central Dronning Maud Land (East Antarctica) range from 312 ± 20 Ma to 135 ± 11 Ma and 304 ± 28 Ma to 104 ± 8 Ma, respectively. The combined age data allows to discriminate between undisturbed cooled (due to exhumation) and thermally overprinted crustal blocks. Profiles at the Zwieselhöhe and the Conradgebirge revealed unusual apatite FT vs. elevation relationships and (U-Th)/He ages older than the corresponding central apatite FT ages, possibly providing evidence for a Jurassic thermal overprint. Most probably Jurassic magmatism and associated advective heating led to total annealing of the apatite fission-tracks but helium only partially diffused. The model developed in this paper suggests that the (U-Th)/He ages from the Zwieselhöhe and Conradgebirge profiles are in part relicts of the pre-Jurassic cooling history. Two thermally undisturbed vertical profiles are used to record the long-term cooling history of central Dronning Maud Land. Time-temperature paths derived from modelled apatite FT data of these profiles revealed two phases of accelerated cooling during the Late Carboniferous and the Early Jurassic. Both phases are followed by slow cooling which is also documented by the spread in apatite (U-Th)/He single grain ages. The cooling at the end of the Carboniferous is most probably related to far field effects associated to the prevailing convergent tectonics. During the initial separation between East Antarctica and Mozambique erosion along an evolving rift shoulder caused the Jurassic cooling. Denudation of the basement was simultaneous with volcanism with both pre-dating (c. 20-10 Ma) sea-floor spreading in the Riser Larsen Sea (c. 155 Ma). Post Jurassic cooling was restricted to the lowest temperature sensitivity of both methods. Combined inverse modelled apatite FT data and forward modelled (U-Th)/He data suggest an Eocene/Oligocene cooling step, possibly

  10. [Segmental testicular infarction].

    PubMed

    Ripa Saldías, L; Guarch Troyas, R; Hualde Alfaro, A; de Pablo Cárdenas, A; Ruiz Ramo, M; Pinós Paul, M

    2006-02-01

    We report the case of a 47 years old man previously diagnosed of left hidrocele. After having a recent mild left testicular pain, an ultrasonografic study revealed a solid hipoecoic testicular lesion rounded by a big hidrocele, suggesting a testicular neoplasm. Radical inguinal orchiectomy was made and pathologic study showed segmental testicular infarction. No malignancy was found. We review the literature of the topic.

  11. Segmentation and Impoverished Youth.

    ERIC Educational Resources Information Center

    Friedman, Judith J.; Friedman, Samuel R.

    1986-01-01

    The following characteristics of jobs held by impoverished youth who applied for a job training program were examined: (1) benefits; (2) skills; (3) career ladders; and (4) unionization. Results imply that segmentation models are not fruitful as guides to labor market experiences of youth at the bottom of wage scale. Other studies were also…

  12. Cast segment evaluation

    NASA Technical Reports Server (NTRS)

    Diem, H. G.; Studhalter, W. R.

    1971-01-01

    Evaluation program to determine feasibility of fabricating segmented rocket engine thrust chambers using low cost, lightweight castings extends state of the art in areas of casting size and complexity, and in ability to provide thin sections and narrow, deep, cooling channels. Related developments are discussed.

  13. Sources of groundwater based on Helium analyses in and near the freshwater/saline-water transition zone of the San Antonio segment of the Edwards Aquifer, South-Central Texas, 2002-03

    USGS Publications Warehouse

    Hunt, Andrew G.; Lambert, Rebecca B.; Fahlquist, Lynne

    2010-01-01

    This report evaluates dissolved noble gas data, specifically helium-3 and helium-4, collected by the U.S. Geological Survey, in cooperation with the San Antonio Water System, during 2002-03. Helium analyses are used to provide insight into the sources of groundwater in the freshwater/saline-water transition zone of the San Antonio segment of the Edwards aquifer. Sixty-nine dissolved gas samples were collected from 19 monitoring wells (categorized as fresh, transitional, or saline on the basis of dissolved solids concentration in samples from the wells or from fluid-profile logging of the boreholes) arranged in five transects, with one exception, across the freshwater/saline-water interface (the 1,000-milligrams-per-liter dissolved solids concentration threshold) of the Edwards aquifer. The concentration of helium-4 (the dominant isotope in atmospheric and terrigenic helium) in samples ranged from 63 microcubic centimeters per kilogram at standard temperature (20 degrees Celsius) and pressure (1 atmosphere) in a well in the East Uvalde transect to 160,587 microcubic centimeters per kilogram at standard temperature and pressure in a well in the Kyle transect. Helium-4 concentrations in the 10 saline wells generally increase from the western transects to the eastern transects. Increasing helium-4 concentrations from southwest to northeast in the transition zone, indicating increasing residence time of groundwater from southwest to northeast, is consistent with the longstanding conceptualization of the Edwards aquifer in which water recharges in the southwest, flows generally northeasterly (including in the transition zone, although more slowly than in the fresh-water zone), and discharges at major springs in the northeast. Excess helium-4 was greater than 1,000 percent for 60 of the 69 samples, indicating that terrigenic helium is largely present and that most of the excess helium-4 comes from sources other than the atmosphere. The helium data of this report cannot be

  14. Segmentation in Tardigrada and diversification of segmental patterns in Panarthropoda.

    PubMed

    Smith, Frank W; Goldstein, Bob

    2016-10-31

    The origin and diversification of segmented metazoan body plans has fascinated biologists for over a century. The superphylum Panarthropoda includes three phyla of segmented animals-Euarthropoda, Onychophora, and Tardigrada. This superphylum includes representatives with relatively simple and representatives with relatively complex segmented body plans. At one extreme of this continuum, euarthropods exhibit an incredible diversity of serially homologous segments. Furthermore, distinct tagmosis patterns are exhibited by different classes of euarthropods. At the other extreme, all tardigrades share a simple segmented body plan that consists of a head and four leg-bearing segments. The modular body plans of panarthropods make them a tractable model for understanding diversification of animal body plans more generally. Here we review results of recent morphological and developmental studies of tardigrade segmentation. These results complement investigations of segmentation processes in other panarthropods and paleontological studies to illuminate the earliest steps in the evolution of panarthropod body plans.

  15. Segmentation of stereo terrain images

    NASA Astrophysics Data System (ADS)

    George, Debra A.; Privitera, Claudio M.; Blackmon, Theodore T.; Zbinden, Eric; Stark, Lawrence W.

    2000-06-01

    We have studied four approaches to segmentation of images: three automatic ones using image processing algorithms and a fourth approach, human manual segmentation. We were motivated toward helping with an important NASA Mars rover mission task -- replacing laborious manual path planning with automatic navigation of the rover on the Mars terrain. The goal of the automatic segmentations was to identify an obstacle map on the Mars terrain to enable automatic path planning for the rover. The automatic segmentation was first explored with two different segmentation methods: one based on pixel luminance, and the other based on pixel altitude generated through stereo image processing. The third automatic segmentation was achieved by combining these two types of image segmentation. Human manual segmentation of Martian terrain images was used for evaluating the effectiveness of the combined automatic segmentation as well as for determining how different humans segment the same images. Comparisons between two different segmentations, manual or automatic, were measured using a similarity metric, SAB. Based on this metric, the combined automatic segmentation did fairly well in agreeing with the manual segmentation. This was a demonstration of a positive step towards automatically creating the accurate obstacle maps necessary for automatic path planning and rover navigation.

  16. Segmental arterial mediolysis.

    PubMed

    Chao, Christine P

    2009-09-01

    Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory arteriopathy, which is characterized by dissecting aneurysms resulting from lysis of the outer media of the arterial wall. The most common presentation is abdominal pain and hemorrhage in the elderly. Computed tomography (CT) and angiography imaging findings overlap with various vasculitides and include segmental changes of aneurysm and stenosis. A key distinguishing feature is the presence of dissections, the principle morphologic expression of SAM. Differentiation and exclusion of an inflammatory arteritis is crucial in appropriate management, as immunosuppressants generally used for treatment of vasculitis may be ineffective or even worsen the vasculopathy. Although the disease can be self-limiting without treatment or with conservative medical therapy, the acute process carries a 50% mortality rate and may necessitate urgent surgical and/or endovascular therapy. Prompt recognition and diagnosis are therefore of utmost importance in appropriate management of this rare entity.

  17. Arabic handwritten: pre-processing and segmentation

    NASA Astrophysics Data System (ADS)

    Maliki, Makki; Jassim, Sabah; Al-Jawad, Naseer; Sellahewa, Harin

    2012-06-01

    This paper is concerned with pre-processing and segmentation tasks that influence the performance of Optical Character Recognition (OCR) systems and handwritten/printed text recognition. In Arabic, these tasks are adversely effected by the fact that many words are made up of sub-words, with many sub-words there associated one or more diacritics that are not connected to the sub-word's body; there could be multiple instances of sub-words overlap. To overcome these problems we investigate and develop segmentation techniques that first segment a document into sub-words, link the diacritics with their sub-words, and removes possible overlapping between words and sub-words. We shall also investigate two approaches for pre-processing tasks to estimate sub-words baseline, and to determine parameters that yield appropriate slope correction, slant removal. We shall investigate the use of linear regression on sub-words pixels to determine their central x and y coordinates, as well as their high density part. We also develop a new incremental rotation procedure to be performed on sub-words that determines the best rotation angle needed to realign baselines. We shall demonstrate the benefits of these proposals by conducting extensive experiments on publicly available databases and in-house created databases. These algorithms help improve character segmentation accuracy by transforming handwritten Arabic text into a form that could benefit from analysis of printed text.

  18. ABL beam control segment

    NASA Astrophysics Data System (ADS)

    Kelchner, Bryan L.; Dauk, Ronald C.

    1998-09-01

    The U.S. Air Force Airborne Laser consists of four primary subsystem segments; aircraft, battle management and C4I, laser device, and beam control segment (BCS). The BCS performs two major function, beam control and fire control, using three primary products, turret assembly, beam transfer assembly, and fire control hardware and software. The fire control sequence involves slewing the turret to the target coordinates as received from the battle management segment, centering the target in the acquisition sensor, acquiring the plume in the coarse track sensor, acquiring the hard body of the missile with the track illuminator laser, and establishing active tracking of the nose of the target theater ballistic missile. The beam control sequence begins after established active nose track by firing another beacon illuminator laser (BILL) to establish the aim point on the missile for the high energy laser. The resulting spot on the missile is imaged in the wavefront sensor and compared with the outgoing sample of the BILL. By applying the conjugate of the wavefront difference from the beacon to a deformable mirror then the atmosphere serves to correct the arriving wavefront on target. At this point the HEL is fired along the same path with similar wavefront correction, and dwells on target until the missile skin is weakened and rips open or buckles.

  19. Example based lesion segmentation

    NASA Astrophysics Data System (ADS)

    Roy, Snehashis; He, Qing; Carass, Aaron; Jog, Amod; Cuzzocreo, Jennifer L.; Reich, Daniel S.; Prince, Jerry; Pham, Dzung

    2014-03-01

    Automatic and accurate detection of white matter lesions is a significant step toward understanding the progression of many diseases, like Alzheimer's disease or multiple sclerosis. Multi-modal MR images are often used to segment T2 white matter lesions that can represent regions of demyelination or ischemia. Some automated lesion segmentation methods describe the lesion intensities using generative models, and then classify the lesions with some combination of heuristics and cost minimization. In contrast, we propose a patch-based method, in which lesions are found using examples from an atlas containing multi-modal MR images and corresponding manual delineations of lesions. Patches from subject MR images are matched to patches from the atlas and lesion memberships are found based on patch similarity weights. We experiment on 43 subjects with MS, whose scans show various levels of lesion-load. We demonstrate significant improvement in Dice coefficient and total lesion volume compared to a state of the art model-based lesion segmentation method, indicating more accurate delineation of lesions.

  20. Segmenting the Adult Education Market.

    ERIC Educational Resources Information Center

    Aurand, Tim

    1994-01-01

    Describes market segmentation and how the principles of segmentation can be applied to the adult education market. Indicates that applying segmentation techniques to adult education programs results in programs that are educationally and financially satisfying and serve an appropriate population. (JOW)

  1. Market Segmentation for Information Services.

    ERIC Educational Resources Information Center

    Halperin, Michael

    1981-01-01

    Discusses the advantages and limitations of market segmentation as strategy for the marketing of information services made available by nonprofit organizations, particularly libraries. Market segmentation is defined, a market grid for libraries is described, and the segmentation of information services is outlined. A 16-item reference list is…

  2. Segmenting the Adult Education Market.

    ERIC Educational Resources Information Center

    Aurand, Tim

    1994-01-01

    Describes market segmentation and how the principles of segmentation can be applied to the adult education market. Indicates that applying segmentation techniques to adult education programs results in programs that are educationally and financially satisfying and serve an appropriate population. (JOW)

  3. Market Segmentation for Information Services.

    ERIC Educational Resources Information Center

    Halperin, Michael

    1981-01-01

    Discusses the advantages and limitations of market segmentation as strategy for the marketing of information services made available by nonprofit organizations, particularly libraries. Market segmentation is defined, a market grid for libraries is described, and the segmentation of information services is outlined. A 16-item reference list is…

  4. Functional Segments in Tongue Movement

    ERIC Educational Resources Information Center

    Stone, Maureen; Epstein, Melissa A.; Iskarous, Khalil

    2004-01-01

    The tongue is a deformable object, and moves by compressing or expanding local functional segments. For any single phoneme, these functional tongue segments may move in similar or opposite directions, and may reach target maximum synchronously or not. This paper will discuss the independence of five proposed segments in the production of speech.…

  5. Functional Segments in Tongue Movement

    ERIC Educational Resources Information Center

    Stone, Maureen; Epstein, Melissa A.; Iskarous, Khalil

    2004-01-01

    The tongue is a deformable object, and moves by compressing or expanding local functional segments. For any single phoneme, these functional tongue segments may move in similar or opposite directions, and may reach target maximum synchronously or not. This paper will discuss the independence of five proposed segments in the production of speech.…

  6. Strehl Ratio Meter for Focusing Segmented Mirrors 1

    NASA Technical Reports Server (NTRS)

    Olivier, Philip D.

    1996-01-01

    Initial focusing segmented mirrors that must be deployed in space, such as the Next Generation Space Telescope (NGST), provide challenges not faced before in the area of adaptive optics. The devices used to focus the mirror must minimize the power used and unnecessary mechanical movement. The device described in this report requires no movable parts except for the essential actuators required to move the mirror segments. Detail description of the components can be found in Coker, 1996. The primary mirror of the NGST will consist of 9 segments, a central annular segment, surrounded by 8 segments. The entire mirror assembly will be an 8 meter nearly filled circle (with the corners of the segments clipped to allow for storage in an Atlas IIe shroud). As the segments of the primary mirror are deployed to their operational positions, they must be positioned to within small fractions of a wavelength of near infrared light. When focused, the NGST will put most of its collected li-ht into the small region near the center of its focal plane. The ratio of the total light in the diffraction limited spot about the center of the focal plane to the total light in the focal plane. The purpose of this research effort is to design and build a device that will measure Strehl ratio and to use demonstrate that the Strehl ratio can be used to focus a segmented mirror.

  7. Spatial segmentation and the black middle class.

    PubMed

    Sharkey, Patrick

    2014-01-01

    Ethnographic studies of the black middle class focus attention on the ways in which residential environments condition the experiences of different segments of the black class structure. This study places these arguments in a larger demographic context by providing a national analysis of neighborhood inequality and spatial inequality of different racial and ethnic groups in urban America. The findings show that there has been no change over time in the degree to which majority-black neighborhoods are surrounded by spatial disadvantage. Predominantly black neighborhoods, regardless of socioeconomic composition, continue to be spatially linked with areas of severe disadvantage. However, there has been substantial change in the degree to which middle- and upper-income African-American households have separated themselves from highly disadvantaged neighborhoods. These changes are driven primarily by the growing segment of middle- and upper-income African-Americans living in neighborhoods in which they are not the majority group, both in central cities and in suburbs.

  8. Segmentation of Unstructured Datasets

    NASA Technical Reports Server (NTRS)

    Bhat, Smitha

    1996-01-01

    Datasets generated by computer simulations and experiments in Computational Fluid Dynamics tend to be extremely large and complex. It is difficult to visualize these datasets using standard techniques like Volume Rendering and Ray Casting. Object Segmentation provides a technique to extract and quantify regions of interest within these massive datasets. This thesis explores basic algorithms to extract coherent amorphous regions from two-dimensional and three-dimensional scalar unstructured grids. The techniques are applied to datasets from Computational Fluid Dynamics and from Finite Element Analysis.

  9. SEGMENTAL CLAVICLE FRACTURE

    PubMed Central

    Grossi, Evander Azevedo

    2015-01-01

    The aim here was to present an unusual case of segmental clavicle fracture associated with ipsilateral rib fracture. Although the clavicle is very superficial, undetected cases of both types of fracture may occur, because these patients usually suffer multiple trauma. The case of a patient with a fracture of the diaphysis and lateral extremity of the clavicle is described: the patient was treated surgically and an excellent result was achieved. Similar cases in the literature are reviewed and their management is discussed. PMID:27047835

  10. Segmented Target Design

    NASA Astrophysics Data System (ADS)

    Merhi, Abdul Rahman; Frank, Nathan; Gueye, Paul; Thoennessen, Michael; MoNA Collaboration

    2013-10-01

    A proposed segmented target would improve decay energy measurements of neutron-unbound nuclei. Experiments like this have been performed at the National Superconducting Cyclotron Laboratory (NSCL) located at Michigan State University. Many different nuclei are produced in such experiments, some of which immediately decay into a charged particle and neutron. The charged particles are bent by a large magnet and measured by a suite of charged particle detectors. The neutrons are measured by the Modular Neutron Array (MoNA) and Large Multi-Institutional Scintillation Array (LISA). With the current target setup, a nucleus in a neutron-unbound state is produced with a radioactive beam impinged upon a beryllium target. The resolution of these measurements is very dependent on the target thickness since the nuclear interaction point is unknown. In a segmented target using alternating layers of silicon detectors and Be-targets, the Be-target in which the nuclear reaction takes place would be determined. Thus the experimental resolution would improve. This poster will describe the improvement over the current target along with the status of the design. Work supported by Augustana College and the National Science Foundation grant #0969173.

  11. Segmental arterial mediolysis.

    PubMed

    Pillai, Anil Kumar; Iqbal, Shams I; Liu, Raymond W; Rachamreddy, Niranjan; Kalva, Sanjeeva P

    2014-06-01

    Segmental arterial mediolysis (SAM) is an uncommon, nonatherosclerotic, noninflammatory, large- to medium-sized arteriopathy first described in 1976. It is characterized histologically by vacuolization and lysis of the outer arterial media leading to dissecting aneurysms and vessel rupture presenting clinically with self-limiting abdominal pain or catastrophic hemorrhages in the abdomen. Patients of all ages are affected with a greater incidence at the fifth and sixth decades. There is a slight male predominance. Imaging findings overlap with inflammatory vasculitis, collagen vascular disease, and fibromuscular dysplasia. The presence of segmental dissections involving the celiac, mesenteric, and/or renal arteries is the key distinguishing features of SAM. Inflammatory markers, genetic tests for collagen vascular disorders, and hypercoagulable studies are negative. Anti-inflammatory agents and immunosuppressants are not effective. A mortality rate of 50 % has been attributed to the acute presentation with aneurysmal rupture necessitating urgent surgical or endovascular treatments; in the absence of the acute presentation, SAM is a self-limiting disease and is treated conservatively. There are no established guidelines on medical therapy, although optimal control of blood pressure is considered the main cornerstone of medical therapy. The long-term prognosis is not known.

  12. Robotic Arm Comprising Two Bending Segments

    NASA Technical Reports Server (NTRS)

    Mehling, Joshua S.; Difler, Myron A.; Ambrose, Robert O.; Chu, Mars W.; Valvo, Michael C.

    2010-01-01

    The figure shows several aspects of an experimental robotic manipulator that includes a housing from which protrudes a tendril- or tentacle-like arm 1 cm thick and 1 m long. The arm consists of two collinear segments, each of which can be bent independently of the other, and the two segments can be bent simultaneously in different planes. The arm can be retracted to a minimum length or extended by any desired amount up to its full length. The arm can also be made to rotate about its own longitudinal axis. Some prior experimental robotic manipulators include single-segment bendable arms. Those arms are thicker and shorter than the present one. The present robotic manipulator serves as a prototype of future manipulators that, by virtue of the slenderness and multiple- bending capability of their arms, are expected to have sufficient dexterity for operation within spaces that would otherwise be inaccessible. Such manipulators could be especially well suited as means of minimally invasive inspection during construction and maintenance activities. Each of the two collinear bending arm segments is further subdivided into a series of collinear extension- and compression-type helical springs joined by threaded links. The extension springs occupy the majority of the length of the arm and engage passively in bending. The compression springs are used for actively controlled bending. Bending is effected by means of pairs of antagonistic tendons in the form of spectra gel spun polymer lines that are attached at specific threaded links and run the entire length of the arm inside the spring helix from the attachment links to motor-driven pulleys inside the housing. Two pairs of tendons, mounted in orthogonal planes that intersect along the longitudinal axis, are used to effect bending of each segment. The tendons for actuating the distal bending segment are in planes offset by an angle of 45 from those of the proximal bending segment: This configuration makes it possible to

  13. Trunk segment numbers and sequential segmentation in myriapods.

    PubMed

    Fusco, Giuseppe

    2005-01-01

    Sequential segmentation from a posterior "proliferative zone" is considered to be the primitive mechanism of segmentation in arthropods. Several studies of embryonic and post-embryonic development and gene expression suggest that this occurs in all major arthropod taxa. Sequential segmentation is often associated with the idea of posterior production of body units that accumulate along the main body axis. However, the precise mechanism of sequential segmentation has not been identified yet, and, while searching for the genetic circuitry able to generate a first periodic pattern in the embryo, we can at least outline the distinctive role in segmentation of a proliferative zone. A perusal of myriapod segmentation patterns suggests that these patterns result from multi-layered developmental processes, where gene expression and epigenetic mechanisms interact in a nonstrictly hierarchical way. The posterior zone is possibly a zone of periodic signal production, but, in general, the resulting segmental pattern is not completely attributable to the activity of the signal generator. In this sense, a posterior proliferative zone would be more a "segmental organizer" than a "segment generator."

  14. Integration of Multiple Speech Segmentation Cues: A Hierarchical Framework

    ERIC Educational Resources Information Center

    Mattys, Sven L.; White, Laurence; Melhorn, James F.

    2005-01-01

    A central question in psycholinguistic research is how listeners isolate words from connected speech despite the paucity of clear word-boundary cues in the signal. A large body of empirical evidence indicates that word segmentation is promoted by both lexical (knowledge-derived) and sublexical (signal-derived) cues. However, an account of how…

  15. Integration of Multiple Speech Segmentation Cues: A Hierarchical Framework

    ERIC Educational Resources Information Center

    Mattys, Sven L.; White, Laurence; Melhorn, James F.

    2005-01-01

    A central question in psycholinguistic research is how listeners isolate words from connected speech despite the paucity of clear word-boundary cues in the signal. A large body of empirical evidence indicates that word segmentation is promoted by both lexical (knowledge-derived) and sublexical (signal-derived) cues. However, an account of how…

  16. Probabilistic retinal vessel segmentation

    NASA Astrophysics Data System (ADS)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  17. Partially segmented deformable mirror

    DOEpatents

    Bliss, E.S.; Smith, J.R.; Salmon, J.T.; Monjes, J.A.

    1991-05-21

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp. 5 figures.

  18. Partially segmented deformable mirror

    DOEpatents

    Bliss, Erlan S.; Smith, James R.; Salmon, J. Thaddeus; Monjes, Julio A.

    1991-01-01

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp.

  19. Bone image segmentation.

    PubMed

    Liu, Z Q; Liew, H L; Clement, J G; Thomas, C D

    1999-05-01

    Characteristics of microscopic structures in bone cross sections carry essential clues in age determination in forensic science and in the study of age-related bone developments and bone diseases. Analysis of bone cross sections represents a major area of research in bone biology. However, traditional approaches in bone biology have relied primarily on manual processes with very limited number of bone samples. As a consequence, it is difficult to reach reliable and consistent conclusions. In this paper we present an image processing system that uses microstructural and relational knowledge present in the bone cross section for bone image segmentation. This system automates the bone image analysis process and is able to produce reliable results based on quantitative measurements from a large number of bone images. As a result, using large databases of bone images to study the correlation between bone structural features and age-related bone developments becomes feasible.

  20. Segmented heat exchanger

    DOEpatents

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  1. Segmented rail linear induction motor

    DOEpatents

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  2. Segmented rail linear induction motor

    DOEpatents

    Cowan, M. Jr.; Marder, B.M.

    1996-09-03

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces. 6 figs.

  3. Multiple-Segment Climbing Robots

    NASA Technical Reports Server (NTRS)

    Kerley, James; May, Edward; Eklund, Wayne

    1994-01-01

    Multiple-segment climbing robots developed to perform such tasks as inspection, sandblasting, welding, and painting on towers and other structures. Look and move like caterpillars. Video camera mounted on one of segments rotated to desired viewing angle. Used in remote inspection of structure, to view motion of robot and/or provides video feedback for control of motion, and/or to guide operation of head mounted on foremost segment with motorized actuators.

  4. Segmentation of Tracking Sequences Using Dynamically Updated Adaptive Learning

    PubMed Central

    Michailovich, Oleg; Tannenbaum, Allen

    2009-01-01

    The problem of segmentation of tracking sequences is of central importance in a multitude of applications. In the current paper, a different approach to the problem is discussed. Specifically, the proposed segmentation algorithm is implemented in conjunction with estimation of the dynamic parameters of moving objects represented by the tracking sequence. While the information on objects’ motion allows one to transfer some valuable segmentation priors along the tracking sequence, the segmentation allows substantially reducing the complexity of motion estimation, thereby facilitating the computation. Thus, in the proposed methodology, the processes of segmentation and motion estimation work simultaneously, in a sort of “collaborative” manner. The Bayesian estimation framework is used here to perform the segmentation, while Kalman filtering is used to estimate the motion and to convey useful segmentation information along the image sequence. The proposed method is demonstrated on a number of both computed-simulated and real-life examples, and the obtained results indicate its advantages over some alternative approaches. PMID:19004712

  5. Chilean Segment Boundary Persistence over the Late Holocene

    NASA Astrophysics Data System (ADS)

    Garrett, E.; Shennan, I.; Woodroffe, S.; Watcham, E.

    2010-12-01

    In May 1960 south-central Chile was struck by the largest earthquake since the inception of modern seismic recording. The Mw 9.5 event unlocked almost 1000 km of the fault that conveys the Nazca plate beneath South America. The 27th February 2010 Mw 8.8 Maule earthquake ruptured a further 500 km long section immediately to the north. More than four centuries of records kept by Spanish settlers and visiting Europeans describe the occurrence and effects of numerous other analogous subduction megathrust events. The inferred distributions of these ruptures suggest that the subduction zone is characterised by persistent seismic segments, bordered by unchanging boundaries. The permanence of these boundaries over longer timescales and the possibility of past earthquakes rupturing multiple segments are currently unknown. This paper presents initial results of fieldwork investigating the influence of segment boundaries in controlling the largest late Holocene ruptures. We aim to develop event chronologies for the Valparaíso, Concepción and Valdivia seismic segments using stratigraphic and microfossil evidence for vertical deformation and tsunami occurrence. Comparison of radiocarbon dates alone is insufficient to differentiate between the synchronous rupture of multiple seismic segments and sequential single segment events. We use the interaction of sediments relating to the 1960 and 2010 events around the Arauco Peninsula as a model for sequential rupturing, assisting in the testing of ideas concerning the role of single and multiple segment ruptures in explaining older stratigraphic evidence from boundary sites.

  6. High volume ULE segment production

    NASA Astrophysics Data System (ADS)

    Hobbs, Thomas; Edwards, Mary; Fox, Andrew

    2016-07-01

    It is expected that many of the next generation large ground based telescopes will utilize a segmented design for the primary mirror and, in some cases, the secondary mirror. Corning Incorporated (Corning) presents a process to manufacture segment mirror blanks from Corning ULE titania silicate glass in segment sizes ranging from 1.0 m to 1.8 m flat to flat. This paper will review ULE properties and describe the facilities, equipment, resources, and processes required to produce a few hundred to a few thousand mirror segment blanks for extremely large telescope (ELT) applications.

  7. Automated medical image segmentation techniques

    PubMed Central

    Sharma, Neeraj; Aggarwal, Lalit M.

    2010-01-01

    Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT) and Magnetic resonance (MR) imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images. PMID:20177565

  8. Asteroid Redirect Mission: Robotic Segment

    NASA Image and Video Library

    This concept animation illustrates the robotic segment of NASA's Asteroid Redirect Mission. The Asteroid Redirect Vehicle, powered by solar electric propulsion, travels to a large asteroid to robot...

  9. Compatibility of segmented thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Snyder, J.; Ursell, T.

    2002-01-01

    It is well known that power generation efficiency improves when materials with appropriate properties are combined either in a cascaded or segmented fashion across a temperature gradient. Past methods for determining materials used in segmentation weremainly concerned with materials that have the highest figure of merit in the temperature range. However, the example of SiGe segmented with Bi2Te3 and/or various skutterudites shows a marked decline in device efficiency even though SiGe has the highest figure of merit in the temperature range. The origin of the incompatibility of SiGe with other thermoelectric materials leads to a general definition of compatibility and intrinsic efficiency. The compatibility factor derived as = (Jl+zr - 1) a is a function of only intrinsic material properties and temperature, which is represented by a ratio of current to conduction heat. For maximum efficiency the compatibility factor should not change with temperature both within a single material, and in the segmented leg as a whole. This leads to a measure of compatibility not only between segments, but also within a segment. General temperature trends show that materials are more self compatible at higher temperatures, and segmentation is more difficult across a larger -T. The compatibility factor can be used as a quantitative guide for deciding whether a material is better suited for segmentation orcascading. Analysis of compatibility factors and intrinsic efficiency for optimal segmentation are discussed, with intent to predict optimal material properties, temperature interfaces, and/or currentheat ratios.

