Sample records for makran active margin

  1. Fluid generation and distribution in the highest sediment input accretionary margin, the Makran

    Smith, Gemma L.; McNeill, Lisa C.; Henstock, Timothy J.; Arraiz, Daniel; Spiess, Volkhard


    Fluids in subduction zones can influence seismogenic behaviour and prism morphology. The Eastern Makran subduction zone, offshore Pakistan, has a very thick incoming sediment section of up to 7.5 km, providing a large potential fluid source to the accretionary prism. A hydrate-related bottom simulating reflector (BSR), zones of high amplitude reflectivity, seafloor seep sites and reflective thrust faults are present across the accretionary prism, indicating the presence of fluids and suggesting active fluid migration. High amplitude free gas zones and seep sites are primarily associated with anticlinal hinge traps, and fluids here appear to be sourced from shallow biogenic sources and migrate to the seafloor along minor normal faults. There are no observed seep sites associated with the surface expression of the wedge thrust faults, potentially due to burial of the surface trace by failure of the steep thrust ridge slopes. Thrust fault reflectivity is restricted to the upper 3 km of sediment and the deeper décollement is non-reflective. We interpret that fluids and overpressure are not common in the deeper stratigraphic section. Thermal modelling of sediments at the deformation front suggests that the deeper sediment section is relatively dewatered and not currently contributing to fluid expulsion in the Makran accretionary prism.

  2. New insights into the active deformation of accretionary prisms: examples from the Western Makran, Iran

    Penney, Camilla; Copley, Alex; Oveisi, Benham


    The Makran subduction zone, along the southern coasts of Iran and Pakistan, hosts one of the largest exposed accretionary wedges in the world. The western Makran has been characterised by a lack of shallow and thrust seismicity in both the instrumental and historical periods. The Mw 6.1 2013 Minab earthquake thus provides a rare opportunity to study the deformation of the accretionary wedge in the transition region between continent-continent collision, in the Zagros, and oceanic subduction, in the Makran. We study the source parameters and slip distribution of this earthquake using seismology, geodesy and field observations. We observe left-lateral strike-slip motion on a fault striking ENE-WSW; approximately perpendicular to the faults of the Minab-Zendan-Palami fault zone, the main structure previously thought to accommodate the right-lateral shear between the Zagros and the Makran. The fault that ruptured in 2013 is one of a series of approximately E-W striking left-lateral faults visible in the geology and geomorphology. These accommodate a velocity field equivalent to right-lateral shear on N-S striking planes by clockwise rotations about vertical axes. The longitudinal range of shear in the western Makran is likely to be controlled by the distance over which the underthrusting Arabian lithosphere deepens in the transition from continent-continent collision to oceanic subduction. The lack of observed megathrust seismicity in the western Makran has led to assertions that the convergence in this region may be aseismic, in contrast to the eastern Makran, which experienced an Mw8.1 earthquake in 1945. The right-lateral Sistan Suture Zone, which runs ~N-S along the Iran-Afghanistan border to the north of the Makran, appears to separate these regimes. However, right-lateral faulting is not observed south of ~27°N, within the wedge. The Minab earthquake and the 2013 Balochistan earthquake show that the Makran accretionary wedge is dominated by strike-slip faulting

  3. Central Makran Range, Pakistan


    A spectacular view of the Makran Range of Pakistan (27.0N, 65.5E) looking north with the Arabian Sea and the city of Karachi in the foreground. In the center, the Indian sub-continent moving slowly north into the Asian continent has caused the folded sedimentary Makran Range to bend from east-west to north-south as well as the uplift forming The Great Himalaya Range and the high Tibetan Plateau to the north.

  4. Actively stressed marginal networks

    Sheinman, M; MacKintosh, F C


    We study the effects of motor-generated stresses in disordered three dimensional fiber networks using a combination of a mean-field, effective medium theory, scaling analysis and a computational model. We find that motor activity controls the elasticity in an anomalous fashion close to the point of marginal stability by coupling to critical network fluctuations. We also show that motor stresses can stabilize initially floppy networks, extending the range of critical behavior to a broad regime of network connectivities below the marginal point. Away from this regime, or at high stress, motors give rise to a linear increase in stiffness with stress. Finally, we demonstrate that our results are captured by a simple, constitutive scaling relation highlighting the important role of non-affine strain fluctuations as a susceptibility to motor stress.

  5. Actively stressed marginal networks.

    Sheinman, M; Broedersz, C P; MacKintosh, F C


    We study the effects of motor-generated stresses in disordered three-dimensional fiber networks using a combination of a mean-field theory, scaling analysis, and a computational model. We find that motor activity controls the elasticity in an anomalous fashion close to the point of marginal stability by coupling to critical network fluctuations. We also show that motor stresses can stabilize initially floppy networks, extending the range of critical behavior to a broad regime of network connectivities below the marginal point. Away from this regime, or at high stress, motors give rise to a linear increase in stiffness with stress. Finally, we demonstrate that our results are captured by a simple, constitutive scaling relation highlighting the important role of nonaffine strain fluctuations as a susceptibility to motor stress.

  6. Assessing the Seismic Potential Hazard of the Makran Subduction Zone

    Frohling, E.; Szeliga, W. M.; Melbourne, T. I.; Abolghasem, A.; Lodi, S. H.


    Long quiescent subduction zones like the Makran, Sunda, and Cascadia, which have long recurrence intervals for large (> Mw 8) earthquakes, often have poorly known seismic histories and are particularly vulnerable and often ill-prepared. The Makran subduction zone has not been studied extensively, but the 1945 Mw 8.1 earthquake and subsequent tsunami, as well as more recent mid magnitude, intermediate depth (50-100 km) seismicity, demonstrates the active seismic nature of the region. Recent increases in regional GPS and seismic monitoring now permit the modeling of strain accumulations and seismic potential of the Makran subduction zone. Subduction zone seismicity indicates that the eastern half of the Makran is presently more active than the western half. It has been hypothesized that the relative quiescence of the western half is due to aseismic behavior. However, based on GPS evidence, the entire subduction zone generally appears to be coupled and has been accumulating stress that could be released in another > 8.0 Mw earthquake. To assess the degree of coupling, we utilize existing GPS data to create a fault coupling model for the Makran using a preliminary 2-D fault geometry derived from ISC hypocenters. Our 2-D modeling is done using the backslip approach and defines the parameters in our coupling model; we forego the generation of a 3-D model due to the low spatial density of available GPS data. We compare the use of both NUVEL-1A plate motions and modern Arabian plate motions derived from GPS station velocities in Oman to drive subduction for our fault coupling model. To avoid non-physical inversion results, we impose second order smoothing to eliminate steep strain gradients. The fit of the modeled inter-seismic deformation vectors are assessed against the observed strain from the GPS data. Initial observations indicate that the entire subduction zone is currently locked and accumulating strain, with no identifiable gaps in the interseismic locking

  7. Segmentation of Makran Subduction Zone and its consequences on tsunami hazard estimations

    Mokhtari, M.


    In a plate tectonic setting like that of the Makran Accretionary Complex of Oman Sea, a fairly high earthquake activity would be expected, as in many of the other major Accretionary complexes/subduction zones around the world. But this region which is located between the Zendan-Minab Fault System and Oranch Fault Zone shows relatively low seismicity in comparison with the surrounding region. Better documented tsunami events in the Makran subduction zones are 3, including two events of seismic origin, and one of unknown origin. The latest event is the major earthquake generated tsunami of 1945 in eastern Makran that ruptured approximately one-fifth the length of the subduction zone. It is important to note that, the epicenter of this event is also close to the Sonne Fault which has created segments on the Makran Subduction Zone. The crossing points between Makran Subduction Zone and these oblique fault zones can be a location for occurrence of major earthquake activities. However, more studies are required for further clarification. In contrast to the east, the plate boundary in western Makran has no clear record of historically as well as instrumental great events. The large changes in seismicity between eastern and western Makran suggest segmentation of the subduction zone. This is being supported by Kukowski et al., (2000) where they introduce a new boundary coinciding very well with the Sonne strike-slip fault. As mentioned the western part is characterized by the absence of events. East of the Sonne fault and west of long 64°E is the only region with a clustering of events within the submarine and southernmost onshore part of the Accretionary Wedge, also including the Mw 8.1 event of 1945 (Byrne et al., 1992). Most events in the wedge appear to be pure-thrust earthquakes and are interpreted as plate boundary events (Quittmeyer and Kafka, 1984; Byrne et al., 1992). The earthquake of August 12, 1963, a few tens of kilometers east of the Sonne fault, had a large

  8. Microearthquakes and crustal structure off the Makran coast of Iran

    Niazi, M.; Shimamura, H.; Matsu' ura, M.


    On the basis of bathymetric an seismic data collected recently off the coast of Makran in the Gulf of Oman, it has been suggested that the folding of the sediments at the northern edge of the abyssal plain is taking place at the present time. The folding is thought to be the consequence of ongoing subduction of the Arabian plate beneath the Eurasian Lithosphere along the Makran coast. Th model assigns a far more significant role to the Makran coast in shaping the tectonics of the region than has thus far been assumed.

  9. Vertical tectonics at an active continental margin

    Houlié, N.; Stern, T. A.


    Direct observations of vertical movements of the earth's surface are now possible with space-based GPS networks, and have applications to resources, hazards and tectonics. Here we present data on vertical movements of the Earth's surface in New Zealand, computed from the processing of GPS data collected between 2000 and 2015 by 189 permanent GPS stations. We map the geographical variation in vertical rates and show how these variations are explicable within a tectonic framework of subduction, volcanic activity and slow slip earthquakes. Subsidence of >3 mm/yr is observed along southeastern North Island and is interpreted to be due to the locked segment of the Hikurangi subduction zone. Uplift of 1-3 mm/yr further north along the margin of the eastern North Island is interpreted as being due to the plate interface being unlocked and underplating of sediment on the subduction thrust. The Volcanic Plateau of the central North Island is being uplifted at about 1 mm/yr, which can be explained by basaltic melts being injected in the active mantle-wedge at a rate of ∼6 mm/yr. Within the Central Volcanic Region there is a 250 km2 area that subsided between 2005 and 2012 at a rate of up to 14 mm/yr. Time series from the stations located within and near the zone of subsidence show a strong link between subsidence, adjacent uplift and local earthquake swarms.


    George Pararas-Carayannis


    Full Text Available Although large earthquakes along the Makran Subduction Zone are infrequent, the potential for the generation of destructive tsunamis in the Northern Arabian Sea cannot be overlooked. It is quite possible that historical tsunamis in this region have not been properly reported or documented. Such past tsunamis must have affected Southern Pakistan, India, Iran, Oman, the Maldives and other countries bordering the Indian Ocean.The best known of the historical tsunamis in the region is the one generated by the great earthquake of November 28, 1945 off Pakistan's Makran Coast (Balochistan in the Northern Arabian Sea. The destructive tsunami killed more than 4,000 people in Southern Pakistan but also caused great loss of life and devastation along the coasts of Western India, Iran, Oman and possibly elsewhere.The seismotectonics of the Makran subduction zone, historical earthquakes in the region, the recent earthquake of October 8, 2005 in Northern Pakistan, and the great tsunamigenic earthquakes of December 26, 2004 and March 28, 2005, are indicative of the active tectonic collision process that is taking place along the entire southern and southeastern boundary of the Eurasian plate as it collides with the Indian plate and adjacent microplates. Tectonic stress transference to other, stress loaded tectonic regions could trigger tsunamigenic earthquakes in the Northern Arabian Sea in the future.The northward movement and subduction of the Oman oceanic lithosphere beneath the Iranian micro-plate at a very shallow angle and at the high rate is responsible for active orogenesis and uplift that has created a belt of highly folded and densely faulted coastal mountain ridges along the coastal region of Makran, in both the Balochistan and Sindh provinces. The same tectonic collision process has created offshore thrust faults. As in the past, large destructive tsunamigenic earthquakes can occur along major faults in the east Makran region, near Karachi, as

  11. A geophysical potential field study to image the Makran subduction zone in SE of Iran

    Abedi, Maysam; Bahroudi, Abbas


    The Makran subduction wedge as one of the largest subduction complexes has been forming due to the Arabian oceanic lithosphere subducting beneath the Lut and the Afghan rigid block microplates. To better visualize the subducting oceanic crust in this region, a geophysical model of magnetic susceptibility from an airborne magnetic survey (line spacing about 7.5 km) over the Makran zone located at southeast of Iran is created to image various structural units in Iran plate. The constructed geophysical model from the 3D inverse modeling of the airborne magnetic data indicates a thin subducting slab to the north of the Makran structural zone. It is demonstrated that the thickness of sedimentary units varies approximately at an interval of 7.5-11 km from north to south of this zone in the Iranian plate, meanwhile the curie depth is also estimated approximately < 26 km. It is also shown the Jazmurian depression zone adjacent to the north of the Makran indicates high intensity magnetic anomalies due to being underlain by an ophiolite oceanic basement, while such intensity reduces over the Makran. The directional derivatives of the magnetic field data have subtle changes in the Makran, but strongly increase in the Jazmurian by enhancing and separating different structural boundaries in this region. In addition, the density variations of the subsurface geological layers were determined by 3D inversion of the ground-based gravity data over the whole study area, where the constructed density model was in good agreement with the magnetic one. According to the outputs of the magnetic susceptibility and the density contrast, the Arabian plate subducts to the north under the Eurasia with a very low dip angle in the Makran structural zone.

