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Sample records for bulk crustal shortening

  1. Foreland shortening and crustal balancing in the Andes at 30°S latitude

    Science.gov (United States)

    Allmendinger, R. W.; Figueroa, D.; Synder, D.; Beer, J.; Mpodozis, C.; Isaacks, B. L.

    1990-08-01

    Excellent surface exposures, known Benioff zone geometry, a dynamic morphology, and the availability of industry seismic reflection data all make the Andes at 30°S an excellent transect for investigating crustal-scale balanced sections. 150-170 km of horizontal shortening has occurred in three major belts located between the trench and the foreland. The thin-skinned, east-verging Precordillera of western Argentina accounts for 60-75% of the total shortening and formed mostly since major volcanism ceased at ˜10 Ma. Industry seismic reflection data show that the décollement of the Precordillera belt is located anomalously deep at ˜15 km. The belt is dominated by fault propagation folds and contains several prominent out-of-sequence thrust faults. Seismic stratigraphie analysis shows that Miocene strata in the Iglesia Valley, located between the Precordillera and the crest of the Andes, accumulated in a piggy-back basin. Onlap relations on the western side indicate that the High Cordillera was uplifted as a major fault bend fold over a buried ramp. Thrusting in the two western belts, both in the High Cordillera of Chile, formed during the waning stages of arc volcanism, 11-16 Ma. and account for 25-40% of the shortening. The observed shortening is probably greater than can be accounted for with reasonable crustal thicknesses, indicating the possibility of continental truncation or erosion along the plate margin or an anomalously thick root held down by the nearly flat subducted Nazca Plate. Our preferred crustal geometry puts the ramp between upper and lower crustal deformation west of the high topography, requiring crustal scale tectonic wedging to thicken the crust beneath the crest of the Andes. This non-unique model provides a simple explanation of the first order morphology of the Andes at this latitude.

  2. Bulk arc strain, crustal thickening, magma emplacement, and mass balances in the Mesozoic Sierra Nevada arc

    Science.gov (United States)

    Cao, Wenrong; Paterson, Scott; Saleeby, Jason; Zalunardo, Sean

    2016-03-01

    Quantifying crustal deformation is important for evaluating mass balance, material transfer, and the interplay between tectonism and magmatism in continental arcs. We present a dataset of >650 finite strain analyses compiled from published works and our own studies with associated structural, geochronologic, and geobarometric information in central and southern Sierra Nevada, California, to quantify the arc crust deformation. Our results show that Mesozoic tectonism results in 65% arc-perpendicular bulk crust shortening under a more or less plane strain condition. Mesozoic arc magmatism replaced ∼80% of this actively deforming arc crust with plutons requiring significantly greater crustal thickening. We suggest that by ∼85 Ma, the arc crust thickness was ∼80 km with a 30-km-thick arc root, resulting in a ∼5 km elevation. Most tectonic shortening and magma emplacement must be accommodated by downward displacements of crustal materials into growing crustal roots at the estimated downward transfer rate of 2-13 km/Myr. The downward transfer of crustal materials must occur in active magma channels, or in "escape channels" in between solidified plutons that decrease in size with time and depth resulting in an increase in the intensity of constrictional strain with depth. We argue that both tectonism and magmatism control the thickness of the crust and surface elevation with slight modification by surface erosion. The downward transported crustal materials initially fertilize the MASH zone thus enhancing to the generation of additional magmas. As the crustal root grows it may potentially pinch out and cool the mantle wedge and thus cause reduction of arc magmatism.

  3. Cenozoic crustal shortening and thickening contributions to Andean orogenesis: Preliminary results from structural mapping in the southern Peruvian Andes

    Science.gov (United States)

    Perez, N.; Horton, B. K.

    2012-12-01

    Estimates of Cenozoic crustal shortening and thickening from the southern Peruvian Andes are necessary to address ongoing debates regarding growth of the Andes and Altiplano plateau. However, limited regional studies in southern Peru prevent accurate assessments of the structural contributions to high topography. This study provides new structural mapping along a >200 km transect spanning the northernmost Altiplano to Subandes at 13-15.5°S and fills the gap between existing central Peruvian and northern Bolivian studies. New stratigraphic data, fault relationships and fold orientations are used to create an updated geologic map and provide insights into the style, timing and magnitude of crustal deformation. Preliminary cross sections accompanying these map transects illustrate deformation style and provide first-order estimates of shortening. Further cross section analyses will be balanced and provide estimates of total crustal shortening and associated thickening in southern Peru. The study transect is subdivided into belts according to the age of exposed rocks and style of deformation. From west to east these belts include: Cretaceous strata dominated by tight folds, closely spaced faults and multiple detachments; Permo-Triassic strata dominated by thicker thrust sheets and fault-fold orientations departing from typical Andean trends; and Paleozoic rocks characterized by thick thrust sheets and deformation focused near major faults. The Cretaceous belt is composed of marine limestones and upward coarsening, siltstone to coarse sandstone progradational sequences. Disharmonic and detachment folds in the Cretaceous section demonstrate the importance of interbedded gypsum and mudstone layers. Fault relationships suggest local shortening during the Early Cretaceous. The Permo-Triassic belt is composed of thick Permian carbonates (Copacabana Formation) and interbedded sandstones, conglomerates and volcanics of the Mitu Formation. This study defines the orientation of

  4. Crustal structure of the Bighorn Mountains region: Precambrian influence on Laramide shortening and uplift in north-central Wyoming

    Science.gov (United States)

    Worthington, Lindsay L.; Miller, Kate C.; Erslev, Eric A.; Anderson, Megan L.; Chamberlain, Kevin R.; Sheehan, Anne F.; Yeck, William L.; Harder, Steven H.; Siddoway, Christine S.

    2016-01-01

    The crustal structure of north-central Wyoming records a history of complex lithospheric evolution from Precambrian accretion to Cretaceous-Paleogene Laramide shortening. We present two active source P wave velocity model profiles collected as part of the Bighorn Arch Seismic Experiment in 2010. Analyses of these velocity models and single-fold reflection data, together with potential field modeling of regional gravity and magnetic signals, constrain crustal structure and thickness of the Bighorn region. We image a west dipping reflection boundary and model a sharp magnetic contact east of the Bighorn Arch that together may delineate a previously undetected Precambrian suture zone. Localized patches of a high-velocity, high-density lower crustal layer (the "7.× layer") occur across the study area but are largely absent beneath the Bighorn Arch culmination. Moho topography is relatively smooth with no large-scale offsets, with depths ranging from ~50 to 37 km, and is largely decoupled from Laramide basement topography. These observations suggest that (1) the edge of the Archean Wyoming craton lies just east of the Bighorn Mountains, approximately 300 km west of previous interpretations, and (2) Laramide deformation localized in an area with thin or absent 7.× layer, due to its relatively weak lower crust, leading to detachment faulting. Our findings show that Precambrian tectonics in northern Wyoming may be more complicated than previously determined and subsequent Laramide deformation may have been critically dependent on laterally heterogeneous crustal structure that can be linked to Precambrian origins.

  5. Measurement of terrace deformation and crustal shortening of some renascent fold zones within Kalpin nappe structure

    Institute of Scientific and Technical Information of China (English)

    YANG XiaoPing; RAN YongKang; CHENG JianWu; CHEN LiChun; XU XiWei

    2007-01-01

    The Kalpin nappe structure is a strongest thrust and fold deformation belt in front of the Tianshan Mountains since the Cenozoic time. The tectonic deformation occurred in 5-6 striking Mesozoic-Cenozoic fold zones, and some renascent folds formed on the recent alluvial-proluvial fans in front of the folded mountains. We used the total station to measure gully terraces along the longitudinal topographic profile in the renascent fold zones and collected samples from terrace deposits for age determination. Using the obtained formation time and shortening amount of the deformed terraces, we calculated the shortening rate of 4 renascent folds to be 0.1±0.03 mm/a, 0.12±0.04 mm/a, 0.59±0.18 mm/a, and 0.26±0.08 mm/a, respectively. The formation time of the renascent folds is some later than the major tectonic uplift event of the Qinghai-Tibet Plateau 0.14 Ma ago. It may be the long-distance effect of this tectonic event on the Tianshan piedmont fold belt.

  6. Evidence of miocene crustal shortening in the North Qilian Shan from cenozoic stratigraphy of the Western Hexi Corridor, Gansu Province, China

    NARCIS (Netherlands)

    Bovet, P.M.; Ritts, B.D.; Gehrels, G.; Abbink, A.O.; Darby, B.; Hourigan, J.

    2009-01-01

    New sedimentologic, stratigraphie, and compositional data from the Paleogene-Neogene stratigraphie succession exposed in the northwest Hexi Corridor and within the North Qilian Shan, provide evidence to suggest that crustal shortening in the North Qilian Shan fold-thrust belt initiated during die Mi

  7. Eocene to late Oligocene history of crustal shortening within the Hoh Xil Basin and implications for the uplift history of the northern Tibetan Plateau

    Science.gov (United States)

    Staisch, Lydia M.; Niemi, Nathan A.; Clark, Marin K.; Chang, Hong

    2016-04-01

    The timing and magnitude of deformation across the northern Tibetan Plateau are poorly constrained but feature prominently in geodynamic models of the plateau's evolution. The Fenghuoshan fold and thrust belt, located in the Hoh Xil Basin, provides a valuable record of the Cenozoic deformation history of the northern Tibetan Plateau. Here we integrate fault gouge geochronology, low-temperature thermochronology, geologic mapping, and a balanced cross section to resolve the deformation history of Hoh Xil Basin. Chronologic data suggest that deformation initiated in the mid-Eocene continued until at least 34 Ma and ceased by 27 Ma. The balanced cross section resolves 34 ± 12 km upper crustal shortening (24 ± 9%). We explore whether the observed Cenozoic shortening can account for the modern elevation and lithospheric thickness in the northern Tibetan Plateau. For a range of reasonable preshortening conditions, we conclude that the observed shortening alone cannot achieve modern crustal and mantle lithospheric thicknesses or modern elevation without either the removal of lithospheric mantle, the influx of lower crustal material, or some combination of these processes. Our results, along with previous studies, suggest that crustal shortening propagated into the northern Tibetan Plateau shortly after the onset of the Indo-Asian collision. The small magnitude of shortening and the late Oligocene cessation of deformation in the northern Tibetan Plateau raise questions of how and where the remaining Indo-Asian convergence was accommodated between Eocene to mid-Miocene time, prior to the approximately late Miocene establishment of the deformation patterns observed in the present day.

  8. Estimation of the Crustal Bulk Properties Beneath Mainland Portugal from P-Wave Teleseismic Receiver Functions

    Science.gov (United States)

    Dündar, Süleyman; Dias, Nuno A.; Silveira, Graça; Kind, Rainer; Vinnik, Lev; Matias, Luís; Bianchi, Marcelo

    2016-06-01

    In this work, we present results from teleseismic P-wave receiver functions (PRFs) obtained in Portugal, Western Iberia. A dense seismic station deployment conducted between 2010 and 2012, in the scope of the WILAS project and covering the entire country, allowed the most spatially extensive probing on the bulk crustal seismic properties of Portugal up to date. The application of the H- κ stacking algorithm to the PRFs enabled us to estimate the crustal thickness ( H) and the average crustal ratio of the P- and S-waves velocities V p/ V s ( κ) for the region. Observations of Moho conversions indicate that this interface is relatively smooth with the crustal thickness ranging between 24 and 34 km, with an average of 30 km. The highest V p/ V s values are found on the Mesozoic-Cenozoic crust beneath the western and southern coastal domain of Portugal, whereas the lowest values correspond to Palaeozoic crust underlying the remaining part of the subject area. An average V p/ V s is found to be 1.72, ranging 1.63-1.86 across the study area, indicating a predominantly felsic composition. Overall, we systematically observe a decrease of V p/ V s with increasing crustal thickness. Taken as a whole, our results indicate a clear distinction between the geological zones of the Variscan Iberian Massif in Portugal, the overall shape of the anomalies conditioned by the shape of the Ibero-Armorican Arc, and associated Late Paleozoic suture zones, and the Meso-Cenozoic basin associated with Atlantic rifting stages. Thickened crust (30-34 km) across the studied region may be inherited from continental collision during the Paleozoic Variscan orogeny. An anomalous crustal thinning to around 28 km is observed beneath the central part of the Central Iberian Zone and the eastern part of South Portuguese Zone.

  9. Crustal shortening in the Palmyride Fold Belt, Syria, and implications for movement along the Dead Sea Fault System

    Science.gov (United States)

    Chaimov, Thomas A.; Barazangi, Muawia; Al-Saad, Damen; Sawaf, Tarif; Gebran, Ali

    1990-12-01

    The Palmyride fold belt is a northeast-trending, 400 by 100 km transpressive belt in central Syria embedded in the northern Arabian platform, bounded to the north by the Aleppo plateau and to the south by the Rutbah uplift. Palinspastically restored cross sections from three transects across the Palmyride fold belt demonstrate a minimum NW-SE shortening of about 20% or 20 km across the southwestern segment of the belt, diminishing to 1-2 km in the northeast, close to the Euphrates graben system. The cross sections are based on the 1∶200,000 scale geologic map of Syria and previously unavailable seismic reflection and well data, all provided by the Syrian Petroleum Company. These results differ significantly from those predicted by kinematic models of Middle East plate motions. In western Syria and eastern Lebanon the Palmyrides obliquely intersect (at about 45°) the roughly north-trending Dead Sea transform fault system. The Dead Sea fault system shows well-documented evidence of 105 km of left-lateral displacement since mid-Tertiary time south of its intersection with the Palmyrides, yet only about 25 km of motion has been documented north of that juncture in Lebanon and western Syria. Thus, kinematic models of Middle East plate motions predict 80 km of shortening in Syria, most of which should be accommodated in the Palmyride fold belt. Several possibilities exist to explain the discrepancy between the 80 km of predicted shortening and the only 20 km of shortening measured from restored cross sections. Restored cross sections offer only minimum shortening estimates, so the calculated 20 km may underestimate shortening. Second, evidence of strike-slip displacement recognized in minimum shortening estimates, so the calculated 20 km may underestimate shortening. Second, evidence of strike-slip displacement recognized in the field and reported in the literature, and indicated by new focal mechanism solutions of two recent earthquakes in the Palmyrides, indicates

  10. Tectonic styles and crustal shortening of the Central Andes "Pampean" flat-slab segment in northern Chile (27-29°S)

    Science.gov (United States)

    Martínez, Fernando; Arriagada, César; Peña, Matías; Deckart, Katja; Charrier, Reynaldo

    2016-01-01

    The Andean orogenic belt, located in the Central Andes "Pampean flat-slab" segment in northern Chile (27-29°S), is composed of two major tectonic regions: the Coastal Cordillera and the Frontal Cordillera. To understand their internal tectonic styles, history of growth and the shortening absorbed by the upper crustal structure of this segment, we combined regional geological mapping data, new ages obtained from radiometric U-Pb dating, and a semibalanced and restored cross-section 225.18 km in length. The results as shown in the previous Mesozoic extensional fault systems, established in northern Chile by the Gondwana breakup, have played a fundamental role in the orogenic buildup. The central structure is characterized by an asymmetric basin (Upper Cretaceous-Paleocene) confined by a doubly vergent fault system composed of inverted faults related to the edges of the Mesozoic Chañarcillo and Lautaro Basins. The U-Pb geochronological data obtained from synorogenic volcano-sedimentary deposits and the angular unconformities recorded between the Cenozoic geological units have revealed that the compressive deformation in this segment started at around ~ 80 Ma by tectonic inversion in the eastern Coastal Cordillera and western Frontal Cordillera, however, the presence of Paleocene and Miocene synorogenic successions at the footwall of the basement reverse faults of the Frontal Cordillera suggests a migration of Andean deformation from the west to the east during the Paleocene-Miocene by propagation of ramps involving inherited basement highs. The pre-compression restoration makes it possible to estimate 40.94 km of minimum shortening, concentrated by inversion anticlines and fault-controlled basement highs across the Frontal Cordillera.

  11. Co-seismic ruptures of the 12 May 2008, Ms 8.0 Wenchuan earthquake, Sichuan: East-west crustal shortening on oblique, parallel thrusts along the eastern edge of Tibet

    Science.gov (United States)

    Liu-Zeng, J.; Zhang, Z.; Wen, L.; Tapponnier, P.; Sun, Jielun; Xing, X.; Hu, G.; Xu, Q.; Zeng, L.; Ding, L.; Ji, C.; Hudnut, K.W.; van der Woerd, J.

    2009-01-01

    The Ms 8.0, Wenchuan earthquake, which devastated the mountainous western rim of the Sichuan basin in central China, produced a surface rupture over 200??km-long with oblique thrust/dextral slip and maximum scarp heights of ~ 10??m. It thus ranks as one of the world's largest continental mega-thrust events in the last 150??yrs. Field investigation shows clear surface breaks along two of the main branches of the NE-trending Longmen Shan thrust fault system. The principal rupture, on the NW-dipping Beichuan fault, displays nearly equal amounts of thrust and right-lateral slip. Basin-ward of this rupture, another continuous surface break is observed for over 70??km on the parallel, more shallowly NW-dipping Pengguan fault. Slip on this latter fault was pure thrusting, with a maximum scarp height of ~ 3.5??m. This is one of the very few reported instances of crustal-scale co-seismic slip partitioning on parallel thrusts. This out-of-sequence event, with distributed surface breaks on crustal mega-thrusts, highlights regional, ~ EW-directed, present day crustal shortening oblique to the Longmen Shan margin of Tibet. The long rupture and large offsets with strong horizontal shortening that characterize the Wenchuan earthquake herald a re-evaluation of tectonic models anticipating little or no active shortening of the upper crust along this edge of the plateau, and require a re-assessment of seismic hazard along potentially under-rated active faults across the densely populated western Sichuan basin and mountains. ?? 2009 Elsevier B.V.

  12. Plate convergence, crustal delamination, extrusion tectonics and minimization of shortening work as main controlling factors of the recent Mediterranean deformation pattern

    Directory of Open Access Journals (Sweden)

    D. Babbucci

    1997-06-01

    Full Text Available It is argued that the time-space distribution of major post middle Miocene deformation events in the Central-Eastern Mediterranean region, deduced from the relevant literature, can be coherently explained as a consequence of the convergence between the Africa/Arabia and Eurasia blocks. This plate convergence has mainly been accommodated by the consumption of the thinnest parts of the Northern African (Ionian and Levantine basins and peri-Adriatic margins. During each evolutionary phase the space distribution of trench zones is controlled by the basic physical requirement of minimizing the work of horizontal forces, induced by plate convergence, against the resisting forces, i.e., the cohesion of the upper brittle crustal layer and the buoyancy forces at the consuming boundaries. The significant changes of tectonic styles which determined the transition from one phase to the next, like those which occurred around the Messinian and the late Pliocene-early Pleistocene, were determined by the suture of consuming boundaries. When such an event occurs, the system must activate alternative consuming processes to accommodate the convergence of the major confining blocks. The observed deformations in the study area suggest that this tectonic reorganization mostly developed by the lateral extrusion of crustal wedges away from the sutured borders. This mechanism allowed the translation of maximum horizontal stresses from the locked collisional fronts to the zones where consumable lithosphere was still present, in order to activate the next consuming processes. The extensional episodes which led to the formation of basins and troughs in the Tyrrhenian and Aegean zones are interpreted as secondary effects of the outward escape of crustal wedges, like those which occurred in response to longitudinal compressional regimes in the Apennines and Aegean regions.

  13. Crustal shortening followed by extensional collapse of the Cordilleran orogenic belt in northwestern Montana: Evidence from vintage seismic reflection profiles acquired in the Swan Range and Swan Valley

    Science.gov (United States)

    Rutherford, B. S.; Speece, M. A.; Stickney, M. C.; Mosolf, J. G.

    2013-12-01

    Reprocessing of one 24-fold (96 channel) and four 30-fold (120 channel) 2D seismic reflection profiles have revealed crustal scale reflections in the Swan Range and adjacent Swan River Valley of northwestern Montana. The five reprocessed profiles constitute 142.6 of the 303.3 linear km acquired in 1983-84 by Techo of Denver, Colorado. The four 30-fold profiles used helicopter-assisted dynamite shooting (Poulter method) and the 24-fold profile used the Vibroseis method. Acquisition parameters were state of the art for the time. The Swan Range lies east of the Rocky Mountain Trench and is part of the Cordilleran foreland thrust belt where the Lewis thrust system emplaced a thick slab of Proterozoic Belt Supergroup strata eastward and over Paleozoic and Mesozoic rocks during the Late Cretaceous to early Paleocene Laramide orogeny. Deeply drilled borehole data are absent within the study area; however, we generated a synthetic seismogram from the Arco-Marathon 1 Paul Gibbs well (total depth=5418 m), located approximately 70 km west of the reprocessed profiles, and correlated the well data to surface seismic profiles. Large impedance contrasts in the log data are interpreted to be tholeiitic Moyie sills within the Prichard Formation argillite (Lower Belt), which produce strong reflection events in regional seismic sections and result in highly reflective, east-dipping events in the reprocessed profiles. We estimate a depth of 10 km (3 to 3.5 seconds) to the basal detachment of the Lewis thrust sheet. The décollement lies within Belt Supergroup strata to the west of the Swan River Valley before contacting unreflective, west-dipping crystalline basement beneath the Swan Range--a geometry that results in a wedge of eastward-thinning, autochthonous Belt rocks. Distinct fault-plane signatures from the west-dipping, range-bounding Swan fault--produced by extensional collapse of the over-thickened Cordillera--are not successfully imaged. However, reflections from Cenozoic

  14. On ultrahigh temperature crustal metamorphism:Phase equilibria, trace element thermometry, bulk composition, heat sources, timescales and tectonic settings

    Institute of Scientific and Technical Information of China (English)

    David E. Kelsey; Martin Hand

    2015-01-01

    Ultrahigh temperature (UHT) metamorphism is the most thermally extreme form of regional crustal metamorphism, with temperatures exceeding 900 ?C. UHT crustal metamorphism is recognised in more than 50 localities globally in the metamorphic rock record and is accepted as‘normal’ in the spectrum of regional crustal processes. UHT metamorphism is typically identified on the basis of diagnostic mineral assemblages such as sapphirine þ quartz, orthopyroxene þ sillimanite ? quartz and osumilite in MgeAl-rich rock compositions, now usually coupled with pseudosection-based thermobarometry using internally-consistent thermodynamic data sets and/or Al-in-Orthopyroxene and ternary feldspar ther-mobarometry. Significant progress in the understanding of regional UHT metamorphism in recent years includes: (1) development of a ferric iron activityecomposition thermodynamic model for sapphirine, allowing phase diagram calculations for oxidised rock compositions;(2) quantification of UHT conditions via trace element thermometry, with Zr-in-rutile more commonly recording higher temperatures than Ti-in-zircon. Rutile is likely to be stable at peak UHT conditions whereas zircon may only grow as UHT rocks are cooling. In addition, the extent to which Zr diffuses out of rutile is controlled by chemical communication with zircon; (3) more fully recognising and utilising temperature-dependent thermal properties of the crust, and the possible range of heat sources causing metamorphism in geodynamic modelling studies; (4) recognising that crust partially melted either in a previous event or earlier in a long-duration event has greater capacity than fertile, unmelted crust to achieve UHT conditions due to the heat energy consumed by partial melting reactions;(5) more strongly linking UePb geochronological data from zircon and monazite to PeT points or path segments through using Y þ REE partitioning between accessory and major phases, as well as phase diagrams incorporating Zr and REE

  15. Pristine rocks (8th Foray) - 'Plagiophile' element ratios, crustal genesis, and the bulk composition of the moon

    Science.gov (United States)

    Warren, P. H.; Kallemeyn, G. W.

    1984-01-01

    Eu/Al, Sr/Al, Eu/Sr, and similar ratios among pristine lunar nonmare lithologies with implications for nonmare petrogenesis and for the bulk composition of the moon are examined. On a plot of Eu/Al versus mg, ferroan anorthosites are separated from all other pristine nonmare rocks by a considerable gap. A nonrandom process must be invoked to account for the gap in the spectrum of ratios. A single magma probably cannot account for even the Mg-rich pristine rocks subset, based on diversity of plagiophile ratios among samples with similar mg ratios. Plagiophile ratios also constrain the bulk composition of the moon. Plagiophile ratios among ferroan anorthosites exactly match those expected under a model in which ferroan anorthosites formed by flotation of plagioclase cumulates over a primordial 'magmasphere'. Ratios among nonvolatile elements confirm that the moon formed out of materials akin to chondritic meteorites.

  16. The curve shortening problem

    CERN Document Server

    Chou, Kai-Seng

    2001-01-01

    Although research in curve shortening flow has been very active for nearly 20 years, the results of those efforts have remained scattered throughout the literature. For the first time, The Curve Shortening Problem collects and illuminates those results in a comprehensive, rigorous, and self-contained account of the fundamental results.The authors present a complete treatment of the Gage-Hamilton theorem, a clear, detailed exposition of Grayson''s convexity theorem, a systematic discussion of invariant solutions, applications to the existence of simple closed geodesics on a surface, and a new, almost convexity theorem for the generalized curve shortening problem.Many questions regarding curve shortening remain outstanding. With its careful exposition and complete guide to the literature, The Curve Shortening Problem provides not only an outstanding starting point for graduate students and new investigations, but a superb reference that presents intriguing new results for those already active in the field.

  17. Broadband regional waveform modeling to investigate crustal structure and tectonics of the central Andes

    Science.gov (United States)

    Swenson, Jennifer Lyn

    We use broadband regional waveform modeling of earthquakes in the central Andes to determine seismic properties of the Altiplano crust. Properties of the shear-coupled P-wavetrain (SPL ) from intermediate-depth events provide particularly important information about the structure of the crust. We utilize broadband seismic data recorded at the BANJO and SEDA stations, and synthetic seismograms computed with a reflectivity technique to study the sensitivity of SPL to crustal and upper mantle parameters at regional distances. We find that the long-period SPL-wavetrain is most sensitive to crustal and mantle Poisson's ratios, average crustal velocity, and crustal thickness. A comprehensive grid search method developed to investigate these four parameters suggests that although trade-offs exist between model parameters, models of the Altiplano which provide the best fit between the data and synthetic seismograms are characterized by low Poisson's ratios, low average crustal velocity and thick crust. We apply our grid search technique and sensitivity analysis results to model the full waveforms from 6 intermediate-depth and 2 shallow-focus earthquakes recorded at regional distances by BANJO and SEDA stations. Results suggest that the Altiplano crust is much thicker (55--65 km) and slower (5.75--6.25 km/s) than global average values. Low crustal and mantle Poisson's ratios together with the lack of evidence for a high-velocity lower crust suggests a bulk felsic crustal composition, resulting in an overall weak crust. Our results favor a model of crustal thickening involving large-scale tectonic shortening of a predominantly felsic crust. To better understand the mechanics of earthquake rupture along the South American subduction zone, we have analyzed broadband teleseismic P-waves and utilize single- and multi-station inversion techniques to constrain source characteristics for the 12 November 1996 Peru subduction zone earthquake. Aftershock locations, intensity reports

  18. The Precambrian crustal structure of East Africa

    Science.gov (United States)

    Tugume, Fred Alex

    In this thesis, the Precambrian crustal structure of East African is investigated along with the crustal structures of three Cenozoic rift basins located in the western branch of the East African Rift System (EARS). In the first part of the thesis, P-wave receiver functions are modeled using the H-k method to obtain new insights about the bulk composition and thickness of the crust for Precambrian terrains throughout East Africa. The average crustal thickness for all but one of the terrains is between 37 and 39 km. An exception is the Ubendian terrain, which has an average crustal thickness 42 km. In all terrains, the average Poisson's ratio is similar, ranging from 0.25 to 0.26, indicating a bulk crustal composition that is felsic to intermediate. The main finding of this study is that crustal structure is similar across all terrains, which span more than 4.0 Ga of earth history. There is no discernable difference in the crustal thicknesses and Poisson's ratios between the Archean and Proterozoic terrains, or between the Proterozoic terrains, unlike the variability in Precambrian crustal structure found in many other continents. In the second part of the thesis, a joint inversion of Rayleigh wave phase and group velocities and receiver functions was used to investigate the shear wave velocity structure of the crust and uppermost mantle beneath the Precambrian terrains of East Africa. In comparison with other areas of similar age in southern and western Africa where the same joint inversion method has been applied, I find that while there is little difference in the mean shear wave velocities for the entire crust across all of the Precambrian terrains, and also few differences in the thickness of the crust, there exists substantial variability in lower crustal structure. This variability is reflected primarily in the thickness of the lower crustal layers with shear wave velocities ≥ 4.0 km/s. This variability is found both within terrains of the same age (i

  19. THE CRUSTAL STRUCTURE OF ELLESMERE ISLAND FROM RECEIVER FUNCTION MODELLING

    DEFF Research Database (Denmark)

    Schiffer, Christian; Stephenson, Randell Alexander; Oakey, Gordon

    Atlantic region. The intraplate Eurekan orogeny in the Cenozoic caused additional crustal shortening in the area, related to the opening of Baffin Bay, the North Atlantic and the Arctic Ocean basins and the complex plate tectonic responses to these plate boundary reconfigurations. Geophysically Ellesmere...

  20. The crustal thickness of West Antarctica

    Science.gov (United States)

    Chaput, J.; Aster, R. C.; Huerta, A.; Sun, X.; Lloyd, A.; Wiens, D.; Nyblade, A.; Anandakrishnan, S.; Winberry, J. P.; Wilson, T.

    2014-01-01

    P-to-S receiver functions (PRFs) from the Polar Earth Observing Network (POLENET) GPS and seismic leg of POLENET spanning West Antarctica and the Transantarctic Mountains deployment of seismographic stations provide new estimates of crustal thickness across West Antarctica, including the West Antarctic Rift System (WARS), Marie Byrd Land (MBL) dome, and the Transantarctic Mountains (TAM) margin. We show that complications arising from ice sheet multiples can be effectively managed and further information concerning low-velocity subglacial sediment thickness may be determined, via top-down utilization of synthetic receiver function models. We combine shallow structure constraints with the response of deeper layers using a regularized Markov chain Monte Carlo methodology to constrain bulk crustal properties. Crustal thickness estimates range from 17.0±4 km at Fishtail Point in the western WARS to 45±5 km at Lonewolf Nunataks in the TAM. Symmetric regions of crustal thinning observed in a transect deployment across the West Antarctic Ice Sheet correlate with deep subice basins, consistent with pure shear crustal necking under past localized extension. Subglacial sediment deposit thicknesses generally correlate with trough/dome expectations, with the thickest inferred subice low-velocity sediment estimated as ˜0.4 km within the Bentley Subglacial Trench. Inverted PRFs from this study and other published crustal estimates are combined with ambient noise surface wave constraints to generate a crustal thickness map for West Antarctica south of 75°S. Observations are consistent with isostatic crustal compensation across the central WARS but indicate significant mantle compensation across the TAM, Ellsworth Block, MBL dome, and eastern and western sectors of thinnest WARS crust, consistent with low density and likely dynamic, low-viscosity high-temperature mantle.

  1. Variability in New Shortening Estimates from Southern Peru (12-14S); Implications for Mass Balance of the Andean Plateau.

    Science.gov (United States)

    Gotberg, N.; McQuarrie, N.

    2008-12-01

    One of the fundamental questions of interest with regards to the Andean Plateau is the mass balance of material needed to create and sustain a 3-4 km high plateau. Is crustal shortening sufficient to support an isostatically compensated crust of 60-70km? We present new estimates of shortening across the northern margin of the Andean Plateau. The cross section extent, from the eastern edge of the volcanic arc to foreland basin, is approximately one half of the physiographic width of the Andean Plateau in Peru. Cross sectional shortening estimates in southern Peru (12-14°S) provide a best estimate of 123 km or 40% shortening with an absolute minimum estimate of 86 km or 30% and absolute maximum estimate of 275 km or 60%. We determined the maximum and minimum shortening estimates using the cross sectional area and possible variations in assumptions made about the amount of erosion, detachment dip, involvement of basement thrusts and displacement along faults. The best estimate of shortening is well short of the required 240-300km of shortening needed in order to account for a 60-70km thick crust under the entire plateau. This suggests that for an isostatically equilibrated crust either 1) there is a significant amount of shortening (~150km) in the western half of the plateau which, is hidden by the volcanic arc or 2) crustal material is being added to the Peruvian section of the Andean Plateau either through lower crustal flow or a process of magmatic underplating followed by differentiation and delamination.

  2. Child Abuse May Shorten Some Women's Lives

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160478.html Child Abuse May Shorten Some Women's Lives Extreme stress may ... 300 middle-aged U.S. adults, female survivors of child abuse were more likely to die over the next ...

  3. Femoral neck shortening after internal fixation

    OpenAIRE

    LIU, YUE; AI, Zi Sheng; Shao, Jin; Yang, Tieyi

    2014-01-01

    Objective: The aim of this study was to assess the factors affecting femoral neck shortening after internal fixation of femoral neck fractures. Methods: Eighty-six patients with femoral neck fractures were treated using three parallel cannulated screws between May 2004 and January 2011. The shortening of the femoral neck in the horizontal (X), vertical (Y), and along the resultant along the (Z) vector (XÆ, YÆ, ZÆ) was measured on anteroposterior radiographs corrected by screw diameter and ...

  4. Crustal-thickness variations in the central Andes

    Science.gov (United States)

    Beck, Susan L.; Zandt, George; Myers, Stephen C.; Wallace, Terry C.; Silver, Paul G.; Drake, Lawrence

    1996-05-01

    We estimated the crustal thickness along an east-west transect across the Andes at lat 20°S and along a north-south transect along the eastern edge of the Altiplano from data recorded on two arrays of portable broadband seismic stations (BANJO and SEDA). Waveforms of deep regional events in the downgoing Nazca slab and teleseismic earthquakes were processed to isolate the P-to-S converted phases from the Moho in order to compute the crustal thickness. We found crustal-thickness variations of nearly 40 km across the Andes. Maximum crustal thicknesses of 70 74 km under the Western Cordillera and the Eastern Cordillera thin to 32 38 km 200 km east of the Andes in the Chaco Plain. The central Altiplano at 20°S has crustal thicknesses of 60 to 65 km. The crust also appears to thicken from north (16°S, 55 60 km) to south (20°S, 70 74 km) along the Eastern Cordillera. The Subandean zone crust has intermediate thicknesses of 43 to 47 km. Crustal-thickness predictions for the Andes based on Airy-type isostatic behavior show remarkable overall correlation with observed crustal thickness in the regions of high elevation. In contrast, at the boundary between the Eastern Cordillera and the Subandean zone and in the Chaco Plain, the crust is thinner than predicted, suggesting that the crust in these regions is supported in part by the flexural rigidity of a strong lithosphere. With additional constraints, we conclude that the observation of Airy-type isostasy is consistent with thickening associated with compressional shortening of a weak lithosphere squeezed between the stronger lithosphere of the subducting Nazca plate and the cratonic lithosphere of the Brazilian craton.

  5. Studies on flagellar shortening in Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    Flagellar shortening of Chlamydomonas reinhardtii was promoted by sodium chloride, pyrophosphate (sodium, potassium and ammonium salts), EDTA and EGTA, succinate, citrate and oxalate (sodium salts), caffeine and aminophylline. Removal of calcium from the medium potentiated the effects of these agents in inducing shortening. Investigations of the release of phosphorylated compounds to the medium during pyrophosphate-induced flagellar shortening of cells pre-labelled with 32P, revealed an as yet unidentified 32P-labelled compound with distinct chromatographic properties. Chromatography and electrophoresis indicates that it is a small, highly polar molecule with a high charge to mass ratio, containing thermo- and acid-labile phosphate linkages. Investigations showed of the release of 35S-labelled protein to the medium from cells pre-labelled with 35S-sulfate showed that flagellated cells released two prominent polypeptides which comigrated with α- and β-flagellar tubulin on SDS polyacrylamide gel electrophoresis, while deflagellated cells did not

  6. Surveying of the deformed terraces and crust shortening rate in the northwestern Tarim Basin: Comment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ The paper of Shen et al., entitled "Surveying of the deformed terraces and crust shortening rate in the northwest Tarim Basin", was published in Chinese Science Bulletin (Vol. 46, No. 12)[1]. Shen et al. found the deformation of Late Pleistocene to Holocene terraces of the Boguzi River across the Artushi Anticline in the northwest Tarim Basin close to the Pamir, and made level survey and differential GPS measurement, which is of great importance to geodynamics for research on the coupling of Tianshan Mountains uplifting and Tarim Basin depression. But their understanding to the deformation mechanics of terraces and the calculation methods of crustal shortening are open to discussion. Therefore, we discuss it with Shen Jun et al.

  7. Numerical Simulation of Pulse Shortening in RBWOs

    Institute of Scientific and Technical Information of China (English)

    GONG Yu-bin; ZHANG Zhang; WANG Wen-xiang; MENG Fan-bao; FAN Zhi-kai; HUANG Min-zhi

    2005-01-01

    Pulse shortening hinders improvement of microwave output energy for high power microwave tubes. So far, it is also an unresolved problem in the field of high power microwave devices. In this paper, relativistic backward wave tube (RBWO) is treated as an example to study the pulse shortening phenomena. The influences of gas existing in the tube and explosive emission in inner surface of RBWO are all investigated by means of the particle-in-cell method. Through the simulation results, it can be predicted that the background gas in the tube is one but not the most important factor resulting in pulse shortening, in order to broaden the pulse width of gas-filled RBWO, the pressure of the filled gas must be controlled in a proper value. The explosive emission in the surface of slow wave structure due to intense electric field is one of the most important factors causing pulse shortening in high power microwave tube.Some methods to overcome this find of explosive emission are also given.

  8. 18 CFR 286.105 - Shortened procedure.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Shortened procedure. 286.105 Section 286.105 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... facts and applicable law that support the position or positions taken regarding the matters at...

  9. 9 CFR 319.701 - Mixed fat shortening.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Mixed fat shortening. 319.701 Section... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Fats, Oils, Shortenings § 319.701 Mixed fat shortening. Shortening prepared with a mixture of meat fats and vegetable oils...

  10. On the link between orogenic shortening and back-arc extensional collapse in low topography orogens

    Science.gov (United States)

    Matenco, L. C.

    2012-04-01

    Classical models of orogenic evolution assume that back arc basins form in the hinterland of orogens, collapsing the upper plate above oceanic subduction zones. This is a common characteristic commonly thought to apply to all low-topography orogens of Mediterranean type driven by the fast roll-back of subducted slabs, or other analogues such as the Miocene to recent evolution of the SE Asia subduction zones. This extension may take place far at the interior of the upper plate, as is the case in various segments of the Carpathians or in the core of the SE Asian domain, but in most cases of the Dinarides, Apennines or Hellenides it take place superposed or far into the foreland of oceanic suture zones. Therefore, the term back-arc extension in many cases is misleading, as exhumation along major detachment zones takes place in the core of the orogen (Rif, Betics), in the accreted crustal material of the lower plate (Apennines, Dinarides) or even in a presumed former fore-arc (Aegean, Sunda-Banda arc). In all these subduction zones, collision has largely duplicated crustal blocks from the lower plate and has gradually shifted subduction zone far towards the lower plate. As a result, crustal thickening takes place in the foreland of the orogen, in contrast with the typical crustal roots of the high convergence orogens, such as the Alps or Himalaya. This demonstrate an active shift of the main subduction zone, the position of slabs detected by teleseismic mantle tomography is displaced to the foreland and cannot be connected with the position of the lower plate crust beneath the orogen. This shift is associated with large scale magmatism with unusual large crustal signatures, atypical for subduction related magmas. These observations demonstrate the need for an active reconsideration of existing orogenic models which should include displacements of subduction zones during orogenic shortening and an active investigation of the role of continental subduction and associated

  11. Mechanism of Shortened Bones in Mucopolysaccharidosis VII

    OpenAIRE

    Jason A. Metcalf; Zhang, Yanming(Institute of Theoretical Physics, Henan Normal University, Xinxiang, 453007, China); Matthew J. Hilton; Long, Fanxin; Ponder, Katherine P.

    2009-01-01

    Mucopolysaccharidosis VII (MPS VII) is a lysosomal storage disease in which deficiency in β-glucuronidase results in glycosaminoglycan (GAG) accumulation in and around cells, causing shortened long bones through mechanisms that remain largely unclear. We demonstrate here that MPS VII mice accumulate massive amounts of the GAG chondroitin-4-sulfate (C4S) in their growth plates, the cartilaginous region near the ends of long bones responsible for growth. MPS VII mice also have only 60% of the n...

  12. Crustal response to lithosphere evolution

    DEFF Research Database (Denmark)

    Artemieva, Irina; Thybo, Hans; Cherepanova, Yulia;

    2012-01-01

    We present a new model for the structure of the crust in an area which stretches from the North Atlantic region in the west to the Verkhoyansk Ridge in the east and encompasses Greenland, Iceland, most of Europe, West Siberian basin, and the Siberian cratons. The model is based on critically...... such as lower crust/lithospheric mantle delamination in the Variscan Europe and large-scale rifting across the entire West Siberian basin. The results are summarized in a series of maps of lateral variations in crustal properties, including the depth to the basement and to the Moho, average crustal velocity......, thicknesses of different crustal layers, and Pn seismic velocities....

  13. Bulk undercooling

    Science.gov (United States)

    Kattamis, T. Z.

    1984-01-01

    Bulk undercooling methods and procedures will first be reviewed. Measurement of various parameters which are necessary to understand the solidification mechanism during and after recalescence will be discussed. During recalescence of levitated, glass-encased large droplets (5 to 8 mm diam) high speed temperature sensing devices coupled with a rapid response oscilloscope are now being used at MIT to measure local thermal behavior in hypoeutectic and eutectic binary Ni-Sn alloys. Dendrite tip velocities were measured by various investigators using thermal sensors or high speed cinematography. The confirmation of the validity of solidification models of bulk-undercooled melts is made difficult by the fineness of the final microstructure, the ultra-rapid evolution of the solidifying system which makes measurements very awkward, and the continuous modification of the microstructure which formed during recalescence because of precipitation, remelting and rapid coarsening.

  14. Crustal thickness controlled by plate tectonics

    DEFF Research Database (Denmark)

    Artemieva, Irina M.; Meissner, Rolf

    2012-01-01

    /gabbro–eclogite phase transition in crustal evolution and the links between lithosphere recycling, mafic magmatism, and crustal underplating. We advocate that plate tectonics processes, togetherwith basalt/gabbro–eclogite transition, limit crustal thickness worldwide by providing effective mechanisms of crustal...

  15. Renal failure induces telomere shortening in the rat heart

    NARCIS (Netherlands)

    Wong, L. S.; Windt, W. A.; Roks, A. J.; van Dokkum, R. P.; Schoemaker, R. G.; de Zeeuw, D.; Henning, R. H.

    2009-01-01

    Background. Renal failure aggravates pathological cardiac remodelling induced by myocardial infarction (MI). Cardiac remodelling is associated with telomere shortening, a marker for biological ageing. We investigated whether mild and severe renal failure shorten cardiac telomeres and excessively sho

  16. Receiver functions and crustal structure of the northwestern Andean region, Colombia

    Science.gov (United States)

    Poveda, Esteban; Monsalve, Gaspar; Vargas, Carlos Alberto

    2015-04-01

    We used the receiver function technique to deduce crustal thickness beneath the northwestern Andean system, using data from the permanent seismic network of Colombia, combined with some of the IRIS and CTBTO stations in Colombia and Ecuador. The estimation of crustal thickness was made using the primary P to s conversion and crustal reverberations. The bulk crustal VP/VS ratio was constrained using a crustal thickness versus VP/VS stacking method, in addition to estimations using a time to depth conversion technique based on results of a modified Wadati diagram analysis. We observed a wide range of crustal thicknesses, including values around 17 km beneath the Malpelo Island on the Pacific Ocean, 20 to 30 km at the coastal Pacific and Caribbean plains of Colombia, 25 to 40 km beneath the eastern plains and foothills, 35 km beneath the Western Cordillera, 45 km at the Magdalena River intermountain valley, 52 to 58 km under the northern Central Cordillera, and reaching almost 60 km beneath some of the volcanoes of the Southern Cordilleran system of Colombia; crustal thickness can be slightly greater than 60 km beneath the plateau of the Eastern Cordillera. The values of VP/VS are particularly high for some of the stations on the volcanic centers, reaching values above 1.79, probably related to the addition of mafic materials to the lower crust, and in the plateau of the Eastern Cordillera near Bogota, where we speculate about the possibility of crustal seismic anisotropy associated with shear zones.

  17. Shortening of construction period of nuclear power plant. Activities of construction industry on construction period shortening

    International Nuclear Information System (INIS)

    Total construction period could be shorten by prefabricating structures efficiently in another yard and reducing working hours on site, which would reduce work at height or congestion work and also upgrade safety at work. Construction period shortening would surely reduce expenses during work and advance operation start of electric utilities. Construction of reactor building, turbine building, water intake and drainage canal was performed on a relatively large scale and a big share of whole schedule. This article summarized basic technologies to shorten construction period for reactor building/turbine building and water intake and drainage canal. Advanced methods of reactor building/turbine building; (1) modularization of equipment and skeleton, (2) utilization of concrete mold, reinforcing bar and steel frame, (3) precedent steel frame method and (4) steel plate reinforced concrete (SC) method, were outlined and their application examples were shown to reduce work on site and improve work efficiency. As for water intake and drainage canal construction, (1) precast concrete method, (2) SC method and (3) steel plate shell method were described with application examples. Construction procedures and problems using mega block method for water intake and drainage canal were also introduced. (T. Tanaka)

  18. Crustal Ages of the Ocean Floor - Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Crustal Ages of the Ocean Floor Poster was created at NGDC using the Crustal Ages of the Ocean Floor database draped digitally over a relief of the ocean floor...

  19. Crustal structure of Nigeria and Southern Ghana, West Africa from P-wave receiver functions

    Science.gov (United States)

    Akpan, Ofonime; Nyblade, Andrew; Okereke, Chiedu; Oden, Michael; Emry, Erica; Julià, Jordi

    2016-04-01

    We report new estimates of crustal thickness (Moho depth), Poisson's ratio and shear-wave velocities for eleven broadband seismological stations in Nigeria and Ghana. Data used for this study came from teleseismic earthquakes recorded at epicentral distances between 30° and 95° and with moment magnitudes greater than or equal to 5.5. P-wave receiver functions were modeled using the Moho Ps arrival times, H-k stacking, and joint inversion of receiver functions and Rayleigh wave group velocities. The average crustal thickness of the stations in the Neoproterozoic basement complex of Nigeria is 36 km, and 23 km for the stations in the Cretaceous Benue Trough. The crustal structure of the Paleoproterozoic Birimian Terrain, and Neoproterozoic Dahomeyan Terrain and Togo Structural Unit in southern Ghana is similar, with an average Moho depth of 44 km. Poisson's ratios for all the stations range from 0.24 to 0.26, indicating a bulk felsic to intermediate crustal composition. The crustal structure of the basement complex in Nigeria is similar to the average crustal structure of Neoproterozoic terrains in other parts of Africa, but the two Neoproterozoic terrains in southern Ghana have a thicker crust with a thick mafic lower crust, ranging in thickness from 12 to 17 km. Both the thicker crust and thick mafic lower crustal section are consistent with many Precambrian suture zones, and thus we suggest that both features are relict from the collisional event during the formation of Gondwana.

  20. Tectonic shortening and coeval volcanism during the Quaternary, Northeast Japan arc

    Indian Academy of Sciences (India)

    Koji Umeda; Masao Ban; Shintaro Hayashi; Tomohiro Kusano

    2013-02-01

    The Northeast Japan arc, a mature volcanic arc with a back-arc marginal basin (Japan Sea), is located on a convergent plate boundary along the subducting Pacific plate and the overriding North American plate. From a compilation and analysis of stratigraphy, radiometric age and data on erupted magma volumes, 176 eruptive episodes identified from 69 volcanoes so far, indicate that notable changes in eruption style, magma discharge rates and distribution of eruptive centres occurred around 1.0 Ma. Before ca.1.0 Ma, large-volume felsic eruptions were dominant, forming large calderas in the frontal arc, a region of low crustal strain rate. After ca. 1.0 Ma to the present, the calc-alkaline andesite magma eruptions in the frontal and rear arcs, synchronous with crustal shortening characterized by reverse faulting, resulted in stratovolcano development along narrow uplifted zones. Although, it is widely assumed that magma cannot rise easily in a compressional setting, some of the magma stored within basal sills could be extruded where N–S-trending uplifted mountains bounded by reverse faults formed since about ca.1.0 Ma.

  1. Telomere shortening correlates to dysplasia but not to DNA aneuploidy in longstanding ulcerative colitis

    DEFF Research Database (Denmark)

    Friis-Ottessen, Mariann; Bendix, Laila; Kølvraa, Steen;

    2014-01-01

    Ulcerative colitis (UC) is a chronic, inflammatory bowel disease which may lead to dysplasia and adenocarcinoma in patients when long-lasting. Short telomeres have been reported in mucosal cells of UC patients. Telomeres are repetitive base sequences capping the ends of linear chromosomes, and pr...... shortening of one or more telomeres to a critical length, rather than bulk shortening of telomeres, seems to be associated with chromosomal instability.......Ulcerative colitis (UC) is a chronic, inflammatory bowel disease which may lead to dysplasia and adenocarcinoma in patients when long-lasting. Short telomeres have been reported in mucosal cells of UC patients. Telomeres are repetitive base sequences capping the ends of linear chromosomes......, and protect them from erosion and subsequent wrongful recombination and end-to-end joining during cell division. Short telomeres are associated with the development of chromosomal instability and aneuploidy, the latter being risk factors for development of dysplasia and cancer. Specifically, the abrupt...

  2. Crustal structure of the Altiplano from broadband regional waveform modeling: Implications for the composition of thick continental crust

    Science.gov (United States)

    Swenson, Jennifer L.; Beck, Susan L.; Zandt, George

    2000-01-01

    We have modeled the full waveforms from six intermediate-depth and two shallow earthquakes recorded at regional distances by the BANJO Broadband Andean Joint Experiment (BANJO) and Seismic Exploration of the Deep Altiplano (SEDA) portable seismic networks in the central Andes. In this study we utilize data from those BANJO and SEDA stations located within the Altiplano and Eastern Cordillera. We used reflectivity synthetic seismograms and a grid search to constrain four parameters of the Altiplano-Eastern Cordillera lithosphere: crustal thickness, average crustal velocity (Vp), and crustal and upper mantle Poisson's ratios (σcrust and σmantle). Using our grid search, we investigated the crustal and upper mantle structure along 36 individual event station paths and applied forward modeling to 56 event station paths. Robust models for the Altiplano that provide the best overall fit between the data and synthetic seismograms are characterized by an average Vp of 5.75-6.25 km/s, crustal thicknesses of 60-65 km, σcrust = 0.25, and σmantle = 0.27-0.29. We find a north-south variation in the structure of the Altiplano, with the crust south of the BANJO transect characterized by either lower than average crustal P wave velocities or a slightly higher σcrust relative to crust north of the BANJO transect. These results are consistent with a model of crustal thickening caused predominantly by tectonic shortening of felsic crust, rather than by underplating or magmatic intrusion from the mantle.

  3. Trans Fatty Acid content in Danish margarines and shortenings

    DEFF Research Database (Denmark)

    Leth, Torben; Bysted, Anette; Hansen, Kirsten;

    2003-01-01

    Margarines and shortenings have been major contributors to the intake by humans of the probably atherogenic trans FA (TFA). In 1999, all 73 brands of margarines and shortenings on the Danish market were analyzed by GLC on a 50-m highly polar capillary column, and the results were compared with si...

  4. Does a detection team shorten duration of untreated psychosis?

    DEFF Research Database (Denmark)

    Nordentoft, Merete; Thorup, Anne; Petersen, Lone;

    2008-01-01

    Duration of untreated psychosis (DUP) is shown to be associated with poor outcome in many domains. It has been shown that it is possible to shorten DUP when combining a detection team and an information campaign. The aim of this study was to evaluate whether DUP was shortened during the first 3 y...

  5. Lava thicknesses: Implications for rheological and crustal development

    Science.gov (United States)

    Kilburn, C. R. J.; Lopes, R. M. C.

    1988-01-01

    The morphology of a lava flow is strongly influenced by its rheological structure. The rheological structure is, in turn, dependent on numerous factors including: (1) bulk composition, (2) crystallingity, (3) vesicularity, and (4) crustal development. Identifying which of the latter factors are most significant, and hence most readily investigated by remote-sensing techniques, is necessary to clarify short-term objectives and expectations from the study of Martian lava flows. Insights into the rheological controls on flow morphology are provided by variations in thickness of undrained lava streams on Etna and Vesuvius, Southern Italy. Both pahoehoe and aa lavas were studied.

  6. Crustal Structure And Magmatism, Coast Mountains Orogen, Latitude 52-53 degrees North, British Columbia, Canada

    Science.gov (United States)

    Rusmore, M. E.; Gehrels, G.; Woodsworth, G. J.

    2007-12-01

    New geologic data and U-Pb ages reveal complex history of arc accretion, crustal thickening and migration of magmatic fronts during deformation. Plutonic ages define distinct western and eastern Jurassic - mid Cretaceous arcs that share a common history after ~90 Ma. Juxtaposition of these arcs occurred during mid- Cretaceous crustal shortening in a dominantly SW-vergent crustal-scale thrust belt. Significant crustal thickening buried 151 Ma granitic clasts to pressures > 6 kb, and mid-Cretaceous plutons were emplaced at this depth along the axis of the orogen. Thrusting continued after establishment of the 90 Ma arc; a regional SW-verging thrust emplaced high-grade metamorphic rocks of the Yukon-Tanana terrane and deep-seated plutons over low- grade rocks of the Alexander and Wrangellia terranes. The shear zone is coincident with the western boundary of 82-89 Ma plutons and a regionally extensive, late-kinematic, sill-like pluton. Dextral shear zones preserved on the flanks of the orogen suggest a component of Late Cretaceous transpression. By 75 Ma, metamorphism, deformation, and magmatism had migrated central portions of the orogen and there is no evidence of ductile deformation and syn-kinematic metarmorphism younger than ~70 - 65 along the western flank of the orogen. The Coast shear zone localized 62-58 Ma synkinematic plutons during NE-side up displacement, creating a sharp western magmatic front. Sparse cooling ages suggest plutons and metamorphic rocks adjacent to the CSZ cooled through 500-600 deg between 54-58 Ma during exhumation along the shear zone. Voluminous granitic plutons were emplaced from ~55-50 Ma, but significant crustal extension that affected the eastern side of the orogen farther north is not evident along this transect. This history supports previous models of crustal subcretion and the generation of arc magmas in thickened crust. Definition of two pre-90 Ma arcs negates models calling for simple Andean-style orogen prior to mid

  7. Crustal thickening and lateral extrution during in the formation of the Tibetan Plateau: Insights from 3D Numerical modeling

    Science.gov (United States)

    Liu, M.; Yang, Y.

    2002-12-01

    Our understanding of the geodynamics of the formation of the Himalayan-Tibetan Plateau has been largely based on two end-member models: the viscous thin-sheet model that suggests crustal thickening as the dominant accommodation for larger than 2000 km crustal shortening following the Indian-Asian collision, and the plasticine indentation model that emphases the role of lateral extrusion of Asian continent along numerous strike-slip faults. To understand better the strain partitioning between crustal thickening and extrusion during the formation of the Tibetan Plateau, we have developed a three-dimensional finite element model with vertically variable power-law rheology and large-scale strike-slip faults, including the Altyn Tagh, Longmen Shan, Xianshuihe and the Ailao Shan-Red River faults. We simulated the formation of the Tibetan plateau resulting from convergence between the Indian and Eurasian plates during the past 50 Myr. The model assumes the Tarim block and the South China block to be relatively fixed, and the Indian plate moved northward as indicated by marine magnetic anomalies. During the early stages following the initial collision, the predicted stress states within the collision zone favor predominantly strike-slip motion, and a large extrusion conduit between the collision zone and the South China block allowed most of the shortened crustal material to be accommodated by east-southeastward extrusion. As the Indian plate continued to indent into the Asian continent, the extrusion conduit was gradually narrowed, leading to reduced rate of crustal extrusion, and increased crustal thickening and lateral expansion of the plateau. The predicted crustal extrusion is significantly greater with the strike-slip faults than without, and ductile flow within the lower crust is shown to play a critical role in reproducing the observed topography of the Tibetan plateau and surrounding regions.

  8. Recent rapid shortening of crust across the Tianshan Mts. and relative motion of tectonic blocks in the north and south

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the multiple-epoch Global Positioning System observations during a period from 1992 to 1999, we document directly a rapid crustal shortening of ~20 mm/a across the western Tianshan Mts. (76°E), in contrast to a 4 mm/a convergent rate across the eastern Tianshan Mts. (87°E)and the north-south convergence across the mountain belt descends laterally from west to east. The direction of current crustal movement inferred by GPS sites along the southern flank of the Tianshan Mts. is approximately perpendicular to the easterly-trending mountain belt, indicating that the Tarim Basin thrust almost rightly into the Tianshan Mts. The Tarim Basin accommodates nearly no or a minor, if any, crustal deformation and rotates clockwise, as a rigid body in a whole, at a rate of 0.64°/Ma around a Euler pole at 95.7°E, 40.3°N (Anxi, Gansu) with respect to the stable Siberia. The relative motion between the Kazakh platform and the Dzungarian Basin is quite apparent. The Dzungar should be regarded as an independent active block from the view of the Asia tectonic settings.

  9. Analysis the 1978–2008 crustal and sub-crustal earthquake catalog of Vrancea region

    Directory of Open Access Journals (Sweden)

    L. Telesca

    2012-05-01

    Full Text Available The crustal and sub-crustal seismicity that occurred in the Vrancea area from 1978 to 2008 is investigated. Due to quarry blast contamination, the analysis of the crustal seismicity was restricted to events that occurred between 20 km and 60 km, considering sub-crustal events as all those that occurred at depths larger than 60 km. The completeness magnitude was estimated between 2.3 and 2.5 for the crustal seismicity and between 2.9 and 3.1 for the sub-crustal one. The Gutenberg-Richter b-values show clear differences between crustal and sub-crustal seismicity, with values around 0.9 and 1.3–1.4, respectively. The analysis performed in this study represents a preliminary issue for the seismic hazard assessment of surrounding regions like Moldova, for which the earthquakes generated in Vrancea represent an important threat.

  10. Collision zone magmatism aids continental crustal growth

    Science.gov (United States)

    Savov, Ivan; Meliksetian, Khachatur; Ralf, Halama; Gevorg, Navasardian; Chuck, Connor; Massimo, D'Antonio; Samuele, Agostini; Osamu, Ishizuka; Sergei, Karapetian; Arkadi, Karakhanian

    2014-05-01

    The continental crust has a broadly andesitic bulk composition and is predominantly generated at convergent margins. However, estimates of the bulk composition of oceanic arcs indicate a bulk composition closer to basalt than to andesite. Hence, reworking processes that transform basaltic island arc crust into andesitic continental crust are essential[1] and explaining growth of andesitic continental crust via accretion of arc crustal fragments remains problematic. Recent studies of magmatism in the Great Tibetan Plateau[2], as site of multiple and still active continent-continent collisions, have proposed that andesitic CC is generated via amalgamation of large volumes of collision-related felsic magmas generated by melting of hydrated oceanic crust with mantle geochemical signatures. We aim to test this hypothesis by evaluating geochemical data from the volcanically and tectonically active Lesser Caucasus region (Armenia, Azerbaijan, Georgia and E. Turkey), as the only other region where active continent-continent collision takes place. We will benefit from the newly compiled volcano-tectonic database of collision-related volcanic and plutonic rocks of Armenia that is comparable in quality and detail to the one available on Tibet. Our dataset combines several detailed studies from the large Aragats shield volcano[3] and associated monogenetic volcanic fields (near the capital city of Yerevan), as well as > 500 Quaternary to Holocene volcanoes from Gegham, Vardenis and Syunik volcanic highlands (toward Armenia-Nagorno-Karabakh-Azerbaijan-Iran border). The Armenian collision-related magmatism is diverse in volume, composition, eruption style and volatile contents. Interestingly, the majority of exposed volcanics are andesitic in composition. Nearly all collision-related volcanic rocks, even the highly differentiated dacite and rhyolite ignimbrites, have elevated Sr concentrations and 87Sr/86Sr and 143Nd/144Nd ratios varying only little (average ~ 0.7043 and ~ 0

  11. Crustal structure beneath Eastern Greenland

    DEFF Research Database (Denmark)

    Reiche, Sönke; Thybo, H.; Kaip, G.;

    2011-01-01

    by the presence of an up to 4 km thick ice sheet, permanently covering the largest part of the land mass. Hence previous seismic surveys have only been carried out offshore and near the coast of Greenland, where little information about the continental part of the crust could be gained. To get...... insight into crustal thickness and composition below the Greenland ice sheet, the TopoGreenland project collects the first ever seismic data onshore Greenland. Wide-angle data was acquired along an EW-trending profile, extending 350 km inland from the approximate edge of the stable ice cap near Scoresby...

  12. Consequences of crown shortening canine teeth in Greenland sled dogs

    DEFF Research Database (Denmark)

    Kortegaard, H E; Anthony Knudsen, T; Dahl, S;

    2015-01-01

    OBJECTIVES: To evaluate the consequences of crown shortening, focusing on the prevalence of pulp exposure and periapical pathology in Greenland sled dogs that had had their canine crowns shortened at an early age. METHODS: Five cadaver heads and 54 sled dogs underwent an oral examination for dental...... fractures and pulp exposure of canines. All canines were radiographed and evaluated for periapical pathology. RESULTS: The prevalence of canine pulp exposure in 12 (5 heads and 7 dogs) crown shortened dogs was 91 · 7%, and 21 · 3% in 47 not-crown shortened dogs. A significant (P ... exposure of the canines in the crown shortened group compared to the not-crown shortened group was seen with a relative risk of 4 · 3 on a dog basis and a relative risk of 12 · 2 on a tooth basis. In dogs with pulp exposure of canines (n = 51) the prevalence of periapical pathology was 82 · 4%, but only 0...

  13. Quantifying Strain Budgets in the Cascadia Forearc Using a Catalog of Quaternary Crustal Faults

    Science.gov (United States)

    McCrory, P. A.

    2002-12-01

    Comparing geologic strain rates with geodetic and plate kinematic rates provides a useful method of separating crustal strain from the much larger interplate strain. Current geodetic models of the Cascadia subduction boundary attempt to separate observed crustal velocities into two components: (1) westward motion attributed to a locked megathrust and (2) northward motion attributed to translation of forearc crustal blocks. Owing to sparse spatial observations, these models treat forearc motion as a continuum defined by rotation about an Euler pole. Yet a significant portion of this motion is localized on crustal faults that occur as narrow zones within the forearc. The current resolution of geodetic measurements is insufficient to resolve the strain associated with these faults. Therefore, cataloging active crustal faults in the Pacific Northwest is crucial for assessing the seismic hazard and identifying areas with differential motion that might benefit from denser geodetic observations. For example, the Oregon Coast Range (OCR) block translates northward at ~8 mm/y in coastal Washington and a fault zone at its NW boundary converts 2-3 mm/y of this translation into permanent crustal shortening. The remaining 5-6 mm/y of differential motion may be accommodated in the Olympic Mountains which are uplifting as much as ~3 mm/y, or as broad-scale buckling of the OCR basement beneath southern Washington. These geologic, geodetic, and kinematic comparisons are also essential for investigating aseismic displacement and constraining its contribution to observed strain. For example, plate convergence at the southern end of the Cascadia forearc is ~45 mm/y. About 15 mm/y of this relative convergence is observed geodetically onshore. Crustal fault slip accounts for ~10 mm/y of the measured contraction, suggesting that only 5 mm/y is accumulating on the megathrust and leaving as much as 30 mm/y to be accounted for as aseismic slip. These two examples demonstrate the complexity

  14. The zoo of solitons for curve shortening in Rn

    International Nuclear Information System (INIS)

    We provide a detailed description and classification of solutions to the curve shortening equation in Rn that are invariant under one-parameter symmetry groups of the equation. We pay particular attention to geometric properties of the curves and asymptotic properties of their ends. We find generalized helices, and a connection with curve shortening on the unit sphere Sn-1. Expanding–rotating solitons turn out to be asymptotic to generalized logarithmic spirals and the rotating–shrinking solitons are most complicated in terms of asymptotic properties of their ends. We find that almost all of the rotating–shrinking solitons are asymptotic to circles. Many of the curve shortening solitons we classify are either space curves, or evolving space curves. In addition to the figures in this paper, we have prepared a number of animations of the solitons, which can be viewed in the online supplementary data (stacks.iop.org/Non/26/1189/mmedia). (paper)

  15. Crustal Structure of Northern Vietnam Based on Analysis of Teleseismic Converted Waves

    Science.gov (United States)

    Duong, N. V.; Huang, B.

    2013-12-01

    Northern Vietnam is located in the southeasternmost extension of the Himalayan syntaxis, which is mechanically linked to the Tibetan plateau by the Red River fault. Little is known about the detailed crustal structure in this region. Using data from 24 broadband seismic stations distributed evenly over northern Vietnam, we analyze P-wave receiver functions to constrain crustal thickness, internal crustal structure, and the bulk seismic velocity characteristics in order to address the crustal heterogeneity and its tectonic implications in northern Vietnam. The optimum crustal thickness and Vp/Vs (where Vp and Vs are the velocities of P- and S-waves, respectively) ratio beneath each station were determined using the H-k (where H is crustal thickness and k is defined as the Vp/Vs ratio) stacking algorithm. The stacked receiver functions were inverted to yield the shear wave velocity of the crust at each station. Determined values of crustal thickness range from 26.5 km to 36.4 km, with an average of 31.0 × 2.1 km. The simple pattern of variation of crustal thickness in the northeastern region of the study area, with a mean of ~31 km, suggests that the sector belongs to the craton of the South China block. A highly variable crustal thickness is found over the northwestern region of northern Vietnam, ranging from ~29.5 km to ~36.4 km, implying that complex tectonic processes have taken place in this region. The thinnest crust is found in the Red River Delta, where it ranges from 26.5 km to 30.4 km, which is suggestive of a recent rifting process. The determinations of crustal thickness show a good linear correlation with Bouguer gravity anomalies. Lower values of Poisson's ratio in the northeastern and Red River Delta sectors suggest a more felsic crust, and larger values in the northwestern sector suggest lithospheric extension in the Song Da depression. The shear velocity structure in the northwestern region is relatively slow and more complex, while the velocity in

  16. Methods for Shortening and Extending the Carbon Chain in Carbohydrates

    DEFF Research Database (Denmark)

    Monrad, Rune Nygaard

    2008-01-01

    Carbohydrates play a central role in a variety of physiological and pathological processes such as HIV, cancer and diabetes. The understanding of these processes and the development of specific therapeutic agents is relying on the ability to chemically synthesize unnatural sugars, glycoconjugates...... in this thesis focuses on the development and application of transition metal mediated methods for shortening and extending the carbon chain in carbohydrates thereby providing access to lower and higher sugars.A new catalytic procedure for shortening unprotected sugars by one carbon atom has been developed...

  17. Lower crustal mush generation and evolution

    Science.gov (United States)

    Karakas, Ozge; Bachmann, Olivier; Dufek, Josef; Wright, Heather; Mangan, Margaret

    2016-04-01

    Recent seismic, field, and petrologic studies on several active and fossil volcanic settings provide important constraints on the time, volume, and melt fraction of their lower crustal magma bodies. However, these studies provide an incomplete picture of the time and length scales involved during their thermal and compositional evolution. What has been lacking is a thermal model that explains the temporal evolution and state of the lower crustal magma bodies during their growth. Here we use a two-dimensional thermal model and quantify the time and length scales involved in the long-term thermal and compositional evolution of the lower crustal mush regions underlying the Salton Sea Geothermal Field (USA), Mt St Helens (USA), and the Ivrea-Verbano Zone (North Italy). Although a number of seismic, tectonic, petrologic, and field studies explained the tectonic and magmatic evolution of these regions, controversy remains on their lower crustal heat sources, melt fraction, and origin of erupted magmas. Our thermal modeling results suggest that given a geologically reasonable range of basalt fluxes (~10^-3 to 10^-4 km3/yr), a long-lived (>105 yr) crystalline mush is formed in the lower crust. The state of the lower crustal mush is strongly influenced by the magma flux, crustal thickness, and water content of intruded basalt, giving an average melt fraction of Geothermal Field) and up to 0.4-0.5 in thicker crust with wet injections (Mt St Helens and Ivrea Zone). The melt in the lower crustal mush is mainly evolving through fractional crystallization of basalt with minor crustal assimilation in all regions, in agreement with isotopic studies. Quantification of the lower crustal mush regions is key to understanding the mass and heat balance in the crust, evolution of magma plumbing systems, and geothermal energy exploration.

  18. Is South-eastward Crustal Flow Possible around East Himalayan Syntax? - New Insights from SINOPROBE Magnetotellurics Array Data

    Science.gov (United States)

    Dong, H.; Wei, W.; Ye, G.; Jin, S.; Jing, J.; Jones, A. G.; Zhang, L.; Xie, C.; Yin, Y.; Wang, G.

    2015-12-01

    The south-eastward expansion of Tibet plateau in eastern Tibet is considered a key process for understanding the large scale uplift and crustal thickening without significant concomitant crustal shortening. However, the geodynamic processes creating this iconic process is still unclear and hotly debated. Two popular geodynamic models, namely crustal flow at mid-to-lower crustal depths and coherent deformation between the crust and lithospheric mantle, are commonly appealed to as the expansion's driving mechanism. However, neither of these mechanisms is able to reconcile all of the abundant geological and geophysical data. In this study we present a three-dimensional (3D) geo-electrical model, derived from SINOPROBE magnetotelluric (MT) array data, which reveals the geo-electrical and rheological structure in southeast Tibet that brings new insights into the region. Instead of continuous NW-SE conductive channels proposed in previous two-dimensional (2D) MT studies, a large-scale N-S directed resistive structure is revealed to disconnect the conductors from the crust to the upper mantle, arguing against the model of south-eastward (downslope) channel flow. Furthermore, distinct NNE directed conductive anomalies, which are perpendicular to the surface structures, are identified in the mid-to-lower crust. We interpret these anomalies as distributed NNE oriented crustal flow channels, which might cause the azimuthal clockwise extension around East Himalayan Syntax and partly contributed to the south-eastward expansion of eastern Tibet.

  19. Telomere shortening reduces Alzheimer's disease amyloid pathology in mice

    NARCIS (Netherlands)

    Rolyan, Harshvardhan; Scheffold, Annika; Heinrich, Annette; Begus-Nahrmann, Yvonne; Langkopf, Britta Heike; Hoelter, Sabine M.; Vogt-Weisenhorn, Daniela M.; Liss, Birgit; Wurst, Wolfgang; Lie, Dieter Chichung; Thal, Dietmar Rudolf; Biber, Knut; Rudolph, Karl Lenhard

    2011-01-01

    Alzheimer's disease is a neurodegenerative disorder of the elderly and advancing age is the major risk factor for Alzheimer's disease development. Telomere shortening represents one of the molecular causes of ageing that limits the proliferative capacity of cells, including neural stem cells. Studie

  20. Challenges in Shortening New Product Introduction in the Pharmaceutical Industry

    DEFF Research Database (Denmark)

    Hansen, Klaus Reinholdt Nyhuus; Grunow, Martin

    2010-01-01

    Drug developing companies are forced to utilize the effective protection of the patent by focusing on shortening the new product introduction [NPI] process measured as Time-to-Market [TTM]. Here the NPI process is considered and the trade-offs, which have to be address in the future are identified...

  1. Swallowing threshold parameters of subjects with shortened dental arches.

    NARCIS (Netherlands)

    Kreulen, C.M.; Witter, D.J.; Tekamp, F.A.; Slagter, A.P.; Creugers, N.H.J.

    2012-01-01

    OBJECTIVES: To quantify swallowing threshold parameters of subjects with a moderate shortened dental arch dentition (SDA: missing molar teeth, but premolar teeth in occluding position and uninterrupted anterior regions) compared to subjects with a complete dental arch dentition (CDA). METHODS: Fourt

  2. Smog May Shorten Lives of Lung Cancer Patients

    Science.gov (United States)

    ... fullstory_160280.html Smog May Shorten Lives of Lung Cancer Patients Large review in California finds lower survival rates among those with most exposure to dirty air To use the sharing features on this page, please enable JavaScript. (*this news item will not ...

  3. Residual force enhancement following shortening is speed-dependent

    Science.gov (United States)

    Fortuna, Rafael; Power, Geoffrey A.; Mende, Esther; Seiberl, Wolfgang; Herzog, Walter

    2016-01-01

    The steady-state isometric force following active muscle shortening or lengthening is smaller (force depression; FD) or greater (residual force enhancement; RFE) than a purely isometric contraction at the corresponding length. The mechanisms underlying these phenomena are not explained within the context of the cross-bridge theory and are rarely studied in concert. Previous studies have shown RFE to be speed-independent. In the present study, we investigated if RFE preceded by active shortening is time-dependent by electrically evoking RFE in the human adductor pollicis muscle. The results shown that a slow stretch following FD fully re-established RFE compared to higher speeds of stretch. The mechanism(s) responsible for the recovery of RFE following a preceding shortening contraction (FD) might be associated with the recovery of cross-bridge based force and/or the re-engagement of a passive structural element (titin). Voluntary interaction with one’s environment involves highly coordinated shortening and lengthening muscle contractions. Therefore comprehending these history-dependent muscle properties in the context of movement control is paramount in understanding the behavior of in vivo motor control. PMID:26869508

  4. Slab detachment during continental collision: Influence of crustal rheology and interaction with lithospheric delamination

    Science.gov (United States)

    Duretz, T.; Gerya, T. V.