  10. Automated medical image segmentation techniques.

    PubMed

    Sharma, Neeraj; Aggarwal, Lalit M

    2010-01-01

    Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT) and Magnetic resonance (MR) imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images.

  11. Compatibility of segmented thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Snyder, J.; Ursell, T.

    2002-01-01

    It is well known that power generation efficiency improves when materials with appropriate properties are combined either in a cascaded or segmented fashion across a temperature gradient. Past methods for determining materials used in segmentation weremainly concerned with materials that have the highest figure of merit in the temperature range. However, the example of SiGe segmented with Bi2Te3 and/or various skutterudites shows a marked decline in device efficiency even though SiGe has the highest figure of merit in the temperature range. The origin of the incompatibility of SiGe with other thermoelectric materials leads to a general definition of compatibility and intrinsic efficiency. The compatibility factor derived as = (Jl+zr - 1) a is a function of only intrinsic material properties and temperature, which is represented by a ratio of current to conduction heat. For maximum efficiency the compatibility factor should not change with temperature both within a single material, and in the segmented leg as a whole. This leads to a measure of compatibility not only between segments, but also within a segment. General temperature trends show that materials are more self compatible at higher temperatures, and segmentation is more difficult across a larger -T. The compatibility factor can be used as a quantitative guide for deciding whether a material is better suited for segmentation orcascading. Analysis of compatibility factors and intrinsic efficiency for optimal segmentation are discussed, with intent to predict optimal material properties, temperature interfaces, and/or currentheat ratios.

  12. Chasing plumes at the Endeavour Segment

    NASA Astrophysics Data System (ADS)

    Book, J. W.; Jeffries, M. A.; Mihaly, S. F.; Jenkyns, R.; Timmerman, R.

    2016-02-01

    The five major hydrothermal vents of the Endeavour Segment along the Juan de Fuca Ridge are estimated to emit the heat energy of a small nuclear power plant. From high temperature vent structures, this energy, along with mineral-rich vent fluids, is emitted chimney-like into the ocean, subsequently mixing with seawater and rising to neutral buoyancy between 150 and 300m above the seafloor. At this elevation, the hydrothermal vent plume is above the protection of the rift valley and is free to be carried away in the ambient ocean currents. In addition to anomalous chemical properties and particulates, the plume also carries planktonic residents of the deep-sea vent area. These larvae are key to the ongoing success of the existing ecosystems and their transport can facilitate the rapid colonization of newly formed venting sites. During Ocean Network Canada's 2015 maintenance expedition at the Endeavour Segment, we surveyed the vent plume both along and across-axis using optical transmission to locate the plume. Analysis of our observations reveals that the plume is retained over the central axis of the valley, thus exhibiting favorable conditions for the promulgation of vent ecosystems. We compare this analysis with earlier surveys conducted by Ocean Networks Canada as well as historic data collected since 1986 by the Institute of Ocean Sciences to estimate the spatial variability of the plume. Using this we propose a "climatology" of plume spreading over the Endeavour Segment.

  13. Segmenting Words from Natural Speech: Subsegmental Variation in Segmental Cues

    ERIC Educational Resources Information Center

    Rytting, C. Anton; Brew, Chris; Fosler-Lussier, Eric

    2010-01-01

    Most computational models of word segmentation are trained and tested on transcripts of speech, rather than the speech itself, and assume that speech is converted into a sequence of symbols prior to word segmentation. We present a way of representing speech corpora that avoids this assumption, and preserves acoustic variation present in speech. We…

  14. A deconstruction of the I-M-L commitment segmentation of forest recreationists

    Treesearch

    James D. Absher; Gerard T. Kyle

    2007-01-01

    Previous work has established the general utility of segmenting forest recreationists according to their commitment profiles into Indifferents, Moderates, and Loyalists (IML) groups. Observed differences between these segments suggest that place identity and affect are more central to management than previously thought. This study extends this finding through the use...

  15. The Importance of Marketing Segmentation

    ERIC Educational Resources Information Center

    Martin, Gillian

    2011-01-01

    The rationale behind marketing segmentation is to allow businesses to focus on their consumers' behaviors and purchasing patterns. If done effectively, marketing segmentation allows an organization to achieve its highest return on investment (ROI) in turn for its marketing and sales expenses. If an organization markets its products or services to…

  16. Automatic segmentation of the colon

    NASA Astrophysics Data System (ADS)

    Wyatt, Christopher L.; Ge, Yaorong; Vining, David J.

    1999-05-01

    Virtual colonoscopy is a minimally invasive technique that enables detection of colorectal polyps and cancer. Normally, a patient's bowel is prepared with colonic lavage and gas insufflation prior to computed tomography (CT) scanning. An important step for 3D analysis of the image volume is segmentation of the colon. The high-contrast gas/tissue interface that exists in the colon lumen makes segmentation of the majority of the colon relatively easy; however, two factors inhibit automatic segmentation of the entire colon. First, the colon is not the only gas-filled organ in the data volume: lungs, small bowel, and stomach also meet this criteria. User-defined seed points placed in the colon lumen have previously been required to spatially isolate only the colon. Second, portions of the colon lumen may be obstructed by peristalsis, large masses, and/or residual feces. These complicating factors require increased user interaction during the segmentation process to isolate additional colon segments. To automate the segmentation of the colon, we have developed a method to locate seed points and segment the gas-filled lumen with no user supervision. We have also developed an automated approach to improve lumen segmentation by digitally removing residual contrast-enhanced fluid resulting from a new bowel preparation that liquefies and opacifies any residual feces.

  17. Segmentation: Slicing the Urban Pie.

    ERIC Educational Resources Information Center

    Keim, William A.

    1981-01-01

    Explains market segmentation and defines undifferentiated, concentrated, and differentiated marketing strategies. Describes in detail the marketing planning process at the Metropolitan Community Colleges. Focuses on the development and implementation of an ongoing recruitment program designed for the market segment composed of business employees.…

  18. Market Segmentation: An Instructional Module.

    ERIC Educational Resources Information Center

    Wright, Peter H.

    A concept-based introduction to market segmentation is provided in this instructional module for undergraduate and graduate transportation-related courses. The material can be used in many disciplines including engineering, business, marketing, and technology. The concept of market segmentation is primarily a transportation planning technique by…

  19. Market segmentation using perceived constraints

    Treesearch

    Jinhee Jun; Gerard Kyle; Andrew Mowen

    2008-01-01

    We examined the practical utility of segmenting potential visitors to Cleveland Metroparks using their constraint profiles. Our analysis identified three segments based on their scores on the dimensions of constraints: Other priorities--visitors who scored the highest on 'other priorities' dimension; Highly Constrained--visitors who scored relatively high on...

  20. Segmentation: Slicing the Urban Pie.

    ERIC Educational Resources Information Center

    Keim, William A.

    1981-01-01

    Explains market segmentation and defines undifferentiated, concentrated, and differentiated marketing strategies. Describes in detail the marketing planning process at the Metropolitan Community Colleges. Focuses on the development and implementation of an ongoing recruitment program designed for the market segment composed of business employees.…

  1. Optimal segmentation and packaging process

    DOEpatents

    Kostelnik, Kevin M.; Meservey, Richard H.; Landon, Mark D.

    1999-01-01

    A process for improving packaging efficiency uses three dimensional, computer simulated models with various optimization algorithms to determine the optimal segmentation process and packaging configurations based on constraints including container limitations. The present invention is applied to a process for decontaminating, decommissioning (D&D), and remediating a nuclear facility involving the segmentation and packaging of contaminated items in waste containers in order to minimize the number of cuts, maximize packaging density, and reduce worker radiation exposure. A three-dimensional, computer simulated, facility model of the contaminated items are created. The contaminated items are differentiated. The optimal location, orientation and sequence of the segmentation and packaging of the contaminated items is determined using the simulated model, the algorithms, and various constraints including container limitations. The cut locations and orientations are transposed to the simulated model. The contaminated items are actually segmented and packaged. The segmentation and packaging may be simulated beforehand. In addition, the contaminated items may be cataloged and recorded.

  2. The LOFT ground segment

    NASA Astrophysics Data System (ADS)

    Bozzo, E.; Antonelli, A.; Argan, A.; Barret, D.; Binko, Pavel; Brandt, S.; Cavazzuti, E.; Courvoisier, T.; den Herder, J. W.; Feroci, M.; Ferrigno, C.; Giommi, P.; Götz, D.; Guy, L.; Hernanz, M.; in't Zand, J. J. M.; Klochkov, D.; Kuulkers, Erik; Motch, C.; Lumb, D.; Papitto, A.; Pittori, Carlotta; Rohlfs, R.; Santangelo, A.; Schmid, C.; Schwope, A. D.; Smith, P. J.; Webb, N. A.; Wilms, J.; Zane, S.

    2014-07-01

    LOFT, the Large Observatory For X-ray Timing, was one of the ESA M3 mission candidates that completed their assessment phase at the end of 2013. LOFT is equipped with two instruments, the Large Area Detector (LAD) and the Wide Field Monitor (WFM). The LAD performs pointed observations of several targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT Burst alert System additionally identifies on-board bright impulsive events (e.g., Gamma-ray Bursts, GRBs) and broadcasts the corresponding position and trigger time to the ground using a dedicated system of ~15 VHF receivers. All WFM data are planned to be made public immediately. In this contribution we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book1. We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving and distribution. Despite LOFT was not selected for launch within the M3 call, its long assessment phase ( >2 years) led to a very solid mission design and an efficient planning of its ground operations.

  3. Evolution of segmented strings

    NASA Astrophysics Data System (ADS)

    Gubser, Steven S.

    2016-11-01

    I explain how to evolve segmented strings in de Sitter and anti-de Sitter spaces of any dimension in terms of forward-directed null displacements. The evolution is described entirely in terms of discrete hops which do not require a continuum spacetime. Moreover, the evolution rule is purely algebraic, so it can be defined not only on ordinary real de Sitter and anti-de Sitter but also on the rational points of the quadratic equations that define these spaces. For three-dimensional anti-de Sitter space, a simpler evolution rule is possible that descends from the Wess-Zumino-Witten equations of motion. In this case, one may replace three-dimensional anti-de Sitter space by a noncompact discrete subgroup of S L (2 ,R ) whose structure is related to the Pell equation. A discrete version of the Bañados-Teitelboim-Zanelli (BTZ) black hole can be constructed as a quotient of this subgroup. This discrete black hole avoids the firewall paradox by a curious mechanism: even for large black holes, there are no points inside the horizon until one reaches the singularity.

  4. Fault segmentation: New concepts from the Wasatch Fault Zone, Utah, USA

    USGS Publications Warehouse

    Duross, Christopher; Personius, Stephen F.; Crone, Anthony J.; Olig, Susan S.; Hylland, Michael D.; Lund, William R.; Schwartz, David P.

    2016-01-01

    The question of whether structural segment boundaries along multisegment normal faults such as the Wasatch fault zone (WFZ) act as persistent barriers to rupture is critical to seismic hazard analyses. We synthesized late Holocene paleoseismic data from 20 trench sites along the central WFZ to evaluate earthquake rupture length and fault segmentation. For the youngest (<3 ka) and best-constrained earthquakes, differences in earthquake timing across prominent primary segment boundaries, especially for the most recent earthquakes on the north-central WFZ, are consistent with segment-controlled ruptures. However, broadly constrained earthquake times, dissimilar event times along the segments, the presence of smaller-scale (subsegment) boundaries, and areas of complex faulting permit partial-segment and multisegment (e.g., spillover) ruptures that are shorter (~20–40 km) or longer (~60–100 km) than the primary segment lengths (35–59 km). We report a segmented WFZ model that includes 24 earthquakes since ~7 ka and yields mean estimates of recurrence (1.1–1.3 kyr) and vertical slip rate (1.3–2.0 mm/yr) for the segments. However, additional rupture scenarios that include segment boundary spatial uncertainties, floating earthquakes, and multisegment ruptures are necessary to fully address epistemic uncertainties in rupture length. We compare the central WFZ to paleoseismic and historical surface ruptures in the Basin and Range Province and central Italian Apennines and conclude that displacement profiles have limited value for assessing the persistence of segment boundaries but can aid in interpreting prehistoric spillover ruptures. Our comparison also suggests that the probabilities of shorter and longer ruptures on the WFZ need to be investigated.

  5. LSM: perceptually accurate line segment merging

    NASA Astrophysics Data System (ADS)

    Hamid, Naila; Khan, Nazar

    2016-11-01

    Existing line segment detectors tend to break up perceptually distinct line segments into multiple segments. We propose an algorithm for merging such broken segments to recover the original perceptually accurate line segments. The algorithm proceeds by grouping line segments on the basis of angular and spatial proximity. Then those line segment pairs within each group that satisfy unique, adaptive mergeability criteria are successively merged to form a single line segment. This process is repeated until no more line segments can be merged. We also propose a method for quantitative comparison of line segment detection algorithms. Results on the York Urban dataset show that our merged line segments are closer to human-marked ground-truth line segments compared to state-of-the-art line segment detection algorithms.

  6. A Segmental Framework for Representing Signs Phonetically

    ERIC Educational Resources Information Center

    Johnson, Robert E.; Liddell, Scott K.

    2011-01-01

    The arguments for dividing the signing stream in signed languages into sequences of phonetic segments are compelling. The visual records of instances of actually occurring signs provide evidence of two basic types of segments: postural segments and trans-forming segments. Postural segments specify an alignment of articulatory features, both manual…

  7. A Segmental Framework for Representing Signs Phonetically

    ERIC Educational Resources Information Center

    Johnson, Robert E.; Liddell, Scott K.

    2011-01-01

    The arguments for dividing the signing stream in signed languages into sequences of phonetic segments are compelling. The visual records of instances of actually occurring signs provide evidence of two basic types of segments: postural segments and trans-forming segments. Postural segments specify an alignment of articulatory features, both manual…

  8. Multiatlas Segmentation as Nonparametric Regression

    PubMed Central

    Awate, Suyash P.; Whitaker, Ross T.

    2015-01-01

    This paper proposes a novel theoretical framework to model and analyze the statistical characteristics of a wide range of segmentation methods that incorporate a database of label maps or atlases; such methods are termed as label fusion or multiatlas segmentation. We model these multiatlas segmentation problems as nonparametric regression problems in the high-dimensional space of image patches. We analyze the nonparametric estimator’s convergence behavior that characterizes expected segmentation error as a function of the size of the multiatlas database. We show that this error has an analytic form involving several parameters that are fundamental to the specific segmentation problem (determined by the chosen anatomical structure, imaging modality, registration algorithm, and label-fusion algorithm). We describe how to estimate these parameters and show that several human anatomical structures exhibit the trends modeled analytically. We use these parameter estimates to optimize the regression estimator. We show that the expected error for large database sizes is well predicted by models learned on small databases. Thus, a few expert segmentations can help predict the database sizes required to keep the expected error below a specified tolerance level. Such cost-benefit analysis is crucial for deploying clinical multiatlas segmentation systems. PMID:24802528

  9. Direct volume estimation without segmentation

    NASA Astrophysics Data System (ADS)

    Zhen, X.; Wang, Z.; Islam, A.; Bhaduri, M.; Chan, I.; Li, S.

    2015-03-01

    Volume estimation plays an important role in clinical diagnosis. For example, cardiac ventricular volumes including left ventricle (LV) and right ventricle (RV) are important clinical indicators of cardiac functions. Accurate and automatic estimation of the ventricular volumes is essential to the assessment of cardiac functions and diagnosis of heart diseases. Conventional methods are dependent on an intermediate segmentation step which is obtained either manually or automatically. However, manual segmentation is extremely time-consuming, subjective and highly non-reproducible; automatic segmentation is still challenging, computationally expensive, and completely unsolved for the RV. Towards accurate and efficient direct volume estimation, our group has been researching on learning based methods without segmentation by leveraging state-of-the-art machine learning techniques. Our direct estimation methods remove the accessional step of segmentation and can naturally deal with various volume estimation tasks. Moreover, they are extremely flexible to be used for volume estimation of either joint bi-ventricles (LV and RV) or individual LV/RV. We comparatively study the performance of direct methods on cardiac ventricular volume estimation by comparing with segmentation based methods. Experimental results show that direct estimation methods provide more accurate estimation of cardiac ventricular volumes than segmentation based methods. This indicates that direct estimation methods not only provide a convenient and mature clinical tool for cardiac volume estimation but also enables diagnosis of cardiac diseases to be conducted in a more efficient and reliable way.

  10. Multiatlas segmentation as nonparametric regression.

    PubMed

    Awate, Suyash P; Whitaker, Ross T

    2014-09-01

    This paper proposes a novel theoretical framework to model and analyze the statistical characteristics of a wide range of segmentation methods that incorporate a database of label maps or atlases; such methods are termed as label fusion or multiatlas segmentation. We model these multiatlas segmentation problems as nonparametric regression problems in the high-dimensional space of image patches. We analyze the nonparametric estimator's convergence behavior that characterizes expected segmentation error as a function of the size of the multiatlas database. We show that this error has an analytic form involving several parameters that are fundamental to the specific segmentation problem (determined by the chosen anatomical structure, imaging modality, registration algorithm, and label-fusion algorithm). We describe how to estimate these parameters and show that several human anatomical structures exhibit the trends modeled analytically. We use these parameter estimates to optimize the regression estimator. We show that the expected error for large database sizes is well predicted by models learned on small databases. Thus, a few expert segmentations can help predict the database sizes required to keep the expected error below a specified tolerance level. Such cost-benefit analysis is crucial for deploying clinical multiatlas segmentation systems.

  11. Segment formation in Annelids: patterns, processes and evolution.

    PubMed

    Balavoine, Guillaume

    2014-01-01

    The debate on the origin of segmentation is a central question in the study of body plan evolution in metazoans. Annelids are the most conspicuously metameric animals as most of the trunk is formed of identical anatomical units. In this paper, I summarize the various patterns of evolution of the metameric body plan in annelids, showing the remarkable evolvability of this trait, similar to what is also found in arthropods. I then review the different modes of segment formation in the annelid tree, taking into account the various processes taking place in the life histories of these animals, including embryogenesis, post-embryonic development, regeneration and asexual reproduction. As an example of the variations that occur at the cellular and genetic level in annelid segment formation, I discuss the processes of teloblastic growth or posterior addition in key groups in the annelid tree. I propose a comprehensive definition for the teloblasts, stem cells that are responsible for sequential segment addition. There are a diversity of different mechanisms used in annelids to produce segments depending on the species, the developmental time and also the life history processes of the worm. A major goal for the future will be to reconstitute an ancestral process (or several ancestral processes) in the ancestor of the whole clade. This in turn will provide key insights in the current debate on ancestral bilaterian segmentation.

  12. Accounting for segment correlations in segmented gamma-ray scans

    SciTech Connect

    Sheppard, G.A.; Prettyman, T.H.; Piquette, E.C.

    1994-08-01

    In a typical segmented gamma-ray scanner (SGS), the detector`s field of view is collimated so that a complete horizontal slice or segment of the desired thickness is visible. Ordinarily, the collimator is not deep enough to exclude gamma rays emitted from sample volumes above and below the segment aligned with the collimator. This can lead to assay biases, particularly for certain radioactive-material distributions. Another consequence of the collimator`s low aspect ratio is that segment assays at the top and bottom of the sample are biased low because the detector`s field of view is not filled. This effect is ordinarily countered by placing the sample on a low-Z pedestal and scanning one or more segment thicknesses below and above the sample. This takes extra time, however, We have investigated a number of techniques that both account for correlated segments and correct for end effects in SGS assays. Also, we have developed an algorithm that facilitates estimates of assay precision. Six calculation methods have been compared by evaluating the results of thousands of simulated, assays for three types of gamma-ray source distribution and ten masses. We will report on these computational studies and their experimental verification.

  13. Ensemble segmentation using efficient integer linear programming.

    PubMed

    Alush, Amir; Goldberger, Jacob

    2012-10-01

    We present a method for combining several segmentations of an image into a single one that in some sense is the average segmentation in order to achieve a more reliable and accurate segmentation result. The goal is to find a point in the "space of segmentations" which is close to all the individual segmentations. We present an algorithm for segmentation averaging. The image is first oversegmented into superpixels. Next, each segmentation is projected onto the superpixel map. An instance of the EM algorithm combined with integer linear programming is applied on the set of binary merging decisions of neighboring superpixels to obtain the average segmentation. Apart from segmentation averaging, the algorithm also reports the reliability of each segmentation. The performance of the proposed algorithm is demonstrated on manually annotated images from the Berkeley segmentation data set and on the results of automatic segmentation algorithms.

  14. Metrology of IXO Mirror Segments

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing

    2011-01-01

    For future x-ray astrophysics mission that demands optics with large throughput and excellent angular resolution, many telescope concepts build around assembling thin mirror segments in a Wolter I geometry, such as that originally proposed for the International X-ray Observatory. The arc-second resolution requirement posts unique challenges not just for fabrication, mounting but also for metrology of these mirror segments. In this paper, we shall discuss the metrology of these segments using normal incidence metrological method with interferometers and null lenses. We present results of the calibration of the metrology systems we are currently using, discuss their accuracy and address the precision in measuring near-cylindrical mirror segments and the stability of the measurements.

  15. Texture segmentation by genetic programming.

    PubMed

    Song, Andy; Ciesielski, Vic

    2008-01-01

    This paper describes a texture segmentation method using genetic programming (GP), which is one of the most powerful evolutionary computation algorithms. By choosing an appropriate representation texture, classifiers can be evolved without computing texture features. Due to the absence of time-consuming feature extraction, the evolved classifiers enable the development of the proposed texture segmentation algorithm. This GP based method can achieve a segmentation speed that is significantly higher than that of conventional methods. This method does not require a human expert to manually construct models for texture feature extraction. In an analysis of the evolved classifiers, it can be seen that these GP classifiers are not arbitrary. Certain textural regularities are captured by these classifiers to discriminate different textures. GP has been shown in this study as a feasible and a powerful approach for texture classification and segmentation, which are generally considered as complex vision tasks.

  16. Morphing of Segmented Bimorph Mirrors

    NASA Astrophysics Data System (ADS)

    Rodrigues, Gonçalo; Bastaits, Renaud; Preumont, André

    2010-08-01

    Atmospheric turbulence compensation for the next generation of terrestrial telescopes (30-40 m diameter) will require deformable mirrors of increasing size and a number of actuators reaching several thousands. However, the mere extrapolation of existing designs leads to complicated and extremely expensive mirrors. This article discusses an alternative solution based on the use of segmented identical hexagonal bimorph mirrors. This allows to indefinitely increase the degree of correction while maintaining the first mechanical resonance at the level of a single segment, and shows an increase in price only proportional to the number of segments. Extensive simulations using random turbulent screens show that the segmentation produces only moderate reductions of the Strehl number, compared to a monolithic bimorph mirror with the same number of actuators (S = 0.86 instead of S = 0.89 in this study).

  17. Upper airway segmentation and measurement in MRI using fuzzy connectedness

    NASA Astrophysics Data System (ADS)

    Liu, Jianguo; Udupa, Jayaram K.; Odhner, Dewey; McDonough, Joe M.; Arens, Raanan

    2002-04-01

    The purpose of this work is to build a computerized system for the delineation of upper airway structures via MRI and to evaluate its effectiveness for routine clinical use in aiding diagnosis of upper airway disorders in children. We use two MRI protocols, axial T1 and T2, to gather information about different aspects of the airway and its surrounding soft tissue structures including adenoid, tonsils, tongue and soft palate. These images are processed and segmented to compute the architectural parameters of the airway such as its surface description, volume, central (medial) line, and cross-sectional areas at planes orthogonal to the central line. We have built a software package based on 3DVIEWNIX and running on a 450 MHz Pentium PC under Linux system (and on a Sun workstation under Unix) for the various operations of visualization, segmentation, registration, prefiltering, interpolation, standardization, and quantitative analysis of the airway. The system has been tested utilizing 40 patient studies. For every study, the system segmented and displayed a smooth 3D rendition of the airway, its central line and a plot of the cross-sectional area of the airway orthogonal to the central line as a function of the distance from one end of the central line. The tests indicate 97% precision and accuracy for segmentation. The mean time taken per study is about 4 minutes for the airway. This includes operator interaction time and processing time. This method provides a robust and fast means of assessing the airway size, shape, and places of restriction, as well as providing a structural data set suitable for use in modeling studies of airflow and mechanics.

  18. Image Segmentation Using Affine Wavelets

    DTIC Science & Technology

    1991-12-12

    2-4 2.7 Artificial Neural Network Radial Basis Function Classifiers . . . 2-5 2.7.1 Localized Receptive Fields...used a radial 1-3 basis function artificial neural network, which accomplishes the segmentation based on the multiresolution features. 1.7 Objectives...as the features? "* Can the Radial Basis Function (RBF) artificial neural network be trained to au- tonomously segment SAR and FLIR imagery using the

  19. Non-Orthogonal Iris Segmentation

    DTIC Science & Technology

    2005-05-09

    pixels ( eyelashes , eyelids, etc.). For example, if all three quality bounds are close in proximity, the iris pattern that was segmented...iris pattern that was segmented by the algorithm contains eyelashes and additional extraneous information. If all automatically generated “test” mask...orthogonal iris images (see Figs. 25-28). This is primarily explained by the increased presence of eyelashes in the non-orthogonal iris masks. As the angle

  20. Central line infections - hospitals

    MedlinePlus

    ... infection; CVC - infection; Central venous device - infection; Infection control - central line infection; Nosocomial infection - central line infection; Hospital acquired infection - central line infection; Patient safety - central ...

  1. Neural network for image segmentation

    NASA Astrophysics Data System (ADS)

    Skourikhine, Alexei N.; Prasad, Lakshman; Schlei, Bernd R.

    2000-10-01

    Image analysis is an important requirement of many artificial intelligence systems. Though great effort has been devoted to inventing efficient algorithms for image analysis, there is still much work to be done. It is natural to turn to mammalian vision systems for guidance because they are the best known performers of visual tasks. The pulse- coupled neural network (PCNN) model of the cat visual cortex has proven to have interesting properties for image processing. This article describes the PCNN application to the processing of images of heterogeneous materials; specifically PCNN is applied to image denoising and image segmentation. Our results show that PCNNs do well at segmentation if we perform image smoothing prior to segmentation. We use PCNN for obth smoothing and segmentation. Combining smoothing and segmentation enable us to eliminate PCNN sensitivity to the setting of the various PCNN parameters whose optimal selection can be difficult and can vary even for the same problem. This approach makes image processing based on PCNN more automatic in our application and also results in better segmentation.

  2. The Envisat-1 ground segment

    NASA Astrophysics Data System (ADS)

    Harris, Ray; Ashton, Martin

    1995-03-01

    The European Space Agency (ESA) Earth Remote Sensing Satellite (ERS-1 and ERS-2) missions will be followed by the Polar Orbit Earth Mission (POEM) program. The first of the POEM missions will be Envisat-1. ESA has completed the design phase of the ground segment. This paper presents the main elements of that design. The main part of this paper is an overview of the Payload Data Segment (PDS) which is the core of the Envisat-1 ground segment, followed by two further sections which describe in more detail the facilities to be offered by the PDS for archiving and for user servcies. A further section describes some future issues for ground segment development. Logica was the prime contractor of a team of 18 companies which undertook the ESA financed architectural design study of the Envisat-1 ground segment. The outputs of the study included detailed specifications of the components that will acquire, process, archive and disseminate the payload data, together with the functional designs of the flight operations and user data segments.

  3. 4D MR phase and magnitude segmentations with GPU parallel computing.

    PubMed

    Bergen, Robert V; Lin, Hung-Yu; Alexander, Murray E; Bidinosti, Christopher P

    2015-01-01

    The increasing size and number of data sets of large four dimensional (three spatial, one temporal) magnetic resonance (MR) cardiac images necessitates efficient segmentation algorithms. Analysis of phase-contrast MR images yields cardiac flow information which can be manipulated to produce accurate segmentations of the aorta. Phase contrast segmentation algorithms are proposed that use simple mean-based calculations and least mean squared curve fitting techniques. The initial segmentations are generated on a multi-threaded central processing unit (CPU) in 10 seconds or less, though the computational simplicity of the algorithms results in a loss of accuracy. A more complex graphics processing unit (GPU)-based algorithm fits flow data to Gaussian waveforms, and produces an initial segmentation in 0.5 seconds. Level sets are then applied to a magnitude image, where the initial conditions are given by the previous CPU and GPU algorithms. A comparison of results shows that the GPU algorithm appears to produce the most accurate segmentation.

  4. Optimal segmentation of pupillometric images for estimating pupil shape parameters.

    PubMed

    De Santis, A; Iacoviello, D

    2006-12-01

    The problem of determining the pupil morphological parameters from pupillometric data is considered. These characteristics are of great interest for non-invasive early diagnosis of the central nervous system response to environmental stimuli of different nature, in subjects suffering some typical diseases such as diabetes, Alzheimer disease, schizophrenia, drug and alcohol addiction. Pupil geometrical features such as diameter, area, centroid coordinates, are estimated by a procedure based on an image segmentation algorithm. It exploits the level set formulation of the variational problem related to the segmentation. A discrete set up of this problem that admits a unique optimal solution is proposed: an arbitrary initial curve is evolved towards the optimal segmentation boundary by a difference equation; therefore no numerical approximation schemes are needed, as required in the equivalent continuum formulation usually adopted in the relevant literature.

  5. Medical image segmentation by MDP model

    NASA Astrophysics Data System (ADS)

    Lu, Yisu; Chen, Wufan

    2011-11-01

    MDP (Dirichlet Process Mixtures) model is applied to segment medical images in this paper. Segmentation can been automatically done without initializing segmentation class numbers. The MDP model segmentation algorithm is used to segment natural images and MR (Magnetic Resonance) images in the paper. To demonstrate the accuracy of the MDP model segmentation algorithm, many compared experiments, such as EM (Expectation Maximization) image segmentation algorithm, K-means image segmentation algorithm and MRF (Markov Field) image segmentation algorithm, have been done to segment medical MR images. All the methods are also analyzed quantitatively by using DSC (Dice Similarity Coefficients). The experiments results show that DSC of MDP model segmentation algorithm of all slices exceed 90%, which show that the proposed method is robust and accurate.