  12. Crustal growth at active continental margins: Numerical modeling

    Vogt, Katharina|info:eu-repo/dai/nl/370618947; Gerya, Taras; Castro, Antonio


    The dynamics and melt sources for crustal growth at active continental margins are analyzed by using a 2D coupled petrological–thermomechanical numerical model of an oceanic-continental subduction zone. This model includes spontaneous slab retreat and bending, dehydration of subducted crust, aqueous

  13. Defining the worst case scenario for the Makran Subduction Zone: the 1008 AD tsunami

    Hoffmann, Goesta


    The Makran Subduction Zone is located within the Arabian Sea (Northern Indian Ocean) and marks the boundary between the Arabian and the Eurasian plate. The sinistral strike-slip Sonne fault separates the subduction zone in an eastern and western segment. The convergence rate is about 40 mm/yr and slightly faster in the east than in the west. The seismicity is low in general and the few documented seismic events are concentrated in the eastern segment. No seismic activity is known from the western segment in historic times. The hazard potential is enigmatic as the only documented and recorded tsunamigenic earthquake (MW 8.1) within the subduction zone occurred in Nov 1945. However, thermal modelling suggests a wide potential seismogenic zone, apparently capable of generating very significant (>MW 8.5) tsunamigenic earthquakes. Furthermore, submarine slumping is another tsunami trigger which has to be taken into account. We used the modelling results as a hypothesis and mapped extreme wave event deposits along the coastline of Oman, bordering the Arabian Sea. We were able to document extensive boulder fields along rocky parts of the coastline. These boulders are decorated with marine sessile organism such as e.g oysters or barnacles testifying for an intertidal setting of the boulder prior to dislocation. The organism remains were used for radiocarbon dating assuming that the death of the organism was related to the relocation of the boulder. Storm-induced boulder movement is possible as the coastline is subject to infrequent tropical cyclone impact. However, boulder movement was not observed during the strongest storm on record in 2007. The dating exercise revealed a cluster of dates around 1000 AD, coinciding with a potential earthquake event known from a historic Persian text dating to the year 1008 AD. Archaeological evidence, mainly pottery artefacts found along the sea shore near the capital area Muscat/Oman also indicate a catastrophic event which may be

  14. The Chahnaly low sulfidation epithermal gold deposit, western Makran volcanic arc, southeastern Iran

    Sholeh, Ali; Rastad, Ebrahim; Huston, David L.; Gemmell, J. Bruce; Taylor, Ryan D.


    The Chahnaly low-sulfidation epithermal Au deposit and nearby Au prospects are located northwest of the intermittently active Bazman stratovolcano on the western end of the Makran volcanic arc, which formed as the result of subduction of the remnant Neo-Tethyan oceanic crust beneath the Lut block. The arc hosts the Siah Jangal epithermal and Kharestan porphyry prospects, near Taftan volcano, as well as the Saindak Cu-Au porphyry deposit and world-class Reko Diq Cu-Au porphyry deposit, near Koh-i-Sultan volcano to the east-northeast in Pakistan. The host rocks for the Chahnaly deposit include early Miocene andesite and andesitic volcaniclastic rocks that are intruded by younger dacitic domes. Unaltered late Miocene dacitic ignimbrites overlie these rocks. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology data yield ages between 21.8 and 9.9 Ma for the acidic-intermediate regional volcanism. The most recent volcanic activity of the Bazman stratovolcano involved extrusion of an olivine basalt during Pliocene to Quaternary times. Interpretation of geochemical data indicate that the volcanic rocks are synsubduction and calc-alkaline to subalkaline. The lack of a significant negative Eu anomaly, a listric-shaped rare earth element pattern, and moderate La/Yb ratios of host suites indicate a high water content of the source magma.

  15. Comparison of turbidite facies associations in modern passive-margin Mississippi fan with ancient active-margin fans

    Shanmugam, G.; Moiola, R. J.; McPherson, J. G.; O'Connell, S.


    Our comparison of the modern passive-margin Mississippi fan (DSDP Leg 96) with ancient active-margin fans (e.g. Eocene Hecho Group, Spain) reveals major differences in turbidite facies associations (Mutti and Ricci Lucchi scheme) and in seismic characteristics in the lower fan area. The lower (outer) Mississippi fan is composed of channel (Facies B and F) and non-channel facies (C? and D), whereas ancient fans are characterized by non-channelized, thickening-upward, depositional lobe facies (C and D). An absence of depositional lobes in the lower Mississippi fan is also suggested by a lack of convex-upward (mounded) seismic reflections with bidirectional downlap. Continuous seismic reflections of the lower Mississippi fan may represent "sheet sands", but not those of true depositional lobes with mounded character. Extensive channelization in modern passive-margin fans appears to be a product of the lateral shifting of a major sinuous distributary system, developed as a consequence of low gradients and the transport of sediment with a relatively low sand/mud ratio. In contrast, channels in active-margin fans are short and of low sinuosity as a result of high gradients and the transport of sediment with a relatively high sand/mud ratio. The turbidite facies association scheme, which was developed exclusively from ancient active-margin fans, should be applied to mature passive-margin fans with qualifications because of the differences in spatial distribution of turbidite facies and their associations.

  16. Probabilistic tsunami hazard assessment for the Makran region with focus on maximum magnitude assumption

    Hoechner, Andreas; Babeyko, Andrey Y.; Zamora, Natalia


    Despite having been rather seismically quiescent for the last decades, the Makran subduction zone is capable of hosting destructive earthquakes and tsunami. In particular, the well-known thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Furthermore, some recent publications discuss rare but significantly larger events at the Makran subduction zone as possible scenarios. We analyze the instrumental and historical seismicity at the subduction plate interface and generate various synthetic earthquake catalogs spanning 300 000 years with varying magnitude-frequency relations. For every event in the catalogs we compute estimated tsunami heights and present the resulting tsunami hazard along the coasts of Pakistan, Iran and Oman in the form of probabilistic tsunami hazard curves. We show how the hazard results depend on variation of the Gutenberg-Richter parameters and especially maximum magnitude assumption.

  17. Automatic Image Segmentation Using Active Contours with Univariate Marginal Distribution

    I. Cruz-Aceves


    Full Text Available This paper presents a novel automatic image segmentation method based on the theory of active contour models and estimation of distribution algorithms. The proposed method uses the univariate marginal distribution model to infer statistical dependencies between the control points on different active contours. These contours have been generated through an alignment process of reference shape priors, in order to increase the exploration and exploitation capabilities regarding different interactive segmentation techniques. This proposed method is applied in the segmentation of the hollow core in microscopic images of photonic crystal fibers and it is also used to segment the human heart and ventricular areas from datasets of computed tomography and magnetic resonance images, respectively. Moreover, to evaluate the performance of the medical image segmentations compared to regions outlined by experts, a set of similarity measures has been adopted. The experimental results suggest that the proposed image segmentation method outperforms the traditional active contour model and the interactive Tseng method in terms of segmentation accuracy and stability.

  18. The determinants of intermediaries’ power over farmers’ margin-related activities

    Xhoxhi, Orjon; Pedersen, Søren Marcus; Lind, Kim Martin Hjorth;


    This paper investigates the determinants of intermediaries’ power over farmers’ margin-related activities in Adana, Turkey. In doing so, a holistic model of intermediaries’ power over farmers’ margin-related activities is proposed. The objective of this model is to contribute to a better...

  19. Trapped waves of the 27 November 1945 Makran tsunami: observations and numerical modeling

    Neetu, S.; Suresh, I.; Shankar, R.; Nagarajan, B.; Sharma, R.; Shenoi, S.S.C.; Unnikrishnan, A.S.; Sundar, D.

    Victoria at Mahe) have been documented in several reports (Ambraseys and Melville, 1982; Beer and Stagg, 1946; Pendse, 1948). An intriguing aspect of these reports is that the leading tsunami wave that arrived at the Makran coast and at Karachi was not high... after the arrival of the initial wave. On the other hand, only one high wave was reported (Ambraseys and Melville, 1982; Pendse, 1948) from Mumbai. Beer and Stagg (1946) report the sea-level measurements of this tsunami from Port Victoria, Mahe...

  20. Enabling socio-economic activities: Opening global markets for the marginalized through secure ICT use

    Phahlamohlaka, Jackie


    Full Text Available This paper identifies and describes five economic activities through which ICT could effectively be used to open global markets for rural and marginalized communities. The activities are identified in contexts where there are no industries...

  1. The 1945 Balochistan earthquake and probabilistic tsunami hazard assessment for the Makran subduction zone

    Höchner, Andreas; Babeyko, Andrey; Zamora, Natalia


    Iran and Pakistan are countries quite frequently affected by destructive earthquakes. For instance, the magnitude 6.6 Bam earthquake in 2003 in Iran with about 30'000 casualties, or the magnitude 7.6 Kashmir earthquake 2005 in Pakistan with about 80'000 casualties. Both events took place inland, but in terms of magnitude, even significantly larger events can be expected to happen offshore, at the Makran subduction zone. This small subduction zone is seismically rather quiescent, but a tsunami caused by a thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Additionally, some recent publications raise the question of the possiblity of rare but huge magnitude 9 events at the Makran subduction zone. We first model the historic Balochistan event and its effect in terms of coastal wave heights, and then generate various synthetic earthquake and tsunami catalogs including the possibility of large events in order to asses the tsunami hazard at the affected coastal regions. Finally, we show how an effective tsunami early warning could be achieved by the use of an array of high-precision real-time GNSS (Global Navigation Satellite System) receivers along the coast.

  2. Active transcurrent fault system along the north African passive margin

    Ben-Avraham, Zvi; Nur, Amos; Giuseppe, Cello


    Along the southern boundary of the eastern Mediterranean extends a WNW-trending narrow zone, about 1000 km long, of possible transcurrent faulting. It terminates on both sides at areas of crustal extension, the Tyrrhenian Sea on the west-northwest and the Gulf of Suez on the east-southeast. From the southern Tyrrhenian Sea the fault zone runs through the Strait of Sicily rift zone, the Ionian Sea, the base of the continental margin of eastern Lybia and western Egypt, into the land area through the apex of the Nile Delta and eventually into the Gulf of Suez. Studies of the fault pattern in the Strait of Sicily indicate that the rifting processes there are associated with a major dextral shear zone. Right-lateral movement is also consistent with the deformation along the southeastern extension of the fault zone: i.e., the sense of offset of a series of bathymetric depressions located along the base of the continental margin of eastern Lybia and western Egypt which we interpret as pull-apart basins formed by transcurrent faulting. Crustal structure may play an important role in controlling the location of the fault zone. On both ends, adjacent to the zones of crustal extension in the Tyrrhenian Sea and the Gulf of Suez, the fault is located within a continental crust, in the Strait of Sicily and in northern Egypt. In between, in the Ionian Sea and at the base of the continental margin of eastern Lybia and western Egypt, it is located in between provinces of continental crust on the south and oceanic crust on the north.