    2013-08-01

    Collision between continents can lead to the subduction of continental material. If the crust remains coupled to the downgoing slab, a large buoyancy force is generated. This force slows down convergence and promotes slab detachment. If the crust resists to subduction, it may decouple from the downgoing slab and be subjected to buoyant extrusion. We employ two-dimensional thermo-mechanical modelling to study the importance of crustal rheology on the evolution of subduction-collision systems. We propose simple quantifications of the mechanical decoupling between lithospheric levels (σ*) and the potential for buoyant extrusion of the crust (ξ*). The modelling results indicate that a variable crustal rheological structure results in slab detachment, delamination, or the combination of both mechanisms. A strong crust provides coupling at the Moho (low σ*) and remains coherent during subduction (low ξ). It promotes deep subduction of the crust (180 km) and slab detachment. Exhumation occurs in coherent manners via eduction and thrusting. Slab detachment triggers the development of topography (> 4.5 km) close to the suture. A contrasting style of collision occurs using a weak crustal rheology. Mechanical decoupling at the Moho (high σ*) promotes the extrusion of the crust (high ξ), disabling slab detachment. Ongoing shortening leads to buckling of the crust and development of topography on the lower plate. Collisions involving rheologically layered crust allow decoupling at mid-crustal depths. This structure favours both the extrusion of upper crust and the subduction of the lower crust. Such collisions are successively affected by delamination and slab detachment. Topography develops together with the buoyant extrusion of crust onto the foreland and is further amplified by slab detachment. Our results suggest that the occurrence of both delamination (Apennines) and slab detachment (Himalayas) in orogens may indicate differences in the initial crustal structure of

  5. Crustal deformation: Earth vs Venus

    International Nuclear Information System (INIS)

    It is timely to consider the possible tectonic regimes on Venus both in terms of what is known about Venus and in terms of deformation mechanisms operative on the earth. Plate tectonic phenomena dominate tectonics on the earth. Horizontal displacements are associated with the creation of new crust at ridges and destruction of crust at trenches. The presence of plate tectonics on Venus is debated, but there is certainly no evidence for the trenches associated with subduction on the earth. An essential question is what kind of tectonics can be expected if there is no plate tectonics on Venus. Mars and the Moon are reference examples. Volcanic constructs appear to play a dominant role on Mars but their role on Venus is not clear. On single plate planets and satellites, tectonic structures are often associated with thermal stresses. Cooling of a planet leads to thermal contraction and surface compressive features. Delamination has been propsed for Venus by several authors. Delamination is associated with the subduction of the mantle lithosphere and possibly the lower crust but not the upper crust. The surface manifestations of delamination are unclear. There is some evidence that delamination is occurring beneath the Transverse Ranges in California. Delamination will certainly lead to lithospheric thinning and is likely to lead to uplift and crustal thinning

  6. Telomere shortening may be associated with human keloids

    Directory of Open Access Journals (Sweden)

    Wilson Robert R

    2009-10-01

    Full Text Available Abstract Background Keloids are benign skin tumors that are the effect of a dysregulated wound-healing process in genetically predisposed patients. They are inherited with an autosomal dominant mode with incomplete clinical penetrance and variable expression. Keloids are characterized by formation of excess scar tissue beyond the boundaries of the wound. The exact etiology is still unknown and there is currently no appropriate treatment for keloid disease. Methods We analyzed sample tissues were obtained from 20 patients with keloid skin lesions and normal skin was obtained from 20 healthy donors. The telomeres were measured by Terminal Restriction Fragment (TRF analysis and Real-Time PCR assay. Quantitative Real-Time RT-PCR analysis of hTERT gene expression was performed and intracellular ROS generation was measured. Results In this study, we determined whether telomeric shortening and the expression of human telomerase reverse transcriptase (hTERT occurs in keloid patients. Using Terminal Restriction Fragment (TRF analysis and Real-Time PCR assay, we detected a significant telomere shortening of 30% in keloid specimens compared to normal skin. Using quantitative Real-Time RT-PCR, telomerase activity was found absent in the keloid tissues. Moreover, an increase in ROS generation was detected in fibroblasts cell cultures from keloid specimens as more time elapsed compared to fibroblasts from normal skin. Conclusion Telomere shortening has been reported in several metabolic and cardiovascular diseases. We found that telomere shortening can also be associated with human keloids. Chronic oxidative stress plays a major role in the pathophysiology of several chronic inflammatory diseases. Here we found increased ROS generation in fibroblasts from keloid fibroblasts cell cultures when compared to normal skin fibroblasts. Hence we conclude that oxidative stress might be an important modulator of telomere loss in keloid because of the absence of active

  7. Investigation of plateau basin crustal structures and thickening mechanisms in the northeastern margin of the Tibetan plateau

    Science.gov (United States)

    Jia, Shixu; Xu, Zhaofan; Liu, Zhi; Zhang, Jianshi; Liu, Baofeng; Lin, Jiyan; Guo, Wenbin

    2012-12-01

    This paper uses deep seismic sounding (DSS) data to contrast and analyze the crustal structures of three plateau basins (Songpan-Garze, Qaidam, Longzhong) in the northeastern margin of the Qinghai-Xizang (Tibetan) plateau, as well as two stable cratonic basins (Ordos, Sichuan) in its peripheral areas. Plateau basin crustal structures, lithological variations and crustal thickening mechanisms were investigated. The results show that, compared to the peripheral stable cratonic basins, the crystalline crusts of plateau basins in the northeastern margin are up to 10-15 km thicker, and the relative medium velocity difference is about 5% less. The medium velocity change in crustal layers of plateau basin indicates that the upper crust undergoes brittle deformation, whereas the lower crust deforms plastically with low velocity. The middle crust shows a brittle-to-plastic transition zone in this region. Thickening in the lower crust (about 5-10 km), and rheological characteristics that show low-medium velocity (relatively reduced by 7%), suggest that crustal thickening mainly takes place in lower crust in the northeastern margin of the Tibetan plateau. The crust along the northeastern margin shows evidence of wholesale block movement, and crustal shortening and thickening seem to be the main deformation features of this region. The GPS data show that the block motion modes and crustal thickening in the Tibetan plateau is closely related to the peripheral tectonic stress field and motion direction of the Indian plate. The Mani-Yushu-Xianshuihe fold belt along the boundary between the Qiangtang block and the Bayan Har block divides the different plateau thickening tectonic environments into the middle-western plateau, the northeastern margin and the southeastern plateau.

  8. Derivation of Crustal Magnetic Anomalies from MAGSAT

    OpenAIRE

    YANAGISAWA, Masahisa

    1984-01-01

    This paper describes various characteristics of the magnetospheric field, induction field, and ionospheric field observed by MAGSAT (Magnetic Field Satellite) and the derivation of crustal magnetic anomalies free from disturbance fields. After eliminating the effect of the disturbance field, anomaly maps were derived for the Japanese area and for the Shatsky Rise area. The magnetic field observed by satellites consists of a core field, induction field, crustal field, ionospheric field, and ma...

  9. A Disequilibrium Melting Spectrum: Partially Melted Crustal Xenoliths from the Wudalianchi Volcanic Field, NE China.

    Science.gov (United States)

    McLeod, C. L.; McGee, L. E.

    2015-12-01

    Disequilibrium melting has been established as a common process occurring during crustal anatexis and thus demonstrates that crustal assimilation by ascending mantle-derived magmas is likley not a closed system. Observations of extreme compositional heterogeneity within partial melts derived from crustal xenoliths have been documented in several recent examples, however, the retention or transfer of elements to and from residues and glasses, and their relative contributions to potential crustal contaminants warrants further investigation. Sampled lavas from the Huoshaoshan volcano in the Holocene Wudalianchi volcanic field of Northeast China contain crustal xenoliths which preserve a spectrum of partial melting both petrographically and geochemically, thus providing an excellent, natural example of crustal anatexis. Correlations exist between the volume of silicic glass preserved within the xenoliths and bulk rock SiO2 (70-83 wt%), Al2O3 (16-8 wt%), glass 87Sr/86Sr (0.715-0.908), abundances of elements common in feldspars and micas (Sr, Ba, Rb) and elements common in accessory minerals (Y, Zr, Nb). These correlations are likely associated with the consumption of feldspars and micas and the varying retention of accessory phases during partial melting. The xenoliths which contain the greater volumes of silicic glass and residual quartz (interpreted as being the most melted) were found within pahoehoe lava, whilst the least melted xenoliths were found within scoria of the summit cone of Huoshaoshan; thus it is interpreted that the extent of melting is linked to the immersion time in the lava. Small-scale (mm) mingling and transfer of material from the enclosing lava to the xenolith is observed, however, modelling of potential contaminant compositions is inconsistent with crustal contamination during lava petrogenesis. It is inferred that crustal contamination in sampled lavas is localized within the open magmatic system and most likely occurs at the contact zone

  10. Ps Reciever Function Analysis of the Crustal Structure Beneath the United States Great Plains

    Science.gov (United States)

    Thurner, S.; Levander, A.; Niu, F.

    2013-12-01

    ; Hammer et al., 2010) , and have been attributed to significant crustal shortening that occurred during Proterozoic terrane accretion.

  11. Cost and Quality Consequences of Shortening the Project Life Cycle

    OpenAIRE

    Rasta, Mohammadreza

    2013-01-01

    Shortening duration of project is a challenging task. If time is reduced with no attention is paid to additional risk, not only no time reduction is achieved but also it can exert counter effect by increasing the time, imposing more expenses, and causing quality loss due to lack of meeting the customer expectations. Two methods were approved by PMI and they have been extensively discussed in literature, they are Fast Tracking and Critical Chain methods. Fast tracking performs two sequential a...

  12. The Randomized Shortened Dental Arch Study: Tooth Loss

    OpenAIRE

    Walter, M H; Weber, A; Marré, B; Gitt, I.; Gerß, J.; Hannak, W.; Hartmann, S.; Heydecke, G; Huppertz, J.; Jahn, F; Ludwig, A.; Mundt, T.; Kern, M; Klein, V; Pospiech, P.

    2010-01-01

    The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA ...

  13. Progressive telomere shortening and telomerase reactivation during hepatocellular carcinogenesis.

    Science.gov (United States)

    Miura, N; Horikawa, I; Nishimoto, A; Ohmura, H; Ito, H; Hirohashi, S; Shay, J W; Oshimura, M

    1997-01-01

    Telomeres shorten progressively with age in normal somatic cells in culture and in vivo. The maintenance of telomere length is assumed to be an obligatory step in the progression and immortalization of most human tumor cells. To understand the role of telomere dynamics in the development of hepatocellular carcinoma (HCC), we examined the length of terminal restriction fragment (TRF), as an indicator for telomere length, in HCC and surrounding tissues with chronic active hepatitis (CAH) or liver cirrhosis (LC). The study was performed in 12 hepatitis C virus (HCV) antibody-positive, 12 hepatitis B virus (HBV) antigen-positive tissues, and 4 tissue samples from virus-negative patients with HCC. The peak TRFs in all 3 types of HCC were significantly shorter than those of the surrounding tissues (i.e., LC or CAH). TRFs examined in one patient with atypical adenomatous hyperplasia (AAH) also was shortened. Thus, progressive TRF shortening occurs from normal to CAH to LC to HCC(AAH). Telomerase, an enzyme that adds repeated telomere sequences onto the chromosome ends and stabilizes telomere length in immortal cells, also was examined in tissues and detected in high levels almost exclusively in HCCs. Interestingly, the intensity of telomerase activity in the AAH case was similar to that of HCC. In addition, the telomerase activity of biopsy samples with a fine 21-gauge needle also was examined in 10 HCCs, 2 adenomatous hyperplasias (AHs), 2 LCs, and 2 CAHs. We found strong telomerase activity in all the HCCs and surprisingly in the 2 cases that were pathologically diagnosed as AH. Thus, the findings strongly suggest that persistent cell proliferation or rapid cell turnover through damage of hepatic cells result in a process of multistep hepatocellular carcinogenesis. Thus, progressive shortening of telomeres and the activation of telomerase may be a useful marker for the early detection of malignant progression in liver disease. PMID:9062581

  14. Fault locking, block rotation and crustal deformation in the Pacific Northwest

    Science.gov (United States)

    McCaffrey, R.; Qamar, A.I.; King, R.W.; Wells, R.; Khazaradze, G.; Williams, C.A.; Stevens, C.W.; Vollick, J.J.; Zwick, P.C.

    2007-01-01

    -like fashion. The relative motions of the Oregon, western Washington and Vancouver Island crustal blocks indicate that the rate of permanent shortening, the type that causes upper plate earthquakes, across the Puget Sound region is 4.4 ?? 0.3 mm yr-1. This shortening is likely distributed over several faults but GPS data alone cannot determine the partitioning of slip on them. The transition from predominantly shear deformation within the continent south of the Mendocino Triple Junction to predominantly block rotations north of it is similar to changes in tectonic style at other transitions from shear to subduction. This similarity suggests that crustal block rotations are enhanced in the vicinity of subduction zones possibly due to lower resisting stress. ?? 2007 The Authors Journal compilation ?? 2007 RAS.

  15. Estimation of circumferential fiber shortening velocity by echocardiography.

    Science.gov (United States)

    Ruschhaupt, D G; Sodt, P C; Hutcheon, N A; Arcilla, R A

    1983-07-01

    The M-mode and two-dimensional echocardiograms of 40 young patients were analyzed to compare the mean circumferential fiber shortening velocity (Vcf) of the left ventricle calculated separately by two methods. The mean circumferential fiber shortening velocity was derived from the M-mode echocardiogram as minor axis shortening/ejection time and derived from the two-dimensional echocardiogram as actual circumference change/ejection time. With computer assistance, circumference was determined from the short-axis two-dimensional echocardiographic images during end-diastole and end-systole. Good correlations were obtained between the left ventricular diameter derived by M-mode echocardiography and the vertical axis during end-diastole (r = 0.79) and end-systole (r = 0.88) derived by two-dimensional echocardiography. Likewise, high correlations were noted between diameter and circumference in end-diastole (r = 0.89) and end-systole (r = 0.88). However, comparison of Vcf obtained by M-mode echocardiography with that obtained by two-dimensional echocardiography showed only fair correlation (r = 0.68). Moreover, the diameter/circumference ratio determined in end-diastole and end-systole differed significantly (p less than 0.001), possibly owing to the change in geometry of the ventricular sector image during systole. Although Vcf derived by M-mode echocardiography is a useful index of left ventricular performance, it does not truly reflect the circumference change during systole.

  16. Meat toughening does not occur when rigor shortening is prevented.

    Science.gov (United States)

    Koohmaraie, M; Doumit, M E; Wheeler, T L

    1996-12-01

    The objective of this experiment was to test the hypothesis that meat toughening during the first 24 h postmortem results from sarcomere shortening during rigor mortis development. Eleven market-weight lambs were used to measure changes in shear force of clamped longissimus during rigor development. Within 15 min of exsanguination, while attached at both ends, each longissimus was separated from the vertebrae body and clamped between three sets of metal plates to prevent muscle shortening (six clamped sections per lamb). Five of the clamped sections were placed at -1.1 degrees C for 0, 3, 6, 12, or 24 h. After storage at their respective times at -1.1 degrees C, the samples were placed at -30 degrees C for 90 min and then at -5 degrees C for 8 d. The sixth section (168-h section) was stored at -1.1 degrees C for the first 24 h, at 4 degrees C for 144 h, and then treated the same as other sampling times. Sections were sampled for pH, sarcomere length, shear force, and Western blot analyses before and after storage at -5 degrees C. Shear force values were the same (P > .05) from 0 to 24 h (4.5 kg at 0 h to 4.9 kg at 24 h) then declined (P slaughter is most likely due to sarcomere shortening.

  17. Magmatic underplating and crustal growth in the Emeishan Large Igneous Province, SW China, revealed by a passive seismic experiment

    Science.gov (United States)

    Chen, Yun; Xu, Yigang; Xu, Tao; Si, Shaokun; Liang, Xiaofeng; Tian, Xiaobo; Deng, Yangfan; Chen, Lin; Wang, Peng; Xu, Yihe; Lan, Haiqiang; Xiao, Fuhui; Li, Wei; Zhang, Xi; Yuan, Xiaohui; Badal, José; Teng, Jiwen

    2015-12-01

    In an attempt to characterize the subsurface structure that is related to fossil mantle plume activity, a comprehensive geophysical investigation was conducted in the Emeishan Large Igneous Province (ELIP). The nature and geometry of the crust were examined within the scheme of the domal structure of ELIP, which comprises the Inner, Intermediate and Outer zones, which are defined on the basis of the biostratigraphy of pre-volcanic sediments. The bulk crustal properties within the Inner Zone are characterized by high density, high P-wave velocity, high Vp/Vs ratios and large crustal thickness. A visible continuous seismic converter is present in the upper part of the crust in the whole Intermediate Zone and the eastern part of the Inner Zone, but it is absent in the Inner Zone, where another seismic converter is observed in the lower part of the crust. The geometric configuration of these converters is attributable to the addition of mantle-derived melts to the pre-existing crust and subsequent interaction between them. The crustal geometry, which is delineated by the migrated image of receiver functions from the passive seismic experiment, and the crustal properties collectively suggest that a mafic layer of 15-20 km thickness and 150-180 km width exists at the base of the crust in the Inner Zone. Such a mafic layer reflects a vertical crustal growth through magmatic underplating at the base of the crust and intraplating within the upper crust. The salient spatial correlation between the deep crustal structure and the dome strongly supports a genetic link between crustal thickening and plume activity, if the pre-volcanic domal uplift is generated by the Permian Emeishan mantle plume. This arrangement is further supported by the consistency of the extent of crustal uplift estimated by isostatic equilibrium modeling and sedimentary data. This study therefore characterizes and provides evidence for a plume-modified crust in a large igneous province.

  18. On crustal movement in Mt. Qomolangma area

    Institute of Scientific and Technical Information of China (English)

    CHEN; Junyong; (陈俊勇); WANG; Zemin; (王泽民); PANG; Shangyi; (庞尚益); ZHANG; Ji; (张; 骥); ZHANG; Quande; (张全德)

    2002-01-01

    Mt. Qomolangma lies in the collision zone between the fringe of Eurasia plate and Indian plate. The crustal movement there is still very active so far. In the past three decades China carried out five geodetic campaigns in Mt. Qomolangma and its north vicinal area, independently or cooperatively with other countries, including triangulation, leveling, GPS positioning, atmospheric, astronomical and gravity measurements. On the basis of the observation results achieved in the campaigns the crustal movements in the area were studied and explored. A non-stationary phenomenon both in time and space of the crustal vertical movement in the area is found. There seems to be some relevance between the phenomenon of non-stationary in time and seismic episode in China. The phenomenon of non-stationary in space is possibly relevant to the no-homo- geneity of crustal medium and non-uniform absorption of terrestrial stress. The horizontal crustal movement in the area is in the direction of NEE at a speed of 6—7 cm per year, and the trend of strike slip movement is manifested evidently in the collision fringe of Indian plate and Qinghai-Xizang block.

  19. Crustal structure of the eastern Qinling orogenic belt and implication for reactivation since the Cretaceous

    Science.gov (United States)

    Guo, Zhen; Chen, Y. John

    2016-06-01

    A high resolution crustal model of the eastern Qinling belt and central North China Craton (central NCC) is obtained along a N-S trending profile (corridor) by joint inversion of surface wave and receiver function. The NCC is one of the oldest cratons on Earth and the Qinling belt is the suture zone between the NCC and South China block (SCB). The Qinling belt is characterized by low crustal velocity (observed just above the Moho, consistent with the regional high bulk Vp/Vs ratio (> 1.8). The forward gravity modeling supports the presence of a high-density layer (3.05 g/cm3) at the base of the crust beneath the central NCC. We propose that the high velocity in the lowermost crust beneath the central NCC is most likely due to the repeated mafic underplating, which also results in high crustal Vp/Vs ratio and is responsible for the rapid crustal uplift during the late Mesozoic.

  20. Revised Thickness of the Lunar Crust from GRAIL Data: Implications for Lunar Bulk Composition

    Science.gov (United States)

    Taylor, G. Jeffrey; Wieczorek, Mark A.; Neumann, Gregory A.; Nimmo, Francis; Kiefer, Walter S.; Melosh, H. Jay; Phillips, Roger J.; Solomon, Sean C.; Andrews-Hanna, Jeffrey C.; Asmar, Sami W.; Konopliv, Alexander S.; Lemoine, Frank G.; Smith, David E.; Watkins, Michael W.; Williams, James G.; Zuber, Maria T.

    2013-01-01

    High-resolution gravity data from GRAIL have yielded new estimates of the bulk density and thickness of the lunar crust. The bulk density of the highlands crust is 2550 kg m-3. From a comparison with crustal composition measured remotely, this density implies a mean porosity of 12%. With this bulk density and constraints from the Apollo seismic experiment, the average global crustal thickness is found to lie between 34 and 43 km, a value 10 to 20 km less than several previous estimates. Crustal thickness is a central parameter in estimating bulk lunar composition. Estimates of the concentrations of refractory elements in the Moon from heat flow, remote sensing and sample data, and geophysical data fall into two categories: those with refractory element abundances enriched by 50% or more relative to Earth, and those with abundances the same as Earth. Settling this issue has implications for processes operating during lunar formation. The crustal thickness resulting from analysis of GRAIL data is less than several previous estimates. We show here that a refractory-enriched Moon is not required

  1. Crustal Structure at a Young Continental Rift: A Receiver Function Study from Lake Tanganyika

    Science.gov (United States)

    Hodgson, I. D. S.; Illsley-Kemp, F.; Gallacher, R. J.; Keir, D.; Ebinger, C. J.; Drooff, C.; Khalfan, M.

    2015-12-01

    Lake Tanganyika, in western Tanzania, spans a large section of the Western rift yet there are very few constraints on bulk crustal and upper mantle structure. The Western rift system has no surface expression of magmatism, which is in stark contrast to the Eastern branch. This observation is difficult to reconcile with the approximately coeval initiation of rifting of the two branches. The variation in the nature of rifting provides a perfect setting to test current hypotheses for the initiation of continental breakup and early-stage development of continental rifts. The deployment of a seismic network of 13 broadband instruments on the south eastern shore of Lake Tanganyika, for 16 months, between 2014 and 2015 provides a unique opportunity to investigate extensional processes in thick continental lithosphere. We present here results from a P to S receiver function study that provides information on bulk crustal Vp/Vs ratio along the rift; a property that is sensitive to the presence of magmatic intrusions in the lower crust. Additionally this method allows us to map variations in crustal thickness both parallel and perpendicular to the rift axis. These results thus provide unprecedented insight into the large-scale mechanics of early-stage continental rifting along the non-volcanic Western rift.

  2. Large area bulk superconductors

    Science.gov (United States)

    Miller, Dean J.; Field, Michael B.

    2002-01-01

    A bulk superconductor having a thickness of not less than about 100 microns is carried by a polycrystalline textured substrate having misorientation angles at the surface thereof not greater than about 15.degree.; the bulk superconductor may have a thickness of not less than about 100 microns and a surface area of not less than about 50 cm.sup.2. The textured substrate may have a thickness not less than about 10 microns and misorientation angles at the surface thereof not greater than about 15.degree.. Also disclosed is a process of manufacturing the bulk superconductor and the polycrystalline biaxially textured substrate material.

  3. Two-layer Crustal Structure of the Contiguous United States from Joint Inversion of USArray Receiver Functions and Gravity

    Science.gov (United States)

    Ma, X.; Lowry, A. R.

    2015-12-01

    The composition and thickness of crustal layering is fundamental to understanding the evolution and dynamics of continental lithosphere. Lowry and Pérez-Gussinyé (2011) found that the western Cordillera of the United States, characterized by active deformation and high heat flow, is strongly correlated with low bulk crustal seismic velocity ratio. They interpreted this observation as evidence that quartz controls continental tectonism and deformation. We will present new imaging of two-layer crustal composition and structure from cross-correlation of observed receiver functions and model synthetics. The cross-correlation coefficient of the two-layer model increases significantly relative to an assumed one-layer model, and the lower crustal thickness map from raw two-layer modeling (prior to Bayesian filtering with gravity models and Optimal Interpolation) clearly shows Colorado plateau and Appalachian boundaries, which are not apparent in upper crustal models, and also the high vP/vS fill the most of middle continental region while low vP/vS are on the west and east continental edge. In the presentation, we will show results of a new algorithm for joint Bayesian inversion of thickness and vP/vS of two-layer continental crustal structure. Recent thermodynamical modeling of geophysical models based on lab experiment data (Guerri et al., 2015) found that a large impedance contrast can be expected in the midcrust due to a phase transition that decreases plagioclase and increases clinopyroxene, without invoking any change in crustal chemistry. The depth of the transition depends on pressure, temperature and hydration, and in this presentation we will compare predictions of layer thicknesses and vP/vS predicted by mineral thermodynamics to those we observe in the USArray footprint.

  4. Simulation studies of circular muscle contraction, longitudinal muscle shortening, and their coordination in esophageal transport.

    Science.gov (United States)

    Kou, Wenjun; Pandolfino, John E; Kahrilas, Peter J; Patankar, Neelesh A

    2015-08-15

    On the basis of a fully coupled active musculomechanical model for esophageal transport, we aimed to find the roles of circular muscle (CM) contraction and longitudinal muscle (LM) shortening in esophageal transport, and the influence of their coordination. Two groups of studies were conducted using a computational model. In the first group, bolus transport with only CM contraction, only LM shortening, or both was simulated. Overall features and detailed information on pressure and the cross-sectional area (CSA) of mucosal and the two muscle layers were analyzed. In the second group, bolus transport with varying delay in CM contraction or LM shortening was simulated. The effect of delay on esophageal transport was studied. For cases showing abnormal transport, pressure and CSA were further analyzed. CM contraction by itself was sufficient to transport bolus, but LM shortening by itself was not. CM contraction decreased the CSA and the radius of the muscle layer locally, but LM shortening increased the CSA. Synchronized CM contraction and LM shortening led to overlapping of muscle CSA and pressure peaks. Advancing LM shortening adversely influenced bolus transport, whereas lagging LM shortening was irrelevant to bolus transport. In conclusion, CM contraction generates high squeezing pressure, which plays a primary role in esophageal transport. LM shortening increases muscle CSA, which helps to strengthen CM contraction. Advancing LM shortening decreases esophageal distensibility in the bolus region. Lagging LM shortening no longer helps esophageal transport. Synchronized CM contraction and LM shortening seems to be most effective for esophageal transport.

  5. AN IMPROVED OPTIMAL CHANNEL SHORTENING ALGORITHM FOR DMT MODULATION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In Discrete Multi-Tone (DMT) modulation systems, the well-known technique to overcome the Inter-Carrier Interference (ICI)/Inter-Symbol Interference (ISI) caused by the inadequate Cyclic Prefix (CP) length is to use a Time-Domain Equalizer (TDE) at the receiver front-end. An algorithm used to calculate the coefficients of the optimal shortening Time Domain Equalizer (TDE) was given by Melsa. However, this al gorithm requires that the length of the TDE must be smaller than or equal to the memory length of the target impulse response. This paper modifies this algorithm and makes it not only fit for calculating the coefficients of the TDE with arbitrary length, but also have a much less computational time.

  6. The randomized shortened dental arch study: tooth loss.

    Science.gov (United States)

    Walter, M H; Weber, A; Marré, B; Gitt, I; Gerss, J; Hannak, W; Hartmann, S; Heydecke, G; Huppertz, J; Jahn, F; Ludwig, A; Mundt, T; Kern, M; Klein, V; Pospiech, P; Stumbaum, M; Wolfart, S; Wöstmann, B; Busche, E; Böning, K; Luthardt, R G

    2010-08-01

    The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA concept. First tooth loss after treatment was the primary outcome measure. This event occurred in 13 patients in the RDP group and nine patients in the SDA group. The respective Kaplan-Meier survival rates at 38 months were 0.83 (95% CI: 0.74-0.91) in the RDP group and 0.86 (95% CI: 0.78-0.95) in the SDA group, the difference being non-significant. PMID:20400723

  7. INVESTIGATION OF CRUSTAL MOTION IN THE TIEN SHAN USING INSAR

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R J

    2011-02-25

    The northern Tien Shan of Central Asia is an area of active mid-continent deformation. Although far from a plate boundary, this region has experienced 5 earthquakes larger than magnitude 7 in the past century and includes one event that may as be as large as Mw 8.0. Previous studies based on GPS measurements indicate on the order of 23 mm/yr of shortening across the entire Tien Shan and up to 15 mm/year in the northern Tien Shan (Figure 1). The seismic moment release rate appears comparable with the geodetic measured slip, at least to first order, suggesting that geodetic rates can be considered a proxy for accumulation rates of stress for seismic hazard estimation. Interferometric synthetic aperture radar may provide a means to make detailed spatial measurements and hence in identifying block boundaries and assisting in seismic hazard. Therefore, we hoped to define block boundaries by direct measurement and by identifying and resolving earthquake slip. Due to political instability in Kyrgzystan, the existing seismic network has not performed as well as required to precisely determine earthquake hypocenters in remote areas and hence InSAR is highly useful. In this paper we present the result of three earthquake studies and show that InSAR is useful for refining locations of teleseismically located earthquakes. ALOS PALSAR data is used to investigate crustal motion in the Tien Shan mountains of Central Asia. As part of the work, considerable software development was undertaken to process PALSAR data. This software has been made freely available. Two damaging earthquakes have been imaged in the Tien Shan and the locations provided by ALOS InSAR have helped to refine seismological velocity models. A third earthquake south of Kyrgyzstan was also imaged. The use of InSAR data and especially L band is therefore very useful in providing groundtruth for earthquake locations.

  8. New results and implications for lunar crustal iron distribution using sensor data fusion techniques

    Science.gov (United States)

    Clark, P. E.; McFadden, L. A.

    2000-02-01

    Remote measurements of the Moon have provided iron maps, and thus essential constraints for models of lunar crustal formation and mare basalt petrogenesis. A bulk crustal iron map was produced for the equatorial region from Apollo gamma-ray (AGR) spectrometer measurements, and a global iron variation map from recent Clementine spectral reflectance (CSR) measurements. Both iron maps show bimodal distribution, but have significantly different peak values and variations. In this paper, CSR data have been recalibrated to pyroxene in lunar landing site soils. A residual iron map is derived from the difference between AGR (bulk) and recalibrated CSR (pyroxene) iron abundances. The most likely interpretation is that the residual represents ferrous iron in olivine. This residual iron is anticorrelated to basin age, with older basins containing less olivine, suggesting segregation of basin basalt sources from a progressively fractionating underlying source region at the time of basin formation. Results presented here provide a quantitative basis for (1) establishing the relationship between direct geochemical (gamma-ray, X-ray) and mineralogical (near-IR) remote sensing data sets using sensor data fusion techniques to allow (2) simultaneous determination of elemental and mineralogical component distribution on remote targets and (3) meaningful interpretation of orbital and ground-based spectral reflectance measurements. When calibrated data from the Lunar Prospector mission are available, mapping of bulk crustal iron and iron-bearing soil components will be possible for the entire Moon. Similar analyses for data from the Near Earth Asteroid Rendezvous (NEAR) mission to asteroid 433 Eros will constrain models of asteroid formation.

  9. Plio-Quaternary thin-skinned tectonics along the crustal front flexure of the southern Central Andes: a record of the regional stress regime or of local tectonic-driven gravitational processes?

    Science.gov (United States)

    Messager, Grégoire; Nivière, Bertrand; Lacan, Pierre; Hervouët, Yves; Xavier, Jean-Paul

    2014-04-01

    We present here a record of Plio-Pleistocene deformations above the flexural front of the southern Central Andes of Argentina. We combine a seismic profile with structural and geomorphological observations to show that thin-skinned extension located on top of the crustal front flexure is coeval with thin-skinned shortening at the toe of the topographic bulge. The seismic line shows that a flat zone with no internal deformation separates the stretched and shortened domains. Such features are usually interpreted as the result of strike-slip faulting along basement faults, or tangential longitudinal strain folding in the soft sedimentary cover above crustal bending. We propose an alternative linking extension at the apex of the crustal anticline, to basal contraction by the downslope translation of a rigid thin nappe of sediments (30 × 30 km2 in area) above evaporites at a depth of 700-900 m. The size of such a process is unusually large onshore (630-810 km3) but mimics the gravity gliding observed in deltas and passive margins. Since this process disconnects zones with a shallow stress field from deeper crustal levels, it could allow extension above a compressive deformation front and should not be interpreted merely as a record of the crustal stress regime. Large-scale gravity gliding of the cover down the slope of a structural high could also explain some of the extension observed in mountain hinterlands.

  10. A new crustal Moho depth model for Iran based on the seismic data

    Science.gov (United States)

    Beheshti, Sayyed Amir Hossein; Kiamehr, Ramin

    2010-05-01

    The Alborz and Zagrous Mountains build the northern and western part of the Iran and belongs to Alpine-Himalayan orogen in western Asia. These regions are the most active tectonic areas in the world as it undergoes extensive crustal deformation and shortening. Recently, the new gravimetric Moho depth model for Iran determined by Kiamehr and Gomez by using the inversion of the Bougure anomaly based on Parker-Oldenburg approach. In this research, we used data from 55 stations of the Iranian Telemetry Seismic Network to estimate the Moho depth thickness by P and S receiver function methods. The main idea of research is evaluation of the gravimetric Moho model based on the independent and precise seismic approach. The minimum, maximum, mean and standard deviation of difference between the seismic and gravimetric models estimated about -8.2, 4.3, -0.8 and 1.2 km, respectively.

  11. On the Crustal Matter of Magnetars

    CERN Document Server

    Nag, Nandini

    2009-01-01

    We have investigated some of the properties of dense sub-nuclear matter at the crustal region (both the outer crust and the inner crust region) of a magnetar. The relativistic version of Thomas-Fermi (TF) model is used in presence of strong quantizing magnetic field for the outer crust matter. The compressed matter in the outer crust, which is a crystal of metallic iron, is replaced by a regular array of spherically symmetric Wigner-Seitz (WS) cells. In the inner crust region, a mixture of iron and heavier neutron rich nuclei along with electrons and free neutrons has been considered. Conventional Harrison-Wheeler (HW) and Bethe-Baym-Pethick (BBP) equation of states are used for the nuclear mass formula. A lot of significant changes in the characteristic properties of dense crustal matter, both at the outer crust and the inner crust, have been observed.

  12. On the crustal matter of magnetars

    Science.gov (United States)

    Nag, Nandini; Ghosh, Sutapa; Chakrabarty, Somenath

    2010-07-01

    We have investigated some of the properties of dense sub-nuclear matter at the crustal region (both the outer crust and the inner crust region) of a magnetar. The relativistic version of the Thomas-Fermi (TF) model is used in the presence of a strong quantizing magnetic field for the outer crust matter. The compressed matter in the outer crust, which is a crystal of metallic iron, is replaced by a regular array of spherically symmetric Wigner-Seitz (WS) cells. In the inner crust region, a mixture of iron and heavier neutron-rich nuclei along with electrons and free neutrons has been considered. Conventional Harrison-Wheeler (HW) and Bethe-Baym-Pethick (BBP) equation of states are used for the nuclear mass formula. A lot of significant changes in the characteristic properties of dense crustal matter, both at the outer crust and at the inner crust, have been observed.

  13. On the crustal matter of magnetars

    Energy Technology Data Exchange (ETDEWEB)

    Nag, Nandini; Ghosh, Sutapa; Chakrabarty, Somenath [Department of Physics, Visva-Bharati, Santiniketan (India)

    2010-07-15

    We have investigated some of the properties of dense sub-nuclear matter at the crustal region (both the outer crust and the inner crust region) of a magnetar. The relativistic version of the Thomas-Fermi (TF) model is used in the presence of a strong quantizing magnetic field for the outer crust matter. The compressed matter in the outer crust, which is a crystal of metallic iron, is replaced by a regular array of spherically symmetric Wigner-Seitz (WS) cells. In the inner crust region, a mixture of iron and heavier neutron-rich nuclei along with electrons and free neutrons has been considered. Conventional Harrison-Wheeler (HW) and Bethe-Baym-Pethick (BBP) equation of states are used for the nuclear mass formula. A lot of significant changes in the characteristic properties of dense crustal matter, both at the outer crust and at the inner crust, have been observed. (orig.)

  14. Magnetar Field Evolution and Crustal Plasticity

    Science.gov (United States)

    Lander, S. K.

    2016-06-01

    The activity of magnetars is believed to be powered by colossal magnetic energy reservoirs. We sketch an evolutionary picture in which internal field evolution in magnetars generates a twisted corona, from which energy may be released suddenly in a single giant flare, or more gradually through smaller outbursts and persistent emission. Given the ages of magnetars and the energy of their giant flares, we suggest that their evolution is driven by a novel mechanism: magnetic flux transport/decay due to persistent plastic flow in the crust, which would invalidate the common assumption that the crustal lattice is static and evolves only under Hall drift and Ohmic decay. We estimate the field strength required to induce plastic flow as a function of crustal depth, and the viscosity of the plastic phase. The star’s superconducting core may also play a role in magnetar field evolution, depending on the star’s spindown history and how rotational vortices and magnetic fluxtubes interact.

  15. Bulk chemicals from biomass

    NARCIS (Netherlands)

    Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2008-01-01

    Given the current robust forces driving sustainable production, and available biomass conversion technologies, biomass-based routes are expected to make a significant impact on the production of bulk chemicals within 10 years, and a huge impact within 20-30 years. In the Port of Rotterdam there is a

  16. Development of conjugate shear bands during bulk simple shearing

    Science.gov (United States)

    Harris, L. B.; Cobbold, P. R.

    In rocks possessing a strong planar fabric, shear bands of constant shear sense and oriented at an oblique angle to the foliation are considered by many authors to be characteristic of a non-coaxial bulk deformation history, whereas conjugate shear bands are considered to indicate coaxial shortening. However, in two areas where bulk deformation history appears to be non-coaxial (Cap Corse, Corsica and Ile de Groix, Brittany), conjugate shear bands are observed. In order to investigate this problem, experiments were performed by bulk simple shearing using Plasticine as a rock analogue. When slip between layers of the model is permitted, shear bands of normal-fault geometry form with both the same and opposite shear sense as the bulk simple shearing at approximately the same angle with the layering (40°) irrespective of layer orientation in the undeformed state (for initial orientations of 50, 30 and 15°). Shear bands are initially formed within individual layers and may propagate across layer interfaces when further movement along these is inhibited. The existence of conjugate shear bands in Corsica and Ile de Groix is therefore not incompatible with a model of bulk simple shearing for these two regions. In field studies, one should perhaps exercise care in using shear bands to determine the kind of motion or the sense of bulk shearing.

  17. PRESENT-DAY CRUSTAL MOVEMENT OFNORTH-EASTERN QINGHAI-TIBET PLATEAU

    Institute of Scientific and Technical Information of China (English)

    WangQingliang; WangWenping; CuiDuxin; ZhuGuizhi; LiangWeifeng

    2003-01-01

    GPS observations of CMONOC and other network reveal that, relative to Dingxin fiducial station in Alashan block, the crustal movements of north-eastern Qinghai-Tibet plateau and its adjacent regions have the following characteristics: (i)The western part of Qilian block is shortening and moving mainly northeastward, the 8 mm/a motion of southern margin of Qaidam basin is almost completely absorbed by compressed subsidence of Qaidam basin and uplift of Qilian mountain; (ii) Eastern part of Qilian block manifests itself mainly as block-like rotation or extrusion along Haiyuan left-lateral fault,with an angular velocity of 0.135 /Ma; (iii) Due to the clockwise rotation of the eastern Qilian sub-block in the NW Liupanshan range, Ordos block shows a slight anticlockwise rotation; (iv) Haiyuan left-lateral fault and northern edge thrust fault of Qilian mountain jointly constitute the major northeastern boundary of Qinghai-Tibet plateau judging from the present-day crustal movement.

  18. Contraction-specific differences in maximal muscle power during stretch-shortening cycle movements in elderly males and females

    DEFF Research Database (Denmark)

    Caserotti, Paolo; Aagaard, Per; Simonsen, Erik Bruun;

    2001-01-01

    Aging, muscle power, stretch-shortening cycle, eccentric muscle actions, concentric contractions......Aging, muscle power, stretch-shortening cycle, eccentric muscle actions, concentric contractions...

  19. Chemical Sharpening, Shortening, and Unzipping of Boron Nitride Nanotubes

    Science.gov (United States)

    Liao, Yunlong; Chen, Zhongfang; Connell, John W.; Fay, Catharine C.; Park, Cheol; Kim, Jae-Woo; Lin, Yi

    2014-01-01

    Boron nitride nanotubes (BNNTs), the one-dimensional member of the boron nitride nanostructure family, are generally accepted to be highly inert to oxidative treatments and can only be covalently modifi ed by highly reactive species. Conversely, it is discovered that the BNNTs can be chemically dispersed and their morphology modifi ed by a relatively mild method: simply sonicating the nanotubes in aqueous ammonia solution. The dispersed nanotubes are significantly corroded, with end-caps removed, tips sharpened, and walls thinned. The sonication treatment in aqueous ammonia solution also removes amorphous BN impurities and shortened BNNTs, resembling various oxidative treatments of carbon nanotubes. Importantly, the majority of BNNTs are at least partially longitudinally cut, or "unzipped". Entangled and freestanding BN nanoribbons (BNNRs), resulting from the unzipping, are found to be approximately 5-20 nm in width and up to a few hundred nanometers in length. This is the fi rst chemical method to obtain BNNRs from BNNT unzipping. This method is not derived from known carbon nanotube unzipping strategies, but is unique to BNNTs because the use of aqueous ammonia solutions specifi cally targets the B-N bond network. This study may pave the way for convenient processing of BNNTs, previously thought to be highly inert, toward controlling their dispersion, purity, lengths, and electronic properties.

  20. Shortening a Patient Experiences Survey for Medical Homes

    Directory of Open Access Journals (Sweden)

    Judy H. Ng

    2015-12-01

    Full Text Available The Consumer Assessment of Healthcare Providers and Systems—Patient-Centered Medical Home (CAHPS PCMH Survey assesses patient experiences reflecting domains of care related to general patient experience (access to care, communication with providers, office staff interaction, provider rating and PCMH-specific aspects of patient care (comprehensiveness of care, self-management support, shared decision making. The current work compares psychometric properties of the current survey and a proposed shortened version of the survey (from 52 to 26 adult survey items, from 66 to 31 child survey items. The revisions were based on initial psychometric analysis and stakeholder input regarding survey length concerns. A total of 268 practices voluntarily submitted adult surveys and 58 submitted child survey data to the National Committee for Quality Assurance in 2013. Mean unadjusted scores, practice-level item and composite reliability, and item-to-scale correlations were calculated. Results show that the shorter adult survey has lower reliability, but still it still meets general definitions of a sound survey for the adult version, and resulted in few changes to mean scores. The impact was more problematic for the pediatric version. Further testing is needed to investigate approaches to improving survey response and the relevance of survey items in informing quality improvement.

  1. Bulk materials handling review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-02-15

    The paper provides details of some of the most important coal handling projects and technologies worldwide. It describes development by Aubema Crushing Technology GmbH, Bedeschi, Cimbria Moduflex, DBT, Dynamic Air Conveying Systems, E & F Services, InBulk Technologies, Nord-Sen Metal Industries Ltd., Pebco Inc, Primasonics International Ltd., R.J.S. Silo Clean (International) Ltd., Takraf GmbH, and The ACT Group. 17 photos.

  2. Modes of continental extension in a crustal wedge

    Science.gov (United States)

    Wu, Guangliang; Lavier, Luc L.; Choi, Eunseo

    2015-07-01

    We ran numerical experiments of the extension of a crustal wedge as an approximation to extension in an orogenic belt or a continental margin. We study the effects of the strength of the lower crust and of a weak mid-crustal shear zone on the resulting extension styles. A weak mid-crustal shear zone effectively decouples upper crustal extension from lower crustal flow. Without the mid-crustal shear zone, the degree of coupling between the upper and the lower crust increases and extension of the whole crust tends to focus on the thickest part of the wedge. We identify three distinct modes of extension determined by the strength of the lower crust, which are characterized by 1) localized, asymmetric crustal exhumation in a single massif when the lower crust is weak, 2) the formation of rolling-hinge normal faults and the exhumation of lower crust in multiple core complexes with an intermediate strength lower crust, and 3) distributed domino faulting over the weak mid-crustal shear zone when the lower crust is strong. A frictionally stronger mid-crustal shear zone does not change the overall model behaviors but extension occurred over multiple rolling-hinges. The 3 modes of extension share characteristics similar to geological models proposed to explain the formation of metamorphic core complexes: 1) the crustal flow model for the weak lower crust, 2) the rolling-hinge and crustal flow models when the lower crust is intermediate and 3) the flexural uplift model when the lower crust is strong. Finally we show that the intensity of decoupling between the far field extension and lower crustal flow driven by the regional pressure gradient in the wedge control the overall style of extension in the models.

  3. Modes of continental extension in a crustal wedge

    KAUST Repository

    Wu, Guangliang

    2015-07-01

    © 2015 Elsevier B.V. We ran numerical experiments of the extension of a crustal wedge as an approximation to extension in an orogenic belt or a continental margin. We study the effects of the strength of the lower crust and of a weak mid-crustal shear zone on the resulting extension styles. A weak mid-crustal shear zone effectively decouples upper crustal extension from lower crustal flow. Without the mid-crustal shear zone, the degree of coupling between the upper and the lower crust increases and extension of the whole crust tends to focus on the thickest part of the wedge. We identify three distinct modes of extension determined by the strength of the lower crust, which are characterized by 1) localized, asymmetric crustal exhumation in a single massif when the lower crust is weak, 2) the formation of rolling-hinge normal faults and the exhumation of lower crust in multiple core complexes with an intermediate strength lower crust, and 3) distributed domino faulting over the weak mid-crustal shear zone when the lower crust is strong. A frictionally stronger mid-crustal shear zone does not change the overall model behaviors but extension occurred over multiple rolling-hinges. The 3 modes of extension share characteristics similar to geological models proposed to explain the formation of metamorphic core complexes: 1) the crustal flow model for the weak lower crust, 2) the rolling-hinge and crustal flow models when the lower crust is intermediate and 3) the flexural uplift model when the lower crust is strong. Finally we show that the intensity of decoupling between the far field extension and lower crustal flow driven by the regional pressure gradient in the wedge control the overall style of extension in the models.

  4. Limitations of H-κ stacking: ambiguous results caused by crustal layering

    Science.gov (United States)

    Wölbern, I.; Rümpker, G.

    2016-07-01

    Over the past decade, the H-κ stacking technique of Zhu and Kanamori (J Geophys Res 105:2969-2980, 2000) has become a standard tool to determine the crustal thickness H and the bulk crustal vP/vS ratio κ from teleseismic receiver functions. It is obvious that unfavorable noise conditions as well as a complex 3D velocity structure can severely hamper the interpretation of receiver-function data. However, we observe that ambiguities can even arise from a simple 1D layered velocity structure which raises a high potential for misinterpretations. To analyze the feasibility and basic limitations of the H-κ stacking method, we conduct a series of tests based on synthetic data. The impact of different given elementary parameters, related either to the velocity structure or to the data processing, is evaluated in a series of eight individual tests. We deliberately exclude complications such as 3D structural variations and/or noise to show that even a simple 1D velocity structure, involving, e.g., an additional inter-crustal discontinuity, can have significant consequences for the interpretation of the results. However, our modeling suggests that more complex crustal structures may lead to even less reliable results. Additionally, our tests illustrate that time shifts of the maxima in the H-κ domain due to the superposition and merging of individual phases can lead to significantly overestimated vP/vS ratios. In general, the depth to the Moho (or other discontinuities of interest) is less significantly affected. Our tests indicate the necessity to accurately check delay times derived from the maxima of the H-κ stacks against corresponding phases in the receiver functions. Repeating the stacking with varied weighting factors and filter ranges can help to reduce the ambiguities and to avoid possible misinterpretation.

  5. Circular smooth muscle contributes to esophageal shortening during peristalsis

    Institute of Scientific and Technical Information of China (English)

    Anil K Vegesna; Keng-Yu Chuang; Ramashesai Besetty; Steven J Phillips; Alan S Braverman; Mary F Barbe; Michael R Ruggieri

    2012-01-01

    AIM:To study the angle between the circular smooth muscle (CSM) and longitudinal smooth muscle (LSM) fibers in the distal esophagus.METHODS:In order to identify possible mechanisms for greater shortening in the distal compared to proximal esophagus during peristalsis,the angles between the LSM and CSM layers were measured in 9 cadavers.The outer longitudinal layer of the muscularis propria was exposed after stripping the outer serosa.The inner circular layer of the muscularis propria was then revealed after dissection of the esophageal mucosa and the underlying muscularis mucosa.Photographs of each specimen were taken with half of the open esophagus folded back showing both the outer longitudinal and inner circular muscle layers.Angles were measured every one cm for 10 cm proximal to the squamocolumnar junction (SCJ) by two independent investigators.Two human esophagi were obtained from organ transplant donors and the angles between the circular and longitudinal smooth muscle layers were measured using micro-computed tomography (micro CT) and Image J software.RESULTS:All data are presented as mean ± SE.The CSM to LSM angle at the SCJ and 1 cm proximal to SCJ on the autopsy specimens was 69.3 ± 4.62 degrees vs 74.9 ± 3.09 degrees,P =0.32.The CSM to LSM angle at SCJ were statistically significantly lower than at 2,3,4 and 5 cm proximal to the SCJ,69.3 ± 4.62 degrees vs 82.58 ± 1.34 degrees,84.04 ± 1.64 degrees,84.87 ± 1.04 degrees and 83.72 ± 1.42 degrees,P =0.013,P =0.008,P =0.004,P =0.009 respectively.The CSM to LSM angle at SCJ was also statistically significantly lower than the angles at 6,7 and 8 cm proximal to the SCJ,69.3 ± 4.62 degrees vs 80.18 ± 2.09 degrees,81.81 ± 1.75 degrees and 80.96 ± 2.04 degrees,P =0.05,P =0.02,P =0.03 respectively.The CSM to LSM angle at 1 cm proximal to SCJ was statistically significantly lower than at 3,4 and 5 cm proximal to the SCJ,74.94 ± 3.09 degrees vs 84.04 ± 1.64 degrees,84.87± 1.04 degrees and 83.72 ± 1

  6. Crustal Growth: In Defense of the Dogma

    Science.gov (United States)

    Albarede, F.; Blichert-Toft, J.; Guitreau, M.

    2012-12-01

    Plate tectonics was not even in its teens when Armstrong suggested that mantle and crust have interacted at steady-state over Earth's history. With the help of new geochemical tools and large-scale compilations, the concept of steady-state crust (as opposed to continuous crustal growth) is being revived with the implications that the equivalent of several volumes of present-day crust (PDCV) may have been subducted through geological times. Here we argue --or recall-- that four different lines of evidence invalidate this model. (i) The subduction filter must be particularly efficient for argon, even more so than for LILE and most other volatile elements. Atmosphere collects 40Ar degassed from both the extant crust and the crust dragged down at subduction zones over geological time. Regardless of the residence time of the crust at the surface, the amount of atmospheric 40Ar limits subduction of continental crust into the mantle to < 30% of the PDCV [1]. (ii) EM II, the only component that undoubtedly represents subducted continental crust in oceanic basalts, is extremely uncommon. (iii) Crustal age histograms are irrepressibly episodic. It has been argued that erosion selectively removes the crust with the elusive ages [2]. Ages of detrital zircons, which in the selective erosion conjecture should fill the voids, do not support this view [3]. Episodicity is difficult to reconcile with a continental protolith isolated by the common geological processes working either at mid-ocean ridges or subduction zones. A role may be recognized for Wilson cycles, if they can be shown to have prevailed for the entire history of the Earth. Geochemistry demonstrates that superplume material makes up the crustal protolith of all the major juvenile provinces. (iv) The residence time in the mantle of the elements distinctive of the crust is similar to the age of the Earth or even longer [4]. Continental crust finds its source in the instabilities of the lower mantle and the irreversible

  7. Crustal structure interpreted from magnetic anomalies

    Science.gov (United States)

    Phillips, Jeffrey D.; Reynolds, Richard L.; Frey, Herbert

    1991-01-01

    This review, discusses publications during the last quadrennium (1987-1990) that used aeromagnetic data, marine magnetic data, satellite magnetic data, and rock magnetic and petrologic data to provide information on the sources of magnetic anomalies. The publications reviewed reflect increased integration of rock magnetic property and petrologic studies with magnetic anomaly interpretation studies, particularly in deep crustal magnetization, exploration for hydrocarbons, and inversion of marine magnetic anomalies. Interpretations of aeromagnetic data featuring image display techniques and using the horizontal gradient method for locating magnetization boundaries became standard.

  8. A numerical model for dynamic crustal-scale fluid flow

    Science.gov (United States)

    Sachau, Till; Bons, Paul; Gomez-Rivas, Enrique; Koehn, Daniel

    2015-04-01

    Fluid flow in the crust is often envisaged and modeled as continuous, yet minimal flow, which occurs over large geological times. This is a suitable approximation for flow as long as it is solely controlled by the matrix permeability of rocks, which in turn is controlled by viscous compaction of the pore space. However, strong evidence (hydrothermal veins and ore deposits) exists that a significant part of fluid flow in the crust occurs strongly localized in both space and time, controlled by the opening and sealing of hydrofractures. We developed, tested and applied a novel computer code, which considers this dynamic behavior and couples it with steady, Darcian flow controlled by the matrix permeability. In this dual-porosity model, fractures open depending on the fluid pressure relative to the solid pressure. Fractures form when matrix permeability is insufficient to accommodate fluid flow resulting from compaction, decompression (Staude et al. 2009) or metamorphic dehydration reactions (Weisheit et al. 2013). Open fractures can close when the contained fluid either seeps into the matrix or escapes by fracture propagation: mobile hydrofractures (Bons, 2001). In the model, closing and sealing of fractures is controlled by a time-dependent viscous law, which is based on the effective stress and on either Newtonian or non-Newtonian viscosity. Our simulations indicate that the bulk of crustal fluid flow in the middle to lower upper crust is intermittent, highly self-organized, and occurs as mobile hydrofractures. This is due to the low matrix porosity and permeability, combined with a low matrix viscosity and, hence, fast sealing of fractures. Stable fracture networks, generated by fluid overpressure, are restricted to the uppermost crust. Semi-stable fracture networks can develop in an intermediate zone, if a critical overpressure is reached. Flow rates in mobile hydrofractures exceed those in the matrix porosity and fracture networks by orders of magnitude

  9. The shortened KK spectrum of IIB supergravity on Y^{p,q}

    CERN Document Server

    Ardehali, Arash Arabi; Szepietowski, Phillip

    2014-01-01

    We present the shortened KK spectrum of IIB supergravity compactified on Y^{p,q}. The (untwisted) shortened spectrum on S^5/Z_{2p} and T^{1,1}/Z_p are obtained as special cases when p=q and q=0, respectively. Knowledge of the shortened spectrum allows us to compute the superconformal index of these theories and to find agreement with earlier calculations from the dual field theories. We also employ the shortened spectrum to perform a 1/N^2 test of AdS/CFT by holographically reproducing the difference of the central charges, c-a=p/8, of the dual CFTs.

  10. Martian sub-crustal stress from gravity and topographic models

    Science.gov (United States)

    Tenzer, Robert; Eshagh, Mehdi; Jin, Shuanggen

    2015-09-01

    The latest Martian gravity and topographic models derived from the Mars Orbiter Laser Altimeter and the Mars Global Surveyor spacecraft tracking data are used to compute the sub-crustal stress field on Mars. For this purpose, we apply the method for a simultaneous determination of the horizontal sub-crustal stress component and the crustal thickness based on solving the Navier-Stokes problem and incorporating the Vening Meinesz-Moritz inverse problem of isostasy. Results reveal that most of the Martian sub-crustal stress is concentrated in the Tharsis region, with the most prominent signatures attributed to a formation of Tharsis major volcanoes followed by crustal loading. The stress distribution across the Valles Marineris rift valleys indicates extensional tectonism. This finding agrees with more recent theories of a tectonic origin of Valles Marineris caused, for instance, by a crustal loading of the Tharsis bulge that resulted in a regional trusting and folding. Aside from these features, the Martian stress field is relatively smooth with only a slightly enhanced pattern of major impact basins. The signatures of active global tectonics and polar ice load are absent. Whereas the signature of the hemispheric dichotomy is also missing, the long-wavelength spectrum of the stress field comprises the signature of additional dichotomy attributed to the isostatically uncompensated crustal load of Tharsis volcanic accumulations. These results suggest a different origin of the Earth's and Martian sub-crustal stress. Whereas the former is mainly related to active global tectonics, the latter is generated by a crustal loading and regional tectonism associated with a volcanic evolution on Mars. The additional sub-crustal stress around major impact basins is likely explained by a crustal extrusion after impact followed by a Moho uplift.

  11. Wormholes in Bulk Viscous Cosmology

    OpenAIRE

    Jamil, Mubasher

    2008-01-01

    We investigate the effects of the accretion of phantom energy with non-zero bulk viscosity onto a Morris-Thorne wormhole. We have found that if the bulk viscosity is large then the mass of wormhole increases rapidly as compared to small or zero bulk viscosity.

  12. Seismic evidence of crustal heterogeneity beneath the northwestern Deccan volcanic province of India from joint inversion of Rayleigh wave dispersion measurements and P receiver functions

    Science.gov (United States)

    Deshpande, A. A.; Mohan, G.

    2016-10-01

    The northwestern Deccan volcanic province (NWDVP) of India, encompassing the Saurashtra peninsula and the adjoining Gulf of Cambay, is investigated through joint inversion of surface wave dispersion measurements and teleseismic P receiver functions, to estimate the crustal and shallow upper mantle shear wave velocity (Vs) structure. The Mw ∼ 7.7 Bhuj earthquake and the post Bhuj regional events, recorded during the period 2001-2010 at 7 stations along 37 source-receiver paths were used along with 35 teleseismic events. A joint curve fitting inversion technique is applied to obtain a best fit for the fundamental mode Rayleigh wave group velocity dispersion curves for time periods 5-50 s and high quality crustal P wave receiver functions obtained at each station. Significant crustal heterogeneity is observed within the study region with the average crustal Vs ranging from 3.5 km/s to 3.8 km/s with the paths cutting across the Gulf of Cambay exhibiting large reduction in shear wave velocities. Utilizing the average crustal Vs ≈ 3.66 km/s estimated for Saurashtra, together with the average crustal P wave velocity (Vp) ≈ 6.54 km/s derived independently through deep seismic sounding studies, yields a bulk Vp/Vs ratio of 1.786 or an equivalent crustal Poisson's ratio of 0.271. A major contribution to the high Poisson's ratio comes from the 12 to 16 km thick lower crustal layers with shear velocities ranging from 3.8 km/s to 4.19 km/s suggesting widespread magmatic underplating due to emplacement of mafic cumulates in the lower crust. The shallow uppermost mantle shear velocities are in the range 4.2-4.5 km/s averaging 4.36 km/s, which is less than that observed for the Indian shield, indicating the effects of residual thermal anomaly. The variation in the crustal Vs, high Poisson's ratios and low upper mantle shear velocities reflect the thermal and compositional effects of the Deccan volcanism which are manifested in terms of pervasive presence of mafic dykes

  13. Crustal structure and composition of the Oslo Graben, Norway

    DEFF Research Database (Denmark)

    Stratford, Wanda Rose; Thybo, Hans

    2011-01-01

    Although more than 250 my old, the Oslo Graben has retained a distinctive distribution of P-wave velocities associated with rifting, intrusion and underplating of the thinned crustal section. We calculate Poisson's ratio values from crustal P and S-wave velocities along an ~400 km long profile ac...

  14. Limb shortening in the course of solitary bone cyst treatment - a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, Maciej [Karol Marcinkowski University of Medical Sciences, Department of Paediatric Orthopaedics, Poznan (Poland); Ignys-O' Byrne, Anna [J. Strus City Hospital, Department of Radiology, Poznan (Poland); Ignys, Iwona [Karol Marcinkowski University of Medical Sciences, Department of Paediatric Gastroenterology and Metabolic Diseases, Poznan (Poland); Wroblewska, Katarzyna [Karol Marcinkowski University of Medical Sciences, Department of Radiology, Poznan (Poland)

    2011-02-15

    The aim of this paper is to evaluate the frequency of limb shortening in the course of solitary bone cyst treatment. The correlation between the mode of treatment as well as the occurrence of pathological fracture, cyst location, volume, and locularity were examined. A retrospective analysis was carried out on 135 patients where 80 underwent curettage and bone grafting and 55 were administered methylprednisolone injection with a mean time to follow-up of 12 years. Based on clinical and radiological evaluation, limb shortening was found in ten patients when the data before and after treatment was compared. Limb shortening ranging from 1 to 5 cm during the course of the treatment was observed: six in humerus, two in femur, two in tibia. Those with epiphyseal changes, magnetic resonance imaging to evaluate the degree of growth plate damage was performed. Patients with and without limb shortening did not differ statistically regarding the applied method of treatment. The cyst volume was significantly larger in the group of patients with limb shortening when compared to the group of patients with no limb shortening. In patients treated with curettage and bone grafting, the mode of treatment does not increase the frequency of occurrence of iatrogenic limb shortening. In patients with limb shortening, a statistically significant larger volume of the cyst was observed. (orig.)

  15. The Shortened Raven Standard Progressive Matrices: Item Response Theory-Based Psychometric Analyses and Normative Data

    Science.gov (United States)

    Van der Elst, Wim; Ouwehand, Carolijn; van Rijn, Peter; Lee, Nikki; Van Boxtel, Martin; Jolles, Jelle

    2013-01-01

    The purpose of the present study was to evaluate the psychometric properties of a shortened version of the Raven Standard Progressive Matrices (SPM) under an item response theory framework (the one- and two-parameter logistic models). The shortened Raven SPM was administered to N = 453 cognitively healthy adults aged between 24 and 83 years. The…

  16. The Incredible Bulk

    CERN Document Server

    Fukushima, Keita; Kumar, Jason; Sandick, Pearl; Yamamoto, Takahiro

    2014-01-01

    Recent experimental results from the LHC have placed strong constraints on the masses of colored superpartners. The MSSM parameter space is also constrained by the measurement of the Higgs boson mass, and the requirement that the relic density of lightest neutralinos be consistent with observations. Although large regions of the MSSM parameter space can be excluded by these combined bounds, leptophilic versions of the MSSM can survive these constraints. In this paper we consider a scenario in which the requirements of minimal flavor violation, vanishing $CP$-violation, and mass universality are relaxed, specifically focusing on scenarios with light sleptons. We find a large region of parameter space, analogous to the original bulk region, for which the lightest neutralino is a thermal relic with an abundance consistent with that of dark matter. We find that these leptophilic models are constrained by measurements of the magnetic and electric dipole moments of the electron and muon, and that these models have ...

  17. Creating bulk nanocrystalline metal.

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

    2008-10-01

    Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

  18. Diffusion or bulk flow

    DEFF Research Database (Denmark)

    Schulz, Alexander

    2015-01-01

    the concentration gradient or bulk flow along a pressure gradient. The driving force seems to depend on the mode of phloem loading. In a majority of plant species phloem loading is a thermodynamically active process, involving the activity of membrane transporters in the sieve-element companion cell complex. Since...... assimilate movement includes an apoplasmic step, this mode is called apoplasmic loading. Well established is also the polymer-trap loading mode, where the phloem-transport sugars are raffinose-family oligomers in herbaceous plants. Also this mode depends on the investment of energy, here for sugar......Assimilates synthesized in the mesophyll of mature leaves move along the pre-phloem transport pathway to the bundle sheath of the minor veins from which they are loaded into the phloem. The present review discusses the most probable driving force(s) for the pre-phloem pathway, diffusion down...

  19. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  20. Evaluation of canola oil oleogels with candelilla wax as an alternative to shortening in baked goods.

    Science.gov (United States)

    Jang, Areum; Bae, Woosung; Hwang, Hong-Sik; Lee, Hyeon Gyu; Lee, Suyong

    2015-11-15

    The oleogels of canola oil with candelilla wax were prepared and utilized as a shortening replacer to produce cookies with a high level of unsaturated fatty acids. The incorporation of candelilla wax (3% and 6% by weight) to canola oil produced the oleogels with solid-like properties. The firmness of the oleogels was lower than that of the shortening at room temperature. A more rapid change in the viscosity with temperature was observed with increasing levels of candelilla wax in the steady shear measurements. The replacement of shortening with oleogels in the cookie formulation reduced both viscoelastic parameters (G' and G") of the cookie doughs. The level of unsaturated fatty acids in the oleogel cookies was distinctly increased up to around 92%, compared to the shortening cookies (47.2%). The cookies with the oleogels showed desirable spreadable property and the replacement of shortening with the oleogels produced cookies with soft eating characteristics.

  1. Crustal deformation evidences for viscous coupling and fragmented lithosphere at the Nubia-Iberia plate boundary (Western Mediterranean)

    Science.gov (United States)

    Palano, Mimmo; González, Pablo J.; Fernández, José

    2016-04-01

    A spatially dense crustal velocity field, based on up to 15 years of GNSS observations at more than 380 sites and extensively covering the Iberian Peninsula and Northern Africa, allow us to provide new insights into two main tectonic processes currently occurring in this area. We detected a slow large-scale clockwise rotation of the Iberian Peninsula with respect to a local pole located closely to the northwestern sector of the Pyrenean mountain range (Palano et al., 2015). Although this crustal deformation pattern could suggest a rigid rotating lithosphere block, this model would predict significant shortening along the Western (off-shore Lisbon) and North Iberian margin which cannot totally ruled out but currently is not clearly observed. Conversely, we favour the interpretation that this pattern reflects the quasi-continuous straining of the ductile lithosphere in some sectors of South and Western Iberia in response to viscous coupling of the NW Nubia and Iberian plate boundary in the Gulf of Cádiz. Furthermore, the western Mediterranean basin appears fragmented into independent crustal tectonic blocks, which delimited by inherited lithospheric shear structures and trapped within the Nubia-Eurasia collision, are currently accommodating most of the plate convergence rate. Among these blocks, an (oceanic-like western) Algerian one is currently transferring a significant fraction of the Nubia-Eurasia convergence rate into the Eastern Betics (SE Iberia) and likely causing the eastward motion of the Baleares Promontory. Most of the observed crustal ground deformation can be attributed to processes driven by spatially variable lithospheric plate forces imposed along the Nubia-Eurasia convergence boundary. Nevertheless, the observed deformation field infers a very low convergence rates as observed also at the eastern side of the western Mediterranean, along the Calabro Peloritan Arc, by space geodesy (e.g. Palano, 2015). References Palano M. (2015). On the present

  2. Visualization and dissemination of global crustal models on virtual globes

    Science.gov (United States)

    Zhu, Liang-feng; Pan, Xin; Sun, Jian-zhong

    2016-05-01

    Global crustal models, such as CRUST 5.1 and its descendants, are very useful in a broad range of geoscience applications. The current method for representing the existing global crustal models relies heavily on dedicated computer programs to read and work with those models. Therefore, it is not suited to visualize and disseminate global crustal information to non-geological users. This shortcoming is becoming obvious as more and more people from both academic and non-academic institutions are interested in understanding the structure and composition of the crust. There is a pressing need to provide a modern, universal and user-friendly method to represent and visualize the existing global crustal models. In this paper, we present a systematic framework to easily visualize and disseminate the global crustal structure on virtual globes. Based on crustal information exported from the existing global crustal models, we first create a variety of KML-formatted crustal models with different levels of detail (LODs). And then the KML-formatted models can be loaded into a virtual globe for 3D visualization and model dissemination. A Keyhole Markup Language (KML) generator (Crust2KML) is developed to automatically convert crustal information obtained from the CRUST 1.0 model into KML-formatted global crustal models, and a web application (VisualCrust) is designed to disseminate and visualize those models over the Internet. The presented framework and associated implementations can be conveniently exported to other applications to support visualizing and analyzing the Earth's internal structure on both regional and global scales in a 3D virtual-globe environment.

  3. Pb isotopes during crustal melting and magma mingling - A cautionary tale from the Miki Fjord macrodike, central east Greenland

    DEFF Research Database (Denmark)

    Waight, Tod Earle; Lesher, Charles

    2010-01-01

    Pb isotopic data are presented for hybrid rocks formed by mingling between mantle-derived tholeiitic magma of the Eocene Miki Fjord macrodike (East Greenland) and melt derived from the adjacent Precambrian basement. Bulk mixing and AFC processes between end-members readily identified in the field...... fail to model the Pb isotope systematics. Selective contamination during diffusional exchange, which can explain the complex Sr and Nd isotope compositions of the hybrid rocks (Blichert-Toft et al., 1992), cannot fully account for the variability of the Pb isotopic data using the identified crustal end......-members. The crustal anatectic end-member, although similar in Sr and Nd isotope composition, has a markedly different Pb isotopic composition than its source gneiss. The differences are consistent with preferential incorporation of radiogenic Pb from accessory phases such as metamict zircon or loosely-bound Pb from...

  4. Tectonic implications of Mars crustal magnetism.

    Science.gov (United States)

    Connerney, J E P; Acuña, M H; Ness, N F; Kletetschka, G; Mitchell, D L; Lin, R P; Reme, H

    2005-10-18

    Mars currently has no global magnetic field of internal origin but must have had one in the past, when the crust acquired intense magnetization, presumably by cooling in the presence of an Earth-like magnetic field (thermoremanent magnetization). A new map of the magnetic field of Mars, compiled by using measurements acquired at an approximately 400-km mapping altitude by the Mars Global Surveyor spacecraft, is presented here. The increased spatial resolution and sensitivity of this map provide new insight into the origin and evolution of the Mars crust. Variations in the crustal magnetic field appear in association with major faults, some previously identified in imagery and topography (Cerberus Rupes and Valles Marineris). Two parallel great faults are identified in Terra Meridiani by offset magnetic field contours. They appear similar to transform faults that occur in oceanic crust on Earth, and support the notion that the Mars crust formed during an early era of plate tectonics.

  5. Investigation of lunar crustal structure and isostasy

    Science.gov (United States)

    Thurber, Clifford H.

    1987-01-01

    The lunar mascon basins have strongly free air gravity anomalies, generally exceeding 100 milligals at an elevation of 100 km. The source of the anomalies is a combination of mantle uplift beneath the impact basins and subsequent infilling by high-density mare basalts. The relative contribution of these two components is still somewhat uncertain, although it is generally accepted that the amount of mantle uplift greatly exceeds the thickness of the basalts. Extensive studies have been carried out of the crustal structure of mare basins, based on gravity data, and their tectonic evolution, based on compressive and extensional tectonic features. The present study endeavored to develop a unified, self-consistent model of the lunar crust and lithosphere incorporating both gravity and tectonic constraints.

  6. Current crustal movement in Chinese mainland

    Institute of Scientific and Technical Information of China (English)

    王琪

    2003-01-01

    The quantification of tectonic deformation in the Eastern and Central Asia is of great significance for the study on global plate motion and lithospheric dynamics. In the past four years, the velocity field of horizontal crustal movement for the Chinese mainland has been established for the first time thanks to the intensified GPS measurements and its improved accuracy. The velocity field derived from GPS measurements delineates the patterns of tectonic deformation in the Chinese mainland in the unprecedented detail, and thus reveals the new features of the ongoing tectonic process resulted from the collision of Indian plate to Eurasian plate. Meanwhile, the surface offset induced by two strong earthquakes occurred in Chinese mainland was sampled precisely using InSAR technique.

  7. Crustal recycling by subduction erosion in the central Mexican Volcanic Belt

    Science.gov (United States)

    Straub, Susanne M.; Gómez-Tuena, Arturo; Bindeman, Ilya N.; Bolge, Louise L.; Brandl, Philipp A.; Espinasa-Perena, Ramón; Solari, Luigi; Stuart, Finlay M.; Vannucchi, Paola; Zellmer, Georg F.

    2015-10-01

    Recycling of upper plate crust in subduction zones, or 'subduction erosion', is a major mechanism of crustal destruction at convergent margins. However, assessing the impact of eroded crust on arc magmas is difficult owing to the compositional similarity between the eroded crust, trench sediment and arc crustal basement that may all contribute to arc magma formation. Here we compare Sr-Nd-Pb-Hf and trace element data of crustal input material to Sr-Nd-Pb-Hf-He-O isotope chemistry of a well-characterized series of olivine-phyric, high-Mg# basalts to dacites in the central Mexican Volcanic Belt (MVB). Basaltic to andesitic magmas crystallize high-Ni olivines that have high mantle-like 3He/4He = 7-8 Ra and high crustal δ18Omelt = +6.3-8.5‰ implying their host magmas to be near-primary melts from a mantle infiltrated by slab-derived crustal components. Remarkably, their Hf-Nd isotope and Nd/Hf trace element systematics rule out the trench sediment as the recycled crust end member, and imply that the coastal and offshore granodiorites are the dominant recycled crust component. Sr-Nd-Pb-Hf isotope modeling shows that the granodiorites control the highly to moderately incompatible elements in the calc-alkaline arc magmas, together with lesser additions of Pb- and Sr-rich fluids from subducted mid-oceanic ridge basalt (MORB)-type altered oceanic crust (AOC). Nd-Hf mass balance suggests that the granodiorite exceeds the flux of the trench sediment by at least 9-10 times, corresponding to a flux of ⩾79-88 km3/km/Myr into the subduction zone. At an estimated thickness of 1500-1700 m, the granodiorite may buoyantly rise as bulk 'slab diapirs' into the mantle melt region and impose its trace element signature (e.g., Th/La, Nb/Ta) on the prevalent calc-alkaline arc magmas. Deep slab melting and local recycling of other slab components such as oceanic seamounts further diversify the MVB magmas by producing rare, strongly fractionated high-La magmas and a minor population of

  8. Plio-Quaternary Shortening on the Algerian Margin: Evidence From Multibeam Bathymetry and Seismic Reflection Survey off Boumerdes

    Science.gov (United States)

    Strzerzynski, P.; Cattaneo, A.; Deverchere, J.; Yelles, K.; Mercier de Lepinay, B.; Domzig, A.; Bracene, R.

    2008-12-01

    The northern limit of Algeria is one of the most seismically active regions of the western Mediterranean, with potential magnitudes estimated at up to 7,5. Instrumental seismicity is detected mainly onshore and expresses a NW-SE dominant shortening. However, since the May 2003 Boumerdès earthquake, offshore deformation attracts scientists' attention. The aim of this note is to describe a system of Plio-Quaternary folds and blind thrusts at the foot of the continental slope offshore Boumerdès based on data acquired in 2003 and 2005 (Maradja 1 and Maradja 2/ Samra cruises). On a S-N oriented transect offshore Boumerdès, three uplifted basins are observed from the mid-continental slope down to 30-40 km within the Balearic abyssal plain. These basins are limited by scarps corresponding to the north-western flanks of Plio-Quaternary anticlines. The geometry of the sedimentary units allows to distinguish Messinian salt features (developed early) from other tectonic (s.s.) compressional structures that formed later as a series of diachronous folds. The folding of the Miocene layers is clearly tectonically (s.s.) controlled. It initiated during the Plio-Quaternary and progressively migrated from the slope toward the abyssal plain. The pattern of perched basins and the folding distribution strongly suggest the occurrence of a system of flat and blind thrust ramps. As no thrusts are observed in the Miocene layers, flats and thrust ramps have to be deeper, probably rooted in the basement, as evidenced during the 2003 Boumerdes Mw 6.9 event. The position of basement highs below the Miocene deposits compared to the active fronts indicates that the shape of the Plio-Quaternary fold and thrust belt is controlled by these previous basement highs. Uplifted basins are less developed in size and depth on the slope than in the abyssal plain, suggesting that the flat length increases from the slope to the abyssal plain. We interpret this increase as being directly related to crustal

  9. Evolution of crustal thickening in the central Andes, Bolivia

    Science.gov (United States)

    Eichelberger, Nathan; McQuarrie, Nadine; Ryan, Jamie; Karimi, Bobak; Beck, Susan; Zandt, George

    2015-09-01

    Paleoelevation histories from the central Andes in Bolivia have suggested that the geodynamic evolution of the region has been punctuated by periods of large-scale lithospheric removal that drive rapid increases in elevation at the surface. Here, we evaluate viable times and locations of material loss using a map-view reconstruction of the Bolivian orocline displacement field to forward-model predicted crustal thicknesses. Two volumetric models are presented that test assumed pre-deformation crustal thicknesses of 35 km and 40 km. Both models predict that modern crustal thicknesses were achieved first in the northern Eastern Cordillera (EC) by 30-20 Ma but remained below modern in the southern EC until ≤10 Ma. The Altiplano is predicted to have achieved modern crustal thickness after 10 Ma but only with a pre-deformation thickness of 50 km, including 10 km of sediment. At the final stage, the models predict 8-25% regional excess crustal volume compared to modern thickness, largely concentrated in the northern EC. The excess predicted volume from 20 to 0 Ma can be accounted for by: 1) crustal flow to the WC and/or Peru, 2) localized removal of the lower crust, or 3) a combination of the two. Only models with initial crustal thicknesses >35 km predict excess volumes sufficient to account for potential crustal thickness deficits in Peru and allow for lower crustal loss. However, both initial thickness models predict that modern crustal thicknesses were achieved over the same time periods that paleoelevation histories indicate the development of modern elevations. Localized removal of lower crust is only necessary in the northern EC where crustal thickness exceeds modern by 20 Ma, prior to paleoelevation estimates of modern elevations by 15 Ma. In the Altiplano, crustal thicknesses match modern values at 10 Ma and can only exceed modern values by 5 Ma, post-dating when modern elevations were thought to have been established. Collectively, these models predict that

  10. The Glacial BuzzSaw, Isostasy, and Global Crustal Models

    Science.gov (United States)

    Levander, A.; Oncken, O.; Niu, F.