  6. Communicative functions integrate segments in prosodies and prosodies in segments.

    PubMed

    Kohler, Klaus J

    2011-01-01

    This paper takes a new look at the traditionally established divide between sounds and prosodies, viewing it as a useful heuristics in language descriptions that focus on the segmental make- up of words. It pleads for a new approach that bridges this reified compartmentalization of speech in a more global communicative perspective. Data are presented from a German perception experiment in the framework of the Semantic Differential that shows interdependence of f0 contours and the spectral characteristics of a following fricative segment, for the expression of semantic functions along the scales questioning - asserting, excited - calm, forceful - not forceful, contrary - agreeable. The results lead to the conclusion that segments shape prosodies and are shaped by them in varying ways in the coding of semantic functions. This implies that the analysis of sentence prosodies needs to integrate the manifestation of segments, just as the analysis of segments needs to consider their prosodic embedding. In communicative interaction, speakers set broad prosodic time windows of varying sizes, and listeners respond to them. So, future phonetic research needs to concentrate on speech analysis in such windows.

  7. Deformable M-Reps for 3D Medical Image Segmentation

    PubMed Central

    Pizer, Stephen M.; Fletcher, P. Thomas; Joshi, Sarang; Thall, Andrew; Chen, James Z.; Fridman, Yonatan; Fritsch, Daniel S.; Gash, Graham; Glotzer, John M.; Jiroutek, Michael R.; Lu, Conglin; Muller, Keith E.; Tracton, Gregg; Yushkevich, Paul; Chaney, Edward L.

    2013-01-01

    M-reps (formerly called DSLs) are a multiscale medial means for modeling and rendering 3D solid geometry. They are particularly well suited to model anatomic objects and in particular to capture prior geometric information effectively in deformable models segmentation approaches. The representation is based on figural models, which define objects at coarse scale by a hierarchy of figures – each figure generally a slab representing a solid region and its boundary simultaneously. This paper focuses on the use of single figure models to segment objects of relatively simple structure. A single figure is a sheet of medial atoms, which is interpolated from the model formed by a net, i.e., a mesh or chain, of medial atoms (hence the name m-reps), each atom modeling a solid region via not only a position and a width but also a local figural frame giving figural directions and an object angle between opposing, corresponding positions on the boundary implied by the m-rep. The special capability of an m-rep is to provide spatial and orientational correspondence between an object in two different states of deformation. This ability is central to effective measurement of both geometric typicality and geometry to image match, the two terms of the objective function optimized in segmentation by deformable models. The other ability of m-reps central to effective segmentation is their ability to support segmentation at multiple levels of scale, with successively finer precision. Objects modeled by single figures are segmented first by a similarity transform augmented by object elongation, then by adjustment of each medial atom, and finally by displacing a dense sampling of the m-rep implied boundary. While these models and approaches also exist in 2D, we focus on 3D objects. The segmentation of the kidney from CT and the hippocampus from MRI serve as the major examples in this paper. The accuracy of segmentation as compared to manual, slice-by-slice segmentation is reported. PMID

  8. Integrated segmentation of cellular structures

    NASA Astrophysics Data System (ADS)

    Ajemba, Peter; Al-Kofahi, Yousef; Scott, Richard; Donovan, Michael; Fernandez, Gerardo

    2011-03-01

    Automatic segmentation of cellular structures is an essential step in image cytology and histology. Despite substantial progress, better automation and improvements in accuracy and adaptability to novel applications are needed. In applications utilizing multi-channel immuno-fluorescence images, challenges include misclassification of epithelial and stromal nuclei, irregular nuclei and cytoplasm boundaries, and over and under-segmentation of clustered nuclei. Variations in image acquisition conditions and artifacts from nuclei and cytoplasm images often confound existing algorithms in practice. In this paper, we present a robust and accurate algorithm for jointly segmenting cell nuclei and cytoplasm using a combination of ideas to reduce the aforementioned problems. First, an adaptive process that includes top-hat filtering, Eigenvalues-of-Hessian blob detection and distance transforms is used to estimate the inverse illumination field and correct for intensity non-uniformity in the nuclei channel. Next, a minimum-error-thresholding based binarization process and seed-detection combining Laplacian-of-Gaussian filtering constrained by a distance-map-based scale selection is used to identify candidate seeds for nuclei segmentation. The initial segmentation using a local maximum clustering algorithm is refined using a minimum-error-thresholding technique. Final refinements include an artifact removal process specifically targeted at lumens and other problematic structures and a systemic decision process to reclassify nuclei objects near the cytoplasm boundary as epithelial or stromal. Segmentation results were evaluated using 48 realistic phantom images with known ground-truth. The overall segmentation accuracy exceeds 94%. The algorithm was further tested on 981 images of actual prostate cancer tissue. The artifact removal process worked in 90% of cases. The algorithm has now been deployed in a high-volume histology analysis application.

  9. Automatic segmentation of psoriasis lesions

    NASA Astrophysics Data System (ADS)

    Ning, Yang; Shi, Chenbo; Wang, Li; Shu, Chang

    2014-10-01

    The automatic segmentation of psoriatic lesions is widely researched these years. It is an important step in Computer-aid methods of calculating PASI for estimation of lesions. Currently those algorithms can only handle single erythema or only deal with scaling segmentation. In practice, scaling and erythema are often mixed together. In order to get the segmentation of lesions area - this paper proposes an algorithm based on Random forests with color and texture features. The algorithm has three steps. The first step, the polarized light is applied based on the skin's Tyndall-effect in the imaging to eliminate the reflection and Lab color space are used for fitting the human perception. The second step, sliding window and its sub windows are used to get textural feature and color feature. In this step, a feature of image roughness has been defined, so that scaling can be easily separated from normal skin. In the end, Random forests will be used to ensure the generalization ability of the algorithm. This algorithm can give reliable segmentation results even the image has different lighting conditions, skin types. In the data set offered by Union Hospital, more than 90% images can be segmented accurately.

  10. Optimal segmentation and packaging process

    DOEpatents

    Kostelnik, K.M.; Meservey, R.H.; Landon, M.D.

    1999-08-10

    A process for improving packaging efficiency uses three dimensional, computer simulated models with various optimization algorithms to determine the optimal segmentation process and packaging configurations based on constraints including container limitations. The present invention is applied to a process for decontaminating, decommissioning (D and D), and remediating a nuclear facility involving the segmentation and packaging of contaminated items in waste containers in order to minimize the number of cuts, maximize packaging density, and reduce worker radiation exposure. A three-dimensional, computer simulated, facility model of the contaminated items are created. The contaminated items are differentiated. The optimal location, orientation and sequence of the segmentation and packaging of the contaminated items is determined using the simulated model, the algorithms, and various constraints including container limitations. The cut locations and orientations are transposed to the simulated model. The contaminated items are actually segmented and packaged. The segmentation and packaging may be simulated beforehand. In addition, the contaminated items may be cataloged and recorded. 3 figs.

  11. Feature extraction for MRI segmentation.

    PubMed

    Velthuizen, R P; Hall, L O; Clarke, L P

    1999-04-01

    Magnetic resonance images (MRIs) of the brain are segmented to measure the efficacy of treatment strategies for brain tumors. To date, no reproducible technique for measuring tumor size is available to the clinician, which hampers progress of the search for good treatment protocols. Many segmentation techniques have been proposed, but the representation (features) of the MRI data has received little attention. A genetic algorithm (GA) search was used to discover a feature set from multi-spectral MRI data. Segmentations were performed using the fuzzy c-means (FCM) clustering technique. Seventeen MRI data sets from five patients were evaluated. The GA feature set produces a more accurate segmentation. The GA fitness function that achieves the best results is the Wilks's lambda statistic when applied to FCM clusters. Compared to linear discriminant analysis, which requires class labels, the same or better accuracy is obtained by the features constructed from a GA search without class labels, allowing fully operator independent segmentation. The GA approach therefore provides a better starting point for the measurement of the response of a brain tumor to treatment.

  12. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  13. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  14. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  15. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  16. 47 CFR 95.853 - Frequency segments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  17. Identifying Benefit Segments among College Students.

    ERIC Educational Resources Information Center

    Brown, Joseph D.

    1991-01-01

    Using concept of market segmentation (dividing market into distinct groups requiring different product benefits), surveyed 398 college students to determine benefit segments among students selecting a college to attend and factors describing each benefit segment. Identified one major segment of students (classroomers) plus three minor segments…

  18. U.S. Army Custom Segmentation System

    DTIC Science & Technology

    2007-06-01

    segmentation is individual or intergroup differences in response to marketing - mix variables. Presumptions about segments: •different demands in a...product or service category, •respond differently to changes in the marketing mix Criteria for segments: •The segments must exist in the environment

  19. Identifying Benefit Segments among College Students.

    ERIC Educational Resources Information Center

    Brown, Joseph D.

    1991-01-01

    Using concept of market segmentation (dividing market into distinct groups requiring different product benefits), surveyed 398 college students to determine benefit segments among students selecting a college to attend and factors describing each benefit segment. Identified one major segment of students (classroomers) plus three minor segments…

  20. Image Information Mining Utilizing Hierarchical Segmentation

    NASA Technical Reports Server (NTRS)

    Tilton, James C.; Marchisio, Giovanni; Koperski, Krzysztof; Datcu, Mihai

    2002-01-01

    The Hierarchical Segmentation (HSEG) algorithm is an approach for producing high quality, hierarchically related image segmentations. The VisiMine image information mining system utilizes clustering and segmentation algorithms for reducing visual information in multispectral images to a manageable size. The project discussed herein seeks to enhance the VisiMine system through incorporating hierarchical segmentations from HSEG into the VisiMine system.

  1. Reproducibility of thalamic segmentation based on probabilistic tractography.

    PubMed

    Traynor, Catherine; Heckemann, Rolf A; Hammers, Alexander; O'Muircheartaigh, Jonathan; Crum, William R; Barker, Gareth J; Richardson, Mark P

    2010-08-01

    Reliable identification of thalamic nuclei is required to improve targeting of electrodes used in Deep Brain Stimulation (DBS), and for exploring the role of thalamus in health and disease. A previously described method using probabilistic tractography to segment the thalamus based on connections to cortical target regions was implemented. Both within- and between-subject reproducibility were quantitatively assessed by the overlap of the resulting segmentations; the effect of two different numbers of target regions (6 and 31) on reproducibility of the segmentation results was also investigated. Very high reproducibility was observed when a single dataset was processed multiple times using different starting conditions. Thalamic segmentation was also very reproducible when multiple datasets from the same subject were processed using six cortical target regions. Within-subject reproducibility was reduced when the number of target regions was increased, particularly in medial and posterior regions of the thalamus. A large degree of overlap in segmentation results from different subjects was obtained, particularly in thalamic regions classified as connecting to frontal, parietal, temporal and pre-central cortical target regions.

  2. Streamline segment statistics of premixed flames with nonunity Lewis numbers

    NASA Astrophysics Data System (ADS)

    Chakraborty, Nilanjan; Wang, Lipo; Klein, Markus

    2014-03-01

    The interaction of flame and surrounding fluid motion is of central importance in the fundamental understanding of turbulent combustion. It is demonstrated here that this interaction can be represented using streamline segment analysis, which was previously applied in nonreactive turbulence. The present work focuses on the effects of the global Lewis number (Le) on streamline segment statistics in premixed flames in the thin-reaction-zones regime. A direct numerical simulation database of freely propagating thin-reaction-zones regime flames with Le ranging from 0.34 to 1.2 is used to demonstrate that Le has significant influences on the characteristic features of the streamline segment, such as the curve length, the difference in the velocity magnitude at two extremal points, and their correlations with the local flame curvature. The strengthenings of the dilatation rate, flame normal acceleration, and flame-generated turbulence with decreasing Le are principally responsible for these observed effects. An expression for the probability density function (pdf) of the streamline segment length, originally developed for nonreacting turbulent flows, captures the qualitative behavior for turbulent premixed flames in the thin-reaction-zones regime for a wide range of Le values. The joint pdfs between the streamline length and the difference in the velocity magnitude at two extremal points for both unweighted and density-weighted velocity vectors are analyzed and compared. Detailed explanations are provided for the observed differences in the topological behaviors of the streamline segment in response to the global Le.

  3. Modeling rupture segmentations on the Cascadia megathrust

    NASA Astrophysics Data System (ADS)

    Yang, H.; Liu, Y.; McGuire, J. J.

    2012-12-01

    The Cascadia subduction zone has produced a series of large to great earthquakes, most recently in 1700 AD. Paleoseismological studies of submarine turbidites suggest a significant difference in recurrence interval between Northern (~500 year) and Southern (~200-300 year) Cascadia. Whether future large ruptures are segmented is very important for estimating hazard in Pacific Northwest, but remains enigmatic from the interpretations of current locking maps. Our approach is to develop rupture scenarios of Cascadia earthquakes by performing numerical simulations using the finite element software, PyLith. Based on the USGS plate interface model of Cascadia, we have constructed a realistic three-dimensional subduction fault model that stretches from Northern California to Central Vancouver Island. We have performed a number of dynamic rupture simulations using a set of artificial friction parameters and uniform stress distributions on the fault governed by a slip-weakening friction law. Preliminary results show that ruptures have initiated from the nucleation zone with higher shear stress than the ambient fault and have propagated on the realistic three-dimensional fault surface. The increase of dip angle with depth has little effect on the rupture propagation because that is governed mostly by the fault strength. The along-strike bend of the fault beneath Washington state and Vancouver Island has not impeded the rupture propagation given the uniform fault strength. To estimate the possible rupture segmentation, we have converted a slip-deficit rate model derived from GPS data into stress change distributions on the fault assuming the entire slip deficit would be released in the next great earthquake. We are also constructing another initial stress map derived from tidal and leveling data, which shows a significant difference in the locking depth beneath Central Oregon. The other important variable, the spatial variation of frictional parameters, however, has to be

  4. Bronchopulmonary segments approximation using anatomical atlas

    NASA Astrophysics Data System (ADS)

    Busayarat, Sata; Zrimec, Tatjana

    2007-03-01

    Bronchopulmonary segments are valuable as they give more accurate localization than lung lobes. Traditionally, determining the segments requires segmentation and identification of segmental bronchi, which, in turn, require volumetric imaging data. In this paper, we present a method for approximating the bronchopulmonary segments for sparse data by effectively using an anatomical atlas. The atlas is constructed from a volumetric data and contains accurate information about bronchopulmonary segments. A new ray-tracing based image registration is used for transferring the information from the atlas to a query image. Results show that the method is able to approximate the segments on sparse HRCT data with slice gap up to 25 millimeters.

  5. Distribution Metrics and Image Segmentation

    PubMed Central

    Georgiou, Tryphon; Michailovich, Oleg; Rathi, Yogesh; Malcolm, James; Tannenbaum, Allen

    2007-01-01

    The purpose of this paper is to describe certain alternative metrics for quantifying distances between distributions, and to explain their use and relevance in visual tracking. Besides the theoretical interest, such metrics may be used to design filters for image segmentation, that is for solving the key visual task of separating an object from the background in an image. The segmenting curve is represented as the zero level set of a signed distance function. Most existing methods in the geometric active contour framework perform segmentation by maximizing the separation of intensity moments between the interior and the exterior of an evolving contour. Here one can use the given distributional metric to determine a flow which minimizes changes in the distribution inside and outside the curve. PMID:18769529

  6. The segmentation of hadron calorimeters

    NASA Astrophysics Data System (ADS)

    Chen, He Sheng

    1987-05-01

    Optimization of the segmentation of large hadron calorimeters is important in order to obtain good resolution for jet physics at minimum construction cost for the next generation of high energy experiments. The principles of the segmentation of hadron calorimeters are discussed. As an example, the Monte Carlo optimization of the segmentation of the L3 hadron calorimeter barrel at CERN is described. Comparisons of results for the reconstructed jet shapes show that the optimum number ADC channels is about 20K for the readout of 450K wires of the proportional chambers. The matching between the sandwiched φ towers and Z towers is the dominant factor for angular resolution. Based on these Monte Carlo simulations, an optimized tower structure is obtained.

  7. Segmental Rescoring in Text Recognition

    DTIC Science & Technology

    2014-02-04

    ttm № tes/m, m* tmvr mowm* a Smyrna Of l δrtA£ACf02S’ A w m - y i p m AmiKSiS € f № ) C № № m .. sg6#?«rA fiθN ; Atφ h Sft№’·’Spxn mm m fim f№b t&m&mm...applying a Hidden Markov Model (HMM) recognition approach. Generating the plurality text hypotheses for the image forming includes generating a first...image. Applying segmental analysis to a segmentation determined by a first OCR engine, such as a segmentation determined by a Hidden Markov Model (HMM

  8. Unsupervised segmentation with dynamical units.

    PubMed

    Rao, A Ravishankar; Cecchi, Guillermo A; Peck, Charles C; Kozloski, James R

    2008-01-01

    In this paper, we present a novel network to separate mixtures of inputs that have been previously learned. A significant capability of the network is that it segments the components of each input object that most contribute to its classification. The network consists of amplitude-phase units that can synchronize their dynamics, so that separation is determined by the amplitude of units in an output layer, and segmentation by phase similarity between input and output layer units. Learning is unsupervised and based on a Hebbian update, and the architecture is very simple. Moreover, efficient segmentation can be achieved even when there is considerable superposition of the inputs. The network dynamics are derived from an objective function that rewards sparse coding in the generalized amplitude-phase variables. We argue that this objective function can provide a possible formal interpretation of the binding problem and that the implementation of the network architecture and dynamics is biologically plausible.

  9. Segmented Mirror Image Degradation Due to Surface Dust, Alignment and Figure

    NASA Technical Reports Server (NTRS)

    Schreur, Julian J.

    1999-01-01

    In 1996 an algorithm was developed to include the effects of surface roughness in the calculation of the point spread function of a telescope mirror. This algorithm has been extended to include the effects of alignment errors and figure errors for the individual elements, and an overall contamination by surface dust. The final algorithm builds an array for a guard-banded pupil function of a mirror that may or may not have a central hole, a central reflecting segment, or an outer ring of segments. The central hole, central reflecting segment, and outer ring may be circular or polygonal, and the outer segments may have trimmed comers. The modeled point spread functions show that x-tilt and y-tilt, or the corresponding R-tilt and theta-tilt for a segment in an outer ring, is readily apparent for maximum wavefront errors of 0.1 lambda. A similar sized piston error is also apparent, but integral wavelength piston errors are not. Severe piston error introduces a focus error of the opposite sign, so piston could be adjusted to compensate for segments with varying focal lengths. Dust affects the image principally by decreasing the Strehl ratio, or peak intensity of the image. For an eight-meter telescope a 25% coverage by dust produced a scattered light intensity of 10(exp -9) of the peak intensity, a level well below detectability.

  10. Four segment piezo based micropump

    NASA Astrophysics Data System (ADS)

    Haldkar, Rakesh Kumar; Sheorey, Tanuja; Gupta, Vijay Kumar; Ansari, M. Zahid

    2017-06-01

    In recent years, micropumps have been investigated by various researchers as drug delivery and disease diagnostic devices. Many of these micropumps have been designed, considering available micro fabrication technologies rather than appropriate pump performance analysis. Piezoelectric based micro pumps are more popular as compared to other smart materials being explored. In this paper, four segment piezoelectric bimorph actuator (FSPB) are compared with circular disc piezoelectric bimorph actuator (CDPB) based pump. The static and transient behaviors under various electric fields have been analyzed by using ANSYS 12.1(R) finite element software. Simulation results show that dividing the actuator in segment can amplify the deflection and improve the performance of the pump.

  11. SExSeg: SExtractor segmentation

    NASA Astrophysics Data System (ADS)

    Coe, Dan

    2015-08-01

    SExSeg forces SExtractor (ascl:1010.064) to run using a pre-defined segmentation map (the definition of objects and their borders). The defined segments double as isophotal apertures. SExSeg alters the detection image based on a pre-defined segmenation map while preparing your "analysis image" by subtracting the background in a separate SExtractor run (using parameters you specify). SExtractor is then run in "double-image" mode with the altered detection image and background-subtracted analysis image.

  12. Document segmentation via oblique cuts

    NASA Astrophysics Data System (ADS)

    Svendsen, Jeremy; Branzan-Albu, Alexandra

    2013-01-01

    This paper presents a novel solution for the layout segmentation of graphical elements in Business Intelligence documents. We propose a generalization of the recursive X-Y cut algorithm, which allows for cutting along arbitrary oblique directions. An intermediate processing step consisting of line and solid region removal is also necessary due to presence of decorative elements. The output of the proposed segmentation is a hierarchical structure which allows for the identification of primitives in pie and bar charts. The algorithm was tested on a database composed of charts from business documents. Results are very promising.

  13. The Time Course of Segmentation and Cue-Selectivity in the Human Visual Cortex

    PubMed Central

    Appelbaum, Lawrence G.; Ales, Justin M.; Norcia, Anthony M.

    2012-01-01

    Texture discontinuities are a fundamental cue by which the visual system segments objects from their background. The neural mechanisms supporting texture-based segmentation are therefore critical to visual perception and cognition. In the present experiment we employ an EEG source-imaging approach in order to study the time course of texture-based segmentation in the human brain. Visual Evoked Potentials were recorded to four types of stimuli in which periodic temporal modulation of a central 3° figure region could either support figure-ground segmentation, or have identical local texture modulations but not produce changes in global image segmentation. The image discontinuities were defined either by orientation or phase differences across image regions. Evoked responses to these four stimuli were analyzed both at the scalp and on the cortical surface in retinotopic and functional regions-of-interest (ROIs) defined separately using fMRI on a subject-by-subject basis. Texture segmentation (tsVEP: segmenting versus non-segmenting) and cue-specific (csVEP: orientation versus phase) responses exhibited distinctive patterns of activity. Alternations between uniform and segmented images produced highly asymmetric responses that were larger after transitions from the uniform to the segmented state. Texture modulations that signaled the appearance of a figure evoked a pattern of increased activity starting at ∼143 ms that was larger in V1 and LOC ROIs, relative to identical modulations that didn't signal figure-ground segmentation. This segmentation-related activity occurred after an initial response phase that did not depend on the global segmentation structure of the image. The two cue types evoked similar tsVEPs up to 230 ms when they differed in the V4 and LOC ROIs. The evolution of the response proceeded largely in the feed-forward direction, with only weak evidence for feedback-related activity. PMID:22479566

  14. Lithologic and physicochemical properties and hydraulics of flow in and near the freshwater/saline-water transition zone, San Antonio segment of the Edwards aquifer, south-central Texas, based on water-level and borehole geophysical log data, 1999-2007

    USGS Publications Warehouse

    Lambert, Rebecca B.; Hunt, Andrew G.; Stanton, Gregory P.; Nyman, Michael B.

    2010-01-01

    The freshwater zone of the San Antonio segment of the Edwards aquifer in south-central Texas (hereinafter, the Edwards aquifer) is bounded to the south and southeast by a zone of transition from freshwater to saline water (hereinafter, the transition zone). The boundary between the two zones is the freshwater/saline-water interface (hereinafter, the interface), defined as the 1,000-milligrams per liter dissolved solids concentration threshold. This report presents the findings of a study, done by the U.S. Geological Survey in cooperation with the San Antonio Water System, to obtain lithologic properties (rock properties associated with known stratigraphic units) and physicochemical properties (fluid conductivity and temperature) and to analyze the hydraulics of flow in and near the transition zone of the Edwards aquifer on the basis of water-level and borehole geophysical log data collected from 15 monitoring wells in four transects during 1999-2007. No identifiable relation between conductivity values from geophysical logs in monitoring wells in all transects and equivalent freshwater heads in the wells at the times the logs were run is evident; and no identifiable relation between conductivity values and vertical flow in the boreholes concurrent with the times the logs were run is evident. The direction of the lateral equivalent freshwater head gradient and thus the potential lateral flow at the interface in the vicinity of the East Uvalde transect fluctuates between into and out of the freshwater zone, depending on recharge and withdrawals. Whether the prevailing direction on average is into or out of the freshwater zone is not clearly indicated. Equivalent freshwater head data do not indicate a prevailing direction of the lateral gradient at the interface in the vicinity of the Tri-County transect. The prevailing direction on average of the lateral gradient and thus potential lateral flow at the interface in the vicinity of the Kyle transect likely is from the

  15. Colorization based on soft segmentation

    NASA Astrophysics Data System (ADS)

    Koo, Hyung-Il; Cho, Nam-Ik

    2011-01-01

    This paper proposes a new colorization method based on the chrominance blending. The weights for the blending are computed by using the random walker algorithm, which is a soft segmentation technique that provides sharp probability transition on object boundaries. As a result, the proposed method reduces color bleeding and provides improved colorization performances compared to conventional ones.

  16. Increasing Enrollment through Benefit Segmentation.

    ERIC Educational Resources Information Center

    Goodnow, Betty

    1982-01-01

    The applicability of benefit segmentation, a market research technique which groups people according to benefits expected from a program offering, was tested at the College of DuPage. Preferences and demographic characteristics were analyzed and program improvements adopted, increasing enrollment by 20 percent. (Author/SK)

  17. Multiple Segment Factorial Vignette Designs

    ERIC Educational Resources Information Center

    Ganong, Lawrence H.; Coleman, Marilyn

    2006-01-01

    The multiple segment factorial vignette design (MSFV) combines elements of experimental designs and probability sampling with the inductive, exploratory approach of qualitative research. MSFVs allow researchers to investigate topics that may be hard to study because of ethical or logistical concerns. Participants are presented with short stories…

  18. Increasing Enrollment through Benefit Segmentation.

    ERIC Educational Resources Information Center

    Goodnow, Betty

    1982-01-01

    The applicability of benefit segmentation, a market research technique which groups people according to benefits expected from a program offering, was tested at the College of DuPage. Preferences and demographic characteristics were analyzed and program improvements adopted, increasing enrollment by 20 percent. (Author/SK)

  19. Multiple Segment Factorial Vignette Designs

    ERIC Educational Resources Information Center

    Ganong, Lawrence H.; Coleman, Marilyn

    2006-01-01

    The multiple segment factorial vignette design (MSFV) combines elements of experimental designs and probability sampling with the inductive, exploratory approach of qualitative research. MSFVs allow researchers to investigate topics that may be hard to study because of ethical or logistical concerns. Participants are presented with short stories…

  20. Metric Learning to Enhance Hyperspectral Image Segmentation

    NASA Technical Reports Server (NTRS)

    Thompson, David R.; Castano, Rebecca; Bue, Brian; Gilmore, Martha S.

    2013-01-01

    Unsupervised hyperspectral image segmentation can reveal spatial trends that show the physical structure of the scene to an analyst. They highlight borders and reveal areas of homogeneity and change. Segmentations are independently helpful for object recognition, and assist with automated production of symbolic maps. Additionally, a good segmentation can dramatically reduce the number of effective spectra in an image, enabling analyses that would otherwise be computationally prohibitive. Specifically, using an over-segmentation of the image instead of individual pixels can reduce noise and potentially improve the results of statistical post-analysis. In this innovation, a metric learning approach is presented to improve the performance of unsupervised hyperspectral image segmentation. The prototype demonstrations attempt a superpixel segmentation in which the image is conservatively over-segmented; that is, the single surface features may be split into multiple segments, but each individual segment, or superpixel, is ensured to have homogenous mineralogy.

  1. Design Considerations for a Highly Segmented Mirror

    NASA Astrophysics Data System (ADS)

    Padin, Stephen

    2003-06-01

    Design issues for a 30-m highly segmented mirror are explored, with emphasis on parametric models of simple, inexpensive segments. A mirror with many small segments offers cost savings through quantity production and permits high-order active and adaptive wave-front corrections. For a 30-m f/1 .5 paraboloidal mirror made of spherical, hexagonal glass segments, with simple warping harnesses and three-point supports, the maximum segment diameter is ~100 mm, and the minimum segment thickness is ~5 mm. Large-amplitude, low-order gravitational deformations in the mirror cell can be compensated if the segments are mounted on a plate floating on astatic supports. Because gravitational deformations in the plate are small, the segment actuators require a stroke of only a few tens of micrometers, and the segment positions can be measured by a wave-front sensor.

  2. Segment Specification for the Payload Segment of the Reusable Reentry Satellite: Rodent Module Version

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Reusable Reentry Satellite (RRS) System is composed of the payload segment (PS), vehicle segment (VS), and mission support (MS) segments. This specification establishes the performance, design, development, and test requirements for the RRS Rodent Module (RM).

  3. Electro-Optic Segment-Segment Sensors for Radio and Optical Telescopes

    NASA Technical Reports Server (NTRS)

    Abramovici, Alex

    2012-01-01

    A document discusses an electro-optic sensor that consists of a collimator, attached to one segment, and a quad diode, attached to an adjacent segment. Relative segment-segment motion causes the beam from the collimator to move across the quad diode, thus generating a measureable electric signal. This sensor type, which is relatively inexpensive, can be configured as an edge sensor, or as a remote segment-segment motion sensor.

  4. Superimposed segmental manifestation of cherry angiomas.

    PubMed

    Jaeger, Teresa; Andres, Christian; Hein, Rüdiger; Ring, Johannes; Chen, Wenchieh

    2011-01-01

    Cherry angioma is a common, acquired, vascular proliferation, probably of a polygenic mode of inheritance. Segmental manifestation of multiple cherry angiomas associated with the development of non-segmental lesions has not yet been reported. We describe a 62-year-old Caucasian woman with early formation of segmental cherry angiomas after pregnancy, which are superimposed on non-segmental lesions of later onset after menopause. In this pattern, segmental cherry angiomas could be taken as a further example of superimposed segmental manifestation of a polygenic skin disorder. Molecular research would be needed to confirm this hypothesis.