  3. Comparison of submarine gully morphologies in passive and active margin settings

    Jackson, C.; Shumaker, L.; Johnstone, S.; Graham, S. A.


    Passive and active tectonic margins have inherently different hypsometry, due to local patterns of deformation and subsequent impacts on the style of sedimentation. One way we can analyze and compare the two settings is through observation of submarine gullies, which are small channel features that form along the continental slope as it descends to the ocean floor. By documenting the geometries of gullies that have formed on passive margins and gullies that have formed on active margins, we attempt to distinguish differences in gully morphologies in these two settings. We manually mapped over 600 gullies and interfluves from shaded relief and contour maps generated from bathymetric data across the globe, including the coast of California, the Beaufort Sea, and the Black Sea. We extrapolated and plotted elevation profiles of the gullies along their downslope distance, and compared a range of gully properties, such as length, spacing, and slope, to look at the correlations among those elements of gullies and their tectonic setting. We find that gullies forming on active margins show the greatest variability in their slopes, exhibiting both the steepest and the shallowest slopes of the dataset. The slopes of the passive margin gullies fall within the range of the active margin gully slopes, but interestingly, we note patterns in the ranges of gully steepness at different localities. These results differ from our our anticipation that active margin gullies are steeper than passive margin gullies, but suggest that gullies in all settings display a variety of morphologies. Additional mapping of active margin gullies will better determine if there are morphological differences between the two settings.

  4. Geochemical discrimination of siliciclastic sediments from active and passive margin settings

    Verma, Surendra P.; Armstrong-Altrin, John S.


    Discrimination of active and passive margins is important from both academic and economic aspects. This can only be successfully achieved, however, if there are major compositional differences among sediments derived from different continental margins. A worldwide database of active and passive margin settings was established from published major and trace element geochemical data of Neogene to Quaternary siliciclastic sediments. These data were used to evaluate the performance of existing discrimination diagrams, which were shown to work unsatisfactorily with success values of mostly between 0% and 30%. Because these diagrams were not based on a statistically coherent methodology, we proposed two new discriminant functions from linear discriminant analysis of multinormally distributed isometric log-transformed ratios of major and combined major and trace elements. These new diagrams showed very high percent success values of about 87%-97% and 84%-86% for the active and passive margins, respectively, for the original database. Excellent performance of the multidimensional diagrams and related discriminant functions was confirmed from 11 test studies involving Quaternary to Holocene siliciclastic sediments from known tectonic margins. The expected result of an active or passive margin was obtained, with most samples plotting correctly in the respective field.

  5. Batch Mode Active Sampling based on Marginal Probability Distribution Matching.

    Chattopadhyay, Rita; Wang, Zheng; Fan, Wei; Davidson, Ian; Panchanathan, Sethuraman; Ye, Jieping


    Active Learning is a machine learning and data mining technique that selects the most informative samples for labeling and uses them as training data; it is especially useful when there are large amount of unlabeled data and labeling them is expensive. Recently, batch-mode active learning, where a set of samples are selected concurrently for labeling, based on their collective merit, has attracted a lot of attention. The objective of batch-mode active learning is to select a set of informative samples so that a classifier learned on these samples has good generalization performance on the unlabeled data. Most of the existing batch-mode active learning methodologies try to achieve this by selecting samples based on varied criteria. In this paper we propose a novel criterion which achieves good generalization performance of a classifier by specifically selecting a set of query samples that minimizes the difference in distribution between the labeled and the unlabeled data, after annotation. We explicitly measure this difference based on all candidate subsets of the unlabeled data and select the best subset. The proposed objective is an NP-hard integer programming optimization problem. We provide two optimization techniques to solve this problem. In the first one, the problem is transformed into a convex quadratic programming problem and in the second method the problem is transformed into a linear programming problem. Our empirical studies using publicly available UCI datasets and a biomedical image dataset demonstrate the effectiveness of the proposed approach in comparison with the state-of-the-art batch-mode active learning methods. We also present two extensions of the proposed approach, which incorporate uncertainty of the predicted labels of the unlabeled data and transfer learning in the proposed formulation. Our empirical studies on UCI datasets show that incorporation of uncertainty information improves performance at later iterations while our studies on 20

  6. Tracking small mountainous river derived terrestrial organic carbon across the active margin marine environment

    Childress, L. B.; Blair, N. E.; Orpin, A. R.


    Active margins are particularly efficient in the burial of organic carbon due to the close proximity of highland sources to marine sediment sinks and high sediment transport rates. Compared with passive margins, active margins are dominated by small mountainous river systems, and play a unique role in marine and global carbon cycles. Small mountainous rivers drain only approximately 20% of land, but deliver approximately 40% of the fluvial sediment to the global ocean. Unlike large passive margin systems where riverine organic carbon is efficiently incinerated on continental shelves, small mountainous river dominated systems are highly effective in the burial and preservation of organic carbon due to the rapid and episodic delivery of organic carbon sourced from vegetation, soil, and rock. To investigate the erosion, transport, and burial of organic carbon in active margin small mountainous river systems we use the Waipaoa River, New Zealand. The Waipaoa River, and adjacent marine depositional environment, is a system of interest due to a large sediment yield (6800 tons km-2 yr-1) and extensive characterization. Previous studies have considered the biogeochemistry of the watershed and tracked the transport of terrestrially derived sediment and organics to the continental shelf and slope by biogeochemical proxies including stable carbon isotopes, lignin phenols, n-alkanes, and n-fatty acids. In this work we expand the spatial extent of investigation to include deep sea sediments of the Hikurangi Trough. Located in approximately 3000 m water depth 120 km from the mouth of the Waipaoa River, the Hikurangi Trough is the southern extension of the Tonga-Kermadec-Hikurangi subduction system. Piston core sediments collected by the National Institute of Water and Atmospheric Research (NIWA, NZ) in the Hikurangi Trough indicate the presence of terrestrially derived material (lignin phenols), and suggest a continuum of deposition, resuspension, and transport across the margin

  7. Cenozoic uplift on the West Greenland margin: active sedimentary basins in quiet Archean terranes.

    Jess, Scott; Stephenson, Randell; Brown, Roderick


    The North Atlantic is believed by some authors to have experienced tectonically induced uplift within the Cenozoic. Examination of evidence, onshore and offshore, has been interpreted to imply the presence of kilometre scale uplift across the margins of the Barents Sea, North Sea, Baffin Bay and Greenland Sea. Development of topography on the West Greenland margin (Baffin Bay), in particular, has been subject to much discussion and dispute. A series of low temperature thermochronological (AFT and AHe) studies onshore and interpretation of seismic architecture offshore have suggested uplift of the entire margin totalling ~3km. However, challenges to this work and recent analysis on the opposing margin (Baffin Island) have raised questions about the validity of this interpretation. The present work reviews and remodels the thermochronological data from onshore West Greenland with the aim of re-evaluating our understanding of the margin's history. New concepts within the discipline, such as effect of radiation damage on Helium diffusivity, contemporary modelling approaches and denudational mapping are all utilised to investigate alternative interpretations to this margins complex post rift evolution. In contrast to earlier studies our new approach indicates slow protracted cooling across much of the region; however, reworked sedimentary samples taken from the Cretaceous Nuussuaq Basin display periods of rapid reheating and cooling. These new models suggest the Nuussuaq Basin experienced a tectonically active Cenozoic, while the surrounding Archean basement remained quiet. Faults located within the basin appear to have been reactivated during the Palaeocene and Eocene, a period of well-documented inversion events throughout the North Atlantic, and may have resulted in subaerial kilometre scale uplift. This interpretation of the margin's evolution has wider implications for the treatment of low temperature thermochronological data and the geological history of the North

  8. Spatial variation in soil active-layer geochemistry across hydrologic margins in polar desert ecosystems

    J. E. Barrett


    Full Text Available Polar deserts are characterized by severe spatial-temporal limitations of liquid water. In soil active layers of the Antarctic Dry Valleys, liquid water is infrequently available over most of the arid terrestrial landscape. However, soils on the margins of glacial melt-water streams and lakes are visibly wet during the brief Austral summer when temperatures permit the existence of liquid water. We examined the role of these hydrologic margins as preferential zones for the transformation and transport of nutrient elements and solutes in an environment where geochemical weathering and biological activity is strictly limited by the dearth of liquid water. We report on hydropedological investigations of aquatic-terrestrial transition zones adjacent to 11 stream and lake systems in the Antarctic Dry Valleys. Our results show that wetted zones extended 1–11 m from the edges of lotic and lentic systems. While capillary demand and surface evaporation drive a one-way flux of water through these zones, the scale of these transition zones is determined by the topography and physical characteristics of the surrounding soils. Nutrient concentrations and fluxes appear to be influenced by both the hydrology and microbial-mediated biogeochemical processes. Salt concentrations are enriched near the distal boundary of the wetted fronts due to evapo-concentration of pore water in lake margin soils, while organic matter, ammonium and phosphate concentrations are highest in stream channel sediments where potential for biological activity is greatest. Thus, in the Antarctic Dry Valleys, intermittently wet soils on the margins of streams and lakes are important zones of both geochemical cycling and biological activity.

  9. Carbonate sedimentation in an extensional active margin: Cretaceous history of the Haymana region, Pontides

    Okay, Aral I.; Altiner, Demir


    The Haymana region in Central Anatolia is located in the southern part of the Pontides close to the İzmir-Ankara suture. During the Cretaceous, the region formed part of the south-facing active margin of the Eurasia. The area preserves a nearly complete record of the Cretaceous system. Shallow marine carbonates of earliest Cretaceous age are overlain by a 700-m-thick Cretaceous sequence, dominated by deep marine limestones. Three unconformity-bounded pelagic carbonate sequences of Berriasian, Albian-Cenomanian and Turonian-Santonian ages are recognized: Each depositional sequence is preceded by a period of tilting and submarine erosion during the Berriasian, early Albian and late Cenomanian, which corresponds to phases of local extension in the active continental margin. Carbonate breccias mark the base of the sequences and each carbonate sequence steps down on older units. The deep marine carbonate deposition ended in the late Santonian followed by tilting, erosion and folding during the Campanian. Deposition of thick siliciclastic turbidites started in the late Campanian and continued into the Tertiary. Unlike most forearc basins, the Haymana region was a site of deep marine carbonate deposition until the Campanian. This was because the Pontide arc was extensional and the volcanic detritus was trapped in the intra-arc basins and did not reach the forearc or the trench. The extensional nature of the arc is also shown by the opening of the Black Sea as a backarc basin in the Turonian-Santonian. The carbonate sedimentation in an active margin is characterized by synsedimentary vertical displacements, which results in submarine erosion, carbonate breccias and in the lateral discontinuity of the sequences, and differs from blanket like carbonate deposition in the passive margins.

  10. Characteristics and features of the submarine landslides in passive and active margin southwestern offshore Taiwan

    Yeh, Y. C.


    In the past decade, numerous multi-channel seismic surveys as well as near seafloor high resolution geophysical investigations were conducted in order to explore and estimate the reserves of gas hydrate southwestern offshore Taiwan. The previous object was focused on searching substitute energy (i.e. gas hydrate) rather than geo-hazards. However, it is suggested that most of the gas hydrate is generally distributed at slope area southwestern offshore Taiwan, which indicates the slope may be failed when steady state was disturbed by some factors, such as sea level or climate change. In addition, once gas hydrate was dissociated, this may induce submarine landslide that further cause devastated tsunami. Thus, it is of great urgency to investigate potential landslide area, particularly, the hydrate-rich continental slope (active and passive margins) in adjacent to populous city like Kaohsiung. In this study, we collected several high resolution multi-channel seismic data with ten seconds shooting rate and 3.125 meters group interval streamer by using R/V ORI and R/V ORV. The seismic data were processed in conventional data processing strategy: bad trace clean, geometry settings, band-pass filter, de-convolution, surface-related multiple rejection, radon filter, stacking,kirchhoff migration and time to depth conversion. Combine the results obtained from the MCS data and subbottom profiles, two major results could be raised in the active margin as followed: (1) Most of the surface creeping and landslide was occurred shallower than 500 meters in water depth, which should be related to the inter-bedded fluid activities. (2) The landslide distribution is lagly affected by the presence of diaper, suggesting the subsequent mud diapirism may destruct slope stability; (3) The submarine landslide deeper than 800 meters in water depth distributes in the thrust fold area, that is probably referred to active thrusting. In the passive margin, large volume mass transportation

  11. The active southwest margin of the Colorado Plateau: uplift of mantle origin

    Parsons, T.; McCarthy, J.