    2015-12-01

    The glacial buzzsaw hypothesis predicts that maximum elevations in orogens at high latitudes are depressed relative to temperate latitudes, as maximum elevation and hypsography of glaciated orogens are functions of the glacial equilibrium line altitude (ELA) and the modern and last glacial maximum (LGM) snowlines. As a consequence crustal thickness, density, or both must change with increasing latitude to maintain isostatic balance. For Airy compensation crustal thickness should decrease toward polar latitudes, whereas for Pratt compensation crustal densities should increase. For similar convergence rates, higher latitude orogens should have higher grade, and presumably higher density rocks in the crustal column due to more efficient glacial erosion. We have examined a number of global and regional crustal models to see if these predictions appear in the models. Crustal thickness is straightforward to examine, crustal density less so. The different crustal models generally agree with one another, but do show some major differences. We used a standard tectonic classification scheme of the crust for data selection. The globally averaged orogens show crustal thicknesses that decrease toward high latitudes, almost reflecting topography, in both the individual crustal models and the models averaged together. The most convincing is the western hemisphere cordillera, where elevations and crustal thicknesses decrease toward the poles, and also toward lower latitudes (the equatorial minimum is at ~12oN). The elevation differences and Airy prediction of crustal thickness changes are in reasonable agreement in the North American Cordillera, but in South America the observed crustal thickness change is larger than the Airy prediction. The Alpine-Himalayan chain shows similar trends, however the strike of the chain makes interpretation ambiguous. We also examined cratons with ice sheets during the last glacial period to see if continental glaciation also thins the crust toward

  11. Pervasive Crustal Melting on a Regional Scale: Sr-Nd Isotopic Evidence from Eocene Intrusions in NE Washington

    Science.gov (United States)

    Loewen, M. W.; Tepper, J. H.; Asmerom, Y.

    2007-12-01

    During the Eocene the Pacific Northwest was the site of a short-lived but voluminous and geochemically diverse magmatic episode, commonly termed the Challis event. To investigate the origins of this event we have measured whole rock Sr and Nd isotopic compositions of 12 plutonic and hypabyssal samples, ranging from basalt to two-mica granite, collected along a 250 km transect across NE Washington. This transect crosses the 0.706 line (Armstrong 1977), the boundary between dominantly Mesozoic crust to the west and older crust to the east. The results reveal a wide spread in isotopic compositions (87Sr/86Srm = 0.7041 - 0.7262; ɛNdm = +3.8 to -18.5) with no systematic relationship between isotopic composition and bulk composition (e.g., MgO). This decoupling of isotopic composition and bulk chemistry suggests mixing between mantle and crustal melts was of minimal importance, and that these rocks are dominantly of crustal origin. The range in ɛNdm also indicates melting of crustal sources that varied considerably in age. Samples with ɛNdm > +2 range from basalt (13 wt.% MgO) to two-mica granite (0.3 wt.% MgO). Such juvenile ɛNdm in a two-mica granite precludes significant involvement of ancient metasedimentary material and implies rapid intracrustal differentiation of a mantle-derived source, which may have been deep arc crust of Mesozoic age. At the other end of the spectrum, samples with ɛNdm Monzonite and attributed to melting of late Archean to Early Proterozoic crust (Whitehouse et al. 1992). Other samples analyzed in this study are broadly similar in isotopic composition (ɛNdm = +1 to -8; 87Sr/86Srm = 0.706-0.709) to rocks of the Colville Igneous Province and probably formed by melting of Proterozoic arc crust (Morris 2000). Geographic variability in Sr-Nd data indicates that isotopically distinct crustal domains are juxtaposed laterally and/or vertically, in some cases on a small scale. The sample with the highest 87Sr/86Srm (0.7262; ɛNdm = -13.3) is a

  12. Revisiting the crustal evolution of the Pyrenees and the Cantabrian Mountains: inferences from new concepts and data

    Science.gov (United States)

    Teixell, Antonio; Labaume, Pierre; Lagabrielle, Yves

    2016-04-01

    crust, currently imaged to depths that do not match the total amount of upper crustal shortening, but are in agreement with the hyperextension. How the orogenic shortening is transferred from the upper crust to lower crust is still the subject of contrasting views, although recent geophysical investigations support crustal wedging. The eastern Cantabrian Mountains have a crustal structure not very different from the Pyrenees. Only one of two Cretaceous basins (Parentis and Basque-Cantabrian) was strongly inverted. In spite of facing the oceanic crust of the Bay of Biscay, the western Cantabrian Mountains are still underlain by N-directed continental subduction. Subduction of the Bay of Biscay oceanic crust under the margin remains elusive, only imaged (possibly) by subcrustal inclined reflections to a maximum depth of 40 km in a strike-parallel profile. In spite of growing databases, major discrepancies remain between the amount of convergence derived from plate reconstructions and that admissible in the light of geological and geophysical observations. Differences in the presumed width of the exhumed mantle domain depicted in different models are of one order of magnitude. The subduction of several tens to hundreds of km of mantle peridotite proposed in some models are hard to reconcile with the lack of signature in the overlying sedimentary basin fill. Satisfactory solutions need to be investigated.

  13. Multiple causes of fatigue during shortening contractions in rat slow twitch skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Kristin Halvorsen Hortemo

    Full Text Available Fatigue in muscles that shorten might have other causes than fatigue during isometric contractions, since both cross-bridge cycling and energy demand are different in the two exercise modes. While isometric contractions are extensively studied, the causes of fatigue in shortening contractions are poorly mapped. Here, we investigate fatigue mechanisms during shortening contractions in slow twitch skeletal muscle in near physiological conditions. Fatigue was induced in rat soleus muscles with maintained blood supply by in situ shortening contractions at 37°C. Muscles were stimulated repeatedly (1 s on/off at 30 Hz for 15 min against a constant load, allowing the muscle to shorten and perform work. Fatigue and subsequent recovery was examined at 20 s, 100 s and 15 min exercise. The effects of prior exercise were investigated in a second exercise bout. Fatigue developed in three distinct phases. During the first 20 s the regulatory protein Myosin Light Chain-2 (slow isoform, MLC-2s was rapidly dephosphorylated in parallel with reduced rate of force development and reduced shortening. In the second phase there was degradation of high-energy phosphates and accumulation of lactate, and these changes were related to slowing of muscle relengthening and relaxation, culminating at 100 s exercise. Slowing of relaxation was also associated with increased leak of calcium from the SR. During the third phase of exercise there was restoration of high-energy phosphates and elimination of lactate, and the slowing of relaxation disappeared, whereas dephosphorylation of MLC-2s and reduced shortening prevailed. Prior exercise improved relaxation parameters in a subsequent exercise bout, and we propose that this effect is a result of less accumulation of lactate due to more rapid onset of oxidative metabolism. The correlation between dephosphorylation of MLC-2s and reduced shortening was confirmed in various experimental settings, and we suggest MLC-2s as an

  14. Crustal types of the Circumpolar Arctic

    Science.gov (United States)

    Kashubin, Sergey; Pavlenkova, Ninel; Petrov, Oleg; Milshtein, Evgenia; Shokalsky, Sergey; Erinchek, Yuri

    2016-04-01

    Deep seismic studies revealed unusual crustal structure in the Arctic Ocean. The thin (about 10 km) oceanic crust with seismic velocities Vp= 6.8-7.2 km/s is observed only in the narrow mid-oceanic ridge zone (the Gakkel ridge). The thick (25-35 km) continental crust covers the whole continental margins and the central part of the ocean. The continental type of the magnetic field with large local anomalies of different signs and irregular shapes is also observed in this area. However, the crust of the central Arctic (the Lomonosov, Mendeleev and Alpha ridges) differ from the crust of the Eurasia by the lower thickness of the upper granite-gneiss layer (velocities Vp=6.0-6.6 km/s): it is only 5-7 km in comparison with 15-20 km in the continent. The origin of such crust may be explained in two ways. Most frequently it is accounted for by the destruction and transformation of the continental crust by the basification that implies the enrichment of the crust by the rocks of basic composition from the mantle and the metamorphization of the continental rocks at the higher temperature and pressure. But in the central part of the Arctic Ocean the crust looks as an original one. The regular form of the large ridges and the continental type magnetic field were not destroyed by the basification processes which are usually irregular and most intensive in some local zones. The basification origin may be proposed for the Canadian and the South-Barents deep sedimentary basins with "suboceanic" crust (10-15 km of sediments and 10-15 km of the lower crust with Vp= 6.8-7.2 km/s). The other basins which stretch along fault zones outlined the central deep water part of the Arctic Ocean have the ''subcontinental' crust: the thickness of the granite-gneiss layer decreases in these basins and sometimes the high velocity intrusions are observed in the lower parts. The different crustal types are observed in the North Atlantic where the oceanic crust with linear magnetic anomalies is

  15. Crustal seismicity of the Black Sea areal

    Science.gov (United States)

    Diaconescu, Mihail; Moldovan, Iren-Adelina; Petruta Constantin, Angela

    2014-05-01

    The main target of the study is to decipher the seismicity of the Black Sea areal from the tsunami-genetic potential. From the seismotectonical point of view the earthquakes which are responsible for tsunami are those associated with thrust faults (subduction zones), normal and inverse faults and less strike slip faults (only if the oblique-slip and deep slip components are predominant), with magnitude higher than 6.5 (even the USGS cited tsunami at 5.1 magnitude) and depth, a shallow one, less than 20 km depth. In order to delimit the seismic sources from Black Sea and to discrimate among them the tsunamigenic ones, the following elements have been taken into account: - depth of the earthquakes foci, that allow separation of two major categories: deeper than 40 km depth and crustal, normal, (less than 40 km deep); - development of the earthquakes epicenters in the orogen zone or in zones with active tectonics (fault systems); - establishment of the areas of active faults along which the earthquakes epicenters are aligned; - the absence of a recent or actual tectonic activity; the epicenters recorded in these tectonically stable zones are considered as the result of a diffuse, accidental seismicity. The studies on active tectonics have clearly shown the position of the seismic sources (connected to well define active fault) which do not interfere and do not result in alternatives of other seismotectonic model constructions. According to the distribution map of earthquakes and as well as to the map of the areas with active tectonics, ten seismic sources were established: Central Dobrogea(S1), Shabla(S2), Istanbul(S3), North Anatolian Fault(S4), Georgia(S5), Novorossjsk(S6), Crimea(S7), West Black Sea Fault(S8) and Mid Black Sea Ridge(S9). The maximum possible magnitude of each seismic source was obtained through three aproaches: (i) using seismotectonics and geological database (the length of the faults, possible apparition on surface, geomorphology, etc

  16. Crustal Thickness and Lower Crustal Velocity Structure Beneath the Endeavour Segment of the Juan de Fuca Ridge

    Science.gov (United States)

    Hill, R.; Soule, D. C.; Wilcock, W. S. D.; Toomey, D. R.; Hooft, E. E. E.; Weekly, R. T.

    2014-12-01

    In 2009, a multi-scale seismic tomography experiment was conducted on the Endeavour segment of the Juan de Fuca Ridge aboard the R/V Marcus G. Langseth. Ocean bottom seismometers were deployed at 64 sites and recorded 5567 shots of a 36-element, 6600 in.3 airgun array. The experiment extended 100 km along-axis and 60 km cross-axis. Two crustal tomographic analyses have previously been completed using data from the experiment. First, 93,000 manually picked crustal refraction arrivals (Pg) were used to develop a three-dimensional model of crustal velocity and thickness in the upper crust (Weekly et al. 2014). Second, this model was used as the starting model in an analysis that incorporated ~19,000 Moho reflection arrivals (PmP) for non-ridge crossing paths to image lower crustal velocity structure and crustal thickness off-axis. A key feature of this model is a ~0.5-1 km increase in crustal thickness beneath a bathymetric plateau that extends to either side of the central portion of the Endeavour segment. We present a tomographic inversions that incorporates ridge-crossing paths to examine spatial variations in lower crustal velocity and crustal thickness beneath the ridge axis. The preliminary results from an inversion that incorporates ~8700 manually picked ridge-crossing PmP arrival times reveals a ~10-km-wide low velocity zone extending throughout the lower crust with a velocity anomaly of -0.3 to -0.5 km/s at ≥4 km depth. This low velocity zone extends both to the north and south of the axial magma chamber reflector imaged previously beneath the central Endeavour. The inversion also shows significant variations in apparent crustal thickness along axis but additional analysis is required to understand whether these variations are well resolved.

  17. The shortened KK spectrum of IIB supergravity on Y{sup p,q}

    Energy Technology Data Exchange (ETDEWEB)

    Ardehali, Arash Arabi; Liu, James T. [Michigan Center for Theoretical Physics, Randall Laboratory of Physics, University of Michigan,Ann Arbor, MI 48109-1040 (United States); Szepietowski, Phillip [Department of Physics, University of Virginia,Box 400714, Charlottesville, VA 22904 (United States)

    2014-02-17

    We examine the shortened KK spectrum of IIB supergravity compactified on Y{sup p,q} and conjecture that the spectrum we have obtained is complete. The (untwisted) shortened spectrum on S{sup 5}/ℤ{sub 2p} and on T{sup 1,1}/ℤ{sub p} are obtained as special cases when p=q and q=0, respectively. Knowledge of the shortened spectrum allows us to compute the superconformal index of these theories and to find agreement with earlier calculations from the dual field theories. We also employ the shortened spectrum to perform a 1/N{sup 2} test of AdS/CFT by holographically reproducing the difference of the central charges, c−a=p/8, of the dual CFTs.

  18. The shortened KK spectrum of IIB supergravity on Yp,q

    International Nuclear Information System (INIS)

    We examine the shortened KK spectrum of IIB supergravity compactified on Yp,q and conjecture that the spectrum we have obtained is complete. The (untwisted) shortened spectrum on S5/ℤ2p and on T1,1/ℤp are obtained as special cases when p=q and q=0, respectively. Knowledge of the shortened spectrum allows us to compute the superconformal index of these theories and to find agreement with earlier calculations from the dual field theories. We also employ the shortened spectrum to perform a 1/N2 test of AdS/CFT by holographically reproducing the difference of the central charges, c−a=p/8, of the dual CFTs

  19. Shortening and Thickening of Metropolitan Los Angeles Measured and Inferred Using Geodesy

    Science.gov (United States)

    Argus, D.; Heflin, M.; Donnellan, A.; Webb, F.; Dong, D.; Hurst, K.; Jefferson, D.; Lyzenga, G.; Watkins, M.; Zumberge, J.

    1999-01-01

    Geodetic measurements using the Global Positioning System and other techniques show north-south shortening near Los Angeles to be fastest across the northern part of the metropolitan area, where an ESE-striking, 5- to 40-km-wide belt lying to the south of San Gabriel Mountains and to the north of downtown and West Los Angeles is shortening at 5 mm/yr.

  20. Continental crustal formation and recycling: Evidence from oceanic basalts

    Science.gov (United States)

    Saunders, A. D.; Tarney, J.; Norry, M. J.

    1988-01-01

    Despite the wealth of geochemical data for subduction-related magma types, and the clear importance of such magmas in the creation of continental crust, there is still no concensus about the relative magnitudes of crustal creation versus crustal destruction (i.e., recycling of crust into the mantle). The role of subducted sediment in the formation of the arc magmas is now well documented; but what proportion of sediment is taken into the deeper mantle? Integrated isotopic and trace element studies of magmas erupted far from presently active subduction zones, in particular basaltic rocks erupted in the ocean basins, are providing important information about the role of crustal recycling. By identifying potential chemical tracers, it is impossible to monitor the effects of crustal recycling, and produce models predicting the mass of material recycled into the mantle throughout long periods of geological time.

  1. Relationship between Crustal Structure and Tin Mineralization in South China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A close relationship between tin metallogenic and crustal structure in South China is demonstrated, which is based on a careful study on crustal structure and a detailed comparison between typical deposits in different tectonic units. Types, locations, emplacement of ore bodies and ore genesis of tin deposits are relative to crustal structure. Tin mineralization zones of South China can be divided into three tin metallogenic units including the west part corresponding to Youjiang fold belt, middle part corresponding to fold belt of Hunan-Guangdong-Jiangxi provinces and the east part corresponding to Southeast China coastal volcanic faulting depression. From the above, it is concluded that crustal compositions and structures are the main facts of Sn concentration in South China.

  2. Low crustal velocities and mantle lithospheric variations in southern Tibet from regional Pnl waveforms

    Science.gov (United States)

    Rodgers, Arthur J.; Schwartz, Susan Y.

    We report low average crustal P-wave velocities (5.9-6.1 km/s, Poisson's ratio 0.23-0.27, thickness 68-76 km) in southern Tibet from modelling regional Pnl waveforms recorded by the 1991-1992 Tibetan Plateau Experiment. We also find that the mantle lithosphere beneath the Indus-Tsangpo Suture and the Lhasa Terrane is shield-like (Pn velocity 8.20-8.25 km/s, lid thickness 80-140 km, positive velocity gradient 0.0015-0.0025 s-1). Analysis of relative Pn travel time residuals requires a decrease in the mantle velocities beneath the northern Lhasa Terrane, the Banggong-Nujiang Suture and the southern Qiangtang Terrane. Tectonic and petrologic considerations suggest that low bulk crustal velocities could result from a thick (50-60 km) felsic upper crust with vertically limited and laterally pervasive partial melt. These results are consistent with underthrusting of Indian Shield lithosphere beneath the Tibetan Plateau to at least the central Lhasa Terrane.

  3. Rates, Mechanisms, and Implications of Crustal Assimilation in Continental Arcs

    Science.gov (United States)

    Dungan, M.; Davidson, J.

    2002-12-01

    Contrary to the limiting constraints postulated by Bowen for the coupled thermal and mass balance implicated in assimilation, many studies [1-6] suggest that multi-stage and multi-component assimilation, abetted by magma mixing, may be volumetrically important and have profound consequences for the chemistry of basaltic and evolved magmas in long-lived continental magmatic systems. The probability of a primitive or evolved basalt arriving at the Earth's surface having undergone perfectly closed-system evolution during passage through 25-60 km of continental crust is vanishingly low. A case-by-case demonstration that the intra-crustal chemical overprint is trivial, or that it can be quantified and subtracted, is an essential step in any evaluation of mantle source-region chemistry and processes based on inversion of continental basalt compositions. In magmatic systems characterized by mafic magma recharge the thermal energy and physical dynamism needed for assimilation are not constrained to come uniquely from one magma batch [7, 8]. Equally important is that assimilation is rarely equivalent to bulk melting of ingested blocks followed by reservoir-wide homogenization. The mechanics of crustal assimilation are governed by grain boundary melting, disaggregation, and dispersal of refractory solids (including xenocryst settling) wherein liberated low-density, incompatible element-enriched partial melts have the capacity to render primitive arc magma batches variably modified, as well as heterogeneous on short length-scales. Evidence that basalts thermally erode surface channels and conduit walls, and new observations constraining the maximum time that some extensively melted xenoliths have resided in their host magmas, indicate that the time required to impose an open-system overprint on a hot basaltic magma (days to yrs) is far shorter than typical repose periods at most arc volcanoes (50-500 yrs). Assimilative recycling of broadly gabbroic arc cumulates has had large

  4. Ionospheric precursors for crustal earthquakes in Italy

    Science.gov (United States)

    Perrone, L.; Korsunova, L. P.; Mikhailov, A. V.

    2010-04-01

    Crustal earthquakes with magnitude 6.0>M≥5.5 observed in Italy for the period 1979-2009 including the last one at L'Aquila on 6 April 2009 were considered to check if the earlier obtained relationships for ionospheric precursors for strong Japanese earthquakes are valid for the Italian moderate earthquakes. The ionospheric precursors are based on the observed variations of the sporadic E-layer parameters (h'Es, fbEs) and foF2 at the ionospheric station Rome. Empirical dependencies for the seismo-ionospheric disturbances relating the earthquake magnitude and the epicenter distance are obtained and they have been shown to be similar to those obtained earlier for Japanese earthquakes. The dependences indicate the process of spreading the disturbance from the epicenter towards periphery during the earthquake preparation process. Large lead times for the precursor occurrence (up to 34 days for M=5.8-5.9) tells about a prolong preparation period. A possibility of using the obtained relationships for the earthquakes prediction is discussed.

  5. Permanent GPS and crustal deformation in Greenland

    Science.gov (United States)

    Khan, S. A.

    2003-12-01

    The National Survey and Cadastre - Denmark (KMS) is responsible for the geodetic definition of the reference network in Greenland. Permanent GPS plays an important role in the monitoring and maintenance of the geodetic network. Furthermore, KMS supports the international GPS infrastructure and research by supporting IGS. In October 1998 KMS has established a permanent GPS station THU2 at Thule Airbase. Besides THU2 the old permanent station THU1 is also running. The Thule stations are important because they are two of the few northernmost stations in the IGS network. THU2 has been operating since March 1999, and it is now a high quality and high performance station contributing to the IGS Low-Earth Orbiters (LEO) network. Besides the GPS stations in Thule, KMS is also running a permanent GPS station SCOB in Scoresbysund, which was established in August 1997, and in October 2001 a permanent station QAQ1 was established in Qaqortoq. This station is registered at IGS. Furthermore, University of Colorado operates the IGS station Kellyville near Kangerlussuaq and a station in Kulusuk. Using the BERNESE software, we have calculated daily baseline solutions between the GPS sites. The time series of the 3D crustal movements are analyzed due to post glacial rebound, plate tectonic and seasonal deformations (e.g. atmosphere loading). In addition, we have used the GIPSY OASIS II software to obtain similar time series. The results are compared with modeled estimates of the glacial rebound.

  6. Ionospheric precursors for crustal earthquakes in Italy

    Directory of Open Access Journals (Sweden)

    L. Perrone

    2010-04-01

    Full Text Available Crustal earthquakes with magnitude 6.0>M≥5.5 observed in Italy for the period 1979–2009 including the last one at L'Aquila on 6 April 2009 were considered to check if the earlier obtained relationships for ionospheric precursors for strong Japanese earthquakes are valid for the Italian moderate earthquakes. The ionospheric precursors are based on the observed variations of the sporadic E-layer parameters (h'Es, fbEs and foF2 at the ionospheric station Rome. Empirical dependencies for the seismo-ionospheric disturbances relating the earthquake magnitude and the epicenter distance are obtained and they have been shown to be similar to those obtained earlier for Japanese earthquakes. The dependences indicate the process of spreading the disturbance from the epicenter towards periphery during the earthquake preparation process. Large lead times for the precursor occurrence (up to 34 days for M=5.8–5.9 tells about a prolong preparation period. A possibility of using the obtained relationships for the earthquakes prediction is discussed.

  7. The crustal dynamics intelligent user interface anthology

    Science.gov (United States)

    Short, Nicholas M., Jr.; Campbell, William J.; Roelofs, Larry H.; Wattawa, Scott L.

    1987-01-01

    The National Space Science Data Center (NSSDC) has initiated an Intelligent Data Management (IDM) research effort which has, as one of its components, the development of an Intelligent User Interface (IUI). The intent of the IUI is to develop a friendly and intelligent user interface service based on expert systems and natural language processing technologies. The purpose of such a service is to support the large number of potential scientific and engineering users that have need of space and land-related research and technical data, but have little or no experience in query languages or understanding of the information content or architecture of the databases of interest. This document presents the design concepts, development approach and evaluation of the performance of a prototype IUI system for the Crustal Dynamics Project Database, which was developed using a microcomputer-based expert system tool (M. 1), the natural language query processor THEMIS, and the graphics software system GSS. The IUI design is based on a multiple view representation of a database from both the user and database perspective, with intelligent processes to translate between the views.

  8. Compression and Combining Based on Channel Shortening and Rank Reduction Technique for Cooperative Wireless Sensor Networks

    KAUST Repository

    Ahmed, Qasim Zeeshan

    2013-12-18

    This paper investigates and compares the performance of wireless sensor networks where sensors operate on the principles of cooperative communications. We consider a scenario where the source transmits signals to the destination with the help of L sensors. As the destination has the capacity of processing only U out of these L signals, the strongest U signals are selected while the remaining (L?U) signals are suppressed. A preprocessing block similar to channel-shortening is proposed in this contribution. However, this preprocessing block employs a rank-reduction technique instead of channel-shortening. By employing this preprocessing, we are able to decrease the computational complexity of the system without affecting the bit error rate (BER) performance. From our simulations, it can be shown that these schemes outperform the channel-shortening schemes in terms of computational complexity. In addition, the proposed schemes have a superior BER performance as compared to channel-shortening schemes when sensors employ fixed gain amplification. However, for sensors which employ variable gain amplification, a tradeoff exists in terms of BER performance between the channel-shortening and these schemes. These schemes outperform channel-shortening scheme for lower signal-to-noise ratio.

  9. Nonlinear multichannel shortening line using ferrite coils with nonrectangular hysteresis loop

    International Nuclear Information System (INIS)

    To control intensive electron beams a design of a new low-impedance nonlinear multichannel shortening line with ferrite coils with a nonrectangular hysteresis loop is described. Results of tests and investigations of the line are presented. An outer conductor is made in the form of cylindrical cavities evenly placed in circumference where nonlinear shortening channels are located. The cylindrical cavities are formed with casings of ten one-and-a-half meter sections of brass tubes placed around a central body. Inner conductors of shortening lines in each channel are made up of a central axis in the form of pin with thread all over the length of 1700 mm and 165 ferrite rings of 12x5x5.5 mm strung on this axis. Characteristics of the investigated set of shortening lines are given: dependences of durations of front and front delay of shock wave on current amplitude, length of shortening line and demagnetization current. It is shown that parallel connection of nonlinear shortening channels in the aggregate coaxial outer conductor permits to reach limiting duration of stationary shock wave front of 0.5 ns

  10. Global Crustal Heat Flow Using Random Decision Forest Prediction

    Science.gov (United States)

    Becker, J. J.; Wood, W. T.; Martin, K. M.

    2014-12-01

    We have applied supervised learning with random decision forests (RDF) to estimate, or predict, a global, densely spaced grid of crustal heat flow. The results are similar to global heat flow predictions that have been previously published but are more accurate and offer higher resolution. The training inputs are measurement values and uncertainties of existing sparsely sampled, (~8,000 locations), geographically biased, yet globally extensive, datasets of crustal heat flow. The RDF estimate is a highly non-linear empirical relationship between crustal heat flow and dozens of other parameters (attributes) that we have densely sampled, global, estimates of (e.g., crustal age, water depth, crustal thickness, seismic sound speed, seafloor temperature, sediment thickness, and sediment grain type). Synthetic attributes were key to obtaining good results using the RDF method. We created synthetic attributes by applying physical intuition and statistical analyses to the fundamental attributes. Statistics include median, kurtosis, and dozens of other functions, all calculated at every node and averaged over a variety of ranges from 5 to 500km. Other synthetic attributes are simply plausible, (e.g., distance from volcanoes, seafloor porosity, mean grain size). More than 600 densely sampled attributes are used in our prediction, and for each we estimated their relative importance. The important attributes included all those expected from geophysics, (e.g., inverse square root of age, gradient of depth, crustal thickness, crustal density, sediment thickness, distance from trenches), and some unexpected but plausible attributes, (e.g., seafloor temperature), but none that were unphysical. The simplicity of the RDF technique may also be of great interest beyond the discipline of crustal heat flow as it allows for more geologically intelligent predictions, decreasing the effect of sampling bias, and improving predictions in regions with little or no data, while rigorously

  11. Contemporary crustal vertical velocity field in the eastern margin of the Tibetan Plateau inferred from precise leveling data

    Science.gov (United States)

    Hao, M.; Wang, Q.; Shen, Z.; Cui, D.; Li, Y.; Ji, L.

    2012-12-01

    is uplifting and the Yinchuan graben is subsiding. The crustal shortening of the Liupan Shan region is the primary drive for uplift. The subsidence of the central and southern Sichuan-Yunnan fragment is caused by the near east-west extension. Our final result will be reported at the meeting.

  12. Geodynamic Drivers of Vertical Crustal Motion: Integrating Paleoaltimetry with Basin Development in the Central Andean Plateau of Southern Peru

    Science.gov (United States)

    Sundell, K. E., II; Saylor, J. E.; Lapen, T. J.; Villarreal, D. P.; Styron, R. H.; Horton, B. K.; Cardenas, J.

    2015-12-01

    Determining the spatial and temporal relationships between surface uplift, tectonic subsidence, and exhumation during periods of oblique crustal shortening is essential to discriminating geodynamic processes controlling formation of high topography in the central Andes. Although subsidence analysis is now a standard tool, paleoelevation estimation remains a challenging task, as estimates based on proxy data can be complicated by uncertainties in the relative controls of tectonics and climate. We therefore adopt an approach of combining established tools of subsidence analysis and detrital geochronology with emerging methods of volcanic glass paleoaltimetry, which enables us to explore a broad range of viable interpretations to understand the development of intermontane basins and their relationship to the development of the central Andean plateau. We investigated a suite of temporally overlapping and spatially separate Cenozoic basins spanning the east-west extent of the central Andean plateau in southern Peru. These basins contain an exceptional record of the vertical movements of this region. We calculate sediment accumulation and subsidence rates through decompaction of measured stratigraphic sections, and reconstruct past environmental conditions based on the stable isotopic composition of ancient waters preserved in hydrated volcanic glass. These data and published records of crustal shortening and exhumation show that although paleoaltimetry data in the study areas may be interpreted in various ways, they are best explained by multiple geodynamic processes driving (i) Eocene-early Miocene development of high topography in the Western Cordillera, then (ii) a pulsed middle Miocene-present building of the central Andean plateau from west to east, consistent with global climate changes as well as regional climate shifts driven by topographic development of the Andean orogen.

  13. The crustal structure of south central Mongolia using receiver functions

    Science.gov (United States)

    He, Jing; Wu, Qingju; Sandvol, Eric; Ni, James; Gallegos, Andrea; Gao, Mengtan; Ulziibat, Munkhuu; Demberel, Sodnomsambuu

    2016-06-01

    The crustal thickness H and average crustal velocity ratio k (Vp/Vs) beneath south central Mongolia are investigated using the H-k stacking method based on teleseismic radial receiver functions. Our primary results reveal that the local crustal thickness varies from 38 to 46 km with an average value of 43 km. Thicker crust is found beneath the western Hentey Mountains, while thinner crust is located in the southern area of the Zuunbayan fault zone. The Bouguer gravity anomalies exhibit a strong correlation with the overall crustal thickness pattern throughout most of our study regime. Moreover, a new approach which integrates the Bouguer anomaly gradient and the receiver function-derived crustal thickness is adopted to calculate the density of the lower crust underneath central Mongolia. Fairly dense lower crust of approximately 3000 kg/m3 is found in the Middle Gobi Desert. The measured crustal Vp/Vs ratio ranges from 1.68 to 1.83 with an average value of 1.74. Low Vp/Vs ratio is found beneath the western Hentey Mountains. In general, low Vp/Vs ratios correlate well with regions of quartz-rich crust and high heat flow. High Vp/Vs ratios occur in the Middle Gobi volcanic regions and the Mesozoic Southern Gobi Basin.

  14. Pb isotopic geochemical study on the crustal structure of Tongbaishan

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Pb isotopic composition of the Tongbai complex, distributed in the Tongbaishan to the west of the Dabieshan, ranges between the Dabie core complex and the Dabie ultral-high pressure (UHP) metamorphic complex, the latter having more radiogenic Pb isotopic composition than the former. Granites from the Jigongshan pluton, which intruded mainly into the Tongbai complex, are distinct from the Tongbai complex but similar to the Dabie core complex in Pb isotopic composition, showing that the magma of the Jigongshan granites was derived from the partial melting of the Dabie core complex. According to Pb isotopic compositional variation model in the vertical crustal section and magma source from the Jigongshan pluton, it is suggested that the Tongbai complex was an upper rock serial of the Dabie core complex, which is beneath the Dabie UHP metamorphic complex in the crustal structure of the Tongbai-Dabie orogenic belt. The Tongbai complex was not well preserved in the Dabie area due to the high exhumed crustal section. However, the crustal section in the Tongbai area was exhumed less than that in the Dabie area, and the deep crust in the Tongbai area still contains the basement composition similar to the Dabie core complex. Therefore, the crustal basements from the Dabie to Tongbai areas are united. The present distribution of the basement blocks in different locations of the Tongbai-Dabie orogenic belt reflects different exposure of the crustal section.

  15. The Sub-Crustal Stress Field in the Taiwan Region

    Directory of Open Access Journals (Sweden)

    Robert Tenzer and Mehdi Eshagh

    2015-01-01

    Full Text Available We investigate the sub-crustal stress in the Taiwan region. A tectonic configuration in this region is dominated by a collision between the Philippine oceanic plate and the Eurasian continental margin. The horizontal components of the sub-crustal stress are computed based on the modified _ formulae in terms of the stress function with a subsequent numerical differentiation. This modification increases the (degree-dependent convergence domain of the asymptotically-convergent series and consequently allows evaluating the stress components to a spectral resolution, which is compatible with currently available global crustal models. Moreover, the solution to the Vening _ (VMM inverse isostasy problem is explicitly incorporated in the stress function definition. The sub-crustal stress is then computed for a variable Moho geometry, instead of assuming only a constant Moho depth. The regional results reveal that the Philippine plate subduction underneath the Eurasian continental margin generates the shear sub-crustal stress along the Ryukyu Trench. Some stress anomalies associated with this subduction are also detected along both sides of the Okinawa Trough. A tensional stress along this divergent tectonic plate boundary is attributed to a back-arc rifting. The sub-crustal stress, which is generated by a (reverse subduction of the Eurasian plate under the Philippine plate, propagates along both sides of the Luzon (volcanic Arc. This stress field has a prevailing compressional pattern.

  16. Monitoring Crustal Movement of the Coastal Zone in Eastern China with GPS Technique

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    In this paper, various dominating factors affecting crustal movement of the coastal zone in eastern China are analyzed, and major characteristics of crustal movement are summarized. Subduction of the pacific plate and Philippine plate and southeastward "escape" of Qinghai-Tibet plateau are believed to be dominating factors affecting crustal movement of that zone. Undoubtedly, it is a best way to monitor this kind of large-scale crustal movement with GPS technique. The feasibility of monitoring crustal m...

  17. Mining the bulk positron lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Aourag, H.; Guittom, A. [Centre de Recherche Nucleaire d' Alger (CRNA), Alger Gare - Algiers (Algeria)

    2009-02-15

    We introduce a new approach to investigate the bulk positron lifetimes of new systems based on data-mining techniques. Through data mining of bulk positron lifetimes, we demonstrate the ability to predict the positron lifetimes of new semiconductors on the basis of available semiconductor data already studied. Informatics techniques have been applied to bulk positron lifetimes for different tetrahedrally bounded semiconductors in order to discover computational design rules. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Mining the bulk positron lifetime

    International Nuclear Information System (INIS)

    We introduce a new approach to investigate the bulk positron lifetimes of new systems based on data-mining techniques. Through data mining of bulk positron lifetimes, we demonstrate the ability to predict the positron lifetimes of new semiconductors on the basis of available semiconductor data already studied. Informatics techniques have been applied to bulk positron lifetimes for different tetrahedrally bounded semiconductors in order to discover computational design rules. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Advances in bulk port development

    Energy Technology Data Exchange (ETDEWEB)

    Soros, P. (Soros Associates Consulting Engineers, New York, NY (USA))

    1991-03-01

    The article features several recently developed bulk ports which illustrate aspects of new technology or concepts in maritime transport. Low handling capacity bulk terminals at Ponta da Madeira, Brazil and Kooragang Island, Australia and the low-cost bulk port at Port of Corpus Christi, Texas are described. Operations at the ports of Pecket and Tocopilla in Chile, which had special technical problems, are mentioned. Coal terminals at Port Kembla, Australia and St. Johns River in Florid Jacksonville, Florida are featured as examples of terminals which had to be designed to meet high environmental standards. 13 refs., 2 figs., 14 photos.

  20. New geological evidence of crustal thickening in the Gangdese block prior to the Indo-Asian collision

    Institute of Scientific and Technical Information of China (English)

    DING Lin; LAI Qingzhou

    2003-01-01

    Recent mapping in the Gangdese block has revealed many leucogranites that are similar to those in the High Himalaya. These leucogranites formed at ~140 Ma as indicated by monazite Th-Pb ion-microprobe dating and cooled at ~130 Ma as indicated by muscovite 40Ar/39Ar dating. In conjunction with previous structural and paleogeographic studies, the new data indicate that the Gangdese block underwent crustal thickening and associated exhumation during ~140-130 Ma. In this regard, the southern margin of Eurasia continent was comparable to the modern South American Altiplano-Puna plateau, the prime example of active ocean-continent subduction and associated thickened crust. Specifically, the early stages of crustal thickening and uplifting of the Gangdese block may result from subduction of the Neo-Tethyan Ocean. If the Tibetan Plateau would form by accretion of a series of blocks with thickened crust, an elevated topographic plateau similar to the Altiplano- Puna plateau had formed before collision between the Indian and Eurasian plates. Then the Tibetan Plateau would have quickly thickened, uplifted, and begun to extend soon after onset of the collision. Thus, the deformational mechanism of the Tibetan Plateau is not distributed shortening, but rather concentrating deformation within regions of thin crust between the accreted blocks.

  1. Mars crustal magnetism, plate tectonics, and more

    Science.gov (United States)

    Connerney, J.; Acuna, M.; Ness, N.

    Mars has no global magnetic field of internal origin, but must have had one in the past when the crust acquired intense magnetization, presumably by cooling in the presence of an Earth-like magnetic field (thermoremanent magnetization or TRM). The Mars crust is at least an order of magnitude more intensely magnetized than that of the Earth. The apparent lack of magnetization associated with major impact basins suggests that the crust acquired magnetic remanence early in its history, about 4 billion years ago. A new map of the magnetic field of Mars, compiled at ˜ 400 km mapping altitude by Mars Global Surveyor, is presented here. The spatial resolution and sensitivity of this global map is unprecedented, inviting geologic interpretation heretofor reserved for aeromagnetic and ship surveys on Earth. These data provide new insight into the origin and evolution of the Mars crust. The apparent lack of magnetization associated with volcanic provinces may indicate that the magnetic layer resides within a few km of the surface, requiring magnetization intensity of order few 100 A/m, almost unthinkable. Two parallel great faults are identified in Terra Meridiani by offset magnetic field contours. They appear similar to transform faults that occur in oceanic crust on Earth, and describe the relative motion of two ancient Mars plates on the surface of a sphere. The magnetic imprint in Meridiani is consistent with that observed above a mid-ocean ridge on Earth. It is a relic of an era of plate tectonics on Mars, an era of crustal spreading, rifting, plate motions, and widespread volcanism following the demise of the dynamo. We present this new data in the context of the early development of plate tectonics on Earth, as advanced by the Vine-Matthews hypothesis and the work of W. Jason Morgan and others. Finally, we discuss the next logical steps in Mars exploration: magnetic surveys on global and regional scales.

  2. Crustal-scale tectonic wedging in the central Longmen Shan: Constraints on the uplift mechanism in the southeastern margin of the Tibetan Plateau

    Science.gov (United States)

    Lu, Renqi; He, Dengfa; Xu, Xiwei; Liu, Bo

    2016-03-01

    This study focuses on the upper-middle crust (UMC) deformation in the central Longmen Shan (LMS). The results of this study are constrained by the surface geology, typical seismic reflection profiles, previously available thermochronology, and deep geophysical data. Regional seismic profiles demonstrate a strata dip of about 2°, northwest trending, from the Sichuan Basin (SB) to LMS. The interpretation of shallow artificial seismic reflection data indicates that an unknown basement structure lead to the uplifting of the sedimentary cover by 3-4 km. A long and wide-angle reflection seismic profile presents evidence that the middle crustal-scale structure is involved in the deformation. Geophysical data support that there is an upper detachment (D1) at the depth of ∼20 km. The other lower detachment (D2) could be generated at approximately 30-40 km depth in the low velocity zone. The ductile middle crust between the D1 and D2, has shortening and forming a wedge tip beneath the transition zone of the LMS and the SB. The deformation of the LMS frontal monocline belt is related to this crustal-scale wedging. Two different tectonic stages are distinguished in the Cenozoic through the axial surface analysis and chronological data. During the first stage, the crustal-scale tectonic wedge was developed between the upper and lower detachment, resulting in the uplift of the UMC. During the second stage, the middle crust could hardly be extruding and uplifting. The brittle upper crust was rapidly uplifted and shortened by the shallow major thrusts, which were developed on the D1. The D1 and D2 controlled the uplifting and shortening in the southeastern margin of the Tibetan Plateau. The lower crust (LC) may be decoupled from the D2 and subducted due to the resistance by the stable craton underlying the SB. The structural model manifests the importance of multi-detachments and the superimposed deformation in the LMS thrust belt. However, we emphasize that this crustal

  3. Bulk Nuclear Properties from Reactions

    OpenAIRE

    Danielewicz, P.

    2002-01-01

    Extraction of bulk nuclear properties by comparing reaction observables to results from semiclassical transport-model simulations is discussed. Specific properties include the nuclear viscosity, incompressibility and constraints on the nuclear pressure at supranormal densities.

  4. An Updated Eurasian Crustal Model Using Multiple Seismic Methods

    Science.gov (United States)

    Detweiler, S.; Mooney, W. D.; McDonald, S.

    2006-12-01

    An updated 2 by 2 degree crustal model for greater Eurasia is being completed from (1) synthesizing existing models, such as WENA 1.0, the new Barents Sea model, and WINPAK; (2) Pn/Sn tomography data; (3) our ongoing compilation of published seismic models for the crust, based on active- and passive-source seismology; and (4) observed and calculated seismic surface wave group and phase velocity maps. In particular, three controlled source studies from China and India completed by the U.S. Geological Survey and colleagues in the past year are contributing to this updated Eurasian crustal model. These include: (1) three short (20-35 km) seismic reflection profiles from the immediate region of the 2001 Mw 7.7 Bhuj (western India) earthquake that yielded a crustal thickening from 35 to 45 km over a distance of about 50 km from the northern margin of the Gulf of Kutch to the epicentral zone of the earthquake; (2) a compilation of over 90 seismic refraction/wide angle reflection profiles, with a cumulative length of more than sixty thousand kilometers, across mainland China that have shown a mid-crustal low velocity layer in unstable regions; and (3) a 1000- km-long geophysical profile from Darlag-Lanzhou-Jingbian extending from the Songpan-Ganzi terrane to the Ordos basin in the NE margin of the Tibetan plateau that yielded a 2-D seismic velocity profile from which crustal composition and continental dynamics of the Tibetan plateau are inferred. New crustal depth and velocity maps for greater Eurasia have been compiled, which incorporate the results from the above three studies and other relevant controlled source experiments. This updated compilation of Eurasian Pn and Sn data in CRUST 2.2 will yield more detailed models of the Earth's structure and subsequently more accurate seismic monitoring. Well-resolved crustal models are critical for determining event locations and size estimations.

  5. [Effects of removable partial dentures on the quality of life in people with shortened dental arches].

    Science.gov (United States)

    Armellini, D B; Heydecke, G; Witter, D J; Creugers, N H J

    2009-12-01

    In order to assess the enhanced value of removable partial dentures on the quality of life, patients at 2 university clinics were screened for the presence of complete or shortened dental arches. Those selected were assigned to 1 of 5 subgroups: 1) a shortened dental arch with all frontal teeth, 2) a shortened dental arch with one or more frontal diastemas, 3) a shortened dental arch with all frontal teeth, restored by a removable partial denture, 4) a shortened dental arch and several diastemas, restored by a removable partial denture, 5) a complete dental arch. The participants completed the Oral Health Impact Profile (OHIP-49) and the Short Form Health Survey (SF-36). Clinical data recorded were: whether any teeth were missing and if so which, whether or not these had been replaced by a removable partial denture, and the number of occluding pairs of (pre)molars. The results revealed that a shortenend dental arch has a certain impact on the quality of life. However, the participants only experienced benefits from a removable partial denture if the denture also replaced frontal teeth. PMID:20101937

  6. Spine biomechanics associated with the shortened, modern one-plane golf swing.

    Science.gov (United States)

    Dale, R Barry; Brumitt, Jason

    2016-06-01

    The purpose of this study was to compare kinetic, kinematic, and performance variables associated with full and shortened modern backswings in a skilled group of modern swing (one-plane) golfers. Shortening the modern golf backswing is proposed to reduce vertebral spine stress, but supporting evidence is lacking and performance implications are unknown. Thirteen male golfers performed ten swings of each swing type using their own 7-iron club. Biomechanical-dependent variables included the X-Factor kinematic data and spine kinetics. Performance-related dependent variables included club head velocity (CHV), shot distance, and accuracy (distance from the target line). Data were analysed with repeated measures ANOVA with an a priori alpha of 0.05 (SPSS 22.0, IBM, Armonk, NY, USA). We found significant reductions for the X-Factor (p < 0.05) between the full and shortened swings. The shortened swing condition ameliorated vertebral compression force from 7.6 ± 1.4 to 7.0 ± 1.7 N (normalised to body weight, p = 0.01) and significantly reduced CHV (p < 0.05) by ~2 m/s with concomitant shot distance diminution by ~10 m (p < 0.05). Further research is necessary to examine the applicability of a shortened swing for golfers with low back pain. PMID:27064175

  7. Telomere shortening correlates with increasing aneuploidy of chromosome 8 in human hepatocellular carcinoma.

    Science.gov (United States)

    Plentz, Ruben R; Schlegelberger, Brigitte; Flemming, Peer; Gebel, Michael; Kreipe, Hans; Manns, Michael P; Rudolph, K Lenhard; Wilkens, Ludwig

    2005-09-01

    Chromosomal instability (CIN) leads to an increase in aneuploidy and chromosomal aberrations in human hepatocellular carcinoma (HCC). Telomere shortening appears as one mechanism fostering the development of CIN. Whether telomere shortening correlates to specific genetic changes that characterize a certain type of cancer has yet to be established. In our recent study, we combined on a cellular level the analysis of hepatocellular telomere fluorescent intensity (TFI) and copy number of chromosome 8-one of the hallmark chromosomal alterations in hepatocellular carcinoma (HCC). We investigated 15 cytological fine-needle biopsies of aneuploid HCC and 5 touch prints of cadaver livers without cancer. Hepatocyte-specific TFI and the measurement of centromere-specific probe for chromosome 8 were both performed by quantitative fluorescence in situ hybridization (qFISH) or FISH. Combined analysis of both methods (coFISH) allowed measurement of telomere length and chromosome 8 copy number on a single cell level. We observed that telomere shortening correlates significantly with increasing copy number of chromosome 8 in HCC on the cellular level. Above the level of 5 copies of chromosome 8 per nucleus, no further shortening of telomeres was found, indicating that telomeres had reached a critically short length at this stage of aneuploidy. In conclusion, our study gives direct evidence that telomere shortening is linked to a specific genetic alteration characteristic for human HCC. PMID:16116624

  8. Estimation of the shortening rate since late Pleistocene in the Aksu area on the southern flank of the Tianshan, China

    Institute of Scientific and Technical Information of China (English)

    WANG; Xin

    2001-01-01

    [1]Molnar, P., Tapponnier, P., Cenozoic tectonics of Asia: Effects on a continental collision, Science, 1975, 189: 419-426.[2]Molnar, P., Deng Qidong, Faulting associated with large earthquakes and the average rate of deformation in central and eastern Asia, J. Geophys. Res., 1984, 89: 6203-6227.[3]Hendrix, M. S., Dumitru, T. A., Graham, S. A., Late Oligocene-early Miocene unroofing in the Chinese Tianshan: An early effect of the India-Asia collision, Geology, 1994, 22: 487-490.[4]Sobel, R. E., Dumitru, T. A., Thrusting and exhumation around the margins of the western Tarim Basin during the India-Asia collision, J. Geophys. Res., 1997, 102: 5043-5063.[5]Ghose, S., Hamburger, M. W., Virieux, J., Three-dimentional velocity structure and earthquake locations beneath the northern Tianshan of Kyrgyzstan, central Asia, J. Geophys. Res., 1998, 103: 2725-2748.[6]Ghose, S., Hamburger, M. W., Ammon, C. J., Source parameters of moderate-sized earthquakes in the Tianshan, central Asia from regional moment tensor inversion, Geophys. Res. lett., 1998, 25: 3181-3184.[7]Abdrakhmatov, K. Ye, Aldazhanov, S. A., Hager, B. H. et al., Relatively recent construction of the Tianshan inferred from GPS measurements of present-day curstal deformation rates, Nature, 1996, 384: 450-452.[8]Wang Qi, Ding Guoyu, Qiao Xuejun et al., Present-day Tianshan's quick shortening and the south-north block's relative movement, Chinese Science Bulletin (in Chinese), 2000, 45(14): 1543-1547.[9]Zhu Wenyao, Wang Xiaoya, Chen Yuyi et al., Crustal motion of Chinese mainland monitored by GPS, Science in China, Ser. D, 2000, 43(2): 394-400.[10]Avouac, J. P., Tapponnier, P., Bai, M. et al., Active thrusting and folding along the northern Tianshan and late cenozoic rotation of the Tarim relative to Dzungaria and Kazakhstan, J. Geopgys. Res., 1993, 98: 6755-6804.[11]Burtman, V. S.,Skobelev, S. F., Molnar, P., Late cenozoic slip on the Talas-Ferghana fault, the Tianshan

  9. Present-Day Crustal Deformation Field in China Continent Inverted from GPS Observations, Earthquake Moment Tensor and Quaternary Fault Slip Rates

    Institute of Scientific and Technical Information of China (English)

    Xu Cai-jun; Wang Hua; Liu Jing-nan

    2003-01-01

    Based on the bi-cubic Bessel spline function method, we have inverted the present-day crustal horizontal velocity field and deformation field in China continent by combining with 410 GPS observations, 327 seismic moment tensors of earthquakes and fault slip rates in China and its neighboring areas, and considered the geological and geophysical parameters at the same time. The results reveal that the crustal movement mostly takes on compression in SN-NE direction and extension in EW-NW direction in China continent. The continent is rotating southeast and takes on a clockwise rotation image from the west to the east, particularly in the southeast of Tibet and Chuan-dian area. Different blocks have different deformation in China continent. The south China, Ordos and Northeast block have good integrity.The deformation in the western part of China is obviously stronger than that in the eastern part. The strong strains are focused on the Himalaya, east Tibet,west Tian Shan and Chuandian block etc. The deformation at the joint of blocks is stronger than that within the blocks. The China continent deformation not only has the strike-slip faulting and extrusion feature but also has the crustal shortening and thickening feature.

  10. Telomere shortening: a new prognostic factor for cardiovascular disease post-radiation exposure

    International Nuclear Information System (INIS)

    Telomere length has been proposed as a marker of mitotic cell age and as a general index of human organism aging. Telomere shortening in peripheral blood lymphocytes has been linked to cardiovascular-related morbidity and mortality. The authors investigated the potential correlation of conventional risk factors, radiation dose and telomere shortening with the development of coronary artery disease (CAD) following radiation therapy in a large cohort of Hodgkin lymphoma (HL) patients. Multivariate analysis demonstrated that hypertension and telomere length were the only independent risk factors. This is the first study in a large cohort of patients that demonstrates significant telomere shortening in patients treated by radiation therapy who developed cardiovascular disease. Telomere length appears to be an independent prognostic factor that could help determine patients at high risk of developing CAD after exposure in order to implement early detection and prevention. (authors)

  11. Early roentgenological grading of femoral shortening is correlated to the late outcome after femoral neck fractures

    International Nuclear Information System (INIS)

    Using orthoradiography, the distance between the centre of the femoral head and the intercondylar notch was assessed at regular intervals in 144 patients who were followed for a 2-year period after osteosynthesis of a femoral neck fracture. Late complications, such as segmental collapse and non-union, occurred in 27% of the patients. The degree of femoral shortening was significantly correlated to the incidence of late complications. At 1 month, femoral shortening of more than 5 mm was observed in 85% of patients who developed late complications, and in only 5% of patients without such complications. Thus, the observation of a shortening of more than 5 mm predicted a greater than 6-fold increase of the incidence of late complications. The prognostic accuracy of this observation 1 month after treatment was 92%. (orig.)

  12. Load-shortening behavior of an initially curved eccentrically loaded column

    Science.gov (United States)

    Fichter, W. B.; Pinson, Mark W.

    1989-01-01

    To explore the feasibility of using buckled columns to provide a soft support system for simulating a free-free boundary condition in dynamic testing, the nonlinear load-shortening behavior of initially imperfect, eccentrically loaded slender columns is analyzed. Load-shortening curves are obtained for various combinations of load eccentricity and uniform initial curvature and are compared, for reference purposes, with the limiting case of the classical elastica. Results for numerous combinations of initial curvature and load eccentricity show that, over a wide range of shortening, an axially loaded slender column exhibits load-deflection compliance which is of the same order as that of a straight but otherwise identical cantilever beam under lateral tip loading.

  13. Effect of carbon ions on life span shortening and tumorigenesis in mice.

    Science.gov (United States)

    Kakinuma, Shizuko; Kubo, Ayumi; Amasaki, Yoshiko; Nohima, Kumie; Imaoka, Tatsuhiko; Nishimura, Mayumi; Shimada, Yoshiya

    2004-11-01

    One of the important concerns for astronauts in space is cancer risk associated with cosmic radiation, including heavy particle ions. But little information on cancer risk is available. We investigated the effect of carbon ions on life span shortening and tumor induction in B6C3F1 mice. The mice were exposed weekly to 0.4 and 2.0 Gy whole-body carbon-ion- or X-ray-irradiation for 4 consecutive weeks. The spectrum of induced tumors varied depending on the dose. The cause of death was thymic lymphomas and liver tumors at high and low dose, respectively. The life span shortening by X-rays was proportional to dose, while carbon ions produced a convex upward relationship. The relative biological effectiveness for the 50% life span shortening was about 1.4. The large effect of carbon ions encourages the study on tumor induction at low doses in the space. PMID:15900637

  14. Edentulism and shortened dental arch in Brazilian elderly from the National Survey of Oral Health 2003

    Directory of Open Access Journals (Sweden)

    Marco Túlio Freitas Ribeiro

    2011-10-01

    Full Text Available OBJECTIVE: To describe the distribution of edentulism and estimate the prevalence of functional dentition and shortened dental arch among elderly population. METHODS: A population-based epidemiological study was carried out with a sample of 5,349 respondents aged 65 to 74 years obtained from the 2002 and 2003 Brazilian Ministry of Health/Division of Oral Health survey database. The following variables were studied: gender; macroregion of residence; missing teeth; percentage that met the World Health Organization goal for oral health in the age group 65 to 74 years (50% having at least 20 natural teeth; presence of shortened dental arch; number of posterior occluding pairs of teeth. The Chi-square test assessed the association between categorical variables. The Kruskal-Wallis and Mann-Whitney tests were used to assess differences of mean between number of posterior occluding pairs teeth, macro-region and gender. RESULTS: The elderly population had an average of 5.49 teeth (SD: 7.93 with a median of 0. The proportion of completely edentulous respondents was 54.7%. Complete edentulism was 18.2% in the upper arch and 1.9% in the lower arch. The World Health Organization goal was achieved in 10% of all respondents studied. However, only 2.7% had acceptable masticatory function and aesthetics (having at least shortened dental arch and a mean number of posterior occluding pairs of 6.94 (SD=2.97. There were significant differences of the percentage of respondents that met the World Health Organization goal and presence of shortened dental arch between men and women. There were differences in shortened dental arch between macroregions. CONCLUSIONS: The Brazilian epidemiological oral health survey showed high rate of edentulism and low rate of shortened dental arch in the elderly population studied, thus suggesting significant functional and aesthetic impairment in all Brazilian macroregions especially among women.

  15. Superimposed folding and thrusting by two phases of mutually orthogonal or oblique shortening in analogue models

    Science.gov (United States)

    Deng, Hongling; Koyi, Hemin A.; Nilfouroushan, Faramarz

    2016-02-01

    Orogens may suffer more than one phase shortening resulting in superposition of structures of different generations. Superimposition of orthogonal or oblique shortening is studied using sandbox and centrifuge modelling. Results of sand models show that in orthogonal superimposition, the two resulting structural trends are approximately orthogonal to each other. In oblique superimposition, structures trend obliquely to each other in the relatively thin areas of the model (foreland), and mutually orthogonal in areas where the model is thickened during the first phase of shortening (i.e. the hinterland). Thrusts formed during the first shortening phase may be reactivated during the later shortening phase. Spacing of the later phase structures is not as wide as expected, considering they across the pre-existing thickened wedge. Superposition of structures results in formation of type 1 fold interference pattern. Bedding is curved outwards both in the dome and basin structures. Folded layers are dipping and plunging outwards in a dome, while they are dipping and plunging inwards in a basin. In the areas between two adjacent domes or basins (i.e. where an anticline is superimposed by a syncline or a syncline is superimposed by an anticline), bedding is curved inwards, and the anticlines plunge inwards and the synclines outwards. The latter feature could be helpful to determine the age relationship for type 2 fold interference pattern. In tectonic regions where multiple phases of shortening have occurred, the orogenic-scale dome-and-basin and arrowhead-shaped interference patterns are commonly formed, as in the models. However, in some areas, the fold interference pattern might be modified by a later phase of thrusting. Similar to models results, superimposition of two and/or even more deformation phases may not be recorded by structures all over the tectonic area.

  16. Force depression following muscle shortening in sub-maximal voluntary contractions of human adductor pollicis.

    Science.gov (United States)

    Rousanoglou, Elissavet N; Oskouei, Ali E; Herzog, Walter

    2007-01-01

    Mechanical properties of skeletal muscles are often studied for controlled, electrically induced, maximal, or supra-maximal contractions. However, many mechanical properties, such as the force-length relationship and force enhancement following active muscle stretching, are quite different for maximal and sub-maximal, or electrically induced and voluntary contractions. Force depression, the loss of force observed following active muscle shortening, has been observed and is well documented for electrically induced and maximal voluntary contractions. Since sub-maximal voluntary contractions are arguably the most important for everyday movement analysis and for biomechanical models of skeletal muscle function, it is important to study force depression properties under these conditions. Therefore, the purpose of this study was to examine force depression following sub-maximal, voluntary contractions. Sets of isometric reference and isometric-shortening-isometric test contractions at 30% of maximal voluntary effort were performed with the adductor pollicis muscle. All reference and test contractions were executed by controlling force or activation using a feedback system. Test contractions included adductor pollicis shortening over 10 degrees, 20 degrees, and 30 degrees of thumb adduction. Force depression was assessed by comparing the steady-state isometric forces (activation control) or average electromyograms (EMGs) (force control) following active muscle shortening with those obtained in the corresponding isometric reference contractions. Force was decreased by 20% and average EMG was increased by 18% in the shortening test contractions compared to the isometric reference contractions. Furthermore, force depression was increased with increasing shortening amplitudes, and the relative magnitudes of force depression were similar to those found in electrically stimulated and maximal contractions. We conclude from these results that force depression occurs in sub

  17. Bilateral Serous Retinal Detachment Associated with Inferior Posterior Staphyloma Treated with Scleral Shortening and Vitrectomy

    OpenAIRE

    Kasai, Akihito; Kanda, Naotaka; Sekiryu, Tetsuju

    2016-01-01

    Purpose We report a case of bilateral serous retinal detachment (SRD) associated with inferior posterior staphyloma (IPS) treated successfully with scleral shortening. Patient and Methods A 63-year-old woman presented with bilateral visual loss due to an SRD with IPS. The best-corrected visual acuity levels were 0.6 (20/30) and 0.5 (20/40) in the right and left eye, respectively. The patient underwent vitrectomy and scleral shortening in the right eye. The lamellar scleral crescent was resect...

  18. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence.

    Science.gov (United States)

    Bernadotte, Alexandra; Mikhelson, Victor M; Spivak, Irina M

    2016-01-01

    The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data. PMID:26805432

  19. Isotopic and chemical studies of early crustal metasedimentary rocks

    Science.gov (United States)

    Jacobsen, Stein B.

    1988-01-01

    The aim, within the bounds of the Early Crustal Genesis Project, was the isotopic and chemical study of selected early crustal meta-sedimentary rocks. Western Australia was chosen as the first field area to examine, as the Yilgarn and Pilbara Blocks comprise one of the largest and most varied Precambrian terranes. Furthermore, the Western Gneiss Terrane (on the western flank of the Yilgarn Block) and the Pilbara Block are both non-greenstone in character; these types of terrane were relatively neglected, but are of great significance in the understanding of early crustal meta-sediments. The meta-sediments of aluminous or peraluminous character, commonly also enriched in Mg and/or Fe relative to the more common pelitic meta-sediments, and at many locations, deficient in one or more of the elements Ca, N, and K, were initially chosen.

  20. Combined crustal-geological cross-section of Ellesmere Island

    DEFF Research Database (Denmark)

    Stephenson, Randell Alexander; Schiffer, Christian; Oakey, Gordon

    resulted in a regional geological cross-section spanning Ellesmere Island from Hansen Point (NW) to the Bache Peninsula (SE). This cross-section, based on the excellent surface exposure afforded in this region, provides a model of the structure of the upper crust to a depth of about 10 km. Although......-sections have been integrated to produce a single, combined crustal-geological 2-D model of Ellesmere Island with the aim of illuminating the relationships between crustal architecture and geology as expressed at the surface of and in the topography of Ellesmere Island.......Ellesmere Island, in Canada’s Arctic, consists of a series of ~SW-NE trending tectonic provinces, the crustal structure and geological expression of which represent a combination of interplate, accretionary orogenesis in the Palaeozoic and, most recently, intraplate deformation in the Cenozoic...

  1. Looking for a bulk point

    CERN Document Server

    Maldacena, Juan; Zhiboedov, Alexander

    2015-01-01

    We consider Lorentzian correlators of local operators. In perturbation theory, singularities occur when we can draw a position-space Landau diagram with null lines. In theories with gravity duals, we can also draw Landau diagrams in the bulk. We argue that certain singularities can arise only from bulk diagrams, not from boundary diagrams. As has been previously observed, these singularities are a clear diagnostic of bulk locality. We analyze some properties of these perturbative singularities and discuss their relation to the OPE and the dimensions of double-trace operators. In the exact nonperturbative theory, we expect no singularity at these locations. We prove this statement in 1+1 dimensions by CFT methods.

  2. Deep crustal structure between the Selkirk Crest, Idaho and the Whitefish Range, Montana from magnetotelluric imaging

    Science.gov (United States)

    Bedrosian, P. A.; Box, S. E.; Pellerin, L.

    2006-12-01

    conductive (1-10 Ømega m) sub-Prichard layer (below the lowest Prichard unit mapped at the surface), and moderately to highly resistive (103-104 Ømega m) pre-Belt crystalline basement. The Eocene Purcell trench detachment fault can be traced dipping 25-30° east down to about 20 km depth, flattening along the base of the shallow conductive layer to its eastern end, fully 100 km east of the surface trace of the fault. Realignment of the eastern edges of the shallow and deep conductive layers produces a single west-dipping horizon and suggests about 35 km of Eocene top-to-the-east extension along the northern Purcell trench detachment fault. Reversal of that displacement reveals the crustal structure as it existed at the end of late Mesozoic Cordilleran thrusting. A major thrust decollement at 10-12 km, well-defined below the Sylvanite anticline, occurs below the deepest exposed Prichard units but above the shallow conductive layer. The shallow and deep conductive layers are suggested to be thrust repetitions of a single original layer separated by a thrust imbricate of Archean crystalline basement, 35 km wide and 5-8 km thick, centered below the Sylvanite anticline. The conductive layers are interpreted as sub-Prichard sedimentary strata with disseminated carbonaceous matter or sulfide grains interconnected by shearing. This interpretation is consistent with disseminated sulfides within the lowest exposed Prichard, and emphasizes the dramatic increase in conductivity effected by shearing. Total Cordilleran thrust shortening of 150-200 km is indicated.

  3. Bulk Viscosity of Interacting Hadrons

    OpenAIRE

    Wiranata, A.; M. Prakash

    2009-01-01

    We show that first approximations to the bulk viscosity $\\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of $\\eta_v$ on the factor $(\\frac 13 - v_s^2)$ is demonstrated in the Chapman-Enskog approximation as well as the variational and relaxation time approaches. The interesting feature of bulk viscosity is that the dominant contributions at a given temperature ari...

  4. Bulk Viscosity of Interacting Hadrons

    CERN Document Server

    Wiranata, A

    2009-01-01

    We show that first approximations to the bulk viscosity $\\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of $\\eta_v$ on the factor $(\\frac 13 - v_s^2)$ is demonstrated in the Chapman-Enskog approximation as well as the variational and relaxation time approaches. The interesting feature of bulk viscosity is that the dominant contributions at a given temperature arise from particles which are neither extremely nonrelativistic nor extremely relativistic. Numerical results for a model binary mixture are reported.

  5. Recent crustal horizontal movement in the Chinese mainland

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to the results of careful re-processing of data obtained from two GPS survey campaigns of crustal movement monitoring network in Chinese mainland carried out in 1994 and 1996, the crustal horizontal movement characteristics in Chinese mainland are studied in the paper. In the analysis, a relatively consummate deformation model in which the deformation is described by the relative movement between the tectonic blocks with interior strain and the corresponding analysis method are used. The magnitude of movement along the boundary zones between the tectonic blocks is calculated. And the characters and intensities between the main boundary zones are compared.

  6. Monitoring Crustal Deformations with Radar Interferometry:A Review

    Institute of Scientific and Technical Information of China (English)

    刘国祥; 丁晓利; 黄丁发

    2004-01-01

    The crustal movements, probably motivating earthquakes, are considered as one of the main geodynamic sources. The quantitative measurements of ground surface deformations are vital for studying mechanisms of the buried faults or even estimating earthquake potential. A new space-geodetic technology, synthetic aperture radar interferometry (InSAR), can be applied to detect such large-area deformations, and has demonstrated some prominent advantages. This paper reviews the capacity and limitations of InSAR, and summarises the existing applications including some of our results in studying the earthquake-related crustal motions.Finally it gives the outlook for the future development of InSAR.

  7. Scaling behaviour in temporal fluctuations of crustal seismicity in Taiwan

    Directory of Open Access Journals (Sweden)

    L. Telesca

    2009-12-01

    Full Text Available The crustal seismicity of Taiwan was investigated by means of the Allan Factor analysis and Count-based Periodogram, which allow to identify scaling behaviour in point processes and to quantify their temporal fluctuations by means of the estimate of the scaling exponent. Our findings point out to the presence of two time-scaling regions in the crustal Taiwanese seismicity. The first region, involving the intermediate timescales can be probably linked with aftershock activity, while the second region, involving the large timescales could be related with the background seismicity.

  8. An assessment of crustal thickness variations on the lunar near side - Models, uncertainties, and implications for crustal differentiation

    Science.gov (United States)

    Thurber, C. H.; Solomon, S. C.

    1978-01-01

    The paper presents a series of models for the structure of lunar nearside crust which are consistent with the observed gravity and topography. Each crustal model is derived subject to a specific set of constraints and assumptions. The assumptions/constraints considered include strict isostatic equilibrium, pure Airy compensation mechanism, pure Pratt compensation mechanism, assignment of assumed fixed values for mare basalt thickness, and attribution of all superisostatic mass in the maria to basalt fill. The resulting models are used to assess the degree and mechanism of isostasy, and to investigate the thickness of the mare basalt. Details of the lateral variations in crustal thickness or density and in the degree of isostatic compensation bear strongly on the mode of early crustal differentiation and on the subsequent thermal history of the moon.

  9. Development of a Shortened Form of the Fennema-Sherman Mathematics Attitudes Scales.

    Science.gov (United States)

    Mulhern, Fiona; Rae, Gordon

    1998-01-01

    Data from 196 Irish school children were analyzed and used to develop a shortened version of the Fennema-Sherman Mathematics Attitudes Scales (E. Fennema and J. Sherman, 1976). Internal consistency estimates of the reliability of scores on the whole scale and each of the subscales of the original and short form were favorable. (SLD)

  10. Changing Quality Controls: The Effects of Increasing Product Variety and Shortening Product Life Cycles

    NARCIS (Netherlands)

    J.D. van Iwaarden (Jos)

    2006-01-01

    textabstractIn many industries (e.g. cars, electronics, clothing) manufacturing complexity and unpredictability have increased in recent years because of increasing product variety and shortening product life cycles. At the same time, manufacturers in these industries appear to have more problems wi

  11. The Shortened Visuospatial Questionnaire for Children: A Useful Tool to Identify Students with Low Visuospatial Abilities

    Science.gov (United States)

    Fastame, Maria Chiara; Cherchi, Rossella; Penna, Maria Pietronilla

    2015-01-01

    The current research was aimed mainly at exploring the reliability of a short-screening tool developed to self-evaluate visuospatial abilities in children. We presented 290 Italian third, fourth, and fifth graders with the 16-item Shortened Visuospatial questionnaire and several objective measures of intellectual efficiency, such as Raven's…

  12. Interlayer material transport during layer-normal shortening. Part I. The model

    NARCIS (Netherlands)

    Molen, I. van der

    1985-01-01

    To analyse mass-transfer during deformation, the case is considered of a multilayer experiencing a layer-normal shortening that is volume constant on the scale of many layers. Strain rate is homogeneously distributed on the layer-scale if diffusion is absent; when transport of matter between the lay

  13. Differential Telomere Shortening in Blood versus Arteries in an Animal Model of Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Samira Tajbakhsh

    2015-01-01

    Full Text Available Vascular dysfunction is an early feature of diabetic vascular disease, due to increased oxidative stress and reduced nitric oxide (NO bioavailability. This can lead to endothelial cell senescence and clinical complications such as stroke. Cells can become senescent by shortened telomeres and oxidative stress is known to accelerate telomere attrition. Sirtuin 1 (SIRT1 has been linked to vascular health by upregulating endothelial nitric oxide synthase (eNOS, suppressing oxidative stress, and attenuating telomere shortening. Accelerated leukocyte telomere attrition appears to be a feature of clinical type 2 diabetes (T2D and therefore the telomere system may be a potential therapeutic target in preventing vascular complications of T2D. However the effect of T2D on vascular telomere length is currently unknown. We hypothesized that T2D gives rise to shortened leukocyte and vascular telomeres alongside reduced vascular SIRT1 expression and increased oxidative stress. Accelerated telomere attrition was observed in circulating leukocytes, but not arteries, in T2D compared to control rats. T2D rats had blunted arterial SIRT1 and eNOS protein expression levels which were associated with reduced antioxidant defense capacity. Our findings suggest that hyperglycemia and a deficit in vascular SIRT1 per se are not sufficient to prematurely shorten vascular telomeres.

  14. Contribution of NHE-1 to cell length cardiac shortening of normal and failing rabbit myocytes

    NARCIS (Netherlands)

    M.M.G.J. van Borren; J.G. Zegers; A. Baartscheer; J.H. Ravesloot

    2006-01-01

    At the same intracellular pH (pH(i)) Na+/H+ exchange (NHE-1) fluxes of ventricular myocytes of hypertrophied failing hearts (HFH) are increased. We assessed how NHE-1 affected cell length shortening. pH(i) was measured fluorimetrically in resting and twitching (1 - 3 Hz)normal and HFH rabbit myocyte

  15. Ulnar Shortening Osteotomy After Distal Radius Fracture Malunion: Review of Literature.

    Science.gov (United States)

    Barbaric, Katarina; Rujevcan, Gordan; Labas, Marko; Delimar, Domagoj; Bicanic, Goran

    2015-01-01

    Malunion of distal radius fracture is often complicated with shortening of the radius with disturbed radio- ulnar variance, frequently associated with lesions of triangular fibrocartilage complex and instability of the distal radioulnar joint. Positive ulnar variance may result in wrist pain located in ulnar part of the joint, limited ulnar deviation and forearm rotation with development of degenerative changes due to the overloading that occurs between the ulnar head and corresponding carpus. Ulnar shortening osteotomy (USO) is the standard procedure for correcting positive ulnar variance. Goal of this procedure is to minimize the symptoms by restoring the neutral radio - ulnar variance. In this paper we present a variety of surgical techniques available for ulnar shorthening osteotomy, their advantages and drawbacks. Methods of ulnar shortening osteotomies are divided into intraarticular and extraarticular. Intraarticular method of ulnar shortening can be performed arthroscopically or through open approach. Extraarticular methods include subcapital osteotomy and osteotomy of ulnar diaphysis, which depending on shape can be transverse, oblique, and step cut. All of those osteotomies can be performed along wrist arthroscopy in order to dispose and treat possibly existing triangular fibrocartilage complex injuries. At the end we described surgical procedures that can be done in case of ulnar shorthening osteotomy failure. PMID:26157524

  16. The addition of lidocaine to bupivacaine does not shorten the duration of spinal anesthesia

    DEFF Research Database (Denmark)

    Jacobsen, Jon; Husum, Bent; Staffeldt, Henrik;

    2011-01-01

    The duration of spinal anesthesia with bupivacaine is often too long for day surgery. A recent study of patients presenting for transurethral surgery suggested that the addition of a small amount of lidocaine to intrathecal hyperbaric bupivacaine could shorten the duration of the sensory and motor...

  17. Bulk viscosity and deflationary universes

    CERN Document Server

    Lima, J A S; Waga, I

    2007-01-01

    We analyze the conditions that make possible the description of entropy generation in the new inflationary model by means of a nearequilibrium process. We show that there are situations in which the bulk viscosity cannot describe particle production during the coherent field oscillations phase.

  18. Longitudinal bulk acoustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja;

    2009-01-01

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10(-15) g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise i...