  5. Central Italy

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Clouds and haze cover most of the Italian peninsula in this view of central Italy (41.5N, 14.0E) but the Bay of Naples region with Mt. Vesuvius and the island of Capri are clear. The Adriatic Sea in the background separates Italy from the cloud covered Balkans of eastern Europe and the Tyrrhenian Sea in the foreground lies between the Italian mainland and the off scene islands of Corsica and Sardinia. Several aircraft contrails can also be seen.

  6. Evaluation of a segment-based LANDSAT full-frame approach to corp area estimation

    NASA Technical Reports Server (NTRS)

    Bauer, M. E. (Principal Investigator); Hixson, M. M.; Davis, S. M.

    1981-01-01

    As the registration of LANDSAT full frames enters the realm of current technology, sampling methods should be examined which utilize other than the segment data used for LACIE. The effect of separating the functions of sampling for training and sampling for area estimation. The frame selected for analysis was acquired over north central Iowa on August 9, 1978. A stratification of he full-frame was defined. Training data came from segments within the frame. Two classification and estimation procedures were compared: statistics developed on one segment were used to classify that segment, and pooled statistics from the segments were used to classify a systematic sample of pixels. Comparisons to USDA/ESCS estimates illustrate that the full-frame sampling approach can provide accurate and precise area estimates.

  7. How Notch establishes longitudinal axon connections between successive segments of the Drosophila CNS

    PubMed Central

    Kuzina, Irina; Song, Jeong K.; Giniger, Edward

    2011-01-01

    Development of the segmented central nerve cords of vertebrates and invertebrates requires connecting successive neuromeres. Here, we show both how a pathway is constructed to guide pioneer axons between segments of the Drosophila CNS, and how motility of the pioneers along that pathway is promoted. First, canonical Notch signaling in specialized glial cells causes nearby differentiating neurons to extrude a mesh of fine projections, and shapes that mesh into a continuous carpet that bridges from segment to segment, hugging the glial surface. This is the direct substratum that pioneer axons follow as they grow. Simultaneously, Notch uses an alternate, non-canonical signaling pathway in the pioneer growth cones themselves, promoting their motility by suppressing Abl signaling to stimulate filopodial growth while presumably reducing substratum adhesion. This propels the axons as they establish the connection between successive segments. PMID:21447553

  8. Interactive 3-dimensional segmentation of MRI data in personal computer environment.

    PubMed

    Yoo, S S; Lee, C U; Choi, B G; Saiviroonporn, P

    2001-11-15

    We describe a method of interactive three-dimensional segmentation and visualization for anatomical magnetic resonance imaging (MRI) data in a personal computer environment. The visual feedback necessary during 3-D segmentation was provided by a ray casting algorithm, which was designed to allow users to interactively decide the visualization quality depending on the task-requirement. Structures such as gray matter, white matter, and facial skin from T1-weighted high-resolution MRI data were segmented and later visualized with surface rendering. Personal computers with central processing unit (CPU) speeds of 266, 400, and 700 MHz, were used for the implementation. The 3-D visualization upon each execution of the segmentation operation was achieved in the order of 2 s with a 700 MHz CPU. Our results suggest that 3-D volume segmentation with semi real-time visual feedback could be effectively implemented in a PC environment without the need for dedicated graphics processing hardware.

  9. Segmentation of an Active Forearc Setting Chile (37°S)

    NASA Astrophysics Data System (ADS)

    Rehak, K.; Strecker, M.; Echtler, H.

    2006-12-01

    Many forearc-regions are characterized by seismo- and morphotectonic segments that may record recurring activity of large earthquakes in the past. Here, we investigate the forearc of the active convergent margin of south-central to southern Chile corresponding to the rupture zone of the Chilean 1960 megathrust earthquake. We apply geomorphological and sedimentological analyses, as well as compiled structural and geophysical data to reconstruct the morphotectonic evolution and segmentation of the active forearc setting, and in a further step, we evaluate the responsible driving forces. It is very important, from a landscape development as well as from an earthquake-hazard perspective, to understand the evolution of forearc segmentation. However, it is not well known on which timescales forearc segments retain their tectono-geomorphic identity, how they are related to earthquake rupture zones, and what may govern their long-term evolution. Our results document a pronounced segmentation of the southern Chilean forearc into three segments that had a semi-independent structural and geomorphic evolution. From north to south we call them Nahuelbuta, Toltén and Bueno segment. Whereas the Toltén segment appears to be quasi-stable, the other two segments record Quaternary uplift. The Nahuelbuta and Bueno segments are characterized by broad, N-S oriented antiformal structures with numerous anomalies in the highly dynamic fluvial network. Our inferred morphotectonic segmentation can be reproduced by structural, seismic as well as gravimetric data, and partly coincides with earthquake rupture zones. Apparently, this segmentation is persistent over time-scales of 104 to 106 years as opposed to transient earthquake rupture zones that exhibit short-term variability over 102 to 103 years. Finally, we propose that this differential forearc evolution is focussed by inherited upper plate structures, but appears to be ultimately controlled by subsequent physical changes in the highly

  10. Evaluating the Illinois Stream Valley segment model as an effective management tool.

    PubMed

    Warrner, Stephen S; Fischer, Robert U; Holtrop, Ann M; Hinz, Leon C; Novak, James M

    2010-11-01

    Stream habitat assessments are conducted to evaluate biological potential, determine anthropogenic impacts, and guide restoration projects. Utilizing these procedures, managers must first select a representative stream reach, which is typically selected based on several criteria. To develop a consistent and unbiased procedure for choosing sampling locations, the Illinois Department of Natural Resources and the Illinois Natural History Survey have proposed a technique by which watersheds are divided into homogeneous stream segments called valley segments. Valley segments are determined by GIS parameters including surficial geology, predicted flow, slope, and drainage area. To date, no research has been conducted to determine if the stream habitat within a valley segment is homogeneous and if different valley segments have varying habitat variables. Two abutting valley segments were randomly selected within 13 streams in the Embarras River watershed, located in east-central Illinois. One hundred meter reaches were randomly selected within each valley segment, and a transect method was used to quantify habitat characteristics of the stream channel. Habitat variables for each stream were combined through a principal components analysis (PCA) to measure environmental variation between abutting valley segments. A multivariate analysis of variance (MANOVA) was performed on PCA axes 1-3. The majority of abutting valley segments were significantly different from each other indicating that habitat variability within each valley segment was less than variability between valley segments (5.37 ≤ F ≤ 245.13; P ≤ 0.002). This comparison supports the use of the valley segment model as an effective management tool for identifying representative sampling locations and extrapolating reach-specific information.

  11. Evaluating the Illinois Stream Valley Segment Model as an Effective Management Tool

    NASA Astrophysics Data System (ADS)

    Warrner, Stephen S.; Fischer, Robert U.; Holtrop, Ann M.; Hinz, Leon C.; Novak, James M.

    2010-11-01

    Stream habitat assessments are conducted to evaluate biological potential, determine anthropogenic impacts, and guide restoration projects. Utilizing these procedures, managers must first select a representative stream reach, which is typically selected based on several criteria. To develop a consistent and unbiased procedure for choosing sampling locations, the Illinois Department of Natural Resources and the Illinois Natural History Survey have proposed a technique by which watersheds are divided into homogeneous stream segments called valley segments. Valley segments are determined by GIS parameters including surficial geology, predicted flow, slope, and drainage area. To date, no research has been conducted to determine if the stream habitat within a valley segment is homogeneous and if different valley segments have varying habitat variables. Two abutting valley segments were randomly selected within 13 streams in the Embarras River watershed, located in east-central Illinois. One hundred meter reaches were randomly selected within each valley segment, and a transect method was used to quantify habitat characteristics of the stream channel. Habitat variables for each stream were combined through a principal components analysis (PCA) to measure environmental variation between abutting valley segments. A multivariate analysis of variance (MANOVA) was performed on PCA axes 1-3. The majority of abutting valley segments were significantly different from each other indicating that habitat variability within each valley segment was less than variability between valley segments (5.37 ≤ F ≤ 245.13; P ≤ 0.002). This comparison supports the use of the valley segment model as an effective management tool for identifying representative sampling locations and extrapolating reach-specific information.

  12. Storing Tooth Segments for Optimal Esthetics.

    PubMed

    Tuzuner, Tamer; Turgut, Sedanur; Ozen, Bugra; Kılınç, Hamiyet; Bagiş, Bora

    2016-01-01

    A fractured whole crown segment can be reattached to its remnant; crowns from extracted teeth may be used as pontics in splinting techniques. We aimed to evaluate the effect of different storage solutions on tooth segment optical properties after different durations. Sixty central incisor crowns were divided into 6 groups (n = 10); Group 1 was kept dry; Groups 2, 3, 4, 5, and 6 were placed in an isotonic solution, water, milk, saliva, and casein-phosphopeptide-amorphous-calcium-phosphate (CPP-ACP), respectively, for 30 min, 12 h, 1 day, 1 week, and 3 weeks. Color values were measured using a colorimeter. Data were analyzed with Kruskal-Wallis tests, Mann-Whitney U-tests, and Friedman Wilcoxon tests with Bonferroni stepwise corrections (p < 0.05). ΔE* values varied from 0.3 to 15.3 over the 3 week period. Group 1 demonstrated the greatest color changes over all durations; Group 6 exhibited the least. L*, a*, b*, and ΔE* values varied between time periods in all groups; the differences were significant (p < 0.01), except for L* and ΔE* values in Group 2 and a* values in Group 6 (p > 0.01). Comparing ΔE* values, Group 6 was significantly different from the other groups for all durations (p < 0.01), except Group 4. A CPP-ACP complex solution seems a good choice for tooth fragment storage. Milk and saliva solutions may cause perceptible color changes if tooth fragments are stored for 3 weeks before use.

  13. NPOESS Interface Data Processing Segment Product Generation

    NASA Astrophysics Data System (ADS)

    Grant, K. D.

    2009-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The NPOESS design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. The IDPS processes NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government. The IDPS will process environmental data products beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. Within the overall NPOESS processing environment, the IDPS must process a data volume nearly 1000 times the size of current systems -- in one-quarter of the time. Further, it must support the calibration, validation, and data quality improvement initiatives of the NPOESS program to ensure the production of atmospheric and environmental products that meet strict requirements for accuracy and precision. This paper will describe the architecture approach that is necessary to meet these challenging, and seemingly exclusive, NPOESS IDPS design requirements, with a focus on the processing relationships required to generate the NPP products.

  14. NPOESS Interface Data Processing Segment (IDPS) Hardware

    NASA Astrophysics Data System (ADS)

    Sullivan, W. J.; Grant, K. D.; Bergeron, C.

    2008-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The NPOESS design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. IDPS processes NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government. IDPS will process environmental data products beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. Within the overall NPOESS processing environment, the IDPS must process a data volume several orders of magnitude the size of current systems -- in one-quarter of the time. Further, it must support the calibration, validation, and data quality improvement initiatives of the NPOESS program to ensure the production of atmospheric and environmental products that meet strict requirements for accuracy and precision. This poster will illustrate and describe the IDPS HW architecture that is necessary to meet these challenging design requirements. In addition, it will illustrate the expandability features of the architecture in support of future data processing and data distribution needs.

  15. Measuring the success of video segmentation algorithms

    NASA Astrophysics Data System (ADS)

    Power, Gregory J.

    2001-12-01

    Appropriate segmentation of video is a key step for applications such as video surveillance, video composing, video compression, storage and retrieval, and automated target recognition. Video segmentation algorithms involve dissecting the video into scenes based on shot boundaries as well as local objects and events based on spatial shape and regional motions. Many algorithmic approaches to video segmentation have been recently reported, but many lack measures to quantify the success of the segmentation especially in comparison to other algorithms. This paper suggests multiple bench-top measures for evaluating video segmentation. The paper suggests that the measures are most useful when 'truth' data about the video is available such as precise frame-by- frame object shape. When precise 'truth' data is unavailable, this paper suggests using hand-segmented 'truth' data to measure the success of the video segmentation. Thereby, the ability of the video segmentation algorithm to achieve the same quality of segmentation as the human is obtained in the form of a variance in multiple measures. The paper introduces a suite of measures, each scaled from zero to one. A score of one on a particular measure is a perfect score for a singular segmentation measure. Measures are introduced to evaluate the ability of a segmentation algorithm to correctly detect shot boundaries, to correctly determine spatial shape and to correctly determine temporal shape. The usefulness of the measures are demonstrated on a simple segmenter designed to detect and segment a ping pong ball from a table tennis image sequence.

  16. Vibration damping for the Segmented Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Maly, Joseph R.; Yingling, Adam J.; Griffin, Steven F.; Agrawal, Brij N.; Cobb, Richard G.; Chambers, Trevor S.

    2012-09-01

    The Segmented Mirror Telescope (SMT) at the Naval Postgraduate School (NPS) in Monterey is a next-generation deployable telescope, featuring a 3-meter 6-segment primary mirror and advanced wavefront sensing and correction capabilities. In its stowed configuration, the SMT primary mirror segments collapse into a small volume; once on location, these segments open to the full 3-meter diameter. The segments must be very accurately aligned after deployment and the segment surfaces are actively controlled using numerous small, embedded actuators. The SMT employs a passive damping system to complement the actuators and mitigate the effects of low-frequency (<40 Hz) vibration modes of the primary mirror segments. Each of the six segments has three or more modes in this bandwidth, and resonant vibration excited by acoustics or small disturbances on the structure can result in phase mismatches between adjacent segments thereby degrading image quality. The damping system consists of two tuned mass dampers (TMDs) for each of the mirror segments. An adjustable TMD with passive magnetic damping was selected to minimize sensitivity to changes in temperature; both frequency and damping characteristics can be tuned for optimal vibration mitigation. Modal testing was performed with a laser vibrometry system to characterize the SMT segments with and without the TMDs. Objectives of this test were to determine operating deflection shapes of the mirror and to quantify segment edge displacements; relative alignment of λ/4 or better was desired. The TMDs attenuated the vibration amplitudes by 80% and reduced adjacent segment phase mismatches to acceptable levels.

  17. Factorization-based texture segmentation

    SciTech Connect

    Yuan, Jiangye; Wang, Deliang; Cheriyadat, Anil M.

    2015-06-17

    This study introduces a factorization-based approach that efficiently segments textured images. We use local spectral histograms as features, and construct an M × N feature matrix using M-dimensional feature vectors in an N-pixel image. Based on the observation that each feature can be approximated by a linear combination of several representative features, we factor the feature matrix into two matrices-one consisting of the representative features and the other containing the weights of representative features at each pixel used for linear combination. The factorization method is based on singular value decomposition and nonnegative matrix factorization. The method uses local spectral histograms to discriminate region appearances in a computationally efficient way and at the same time accurately localizes region boundaries. Finally, the experiments conducted on public segmentation data sets show the promise of this simple yet powerful approach.

  18. Factorization-based texture segmentation

    DOE PAGES

    Yuan, Jiangye; Wang, Deliang; Cheriyadat, Anil M.

    2015-06-17

    This study introduces a factorization-based approach that efficiently segments textured images. We use local spectral histograms as features, and construct an M × N feature matrix using M-dimensional feature vectors in an N-pixel image. Based on the observation that each feature can be approximated by a linear combination of several representative features, we factor the feature matrix into two matrices-one consisting of the representative features and the other containing the weights of representative features at each pixel used for linear combination. The factorization method is based on singular value decomposition and nonnegative matrix factorization. The method uses local spectral histogramsmore » to discriminate region appearances in a computationally efficient way and at the same time accurately localizes region boundaries. Finally, the experiments conducted on public segmentation data sets show the promise of this simple yet powerful approach.« less

  19. Printed Arabic optical character segmentation

    NASA Astrophysics Data System (ADS)

    Mohammad, Khader; Ayyesh, Muna; Qaroush, Aziz; Tumar, Iyad

    2015-03-01

    A considerable progress in recognition techniques for many non-Arabic characters has been achieved. In contrary, few efforts have been put on the research of Arabic characters. In any Optical Character Recognition (OCR) system the segmentation step is usually the essential stage in which an extensive portion of processing is devoted and a considerable share of recognition errors is attributed. In this research, a novel segmentation approach for machine Arabic printed text with diacritics is proposed. The proposed method reduces computation, errors, gives a clear description for the sub-word and has advantages over using the skeleton approach in which the data and information of the character can be lost. Both of initial evaluation and testing of the proposed method have been developed using MATLAB and shows 98.7% promising results.

  20. Multiple images segmentation based on saliency map

    NASA Astrophysics Data System (ADS)

    Ning, XiaoLan; Xu, Cheng; Li, SiQi; Li, ShiYing; Li, ZhiQi

    2017-06-01

    Aiming at discovering and segmenting out common objects from multiple images, co-segmentation is a effective method. It is more accurate to make full use of the relationships between images in segmenting than only single image. The first step is to deal with single image with employing hierarchical segmentation to get a Contour Map, saliency detection to obtain the saliency map and object detection to find the possible common part. Then, constructing a digraph with the multiple local regions, and dealing with the digraph. When a digraph is constructed, the corresponding between adjacent two images is influential to the co-segmentation results. This paper develops a method to sort the images to co-segment. Also, we test the method on ICOSEG and MSRC datasets, and compare it with four proposed method. And the results show that it is efficient in co-segmentation with higher precision than many existing and conventional co-segmentation methods.

  1. Spectral clustering algorithms for ultrasound image segmentation.

    PubMed

    Archip, Neculai; Rohling, Robert; Cooperberg, Peter; Tahmasebpour, Hamid; Warfield, Simon K

    2005-01-01

    Image segmentation algorithms derived from spectral clustering analysis rely on the eigenvectors of the Laplacian of a weighted graph obtained from the image. The NCut criterion was previously used for image segmentation in supervised manner. We derive a new strategy for unsupervised image segmentation. This article describes an initial investigation to determine the suitability of such segmentation techniques for ultrasound images. The extension of the NCut technique to the unsupervised clustering is first described. The novel segmentation algorithm is then performed on simulated ultrasound images. Tests are also performed on abdominal and fetal images with the segmentation results compared to manual segmentation. Comparisons with the classical NCut algorithm are also presented. Finally, segmentation results on other types of medical images are shown.

  2. Segmented Coil Fails In Steps

    NASA Technical Reports Server (NTRS)

    Stedman, Ronald S.

    1990-01-01

    Electromagnetic coil degrades in steps when faults occur, continues to operate at reduced level instead of failing catastrophically. Made in segments connected in series and separated by electrically insulating barriers. Fault does not damage adjacent components or create hazard. Used to control valves in such critical applications as cooling systems of power generators and chemical process equipment, where flammable liquids or gases handled. Also adapts to electrical control of motors.

  3. A compact method for prostate zonal segmentation on multiparametric MRIs

    NASA Astrophysics Data System (ADS)

    Chi, Y.; Ho, H.; Law, Y. M.; Tian, Q.; Chen, H. J.; Tay, K. J.; Liu, J.

    2014-03-01

    Automatic segmentation of the prostate zones has great potential of improving the accuracy of lesion detection during the image-guided prostate interventions. In this paper, we present a novel compact method to segment the prostate and its zones using multi-parametric magnetic resonance imaging (MRI) and the anatomical priors. The proposed method comprises of a prostate tissue representation using Gaussian mixture model (GMM), a prostate localization using the mean shift with the kernel of the prostate atlas and a prostate partition using the probabilistic valley between zones. The proposed method was tested on four sets of multi-parametric MRIs. The average Dice coefficient resulted from the segmentation of the prostate is 0.80 +/- 0.03, the central zone 0.83 +/- 0.04, and the peripheral zone 0.52 +/- 0.09. The average computing time of the online segmentation is 1 min and 10 s per datasets on a PC with 2.4 GHz and 4.0 GB RAM. The proposed method is fast and has the potential to be used in clinical practices.

  4. Iris hamartomas (Lisch nodules) in a case of segmental neurofibromatosis.

    PubMed

    Weleber, R G; Zonana, J

    1983-12-01

    Iris hamartomas (Lisch nodules), previously reported in cases of peripheral neurofibromatosis, were found in a 14-year-old girl with segmental neurofibromatosis. The girl was in the 75th percentile for height (168 cm), the 90th percentile for weight (63 kg), and the 50th percentile for head circumference (55 cm). Her blood pressure was 105/70 mm Hg. Her visual acuity (20/20 and J 1), ocular motility, pupillary responses, visual fields, color vision, stereopsis, and intraocular pressure were within normal limits. Biomicroscopy showed several tan elevated nodular hamartomas on the anterior surface of the right peripheral iris but none elsewhere in the right eye and none in the left eye. Café-au-lait spots and freckling were also limited to the right side of the body. The child had no palpable neurofibromas and was in good health and of normal intelligence. There was no family history of neurofibromatosis, multiple café-au-lait spots, axillary freckling, macrocephaly, or learning disabilities. The absence of iris hamartomas has been used to distinguish segmental neurofibromatosis from the peripheral and central or acoustic forms. Thus, their presence in this case is clinically significant. The segmental form not only produces fewer complications but carries less genetic risk. In segmental neurofibromatosis, the Lisch nodules would be expected to be unilateral rather than bilateral, ipsilateral to the side of the cutaneous involvement, and more frequently associated with contiguous cutaneous lesions.

  5. Robust Optic Nerve Segmentation on Clinically Acquired CT.

    PubMed

    Panda, Swetasudha; Asman, Andrew J; Delisi, Michael P; Mawn, Louise A; Galloway, Robert L; Landman, Bennett A

    2014-03-21

    The optic nerve is a sensitive central nervous system structure, which plays a critical role in many devastating pathological conditions. Several methods have been proposed in recent years to segment the optic nerve automatically, but progress toward full automation has been limited. Multi-atlas methods have been successful for brain segmentation, but their application to smaller anatomies remains relatively unexplored. Herein we evaluate a framework for robust and fully automated segmentation of the optic nerves, eye globes and muscles. We employ a robust registration procedure for accurate registrations, variable voxel resolution and image field-of-view. We demonstrate the efficacy of an optimal combination of SyN registration and a recently proposed label fusion algorithm (Non-local Spatial STAPLE) that accounts for small-scale errors in registration correspondence. On a dataset containing 30 highly varying computed tomography (CT) images of the human brain, the optimal registration and label fusion pipeline resulted in a median Dice similarity coefficient of 0.77, symmetric mean surface distance error of 0.55 mm, symmetric Hausdorff distance error of 3.33 mm for the optic nerves. Simultaneously, we demonstrate the robustness of the optimal algorithm by segmenting the optic nerve structure in 316 CT scans obtained from 182 subjects from a thyroid eye disease (TED) patient population.

  6. Robust optic nerve segmentation on clinically acquired CT

    NASA Astrophysics Data System (ADS)

    Panda, Swetasudha; Asman, Andrew J.; DeLisi, Michael P.; Mawn, Louise A.; Galloway, Robert L.; Landman, Bennett A.

    2014-03-01

    The optic nerve is a sensitive central nervous system structure, which plays a critical role in many devastating pathological conditions. Several methods have been proposed in recent years to segment the optic nerve automatically, but progress toward full automation has been limited. Multi-atlas methods have been successful for brain segmentation, but their application to smaller anatomies remains relatively unexplored. Herein we evaluate a framework for robust and fully automated segmentation of the optic nerves, eye globes and muscles. We employ a robust registration procedure for accurate registrations, variable voxel resolution and image fieldof- view. We demonstrate the efficacy of an optimal combination of SyN registration and a recently proposed label fusion algorithm (Non-local Spatial STAPLE) that accounts for small-scale errors in registration correspondence. On a dataset containing 30 highly varying computed tomography (CT) images of the human brain, the optimal registration and label fusion pipeline resulted in a median Dice similarity coefficient of 0.77, symmetric mean surface distance error of 0.55 mm, symmetric Hausdorff distance error of 3.33 mm for the optic nerves. Simultaneously, we demonstrate the robustness of the optimal algorithm by segmenting the optic nerve structure in 316 CT scans obtained from 182 subjects from a thyroid eye disease (TED) patient population.

  7. Production of anterior segment ischemia.

    PubMed Central

    Hiatt, R L

    1977-01-01

    Anterior segment ischemic changes can occur without detachment of any muscles. The most common cause of such ischemic changes of the anterior segment is the removal of too many rectus muscles in one operation. Twenty dog eyes and eight monkey eyes were subjected to the disinsertion and detachment of various combinations of extraocular muscles. The dogs were sacrificed at intervals from 30 to 90 days. During the observation period, they were observed for gross and slit-lamp changes. The enucleated eyes were studied microscopically for signs of ischemic and necrotic changes. Two patients who were studied, observed, and treated for anterior segment ischemia following muscle surgery are described. The changes which occur after extraocular muscle surgery are extensive and include corneal edema, cataract, chemosis, corneal changes, decreases in intraocular pressure, decreases in outflow or glaucoma, and frank necrosis. The variables which lead to this reaction are described in detail. Also, some unanswered queries, such as the duration of the reaction and the time interval of the reaction after multiple muscle operations are discussed. Images FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 2 A FIGURE 2 B FIGURE 2 C FIGURE 2 D FIGURE 3 FIGURE 4 PMID:418549

  8. Segmentation of the Farallon slab

    NASA Astrophysics Data System (ADS)

    Liu, L.; Stegman, D. R.

    2011-12-01

    Recent tomography images reveal a complex 3D mantle structure beneath western United States, with feature morphology varying rapidly with depth. By assimilating plate motion history, paleo-age of sea floor, and paleo-geography of plate boundaries in a 3-D numerical model, we simulate the Farallon-Juan de Fuca subduction during the past 40 Ma. We find that the highly segmented upper mantle structure of western U.S. is a direct result of the Farallon subduction. We show that the tilted 'horseshoe'-shaped fast seismic anomaly beneath Nevada and Utah at 300-600 km depth range is in fact a segment of curled slab subducted since 15 Ma, and the shallower linear slab beneath the Cascades is younger than 5 Ma. The distinct morphology between these two parts of the subduction system indicates the strong influence of the fast trench rollback since 20 Ma, the northward migrating JF-PA-NA triple-junction, and the toroidal flow around slab edges. The observed mantle structures are used to constrain the rheology of the upper mantle through matching the shape, depth, and location of modeled subducted slab segments. The inferred viscosity for the asthenosphere is 5×10^19 Pa s and that for the transition zone is 1.5×10^21 Pa s. The slab is found to be about 2 orders of magnitude stronger than the ambient mantle above 410 km depth, but of similar order of magnitude viscosity in the transition zone.

  9. Segmentation in local hospital markets.

    PubMed

    Dranove, D; White, W D; Wu, L

    1993-01-01

    This study examines evidence of market segmentation on the basis of patients' insurance status, demographic characteristics, and medical condition in selected local markets in California in the years 1983 and 1989. Substantial differences exist in the probability patients may be admitted to particular hospitals based on insurance coverage, particularly Medicaid, and race. Segmentation based on insurance and race is related to hospital characteristics, but not the characteristics of the hospital's community. Medicaid patients are more likely to go to hospitals with lower costs and fewer service offerings. Privately insured patients go to hospitals offering more services, although cost concerns are increasing. Hispanic patients also go to low-cost hospitals, ceteris paribus. Results indicate little evidence of segmentation based on medical condition in either 1983 or 1989, suggesting that "centers of excellence" have yet to play an important role in patient choice of hospital. The authors found that distance matters, and that patients prefer nearby hospitals, moreso for some medical conditions than others, in ways consistent with economic theories of consumer choice.

  10. Turbo segmentation of textured images.

    PubMed

    Lehmann, Frederic

    2011-01-01

    We consider the problem of semi-supervised segmentation of textured images. Existing model-based approaches model the intensity field of textured images as a Gauss-Markov random field to take into account the local spatial dependencies between the pixels. Classical Bayesian segmentation consists of also modeling the label field as a Markov random field to ensure that neighboring pixels correspond to the same texture class with high probability. Well-known relaxation techniques are available which find the optimal label field with respect to the maximum a posteriori or the maximum posterior mode criterion. But, these techniques are usually computationally intensive because they require a large number of iterations to converge. In this paper, we propose a new Bayesian framework by modeling two-dimensional textured images as the concatenation of two one-dimensional hidden Markov autoregressive models for the lines and the columns, respectively. A segmentation algorithm, which is similar to turbo decoding in the context of error-correcting codes, is obtained based on a factor graph approach. The proposed method estimates the unknown parameters using the Expectation-Maximization algorithm.

  11. Central Campus

    NASA Image and Video Library

    2017-05-17

    A long exposure photograph of the new headquarters building, part of the Central Campus in the industrial area at NASA’s Kennedy Space Center in Florida. The nearly-complete seven-story, 200,000-square-foot facility will house about 500 NASA civil service and contractor employees. The building will be more energy efficient than the current Headquarters building and will feature the latest in office and administrative building technology to fulfill Kennedy's role as the premiere spaceport for NASA and, increasingly, commercial entities.

  12. Central pain.

    PubMed

    Singh, Supreet

    2014-12-01

    Questions from patients about pain conditions and analgesic pharmacotherapy and responses from authors are presented to help educate patients and make them more effective self-advocates. The topic addressed in this issue is central pain, a neuropathic pain syndrome caused by a lesion in the brain or spinal cord that sensitizes one's perception of pain. It is a debilitating condition caused by various diseases such as multiple sclerosis, strokes, spinal cord injuries, or brain tumors. Varied symptoms and the use of pharmacological medicines and nonpharmacological therapies will be addressed.

  13. Video Segmentation Descriptors for Event Recognition

    DTIC Science & Technology

    2014-12-08

    spatial sizes and motion intensities (2. k ). IV. VIDEO SEGMENTATION Various video segmentation techniques have been proposed based on superpixels [26...to cluster STTs according to color and motion through a meanshift [24] over- segmentation . The second pass iteratively fuses the yielded supertubes...video motion descriptor based on a multi-scale video segmentation to provide a multi- layered output as well as connections with the rich interactions

  14. Neural development in Onychophora (velvet worms) suggests a step-wise evolution of segmentation in the nervous system of Panarthropoda.