    During Cenozoic time, the Colorado Plateau was raised about 2km above sea level. The most-recent and best-documented uplift of the plateau (~1km) has been concentrated at its southwest margin between 6 and 1 Ma, whereas the eastern Colorado Plateau may have been at high elevations since Eocene time. To better understand the recent tectonic activity at the southwest margin of the Colorado Plateau, we compile detailed crustal thickness and density information from seismic and gravity data for a region that includes northwest Arizona and the southern tip of Nevada. This information is used to isolate the mantle contribution to uplift. We speculate that uplift may result from subduction-related thinning of the continental lithosphere. -from Authors

  12. Quaternary volcano-tectonic activity in the Soddo region, western margin of the Southern Main Ethiopian Rift

    Corti, G.; Sani, F.; Philippon, M.; Sokoutis, D.; Willingshofer, E.; Molin, P.


    We present an analysis of the distribution, timing, and characteristics of the volcano-tectonic activity on the western margin of the Southern Main Ethiopian Rift in the Soddo area (latitudes between ~7°10'N and ~6°30'N). The margin is characterized by the presence of numerous normal faults, with li

  13. Margin requirements, margin loans, and margin rates: practice and principles

    Peter Fortune


    The Board of Governors of the Federal Reserve System establishes initial margin requirements under Regulations T, U, and X. Recent margin loan increases, both in aggregate value and relative to market capitalization, have rekindled the debate about using margin requirements as an instrument to affect the prices of common stocks. Proponents of a more active margin requirement policy see the regulations as instruments for affecting the level and volatility of stock prices by influencing investo...

  14. Links among Slope Morphology, Canyon Types and Tectonics on Passive and Active Margins in the Northernmost South China Sea

    Ho-Shing Yu; Emmy T Y Chang


    We examine slope profile types and variations in slope gradient and slope relief with depth for both passive and active margins in the northern most South China Sea.The passive South China margin is characterized by an exponential slope profile,mainly assodated with clustered slope-confined canyons.The active Taiwan margin shows a linear-like shape with great variations along the lower slope.Fewer eanyom occur on the Taiwau margin,and hence the influence of canyon incision on slope morphology is relatively less significant.Quantitative analyses of slope curvature,slope gradleut and square root of relief variance are useful statistical parameters to explain characteristics and variability of morphology of the slope of the South China margin,but not for the Kaoping slope on the Talwan side.On the active Taiwan margin,tectonic activities are dominant over sediment deposition and surface erosion,producing a slope profile quite different from those of passive margins of the Middle Atlantic,KwaZulu-Natal,South Africa where failure on slope and accompanying canyon incision are the dominant processes shaping the slope morphology.

  15. Shallow marine sedimentation within an active margin basin, James Ross Island, Antarctica

    Pirrie, Duncan


    The Santa Marta Formation exposed on northern James Ross Island, Antarctica, represents shallow marine shelf sedimentation within an active margin basin. The formation is approximately 1000 m thick, is of uppermost Santonian to Campanian age and represents part of a 5000-6000 m thick sedimentary sequence forming the Larsen Basin. The Larsen Basin represents either a back-arc basin, or a half-graben basin, developed on the extending margin of the Weddell Sea. Twelve sedimentary facies have been recognised, which can be subdivided into two groups: those which are controlled by shelf processes and those which are related to active arc volcanism. Background shelf processes include fair-weather suspension sedimentation, storm sands and rare tidal current reworking. Active arc processes include direct settling of airfall detritus and rapid resedimentation of volcaniclastic detritus by sandy debris-flows and both high- and low-concentration turbidity currents. In addition sheet conglomerates represent debris flows that evolved from syn-sedimentary slumps. Two facies associations representing a mid to outer shelf and an inner shelf depositional setting respectively can be distinguished, with an apparent regression in the ?mid to late Campanian.

  16. Magmatism evolution on the last Neoproterozoic development stage of the western Siberian active continental margin

    Vernikovskaya, Antonina E.; Vernikovsky, Valery A.; Matushkin, Nikolay Yu.; Kadilnikov, Pavel I.; Romanova, Irina V.


    Rocks from active continental margin complexes are characterized by a wide variety of chemical compositions from depleted in alkali to alkali differentiates. When addressing issues of geodynamic settings in which such rocks form, it is important to understand the evolution of the host tectonic structure, as well as the chemical affiliation of the various rocks composing it. The Yenisey Ridge orogen located in the south-western framing of Siberia is one of the more studied regions with a long history of Neoproterozoic magmatic events. This orogen was formed during the collision of the Central Angara terrane with Siberia, which took place 761-718 Ma. Subsequent subduction-related events in the orogen have been recorded in the coeval magmatism (711-629 Ma) of two complexes: one is the active continental margin complex (Nb enriched igneous rocks - gabbroids, trachybasalts, A-type granites and carbonatites, including contact metasomatites zones with Nb mineralization), and the other one is an island arc complex (differentiated series volcanics, gabbroids and plagiogranites). The rocks of these complexes are respectively located in two suture zones: the Tatarka-Ishimba zone that formed due to the collision mentioned above, and the Yenisei suture marking the subduction zone [Vernikovsky et al., 2003; 2008]. The final Neoproterozoic stage in the evolution of the active margin of Siberia is manifested as adakite-gabbro-anorthosite magmatism in the 576-546 Ma interval. Our results indicate a genetic relationship between the adakites and their host NEB-type metabasites of the Zimovey massif. These Neoproterozoic adakites could have formed in a setting of transform-strike-slip drift of lithospheric plates after the subduction stopped, both from a crustal and mantle-crustal source, similarly to the Cenozoic magmatic complexes of the transform margin in the eastern framing of Eurasia [Khanchuk et al., 2016]. Vernikovsky V.A., Vernikovskaya A.E., Kotov A.B., Sal'nikova E

  17. Evidence of active methanogen communities in shallow sediments of the sonora margin cold seeps.

    Vigneron, Adrien; L'Haridon, Stéphane; Godfroy, Anne; Roussel, Erwan G; Cragg, Barry A; Parkes, R John; Toffin, Laurent


    In the Sonora Margin cold seep ecosystems (Gulf of California), sediments underlying microbial mats harbor high biogenic methane concentrations, fueling various microbial communities, such as abundant lineages of anaerobic methanotrophs (ANME). However, the biodiversity, distribution, and metabolism of the microorganisms producing this methane remain poorly understood. In this study, measurements of methanogenesis using radiolabeled dimethylamine, bicarbonate, and acetate showed that biogenic methane production in these sediments was mainly dominated by methylotrophic methanogenesis, while the proportion of autotrophic methanogenesis increased with depth. Congruently, methane production and methanogenic Archaea were detected in culture enrichments amended with trimethylamine and bicarbonate. Analyses of denaturing gradient gel electrophoresis (DGGE) fingerprinting and reverse-transcribed PCR-amplified 16S rRNA sequences retrieved from these enrichments revealed the presence of active methylotrophic Methanococcoides burtonii relatives and several new autotrophic Methanogenium lineages, confirming the cooccurrence of Methanosarcinales and Methanomicrobiales methanogens with abundant ANME populations in the sediments of the Sonora Margin cold seeps. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  18. Crustal recycling at active convergent margins and growth of the continents

    Morris, J. (Washington Univ., St. Louis, MO (United States). Dept. of Earth and Planetary Sciences Carnegie Institution of Washington, DC (United States)); Zheng, S.H. (Univ. of California, Irvine, CA (United States). Dept. of Geological Sciences)


    Subduction of continental materials at active convergent margins provides an opportunity to evaluate mechanisms and magnitude of subduction-driven crustal recycling and its potential role in continental growth. Continental materials, in the form of detrital sediments and elements adsorbed out of seawater onto settling sediment particles, are continuously supplied to subduction trenches. The sediments may be accreted and re-attached to the continental crust through collisional processes subducted to depth and subsequently involved in arc magma generation (magmatic recycling) or subducted past the arc into the deep mantle. Cosmogenic 10Be, which is strongly adsorbed onto settling sediment particles, may be used to investigate all aspects of sediment recycling. Because of its atmospheric source and short half-life, the high 10Be concentrations observed in many volcanic arc magmas require that the uppermost part of the sediment column be subducted to depth and some part of it returned to the surface in arc magmas within the measurable 10Be lifetime, effectively a few million years. In the Aleutians, Middle America and Marianas, 10Be is present only in the upper 12m, 100m and 25m, respectively of the subducting oceanic sediment column. Using von Huene and Scholl's 1991 estimate of oceanic sediment supply to trenches, the authors evidence for sediment bypassing of accretionary margins, and the limited recycling of most major elements in arc volcanism, estimates of sediment subduction are nearly equal to those required in a steady-state, recycling model for growth of the continents through time.

  19. Late Permian to recent magmatic activity on the African-Arabian margin of Tethys

    Wilson, M. [Leeds University (United Kingdom). School of Earth Sciences; Guiraud, R. [Universite de Montpellier II (France). Laboratoire de Geophysique et Tectonique; Moreau, C. [Universite de la Rochelle (France). Departement des Sciences de la Terre; Bellion, Y.J.-C. [Laboratoire de Geologie, Avignon (France). Faculte des Science


    Magmatic activity on the African-Arabian margin of Tethys has fluctuated significantly during the past 250 Ma in response to major phases of mantle plume activity and to extensional stresses within the African plate related to periods of continental break-up. A series of maps have been compiled, based upon stratigraphic constraints and K-Ar and {sup 40}Ar-{sup 39}Ar age determinations, to illustrate the changing patterns of igneous activity since the Late Permian. These are divided into five stages: I, Late Permian (256 Ma)-Latest Triassic (208 MA); II, Early Jurassic (208 Ma, Liassic)-Mid Jurassic (157 Ma, Dogger); III, Late Jurassic (157 Ma)-Earliest Aptian (120 Ma); IV, Mid Aptian (119 Ma)-Mid Eocene (42 Ma); V, Late Eocene (42 Ma)-Recent. Magmatism appears to be extremely long-lived in a number of areas (e.g. Sudan, Air), with volcanic centres located along major basement fault zones, such as the Guinean-Nubian lineaments. (author)

  20. Three-Dimensional Numerical Modeling of Crustal Growth at Active Continental Margins

    Zhu, G.; Gerya, T.; Tackley, P. J.


    Active margins are important sites of new continental crust formation by magmatic processes related to the subduction of oceanic plates. We investigate these phenomena using a three-dimensional coupled petrological-geochemical-thermomechanical numerical model, which combines a finite-difference flow solver with a non-diffusive marker-in-cell technique for advection (I3ELVIS code, Gerya and Yuen, PEPI,2007). The model includes mantle flow associated with the subducting plate, water release from the slab, fluid propagation that triggers partial melting at the slab surface, melt extraction and the resulting volcanic crustal growth at the surface. The model also accounts for variations in physical properties (mainly density and viscosity) of both fluids and rocks as a function of local conditions in temperature, pressure, deformation, nature of the rocks, and chemical exchanges. Our results show different patterns of crustal growth and surface topography, which are comparable to nature, during subduction at active continental margins. Often, two trench-parallel lines of magmatic activity, which reflect two maxima of melt production atop the slab, are formed on the surface. The melt extraction rate controls the patterns of new crust at different ages. Moving free water reflects the path of fluids, and the velocity of free water shows the trend of two parallel lines of magmatic activity. The formation of new crust in particular time intervals is distributed in finger-like shapes, corresponding to finger-like and ridge-like cold plumes developed atop the subducting slabs (Zhu et al., G-cubed,2009; PEPI,2011). Most of the new crust is basaltic, formed from peridotitic mantle. Granitic crust extracted from melted sediment and upper crust forms in a line closer to the trench, and its distribution reflects the finger-like cold plumes. Dacitic crust extracted from the melted lower crust forms in a line farther away from the trench, and its distribution is anticorrelated with

  1. Methane in the water column above an active mud volcano in the Calabrian margin, SE Italy

    Geprägs, Patrizia; Torres, Marta E.; Römer, Miriam; Pape, Thomas; Mau, Susan; Wintersteller, Paul; Bohrmann, Gerhard


    Methane release from submarine mud volcanoes (MV) is well known, but most of the input estimates are based on sediment fluxes or visual observations in the water column. We combined hydroacoustic mapping, bottom water sampling and collection of gases at the seafloor in two contrasting settings (mud flows and gas seeps) of the Venere MV, an active mud volcano in the Calabrian Margin, Ionian Sea, to derive methane input. Active seafloor gas discharge at five locations showed strong variability in intensity over repeated surveys over 31 days in November/December 2014. Four of these flare sites were arranged nearly concentrically around the mud volcano, with one weak bubble emission site located in the vicinity of the summit. Gas bubbles collected at these sites a few centimeters above seafloor consisted mainly of methane (> 99.9 %) with smaller portions of non-methane hydrocarbons. Bottom waters above gas flare emission sites and mud flow sites had very high methane concentrations up to 566 µM but only in close proximity to the seafloor, while methane was strongly depleted ( 100 nM) were relatively small and stationary with a vertical extend of 5 m above the seafloor and a maximum horizontal distribution of 50 m. No methane appeared to reach surface waters, therefore, methane is most likely microbially oxidized in the water column.