  19. Design real-time reversal of tumor multidrug resistance cleverly with shortened carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Wu P

    2014-12-01

    Full Text Available Pingping Wu,1 Shang Li,2 Haijun Zhang2 1Jiangsu Cancer Hospital, Nanjing, People’s Republic of China; 2Department of Oncology, Zhongda Hospital, Medical School, Southeast University, Nanjing, People’s Republic of ChinaAbstract: Multidrug resistance (MDR in tumors renders many currently available chemotherapeutic drugs ineffective. Research in nanobiotechnology-based therapeutic alternatives has provided innovative and promising strategies to overcome MDR. The aim of this study was to investigate whether the new strategy of a co-loaded reversal agent and chemotherapeutic drug with shortened carbon nanotubes (CNTs would show useful effects on the real-time reversal of tumor MDR. CNTs were cut and purified via ultrasonication and oxidative acid treatment to optimize their length for drug-delivery vehicles, then verapamil (Ver and doxorubicin (Dox were co-loaded on shortened CNTs (denoted as Ver/Dox/shortened CNTs, which acted as a drug delivery system. The multidrug resistant leukemia K562/A02 cells were treated with the denoted Ver/Dox/shortened CNTs. The real-time reversal of tumor MDR were evaluated by flow cytometer, 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assays, acridine orange/ethidium bromide staining, and Western blot analysis. In the same MDR tumor cells the new strategy of a co-loaded reversal agent and chemotherapeutic drug with CNTs could inhibit the function of P-glycoprotein in real-time by Ver as reversal agent, significantly increase the uptake of Dox, enhance the sensitivity of the MDR cancer cells to the chemotherapeutic agent, and induce apoptosis. It was therefore concluded that a co-loaded reversal agent and chemotherapeutic drug with shortened CNTs could have real-time reversal ability of MDR in tumors, which could represent a promising approach in cancer therapy.Keywords: multidrug resistance, carbon nanotubes, drug delivery system, tumor

  20. A method for measuring mean circumferential fiber shortening rate from gated blood pool scans

    International Nuclear Information System (INIS)

    Ejection fraction and ejection rate are easily obtained from gated cardiac images, but no method is available for calculating mean circumferential fiber shortening rate. We assumed that the cube root of left ventricular end-diastolic volume or counts is proportional to the minor axis of the left ventricle at end-diastole or end-systole. Mean circumferential fiber shortening rate is then equal to the [cube root of the end-diastolic volume (count) minus cube root of end-systolic volume (count)] divided by [cube root of end-diastolic volume (count) multiplied by the ejection time]. In 250 contrast ventriculograms, the standard mean circumferential fiber shortening rate (MCFSR) and that derived by the cube root method correlated well (r = 0.94). The mean value of MCFSR (0.85 +- 0.35) was greater than the cube root value (0.75 +- 0.35) (P < 0.001). The regression equation was y = 0.86x + 0.02. Similar correlations were obtained from gated radionuclide images using a semiautomated program (r = 0.93) in 24 subjects or completely automated program (r = 0.85) in 28 patients. The regression equation between MCFSR and that derived from the cube root of counts for the semiautomated program was y = 0.82x + 0.04 and for the automated program was y = 0.84x + 0.004. Similar correlations, slopes, and intercepts were seen using circumferential fractional shortening for angiographic data when correlated with both the semiautomated and automated gated blood pool scan programs. These data indicate that MCFSR and circumferential fractional shortening may be obtained from gated blood pool images using cube root estimates of end-diastolic and end-systolic radii with a high degree of correlation with the standard contrast ventriculographic technique. (orig.)

  1. Oxidative Stress-induced Telomere Length Shortening of Circulating Leukocyte in Patients with Obstructive Sleep Apnea

    Science.gov (United States)

    Kim, Kyung Soo; Kwak, Jin Wook; Lim, Su Jin; Park, Yong Kyun; Yang, Hoon Shik; Kim, Hyun Jik

    2016-01-01

    The main mechanism of pathogenesis which causes systemic complications in obstructive sleep apnea (OSA) patients is believed to be intermittent hypoxia-induced intermediary effect and it depends on the burden of oxidative stress during sleep. We aimed to search the predictive markers which reflect the burden of systemic oxidative stress in patients with OSA and whether excessive telomere length shortening is a characteristic feature that can assess oxidative stress levels. We used quantitative PCR to measure telomere length using peripheral blood genomic DNA. Telomere lengths were compared in an age- and body mass index (BMI)-dependent manner in 34 healthy volunteers and 43 OSA subjects. We also performed reactive oxygen species assay to measure the concentration of hydrogen peroxide in the peripheral blood of healthy volunteers and OSA subjects. We found that the serum concentration of hydrogen peroxide was considerably higher in OSA patients, and that this was closely related with the severity of OSA. Significantly shortened telomere length was observed in the circulating leukocytes of the peripheral blood of OSA patients, and telomere length shortening was aggravated more acutely in an age- and BMI-dependent manner. An inverse correlation was observed between the concentration of hydrogen peroxide and the telomere length of OSA patients and excessive telomere length shortening was also linked to severity of OSA. The results provided evidence that telomere length shortening or excessive cellular aging might be distinctive in circulating leukocyte of OSA patients and may be an predictive biomarker for reflect the burden of oxidative stress in the peripheral blood of OSA patients. PMID:27699083

  2. Two-Stage Surgical Treatment for Non-Union of a Shortened Osteoporotic Femur

    Directory of Open Access Journals (Sweden)

    Galal Zaki Said

    2013-01-01

    Full Text Available Introduction: We report a case of non-union with severe shortening of the femur following diaphysectomy for chronic osteomyelitis.Case Presentation: A boy, aged 16 years presented with a dangling and excessively short left lower limb. He was using an elbow crutch in his right hand to help him walk. He had a history of diaphysectomy for chronic osteomyelitis at the age of 9. Examination revealed a freely mobile non-union of the left femur. The femur was the seat of an 18 cm shortening and a 4 cm defect at the non-union site; the knee joint was ankylosed in extension. The tibia and fibula were 10 cm short. Considering the extensive shortening in the femur and tibia in addition to osteoporosis, he was treated in two stages. In stage I, the femoral non-union was treated by open reduction, internal fixation and iliac bone grafting. The patient was then allowed to walk with full weight bearing in an extension brace for 7 months. In Stage II, equalization of leg length discrepancy (LLD was achieved by simultaneous distraction of the femur and tibia by unilateral frames. At the 6 month follow- up, he was fully weight bearing without any walking aid, with a heel lift to compensate the 1.5 cm shortening. Three years later he reported that he was satisfied with the result of treatment and was leading a normal life as a university student.Conclusions: Two-stage treatment succeeded to restore about 20 cm of the femoral shortening in a severely osteoporotic bone. It has also succeeded in reducing the treatment time of the external fixator.

  3. Upper mantle and crustal structure of the East Greenland Caledonides

    DEFF Research Database (Denmark)

    Schiffer, Christian; Balling, N.; Jacobsen, B. H.;

    The East Greenland and Scandinavian Caledonides once formed a major coherent mountain range, as a consequence of the collision of the continents of Laurentia and Baltica. The crustal and upper mantle structure was furthermore influenced by several geodynamic processes leading to the formation...

  4. Multi-quadric collocation model of horizontal crustal movement

    Science.gov (United States)

    Chen, Gang; Zeng, Anmin; Ming, Feng; Jing, Yifan

    2016-05-01

    To establish the horizontal crustal movement velocity field of the Chinese mainland, a Hardy multi-quadric fitting model and collocation are usually used. However, the kernel function, nodes, and smoothing factor are difficult to determine in the Hardy function interpolation. Furthermore, the covariance function of the stochastic signal must be carefully constructed in the collocation model, which is not trivial. In this paper, a new combined estimation method for establishing the velocity field, based on collocation and multi-quadric equation interpolation, is presented. The crustal movement estimation simultaneously takes into consideration an Euler vector as the crustal movement trend and the local distortions as the stochastic signals, and a kernel function of the multi-quadric fitting model substitutes for the covariance function of collocation. The velocities of a set of 1070 reference stations were obtained from the Crustal Movement Observation Network of China, and the corresponding velocity field was established using the new combined estimation method. A total of 85 reference stations were used as checkpoints, and the precision in the north and east component was 1.25 and 0.80 mm yr-1, respectively. The result obtained by the new method corresponds with the collocation method and multi-quadric interpolation without requiring the covariance equation for the signals.

  5. Ellipticity and crustal corrections for seismic body wave paths: application to Mars and Moon

    Science.gov (United States)

    Hempel, S.; Garcia, R.; Wieczorek, M. A.

    2015-12-01

    Forward modeling of seismic body wave travel times and ray parameters for a given density and seismic velocity model is an important tool to investigate the interior structure of planets. The popular toolbox TauP by Crotwell et al. (1999) facilitates application to planets other than Earth, but does not consider a planet's ellipticity nor its surface topography. Due to their ellipticity, smaller radii and larger relative surface topography, these corrections become more significant in predicting seismic observations for celestial bodies like the Moon and Mars. In preparation for NASA's INSIGHT discovery mission (launch in March 2016), we include ellipticity corrections, geometrical spreading and topography corrections into TauP. The respective TauP extensions, as well as Lunar and Martian applications are presented: Previously, Lunar and Martian seismic velocity models have been proposed based on mass, moment of inertia, Love numbers and estimated bulk composition, and in case of the Moon also based on seismic data acquired during the Apollo Program (1969-1977). Due to the lack of direct seismic evidence, current Martian seismic velocity models vary widely and exhibit large travel time excursions, as well as considerable variations in epicentral distance ranges for which a given body wave is predicted to arrive. We discuss the effects of Lunar and Martian ellipticity and crustal structure on seismic travel times for a set of seismic velocity models and compare these to variations observed between the different 1D models. This comparison demonstrates the relevance of modeling the effects of ellipticity and crustal thickness during interpretation of seismic data acquired on planets like Mars or Moon.

  6. Crustal Seismicity and Recent Faults in Southern Peru

    Science.gov (United States)

    David, C.; Comte, D.; Tavera, H.; Audin, L.; Herail, G.

    2004-12-01

    Most seismological studies in southern Peru have been focused on the downgoing slab seismicity in order to constrain the Wadati-Benioff zone. This study deals with the intra-continental seismicity of the southern Peru forearc (17,3° S - 18,5° S) in a post-seismic context (Arequipa thrust earthquake, Mw=8.4, 23 June, 2001). It is difficult to identify historical crustal earthquake from available catalogues, however some crustal events teleseismically recorded can be found since 1976; they exhibit normal focal mechanism solutions in the southern Peru volcanic arc and inverse focal mechanism solutions in the Central Depression. Following a notable increase of shallow crustal seismicity located close to the Western Cordillera after the 23 June 2001, a temporary seismic network was deployed between January and March 2003 in order to study the Wadati-Benioff zone and monitoring the crustal seismicity in southern Peru. From the about 1700 events locally recorded by the local network, 300 crustal earthquakes were identified in the Peruvian forearc between Tacna and Moquegua. This crustal seismicity is distributed along a lineament located at depths between 0 and 60 km, dipping at about 45° from the Western Cordillera towards the coast, almost perpendicular to the subducting slab; this behaviour was previously observed in northern Chile and in southern Peru, north of the study zone (16° S). In the Central Depression, seismic activity is not superficial occurring between 25-60 km depth and it is mostly characterized by inverse focal mechanism solutions. Superficial faults situated in the Central Depression and in the Coastal Cordillera can not be associated with the seismic activity observed in this area. However, in the Pre-Cordillera, crustal seismicity occurs at depths between 0-15 km and can be correlated with shallow fault systems recognized by satellite images and on the field. For examples, the Incapuquio fault system which was a transpressive system in Cretaceous

  7. Central Andean crustal structure from receiver function analysis

    Science.gov (United States)

    Ryan, Jamie; Beck, Susan; Zandt, George; Wagner, Lara; Minaya, Estela; Tavera, Hernado

    2016-07-01

    The Central Andean Plateau (15°-27°S) is a high plateau in excess of 3 km elevation, associated with thickened crust along the western edge of the South America plate, in the convergent margin between the subducting Nazca plate and the Brazilian craton. We have calculated receiver functions using seismic data from a recent portable deployment of broadband seismometers in the Bolivian orocline (12°-21°S) region and combined them with waveforms from 38 other stations in the region to investigate crustal thickness and crust and mantle structures. Results from the receiver functions provide a more detailed map of crustal thickness than previously existed, and highlight mid-crustal features that match well with prior studies. The active volcanic arc and Altiplano have thick crust with Moho depths increasing from the central Altiplano (65 km) to the northern Altiplano (75 km). The Eastern Cordillera shows large along strike variations in crustal thickness. Along a densely sampled SW-NE profile through the Bolivian orocline there is a small region of thin crust beneath the high peaks of the Cordillera Real where the average elevations are near 4 km, and the Moho depth varies from 55 to 60 km, implying the crust is undercompensated by ~ 5 km. In comparison, a broader region of high elevations in the Eastern Cordillera to the southeast near ~ 20°S has a deeper Moho at ~ 65-70 km and appears close to isostatic equilibrium at the Moho. Assuming the modern-day pattern of high precipitation on the flanks of the Andean plateau has existed since the late Miocene, we suggest that climate induced exhumation can explain some of the variations in present day crustal structure across the Bolivian orocline. We also suggest that south of the orocline at ~ 20°S, the thicker and isostatically compensated crust is due to the absence of erosional exhumation and the occurrence of lithospheric delamination.

  8. Effects of Martian crustal magnetic field on its ionosphere

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The effect of the Martian crustal magnetic field is one of the hot topics of the study of Martian ionosphere.The studies on this topic are summarized in this paper.Main data of the Martian ionosphere were resulted from radio occultation experiments.According to the observations,the electron density scale height and the peak electron density of the Martian ionosphere are influenced by its crustal magnetic field.The strong horizontal magnetic field prevents the vertical diffusion of the plasma and makes the electron density scale height in the topside ionosphere close to that in the photo equilibrium region.In the cusp-like regions with strong vertical magnetic field,the enhanced vertical diffusion leads to a larger electron density scale height in the diffusion equilibrium region.The observation of radio occultation experiment onboard Mars Global Surveyor (MGS) showed that the averaged peak electron density observed in the southern hemisphere with strong crustal magnetic field was slightly larger than that in the northern hemisphere with weak crustal magnetic field.The Mars advanced radar for subsurface and ionosphere sounding (MARSIS) onboard Mars Express (MEX) was the first topside sounder to be used to observe Martian ionosphere.The MARSIS results confirmed that the enhancement of the peak electron density occurred in cusp-like regions with open field lines,and the amount of the enhancement was much larger than that observed by the radio occultation experiment.There are two possible mechanisms for the peak electron density enhancement in the cusp-like crustal magnetic field regions:One is the precipitation of the energetic particles and the other is the heating by the waves excited by plasma instabilities.It’s difficult to determine which one is the key mechanism for the peak electron density enhancement.Based on these studies,several interesting problems on the Martian ionosphere and plasma environment are presented.

  9. Serotonin in the solitary tract nucleus shortens the laryngeal chemoreflex in anaesthetized neonatal rats.

    Science.gov (United States)

    Donnelly, William T; Bartlett, Donald; Leiter, J C

    2016-07-01

    What is the central question of this study? Failure to terminate apnoea and arouse is likely to contribute to sudden infant death syndrome (SIDS). Serotonin is deficient in the brainstems of babies who died of SIDS. Therefore, we tested the hypothesis that serotonin in the nucleus of the solitary tract (NTS) would shorten reflex apnoea. What is the main finding and its importance? Serotonin microinjected into the NTS shortened the apnoea and respiratory inhibition associated with the laryngeal chemoreflex. Moreover, this effect was achieved through a 5-HT3 receptor. This is a new insight that is likely to be relevant to the pathogenesis of SIDS. The laryngeal chemoreflex (LCR), an airway-protective reflex that causes apnoea and bradycardia, has long been suspected as an initiating event in the sudden infant death syndrome. Serotonin (5-HT) and 5-HT receptors may be deficient in the brainstems of babies who die of sudden infant death syndrome, and 5-HT seems to be important in terminating apnoeas directly or in causing arousals or as part of the process of autoresuscitation. We hypothesized that 5-HT in the brainstem would limit the duration of the LCR. We studied anaesthetized rat pups between 7 and 21 days of age and made microinjections into the cisterna magna or into the nucleus of the solitary tract (NTS). Focal, bilateral microinjections of 5-HT into the caudal NTS significantly shortened the LCR. The 5-HT1a receptor antagonist, WAY 100635, did not affect the LCR consistently, nor did a 5-HT2 receptor antagonist, ketanserin, alter the duration of the LCR. The 5-HT3 specific agonist, 1-(3-chlorophenyl)-biguanide, microinjected bilaterally into the caudal NTS significantly shortened the LCR. Thus, endogenous 5-HT released within the NTS may curtail the respiratory depression that is part of the LCR, and serotonergic shortening of the LCR may be attributed to activation of 5-HT3 receptors within the NTS. 5-HT3 receptors are expressed presynaptically on C

  10. Serotonin in the solitary tract nucleus shortens the laryngeal chemoreflex in anaesthetized neonatal rats.

    Science.gov (United States)

    Donnelly, William T; Bartlett, Donald; Leiter, J C

    2016-07-01

    What is the central question of this study? Failure to terminate apnoea and arouse is likely to contribute to sudden infant death syndrome (SIDS). Serotonin is deficient in the brainstems of babies who died of SIDS. Therefore, we tested the hypothesis that serotonin in the nucleus of the solitary tract (NTS) would shorten reflex apnoea. What is the main finding and its importance? Serotonin microinjected into the NTS shortened the apnoea and respiratory inhibition associated with the laryngeal chemoreflex. Moreover, this effect was achieved through a 5-HT3 receptor. This is a new insight that is likely to be relevant to the pathogenesis of SIDS. The laryngeal chemoreflex (LCR), an airway-protective reflex that causes apnoea and bradycardia, has long been suspected as an initiating event in the sudden infant death syndrome. Serotonin (5-HT) and 5-HT receptors may be deficient in the brainstems of babies who die of sudden infant death syndrome, and 5-HT seems to be important in terminating apnoeas directly or in causing arousals or as part of the process of autoresuscitation. We hypothesized that 5-HT in the brainstem would limit the duration of the LCR. We studied anaesthetized rat pups between 7 and 21 days of age and made microinjections into the cisterna magna or into the nucleus of the solitary tract (NTS). Focal, bilateral microinjections of 5-HT into the caudal NTS significantly shortened the LCR. The 5-HT1a receptor antagonist, WAY 100635, did not affect the LCR consistently, nor did a 5-HT2 receptor antagonist, ketanserin, alter the duration of the LCR. The 5-HT3 specific agonist, 1-(3-chlorophenyl)-biguanide, microinjected bilaterally into the caudal NTS significantly shortened the LCR. Thus, endogenous 5-HT released within the NTS may curtail the respiratory depression that is part of the LCR, and serotonergic shortening of the LCR may be attributed to activation of 5-HT3 receptors within the NTS. 5-HT3 receptors are expressed presynaptically on C

  11. Coulombic Fluids Bulk and Interfaces

    CERN Document Server

    Freyland, Werner

    2011-01-01

    Ionic liquids have attracted considerable interest in recent years. In this book the bulk and interfacial physico-chemical characteristics of various fluid systems dominated by Coulomb interactions are treated which includes molten salts, ionic liquids as well as metal-molten salt mixtures and expanded fluid metals. Of particular interest is the comparison of the different systems. Topics in the bulk phase concern the microscopic structure, the phase behaviour and critical phenomena, and the metal-nonmetal transition. Interfacial phenomena include wetting transitions, electrowetting, surface freezing, and the electrified ionic liquid/ electrode interface. With regard to the latter 2D and 3D electrochemical phase formation of metals and semi-conductors on the nanometer scale is described for a number of selected examples. The basic concepts and various experimental methods are introduced making the book suitable for both graduate students and researchers interested in Coulombic fluids.

  12. Bulk Superconductors in Mobile Application

    Science.gov (United States)

    Werfel, F. N.; Delor, U. Floegel-; Rothfeld, R.; Riedel, T.; Wippich, D.; Goebel, B.; Schirrmeister, P.

    We investigate and review concepts of multi - seeded REBCO bulk superconductors in mobile application. ATZ's compact HTS bulk magnets can trap routinely 1 T@77 K. Except of magnetization, flux creep and hysteresis, industrial - like properties as compactness, power density, and robustness are of major device interest if mobility and light-weight construction is in focus. For mobile application in levitated trains or demonstrator magnets we examine the performance of on-board cryogenics either by LN2 or cryo-cooler application. The mechanical, electric and thermodynamical requirements of compact vacuum cryostats for Maglev train operation were studied systematically. More than 30 units are manufactured and tested. The attractive load to weight ratio is more than 10 and favours group module device constructions up to 5 t load on permanent magnet (PM) track. A transportable and compact YBCO bulk magnet cooled with in-situ 4 Watt Stirling cryo-cooler for 50 - 80 K operation is investigated. Low cooling power and effective HTS cold mass drives the system construction to a minimum - thermal loss and light-weight design.

  13. Does postsystolic motion or shortening predict recovery of myocardial function after primary percutanous coronary intervention?

    DEFF Research Database (Denmark)

    Terkelsen, Christian Juhl; Poulsen, Steen Hvitfeldt; Nørgaard, Bjarne Linde;

    2007-01-01

    or shortening appears more frequently in the acute phase in myocardial segments with impaired systolic function compared with normally functioning segments. However, presence of postsystolic contraction is not associated with improvement in strain or wall-motion score at follow-up, and does not seem......OBJECTIVE: The purpose of the study was to evaluate whether presence of postsystolic motion or shortening defined by Doppler tissue imaging may predict recovery of regional myocardial function in patients with ST-elevation myocardial infarction. METHODS: Echocardiography was performed a few hours......); and normal myocardial function in the acute phase (type E, n = 759). RESULTS: There were no differences among type A, B, C, and D segments with regard to the proportion presenting postsystolic tissue velocity equal to or greater than 1.0 cm/s (0.52, 0.54, 0.60, and 0.47, respectively, P = .20...

  14. Telomeric noncoding RNA TERRA is induced by telomere shortening to nucleate telomerase molecules at short telomeres.

    Science.gov (United States)

    Cusanelli, Emilio; Romero, Carmina Angelica Perez; Chartrand, Pascal

    2013-09-26

    Elongation of a short telomere depends on the action of multiple telomerase molecules, which are visible as telomerase RNA foci or clusters associated with telomeres in yeast and mammalian cells. How several telomerase molecules act on a single short telomere is unknown. Herein, we report that the telomeric noncoding RNA TERRA is involved in the nucleation of telomerase molecules into clusters prior to their recruitment at a short telomere. We find that telomere shortening induces TERRA expression, leading to the accumulation of TERRA molecules into a nuclear focus. Simultaneous time-lapse imaging of telomerase RNA and TERRA reveals spontaneous events of telomerase nucleation on TERRA foci in early S phase, generating TERRA-telomerase clusters. This cluster is subsequently recruited to the short telomere from which TERRA transcripts originate during S phase. We propose that telomere shortening induces noncoding RNA expression to coordinate the recruitment and activity of telomerase molecules at short telomeres.

  15. A critical examination of the maximum velocity of shortening used in simulation models of human movement.

    Science.gov (United States)

    Domire, Zachary J; Challis, John H

    2010-12-01

    The maximum velocity of shortening of a muscle is an important parameter in musculoskeletal models. The most commonly used values are derived from animal studies; however, these values are well above the values that have been reported for human muscle. The purpose of this study was to examine the sensitivity of simulations of maximum vertical jumping performance to the parameters describing the force-velocity properties of muscle. Simulations performed with parameters derived from animal studies were similar to measured jump heights from previous experimental studies. While simulations performed with parameters derived from human muscle were much lower than previously measured jump heights. If current measurements of maximum shortening velocity in human muscle are correct, a compensating error must exist. Of the possible compensating errors that could produce this discrepancy, it was concluded that reduced muscle fibre excursion is the most likely candidate.

  16. A near-term ion-beam experiment to demonstrate pulse shortening

    Energy Technology Data Exchange (ETDEWEB)

    Shih, K., E-mail: kaishihchi@gmail.com [Physics Department, The Chinese University of Hong Kong, Hong Kong (China); Woo, K.M. [Physics Department, The Chinese University of Hong Kong, Hong Kong (China); Physics Department, University of Rochester, NY 14627 (United States); Yu, S.S. [Physics Department, The Chinese University of Hong Kong, Hong Kong (China); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2014-04-21

    Short beam pulse at a target is essential for High Energy Density Physics and Heavy Ion Fusion (HIF). A technique for ion-beam pulse shortening by the reduction of longitudinal emittance has recently been developed. An experimental demonstration of this technique would be important not only for the long-term design of HIF and HEDP targets, but would have immediate applications for near-term target experiments as well. To this end, using 3D PIC simulation code WARP, we have designed an experiment based on beam parameters of the existing NDCX-II machine at the Lawrence Berkeley National Laboratory. The proposed experiment only requires non-invasive beam current measurements at two existing diagnostic stations and the implementation of two induction cells with special voltage waveforms, one for energy correction and a second one for final pulse compression. We show that the final pulse length in the NDCX-II experiment can be shortened by 46%.

  17. Telomere shortening leads to earlier age of onset in ALS mice

    Science.gov (United States)

    Linkus, Birgit; Wiesner, Diana; MeΔner, Martina; Karabatsiakis, Alexander; Scheffold, Annika; Rudolph, K. Lenhard; Thal, Dietmar R.; Weishaupt, Jochen H.; Ludolph, Albert C.; Danzer, Karin M.

    2016-01-01

    Telomere shortening has been linked to a variety of neurodegenerative diseases. Recent evidence suggests that reduced telomerase expression results in shorter telomeres in leukocytes from sporadic patients with amyotrophic lateral sclerosis (ALS) compared with healthy controls. Here, we have characterized telomere length in microglia, astroglia and neurons in human post mortem brain tissue from ALS patients and healthy controls. Moreover, we studied the consequences of telomerase deletion in a genetic mouse model for ALS. We found a trend towards longer telomeres in microglia in the brains of ALS patients compared to non-neurologic controls. Knockout of telomerase leading to telomere shortening accelerated the ALS phenotype in SOD1G93A–transgenic mice. Our results suggest that telomerase dysfunction might contribute to the age-related risk for ALS. PMID:26978042

  18. Development of advanced concept for shortening construction period of ABWR plant (Part 3)

    International Nuclear Information System (INIS)

    The reinforced concrete containment vessel (RCCV) is the most critical part in construction of an ABWR plant. Use of steel plate reinforced concrete (SC) and a large modular construction method are effective in shortening the construction period (Ijichi et al., 2004)1). This research is aimed at a remarkable shortening of the construction period of an ABWR plant (period from 1st concrete placement to Fuel/Loading is less than 22 months). Conceptual design of a steel plate reinforced concrete containment vessel (SCCV) using an SC structure is carried out and structural experiments are conducted. It is thus confirmed that SCCV shows outstanding structural performance, compared with RCCV. This paper outlines the study results. (authors)

  19. Signs and symptoms related to temporomandibular disorders--Follow-up of subjects with shortened and complete dental arches.

    NARCIS (Netherlands)

    Witter, D.J.; Kreulen, C.M.; Mulder, J.; Creugers, N.H.J.

    2007-01-01

    OBJECTIVE: To assess prevalence of cardinal signs and symptoms related to temporomandibular disorders (TMD) in subjects with shortened dental arches and to clarify the individual course of these signs and symptoms. METHODS: In this 9-year follow-up study, subjects with shortened dental arches (n=74)

  20. Diaphragm muscle shortening modulates kinematics of lower rib cage in dogs

    OpenAIRE

    Chu, Iris; Fernandez, Cristina; Rodowicz, Kathleen Allen; Lopez, Michael A.; Lu, Raymond; Hubmayr, Rolf D.; Boriek, Aladin M.

    2010-01-01

    We tested the hypothesis that diaphragm muscle shortening modulates volume displacement and kinematics of the lower rib cage in dogs and that posture and mode of ventilation affect such modulation. Radiopaque markers were surgically attached to the lower three ribs of the rib cage and to the midcostal region of the diaphragm in six dogs of ∼8 kg body masses, and the locations of these markers were determined by a biplane fluoroscopy system. Three-dimensional software modeling techniques were ...

  1. Effect of Preactivation on Torque Enhancement by the Stretch-Shortening Cycle in Knee Extensors.

    Science.gov (United States)

    Fukutani, Atsuki; Misaki, Jun; Isaka, Tadao

    2016-01-01

    The stretch-shortening cycle is one of the most interesting topics in the field of sport sciences, because the performance of human movement is enhanced by the stretch-shortening cycle (eccentric contraction). The purpose of the present study was to examine whether the influence of preactivation on the torque enhancement by stretch-shortening cycle in knee extensors. Twelve men participated in this study. The following three conditions were conducted for knee extensors: (1) concentric contraction without preactivation (CON), (2) concentric contraction with eccentric preactivation (ECC), and (3) concentric contraction with isometric preactivation (ISO). Muscle contractions were evoked by electrical stimulation to discard the influence of neural activity. The range of motion of the knee joint was set from 80 to 140 degrees (full extension = 180 degrees). Angular velocities of the concentric and eccentric contractions were set at 180 and 90 degrees/s, respectively. In the concentric contraction phase, joint torques were recorded at 85, 95, and 105 degrees, and they were compared among the three conditions. In the early phase (85 degrees) of concentric contraction, the joint torque was larger in the ECC and ISO conditions than in the CON condition. However, these clear differences disappeared in the later phase (105 degrees) of concentric contraction. The results showed that joint torque was clearly different among the three conditions in the early phase whereas this difference disappeared in the later phase. Thus, preactivation, which is prominent in the early phase of contractions, plays an important role in torque enhancement by the stretch-shortening cycle in knee extensors.

  2. Assessment of plantarflexor function during a stretch-shortening cycle task

    OpenAIRE

    Furlong, Laura-Anne M

    2014-01-01

    peer-reviewed The plantarflexors are important due to their role in locomotion and stiffness control, high prevalence of injury, link to knee stability and anterior cruciate ligament injury. Current methods of assessing the plantarflexors are limited primarily by issues of validity and reliability. The aims of this thesis were to develop a method of measuring plantarflexor function in a dynamic yet controlled stretch-shortening cycle (SSC) task and to assess plantarflexor muscle-tendon uni...

  3. Lengthening of the first metatarsal bone. A case of congenital shortening

    OpenAIRE

    Amillo, S.; Gil-Albarova, J. (Jorge); Pampliega, T. (Tomás)

    1991-01-01

    A 14-year-old boy had a congenital shortening of the first right metatarsal bone, with overloading of the central metatarsals and medial deviation of the second toe. A percutaneous osteotomy and slow distraction by an external fixator for 10 weeks lengthened the bone from 32 mm to 60 mm. After the distraction, a bone graft was performed, and tenotomies and a capsulotomy corrected a threatening subluxation. Consolidation of the lengthening focus required 16 weeks.

  4. Shortened Length of Stay Improves Financial Outcomes in Living Donor Kidney Transplantation

    Science.gov (United States)

    Villa, Manuel; Siskind, Eric; Sameyah, Emil; Alex, Asha; Blum, Mark; Tyrell, Richard; Fana, Melissa; Mishler, Marni; Godwin, Andrew; Kuncewitch, Michael; Alexander, Mohini; Israel, Ezra; Bhaskaran, Madhu; Calderon, Kellie; Jhaveri, Kenar D.; Sachdeva, Mala; Bellucci, Alessandro; Mattana, Joseph; Fishbane, Steven; Coppa, Gene; Molmenti, Ernesto

    2013-01-01

    Kidney transplantation is the preferred clinical and most cost-effective option for end-stage renal disease. Significant advances have taken place in the care of the transplant patients with improvements in clinical outcomes. The optimization of the costs of transplantation has been a constant goal as well. We present herein the impact in financial outcomes of a shortened length of stay after kidney transplant. PMID:24436592

  5. A shortened version of the basic IY Program : effects four years after parent training

    OpenAIRE

    Vik, Heidi Haukebøe; Heggelund, Kjetil

    2010-01-01

    Background: To test whether the effects of a shortened version of the Basic Incredible Years program, aimed at preventing child behavior problems, were sustained 4 years after the initial intervention. Method: Data were obtained from parents in a randomized controlled trial for children aged 6 to 12 (N = 117). Results: Significant increases on positive parenting and parents’ sense of competence, and significant decreases of harsh parenting were observed. No significant difference between g...

  6. A TIN2 dyskeratosis congenita mutation causes telomerase-independent telomere shortening in mice

    OpenAIRE

    Frescas, David; de Lange, Titia

    2014-01-01

    The progressive bone marrow failure syndrome dyskeratosis congenita (DC) is often caused by mutations in telomerase or factors involved in telomerase biogenesis and trafficking. However, a subset of DC patients is heterozygous for mutations in the shelterin component TIN2. Here, heterozygous TIN2-DC mice showed a telomere-shortening phenotype in both telomerase-proficient and telomerase-deficient backgrounds. This study raises the possibility that some of the TIN2-DC mutations may affect telo...

  7. Diabetes mellitus as a cause of life span shortening in locally exposed rats

    International Nuclear Information System (INIS)

    A study was made of the development of remote radiation pathology of pancreas in male rats after local irradiation of abdomen with doses of 5, 10 (two fractions of 5 Gy at a 30-day interval) and 15 Gy (three fractions of 5 Gy at a 30-day interval). The clinical and morphological estimates show the dose-dependent development of diabetes mellitus and 1.8-fold shortening of the life span, as compared to biological control

  8. Mitochondrial genome instability resulting from SUV3 haploinsufficiency leads to tumorigenesis and shortened lifespan

    OpenAIRE

    Chen, Phang-Lang; Chen, Chi-Fen; Chen, Yumay; Guo, Xuning Emily; Huang, Chun-Kai; Shew, Jin-Yuh; Reddick, Robert L.; Wallace, Douglas C.; Lee, Wen-Hwa

    2012-01-01

    Mitochondrial dysfunction has been a hallmark of cancer. However, whether it plays a causive role awaits to be elucidated. Here, using an animal model derived from inactivation of SUV3, a mitochondrial helicase, we demonstrated that mSuv3+/− mice harbored increased mtDNA mutations and decreased mtDNA copy numbers, leading to tumor development in various sites and shortened lifespan. These phenotypes were transmitted maternally, indicating the etiological role of the mitochondria. Importantly,...

  9. Effect of Preactivation on Torque Enhancement by the Stretch-Shortening Cycle in Knee Extensors.

    Directory of Open Access Journals (Sweden)

    Atsuki Fukutani

    Full Text Available The stretch-shortening cycle is one of the most interesting topics in the field of sport sciences, because the performance of human movement is enhanced by the stretch-shortening cycle (eccentric contraction. The purpose of the present study was to examine whether the influence of preactivation on the torque enhancement by stretch-shortening cycle in knee extensors. Twelve men participated in this study. The following three conditions were conducted for knee extensors: (1 concentric contraction without preactivation (CON, (2 concentric contraction with eccentric preactivation (ECC, and (3 concentric contraction with isometric preactivation (ISO. Muscle contractions were evoked by electrical stimulation to discard the influence of neural activity. The range of motion of the knee joint was set from 80 to 140 degrees (full extension = 180 degrees. Angular velocities of the concentric and eccentric contractions were set at 180 and 90 degrees/s, respectively. In the concentric contraction phase, joint torques were recorded at 85, 95, and 105 degrees, and they were compared among the three conditions. In the early phase (85 degrees of concentric contraction, the joint torque was larger in the ECC and ISO conditions than in the CON condition. However, these clear differences disappeared in the later phase (105 degrees of concentric contraction. The results showed that joint torque was clearly different among the three conditions in the early phase whereas this difference disappeared in the later phase. Thus, preactivation, which is prominent in the early phase of contractions, plays an important role in torque enhancement by the stretch-shortening cycle in knee extensors.

  10. Ulnar Shortening Osteotomy After Distal Radius Fracture Malunion: Review of Literature

    OpenAIRE

    Barbaric, Katarina; Rujevcan, Gordan; Labas, Marko; Delimar, Domagoj; Bicanic, Goran

    2015-01-01

    Malunion of distal radius fracture is often complicated with shortening of the radius with disturbed radio- ulnar variance, frequently associated with lesions of triangular fibrocartilage complex and instability of the distal radioulnar joint. Positive ulnar variance may result in wrist pain located in ulnar part of the joint, limited ulnar deviation and forearm rotation with development of degenerative changes due to the overloading that occurs between the ulnar head and corresponding carpus...

  11. Edentulism and shortened dental arch in Brazilian elderly from the National Survey of Oral Health 2003

    OpenAIRE

    Marco Túlio de Freitas Ribeiro; Marco Aurélio Camargo da Rosa; Rosa Maria Natal de Lima; Andréa Maria Duarte Vargas; João Paulo Amaral Haddad; Ferreira, Efigênia Ferreira e

    2011-01-01

    OBJECTIVE: To describe the distribution of edentulism and estimate the prevalence of functional dentition and shortened dental arch among elderly population. METHODS: A population-based epidemiological study was carried out with a sample of 5,349 respondents aged 65 to 74 years obtained from the 2002 and 2003 Brazilian Ministry of Health/Division of Oral Health survey database. The following variables were studied: gender; macroregion of residence; missing teeth; percentage that met the World...

  12. The randomized shortened dental arch study (RaSDA): design and protocol

    OpenAIRE

    Kern Matthias; Jahn Florentine; Heydecke Guido; Hartmann Sinsa; Hannak Wolfgang; Gitt Ingrid; Dressler Paul; Busche Eckhard; Aggstaller Hans; Heinecke Achim; Gerss Joachim; Marré Birgit; Luthardt Ralph G; Mundt Torsten; Pospiech Peter

    2010-01-01

    Abstract Background Various treatment options for the prosthetic treatment of jaws where all molars are lost are under discussion. Besides the placement of implants, two main treatment types can be distinguished: replacement of the missing molars with removable dental prostheses and non-replacement of the molars, i.e. preservation of the shortened dental arch. Evidence is lacking regarding the long-term outcome and the clinical performance of these approaches. High treatment costs and the lon...

  13. Evolution of crustal stress, pressure and temperature around shear zones during orogenic wedge formation: a 2D thermo-mechanical numerical study

    Science.gov (United States)

    Markus Schmalholz, Stefan; Jaquet, Yoann

    2016-04-01

    We study the formation of an orogenic wedge during lithospheric shortening with 2D numerical simulations. We consider a viscoelastoplastic rheology, thermo-mechanical coupling by shear heating and temperature-dependent viscosities, gravity and erosion. In the initial model configuration there is either a lateral temperature variation at the model base or a lateral variation in crustal thickness to generate slight stress variations during lithospheric shortening. These stress variations can trigger the formation of shear zones which are caused by thermal softening associated with shear heating. We do not apply any kind of strain softening, such as reduction of friction angle with progressive plastic strain. The first major shear zone that appears during shortening crosscuts the entire crust and initiates the asymmetric subduction/underthrusting of mainly the mechanically strong lower crust. After some deformation, the first shear zone in the upper crust is abandoned, the deformation propagates towards the foreland and a new shear zone forms only in the upper crust. The shear zone propagation occurs several times where new shear zones form in the upper crust and the mechanically strong top of the lower crust acts as detachment horizon. We calculate the magnitudes of the maximal and minimal principal stresses and of the mean stress (or dynamic pressure), and we record also the temperature for several marker points in the upper and lower crust. We analyse the evolution of stresses and temperature with burial depth and time. Deviatoric stresses (half the differential stress) in the upper crust are up to 200 MPa and associated shear heating in shear zones ranges between 40 - 80 °C. Lower crustal rocks remain either at the base of the orogenic wedge at depths of around 50 km or are subducted to depths of up to 120 km, depending on their position when the first shear zone formed. Largest deviatotric stresses in the strong part of the lower crust are about 1000 MPa and

  14. INFLUENCE OF SHORTENED AND LENGTHENED IMMOBILIZATION ON RAT SOLEUS MUSCLE ATROPHY

    Institute of Scientific and Technical Information of China (English)

    邢国刚; 樊小力; 吴苏娣; 宋新爱; 朱保恭; 唐斌

    2001-01-01

    Objective: To study the possible mechanism and prevention of disuse muscle atrophy. Methods: The shortened immobilization (plaster fixation) of rat' s soleus muscle (SOL) was used as the model of muscle and the lengthened immobilization of rat' s SOL muscle as "passive stretch" method. Types of skeletal muscle fibers were differentiated with m - ATPase staining technique. The changes of rat' s SOL muscle weight (wet weight) as well as the types and the mean cross - sectional area (CSA) of muscle fibers were examined respectively on day 2, 4,7, 14 and 21 under both shortened and lengthened immobilization and then the effect of passive stretch on soleus muscle atrophy in immobilized rats was observed. Results: When shortened immobilization was applied for 4 days, SOL muscle weight (wet weight) became lighter; the fiber crosssectional area (CSA) shrank and type Ⅰ muscle fibers started transforming into type Ⅱ, which all indicated immobilized muscles began to atrophy and as immobilization proceeded, muscle atrophy proceeded toward higher level. In contrast to that, when lengthened immobilization was applied, SOL muscle didn' t show any sign of atrophy until 7th day, and reached its highest level on day 14 and maintained that level even though immobilization continued. Conclusion: From the results, we conclude that passive stretch can either relieve or defer disuse muscle atrophy.

  15. Field Monitoring of Column Shortenings in a High-Rise Building during Construction

    Directory of Open Access Journals (Sweden)

    Hyo Seon Park

    2013-10-01

    Full Text Available The automatic monitoring of shortenings of vertical members in high-rise buildings under construction is a challenging issue in the high-rise building construction field. In this study, a practical system for monitoring column shortening in a high-rise building under construction is presented. The proposed monitoring system comprises the following components: (1 a wireless sensing system and (2 the corresponding monitoring software. The wireless sensing system comprises the sensors and energy-efficient wireless sensing units (sensor nodes, master nodes, and repeater nodes, which automate the processes for measuring the strains of vertical members and transmitting the measured data to the remote server. The monitoring software enables construction administrators to monitor real-time data collected by the server via an Internet connection. The proposed monitoring system is applied to actual 66-floor and 72-floor high-rise buildings under construction. The system enables automatic and real-time measurements of the shortening of vertical members, which can result in more precise construction.

  16. Shortened Lifespan and Lethal Hemorrhage in a Hemophilia A Mouse Model.

    Directory of Open Access Journals (Sweden)

    Janice M Staber

    Full Text Available Hemophilia A animal models have helped advance our understanding of factor VIII deficiency. Previously, factor VIII deficient mouse models were reported to have a normal life span without spontaneous bleeds. However, the bleeding frequency and survival in these animals has not been thoroughly evaluated.To investigate the survival and lethal bleeding frequency in two strains of E-16 hemophilia A mice.We prospectively studied factor VIII deficient hemizygous affected males (n = 83 and homozygous affected females (n = 55 for survival and bleeding frequency. Animals were evaluated for presence and location of bleeds as potential cause of death.Hemophilia A mice had a median survival of 254 days, which is significantly shortened compared to wild type controls (p < 0.0001. In addition, the hemophilia A mice experienced hemorrhage in several tissues. This previously-underappreciated shortened survival in the hemophilia A murine model provides new outcomes for investigation of therapeutics and also reflects the shortened lifespan of patients if left untreated.

  17. Decreasing initial telomere length in humans intergenerationally understates age-associated telomere shortening.

    Science.gov (United States)

    Holohan, Brody; De Meyer, Tim; Batten, Kimberly; Mangino, Massimo; Hunt, Steven C; Bekaert, Sofie; De Buyzere, Marc L; Rietzschel, Ernst R; Spector, Tim D; Wright, Woodring E; Shay, Jerry W

    2015-08-01

    Telomere length shortens with aging, and short telomeres have been linked to a wide variety of pathologies. Previous studies suggested a discrepancy in age-associated telomere shortening rate estimated by cross-sectional studies versus the rate measured in longitudinal studies, indicating a potential bias in cross-sectional estimates. Intergenerational changes in initial telomere length, such as that predicted by the previously described effect of a father's age at birth of his offspring (FAB), could explain the discrepancy in shortening rate measurements. We evaluated whether changes occur in initial telomere length over multiple generations in three large datasets and identified paternal birth year (PBY) as a variable that reconciles the difference between longitudinal and cross-sectional measurements. We also clarify the association between FAB and offspring telomere length, demonstrating that this effect is substantially larger than reported in the past. These results indicate the presence of a downward secular trend in telomere length at birth over generational time with potential public health implications.

  18. Microstructures of bread dough and the effects of shortening on frozen dough.

    Science.gov (United States)

    Aibara, Shigeo; Ogawa, Noriko; Hirose, Masaaki

    2005-02-01

    Three types of straight doughs different in combination of yeast and shortenings (RLS20, FTS20, and FTS80) were prepared, and the structure of the frozen doughs was examined under a microscope after staining protein or lipid droplets. Even after 2 months of frozen storage, distinct changes were not found in the gluten network of FTS80, although significant damages in the dough structures of FTS20 and RLS20 appeared after only one month of frozen storage. These results suggest that the gluten networks loosen and decrease in the water retention ability, and it may be concluded that the lipid is removed from the gluten protein due to the decrease in water in the continuous protein phase. The resulting product from the damage to the gluten matrix gave rise to fusion of lipid droplets and an increase in their size. Because of the difference in fatty acid composition, the lipids of shortening S80 are presumed to interact more strongly with gluten proteins and to keep the gluten matrix from damage in comparison with the lipids of shortening S20. PMID:15725667

  19. Parallel telomere shortening in multiple body tissues owing to malaria infection.

    Science.gov (United States)

    Asghar, Muhammad; Palinauskas, Vaidas; Zaghdoudi-Allan, Nadège; Valkiūnas, Gediminas; Mukhin, Andrey; Platonova, Elena; Färnert, Anna; Bensch, Staffan; Hasselquist, Dennis

    2016-08-17

    Several studies have shown associations between shorter telomere length in blood and weakened immune function, susceptibility to infections, and increased risk of morbidity and mortality. Recently, we have shown that malaria accelerates telomere attrition in blood cells and shortens lifespan in birds. However, the impact of infections on telomere attrition in different body tissues within an individual is unknown. Here, we tested whether malarial infection leads to parallel telomere shortening in blood and tissue samples from different organs. We experimentally infected siskins (Spinus spinus) with the avian malaria parasite Plasmodium ashfordi, and used real-time quantitative polymerase chain reaction (PCR) to measure telomere length in control and experimentally infected siskins. We found that experimentally infected birds showed faster telomere attrition in blood over the course of infection compared with control individuals (repeatedly measured over 105 days post-infection (DPI)). Shorter telomeres were also found in the tissue of all six major organs investigated (liver, lungs, spleen, heart, kidney, and brain) in infected birds compared with controls at 105 DPI. To the best of our knowledge, this is the first study showing that an infectious disease results in synchronous telomere shortening in the blood and tissue cells of internal organs within individuals, implying that the infection induces systemic stress. Our results have far-reaching implications for understanding how the short-term effects of an infection can translate into long-term costs, such as organ dysfunction, degenerative diseases, and ageing. PMID:27488651

  20. Hepatocellular telomere shortening correlates with chromosomal instability and the development of human hepatoma.

    Science.gov (United States)

    Plentz, Ruben R; Caselitz, Martin; Bleck, Joerg S; Gebel, Michael; Flemming, Peer; Kubicka, Stefan; Manns, Michael P; Rudolph, K Lenhard

    2004-07-01

    The telomere hypothesis of cancer initiation indicates that telomere shortening initiates cancer by induction of chromosomal instability. To test whether this hypothesis applies to human hepatocellular carcinoma (HCC), we analyzed the telomere length of hepatocytes in cytological smears of fine-needle biopsies of liver tumors from patients with cirrhosis (n = 39). The tumors consisted of 24 HCC and 15 regenerative nodules as diagnosed by combined histological and cytological diagnostics. In addition, we analyzed the telomere length of hepatocytes in HCC and surrounding noncancerous liver tissue within individual patients in another cohort of 10 patients with cirrhosis. Telomere length analysis of hepatocytes was correlated with tumor pathology and ploidy grade of the tumors, which was analyzed by cytophotometry. Telomeres were significantly shortened in hepatocytes of HCC compared to hepatocytes in regenerative nodules or surrounding noncancerous liver tissue. Hepatocyte telomere shortening in HCC was independent of the patient's age. There was no overlap in mean telomere lengths of individual samples when comparing HCC with regenerative nodules or noncancerous surrounding liver. Within the HCC group, telomeres were significantly shorter in hepatocytes of aneuploid tumors compared to diploid tumors. In conclusion, our data suggest that the telomere hypothesis of cancer initiation applies to human HCC and that cell type-specific telomere length analysis might indicate the risk of HCC development. PMID:15239089

  1. The Crustal Structure and Seismicity of Eastern Venezuela

    Science.gov (United States)

    Schmitz, M.; Martins, A.; Sobiesiak, M.; Alvarado, L.; Vasquez, R.

    2001-12-01

    Eastern Venezuela is characterized by a moderate to high seismicity, evidenced recently by the 1997 Cariaco earthquake located on the El Pilar Fault, a right lateral strike slip fault which marks the plate boundary between the Caribbean and South-American plates in this region. Recently, the seismic activity seems to migrate towards the zone of subduction of the Lesser Antilles in the northeast, where a mb 6.0 earthquake occurred in October 2000 at 120 km of depth. Periodical changes in the seismic activity are related to the interaction of the stress fields of the strike-slip and the subduction regimes. The seismic activity decreases rapidly towards to the south with some disperse events on the northern edge of the Guayana Shield, related to the Guri fault system. The crustal models used in the region are derived from the information generated by the national seismological network since 1982 and by microseismicity studies in northeastern Venezuela, coinciding in a crustal thickness of about 35 km in depth. Results of seismic refraction measurements for the region were obtained during field campains in 1998 (ECOGUAY) for the Guayana Shield and the Cariaco sedimentary basin and in 2001 (ECCO) for the Oriental Basin. The total crustal thickness decreases from about 45 km on the northern edge of the Guayana Shield to some 36 km close to El Tigre in the center of the Oriental Basin. The average crustal velocity decreases in the same sense from 6.5 to 5.8 km/s. In the Cariaco sedimentary basin a young sedimentary cover of 1 km thickness with a seismic velocity of 2 km/s was derived. Towards the northern limit of the South-American plate, no deep seismic refraction data are available up to now. The improvement of the crustal models used in that region would constitute a step forward in the analysis of the seismic hazard. Seismic refraction studies funded by CONICIT S1-97002996 and S1-2000000685 projects and PDVSA (additional drilling and blasting), recording equipment

  2. A Crustal Cross Section over the Central North Iberian Margin: New Insights into the Bay of Biscay Inverted Hyperextended Rift

    Science.gov (United States)

    Cadenas Martínez, P.; Fernandez Viejo, G.; Pulgar, J. A.; Minshull, T. A.

    2015-12-01

    The Bay of Biscay is a V-shape failed arm of the Atlantic rift which was opened during the Mesozoic and partially closed during the Alpine orogeny in the Cenozoic, when the convergence of the Iberian and European Plates drove to the formation of the Pyrenean-Cantabrian realm in the North Iberian peninsula. A complete crustal cross section through the central part of the North Iberian Margin, representing the southern margin of the Bay of Biscay, is presented here from the interpretation of a high quality deep seismic reflection profile together with boreholes and well logs, acquired for oil and gas exploration purposes. The studied segment of this margin includes a basement high so called Le Danois Bank, and the Asturian basin, one of the sedimentary basins developed during the Mesozoic extensional processes, which was subsequently inverted during the Alpine orogeny. Most of the compression seems to have taken place through uplift of the continental platform and slope and the formation of an accretionary wedge at the bottom of the slope, so it is still possible to elucidate both extensional and compressional features. The basin appears as an asymmetric bowl bounded by synsedimentary normal faults with a maximum thickness of about 6 s TWT, which has been estimated to be equivalent to about 7 km. Depth migration of the seismic profile has revealed the presence of a deeper trough, with a maximum thickness of 13. 5 km at its main depocenter, which closely resembles the sedimentary thickness proposed for other contemporaneous proximal basins. These results support the high degree of extension and the exhumation processes proposed for this margin, deduced from refraction velocities and from the upper crustal and mantle rocks dredged at the slopes of Le Danois High. They will bring new insights to, and further constraints on, geodynamical models for this margin, where the amount of shortening linked with Cenozoic compression and the role of the rift structure during the

  3. Dyslipidemia and chronic inflammation markers are correlated with telomere length shortening in Cushing's syndrome.

    Directory of Open Access Journals (Sweden)

    Anna Aulinas

    Full Text Available Cushing's syndrome (CS increases cardiovascular risk (CVR and adipocytokine imbalance, associated with an increased inflammatory state. Telomere length (TL shortening is a novel CVR marker, associated with inflammation biomarkers. We hypothesized that inflammatory state and higher CVR in CS might be related to TL shortening, as observed in premature aging.To evaluate relationships between TL, CVR and inflammation markers in CS.In a cross-sectional study, 77 patients with CS (14 males, 59 pituitary-, 17 adrenal- and 1 ectopic-origin; 21 active disease and 77 age-, gender-, smoking-matched controls were included. Total white blood cell TL was measured by TRF-Southern technique. Clinical data and blood samples were collected (lipids, adrenal function, glucose. Adiponectin, interleukin-6 (IL6 and C-reactive protein (CRP were available in a subgroup of patients (n=32. Correlations between TL and clinical features were examined and multiple linear regression analysis was performed to investigate potential predictors of TL.Dyslipidemic CS had shorter TL than non-dyslipidemic subjects (7328±1274 vs 7957±1137 bp, p<0.05. After adjustment for age and body mass index, cured and active CS dyslipidemic patients had shorter TL than non-dyslipidemic CS (cured: 7187±1309 vs 7868±1104; active: 7203±1262 vs 8615±1056, respectively, p<0.05. Total cholesterol and triglycerides negatively correlated with TL (r-0.279 and -0.259, respectively, p<0.05, as well as CRP and IL6 (r-0.412 and -0.441, respectively, p<0.05. No difference in TL according the presence of other individual CVR factors (hypertension, diabetes mellitus, obesity were observed in CS or in the control group. Additional TL shortening was observed in dyslipidemic obese patients who were also hypertensive, compared to those with two or less CVR factors (6956±1280 vs 7860±1180, respectively, p<0.001. Age and dyslipidemia were independent negative predictors of TL.TL is shortened in dyslipidemic CS

  4. Separation of core and crustal magnetic field sources

    Science.gov (United States)

    Shure, L.; Parker, R. L.; Langel, R. A.

    1985-01-01

    Fluid motions in the electrically conducting core and magnetized crustal rocks are the two major sources of the magnetic field observed on or slightly above the Earth's surface. The exact separation of these two contributions is not possible without imposing a priori assumptions about the internal source distribution. Nonetheless models like these were developed for hundreds of years Gauss' method, least squares analysis with a truncated spherical harmonic expansion was the method of choice for more than 100 years although he did not address separation of core and crustal sources, but rather internal versus external ones. Using some arbitrary criterion for appropriate truncation level, we now extrapolate downward core field models through the (approximately) insulating mantle. Unfortunately our view can change dramatically depending on the degree of truncation for describing core sources.

  5. Detailed Northern Anatolian Fault Zone crustal structure from receiver functions

    Science.gov (United States)

    Cornwell, D. G.; Kahraman, M.; Thompson, D. A.; Houseman, G. A.; Rost, S.; Turkelli, N.; Teoman, U.; Altuncu Poyraz, S.; Gülen, L.; Utkucu, M.

    2013-12-01

    We present high resolution images derived from receiver functions of the continental crust in Northern Turkey that is dissected by two fault strands of the Northern Anatolian Fault Zone (NAFZ). The NAFZ is a major continental strike-slip fault system that is comparable in length and slip rate to the San Andreas Fault Zone. Recent large earthquakes occurred towards the western end of the NAFZ in 1999 at Izmit (M7.5) and Düzce (M7.2). As part of the multi-disciplinary Faultlab project, we aim to develop a model of NAFZ crustal structure and locate deformation by constraining variations in seismic properties and anisotropy in the upper and lower crust. The crustal model will be an input to test deformation scenarios in order to match geodetic observations from different phases of the earthquake loading cycle. We calculated receiver functions from teleseismic earthquakes recorded by a rectangular seismometer array spanning the NAFZ with 66 stations at a nominal inter-station spacing of 7 km and 7 additional stations further afield. This Dense Array for North Anatolia (DANA) was deployed from May 2012 until September 2013 and we selected large events (Mw>5.5) from the high quality seismological dataset to analyze further. Receiver functions were calculated for different frequency bands then collected into regional stacks before being inverted for crustal S-wave velocity structure beneath the entire DANA array footprint. In addition, we applied common conversion point (CCP) migration using a regional velocity model to construct a migrated 3D volume of P-to-S converted and multiple energy in order to identify the major crustal features and layer boundaries. We also performed the CCP migration with transverse receiver functions in order to identify regions of anisotropy within the crustal layers. Our preliminary results show a heterogeneous crust above a flat Moho that is typically at a depth of 33 km. We do not observe a prominent step in the Moho beneath the surface

  6. Crustal displacements in Greenland caused by ice mass variability

    DEFF Research Database (Denmark)

    Nielsen, Karina

    . Gradients of crustal displacement rates near Upernavik Isstrøm and Jakobshavn Isbræ are modeled and compared to observed rates, to assess the mass balance of these glaciers. By considering displacement gradients, contributions from the mass loss of the rest of the ice sheet and GIA are reduced. Hence......The climate of the Earth is changing. A consequence of this is observed at the polar regions such as Greenland, where the ice sheet is melting with an increasing rate. The unloading of ice causes the Earth to respond elastically in terms of uplift and an outward horizontal deformation of the crust....... This motion can be measured by permanent Global Positioning System (GPS) receivers. Hence, the rates of crustal displacement are an indirect measure of the occurring mass changes. Currently, 55 GPS sites are located around the margin of the Greenland ice sheet, continuously providing information about...

  7. Compositional stratigraphy of crustal material from near-infrared spectra

    Science.gov (United States)

    Pieters, Carle M.

    1987-01-01

    An Earth-based telescopic program to acquire near-infrared spectra of freshly exposed lunar material now contains data for 17 large impact craters with central peaks. Noritic, gabbroic, anorthositic and troctolitic rock types can be distinguished for areas within these large craters from characteristic absorptions in individual spectra of their walls and central peaks. Norites dominate the upper lunar crust while the deeper crustal zones also contain significant amounts of gabbros and anorthosites. Data for material associated with large craters indicate that not only is the lunar crust highly heterogeneous across the nearside, but that the compositional stratigraphy of the lunar crust is nonuniform. Crustal complexity should be expected for other planetary bodies, which should be studied using high spatial and spectral resolution data in and around large impact craters.

  8. Iron - based bulk amorphous alloys

    Directory of Open Access Journals (Sweden)

    R. Babilas

    2010-07-01

    Full Text Available Purpose: The paper presents a structure characterization, thermal and soft magnetic properties analysis of Fe-based bulk amorphous materials in as-cast state and after crystallization process. In addition, the paper gives some brief review about achieving, formation and structure of bulk metallic glasses as a special group of amorphous materials.Design/methodology/approach: The studies were performed on Fe72B20Si4Nb4 metallic glass in form of ribbons and rods. The amorphous structure of tested samples was examined by X-ray diffraction (XRD, transmission electron microscopy (TEM and scanning electron microscopy (SEM methods. The thermal properties of the glassy samples were measured using differential thermal analysis (DTA and differential scanning calorimetry (DSC. The magnetic properties contained initial and maximum magnetic permeability, coercive force and magnetic after-effects measurements were determined by the Maxwell-Wien bridge and VSM methods.Findings: The X-ray diffraction and transmission electron microscopy investigations revealed that the studied as-cast bulk metallic glasses in form of ribbons and rods were amorphous. Two stage crystallization process was observed for studied bulk amorphous alloy. The differences of crystallization temperature between ribbons and rods with chosen thickness are probably caused by different amorphous structures as a result of the different cooling rates in casting process. The SEM images showed that studied fractures could be classified as mixed fractures with indicated two zones contained “river” and “smooth” areas. The changing of chosen soft magnetic properties (μr, Bs, Hc obtained for samples with different thickness is a result of the non-homogenous amorphous structure of tested metallic glasses. The annealing process in temperature range from 373 to 773 K causes structural relaxation of tested amorphous materials, which leads to changes in their physical properties. The qualitative

  9. Effect of Crustal Density Structures on GOCE Gravity Gradient Observables

    Directory of Open Access Journals (Sweden)

    Robert Tenzer and Pavel Novák

    2013-01-01

    Full Text Available We investigate the gravity gradient components corrected for major known anomalous density structures within the _ crust. Heterogeneous mantle density structures are disregarded. The gravimetric forward modeling technique is utilized to compute the gravity gradients based on methods for a spherical harmonic analysis and synthesis of a gravity field. The _ gravity gradient components are generated using the global geopotential model GOCO-03s. The topographic and stripping gravity corrections due to the density contrasts of the ocean and ice are computed from the global topographic/bathymetric model DTM2006.0 (which also includes the ice-thickness dataset. The discrete data of sediments and crust layers taken from the CRUST2.0 global crustal model are then used to apply the additional stripping corrections for sediments and remaining anomalous crustal density structures. All computations are realized globally on a one arc-deg geographical grid at a mean satellite elevation of 255 km. The global map of the consolidated crust-stripped gravity gradients reveals distinctive features which are attributed to global tectonics, lithospheric plate configuration, lithosphere structure and mantle dynamics (e.g., glacial isostatic adjustment, mantle convection. The Moho signature, which is the most pronounced signal in these refined gravity gradients, is superimposed over a weaker gravity signal of the lithospheric mantle. An interpretational quality of the computed (refined gravity gradient components is mainly limited by a low accuracy and resolution of the CRUST2.0 sediment and crustal layer data and unmodeled mantle structures.

  10. The Crustal Structure Character of East China Sea

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper presents actuality of investigation and study of the crustal structure characters of East China Sea at home and abroad. Based on lots of investigation and study achievements and the difference of the crustal velocity structure from west to east, the East China Sea is divided into three parts - East China Sea shelf zone, Okinawa Trough zone and Ryukyu arc-trench zone. The East China Sea sheff zone mostly has three velocity layers, i.e.,the sediment blanket layer (the velocity is 5.8-5.9 km/s), the basement layer (the velocity is 6.0-6.3 km/s), and the lower crustal layer (the velocity is 6.8-7.6 km/s). So the East China Sea shelf zone belongs to the typical continental crust. The Okinawa Trough zone is located at the transitional belt between the continental crust and the oceanic crust. It still has the structural characters of the continental crust, and no formation of the oceanic crust, but the crust of the central trough has become to thinning down. The Ryukyu arc-trench zone belongs to the transitional type crust as a whole, but the ocean side of the trench already belongs to the oceanic crust. And the northwest Philippine Basin to the east of the Ryukyu Trench absolutely belongs to the typical oceanic crust.

  11. Moho depth and crustal composition in Southern Africa

    DEFF Research Database (Denmark)

    Soliman, Mohammad Youssof Ahmad; Thybo, Hans; Artemieva, Irina;

    2013-01-01

    heterogeneous crustal structure with short wavelength variations in thickness (H), Vp/Vs-ratio (composition), and Moho sharpness, which defines ~20 blocks that do not everywhere coincide with surface tectonic features. In the Zimbabwe Craton, the Tokwe block has H = 35–38 km and Vp/Vs = 1.74–1.79 whereas...... the thicker crust in the Tati block (H = 47–51 km)may be related to deformation of the Archean crust along the cratonicmargin. Two distinct crustal blocks with similar crustal thickness (42–46 km) but significantly different Vp/Vs-ratios are recognized in the Limpopo Belt. Extreme values of 1......-existing lower crust, which is further supported by a very sharp Moho transition. The exposed cross-section in the Vredefort impact crater is non-representative of cratonic crust due to shallowMoho (34 km) and high Vp/Vs ~ 1.80 attributed to shock metamorphism. High Vp/Vs = 1.76 is typical of the Witwatersrand...

  12. Boron isotope fractionation in magma via crustal carbonate dissolution.

    Science.gov (United States)

    Deegan, Frances M; Troll, Valentin R; Whitehouse, Martin J; Jolis, Ester M; Freda, Carmela

    2016-01-01

    Carbon dioxide released by arc volcanoes is widely considered to originate from the mantle and from subducted sediments. Fluids released from upper arc carbonates, however, have recently been proposed to help modulate arc CO2 fluxes. Here we use boron as a tracer, which substitutes for carbon in limestone, to further investigate crustal carbonate degassing in volcanic arcs. We performed laboratory experiments replicating limestone assimilation into magma at crustal pressure-temperature conditions and analysed boron isotope ratios in the resulting experimental glasses. Limestone dissolution and assimilation generates CaO-enriched glass near the reaction site and a CO2-dominated vapour phase. The CaO-rich glasses have extremely low δ(11)B values down to -41.5‰, reflecting preferential partitioning of (10)B into the assimilating melt. Loss of (11)B from the reaction site occurs via the CO2 vapour phase generated during carbonate dissolution, which transports (11)B away from the reaction site as a boron-rich fluid phase. Our results demonstrate the efficacy of boron isotope fractionation during crustal carbonate assimilation and suggest that low δ(11)B melt values in arc magmas could flag shallow-level additions to the subduction cycle. PMID:27488228

  13. Plate tectonics and crustal deformation around the Japanese Islands

    Science.gov (United States)

    Hashimoto, Manabu; Jackson, David D.

    1993-01-01

    We analyze over a century of geodetic data to study crustal deformation and plate motion around the Japanese Islands, using the block-fault model for crustal deformation developed by Matsu'ura et al. (1986). We model the area including the Japanese Islands with 19 crustal blocks and 104 faults based on the distribution of active faults and seismicity. Geodetic data are used to obtain block motions and average slip rates of faults. This geodetic model predicts that the Pacific plate moves N deg 69 +/- 2 deg W at about 80 +/- 3 mm/yr relative to the Eurasian plate which is much lower than that predicted in geologic models. Substantial aseismic slip occurs on the subduction boundaries. The block containing the Izu Peninsula may be separated from the rigid part of the Philippine Sea plate. The faults on the coast of Japan Sea and the western part of the Median Tectonic Line have slip rates exceeding 4 mm/yr, while the Fossa Magna does not play an important role in the tectonics of the central Japan. The geodetic model requires the division of northeastern Japan, contrary to the hypothesis that northeastern Japan is a part of the North American plate. Owing to rapid convergence, the seismic risk in the Nankai trough may be larger than that of the Tokai gap.

  14. Boron isotope fractionation in magma via crustal carbonate dissolution

    Science.gov (United States)

    Deegan, Frances M.; Troll, Valentin R.; Whitehouse, Martin J.; Jolis, Ester M.; Freda, Carmela

    2016-08-01

    Carbon dioxide released by arc volcanoes is widely considered to originate from the mantle and from subducted sediments. Fluids released from upper arc carbonates, however, have recently been proposed to help modulate arc CO2 fluxes. Here we use boron as a tracer, which substitutes for carbon in limestone, to further investigate crustal carbonate degassing in volcanic arcs. We performed laboratory experiments replicating limestone assimilation into magma at crustal pressure-temperature conditions and analysed boron isotope ratios in the resulting experimental glasses. Limestone dissolution and assimilation generates CaO-enriched glass near the reaction site and a CO2-dominated vapour phase. The CaO-rich glasses have extremely low δ11B values down to ‑41.5‰, reflecting preferential partitioning of 10B into the assimilating melt. Loss of 11B from the reaction site occurs via the CO2 vapour phase generated during carbonate dissolution, which transports 11B away from the reaction site as a boron-rich fluid phase. Our results demonstrate the efficacy of boron isotope fractionation during crustal carbonate assimilation and suggest that low δ11B melt values in arc magmas could flag shallow-level additions to the subduction cycle.

  15. The role of block rotations and oroclinal bending in Iran during the Cenozoic Arabia-Eurasia shortening

    Science.gov (United States)

    Cifelli, F.; Mattei, M.; Alimohammadian, H.; Sabouri, J.; Rashid, H.; Ghassemi, M.

    2012-04-01

    Shortening related to the Arabia-Eurasia convergence in the Cenozoic has been - and is at present being - taken up mainly by displacements in the Zagros, Alborz, and Kopeh Dag thrust-and-fold belts of Iran, whereas the intervening, fault-bounded crustal blocks of Central Iran (Yazd, Tabas and Lut blocks) show little internal deformation. Central Iran is separated from the Alborz belt by NE-SW left-lateral strike-slip and thrust faults (e.g., the Great Kavir fault), whereas N-S right-lateral strike-slip faults define the boundary between the Tabas and Lut blocks within Central Iran (e.g., the Neyband fault). Based on structural and seismological data, it has been proposed that NE-SW left-lateral and N-S right-lateral faults can accommodate the NNE-SSW Arabia-Eurasia convergence if they are allowed to rotate clockwise (CW) and counterclockwise (CCW), respectively. A rotating-fault deformation model predicts that the intervening fault-bounded rigid blocks should rotate accordingly. To test this hypothesis, paleomagnetic sampling was carried out on Oligocene-Miocene sediments from different areas of Central Iran (Torud, Jandaq, Anarak, Tabas, Yazd, Bafq, Ferdows), dominated by right-lateral and left-lateral strike slip faults activity, and along the southeastern margin of the Alborz Mts. (Bastam, Tall, Gardaneye-Ahovan, Momenabad Abdolabad), where left lateral and thrust faults prevail. Large counterclockwise (CCW) rotations (20°-35°) have been measured in the Tabas and Yazd blocks, characterized by the presence of N-S to NNW-SSE trending, right-lateral strike-slip faults. This structural domain is bounded to the north by the ENE-WSW oriented Great Kavir-Doruneh left-lateral strike-slip fault system. North of this fault paleomagnetic data show a different behaviour, with no or small CW rotation about vertical axis during the late Tertiary. In particular a small amount of CW rotation has been measured in the Jandaq and Torud area, to the north of the Great Kavir fault

  16. Palaeoproterozoic high-pressure granulite overprint of the Archaean continental crust: evidence for homogeneous crustal thickening (Man Rise, Ivory Coast)

    Science.gov (United States)

    Pitra, Pavel; Kouamelan, Alain N.; Ballèvre, Michel; Peucat, Jean-Jacques

    2010-05-01

    well as coeval intrusion of juvenile magmas. Crustal shortening was mainly accommodated by transpressive shear zones and by lateral crustal spreading rather than large-scale thrust systems. The occurrence of high-pressure granulites does not imply thrust-dominated tectonics. Feybesse, J.-L. & Milési, J.-P., 1994. The Archean/Proterozoic contact zone in West Africa: a mountain belt of décollement thrusting and folding on a continental margin related to 2.1 Ga convergence of Archean cratons? Precambrian Research, 69, 199-227. Schulmann, K., Schaltegger, U., Ježek, J., et al. 2002. Rapid burial and exhumation during orogeny: thickening and synconvergent exhumation of thermally weakened and thinned crust (Variscan orogen in Western Europe). American Journal of Science, 302, 856-879. Schulmann, K., Lexa, O., Štípská, P. et al., 2008. Vertical extrusion and horizontal channel flow of orogenic lower crust: key exhumation mechanisms in large hot orogens? Journal of Metamorphic Geology, 26(2), 273-297.

  17. Handling of bulk solids theory and practice

    CERN Document Server

    Shamlou, P A

    1990-01-01

    Handling of Bulk Solids provides a comprehensive discussion of the field of solids flow and handling in the process industries. Presentation of the subject follows classical lines of separate discussions for each topic, so each chapter is self-contained and can be read on its own. Topics discussed include bulk solids flow and handling properties; pressure profiles in bulk solids storage vessels; the design of storage silos for reliable discharge of bulk materials; gravity flow of particulate materials from storage vessels; pneumatic transportation of bulk solids; and the hazards of solid-mater

  18. Varying mechanical coupling along the Andean margin: Implications for trench curvature, shortening and topography

    Science.gov (United States)

    Iaffaldano, G.; Di Giuseppe, E.; Corbi, F.; Funiciello, F.; Faccenna, C.; Bunge, H.-P.

    2012-03-01

    Convergent margins often exhibit spatial and temporal correlations between trench curvature, overriding plate shortening and topography uplift that provide insights into the dynamics of subduction. The Andean system, where the Nazca plate plunges beneath continental South America, is commonly regarded as the archetype of this class of tectonics systems. There is distinctive evidence that the degree of mechanical coupling between converging plates, i.e. the amount of resistive force mutually transmitted in the direction opposite to their motions, may be at the present-day significantly higher along the central Andean margin compared to the northern and southern limbs. However quantitative estimates of such resistance are still missing and would be desirable. Here we present laboratory models of subduction performed to investigate quantitatively how strong lateral coupling variations need to be to result in trench curvature, tectonic shortening and distribution of topography comparable to estimates from the Andean margin. The analogue of a two-layers Newtonian lithosphere/upper mantle system is established in a silicone putty/glucose syrup tank-model where lateral coupling variations along the interface between subducting and overriding plates are pre-imposed. Despite the simplicity of our setup, we estimate that coupling in the central margin as large as 20% of the driving force is sufficient to significantly inhibit the ability of the experimental overriding plate to slide above the subducting one. As a consequence, the central margin deforms and shortens more than elsewhere while the trench remains stationary, as opposed to the advancing lateral limbs. This causes the margin to evolve into a peculiar shape similar to the present-day trench of the Andean system.

  19. Mid-term clinical outcome of radial shortening for kienbock disease

    Directory of Open Access Journals (Sweden)

    Mohammad H Ebrahimzadeh

    2015-01-01

    Full Text Available Background: To evaluate the intermediate-term outcomes of radius shortening as a treatment for Kienbock′s disease. Materials and Methods: In a historical cohort, 16 skeletally mature patients (9 men and 7 women with Kienbock disease, who were treated with radial shortening osteotomy between 2002 and 2012, were reviewed in our study. The mean age of our patients was 30 (range 18-43 years old. According to Litchman staging, there were 7 wrists at stage II and 9 wrists at stage III (6 at stage IIIA and 3 at stage IIIB. The data of grip strength, pain (visual analog scale (VAS score, wrist range of motion (ROM, ulnar variance (according to Palmer method, and the Lichtman stage were gathered before and after surgery. We evaluated overall wrist function using the Mayo Wrist score and disabilities of the arm shoulder and hand (DASH score before surgery and at the last follow-up. Results: The average of follow-up was 7 years (range from 5 to 9 years. Preoperative ulnar variance was -1.3 mm (range from 2.5 to 1 preoperatively. The mean postoperative ulnar variance was 1 mm positive (range from 0.5 to 1.5. The VAS pain score, the mean arc of wrist flexion and extension, and grip strength improved significantly preoperatively compared to after recovery from surgery. The Lichtman stage was unchanged in nine patients, one grade worse in six patients, and one grade better in one patient. The mean DASH and Mayo scores improved significantly postoperatively compare with preoperation. Comparing preoperative positive, neuter, and negative ulnar variance, there was no significant difference in terms of VAS, DASH, and Mayo scores as well as ROM and grip strength. Conclusion: Our study shows that radius shortening surgery improves pain and disability regardless of ulnar variance.