    PubMed

    Mayer, Georg; Whitington, Paul M

    2009-11-01

    A fundamental question in biology is how animal segmentation arose during evolution. One particular challenge is to clarify whether segmental ganglia of the nervous system evolved once, twice, or several times within the Bilateria. As close relatives of arthropods, Onychophora play an important role in this debate since their nervous system displays a mixture of both segmental and non-segmental features. We present evidence that the onychophoran "ventral organs," previously interpreted as segmental anlagen of the nervous system, do not contribute to nerve cord formation and therefore cannot be regarded as vestiges of segmental ganglia. The early axonal pathways in the central nervous system arise by an anterior-to-posterior cascade of axonogenesis from neuronal cell bodies, which are distributed irregularly along each presumptive ventral cord. This pattern contrasts with the strictly segmental neuromeres present in arthropod embryos and makes the assumption of a secondary loss of segmentation in the nervous system during the evolution of the Onychophora less plausible. We discuss the implications of these findings for the evolution of neural segmentation in the Panarthropoda (Arthropoda+Onychophora+Tardigrada). Our data best support the hypothesis that the ancestral panarthropod had only a partially segmented nervous system, which evolved progressively into the segmental chain of ganglia seen in extant tardigrades and arthropods.

  15. Quick Dissection of the Segmental Bronchi

    ERIC Educational Resources Information Center

    Nakajima, Yuji

    2010-01-01

    Knowledge of the three-dimensional anatomy of the bronchopulmonary segments is essential for respiratory medicine. This report describes a quick guide for dissecting the segmental bronchi in formaldehyde-fixed human material. All segmental bronchi are easy to dissect, and thus, this exercise will help medical students to better understand the…

  16. Quick Dissection of the Segmental Bronchi

    ERIC Educational Resources Information Center

    Nakajima, Yuji

    2010-01-01

    Knowledge of the three-dimensional anatomy of the bronchopulmonary segments is essential for respiratory medicine. This report describes a quick guide for dissecting the segmental bronchi in formaldehyde-fixed human material. All segmental bronchi are easy to dissect, and thus, this exercise will help medical students to better understand the…

  17. Market Segmentation from a Behavioral Perspective

    ERIC Educational Resources Information Center

    Wells, Victoria K.; Chang, Shing Wan; Oliveira-Castro, Jorge; Pallister, John

    2010-01-01

    A segmentation approach is presented using both traditional demographic segmentation bases (age, social class/occupation, and working status) and a segmentation by benefits sought. The benefits sought in this case are utilitarian and informational reinforcement, variables developed from the Behavioral Perspective Model (BPM). Using data from 1,847…

  18. Segmenting the mental health care market.

    PubMed

    Stone, T R; Warren, W E; Stevens, R E

    1990-03-01

    The authors report the results of a segmentation study of the mental health care market. A random sample of 387 residents of a western city were interviewed by telephone. Cluster analysis of the data identified six market segments. Each is described according to the mental health care services to which it is most sensitive. Implications for targeting the segments are discussed.

  19. Market Segmentation from a Behavioral Perspective

    ERIC Educational Resources Information Center

    Wells, Victoria K.; Chang, Shing Wan; Oliveira-Castro, Jorge; Pallister, John

    2010-01-01

    A segmentation approach is presented using both traditional demographic segmentation bases (age, social class/occupation, and working status) and a segmentation by benefits sought. The benefits sought in this case are utilitarian and informational reinforcement, variables developed from the Behavioral Perspective Model (BPM). Using data from 1,847…

  20. Detection and Segmentation of Erythrocytes in Blood Smear Images Using a Line Operator and Watershed Algorithm

    PubMed Central

    Khajehpour, Hassan; Dehnavi, Alireza Mehri; Taghizad, Hossein; Khajehpour, Esmat; Naeemabadi, Mohammadreza

    2013-01-01

    Most of the erythrocyte related diseases are detectable by hematology images analysis. At the first step of this analysis, segmentation and detection of blood cells are inevitable. In this study, a novel method using a line operator and watershed algorithm is rendered for erythrocyte detection and segmentation in blood smear images, as well as reducing over-segmentation in watershed algorithm that is useful for segmentation of different types of blood cells having partial overlap. This method uses gray scale structure of blood cell, which is obtained by exertion of Euclidian distance transform on binary images. Applying this transform, the gray intensity of cell images gradually reduces from the center of cells to their margins. For detecting this intensity variation structure, a line operator measuring gray level variations along several directional line segments is applied. Line segments have maximum and minimum gray level variations has a special pattern that is applicable for detections of the central regions of cells. Intersection of these regions with the signs which are obtained by calculating of local maxima in the watershed algorithm was applied for cells’ centers detection, as well as a reduction in over-segmentation of watershed algorithm. This method creates 1300 sign in segmentation of 1274 erythrocytes available in 25 blood smear images. Accuracy and sensitivity of the proposed method are equal to 95.9% and 97.99%, respectively. The results show the proposed method's capability in detection of erythrocytes in blood smear images. PMID:24672764

  1. Detection and segmentation of erythrocytes in blood smear images using a line operator and watershed algorithm.

    PubMed

    Khajehpour, Hassan; Dehnavi, Alireza Mehri; Taghizad, Hossein; Khajehpour, Esmat; Naeemabadi, Mohammadreza

    2013-07-01

    Most of the erythrocyte related diseases are detectable by hematology images analysis. At the first step of this analysis, segmentation and detection of blood cells are inevitable. In this study, a novel method using a line operator and watershed algorithm is rendered for erythrocyte detection and segmentation in blood smear images, as well as reducing over-segmentation in watershed algorithm that is useful for segmentation of different types of blood cells having partial overlap. This method uses gray scale structure of blood cell, which is obtained by exertion of Euclidian distance transform on binary images. Applying this transform, the gray intensity of cell images gradually reduces from the center of cells to their margins. For detecting this intensity variation structure, a line operator measuring gray level variations along several directional line segments is applied. Line segments have maximum and minimum gray level variations has a special pattern that is applicable for detections of the central regions of cells. Intersection of these regions with the signs which are obtained by calculating of local maxima in the watershed algorithm was applied for cells' centers detection, as well as a reduction in over-segmentation of watershed algorithm. This method creates 1300 sign in segmentation of 1274 erythrocytes available in 25 blood smear images. Accuracy and sensitivity of the proposed method are equal to 95.9% and 97.99%, respectively. The results show the proposed method's capability in detection of erythrocytes in blood smear images.

  2. Obtaining Thickness Maps of Corneal Layers Using the Optimal Algorithm for Intracorneal Layer Segmentation.

    PubMed

    Rabbani, Hossein; Kafieh, Rahele; Kazemian Jahromi, Mahdi; Jorjandi, Sahar; Mehri Dehnavi, Alireza; Hajizadeh, Fedra; Peyman, Alireza

    2016-01-01

    Optical Coherence Tomography (OCT) is one of the most informative methodologies in ophthalmology and provides cross sectional images from anterior and posterior segments of the eye. Corneal diseases can be diagnosed by these images and corneal thickness maps can also assist in the treatment and diagnosis. The need for automatic segmentation of cross sectional images is inevitable since manual segmentation is time consuming and imprecise. In this paper, segmentation methods such as Gaussian Mixture Model (GMM), Graph Cut, and Level Set are used for automatic segmentation of three clinically important corneal layer boundaries on OCT images. Using the segmentation of the boundaries in three-dimensional corneal data, we obtained thickness maps of the layers which are created by these borders. Mean and standard deviation of the thickness values for normal subjects in epithelial, stromal, and whole cornea are calculated in central, superior, inferior, nasal, and temporal zones (centered on the center of pupil). To evaluate our approach, the automatic boundary results are compared with the boundaries segmented manually by two corneal specialists. The quantitative results show that GMM method segments the desired boundaries with the best accuracy.

  3. Obtaining Thickness Maps of Corneal Layers Using the Optimal Algorithm for Intracorneal Layer Segmentation

    PubMed Central

    Rabbani, Hossein; Kazemian Jahromi, Mahdi; Jorjandi, Sahar; Mehri Dehnavi, Alireza; Hajizadeh, Fedra; Peyman, Alireza

    2016-01-01

    Optical Coherence Tomography (OCT) is one of the most informative methodologies in ophthalmology and provides cross sectional images from anterior and posterior segments of the eye. Corneal diseases can be diagnosed by these images and corneal thickness maps can also assist in the treatment and diagnosis. The need for automatic segmentation of cross sectional images is inevitable since manual segmentation is time consuming and imprecise. In this paper, segmentation methods such as Gaussian Mixture Model (GMM), Graph Cut, and Level Set are used for automatic segmentation of three clinically important corneal layer boundaries on OCT images. Using the segmentation of the boundaries in three-dimensional corneal data, we obtained thickness maps of the layers which are created by these borders. Mean and standard deviation of the thickness values for normal subjects in epithelial, stromal, and whole cornea are calculated in central, superior, inferior, nasal, and temporal zones (centered on the center of pupil). To evaluate our approach, the automatic boundary results are compared with the boundaries segmented manually by two corneal specialists. The quantitative results show that GMM method segments the desired boundaries with the best accuracy. PMID:27247559

  4. Segmentation of the Clustered Cells with Optimized Boundary Detection in Negative Phase Contrast Images.

    PubMed

    Wang, Yuliang; Zhang, Zaicheng; Wang, Huimin; Bi, Shusheng

    2015-01-01

    Cell image segmentation plays a central role in numerous biology studies and clinical applications. As a result, the development of cell image segmentation algorithms with high robustness and accuracy is attracting more and more attention. In this study, an automated cell image segmentation algorithm is developed to get improved cell image segmentation with respect to cell boundary detection and segmentation of the clustered cells for all cells in the field of view in negative phase contrast images. A new method which combines the thresholding method and edge based active contour method was proposed to optimize cell boundary detection. In order to segment clustered cells, the geographic peaks of cell light intensity were utilized to detect numbers and locations of the clustered cells. In this paper, the working principles of the algorithms are described. The influence of parameters in cell boundary detection and the selection of the threshold value on the final segmentation results are investigated. At last, the proposed algorithm is applied to the negative phase contrast images from different experiments. The performance of the proposed method is evaluated. Results show that the proposed method can achieve optimized cell boundary detection and highly accurate segmentation for clustered cells.

  5. Morphotectonic segmentation of an active forearc, 37° 41°S, Chile

    NASA Astrophysics Data System (ADS)

    Rehak, Katrin; Strecker, Manfred R.; Echtler, Helmut P.

    2008-02-01

    Active forearc regions are characterized by seismo- and morphotectonic segments that record recurrent seismic activity and subduction-related tectonic deformation on different timescales. However, it is not well known on which timescales morphotectonic forearc segments retain their tectono-geomorphic identity, how they are related to earthquake-rupture zones, and what governs their long-term evolution. The forearc of the active convergent margin of south-central Chile (37°-41°S) is located within the rupture zone of the 1960 Chile Mw 9.6 megathrust earthquake. In this region, we combine geomorphological, sedimentologic, and morphometric DEM analysis with compiled structural and geophysical data to reconstruct the morphotectonic evolution of the forearc. The southern Chile forearc comprises three segments (Nahuelbuta, Toltén and Bueno segments) that record a differential structural and geomorphic evolution. Whereas the Toltén segment appears to be quasi-stable, the other two segments record pronounced ongoing Quaternary uplift. The Nahuelbuta and Bueno segments contain the N-S oriented Coastal Cordillera, characterized by numerous tectonically controlled drainage anomalies and evidence of sediment rerouting. The morphotectonic segmentation appears to have persisted over timescales of 10 5 to 10 6 years. Importantly, these segments do not correlate with earthquake-rupture zones that exhibit a short-term variability over 10 2 to 10 3 years. Thus, earthquake-rupture zones are transient, second-order phenomena, which do not determine the long-term morphotectonic forearc segmentation. Overall, the differential forearc evolution and segmentation is influenced by a complex interplay of inherited upper-plate structures and physical properties of the subducting oceanic Nazca plate.

  6. Three-dimensional digital line segments.

    PubMed

    Kim, C E

    1983-02-01

    Digital arcs in 3-D digital pictures are defined. The digital image of an arc is also defined. A digital arc is defined to be a digital line segment if it is the digital image of a line segment. It is shown that a digital line segment may be characterized by the chord property holding for its projections onto the coordinate planes. It is also shown that a digital line segment may not be characterized by its own chord property. A linear time algorithm is presented that determines whether or not a digital arc is a digital line segment.

  7. Segmented ceramic liner for induction furnaces

    DOEpatents

    Gorin, A.H.; Holcombe, C.E.

    1994-07-26

    A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace. 5 figs.

  8. Segmented ceramic liner for induction furnaces

    DOEpatents

    Gorin, Andrew H.; Holcombe, Cressie E.

    1994-01-01

    A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace.

  9. Metric Learning for Hyperspectral Image Segmentation

    NASA Technical Reports Server (NTRS)

    Bue, Brian D.; Thompson, David R.; Gilmore, Martha S.; Castano, Rebecca

    2011-01-01

    We present a metric learning approach to improve the performance of unsupervised hyperspectral image segmentation. Unsupervised spatial segmentation can assist both user visualization and automatic recognition of surface features. Analysts can use spatially-continuous segments to decrease noise levels and/or localize feature boundaries. However, existing segmentation methods use tasks-agnostic measures of similarity. Here we learn task-specific similarity measures from training data, improving segment fidelity to classes of interest. Multiclass Linear Discriminate Analysis produces a linear transform that optimally separates a labeled set of training classes. The defines a distance metric that generalized to a new scenes, enabling graph-based segmentation that emphasizes key spectral features. We describe tests based on data from the Compact Reconnaissance Imaging Spectrometer (CRISM) in which learned metrics improve segment homogeneity with respect to mineralogical classes.

  10. Efficient graph-cut tattoo segmentation

    NASA Astrophysics Data System (ADS)

    Kim, Joonsoo; Parra, Albert; Li, He; Delp, Edward J.

    2015-03-01

    Law enforcement is interested in exploiting tattoos as an information source to identify, track and prevent gang-related crimes. Many tattoo image retrieval systems have been described. In a retrieval system tattoo segmentation is an important step for retrieval accuracy since segmentation removes background information in a tattoo image. Existing segmentation methods do not extract the tattoo very well when the background includes textures and color similar to skin tones. In this paper we describe a tattoo segmentation approach by determining skin pixels in regions near the tattoo. In these regions graph-cut segmentation using a skin color model and a visual saliency map is used to find skin pixels. After segmentation we determine which set of skin pixels are connected with each other that form a closed contour including a tattoo. The regions surrounded by the closed contours are considered tattoo regions. Our method segments tattoos well when the background includes textures and color similar to skin.

  11. Image Segmentation Using Hierarchical Merge Tree.

    PubMed

    Liu, Ting; Seyedhosseini, Mojtaba; Tasdizen, Tolga

    2016-07-18

    This paper investigates one of the most fundamental computer vision problems: image segmentation. We propose a supervised hierarchical approach to object-independent image segmentation. Starting with over-segmenting superpixels, we use a tree structure to represent the hierarchy of region merging, by which we reduce the problem of segmenting image regions to finding a set of label assignment to tree nodes. We formulate the tree structure as a constrained conditional model to associate region merging with likelihoods predicted using an ensemble boundary classifier. Final segmentations can then be inferred by finding globally optimal solutions to the model efficiently. We also present an iterative training and testing algorithm that generates various tree structures and combines them to emphasize accurate boundaries by segmentation accumulation. Experiment results and comparisons with other recent methods on six public data sets demonstrate that our approach achieves state-of-the-art region accuracy and is competitive in image segmentation without semantic priors.

  12. Augmented-reality-based segmentation refinement

    NASA Astrophysics Data System (ADS)

    Bornik, Alexander; Reitinger, Bernhard; Beichel, Reinhard; Sorantin, Erich; Werkgartner, Georg

    2004-05-01

    Planning of surgical liver tumor resections based on image data from X-ray computed tomography requires correct segmentation of the liver, liver vasculature and pathological structures. Automatic liver segmentation methods frequently fail in cases where the anatomy is degenerated by lesions or other present liver diseases. On the other hand performing a manual segmentation is a tedious and time consuming task. Therefore Augmented Reality based segmentation refinement tools are reported, that aid radiologists to efficiently correct incorrect segmentations in true 3D using head-mounted displays and tracked input devices. The developed methods facilitate segmentation refinement by interactively deforming a mesh data structure reconstructed from an initial segmentation. The variety of refinement methods are all accessible through the intuitive, direct 3D user interface of an Augmented Reality system.

  13. Use of Model-Segmentation Criteria in Clustering and Segmentation of Time Series and Digital Images.

    DTIC Science & Technology

    1983-05-05

    DANS LAS REPARTITION? ET LA SEGMENTATION DES SERIES TEMPORELLES ET DES IMAGES NUMtRICALES Cet article traite le d~veloppement et l’utilisation des...multidimensionnelles et du no-bre des classes des segments dans la segmentation des series temporelles et des imaqes numericales. Les criteres comme ceux de Akaike...NATIONAL BURCAU OF STAND)AROS 1963 A USE OF MODEL-SEGMENTATION CRITERIA IN CLUSTERING AND SEGMENTATION OF TIME SERIES AND DIGITAL IMAGES by STANLEY L

  14. Segmentation of the Farallon slab

    NASA Astrophysics Data System (ADS)

    Liu, Lijun; Stegman, Dave R.

    2011-11-01

    Recent tomography images reveal a complex 3D mantle structure beneath western United States, with feature morphology varying rapidly with depth. By assimilating plate motion history, paleo-age of sea floor, and paleo-geography of plate boundaries in a 3-D numerical model, we simulate the Farallon-Juan de Fuca subduction during the past 40 Ma. We find that the highly segmented upper mantle structure of western U.S. is a direct result of the Farallon subduction. We show that the tilted 'horseshoe'-shaped fast seismic anomaly beneath Nevada and Utah at 300-600 km depth range is in fact a segment of curled slab subducted since 15 Ma, and the shallower linear slab beneath the Cascades is younger than 5 Ma. The distinct morphology between these two parts of the subduction system indicates the strong influence of the fast trench rollback since 20 Ma, the northward migrating JF-PA-NA triple-junction, and the toroidal flow around slab edges. The observed mantle structures are used to constrain the rheology of the upper mantle through matching the shape, depth, and location of modeled subducted slab segments. The inferred viscosity for the asthenosphere is 5 × 10 19 Pa s and those for the transition zone and lower mantle are 1.5 × 10 21 Pa s and 2 × 10 22 Pa s, respectively. The slab is found to be about 2 orders of magnitude stronger than the ambient mantle above 410 km depth, but of similar order of magnitude viscosity in the transition zone.

  15. An efficient iris segmentation approach

    NASA Astrophysics Data System (ADS)

    Gomai, Abdu; El-Zaart, A.; Mathkour, H.

    2011-10-01

    Iris recognition system became a reliable system for authentication and verification tasks. It consists of five stages: image acquisition, iris segmentation, iris normalization, feature encoding, and feature matching. Iris segmentation stage is one of the most important stages. It plays an essential role to locate the iris efficiently and accurately. In this paper, we present a new approach for iris segmentation using image processing technique. This approach is composed of four main parts. (1) Eliminating reflections of light on the eye image based on inverting the color of the grayscale image, filling holes in the intensity image, and inverting the color of the intensity image to get the original grayscale image without any reflections. (2) Pupil boundary detection based on dividing an eye image to nine sub-images and finding the minimum value of the mean intensity for each sub-image to get a suitable threshold value of pupil. (3) Enhancing the contrast of outer iris boundary using exponential operator to have sharp variation. (4) Outer iris boundary localization based on applying a gray threshold and morphological operations on the rectangular part of an eye image including the pupil and the outer boundaries of iris to find the small radius of outer iris boundary from the center of pupil. The proposed approach has been tested on CASIA v1.0 iris image database and other collected iris image database. The experimental results show that the approach is able to detect pupil and outer iris boundary with high accuracy results approximately 100% and reduce time consuming.

  16. Heterologous Packaging Signals on Segment 4, but Not Segment 6 or Segment 8, Limit Influenza A Virus Reassortment.

    PubMed

    White, Maria C; Steel, John; Lowen, Anice C

    2017-06-01

    Influenza A virus (IAV) RNA packaging signals serve to direct the incorporation of IAV gene segments into virus particles, and this process is thought to be mediated by segment-segment interactions. These packaging signals are segment and strain specific, and as such, they have the potential to impact reassortment outcomes between different IAV strains. Our study aimed to quantify the impact of packaging signal mismatch on IAV reassortment using the human seasonal influenza A/Panama/2007/99 (H3N2) and pandemic influenza A/Netherlands/602/2009 (H1N1) viruses. Focusing on the three most divergent segments, we constructed pairs of viruses that encoded identical proteins but differed in the packaging signal regions on a single segment. We then evaluated the frequency with which segments carrying homologous versus heterologous packaging signals were incorporated into reassortant progeny viruses. We found that, when segment 4 (HA) of coinfecting parental viruses was modified, there was a significant preference for the segment containing matched packaging signals relative to the background of the virus. This preference was apparent even when the homologous HA constituted a minority of the HA segment population available in the cell for packaging. Conversely, when segment 6 (NA) or segment 8 (NS) carried modified packaging signals, there was no significant preference for homologous packaging signals. These data suggest that movement of NA and NS segments between the human H3N2 and H1N1 lineages is unlikely to be restricted by packaging signal mismatch, while movement of the HA segment would be more constrained. Our results indicate that the importance of packaging signals in IAV reassortment is segment dependent.IMPORTANCE Influenza A viruses (IAVs) can exchange genes through reassortment. This process contributes to both the highly diverse population of IAVs found in nature and the formation of novel epidemic and pandemic IAV strains. Our study sought to determine the

  17. Interferon Induced Focal Segmental Glomerulosclerosis

    PubMed Central

    Bayram Kayar, Nuket; Alpay, Nadir; Hamdard, Jamshid; Emegil, Sebnem; Bag Soydas, Rabia; Baysal, Birol

    2016-01-01

    Behçet's disease is an inflammatory disease of unknown etiology which involves recurring oral and genital aphthous ulcers and ocular lesions as well as articular, vascular, and nervous system involvement. Focal segmental glomerulosclerosis (FSGS) is usually seen in viral infections, immune deficiency syndrome, sickle cell anemia, and hyperfiltration and secondary to interferon therapy. Here, we present a case of FSGS identified with kidney biopsy in a patient who had been diagnosed with Behçet's disease and received interferon-alpha treatment for uveitis and presented with acute renal failure and nephrotic syndrome associated with interferon. PMID:27847659

  18. Combining segmentation and attention: a new foveal attention model

    PubMed Central

    Marfil, Rebeca; Palomino, Antonio J.; Bandera, Antonio

    2014-01-01

    Artificial vision systems cannot process all the information that they receive from the world in real time because it is highly expensive and inefficient in terms of computational cost. Inspired by biological perception systems, artificial attention models pursuit to select only the relevant part of the scene. On human vision, it is also well established that these units of attention are not merely spatial but closely related to perceptual objects (proto-objects). This implies a strong bidirectional relationship between segmentation and attention processes. While the segmentation process is the responsible to extract the proto-objects from the scene, attention can guide segmentation, arising the concept of foveal attention. When the focus of attention is deployed from one visual unit to another, the rest of the scene is perceived but at a lower resolution that the focused object. The result is a multi-resolution visual perception in which the fovea, a dimple on the central retina, provides the highest resolution vision. In this paper, a bottom-up foveal attention model is presented. In this model the input image is a foveal image represented using a Cartesian Foveal Geometry (CFG), which encodes the field of view of the sensor as a fovea (placed in the focus of attention) surrounded by a set of concentric rings with decreasing resolution. Then multi-resolution perceptual segmentation is performed by building a foveal polygon using the Bounded Irregular Pyramid (BIP). Bottom-up attention is enclosed in the same structure, allowing to set the fovea over the most salient image proto-object. Saliency is computed as a linear combination of multiple low level features such as color and intensity contrast, symmetry, orientation and roundness. Obtained results from natural images show that the performance of the combination of hierarchical foveal segmentation and saliency estimation is good in terms of accuracy and speed. PMID:25177289

  19. Combining segmentation and attention: a new foveal attention model.

    PubMed

    Marfil, Rebeca; Palomino, Antonio J; Bandera, Antonio

    2014-01-01

    Artificial vision systems cannot process all the information that they receive from the world in real time because it is highly expensive and inefficient in terms of computational cost. Inspired by biological perception systems, artificial attention models pursuit to select only the relevant part of the scene. On human vision, it is also well established that these units of attention are not merely spatial but closely related to perceptual objects (proto-objects). This implies a strong bidirectional relationship between segmentation and attention processes. While the segmentation process is the responsible to extract the proto-objects from the scene, attention can guide segmentation, arising the concept of foveal attention. When the focus of attention is deployed from one visual unit to another, the rest of the scene is perceived but at a lower resolution that the focused object. The result is a multi-resolution visual perception in which the fovea, a dimple on the central retina, provides the highest resolution vision. In this paper, a bottom-up foveal attention model is presented. In this model the input image is a foveal image represented using a Cartesian Foveal Geometry (CFG), which encodes the field of view of the sensor as a fovea (placed in the focus of attention) surrounded by a set of concentric rings with decreasing resolution. Then multi-resolution perceptual segmentation is performed by building a foveal polygon using the Bounded Irregular Pyramid (BIP). Bottom-up attention is enclosed in the same structure, allowing to set the fovea over the most salient image proto-object. Saliency is computed as a linear combination of multiple low level features such as color and intensity contrast, symmetry, orientation and roundness. Obtained results from natural images show that the performance of the combination of hierarchical foveal segmentation and saliency estimation is good in terms of accuracy and speed.

  20. Geomorphometirc Segmentation of Shield Deserts by Self-Organizing Maps

    NASA Astrophysics Data System (ADS)

    Foroutan, M.; Kompanizare, M.; Ehsani, A. H.

    2015-12-01

    Shield deserts have developed on ancient crystalline bedrocks and mainly composed of folded and faulted rocks hardened by heat and pressure over millions of years. They were unearthed by erosion and form steep-sided hills and basins filled with sediments. The Sahara, Arabian, southern African, central Kavir and Australian deserts are in this group. Their ranges usually supply groundwater resources or in some regions contain huge oil reservoirs. Geomorphological segmentation of shield deserts is one of the fundamental tools in their land use or site investigation planning as well as in their surface water and groundwater management. In many studies the morphology of shield deserts has been investigated by limited qualitative and subjective methods using limited number of simple parameters such as surface elevation and slope. However the importance of these regions supports the need for their accurate and quantitative morphologic classification. The present study attempts to implement a quantitative method, Self-Organizing Map (SOM), for geomorphological classification of a typical shield desert within Kavir Desert, Iran. The area is tectonically stable and characterized by flat clay pans, playas, well-developed pediments around scattered and low elevation ranges. Twenty-two multi-scale morphometric parameters were derived from the first- to third-orders partial derivatives of the surface elevation. Seven optimized parameters with their proper scales were selected by Artificial Neural Networks, Optimum Index Factor, Davies-Bouldin Index and statistic models. Finally, the area was segmented to seven homogeneous areas by SOM algorithm. The results revealed the most distinguishing parameter set (MDPS) for morphologic segmentation of shield deserts. The same segmentation results through using MDPS for another shield deserts in Australia proves the applicability of MDPS for shield deserts segmentation.

  1. Segmentation of the Cascade Arc Based on Compositional and Sr and Nd Isotopic Variations in Primitive Volcanic Rocks

    NASA Astrophysics Data System (ADS)

    Schmidt, M. E.; Grunder, A. L.

    2006-12-01

    We define four segments in the Cascade Volcanic Arc based on 87Sr/86Sr and 143Nd/144Nd of primitive volcanic rocks: 1) The North segment extends 450 km from Mt. Meager to Glacier Peak; 2) the 350-km Columbia segment includes volcanoes from Mt. Rainier to Mt. Jefferson; 3) the 250 km Central segment comprises the portion of the arc between the Three Sisters and Crater Lake; and 4) the 350-km South segment includes Mt. Shasta to Mt. Lassen. Isotopic data were compiled for primitive bulk composition (MgO concentrations >8 wt.% MgO) as a fingerprint mantle sources. The North segment has a range in 87Sr/86Sr of 0.7030-0.7037 and is distinguished by the predominance of calcalkaline basalts (CAB) and few low K tholeiites (LKT). The North segment lies on the North Cascade craton where convergence is near orthogonal. Oblique subduction occurs beneath the Columbia, Central, and South segments. The Columbia segment (87Sr/86Sr of 0.7028-0.7037) has both LKT and CABs as well as enriched ocean island-like basalts (OIB) that are found both on the arc axis and, especially at the Simcoe Volcanic Field, behind the arc. This segment lies primarily on the accreted Tertiary oceanic plateau terrane of the Columbia Embayment. The Central segment is dominated by LKT with lesser CAB and has the most restricted Sr isotopic range (0.7034- 0.7038). Like the South segment, the Central segment mainly overlies accreted terranes stitched by Mesozoic plutons and has Basin and Range (B&R) extension behind as well as locally within the arc. Medicine Lake Volcano, on the margin of the B&R behind Mt. Shasta is also dominated by LKT and has a narrow isotopic range like the Central segment. This suggests that the LKT's are related to extension in the arc. The South segment is distinguished by the widest Sr isotopic range (0.7028-0.7042) and the presence of high Mg basaltic andesite and andesite compositions in addition to LKT and CABs. These arc segments broadly correspond to physical segments that were

  2. SAR Segmentation using Anisotropic Diffusion

    NASA Astrophysics Data System (ADS)

    Intajag, Sathit; Tipsuwanporn, Vittaya; Cheevasuwit, Fusak

    Speckle effects are commonly observed in synthetic aperture radar (SAR) images. The human eye is capable of deriving meaningful information from SAR images; however, an automatic or semi-automatic processing algorithm has difficulty in distinguishing objects in the images because of noise effects present in those images. This paper presents a segmentation method for SAR images, which employs an anisotropic diffusion algorithm. In the proposed scheme, a SAR image is transformed into a logarithmic domain where the diffusion process is used to grow homogeneous regions in the noise environment until the regions reach some criteria for homogeneity; consequently, the segmented image in the logarithm domain is converted to the intensity domain by an exponential function. To grow homogeneous regions the adaptive diffusion method is introduced with a tensor technique in which tensor data are varied with the neighboring pixels. The diffusion algorithm will stop itself by a standard deviation divided by the mean, which is provided according to the homogeneity criteria. Results are shown on both synthetic and satellite SAR images. The evaluation of the proposed method employs the theoretical gain of equivalent numbers of looks (ENL).