  2. Mass transport deposits as witness of Holocene seismic activity on the Ligurian margin, Western Mediterranean (ASTARTE project)

    Samalens, Kevin; Cattaneo, Antonio; Migeon, Sébastien


    The Ligurian Margin (Western Mediterranean) is at the transition between the Southern Alpes and the Liguro-Provençal margin and it is one of the most seismic areas of France. Several historic earthquakes have been indexed; the strongest, on February 23rd, 1887, occurred offshore Menton and Imperia and also caused a tsunami wave. Its equivalent magnitude has been estimated between 6 and 6.5. In addition, a moderate recurrent seismicity shakes the margin. The aim of this study is to understand the link between seismic activity and slope destabilization, and to identify the sedimentary deposits resulting from mass transport or turbidity currents. During Malisar (Geoazur laboratory), Prisme 2 and Prisme 3 (Ifremer) cruises, bathymetry, seafloor imagery (SAR), geophysics data (CHIRP SYSIF and high resolution seismics), and sediment cores have been acquired on the continental slope, focussing on canyons and submarine landslides, and in the basin. These data record numerous mass transport deposits (slump, debrites) in the different physiographic areas of the margin. To search for evidences of past Ligurian margin seismicity during the Holocene, we focused on the northeast part of the margin, the Finale area. We identified and sampled acoustically transparent Mass Transport Deposits up to 20-m thick in the bottom of three coaleshing canyons: Noli, Pora and Centa canyons from W to E in the area offshore Finale Ligure. We also recovered an MTD in the collecting deeper canyon system. MTDs in cores appear as sediment with different degrees of deformation (tilted blocks, slump, debrites) and are topped by hemipelagites. The radiocarbon age of the top of MTDs can be considered synchronous and centered around 4900 yr BP. Mass wasting occurring over more than 50 km of the Ligurian margin could indicate that an earthquake stroke the Finale area sector at that time.

  3. Active Tectonics and Erosional Unloading at the Eastern Margin of the Tibetan Plateau

    Alexander L. Densmore; LI Yong; Michael A. Ellis; ZHOU Rongjun


    The eastern margin of the Tibetan Plateau is marked by an extremely steep mountain front with relief of over 5 km. This topography, coupled with abundant Mesozoic thrusts within the margin, explains why tectonic maps of the India-Asia collision typically show the eastern margin as a major thrust zone. Actually, it does not like that. Field observations suggest that the margin is better characterized as a zone of NNE-directed dextral shear with extensive strike-slip faulting and secondary thrusting. The high relief and steep gradients are partially explained by erosional unloading of an elastic lithosphere; the pre-erosion inherited topography may be the inherited Mesozoic thrust belt landscape modified by a component of Cenozoic tectonic shortening.

  4. Three-dimensional representations of salt-dome margins at four active strategic petroleum reserve sites.

    Rautman, Christopher Arthur; Stein, Joshua S.


    Existing paper-based site characterization models of salt domes at the four active U.S. Strategic Petroleum Reserve sites have been converted to digital format and visualized using modern computer software. The four sites are the Bayou Choctaw dome in Iberville Parish, Louisiana; the Big Hill dome in Jefferson County, Texas; the Bryan Mound dome in Brazoria County, Texas; and the West Hackberry dome in Cameron Parish, Louisiana. A new modeling algorithm has been developed to overcome limitations of many standard geological modeling software packages in order to deal with structurally overhanging salt margins that are typical of many salt domes. This algorithm, and the implementing computer program, make use of the existing interpretive modeling conducted manually using professional geological judgement and presented in two dimensions in the original site characterization reports as structure contour maps on the top of salt. The algorithm makes use of concepts of finite-element meshes of general engineering usage. Although the specific implementation of the algorithm described in this report and the resulting output files are tailored to the modeling and visualization software used to construct the figures contained herein, the algorithm itself is generic and other implementations and output formats are possible. The graphical visualizations of the salt domes at the four Strategic Petroleum Reserve sites are believed to be major improvements over the previously available two-dimensional representations of the domes via conventional geologic drawings (cross sections and contour maps). Additionally, the numerical mesh files produced by this modeling activity are available for import into and display by other software routines. The mesh data are not explicitly tabulated in this report; however an electronic version in simple ASCII format is included on a PC-based compact disk.

  5. Tectonic regimes at the N-Ecuador SW-Colombia active margin from multichannel seismic reflection data

    Marcaillou, B.; Collot, J.-Y.; Sage, F.


    The North Andean convergent margin displays wide lateral variations in structural and sedimentary characters, which reflect the interaction between large sedimentary input derived from the nearby Andes, inherited structures, and the long-term tectonic deformation resulting from the Nazca plate subduction beneath the South America plate at ~5cm/yr. We use Multichannel Seismic Reflection lines as well as bathymetric data collected during the SISTEUR cruise to construct a tectonic and sedimentary model of the margin between latitudes 0°N and 3.5 °N. The margin shows a prominent re-entrant that is cut transversally by a major crustal fault, i.e. the Manglares Fault (MF). The northern and southern walls of the re-entrant together with the MF divide the margin into four morphostructural segments, with distinct tectonic regimes. The Esmeraldas segment, south of the re-entrant, shows a 100m-deep continental shelf, evidences for mass wasting, and a 10° steep innertrench wall underlain by steeply trenchward dipping horizons, suggesting tectonic erosion. The Manglares segment, located between the southern wall of the re-entrant and the MF, exhibits an up to 3-km-thick trench fill thrust beneath possible narrow frontal thrusts, a wide and largely un-deformed fore-arc basin that is split by a major crustal splay fault. Seaward of the splay fault, the fore-arc basin is tilted trenchward and overlays a thinned margin basement, supporting tectonic erosion. The Tumaco segment, between the MF and the reentrant northern wall, exhibits a 2.5-km-thick trench fill, which underthrusts the margin in the south, and shows clear incipient accretionary thrusts in the north. Splay faults across the margin are unclear, but an uplifted, folded and thrust faulted basement ridge and deformed fore-ar basins indicate active deformation across most of the margin width. The Patia segment, to the north of the re-entrant, shows a highly deformed fore-arc basin and outer ridge fronted by growing 30km

  6. Violent Gas Venting on the Heng-Chun Mud Volcano, South China Sea Active Continental Margin offshore SW Taiwan

    Lin, S.; Cheng, W. Y.; Tseng, Y. T.; Chen, N. C.; Hsieh, I. C.; Yang, T. F.


    Accumulation of methane as gas hydrate under the sea floor has been considered a major trap for both thermal and biogenic gas in marine environment. Aided by rapid AOM process near the sea floor, fraction of methane escaping the sea floor has been considered at minuscule. However, most studies focused mainly on deepwater gas hydrate systems where gas hydrate remain relatively stable. We have studied methane seeps on the active margin offshore Taiwan, where rapid tectonic activities occur. Our intention is to evaluate the scale and condition of gas seeps in the tectonic active region. Towcam, coring, heat probe, chirp, multibeam bathymetric mapping and echo sounding were conducted at the study areas. Our results showed that gas is violently venting at the active margin, not only through sediments, but also through overlying sea water, directly into the atmosphere. Similar ventings, but, not in this scale, have also been identified previously in the nearby region. High concentrations of methane as well as traces of propane were found in sediments and in waters with flares. In conjunction, abundant chemosynthetic community, life mussel, clams, tube worms, bacterial mats together with high concentrations of dissolve sulfide, large authigenic carbonate buildups were also found. Our results indicate that methane could be another major green house gas in the shallow water active margin region.

  7. Stress fields of the overriding plate at convergent margins and beneath active volcanic arcs.

    Apperson, K D


    Tectonic stress fields in the overriding plate at convergent plate margins are complex and vary on local to regional scales. Volcanic arcs are a common element of overriding plates. Stress fields in the volcanic arc region are related to deformation generated by subduction and to magma generation and ascent processes. Analysis of moment tensors of shallow and intermediate depth earthquakes in volcanic arcs indicates that the seismic strain field in the arc region of many convergent margins is subhorizontal extension oriented nearly perpendicular to the arc. A process capable of generating such a globally consistent strain field is induced asthenospheric corner flow below the arc region.

  8. AHC (Active Heave Compensation) - 800 Drilling on the Atlantic (New Jersey) Margin

    Austin, J. A.


    The New Jersey continental shelf, an old, stable passive margin, has been a focus of latest Pleistocene-Holocene sea-level studies for decades, because eustasy is a major driving force in the production of the surficial stratigraphic record there. This margin is also geographically proximal to diverse oceanographic resources - laboratories, ports and ships - so hypothesis-testing using a "natural laboratory" approach has been suitable for data acquisition, analysis and interpretation. The Office of Naval Research has taken advantage of this shelf's characteristics to support collection and interpretation of a huge and diverse suite of geophysical data off New Jersey since the late 1980's - MCS profiles at multiple frequencies, deep-towed boomer and chirp profiles, multibeam bathymetry/ backscatter control, and most recently sediment samples using a lake-drilling system owned and operated by Drilling, Observation and Sampling of the Earth's Continental Crust (DOSECC), Inc., modified with active heave compensation for deployment off the Woods Hole Oceanographic Institution research vessel Knorr. The goal is to understand how the diverse interaction of depositional and erosional processes culminates in the preserved stratigraphic record. A first test of the AHC-800 drilling system took place in November 2001 in Block Island Sound off southern New England, with the following results: 1) some success was achieved in sampling mud, 2) fall weather was a limiting factor (heave compensation limits of 2.44 m in 8 s were often exceeded), 3) the vessel's dynamic positioning (DP) system was not always capable of maintaining station in shifting winds; precise navigation (beyond differential GPS) was required, and 4) the need for automated drillpipe handling to increase efficiency was recognized. A second test took place on the New Jersey shelf in September-October 2002, using updated software, automated pipe handling, and differential GPS navigation supplemented by a POS/MV 320

  9. Sedimentology of seismo-turbidites off the Cascadia and northern California active tectonic continental margins, Pacific Ocean