  20. Incorporated fish oil fatty acids prevent action potential shortening induced by circulating fish oil fatty acids

    Directory of Open Access Journals (Sweden)

    Hester M Den Ruijter

    2010-11-01

    Full Text Available Increased consumption of fatty fish, rich in omega-3 polyunsaturated fatty acids (3-PUFAs reduces the severity and number of arrhythmias. Long term 3-PUFA-intake modulates the activity of several cardiac ion channels leading to cardiac action potential shortening. Circulating 3-PUFAs in the bloodstream and incorporated 3-PUFAs in the cardiac membrane have a different mechanism to shorten the action potential. It is, however, unknown whether circulating 3-PUFAs in the bloodstream enhance or diminish the effects of incorporated 3-PUFAs. In the present study, we address this issue. Rabbits were fed a diet rich in fish oil (3 or sunflower oil (9, as control for 3 weeks. Ventricular myocytes were isolated by enzymatic dissociation and action potentials were measured using the perforated patch clamp technique in the absence and presence of acutely administered 3-PUFAs. Plasma of 3 fed rabbits contained more free eicosapentaenoic acid (EPA and isolated myocytes of 3 fed rabbits contained higher amounts of both EPA and docosahexaenoic acid (DHA in their sarcolemma compared to control. In the absence of acutely administered fatty acids, 3 myocytes had a shorter action potential with a more negative plateau than 9 myocytes. In the 9 myocytes, but not in the 3 myocytes, acute administration of a mixture of EPA+DHA shortened the action potential significantly. From these data we conclude that incorporated 3-PUFAs into the sarcolemma and acutely administered 3 fatty acids do not have a cumulative effect on action potential duration and morphology. As a consequence, patients with a high cardiac 3-PUFA status will probably not benefit from short term 3 supplementation as an antiarrhythmic therapy.

  1. Stretch-shortening cycle muscle power in women and men aged 18-81 years

    DEFF Research Database (Denmark)

    Edwén, C E; Thorlund, Jonas Bloch; Magnusson, Stig Peter;

    2014-01-01

    This study explored the age-related deterioration in stretch-shortening cycle (SSC) muscle power and concurrent force-velocity properties in women and men across the adult life span. A total of 315 participants (women: n = 188; men: n = 127) aged 18-81 years performed maximal countermovement jumps...... on an instrumented force plate. Maximal SSC leg extension power expressed per kg body mass (Ppeak) was greater in men than in women across the adult age span (P ...

  2. Lactose tolerance test shortened to 30 minutes: an exploratory study of its feasibility and impact

    Directory of Open Access Journals (Sweden)

    José Luis Domínguez-Jiménez

    2014-06-01

    Full Text Available Introduction: Lactose malabsorption (LM is a very common condition with a high prevalence in our setting. Lactose tolerance test (LTT is a basic, affordable test for diagnosis that requires no complex technology. It has been recently shown that this test can be shortened to 3 measurements (baseline, 30 min, 60 min with no impact on final results. The purpose of our study was to assess the feasibility and benefits of LTT simplification and shortening to 30 min, as well as the financial impact entailed. Material and methods: A multicenter, observational study of consecutive patients undergoing LTT for LM suspicion. Patients received 50 g of lactose following a fasting period of 12 h, and had blood collected from a vein at all 3 time points for the measurement of blood glucose (mg/dl. Differences between the shortened and complete test forms were analyzed using McNemar's test. A comparison of blood glucose levels between patients with normal and abnormal results was performed using Student's T-test for independent mean values. Consistency was assessed using the kappa index. A p < 0.05 was considered to be statistically significant. Results: A total of 270 patients (69.6% females were included, with a mean age of 39.9 ± 16 years. LTT was abnormal for 151 patients (55.9%. We observed no statistically significant differences in baseline blood glucose levels between patients with normal and abnormal LTT results (p = 0.13; however, as was to be expected, such differences were obvious for the remaining time points (p < 0.01. Deleting blood glucose measurements at 60 minutes only led to overdiagnose LM (false positive results in 6 patients (2.22 %, with a kappa index of 0.95 (95% CI: 0.92-0.99 (p < 0.001 versus the complete test. Suppressing measurements at 60 min would have saved at least € 7,726. Conclusion: The shortening of LTT to only 2 measurements (baseline and 30-min hardly leads to any differences in final results, and would entail savings in

  3. New fermions in the bulk

    CERN Document Server

    de Brito, K P S

    2016-01-01

    Spinor fields on 5-dimensional Lorentzian manifolds are classified, according to the geometric Fierz identities that involve their bilinear covariants. Based upon this classification that generalises the celebrated 4-dimensional Lounesto classification of spinor fields, new non-trivial classes of 5-dimensional spinor fields are, hence, found, with important potential applications regarding bulk fermions and their subsequent localisation on brane-worlds. In addition, quaternionic bilinear covariants are used to derive the quaternionic spin density, through the truncated exterior bundle. In order to accomplish a realisation of these new spinors, a Killing vector field is constructed on the horizon of 5-dimensional Kerr black holes. This Killing vector field is shown to reach the time-like Killing vector field at the spatial infinity, through a current 1-form density, constructed with the derived new spinor fields. The current density is, moreover, expressed as the f\\"unfbein components, assuming a condensed for...

  4. Ordered bulk degradation via autophagy

    DEFF Research Database (Denmark)

    Dengjel, Jörn; Kristensen, Anders Riis; Andersen, Jens S

    2008-01-01

    During amino acid starvation, cells undergo macroautophagy which is regarded as an unspecific bulk degradation process. Lately, more and more organelle-specific autophagy subtypes such as reticulophagy, mitophagy and ribophagy have been described and it could be shown, depending on the experimental...... setup, that autophagy specifically can remove certain subcellular components. We used an unbiased quantitative proteomics approach relying on stable isotope labeling by amino acids in cell culture (SILAC) to study global protein dynamics during amino acid starvation-induced autophagy. Looking...... at proteasomal and lysosomal degradation ample cross-talk between the two degradation pathways became evident. Degradation via autophagy appeared to be ordered and regulated at the protein complex/organelle level. This raises several important questions such as: can macroautophagy itself be specific and what...

  5. Microwave disinfestation of bulk timber.

    Science.gov (United States)

    Plaza, Pedro Jose; Zona, Angela Tatiana; Sanchís, Raul; Balbastre, Juan Vicente; Martínez, Antonio; Muñoz, Eva Maria; Gordillo, Javier; de los Reyes, Elías

    2007-01-01

    In this paper a complete microwave system for bulk timber disinfestation is developed and tested. A commercial FEM simulator has been used to design the applicator, looking for structures providing uniform field distributions, which is a factor of capital relevance for a successful treatment. Special attention has also been given to the reduction of electromagnetic energy leakage. A dual polarized cylindrical applicator with a corrugated flange has been designed. The applicator has also been numerically tested emulating some real-life operating conditions. A prototype has been built using two low-cost magnetrons of 900 W and high power coaxial cables and it has been tested inside a shielded semianechoic chamber. The tests have been carried out in three stages: validation of the applicator design, determination of the lethal dosage as a function of the insect position and the maximum wood temperature allowed and statement of safe operation procedures. PMID:18351001

  6. Isotopic signatures by bulk analyses

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory has developed a series of measurement techniques for identification of nuclear signatures by analyzing bulk samples. Two specific applications for isotopic fingerprinting to identify the origin of anthropogenic radioactivity in bulk samples are presented. The first example is the analyses of environmental samples collected in the US Arctic to determine the impact of dumping of radionuclides in this polar region. Analyses of sediment and biota samples indicate that for the areas sampled the anthropogenic radionuclide content of sediments was predominantly the result of the deposition of global fallout. The anthropogenic radionuclide concentrations in fish, birds and mammals were very low. It can be surmised that marine food chains are presently not significantly affected. The second example is isotopic fingerprinting of water and sediment samples from the Rocky Flats Facility (RFP). The largest source of anthropogenic radioactivity presently affecting surface-waters at RFP is the sediments that are currently residing in the holding ponds. One gram of sediment from a holding pond contains approximately 50 times more plutonium than 1 liter of water from the pond. Essentially 100% of the uranium in Ponds A-1 and A-2 originated as depleted uranium. The largest source of radioactivity in the terminal Ponds A-4, B-5 and C-2 was naturally occurring uranium and its decay product radium. The uranium concentrations in the waters collected from the terminal ponds contained 0.05% or less of the interim standard calculated derived concentration guide for uranium in waters available to the public. All of the radioactivity observed in soil, sediment and water samples collected at RFP was naturally occurring, the result of processes at RFP or the result of global fallout. No extraneous anthropogenic alpha, beta or gamma activities were detected. The plutonium concentrations in Pond C-2 appear to vary seasonally

  7. Effects of Crustal Fields on the Ionosphere of Mars as seen by MAVEN

    Science.gov (United States)

    Vogt, Marissa F.; Withers, Paul; Flynn, Casey L.; Andersson, Laila; Brain, David; Mitchell, David; Connerney, Jack; Espley, Jared R.

    2016-10-01

    Mars lacks a global intrinsic magnetic field but possesses regions of strong crustal magnetic field that are concentrated in the southern hemisphere. Previous studies have used Mars Global Surveyor or Mars Express data to show that these crustal fields influence the electron densities in the Martian ionosphere. However, many of these studies relied on remote radio occultation or radar sounding measurements and therefore relied on models to infer the crustal magnetic field strength and direction. In fall 2015 the MAVEN spacecraft passed through these crustal field regions at low altitudes, on the day side, and collected comprehensive measurements of the local plasma and magnetic field properties. The MAVEN observations therefore provide an excellent dataset with which to examine the effects of crustal fields on the ionosphere. We report on the MAVEN electron density measurements in the southern crustal field regions and discuss the influence of the magnetic field direction and topology on the dayside Martian ionosphere.

  8. Two-stage revision of infected hip arthroplasty using a shortened post-operative course of antibiotics.

    LENUS (Irish Health Repository)

    McKenna, Paul B

    2009-04-01

    We present a series of 30 consecutive patients with 31 infected total hip arthroplasties treated by a single surgeon over a 4-year period in whom a shortened post-operative course of antimicrobial chemotherapy was used.

  9. Comprehensive stabilization mechanism of electron-beam irradiated polyacrylonitrile fibers to shorten the conventional thermal treatment.

    Science.gov (United States)

    Park, Sejoon; Yoo, Seung Hwa; Kang, Ha Ri; Jo, Seong Mu; Joh, Han-Ik; Lee, Sungho

    2016-01-01

    An electron beam was irradiated on polyacrylonitrile (PAN) fibers prior to thermal stabilization. The electron-beam irradiation effectively shortened the thermal stabilization process by one fourth compared with the conventional thermal stabilization process. A comprehensive mechanistic study was conducted regarding this shortening of the thermal stabilization by electron-beam irradiation. Various species of chain radicals were produced in PAN fibers by electron-beam irradiation and existed for a relatively long duration, as observed by electron spin resonance spectroscopy. Subsequently, these radicals were gradually oxidized to peroxy radicals in the presence of oxygen under storage or heating. We found that these peroxy radicals (CO) enabled such an effective shortcut of thermal stabilization by acting as intermolecular cross-linking and partial aromatization points in the low temperature range (100-130 °C) and as earlier initiation seeds of successive cyclization reactions in the next temperature range (>130-140 °C) of thermal stabilization. Finally, even at a low irradiation dose (200 kGy), followed by a short heat treatment (230 °C for 30 min), the PAN fibers were sufficiently stabilized to produce carbon fibers with tensile strength and modulus of 2.3 and 216 GPa, respectively, after carbonization. PMID:27349719

  10. Mechanical versus kinematical shortening reconstructions of the Zagros High Folded Zone (Kurdistan region of Iraq)

    Science.gov (United States)

    Frehner, Marcel; Reif, Daniel; Grasemann, Bernhard

    2012-06-01

    This paper compares kinematical and mechanical techniques for the palinspastic reconstruction of folded cross sections in collision orogens. The studied area and the reconstructed NE-SW trending, 55.5 km long cross section is located in the High Folded Zone of the Zagros fold-and-thrust belt in the Kurdistan region of Iraq. The present-day geometry of the cross section has been constructed from field as well as remote sensing data. In a first step, the structures and the stratigraphy are simplified and summarized in eight units trying to identify the main geometric and mechanical parameters. In a second step, the shortening is kinematically estimated using the dip domain method to 11%-15%. Then the same cross section is used in a numerical finite element model to perform dynamical unfolding simulations taking various rheological parameters into account. The main factor allowing for an efficient dynamic unfolding is the presence of interfacial slip conditions between the mechanically strong units. Other factors, such as Newtonian versus power law viscous rheology or the presence of a basement, affect the numerical simulations much less strongly. If interfacial slip is accounted for, fold amplitudes are reduced efficiently during the dynamical unfolding simulations, while welded layer interfaces lead to unrealistic shortening estimates. It is suggested that interfacial slip and decoupling of the deformation along detachment horizons is an important mechanical parameter that controlled the folding processes in the Zagros High Folded Zone.

  11. Comprehensive stabilization mechanism of electron-beam irradiated polyacrylonitrile fibers to shorten the conventional thermal treatment

    Science.gov (United States)

    Park, Sejoon; Yoo, Seung Hwa; Kang, Ha Ri; Jo, Seong Mu; Joh, Han-Ik; Lee, Sungho

    2016-06-01

    An electron beam was irradiated on polyacrylonitrile (PAN) fibers prior to thermal stabilization. The electron-beam irradiation effectively shortened the thermal stabilization process by one fourth compared with the conventional thermal stabilization process. A comprehensive mechanistic study was conducted regarding this shortening of the thermal stabilization by electron-beam irradiation. Various species of chain radicals were produced in PAN fibers by electron-beam irradiation and existed for a relatively long duration, as observed by electron spin resonance spectroscopy. Subsequently, these radicals were gradually oxidized to peroxy radicals in the presence of oxygen under storage or heating. We found that these peroxy radicals (CO) enabled such an effective shortcut of thermal stabilization by acting as intermolecular cross-linking and partial aromatization points in the low temperature range (100–130 °C) and as earlier initiation seeds of successive cyclization reactions in the next temperature range (>130–140 °C) of thermal stabilization. Finally, even at a low irradiation dose (200 kGy), followed by a short heat treatment (230 °C for 30 min), the PAN fibers were sufficiently stabilized to produce carbon fibers with tensile strength and modulus of 2.3 and 216 GPa, respectively, after carbonization.

  12. Leucocyte Telomere Shortening in relation to Newly Diagnosed Type 2 Diabetic Patients with Depression

    Directory of Open Access Journals (Sweden)

    Zhelong Liu

    2014-01-01

    Full Text Available The goal of this study is to investigate the association between oxidative stress and telomere length shortening in the comorbid depression and diabetes. Therefore, 71 patients with newly diagnosed type 2 diabetes (T2D and 52 subjects with normal glycemic level (control, Ctrl were enrolled. Depressive status was identified with the Depression Subscale of Hospital Anxiety and Depression Scale (HADS-D. Leukocyte telomere length ratio (T/S ratio was determined with quantitative PCR. Oxidative stress status was evaluated with 8-hydroxy-desoxyguanosine (8-OHdG assay kit. Some other biochemical blood testing was also performed. The data showed that T2D patients had higher proportion of depression evaluated by the HADS-D (x2=4.196, P=0.041. T/S ratio was significantly negatively correlated with 8-OHdG, HADS-D, age, HbA1c, FPG, and HOMA-IR. In addition, HADS-D was significantly positively correlated with HbA1c, FPG, HOMA-IR, and 8-OHdG. Both HADS-D and 8-OHdG were the major independent predictors for T/S ratio. This study indicates that oxidative stress contributes to both telomere length shortening and depression development in newly diagnosed type 2 diabetic patients, while in depression status, some other mechanisms besides oxidative stress may also affect the telomere length.

  13. [Shortening undergraduate medical training: now and for all medical schools in Chile?].

    Science.gov (United States)

    Reyes B, Humberto

    2016-01-01

    In Chile, undergraduate medical education starts after High School, it lasts seven years, with the final two dedicated to a rotary internship, taking to an M.D. degree that allows the graduate to enter working activities. The country needs more M.D.s in primary care, but there is also a shortage of specialists, mainly out of the main cities. In recent decades, post graduate programs leading to specialty titles have become competitively adopted by a large proportion of medical graduates. This is the case at the Pontificia Universidad Católica de Chile, stimulating its faculties and medical students to develop a collaborative review of their teaching programs, leading to a curricular reform with a new graduate profile and a new curriculum oriented to learning objectives, that will allow to obtain the M.D. degree in six instead of seven years of undergraduate education. This new program awakened expectations in other universities in Chile, that will have to face the attraction of this shortened program for future candidates to enter medical schools. However, any shortening of medical school careers should first consider the local conditions in quality of applicants, number of accepted students, the training of teachers in integrated teaching programs, the availability of adequate campuses. Furthermore, for students with different academic backgrounds and diverse personal and familial interests, the seven years programs may still be necessary to gain the expertise required to become medical doctors. PMID:26998976

  14. Do crustal deformations observed by GPS in Tierra del Fuego (Argentina) reflect glacial-isostatic adjustment?

    OpenAIRE

    Mendoza, L.; A. Richter; Hormaechea, J. L.; Perdomo, R.; Cogliano, D.; R. Dietrich; Fritsche, M.

    2010-01-01

    Vertical site velocities determined by geodetic GPS observations in the Lago Fagnano area, Tierra del Fuego main island, are interpreted with respect to their potential relation with the glacial-isostatic crustal response to ice mass changes. The spatial pattern of the uplift rates, in combination with the horizontal crustal deformation pattern, point towards a fault-tectonic rather than glacial-isostatic origin of the determined vertical crustal deformations. This implies rather small GIA ef...

  15. Shortening spinal column reconstruction through posterior only approach for the treatment of unstable osteoporotic burst lumber fracture: a case report

    OpenAIRE

    Shawky, Ahmed; Kroeber, Markus

    2012-01-01

    Study design Case report. Clinical question This study reports if shortening reconstruction procedure through posterior approach only can be used in osteoporotic unstable fracture as well as post-traumatic burst fracture. Methods An 80-year-old female patient with unstable burst osteoporotic fracture of L1 underwent posterior approach corpectomy and shortening reconstruction of the spinal column by non-expandable cages. Result The surgery was uneventful, with average blood loss. Using of smal...

  16. Effect of shortening replacement with flaxseed oil on physical, sensory, fatty acid and storage characteristics of cookies

    OpenAIRE

    Rangrej, V.; Shah, V; Patel, J.; Ganorkar, P. M.

    2014-01-01

    Omega-3 fatty acid imparted good evidence of health benefits. Flaxseed oil, being the richest vegetarian source of alpha linolenic acid (omega-3 fatty acid), was incorporated in cookies by replacing shortening at level of 5 %, 10 %, 20 %, 30 %, 40 % and 50 %. Effect of shortening replacement with flaxseed oil on physical, textural and sensory attributes were investigated. Spread ratio and breaking strength of cookies increased as flaxseed oil level increased. Sensory score was not significant...

  17. In-treatment midwall and endocardial fractional shortening predict cardiovascular outcome in hypertensive patients with preserved baseline systolic ventricular function: the Losartan Intervention For Endpoint reduction study

    DEFF Research Database (Denmark)

    Wachtell, Kristian; Gerdts, Eva; Palmieri, Vittorio;

    2010-01-01

    Endocardial fractional shortening (EFS) and midwall shortening (MWS) are impaired in patients with left ventricular hypertrophy. However, it remains unknown whether improvement of left ventricular systolic function during treatment reduces cardiovascular morbidity and mortality in hypertensive pa...

  18. Regional crustal thickness and precipitation in young mountain chains.

    Science.gov (United States)

    Ernst, W G

    2004-10-19

    Crustal thickness is related to climate through precipitation-induced erosion. Along the Andes, the highest mountains and thickest crust (approximately 70 km) occur at 25 degrees south, a region of low precipitation. Westerly winds warm passing over the Atacama Desert; precipitation is modest in the High Andes and eastward over the Altiplano. Severe aridity, hence low erosion rates, helps to account for the elevated volcanogenic contractional arc and high, internally draining plateau in its rain shadow. Weak erosion along the north-central arc provides scant amounts of sediment to the Chile-Peru Trench, starving the subduction channel. Subcrustal removal might be expected to reduce the crustal thickness, but is not a factor at 25 degrees south. The thickness of the gravitationally compensated continental crust cannot reflect underplating and/or partial fusion of sediments, but must be caused chiefly by volcanism-plutonism and contraction. Contrasting climate typifies the terrain at 45 degrees south where moisture-laden westerly winds encounter a cool margin, bringing abundant precipitation. The alpine landscape is of lower average elevation compared with the north-central Andes and is supported by thinner continental crust (approximately 35 km). Intense erosion supplies voluminous clastic debris to the offshore trench, and vast quantities are subducted. However, the southern Andean crust is only about half as thick as that at 25 degrees south, suggesting that erosion, not subcrustal sediment accretion or anatexis, is partly responsible for the thickness of the mountain belt. The Himalayas plus Tibetan Plateau, the Sierra Nevada plus Colorado Plateau, and the Japanese Islands exhibit analogous relationships between crustal thickness and climate. PMID:15471988

  19. Crustal structure beneath southern Norway imaged by magnetotellurics

    Science.gov (United States)

    Cherevatova, M.; Smirnov, M.; Korja, T.; Kaikkonen, P.; Pedersen, L. B.; Hübert, J.; Kamm, J.; Kalscheuer, T.

    2014-07-01

    We use data from two magnetotelluric profiles, ToSca10 and ToSca'09, over the Scandinavian Mountains to study the crustal structure in southern Norway. The profiles cross the major tectonic structures of the Caledonian orogen as well as the western margin of the Precambrian Baltica. Dimensionality and strike analyses indicate generally 3-D behavior of the data. However, the majority of the used data distinguishes a preferable strike direction, which is supported by the geology of the region. Hence, we employ 2-D inversion and choose to invert the determinant of the impedance tensor to mitigate 3-D effects in the data on our 2-D models. Magnetotelluric data from both profiles are inverted using a damped least squares solution based on a singular value decomposition. We improved the solution by defining the inverse model covariance matrix through gradient or Laplacian smoothing operators. The two-dimensional inversion models of the ToSca'09 and ToSca'10 field data from southern Norway derived from the damped least squares scheme with the Laplacian inverse model covariance matrix are presented. Resistive rocks, extending to the surface, image the autochthonous Southwest Scandinavian Domain and the allochthonous Western Gneiss Region. Near-surface conductors, which are located between the resistive Caledonian nappes and Precambrian basement, delineate highly conductive shallow-sea sediments, so called alum shales. They exhibit a decollement along which the Caledonian nappes were overthrust. A deeper, upper to mid-crustal conducting layer in the Southwest Scandinavian Domain may depict the remnants of closed ocean basins formed during the accretions and collisions of various Sveconorwegian terranes. In ToSca'10, the Caledonian nappes, the conducting alum shales and the deeper conductor are terminated in the west by the Faltungsgraben shear complex which represents a crustal scale boundary between the Western Gneiss Region in the west and the Southwest Scandinavian

  20. Crustal structure beneath northeast India inferred from receiver function modeling

    Science.gov (United States)

    Borah, Kajaljyoti; Bora, Dipok K.; Goyal, Ayush; Kumar, Raju

    2016-09-01

    We estimated crustal shear velocity structure beneath ten broadband seismic stations of northeast India, by using H-Vp/Vs stacking method and a non-linear direct search approach, Neighbourhood Algorithm (NA) technique followed by joint inversion of Rayleigh wave group velocity and receiver function, calculated from teleseismic earthquakes data. Results show significant variations of thickness, shear velocities (Vs) and Vp/Vs ratio in the crust of the study region. The inverted shear wave velocity models show crustal thickness variations of 32-36 km in Shillong Plateau (North), 36-40 in Assam Valley and ∼44 km in Lesser Himalaya (South). Average Vp/Vs ratio in Shillong Plateau is less (1.73-1.77) compared to Assam Valley and Lesser Himalaya (∼1.80). Average crustal shear velocity beneath the study region varies from 3.4 to 3.5 km/s. Sediment structure beneath Shillong Plateau and Assam Valley shows 1-2 km thick sediment layer with low Vs (2.5-2.9 km/s) and high Vp/Vs ratio (1.8-2.1), while it is observed to be of greater thickness (4 km) with similar Vs and high Vp/Vs (∼2.5) in RUP (Lesser Himalaya). Both Shillong Plateau and Assam Valley show thick upper and middle crust (10-20 km), and thin (4-9 km) lower crust. Average Vp/Vs ratio in Assam Valley and Shillong Plateau suggest that the crust is felsic-to-intermediate and intermediate-to-mafic beneath Shillong Plateau and Assam Valley, respectively. Results show that lower crust rocks beneath the Shillong Plateau and Assam Valley lies between mafic granulite and mafic garnet granulite.

  1. Recent crustal deformation in west-central South America

    Science.gov (United States)

    Pritchard, Matthew Earl

    I use interferometric synthetic aperture radar (InSAR) to create maps of crustal deformation along the coast and within the volcanic arc of central South America. I image deformation associated with six subduction zone earthquakes, four volcanic centers, at least one shallow crustal earthquake, and several salt flats. In addition, I constrain the magnitude and location of post-seismic deformation from the aforementioned subduction zone earthquakes. I combine InSAR observations with data from the Global Positioning System (GPS) and teleseismic data to explore each source of deformation. I use the observations to constrain earthquake and volcanic processes of this subduction zone, including the plumbing system of the volcanoes and the decadal along strike variations in the subduction zone earthquake cycle. I created interferograms of over 900 volcanoes in the central Andes spanning 1992--2002, and found four areas of deformation. I constrained the temporal variability of the deformation, the depth of the sources of deformation assuming a variety of source geometries and crustal structures, and the possible cause of the deformation. I do not observe deformation associated with eruptions at several volcanoes, and I discuss the possible explanations for this lack of deformation. In addition, I constrain the amount of co-seismic and post-seismic slip on the subduction zone fault interface from the following earthquakes: 1995 Mw 8.1 Antofagasta, Chile; 1996 Mw 7.7 Nazca, Peru; 1998 Mw 7.1 Antofagasta, Chile; and 2001 Mw 8.4 Arequipa, Peru. In northern Chile, I compare the location and magnitude of co-seismic slip from 5 Mw > 7 earthquakes during the past 15 years with the post-seismic slip distribution. There is little post-seismic slip from the 1995 and 1996 earthquakes relative to the 2001 event and other recent subduction zone earthquakes.

  2. Quaternary crustal deformation along a major branch of the San Andreas fault in central California

    Science.gov (United States)

    Weber, G.E.; Lajoie, K.R.; Wehmiller, J. F.

    1979-01-01

    Deformed marine terraces and alluvial deposits record Quaternary crustal deformation along segments of a major, seismically active branch of the San Andreas fault which extends 190 km SSE roughly parallel to the California coastline from Bolinas Lagoon to the Point Sur area. Most of this complex fault zone lies offshore (mapped by others using acoustical techniques), but a 4-km segment (Seal Cove fault) near Half Moon Bay and a 26-km segment (San Gregorio fault) between San Gregorio and Point Ano Nuevo lie onshore. At Half Moon Bay, right-lateral slip and N-S horizontal compression are expressed by a broad, synclinal warp in the first (lowest: 125 ka?) and second marine terraces on the NE side of the Seal Cove fault. This structure plunges to the west at an oblique angle into the fault plane. Linear, joint0controlled stream courses draining the coastal uplands are deflected toward the topographic depression along the synclinal axis where they emerge from the hills to cross the lowest terrace. Streams crossing the downwarped part of this terrace adjacent to Half Moon Bay are depositing alluvial fans, whereas streams crossing the uplifted southern limb of the syncline southwest of the bay are deeply incised. Minimum crustal shortening across this syncline parallel to the fault is 0.7% over the past 125 ka, based on deformation of the shoreline angle of the first terrace. Between San Gregorio and Point Ano Nuevo the entire fault zone is 2.5-3.0 km wide and has three primary traces or zones of faulting consisting of numerous en-echelon and anastomozing secondary fault traces. Lateral discontinuities and variable deformation of well-preserved marine terrace sequences help define major structural blocks and document differential motions in this area and south to Santa Cruz. Vertical displacement occurs on all of the fault traces, but is small compared to horizontal displacement. Some blocks within the fault zone are intensely faulted and steeply tilted. One major block 0

  3. Spectral Properties of the Martian Crustal Magnetic Field

    Science.gov (United States)

    Lewis, K. W.; Simons, F. J.

    2010-12-01

    Although the planet Mars no longer possesses an internal dynamo, its crustal rocks retain strong remanent magnetization thought to have been induced by an ancient core-sourced field. The strength and distribution of the crustal field is extremely heterogeneous, and particularly strong in the Terra Cimmeria region of the southern hemisphere. The field as a whole is inconsistent with induction from a single dipolar source, although previous studies have attempted to isolate individual magnetic anomalies to deduce paleopolar orientations. While several areas of the planet appear to have been demagnetized, including large impact basins and the Tharsis volcanic province, the distribution of the field is generally poorly correlated with surface geologic structures. However, beyond the spatial pattern of crustal magnetization, the magnetic power spectrum can provide information about the nature of the source and formation processes. Previous studies have used the power spectrum of the Martian field to estimate the approximate depth of the magnetic anomalies. We extend this approach by applying the spatiospectral localization technique of Wieczorek and Simons (2005) and Dahlen and Simons (2008) to isolate the magnetic power spectra of several areas of the Martian surface. This method allows us to look beyond the strongly magnetized Terra Cimmeria region, which dominates the global power spectrum. Localized spectral estimates, along with their appropriate errors, allow us to examine the significance of observed variations between distinct regions of the planet, and to evaluate the validity of analyses which operate on the whole sphere. Significant differences are observed between spectra of the Terra Cimmeria region and the remainder of the planet, a result of the concentration of power at certain spherical harmonic degrees in this anomalous region. Approximate depths to the magnetic sources are calculated for tiled windows on the planet using the stochastic magnetized

  4. Crustal Boundaries in the Southern MidContinent

    Science.gov (United States)

    Gilbert, M. C.

    2006-12-01

    Four crustal boundaries appear to intersect in the area of southern Oklahoma and north-central Texas. These span the period 1.4Ga to 300Ma. Thus part of the EarthScope effort should be focussed on following these boundaries from where they are more simply displayed and known toward the area of intersection with the attempt to decipher how the lithosphere was created or modified during these 4 events. These events have effectively defined the southern boundary (in today's coordinates) of Laurentia and the North American Plate. The oldest of these events is a compressive plate margin recorded in geochemistry of the Arbuckle basement 3.9 to 3.7Ga by Lidiak and colleagues. This boundary marks the southern terminus of the Granite-Rhyolite Terrane, but does not seem widely appreciated. The next oldest of these events is the Grenville Suture (Llano Front) of west Texas whose age is ~1.0Ga. This suture marks the joining of the Texas Craton to Laurentia but it has not been well tracked to the intersection area. The next youngest event is the rifting represented by the Southern Oklahoma Aulacogen, which marks the departure of part of the Texas Craton to the present Precordillera of Argentina. This rifting event created the Paleozoic southern margin of North America, and now seems to be fairly well-defined at 540-525Ma, with the age of the Mount Scott Granite at 534 +/- 1.5Ma from Hogan, Wright, and Gilbert, as a specific tie point. The last event is the Ouachita closure at 350-300Ma. Crustal structure of the eastern part of this boundary is perhaps best known through the work of COCORP and Keller and associates. Although work has been done on each of these boundaries to the sides of the intersection area, the crustal structure and lithosphere of the intersection area itself has not been well studied. The upper crust of the area is known extremely well because of its famous petroleum potential, but the lower crust and upper mantle have been largely ignored. A crustal model

  5. GEODYNAMICAL MODELING OF CRUSTAL DEFORMATION OF THE NORTH CHINA BLOCK

    Institute of Scientific and Technical Information of China (English)

    LIN Ge; ZHANG Yan-hua; GUO Feng; WANG Yue-jun; FAN Wei-ming

    2001-01-01

    @@ The North China block,the western portion of the Sino-Korean Craton,is rounded by Yanshanian in the north and Qinling-Dabie orogenic belts in the south.The widespread development of extensional basins in this block indicates horizontal extension or continued thinning of a previousely thickened,trnstable lithosphere throughout the Mesozoic.In this paper,we attempt to simulate numerically the geodynamical process of the basin formation by using the mountain-basin evolution system.We assume that the formation of numerous sedimentary basins in the North China block is the result of the crustal extension,which destructs rapidly the previously thickened crust.

  6. Crustal structure and active tectonics in the Eastern Alps

    DEFF Research Database (Denmark)

    Brückl, E.; Behm, M.; Decker, K.;

    2010-01-01

    During the last decade, a series of controlled source seismic experiments brought new insight into the crustal and lithospheric structure of the Eastern Alps and their adjacent tectonic provinces. A fragmentation of the lithosphere into three blocks, Europe (EU), Adria (AD), and the new Pannonian...... compensated by the lateral extrusion of the central Eastern Alps. The Periadriatic (Insubric) line east of the triple junction and the mid-Hungarian fault zone have relatively recently lost their role as first-order active structures. We favor the idea that the Pannonian fragment and the TISZA block merged to...

  7. Testing Predictions of Continental Insulation using Oceanic Crustal Thicknesses

    Science.gov (United States)

    Hoggard, Mark; Shorttle, Oliver; White, Nicky

    2016-04-01

    The thermal blanketing effect of continental crust has been predicted to lead to elevated temperatures within the upper mantle beneath supercontinents. Initial break-up is associated with increased magmatism and the generation of flood basalts. Continued rifting and sea-floor spreading lead to a steady reduction of this thermal anomaly. Recently, evidence in support of this behaviour has come from the major element geochemistry of mid-ocean ridge basalts, which suggest excess rifting temperatures of ˜ 150 °C that decay over ˜ 100 Ma. We have collated a global inventory of ˜ 1000 seismic reflection profiles and ˜ 500 wide-angle refraction experiments from the oceanic realm. Data are predominantly located along passive margins, but there are also multiple surveys in the centres of the major oceanic basins. Oceanic crustal thickness has been mapped, taking care to avoid areas of secondary magmatic thickening near seamounts or later thinning such as across transform faults. These crustal thicknesses are a proxy for mantle potential temperature at the time of melt formation beneath a mid-ocean ridge system, allowing us to quantify the amplitude and duration of thermal anomalies generated beneath supercontinents. The Jurassic break-up of the Central Atlantic and the Cretaceous rifting that formed the South Atlantic Ocean are both associated with excess temperatures of ˜ 50 °C that have e-folding times of ˜ 50 Ma. In addition to this background trend, excess temperatures reach > 150 °C around the region of the Rio Grande Rise, associated with the present-day Tristan hotspot. The e-folding time of this more local event is ˜ 10 Ma, which mirrors results obtained for the North Atlantic Ocean south of Iceland. In contrast, crustal thicknesses from the Pacific Ocean reveal approximately constant potential temperature through time. This observation is in agreement with predictions, as the western Pacific was formed by rifting of an oceanic plate. In summary

  8. Magnetar Outbursts from Avalanches of Hall Waves and Crustal Failures

    CERN Document Server

    Li, Xinyu; Belovorodov, Andrei M

    2016-01-01

    We explore the interaction between Hall waves and mechanical failures inside a magnetar crust, using detailed one-dimentional models that consider temperature-sensitive plastic flow, heat transport and cooling by neutrino emission, as well as the coupling of the crustal motion to the magnetosphere. We find that the dynamics is enriched and accelerated by the fast, short-wavelength Hall waves that are emitted by each failure. The waves propagate and cause failures elsewhere, triggering avalanches. We argue that these avalanches are the likely sources of outbursts in transient magnetars.

  9. Crustal structure beneath China from receiver function analysis

    Science.gov (United States)

    Chen, Youlin; Niu, Fenglin; Liu, Ruifeng; Huang, Zhibin; TkalčIć, Hrvoje; Sun, Li; Chan, Winston

    2010-03-01

    We collected and processed a large amount of high-quality broadband teleseismic waveform data recorded by the 48 Chinese National Digital Seismic Network stations to estimate large-scale lateral variations of crustal thickness and Vp/Vs ratio (hence Poisson's ratio) beneath China. A statistical method was used to select mutually coherent receiver functions at each station, which yielded over 200 traces for most of the stations. With the conventional H-κ (the crustal thickness and Vp/Vs ratio) approach, there is a large trade-off between H and κ. Consequently, multiple maxima are frequently observed in the H-κ domain. We introduced a weight function that measures the coherence between the P-to-S conversion and the reverberation phases at each H-κ grid to reduce the trade-off. A 4th-root stacking method was further applied to reduce uncorrelated noise relative to the linear stack. These modifications turned out to be very effective in reducing the H-κ trade-off and yielded reliable estimates of crustal thickness and Vp/Vs ratio. The crust beneath eastern China is as thin as 31-33 km and the underlying Moho is relatively flat and sharp. In the western part of China, the crust is considerably thicker and shows large variations. The Moho is observed at about 51 km depth along the Tian Shan fold system and about 84 km deep beneath the central part of the Tibetan Plateau. The transition occurs at the so-called N-S belt between about 100° and 110°E, which is featured by unusually high seismicity and large gravity anomalies. The average Vp/Vs ratio over the mainland China crust is about 1.730 (σ = 0.249), significantly lower than the global average 1.78 (σ = 0.27) of the continental crust. This lower Vp/Vs ratio may suggest a general absence of mafic lowermost crustal layer beneath China.

  10. Crustal structure variations along the Lesser Antilles Arc

    Science.gov (United States)

    Schlaphorst, D.; Kendall, J. M.; Melekhova, E.; Blundy, J.; Baptie, B.; Latchman, J. L.

    2013-12-01

    Continental crust is predominantly formed along subduction zones. Therefore, an investigation of the crustal and mantle structure variation of these areas is crucial for understanding the growth of continental crust. This work deals with the seismological characteristics along the Lesser Antilles Arc, an island arc system built by the relatively slow subduction (~2cm/yr) of the North and South American plates beneath the Caribbean plate. The amount of subducted sediments changes significantly from sediment-rich subduction in the South to sediment-poor subduction in the North. The abundance of broadband seismic stations on the Lesser Antilles islands enables a range of seismic methods to be used to study arc processes. Furthermore, the abundance of cumulate samples allows for a detailed petrological analysis, which can be related to the seismological patterns. We use data from three component broadband stations located on the individual islands along the arc. From the island of Grenada in the South to the Virgin Islands in the North significant variations in sediment load, petrology and volcanism are observed along the arc. In this work, we investigate crustal structure using receiver functions to determine Moho depth and Vp/Vs ratio. The ratio gives an idea about the material of the subsurface as well as its water and its melt contents. The receiver functions are computed using the extended-time multitaper frequency domain cross-correlation receiver-function (ETMTRF) by Helffrich (2006). This method has the advantage of resistance to noise, which is helpful since most of the data around the arc will have been collected by stations close to the ocean, thus containing a large amount of noise. Our results show clear variations in these measurements. There are also regions where the Moho is not very sharp due to a low velocity contrast. The real data results were then compared to synthetic receiver functions from subsurface models. We compute a range of synthetic

  11. Relative entropy equals bulk relative entropy

    CERN Document Server

    Jafferis, Daniel L; Maldacena, Juan; Suh, S Josephine

    2015-01-01

    We consider the gravity dual of the modular Hamiltonian associated to a general subregion of a boundary theory. We use it to argue that the relative entropy of nearby states is given by the relative entropy in the bulk, to leading order in the bulk gravitational coupling. We also argue that the boundary modular flow is dual to the bulk modular flow in the entanglement wedge, with implications for entanglement wedge reconstruction.

  12. Coupling brane fields to bulk supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Parameswaran, Susha L. [Uppsala Univ. (Sweden). Theoretical Physics; Schmidt, Jonas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-12-15

    In this note we present a simple, general prescription for coupling brane localized fields to bulk supergravity. We illustrate the procedure by considering 6D N=2 bulk supergravity on a 2D orbifold, with brane fields localized at the fixed points. The resulting action enjoys the full 6D N=2 symmetries in the bulk, and those of 4D N=1 supergravity at the brane positions. (orig.)

  13. Coupling brane fields to bulk supergravity

    International Nuclear Information System (INIS)

    In this note we present a simple, general prescription for coupling brane localized fields to bulk supergravity. We illustrate the procedure by considering 6D N=2 bulk supergravity on a 2D orbifold, with brane fields localized at the fixed points. The resulting action enjoys the full 6D N=2 symmetries in the bulk, and those of 4D N=1 supergravity at the brane positions. (orig.)

  14. Diagnosis of Dry Bulk Shipping Market

    Institute of Scientific and Technical Information of China (English)

    Wendy Wu

    2009-01-01

    @@ A sudden severe winter for dry bulk shipping market Since the second half of last year,dry bulk shipping market experienced a sudden and dramatical change which caught everyone off guard in just a few months'time.As the wind vane of dry bulk shipping market,BDI index(Baltic index)has been climbing higher and higher from the middle of 2005.It began to nearly shoot up into the 2007.

  15. Shortened telomere length is associated with increased risk of cancer: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Hongxia Ma

    Full Text Available BACKGROUND: Telomeres play a key role in the maintenance of chromosome integrity and stability, and telomere shortening is involved in initiation and progression of malignancies. A series of epidemiological studies have examined the association between shortened telomeres and risk of cancers, but the findings remain conflicting. METHODS: A dataset composed of 11,255 cases and 13,101 controls from 21 publications was included in a meta-analysis to evaluate the association between overall cancer risk or cancer-specific risk and the relative telomere length. Heterogeneity among studies and their publication bias were further assessed by the χ(2-based Q statistic test and Egger's test, respectively. RESULTS: The results showed that shorter telomeres were significantly associated with cancer risk (OR = 1.35, 95% CI = 1.14-1.60, compared with longer telomeres. In the stratified analysis by tumor type, the association remained significant in subgroups of bladder cancer (OR = 1.84, 95% CI = 1.38-2.44, lung cancer (OR = 2.39, 95% CI = 1.18-4.88, smoking-related cancers (OR = 2.25, 95% CI = 1.83-2.78, cancers in the digestive system (OR = 1.69, 95% CI = 1.53-1.87 and the urogenital system (OR = 1.73, 95% CI = 1.12-2.67. Furthermore, the results also indicated that the association between the relative telomere length and overall cancer risk was statistically significant in studies of Caucasian subjects, Asian subjects, retrospective designs, hospital-based controls and smaller sample sizes. Funnel plot and Egger's test suggested that there was no publication bias in the current meta-analysis (P = 0.532. CONCLUSIONS: The results of this meta-analysis suggest that the presence of shortened telomeres may be a marker for susceptibility to human cancer, but single larger, well-design prospective studies are warranted to confirm these findings.

  16. Bulk scalar field in DGP braneworld cosmology

    CERN Document Server

    Ansari, Rizwan ul Haq

    2007-01-01

    We investigated the effects of bulk scalar field in the braneworld cosmological scenario. The Friedmann equations and acceleration condition in presence of the bulk scalar field for a zero tension brane and cosmological constant are studied. In DGP model the effective Einstein equation on the brane is obtained with bulk scalar field. The rescaled bulk scalar field on the brane in the DGP model behaves as an effective four dimensional field, thus standard type cosmology is recovered. In present study of the DGP model, the late-time accelerating phase of the universe can be explained .

  17. Ellipticity of Rayleigh waves and crustal structure in northern Italy

    Science.gov (United States)

    Berbellini, Andrea; Morelli, Andrea; Ferreira, Ana M. G.

    2016-04-01

    Horizontal-to-vertical amplitude ratio of elliptically-polarised ground motion of Rayleigh waves depends on the local crustal structure. Its measurement therefore adds another, seldom used, tool to image shallow earth structure. Frequency-dependent sensitivity kernels are dominated by shear-wave velocity and are rather shallow, so they are a convenient tool to model sedimentary layers that nicely complement surface wave studies. We perform extensive measurements, in the period range between 10 and 110 s, on traces from about 500 globally-distributed earthquakes, occurred in years 2008 ÷ 2014, recorded by 95 stations in northern Italy - - a region including the wide basin of the Po Plain and encircling Alps and northern Apennines. The observations are well correlated with known strucure: high ellipticity correlates well with low seismic velocity (such as in the Po Plain), and low ellipticity corresponds to fast seismic velocity in hard rock environments in correspondence of Alps and Apennines. Comparison between observations and predicted ellipticity from a reference crustal model of the region (Molinari et al., 2015) shows substantial fit. Sensitivity to vS is quite non linear, but inversion is possible and may provide very useful complementary information to, e.g., surface wave phase or group velocity or receiver functions.

  18. Mapping Weak Crustal Magnetic Fields on Mars with Electron Reflectometry

    Science.gov (United States)

    Mitchell, D. L.; Lillis, R.; Lin, R. P.; Connerney, J. E. P.; Acuna, M. H.

    2004-01-01

    One of the great surprises of the Mars Global Surveyor (MGS) mission was the discovery of intensely magnetized crust. These magnetic sources are at least ten times stronger than their terrestrial counterparts, probably requiring large volumes of coherently magnetized material, very strong remanence, or both. Perhaps the most intriguing aspect of these fields is their large scale coherence and organization into east-west stripes thousands of kilometers long. The anomalies were almost certainly created by thermoremanent magnetization (TRM) in the presence of a strong Martian dynamo. With few exceptions, the crustal fields are associated with the oldest terrain on Mars. Much of the northern lowlands appears to be non-magnetic, except for the relatively weak north polar anomalies and a few sources adja-cent to the dichotomy boundary, which appear to be associated with strongly magnetized crust south of the boundary. There is clear evidence for impact demagnetization of the Hellas, Argyre, and Isidis basins. Thus, Mars' crustal magnetic fields are among the oldest preserved geologic features on the planet.

  19. Gravitational radiation from neutron stars deformed by crustal Hall drift

    CERN Document Server

    Suvorov, Arthur George; Geppert, Ulrich

    2016-01-01

    A precondition for the radio emission of pulsars is the existence of strong, small-scale magnetic field structures (`magnetic spots') in the polar cap region. Their creation can proceed via crustal Hall drift out of two qualitatively and quantitatively different initial magnetic field configurations: a field confined completely to the crust and another which penetrates the whole star. The aim of this study is to explore whether these magnetic structures in the crust can deform the star sufficiently to make it an observable source of gravitational waves. We model the evolution of these field configurations, which can develop, within $\\sim 10^4$ -- $10^5$ yr, magnetic spots with local surface field strengths $\\sim 10^{14}$ G maintained over $\\gtrsim 10^6$ yr. Deformations caused by the magnetic forces are calculated. We show that, under favourable initial conditions, a star undergoing crustal Hall drift can have ellipticity $\\epsilon\\sim 10^{-6}$, even with sub-magnetar polar field strengths, after $\\sim 10^5$ ...

  20. Gravitational radiation from neutron stars deformed by crustal Hall drift

    Science.gov (United States)

    Suvorov, A. G.; Mastrano, A.; Geppert, U.

    2016-07-01

    A precondition for the radio emission of pulsars is the existence of strong, small-scale magnetic field structures (`magnetic spots') in the polar cap region. Their creation can proceed via crustal Hall drift out of two qualitatively and quantitatively different initial magnetic field configurations: a field confined completely to the crust and another which penetrates the whole star. The aim of this study is to explore whether these magnetic structures in the crust can deform the star sufficiently to make it an observable source of gravitational waves. We model the evolution of these field configurations, which can develop, within ˜104-105 yr, magnetic spots with local surface field strengths ˜1014 G maintained over ≳106 yr. Deformations caused by the magnetic forces are calculated. We show that, under favourable initial conditions, a star undergoing crustal Hall drift can have ellipticity ɛ ˜ 10-6, even with sub-magnetar polar field strengths, after ˜105 yr. A pulsar rotating at ˜102 Hz with such ɛ is a promising gravitational wave source candidate. Since such large deformations can be caused only by a particular magnetic field configuration that penetrates the whole star and whose maximum magnetic energy is concentrated in the outer core region, gravitational wave emission observed from radio pulsars can thus inform us about the internal field structures of young neutron stars.

  1. Shortened constraint-induced movement therapy in subacute stroke - no effect of using a restraint

    DEFF Research Database (Denmark)

    Brogårdh, Christina; Vestling, Monika; Sjölund, Bengt H

    2009-01-01

    Scale, the Sollerman hand function test, the 2-Point Discrimination test and Motor Activity Log test. RESULTS: Patients in both groups showed significant improvements in arm and hand motor performance and on self-reported motor ability after 2 weeks of therapy and at 3 months follow-up. However......, no statistically significant differences between the groups were found in any measures at any point in time. CONCLUSION: In this study, no effect of using a restraint in patients with subacute stroke was found. Thus, this component in the constraint-induced therapy concept seems to be of minor importance......OBJECTIVE: To examine the effect of using a mitt during shortened constraint-induced movement therapy for patients in the subacute phase after stroke. SUBJECTS: Twenty-four patients with stroke (mean age 57.6 (standard deviation (SD) 8.5) years; average 7 weeks post-stroke) with mild to moderate...

  2. To the problem of cross-bridge tension in steady muscle shortening and lengthening

    CERN Document Server

    Kokshenev, Valery B

    2009-01-01

    Despite the great success of the Huxley sliding filament model proposed half a century ago for actin-myosin linkages (cross-bridges), it fails to explain the force-velocity behavior of stretching skeletal muscles. Huxley's two-state kinetic equation for cross-bridge proportions is therefore reconsidered and a new solution to the problem of steady muscle eccentric and concentric contractions is reported. When the second law of statistical thermodynamics is applied to cross-bridge proportions, the weakly bound states appear to be correlated to the strongly bound states via structural and kinetic intrinsic muscle characteristics. The explicit force-velocity curve fits the empirical tension-velocity data on frog muscle shortening using only one adjustable parameter, while the Huxley model employed four parameters.

  3. Dynamic Route Shortening and Route Repairing Mechanism for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    T. R. Rangaswamy

    2012-01-01

    Full Text Available Problem statement: Ad hoc Networks are wireless networks without any fixed infrastructure. The network topology changes frequently and unpredictably due to the random movement of the nodes. The ad hoc on Demand Distant Vector Routing (AODV protocol works in a dynamic fashion, by establishing a route on demand and continues that route until it breaks. Due to the changing network topology of ad hoc networks, if other routes with less hop count become available, the network topology is not able to adapt until the route break occurs. Hence in the route shortening scheme is some redundant nodes in the active route is replaced with a node that is not on the active route. When there is any link failure between any two nodes, the alternative route with optimum route to be constructed and not sending RRER message to the source node to initiate the route discovery process again. Approach: This study proposes a new routing protocol called, Dynamic Route Shortening and Repairing mechanism (DRSR. The route shortening is incorporated with route repairing mechanism, to improve the performance of the AODV. The route shortening scheme works by replacing some redundant nodes in the active route, with a node that is not on the active route. If there is a link failure between the two nodes, the route repairing mechanism repairs the route, by using the nodes that are close enough to the route to overhear the message. Whenever the links go down, the DRSR replaces the failed links with the optimum route that is adjacent to the main route and not sending and RRER message to the source node to initiate the route discovery process again. The alternative route construction process could be initiated at any time, not just when a route has failed. The dynamically constructed alternative route’s information is passed on to the upstream nodes, which then determine by themselves when to direct their packets to the Normal 0 false false false EN-US X

  4. Prediction of peak forces for a shortening smooth muscle tissue subjected to vibration.

    Science.gov (United States)

    Pidaparti, Ramana M; Dhanaraj, Nandhini; Meiss, Richard A

    2008-01-01

    The objective of the present study is to investigate the peak forces for a tracheal smooth muscle tissue subjected to an applied longitudinal vibration following isotonic shortening. A non-linear finite element analysis was carried out to simulate the vibratory response under experimental conditions that corresponds to forced length oscillations at 33 Hz for 1 second. The stiffness change and hysteresis estimated from the experimental data was used in the analysis. The finite element results of peak forces are compared to the experimental data obtained. The comparison of results indicate that the approach and the vibratory response obtained may be useful for describing the cross-bridge de-attachments within the cells as well as connective tissue connections characteristic of tracheal smooth muscle tissue.

  5. Present-day shortening in Southern Haiti from GPS measurements and implications for seismic hazard

    Science.gov (United States)

    Symithe, Steeve; Calais, Eric

    2016-06-01

    The ~ 3 M inhabitant capital region of Haiti, severely affected by the devastating January 12, 2010, M7.0 earthquake, continues to expand at a fast rate. Accurate characterization of regional earthquake sources is key to inform urban development and construction practices through improved regional seismic hazard estimates. Here we use a recently updated Global Positioning System (GPS) data set to show that seismogenic strain accumulation in southern Haiti involves an overlooked component of shortening on a south-dipping reverse fault along the southern edge of the Cul-de-Sac basin, in addition to the well-known component of left-lateral strike-slip motion. This tectonic model implies that ground shaking may be twice that expected if the major fault was purely strike-slip, as assumed in the current seismic hazard map for the region.

  6. Constraints on plateau architecture and assembly from deep crustal xenoliths, northern Altiplano (SE Peru)

    Science.gov (United States)

    Chapman, Alan; Ducea, Mihai; McQuarrie, Nadine; Coble, Matthew; Petrescu, Lucian; Hoffman, Derek

    2016-04-01

    northernmost Altiplano at ~30-40 km below the surface. Together, these results indicate that crustal thickening under the northernmost Altiplano started earlier than major latest Oligocene and Miocene uplift episodes affecting the region and was coeval with a flat slab-related regional episode of deformation. Total shortening must have been at least 20% more than previous estimates in order to satisfy the basement to cover depth constraints provided by the xenolith data. Sedimentary rocks at >30 km paleodepth require that Andean basement thrusts decapitated earlier Triassic normal faults, trapping Paleozoic and Mesozoic rocks below the main décollement. Magma loading from intense Cenozoic plutonism within the plateau probably played an additional role in transporting Mesozoic cover rocks to >30 km and thickening the crust beneath the northern Altiplano.

  7. Subduction zone and crustal dynamics of western Washington; a tectonic model for earthquake hazards evaluation

    Science.gov (United States)

    Stanley, Dal; Villaseñor, Antonio; Benz, Harley

    1999-01-01

    buttress occurs under the North Cascades region of Washington and under southern Vancouver Island. We find that regional faults zones such as the Devils Mt. and Darrington zones follow the margin of this buttress and the Olympic-Wallowa lineament forms its southern boundary east of the Puget Lowland. Thick, high-velocity, lower-crustal rocks are interpreted to be a mafic/ultramafic wedge occuring just above the subduction thrust. This mafic wedge appears to be jointly deformed with the arch, suggesting strong coupling between the subducting plate and upper plate crust in the Puget Sound region at depths >30 km. Such tectonic coupling is possible if brittle-ductile transition temperatures for mafic/ultramafic rocks on both sides of the thrust are assumed. The deformation models show that dominant north-south compression in the coast ranges of Washington and Oregon is controlled by a highly mafic crust and low heat flow, allowing efficient transmission of margin-parallel shear from Pacific plate interaction with North America. Complex stress patterns which curve around the Puget Sound region require a concentration of northwest-directed shear in the North Cascades of Washington. The preferred model shows that greatest horizontal shortening occurs across the Devils Mt. fault zone and the east end of the Seattle fault.

  8. Unloaded shortening velocity of voluntarily and electrically activated human dorsiflexor muscles in vivo.

    Directory of Open Access Journals (Sweden)

    Kazushige Sasaki

    Full Text Available We have previously shown that unloaded shortening velocity (V(0 of human plantar flexors can be determined in vivo, by applying the "slack test" to submaximal voluntary contractions (J Physiol 567:1047-1056, 2005. In the present study, to investigate the effect of motor unit recruitment pattern on V(0 of human muscle, we modified the slack test and applied this method to both voluntary and electrically elicited contractions of dorsiflexors. A series of quick releases (i.e., rapid ankle joint rotation driven by an electrical dynamometer was applied to voluntarily activated dorsiflexor muscles at three different contraction intensities (15, 50, and 85% of maximal voluntary contraction; MVC. The quick-release trials were also performed on electrically activated dorsiflexor muscles, in which three stimulus conditions were used: submaximal (equal to 15%MVC 50-Hz stimulation, supramaximal 50-Hz stimulation, and supramaximal 20-Hz stimulation. Modification of the slack test in vivo resulted in good reproducibility of V(0, with an intraclass correlation coefficient of 0.87 (95% confidence interval: 0.68-0.95. Regression analysis showed that V(0 of voluntarily activated dorsiflexor muscles significantly increased with increasing contraction intensity (R(2 = 0.52, P<0.001. By contrast, V(0 of electrically activated dorsiflexor muscles remained unchanged (R(2<0.001, P = 0.98 among three different stimulus conditions showing a large variation of tetanic torque. These results suggest that the recruitment pattern of motor units, which is quite different between voluntary and electrically elicited contractions, plays an important role in determining shortening velocity of human skeletal muscle in vivo.

  9. Shortening Infusion Time for High-Dose Methotrexate Alters Antileukemic Effects: A Randomized Prospective Clinical Trial

    Science.gov (United States)

    Mikkelsen, Torben S.; Sparreboom, Alex; Cheng, Cheng; Zhou, Yinmei; Boyett, James M.; Raimondi, Susana C.; Panetta, John C.; Bowman, W. Paul; Sandlund, John T.; Pui, Ching-Hon; Relling, Mary V.; Evans, William E.

    2011-01-01

    Purpose To determine whether shortening the infusion duration of high-dose methotrexate (HDMTX; 1 g/m2) affects the in vivo accumulation of active methotrexate polyglutamates (MTXPG1-7) in leukemia cells and whether this differs among major acute lymphoblastic leukemia (ALL) subtypes. Methods From June 2000 through October 2007, 356 children with ALL were randomly assigned to receive initial single-agent treatment with HDMTX (1 g/m2) as either a 24-hour infusion or a 4-hour infusion at two pediatric hospitals in the United States. The primary outcome measures were the accumulation of MTXPG1-7 in leukemia cells and the antileukemic effects (eg, inhibition of de novo purine synthesis in bone marrow ALL cells, and decrease in circulating ALL cells). Results The 24-hour infusion resulted in significantly higher amounts of MTXPG1-7 in bone marrow leukemia cells (median: 1,695 v 1,150 pmol/109 cells, P = .0059), and better antileukemic effects. The 24-hour infusion had the greatest effect on MTXPG1-7 accumulation in hyperdiploid ALL (median: 3,919 v 2,417 pmol/109 cells, P = .0038); T-cell ALL exhibited smaller differences in MTXPG1-7 but greater antileukemic effects with the longer infusion (median decrease in leukemia cells: 88.4% v 51.8%, P = .0075). In contrast, infusion duration had no significant impact on MTXPG1-7 accumulation or antileukemic effects in ALL with the t(12;21)/(ETV6-RUNX1) chromosomal translocation. Conclusion Shortening the infusion time of HDMTX reduces accumulation of active methotrexate in leukemia cells and decreases antileukemic effects, with differing consequences among major ALL subtypes. PMID:21444869

  10. A novel shortened electrospun nanofiber modified with a 'concentrated' polymer brush

    Directory of Open Access Journals (Sweden)

    Chiaki Yoshikawa, Kun Zhang, Ewelina Zawadzak and Hisatoshi Kobayashi

    2011-01-01

    Full Text Available We report the fabrication of shortened electrospun polymer fibers with a well-defined concentrated polymer brush. We first prepared electrospun nanofibers from a random copolymer of styrene and 4-vinylbenzyl 2-bromopropionate, with number-average molecular weight Mn=105 200 and weight-average molecular weight Mw=296 700 (Mw/Mn=2.82. The fibers had a diameter of 593±74 nm and contained initiating sites for surface-initiated atom transfer radical polymerization (SI-ATRP. Then, SI-ATRP of hydrophilic styrene sodium sulfonate (SSNa was carried out in the presence of a free initiator and the hydrophobic fibers. Gel permeation chromatography confirmed that Mn and Mw/Mn values were almost the same for free polymers and graft polymers. Mn agreed well with the theoretical prediction, and Mw/Mn was relatively low (<1.3 in all the examined cases, indicating that this polymerization proceeded in a living manner. Using the values of the graft amount measured by Fourier transform infrared spectroscopy, the surface area, and Mn, we calculated the graft density σ as 0.22 chains nm−2. This value was nearly equal to the density obtained on silicon wafers (σ=0.24 chains nm−2, which is categorized into the concentrated brush regime. Finally, we mechanically cut the fibers with a concentrated poly(SSNa brush by a homogenizer. With increasing cutting time, the fiber length became shorter and more homogenous (11±17 μm after 3 h. The shortened fibers exhibited excellent water dispersibility owing to the hydrophilic poly(SSNa brush layer.

  11. New reconstruction algorithm allows shortened acquisition time for myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Shortening scan time and/or reducing radiation dose at maintained image quality are the main issues of the current research in radionuclide myocardial perfusion imaging (MPI). We aimed to validate a new iterative reconstruction (IR) algorithm for SPECT MPI allowing shortened acquisition time (HALF time) while maintaining image quality vs. standard full time acquisition (FULL time). In this study, 50 patients, referred for evaluation of known or suspected coronary artery disease by SPECT MPI using 99mTc-Tetrofosmin, underwent 1-day adenosine stress 300 MBq/rest 900 MBq protocol with standard (stress 15 min/rest 15 min FULL time) immediately followed by short emission scan (stress 9 min/rest 7 min HALF time) on a Ventri SPECT camera (GE Healthcare). FULL time scans were processed with IR, short scans were additionally processed with a recently developed software algorithm for HALF time emission scans. All reconstructions were subsequently analyzed using commercially available software (QPS/QGS, Cedars Medical Sinai) with/without X-ray based attenuation correction (AC). Uptake values (percent of maximum) were compared by regression and Bland-Altman (BA) analysis in a 20-segment model. HALF scans yielded a 96% readout and 100% clinical diagnosis concordance compared to FULL. Correlation for uptake in each segment (n = 1,000) was r = 0.87at stress (p < 0.001) and r = 0.89 at rest (p < 0.001) with respective BA limits of agreement of -11% to 10% and -12% to 11%. After AC similar correlation (r = 0.82, rest; r = 0.80, stress, both p < 0.001) and BA limits were found (-12% to 10%; -13% to 12%). With the new IR algorithm, SPECT MPI can be acquired at half of the scan time without compromising image quality, resulting in an excellent agreement with FULL time scans regarding to uptake and clinical conclusion. (orig.)

  12. Apoptosis and telomeres shortening related to HIV-1 induced oxidative stress in an astrocytoma cell line

    Directory of Open Access Journals (Sweden)

    Mollace Vincenzo

    2009-05-01

    Full Text Available Abstract Background Oxidative stress plays a key role in the neuropathogenesis of Human Immunodeficiency Virus-1 (HIV-1 infection causing apoptosis of astroglia cells and neurons. Recent data have shown that oxidative stress is also responsible for the acceleration of human fibroblast telomere shortening in vitro. In the present study we analyzed the potential relations occurring between free radicals formation and telomere length during HIV-1 mediated astroglial death. Results To this end, U373 human astrocytoma cells have been directly exposed to X4-using HIV-1IIIB strain, for 1, 3 or 5 days and treated (where requested with N-acetylcysteine (NAC, a cysteine donor involved in the synthesis of glutathione (GSH, a cellular antioxidant and apoptosis has been evaluated by FACS analysis. Quantitative-FISH (Q-FISH has been employed for studying the telomere length while intracellular reduced/oxidized glutathione (GSH/GSSG ratio has been determined by High-Performance Liquid Chromatography (HPLC. Incubation of U373 with HIV-1IIIB led to significant induction of cellular apoptosis that was reduced in the presence of 1 mM NAC. Moreover, NAC improved the GSH/GSSG, a sensitive indicator of oxidative stress, that significantly decreased after HIV-1IIIB exposure in U373. Analysis of telomere length in HIV-1 exposed U373 showed a statistically significant telomere shortening, that was completely reverted in NAC-treated U373. Conclusion Our results support the role of HIV-1-mediated oxidative stress in astrocytic death and the importance of antioxidant compounds in preventing these cellular damages. Moreover, these data indicate that the telomere structure, target for oxidative damage, could be the key sensor of cell apoptosis induced by oxidative stress after HIV infection.

  13. HIV Infection Is Associated with Shortened Telomere Length in Ugandans with Suspected Tuberculosis

    Science.gov (United States)

    Auld, Elizabeth; Lin, Jue; Chang, Emily; Byanyima, Patrick; Ayakaka, Irene; Musisi, Emmanuel; Worodria, William; Davis, J. Lucian; Segal, Mark; Blackburn, Elizabeth; Huang, Laurence

    2016-01-01

    Introduction HIV infection is a risk factor for opportunistic pneumonias such as tuberculosis (TB) and for age-associated health complications. Short telomeres, markers of biological aging, are also associated with an increased risk of age-associated diseases and mortality. Our goals were to use a single cohort of HIV-infected and HIV-uninfected individuals hospitalized with pneumonia to assess whether shortened telomere length was associated with HIV infection, TB diagnosis, and 2-month mortality. Methods This was a sub-study of the IHOP Study, a prospective observational study. Participants consisted of 184 adults admitted to Mulago Hospital in Kampala, Uganda who underwent evaluation for suspected TB and were followed for 2 months. Standardized questionnaires were administered to collect demographic and clinical data. PBMCs were isolated and analyzed using quantitative PCR to determine telomere length. The association between HIV infection, demographic and clinical characteristics, and telomere length was assessed, as were the associations between telomere length, TB diagnosis and 2-month mortality. Variables with a P≤0.2 in bivariate analysis were included in multivariate models. Results No significant demographic or clinical differences were observed between the HIV-infected and HIV-uninfected subjects. Older age (Ptelomere length in bivariate analysis. In multivariate analysis adjusting for these five variables, HIV-positive participants had significantly shorter telomeres than HIV-negative participants (β = -0.0621, 95% CI -0.113 to -0.011, P = 0.02). Shortened telomeres were not associated with TB or short-term mortality. Conclusions The association between HIV infection and shorter telomeres suggests that HIV may play a role in cellular senescence and biological aging and that shorter telomeres may be involved in age-associated health complications seen in this population. The findings indicate a need to further research the impact of HIV on aging. PMID

  14. Analysis of combination drug therapy to develop regimens with shortened duration of treatment for tuberculosis.

    Directory of Open Access Journals (Sweden)

    George L Drusano

    Full Text Available Tuberculosis remains a worldwide problem, particularly with the advent of multi-drug resistance. Shortening therapy duration for Mycobacterium tuberculosis is a major goal, requiring generation of optimal kill rate and resistance-suppression. Combination therapy is required to attain the goal of shorter therapy.Our objective was to identify a method for identifying optimal combination chemotherapy. We developed a mathematical model for attaining this end. This is accomplished by identifying drug effect interaction (synergy, additivity, antagonism for susceptible organisms and subpopulations resistant to each drug in the combination.We studied the combination of linezolid plus rifampin in our hollow fiber infection model. We generated a fully parametric drug effect interaction mathematical model. The results were subjected to Monte Carlo simulation to extend the findings to a population of patients by accounting for between-patient variability in drug pharmacokinetics.All monotherapy allowed emergence of resistance over the first two weeks of the experiment. In combination, the interaction was additive for each population (susceptible and resistant. For a 600 mg/600 mg daily regimen of linezolid plus rifampin, we demonstrated that >50% of simulated subjects had eradicated the susceptible population by day 27 with the remaining organisms resistant to one or the other drug. Only 4% of patients had complete organism eradication by experiment end.These data strongly suggest that in order to achieve the goal of shortening therapy, the original regimen may need to be changed at one month to a regimen of two completely new agents with resistance mechanisms independent of the initial regimen. This hypothesis which arose from the analysis is immediately testable in a clinical trial.

  15. Mechanisms and Magnitude of Cenozoic Crustal Extension in the Vicinity of Lake Mead, Nevada and the Beaver Dam Mountains, Utah: Geochemical, Geochronological,Thermochronological and Geophysical Constraints

    Science.gov (United States)

    Almeida, Rafael V.

    The central Basin and Range Province of Nevada and Utah was one of the first areas in which the existence of widespread low-angle normal faults or detachments was first recognized. The magnitude of associated crustal extension is estimated by some to be large, in places increasing original line lengths by as much as a factor of four. However, rock mechanics experiments and seismological data cast doubt on whether these structures slipped at low inclination in the manner generally assumed. In this dissertation, I review the evidence for the presence of detachment faults in the Lake Mead and Beaver Dam Mountains areas and place constraints on the amount of extension that has occurred there since the Miocene. Chapter 1 deals with the source-provenance relationship between Miocene breccias cropping out close to Las Vegas, Nevada and their interpreted source at Gold Butte, currently located 65 km to the east. Geochemical, geochronological and thermochronological data provide support for that long-accepted correlation, though with unexpected mismatches requiring modification of the original hypothesis. In Chapter 2, the same data are used to propose a refinement of the timing of ~1.45 Ga anorogenic magmatism, and the distribution of Proterozoic crustal boundaries. Chapter 3 uses geophysical methods to address the subsurface geometry of faults along the west flank of the Beaver Dam Mountains of southwestern Utah. The data suggest that the range is bounded by steeply inclined normal faults rather than a regional-scale detachment fault. Footwall folding formerly ascribed to Miocene deformation is reinterpreted as an expression of Cretaceous crustal shortening. Fission track data presented in Chapter 4 are consistent with mid-Miocene exhumation adjacent to high-angle normal faults. They also reveal a protracted history dating back to the Pennsylvanian-Permian time, with implications for the interpretation of other basement-cored uplifts in the region. A key finding of this

  16. 27 CFR 20.191 - Bulk articles.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bulk articles. 20.191... Users of Specially Denatured Spirits Operations by Users § 20.191 Bulk articles. Users who convey articles in containers exceeding one gallon may provide the recipient with a photocopy of subpart G of...

  17. Crustal and upper mantle structure of Siberia from teleseismic receiver functions

    DEFF Research Database (Denmark)

    Soliman, Mohammad Youssof Ahmad; Thybo, Hans; Artemieva, Irina;

    2015-01-01

    -frequency P-RF component as it has about an order of magnitude better resolution than S-RF. We find no indication for significant crustal anisotropy in the cratonic areas of Siberia. The preliminary crustal thickness results from the Hk stacking and from the inversion approach agree with a previous study...

  18. Satellite gravity anomalies and crustal features of the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.G.; Krishna, K.S.; Neprochnov, Y.P.; Grinko, B.N.

    Satellite free-air gravity anomaly contour map at 5 mGal interval, seismic reflection and bathymetric data lead to the identification of deformed crustal structure of the Central Indian Ocean Basin. Twenty-three NE-SW trending deformed crustal...

  19. Crustal Flows beneath the Eastern Tibetan Plateau Revealed by Magnetotelluric Observations

    Institute of Scientific and Technical Information of China (English)

    BAI Dengha; TENG Jiwen; MA Xiaobing; KONG Xiangru

    2011-01-01

    The ongoing collision of the Indian and Asian continents has created the Himalayan and Tibetan plateau through a range of deformation processes that include crustal thickening, delamination, lateral extrusion and crustal flow. A debate continues as to which of these processes are most significant in terms of the overall mass balance of this continent-continent collision.

  20. Basin Excavation, Lower Crust, Composition, and Bulk Moon Mass balance in Light of a Thin Crust

    Science.gov (United States)

    Jolliff, B. L.; Korotev, R. L.; Ziegler, R. A.

    2013-01-01

    New lunar gravity results from GRAIL have been interpreted to reflect an overall thin and low-density lunar crust. Accordingly, crustal thickness has been modeled as ranging from 0 to 60 km, with thinnest crust at the locations of Crisium and Moscoviense basins and thickest crust in the central farside highlands. The thin crust has cosmochemical significance, namely in terms of implications for the Moon s bulk composition, especially refractory lithophile elements that are strongly concentrated in the crust. Wieczorek et al. concluded that the bulk Moon need not be enriched compared to Earth in refractory lithophile elements such as Al. Less Al in the crust means less Al has been extracted from the mantle, permitting relatively low bulk lunar mantle Al contents and low pre- and post-crust-extraction values for the mantle (or the upper mantle if only the upper mantle underwent LMO melting). Simple mass-balance calculations using the method of [4] suggests that the same conclusion might hold for Th and the entire suite of refractory lithophile elements that are incompatible in olivine and pyroxene, including the KREEP elements, that are likewise concentrated in the crust.

  1. Bulk equations of motion from CFT correlators

    CERN Document Server

    Kabat, Daniel

    2015-01-01

    To O(1/N) we derive, purely from CFT data, the bulk equations of motion for interacting scalar fields and for scalars coupled to gauge fields and gravity. We first uplift CFT operators to mimic local AdS fields by imposing bulk microcausality. This requires adding an infinite tower of smeared higher-dimension double-trace operators to the CFT definition of a bulk field, with coefficients that we explicitly compute. By summing the contribution of the higher-dimension operators we derive the equations of motion satisfied by these uplifted CFT operators and show that we precisely recover the expected bulk equations of motion. We exhibit the freedom in the CFT construction which corresponds to bulk field redefinitions.

  2. Density heterogeneity of the North American upper mantle from satellite gravity and a regional crustal model

    DEFF Research Database (Denmark)

    Herceg, Matija; Artemieva, Irina; Thybo, Hans

    2014-01-01

    and by introducing variations into the crustal structure which corresponds to the uncertainty of its resolution by highquality and low-quality seismic models. We examine the propagation of these uncertainties into determinations of lithospheric mantle density. Given a relatively small range of expected density......We present a regional model for the density structure of the North American upper mantle. The residual mantle gravity anomalies are based on gravity data derived from the GOCE geopotential models with crustal correction to the gravity field being calculated from a regional crustal model. We analyze...... how uncertainties and errors in the crustal model propagate from crustal densities to mantle residual gravity anomalies and the density model of the upper mantle. Uncertainties in the residual upper (lithospheric) mantle gravity anomalies result from several sources: (i) uncertainties in the velocity-density...

  3. Mapping sub-crustal reflectors in southwestern Spain

    Science.gov (United States)

    Palomeras, I.; Ayarza, P.; Carbonell, R.; Ehsan, S. A.; Afonso, J. C.; Diaz Cusi, J.