  3. Colony image acquisition and segmentation

    NASA Astrophysics Data System (ADS)

    Wang, W. X.

    2007-12-01

    For counting of both colonies and plaques, there is a large number of applications including food, dairy, beverages, hygiene, environmental monitoring, water, toxicology, sterility testing, AMES testing, pharmaceuticals, paints, sterile fluids and fungal contamination. Recently, many researchers and developers have made efforts for this kind of systems. By investigation, some existing systems have some problems. The main problems are image acquisition and image segmentation. In order to acquire colony images with good quality, an illumination box was constructed as: the box includes front lightning and back lightning, which can be selected by users based on properties of colony dishes. With the illumination box, lightning can be uniform; colony dish can be put in the same place every time, which make image processing easy. The developed colony image segmentation algorithm consists of the sub-algorithms: (1) image classification; (2) image processing; and (3) colony delineation. The colony delineation algorithm main contain: the procedures based on grey level similarity, on boundary tracing, on shape information and colony excluding. In addition, a number of algorithms are developed for colony analysis. The system has been tested and satisfactory.

  4. Segmented holographic spectrum splitting concentrator

    NASA Astrophysics Data System (ADS)

    Ayala, Silvana P.; Vorndran, Shelby; Wu, Yuechen; Chrysler, Benjamin; Kostuk, Raymond K.

    2016-09-01

    This paper presents a segmented parabolic concentrator employing holographic spectral filters that provide focusing and spectral bandwidth separation capability to the system. Strips of low band gap silicon photovoltaic (PV) cells are formed into a parabolic surface as shown by Holman et. al. [1]. The surface of the PV segments is covered with holographic elements formed in dichromated gelatin. The holographic elements are designed to transmit longer wavelengths to silicon cells, and to reflect short wavelength light towards a secondary collector where high-bandgap PV cells are mounted. The system can be optimized for different combinations of diffuse and direct solar illumination conditions for particular geographical locations by controlling the concentration ratio and filtering properties of the holographic elements. In addition, the reflectivity of the back contact of the silicon cells is used to increase the optical path length and light trapping. This potentially allows the use of thin film silicon for the low bandgap PV cell material. The optical design combines the focusing properties of the parabolic concentrator and the holographic element to control the concentration ratio and uniformity of the spectral distribution at the high bandgap cell location. The presentation concludes with a comparison of different spectrum splitting holographic filter materials for this application.

  5. WCE video segmentation using textons

    NASA Astrophysics Data System (ADS)

    Gallo, Giovanni; Granata, Eliana

    2010-03-01

    Wireless Capsule Endoscopy (WCE) integrates wireless transmission with image and video technology. It has been used to examine the small intestine non invasively. Medical specialists look for signicative events in the WCE video by direct visual inspection manually labelling, in tiring and up to one hour long sessions, clinical relevant frames. This limits the WCE usage. To automatically discriminate digestive organs such as esophagus, stomach, small intestine and colon is of great advantage. In this paper we propose to use textons for the automatic discrimination of abrupt changes within a video. In particular, we consider, as features, for each frame hue, saturation, value, high-frequency energy content and the responses to a bank of Gabor filters. The experiments have been conducted on ten video segments extracted from WCE videos, in which the signicative events have been previously labelled by experts. Results have shown that the proposed method may eliminate up to 70% of the frames from further investigations. The direct analysis of the doctors may hence be concentrated only on eventful frames. A graphical tool showing sudden changes in the textons frequencies for each frame is also proposed as a visual aid to find clinically relevant segments of the video.

  6. Pathogenesis of Focal Segmental Glomerulosclerosis

    PubMed Central

    Lim, Beom Jin; Yang, Jae Won; Do, Woo Sung; Fogo, Agnes B.

    2016-01-01

    Focal segmental glomerulosclerosis (FSGS) is characterized by focal and segmental obliteration of glomerular capillary tufts with increased matrix. FSGS is classified as collapsing, tip, cellular, perihilar and not otherwise specified variants according to the location and character of the sclerotic lesion. Primary or idiopathic FSGS is considered to be related to podocyte injury, and the pathogenesis of podocyte injury has been actively investigated. Several circulating factors affecting podocyte permeability barrier have been proposed, but not proven to cause FSGS. FSGS may also be caused by genetic alterations. These genes are mainly those regulating slit diaphragm structure, actin cytoskeleton of podocytes, and foot process structure. The mode of inheritance and age of onset are different according to the gene involved. Recently, the role of parietal epithelial cells (PECs) has been highlighted. Podocytes and PECs have common mesenchymal progenitors, therefore, PECs could be a source of podocyte repopulation after podocyte injury. Activated PECs migrate along adhesion to the glomerular tuft and may also contribute to the progression of sclerosis. Markers of activated PECs, including CD44, could be used to distinguish FSGS from minimal change disease. The pathogenesis of FSGS is very complex; however, understanding basic mechanisms of podocyte injury is important not only for basic research, but also for daily diagnostic pathology practice. PMID:27744657

  7. 15. The second story in the north segment of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. The second story in the north segment of the building was originally constructed as a restaurant. The north wall of the dining room retains the original wood wainscot and double-hung windows. At some undetermined time, a building was constructed on the adjacent property; blocking the windows in the dining room. Several chimneys with stove-pipe connections occur in the room. The members seen on the floor are part of a system recently installed to support the failing roof. Credit GADA/MRM. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

  8. 13. The south segment of the building has a stone ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. The south segment of the building has a stone basement. The alley wall had a number of areaway windows that are now infilled with bricks. These areaways were subsequently filled with earth, probably when the alley was paved. Here the first-floor joists are seen with a make-shift support beam and column. The basement floor originally was part earth and part wood. Some of the earth floor is now covered with a concrete slab; the wood floor remains. Credit GADA/MRM. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

  9. FIST: a fast interactive segmentation technique

    NASA Astrophysics Data System (ADS)

    Padfield, Dirk; Bhotika, Rahul; Natanzon, Alexander

    2015-03-01

    Radiologists are required to read thousands of patient images every day, and any tools that can improve their workflow to help them make efficient and accurate measurements is of great value. Such an interactive tool must be intuitive to use, and we have found that users are accustomed to clicking on the contour of the object for segmentation and would like the final segmentation to pass through these points. The tool must also be fast to enable real-time interactive feedback. To meet these needs, we present a segmentation workflow that enables an intuitive method for fast interactive segmentation of 2D and 3D objects. Given simple user clicks on the contour of an object in one 2D view, the algorithm generates foreground and background seeds and computes foreground and background distributions that are used to segment the object in 2D. It then propagates the information to the two orthogonal planes in a 3D volume and segments all three 2D views. The automated segmentation is automatically updated as the user continues to add points around the contour, and the algorithm is re-run using the total set of points. Based on the segmented objects in these three views, the algorithm then computes a 3D segmentation of the object. This process requires only limited user interaction to segment complex shapes and significantly improves the workflow of the user.

  10. Anatomy-aware measurement of segmentation accuracy

    NASA Astrophysics Data System (ADS)

    Tizhoosh, H. R.; Othman, A. A.

    2016-03-01

    Quantifying the accuracy of segmentation and manual delineation of organs, tissue types and tumors in medical images is a necessary measurement that suffers from multiple problems. One major shortcoming of all accuracy measures is that they neglect the anatomical significance or relevance of different zones within a given segment. Hence, existing accuracy metrics measure the overlap of a given segment with a ground-truth without any anatomical discrimination inside the segment. For instance, if we understand the rectal wall or urethral sphincter as anatomical zones, then current accuracy measures ignore their significance when they are applied to assess the quality of the prostate gland segments. In this paper, we propose an anatomy-aware measurement scheme for segmentation accuracy of medical images. The idea is to create a "master gold" based on a consensus shape containing not just the outline of the segment but also the outlines of the internal zones if existent or relevant. To apply this new approach to accuracy measurement, we introduce the anatomy-aware extensions of both Dice coefficient and Jaccard index and investigate their effect using 500 synthetic prostate ultrasound images with 20 different segments for each image. We show that through anatomy-sensitive calculation of segmentation accuracy, namely by considering relevant anatomical zones, not only the measurement of individual users can change but also the ranking of users' segmentation skills may require reordering.

  11. RSRM Segment Train Derailment and Recovery

    NASA Technical Reports Server (NTRS)

    Taylor Jr., Robert H.; McConnaugghey, Paul K.; Beaman, David E.; Moore, Dennis R.; Reed, Harry

    2008-01-01

    On May 2, 2007, a freight train carrying segments of the space shuttle's solid rocket boosters derailed in Myrtlewood, Alabama, after a rail trestle collapsed. The train was carrying Reusable Solid Rocket Motors (RSRM) 98 center and forward segments (STS-120) and RSRM 99 aft segments (STS-122). Initially, it was not known if the segments had been seriously damaged. Four segments dropped approximately 10 feet when the trestle collapsed and one of those four rolled off the track onto its side. The exit cones and the other four segments, not yet on the trestle, remained on solid ground. ATK and NASA immediately dispatched an investigation and recovery team to determine the safety of the situation and eventually the usability of the segments and exit cones for flight. Instrumentation on each segment provided invaluable data to determine the acceleration loads imparted into each loaded segment and exit cone. This paper details the incident, recovery plan and the team work that created a success story that ended with the safe launch of STS120 using the four center segments and the launch of STS122 using the Aft exit cones assemblies.

  12. Hierarchical morphological segmentation for image sequence coding.

    PubMed

    Salembier, P; Pardas, M

    1994-01-01

    This paper deals with a hierarchical morphological segmentation algorithm for image sequence coding. Mathematical morphology is very attractive for this purpose because it efficiently deals with geometrical features such as size, shape, contrast, or connectivity that can be considered as segmentation-oriented features. The algorithm follows a top-down procedure. It first takes into account the global information and produces a coarse segmentation, that is, with a small number of regions. Then, the segmentation quality is improved by introducing regions corresponding to more local information. The algorithm, considering sequences as being functions on a 3-D space, directly segments 3-D regions. A 3-D approach is used to get a segmentation that is stable in time and to directly solve the region correspondence problem. Each segmentation stage relies on four basic steps: simplification, marker extraction, decision, and quality estimation. The simplification removes information from the sequence to make it easier to segment. Morphological filters based on partial reconstruction are proven to be very efficient for this purpose, especially in the case of sequences. The marker extraction identifies the presence of homogeneous 3-D regions. It is based on constrained flat region labeling and morphological contrast extraction. The goal of the decision is to precisely locate the contours of regions detected by the marker extraction. This decision is performed by a modified watershed algorithm. Finally, the quality estimation concentrates on the coding residue, all the information about the 3-D regions that have not been properly segmented and therefore coded. The procedure allows the introduction of the texture and contour coding schemes within the segmentation algorithm. The coding residue is transmitted to the next segmentation stage to improve the segmentation and coding quality. Finally, segmentation and coding examples are presented to show the validity and interest of

  13. In vivo and in vitro heterogeneity of segment length changes in the semimembranosus muscle of the toad.

    PubMed

    Ahn, A N; Monti, R J; Biewener, A A

    2003-06-15

    Many studies examine sarcomere dynamics in single fibres or length-tension dynamics in whole muscles in vivo or in vitro, but few studies link the various levels of organisation. To relate data addressing in vitro muscle segment behaviour with in vivo whole muscle behaviour during locomotion, we measured in vivo strain patterns of muscle segments using three sonomicrometry crystals implanted along a fascicle of the semimembranosus muscle in the American toad (Bufo americanus; n = 6) during hopping. The centre crystal emitted an ultrasonic signal, while the outer crystals received the signal allowing the instantaneous measurement of lengths from two adjacent muscle segments. On the first day, we recorded from the central and distal segments. On the second day of recordings, the most distal crystal was moved to a proximal position to record from a proximal segment and the same central segment. When the toads hopped a distance of two body lengths, the proximal and central segments strained -15.1 +/- 6.1 and -14.0 +/- 4.9 % (i.e. shortening), respectively. Strain of the distal segment, however, was significantly lower and more variable in pattern, often lengthening before shortening during a hop. From rest length, the distal segment initially lengthened by 2.6 +/- 2.0 % before shortening by 6.5 +/- 3.2 % at the same hop distance. Under in vitro conditions, the central segment always shortened more than the distal segment, except when passively cycled, during which the segments strained similarly. When the whole muscle was cycled sinusoidally and stimulated phasically in vitro, the two adjacent segments strained in opposite directions over much (up to 34 %) of the cycle. These differences in strain amplitude and direction imply that two adjacent segments can not only produce and/or absorb varying amounts of mechanical energy, but can also operate on different regions of their force-length and force-velocity relationships when activated by the same neural signal

  14. Coordination of Fictive Motor Activity in the Larval Zebrafish Is Generated by Non-Segmental Mechanisms

    PubMed Central

    Wiggin, Timothy D.; Peck, Jack H.; Masino, Mark A.

    2014-01-01

    The cellular and network basis for most vertebrate locomotor central pattern generators (CPGs) is incompletely characterized, but organizational models based on known CPG architectures have been proposed. Segmental models propose that each spinal segment contains a circuit that controls local coordination and sends longer projections to coordinate activity between segments. Unsegmented/continuous models propose that patterned motor output is driven by gradients of neurons and synapses that do not have segmental boundaries. We tested these ideas in the larval zebrafish, an animal that swims in discrete episodes, each of which is composed of coordinated motor bursts that progress rostrocaudally and alternate from side to side. We perturbed the spinal cord using spinal transections or strychnine application and measured the effect on fictive motor output. Spinal transections eliminated episode structure, and reduced both rostrocaudal and side-to-side coordination. Preparations with fewer intact segments were more severely affected, and preparations consisting of midbody and caudal segments were more severely affected than those consisting of rostral segments. In reduced preparations with the same number of intact spinal segments, side-to-side coordination was more severely disrupted than rostrocaudal coordination. Reducing glycine receptor signaling with strychnine reversibly disrupted both rostrocaudal and side-to-side coordination in spinalized larvae without disrupting episodic structure. Both spinal transection and strychnine decreased the stability of the motor rhythm, but this effect was not causal in reducing coordination. These results are inconsistent with a segmented model of the spinal cord and are better explained by a continuous model in which motor neuron coordination is controlled by segment-spanning microcircuits. PMID:25275377

  15. Comparison between Two Scheimpflug Anterior Segment Analyzers

    PubMed Central

    Baradaran-Rafii, Alireza; Motevasseli, Tahmineh; Yazdizadeh, Forouzan; Karimian, Farid; Fekri, Sahba; Baradaran-Rafii, Amir

    2017-01-01

    Purpose: To compare the anterior segment indices measured by two Scheimpflug camera machines; Galilei and Pentacam. Methods: In this observational case series, the anterior segment indices of myopic healthy subjects seeking for refractive surgery were measured by Pentacam and Galilei on the same day. Analyzed parameters were anterior and posterior best fit spheres (BFS), axial curvature, true corneal power, central corneal thickness (CCT), anterior chamber (AC) depth, AC volume, AC angle, and pupil diameter. Results: This study included 176 eyes of 88 participants. Mean radius of the anterior BFS was 7.79 ± 0.34 mm versus 7.75 ± 0.39 mm measured by Pentacam and Galilei, respectively (r = 0.877, P < 0.001). Corresponding values for the mean radius of posterior BFS were 6.42 ± 0.32 and 6.47 ± 0.38 mm, respectively (r = 0.879, P < 0.001). Anterior corneal mean power was 43.8 ± 1.9 diopters (D) with Pentacam and 43.8 ± 2.4 D with Galilei (r = 0.905,P < 0.001). Posterior corneal mean power was measured − 6.3 ± 0.3 and − 6.3 ± 0.4 D using Pentacam and Galilei, respectively (r = 0.873, P < 0.001). True corneal power was 43.9 ± 1.9 D with Pentacam and 43.5 ± 2.3 D with Galilei (r = 0.909, P < 0.001). CCT was 537 ± 44 and 553 ± 51 μm measured by Pentacam and Galilei, respectively (r = 0.796, P < 0.001). AC depth measurements using Pentacam and Galilei were 3.29 ± 0.4 and 3.3 ± 0.38 mm (P < 0.001), respectively; AC volume was 207 ± 50 and 129 ± 39 mm3≥ (P = 0.004), and AC angle was 39.7 ± 9.2 and 54.2 ± 5.2 degrees (P = 0.051), respectively. Average pupil diameter was measured 3.91 ± 1.77 mm by Pentacam and 3.34 ± 0.89 mm by Galilei (P = 0.018). Conclusions: There was a significant correlation between the Pentacam and Galilei in all measured parameters except AC angle, AC volume, and average pupil diameter. PMID:28299003

  16. Research on a Pulmonary Nodule Segmentation Method Combining Fast Self-Adaptive FCM and Classification

    PubMed Central

    Liu, Hui; Zhang, Cai-Ming; Su, Zhi-Yuan; Wang, Kai; Deng, Kai

    2015-01-01

    The key problem of computer-aided diagnosis (CAD) of lung cancer is to segment pathologically changed tissues fast and accurately. As pulmonary nodules are potential manifestation of lung cancer, we propose a fast and self-adaptive pulmonary nodules segmentation method based on a combination of FCM clustering and classification learning. The enhanced spatial function considers contributions to fuzzy membership from both the grayscale similarity between central pixels and single neighboring pixels and the spatial similarity between central pixels and neighborhood and improves effectively the convergence rate and self-adaptivity of the algorithm. Experimental results show that the proposed method can achieve more accurate segmentation of vascular adhesion, pleural adhesion, and ground glass opacity (GGO) pulmonary nodules than other typical algorithms. PMID:25945120

  17. Hierarchical image segmentation for learning object priors

    SciTech Connect

    Prasad, Lakshman; Yang, Xingwei; Latecki, Longin J; Li, Nan

    2010-11-10

    The proposed segmentation approach naturally combines experience based and image based information. The experience based information is obtained by training a classifier for each object class. For a given test image, the result of each classifier is represented as a probability map. The final segmentation is obtained with a hierarchial image segmentation algorithm that considers both the probability maps and the image features such as color and edge strength. We also utilize image region hierarchy to obtain not only local but also semi-global features as input to the classifiers. Moreover, to get robust probability maps, we take into account the region context information by averaging the probability maps over different levels of the hierarchical segmentation algorithm. The obtained segmentation results are superior to the state-of-the-art supervised image segmentation algorithms.

  18. Self-correcting multi-atlas segmentation

    NASA Astrophysics Data System (ADS)

    Gao, Yi; Wilford, Andrew; Guo, Liang

    2016-03-01

    In multi-atlas segmentation, one typically registers several atlases to the new image, and their respective segmented label images are transformed and fused to form the final segmentation. After each registration, the quality of the registration is reflected by the single global value: the final registration cost. Ideally, if the quality of the registration can be evaluated at each point, independent of the registration process, which also provides a direction in which the deformation can further be improved, the overall segmentation performance can be improved. We propose such a self-correcting multi-atlas segmentation method. The method is applied on hippocampus segmentation from brain images and statistically significantly improvement is observed.

  19. Intelligent multi-spectral IR image segmentation

    NASA Astrophysics Data System (ADS)

    Lu, Thomas; Luong, Andrew; Heim, Stephen; Patel, Maharshi; Chen, Kang; Chao, Tien-Hsin; Chow, Edward; Torres, Gilbert

    2017-05-01

    This article presents a neural network based multi-spectral image segmentation method. A neural network is trained on the selected features of both the objects and background in the longwave (LW) Infrared (IR) images. Multiple iterations of training are performed until the accuracy of the segmentation reaches satisfactory level. The segmentation boundary of the LW image is used to segment the midwave (MW) and shortwave (SW) IR images. A second neural network detects the local discontinuities and refines the accuracy of the local boundaries. This article compares the neural network based segmentation method to the Wavelet-threshold and Grab-Cut methods. Test results have shown increased accuracy and robustness of this segmentation scheme for multi-spectral IR images.

  20. Cooling system for three hook ring segment

    DOEpatents

    Campbell, Christian X.; Eng, Darryl; Lee, Ching-Pang; Patat, Harry

    2014-08-26

    A triple hook ring segment including forward, midsection and aft mounting hooks for engagement with respective hangers formed on a ring segment carrier for supporting a ring segment panel, and defining a forward high pressure chamber and an aft low pressure chamber on opposing sides of the midsection mounting hook. An isolation plate is provided on the aft side of the midsection mounting hook to form an isolation chamber between the aft low pressure chamber and the ring segment panel. High pressure air is supplied to the forward chamber and flows to the isolation chamber through crossover passages in the midsection hook. The isolation chamber provides convection cooling air to an aft portion of the ring segment panel and enables a reduction of air pressure in the aft low pressure chamber to reduce leakage flow of cooling air from the ring segment.

  1. Fluidized bed boiler having a segmented grate

    DOEpatents

    Waryasz, Richard E.

    1984-01-01

    A fluidized bed furnace (10) is provided having a perforate grate (9) within a housing which supports a bed of particulate material including some combustibles. The grate is divided into a plurality of segments (E2-E6, SH1-SH5, RH1-RH5), with the airflow to each segment being independently controlled. Some of the segments have evaporating surface imbedded in the particulate material above them, while other segments are below superheater surface or reheater surface. Some of the segments (E1, E7) have no surface above them, and there are ignitor combustors (32, 34) directed to fire into the segments, for fast startup of the furnace without causing damage to any heating surface.

  2. Milling Stability Analysis Based on Chebyshev Segmentation

    NASA Astrophysics Data System (ADS)

    HUANG, Jianwei; LI, He; HAN, Ping; Wen, Bangchun

    2016-09-01

    Chebyshev segmentation method was used to discretize the time period contained in delay differential equation, then the Newton second-order difference quotient method was used to calculate the cutter motion vector at each time endpoint, and the Floquet theory was used to determine the stability of the milling system after getting the transfer matrix of milling system. Using the above methods, a two degree of freedom milling system stability issues were investigated, and system stability lobe diagrams were got. The results showed that the proposed methods have the following advantages. Firstly, with the same calculation accuracy, the points needed to represent the time period are less by the Chebyshev Segmentation than those of the average segmentation, and the computational efficiency of the Chebyshev Segmentation is higher. Secondly, if the time period is divided into the same parts, the stability lobe diagrams got by Chebyshev segmentation method are more accurate than those of the average segmentation.

  3. Discriminative parameter estimation for random walks segmentation.

    PubMed

    Baudin, Pierre-Yves; Goodman, Danny; Kumrnar, Puneet; Azzabou, Noura; Carlier, Pierre G; Paragios, Nikos; Kumar, M Pawan

    2013-01-01

    The Random Walks (RW) algorithm is one of the most efficient and easy-to-use probabilistic segmentation methods. By combining contrast terms with prior terms, it provides accurate segmentations of medical images in a fully automated manner. However, one of the main drawbacks of using the RW algorithm is that its parameters have to be hand-tuned. we propose a novel discriminative learning framework that estimates the parameters using a training dataset. The main challenge we face is that the training samples are not fully supervised. Specifically, they provide a hard segmentation of the images, instead of a probabilistic segmentation. We overcome this challenge by treating the optimal probabilistic segmentation that is compatible with the given hard segmentation as a latent variable. This allows us to employ the latent support vector machine formulation for parameter estimation. We show that our approach significantly outperforms the baseline methods on a challenging dataset consisting of real clinical 3D MRI volumes of skeletal muscles.

  4. Livewire based single still image segmentation

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Yang, Rong; Liu, Xiaomao; Yue, Hao; Zhu, Hao; Tian, Dandan; Chen, Shu; Li, Yiquan; Tian, Jinwen

    2011-11-01

    In the application of the video contactless measurement, the quality of the image taken from underwater is not very well. It is well known that automatic image segmental method cannot provide acceptable segmentation result with low quality single still image. Snake algorithm can provide better result in this case with the aiding of human. However, sometimes the segmental result of Snake may far from the initial segmental contour drawn by user. Livewire algorithm can keep the location of the seed points that user selected nailed from the beginning to the end. But the contour may have burrs when the image's noise is quite high and the contrast is low. In this paper, we modified the cost function of Livewire algorithm and proposed a new segmentation method that can be used for single still image segmentation with high noise and low contrast.

  5. Contour Completion Without Region Segmentation.

    PubMed

    Ming, Yansheng; Li, Hongdong; He, Xuming

    2016-08-01

    Contour completion plays an important role in visual perception, where the goal is to group fragmented low-level edge elements into perceptually coherent and salient contours. Most existing methods for contour completion have focused on pixelwise detection accuracy. In contrast, fewer methods have addressed the global contour closure effect, despite psychological evidences for its importance. This paper proposes a purely contour-based higher order CRF model to achieve contour closure, through local connectedness approximation. This leads to a simplified problem structure, where our higher order inference problem can be transformed into an integer linear program and be solved efficiently. Compared with the methods based on the same bottom-up edge detector, our method achieves a superior contour grouping ability (measured by Rand index), a comparable precision-recall performance, and more visually pleasing results. Our results suggest that contour closure can be effectively achieved in contour domain, in contrast to a popular view that segmentation is essential for this purpose.

  6. Community study suggests segmentation strategies.

    PubMed

    Gagnard, A

    1989-01-01

    Results of a sample survey commissioned by a voluntary health organization in a major metropolitan area describes why individuals give their time and money to charitable organizations and what approaches are likely to result in such donations. Within demographic subgroups, the variables of age and income proved to be important factors with respect to why people gave and what appeals they prefer. The variables of gender and education were found to be of somewhat less importance. Findings were compared with a national Gallup study conducted in 1987. In an era of increasingly specialized marketing for all organizations, the findings offer voluntary and fund-raising organizations a basis for determining appropriate appeals for demographic segments in a community.

  7. Core Recursive Hierarchical Image Segmentation

    NASA Technical Reports Server (NTRS)

    Tilton, James

    2011-01-01

    The Recursive Hierarchical Image Segmentation (RHSEG) software has been repackaged to provide a version of the RHSEG software that is not subject to patent restrictions and that can be released to the general public through NASA GSFC's Open Source release process. Like the Core HSEG Software Package, this Core RHSEG Software Package also includes a visualization program called HSEGViewer along with a utility program HSEGReader. It also includes an additional utility program called HSEGExtract. The unique feature of the Core RHSEG package is that it is a repackaging of the RHSEG technology designed to specifically avoid the inclusion of the certain software technology. Unlike the Core HSEG package, it includes the recursive portions of the technology, but does not include processing window artifact elimination technology.

  8. Segmented cold cathode display panel

    NASA Technical Reports Server (NTRS)

    Payne, Leslie (Inventor)

    1998-01-01

    The present invention is a video display device that utilizes the novel concept of generating an electronically controlled pattern of electron emission at the output of a segmented photocathode. This pattern of electron emission is amplified via a channel plate. The result is that an intense electronic image can be accelerated toward a phosphor thus creating a bright video image. This novel arrangement allows for one to provide a full color flat video display capable of implementation in large formats. In an alternate arrangement, the present invention is provided without the channel plate and a porous conducting surface is provided instead. In this alternate arrangement, the brightness of the image is reduced but the cost of the overall device is significantly lowered because fabrication complexity is significantly decreased.

  9. Performance Measures For Statistical Segmentation

    NASA Astrophysics Data System (ADS)

    Shazeer, Dov J.

    1983-03-01

    Performance measures for statistical segmentation have been developed for a space-and-time critical Bayesian statistical tracker. They are intended to become an integral part of a knowledge-based tracking algorithm, which has been developed by RCA. The performance measures are serving to quantify the usefulness of the processed input, to assist in the identification of each tracking state and give its reliability, and to predict impending changes of state. They have been tested using stochastically generated target-background frames. Performance measure results have correlated well with the parameters which characterize the difference in the target and background distributions. A host of possible performance measures are discussed in relation to their strengths and weaknesses. Experimental results for the measures currently being employed by RCA are given, and areas for future research are indicated.

  10. Prostate segmentation in HIFU therapy

    PubMed Central

    Garnier, Carole; Bellanger, Jean-Jacques; Wu, Ke; Shu, Huazhong; Costet, Nathalie; Mathieu, Romain; De Crevoisier, Renaud; Coatrieux, Jean-Louis

    2011-01-01

    Prostate segmentation in 3-D transrectal ultrasound images is an important step in the definition of the intra-operative planning of high intensity focused ultrasound (HIFU) therapy. This paper presents two main approaches for the semi-automatic methods based on discrete dynamic contour and optimal surface detection. They operate in 3-D and require a minimal user interaction. They are considered both alone or sequentially combined, with and without postregularization, and applied on anisotropic and isotropic volumes. Their performance, using different metrics, has been evaluated on a set of 28 3-D images by comparison with two expert delineations. For the most efficient algorithm, the symmetric average surface distance was found to be 0.77 mm. PMID:21118767

  11. Segment adaptive gradient angle interpolation.

    PubMed

    Zwart, Christine M; Frakes, David H

    2013-08-01

    We introduce a new edge-directed interpolator based on locally defined, straight line approximations of image isophotes. Spatial derivatives of image intensity are used to describe the principal behavior of pixel-intersecting isophotes in terms of their slopes. The slopes are determined by inverting a tridiagonal matrix and are forced to vary linearly from pixel-to-pixel within segments. Image resizing is performed by interpolating along the approximated isophotes. The proposed method can accommodate arbitrary scaling factors, provides state-of-the-art results in terms of PSNR as well as other quantitative visual quality metrics, and has the advantage of reduced computational complexity that is directly proportional to the number of pixels.