    Gutierrez Pastor, Julia; Nelson, Hans; Goldfinger, Chris; Escutia, Carlota


    Holocene turbidites from turbidite channel systems along the active tectonic continental margins of the Cascadia subduction zone (offshore Vancouver Island to Mendocino Triple Junction) and the northern San Andreas Transform Fault (the Triple Junction to San Francisco Bay), have been analyzed for sedimentologic features related to their seismic origin. Centimeter thick silt/sand beds (turbidite base) capped by mud layers (turbidite tail) and interbedded with hemipelagic silty clay intervals with high biogenic content have been characterized by visual core descriptions, grain-size analysis, X-ray radiographs and physical properties. Along the northern California margin in upstream single tributary canyons and channels, most turbidites are uni-pulsed (classic fining up) whereas downstream below multiple tributary canyon and channel confluences, most deposits are stacked turbidites. Because each set of stacked turbidites has no hemipelagic sediment between each turbidite unit and each unit has a distinct mineralogy from a different tributary canyon, we interpret that a stacked turbidite is deposited by several coeval turbidity currents fed by multiple tributary canyons and channels with synchronous triggering from a single San Andreas Fault earthquake. The Cascadia margin is characterized by individual multi-pulsed turbidites that contain multiple coarse-grained sub-units without hemipelagic sediment between pulses. Because the number and character of multiple coarse-grained pulses for each correlative multi-pulsed turbidite is almost always constant both upstream and downstream in different channel systems for 600 km along the margin,we interpret that the earthquake shaking or aftershock signature is usually preserved, for the much stronger Cascadia (≥9 Mw) compared to weaker California (≥8Mw) earthquakes, which result in upstream uni-pulsed turbidites and downstream stacked turbidites. Consequently, both the strongest (≥9 Mw) great earthquakes and downstream

  10. Interaction between hydrocarbon seepage, chemosynthetic communities, and bottom water redox at cold seeps of the Makran accretionary prism: insights from habitat-specific pore water sampling and modeling

    D. Fischer


    Full Text Available The interaction between fluid seepage, bottom water redox, and chemosynthetic communities was studied at cold seeps across one of the world's largest oxygen minimum zones (OMZ located at the Makran convergent continental margin. Push cores were obtained from seeps within and below the core-OMZ with a remotely operated vehicle. Extracted sediment pore water was analyzed for sulfide and sulfate concentrations. Depending on oxygen availability in the bottom water, seeps were either colonized by microbial mats or by mats and macrofauna. The latter, including ampharetid polychaetes and vesicomyid clams, occurred in distinct benthic habitats, which were arranged in a concentric fashion around gas orifices. At most sites colonized by microbial mats, hydrogen sulfide was exported into the bottom water. Where macrofauna was widely abundant, hydrogen sulfide was retained within the sediment.

    Numerical modeling of pore water profiles was performed in order to assess rates of fluid advection and bioirrigation. While the magnitude of upward fluid flow decreased from 11 cm yr−1 to <1 cm yr−1 and the sulfate/methane transition (SMT deepened with increasing distance from the central gas orifice, the fluxes of sulfate into the SMT did not significantly differ (6.6–9.3 mol m−2 yr−1. Depth-integrated rates of bioirrigation increased from 120 cm yr−1 in the central habitat, characterized by microbial mats and sparse macrofauna, to 297 cm yr−1 in the habitat of large and few small vesicomyid clams. These results reveal that chemosynthetic macrofauna inhabiting the outer seep habitats below the core-OMZ efficiently bioirrigate and thus transport sulfate down into the upper 10 to 15 cm of the sediment. In this way the animals deal with the lower upward flux of methane in outer habitats by stimulating rates of anaerobic oxidation of methane (AOM with sulfate high enough to provide

  11. Modifications of the alpha,beta-double bond in chalcones only marginally affect the antiprotozoal activities

    Nielsen, S F; Kharazmi, A; Christensen, S B


    Methods for selective alkylation of chalcones in the alpha- or beta-position and for selective reduction of the alpha,beta-double bond have been developed. The antiparasitic potencies of the alpha,beta-double bond modified chalcones only differ marginally from the potencies of the parent chalcones...

  12. Hanging canyons of Haida Gwaii, British Columbia, Canada: Fault-control on submarine canyon geomorphology along active continental margins

    Harris, Peter T.; Barrie, J. Vaughn; Conway, Kim W.; Greene, H. Gary


    Faulting commonly influences the geomorphology of submarine canyons that occur on active continental margins. Here, we examine the geomorphology of canyons located on the continental margin off Haida Gwaii, British Columbia, that are truncated on the mid-slope (1200-1400 m water depth) by the Queen Charlotte Fault Zone (QCFZ). The QCFZ is an oblique strike-slip fault zone that has rates of lateral motion of around 50-60 mm/yr and a small convergent component equal to about 3 mm/yr. Slow subduction along the Cascadia Subduction Zone has accreted a prism of marine sediment against the lower slope (1500-3500 m water depth), forming the Queen Charlotte Terrace, which blocks the mouths of submarine canyons formed on the upper slope (200-1400 m water depth). Consequently, canyons along this margin are short (4-8 km in length), closely spaced (around 800 m), and terminate uniformly along the 1400 m isobath, coinciding with the primary fault trend of the QCFZ. Vertical displacement along the fault has resulted in hanging canyons occurring locally. The Haida Gwaii canyons are compared and contrasted with the Sur Canyon system, located to the south of Monterey Bay, California, on a transform margin, which is not blocked by any accretionary prism, and where canyons thus extend to 4000 m depth, across the full breadth of the slope.

  13. Rekonstruktion von Paläosäkularvariationen des Erdmagnetfeldes an holozänen marinen Sedimenten aus der Region des Makran Akkretionskeils

    Müller, Marion Irmgard


    Annually laminated marine sediments from the Makran accretionary wedge off Pakistan were cored during cruises SO 90 (1993) and SO 130 (1998) with the RV SONNE. Sediments from the earlier cruise have been dated by varve counting and other methods back to 5000 y.b.p. From the same site core 315KA (24°49´N/65°54´E; SO130) has been retrieved, correlated to the dated core and continuously sampled at 2.5 cm intervals. Detailed rock magnetic analysis suggests that the main carriers of the magnetizat...

  14. Magmatic evolution of Sulawesi (Indonesia): constraints on the Cenozoic geodynamic history of the Sundaland active margin

    Polvé, M.; Maury, R. C.; Bellon, H.; Rangin, C.; Priadi, B.; Yuwono, S.; Joron, J. L.; Atmadja, R. Soeria


    Tertiary and Quaternary magmatic rocks from West Sulawesi record the complex history of part of the Sundaland margin where subduction and collision have been and are still active. The present study, based on petrographic data, major- and trace-element chemistry and 40K 40Ar dating aims to document the age and chemical characteristics of the magmatic formations from West Sulawesi and to determine the corresponding constraints on the geodynamic evolution of the Sundaland border. The West Sulawesi magmatic province includes the South Arm of Sulawesi (Ujung Pandang area), the western part of Central Sulawesi with the Toraja and Palu areas, and finally, the North Arm, extending from Palu to Manado, which includes the Tolitoli and Manado areas. Paleocene magmatic activity seems to be restricted to an episode of calc-alkaline magmatism in the Ujung Pandang area (61-59 Ma). The major Eocene (50-40 Ma) magmatic event is tholeiitic and is documented in all areas except in Ujung Pandang. It led to the emplacement of tholeiitic pillow-lavas and basaltic dykes of back-arc basin (BAB) affinity. These rocks are potential equivalents to the Celebes Sea basaltic basement. From Oligocene to Miocene, magmatic eruptions produced successively island-arc tholeiitic (IAT) and calc-alkaline (CA) rock series. The youngest IAT activity occurred around 18 Ma in the central part (Palu area) and around 14 Ma in the North Arm (Tolitoli area) while CA magmas were emplaced in the North Arm at ca. 18 Ma (Tolitoli and Manado areas). Typical calc-alkaline activity resumed only in the North Arm (Tolitoli and Manado areas) during the Late Miocene (9 Ma) and is still active in the Manado region. In other areas (Palu, Toraja and Ujung Pandang areas) an important and widespread magmatic event occurred between 13 and 10 Ma and emplaced K-rich magmas, either silica-undersaturated alkali-potassic basalts (AK), ultrapotassic basanites (UK) or shoshonites (SH). K-rich activity continued in the south until

  15. Morphotectonic evolution of passive margins undergoing active surface processes: large-scale experiments using numerical models.

    Beucher, Romain; Huismans, Ritske S.


    Extension of the continental lithosphere can lead to the formation of a wide range of rifted margins styles with contrasting tectonic and geomorphological characteristics. It is now understood that many of these characteristics depend on the manner extension is distributed depending on (among others factors) rheology, structural inheritance, thermal structure and surface processes. The relative importance and the possible interactions of these controlling factors is still largely unknown. Here we investigate the feedbacks between tectonics and the transfers of material at the surface resulting from erosion, transport, and sedimentation. We use large-scale (1200 x 600 km) and high-resolution (~1km) numerical experiments coupling a 2D upper-mantle-scale thermo-mechanical model with a plan-form 2D surface processes model (SPM). We test the sensitivity of the coupled models to varying crust-lithosphere rheology and erosional efficiency ranging from no-erosion to very efficient erosion. We discuss how fast, when and how the topography of the continents evolves and how it can be compared to actual passive margins escarpment morphologies. We show that although tectonics is the main factor controlling the rift geometry, transfers of masses at the surface affect the timing of faulting and the initiation of sea-floor spreading. We discuss how such models may help to understand the evolution of high-elevated passive margins around the world.

  16. Late Pleistocene and Holocene uplift history of Cyprus: implications for active tectonics along the southern margin of the Anatolian microplate

    Harrison, R.W.; Tsiolakis, E.; Stone, B.D.; Lord, A.; McGeehin, J.P.; Mahan, S.A.; Chirico, P.


    The nature of the southern margin of the Anatolian microplate during the Neogene is complex, controversial and fundamental in understanding active plate-margin tectonics and natural hazards in the Eastern Mediterranean region. Our investigation provides new insights into the Late Pleistocene uplift history of Cyprus and the Troodos Ophiolite. We provide isotopic (14C) and radiogenic (luminescence) dates of outcropping marine sediments in eastern Cyprus that identify periods of deposition during marine isotope stages (MIS) 3, 4, 5 and 6. Past sea-levels indicated by these deposits are c. 95±25 m higher in elevation than estimates of worldwide eustatic sea-level. An uplift rate of c. 1.8 mm/year and possibly as much as c. 4.1 mm/year in the past c. 26–40 ka is indicated. Holocene marine deposits also occur at elevations higher than those expected for past SL and suggest uplift rates of c. 1.2–2.1 mm/year. MIS-3 marine deposits that crop out in southern and western Cyprus indicate uniform island-wide uplift. We propose a model of tectonic wedging at a plate-bounding restraining bend as a mechanism for Late Pleistocene to Holocene uplift of Cyprus; uplift is accommodated by deformation and seismicity along the margins of the Troodos Ophiolite and re-activation of its low-angle, basal shear zone.

  17. Different bulk and active bacterial communities in cryoconite from the margin and interior of the Greenland ice sheet

    Stibal, Marek; Nielsen, Morten Schostag; Cameron, Karen A.;


    composition of cryoconite over a melt season at two contrasting sites at the margin and in the interior of the Greenland ice sheet, using sequence analysis and quantitative polymerase chain reaction of coextracted 16S rDNA and rRNA. Significant differences were found between bulk (rDNA) and potentially active......Biological processes in the supraglacial ecosystem, including cryoconite, contribute to nutrient cycling within the cryosphere and may affect surface melting, yet little is known of the diversity of the active microbes in these environments. We examined the bacterial abundance and community...

  18. Online Classroom Research and Analysis Activities Using MARGINS-Related Resources for the Izu-Bonin-Mariana Subduction System

    Ryan, J. G.