    2015-12-01

    During the last 15 years, the IBERSEIS and ALCUDIA controlled source experiments have acquired vertical incidence and wide angle seismic reflection data in southwest Spain, in the Variscan Sub-Portuguese, Ossa-Morena and Central-Iberian Zones. Apart from providing detailed information of the crust, these datasets have also imaged a conspicuous sub-crustal reflector. First identified on the IBERSEIS wide-angle reflection dataset, this interface seemed to feature a positive seismic impedance contrast. A boundary located between 61-72 km depth, with a Vp increase from 8.2 km/s to 8.3 km/s allowed us to model clear wide-angle reflections found above 180 km offsets. The fact that this reflector was not identified in the coincident vertical incidence dataset led us to interpret it as a gradient zone. A correlation with the 'Hales gradient zone', i.e. the boundary between spinel and garnet peridotites was our preferred interpretation. The ALCUDIA experiment, later acquired northwards of the IBERSEIS profiles, also shows prominent sub-crustal arrivals with the same characteristics as those observed in the IBERSEIS wide-angle data. However, these reflections also appear, locally and at 19 s TWT, in the vertical incidence dataset, further constraining the depth at which this feature is located. In addition, the ALCUDIA wide-angle dataset shows deeper sub-horizontal reflectivity (at Vred=8 km/s) that maybe preliminarily associated with mantle anisotropy or even, with the lithosphere-astenosphere boundary. Integration of the information provided by the IBERSEIS and ALCUDIA datasets with older and lower resolution data from the ILIHA project, where three sub-crustal phases were identified in SW Iberia, allows us to conclude that, in this area, mantle reflectivity is outstanding. Also, modeling of all the datasets contributes to map, at a regional scale, the Hales discontinuity or gradient zone in southwest Iberia. Further research, involving receiver function analysis is

  4. Continental Lower-crustal Flow: Channel Flow and Laminar Flow

    Science.gov (United States)

    LI, Dewei

    Numerous geological, geophysical and geochemical investigations and finite element modeling indicate that crustal flow layers exist in the continental crust. Both channel flow model and laminar flow model have been created to explain the flow laws and flow mechanisms. As revealed by the channel flow model, a low-viscosity channel in middle to lower crust in orogen or plateau with thick crust and high elevation would flow outward from mountain root in response to lateral pressure gradient resulted from topographic loading or to denudation. However, according to the laminar flow model proposed based on investigation of the Qinghai-Tibet plateau, circulative movement of crustal lithologies with different rheological properties between basin and orogen would occur, under the driving forces resulted from dehydration and melting of subduction plate on active continental margin and from thermal energy related to upwelling and diapiring of intercontinental mantle plume or its gravitational interactions. Similarly, when driven by gravity, the softened or melted substances of the lower crust in a basin would flow laterally toward adjacent mountain root, which would result in a thinned basin crust and a thickened orogenic crust. Partially melted magma within the thickened orogenic lower crust would cause vertical movement of metamorphic rocks of lower to middle crust due to density inversion, and the vertical main stress induced by thermal underplating of lower crust would in turn lead to formation of metamorphic core complexes and low-angle detachment fault systems. Lateral spreading of uplifting mountain due to gravitation potential would result in thrust fault systems on the border between mountain and basin. Meanwhile, detritus produced synchronously by intense erosion of uplifting mountain would be transported and deposited along the marginal deep depression in the foreland basin dragged by lower crust flow. Channel flow is similar to laminar flow in a variety of aspects

  5. Emission-energy dependence of ultrafast P-emission decay in ZnO from bulk to nanofilm

    International Nuclear Information System (INIS)

    We have performed time-resolved photoluminescence (PL) spectroscopy for ZnO thin films with thicknesses of 90, 460, and 2800 nm under intense excitation condition. We clearly observed the P emission due to inelastic exciton–exciton scattering. It was found that, in the 460- and 2800-nm thick samples, the decay time of the P emission considerably depends on the detection energy inversely proportional to the group velocity of the polariton in a bulk crystal with each factor of proportionality. In contrast, the energy dependence is less remarkable in the 90-nm thick sample. The decay times are basically shortened with a decrease in the film thickness. The thickness dependence of the P-emission-decay profiles is explained by considering the crossover from the polariton modes in the 2800-nm thick sample (bulk-like film) to the exciton-/photon-like modes in the 90-nm thick sample (nanofilm). - Highlights: • We clearly observed the P-PL dynamics due to inelastic exciton–exciton scattering. • The P-PL decay times are basically shortened with a decrease in the film thickness. • The P-PL decay time depends on the detection energy in the bulk-like sample. • The energy dependence of the P-PL decay time almost disappears in the 90-nm sample. • The thickness dependence is explained by the crossover between exciton and photon

  6. Emission-energy dependence of ultrafast P-emission decay in ZnO from bulk to nanofilm

    Energy Technology Data Exchange (ETDEWEB)

    Wakaiki, Shuji, E-mail: s.wakaiki@mls.eng.osaka-u.ac.jp [Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Ichida, Hideki [Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Science and Technology Entrepreneurship Laboratory, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Bamba, Motoaki [Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Kawase, Toshiki; Kawakami, Masaki [Department of Applied Physics, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Mizoguchi, Kohji [Department of Physical Science, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen, Naka-ku, Sakai, Osaka 599-8531 (Japan); Kim, DaeGwi; Nakayama, Masaaki [Department of Applied Physics, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Kanematsu, Yasuo [Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Science and Technology Entrepreneurship Laboratory, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2014-08-01

    We have performed time-resolved photoluminescence (PL) spectroscopy for ZnO thin films with thicknesses of 90, 460, and 2800 nm under intense excitation condition. We clearly observed the P emission due to inelastic exciton–exciton scattering. It was found that, in the 460- and 2800-nm thick samples, the decay time of the P emission considerably depends on the detection energy inversely proportional to the group velocity of the polariton in a bulk crystal with each factor of proportionality. In contrast, the energy dependence is less remarkable in the 90-nm thick sample. The decay times are basically shortened with a decrease in the film thickness. The thickness dependence of the P-emission-decay profiles is explained by considering the crossover from the polariton modes in the 2800-nm thick sample (bulk-like film) to the exciton-/photon-like modes in the 90-nm thick sample (nanofilm). - Highlights: • We clearly observed the P-PL dynamics due to inelastic exciton–exciton scattering. • The P-PL decay times are basically shortened with a decrease in the film thickness. • The P-PL decay time depends on the detection energy in the bulk-like sample. • The energy dependence of the P-PL decay time almost disappears in the 90-nm sample. • The thickness dependence is explained by the crossover between exciton and photon.

  7. Quaternary N-S shortening across the Garlock fault in Pilot Knob Valley, California

    Science.gov (United States)

    Rittase, W. M.; Walker, J. D.; Kirby, E.; McDonald, E.; Gosse, J.; Spencer, J. Q.; Wan, E.; Herrs, A. J.

    2011-12-01

    New constraints on differential vertical motions along the Garlock fault (GF) in eastern Pilot Knob Valley (PKV) provide insight into the interactions between the Panamint Valley fault system (PVFS) and the GF. The nature of strain transfer between orthogonal active fault systems such as occurs where faults of the Eastern California Shear Zone apparently accommodate dextral shear both north and south of the sinistral GF is a question of first-order importance for both the dynamics of deforming lithosphere and hazard. New mapping (based on field as well as both airborne and ground-based LiDAR) and chronology of Quaternary deposits exposed along the GF place bounds on the vertical components of recent deformation and include: (1) 2 10Be depth profiles, (2) soil descriptions and (3) tephrochronologic correlation of Quaternary volcanic deposits. Here we focus on two terrace treads adjacent to the GF and one adjacent to the southern Slate Range (SSR), which are displaced vertically relative to base-level. Uplift of the two terraces adjacent to the GF are inferred from modern stream channel incisions. A ~46 ka 10Be profile age for a 16-m-high terrace tread adjacent to the GF suggests a minimum differential uplift rate of ~0.34 mm/yr. A ~56 ka 10Be profile age from a 12.5-m-high tread located 4.5 km west on the GF suggests a differential uplift rate of ~0.22 mm/yr. A 25.5-m-high terrace adjacent to the SSR was dated via TCN, OSL and PDI. Acquiring reliable TCN and OSL data were problematic here. However, a soil PDI age estimate of ~164 ka brackets the maximum age of uplift and thus a minimum uplift rate of ~0.16 mm/yr here. Tephrochronologic data bracket the minimum age of the PKV at ~0.7 Ma (new unit). These sediments sit up to 430 m above the modern PKV floor. If faults controlling ~430 m of uplifted PKV sediments dip 70-80°, 155-76 m of N-S shortening is expected between the GF and SSR. A long-term uplift rate of ~0.61 mm/yr and N-S shortening rate of 0.22-0.11 mm

  8. The interpretation of crustal dynamics data in terms of plate motions and regional deformation near plate boundaries

    Science.gov (United States)

    Solomon, Sean C.

    During our participation in the NASA Crustal Dynamics Project under NASA contract NAS-27339 and grant NAG5-814 for the period 1982-1991, we published or submitted for publication 30 research papers and 52 abstracts of presentations at scientific meetings. In addition, five M.I.T. Ph.D. students (Eric Bergman, Steven Bratt, Dan Davis, Jeanne Sauber, Anne Sheehan) were supported wholly or in part by this project during their thesis research. Highlights of our research progress during this period include the following: application of geodetic data to determine rates of strain in the Mojave block and in central California and to clarify the relation of such strain to the San Andreas fault and Pacific-North American plate motions; application of geodetic data to infer post seismic deformation associated with large earthquakes in the Imperial Valley, Hebgen Lake, Argentina, and Chile; determination of the state of stress in oceanic lithosphere from a systematic study of the centroid depths and source mechanisms of oceanic intraplate earthquakes; development of models for the state of stress in young oceanic regions arising from the differential cooling of the lithosphere; determination of the depth extent and rupture characteristics of oceanic transform earthquakes; improved determination of earthquake slip vectors in the Gulf of California, an important data set for the estimation of Pacific-North American plate motions; development of models for the state of stress and mechanics of fold-and-thrust belts and accretionary wedges; development of procedures to invert geoid height, residual bathymetry, and differential body wave travel time residuals for lateral variations in the characteristic temperature and bulk composition of the oceanic upper mantle; and initial GPS measurements of crustal deformation associated with the Imperial-Cerro Prieto fault system in southern California and northern Mexico. Full descriptions of the research conducted on these topics may be

  9. Crustal structure in Nevada and southern Idaho from nuclear explosions

    Science.gov (United States)

    Pakiser, L.C.; Hill, D.P.

    1962-01-01

    The time of first arrival of seismic waves generated by 4 underground nuclear explosions at the Nevada Test Site (NTS) and recorded along a line extending north into southern Idaho is expressed as T0 = 0. 00 + Δ/3.0 (assumed), T1 = 0 .40 + Δ/6.03, and T2 = 6.15 + Δ/7.84, where time is in seconds and the shot-detector distance (Δ) is in km. Assuming constant velocities and horizontal layers, crustal thickness in the vicinity of NTS was determined to be 28 km. Delays in the traveltime segment T2, which represents Pn, indicate that the crust may thicken to 32 km in northern Nevada. A third phase, expressed as T3 = 14.48 + Δ/7.84, was also recognized and has arrival times appropriate for SPS. Amplitudes of Pn were determined at 7 places from recordings of seismic waves from one underground nuclear explosion (ANTLER).

  10. Investigation of lunar crustal structure and isostasy. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Thurber, C.H.

    1987-07-01

    The lunar mascon basins have strongly free air gravity anomalies, generally exceeding 100 milligals at an elevation of 100 km. The source of the anomalies is a combination of mantle uplift beneath the impact basins and subsequent infilling by high-density mare basalts. The relative contribution of these two components is still somewhat uncertain, although it is generally accepted that the amount of mantle uplift greatly exceeds the thickness of the basalts. Extensive studies have been carried out of the crustal structure of mare basins, based on gravity data, and their tectonic evolution, based on compressive and extensional tectonic features. The present study endeavored to develop a unified, self-consistent model of the lunar crust and lithosphere incorporating both gravity and tectonic constraints.

  11. Do Satellite Magnetic Anomaly Data Accurately Portray the Crustal Component?

    Science.gov (United States)

    Vonfrese, R. R. B.; Hinze, W. J. (Principal Investigator)

    1984-01-01

    Scalar aeromagnetic data obtained during the U.S. Naval Oceanographic Office (NOO)-Vector Magnetic Survey of the conterminous United States were upward continued by equivalent point source inversion and compared with POGO satellite magnetic anomaly and preliminary scalar MAGSAT data. Initial comparisons indicate that the upward continued NOO data is dominated by long wavelength (approximately equal to 1000 to 3000 km) anomalies which are not present in the satellite anomaly data. Thus, the comparison of the data sets is poor. Several possible sources for these differences are present in the data analysis chain. However, upon removal of these long wavelengths from the upward continued NOO data, a close comparison observed between the anomalies verifies that satellite magnetic anomaly data do portray the crustal component within a range of wavelengths from roughly 1000 km down to the resolution limit of the observations.

  12. Crustal deformations at permanent GPS sites in Denmark

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Knudsen, Per; Tscherning, Carl Christian

    2005-01-01

    The National Survey and Cadastre (KMS) is responsible for the geodetic definition of the reference network in Denmark. Permanent GPS stations play an important role in the monitoring and maintenance of the geodetic network. During 1998 and 1999 KMS established three permanent GPS station in Denmark......, SMID, SULD and BUDP. Using almost 4.5 years of continuous data from the Danish station and the Swedish station, ONSA, we analyse the daily GPS solution due to crustal deformation caused by glacial isostatic adjustment (GIA). Although, displacements due to GIA are only 1–3 mm/year at the Danish GPS...... sites, the current precision of positioning using GPS allows us to observe these effects. The modelled horizontal GIA velocities and the observed horizontal residuals obtained from GPS show almost the same direction for all station. However, the observed velocity residuals are larger than the modelled...

  13. GEODYNAMICAL MODELING OF CRUSTAL DEFORMATION OF THE NORTH CHINA BLOCK

    Institute of Scientific and Technical Information of China (English)

    LIN; Ge; ZHANG; Yan-hua; GUO; Feng; WANG; Yue-jun; FAN; Wei-ming

    2001-01-01

    The North China block,the western portion of the Sino-Korean Craton,is rounded by Yanshanian in the north and Qinling-Dabie orogenic belts in the south.The widespread development of extensional basins in this block indicates horizontal extension or continued thinning of a previousely thickened,trnstable lithosphere throughout the Mesozoic.In this paper,we attempt to simulate numerically the geodynamical process of the basin formation by using the mountain-basin evolution system.We assume that the formation of numerous sedimentary basins in the North China block is the result of the crustal extension,which destructs rapidly the previously thickened crust.……

  14. The crustal micro-deformation anomaly and the credible precursor*

    Institute of Scientific and Technical Information of China (English)

    张雁滨; 蒋骏; 钱家栋; 陈京; 和升棋; 张燕; 和平

    2002-01-01

    @@ What is a credible seismic precursor in observation of deformation A real seismic precursor ought to be resulted from the variations in the earth strain and stress. The deformation observation can provide the information during earthquake gestation and occurrence period for us. Usually the seismic precursors can be divided into field and epicentral region precursors. The precursor information is very useful for seismic prediction from epicentral region or near epicentral region. Micro-deformation observation mainly includes tilt, strain and gravity observation. Compared with GPS, geodesy and mobile deformation observation, micro-deformation (tilt, strain) shows the change of deformation which is continual in a limited volume with dominant observed range of 10(6~10(10 m. Because the variation of the crustal nature and cracking can be directly obtained by micro-deformation observation, it is an effective way to find middle-short term and short-term precursor.

  15. Crustal structure of the Eastern Alps and their foreland

    DEFF Research Database (Denmark)

    Grad, M.; Brückl, E.; Majdanski, M.;

    2009-01-01

    ) and are also characterized by variations in apparent velocity and amplitude. The Moho reflections are usually strong and well correlated, while Pn arrivals are only fragmentarily recorded. Detailed 2-D forward modelling of all refracted, post-critical and reflected phases, identified in the correlation process......) are distinct up to 60-90 km offset and are characterized by large variations in apparent velocity and amplitude. The contact between the Molasse basin and the Eastern Alps represents a barrier for seismic waves. Mid-crustal reflections (Pc) are usually recorded at short distance intervals (20-50 km......, was undertaken using a ray-tracing technique. The P-wave velocity in the crystalline upper crust of the Bohemian Massif and Molasse basin is about 6.15 km s-1, which is slightly higher than in the Alpine area (about 6.0 km s-1). Below the northern accretionary wedge of the Eastern Alps low-velocity sediments...

  16. CHARACTERISTICS OF CRUSTAL DEFORMATIONRELATED TO Ms8. 1 KUNLUNSHAN EARTHQUAKE

    Institute of Scientific and Technical Information of China (English)

    QiaoXuejun; WangQi; DuRuilin; ChenZongshi; YouXinzhao; TanKai

    2003-01-01

    The co-seismic and post-seismic deformation velocities of Ms 8. 1 Kunlunshan earthquake on Nov. 14, 2001 were calculated from the results of 1991—2001 GPS data and 4 repeated GPS surveys after the event. The result indicates the maximum co-seismic and post-seismic changes are 1.9 m and 0.08 m respectively. On the basis of the result of post-seismic velocity, we used an elastic dislocation model to inverse the crustal deformation characteristics of eastern Kunlun active fault. The result shows that the domain motion of eastern Kunlun fault is leftlateral and strike-slip. The trend of eastward motion for the southern block of Kunlun fault implies redistribution and reaccumulation of energy after the earthquake. It is possible that the seismicity will migrate to eastern region in the future according to the trend that strong earthquakes along Kunlun fault extended from west to east during the last several decades.

  17. Crustal structure of Australia from ambient seismic noise tomography

    Science.gov (United States)

    Saygin, Erdinc; Kennett, B. L. N.

    2012-01-01

    Surface wave tomography for Australian crustal structure has been carried out using group velocity measurements in the period range 1-32 s extracted from stacked correlations of ambient noise between station pairs. Both Rayleigh wave and Love wave group velocity maps are constructed for each period using the vertical and transverse component of the Green's function estimates from the ambient noise. The full suite of portable broadband deployments and permanent stations on the continent have been used with over 250 stations in all and up to 7500 paths. The permanent stations provide a useful link between the various shorter-term portable deployments. At each period the group velocity maps are constructed with a fully nonlinear tomographic inversion exploiting a subspace technique and the Fast Marching Method for wavefront tracking. For Rayleigh waves the continental coverage is good enough to allow the construction of a 3D shear wavespeed model in a two stage approach. Local group dispersion information is collated for a distribution of points across the continent and inverted for a 1D SV wavespeed profile using a Neighbourhood Algorithm method. The resulting set of 1D models are then interpolated to produce the final 3D wavespeed model. The group velocity maps show the strong influence of thick sediments at shorter periods, and distinct fast zones associated with cratonic regions. Below the sediments the 3D shear wavespeed model displays significant heterogeneity with only moderate correlation with surface tectonic features. For example, there is no evident expression of the Tasman Line marking the eastern edge of Precambrian outcrop. The large number of available inter-station paths extracted from the ambient noise analysis provide detailed shear wavespeed information for crustal structure across the Australian continent for the first time, including regions where there was no prior sampling because of difficult logistics.

  18. Constraining Moment Deficit Rate on Crustal Faults from Geodetic Data

    Science.gov (United States)

    Maurer, J.; Bradley, A. M.; Segall, P.

    2014-12-01

    Constraining moment deficit rates on crustal faults using geodetic data is currently an under-utilized but powerful method for estimating the potential seismic hazard presented by crustal faults. Two previous approaches to moment-bounding, bootstrapping and Metropolis-Hastings sampling, can both fail catastrophically when estimating the probability distribution of moment given data, p(Mo|d). Straightforward application of traditional Metropolis-Hastings sampling with uniform prior probabilities on slip leads to a mesh-dependent estimate of moment with a variance inversely related to the number of model elements. Moment thus estimated exhibits an "effective prior" on p(MO) that tends toward a delta function halfway between the bounds as the fault discretization becomes finer! Thus, it is incorrect to estimate the uncertainty in moment directly from the uncertainty in slip. Bootstrapping can produce optimistic bounds and give biased results. A third approach is functional moment bounding (FMB), which obtains bounds on moment by minimizing the data misfit over slip for all possible values of Mo and accepting only those values with a total misfit less than some threshold. We present a modified version of this method that creates a probability distribution function on Mo from the misfit and uses this pdf to obtain confidence bounds. We also present a fourth method that we term Probabilistic Moment Bounding (PMB) that we derive within a Bayesian framework and incorporate a smoothed slip prior. Both of these approaches produce conservative results and do not exhibit mesh dependence. We compare the results from FMB and PMB to those obtained from other methods and assess the results.

  19. Crustal anisotropy from tectonic tremor in Guerrero, Mexico

    Science.gov (United States)

    Huesca-Pérez, Eduardo; Valenzuela, Raúl W.; Ortega, Roberto

    2016-06-01

    We present new shear wave anisotropy measurements in the continental crust in northern Guerrero obtained from tectonic tremor. Measurements of crustal anisotropy had not been performed in this area due to the lack of seismicity. However, tectonic tremor activity is abundant and offers an opportunity to determine anisotropy parameters. Polarization and splitting analyses were performed using broadband three-component seismograms. Results show that splitting times range between 0.07 and 0.36 s. These values are similar to the splitting magnitudes typically observed in the continental crust. The state of stress in the continental crust was investigated by inverting focal mechanisms determined in this study, and also from previous structural geology studies. Unfortunately, no stress measurements were possible in the area where tectonic tremor occurs. It was determined that, to the south of the study area, near the Pacific coast, and to the north, in the volcanic arc, the maximum compressive stress shows a general E-W trend. The fast polarization directions are oriented NE-SW and are oblique to the observed maximum compressive stress surrounding the study area. Thus, the relationship between the maximum compressive stress and the observed anisotropic pattern cannot be conclusively established. Several factors such as nonlinear strain in the continental crust as a result of Slow Slip Events, variations of pore fluid pressure, deep crustal mineralogy, and/or upper crust foliations and schistosity could be inducing the observed anisotropy pattern. In general, the fast axes tend to parallel the regional Laramide and Tertiary folds-and-thrusts which strike NNE-SSW. This system of folds-and-thrusts is highly foliated in low-grade schist and seems likely to control the anisotropic structure observed within the tectonic tremor region in Guerrero.

  20. Observatory crustal magnetic biases during CHAMP satellite mission

    Directory of Open Access Journals (Sweden)

    G. Verbanac

    2015-01-01

    Full Text Available Taking advantage of nine years of CHAMP satellite mission (June 2000–August 2009, we investigate the temporal evolution of the observatory monthly crustal magnetic biases. To determine biases we compute X (northward, Y (eastward and Z (vertically downward monthly means from 42 observatory one-minute or hourly values, and compare them to synthetic monthly means obtained from a GRIMM3 core field model (V. Lesur, personal communication, 2014. Both short period variations and long term trends in the monthly bias time series are analyzed. A comparison with biases based on MAGSAT and Ørsted satellite data, related to the 1979.92 and 1992.92 epochs is performed. Generally, the larger biases averaged over nine years and the larger differences between biases based on different models are found in Z component. This can be the signature of the induced magnetic fields. Although annual trends in most bias series are observed, no clear evidence that the constant crustal field changed significantly over the studied period is found. Time series of monthly biases exhibit distinct oscillatory pattern in the whole time span, which we assign to the external field contributions. The amplitudes of these variations are linked with the phase of the solar cycle, being significantly larger in the period 2000–2005 than in the period 2006–2009. Clear semi-annual variations are evident in all components, with extremes in spring and fall months of each year. Common external field pattern is found for European monthly biases. A dependence of the bias monthly variations on geomagnetic latitudes is not found for the non-European observatories. The results from this study represent a base to further exploit the observatory and repeat stations magnetic biases together with the data from the new satellite mission SWARM.

  1. Komsomolskaya diamondiferous eclogites: evidence for oceanic crustal protoliths

    Science.gov (United States)

    Pernet-Fisher, John F.; Howarth, Geoffrey H.; Liu, Yang; Barry, Peter H.; Carmody, Laura; Valley, John W.; Bodnar, Robert J.; Spetsius, Zdislav V.; Taylor, Lawrence A.

    2014-03-01

    The Komsomolskaya kimberlite is one of numerous (>1,000) kimberlite pipes that host eclogite xenoliths on the Siberian craton. Eclogite xenoliths from the adjacent Udachnaya kimberlite pipe have previously been geochemically well characterized; however, data from surrounding diamond-bearing kimberlite pipes from the center of the craton are relatively sparse. Here, we report major- and trace-element data, as well as oxygen isotope systematics, for mineral separates of diamondiferous eclogite xenoliths from the Komsomolskaya kimberlite, suggesting two distinct subgroups of a metamorphosed, subducted oceanic crustal protolith. Using almandine contents, this suite can be divided into two subgroups: group B1, with a high almandine component (>20 mol%) and group B2, with a low almandine component (oxygen isotope values, which are interpreted to reflect isotopic exchange with seawater at low temperatures (oxygen isotope values, suggesting an origin deep within the crustal pile, where little-to-no interaction with hydrothermal fluids has occurred. Major-element systematics were reconstructed based on mineral modes; group B1 eclogites have higher MgO wt% and lower SiO2 wt%, with respect to typical oceanic basalts, reflecting a partial melting event during slab subduction. Calculated residues from batch partial melt modeling of a range of Precambrian basalts overlap with group B1 trace-element chemistry. When taken together with the respective partial melt trajectories, these melting events are clearly linked to the formation of Tonalite-Trondhjemite-Granodiorite (TTG) complexes. As a result, we propose that many, if not all, diamondiferous eclogite xenoliths from Komsomolskaya represent mantle `restites' that preserve chemical signatures of Precambrian oceanic crust.

  2. GPS derived Crustal Deformation and Strain determination in India

    Directory of Open Access Journals (Sweden)

    Abhay P. Singh,

    2011-06-01

    Full Text Available The theory of Plate tectonics has revolutionized the way thinking about the processes of Earth. According to this theory, the surface of the Earth is broken into large plates. The size and position of these plates change over time. The edges of these plates, where they move against each other, are sites of intense tectonic activity, suchas earthquakes, volcanism, and mountain building. It is well known that Indian Plate is currently moving in the northeast direction, while the Eurasian Plate is moving north. This is causing the Indian and Eurasian Plate to deform at the point of contact besides its interior. Modern geophysical and space geodetic techniques such asseismology and GPS (Global Positioning system, have become important tools in the study of the deformation in the Earth due to tectonic processes, leading to earthquakes. Geodesy has provided an important role for plate tectonics study with high temporal resolution of the plate movements, particular from space technologies such as GPS and VLBI. The Global Positioning System (GPS provides accurate measurements of the rate of displacement of crustal. Indeed, the GPS velocity field can only be compared to finite strain if one assumes adeformation mechanism and that the style of deformation has been the same over long periods of geological time. For study of crustal deformation National Center of Mineralogy and Petrology, University of Allahabad, Allahabad installed highly efficient and accurate LEICA GRX1200 Pro receiver at Ghoorpur near to Allahabad. This instrument is also equipped withMET3A sensor to record pressure, temperature, humidity at regular interval of 30 second. The Latitude and longitude of the GPS sites is 25.21N, 81.28E.

  3. Crustal differentiation on Earth and Mars from Potassium and Thorium multi-scale distributions

    Science.gov (United States)

    Baratoux, D.; Jessell, M. W.; Fall, M.; Ndiaye, P. M.; Vanderhaeghe, O.; Baratoux, L.; MacFarlane, H.; Boamah, K.; André-Mayer, A. S.

    2015-12-01

    Potassium (K) and Thorium (Th) are useful tracers of crustal differentiation and secondary processes as these elements concentrate in melts during magmatic processes but are not equally mobile during alteration. They may be mapped by airborne or orbiting gamma ray spectrometers measuring the natural activity of 232Th and 40K. Such data are commonly used in geological mapping and mineral exploration on the Earth and have been produced for other planets. However, the direct comparison of spatially averaged concentrations measured remotely with bulk rock analyses of surface samples may be challenging. In the case of Mars, there is a notable shift between K, Th concentrations in Martian meteorites with those from orbital data [1]. We observe a similar discrepancy when airborne radiometric surveys on portions of the continental crusts are statistically compared with bulk analyses of rock samples. We argue that the generally right-skewed characteristics of the distributions of K, Th concentrations for the terrestrial crust may be extrapolated to the Martian crust. We illustrate how such distributions transform with resolution in remote sensing data, and evolve as normal laws as expected from the central limit theorem. This well-known statistical effect offers a simple explanation for the shift between K, Th concentrations in meteorites and orbital data. The shift would reflect the existence of disseminated occurrences of differentiated rocks on Mars, adding to other pieces of evidence for magmatic diversity [2-4]. The characteristics of the distribution of K and Th within the GRS footprint appears to be critical for a correct interpretation or these data, but such distribution cannot be directly documented on Mars due to the lack of appropriate data. However, interpretation of airborne remote sensing data sets on Earth will clearly benefit from the characterization of the spatial organization of K and Th concentrations at the outcrop scale (1 - 100 m), which is now

  4. Crustal structure of the rifted volcanic margins and uplifted plateau of Western Yemen from receiver function analysis

    Science.gov (United States)

    Ahmed, Abdulhakim; Tiberi, Christel; Leroy, Sylvie; Stuart, Graham W.; Keir, Derek; Sholan, Jamal; Khanbari, Khaled; Al-Ganad, Ismael; Basuyau, Clémence

    2013-06-01

    We analyse P-wave receiver functions across the western Gulf of Aden and southern Red Sea continental margins in Western Yemen to constrain crustal thickness, internal crustal structure and the bulk seismic velocity characteristics in order to address the role of magmatism, faulting and mechanical crustal thinning during continental breakup. We analyse teleseismic data from 21 stations forming the temporary Young Conjugate Margins Laboratory (YOCMAL) network together with GFZ and Yemeni permanent stations. Analysis of computed receiver functions shows that (1) the thickness of unextended crust on the Yemen plateau is ˜35 km; (2) this thins to ˜22 km in coastal areas and reaches less than 14 km on the Red Sea coast, where presence of a high-velocity lower crust is evident. The average Vp/Vs ratio for the western Yemen Plateau is 1.79, increasing to ˜1.92 near the Red Sea coast and decreasing to 1.68 for those stations located on or near the granitic rocks. Thinning of the crust, and by inference extension, occurs over a ˜130-km-wide transition zone from the Red Sea and Gulf of Aden coasts to the edges of the Yemen plateau. Thinning of continental crust is particularly localized in a <30-km-wide zone near the coastline, spatially co-incident with addition of magmatic underplate to the lower crust, above which on the surface we observe the presence of seaward dipping reflectors (SDRs) and thickened Oligo-Miocene syn-rift basaltic flows. Our results strongly suggest the presence of high-velocity mafic intrusions in the lower crust, which are likely either synrift magmatic intrusion into continental lower crust or alternatively depleted upper mantle underplated to the base of the crust during the eruption of the SDRs. Our results also point towards a regional breakup history in which the onset of rifting was synchronous along the western Gulf of Aden and southern Red Sea volcanic margins followed by a second phase of extension along the Red Sea margin.

  5. Density heterogeneity of the upper mantle beneath Siberia from satellite gravity and a new regional crustal model

    DEFF Research Database (Denmark)

    Herceg, Matija; Thybo, Hans; Artemieva, Irina;

    2013-01-01

    on regional and global crustal models. We analyze how uncertainties and errors in the crustal model propagate from crustal densities to mantle residual gravity anomalies and the density model of the upper mantle. The new regional density model for the Siberian craton and the West Siberian Basin complements...

  6. The crustal structure of the Southern Nain and Makkovik Provinces of Labrador deriverd from seismic refraction data

    DEFF Research Database (Denmark)

    Funck, T.; Hansen, A.K.; Reid, Ian Derry;

    2008-01-01

    the crust has P-wave velocity 5.8 -6.9 km/s. Further south, upper crustal velocities iand the Poisson's ratio increase. This zone correlates with a gravity low interpreted as the NPS. The upper crustal velocities are compatible with the  NPS. There is a  lower crustal reflector under the NPS...

  7. Influence of joint angular velocity on electrically evoked concentric force potentiation induced by stretch-shortening cycle in young adults

    OpenAIRE

    Fukutani, Atsuki; Kurihara, Toshiyuki; Isaka, Tadao

    2015-01-01

    Background During a stretch- shortening cycle (SSC), muscle force attained during concentric contractions (shortening phase) is potentiated by the preceding eccentric contractions (lengthening phase). The purpose of this study was to examine the influence of joint angular velocity on force potentiation induced by SSC (SSC effect). Findings Twelve healthy men (age, 24.2 ± 3.2 years; height, 1.73 ± 0.05 m; body mass, 68.1 ± 11.0 kg) participated in this study. Ankle joint angle was passively mo...

  8. Holographic representation of local bulk operators

    CERN Document Server

    Hamilton, A; Lifschytz, G; Lowe, D A; Hamilton, Alex; Kabat, Daniel; Lifschytz, Gilad; Lowe, David A.

    2006-01-01

    The Lorentzian AdS/CFT correspondence implies a map between local operators in supergravity and non-local operators in the CFT. By explicit computation we construct CFT operators which are dual to local bulk fields in the semiclassical limit. The computation is done for general dimension in global, Poincare and Rindler coordinates. We find that the CFT operators can be taken to have compact support in a region of the complexified boundary whose size is set by the bulk radial position. We show that at finite N the number of independent commuting operators localized within a bulk volume saturates the holographic bound.

  9. Bulk viscosity in holographic Lifshitz hydrodynamics

    OpenAIRE

    Carlos Hoyos; Bom Soo Kim; Yaron Oz

    2014-01-01

    We compute the bulk viscosity in holographic models dual to theories with Lifshitz scaling and/or hyperscaling violation, using a generalization of the bulk viscosity formula derived in arXiv:1103.1657 from the null focusing equation. We find that only a class of models with massive vector fields are truly Lifshitz scale invariant, and have a vanishing bulk viscosity. For other holographic models with scalars and/or massless vector fields we find a universal formula in terms of the dynamical ...

  10. Bulk viscosity in holographic Lifshitz hydrodynamics

    International Nuclear Information System (INIS)

    We compute the bulk viscosity in holographic models dual to theories with Lifshitz scaling and/or hyperscaling violation, using a generalization of the bulk viscosity formula derived in arXiv:1103.1657 from the null focusing equation. We find that only a class of models with massive vector fields are truly Lifshitz scale invariant, and have a vanishing bulk viscosity. For other holographic models with scalars and/or massless vector fields we find a universal formula in terms of the dynamical exponent and the hyperscaling violation exponent

  11. Bulk viscosity of hot and dense hadrons

    International Nuclear Information System (INIS)

    The bulk viscosity of hot and dense hadrons has been estimated within the framework of hadronic resonance gas model. We observe that the bulk viscosity to entropy ratio increases faster with temperature for higher μB. The magnitude of ζ is more at high μB. This results will have crucial importance for fire-ball produced at low energy nuclear collisions (FAIR, NICA). We note that the bulk to shear viscosity ratio remains above the bound set by AdS/CFT

  12. Palliative sedation in advanced cancer patients: Does it shorten survival time? - A systematic review

    Directory of Open Access Journals (Sweden)

    B Barathi

    2013-01-01

    Full Text Available Background: Patients with advanced cancer often suffer from multiple refractory symptoms in the terminal phase of their life. Palliative sedation is one of the few ways to relieve this refractory suffering. Objectives: This systematic review investigated the effect of palliative sedation on survival time in terminally ill cancer patients. Materials and Methods: Six electronic databases were searched for both prospective and retrospective studies which evaluated the effect of palliative sedation on survival time. Only those studies which had a comparison group that did not receive palliative sedation were selected for the review. Abstracts of all retrieved studies were screened to include the most relevant studies and only studies which met inclusion criteria were selected. References of all retrieved studies were also screened for relevant studies. Selected studies were assessed for quality and data extraction was done using the structured data extraction form. Results: Eleven studies including four prospective and seven retrospective studies were identified. Mean survival time (MST was measured as the time from last admission until death. A careful analysis of the results of all the 11 studies indicated that MST of sedated and non-sedated group was not statistically different in any of the studies. Conclusion: This systematic review supports the fact that palliative sedation does not shorten survival in terminally ill cancer patients. However, this conclusion needs to be taken with consideration of the methodology, study design, and the population studied of the included studies in this review.

  13. The implementation of an Intensive Care Information System allows shortening the ICU length of stay.

    Science.gov (United States)

    Levesque, Eric; Hoti, Emir; Azoulay, Daniel; Ichai, Philippe; Samuel, Didier; Saliba, Faouzi

    2015-04-01

    Intensive care information systems (ICIS) implemented in intensive care unit (ICU) were shown to improve patient safety, reduce medical errors and increase the time devolved by medical/nursing staff to patients care. Data on the real impact of ICIS on patient outcome are scarce. This study aimed to evaluate the effects of ICIS on the outcome of critically-ill patients. From January 2004 to August 2006, 1,397 patients admitted to our ICU were enrolled in this observational study. This period was divided in two phases: before the implementation of ICIS (BEFORE) and after implementation of ICIS (AFTER). We compared standard ICU patient's outcomes: mortality, length of stay in ICU, hospital stay, and the re-admission rate depending upon BEFORE and AFTER. Although patients admitted AFTER were more severely ill than those of BEFORE (SAPS II: 32.1±17.5 vs. 30.5±18.5, p=0.014, respectively), their ICU length of stay was significantly shorter (8.4±15.2 vs. 6.8±12.9 days; p=0.048) while the re-admission rate and mortality rate were similar (4.4 vs. 4.2%; p=0.86, and 9.6 vs 11.2% p=0.35, respectively) in patients admitted AFTER. We observed that the implementation of ICIS allowed shortening of ICU length of stay without altering other patient outcomes. PMID:24973014

  14. Accelerated Telomere Shortening and Replicative Senescence in Human Fibroblasts Overexpressing Mutant and Wild Type Lamin A

    Science.gov (United States)

    Huang, Shurong; Risques, Rosa Ana; Martin, George M.; Rabinovitch, Peter S.; Oshima, Junko

    2008-01-01

    LMNA mutations are responsible for a variety of genetic disorders, including muscular dystrophy, lipodystrophy, and certain progeroid syndromes, notably Hutchinson-Gilford Progeria. Although a number of clinical features of these disorders are suggestive of accelerated aging, it is not known whether cells derived from these patients exhibit cellular phenotypes associated with accelerated aging. We examined a series of isogenic skin fibroblast lines transfected with LMNA constructs bearing known pathogenic point mutations or deletion mutations found in progeroid syndromes. Fibroblasts overexpressing mutant lamin A exhibited accelerated rates of loss of telomeres and shortened replicative lifespans, in addition to abnormal nuclear morphology. To our surprise, these abnormalities were also observed in lines overexpressing wild-type lamin A. Copy number variants are common in human populations; those involving LMNA, whether arising meiotically or mitotically, might lead to progeroid phenotypes. In an initial pilot study of 23 progeroid cases without detectible WRN or LMNA mutations, however, no cases of altered LMNA copy number were detected. Nevertheless, our findings raise a hypothesis that changes in lamina organization may cause accelerated telomere attrition, with different kinetics for overexpession of wild-type and mutant lamin A, which leads to rapid replicative senescence and progroid phenotypes. PMID:17870066

  15. Designing cobalt chromium removable partial dentures for patients with shortened dental arches: a pilot survey.

    Science.gov (United States)

    Nassani, M Z; Devlin, H; Tarakji, B; McCord, J F

    2011-08-01

    The aim of this survey was to investigate the quality of prescription for the fabrication of cobalt chromium removable partial dentures (RPDs) that are used to extend the shortened dental arches (SDAs). A survey of four commercial dental laboratories located in northern England was conducted. The target of this survey was cobalt chromium RPDs that were requested to restore SDAs comprising the anterior teeth and 2-4 premolars. Dentists' prescriptions were scrutinised, and a special data collection form was completed accordingly. A total of 94 dentists' prescriptions and associated SDA casts were examined. Almost all the requested cobalt chromium RPDs were clasp-retained RPDs (97%). Scrutinising the 91 prescriptions for clasp-retained cobalt chromium RPDs showed that dentists' prescriptions did not have any instructions about the design of the partial denture in a considerable proportion of the cases (32%). Teeth to be clasped were identified clearly in 45% of the prescriptions. A majority of the dentists (64%) failed to provide any instructions about the design of the rests to be placed on the most posterior premolar abutment teeth. A considerable proportion of the dentists delegated the task of selecting the type of the major connector to the dental technician (41%). Only 21 (23%) of the examined casts had clearly defined rest seat preparation. The outcome of this pilot survey shows inadequate quality of prescription in designing RPDs for patients with SDAs. This finding has an ethical and clinical bearing and does not fit with current legal guidelines relevant to designing RPDs. PMID:21175736

  16. Update: Shortened Interval for Postvaccination Serologic Testing of Infants Born to Hepatitis B-Infected Mothers.

    Science.gov (United States)

    Schillie, Sarah; Murphy, Trudy V; Fenlon, Nancy; Ko, Stephen; Ward, John W

    2015-10-01

    Infants born to hepatitis B-infected mothers receive postexposure prophylaxis to reduce their risk for perinatal hepatitis B virus (HBV) infection. Postexposure prophylaxis consists of hepatitis B (HepB) vaccine and hepatitis B immune globulin administered within 12 hours of birth, followed by completion of the 3-dose or 4-dose HepB vaccine series. Postvaccination serologic testing (PVST) assesses an infant's response to HepB vaccination and has typically occurred at age 9-18 months. This report provides a CDC update recommending shortening the interval for PVST from age 9-18 months to age 9-12 months. Providers should order PVST (consisting of hepatitis B surface antigen [HBsAg] and antibody to HBsAg [anti-HBs]) for infants born to HBsAg-positive mothers at age 9-12 months (or 1-2 months after the final dose of the vaccine series, if the series is delayed). This recommendation was prompted by the discontinuation of production of Hib/HepB vaccine (Comvax) and new data from the Enhanced Perinatal Hepatitis B Prevention Program supporting PVST 1・2 months after receipt of the last HepB vaccine dose, and at age ≥9 months. PMID:26447601

  17. Stability of lower limb minimal perceptible difference in floor height during hopping stretch-shortening cycles

    International Nuclear Information System (INIS)

    This study aimed to investigate a novel proprioceptive test, the minimal perceptible difference (MPD) test, that assessed participants' ability to perceive floor height changes whilst hopping. Sixteen healthy volunteers performed multiple trials of five hops on a custom built sleigh apparatus that permitted a floor height change (range 3 –48 mm) or no change, as dictated by a structured searching algorithm. Minimum detected surface height change was recorded for eight different hopping conditions (factors–technique: alternate/bilateral hopping; side: dominant/non-dominant; direction of change: up/down) over two separate testing occasions. Within day and between day reliability were assessed using intraclass correlation coefficient (ICC) and 95% confidence intervals. The only factor which significantly influenced the sensitivity of subjects to detect changes in floor height was the hopping technique (bilateral or alternate). The mean MPD was significantly lower (p < 0.0001) for the bilateral hopping technique (MPDmean = 15.7 mm) when compared to the alternate hopping technique (MPDmean = 26.6 mm). All bilateral hopping techniques yielded moderate to high ICC for within (0.60–0.79) and between day (0.67–0.88) reliability. The results suggest that the bilateral hopping MPD assessment is a reliable, functional assessment of proprioception sensitivity during repeated stretch-shortening cycles that may better reflect human gait than established static assessment. Increased sensitivity to detection during bilateral hopping may reflect strategy dependent utility of proprioceptive information. (paper)

  18. Tooth loss as a predictor of shortened longevity: exploring the hypothesis.

    Science.gov (United States)

    Friedman, Paula K; Lamster, Ira B

    2016-10-01

    Many factors contribute to human tooth loss, including oral hygiene practices, trauma, smoking, health status, socio-economic status and individual preferences. Loss of teeth impairs quality-of-life measures, including the eating of most foods that require full masticatory function. A recent study of centenarians found that at age 65-74 years, those who lived to be 100 had a lower rate of edentulism than did younger members of their birth cohort at ages 65-74 years. Oral health was consistent with compression of morbidity toward the end of life. This article explores the hypothesis that factors associated with oral disease and noncommunicable diseases may increase the risk of tooth loss and lead to diminished longevity as a result of multifactorial interactions. It specifically addresses two critical questions. The first is: 'Can we conclude that the number of teeth in aging humans can affect longevity and life expectancy?' The answer is yes. The second is: 'Is tooth loss a predictor of shortened longevity?' Again, the answer is yes. Edentulism and partial edentulism are discussed as a disability, and how the philosophy/belief systems of dental providers and patients toward retaining teeth influences the outcome of tooth loss is also examined. Osteoporosis and cognitive impairment provide examples of modifying risk factors. PMID:27501497

  19. A diversity compression and combining technique based on channel shortening for cooperative networks

    KAUST Repository

    Hussain, Syed Imtiaz

    2012-02-01

    The cooperative relaying process with multiple relays needs proper coordination among the communicating and the relaying nodes. This coordination and the required capabilities may not be available in some wireless systems where the nodes are equipped with very basic communication hardware. We consider a scenario where the source node transmits its signal to the destination through multiple relays in an uncoordinated fashion. The destination captures the multiple copies of the transmitted signal through a Rake receiver. We analyze a situation where the number of Rake fingers N is less than that of the relaying nodes L. In this case, the receiver can combine N strongest signals out of L. The remaining signals will be lost and act as interference to the desired signal components. To tackle this problem, we develop a novel signal combining technique based on channel shortening principles. This technique proposes a processing block before the Rake reception which compresses the energy of L signal components over N branches while keeping the noise level at its minimum. The proposed scheme saves the system resources and makes the received signal compatible to the available hardware. Simulation results show that it outperforms the selection combining scheme. © 2012 IEEE.

  20. A signal combining technique based on channel shortening for cooperative sensor networks

    KAUST Repository

    Hussain, Syed Imtiaz

    2010-06-01

    The cooperative relaying process needs proper coordination among the communicating and the relaying nodes. This coordination and the required capabilities may not be available in some wireless systems, e.g. wireless sensor networks where the nodes are equipped with very basic communication hardware. In this paper, we consider a scenario where the source node transmits its signal to the destination through multiple relays in an uncoordinated fashion. The destination can capture the multiple copies of the transmitted signal through a Rake receiver. We analyze a situation where the number of Rake fingers N is less than that of the relaying nodes L. In this case, the receiver can combine N strongest signals out of L. The remaining signals will be lost and act as interference to the desired signal components. To tackle this problem, we develop a novel signal combining technique based on channel shortening. This technique proposes a processing block before the Rake reception which compresses the energy of L signal components over N branches while keeping the noise level at its minimum. The proposed scheme saves the system resources and makes the received signal compatible to the available hardware. Simulation results show that it outperforms the selection combining scheme. ©2010 IEEE.

  1. Relationships between muscle power output using the stretch-shortening cycle and eccentric maximum strength.

    Science.gov (United States)

    Miyaguchi, Kazuyoshi; Demura, Shinichi

    2008-11-01

    This study aimed to examine the relationships between muscle power output using the stretch-shortening cycle (SSC) and eccentric maximum strength under elbow flexion. Eighteen young adult males pulled up a constant light load (2 kg) by ballistic elbow flexion under the following two preliminary conditions: 1) the static relaxed muscle state (SR condition), and 2) using the SSC with countermovement (SSC condition).Muscle power was determined from the product of the pulling velocity and the load mass by a power measurement instrument that adopted the weight-loading method. We assumed the pulling velocity to be the subject's muscle power parameters as a matter of convenience, because we used a constant load. The following two parameters were selected in reference to a previous study: 1) peak velocity (m x s(-1)) (peak power) and 2) 0.1-second velocity during concentric contraction (m x s(-1)) (initial power). Eccentric maximum strength by elbow flexion was measured by a handheld dynamometer.Initial power produced in the SSC condition was significantly larger than that in the SR condition. Eccentric maximum strength showed a significant and high correlation (r = 0.70) with peak power in the SSC condition but not in the SR condition. Eccentric maximum strength showed insignificant correlations with initial power in both conditions. In conclusion, it was suggested that eccentric maximum strength is associated with peak power in the SSC condition, but the contribution of the eccentric maximum strength to the SSC potentiation (initial power) may be low.

  2. Deciphering oblique shortening of central Alborz in Iran using geodetic data

    Science.gov (United States)

    Vernant, Ph.; Nilforoushan, F.; Chéry, J.; Bayer, R.; Djamour, Y.; Masson, F.; Nankali, H.; Ritz, J.-F.; Sedighi, M.; Tavakoli, F.

    2004-06-01

    The Alborz is a narrow (100 km) and elevated (3000 m) mountain belt which accommodates the differential motion between the Sanandaj-Sirjan zone in central Iran and the South Caspian basin. GPS measurements of 12 geodetic sites in Central Alborz between 2000 and 2002 allow to constrain the motion of the belt with respect to western Eurasia. One site velocity on the Caspian shoreline suggests that the South Caspian basin moves northwest at a rate of 6±2 mm/year with respect to western Eurasia. North-South shortening across the Alborz occurs at 5±2 mm/year. To the South, deformation seems to extend beyond the piedmont area, probably due to active thrusting on the Pishva fault. We also observe a left-lateral shear of the overall belt at a rate of 4±2 mm/year, consistent with the geological motion observed along E-W active strike-slip faults inside the belt (e.g., the Mosha fault).

  3. Reliability and consistency of plantarflexor stretch-shortening cycle function using an adapted force sledge apparatus

    International Nuclear Information System (INIS)

    There are various limitations to existing methods of studying plantarflexor stretch-shortening cycle (SSC) function and muscle-tendon unit (MTU) mechanics, predominantly related to measurement validity and reliability. This study utilizes an innovative adaptation to a force sledge which isolates the plantarflexors and ankle for analysis. The aim of this study was to determine the sledge loading protocol to be used, most appropriate method of data analysis and measurement reliability in a group of healthy, non-injured subjects. Twenty subjects (11 males, 9 females; age: 23.5 ±2.3 years; height: 1.73 ±0.08 m; mass: 74.2 ±11.3 kg) completed 11 impacts at five different loadings rated on a scale of perceived exertion from 1 to 5, where 5 is a loading that the subject could only complete the 11 impacts using the adapted sledge. Analysis of impacts 4–8 or 5–7 using loading 2 provided consistent results that were highly reliable (single intra-class correlation, ICC > 0.85, average ICC > 0.95) and replicated kinematics found in hopping and running. Results support use of an adapted force sledge apparatus as an ecologically valid, reliable method of investigating plantarflexor SSC function and MTU mechanics in a dynamic controlled environment. (paper)

  4. Active shortening within the Himalayan orogenic wedge implied by the 2015 Gorkha earthquake

    Science.gov (United States)

    Whipple, Kelin X.; Shirzaei, Manoochehr; Hodges, Kip V.; Ramon Arrowsmith, J.

    2016-09-01

    Models of Himalayan neotectonics generally attribute active mountain building to slip on the Himalayan Sole Thrust, also termed the Main Himalayan Thrust, which accommodates underthrusting of the Indian Plate beneath Tibet. However, the geometry of the Himalayan Sole Thrust and thus how slip along it causes uplift of the High Himalaya are unclear. We show that the geodetic record of the 2015 Gorkha earthquake sequence significantly clarifies the architecture of the Himalayan Sole Thrust and suggests the need for revision of the canonical view of how the Himalaya grow. Inversion of Gorkha surface deformation reveals that the Himalayan Sole Thrust extends as a planar gently dipping fault surface at least 20-30 km north of the topographic front of the High Himalaya. This geometry implies that building of the high range cannot be attributed solely to slip along the Himalayan Sole Thrust over a steep ramp; instead, shortening within the Himalayan wedge is required to support the topography and maintain rapid rock uplift. Indeed, the earthquake sequence may have included a moderate rupture (Mw 6.9) on an out-of-sequence thrust fault at the foot of the High Himalaya. Such internal deformation is an expected response to sustained, focused rapid erosion, and may be common to most compressional orogens.

  5. NEW INSIGHTS INTO THE THEORY OF CROSS-BRIDGE TENSION OF STEADILY SHORTENING AND STRETCHING MUSCLES

    Directory of Open Access Journals (Sweden)

    KOKSHENEV V.B.

    2015-01-01

    Full Text Available Despite the great success, seminal Huxley's sliding filament model broadly fails to explain the steady state behavior of stretched activated skeletal muscles. Here, a new self-consistent solution to the fundamental kinetic equation for the distribution of actin-myosin linkages (cross-bridges is proposed in light of the generalized thermodynamic theory of fluctuations, thus substituting the transition state theory traditionally used for the transition rates. The unified description for mechanism of the force output in both shortening and stretching regimes is attributed to the interplay between the uniformly-state distributed, thermodynamically equilibrated myosin heads attached to actin filaments and asymmetrically-state distributed, mechanically equilibrated rotating myosin heads. The crossover between two steady regimes is associated with a reconstruction of the cross-bridge domains and change their attach-detach rates, leaving unchanged basic mechanical characteristics. Theory suggests a unified generic force-velocity equation, using only a single combination of the cross-bridge parameters for each regime, while Huxley's approach (1957 as well as its subsequent modifications, requires four adjustable parameters to fit the same data.

  6. Urban environment shortens telomere length in nestling great tits, Parus major.

    Science.gov (United States)

    Salmón, P; Nilsson, J F; Nord, A; Bensch, S; Isaksson, C

    2016-06-01

    Urban environments are expanding rapidly, and with urbanization come both challenges and opportunities for wildlife. Challenges include combating the anthropogenic disturbances such as light, noise and air pollution and lower availability of natural food sources. The benefits are many, including the availability of anthropogenic food sources, breeding boxes and warmer temperatures. Thus, depending on the context, urbanization can have both positive and negative effects on fitness related traits. It is well known that early-life conditions can have lifelong implications on fitness; little is however known about development in urban environments. We reciprocally cross-fostered urban and rural nestling great tits (Parus major L.) to study how growing up in an urban versus rural habitat affected telomere length (TL)-a suggested biomarker of longevity. We show, for the first time, that growing up in an urban environment significantly shortens TL, independently of natal origin (i.e. urban or rural). This implies that the urban environment imposes a challenge to developing birds, with potentially irreversible effects on lifespan. PMID:27303051

  7. Pinealectomy shortens resynchronisation times of house sparrow ( Passer domesticus) circadian rhythms

    Science.gov (United States)

    Kumar, Vinod; Gwinner, Eberhard

    2005-09-01

    In many birds periodic melatonin secretion by the pineal organ is essential for the high-amplitude self-sustained output of the circadian pacemaker, and thus for the persistence of rhythmicity in 24 h oscillations controlled by it. The elimination of the pineal melatonin rhythm, or a reduction of its amplitude, renders the circadian pacemaker a less self-sustained, often highly damped, oscillatory system. A reduction in the degree of self-sustainment of a rhythm should not only increase its range of entrainment but also shorten the resynchronization times following phase-shifts of the zeitgeber. This hypothesis has not yet been directly tested. We therefore carried out the present study in which house sparrows (Passer domesticus) were subjected to both 6-h advance and 6-h delay phase-shifts of the light-dark cycle before and after the pinealectomy, and the rhythms in locomotion and feeding were recorded. The results indicate that following the delay, but not the advance, phase shift, resynchronization times were significantly shorter after pinealectomy. The dependence of resynchronization times on the presence or absence of the pineal organ is not only of theoretical interest but might also be of functional significance in the natural life of birds. A reduction or elimination of the amplitude of the melatonin secretion rhythm by the pineal organ might be responsible for faster adjustment to changes in zeitgeber conditions in nature.

  8. Fatigue and muscle-tendon stiffness after stretch-shortening cycle and isometric exercise.

    Science.gov (United States)

    Toumi, Hechmi; Poumarat, Georges; Best, Thomas M; Martin, Alain; Fairclough, John; Benjamin, Mike

    2006-10-01

    The purpose of the present study was to compare vertical jump performance after 2 different fatigue protocols. In the first protocol, subjects performed consecutive sets of 10 repetitions of stretch-shortening cycle (SSC) contractions. In the second protocol, successive sets of 10 repetitions of isometric contractions were performed for 10 s with the knee at 90 degrees of flexion. The exercises were stopped when the subjects failed to reach 50% of their maximum voluntary isometric contractions. Maximal isometric force and maximal concentric power were assessed by performing supine leg presses, squat jumps, and drop jumps. Surface EMG was used to determine changes in muscle activation before and after fatigue. In both groups, the fatigue exercises reduced voluntary isometric force, maximal concentric power, and drop jump performance. Kinematic data showed a decrease in knee muscle-tendon stiffness accompanied by a lengthened ground contact time. EMG analysis showed that the squat and drop jumps were performed similarly before and after the fatigue exercise for both groups. Although it was expected that the stiffness would decrease more after SSC than after isometric fatigue (as a result of a greater alteration of the reflex sensitivity SSC), our results showed that both protocols had a similar effect on knee muscle stiffness during jumping exercises. Both fatigue protocols induced muscle fatigue, and the decrease in jump performance was linked to a decrease in the strength and stiffness of the knee extensor muscles. PMID:17111011

  9. Chemical protection against life shortening and radio-induced leukemias and cancers

    International Nuclear Information System (INIS)

    The advantage gained on the long term survival and the induction of leukemias and cancers in mice exposed to a single dose of ionizing radiation by a combination of radiochemical protectors, are examined. The results show clearly that chemical protective compounds protect mice against radiation-induced life-shortening, They demonstrate also that the obtained protection was improved by combination of various protectors acting in a supplementary manner. The optimum dose reduction factor obtained was 1.5 for AET and about 2 for a mixture of 5 radioprotectors. These dose reduction factors are lower than those offered with these two treatments against the acute effects of ionizing radiation. In addition, the dose effect curve for the long term survival obtained for irradiated untreated mice and for mice treated with a mixture of radioprotectors are not parallel. Thus, the dose reduction factors vary with the X-ray dose administered. The best protection was achieved for X-ray doses from 500 to 1000 R. After an exposure to 100 R (BALB/c+ mice) and 350 R (C5781 mice) of X-rays, the total incidence of leukemias and cancers was significantly lower in treated irradiated mice than in non treated mice

  10. Genetic Heterogeneity of HER2 Amplification and Telomere Shortening in Papillary Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Paola Caria

    2016-10-01

    Full Text Available Extensive research is dedicated to understanding if sporadic and familial papillary thyroid carcinoma are distinct biological entities. We have previously demonstrated that familial papillary thyroid cancer (fPTC cells exhibit short relative telomere length (RTL in both blood and tissues and that these features may be associated with chromosome instability. Here, we investigated the frequency of HER2 (Human Epidermal Growth Factor Receptor 2 amplification, and other recently reported genetic alterations in sporadic PTC (sPTC and fPTC, and assessed correlations with RTL and BRAF mutational status. We analyzed HER2 gene amplification and the integrity of ALK, ETV6, RET, and BRAF genes by fluorescence in situ hybridization in isolated nuclei and paraffin-embedded formalin-fixed sections of 13 fPTC and 18 sPTC patients. We analyzed BRAFV600E mutation and RTL by qRT-PCR. Significant HER2 amplification (p = 0.0076, which was restricted to scattered groups of cells, was found in fPTC samples. HER2 amplification in fPTCs was invariably associated with BRAFV600E mutation. RTL was shorter in fPTCs than sPTCs (p < 0.001. No rearrangements of other tested genes were observed. These findings suggest that the association of HER2 amplification with BRAFV600E mutation and telomere shortening may represent a marker of tumor aggressiveness, and, in refractory thyroid cancer, may warrant exploration as a site for targeted therapy.

  11. Telomere shortening and cell senescence induced by perylene derivatives in A549 human lung cancer cells.

    Science.gov (United States)

    Taka, Thanachai; Huang, Liming; Wongnoppavich, Ariyaphong; Tam-Chang, Suk-Wah; Lee, T Randall; Tuntiwechapikul, Wirote

    2013-02-15

    Cancer cells evade replicative senescence by re-expressing telomerase, which maintains telomere length and hence chromosomal integrity. Telomerase inhibition would lead cancer cells to senesce and therefore prevent cancer cells from growing indefinitely. G-quadruplex ligands can attenuate telomerase activity by inducing G-quadruplex formation at the 3'-overhang of telomere and at the human telomerase reverse transcriptase (hTERT) promoter; the former prevents telomerase from accessing the telomere, and the latter acts as a transcriptional silencer. The present investigation found that perylene derivatives PM2 and PIPER induced G-quadruplex formation from both telomeric DNA and the hTERT promoter region in vitro. Further, TRAP assay showed that these compounds inhibited telomerase in a dose-dependent manner. When A549 human lung cancer cells were treated with these compounds, hTERT expression was down-regulated. Moreover, the crude protein extract from these treated cells exhibited less telomerase activity. In the long-term treatment of A549 lung cancer cells with sub-cytotoxic dose of these perylenes, telomere shortening, reduction of cell proliferation and tumorigenicity, and cell senescence were observed. The results of this study indicate that perylene derivatives warrant further consideration as effective agents for cancer therapy.

  12. Response of tibialis anterior tendon to a chronic exposure of stretch-shortening cycles: age effects

    Directory of Open Access Journals (Sweden)

    Baker Brent B

    2009-06-01

    Full Text Available Abstract Background The purpose of the current study was to investigate the effects of aging on tendon response to repetitive exposures of stretch-shortening cycles (SSC's. Methods The left hind limb from young (3 mo, N = 4 and old (30 mo, N = 9 male Fisher 344 × Brown Norway rats were exposed to 80 maximal SSCs (60 deg/s, 50 deg range of motion 3x/week for 4.5 weeks in vivo. After the last exposure, tendons from the tibialis anterior muscle were isolated, stored at -80°C, and then tested using a micro-mechanical testing machine. Deformation of each tendon was evaluated using both relative grip-to-grip displacements and reference marks via a video system. Results At failure, the young control tendons had higher strain magnitude than the young exposed (p Conclusion The chronic protocol enhanced the elastic stiffness of young tendon and the loads in both the young and old tendons. The old exposed tendons were found to exhibit higher load capacity than their younger counterparts, which differed from our initial hypothesis.

  13. The bulk radio expansion of Cassiopeia A

    International Nuclear Information System (INIS)

    Comparison, in the visibility plane, or radio observations of Cassiopeia A made at 151 MHz over a 2.3 yr interval indicates that the bulk of the radio emitting material has not been decelerated strongly

  14. PHONON ECHOES IN BULK AND POWDERED MATERIALS

    OpenAIRE

    Kajimura, K.

    1981-01-01

    Experimental and theoretical studies of phonon echoes in bulk and powdered materials are reviewed. Phonon echoes have been observed in many materials such as bulk piezoelectric crystals, paramagnets, glasses, doped semiconductors, and piezoelectric, magnetic, and metallic powders, etc. The echoes arise from a time reversal of the phase, like spin echoes, of a primary pulsed acoustic excitation due to a second acoustic or rf pulse. The phase reversal occurs through the nonlinear interactions o...

  15. An intrinsic mobility ceiling of Si bulk

    OpenAIRE

    Garcia-Castello, Nuria; Prades, Joan Daniel; Cirera, Albert

    2011-01-01

    We compute by Density Functional Theory-Non Equilibrium Green Functions Formalism (DFT-NEGFF) the conductance of bulk Si along different crystallographic directions. We find a ceiling value for the intrinsic mobility of bulk silicon of $8.4\\cdot10^6 cm^2/V\\cdot s$. We suggest that this result is related to the lowest effective mass of the $$ direction.

  16. Models of crustal thickness for South America from seismic refraction, receiver functions and surface wave tomography

    Science.gov (United States)

    Assumpção, Marcelo; Feng, Mei; Tassara, Andrés; Julià, Jordi

    2013-12-01

    An extensive compilation of crustal thicknesses is used to develop crustal models in continental South America. We consider point crustal thicknesses from seismic refraction experiments, receiver function analyses, and surface-wave dispersion. Estimates of crustal thickness derived from gravity anomalies were only included along the continental shelf and in some areas of the Andes to fill large gaps in seismic coverage. Two crustal models were developed: A) by simple interpolation of the point estimates, and B) our preferred model, based on the same point estimates, interpolated with surface-wave tomography. Despite gaps in continental coverage, both models reveal interesting crustal thickness variations. In the Andean range, the crust reaches 75 km in Southern Peru and the Bolivian Altiplano, while crustal thicknesses seem to be close to the global continental average (~ 40 km) in Ecuador and southern Colombia (despite high elevations), and along the southern Andes of Chile-Argentina (elevation lower than 2000 m). In the stable continental platform the average thickness is 38 ± 5 km (1-st. deviation) and no systematic differences are observed among Archean-Paleoproterozoic cratons, NeoProterozoic fold belts, and low-altitude intracratonic sedimentary basins. An exception is the Borborema Province (NE Brazil) with crust ~ 30-35 km thick. Narrow belts surrounding the cratons are suggested in central Brazil, parallel to the eastern and southern border of the Amazon craton, and possibly along the TransBrasiliano Lineament continuing into the Chaco basin, where crust thinner than 35 km is observed. In the sub-Andean region, between the mid-plate cratons and the Andean cordillera, the crust tends to be thinner (~ 35 km) than the average crust in the stable platform, a feature possibly inherited from the old pre-Cambrian history of the continent. We expect that these crustal models will be useful for studies of isostasy, dynamic topography, and crustal evolution of the

  17. Cost effectiveness of shortening screening interval or extending age range of NHS breast screening programme: computer simulation study

    NARCIS (Netherlands)

    R. Boer (Rob); A. Threlfall; P. Warmerdam (Peter); A. Street (Andrew); E. Friedman (Eitan); C. Woodman; H.J. de Koning (Harry)

    1998-01-01

    markdownabstract__OBJECTIVE__: To compare the cost effectiveness of two possible modifications to the current UK screening programme: shortening the screening interval from three to two years and extending the age of invitation to a final screen from 64 to 69. __DESIG

  18. An Examination of the Stretch-Shortening Cycle of the Dorsiflexors and Evertors in Uninjured and Functionally Unstable Ankles

    OpenAIRE

    Porter, Gary K.; Kaminski, Thomas W.; Hatzel, Brian; Powers, Michael E.; Horodyski, MaryBeth

    2002-01-01

    Objective: To determine if there were differences in concentric peak torque/body-weight (PT/BW) ratios and concentric time to peak torque (TPT) of the dorsiflexors and evertors in uninjured and functionally unstable ankles using a stretch-shortening cycle (SSC) protocol on an isokinetic dynamometer.

  19. 3'UTR Shortening Potentiates MicroRNA-Based Repression of Pro-differentiation Genes in Proliferating Human Cells.

    Directory of Open Access Journals (Sweden)

    Yonit Hoffman

    2016-02-01

    Full Text Available Most mammalian genes often feature alternative polyadenylation (APA sites and hence diverse 3'UTR lengths. Proliferating cells were reported to favor APA sites that result in shorter 3'UTRs. One consequence of such shortening is escape of mRNAs from targeting by microRNAs (miRNAs whose binding sites are eliminated. Such a mechanism might provide proliferation-related genes with an expression gain during normal or cancerous proliferation. Notably, miRNA sites tend to be more active when located near both ends of the 3'UTR compared to those located more centrally. Accordingly, miRNA sites located near the center of the full 3'UTR might become more active upon 3'UTR shortening. To address this conjecture we performed 3' sequencing to determine the 3' ends of all human UTRs in several cell lines. Remarkably, we found that conserved miRNA binding sites are preferentially enriched immediately upstream to APA sites, and this enrichment is more prominent in pro-differentiation/anti-proliferative genes. Binding sites of the miR17-92 cluster, upregulated in rapidly proliferating cells, are particularly enriched just upstream to APA sites, presumably conferring stronger inhibitory activity upon shortening. Thus 3'UTR shortening appears not only to enable escape from inhibition of growth promoting genes but also to potentiate repression of anti-proliferative genes.

  20. Multi-carrier Equalization by Restoration of RedundancY (MERRY) for Adaptive Channel Shortening in Multi-carrier Systems

    OpenAIRE

    Samir Abd Elghafar; Salaheldin M. Diab; Sallam, Bassiouny M.; Moawad I. Dessouky; El-Sayed M. El-Rabaie; Fathi E. Abd El-Samie

    2013-01-01

    This paper proposes a new blind adaptive channel shortening approach for multi-carrier systems. Theperformance of the discrete Fourier transform-DMT (DFT-DMT) system is investigated with the proposedDST-DMT system over the standard carrier serving area (CSA) loop1. Enhanced bit rates demonstratedand less complexity also involved by the simulationof the DST-DMT system.

  1. Micro-Sugar-Snap and -Wire-Cut Cookie Baking with Trans- and Zero-Trans-Fat Shortenings

    Science.gov (United States)

    The effect of trans- and zero-trans-fat shortenings on cookie-baking performance was evaluated, using the two AACC micro-cookie-baking methods. Regardless of fat type, sugar-snap cookies made with a given flour were larger in diameter, smaller in height, and greater in weight loss during baking tha...

  2. Item response theory was used to shorten EORTC QLQ-C30 scales for use in palliative care

    NARCIS (Netherlands)

    M.A. Petersen; M. Groenvold; N. Aaronson; J. Blazeby; Y. Brandberg; A. de Graeff; P. Fayers; E. Hammerlid; M. Sprangers; G. Velikova; J.B. Bjorner

    2006-01-01

    Background and Objective: The goal was to develop a shortened version of the EORTC QLQ-C30 for use in palliative care. We wanted to keep as few items as possible in each scale while still being able to compare results with studies using the original scales. We examined the possibilities of shortenin

  3. Do crustal deformations observed by GPS in Tierra del Fuego (Argentina) reflect glacial-isostatic adjustment?

    Science.gov (United States)

    Mendoza, L.; Richter, A.; Hormaechea, J. L.; Perdomo, R.; Del Cogliano, D.; Dietrich, R.; Fritsche, M.

    2010-09-01

    Vertical site velocities determined by geodetic GPS observations in the Lago Fagnano area, Tierra del Fuego main island, are interpreted with respect to their potential relation with the glacial-isostatic crustal response to ice mass changes. The spatial pattern of the uplift rates, in combination with the horizontal crustal deformation pattern, point towards a fault-tectonic rather than glacial-isostatic origin of the determined vertical crustal deformations. This implies rather small GIA effects pointing towards relatively small Holocene ice-mass changes in Tierra del Fuego. However, these findings are considered to be preliminary. They should be confirmed by additional observations covering an extended area with GPS sites.

  4. Treatment of tibial defect and bone nonunion with limb shortening with external fixator and reconstituted bone xenograft

    Institute of Scientific and Technical Information of China (English)

    王志刚; 刘建; 胡蕴玉; 孟国林; 金格勒; 袁志; 王海强; 戴先文

    2003-01-01

    Objective: To explore the effect of external fixator and reconstituted bone xenograft (RBX) in the treatment of tibial bone defect, tibial bone nonunion and congenital pseudarthrosis of the tibia with limb shortening. Methods: Twenty patients ( 13 males and 7 females) with tibial bone defect, tibial bone nonunion or congenital pseudarthrosis of the tibia with limb shortening were treated with external fixation. Two kinds of external fixators were used: a half ring sulcated external fixator used in 13 patients and a combined external fixator in 7 patients. Foot-drop was corrected at the same time with external fixation in 4 patients. The shortened length of the tibia was in the range of 2-9 cm, with an average of 4.8 cm. For bone grafting, RBX was used in 12 patients, autogenous ilium was used in 3 patients and autogenous fibula was implanted as a bone plug into the medullary canal in 1 case, and no bone graft was used in 4 patients. Results: All the 20 patients were followed-up for 8 months to 7 years, averaging 51 months. Satisfactory function of the affected extremities was obtained. All the shortened extremities were lengthened to the expected length. For all the lengthening area and the fracture sites, bone union was obtained at the last. The average healing time of 12 patients treated with RBX was 4.8 months. Conclusions: Both the half ring sulcated external fixator and the combined external fixator have the advantages of small trauma, simple operation, elastic fixation without stress shielding and non-limitation from local soft tissue conditions, and there is satisfactory functional recovery of affected extremities in the treatment of tibial bone defects, tibial bone nonunion and congenital pseudarthrosis of the tibia combined with limb shortening. RBX has good biocompatibility and does not cause immunological rejections. It can also be safely used in treatment of bone nonunion and has reliable effect to promote bone healing.

  5. Variation in Crustal Structure and Deformation along the Tonga-Kermadec Forearc: Temporal and Spatial Changes in the Structure and Morphology of the Subducting Pacific Plate

    Science.gov (United States)

    Funnell, M.

    2015-12-01

    Pacific oceanic lithosphere has been subducting along the Tonga-Kermadec Trench for at least 28 Myr. Variations in the sediment thickness, subduction angle and roughness of the subducting plate over this time have controlled deformation along the forearc. This constant process of forearc evolution has been punctuated since at least 7 Ma by the subduction of seamounts, as the trench-oblique Louisville Seamount Chain (LSC) migrates southward along the trench. The subduction of these seamounts is associated with accelerated tectonic erosion, the tilting of sedimentary units and 80 km of forearc shortening north of the present-day collision zone at 26°S. South of this collision zone, the overriding and subducting plates exhibit structures expected of normal Pacific plate subduction. In 2011, a series of integrated geophysical profiles were acquired to image the crustal and upper mantle structure along the Tonga-Kermadec subduction system and LSC, with the aim of: a) establishing the nature of major structural variations along the forearc; b) resolving the flexural state of the overriding and underthrusting plates in regions of normal subduction and at the point of LSC-collision; and from these c) determining the primary influences on the flexural behaviour and nature of deformation in the underthrusting and overriding plates along the Tonga-Kermadec subduction system. From the 2011 acquisition, we present multichannel reflection and wide-angle refraction seismic data that reveal the dominant structural differences between the Kermadec forearc and the raised Tonga Platform. Superimposed on these are structures associated with differing modes and extents of tectonic deformation that have occurred more recently along the margin. Most notably, the increased crustal strength around the seamounts results in an ~2 km shallowing of the trench and the development of an ~100 km-wide complex network of faulting on the overriding plate in the area of seamount collision.

  6. Development of Advanced Concept for Shortening Construction Period of ABWR Plant

    International Nuclear Information System (INIS)

    Construction of a nuclear power plant (NPP) requires a very long period because of large amount of construction materials and many issues for negotiation among multiple sections. Shortening the construction period advances the date of return on an investment, and can also result in reduced construction cost. Therefore, the study of this subject has a very high priority for utilities. We achieved a construction period of 37 months from the first concrete work to fuel loading (F/L) (51.5 months from the inspection of the foundation (I/F) to the start of commercial operation (C/O)) at the Kashiwazaki-Kariwa NPPs No. 6 and 7 (KK-6/7), which are the first ABWR plants in the world. At TEPCO's next plant, we think that a construction period of less than 36 months (45 months from I/F to C/O) can be realized based on conventional methods such as early start of equipment installation and blocking of equipment to be brought in advance. Furthermore, we are studying the feasibility of a 21.5-month construction period (30 months from I/F to C/O) with advanced ideas and methods. The important concepts for a 21.5-month construction period are adoption of a new building structure that is the steel plate reinforced concrete (SC) structure and promotion of extensive modularization of equipment and building structure. With introducing these new concepts, we are planning the master schedule (M/S) and finding solutions to conflicts in the schedule of area release from building construction work to equipment installation work (schedule-conflicts.) In this report, we present the shortest construction period and an effective method to put it into practice for the conventional general arrangement (GA) of ABWR. In the future, we will continue the study on the improvement of building configuration and arrangements, and make clear of the concept for large composite modules of building structures and equipment. (authors)

  7. Biophysical Mechanisms Underlying Hearing Loss Associated with a Shortened Tectorial Membrane

    Science.gov (United States)

    Oghalai, John S.; Xia, Anping; Liu, Christopher C.; Gao, Simon S.; Applegate, Brian E.; Puria, Sunil; Rousso, Itay; Steele, Charles

    2011-11-01

    The tectorial membrane (TM) connects to the stereociliary bundles of outer hair cells (OHCs). Herein, we summarize key experimental data and modeling analyses that describe how biophysical alterations to these connections underlie hearing loss. The heterozygous C1509G mutation in alpha tectorin produces partial congenital hearing loss that progresses in humans. We engineered this mutation in mice, and histology revealed that the TM was shortened. DIC imaging of freshly-dissected cochlea as well as imaging with optical coherence tomography indicated that the TM is malformed and only stimulates the first row of OHCs. Noise exposure produced acute threshold shifts that fully recovered in Tecta+/+ mice although there was some OHC loss within all three rows at the cochlear base. In contrast, threshold shifts only partially recovered in TectaC1509G/+ mice. This was associated with OHC loss more apically and nearly entirely within the first row. Young's modulus of the TM, measured using atomic force microscopy, was substantially reduced at the middle and basal regions. Both the wild-type and heterozygous conditions were simulated in a computational model. This demonstrated that the normalized stress distribution levels between the TM and the tall cilia were significantly elevated in the middle region of the heterozygous cochlea. Another feature of the TectaC1509G/+ mutation is higher prestin expression within all three rows of OHCs. This increased electricallyevoked movements of the reticular lamina and otoacoustic emissions. Furthermore, electrical stimulation was associated with an increased risk of OHC death as measured by vital dye staining. Together, these findings indicate that uncoupling of the TM from some OHCs not only leads to partial hearing loss, but also puts the OHCs that remain coupled at higher risk. Both the mechanics of the malformed TM and increased electromotility contribute to this higher risk profile.