  12. Segmenting data sets for RIP.

    PubMed

    de Sanctis, Daniele; Nanao, Max H

    2012-09-01

    Specific radiation damage can be used for the phasing of macromolecular crystal structures. In practice, however, the optimization of the X-ray dose used to `burn' the crystal to induce specific damage can be difficult. Here, a method is presented in which a single large data set that has not been optimized in any way for radiation-damage-induced phasing (RIP) is segmented into multiple sub-data sets, which can then be used for RIP. The efficacy of this method is demonstrated using two model systems and two test systems. A method to improve the success of this type of phasing experiment by varying the composition of the two sub-data sets with respect to their separation by image number, and hence by absorbed dose, as well as their individual completeness is illustrated.

  13. Precision segmented reflector, figure verification sensor

    NASA Technical Reports Server (NTRS)

    Manhart, Paul K.; Macenka, Steve A.

    1989-01-01

    The Precision Segmented Reflector (PSR) program currently under way at the Jet Propulsion Laboratory is a test bed and technology demonstration program designed to develop and study the structural and material technologies required for lightweight, precision segmented reflectors. A Figure Verification Sensor (FVS) which is designed to monitor the active control system of the segments is described, a best fit surface is defined, and an image or wavefront quality of the assembled array of reflecting panels is assessed

  14. A unique case of segmental vasal atresia

    PubMed Central

    Alalayet, Yasen Fayez; Alkasim, F; Shiba, N; Aldhuayan, I; Alhamaidi, S; Alghamdi, G; Aljobair, F; Shoura, J; Alkhlaif, R

    2014-01-01

    We report a case of a 2-year-old boy who presented with an empty left scrotum. Clinical examination revealed a left palpable undescended testis. During orchidopexy, segmental atresia of the vas deferens was found, and microsurgical repair was carried out. Segmental vasal atresia is an extremely rare condition and is infrequently diagnosed, especially in the pediatric age group. This is the first reported case of segmental vasal atresia without an association with cystic fibrosis. PMID:25419520

  15. Segmentation in dermatological hyperspectral images: dedicated methods.

    PubMed

    Koprowski, Robert; Olczyk, Paweł

    2016-08-17

    Segmentation of hyperspectral medical images is one of many image segmentation methods which require profiling. This profiling involves either the adjustment of existing, known image segmentation methods or a proposal of new dedicated methods of hyperspectral image segmentation. Taking into consideration the size of analysed data, the time of analysis is of major importance. Therefore, the authors proposed three new dedicated methods of hyperspectral image segmentation with special reference to the time of analysis. The segmentation methods presented in this paper were tested and profiled to the images acquired from different hyperspectral cameras including SOC710 Hyperspectral Imaging System, Specim sCMOS-50-V10E. Correct functioning of the method was tested for over 10,000 2D images constituting the sequence of over 700 registrations of the areas of the left and right hand and the forearm. As a result, three new methods of hyperspectral image segmentation have been proposed: fast analysis of emissivity curves (SKE), 3D segmentation (S3D) and hierarchical segmentation (SH). They have the following features: are fully automatic; allow for implementation of fast segmentation methods; are profiled to hyperspectral image segmentation; use emissivity curves in the model form, can be applied in any type of objects not necessarily biological ones, are faster (SKE-2.3 ms, S3D-1949 ms, SH-844 ms for the computer with Intel(®) Core i7 4960X CPU 3.6 GHz) and more accurate (SKE-accuracy 79 %, S3D-90 %, SH-92 %) in comparison with typical methods known from the literature. Profiling and/or proposing new methods of hyperspectral image segmentation is an indispensable element of developing software. This ensures speed, repeatability and low sensitivity of the algorithm to changing parameters.

  16. Design Gabor Filters for Texture Segmentation

    DTIC Science & Technology

    1992-10-01

    DESIGNING GABOR FILTERS FOR TEXTURE SEGMENTATION by D. F. Dunn, W. Higgins, A. Maida, J. Wakeley DTIC ELECTE CT 141992 SA D m Technical Report No. TR 92...REPORT TYPE AND DATES COVEREDOctober 1992 4. T•TLE AND SUBTI’TE S. FUNONG NUMBElS Design Gabor Filters for Texture Segmentation 4. AUTHOR(S) D. F. Dunn, W...TERMS IS. NUMBER OF PAGES Gabor filters , texture segmentation , filters 178 16. PRKIC coot 17.

  17. An algorithm for segmenting range imagery

    SciTech Connect

    Roberts, R.S.

    1997-03-01

    This report describes the technical accomplishments of the FY96 Cross Cutting and Advanced Technology (CC&AT) project at Los Alamos National Laboratory. The project focused on developing algorithms for segmenting range images. The image segmentation algorithm developed during the project is described here. In addition to segmenting range images, the algorithm can fuse multiple range images thereby providing true 3D scene models. The algorithm has been incorporated into the Rapid World Modelling System at Sandia National Laboratory.

  18. Robust GM/WM segmentation of the spinal cord with iterative non-local statistical fusion.

    PubMed

    Asman, Andrew J; Smith, Seth A; Reich, Daniel S; Landman, Bennett A

    2013-01-01

    New magnetic resonance imaging (MRI) sequences are enabling clinical study of the in vivo spinal cord's internal structure. Yet, low contrast-to-noise ratio, artifacts, and imaging distortions have limited the applicability of tissue segmentation techniques pioneered elsewhere in the central nervous system. Recently, methods have been presented for cord/non-cord segmentation on MRI and the feasibility of gray matter/white matter tissue segmentation has been evaluated. To date, no automated algorithms have been presented. Herein, we present a non-local multi-atlas framework that robustly identifies the spinal cord and segments its internal structure with submillimetric accuracy. The proposed algorithm couples non-local fusion with a large number of slice-based atlases (as opposed to typical volumetric ones). To improve performance, the fusion process is interwoven with registration so that segmentation information guides registration and vice versa. We demonstrate statistically significant improvement over state-of-the-art benchmarks in a study of 67 patients. The primary contributions of this work are (1) innovation in non-volumetric atlas information, (2) advancement of label fusion theory to include iterative registration/segmentation, and (3) the first fully automated segmentation algorithm for spinal cord internal structure on MRI.

  19. Military display market segment: helicopters

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    2004-09-01

    The military display market is analyzed in terms of one of its segments: helicopter displays. Parameters requiring special consideration, to include luminance ranges, contrast ratio, viewing angles, and chromaticity coordinates, are examined. Performance requirements for rotary-wing displays relative to several premier applications are summarized. Display sizes having aggregate defense applications of 5,000 units or greater and having DoD applications across 10 or more platforms, are tabulated. The issue of size commonality is addressed where distribution of active area sizes across helicopter platforms, individually, in groups of two through nine, and ten or greater, is illustrated. Rotary-wing displays are also analyzed by technology, where total quantities of such displays are broken out into CRT, LCD, AMLCD, EM, LED, Incandescent, Plasma and TFEL percentages. Custom, versus Rugged commercial, versus commercial off-the-shelf designs are contrasted. High and low information content designs are identified. Displays for several high-profile military helicopter programs are discussed, to include both technical specifications and program history. The military display market study is summarized with breakouts for the helicopter market segment. Our defense-wide study as of March 2004 has documented 1,015,494 direct view and virtual image displays distributed across 1,181 display sizes and 503 weapon systems. Helicopter displays account for 67,472 displays (just 6.6% of DoD total) and comprise 83 sizes (7.0% of total DoD) in 76 platforms (15.1% of total DoD). Some 47.6% of these rotary-wing applications involve low information content displays comprising just a few characters in one color; however, as per fixed-wing aircraft, the predominant instantiation involves higher information content units capable of showing changeable graphics, color and video.

  20. Image segmentation using fuzzy LVQ clustering networks

    NASA Technical Reports Server (NTRS)

    Tsao, Eric Chen-Kuo; Bezdek, James C.; Pal, Nikhil R.

    1992-01-01

    In this note we formulate image segmentation as a clustering problem. Feature vectors extracted from a raw image are clustered into subregions, thereby segmenting the image. A fuzzy generalization of a Kohonen learning vector quantization (LVQ) which integrates the Fuzzy c-Means (FCM) model with the learning rate and updating strategies of the LVQ is used for this task. This network, which segments images in an unsupervised manner, is thus related to the FCM optimization problem. Numerical examples on photographic and magnetic resonance images are given to illustrate this approach to image segmentation.

  1. Phasing piston error in segmented telescopes.

    PubMed

    Jiang, Junlun; Zhao, Weirui

    2016-08-22

    To achieve a diffraction-limited imaging, the piston errors between the segments of the segmented primary mirror telescope should be reduced to λ/40 RMS. We propose a method to detect the piston error by analyzing the intensity distribution on the image plane according to the Fourier optics principle, which can capture segments with the piston errors as large as the coherence length of the input light and reduce these to 0.026λ RMS (λ = 633nm). This method is adaptable to any segmented and deployable primary mirror telescope. Experiments have been carried out to validate the feasibility of the method.

  2. Parallel Fuzzy Segmentation of Multiple Objects*

    PubMed Central

    Garduño, Edgar; Herman, Gabor T.

    2009-01-01

    The usefulness of fuzzy segmentation algorithms based on fuzzy connectedness principles has been established in numerous publications. New technologies are capable of producing larger-and-larger datasets and this causes the sequential implementations of fuzzy segmentation algorithms to be time-consuming. We have adapted a sequential fuzzy segmentation algorithm to multi-processor machines. We demonstrate the efficacy of such a distributed fuzzy segmentation algorithm by testing it with large datasets (of the order of 50 million points/voxels/items): a speed-up factor of approximately five over the sequential implementation seems to be the norm. PMID:19444333

  3. Segmenting hospitals for improved management strategy.

    PubMed

    Malhotra, N K

    1989-09-01

    The author presents a conceptual framework for the a priori and clustering-based approaches to segmentation and evaluates them in the context of segmenting institutional health care markets. An empirical study is reported in which the hospital market is segmented on three state-of-being variables. The segmentation approach also takes into account important organizational decision-making variables. The sophisticated Thurstone Case V procedure is employed. Several marketing implications for hospitals, other health care organizations, hospital suppliers, and donor publics are identified.

  4. Adaptive textural segmentation of medical images

    NASA Astrophysics Data System (ADS)

    Kuklinski, Walter S.; Frost, Gordon S.; MacLaughlin, Thomas

    1992-06-01

    A number of important problems in medical imaging can be described as segmentation problems. Previous fractal-based image segmentation algorithms have used either the local fractal dimension alone or the local fractal dimension and the corresponding image intensity as features for subsequent pattern recognition algorithms. An image segmentation algorithm that utilized the local fractal dimension, image intensity, and the correlation coefficient of the local fractal dimension regression analysis computation, to produce a three-dimension feature space that was partitioned to identify specific pixels of dental radiographs as being either bone, teeth, or a boundary between bone and teeth also has been reported. In this work we formulated the segmentation process as a configurational optimization problem and discuss the application of simulated annealing optimization methods to the solution of this specific optimization problem. The configurational optimization method allows information about both, the degree of correspondence between a candidate segment and an assumed textural model, and morphological information about the candidate segment to be used in the segmentation process. To apply this configurational optimization technique with a fractal textural model however, requires the estimation of the fractal dimension of an irregularly shaped candidate segment. The potential utility of a discrete Gerchberg-Papoulis bandlimited extrapolation algorithm to the estimation of the fractal dimension of an irregularly shaped candidate segment is also discussed.

  5. DT-MRI segmentation using graph cuts

    NASA Astrophysics Data System (ADS)

    Weldeselassie, Yonas T.; Hamarneh, Ghassan

    2007-03-01

    An important problem in medical image analysis is the segmentation of anatomical regions of interest. Once regions of interest are segmented, one can extract shape, appearance, and structural features that can be analyzed for disease diagnosis or treatment evaluation. Diffusion tensor magnetic resonance imaging (DT-MRI) is a relatively new medical imaging modality that captures unique water diffusion properties and fiber orientation information of the imaged tissues. In this paper, we extend the interactive multidimensional graph cuts segmentation technique to operate on DT-MRI data by utilizing latest advances in tensor calculus and diffusion tensor dissimilarity metrics. The user interactively selects certain tensors as object ("obj") or background ("bkg") to provide hard constraints for the segmentation. Additional soft constraints incorporate information about both regional tissue diffusion as well as boundaries between tissues of different diffusion properties. Graph cuts are used to find globally optimal segmentation of the underlying 3D DT-MR image among all segmentations satisfying the constraints. We develop a graph structure from the underlying DT-MR image with the tensor voxels corresponding to the graph vertices and with graph edge weights computed using either Log-Euclidean or the J-divergence tensor dissimilarity metric. The topology of our segmentation is unrestricted and both obj and bkg segments may consist of several isolated parts. We test our method on synthetic DT data and apply it to real 2D and 3D MRI, providing segmentations of the corpus callosum in the brain and the ventricles of the heart.

  6. A molecular view of onychophoran segmentation.

    PubMed

    Janssen, Ralf

    2017-02-14

    This paper summarizes our current knowledge on the expression and assumed function of Drosophila and (other) arthropod segmentation gene orthologs in Onychophora, a closely related outgroup to Arthropoda. This includes orthologs of the so-called Drosophila segmentation gene cascade including the Hox genes, as well as other genetic factors and pathways involved in non-drosophilid arthropods. Open questions about and around the topic are addressed, such as the definition of segments in onychophorans, the unclear regulation of conserved expression patterns downstream of non-conserved factors, and the potential role of mesodermal patterning in onychophoran segmentation.

  7. Dynamic Aperture-based Solar Loop Segmentation

    NASA Technical Reports Server (NTRS)

    Lee, Jon Kwan; Newman, Timothy S.; Gary, G. Allen

    2006-01-01

    A new method to automatically segment arc-like loop structures from intensity images of the Sun's corona is introduced. The method constructively segments credible loop structures by exploiting the Gaussian-like shape of loop cross-sectional intensity profiles. The experimental results show that the method reasonably segments most of the well-defined loops in coronal images. The method is only the second published automated solar loop segmentation method. Its advantage over the other published method is that it operates independently of supplemental time specific data.

  8. Segmented amplifier configurations for laser amplifier

    DOEpatents

    Hagen, Wilhelm F.

    1979-01-01

    An amplifier system for high power lasers, the system comprising a compact array of segments which (1) preserves high, large signal gain with improved pumping efficiency and (2) allows the total amplifier length to be shortened by as much as one order of magnitude. The system uses a three dimensional array of segments, with the plane of each segment being oriented at substantially the amplifier medium Brewster angle relative to the incident laser beam and with one or more linear arrays of flashlamps positioned between adjacent rows of amplifier segments, with the plane of the linear array of flashlamps being substantially parallel to the beam propagation direction.

  9. Arbitrary segments of absolute negative mobility

    NASA Astrophysics Data System (ADS)

    Chen, Ruyin; Nie, Linru; Chen, Chongyang; Wang, Chaojie

    2017-01-01

    In previous research work, investigators have reported only one or two segments of absolute negative mobility (ANM) in a periodic potential. In fact, many segments of ANM also occur in the system considered here. We investigate transport of an inertial particle in a gating ratchet periodic potential subjected to a constant bias force. Our numerical results show that its mean velocity can decrease with the bias force increasing, i.e. ANM phenomenon. Furthermore, the ANM can take place arbitrary segments, even up to more than thirty. Intrinsic physical mechanism and conditions for arbitrary segments of ANM to occur are discussed in detail.

  10. Wavelet-based technique for target segmentation

    NASA Astrophysics Data System (ADS)

    Sadjadi, Firooz A.

    1995-07-01

    Segmentation of targets embedded in clutter obtained by IR imaging sensors is one of the challenging problems in automatic target recognition (ATR). In this paper a new texture-based segmentation technique is presented that uses the statistics of 2D wavelet decomposition components of the lcoal sections of the image. A measure of statistical similarity is then used to segment the image and separate the target from the background. This technique is applied on a set of real sequential IR imagery and has shown to produce a high degree of segmentation accuracy across varying ranges.

  11. Segmentation-free ocular detection and recognition

    NASA Astrophysics Data System (ADS)

    Rodriguez, Andres; Panza, Jeffrey; Vijaya Kumar, B. V. K.

    2011-06-01

    Iris recognition is a well-known technique to identify persons. However this technique requires high resolution images in order to automatically segment the iris. In some scenarios obtaining the required resolution may be difficult. In this paper, we investigate the recognition of ocular regions using correlation filters without segmenting the iris region. This method uses the whole eye region and surrounding areas, i.e., the ocular region, for identification. In our experiments we use the recently developed Quadratic Correlation Filter and show that at low resolutions segmentation-free ocular recognition can succeed while iris segmentation fails.

  12. Simultaneous Segmentation and Statistical Label Fusion.

    PubMed

    Asman, Andrew J; Landmana, Bennett A

    2012-02-23

    Labeling or segmentation of structures of interest in medical imaging plays an essential role in both clinical and scientific understanding. Two of the common techniques to obtain these labels are through either fully automated segmentation or through multi-atlas based segmentation and label fusion. Fully automated techniques often result in highly accurate segmentations but lack the robustness to be viable in many cases. On the other hand, label fusion techniques are often extremely robust, but lack the accuracy of automated algorithms for specific classes of problems. Herein, we propose to perform simultaneous automated segmentation and statistical label fusion through the reformulation of a generative model to include a linkage structure that explicitly estimates the complex global relationships between labels and intensities. These relationships are inferred from the atlas labels and intensities and applied to the target using a non-parametric approach. The novelty of this approach lies in the combination of previously exclusive techniques and attempts to combine the accuracy benefits of automated segmentation with the robustness of a multi-atlas based approach. The accuracy benefits of this simultaneous approach are assessed using a multi-label multi- atlas whole-brain segmentation experiment and the segmentation of the highly variable thyroid on computed tomography images. The results demonstrate that this technique has major benefits for certain types of problems and has the potential to provide a paradigm shift in which the lines between statistical label fusion and automated segmentation are dramatically blurred.

  13. Segmentation of the ovine lung in 3D CT Images

    NASA Astrophysics Data System (ADS)

    Shi, Lijun; Hoffman, Eric A.; Reinhardt, Joseph M.

    2004-04-01

    Pulmonary CT images can provide detailed information about the regional structure and function of the respiratory system. Prior to any of these analyses, however, the lungs must be identified in the CT data sets. A popular animal model for understanding lung physiology and pathophysiology is the sheep. In this paper we describe a lung segmentation algorithm for CT images of sheep. The algorithm has two main steps. The first step is lung extraction, which identifies the lung region using a technique based on optimal thresholding and connected components analysis. The second step is lung separation, which separates the left lung from the right lung by identifying the central fissure using an anatomy-based method incorporating dynamic programming and a line filter algorithm. The lung segmentation algorithm has been validated by comparing our automatic method to manual analysis for five pulmonary CT datasets. The RMS error between the computer-defined and manually-traced boundary is 0.96 mm. The segmentation requires approximately 10 minutes for a 512x512x400 dataset on a PC workstation (2.40 GHZ CPU, 2.0 GB RAM), while it takes human observer approximately two hours to accomplish the same task.

  14. Segmentation and object-oriented classification of wetlands in a karst Florida landscape using multi-season Landsat-7 ETM+ Imagery

    EPA Science Inventory

    Segmentation and object-oriented processing of single-season and multi-season Landsat-7 ETM+ data was utilized for the classification of wetlands in a 1560 km2 study area of north central Florida. This segmentation and object-oriented classification outperformed the traditional ...

  15. Segmentation and object-oriented classification of wetlands in a karst Florida landscape using multi-season Landsat-7 ETM+ Imagery

    EPA Science Inventory

    Segmentation and object-oriented processing of single-season and multi-season Landsat-7 ETM+ data was utilized for the classification of wetlands in a 1560 km2 study area of north central Florida. This segmentation and object-oriented classification outperformed the traditional ...

  16. Evaluation of Segmentation of the Superficial and Deep Vascular Layers of the Retina by Optical Coherence Tomography Angiography Instruments in Normal Eyes.

    PubMed

    Spaide, Richard F; Curcio, Christine A

    2017-03-01

    Correct attribution of vascular features in optical coherence tomography (OCT) angiography depends on accurate segmentation of retinal layers. To evaluate the segmentation of retinal layers among 3 OCT angiography instruments in the central macula, an area where the superficial and deep vascular plexuses terminate. A retrospective review of a representative OCT angiogram from 1 patient and an evaluation of the vascular pattern in an autopsied eye were conducted at a community retina practice at a university laboratory. A set of 3 × 3-mm scans centered on the fovea using the Cirrus 5000, RTVue XR Avanti, and Triton DRI OCT platforms with default layer segmentations were used to evaluate segmentation accuracy of a normal macula of a white man in his 60s as an emblematic example. A representative histologic section from the central macula of a normal eye was used as an exemplar. Retinal layer segmentation and resultant vascular image compared with vessels as seen in histologic section. The segmentation slab designed to isolate the superficial vascular plexus included the deep vascular plexus in the central macula for all 3 instruments. None of the instruments produced segmented regions that followed the relevant anatomic layers correctly. Because of inherent errors in segmentation, studies of the superficial and deep vascular plexuses using manufacturer-recommended default settings are likely to be biased. A proposal for an improved segmentation strategy is presented.

  17. Automated area segmentation for ocean bottom surveys

    NASA Astrophysics Data System (ADS)

    Hyland, John C.; Smith, Cheryl M.

    2015-05-01

    In practice, environmental information about an ocean bottom area to be searched using SONAR is often known a priori to some coarse level of resolution. The SONAR search sensor then typically has a different performance characterization function for each environmental classification. Large ocean bottom surveys using search SONAR can pose some difficulties when the environmental conditions vary significantly over the search area because search planning tools cannot adequately segment the area into sub-regions of homogeneous search sensor performance. Such segmentation is critically important to unmanned search vehicles; homogenous bottom segmentation will result in more accurate predictions of search performance and area coverage rate. The Naval Surface Warfare Center, Panama City Division (NSWC PCD) has developed an automated area segmentation algorithm that subdivides the mission area under the constraint that the variation of the search sensor's performance within each sub-mission area cannot exceed a specified threshold, thereby creating sub-regions of homogeneous sensor performance. The algorithm also calculates a new, composite sensor performance function for each sub-mission area. The technique accounts for practical constraints such as enforcing a minimum sub-mission area size and requiring sub-mission areas to be rectangular. Segmentation occurs both across the rows and down the columns of the mission area. Ideally, mission planning should consider both segmentation directions and choose the one with the more favorable result. The Automated Area Segmentation Algorithm was tested using two a priori bottom segmentations: rectangular and triangular; and two search sensor configurations: a set of three bi-modal curves and a set of three uni-modal curves. For each of these four scenarios, the Automated Area Segmentation Algorithm automatically partitioned the mission area across rows and down columns to create regions with homogeneous sensor performance. The

  18. Developmental control of segment numbers in vertebrates

    PubMed Central

    Gomez, Céline; Pourquié, Olivier

    2011-01-01

    Segmentation or metamery in vertebrates is best illustrated by the repetition of the vertebrae and ribs, their associated skeletal muscles and blood vessels, and the spinal nerves and ganglia. The segment number varies tremendously among the different vertebrate species, ranging from as few as six vertebrae in some frogs to as many as several hundred in some snakes and fish. In vertebrates, metameric segments or somites form sequentially during body axis formation. This results in the embryonic axis becoming entirely segmented into metameric units from the level of the otic vesicle almost to the very tip of the tail. The total segment number mostly depends on two parameters: (1) the control of the posterior growth of the body axis during somitogenesis—more same-size segments can be formed in a longer axis and (2) segment size—more smaller-size segments can be formed in a same-size body axis. During evolution, independent variations of these parameters could explain the huge diversity in segment numbers observed among vertebrate species. These variations in segment numbers are accompanied by diversity in the regionalization of the vertebral column. For example, amniotes can exhibit up to five different types of vertebrae: cervical, thoracic, lumbar, sacral and caudal, the number of which varies according to the species. This regionalization of the vertebral column is controlled by the Hox family of transcription factors. We propose that during development, dissociation of the Hox- and segmentation-clock-dependent vertebral patterning systems explains the enormous diversity of vertebral formulae observed in vertebrates. PMID:19621429

  19. Short Segment versus Long Segment Pedicle Screws Fixation in Management of Thoracolumbar Burst Fractures: Meta-Analysis

    PubMed Central

    2017-01-01

    Posterior pedicle screw fixation has become a popular method for treating thoracolumbar burst fractures. However, it remains unclear whether additional fixation of more segments could improve clinical and radiological outcomes. This meta-analysis was performed to evaluate the effectiveness of fixation levels with pedicle screw fixation for thoracolumbar burst fractures. MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Springer, and Google Scholar were searched for relevant randomized and quasirandomized controlled trials that compared the clinical and radiological efficacy of short versus long segment for thoracolumbar burst fractures managed by posterior pedicle screw fixation. Risk of bias in included studies was assessed using the Cochrane Risk of Bias tool. Based on predefined inclusion criteria, Nine eligible trials with a total of 365 patients were included in this meta-analysis. Results were expressed as risk difference for dichotomous outcomes and standard mean difference for continuous outcomes with 95% confidence interval. Baseline characteristics were similar between the short and long segment fixation groups. No significant difference was identified between the two groups regarding radiological outcome, functional outcome, neurologic improvement, and implant failure rate. The results of this meta-analysis suggested that extension of fixation was not necessary when thoracolumbar burst fracture was treated by posterior pedicle screw fixation. More randomized controlled trials with high quality are still needed in the future. PMID:28243383

  20. Automatic segmentation of seven retinal layers in SDOCT images congruent with expert manual segmentation.

    PubMed

    Chiu, Stephanie J; Li, Xiao T; Nicholas, Peter; Toth, Cynthia A; Izatt, Joseph A; Farsiu, Sina

    2010-08-30

    Segmentation of anatomical and pathological structures in ophthalmic images is crucial for the diagnosis and study of ocular diseases. However, manual segmentation is often a time-consuming and subjective process. This paper presents an automatic approach for segmenting retinal layers in Spectral Domain Optical Coherence Tomography images using graph theory and dynamic programming. Results show that this method accurately segments eight retinal layer boundaries in normal adult eyes more closely to an expert grader as compared to a second expert grader.

  1. Evaluation of anterior segment parameters during and after pregnancy.

    PubMed

    Ataş, Mustafa; Duru, Necati; Ulusoy, Döndü Melek; Altınkaynak, Hasan; Duru, Zeynep; Açmaz, Gökhan; Ataş, Fatma Kaya; Zararsız, Gökmen

    2014-12-01

    To compare the anterior segment parameters during pregnancy and post-pregnancy. Fifty-four healthy pregnant women in their third trimester with ages ranging from 18 to 38 years were included in the study. All of the patients underwent comprehensive ophthalmologic examinations, including refraction, anterior segment, and fundus examinations, intraocular pressure, and axial length measurements. In addition, anterior chamber angle, anterior chamber depth, anterior chamber volume, corneal volume, central corneal thickness, and keratometry values were measured by Pentacam Scheimpflug camera. All measurements were measured again 3 months after delivery. The mean intraocular pressure, anterior chamber angle, anterior chamber depth, anterior chamber volume, corneal volume, central corneal thickness, and keratometry measurements were significantly different during pregnancy and post-pregnancy (p<0.05 for all); however, the mean spherical refraction, cylindrical refraction, and axial length were not statistically significantly different during pregnancy and post-pregnancy (p>0.05 for all). We found that there is an increase in the anterior chamber parameters, corneal volume, corneal thickness, and corneal curvature and a decrease in intraocular pressure in the third trimester. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  2. Segmentation of the Andean margin by isostatic models and gradients

    NASA Astrophysics Data System (ADS)

    Schaller, T.; Andersen, J.; Götze, H.-J.; Koproch, N.; Schmidt, S.; Sobiesiak, M.; Splettstößer, S.

    2015-04-01

    The gravity gradients of the South American continental margin are the highest on Earth. These gradients are proxies for the strong horizontal stresses due to the convergent movement of the Nazca plate and the overriding South American plate. The frequently occurring large earthquakes in this zone suggest a correlation of gravity anomalies and seismogenic structures which is the major target of our research. Numerical analyses of the Central Andean gravity field were conducted using different techniques such as isostatic calculations, inversion and edge detection while varying the key parameters of the respective methods. Also, a constrained 3D density model was built through forward modelling of the terrestrial Bouguer anomaly. The results point out that a Vening-Meinesz model with a rigidity of 1023 Nm fits optimally the isostatic behaviour of the Central Andes. For numerical inversion the following parameters provided best results: density contrasts between 430-500 kg/m3, compensation depths of 30-40 km and a 400/300-km-wavelength filter. Moho depths obtained from the different methods agree reasonably well in the continental and oceanic area but defer the most in the transition zone between the two. In this coastal area, north-south segmentation of the residual fields is evident. The respective gravity defined segments correspond well with the extent of large earthquake rupture planes in the southern part of the investigation area. We propose that this segmentation is reflected by changing thicknesses of high density crustal bodies modelled in the 3D density model. These old batholiths fit extremely well to high-velocity domains from seismic tomography. Further seismic asperity structures also display a good correlation with different features of the residual fields.

  3. GeoSegmenter: A statistically learned Chinese word segmenter for the geoscience domain

    NASA Astrophysics Data System (ADS)

    Huang, Lan; Du, Youfu; Chen, Gongyang

    2015-03-01

    Unlike English, the Chinese language has no space between words. Segmenting texts into words, known as the Chinese word segmentation (CWS) problem, thus becomes a fundamental issue for processing Chinese documents and the first step in many text mining applications, including information retrieval, machine translation and knowledge acquisition. However, for the geoscience subject domain, the CWS problem remains unsolved. Although a generic segmenter can be applied to process geoscience documents, they lack the domain specific knowledge and consequently their segmentation accuracy drops dramatically. This motivated us to develop a segmenter specifically for the geoscience subject domain: the GeoSegmenter. We first proposed a generic two-step framework for domain specific CWS. Following this framework, we built GeoSegmenter using conditional random fields, a principled statistical framework for sequence learning. Specifically, GeoSegmenter first identifies general terms by using a generic baseline segmenter. Then it recognises geoscience terms by learning and applying a model that can transform the initial segmentation into the goal segmentation. Empirical experimental results on geoscience documents and benchmark datasets showed that GeoSegmenter could effectively recognise both geoscience terms and general terms.