    Students today have online access to nearly unlimited scientific information in an entirely unfiltered state. As such, they need guidance and training in identifying and assessing high-quality information resources for educational and research use. The extensive research data resources available online for the Izu-Bonin-Mariana (IBM) subduction system that have been developed with MARGINS Program and related NSF funding are an ideal venue for focused Web research exercises that can be tailored to a range of undergraduate geoscience courses. This presentation highlights student web research activities examining: a) The 2003-2005 eruptions of Anatahan Volcano in the Mariana volcanic arc. MARGINS-supported geophysical research teams were in the region when the eruption initiated, permitting a unique "event response" data collection and analysis process, with preliminary results presented online at websites linked to the MARGINS homepage, and ultimately published in a special issue of the Journal of Volcanology and Geothermal Research. In this activity, students will conduct a directed Web surf/search effort for information on and datasets from the Anatahan arc volcano, which they will use in an interpretive study of recent magmatic activity in the Mariana arc. This activity is designed as a homework exercise for use in a junior-senior level Petrology course, but could easily be taken into greater depth for the benefit of graduate-level volcanology or geochemistry offerings. b) Geochemical and mineralogical results from ODP Legs 125 and 195 focused on diapiric serpentinite mud volcanoes, which erupt cold, high pH fluids, serpentine muds, and serpentinized ultramafic clasts at a number of sites in the forearc region of the Mariana subduction zone. The focus of this activity is an examination of the trace element chemistry of the forearc serpentines and their associated upwelling porefluids as a means of understanding the roles of ionic radius, valence, and system

  19. Is earthquake activity along the French Atlantic margin favoured by local rheological contrasts?

    Mazabraud, Yves; Béthoux, Nicole; Delouis, Bertrand


    The seismological study of recent seismic crises near Oleron Island confirms the coexistence of an extensional deformation and a transtensive regime in the Atlantic margin of France, which is different from the general western European stress field corresponding to a strike-slip regime. We argue that the switch of the principal stress axes σ1/σ2 in a NW-SE vertical plane is linked with the existence of crustal heterogeneities. Events of magnitude larger than 5 sometimes occur along the Atlantic margin of France, such as the 7 September 1972 (ML = 5.2) earthquake near Oleron island and the 30 September 2002 (ML = 5.7) Hennebont event in Brittany. To test the mechanism of local strain localization, we model the deformation of the hypocentral area of the Hennebont earthquake using a 3D thermo-mechanical finite element code. We conclude that the occurrence of moderate earthquakes located in limited parts of the Hercynian shear zones (as the often reactivated swarms near Oleron) could be due to local reactivation of pre-existing faults. These sporadic seismic ruptures are favoured by stress concentration due to rheological heterogeneities.

  20. Structural Control on the Megathrust Slip: the Example of the Ecuador-Colombia Active Margin.

    Collot, J.; Marcaillou, B.; Agudelo, W.; Sage, F.; Ribodetti, A.


    Along subduction zones, earthquake nucleation and megathrust slip are controlled by parameters including the rheology of the fore-arc, the magnitude of transient shear stress and the physical properties of the megathrust. Furthermore, geological structures play a major role on stress and strain distribution both across and along the megathrust, and consequently affect the earthquake cycle. A marine geophysical study of the Ecuador-SW Colombia subduction zone, where three large (7.71000-km scale, the subduction trench is segmented from south to north, into NS-, NNE- and NS-trending segments, respectively associated with normal, oblique, and normal plate convergence settings. These segments relate to large-scale, structural domains of both the Nazca Plate (Carnegie Ridge, Panama Basin) and the margin of the South American Plate, which consists of a mosaic of accreted oceanic terranes. The 1906 event likely ruptured the entire NNE-trending, obliquely convergent segment. The slip was blocked southward by the buoyant subducting Carnegie Ridge, and northward by the sharp change in structural trend associated with the accreted Choco arc. On a 100-300-km scale, multichannel seismic reflection and multibeam bathymetry data show that the margin is segmented by transverse crustal faults. The faults correlate with the limits of large earthquake rupture zones, suggesting that transverse faults are weak and contribute to placing a limit on the along strike propagation of the co-seismic slip. On a 20-100-km scale, geophysical data collected on the Nazca Plate reveal oceanic asperities entering the subduction. Downdip, these features may correlate with seismological asperities, which, upon rupture, can trigger large events. On a ~50 km-scale, a crustal splay fault and the underlying updip segment of the plate interface may have respectively controlled the updip coseismic and postseismic slips of the M7.7 1958 earthquake. The splay fault is interpreted as an inverted, landward

  1. Repeated remobilisation of submarine landslide debris on an active subduction margin interpreted from multibeam bathymetry and multichannel seismic data

    Mountjoy, J. J.; Barnes, P. M.; McKean, J.; Pettinga, J. R.


    EM300 multibeam and multichannel seismic data reveal a 230 square kilometre submarine landslide complex which exhibits many of the characteristic features of equivalent terrestrial creeping earthflow complexes. Slope failures are sourced from the shelf edge/upper slope of the Poverty Bay reentrant on the active Hikurangi subduction margin of New Zealand where tectonic deformation, via major thrust faults with slip rates of c. 3-4 mm/yr, exerts a controlling influence on seafloor physiography. Individual landslides within this submarine complex are up to 14 km long over a vertical elevation drop of 700 m. Debris streams are in excess of 2 km wide with a debris thickness of 100 m. While multibeam data is limited to c. 10 m resolution, the scale of submarine landslide features allows us to resolve internal debris detail equivalent to terrestrial landslide examples using terrestrial techniques (e.g. airborne lidar). DEM derivative surface roughness techniques are employed to delineate the geomorphic expression of features including active and abandoned lateral shears, and contractional and extensional deformation of the landslide debris. From these interpretations multiple internal failures are recognised along the length of the landslide debris. Debris deformation is also imaged in high fold multichannel seismic data and correlated to the imaged surface geomorphic features, providing insight into the failure mechanics of the landslides. Failures initiate and evolve within the quasi-stable prograding sediment wedge built onto the upper slope during lowstand sealevels. Landslides within the greater complex are at different stages of development providing information on their spatial and temporal evolution headward and laterally along the transition from shelf to upper slope margin. We infer that failures are triggered and evolve in response to sealevel rise, and/or the frequent occurrence large earthquakes along the margin.

  2. Neogene and active shortening offshore the reactivated Levant margin in Lebanon: results of the SHALIMAR cruise

    Briais, A.; Singh, S. C.; Tapponnier, P.; Elias, A.; Sursock, A.; Jomaa, R.; Carton, H.; Daeron, M.; King, G.; Jacques, E.


    The objectives of the SHALIMAR cruise were to study recent deformation of the Mediterranean seafloor west of Mt Lebanon. We collected multibeam bathymetry and back-scatter images, reflection seismic profiles - surface and deep-towed, 3.5 kHz echo-sounder data, gravity and magnetic data over an 80 km-wide zone offshore the entire Lebanese coast. The bathymetry reveals a very steep slope between Beyrouth and Batroun, with a water depth of 1500 m only 5 km offshore. Between Saida and Tripoli (33.5N to 34.5N), both the bathymetry and seismic lines show a series of ramp anticlines affecting Plio-Quaternary deposits and a seismically transparent layer with variable thickness corresponding to the Messinian evaporites (5.6 Ma). This fold-and-thrust belt is the offshore expression of shortening related to the formation of Mt Lebanon. It is limited westwards by a prominent fold front 30 km from shore. Some ramps appear to be submarine continuations of faults documented ashore (e.g., Aabde and Tripoli thrusts). The strikes of fold axes are consistent with WNW-ESE shortening and slip-partitioning along the 30° Lebanese bend of the Levant fault. North of Tripoli and south of Saida, the continental margin displays a wider shelf (20 km) and gentler slope. In the south, at 1200-1500 m depth small, closely spaced, NE-trending scarps attest to young, distributed dip-slip faulting, although deformation is much less than north of Beyrouth. At the southern extremity of our survey, NW-trending normal fault scarps roughly aligned with the Mt Carmel-Haifa fault vanish 50 km offshore in the Levant basin. Bouguer gravity anomalies, estimated by removing from free-air gravity data the effect of bathymetry, display a very steep gradient between Beyrouth and Tripoli, marking the passage from thickened Mt Lebanon crust to thin crust in the Levant basin. Gravity anomalies also outline large, NE-SW trending steps between the basin crust and thinned continental crust near and south of Beyrouth

  3. Paleozoic evolution of active margin basins in the southern Central Andes (northwestern Argentina and northern Chile)

    Bahlburg, H.; Breitkreuz, C.

    The geodynamic evolution of the Paleozoic continental margin of Gondwana in the region of the southern Central Andes is characterized by the westward progression of orogenic basin formation through time. The Ordovician basin in the northwest Argentinian Cordillera Oriental and Puna originated as an Early Ordovician back-arc basin. The contemporaneous magmatic arc of an east-dipping subduction zone was presumably located in northern Chile. In the back-arc basin, a ca. 3500 meter, fining-up volcaniclastic apron connected to the arc formed during the Arenigian. Increased subsidence in the late Arenigian allowed for the accomodation of large volumes of volcaniclastic turbidites during the Middle Ordovician. Subsidence and sedimentation were caused by the onset of collision between the para-autochthonous Arequipa Massif Terrane (AMT) and the South American margin at the Arenigian-Llanvirnian transition. This led to eastward thrusting of the arc complex over its back-arc basin and, consequently, to its transformation into a marine foreland basin. As a result of thrusting in the west, a flexural bulge formed in the east, leading to uplift and emergence of the Cordillera Oriental shelf during the Guandacol Event at the Arenigian-Llanvirnian transition. The basin fill was folded during the terminal collision of the AMT during the Oclóyic Orogeny (Ashgillian). The folded strata were intruded post-tectonically by the presumably Silurian granitoids of the "Faja Eruptiva de la Puna Oriental." The orogeny led to the formation of the positive area of the Arco Puneño. West of the Arco Puneño, a further marine basin developed during the Early Devonian, the eastern shelf of which occupied the area of the Cordillera Occidental, Depresión Preandina, and Precordillera. The corresponding deep marine turbidite basin was located in the region of the Cordillera de la Costa. Deposition continued until the basin fill was folded in the early Late Carboniferous Toco Orogeny. The basin

  4. Flare-Shaped Acoustic Anomalies in the Water Column Along the Ecuadorian Margin: Relationship with Active Tectonics and Gas Hydrates

    Michaud, Francois; Proust, Jean-Noël; Dano, Alexandre; Collot, Jean-Yves; Guiyeligou, Grâce Daniella; Hernández Salazar, María José; Ratzov, Gueorgui; Martillo, Carlos; Pouderoux, Hugo; Schenini, Laure; Lebrun, Jean-Frederic; Loayza, Glenda


    With hull-mounted multibeam echosounder data, we report for the first time along the active Ecuadorian margin, acoustic signatures of water column fluid emissions and seep-related structures on the seafloor. In total 17 flare-shaped acoustic anomalies were detected from the upper slope (1250 m) to the shelf break (140 m). Nearly half of the flare-shaped acoustic anomalies rise 200-500 m above the seafloor. The base of the flares is generally associated with high-reflectivity backscatter patches contrasting with the neighboring seafloor. We interpret these flares as caused by fluid escape in the water column, most likely gases. High-resolution seismic profiles show that most flares occur close to the surface expression of active faults, deformed areas, slope instabilities or diapiric structures. In two areas tectonic deformation disrupts a Bottom Simulating Reflector (BSR), suggesting that buried frozen gas hydrates are destabilized, thus supplying free gas emissions and related flares. This discovery is important as it opens the way to determine the nature and origin of the emitted fluids and their potential link with the hydrocarbon system of the forearc basins along the Ecuadorian margin.

  5. Carbonate Chemistry Dynamics in an Area of Active Gas Seepage: the Hudson Canyon, US Atlantic Margin

    Garcia-Tigreros Kodovska, F.; Kessler, J. D.; Leonte, M.; Chepigin, A.; Kellermann, M. Y.; Arrington, E. C.; Valentine, D. L.


    The fate of oceanic methane and its impact on the global climate has been of particular interest to the global community. The potential for vast amounts of methane to be emitted from the seafloor into the atmosphere due to gas hydrate decomposition has been under scientific evaluation. However, despite the great extent of these geological reservoirs, much of the methane released from the seafloor in deep ocean environments does not reach the atmosphere. Once dissolved in ocean water, the emitted methane can be microbially converted to either carbon dioxide or assimilated to biomass. Here, we will present results from a research cruise to the Hudson Canyon, northern US Atlantic Margin, where we investigated changes in ocean water carbonate chemistry induced by the oxidation of methane released from gas seeps. We will be presenting high precision pH data as well as methane and DIC concentrations, natural stable isotopes, and methane oxidation rates collected inside and adjacent to the Hudson Canyon in the summer of 2014.

  6. Evidence and biogeochemical implications for glacially-derived sediments in an active margin cold seep

    Pohlman, John W.; Riedel, Michael; Novosel, Ivana; Bauer, James E.; Canuel, Elizabeth A.; Paull, Charles K.; Coffin, Richard B.; Grabowski, Kenneth S.; Knies, David L.; Hyndman, Roy D.; Spence, George D.