  8. Brain targeted transcranial administration of diazepam and shortening of sleep latency in healthy human volunteers

    Directory of Open Access Journals (Sweden)

    W Pathirana

    2011-01-01

    Full Text Available Application of medicated oils on scalp had been practiced for centuries in the Ayurvedic system of medicine in diseases associated with the central nervous system. It is possible that the effectiveness of the therapy may be a result of targeted delivery of active compounds to the brain transcranially. Evidence also comes from two previous studies with positive results on brain targeted transcranial delivery of methadone base and diazepam on rat models. Possibility of transcranial drug delivery was investigated in healthy human volunteers using electroencephalography techniques by assessing the ability of transcranially administered diazepam in bringing about β activity in the electroencephalographic wave patterns and shortening of the sleep latency period. Non polar drug molecules dissolved in a non-aqueous sesame oil based vehicle is a significant feature in the transcranial dosage design. The study was under taken in two phases. In the Phase-I study scalp application of a single dose of 2 mg/3 ml of the oil was employed and in the Phase-II study repeat application of three doses 24 h apart were employed. Sleep latency changes were monitored with Multiple Sleep Latency Tests with 5 naps employing the standard electroencephalography, electroocculography and electromyography electrodes. Sleep onset was identified with the first epoch of any sleep stage non rapid eye movement 1, 2, 3, 4 or rapid eye movement using electroencephalography, electroocculography and electromyography criteria. In both phases of the study there was significant reduction in the sleep latencies. It was much more pronounced in the Phase-II study. None of the subjects however displayed beta activity in the electroencephalography. Sleep latency reduction following scalp application in both the phases are suggestive of transcranial migration of diazepam molecules to the receptor sites of the nerve tissue of the brain eliciting its pharmacological effect of sedation

  9. Effect of prosthetic restoration on masticatory function in patients with shortened dental arches: a multicentre study.

    Science.gov (United States)

    Fueki, K; Igarashi, Y; Maeda, Y; Baba, K; Koyano, K; Sasaki, K; Akagawa, Y; Kuboki, T; Kasugai, S; Garrett, N R

    2016-07-01

    The aim of this multicentre study was to investigate the effect of prosthetic restoration for missing posterior teeth on mastication in patients with shortened dental arches (SDAs). Partially dentate patients who had an intact teeth in anterior region and missed distal molar(s) (2-12 missing occlusal units) classified as Kennedy Class I or Class II were recruited from seven university-based dental hospitals in Japan. Of the 125 subjects who underwent baseline (pre-treatment) and follow-up/post-treatment evaluation, 53 chose no replacement of missing teeth and 72 chose treatment with removable partial dentures (n = 53) or implant-supported fixed partial dentures (n = 19). Objective masticatory performance (MP) was evaluated using a gummy jelly test. Perception of chewing ability (CA) was rated using a food intake questionnaire. In the no-treatment group, mean MP and CA scores at baseline were similar to those at follow-up evaluation (P > 0·05). In the treatment group, mean MP after treatment was significantly greater than the pre-treatment mean MP (P 0·05). In a subgroup analysis of subjects in the treatment group, subjects with lower pre-treatment CA showed a significant CA increase after treatment (P = 0·004), but those with higher pre-treatment CA showed a significant decrease in CA (P = 0·001). These results suggest that prosthetic restoration for SDAs may benefit objective masticatory performance in patients needing replacement of missing posterior teeth, but the benefit in subjective chewing ability seems to be limited in subjects with perceived impairment in chewing ability before treatment. PMID:26854877

  10. Life shortening and carcinogenesis in mice irradiated at the perinatal period with gamma rays

    International Nuclear Information System (INIS)

    This study elucidates the life-span radiation effects in mice irradiated at the perinatal period in comparison to mice irradiated at the young adult period. B6C3F1 female mice were irradiated at 17 days of prenatal age, at 0 days of postnatal age, or as young adults at 15 weeks of age with 190, 380, or 570 rads of 137Cs gamma rays. Mice irradiated at the late fetal period showed dose-dependent life shortening of somewhat lesser magnitude than that seen after neonatal or young adult irradiation. Mice exposed at the late fetal period were highly susceptible to induction of pituitary tumors for which the latent period was the longest of all induced neoplasms. Incidence of lung tumors in mice irradiated at the late fetal period with 190 and 380 rads was higher than in controls. Malignant lymphomas of the lymphocytic type developed in excess, after a short latent period, in mice irradiated fetally with the highest dose; susceptibility of prenatally exposed mice was lower than that of early postnatally exposed mice. Liver tumors developed more frequently in mice irradiated in utero than in controls; susceptibility to induction of this type of neoplasm was highest at the neonatal period. In general, carcinogenic response of mice exposed at the late fetal period resembled that of neonatally exposed mice but was quite different from that of young adult mice. Mice exposed as young adults have no, or low, susceptibility to induction of pituitary, lung, and liver tumors; and a higher susceptibility to induction of myeloid leukemias and Harderian gland tumors. 19 refs., 4 figs., 3 tabs

  11. Reduced stretch-reflex sensitivity after exhausting stretch-shortening cycle exercise.

    Science.gov (United States)

    Nicol, C; Komi, P V; Horita, T; Kyröläinen, H; Takala, T E

    1996-01-01

    The stretch-shortening cycle (SSC) is an effective and natural form of muscle function but, when repeated with sufficient intensity or duration, it may lead to muscle damage and functional defects. A reduced tolerance to impact has been reported, which may be partly attributed to a reduced stretch-reflex potentiation. The aim of the present study was to examine the influence of SSC-induced metabolic fatigue and muscle damage on the efficacy of stretch reflexes, as judged by the electromyograph (EMG) response of two shank muscles (lateral gastrocnemius LG, soleus SOL) to controlled ramp stretches. These EMG responses were recorded before and immediately after exhausting SSC-type leg exercise and 2 h, 2 days and 4 days later. Serum concentrations of creatine kinase ([CK]), myoglobin and lactate were measured repetitively along the protocol. Two maximal vertical drop jumps and counter-movement jumps were performed after each reflex test. The exhausting SSC-type exercise induced an immediate reduction (P drop jump performance remained slightly but significantly reduced (P drop jump height. Furthermore, a significant relationship (P < 0.05) was found between recovery of the stretch reflex in LG and the decrease of [CK] between the 2nd and the 4th day. These findings support the hypothesis of a reduced stretch-reflex sensitivity. While the exact mechanisms of the reflex inhibition remain unclear, it is emphasized that the delayed recovery of the reflex sensitivity could have resulted from the progressive inflammation that develops in cases of muscle damage. PMID:8925809

  12. Characteristics of myocardial postsystolic shortening in patients with coronary artery disease assessed by strain rate imaging

    Institute of Scientific and Technical Information of China (English)

    YANG Li; QIU Qiong; ZHANG Hui-zhong; XIA Jin-xi

    2007-01-01

    Background Postsystolic shortening (PSS) has been proposed as a marker of myocardial dysfunction. Strain rate imaging (SRI)is a novel ultrasonic technique, allowing reliable and noninvasive measurement of myocardial deformation.The purpose of this study was to investigate the characteristics of myocardial longitudinal PSS by SRI in ischemic and infarct myocardium in patients with coronary artery disease, and to explore its clinical applicability.Methods Eleven patients with angina pectoris, 21 patients with myocardial infarction and 20 healthy subjects were included in the study. Apical four-, three- and two-chamber views were displayed; and septal, lateral, anteroseptal,posterior, anterior and inferior walls of the left ventricle were scanned, respectively. PSS strain (εpss), the ratio of εpss and systolic strain (εpss/εsys), the ratio of εpss and maximum strain (εpss/εmax) and the duration of PSS (Tpss) in ischemic, infarct and normal myocardium were analyzed.Results PSS was found more frequent in the ischemic and infarct segments compared with the normal segments (39%vs 22% and 56% vs 22%, respectively; both P<0.01). It was even more frequent in the infarct segments than in the ischemic segments (56% vs 39%, P<0.01). The absolute magnitude of εpss, εpss/εsys, εpss/εmax were significantly larger and Tpss significantly longer in the ischemic and infarct segments compared with that in the normal myocardium (P<0.01).εpss/εsys, εpss/εmax were even larger and Tpss even longer in the infarct than in the ischemic segments (P<0.01).Conclusions PSS is a common and important feature of the ischemic and infarct myocardium. εpss, εpss/εsys, εpss/εmax and Tpss as measured by SRI may be promising markers for the quantitative assessment of regional myocardial dysfunction in patients with coronary artery disease. εpss/εsys, εpss/εmax and Tpss may be helpful in differentiating infarct from ischemic myocardium.

  13. An increase in telomere sister chromatid exchange in murine embryonic stem cells possessing critically shortened telomeres

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yisong [ORNL; Giannone, Richard J [ORNL; Wu, Jun [ORNL; Gomez, Marla V [ORNL; Liu, Yie [ORNL

    2005-01-01

    Telomerase deficiency leads to a progressive loss of telomeric DNA that eventually triggers cell apoptosis in human primary cells during prolonged growth in culture. Rare survivors can maintain telomere length through either activation of telomerase or recombination-based telomere lengthening, and thus proliferate indefinitely. We have explored the possibility that telomeres may be maintained through telomere sister chromatid exchange (T-SCE) in murine telomere reverse transcriptase-deficient (mTert -/-) splenocytes and ES cells. Because telomerase deficiency leads to gradual loss of telomeric DNA in mTert -/- splenocytes and ES cells and eventually to chromosomes with telomere signal-free ends (SFEs), we examined these cell types for evidence of sister chromatid exchange at telomeres, and observed an increase in T-SCEs only in a subset of mTert -/- splenocytes or ES cells that possessed multiple SFEs. Furthermore, T-SCEs were more often detected in ES cells than in splenocytes that harbored a similar frequency of SFEs. In mTert heterozygous (mTert +/-) ES cells or splenocytes, which are known to exhibit a decrease in average telomere length but no SFEs, no increase in T-SCE was observed. In addition to T-SCE, other genomic rearrangements (i.e., SCE) were also significantly increased in mTert -/- ES cells possessing critically short telomeres, but not in splenocytes. Our results suggest that animals and cell culture differ in their ability to carry out genomic rearrangements as a means of maintaining telomere integrity when telomeres become critically shortened.

  14. Crustal and deep seismicity in Italy (30 years after

    Directory of Open Access Journals (Sweden)

    G. Selvaggi

    1997-06-01

    Full Text Available The first modern studies of seismicity in Italy date back to the late 60's and early 70's. Although with a sparse seismic network available and only a few telemetered short-period stations, significant studies were carried out that outlined the main features of Italian seismicity (see, e.g., Boschi et al., 1969. Among these studies, one of the most important achievements was the reconnaissance of a Wadati-Benioff zone in Southern Tyrrhenian, described for the first time in detail in the papers of Caputo et al.(1970, 1973. Today, after three decades of more and more detailed seismological monitoring of the Italian region and tens of thousands earthquakes located since then, the knowledge of the earthquake generation processes in our country is much improved, although some of the conclusions reached in these early papers still hold. These improvements were made possible by the efforts of many institutions and seismologists who have been working hard to bring seismological research in Italy to standards of absolute quality, under the pivoting role of the Istituto Nazionale di Geofisica (ING. From the relocation of about 30000 crustal earthquakes and detailed studies on intermediate and deep shocks carried out in the last few years, we show that seismic release in peninsular Italy is only weakly related to the Africa-Eurasia convergence, but rather is best explained by the existence of two separate subduction/collision arcs (Northern Apennines and Southern Apennines-Calabria-Sicily. The width of the deforming belt running along peninsular Italy is 30 to 60 km, it is broader in the north than in the south, and the two arcs are separated by a region of more distributed deformation and stress rotations in the Central Apennines. Along the belt, the reconnaissance of regions of continuous and weak release of seismic energy, adjacent to fault areas which are currently «locked» (and therefore are the best candidates for future earthquakes is another

  15. Deep crustal reflections from a Vibroseis survey in northern Switzerland

    Science.gov (United States)

    Finckh, P.; Ansorge, J.; Mueller, St.; Sprecher, Chr.

    1984-10-01

    In 1982 a Vibroseis survey comprising 180 km of reflection profiles was run in northern Switzerland in order to investigate the suitability of the crystalline basement for the deposition of highly radioactive waste. A configuration was chosen with 144 channels, 25 m of geophone spacing, 20 s sweeps ranging from 11 to 61 Hz and stacking of 4 or 8 sweeps of 3 simultaneous vibrators at twice the geophone spacing. The listening time was generally 4 s and at 4 sites it was extended to 11s for the detection of deeper crustal reflectors. This survey unravelled the complicated fault and thrust system beneath the Swiss folded Jura mountains. The stack from 4 s to 11 s reveals clearly a strong sloping reflector between 3.0 and 3.5 s which is strong evidence for a pronounced differentiation in the upper crust. A series of reflections is observed between 5.8 and 7.2 s the top of which can be correlated with the Conrad discontinuity. A strong "layered" signal between 9.0 and 9.5 s is interpreted as reflections from the M-discontinuity. The main features are compatible with results from nearby refraction surveys in the southern Rhinegraben rift system which show a distinct velocity increase of about 0.5 km/s in the lower crust at a depth ranging from 15 to 20 km, followed by an inversion zone or a laminated structure before reaching the Moho at about 27 km depth. The correlation of the field recordings with the first 10 s of the up-sweep only, shows some loss of resolution in the uppermost 3 s because of the lower frequency content of the signal. However, the lower parts of the sections are nearly identical. The fact that the deeper reflectors in the sections can consistently be traced laterally is a strong argument for using this processing technique. Thus high-coverage Vibroseis surveys utilizing up-sweep can be processed for deep crustal reflections even if the recording time is restricted to the standard 4 s, provided the surface static corrections are carried out with high

  16. Crustal structure of the Nordland region, northern Norway

    Science.gov (United States)

    Maystrenko, Yuriy P.; Olesen, Odleiv; Gernigon, Laurent; Gradmann, Sofie

    2016-04-01

    To understand the major structural features of the sedimentary cover and crystalline crust within the Nordland County area of Norway, a data-based 3D structural model has been constructed in the framework of the Neonor2 project, "Neotectonics in Nordland - implications for petroleum exploration". The 3D structural model covers the Lofoten Ridge, the Ribban and Vestfjorden basins and adjacent areas of the Norwegian mainland. The model also covers the northern part of the adjacent Vøring Basin. At the regional scale, the 3D model includes the rifted margin which is located at the transition from the exposed crystalline rocks of the Fennoscandian Shield in the east to the Cenozoic oceanic domain of the Norwegian-Greenland Sea in the west. During the construction of the 3D structural model, all recently published and/or released data have been compiled in order to set the initial model. This initial 3D model has been validated by a 3D density modelling in order to obtain a gravity-consistent 3D structural model of the entire study area. The 3D density modelling has been carried out by using the IGMAS plus software (the Interactive Gravity and Magnetic Application System). During the 3D density modelling, densities have been assigned as constant values for the crystalline rocks. In contrast, densities of sedimentary rocks have been set to be depth-dependent in order to reflect the compaction of sedimentary rocks with depth. According to the results of the 3D density modeling, the crystalline crust of the investigated region consists of several layers with different densities. The deepest crustal layer is the high-density lower crust which corresponds to the high-velocity lower crustal layer. The regional-scale gravity response associated with the positions of the Moho and lithosphere-asthenosphere boundary is one of the key factors for performing a proper 3D density model of the study area. At the regional scale, the Moho and lithosphere-asthenosphere boundary are

  17. Analytical formulas for shear and bulk viscosities in relativistic gaseous mixtures with constant cross sections

    CERN Document Server

    Moroz, O

    2014-01-01

    Using Mathematica package, we derive analytical closed-form expressions for the shear and the bulk viscosity coefficients in multicomponent relativistic gases with constant cross sections, being the relativistic generalization for the hard spheres model. Some of them are cumbersome and require symbolic manipulations in an algebraic package. The constant cross sections are of the elastic processes, while the inelastic (or number-changing) processes (collisions or decays) are considered only partly. As examples, we find explicit expressions of the correct single-component first-order shear viscosity coefficient and some explicit analytical results for the binary mixture. These formulas have numerous applications in approximate nonequilibrium descriptions of gases of particles or quasiparticles with averaged (temperature dependent) cross sections. In addition to this, we present formulas for collision rates and some other related formulas. This paper is a shortened version of a previous one.

  18. Large bulk Y-Ba-Cu-O superconductors fabricated by multiseeding melt growth methods

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    We have fabricated the large single domain YBaCuO bulk superconductors by using multiseeding technique combined with composition gradient in the precursor. Obviously, the growth time can be shortened by multiseeding method and the weak links between grain boundaries originated from different seeds can be also overcome with introducing the chemical component gradient and arranging the seeds exactly. For these YBCO disks, only single peak occurs in the distributions of trapped field, and the magnetic levitation force is equal to that of the same size sample fabricated with single seed. Although the arrangement of seeds is similar, the distribution of trapped field still shows four peaks for the sample without composition gradient.

  19. JERS-1 Synthetic Aperture Radar Interferometry Applications: Mapping of Rain Forest Environments and Crustal Deformation Studies

    Science.gov (United States)

    Rosen, P.; Hensley, S.; Peltzer, G.; Rignot, E.; Werner, C.

    1999-01-01

    This research using JERS-1 SAR data has been very fruitful, resulting in a strong collaboration with geodesists and geophysicists in Japan, and several important papers characterizing crustal deformation, and the capabilities and limitations of JERS data for these studies.

  20. Crustal processes cause adakitic chemical signatures in syn-collision magmatism from SE Iran

    Science.gov (United States)

    Allen, Mark; Kheirkhah, Monireh; Neill, Iain

    2015-04-01

    We report new elemental and Nd-Sr isotopic analyses for Late Cenozoic intrusive and extrusive rocks emplaced in SE Iran as part of the wider syn-collision magmatic province within the Turkish-Iranian Plateau. The sample sites are near the town of Dehaj in Kerman Province. Most of the rocks are from stocks and batholiths, interpreted as the roots of central volcanoes. Age controls are not precise, but the rocks are likely to be Late Miocene-Quaternary in age. Basaltic to andesitic lavas crop out nearby; their relationships to the intrusive rocks are uncertain. Geochemically, the entire range of rocks from basalt lavas through to rhyolitic intrusives ranges from 51-71 wt.% silica and isotopic signatures are similar to Bulk Earth, without any clear evidence for large-scale crustal contamination. The basaltic to andesitic lavas appear to have variable and often high La/Yb and Sr/Y such that they range from calc-alkaline arc-like rocks to adakitic compositions depending on the degree of fractionation. The intrusive rocks seem to form a separate suite, with clear indications of increasing Sr/Y and Dy/Yb with fractionation. Previous interpretations relate adakitic magmatism to Tethyan oceanic slab break-off and slab melting beneath the collision zone. However, as the 'adakitic signature' is increasingly apparent in more evolved magmas, at least in the intrusives, adakite generation is more likely to have occurred during melt evolution from an initial low Sr/Y and low La/Yb parent. This parental melt may have been similar in starting composition to proposed non-adakitic basaltic melts from elsewhere in the collision zone. The high Sr/Yb and La/Yb signatures are best explained by the suppression of plagioclase fractionation by high magmatic water contents, promoting incompatible behaviour of Sr. Conversely, Y and Yb are compatible during amphibole and garnet fractionation at crustal or uppermost mantle levels. Rather than a localised slab break-off or melting effect, the

  1. Crustal deformation across the Southern Patagonian Icefield observed by GNSS

    Science.gov (United States)

    Richter, A.; Ivins, E.; Lange, H.; Mendoza, L.; Schröder, L.; Hormaechea, J. L.; Casassa, G.; Marderwald, E.; Fritsche, M.; Perdomo, R.; Horwath, M.; Dietrich, R.

    2016-10-01

    Geodetic GNSS observations at 43 sites well distributed over the Southern Patagonian Icefield region yield site velocities with a mean accuracy of 1 mm/a and 6 mm/a for the horizontal and vertical components, respectively. These velocities are analyzed to reveal the magnitudes and patterns of vertical and horizontal present-day crustal deformation as well as their primary driving processes. The observed vertical velocities confirm a rapid uplift, with rates peaking at 41 mm/a, causally related to glacial-isostatic adjustment (GIA). They yield now an unambiguous preference between two competing GIA models. Remaining discrepancies between the preferred model and our observations point toward an effective upper mantle viscosity even lower than 1.6 ṡ1018 Pas and effects of lateral rheological heterogeneities. An analysis of the horizontal strain and strain-rate fields reveals some complex superposition, with compression dominating in the west and extension in the east. This deformation field suggests significant contributions from three processes: GIA, a western interseismic tectonic deformation field related to plate subduction, and an extensional strain-rate field related to active Patagonian slab window tectonics.

  2. Reflection Character of the Continental Lithosphere and Crustal Evolution

    Science.gov (United States)

    Brown, L. D.

    2015-12-01

    Reflection images represent the high-frequency end member of the suite of seismological tools commonly used to probe the lithosphere. The global inventory of deep reflection profiles has documented reflection characters as varied as the surface geology that provides the primary boundary condition for the interpretation of reflection images. Past reviews of reflection results have stressed similarities in reflection patterns between various geographic regions and attempted to associate these patterns with specific tectonic processes. Examples include: laminated sequences (shear fabrics formed during extension or collision), reflective Mohos (mafic underplating), bright spots (contemporary and fossil magma bodies), dipping mantle reflections rooted in the lower crust (fossil subduction zones) and subhorizontal mantle reflections (phase changes in the lower lithosphere). Here I focus on relating reflection character to the inversion and/or interpretation of results from broadband techniques such as receiver functions, body wave and surface wave tomography. Among the underappreciated aspects of reflectivity are its dependence upon density as well as velocity, and the limitations of 2D images in a 3D world. A core consideration is the need to meaningfully relate integrated physical properties (e.g. velocity inferred from refraction and surface wave measurements) with the differential physical properties (e.g. reflection coefficients) to which reflection images are primarily sensitive. Examples from Tibet and Eurasia are used to illustrate examples of successful integration of controlled (active) and natural (passive) source observations to constrain models of crustal evolution.

  3. The moon: Sources of the crustal magnetic anomalies

    Science.gov (United States)

    Hood, L.L.; Coleman, P.J., Jr.; Wilhelms, D.E.

    1979-01-01

    Previously unmapped Apollo 16 subsatellite magnetometer data collected at low altitudes over the lunar near side are presented. Medium-amplitude magnetic anomalies exist over the Fra Mauro and Cayley Formations (primary and secondary basin ejecta emplaced 3.8 to 4.0 billion years ago) but are nearly absent over the maria and over the craters Copernicus, Kepler, and Reiner and their encircling ejecta mantles. The largest observed anomaly (radial component ??? 21 gammas at an altitude of 20 kilometers) is exactly correlated with a conspicuous light-colored deposit on western Oceanus Procellarum known as Reiner ??. Assuming that the Reiner ?? deposit is the source body and estimating its maximum average thickness as 10 meters, a minimum mean magnetization level of 5.2 ?? 2.4 ?? 10-2 electromagnetic units per gram, or ??? 500 times the stable magnetization component of the most magnetic returned sample, is calculated. An age for its emplacement of ??? 2.9 billion years is inferred from photogeologic evidence, implying that magnetization of lunar crustal materials must have continued for a period exceeding 1 billion years. Copyright ?? 1979 AAAS.

  4. Investigation of upper crustal structure beneath eastern Java

    Science.gov (United States)

    Martha, Agustya Adi; Widiyantoro, Sri; Cummnins, Phil; Saygin, Erdinc; Masturyono

    2016-05-01

    The complexity of geology structure in eastern Java causes this region has many potential resources as much as the disasters. Therefore, the East Java province represents an interesting area to be explored, especially regarding its upper crustal structure. To investigate this structure, we employ the Ambient Noise Tomography (ANT) method. We have used seismic waveform data from 25 Meteorological, Climatological and Geophysical Agency (BMKG) stationary seismographic stations and 26 portable seismographs installed for 2 to 8 weeks. Inter-station cross-correlation produces more than 800 Rayleigh wave components, which depict the structure beneath eastern Java. Based on the checkerboard resolution test, we found that the optimal grid size is 0.25ox0.25o. Our inversion results for the periods of 1 to 10 s indicate a good agreement with geological and Bouguer anomaly maps. Rembang high depression, most of the southern mountains zone, the northern part of Rembang zone and the central part of the Madura Island, the area of high gravity anomaly and areas dominated with igneous rocks are associated with high velocity zones. On the other hand, Kendeng zone and most of the basin in the Rembang zone are associated with low velocity zones.

  5. Maps of North American crustal stability and geothermal potential

    Energy Technology Data Exchange (ETDEWEB)

    Fairbridge, R.W.

    1977-01-01

    A three-year program of analysis of crustal movements in North America was planned with the objective of preparing a series of 1 = 5 million scale maps depicting relative stability/instability. The part of the proposal completed during the first year is described; much of this first year's work was preparatory. Three time scales were considered for the data analysis: 1 - 10/sup 2/ yr., 10/sup 4/ yr., and 10/sup 8/ yr. Significant differences in sign and rate were suspected between short and long-term motions and these are now confirmed. The first part of the program is now complete. It consisted of two principal activities: (a) data collection for the short and mid-term scales on a U.S.-wide basis, excluding Alaska and Hawaii (all of this material has been reduced to compatible computer language and is stored on tape ready for further study, analysis and final cartography); (b) map and data analysis of the long-term scale with a completed draft map, applied specifically to the Mid-West and eastern U.S.

  6. Crustal structure off Norway, 62° to 70° north

    Science.gov (United States)

    Planke, Sverre; Skogseid, Jakob; Eldholm, Olav

    1991-04-01

    Extensive geophysical surveys have been undertaken on the volcanic passive continental margin offshore Norway between 62° and 70°N during the last 25 years. Three main margin segments have been identified, the Lofoten-Vesteralen Margin, the Vøring Margin and the Møre Margin. The main features of the margins are prominent marginal highs, including seaward dipping reflector sequences and an up to 22 km thick volcanic and transitional crust, prominent escarpments (the Vøring Plateau Escarpment and the Faeroe-Shetland Escarpment), and up to 12 km deep post-Jurassic sedimentary basins east of the escarpments. Velocity-depth solutions from about 250 sonobuoys, expanding spread profiles and refraction profiles have been compiled and contoured. Isovelocity horizon contour maps and velocity transects outline a crust which broadly thickens from an oceanic crust with a normal oceanic-type velocity structure to a ca. 35 km thick continental crust with a continental velocity structure, beneath the Norwegian coast. Anomalous features include local crustal thickening below the Møre and Vering marginal highs, and high-velocity bodies in the lower crust in the extension of the Precambrian Lofoten-Vesterålen archipelago. The free-air SEASAT-derived gravity anomalies show a good correlation with the high-velocity bodies, and show prominent NE-trending highs from the Rockall Plateau/Porcupine Plateau region, over the Møre, Vøring and Lofoten-Vesterålen margins, to the southwestern Barents Sea.

  7. Development of superconductor bulk for superconductor bearing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Joong; Jun, Byung Hyuk; Park, Soon Dong (and others)

    2008-08-15

    Current carrying capacity is one of the most important issues in the consideration of superconductor bulk materials for engineering applications. There are numerous applications of Y-Ba-Cu-O (YBCO) bulk superconductors e.g. magnetic levitation train, flywheel energy storage system, levitation transportation, lunar telescope, centrifugal device, magnetic shielding materials, bulk magnets etc. Accordingly, to obtain YBCO materials in the form of large, single crystals without weak-link problem is necessary. A top seeded melt growth (TSMG) process was used to fabricate single crystal YBCO bulk superconductors. The seeded and infiltration growth (IG) technique was also very promising method for the synthesis of large, single-grain YBCO bulk superconductors with good superconducting properties. 5 wt.% Ag doped Y211 green compacts were sintered at 900 .deg. C {approx} 1200 .deg.C and then a single crystal YBCO was fabricated by an infiltration method. A refinement and uniform distribution of the Y211 particles in the Y123 matrix were achieved by sintering the Ag-doped samples. This enhancement of the critical current density was ascribable to a fine dispersion of the Y211 particles, a low porosity and the presence of Ag particles. In addition, we have designed and manufactured large YBCO single domain with levitation force of 10-13 kg/cm{sup 2} using TSMG processing technique.

  8. Into the Bulk: A Covariant Approach

    CERN Document Server

    Engelhardt, Netta

    2016-01-01

    I propose a general, covariant way of defining when one region is "deeper in the bulk" than another. This definition is formulated outside of an event horizon (or in the absence thereof) in generic geometries; it may be applied to both points and surfaces, and may be used to compare the depth of bulk points or surfaces relative to a particular boundary subregion or relative to the entire boundary. Using the recently proposed "lightcone cut" formalism, the comparative depth between two bulk points can be determined from the singularity structure of Lorentzian correlators in the dual field theory. I prove that, by this definition, causal wedges of progressively larger regions probe monotonically deeper in the bulk. The definition furthermore matches expectations in pure AdS and in static AdS black holes with isotropic spatial slices, where a well-defined holographic coordinate exists. In terms of holographic RG flow, this new definition of bulk depth makes contact with coarse-graining over both large distances ...

  9. The role of length scales in bridging the gap between rock CPO and seismic signals of crustal anisotropy

    Science.gov (United States)

    Okaya, D.; Johnson, S. E.; Vel, S. S.; Song, W. J.; Christensen, N. I.

    2012-04-01

    Recent studies based on laboratory petrophysics and in particular EBSD-based calculations indicate material rock anisotropy for crustal rocks can possess significant low orders of symmetry. These symmetries based on elastic tensor calculations can range from hexagonal and orthorhombic down to monoclinic and triclinic. On the other hand, interpretation of field seismic data yield crustal anisotropy of fast- or slow-axis transverse isotropy (hexagonal) symmetry at best; identification of orthorhombic symmetry is barely possible. Seismic results are often limited to simple orientations of the symmetry axes, such as vertical (radial anisotropy) or horizontal (azimuthal anisotropy). The physical scales of earth anisotropic fabrics and of seismic waves affect the types of information that may be extracted from seismic signals. A seismic wave has inherent limits to resolving capabilities, usually measured as some percentage of its wavelength, λ. This wave will accumulate anisotropic signal in two ways based on its path through anisotropic media of physical size, L: (1) When the wave is much smaller than the anisotropic material (λ material (λ >> L), the wave will not see details of the material but will respond to just the bulk average of the material. In the first case, the wave will be sensitive to large scale earth changes such as limbs of an antiformal mountain range. The accumulating anisotropic seismic signal can get complicated (e.g., shear wave splits of splits). In the second case, the wave is too large to see any fine detail, and the material can be represented by an equivalent "effective media" that produces the same seismic response. Geometrical structure is a factor that helps bridge the scales of rock CPO to lower resolution seismic signals. Local rock CPO can fill or be mapped into a structure that is large enough for a seismic wave to respond to. We use tensor representation of anisotropic elasticity to formulate a way to separate structural effects

  10. A COMPARISON OF TWO METHODS FADING MEMORY FILTER AND ADAPTIVE KALMAN FILTER IN MONITORING CRUSTAL MOVEMENT

    OpenAIRE

    Cahit Tağı ÇELİK

    2004-01-01

    Monitoring the Crustal Movement in Geodesy is performed by the deformation survey and analysis. If monitoring the crustal movements involves more than two epochs of survey campaign then from the plate tectonic theory, stations do not move randomly from one epoch to the other, therefore Kalman Filter may be suitable to use. However, if sudden movements happened in the crust in particular earthquake happened, the crust moves very fast in a very short period of time. When Kalman Filter used for ...

  11. Use of MAGSAT anomaly data for crustal structure and mineral resources in the US midcontinent

    Science.gov (United States)

    Carmichael, R. S.

    1983-01-01

    Magnetic field data acquired by NASA's MAGSAT satellite is used to construct a long-wavelength magnetic anomaly map for the U.S. midcontinent. This aids in interpretation of gross crustal geology (structure, lithologic composition, resource potential) of the region. Magnetic properties of minerals and rocks are investigated and assessed, to help in evaluation and modelling of crustal magnetization sources and depth to the Curie-temperature isotherm.

  12. Crustal structure of the northern Gulf of Mexico from potential fields and seismic refraction

    Science.gov (United States)

    Norton, I. O.; Van Avendonk, H. J.; Christeson, G. L.; Eddy, D. R.

    2013-12-01

    A recent seismic refraction program in the northern offshore Gulf of Mexico (US waters) has greatly enhanced understanding of the crustal structure of this previously poorly-known region. These data are the first to show how crustal thickness varies across this area. Interpretations of crustal types derived from the refraction data have helped to delineate regions of oceanic and extended continental crust, as well as regions of crustal thickening probably associated with synrift volcanism. Onshore, however, there is still a lack of refraction data so understanding of crustal structure and therefore extension history is poorly constrained. Potential field modeling can help address this issue. It is well know that gravity modeling by itself can yield many different interpretations of density distributions and hence crustal structure. Combined with refraction data these interpretations can be much better constrained. In this study crustal structure for the onshore northern Gulf of Mexico is derived from the offshore refraction data combined with regional gravity and magnetic data, along with EarthScope interpretations of crust thickness. The lack of observed rift faulting in deep seismic reflection data in the region has long been a puzzle, as the several hundreds of kilometers of extension implied by plate reconstructions should have resulted in extensive faulting. The potential field data does suggest the existence of deep grabens parallel to the coast, associated with large magnetic anomalies that may indicate a partly magmatic margin in agreement with some published interpretations. These new interpretations are used to build a model of crustal evolution of the Gulf of Mexico.

  13. A Domain Decomposition Approach to Implementing Fault Slip in Finite-Element Models of Quasi-static and Dynamic Crustal Deformation

    CERN Document Server

    Aagaard, Brad T; Williams, Charles A

    2013-01-01

    We employ a domain decomposition approach with Lagrange multipliers to implement fault slip in a finite-element code, PyLith, for use in both quasi-static and dynamic crustal deformation applications. This integrated approach to solving both quasi-static and dynamic simulations leverages common finite-element data structures and implementations of various boundary conditions, discretization schemes, and bulk and fault rheologies. We have developed a custom preconditioner for the Lagrange multiplier portion of the system of equations that provides excellent scalability with problem size compared to conventional additive Schwarz methods. We demonstrate application of this approach using benchmarks for both quasi-static viscoelastic deformation and dynamic spontaneous rupture propagation that verify the numerical implementation in PyLith.

  14. Repeatability of corticospinal and spinal measures during lengthening and shortening contractions in the human tibialis anterior muscle.

    Directory of Open Access Journals (Sweden)

    Jamie Tallent

    Full Text Available UNLABELLED: Elements of the human central nervous system (CNS constantly oscillate. In addition, there are also methodological factors and changes in muscle mechanics during dynamic muscle contractions that threaten the stability and consistency of transcranial magnetic stimulation (TMS and perpherial nerve stimulation (PNS measures. PURPOSE: To determine the repeatability of TMS and PNS measures during lengthening and shortening muscle actions in the intact human tibialis anterior. METHODS: On three consecutive days, 20 males performed lengthening and shortening muscle actions at 15, 25, 50 and 80% of maximal voluntary contraction (MVC. The amplitude of the Motor Evoked Potentials (MEPs produced by TMS was measured at rest and during muscle contraction at 90° of ankle joint position. MEPs were normalised to Mmax determined with PNS. The corticospinal silent period was recorded at 80% MVC. Hoffman reflex (H-reflex at 10% isometric and 25% shortening and lengthening MVCs, and V-waves during MVCs were also evoked on each of the three days. RESULTS: With the exception of MEPs evoked at 80% shortening MVC, all TMS-derived measures showed good reliability (ICC = 0.81-0.94 from days 2 to 3. Confidence intervals (CI, 95% were lower between days 2 and 3 when compared to days 1 and 2. MEPs significantly increased at rest from days 1 to 2 (P = 0.016 and days 1 to 3 (P = 0.046. The H-reflex during dynamic muscle contraction was reliable across the three days (ICC = 0.76-0.84. V-waves (shortening, ICC = 0.77, lengthening ICC = 0.54 and the H-reflex at 10% isometric MVC (ICC = 0.66 was generally less reliable over the three days. CONCLUSION: Although it is well known that measures of the intact human CNS exhibit moment-to-moment fluctuations, careful experimental arrangements make it possible to obtain consistent and repeatable measurements of corticospinal and spinal excitability in the actively lengthening and shortening human

  15. Seismic evidence for widespread western-US deep-crustal deformation caused by extension.

    Science.gov (United States)

    Moschetti, M P; Ritzwoller, M H; Lin, F; Yang, Y

    2010-04-01

    Laboratory experiments have established that many of the materials comprising the Earth are strongly anisotropic in terms of seismic-wave speeds. Observations of azimuthal and radial anisotropy in the upper mantle are attributed to the lattice-preferred orientation of olivine caused by the shear strains associated with deformation, and provide some of the most direct evidence for deformation and flow within the Earth's interior. Although observations of crustal radial anisotropy would improve our understanding of crustal deformation and flow patterns resulting from tectonic processes, large-scale observations have been limited to regions of particularly thick crust. Here we show that observations from ambient noise tomography in the western United States reveal strong deep (middle to lower)-crustal radial anisotropy that is confined mainly to the geological provinces that have undergone significant extension during the Cenozoic Era (since approximately 65 Myr ago). The coincidence of crustal radial anisotropy with the extensional provinces of the western United States suggests that the radial anisotropy results from the lattice-preferred orientation of anisotropic crustal minerals caused by extensional deformation. These observations also provide support for the hypothesis that the deep crust within these regions has undergone widespread and relatively uniform strain in response to crustal thinning and extension. PMID:20376148

  16. Crustal anisotropy and ductile flow beneath the eastern Tibetan Plateau and adjacent areas

    Science.gov (United States)

    Kong, Fansheng; Wu, Jing; Liu, Kelly H.; Gao, Stephen S.

    2016-05-01

    Crustal anisotropy beneath 71 broadband seismic stations situated at the eastern Tibetan Plateau and the Sichuan Basin is investigated based on the sinusoidal moveout of P-to-S conversions from the Moho and an intra-crustal discontinuity. Significant crustal anisotropy is pervasively detected beneath the study area with an average splitting time of 0.39 ± 0.18 s. The resulting fast orientations are mostly parallel to the major shear zones in the Songpan-Ganzi Terrane, and can be explained by fluid-filled fractures, favoring the model of rigid block motion with deformations concentrated on the block boundaries. In the vicinity of the Xianshuihe-Xiaojiang Fault Zone in the southern Songpan-Ganzi Terrane, our results, when combined with previously revealed high crustal Poisson's ratio in the area, support the existence of mid/lower crustal flow. The Longmenshan Fault Zone and adjacent areas are dominated by strike-orthogonal fast orientations, which are consistent with alignments of cracks associated with compressional stress between the Plateau and the Sichuan Basin. The observations suggest that crustal thickening is the main cause of the high topographic relief across the Longmenshan Fault Zone.

  17. Near-axis crustal structure and thickness of the Endeavour Segment, Juan de Fuca Ridge

    Science.gov (United States)

    Soule, Dax; Wilcock, William S. D.; Toomey, Douglas R.; Hooft, Emilie E. E.; Weekly, Robert T.

    2016-06-01

    A model of crustal thickness and lower crustal velocities is obtained for crustal ages of 0.1-1.2 Ma on the Endeavour Segment of the Juan de Fuca Ridge by inverting travel times of crustal paths and non-ridge-crossing wide-angle Moho reflections obtained from a three-dimensional tomographic experiment. The crust is thicker by 0.5-1 km beneath a 200 m high plateau that extends across the segment center. This feature is consistent with the influence of the proposed Heckle melt anomaly on the spreading center. The history of ridge propagation on the Cobb overlapping spreading center may also have influenced the formation of the plateau. The sharp boundaries of the plateau and crustal thickness anomaly suggest that melt transport is predominantly upward in the crust. Lower crustal velocities are lower at the ends of the segment, likely due to increased hydrothermal alteration in regions influenced by overlapping spreading centers, and possibly increased magmatic differentiation.

  18. Orchestrating Bulk Data Movement in Grid Environments

    Energy Technology Data Exchange (ETDEWEB)

    Vazhkudai, SS

    2005-01-25

    Data Grids provide a convenient environment for researchers to manage and access massively distributed bulk data by addressing several system and transfer challenges inherent to these environments. This work addresses issues involved in the efficient selection and access of replicated data in Grid environments in the context of the Globus Toolkit{trademark}, building middleware that (1) selects datasets in highly replicated environments, enabling efficient scheduling of data transfer requests; (2) predicts transfer times of bulk wide-area data transfers using extensive statistical analysis; and (3) co-allocates bulk data transfer requests, enabling parallel downloads from mirrored sites. These efforts have demonstrated a decentralized data scheduling architecture, a set of forecasting tools that predict bandwidth availability within 15% error and co-allocation architecture, and heuristics that expedites data downloads by up to 2 times.

  19. A diphoton resonance from bulk RS

    Science.gov (United States)

    Csáki, Csaba; Randall, Lisa

    2016-07-01

    Recent LHC data hinted at a 750 GeV mass resonance that decays into two photons. A significant feature of this resonance is that its decays to any other Standard Model particles would be too low to be detected so far. Such a state has a compelling explanation in terms of a scalar or a pseudoscalar that is strongly coupled to vector states charged under the Standard Model gauge groups. Such a scenario is readily accommodated in bulk RS with a scalar localized in the bulk away from but close to the Higgs. Turning this around, we argue that a good way to find the elusive bulk RS model might be the search for a resonance with prominent couplings to gauge bosons.

  20. Bulk fields from the boundary OPE

    CERN Document Server

    Guica, Monica

    2016-01-01

    Previous work has established an equality between the geodesic integral of a free bulk field in AdS and the contribution of the conformal descendants of its dual CFT primary operator to the OPE of two other operators inserted at the endpoints of the geodesic. Working in the context of AdS$_3$/CFT$_2$, we extend this relation to include all $1/N$ corrections to the bulk field obtained by dressing it with i) a $U(1)$ current and ii) the CFT stress tensor, and argue it equals the contribution of the Ka\\v{c}-Moody/the Virasoro block to the respective boundary OPE. This equality holds for a particular framing of the bulk field to the boundary that involves a split Wilson line.

  1. Multiphase composites with extremal bulk modulus

    DEFF Research Database (Denmark)

    Gibiansky, L. V.; Sigmund, Ole

    2000-01-01

    This paper is devoted to the analytical and numerical study of isotropic elastic composites made of three or more isotropic phases. The ranges of their effective bulk and shear moduli are restricted by the Hashin-Shtrikman-Walpole (HSW) bounds. For two-phase composites, these bounds are attainable......, that is, there exist composites with extreme bulk and shear moduli. For multiphase composites, they may or may not be attainable depending on phase moduli and volume fractions. Sufficient conditions of attainability of the bounds and various previously known and new types of optimal composites...... are described. Most of our new results are related to the two-dimensional problem. A numerical topology optimization procedure that solves the inverse homogenization problem is adopted and used to look for two-dimensional three-phase composites with a maximal effective bulk modulus. For the combination...

  2. A Diphoton Resonance from Bulk RS

    CERN Document Server

    Csaki, Csaba

    2016-01-01

    Recent LHC data hints at a 750 GeV mass resonance that decays into two photons. A significant feature of this resonance is that its decays to Higges and to any other Standard Model particles are so far too low to be detected. Such a state has a compelling explanation in terms of a scalar or a pseudoscalar that is strongly coupled to vector states charged under the Standard Model gauge groups. We argue that if the state is a scalar, some form of sequestering is likely to be necessary to naturally explain the suppressed scalar-Higgs interactions. Such a scenario is readily accommodated in bulk RS with a scalar localized in the bulk away from the Higgs. Turning this around, we argue that a good way to find the elusive bulk RS model might be the search for a resonance with prominent couplings to gauge bosons.

  3. Bulk Comptonization by Turbulence in Accretion Disks

    CERN Document Server

    Kaufman, J

    2016-01-01

    Radiation pressure dominated accretion discs around compact objects may have turbulent velocities that greatly exceed the electron thermal velocities within the disc. Bulk Comptonization by the turbulence may therefore dominate over thermal Comptonization in determining the emergent spectrum. Bulk Comptonization by divergenceless turbulence is due to radiation viscous dissipation only. It can be treated as thermal Comptonization by solving the Kompaneets equation with an equivalent "wave" temperature, which is a weighted sum over the power present at each scale in the turbulent cascade. Bulk Comptonization by turbulence with non-zero divergence is due to both pressure work and radiation viscous dissipation. Pressure work has negligible effect on photon spectra in the limit of optically thin turbulence, and in this limit radiation viscous dissipation alone can be treated as thermal Comptonization with a temperature equivalent to the full turbulent power. In the limit of extremely optically thick turbulence, ra...

  4. Shortening treatment time in robotic radiosurgery using a novel node reduction technique

    Energy Technology Data Exchange (ETDEWEB)

    Water, Steven van de; Hoogeman, Mischa S.; Breedveld, Sebastiaan; Heijmen, Ben J. M. [Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands)

    2011-03-15

    Purpose: The fraction duration of robotic radiosurgery treatments can be reduced by generating more time-efficient treatment plans with a reduced number of node positions, beams, and monitor units (MUs). Node positions are preprogramed locations where the robot can position the focal spot of the x-ray beam. As the time needed for the robot to travel between node positions takes up a large part of the treatment time, the aim of this study was to develop and evaluate a node reduction technique in order to reduce the treatment time per fraction for robotic radiosurgery. Methods: Node reduction was integrated into the inverse planning algorithm, developed in-house for the robotic radiosurgery modality. It involved repeated inverse optimization, each iteration excluding low-contribution node positions from the planning and resampling new candidate beams from the remaining node positions. Node reduction was performed until the exclusion of a single node position caused a constraint violation, after which the shortest treatment plan was selected retrospectively. Treatment plans were generated with and without node reduction for two lung cases of different complexity, one oropharyngeal case and one prostate case. Plan quality was assessed using the number of node positions, beams and MUs, and the estimated treatment time per fraction. All treatment plans had to fulfill all clinical dose constraints. Extra constraints were added to maintain the low-dose conformality and restrict skin doses during node reduction. Results: Node reduction resulted in 12 residual node positions, on average (reduction by 77%), at the cost of an increase in the number of beams and total MUs of 28% and 9%, respectively. Overall fraction durations (excluding patient setup) were shortened by 25% (range of 18%-40%), on average. Dose distributions changed only little and dose in low-dose regions was effectively restricted by the additional constraints. Conclusions: The fraction duration of robotic

  5. Decoupling of modern shortening rates, climate, and topography in the Caucasus

    Science.gov (United States)

    Forte, Adam M.; Whipple, Kelin X.; Bookhagen, Bodo; Rossi, Matthew W.

    2016-09-01

    The Greater and Lesser Caucasus mountains and their associated foreland basins contain similar rock types, experience a similar two-fold, along-strike variation in mean annual precipitation, and were affected by extreme base-level drops of the neighboring Caspian Sea. However, the two Caucasus ranges are characterized by decidedly different tectonic regimes and rates of deformation that are subject to moderate (less than an order of magnitude) gradients in climate, and thus allow for a unique opportunity to isolate the effects of climate and tectonics in the evolution of topography within active orogens. There is an apparent disconnect between modern climate, shortening rates, and topography of both the Greater Caucasus and Lesser Caucasus which exhibit remarkably similar topography along-strike despite the gradients in forcing. By combining multiple datasets, we examine plausible causes for this disconnect by presenting a detailed analysis of the topography of both ranges utilizing established relationships between catchment-mean erosion rates and topography (local relief, hillslope gradients, and channel steepness) and combining it with a synthesis of previously published low-temperature thermochronologic data. Modern climate of the Caucasus region is assessed through an analysis of remotely-sensed data (TRMM and MODIS) and historical streamflow data. Because along-strike variation in either erosional efficiency or thickness of accreted material fail to explain our observations, we suggest that the topography of both the western Lesser and Greater Caucasus are partially supported by different geodynamic forces. In the western Lesser Caucasus, high relief portions of the landscape likely reflect uplift related to ongoing mantle lithosphere delamination beneath the neighboring East Anatolian Plateau. In the Greater Caucasus, maintenance of high topography in the western portion of the range despite extremely low (<2-4 mm/y) modern convergence rates may be related

  6. Is it Possible to Shorten the Duration of Schirmer Test I?

    Directory of Open Access Journals (Sweden)

    Ömer Faruk Recep

    2012-10-01

    Full Text Available Pur po se: Schirmer test I is commonly used in the diagnosis of dry eye, but its longer duration is a major problem in crowded clinics. In this study, Schirmer tests shorter than 5 minutes were compared with the results of 5-min Schirmer test. Ma te ri al and Met hod: In this study, 540 eyes of 270 patients having dry eye symptoms were evaluated. Those patients having lid abnormalities were not included in the study. The measurements were performed in 1st, 2nd, 3rd, 4th and 5th minutes using 5x37 mm Whatman No. 41 test papers. The results were analyzed using one-way ANOVA and Tukey’s test. Then probable wetting values were calculated for every minute and the results were compared with 5-min results. Re sults: Of the cases, 214 were female and 56 were male. The mean age was 57.62 years (range: 12-90 years, standard deviation: 14.35. We could not find any statistical significance among the measurements performed every minute (p>0.05. We found statistically significant difference between the measurements performed in the 1st and 3rd minutes, 1st and 4th minutes, and 1st and 5th minutes ( p<0,05. The same tests were applied to the cases having 9 mm or below Schirmer test results at the end of 5 minutes and the only statistical significance was found between the measurement taken in the 1st and 4th minutes (p<0.05. The probable dry eye values in the 1st, 2nd, 3rd and 4th minutes were compared with the result of 5th minute and the nearest values were obtained in the 2nd-minute measurements. Out of 114 dry eye cases according to 5-min results, 87 (76.32% were detected at the end of 2-min test. Dis cus si on: The values obtained in the 1st, 2nd, 3rd and 4th minutes did not correspond to the Schirmer test result obtained in the 5th minute. If the results obtained in the early minutes were regarded as correct, a lot of dry eye patients could not be diagnosed. So, we found inappropriate to shorten the duration of Schirmer test I. (Turk J Ophthalmol 2012

  7. Telomeres shorten more slowly in slow-aging wild animals than in fast-aging ones.

    Science.gov (United States)

    Dantzer, Ben; Fletcher, Quinn E

    2015-11-01

    Research on the physiological causes of senescence aim to identify common physiological mechanisms that explain age-related declines in fitness across taxonomic groups. Telomeres are repetitive nucleotide sequences found on the ends of eukaryotic chromosomes. Past research indicates that telomere attrition is strongly correlated with inter-specific rates of aging, though these studies cannot distinguish whether telomere attrition is a cause or consequence of the aging process. We extend previous research on this topic by incorporating recent studies to test the hypothesis that telomeres shorten more slowly with age in slow-aging animals than in fast-aging ones. We assembled all studies that have quantified cross-sectional (i.e. between-individual) telomere rates of change (TROC) over the lifespans of wild animals. This included 22 estimates reflecting absolute TROC (TROCabs, bp/yr, primarily measured using the terminal restriction fragment length method), and 10 estimates reflecting relative TROC (TROCrel, relative telomere length/yr, measured using qPCR), from five classes (Aves, Mammalia, Bivalvia, Reptilia, and Actinopterygii). In 14 bird species, we correlated between-individual (i.e. cross-sectional) TROCabs estimates with both maximum lifespan and a phylogenetically-corrected principle component axis (pcPC1) that reflected the slow-fast axis of life-history variation. Bird species characterized by faster life-histories and shorter maximum lifespans had faster TROCabs. In nine studies, both between-individual and within-individual TROC estimates were available (n=8 for TROCabs, n=1 for TROCrel). Within-individual TROC estimates were generally greater than between-individual TROC estimates, which is indicative of selective disappearance of individuals with shorter telomeres. However, the difference between within- and between-individual TROC estimates was only significant in two out of nine studies. The relationship between within-individual TROCabs and maximum

  8. The randomized shortened dental arch study (RaSDA: design and protocol

    Directory of Open Access Journals (Sweden)

    Kern Matthias

    2010-02-01

    Full Text Available Abstract Background Various treatment options for the prosthetic treatment of jaws where all molars are lost are under discussion. Besides the placement of implants, two main treatment types can be distinguished: replacement of the missing molars with removable dental prostheses and non-replacement of the molars, i.e. preservation of the shortened dental arch. Evidence is lacking regarding the long-term outcome and the clinical performance of these approaches. High treatment costs and the long time required for the treatment impede respective clinical trials. Methods/design This 14-center randomized controlled investigator-initiated trial is ongoing. Last patient out will be in 2010. Patients over 35 years of age with all molars missing in one jaw and with at least both canines and one premolar left on each side were eligible. One group received a treatment with removable dental prostheses for molar replacement (treatment A. The other group received a treatment limited to the replacement of all missing anterior and premolar teeth using fixed bridges (treatment B. A pilot trial with 32 patients was carried out. Two hundred and fifteen patients were enrolled in the main trial where 109 patients were randomized for treatment A and 106 for treatment B. The primary outcome measure is further tooth loss during the 5-year follow-up. The secondary outcome measures encompassed clinical, technical and subjective variables. The study is funded by the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG WA 831/2-1, 2-2, 2-3, 2-4, 2-5. Discussion The particular value of this trial is the adaptation of common design components to the very specific features of complex dental prosthetic treatments. The pilot trial proved to be indispensable because it led to a number of adjustments in the study protocol that considerably improved the practicability. The expected results are of high clinical relevance and will show the efficacy of two common

  9. Radiation-hardened bulk CMOS technology

    International Nuclear Information System (INIS)

    The evolutionary development of a radiation-hardened bulk CMOS technology is reviewed. The metal gate hardened CMOS status is summarized, including both radiation and reliability data. The development of a radiation-hardened bulk silicon gate process which was successfully implemented to a commercial microprocessor family and applied to a new, radiation-hardened, LSI standard cell family is also discussed. The cell family is reviewed and preliminary characterization data is presented. Finally, a brief comparison of the various radiation-hardened technologies with regard to performance, reliability, and availability is made

  10. Remedial investigations for quarry bulk wastes

    International Nuclear Information System (INIS)

    The US Department of Energy proposes, as a separate operable unit of the Weldon Spring Site Remedial Action Project, to remove contaminated bulk wastes from the Weldon Spring quarry and transport them approximately four miles to the chemical plant portion of the raffinate pits and chemical plant area. The wastes will be held in temporary storage prior to the record of decision for the overall remedial action. The decision on the ultimate disposal of these bulk wastes will be included as part of the decision for management of the waste materials resulting from remedial action activities at the raffinate pits and chemical plant area. 86 refs., 71 figs., 83 tabs

  11. Bulk Entropy in Loop Quantum Gravity

    OpenAIRE

    Livine, Etera R; Terno, Daniel R.

    2007-01-01

    In the framework of loop quantum gravity (LQG), having quantum black holes in mind, we generalize the previous boundary state counting (gr-qc/0508085) to a full bulk state counting. After a suitable gauge fixing we are able to compute the bulk entropy of a bounded region (the "black hole") with fixed boundary. This allows us to study the relationship between the entropy and the boundary area in details and we identify a holographic regime of LQG where the leading order of the entropy scales w...

  12. Bulk Entropy in Loop Quantum Gravity

    CERN Document Server

    Livine, Etera R

    2007-01-01

    In the framework of loop quantum gravity (LQG), having quantum black holes in mind, we generalize the previous boundary state counting (gr-qc/0508085) to a full bulk state counting. After a suitable gauge fixing we are able to compute the bulk entropy of a bounded region (the "black hole") with fixed boundary. This allows us to study the relationship between the entropy and the boundary area in details and we identify a holographic regime of LQG where the leading order of the entropy scales with the area. We show that in this regime we can fine tune the factor between entropy and area without changing the Immirzi parameter.

  13. Thermal relics in cosmology with bulk viscosity

    International Nuclear Information System (INIS)

    In this paper we discuss some consequences of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. The latter takes into account the dissipative effects (bulk viscosity) arising from different cooling rates of the fluid components in the expanding Universe. We discuss, in particular, the effects of the bulk viscosity on Big Bang Nucleosynthesis and on the thermal relic abundance of particles, looking at recent results of PAMELA experiment. The latter has determined an anomalous excess of positron events, which cannot be explained by conventional cosmology and particle physics. (orig.)

  14. Synthesis of Bulk Superconducting Magnesium Diboride

    Directory of Open Access Journals (Sweden)

    Margie Olbinado

    2002-06-01

    Full Text Available Bulk polycrystalline superconducting magnesium diboride, MgB2, samples were successfully prepared via a one-step sintering program at 750°C, in pre Argon with a pressure of 1atm. Both electrical resistivity and magnetic susceptibility measurements confirmed the superconductivity of the material at 39K, with a transition width of 5K. The polycrystalline nature, granular morphology, and composition of the sintered bulk material were confirmed using X-ray diffractometry (XRD, scanning electron microscopy (SEM, and energy dispersive X-ray analysis (EDX.

  15. Shortening day length as a previously unrecognized selective pressure for early breeding in a bird with long parental care

    OpenAIRE

    Podlaszczuk, Marcin; Wojciechowski, Zbigniew; Podlaszczuk, Patrycja; Minias, Piotr; Janiszewski, Tomasz; Wojciechowska, Agnieszka

    2014-01-01

    Several different selective pressures have been suggested to explain an intense competition for early return to breeding grounds in birds. In this study we hypothesized that shortening day length during summer months may constitute additional selective force acting towards early breeding in avian species with long parental care. To test this hypothesis, we studied time budget and foraging activities of early-nesting and late-nesting white storks Ciconia ciconia from th...

  16. Crystallization and preliminary X-ray crystallographic analysis of yeast prion protein Ure2p with shortened N-terminal

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An orthorhombic crystal form of a recombinant yeast prion protein with shortened N-terminal, 90Ure2p, has been obtained. Crystals were grown by the vapordiffusion technique against a mother liquor containing imidazole. Crystals belong to the primitive orthorhombic lattice with the cell parameters a = 54.5 ?, b = 74.7 ?, c = 131.0 ?. The crystals diffract to beyond 3.0 ? resolution at a synchrotron beamline.

  17. Magnetic resonance (MR) imaging of lumbar spine: use of a shortened protocol for initial investigation of degenerative disease.

    OpenAIRE

    Mullan, C. P.; Kelly, B. E.

    2005-01-01

    PURPOSE: To assess the potential use of shortened protocol MRI of lumbar spine in the investigation of degenerative disc disease in Northern Ireland. MATERIALS & METHODS: Prospective study of 35 patients having MR imaging of lumbar spine performed during a 12-month period by one consultant radiologist. T1-weighted and T2-weighted sagittal images of lumbar spine were obtained in all cases, as well as T2-weighted axial images. The detection of degenerative disc disease by sagittal T2-weighted i...

  18. Shortening of the 3' untranslated region: an important mechanism leading to overexpression of HMGA2 in serous ovarian cancer

    Institute of Scientific and Technical Information of China (English)

    He Xiangjun; Yang Jing; Zhang Qi; Cui Heng; Zhang Yujun

    2014-01-01

    Background Oncofetal protein high-mobility-group AT-hook protein 2 (HMGA2) is reactivated in serous ovarian cancer (SOC) and its overexpression correlates with poor prognosis.To explore the mechanism,we investigated whether HMGA2 could avoid microRNA regulation due to gene truncation or 3' UTR shortening by alternative polyadenylation.Methods Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to evaluate the abundance of different regions of HMGA2 mRNA in 46 SOC samples.Rapid amplification of cDNA 3' ends (3' RACE) and Southern blotting were used to confirm the shortening of 3' untranslated region (UTR).5' RACE and Southern blotting were used to prove the mRNA decay.Results No significant difference in the ratio of the stable coding region to the fragile region was observed between SOC and control normal fallopian tubes,indicating that the HMGA2 gene is not truncated in SOC.Varying degrees of 3' UTR shortening in SOC samples were observed by comparing the abundance of the proximal region and distal region of the HMGA2 3' UTR.The ratio of the proximal to the distal region of the 3' UTR correlated significantly with expression of the HMGA2 coding region in SOC (r=0.579,P <0.01).Moreover,although the abundance of the HMGA2 coding region varied,all samples,including the very low expressed samples,exhibit relatively high levels of the proximal 3' UTR region,suggesting a dynamic decay of HMGA2 mRNA from the 5' end.The shortening of 3' UTR and the decay from the 5' end were confirmed by 3' RACE,5' RACE and subsequent Southern blotting.Conclusion Heterogeneous 3' UTR lengths render HMGA2 susceptible to different levels of negative regulation by microRNAs,which represents an important mechanism of HMGA2 reactivation in SOC.

  19. Crustal structure across the Xisha Trough, northwestern South China Sea

    Science.gov (United States)

    Qiu, Xuelin; Ye, Sanyu; Wu, Shimin; Shi, Xiaobin; Zhou, Di; Xia, Kanyuan; Flueh, Ernst R.

    2001-11-01

    Located at the northwestern part of the South China Sea (SCS) between the Hainan and Xisha (Paracel) Islands, the Xisha Trough represents a failed rift in conjunction with the opening of the SCS between 32 and 17 Ma. From west towards east within a scale of several hundred kilometers, it presents all major stages of the rifting process, and thus, provides an ideal place to study the rifting process in great details. In the autumn of 1996, a joint team of Sino-German scientists carried out a wide-angle seismic experiment across the Xisha Trough with 10 ocean bottom hydrophones (OBH) along a 237-km NNW-SSE-oriented profile, which was surveyed in 1987 with multi-channel seismic (MCS) method by BGR of Germany and SOA of China. Favorable weather conditions and the powerful 4×12-l air gun array rendered very good quality data with seismic signals observed at the offset of up to 110 km. A detailed velocity-depth model was obtained by using an interactive trial-and-error 2D ray-tracing method. Interpretation of the MCS data published by BGR provides very good geometrical constraints of the complex upper crustal structure, which is characterized by fault blocks, half-horsts and half-grabens filled with syn- and post-rift Cenozoic sediments. The velocity model in turn confirms the major structure outlined by the interpretation of the MCS data, showing a varying sedimentary layer between 1 and 4 km of thickness and velocities between 1.7 and 4.5 km/s. The P-wave velocity of 5.5 km/s on the top of the crystalline basement is relatively low, suggesting strong weathering. Within the crystalline crust, the velocity increases downward continuously to 6.8 km/s at the bottom of the crust without a clear differentiation in the middle crust, showing clearly its continental nature even beneath the Xisha Trough. The Moho is marked by a sharp first-order interface with a velocity of 8.0-8.1 km/s at the uppermost mantle. The Moho depth is 15 km beneath the center of the trough and

  20. The crustal structure of Beira High, Central Mozambique

    Science.gov (United States)

    Olaf Müller, Christian; Franke, Dieter; Heyde, Ingo; Schreckenberger, Bernd; Jokat, Wilfried

    2015-04-01

    Up to Jurassic times the Antarctic and African continents were part of the supercontinent Gondwana. Since some 185 Ma the rifting in our research area caused the dispersal of Gondwana and Eastern Africa. The timing and geometry of the break-up as well as the amount of volcanism connected to the Jurassic rifting are still controversial. In the southern part of the Mozambique channel a prominent basement high, the Beira High, forms a specific crustal anomaly along the margin. It is still controversial if this high is a continental fragment or was formed during a period of enhanced magmatism. Therefore a deep seismic profile with 37 OBS/H was acquired from the deep Mozambique Channel, across the Beira High and terminating on the shelf. The main objectives are to provide constraints on the crustal composition and origin of the Beira High as well as the amount of volcanism and the continent-ocean transition below the Zambezi Delta. To obtain a P-wave velocity model of this area the data was forward modelled by means of 2D-Raytracing. Furthermore, potential field data acquired in parallel to the seismic data were used to calculate a 2D gravity model. Preliminary results indicate a 20-24 km thick crust for the Beira High. In good agreement to the adjacent oceanic crust in the Mozambique Channel the upper crust has velocities between 5.5-5.9 km/s. The middle crust is characterised by velocities between 6.2-6.7 km/s and the lower crust higher than 6.7 km/s and a density of 3.0 g/cm3. However, these velocities are only constrained by Moho reflections, since no diving waves are observed for the lower crust. In the area of the Zambezi Delta Depression the top of the acoustic basement is at 11.5 km depth and the crust thickness thins to 7 km. The basement here is overlain by a 2 km thick layer of 4.9-5.1 km/s, which we interpret as pre-rift sediments (Karoo-Belo-Group, including Lava Flows on top). Furthermore, evidence for the presence of a high velocity body (HVB) at below

  1. Crustal structure of the Alps as seen by attenuation tomography

    Science.gov (United States)

    Mayor, Jessie; Calvet, Marie; Margerin, Ludovic; Vanderhaeghe, Olivier; Traversa, Paola

    2016-04-01

    We develop a simple tomographic approach exploiting the decay rate of coda waves to map the absorption properties of the crust in a region delimited approximately by the Rhine Graben to the North, the Apennines to the South, the Massif Central to the West and the Dinarides to the East. Our dataset comprises 40 000 coda records of about 2000 weak to moderate crustal earthquakes, with magnitude ranging from 2.8 to 6 and recorded by broad-band, accelerometric and short-period stations. After proper choice of a coda window minimizing the effects of variable epicentral distances, we measure the coda quality factor Qc in five non-overlapping frequency windows covering the 1-32 Hz band for all available source station pairs. These measurements are subsequently converted into maps of absorption quality factor (Qi) using a linearized, approximate relation between Qc and Qi. In practice the following procedure is applied in each frequency band: (1) we divide the target region into 40 × 40 km cells; (2) for each source-station pair, we assign the measured Qc value to each pixel intercepted by the direct ray path; (3) the results are averaged over all paths and subsequently smoothed with a 3 × 3 pixels moving window. Our approach is consistent with the high sensitivity of Qc to the value of Qi between source and station. Our tomographic approach reveals strong lateral variations of absorption with length scales ranging from 100 km to 1000 km. At low frequency (˜ 1 Hz), the correlation with the surface geology is clear, Cenozoic and Mesozoic sedimentary basins (resp. crystalline massifs) being recognized as high (resp. low)-absorption regions. Furthermore the Qi map delineates finer geological features such as the Ivrea Body, the Rhône Valley, or felsic intrusions in the central Alps. At high-frequency (>16 Hz), only the thickest Cenozoic sedimentary deposits show up as high-attenuation regions and a north/south dichotomy is apparent in the absorption structure. The limit

  2. The role of detrital zircons in Hadean crustal research

    Science.gov (United States)

    Nebel, Oliver; Rapp, Robert P.; Yaxley, Gregory M.

    2014-03-01

    Meso-Archean sedimentary sequences at Mt. Narryer and the Jack Hills of the Narryer Terrane in Western Australia's Yilgarn Craton contain detrital zircon grains with ages as old as 4.37 Ga, the oldest preserved terrestrial matter. These grains are rare remnants of Hadean (4.5-4.0 Ga) terrestrial crust and their survival stems from the crystallographic properties of zircon during crustal reworking: they are resistant to physical and chemical weathering. Zircons are further suitable for single grain, precise age determinations making them a unique archive of the crustal past. Only a small proportion of all detrital zircons from the Narryer Terrane show Hadean age spectra and younger overgrowth rims on all 'Hadean' grains indicate multiple recycling events. Numerous studies that applied a spectacular range of analytical tools and proxies have been undertaken to decipher the geochemical nature of these zircons' host rocks, in order to place constraints on Hadean geodynamics and the processes responsible for creating the earliest terrestrial crust. Their elemental and isotope budget and mineral inclusions have helped to develop an emerging picture of a water-rich, evolved Hadean crust. However, subsequent studies have challenged this view and it seems that each piece of new evidence indicative of an early, evolved continental crust has non-unique interpretations also permissive of mafic to ultra-mafic crust. In this review we examine these disparate interpretations and their possible implications and conclude that at least parts of the earliest terrestrial crust were hydrated. However, to date there is no conclusive evidence for preserved granitic, continental crust. The protoliths of the Hadean detrital zircons were likely acidic in nature, yet the composition of the greater terrane from which these melts were derived was probably mafic. It remains unclear if the zircons formed in a geodynamic environment that includes Hadean subduction. We suspect that the Hadean

  3. Microearthquakes and Crustal Structures in the Southern Okinawa Trough

    Science.gov (United States)

    Lin, J.; Sibuet, J.; Lee, C.; Hsu, S.; Klingelhoefer, F.; Auffret, Y.; Pelleau, P.; Crozon, J.

    2004-12-01

    Located east of Taiwan, the southern Okinawa Trough (SOT) is a portion of a young continental backarc basin, which is still in the rifting stage. Based on seismicity data, a slab tear was identified along 123.3°E. In order to better understand the nature and role of tectonic features in this region, a passive seismic Ocean Bottom Seismometer (OBS) experiment was conducted from November 19 to December 1, 2003. 15 OBSs were deployed in a 130 x 90 km area including the Ryukyu slab tear and the Cross Backarc Volcanic Trail (CBVT). OBSs with three 4.5 Hz component geophones and an hydrophone recorded about 4000 microearthquakes. Most of them (about 94%) are crustal earthquakes (0-20 km) which occured in the SOT central graben. Just a few earthquakes were recorded from the upper slope of the northern SOT and from the Ryukyu forearc. Most of the earthquake local magnitudes (ML) range from 1 to 2, even if the whole range of magnitudes spans from 0.9 to 4. Three clusters of high microearthquake activity are observed in : (1) the CBVT area (24.7-25°N; 122.5-123°E); (2) the southern central graben area (24.65-24.85°N;123-123.3°E); and (3) the northern central graben area (24.9-25.2°N ;123.2-123.65°E). The southern central graben cluster is also identified by the Japan Meteorological Agency (JMA). The earthquakes determined by the JMA in the northern central graben present larger magnitudes than ours, but are globally located 10-km south of our cluster. The CBVT cluster is not recorded in JMA data probably because the shallow (O-5 km) volcanic activity only involved small earthquakes which are too far from the JMA's network. Based on swath bathymetric and seismic data, most of the epicenters lie along already identified normal faults. Thus, except the volcanic activity, which occurs in the CBVT area, the main factor controlling the SOT tectonic activity is normal faulting. On the northern and southern slopes of the central graben, hypocenters occur along normal fauls

  4. Tracing crustal contamination along the Java segment of the Sunda Arc, Indonesia

    Science.gov (United States)

    Jolis, E. M.; Troll, V.; Deegan, F.; Blythe, L.; Harris, C.; Freda, C.; Hilton, D.; Chadwick, J.; Van Helden, M.

    2012-04-01

    Arc magmas typically display chemical and petrographic characteristics indicative of crustal input. Crustal contamination can take place either in the mantle source region or as magma traverses the upper crust (e.g. [1]). While source contamination is generally considered the dominant process (e.g. [2]), late-stage crustal contamination has been recognised at volcanic arcs too (e.g. [3]). In light of this, we aim to test the extent of upper crustal versus source contamination along the Java segment of the Sunda arc, which, due its variable upper crustal structure, is an exemplary natural laboratory. We present a detailed geochemical study of 7 volcanoes along a traverse from Anak-Krakatau in the Sunda strait through Java and Bali, to characterise the impact of the overlying crust on arc magma composition. Using rock and mineral elemental geochemistry, radiogenic (Sr, Nd and Pb) and, stable (O) isotopes, we show a correlation between upper crustal composition and the degree of upper crustal contamination. We find an increase in 87Sr/86Sr and δ18O values, and a decrease in 143Nd/144Nd values from Krakatau towards Merapi, indicating substantial crustal input from the thick continental basement present. Volcanoes to the east of Merapi and the Progo-Muria fault transition zone, where the upper crust is thinner, in turn, show considerably less crustal input in their isotopic signatures, indicating a stronger influence of the mantle source. Our new data represent a systematic and high-resolution arc-wide sampling effort that allows us to distinguish the effects of the upper crust on the compositional spectrum of individual volcanic systems along the Sunda arc. [1] Davidson, J.P, Hora, J.M, Garrison, J.M & Dungan, M.A 2005. Crustal Forensics in Arc Magmas. J. Geotherm. Res. 140, 157-170; [2] Debaille, V., Doucelance, R., Weis, D., & Schiano, P. 2005. Geochim. Cosmochim. Acta, 70,723-741; [3] Gasparon, M., Hilton, D.R., & Varne, R. 1994. Earth Planet. Sci. Lett., 126, 15-22.

  5. Lower crustal relaxation beneath the Tibetan Plateau and Qaidam Basin following the 2001 Kokoxili earthquake

    Science.gov (United States)

    Ryder, I.; Burgmann, R.; Pollitz, F.

    2011-01-01

    In 2001 November a magnitude 7.8 earthquake ruptured a 400 km long portion of the Kunlun fault, northeastern Tibet. In this study, we analyse over five years of post-seismic geodetic data and interpret the observed surface deformation in terms of stress relaxation in the thick Tibetan lower crust. We model GPS time-series (first year) and InSAR line of sight measurements (years two to five) and infer that the most likely mechanism of post-seismic stress relaxation is time-dependent distributed creep of viscoelastic material in the lower crust. Since a single relaxation time is not sufficient to model the observed deformation, viscous flow is modelled by a lower crustal Burgers rheology, which has two material relaxation times. The optimum model has a transient viscosity 9 ?? 1017 Pa s, steady-state viscosity 1 ?? 1019 Pa s and a ratio of long term to Maxwell shear modulus of 2:3. This model gives a good fit to GPS stations south of the Kunlun Fault, while displacements at stations north of the fault are over-predicted. We attribute this asymmetry in the GPS residual to lateral heterogeneity in rheological structure across the southern margin of the Qaidam Basin, with thinner crust/higher viscosities beneath the basin than beneath the Tibetan Plateau. Deep afterslip localized in a shear zone beneath the fault rupture gives a reasonable match to the observed InSAR data, but the slip model does not fit the earlier GPS data well. We conclude that while some localized afterslip likely occurred during the early post-seismic phase, the bulk of the observed deformation signal is due to viscous flow in the lower crust. To investigate regional variability in rheological structure, we also analyse post-seismic displacements following the 1997 Manyi earthquake that occurred 250 km west of the Kokoxili rupture. We find that viscoelastic properties are the same as for the Kokoxili area except for the transient viscosity, which is 5 ?? 1017 Pa s. The viscosities estimated for the

  6. Shallow Crustal Thermal Structures of Central Taiwan Foothills Region

    Directory of Open Access Journals (Sweden)

    Shao-Kai Wu

    2013-01-01

    Full Text Available Crustal thermal structures are closely related to metamorphism, rock rheology, exhumation processes, hydrocarbon maturation levels, frictional faulting and other processes. Drilling is the most direct way to access the temperature fields in the shallow crust. However, a regional drilling program for geological investigation is usually very expensive. Recently, a large-scale in-situ investigation program in the Western Foothills of Central Taiwan was carried out, providing a rare opportunity to conduct heat flow measurements in this region where there are debates as to whether previous measured heat flows are representative of the thermal state in this region. We successfully collected 28 geothermal gradients from these wells and converted them into heat flows. The new heat flow dataset is consistent with previous heat flows, which shows that the thermal structures of Central Taiwan are different from that of other subduction accretionary prisms. We then combine all the available heat flow information to analyze the frictional parameters of the Chelungpu fault zone that ruptured during the 1999, Chi-Chi, Taiwan, earthquake. The heat flow dataset gave consistent results compared with the frictional parameters derived from another independent study that used cores recovered from the Chelungpu fault zone at depth. This study also shows that it is suitable for using heat-flow data obtained from shallow subsurface to constrain thrusting faulting parameters, similar to what had been done for the strike-slip San Andreas Fault in California. Additional fieldworks are planned to study heat flows in other mountainous regions of Taiwan for more advanced geodynamic modeling efforts.