  4. Blastoderm segmentation in Oncopeltus fasciatus and the evolution of insect segmentation mechanisms.

    PubMed

    Stahi, Reut; Chipman, Ariel D

    2016-10-12

    Segments are formed simultaneously in the blastoderm of the fly Drosophila melanogaster through a hierarchical cascade of interacting transcription factors. Conversely, in many insects and in all non-insect arthropods most segments are formed sequentially from the posterior. We have looked at segmentation in the milkweed bug Oncopeltus fasciatus. Posterior segments are formed sequentially, through what is probably the ancestral arthropod mechanism. Formation of anterior segments bears many similarities to the Drosophila segmentation mode. These segments appear nearly simultaneously in the blastoderm, via a segmentation cascade that involves orthologues of Drosophila gap genes working through a functionally similar mechanism. We suggest that simultaneous blastoderm segmentation evolved at or close to the origin of holometabolous insects, and formed the basis for the evolution of the segmentation mode seen in Drosophila We discuss the changes in segmentation mechanisms throughout insect evolution, and suggest that the appearance of simultaneous segmentation as a novel feature of holometabolous insects may have contributed to the phenomenal success of this group.

  5. Blastoderm segmentation in Oncopeltus fasciatus and the evolution of insect segmentation mechanisms

    PubMed Central

    Stahi, Reut

    2016-01-01

    Segments are formed simultaneously in the blastoderm of the fly Drosophila melanogaster through a hierarchical cascade of interacting transcription factors. Conversely, in many insects and in all non-insect arthropods most segments are formed sequentially from the posterior. We have looked at segmentation in the milkweed bug Oncopeltus fasciatus. Posterior segments are formed sequentially, through what is probably the ancestral arthropod mechanism. Formation of anterior segments bears many similarities to the Drosophila segmentation mode. These segments appear nearly simultaneously in the blastoderm, via a segmentation cascade that involves orthologues of Drosophila gap genes working through a functionally similar mechanism. We suggest that simultaneous blastoderm segmentation evolved at or close to the origin of holometabolous insects, and formed the basis for the evolution of the segmentation mode seen in Drosophila. We discuss the changes in segmentation mechanisms throughout insect evolution, and suggest that the appearance of simultaneous segmentation as a novel feature of holometabolous insects may have contributed to the phenomenal success of this group. PMID:27708151

  6. Development and evolution of segmentation assessed by geometric morphometrics: The centipede Strigamia maritima as a case study.

    PubMed

    Savriama, Yoland; Gerber, Sylvain; Baiocco, Matteo; Debat, Vincent; Fusco, Giuseppe

    2017-03-21

    Using the centipede model species Strigamia maritima as a subject of study, we illustrate the potential of geometric morphometrics for investigating the development and evolution of segmentation, with a specific focus on post-embryonic segmental patterning. We show how these techniques can contribute detailed descriptive data for comparative purposes, but also precious information on some features of the developmental system that are considered relevant for the evolvability of a segmented body architecture, such as developmental stability and canalization. Morphometric analyses allow to separately investigate several sources of phenotypic variation along a segmented body axis, like constitutive and random segment heteronomy, both within and among individuals. Specifically, in S. maritima, the segmental pattern of ventral sclerite shapes mirrors that of their bilateral fluctuating asymmetry and among-individual variation in associating the most anterior and most posterior segments in diverging from the central ones. Also, among segments, there seems to be a correlation between fluctuating asymmetry and shape variation among individuals, suggesting that canalization and developmental stability are somehow associated. Overall, these associations might stem from a joint influence of the segmental position on the two processes of developmental buffering.

  7. Boundary overlap for medical image segmentation evaluation

    NASA Astrophysics Data System (ADS)

    Yeghiazaryan, Varduhi; Voiculescu, Irina

    2017-03-01

    All medical image segmentation algorithms need to be validated and compared, and yet no evaluation framework is widely accepted within the imaging community. Collections of segmentation results often need to be compared and ranked by their effectiveness. Evaluation measures which are popular in the literature are based on region overlap or boundary distance. None of these are consistent in the way they rank segmentation results: they tend to be sensitive to one or another type of segmentation error (size, location, shape) but no single measure covers all error types. We introduce a new family of measures, with hybrid characteristics. These measures quantify similarity/difference of segmented regions by considering their overlap around the region boundaries. This family is more sensitive than other measures in the literature to combinations of segmentation error types. We compare measure performance on collections of segmentation results sourced from carefully compiled 2D synthetic data, and also on 3D medical image volumes. We show that our new measure: (1) penalises errors successfully, especially those around region boundaries; (2) gives a low similarity score when existing measures disagree, thus avoiding overly inflated scores; and (3) scores segmentation results over a wider range of values. We consider a representative measure from this family and the effect of its only free parameter on error sensitivity, typical value range, and running time.

  8. Infants Segment Continuous Events Using Transitional Probabilities

    ERIC Educational Resources Information Center

    Stahl, Aimee E.; Romberg, Alexa R.; Roseberry, Sarah; Golinkoff, Roberta Michnick; Hirsh-Pasek, Kathryn

    2014-01-01

    Throughout their 1st year, infants adeptly detect statistical structure in their environment. However, little is known about whether statistical learning is a primary mechanism for event segmentation. This study directly tests whether statistical learning alone is sufficient to segment continuous events. Twenty-eight 7- to 9-month-old infants…

  9. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An...

  10. Unsupervised Retinal Vessel Segmentation Using Combined Filters

    PubMed Central

    Oliveira, Wendeson S.; Teixeira, Joyce Vitor; Ren, Tsang Ing; Cavalcanti, George D. C.; Sijbers, Jan

    2016-01-01

    Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels’ appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi’s filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods. PMID:26919587

  11. Program Structure Combines Segmentation and Dynamic Storage

    NASA Technical Reports Server (NTRS)

    Tiffany, S. H.

    1982-01-01

    Programing techniques incorporate advantages of overlaying into segmented loads while retaining all dynamic load advantages of segmentation, employing those capabilities that best suit mode of operation, whether batch or interactive. User is allowed to load a program automatically in a variable manner, based solely on a single data input to the program, to maintain minimal field lengths for interactive use.

  12. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An entity...

  13. Automatic evaluation of uterine cervix segmentations

    NASA Astrophysics Data System (ADS)

    Lotenberg, Shelly; Gordon, Shiri; Long, Rodney; Antani, Sameer; Jeronimo, Jose; Greenspan, Hayit

    2007-03-01

    In this work we focus on the generation of reliable ground truth data for a large medical repository of digital cervicographic images (cervigrams) collected by the National Cancer Institute (NCI). This work is part of an ongoing effort conducted by NCI together with the National Library of Medicine (NLM) at the National Institutes of Health (NIH) to develop a web-based database of the digitized cervix images in order to study the evolution of lesions related to cervical cancer. As part of this effort, NCI has gathered twenty experts to manually segment a set of 933 cervigrams into regions of medical and anatomical interest. This process yields a set of images with multi-expert segmentations. The objectives of the current work are: 1) generate multi-expert ground truth and assess the diffculty of segmenting an image, 2) analyze observer variability in the multi-expert data, and 3) utilize the multi-expert ground truth to evaluate automatic segmentation algorithms. The work is based on STAPLE (Simultaneous Truth and Performance Level Estimation), which is a well known method to generate ground truth segmentation maps from multiple experts' observations. We have analyzed both intra- and inter-expert variability within the segmentation data. We propose novel measures of "segmentation complexity" by which we can automatically identify cervigrams that were found difficult to segment by the experts, based on their inter-observer variability. Finally, the results are used to assess our own automated algorithm for cervix boundary detection.

  14. Benefit segmentation of the fitness market.

    PubMed

    Brown, J D

    1992-01-01

    While considerate attention is being paid to the fitness and wellness needs of people by healthcare and related marketing organizations, little research attention has been directed to identifying the market segments for fitness based upon consumers' perceived benefits of fitness. This article describes three distinct segments of fitness consumers comprising an estimated 50 percent of households. Implications for marketing strategies are also presented.

  15. Segmenting Michigan tourists based on distance traveled

    Treesearch

    Xiamei Xu; Tsao-Fang Yuan; Edwin Gomez; Joseph D. Fridgen

    1998-01-01

    The purpose of this study was to segment Michigan travelers into short, medium and long distance traveler groups by distance that they traveled from home to a primary destination in Michigan, and to compare travel behavior, trip characteristics and sociodemographics among these segments. Significant differences were identified in past trip experiences in Michigan,...

  16. Manifold Warp Segmentation of Human Action.

    PubMed

    Liu, Shenglan; Feng, Lin; Liu, Yang; Qiao, Hong; Wu, Jun; Wang, Wei

    2017-03-08

    Human action segmentation is important for human action analysis, which is a highly active research area. Most segmentation methods are based on clustering or numerical descriptors, which are only related to data, and consider no relationship between the data and physical characteristics of human actions. Physical characteristics of human motions are those that can be directly perceived by human beings, such as speed, acceleration, continuity, and so on, which are quite helpful in detecting human motion segment points. We propose a new physical-based descriptor of human action by curvature sequence warp space alignment (CSWSA) approach for sequence segmentation in this paper. Furthermore, time series-warp metric curvature segmentation method is constructed by the proposed descriptor and CSWSA. In our segmentation method, descriptor can express the changes of human actions, and CSWSA is an auxiliary method to give suggestions for segmentation. The experimental results show that our segmentation method is effective in both CMU human motion and video-based data sets.

  17. Segmental lichen planus pigmentosus: An unusual presentation.

    PubMed

    Kumar, Y Hari Kishan; Babu, Anagha Ramesh

    2014-04-01

    Lichen planus pigmentosus (LPP) is a distinct clinical entity commonly encountered in the Indian population. It is considered a variant of lichen planus (LP). A 40-year-old male presented with asymptomatic hyperpigmented macules in a segmental distribution since 10 years that were clinically and histopathologically suggestive of LPP. We propose the terminology "segmental lichen planus pigmentosus" and report this unusual presentation.

  18. Design of ground segments for small satellites

    NASA Technical Reports Server (NTRS)

    Mace, Guy

    1994-01-01

    New concepts must be implemented when designing a Ground Segment (GS) for small satellites to conform to their specific mission characteristics: low cost, one main instrument, spacecraft autonomy, optimized mission return, etc. This paper presents the key cost drivers of such ground segments, the main design features, and the comparison of various design options that can meet the user requirements.

  19. Effects of Syntactic Expectations on Speech Segmentation

    ERIC Educational Resources Information Center

    Mattys, Sven L.; Melhorn, James F.; White, Laurence

    2007-01-01

    Although the effect of acoustic cues on speech segmentation has been extensively investigated, the role of higher order information (e.g., syntax) has received less attention. Here, the authors examined whether syntactic expectations based on subject-verb agreement have an effect on segmentation and whether they do so despite conflicting acoustic…

  20. Effects of Syntactic Expectations on Speech Segmentation

    ERIC Educational Resources Information Center

    Mattys, Sven L.; Melhorn, James F.; White, Laurence

    2007-01-01

    Although the effect of acoustic cues on speech segmentation has been extensively investigated, the role of higher order information (e.g., syntax) has received less attention. Here, the authors examined whether syntactic expectations based on subject-verb agreement have an effect on segmentation and whether they do so despite conflicting acoustic…

  1. Segmenting the senior health care market.

    PubMed

    Pak, S; Pol, L G

    1996-01-01

    This paper addresses the issue of health market segment comparisons for the senior population. The analysis demonstrates how initial self-assessed health comparisons among three racial/ethnic categories can be adjusted to reflect compositional (age and income) differences among the three groups. The adjustments provide additional insight into the nature of these segments.

  2. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An...

  3. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An...

  4. Spinal cord grey matter segmentation challenge.

    PubMed

    Prados, Ferran; Ashburner, John; Blaiotta, Claudia; Brosch, Tom; Carballido-Gamio, Julio; Cardoso, Manuel Jorge; Conrad, Benjamin N; Datta, Esha; Dávid, Gergely; Leener, Benjamin De; Dupont, Sara M; Freund, Patrick; Wheeler-Kingshott, Claudia A M Gandini; Grussu, Francesco; Henry, Roland; Landman, Bennett A; Ljungberg, Emil; Lyttle, Bailey; Ourselin, Sebastien; Papinutto, Nico; Saporito, Salvatore; Schlaeger, Regina; Smith, Seth A; Summers, Paul; Tam, Roger; Yiannakas, Marios C; Zhu, Alyssa; Cohen-Adad, Julien

    2017-03-07

    An important image processing step in spinal cord magnetic resonance imaging is the ability to reliably and accurately segment grey and white matter for tissue specific analysis. There are several semi- or fully-automated segmentation methods for cervical cord cross-sectional area measurement with an excellent performance close or equal to the manual segmentation. However, grey matter segmentation is still challenging due to small cross-sectional size and shape, and active research is being conducted by several groups around the world in this field. Therefore a grey matter spinal cord segmentation challenge was organised to test different capabilities of various methods using the same multi-centre and multi-vendor dataset acquired with distinct 3D gradient-echo sequences. This challenge aimed to characterize the state-of-the-art in the field as well as identifying new opportunities for future improvements. Six different spinal cord grey matter segmentation methods developed independently by various research groups across the world and their performance were compared to manual segmentation outcomes, the present gold-standard. All algorithms provided good overall results for detecting the grey matter butterfly, albeit with variable performance in certain quality-of-segmentation metrics. The data have been made publicly available and the challenge web site remains open to new submissions. No modifications were introduced to any of the presented methods as a result of this challenge for the purposes of this publication.

  5. Algorithmic evaluation of lower jawbone segmentations

    NASA Astrophysics Data System (ADS)

    Egger, Jan; Hochegger, Kerstin; Gall, Markus; Chen, Xiaojun; Reinbacher, Knut; Schwenzer-Zimmerer, Katja; Schmalstieg, Dieter; Wallner, Jürgen

    2017-03-01

    The lower jawbone (or mandible), is due to its exposure to complex biomechanical forces the largest and strongest facial bone in humans. In this publication, an algorithmic evaluation of lower jawbone segmentation with a cellular automata algorithm called GrowCut is presented. For an evaluation, the algorithmic segmentation results were compared with slice-by-slice segmentations from two specialized physicians, which is considered to assess the given ground truth. As a result, pure manual slice-by-slice outlining took on average 39 minutes (minimum 35 minutes and maximum 46 minutes). This stands in strong contrast to an algorithmic segmentation which needed only about one minute for an initialization, hence needing just a fraction of the manual contouring time. At the same time, the algorithmic segmentations could achieve an acceptable Dice Similarity Score (DSC) of nearly ninety percent when compared to the ground truth slice-by-slice segmentations generated by the physicians. This stands in direct comparison to somewhat above ninety percent Dice Score between the two manual segmentations of the jawbones. In summary, this contribution shows that an algorithmic GrowCut segmentation can be an alternative to the very time consuming manual slice-by-slice outlining in the clinical practice.

  6. 47 CFR 101.1505 - Segmentation plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An...

  7. Contour-Driven Atlas-Based Segmentation

    PubMed Central

    Wachinger, Christian; Fritscher, Karl; Sharp, Greg; Golland, Polina

    2016-01-01

    We propose new methods for automatic segmentation of images based on an atlas of manually labeled scans and contours in the image. First, we introduce a Bayesian framework for creating initial label maps from manually annotated training images. Within this framework, we model various registration- and patch-based segmentation techniques by changing the deformation field prior. Second, we perform contour-driven regression on the created label maps to refine the segmentation. Image contours and image parcellations give rise to non-stationary kernel functions that model the relationship between image locations. Setting the kernel to the covariance function in a Gaussian process establishes a distribution over label maps supported by image structures. Maximum a posteriori estimation of the distribution over label maps conditioned on the outcome of the atlas-based segmentation yields the refined segmentation. We evaluate the segmentation in two clinical applications: the segmentation of parotid glands in head and neck CT scans and the segmentation of the left atrium in cardiac MR angiography images. PMID:26068202

  8. Infants Segment Continuous Events Using Transitional Probabilities

    ERIC Educational Resources Information Center

    Stahl, Aimee E.; Romberg, Alexa R.; Roseberry, Sarah; Golinkoff, Roberta Michnick; Hirsh-Pasek, Kathryn

    2014-01-01

    Throughout their 1st year, infants adeptly detect statistical structure in their environment. However, little is known about whether statistical learning is a primary mechanism for event segmentation. This study directly tests whether statistical learning alone is sufficient to segment continuous events. Twenty-eight 7- to 9-month-old infants…

  9. Feature-driven model-based segmentation

    NASA Astrophysics Data System (ADS)

    Qazi, Arish A.; Kim, John; Jaffray, David A.; Pekar, Vladimir

    2011-03-01

    The accurate delineation of anatomical structures is required in many medical image analysis applications. One example is radiation therapy planning (RTP), where traditional manual delineation is tedious, labor intensive, and can require hours of clinician's valuable time. Majority of automated segmentation methods in RTP belong to either model-based or atlas-based approaches. One substantial limitation of model-based segmentation is that its accuracy may be restricted by the uncertainties in image content, specifically when segmenting low-contrast anatomical structures, e.g. soft tissue organs in computed tomography images. In this paper, we introduce a non-parametric feature enhancement filter which replaces raw intensity image data by a high level probabilistic map which guides the deformable model to reliably segment low-contrast regions. The method is evaluated by segmenting the submandibular and parotid glands in the head and neck region and comparing the results to manual segmentations in terms of the volume overlap. Quantitative results show that we are in overall good agreement with expert segmentations, achieving volume overlap of up to 80%. Qualitatively, we demonstrate that we are able to segment low-contrast regions, which otherwise are difficult to delineate with deformable models relying on distinct object boundaries from the original image data.

  10. Labor Market Segmentation and Librarian Salaries.

    ERIC Educational Resources Information Center

    Van House, Nancy A.

    1987-01-01

    Segmented labor market theory is used to explain how the structure of the library labor market may determine salary differences by type of library. Evidence that segmentation exists at intraoccupational levels and the possibility that comparing entire occupations may obscure results are also reported. (Author/CLB)

  11. Webpage Segments Classification with Incremental Knowledge Acquisition

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Kim, Yang Sok; Kang, Byeong Ho

    This paper suggests an incremental information extraction method for social network analysis of web publications. For this purpose, we employed an incremental knowledge acquisition method, called MCRDR (Multiple Classification Ripple-Down Rules), to classify web page segments. Our experimental results show that our MCRDR-based web page segments classification system successfully supports easy acquisition and maintenance of information extraction rules.

  12. ESL batteries and multi-segment applications

    NASA Astrophysics Data System (ADS)

    Hay, J. L.; Pearce, J. G.; Turnbull, L.; Owen, J. R.

    1987-06-01

    A simulation model for nickel cadmium battery cells operating in the environment of a low Earth orbit satellite; simulation applications to investigate the performance of the ESA Simulation Language (ESL) segment or multiprocessor emulation features; a double-precision version of ESL; and development of ESL in equation sorting, segmentation, character handling, and file input/output are described.

  13. Unsupervised Retinal Vessel Segmentation Using Combined Filters.

    PubMed

    Oliveira, Wendeson S; Teixeira, Joyce Vitor; Ren, Tsang Ing; Cavalcanti, George D C; Sijbers, Jan

    2016-01-01

    Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels' appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi's filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods.

  14. Ocular neovascularization associated with central and hemicentral retinal vein occlusion.

    PubMed

    Hayreh, Sohan Singh; Zimmerman, M Bridget

    2012-09-01

    To investigate the incidence of ocular neovascularization (NV) in central and hemicentral retinal vein occlusion. The study comprised consecutive 912 (673 nonischemic and 239 ischemic) central retinal vein occlusion and 190 (147 nonischemic, 43 ischemic) hemicentral retinal vein occlusion eyes. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography. In ischemic central retinal vein occlusion, within 6 months from time of onset, the cumulative probability of development of iris NV was 49%, angle NV 37%, NV glaucoma 29%, retinal NV 9%, and disk NV 6%. More severe peripheral retinal hemorrhages were significantly associated with iris NV (P = 0.005), angle NV (P = 0.0004), and NV glaucoma (P = 0.012). Eyes that developed disk NV had more cotton wool spots (P = 0.058) than those without. In ischemic hemicentral retinal vein occlusion, within 12 months of onset, the cumulative probability of development of retinal NV was 29%, disk NV 12%, and iris NV 12%; within 6 months of onset, angle NV was found in 10% and NV glaucoma in 5%. Anterior chamber flare was associated with anterior segment NV and may precede the development of NV. Patients who developed NV were significantly younger, and there was a greater prevalence of NV glaucoma in patients with primary open angle glaucoma. In ischemic central retinal vein occlusion, anterior segment NV is much more common than posterior segment NV, and the cumulative chance of developing anterior segment NV is maximum during the first 6 months. In ischemic hemicentral retinal vein occlusion, posterior segment NV is much more common than anterior segment NV.

  15. Segmentation of organs at risk in CT volumes of head, thorax, abdomen, and pelvis

    NASA Astrophysics Data System (ADS)

    Han, Miaofei; Ma, Jinfeng; Li, Yan; Li, Meiling; Song, Yanli; Li, Qiang

    2015-03-01

    Accurate segmentation of organs at risk (OARs) is a key step in treatment planning system (TPS) of image guided radiation therapy. We are developing three classes of methods to segment 17 organs at risk throughout the whole body, including brain, brain stem, eyes, mandible, temporomandibular joints, parotid glands, spinal cord, lungs, trachea, heart, livers, kidneys, spleen, prostate, rectum, femoral heads, and skin. The three classes of segmentation methods include (1) threshold-based methods for organs of large contrast with adjacent structures such as lungs, trachea, and skin; (2) context-driven Generalized Hough Transform-based methods combined with graph cut algorithm for robust localization and segmentation of liver, kidneys and spleen; and (3) atlas and registration-based methods for segmentation of heart and all organs in CT volumes of head and pelvis. The segmentation accuracy for the seventeen organs was subjectively evaluated by two medical experts in three levels of score: 0, poor (unusable in clinical practice); 1, acceptable (minor revision needed); and 2, good (nearly no revision needed). A database was collected from Ruijin Hospital, Huashan Hospital, and Xuhui Central Hospital in Shanghai, China, including 127 head scans, 203 thoracic scans, 154 abdominal scans, and 73 pelvic scans. The percentages of "good" segmentation results were 97.6%, 92.9%, 81.1%, 87.4%, 85.0%, 78.7%, 94.1%, 91.1%, 81.3%, 86.7%, 82.5%, 86.4%, 79.9%, 72.6%, 68.5%, 93.2%, 96.9% for brain, brain stem, eyes, mandible, temporomandibular joints, parotid glands, spinal cord, lungs, trachea, heart, livers, kidneys, spleen, prostate, rectum, femoral heads, and skin, respectively. Various organs at risk can be reliably segmented from CT scans by use of the three classes of segmentation methods.

  16. Model-based segmentation of the facial nerve and chorda tympani in pediatric CT scans

    NASA Astrophysics Data System (ADS)

    Reda, Fitsum A.; Noble, Jack H.; Rivas, Alejandro; Labadie, Robert F.; Dawant, Benoit M.

    2011-03-01

    In image-guided cochlear implant surgery an electrode array is implanted in the cochlea to treat hearing loss. Access to the cochlea is achieved by drilling from the outer skull to the cochlea through the facial recess, a region bounded by the facial nerve and the chorda tympani. To exploit existing methods for computing automatically safe drilling trajectories, the facial nerve and chorda tympani need to be segmented. The effectiveness of traditional segmentation approaches to achieve this is severely limited because the facial nerve and chorda are small structures (~1 mm and ~0.3 mm in diameter, respectively) and exhibit poor image contrast. We have recently proposed a technique to achieve this task in adult patients, which relies on statistical models of the structures. These models contain intensity and shape information along the central axes of both structures. In this work we use the same method to segment pediatric scans. We show that substantial differences exist between the anatomy of children and the anatomy of adults, which lead to poor segmentation results when an adult model is used to segment a pediatric volume. We have built a new model for pediatric cases and we have applied it to ten scans. A leave-one-out validation experiment was conducted in which manually segmented structures were compared to automatically segmented structures. The maximum segmentation error was 1 mm. This result indicates that accurate segmentation of the facial nerve and chorda in pediatric scans is achievable, thus suggesting that safe drilling trajectories can also be computed automatically.

  17. Protein-segment universe exhibiting transitions at intermediate segment length in conformational subspaces.

    PubMed

    Ikeda, Kazuyoshi; Hirokawa, Takatsugu; Higo, Junichi; Tomii, Kentaro

    2008-08-13

    Many studies have examined rules governing two aspects of protein structures: short segments and proteins' structural domains. Nevertheless, the organization and nature of the conformational space of segments with intermediate length between short segments and domains remain unclear. Conformational spaces of intermediate length segments probably differ from those of short segments. We investigated the identification and characterization of the boundary(s) between peptide-like (short segment) and protein-like (long segment) distributions. We generated ensembles embedded in globular proteins comprising segments 10-50 residues long. We explored the relationships between the conformational distribution of segments and their lengths, and also protein structural classes using principal component analysis based on the intra-segment Calpha-Calpha atomic distances. Our statistical analyses of segment conformations and length revealed critical dual transitions in their conformational distribution with segments derived from all four structural classes. Dual transitions were identified with the intermediate phase between the short segments and domains. Consequently, protein segment universes were categorized. i) Short segments (10-22 residues) showed a distribution with a high frequency of secondary structure clusters. ii) Medium segments (23-26 residues) showed a distribution corresponding to an intermediate state of transitions. iii) Long segments (27-50 residues) showed a distribution converging on one huge cluster containing compact conformations with a smaller radius of gyration. This distribution reflects the protein structures' organization and protein domains' origin. Three major conformational components (radius of gyration, structural symmetry with respect to the N-terminal and C-terminal halves, and single-turn/two-turn structure) well define most of the segment universes. Furthermore, we identified several conformational components that were unique to each

  18. Protein-segment universe exhibiting transitions at intermediate segment length in conformational subspaces

    PubMed Central

    Ikeda, Kazuyoshi; Hirokawa, Takatsugu; Higo, Junichi; Tomii, Kentaro

    2008-01-01

    Background Many studies have examined rules governing two aspects of protein structures: short segments and proteins' structural domains. Nevertheless, the organization and nature of the conformational space of segments with intermediate length between short segments and domains remain unclear. Conformational spaces of intermediate length segments probably differ from those of short segments. We investigated the identification and characterization of the boundary(s) between peptide-like (short segment) and protein-like (long segment) distributions. We generated ensembles embedded in globular proteins comprising segments 10–50 residues long. We explored the relationships between the conformational distribution of segments and their lengths, and also protein structural classes using principal component analysis based on the intra-segment Cα-Cα atomic distances. Results Our statistical analyses of segment conformations and length revealed critical dual transitions in their conformational distribution with segments derived from all four structural classes. Dual transitions were identified with the intermediate phase between the short segments and domains. Consequently, protein segment universes were categorized. i) Short segments (10–22 residues) showed a distribution with a high frequency of secondary structure clusters. ii) Medium segments (23–26 residues) showed a distribution corresponding to an intermediate state of transitions. iii) Long segments (27–50 residues) showed a distribution converging on one huge cluster containing compact conformations with a smaller radius of gyration. This distribution reflects the protein structures' organization and protein domains' origin. Three major conformational components (radius of gyration, structural symmetry with respect to the N-terminal and C-terminal halves, and single-turn/two-turn structure) well define most of the segment universes. Furthermore, we identified several conformational components that were

  19. Gene expression suggests double-segmental and single-segmental patterning mechanisms during posterior segment addition in the beetle Tribolium castaneum.

    PubMed

    Janssen, Ralf

    2014-01-01

    In the model arthropod Drosophila, all segments are patterned simultaneously in the blastoderm. In most other arthropods, however, posterior segments are added sequentially from a posterior segment addition zone. Posterior addition of single segments likely represents the ancestral mode of arthropod segmentation, although in Drosophila, segments are patterned in pairs by the pair-rule genes. It has been shown that in the new model insect, the beetle Tribolium, a segmentation clock operates that apparently patterns all segments in pairs as well. Here, I report on the expression of the segment polarity gene H15/midline in Tribolium. In the anterior embryo, segmental stripes of H15 appear in pairs, but in the posterior of the embryo stripes appear in a single-segmental periodicity. This implies that either two completely different segmentation-mechanisms may act in the germ band of Tribolium, that the segmentation clock changes its periodicity during development, or that the speed in which posterior segments are patterned changes. In any case, the data suggest the presence of another (or modified), yet undiscovered, mechanism of posterior segment addition in one of the best-understood arthropod models. The finding of a hitherto unrecognized segmentation mechanism in Tribolium may have major implications for the understanding of the origin of segmentation mechanisms, including the origin of pair rule patterning. It also calls for (re)-investigation of posterior segment addition in Tribolium and other previously studied arthropod models.

  20. Bench surgical training with lyophilized esophageal segments.

    PubMed

    Sotres-Vega, Avelina; Osorio-Necoechea, María Elba; Salas-Galindo, Gabriela; González-Ramón, Soemi Careli; Guadarrama-Sánchez, Isabel; Villalba-Caloca, Jaime; Santibáñez-Salgado, José Alfredo

    2013-08-01

    To present lyophilized esophageal segments that can be used to learn surgical skills. Four esophagus were harvested from four non-esophagus related research dogs at the moment of euthanasia. Each esophagus was trimmed in 3 cm long segments. They were lyophilized and stored during 30 days. The day programmed for surgical skills practice, they were rehydrated. Sixteen segments have been used. After rehydrating, all the segments kept their normal anatomic shape and structural integrity. One incision was made on every esophageal segment and sutured with running stitches of 3-0 polyglactin 910. There were no complications, such as tissue tears, nor esophageal hardening. The lyophilized esophagus is a high fidelity, practical, reproducible, portable, low-cost bench model. It allows general surgery apprentices to learn how to handle an esophagus, as well as to perfect their surgical and suture abilities before applying them on real patient's esophagus.