  7. New Crustal Stress Map of the Mediterranean and Central Europe

    Science.gov (United States)

    Heidbach, Oliver; Custodio, Susana; Kingdon, Andrew; Mariucci, Maria Teresa; Montone, Paola; Müller, Birgit; Pierdominicini, Simona; Rajabi, Mojtaba; Reinecker, John; Reiter, Karsten; Tingay, Mark; Williams, John; Ziegler, Moritz

    2016-04-01

    The World Stress Map (WSM) Project was initiated in 1986 under the auspices of the International Lithosphere Program in order to compile globally the information on the contemporary crustal stress state. For the 30th anniversary the WSM database has been updated and increased the number of data records from 21,750 to 42,410 worldwide. For the Mediterranean and Central European stress map the number of data records has increased from 3877 to 8192. The data come from a wide range of stress indicators such as borehole data (e.g. hydraulic fracturing, drilling induced tensile fractures, borehole breakouts), earthquake focal mechanism solutions and stress inversions from these, engineering methods (overcoring, borehole slotter) and geological data (e.g. volcanic alignment, inversion of fault slip data). To guarantee the comparability of the different stress indicator the resulting data are quality-ranked using the WSM quality ranking scheme. The new data set has a better coverage and enables us to identifying the regional and local variability of the stress pattern. For the Mediterranean and Central Europe we analysed the wave-length of the stress pattern by determining the mean orientation of the maximum horizontal stress SHmax on a regular grid using an updated version of the hybrid approach of Heidbach et al. [2010]. The preliminary results show that the Africa-Eurasia plate convergence is a key control of the overall stress pattern. However, given the complex tectonic setting in particular due to the indentation/collision of the Adriatic micro block, the Alpine topography as well as forces that control the movement of the Anatolian and Aegean block, the stress pattern shows in these regions significant changes in the mean SHmax orientation as well as in the tectonic regime.

  8. Effect of shortening replacement with flaxseed oil on physical, sensory, fatty acid and storage characteristics of cookies.

    Science.gov (United States)

    Rangrej, V; Shah, V; Patel, J; Ganorkar, P M

    2015-06-01

    Omega-3 fatty acid imparted good evidence of health benefits. Flaxseed oil, being the richest vegetarian source of alpha linolenic acid (omega-3 fatty acid), was incorporated in cookies by replacing shortening at level of 5 %, 10 %, 20 %, 30 %, 40 % and 50 %. Effect of shortening replacement with flaxseed oil on physical, textural and sensory attributes were investigated. Spread ratio and breaking strength of cookies increased as flaxseed oil level increased. Sensory score was not significantly affected up to 30 % shortening replacement with flaxseed oil as compared with the control cookies. Above 30 % flaxseed oil, sensory score was adversely affected. Fatty acid profile confirmed the enhancement of omega-3 fatty acid from 0 (control) to 14.14 % (30 % flaxseed oil cookies). The poly-unsaturated to saturated fatty acid ratio (P/S) increased from 0.088 (control) to 0.57 while ω - 6 to ω -3 fatty acid ratio of flaxseed oil cookies decreased from 4.51 (control) to 0.65 in the optimized cookies. The data on storage characteristics of the control and 30 % flaxseed oil cookies showed that there was significant change in the moisture content, Peroxide value (PV) and overall acceptability (OAA) up to 28 days of storage at 45 °C packed in polyethylene bags. Flaxseed oil cookies were acceptable up to 21 days of storage and afterwards noticeable off flavour was perceived. PMID:26028753

  9. Lipid Peroxidation-Mediated Telomere Shortening in Hydroxyl Radical-Induced Apoptosis in HeLa Cells

    Institute of Scientific and Technical Information of China (English)

    任建国; 陈晶; 戴尧仁

    2001-01-01

    Many anti-cancer drugs have been found to trigger apoptosis in tumor cells through the production of reactive oxygen species (ROS) including hydroxyl radicals (@ OH) regardless of chemical types. At the same time, telomerase is found to be associated with malignancy and reduced apoptosis. However, little is known about the linkage between ROS (such as @ OH) and telomerase/telomere. The focus of this investigation was to examine the possible pathway of the apoptosis induced by @ OH production via Fe2+ and H2O2. Results of the present study demonstrated that after exposure of HeLa cells to Fe2+-H2O2 system, an increase in lipid peroxidation and reduction of GSH was observed. These events proceeded and triggered apoptosis, resulting in DNA fragmentation. More interestingly, we did not observe any changes of telomerase activity. However, the telomere length in apoptotic cells shortened significantly. We also found that GSH rescued @ OH-induced HeLa cell death and prevened telomere shortening, and that 3,3'-diethyoxadicarbocyanine (DODCB), a telomerase inhibitor, increased susceptibility of HeLa cells to @ OH-induced apoptosis. Our results suggest that @ OH-induced telomere shortening is not through telomerase inhibition but possibly a direct effect of @ OH on telomeres themselves via lipid peroxidation.

  10. THE OPTIMIZATION OF PLUSH YARNS BULKING PROCESS

    Directory of Open Access Journals (Sweden)

    VINEREANU Adam

    2014-05-01

    Full Text Available This paper presents the experiments that were conducted on the installation of continuous bulking and thermofixing “SUPERBA” type TVP-2S for optimization of the plush yarns bulking process. There were considered plush yarns Nm 6.5/2, made of the fibrous blend of 50% indigenous wool sort 41 and 50% PES. In the first stage, it performs a thermal treatment with a turboprevaporizer at a temperature lower than thermofixing temperature, at atmospheric pressure, such that the plush yarns - deposed in a freely state on a belt conveyor - are uniformly bulking and contracting. It was followed the mathematical modeling procedure, working with a factorial program, rotatable central composite type, and two independent variables. After analyzing the parameters that have a direct influence on the bulking degree, there were selected the pre-vaporization temperature (coded x1,oC and the velocity of belt inside pre-vaporizer (coded x 2, m/min. As for the dependent variable, it was chosen the plush yarn diameter (coded y, mm. There were found the coordinates of the optimal point, and then this pair of values was verified in practice. These coordinates are: x1optim= 90oC and x 2optim= 6.5 m/min. The conclusion is that the goal was accomplished: it was obtained a good cover degree f or double-plush carpets by reducing the number of tufts per unit surface.

  11. A Stereoscopic Look into the Bulk

    CERN Document Server

    Czech, Bartlomiej; McCandlish, Samuel; Mosk, Benjamin; Sully, James

    2016-01-01

    We present the foundation for a holographic dictionary with depth perception. The dictionary consists of natural CFT operators whose duals are simple, diffeomorphism-invariant bulk operators. The CFT operators of interest are the "OPE blocks," contributions to the OPE from a single conformal family. In holographic theories, we show that the OPE blocks are dual at leading order in 1/N to integrals of effective bulk fields along geodesics or homogeneous minimal surfaces in anti-de Sitter space. One widely studied example of an OPE block is the modular Hamiltonian, which is dual to the fluctuation in the area of a minimal surface. Thus, our operators pave the way for generalizing the Ryu-Takayanagi relation to other bulk fields. Although the OPE blocks are non-local operators in the CFT, they admit a simple geometric description as fields in kinematic space--the space of pairs of CFT points. We develop the tools for constructing local bulk operators in terms of these non-local objects. The OPE blocks also allow ...

  12. Bulk metamaterials: Design, fabrication and characterization

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Malureanu, Radu; Alabastri, Alessandro;

    2009-01-01

    Bulk metamaterials claim a lot of attention worldwide. We report about our activity and advances in design, fabrication and characterization of metal-dielectric composites with three-dimensional lattices. The nomenclature of designs exhibiting negative index behaviour in the near infrared includes...

  13. Realistic anomaly mediation with bulk gauge fields

    International Nuclear Information System (INIS)

    We present a simple general framework for realistic models of supersymmetry breaking driven by anomaly mediation. We consider a 5-dimensional 'brane universe' where the visible and hidden sectors are localized on different branes, and the standard model gauge bosons propagate in the bulk. In this framework there can be charged scalar messengers that have contact interactions with the hidden sector, either localized in the hidden sector or in the bulk. These scalars obtain soft masses that feed into visible sector scalar masses at two loop order via bulk gauge interactions. This contribution is automatically flavor-blind, and can be naturally positive. If the messengers are in the bulk this contribution is automatically the same order of magnitude as the anomaly mediated contribution, independent of the brane spacing. If the messengers are localized to a brane the two effects are of the same order for relatively small brane spacings. The gaugino masses and A terms are determined completely by anomaly mediation. In order for anomaly mediation to dominate over radion mediation the radion must be is stabilized in a manner that preserves supersymmetry, with supergravity effects included. We show that this occurs in simple models. We also show that the mu problem can be solved by the vacuum expectation value of a singlet in this framework. (author)

  14. Longitudinal bulk a coustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja;

    2009-01-01

    Design, fabrication and characterization, in terms of mass sensitivity, is presented for a polycrystalline silicon longitudinal bulk acoustic cantilever. The device is operated in air at 51 MHz, resulting in a mass sensitivity of 100 HZ/fg (1 fg = 10{su−15 g). The initial characterization...

  15. A comparison study on the electronic structures, lattice dynamics and thermoelectric properties of bulk silicon and silicon nanotubes

    Science.gov (United States)

    Lu, Peng-Xian; Qu, Ling-Bo; Cheng, Qiao-Huan

    2013-11-01

    In order to investigate the mechanism of the electron and phonon transport in a silicon nanotube (SiNT), the electronic structures, the lattice dynamics, and the thermoelectric properties of bulk silicon (bulk Si) and a SiNT have been calculated in this work using density functional theory and Boltzmann transport theory. Our results suggest that the thermal conductivity of a SiNT is reduced by a factor of 1, while its electrical conductivity is improved significantly, although the Seebeck coefficient is increased slightly as compared to those of the bulk Si. As a consequence, the figure of merit (ZT) of a SiNT at 1200 K is enhanced by 12 times from 0.08 for bulk Si to 1.10. The large enhancement in electrical conductivity originates from the largely increased density of states at the Fermi energy level and the obviously narrowed band gap. The significant reduction in thermal conductivity is ascribed to the remarkably suppressed phonon thermal conductivity caused by a weakened covalent bonding, a decreased phonon density of states, a reduced phonon vibration frequency, as well as a shortened mean free path of phonons. The other factors influencing the thermoelectric properties have also been studied from the perspective of electronic structures and lattice dynamics.

  16. Integration of bulk piezoelectric materials into microsystems

    Science.gov (United States)

    Aktakka, Ethem Erkan

    Bulk piezoelectric ceramics, compared to deposited piezoelectric thin-films, provide greater electromechanical coupling and charge capacity, which are highly desirable in many MEMS applications. In this thesis, a technology platform is developed for wafer-level integration of bulk piezoelectric substrates on silicon, with a final film thickness of 5-100microm. The characterized processes include reliable low-temperature (200°C) AuIn diffusion bonding and parylene bonding of bulk-PZT on silicon, wafer-level lapping of bulk-PZT with high-uniformity (+/-0.5microm), and low-damage micro-machining of PZT films via dicing-saw patterning, laser ablation, and wet-etching. Preservation of ferroelectric and piezoelectric properties is confirmed with hysteresis and piezo-response measurements. The introduced technology offers higher material quality and unique advantages in fabrication flexibility over existing piezoelectric film deposition methods. In order to confirm the preserved bulk properties in the final film, diaphragm and cantilever beam actuators operating in the transverse-mode are designed, fabricated and tested. The diaphragm structure and electrode shapes/sizes are optimized for maximum deflection through finite-element simulations. During tests of fabricated devices, greater than 12microm PP displacement is obtained by actuation of a 1mm2 diaphragm at 111kHz with management IC, which incorporates a supply-independent bias circuitry, an active diode for low-dropout rectification, a bias-flip system for higher efficiency, and a trickle battery charger. The overall system does not require a pre-charged battery, and has power consumption of sleep-mode (simulated). Under lg vibration at 155Hz, a 70mF ultra-capacitor is charged from OV to 1.85V in 50 minutes.

  17. Bulk sulfur (S) deposition in China

    Science.gov (United States)

    Liu, Lei; Zhang, Xiuying; Wang, Shanqian; Zhang, Wuting; Lu, Xuehe

    2016-06-01

    A systematic dataset of an observation network on a national scale has been organized to investigate the spatial distribution of bulk sulfur (S) deposition (Sdep) throughout China during 2000-2013, representing by far the most detailed data set to track the bulk sulfur deposition throughout China since 2000. Such a dataset is needed for ecosystem studies and for developing emission control policies. Bulk Sdep values showed great variations, ranging from 2.17 to 70.55 kg ha-1 y-1, with an average of 22.99 kg ha-1 y-1. The average rate of bulk Sdep located in East Coastal region (35.97 kg ha-1 y-1), Middle Yangtze region (57.90 kg ha-1 y-1), Middle Yellow River region (23.42 kg ha-1 y-1), North Coastal region (42.19 kg ha-1 y-1), Northeast region (34.28 kg ha-1 y-1), South Coastal region (36.97 kg S ha-1 y-1), Southwest region (33.85 kg ha-1 y-1) was 4.50, 7.24, 2.93, 5.28, 4.29, 4.63 and 4.24 times than that in Northwest region (7.99 kg ha-1 y-1). Bulk Sdep over China was mainly from fossil fuel combustion (76.96%), biomass burning (7.64%), crust (6.22%), aged sea salt (5.48%) and agriculture (3.68%). A systematic observation network on a national scale should be established to conduct a long-term monitoring atmospheric Sdep (including wet and dry deposition), based on exiting ecological stations administrated by different departments in China.

  18. Constraints on the crustal structure of northern Vietnam based on analysis of teleseismic converted waves

    Science.gov (United States)

    Nguyen, Van-Duong; Huang, Bor-Shouh; Le, Tu-Son; Dinh, Van-Toan; Zhu, Lupei; Wen, Kuo-Liang

    2013-08-01

    Here we report estimates of crustal thickness and Poisson's ratios for northern Vietnam, based on teleseismic receiver function analysis of observations from a dense broadband seismic array. The seismic array comprised of 24 stations distributed evenly over northern Vietnam, from whose records we examined 190 teleseismic events of Mw > 5.5 for the period 2006-2008. Using the radial receiver functions calculated from teleseismic records at individual stations, the optimum crustal thickness and Vp/Vs (where Vp and Vs are the velocities of P- and S-waves, respectively) ratio beneath each station were determined using the H-κ (where H is crustal thickness and κ is defined as the Vp/Vs ratio) stacking algorithm. Determined values of crustal thickness range from 26.5 km to 36.4 km, with an average of 31.0 ± 2.1 km. The simple pattern of variation of crustal thickness in the northeastern region of the study area, with a mean of ~ 31 km, suggests that the sector belongs to the craton of the South China block. A highly variable crustal thickness is found over the northwestern region of northern Vietnam, ranging from ~ 29.5 km to ~ 36.4 km, implying that complex tectonic processes have taken place in this region. The thinnest crust is found in the Red River Delta, where it ranges from 26.5 km to 30.4 km, which is suggestive of a recent rifting process. The determinations of crustal thickness show a good linear correlation with Bouguer gravity anomalies. Lower values of Poisson's ratio in the northeastern and Red River Delta sectors suggest a more felsic crust, and larger values in the northwestern sector suggest lithospheric extension in the Song Da depression. The findings enhance our understanding of the geotectonic architecture of the northern Vietnam region.

  19. Crustal shear velocity structure in the Southern Lau Basin constrained by seafloor compliance

    Science.gov (United States)

    Zha, Yang; Webb, Spahr C.

    2016-05-01

    Seafloor morphology and crustal structure vary significantly in the Lau back-arc basin, which contains regions of island arc formation, rifting, and seafloor spreading. We analyze seafloor compliance: deformation under long period ocean wave forcing, at 30 ocean bottom seismometers to constrain crustal shear wave velocity structure along and across the Eastern Lau Spreading Center (ELSC). Velocity models obtained through Monte Carlo inversion of compliance data show systematic variation of crustal structure in the basin. Sediment thicknesses range from zero thickness at the ridge axis to 1400 m near the volcanic arc. Sediment thickness increases faster to the east than to the west of the ELSC, suggesting a more abundant source of sediment near the active arc volcanoes. Along the ELSC, upper crustal velocities increase from the south to the north where the ridge has migrated farther away from the volcanic arc front. Along the axial ELSC, compliance analysis did not detect a crustal low-velocity body, indicating less melt in the ELSC crustal accretion zone compared to the fast spreading East Pacific Rise. Average upper crust shear velocities for the older ELSC crust produced when the ridge was near the volcanic arc are 0.5-0.8 km/s slower than crust produced at the present-day northern ELSC, consistent with a more porous extrusive layer. Crust in the western Lau Basin, which although thought to have been produced through extension and rifting of old arc crust, is found to have upper crustal velocities similar to older oceanic crust produced at the ELSC.

  20. Mercury's Crustal Magnetic Field from Low-Altitude Measurements by MESSENGER.

    Science.gov (United States)

    Johnson, C. L.; Phillips, R. J.; Purucker, M. E.; Anderson, B. J.; Byrne, P. K.; Denevi, B. W.; Fan, K. A.; Feinberg, J. M.; Hauck, S. A., II; Head, J. W., III; Korth, H.; James, P. B.; Mazarico, E.; Neumann, G. A.; Philpott, L. C.; Siegler, M. A.; Strauss, B. E.; Tsyganenko, N. A.; Solomon, S. C.

    2015-12-01

    Magnetized rocks can record the history of a planet's magnetic field, a key constraint for understanding interior evolution. From orbital vector magnetic field measurements of Mercury taken by the MESSENGER spacecraft at altitudes below 150 km, we have detected fields indicative of crustal magnetization. Fields from non-crustal sources, which dominate the observations even at low altitudes, were estimated and subtracted from the observations using both magnetospheric models and signal filtering. The resulting high-pass filtered fields have amplitudes of a few to 20 nT. The first low-altitude signals were detected over the Suisei Planitia region and were confirmed by upward continuation to be of crustal origin. At least some contribution from thermoremanent magnetization is required to account for these signals, and we infer a lower bound on the average age of magnetization of 3.7-3.9 Ga on the basis of correlation of crustal magnetic fields with volcanic units of that age range. Ancient field strengths that range from those similar to Mercury's present dipole field to Earth-like values are consistent with the magnetic field observations and with the low iron content of Mercury's crust derived from MESSENGER elemental composition data. Here, we extend these initial results with observations obtained at spacecraft altitudes below 60 km at all body-fixed longitudes from ~40°N to ~75°N. The strongest crustal fields occur in the region 120°E to 210°E, and weaker signals characterize the northern volcanic plains. We test the hypothesis that the longest-wavelength crustal field signals in this region reflect magnetization contrasts between the Caloris basin and the surrounding intercrater plains and circum-Caloris plains. We report the spatial distribution of observed crustal fields, together with magnetization models derived from them and the implications of these models, particularly for the depth distribution of sources compatible with the observations.

  1. Major temporal variations in shortening rate absorbed along a large active fold of the southeastern Tianshan piedmont (China)

    Science.gov (United States)

    Saint-Carlier, Dimitri; Charreau, Julien; Lavé, Jérôme; Blard, Pierre-Henri; Dominguez, Stéphane; Avouac, Jean-Philippe; Wang, Shengli

    2016-01-01

    The investigation of deformation rates on a mountain piedmont can provide key information for improving our understanding of the overall dynamics of a mountain range. Here, we estimate the shortening rate absorbed by a Quaternary emergent detachment fold on the southeastern piedmont of the Tianshan (China). Our work is primarily based on new 10Be cosmogenic exposure dating of deformed alluvial surfaces. The method we have developed combines depth profiling with sampling of surface cobbles, thereby allowing exposure time, erosion rate and inheritance to be simultaneously constrained. The exposure ages of the uppermost uplifted alluvial surfaces are around 140 ± 17 ka, 130 ± 9 ka and 47 ± 9 ka, from west to east. A terrace lying below the 140 ka surface is dated at 65 ± 5 ka. The ages of the uplifted and folded alluvial surfaces were then combined with estimates of shortening obtained using two distinct methods: (1) the excess area method, where sedimentation rates, extracted from magnetostratigraphic studies, are used to determine the amount of sedimentation after the abandonment of the river; and (2) a folding model derived from sandbox experiments. The late Pleistocene shortening rates are shown to be between 0.4 ± 0.1 mm /yr and 0.8 ± 0.5 mm /yr on the western part of the fold and 2.1 ± 0.4 mm /yr along its central part. The central part of the frontal Yakeng anticline therefore accommodates up to 25% of the total shortening currently absorbed across the whole Eastern Tianshan range (8 mm/yr). However, this situation seems to have prevailed for only the last 150 ka, as the shortening rate absorbed by this nascent fold was previously ten times slower. While the initiation of folding of the Yakeng anticline can be traced back to 5.5 Ma ago, the basinward migration of the active deformation front onto the Yakeng fold is a relatively recent phenomenon and appears to be diachronous from west to east, probably in relation to the tectonic activity of the folds in

  2. Crustal implications of bedrock geology along the Trans-Alaska Crustal Transect (TACT) in the Brooks Range, northern Alaska

    Science.gov (United States)

    Moore, T.E.; Wallace, W.K.; Mull, C.G.; Adams, K.E.; Plafker, G.; Nokleberg, W.J.

    1997-01-01

    Geologic mapping of the Trans-Alaska Crustal Transect (TACT) project along the Dalton Highway in northern Alaska indicates that the Endicott Mountains allochthon and the Hammond terrane compose a combined allochthon that was thrust northward at least 90 km in the Early Cretaceous. The basal thrust of the combined allochthon climbs up section in the hanging wall from a ductile shear zone, in the south through lower Paleozoic rocks of the Hammond terrane and into Upper Devonian rocks of the Endicott Mountains allochthon at the Mount Doonerak antiform, culminating in Early Cretaceous shale in the northern foothills of the Brooks Range. Footwall rocks north of the Mount Doonerak antiform are everywhere parautochthonous Permian and Triassic shale of the North Slope terrane rather than Jurassic and Lower Cretaceous strata of the Colville Basin as shown in most other tectonic models of the central Brooks Range. Stratigraphic and structural relations suggest that this thrust was the basal detachment for Early Cretaceous deformation. Younger structures, such as the Tertiary Mount Doonerak antiform, deform the Early Cretaceous structures and are cored by thrusts that root at a depth of about 10 to 30 km along a deeper detachment than the Early Cretaceous detachment. The Brooks Range, therefore, exposes (1) an Early Cretaceous thin-skinned deformational belt developed during arc-continent collision and (2) a mainly Tertiary thick-skinned orogen that is probably the northward continuation of the Rocky Mountains erogenic belt. A down-to-the-south zone of both ductile and brittle normal faulting along the southern margin of the Brooks Range probably formed in the mid-Cretaceous by extensional exhumation of the Early Cretaceous contractional deformation. copyright. Published in 1997 by the American Geophysical Union.

  3. Upper crustal seismic structure of the Endeavour segment, Juan de Fuca Ridge from traveltime tomography: Implications for oceanic crustal accretion

    Science.gov (United States)

    Weekly, Robert T.; Wilcock, William S. D.; Toomey, Douglas R.; Hooft, Emilie E. E.; Kim, Eunyoung

    2014-04-01

    isotropic and anisotropic P wave velocity structure of the upper oceanic crust on the Endeavour segment of the Juan de Fuca Ridge is studied using refracted traveltime data collected by an active-source, three-dimensional tomography experiment. The isotropic velocity structure is characterized by low crustal velocities in the overlapping spreading centers (OSCs) at the segment ends. These low velocities are indicative of pervasive tectonic fracturing and persist off axis, recording the history of ridge propagation. Near the segment center, velocities within the upper 1 km show ridge-parallel bands with low velocities on the outer flanks of topographic highs. These features are consistent with localized thickening of the volcanic extrusive layer from eruptions extending outside of the axial valley that flow down the fault-tilted blocks that form the abyssal hill topography. On-axis velocities are generally relatively high beneath the hydrothermal vent fields likely due to the infilling of porosity by mineral precipitation. Lower velocities are observed beneath the most vigorous vent fields in a seismically active region above the axial magma chamber and may reflect increased fracturing and higher temperatures. Seismic anisotropy is high on-axis but decreases substantially off axis over 5-10 km (0.2-0.4 Ma). This decrease coincides with an increase in seismic velocities resolved at depths ≥1 km and is attributed to the infilling of cracks by mineral precipitation associated with near-axis hydrothermal circulation. The orientation of the fast-axis of anisotropy is ridge-parallel near the segment center but curves near the segment ends reflecting the tectonic fabric within the OSCs.

  4. Crustal evolution and recycling in a juvenile continent: Oxygen isotope ratio of zircon in the northern Arabian Nubian Shield

    Science.gov (United States)

    Be'eri-Shlevin, Yaron; Katzir, Yaron; Valley, John W.

    2009-02-01

    Crustal recycling patterns during the evolution of the Neoproterozoic Arabian-Nubian Shield (ANS) were defined using the oxygen isotope ratio of zircon [ δ18O(Zrn)]. Evidence for early (~ 870-740 Ma) crustal recycling in the northernmost ANS (southern Israel and Sinai, Egypt) is given by laser fluorination analysis of bulk zircon separates, which yield higher than mantle δ18O(Zrn) values of several island arc complex (IAC) orthogneisses (6.9 to 8.2‰) and also from the average δ18O(Zrn) value of 6.4‰ determined for detrital zircons (~ 870-780 Ma) from the Elat-schist; the latter representing the oldest known rock sources in the region. These results indicate prolonged availability of surface-derived rocks for burial or subduction, melting, and assimilation at the very early stages of island arc formation in the ANS. Other IAC intrusions of ~ 800 Ma show mantle-like δ18O(Zrn) values, implying that not all magmas involved supracrustal contribution. Much younger (650-625 Ma) deformed syn-collisional calc-alkaline (CA1) intrusions are characterized by δ18O(Zrn) values of 5.0 to 7.9‰ indicating continued recycling of the felsic crust. The main sample set of this study comprises rocks from the mostly granitic, post-collisional calc-alkaline (CA2: ~ 635-590 Ma) and alkaline (AL: ~ 608-580 Ma) magmatic suites. Despite having distinct geochemical characteristics and petrogenetic paths and spans of magmatic activity, the two suites are indistinguishable by their average δ18O(Zrn) values of 5.7 and 5.8‰ pointing to the dominance of mantle-like δ18O sources in their formation. Nonetheless, grouping the two suites together reveals geographical zoning in δ18O(Zrn) where a large southeastern region of δ18O(Zrn) = 4.5 to 5.9‰ is separated from a northwestern belt with δ18O(Zrn) = 6 to 8‰ by a '6‰ line'. It is thus suggested that all CA2 and AL magmas of the northernmost ANS were derived from mantle-like δ18O reservoirs in the mafic lower-crust and the

  5. Bulk solitary waves in elastic solids

    Science.gov (United States)

    Samsonov, A. M.; Dreiden, G. V.; Semenova, I. V.; Shvartz, A. G.

    2015-10-01

    A short and object oriented conspectus of bulk solitary wave theory, numerical simulations and real experiments in condensed matter is given. Upon a brief description of the soliton history and development we focus on bulk solitary waves of strain, also known as waves of density and, sometimes, as elastic and/or acoustic solitons. We consider the problem of nonlinear bulk wave generation and detection in basic structural elements, rods, plates and shells, that are exhaustively studied and widely used in physics and engineering. However, it is mostly valid for linear elasticity, whereas dynamic nonlinear theory of these elements is still far from being completed. In order to show how the nonlinear waves can be used in various applications, we studied the solitary elastic wave propagation along lengthy wave guides, and remarkably small attenuation of elastic solitons was proven in physical experiments. Both theory and generation for strain soliton in a shell, however, remained unsolved problems until recently, and we consider in more details the nonlinear bulk wave propagation in a shell. We studied an axially symmetric deformation of an infinite nonlinearly elastic cylindrical shell without torsion. The problem for bulk longitudinal waves is shown to be reducible to the one equation, if a relation between transversal displacement and the longitudinal strain is found. It is found that both the 1+1D and even the 1+2D problems for long travelling waves in nonlinear solids can be reduced to the Weierstrass equation for elliptic functions, which provide the solitary wave solutions as appropriate limits. We show that the accuracy in the boundary conditions on free lateral surfaces is of crucial importance for solution, derive the only equation for longitudinal nonlinear strain wave and show, that the equation has, amongst others, a bidirectional solitary wave solution, which lead us to successful physical experiments. We observed first the compression solitary wave in the

  6. Melt evolution and residence in extending crust: Thermal modeling of the crust and crustal magmas

    Science.gov (United States)

    Karakas, Ozge; Dufek, Josef

    2015-09-01

    Tectonic extension and magmatism often act in concert to modify the thermal, mechanical, and chemical structure of the crust. Quantifying the effects of extension and magma flux on melting relationships in the crust is fundamental to determining the rate of crustal melting versus fractionation, magma residence time, and the growth of continental crust in rift environments. In order to understand the coupled control of tectonic extension and magma emplacement on crustal thermal evolution, we develop a numerical model that accounts for extension and thermal-petrographic processes in diverse extensional settings. We show that magma flux exerts the primary control on melt generation and tectonic extension amplifies the volume of melt residing in the crustal column. Diking into an extending crust produces hybrid magmas composed of 1) residual melt remaining after partial crystallization of basalt (mantle-derived melt) and 2) melt from partial melting of the crust (crustal melt). In an extending crust, mantle-derived melts are more prevalent than crustal melts across a range of magma fluxes, tectonic extension rates, and magmatic water contents. In most of the conditions, crustal temperatures do not reach their solidus temperatures to initiate partial melting of these igneous lithologies. Energy balance calculations show that the total enthalpy transported by dikes is primarily used for increasing the sensible heat of the cold surrounding crust with little energy contributing to latent heat of melting the crust (maximum crustal melting efficiency is 6%). In the lower crust, an extensive mush region develops for most of the conditions. Upper crustal crystalline mush is produced by continuous emplacement of magma with geologically reasonable flux and extension rates on timescales of 106 yr. Addition of tectonic effects and non-linear melt fraction relationships demonstrates that the magma flux required to sustain partially molten regions in the upper crust is within the

  7. Crustal Structure and Extension from Slope to Deepsea Basin in the Northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Hu Dengke; Zhou Di; Wu Xiangjie; He Min; Pang Xiong; Wang Yuwei

    2009-01-01

    The newly acquired long-cable multi-channel seismic (MCS) lines were used to study the crustal structure and extension in an NW-SE elongated 150 km by 260 Van strip from the slope to the deepsea basin in the northern South China Sea (SCS).These profdes are of good penetration that Moho is recognizable in ~70% length of the lines.Seismostrattgraphic interpretation and time-depth conversion were conducted.A power function D = atb+ c was used in the time-depth conversion,which avoided the under-or over-estimation of the depths of deep-seated interfaces by cubic or quadratic polynomial functions.Contour maps of basement depth,Moho depth,crustal thickness,and crustal stretching factor were obtained for the study area.In the dip direction,the Moho depth decreases stepwisely from 28 km in the outer shelf southwards to 19,15,and 12 km in the deepsea basin,with ramps at the shelf break,lower slope,and the continent ocean boundary (COB),respectively.Accordingly,the crustal thickness decreased southwards from 3,and 7 km spectively.Under the center of the Balynn (白云) sag,the crust thins significantly to < 7 kin.The crustal stretching factor βc was calculated by assuming the original crust thickness of 30 km.In the centers of the Baiyun sag,βc exceeds 5.Tertiary and Quaternary volcanic activities show a general trend of intensifying towards the COB.An important finding of this study is the along-strike variation of the crustal structure.A Moho rise extends from the COB NW-ward until the shelf break,about 170 km long and 50-100 km wide,with Moho depth < 20 kin.This is called the Balyun Moho Nose,which is bounded to the east,west,and north by belts of high Moho gradients indicative of crustal or even lithospheric faults.The doming of Moho in the nose area might he the cause of the W-E segmentation of the crustal and geological structures along the slope of the northern South China Sea,and the cause of the strong crustal

  8. The Cora Lake Shear Zone, an Exhumed Deep Crustal Lithotectonic Discontinuity, Western Churchill Province, Canada

    Science.gov (United States)

    Regan, S.; Leslie, S.; Holland, M. E.; Williams, M. L.; Mahan, K. H.; Jercinovic, M. J.

    2011-12-01

    Deep crustal flow is a fundamental tectonic process that may serve to reduce topographic gradients, especially in overthickened collisional orogens. Recent studies have utilized numerical models and seismic interpretations, but generally in two dimensions. Although useful, two dimensional models can not fully characterize lower crustal flow or coupling of crustal layers because they cannot fully incorporate lateral heterogeneity in the flow field. The Athabasca Granulite terrane, in northern Saskatchewan, is an exposed deep crustal terrane that underwent granulite grade deformation during the Neoarchean (ca. 2.55), then cooled isobarically for 600 m.y., and then was reactivated during the Paleoproterozoic (ca. 1.9 Ga). Regional exhumation occurred at roughly 1.85 Ga. This exposure, is a field laboratory for studying lower crustal flow, stabilization, and reactivation. Recent work suggests that the northwestern domain, dominated by the multiphase, opx-bearing, Mary batholith, underwent top-to-the-east lower crustal flow during the Neoarchean. The Chipman domain, to the SE , is primarily underlain by the 3.2 Ga, Chipman tonalite straight gneiss, which was likely restitic, and rheologically strong during the 2.6 Ga flow event. The Cora Lake shear zone (CLsz), which divides the two domains, is interpreted to represent a lithotectonic, compositional, and rheologic boundary within the deep crust. Recent mapping of the western gradient of the CLsz has provided insight into the role and evolution of the rheologic discontinuity and its relationship to crustal flow. The Mary granite (gneiss) contains excellent assemblages for P-T and pseudosection analysis. Interlayered felsic granulite contain abundant monazite for in-situ geochronology. An intense subhorizontal tectonic fabric (S1), interpreted to be the product of crustal flow, is present in both units. This early fabric was locally crenulated, folded, and transposed, by a sub-vertical S2 fabric. Current work involves

  9. Crustal structure from the Faroes Shelf to the Norwegian Basin

    Science.gov (United States)

    Roberts, A. W.; White, R. S.; Kusznir, N. J.; Christie, P.; Roberts, A. M.; Isimm Team

    2003-04-01

    We show the crustal structure along a 400km seismic profile extending across a prime example of a volcanically rifted margin, from the Faroes shelf across the continent-ocean boundary northeast of the Faroe Islands, and 100km into oceanic crust of the Norwegian Sea formed immediately after continental break-up. 85 4-component OBS were used for the survey, giving wide-angle arrivals visible to beyond 120km offset. The survey was complemented by a 12 km Q-streamer profile along the same line. Integration of the normal incidence through wide-angle arrivals for the OBS and streamer data allow us to make a constrained velocity model through the active crust and into the upper mantle. We used a large airgun source comprising 14 guns with a total volume of 6,360 cu. in. towed at 20m depth. The resulting output was dominated by low frequencies (peak at 9Hz) to allow improved imaging through the basalts. A thickened oceanic crust is found, indicative of high temperatures caused by the Iceland mantle plume, and the presence of clear seaward dipping reflectors is evidence of extrusive lavas. Underplating is also inferred on the margin from the high seismic velocities in the lower crust. Academia and industry seek to understand magmatic margin evolution for its impact on deep water hydrocarbon prospecting. The NE Atlantic has been chosen as our research area because of its accessibility, wealth of related data and current exploration on the Atlantic margin. The iSIMM programme's long term goals are to characterise volcanically rifted margins and to develop theoretical models of the formation and subsidence of rifted margins. iSIMM investigators are: R.S. White (1), N.J. Kusznir (2), P.A.F. Christie (3), A.M. Roberts (4), N. Hurst (2), Z.C. Lunnon (1,3), C.J. Parkin (1), A.W. Roberts (1), L.K. Smith (1), R. Spitzer (1), V. Tymms (2), A. Davies (1), A. Surendra (1), with funding from NERC, Agip UK, BP, Amerada Hess Ltd., Anadarko, Conoco, Phillips, Shell, Statoil, and WesternGeco.

  10. Analysis of Crustal Magnetisation in Cartesian Vector Harmonics

    Science.gov (United States)

    Gubbins, D.; Ivers, D.; Williams, S.

    2015-12-01

    We present a new set of functions, Vector Cartesian Harmonics (VCH), analogous to the Vector Spherical Harmonics that we have applied recently to global models of crustal and lithospheric magnetisation. Like their spherical counterpart, the VCH form a complete, orthogonal set: planar models of magnetisation can be expanded in them. There are 3 distinct types of VCH, one representing that part of the magnetisation which generates the potential magnetic field above the surface, another the potential magnetic field below the surface, and a toroidal function that generates only a non-potential field. One function therefore describes the magnetisation detected by observations of the magnetic anomaly while the other two describe the null space of an inversion of magnetic observations for magnetisation. The formalism is therefore ideal for analysing the results of inversions for magnetic structures in plane layers such as local or regional surveys where Earth's curvature can be ignored. The null space is in general very large, being an arbitrary combination of a doubly-infinite set of vector functions. However, in the absence of remanence and when the inducing field is uniform the null space reduces to only 2 types of structure, uniform susceptibility (Runcorn's Theorem) and a pattern of susceptibility induced by a uniform field, the null space is restricted to uniform magnetisation and 1D patterns of susceptibility aligned with a horizontal inducing field. Both these cases are already well known, but this analysis shows them to be the ONLY members of the null space. We also give results for familiar text-book structures to show the nature of the null space in each case. Curiously, inversion of the magnetic field from a buried dipole returns exactly half the correct magnitude plus a spurious distributed magnetisation. A more complex application is the topographic structure based on the Bishop formation in California (Fairhead and Williams, SEG exp. abstr. 25, 845, 2006

  11. Detection of crustal deformation prior to the 2014 Mt. Ontake eruption by the stacking method

    Science.gov (United States)

    Miyaoka, Kazuki; Takagi, Akimichi

    2016-04-01

    The phreatic eruption of Mt. Ontake in central Japan occurred in September 27, 2014. No obvious crustal deformation was observed prior to the eruption, and the magnitudes of other precursor phenomena were very small. In this study, we used the stacking method to detect crustal deformation prior to the eruption. The stacking method is a technique to improve the signal-to-noise ratio by stacking multiple records of crustal deformation. We succeeded in detecting a slight crustal deformation caused by a volume change in the shallow region beneath the volcano's summit from 1 month prior to the eruption. We also detected a slight crustal deformation that may have been caused by a volume increase in the deep region from one and a half months before the eruption. The magnitude of the volume change in the shallow region did not differ significantly in the 2014 eruption compared to the volume change during the small Mt. Ontake eruption in 2007, and the volume change in the deep region was rather smaller in 2014 than in 2007.

  12. Deep crustal structure of the Adare and Northern Basins, Ross Sea, Antarctica, from sonobuoy data

    Science.gov (United States)

    Selvans, M. M.; Stock, J. M.; Clayton, R. W.; Cande, S.; Granot, R.

    2014-11-01

    Extension associated with ultraslow seafloor spreading within the Adare Basin, in oceanic crust just north of the continental shelf in the Ross Sea, Antarctica, extended south into the Northern Basin. Magnetic and gravity anomaly data suggest continuity of crustal structure across the continental shelf break that separates the Adare and Northern Basins. We use sonobuoy refraction data and multi-channel seismic (MCS) reflection data collected during research cruise NBP0701, including 71 new sonobuoy records, to provide constraints on crustal structure in the Adare and Northern Basins. Adjacent 1D sonobuoy profiles along several MCS lines reveal deep crustal structure in the vicinity of the continental shelf break, and agree with additional sonobuoy data that document fast crustal velocities (6000-8000 m/s) at shallow depths (1-6 km below sea level) from the Adare Basin to the continental shelf, a structure consistent with that of other ultraslow-spread crust. Our determination of crustal structure in the Northern Basin only extends through sedimentary rock to the basement rock, and so cannot help to distinguish between different hypotheses for formation of the basin.

  13. Calibration of the Regional Crustal Waveguide and the Retrieval of Source Parameters Using Waveform Modeling

    Science.gov (United States)

    Saikia, C. K.; Woods, B. B.; Thio, H. K.

    - Regional crustal waveguide calibration is essential to the retrieval of source parameters and the location of smaller (MPnl waves to the surface waves and the interaction of regional sPmP and pPmP phases being good indicators of event depths. We also found that for deep events a seismic phase which follows an S-wave path to the surface and becomes critical, developing a head wave by S to P conversion is also indicative of depth. The detailed characteristic of this phase is controlled by the crustal waveguide. The key to calibrating regionalized crustal velocity structure is to determine depths for a set of master events by applying the above methods and then by modeling characteristic features that are recorded on the regional waveforms. The regionalization scheme can also incorporate mixed-path crustal waveguide models for cases in which seismic waves traverse two or more distinctly different crustal structures. We also demonstrate that once depths are established, we need only two-stations travel-time data to obtain reliable epicentral locations using a new adaptive grid-search technique which yields locations similar to those determined using travel-time data from local seismic networks with better azimuthal coverage.

  14. NPP bulk equipment dismantling problems and experience

    International Nuclear Information System (INIS)

    NPP bulk equipment dismantling problems and experience are summarized. 'ECOMET-S' JSC is shown as one of the companies which are able to make NPPs industrial sites free from stored bulk equipment with its further utilization. 'ECOMET-S' JSC is the Russian Federation sole specialized metallic LLW (MLLW) treatment and utilization facility. Company's main objectives are waste predisposal volume reduction and treatment for the unrestricted release as a scrap. Leningrad NPP decommissioned main pumps and moisture separators/steam super heaters dismantling results are presented. Prospective fragmentation technologies (diamond and electro-erosive cutting) testing results are described. The electro-erosive cutting machine designed by 'ECOMET-S' JSC is presented. The fragmentation technologies implementation plans for nuclear industry are presented too. (author)

  15. Bulk and shear viscosity in Hagedorn fluid

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, A.; Wahba, M. [Egyptian Center for Theoretical Physics (ECTP), MTI University, Faculty of Engineering, Cairo (Egypt)

    2010-11-15

    Assuming that the Hagedorn fluid composed of known particles and resonances with masses m <2 GeV obeys the first-order theory (Eckart) of relativistic fluid, we discuss the transport properties of QCD confined phase. Based on the relativistic kinetic theory formulated under the relaxation time approximation, expressions for bulk and shear viscosity in thermal medium of hadron resonances are derived. The relaxation time in the Hagedorn dynamical fluid exclusively takes into account the decay and eventually van der Waals processes. We comment on the in-medium thermal effects on bulk and shear viscosity and averaged relaxation time with and without the excluded-volume approach. As an application of these results, we suggest the dynamics of heavy-ion collisions, non-equilibrium thermodynamics and the cosmological models, which require thermo- and hydro-dynamics equations of state. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  16. Bulk and Shear Viscosity in Hagedorn Fluid

    CERN Document Server

    Tawfik, A

    2010-01-01

    Assuming that the Hagedorn fluid composed of known particles and resonances with masses $m<2\\,$GeV obeys the {\\it first-order} theory (Eckart) of relativistic fluid, we discuss the transport properties of QCD confined phase. Based on the relativistic kinetic theory formulated under the relaxation time approximation, expressions for bulk and shear viscosity in thermal medium are derived. The relaxation time in the Hagedorn dynamical fluid exclusively takes into account the decay and eventually van der Waals processes. We comment on the {\\it in-medium} thermal effects on bulk and shear viscosities and averaged relaxation time with and without the excluded-volume approach. As an application of these results, we suggest the dynamics of heavy-ion collisions, non-equlibrium thermodynamics and the cosmological models, which require thermo and hydrodynamics equations of state.

  17. Bulk Locality and Boundary Creating Operators

    CERN Document Server

    Nakayama, Yu

    2015-01-01

    We formulate a minimum requirement for CFT operators to be localized in the dual AdS. In any spacetime dimensions, we show that a general solution to the requirement is a linear superposition of operators creating spherical boundaries in CFT, with the dilatation by the imaginary unit from their centers. This generalizes the recent proposal by Miyaji et al. for bulk local operators in the three dimensional AdS. We show that Ishibashi states for the global conformal symmetry in any dimensions and with the imaginary dilatation obey free field equations in AdS and that incorporating bulk interactions require their superpositions. We also comment on the recent proposals by Kabat et al., and by H. Verlinde.

  18. Bulk band gaps in divalent hexaborides

    Energy Technology Data Exchange (ETDEWEB)

    Denlinger, Jonathan; Clack, Jules A.; Allen, James W.; Gweon, Gey-Hong; Poirier, Derek M.; Olson, Cliff G.; Sarrao, John L.; Bianchi, Andrea D.; Fisk, Zachary

    2002-08-01

    Complementary angle-resolved photoemission and bulk-sensitive k-resolved resonant inelastic x-ray scattering of divalent hexaborides reveal a >1 eV X-point gap between the valence and conduction bands, in contradiction to the band overlap assumed in several models of their novel ferromagnetism. This semiconducting gap implies that carriers detected in transport measurements arise from defects, and the measured location of the bulk Fermi level at the bottom of the conduction band implicates boron vacancies as the origin of the excess electrons. The measured band structure and X-point gap in CaB6 additionally provide a stringent test case for proper inclusion of many-body effects in quasi-particle band calculations.

  19. Brane plus Bulk Supersymmetry in Ten Dimensions

    CERN Document Server

    Bergshoeff, E A; Ortín, Tomas; Roest, D; Van Proeyen, A

    2001-01-01

    We discuss a generalized form of IIA/IIB supergravity depending on all R-R potentials C^(p) (p=0,1,...,9) as the effective field theory of Type IIA/IIB superstring theory. For the IIA case we explicitly break this R-R democracy to either p=5 which allows us to write a new bulk action that can be coupled to N=1 supersymmetric brane actions. The case of 8-branes is studied in detail using the new bulk & brane action. The supersymmetric negative tension branes without matter excitations can be viewed as orientifolds in the effective action. These D8-branes and O8-planes are fundamental in Type I' string theory. A BPS 8-brane solution is given which satisfies the jump conditions on the wall. As an application of our results we derive a quantization of the mass parameter and the cosmological constant in string units.

  20. Surface-Bulk Vibrational Correlation Spectroscopy.

    Science.gov (United States)

    Roy, Sandra; Covert, Paul A; Jarisz, Tasha A; Chan, Chantelle; Hore, Dennis K

    2016-05-01

    Homo- and heterospectral correlation analysis are powerful methods for investigating the effects of external influences on the spectra acquired using distinct and complementary techniques. Nonlinear vibrational spectroscopy is a selective and sensitive probe of surface structure changes, as bulk molecules are excluded on the basis of symmetry. However, as a result of this exquisite specificity, it is blind to changes that may be occurring in the solution. We demonstrate that correlation analysis between surface-specific techniques and bulk probes such as infrared absorption or Raman scattering may be used to reveal additional details of the adsorption process. Using the adsorption of water and ethanol binary mixtures as an example, we illustrate that this provides support for a competitive binding model and adds new insight into a dimer-to-bilayer transition proposed from previous experiments and simulations. PMID:27058265

  1. Bulk entropy in loop quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Livine, Etera R. [Laboratoire de Physique ENS Lyon, CNRS UMR 5672, 46 Allee d' Italie, 69364 Lyon Cedex 07 (France)], E-mail: etera.livine@ens-lyon.fr; Terno, Daniel R. [Centre for Quantum Computer Technology, Department of Physics, Macquarie University, Sydney NSW 2109 (Australia)], E-mail: dterno@physics.mq.edu.au

    2008-05-01

    In the framework of loop quantum gravity (LQG), we generalize previous boundary state counting for black hole entropy [E.R. Livine, D.R. Terno, Quantum black holes: Entropy and entanglement on the horizon, Nucl. Phys. B 741 (2006) 131, (gr-qc/0508085)] to a full bulk state counting. After suitable gauge fixing, we show how to compute the bulk entropy of a bounded region of space (the 'black hole') with fixed boundary conditions. This allows to study in detail the relationship between the entropy and the boundary area and to identify a holographic regime for LQG where the leading order of the entropy scales with the area. In this regime we can fine tune the factor between entropy and area without changing the Immirzi parameter.

  2. Raman characterization of bulk ferromagnetic nanostructured graphite

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, Helena, E-mail: hpardo@fq.edu.uy [Centro NanoMat, Polo Tecnologico de Pando, Facultad de Quimica, Universidad de la Republica, Cno. Aparicio Saravia s/n, 91000, Pando, Canelones (Uruguay); Crystallography, Solid State and Materials Laboratory (Cryssmat-Lab), DETEMA, Facultad de Quimica, Universidad de la Republica, Gral. Flores 2124, P.O. Box 1157, Montevideo (Uruguay); Divine Khan, Ngwashi [Mantfort University, Leicester (United Kingdom); Faccio, Ricardo [Centro NanoMat, Polo Tecnologico de Pando, Facultad de Quimica, Universidad de la Republica, Cno. Aparicio Saravia s/n, 91000, Pando, Canelones (Uruguay); Crystallography, Solid State and Materials Laboratory (Cryssmat-Lab), DETEMA, Facultad de Quimica, Universidad de la Republica, Gral. Flores 2124, P.O. Box 1157, Montevideo (Uruguay); Araujo-Moreira, F.M. [Grupo de Materiais e Dispositivos-CMDMC, Departamento de Fisica e Engenharia Fisica, UFSCar, Caixa Postal 676, 13565-905, Sao Carlos SP (Brazil); Fernandez-Werner, Luciana [Centro NanoMat, Polo Tecnologico de Pando, Facultad de Quimica, Universidad de la Republica, Cno. Aparicio Saravia s/n, 91000, Pando, Canelones (Uruguay); Crystallography, Solid State and Materials Laboratory (Cryssmat-Lab), DETEMA, Facultad de Quimica, Universidad de la Republica, Gral. Flores 2124, P.O. Box 1157, Montevideo (Uruguay)

    2012-08-15

    Raman spectroscopy was used to characterize bulk ferromagnetic graphite samples prepared by controlled oxidation of commercial pristine graphite powder. The G:D band intensity ratio, the shape and position of the 2D band and the presence of a band around 2950 cm{sup -1} showed a high degree of disorder in the modified graphite sample, with a significant presence of exposed edges of graphitic planes as well as a high degree of attached hydrogen atoms.

  3. Material profile influences in bulk-heterojunctions

    OpenAIRE

    Roehling, J.D.; Rochester, C.W.; Ro, H.W.; Wang, P.; Majewski, J; Batenburg, Joost; Arslan, I; Delongchamp, D.M.; Moulé, A.J.

    2014-01-01

    The morphology in mixed bulk-heterojunction films are compared using three different quantitative measurement techniques. We compare the vertical composition changes using high-angle annular dark-field scanning transmission electron microscopy with electron tomography and neutron and x-ray reflectometry. The three measurement techniques yield qualitatively comparable vertical concentration measurements. The presence of a metal cathode during thermal annealing is observed to alter the fulleren...

  4. Superconducting RF cavities film of bulk

    CERN Document Server

    Darriulat, Pierre

    1999-01-01

    The successful operation of LEP2 has demonstrated the feasibility of using on a large scale copper accelerating cavities coated with a thin superconducting niobium film. Yet other existing or planned installations such as CEBAF and TESLA, rely instead on the bulk niobium technology. The reason is a wide spread belief that the film technology would suffer from fundamental limitations preventing high gradients to be reached...

  5. Depleted Bulk Heterojunction Colloidal Quantum Dot Photovoltaics

    KAUST Repository

    Barkhouse, D. Aaron R.

    2011-05-26

    The first solution-processed depleted bulk heterojunction colloidal quantum dot solar cells are presented. The architecture allows for high absorption with full depletion, thereby breaking the photon absorption/carrier extraction compromise inherent in planar devices. A record power conversion of 5.5% under simulated AM 1.5 illumination conditions is reported. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. S-wave crustal and upper mantle's velocity structure in the eastern Tibetan Plateau-Deep environment of lower crustal flow

    Institute of Scientific and Technical Information of China (English)

    WANG ChunYong; Paul SILVER; L(U) Hai; LOU ZhiYong; WU JianPing; CHANG LiJun; DAI ShiGui; YOU HuiChuan; TANG FangTou; ZHU LuPei

    2008-01-01

    A teleseismic profile consisting of 26 stations was deployed along 30°N latitude in the eastern Tibetan Plateau. By use of the inversion of P-wave receiver function, the S-wave velocity structures at depth from surface to 80 km beneath the profile have been determined. The inversion results reveal that there is significant lateral variation of the crustal structure between the tectonic blocks on the profile. From Linzhi north of the eastern Himalayan Syntaxis, the crust is gradually thickened in NE direction; the crustal thickness reaches to the maximum value (~72 km) at the Bangong-Nujiang suture, and then decreased to 65 km in the Qiangtang block, to 57-64 km in the Bayan Har block, and to 40-45 km in the Sichuan Basin. The eastern segment of the teleseismic profile (to the east of Batang) coincides geographically with the Zhubalong-Zizhong deep seismic sounding profile carried out in 2000, and the S-wave velocity structure determined from receiver functions is consistent with the P-wave velocity structure obtained by deep seismic sounding in respect of the depths of Mono and major crustal interfaces. In the Qiangtang and the Bayan Har blocks, the lower velocity layer is widespread in the lower crust (at depth of 30-60 km) along the profile, while there is a normal velocity distribution in lower crust in the Sichuan Basin. On an average, the crustal velocity ratio (Poisson ratio) in tectonic blocks on the profile is 1.73 (σ= 0.247) in the Lhasa block, 1.78 (σ= 0.269) in the Banggong-Nujiang suture, 1.80 (σ = 0.275) in the Qiangtang block, 1.86 (σ= 0.294) in the Bayan Har blocks, and 1.77 (σ=0.265) in the Yangtze block, respectively. The Qiangtang and the Bayan Har blocks are characterized by lower S-wave velocity anomaly in lower crust, complicated Moho transition, and higher crustal Poisson ratio,indicating that there is a hot and weak medium in lower crust. These are considered as the deep environment of lower crustal flow in the eastern Tibetan Plateau

  7. Crustal evolution of South American Platform based on Sm-Nd isotope geochemistry; Evolucao crustal da plataforma sul americana com base na geoquimica isotopica Sm-Nd

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kei

    1998-07-01

    Sm-Nd isotopic systematics is relevant to the topics of origin and evolution the of continental crust, where model ages refer to the time when crustal material was differentiated from the upper mantle. Alternative interpretations are due to a lack of adequate information on crustal processes and the variable composition of the mantle sources. The Sm-Nd methods are presented, and applied on rock materials from the South American Platform. The main conclusions indicate juvenile accretion with higher growth rates (peaks), around 3.7-3.5 Ga ({approx} 0.5% in volume), 3.1 - 2.9 Ga ({approx}16%), 2.7 - 2.6 ({approx} 9%), 2.2 - 1.9 (35%) and 1.3-1.0 (7%). The continental growth curve indicates that about 35 % of the crust was formed by 2.5 Ga, 88% by 1.8 Ga and 99% by 1.0 Ga, and the remaining {approx} 1 % was added in the Phanerozoic. Rapid crustal growth occurred between 2.2 and 1.9 Ga. The main period of continental crust formation occurred during the Paleoproterozoic, corresponding to 54 % in volume. Sm-Nd model ages, when compared with the crystallisation ages of granitoid rocks, furnish a rough estimate of juvenile vs. reworked material. Within the South American Platform about 45% of juvenile continental crust is still preserved within tectonic provinces of different ages. The remainder represents continental crust reworked in younger tectono-thermal events. In particular crustal reworking was predominating over juvenile accretion during Meso-Neoproterozoic. The Transbrasiliano Lineament is a megasuture, active in the Neoproterozoic, which separates a large northwestern mass, including the Amazonian and Sao Luis Cratons, from a southeastern mass, formed by a collage of cratonic fragments, of which the Sao Francisco and Rio de La Plata are the largest. The crustal evolutions of these two large continental masses are considered individually, and can be resumed following form: I - Old Archean rocks (>3.4 Ga) are found only within the south-eastern part (Gaviao Block

  8. Reluctance motors with bulk HTS material

    International Nuclear Information System (INIS)

    In recent years we have successfully designed, built and tested several reluctance motors with YBCO bulk material incorporated into the rotor, working at 77 K. Our last motor type SRE150 was tested up to 200 kW. The aim of our investigations is the construction of motors with extremely high power density and dynamics. In comparison to conventional motor types the advantage of HTS reluctance motors with respect to size and dynamics could be demonstrated. Some fields of possible future applications will be described. These motors show a significant improvement in performance using high quality HTS bulk elements in the rotor. Until now the motor parameters have been limited by the current density which could be obtained in the bulk material at 77 K and by the geometric dimensions of the segments available. Therefore we expect further improvements in the case of these materials. Since the total motor including stator and rotor is working at low temperature we have to optimize the windings and the magnetic circuit to these operation conditions. A new design of a 200 kW motor in order to achieve increased power density and the theoretical results of our calculations will be shown

  9. Evidence for Bulk Ripplocations in Layered Solids

    Science.gov (United States)

    Gruber, Jacob; Lang, Andrew C.; Griggs, Justin; Taheri, Mitra L.; Tucker, Garritt J.; Barsoum, Michel W.

    2016-01-01

    Plastically anisotropic/layered solids are ubiquitous in nature and understanding how they deform is crucial in geology, nuclear engineering, microelectronics, among other fields. Recently, a new defect termed a ripplocation–best described as an atomic scale ripple–was proposed to explain deformation in two-dimensional solids. Herein, we leverage atomistic simulations of graphite to extend the ripplocation idea to bulk layered solids, and confirm that it is essentially a buckling phenomenon. In contrast to dislocations, bulk ripplocations have no Burgers vector and no polarity. In graphite, ripplocations are attracted to other ripplocations, both within the same, and on adjacent layers, the latter resulting in kink boundaries. Furthermore, we present transmission electron microscopy evidence consistent with the existence of bulk ripplocations in Ti3SiC2. Ripplocations are a topological imperative, as they allow atomic layers to glide relative to each other without breaking the in-plane bonds. A more complete understanding of their mechanics and behavior is critically important, and could profoundly influence our current understanding of how graphite, layered silicates, the MAX phases, and many other plastically anisotropic/layered solids, deform and accommodate strain. PMID:27640724

  10. Cosmological Implications of QGP Bulk Viscosity

    CERN Document Server

    Anand, Sampurn; Bhatt, Jitesh R

    2016-01-01

    Recent studies of the hot QCD matter indicate that the bulk viscosity ($\\zeta$) of quark-gluon plasma (QGP) rises sharply near the critical point of the QCD phase transition. In this work, we show that such a sharp rise of the bulk viscosity will lead to an effective negative pressure near the critical temperature, $T_{c}$ which in turn drives the Universe to inflate. This inflation has a natural graceful exist when the viscous effect evanesce. We estimate that, depending upon the peak value of $\\zeta$, universe expands by a factor of $10$ to $80$ times in a very short span ($\\Delta t\\sim 10^{-8}$ seconds). Another important outcome of the bulk viscosity dominated dynamics is the cavitation of QGP around $T \\sim 1.5T_{c}$. This would lead to the phenomenon of formation of cavitation bubbles within the QGP phase. The above scenario is independent of the order of QCD phase transition. We delineate some of the important cosmological consequences of the inflation and the cavitation.

  11. Superconducting State Parameters of Bulk Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    Aditya M. Vora

    2012-12-01

    Full Text Available Well recognized empty core (EMC pseudopotential of Ashcroft is used to investigate the superconducting state parameters viz; electron-phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature TC, isotope effect exponent α and effective interaction strength NOV of some (Ni33Zr671 – xVx (x = 0, 0.05, 0.1, 0.15 bulk amorphous alloys. We have incorporated five different types of local field correction functions, proposed by Hartree (H, Taylor (T, Ichimaru-Utsumi (IU, Farid et al. (F and Sarkar et al. (S to show the effect of exchange and correlation on the aforesaid properties. Very strong influence of the various exchange and correlation functions is concluded from the present study. The TC obtained from Sarkar et al. (S local field correction function are found an excellent agreement with available theoretical data. Quadratic TC equation has been proposed, which provide successfully the TC values of bulk amorphous alloys under consideration. Also, the present results are found in qualitative agreement with other such earlier reported data, which confirms the superconducting phase in the s bulk amorphous alloys.

  12. Bulk viscous cosmology in early Universe

    Indian Academy of Sciences (India)

    C P Singh

    2008-07-01

    The effect of bulk viscosity on the early evolution of Universe for a spatially homogeneous and isotropic Robertson-Walker model is considered. Einstein's field equations are solved by using `gamma-law' equation of state = ( - 1)ρ, where the adiabatic parameter gamma () depends on the scale factor of the model. The `gamma' function is defined in such a way that it describes a unified solution of early evolution of the Universe for inflationary and radiation-dominated phases. The fluid has only bulk viscous term and the coefficient of bulk viscosity is taken to be proportional to some power function of the energy density. The complete general solutions have been given through three cases. For flat space, power-law as well as exponential solutions are found. The problem of how the introduction of viscosity affects the appearance of singularity, is briefly discussed in particular solutions. The deceleration parameter has a freedom to vary with the scale factor of the model, which describes the accelerating expansion of the Universe.

  13. Evidence for Bulk Ripplocations in Layered Solids

    Science.gov (United States)

    Gruber, Jacob; Lang, Andrew C.; Griggs, Justin; Taheri, Mitra L.; Tucker, Garritt J.; Barsoum, Michel W.

    2016-09-01

    Plastically anisotropic/layered solids are ubiquitous in nature and understanding how they deform is crucial in geology, nuclear engineering, microelectronics, among other fields. Recently, a new defect termed a ripplocation–best described as an atomic scale ripple–was proposed to explain deformation in two-dimensional solids. Herein, we leverage atomistic simulations of graphite to extend the ripplocation idea to bulk layered solids, and confirm that it is essentially a buckling phenomenon. In contrast to dislocations, bulk ripplocations have no Burgers vector and no polarity. In graphite, ripplocations are attracted to other ripplocations, both within the same, and on adjacent layers, the latter resulting in kink boundaries. Furthermore, we present transmission electron microscopy evidence consistent with the existence of bulk ripplocations in Ti3SiC2. Ripplocations are a topological imperative, as they allow atomic layers to glide relative to each other without breaking the in-plane bonds. A more complete understanding of their mechanics and behavior is critically important, and could profoundly influence our current understanding of how graphite, layered silicates, the MAX phases, and many other plastically anisotropic/layered solids, deform and accommodate strain.

  14. Evidence for Bulk Ripplocations in Layered Solids.

    Science.gov (United States)

    Gruber, Jacob; Lang, Andrew C; Griggs, Justin; Taheri, Mitra L; Tucker, Garritt J; Barsoum, Michel W

    2016-01-01

    Plastically anisotropic/layered solids are ubiquitous in nature and understanding how they deform is crucial in geology, nuclear engineering, microelectronics, among other fields. Recently, a new defect termed a ripplocation-best described as an atomic scale ripple-was proposed to explain deformation in two-dimensional solids. Herein, we leverage atomistic simulations of graphite to extend the ripplocation idea to bulk layered solids, and confirm that it is essentially a buckling phenomenon. In contrast to dislocations, bulk ripplocations have no Burgers vector and no polarity. In graphite, ripplocations are attracted to other ripplocations, both within the same, and on adjacent layers, the latter resulting in kink boundaries. Furthermore, we present transmission electron microscopy evidence consistent with the existence of bulk ripplocations in Ti3SiC2. Ripplocations are a topological imperative, as they allow atomic layers to glide relative to each other without breaking the in-plane bonds. A more complete understanding of their mechanics and behavior is critically important, and could profoundly influence our current understanding of how graphite, layered silicates, the MAX phases, and many other plastically anisotropic/layered solids, deform and accommodate strain. PMID:27640724

  15. Bulk Comptonization by turbulence in accretion discs

    Science.gov (United States)

    Kaufman, J.; Blaes, O. M.

    2016-06-01

    Radiation pressure dominated accretion discs around compact objects may have turbulent velocities that greatly exceed the electron thermal velocities within the disc. Bulk Comptonization by the turbulence may therefore dominate over thermal Comptonization in determining the emergent spectrum. Bulk Comptonization by divergenceless turbulence is due to radiation viscous dissipation only. It can be treated as thermal Comptonization by solving the Kompaneets equation with an equivalent `wave' temperature, which is a weighted sum over the power present at each scale in the turbulent cascade. Bulk Comptonization by turbulence with non-zero divergence is due to both pressure work and radiation viscous dissipation. Pressure work has negligible effect on photon spectra in the limit of optically thin turbulence, and in this limit radiation viscous dissipation alone can be treated as thermal Comptonization with a temperature equivalent to the full turbulent power. In the limit of extremely optically thick turbulence, radiation viscous dissipation is suppressed, and the evolution of local photon spectra can be understood in terms of compression and expansion of the strongly coupled photon and gas fluids. We discuss the consequences of these effects for self-consistently resolving and interpreting turbulent Comptonization in spectral calculations in radiation magnetohydrodynamic simulations of high luminosity accretion flows.

  16. Telomere shortening impairs regeneration of the olfactory epithelium in response to injury but not under homeostatic conditions.

    Directory of Open Access Journals (Sweden)

    Masami Watabe-Rudolph

    Full Text Available Atrophy of the olfactory epithelium (OE associated with impaired olfaction and dry nose represents one of the most common phenotypes of human aging. Impairment in regeneration of a functional olfactory epithelium can also occur in response to injury due to infection or nasal surgery. These complications occur more frequently in aged patients. Although age is the most unifying risk factor for atrophic changes and functional decline of the olfactory epithelium, little is known about molecular mechanisms that could influence maintenance and repair of the olfactory epithelium. Here, we analyzed the influence of telomere shortening (a basic mechanism of cellular aging on homeostasis and regenerative reserve in response to chemical induced injury of the OE in late generation telomere knockout mice (G3 mTerc(-/- with short telomeres compared to wild type mice (mTerc(+/+ with long telomeres. The study revealed no significant influence of telomere shortening on homeostatic maintenance of the OE during mouse aging. In contrast, the regenerative response to chemical induced injury of the OE was significantly impaired in G3 mTerc(-/- mice compared to mTerc(+/+ mice. Seven days after chemical induced damage, G3 mTerc(-/- mice exhibited significantly enlarged areas of persisting atrophy compared to mTerc(+/+ mice (p = 0.031. Telomere dysfunction was associated with impairments in cell proliferation in the regenerating epithelium. Deletion of the cell cycle inhibitor, Cdkn1a (p21 rescued defects in OE regeneration in telomere dysfunctional mice. Together, these data indicate that telomere shortening impairs the regenerative capacity of the OE by impairing cell cycle progression in a p21-dependent manner. These findings could be relevant for the impairment in OE function in elderly people.

  17. Radiation and chemotherapy bystander effects induce early genomic instability events: telomere shortening and bridge formation coupled with mitochondrial dysfunction.

    LENUS (Irish Health Repository)

    Gorman, Sheeona

    2012-02-01

    The bridge breakage fusion cycle is a chromosomal instability mechanism responsible for genomic changes. Radiation bystander effects induce genomic instability; however, the mechanism driving this instability is unknown. We examined if radiation and chemotherapy bystander effects induce early genomic instability events such as telomere shortening and bridge formation using a human colon cancer explant model. We assessed telomere lengths, bridge formations, mitochondrial membrane potential and levels of reactive oxygen species in bystander cells exposed to medium from irradiated and chemotherapy-treated explant tissues. Bystander cells exposed to media from 2Gy, 5Gy, FOLFOX treated tumor and matching normal tissue showed a significant reduction in telomere lengths (all p values <0.018) and an increase in bridge formations (all p values <0.017) compared to bystander cells treated with media from unirradiated tissue (0Gy) at 24h. There was no significant difference between 2Gy and 5Gy treatments, or between effects elicited by tumor versus matched normal tissue. Bystander cells exposed to media from 2Gy irradiated tumor tissue showed significant depolarisation of the mitochondrial membrane potential (p=0.012) and an increase in reactive oxygen species levels. We also used bystander cells overexpressing a mitochondrial antioxidant manganese superoxide dismutase (MnSOD) to examine if this antioxidant could rescue the mitochondrial changes and subsequently influence nuclear instability events. In MnSOD cells, ROS levels were reduced (p=0.02) and mitochondrial membrane potential increased (p=0.04). These events were coupled with a decrease in percentage of cells with anaphase bridges and a decrease in the number of cells undergoing telomere length shortening (p values 0.01 and 0.028 respectively). We demonstrate that radiation and chemotherapy bystander responses induce early genomic instability coupled with defects in mitochondrial function. Restoring mitochondrial

  18. Platinum(II) phenanthroimidazole G-quadruplex ligand induces selective telomere shortening in A549 cancer cells.

    Science.gov (United States)

    Mancini, Johanna; Rousseau, Philippe; Castor, Katherine J; Sleiman, Hanadi F; Autexier, Chantal

    2016-02-01

    Telomere maintenance, achieved by the binding of protective shelterin capping proteins to telomeres and by either telomerase or a recombination-based alternative lengthening of telomere (ALT) mechanism, is critical for cell proliferation and survival. Extensive telomere shortening or loss of telomere integrity activates DNA damage checkpoints, leading to cell senescence or death. Although telomerase upregulation is an attractive target for anti-cancer therapy, the lag associated with telomere shortening and the potential activation of ALT pose a challenge. An alternative approach is to modify telomere interactions with binding proteins (telomere uncapping). G-quadruplex ligands stabilize structures generated from single-stranded G-rich 3'-telomere end (G-quadruplex) folding, which in principle, cannot be elongated by telomerase, thus leading to telomere shortening. Ligands can also mediate rapid anti-proliferative effects by telomere uncapping. We previously reported that the G-quadruplex ligand, phenylphenanthroimidazole ethylenediamine platinum(II) (PIP), inhibits telomerase activity in vitro[47]. In the current study, a long-term seeding assay showed that PIP significantly inhibited the seeding capacity of A549 lung cancer cells and to a lesser extent primary MRC5 fibroblast cells. Importantly, treatment with PIP caused a significant dose- and time-dependent decrease in average telomere length of A549 but not MRC5 cells. Moreover, cell cycle analysis revealed a significant increase in G1 arrest upon treatment of A549 cells, but not MRC5 cells. Both apoptosis and cellular senescence may contribute to the anti-proliferative effects of PIP. Our studies validate the development of novel and specific therapeutic ligands targeting telomeric G-quadruplex structures in cancer cells. PMID:26724375

  19. Increased genomic alteration complexity and telomere shortening in B-CLL cells resistant to radiation-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Salin, H.; Ricoul, M.; Morat, L.; Sabatier, L. [CEA, DSV, iRCM, LRO, F-92265 Fontenay Aux Roses (France); Salin, H. [Museum Natl Hist Nat, F-75231 Paris (France)

    2008-07-01

    B-cell chronic lymphocytic leukemia (B-CLL) results in an accumulation of mature CD5{sup +}/CD23{sup +} B cells due to an uncharacterised defect in apoptotic cell death. B-CLL is not characterized by a unique recurrent genomic alteration but rather by genomic instability giving rise frequently to several chromosomal aberrations. Besides we reported that similar to 15% of B-CLL patients present malignant B-cells resistant to irradiation-induced apoptosis, contrary to similar to 85% of patients and normal human lymphocytes. Telomere length shortening is observed in radioresistant B-CLL cells. Using fluorescence in situ hybridization (FISH) and multicolour FISH, we tested whether specific chromosomal aberrations might be associated with the radioresistance of a subset of B-CLL cells and whether they are correlated with telomere shortening. In a cohort of 30 B-CLL patients, all of the radioresistant B-CLL cell samples exhibited homozygous or heterozygous deletion of 13q14.3 in contrast to 52% of the radiosensitive samples. In addition to the 13q14.3 deletion, ten out of the 11 radioresistant B-cell samples had another clonal genomic alteration such as trisomy 12, deletion 17p13.1, mutation of the p53 gene or translocations in contrast to only three out of 19 radiosensitive samples. Telomere fusions and non-reciprocal translocations, hallmarks of telomere dysfunction, are not increased in radioresistant B-CLL cells. These findings suggest (i) that the 13q14.3 deletion accompanied by another chromosomal aberration is associated with radioresistance of B-CLL cells and (ii) that telomere shortening is not causative of increased clonal chromosomal aberrations in radioresistant B-CLL cells. (authors)

  20. Radiation and chemotherapy bystander effects induce early genomic instability events: Telomere shortening and bridge formation coupled with mitochondrial dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Gorman, Sheeona; Tosetto, Miriam [Centre for Colorectal Disease, St. Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); Lyng, Fiona; Howe, Orla [Radiation and Environmental Science Centre, Dublin Institute of Technology and St. Luke' s Hospital, Dublin (Ireland); Sheahan, Kieran; O' Donoghue, Diarmuid; Hyland, John; Mulcahy, Hugh [Centre for Colorectal Disease, St. Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); O' Sullivan, Jacintha, E-mail: jacintha.osullivan@ucd.ie [Centre for Colorectal Disease, St. Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland)

    2009-10-02

    The bridge breakage fusion cycle is a chromosomal instability mechanism responsible for genomic changes. Radiation bystander effects induce genomic instability; however, the mechanism driving this instability is unknown. We examined if radiation and chemotherapy bystander effects induce early genomic instability events such as telomere shortening and bridge formation using a human colon cancer explant model. We assessed telomere lengths, bridge formations, mitochondrial membrane potential and levels of reactive oxygen species in bystander cells exposed to medium from irradiated and chemotherapy-treated explant tissues. Bystander cells exposed to media from 2 Gy, 5 Gy, FOLFOX treated tumor and matching normal tissue showed a significant reduction in telomere lengths (all p values <0.018) and an increase in bridge formations (all p values <0.017) compared to bystander cells treated with media from unirradiated tissue (0 Gy) at 24 h. There was no significant difference between 2 Gy and 5 Gy treatments, or between effects elicited by tumor versus matched normal tissue. Bystander cells exposed to media from 2 Gy irradiated tumor tissue showed significant depolarisation of the mitochondrial membrane potential (p = 0.012) and an increase in reactive oxygen species levels. We also used bystander cells overexpressing a mitochondrial antioxidant manganese superoxide dismutase (MnSOD) to examine if this antioxidant could rescue the mitochondrial changes and subsequently influence nuclear instability events. In MnSOD cells, ROS levels were reduced (p = 0.02) and mitochondrial membrane potential increased (p = 0.04). These events were coupled with a decrease in percentage of cells with anaphase bridges and a decrease in the number of cells undergoing telomere length shortening (p values 0.01 and 0.028 respectively). We demonstrate that radiation and chemotherapy bystander responses induce early genomic instability coupled with defects in mitochondrial function. Restoring