    Delineating sediment organic matter origins and sediment accumulation rates at gas hydratebearing and hydrocarbon seeps is complicated by the microbial transfer of 13C-depleted and 14Cdepleted methane carbon into sedimentary pools. Sediment 13C and 14C measurements from four cores recovered at Bullseye vent on the northern Cascadia margin are used to identify methane carbon assimilation into different carbon pools. While the total organic carbon (TOC) is mostly unaltered and primarily terrigenous in origin, planktonic foraminifera and the bulk carbonate display evidence of methane overprinting. Mass balance models are applied to determine the extent to which methane overprinting increased the radiocarbon ages of the biogenic foraminifera. The corrected and calibrated foraminifera ages between sediment depths of 70 and 573 cm are from 14.9 to 15.9 ka BP, which coincides with the retreat of the late Quaternary Cordilleran Ice Sheet from Vancouver Island. Uniform TOC _13C values of -24.5 ± 0.5‰ from the upper 8 meters of sediment at Bullseye vent suggest all cored material is Pleistocene-derived glacimarine material deposited as the ice edge retreated landward. Bullseye vent is located within an uplifted sediment block isolated from turbidite deposition and has been a site of non-deposition since the ice sheet retreated from the shelf. Biogeochemical implications of seep sediments being dominated by aged, organic-poor (seep microbial community.

  7. Biological Ocean Margins Program. Active Microbes Responding to Inputs from the Orinoco River Plume. Final Report

    Jorge E. Corredor


    The overall goal of the proposed work is to identify the active members of the heterotrophic community involved in C and N cycling in the perimeter of the Orinoco River Plume (ORP), assess their spatial distribution, quantify their metabolic activity, and correlate these parameters to plume properties such as salinity, organic matter content and phytoplankton biomass.

  8. From Margins to Mainstream: Social Media as a Tool for Campus Sexual Violence Activism

    Linder, Chris; Myers, Jess S.; Riggle, Colleen; Lacy, Marvette


    Using Internet-related ethnography (Postill & Pink, 2012), we examined the role of social media in campus sexual violence activism. Based on observations of online activist communities and interviews with 23 activists, we highlight raising awareness, community building, and interrupting power dynamics as activism strategies enhanced by social…

  9. Synthesis and tectonic interpretation of the westernmost Paleozoic Variscan orogen in southern Mexico: From rifted Rheic margin to active Pacific margin

    Keppie, J. Duncan; Dostal, Jaroslav; Murphy, J. Brendan; Nance, R. Damian


    Paleozoic rocks in southern Mexico occur in two terranes, Oaxaquia (Oaxacan Complex) and Mixteca (Acatlán Complex) that appear to record: (1) Ordovician rifting on the southern margin of the Rheic Ocean, (2) passive drifting with Amazonia during the Silurian, (3) Devonian-Permian subduction beneath southern Mexico producing an arc complex that was partially removed by subduction erosion, subjected to HP metamorphism and Mississippian extrusion into the upper plate, followed by reestablishment of a Permian arc. In the Oaxaquia terrane, the 920-1300 Ma basement is unconformably overlain by a ˜ 200 m uppermost Cambrian-lowest Ordovician shelf sequence containing Gondwanan fauna (Tiñu Formation), unconformably overlain by 650 m of shallow marine-continental Carboniferous sedimentary rocks containing a Midcontinent (USA) fauna. In the Mixteca terrane, the low-grade Paleozoic sequence is composed of: (a) a ?Cambrian-Ordovician clastic sequence intruded by ca. 480-440 Ma bimodal, rift-related igneous rocks; and (b) a latest Devonian-Permian shallow marine sequence (> 906 m) consisting of metapsammites, metapelites and tholeiitic mafic volcanic rocks. High pressure (HP) metamorphic rocks in the Mixteca terrane consists of: (i) a Cambro-Ordovician rift-shelf intruded by bimodal rift-related intrusions that are similar to the low-grade rocks; (ii) periarc ultramafic rocks, and (iii) arc and MORB rocks. The Ordovician granitoids contain concordant inherited zircons that range in age from ca. 900 to 1300 Ma, indicating a source in the Oaxacan Complex. Concordant ages of detrital zircons in both the low- and high-grade Cambro-Ordovician metasedimentary rocks indicate a provenance in local Ordovician plutons and/or ca. 1 Ga Oaxacan basement, and distal northwestern Gondwana sources with a unique source in the 900-750 Ma Goiás magmatic arc within the Brasiliano orogen. These data combined with the rift-related nature of the Cambro-Ordovician rocks are most consistent with an

  10. Probabilistic tsunami hazard assessment for Makran considering recently suggested larger maximum magnitudes and sensitivity analysis for GNSS-based early warning

    Zamora, N.; Hoechner, A.; Babeyko, A. Y.


    Iran and Pakistan are countries frequently affected by destructive earthquakes, as for instance, the magnitude 6.6 Bam earthquake in 2003 in Iran with about 30 000 casualties, or the magnitude 7.6 Kashmir earthquake 2005 in Pakistan with about 80'000 casualties. Both events took place inland, but in terms of magnitude, even significantly larger events can be expected to happen offshore, at the Makran subduction zone. This small subduction zone is seismically rather quiescent, nevertheless a tsunami caused by a thrust event in 1945 (Balochistan earthquake) led to about 4000 casualties. Nowadays, the coastal regions are more densely populated and vulnerable to similar events. Furthermore, some recent publications discuss the possiblity of rather rare huge magnitude 9 events at the Makran subduction zone. We analyze the seismicity at the subduction plate interface and generate various synthetic earthquake catalogs spanning 100000 years. All the events are projected onto the plate interface using scaling relations and a tsunami model is run for every scenario. The tsunami hazard along the coast is computed and presented in the form of annual probability of exceedance, probabilistic tsunami height for different time periods and other measures. We show how the hazard reacts to variation of the Gutenberg-Richter parameters and maximum magnitudes.We model the historic Balochistan event and its effect in terms of coastal wave heights. Finally, we show how an effective tsunami early warning could be achieved by using an array of high-precision real-time GNSS (Global Navigation Satellite System) receivers along the coast by applying it to the 1945 event and by performing a sensitivity analysis.

  11. A Deep Structured Model with Radius-Margin Bound for 3D Human Activity Recognition

    Lin, Liang; Wang, Keze; Zuo, Wangmeng; Wang, Meng; Luo, Jiebo; Zhang, Lei


    Understanding human activity is very challenging even with the recently developed 3D/depth sensors. To solve this problem, this work investigates a novel deep structured model, which adaptively decomposes an activity instance into temporal parts using the convolutional neural networks (CNNs). Our model advances the traditional deep learning approaches in two aspects. First, { we incorporate latent temporal structure into the deep model, accounting for large temporal variations of diverse huma...

  12. Modeling 210Pb-derived mixing activity in ocean margin sediments: Diffusive versus nonlocal mixing

    Soetaert, K.E.R.; Herman, P.M.J.; Middelburg, J.J.; Heip, C.H.R.; De Stigter, H.; Van Weering, T.C.E.; Epping, E.; Helder, W.


    The influence of sediment mixing on activity versus depth profiles of the radionuclide (210)pb in the upper 20 cm of the sediments has been investigated along a depth transect (208 m- 4500 m, 17 stations) in the OMEX study area (Goban Spur, NE Atlantic Ocean). A hierarchical family of bioturbation/n

  13. Widening margin in activity profile between elite and sub-elite Australian football: a case study.

    Aughey, Robert J


    It is not known if the activity profile of elite Australian football players changes across two levels of competition. The aims of this study were therefore to: (1) classify the activity profile of elite and sub-elite Australian football for players from one elite Australian football club; and (2) compare the activity profile of elite footballers across both elite and sub-elite competitions. Quantitative case-study approach. Movement was recorded by 5Hz global positioning system and expressed relative to game time for total; and high-velocity running distance (4.17-10.00ms(-1)) and maximal accelerations (2.78-10.00ms(-2)). The difference was expressed as a percentage and effect size statistic with confidence intervals. Elite Australian football players had 8% greater total 11% more high intensity running; and 16% more maximal accelerations during matches in 2009 compared to 2008. Players at a sub-elite level had no change in total; 9% less high intensity running but 23% greater maximal accelerations during the same period. In 2008 there was a 5% lower total covered by players in sub-elite competition; no difference in high intensity running; and 28% less maximal accelerations compared to elite. In 2009 the gap was larger for distance of running as sub-elite had 15% less total and 20% less high intensity running than elite. Similar to 2008, sub-elite players had 23% less maximal accelerations in 2009. The activity profile of players in the elite competition has increased over these two seasons, but not in the sub-elite. This has implications for teams where players must move between competitions during the season. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  14. Coastal and submarine instabilities distribution in the tectonically active SW margin of the Corinth Rift (Psathopyrgos, Achaia, Greece)

    Simou, Eirini; Papanikolaou, Dimitrios; Lykousis, Vasilios; Nomikou, Paraskevi; Vassilakis, Emmanuel


    The Corinth Rift, one of the most active rifts in the world as local extension trending NE-SW reaches the amount of 14±2 mm/yr, corresponds to one of the largest zones of seismically active normal faulting. The formation, growth and migration southwards of the prevailing fault systems, which evolve simultaneously with the intense morphogenetic processes, are overprinted in the age, facies and thickness of the Plio-Pleistocene sequences constructing the south margin of the western Gulf of Corinth. The dominant fault blocks, defined by east-west trending, north dipping normal faults, are accompanied by several morphological features and anomalies, noticed in both the terrestrial and the marine environment. Our main aim has been to examine how the tectonic evolution, in combination with the attendant fierce erosional and sedimentary processes, has affected the morphology through geodynamic processes expressed as failures in the wider coastal area. High resolution multibeam bathymetry in combination with the available land surface data have contributed to submarine and subaerial morphological mapping. These have been used as a basis for the detection of all those geomorphic features that indicate instabilities probably triggered, directly or indirectly, by the ongoing active tectonic deformation. The interpretation of the combined datasets shows that the southwestern margin of the Corinth Rift towards Psathopyrgos fault zone is characterized by intense coastal relief and a narrow, almost absent, continental shelf, which passes abruptly to steep submarine slopes. These steep slope values denote the effects of the most recent brittle deformation and are related to coastal and submarine instabilities and failures. High uplift rates and rapid sedimentation, indicative of the regional high-energy terrestrial and submarine environment, are subsequently balanced by the transportation of the seafloor currents, especially where slope gradients decrease, disintegrating the

  15. Active Flow Control in a Radial Vaned Diffuser for Surge Margin Improvement: A Multislot Suction Strategy

    Aurélien Marsan


    Full Text Available This work is the final step of a research project that aims at evaluating the possibility of delaying the surge of a centrifugal compressor stage using a boundary-layer suction technique. It is based on Reynolds-Averaged Navier-Stokes numerical simulations. Boundary-layer suction is applied within the radial vaned diffuser. Previous work has shown the necessity to take into account the unsteady behavior of the flow when designing the active flow control technique. In this paper, a multislot strategy is designed according to the characteristics of the unsteady pressure field. Its implementation results in a significant increase of the stable operating range predicted by the unsteady RANS numerical model. A hub-corner separation still exists further downstream in the diffuser passage but does not compromise the stability of the compressor stage.

  16. Late Quaternary loess landscape evolution on an active tectonic margin, Charwell Basin, South Island, New Zealand

    Hughes, Matthew W.; Almond, Peter C.; Roering, Joshua J.; Tonkin, Philip J.


    Loess deposits constitute an important archive of aeolian deposition reflecting wider patterns of glacial atmospheric circulation, and more localised interactions between riverine source areas, loess trapping efficiency and geomorphic controls on erosion rate. Conceptual models have been formulated to explain the coeval evolution of loess mantles and associated landscapes (loess landscape models) but none apply to areas of tectonically induced base-level lowering. This study uses an age sequence of alluvial fill terraces in the Charwell Basin, north-eastern South Island New Zealand, which straddles the transpressive Hope Fault, to investigate geomorphic controls on loess landscape evolution in an active tectonic region. We hypothesize that the more evolved drainage networks on older terraces will more effectively propagate base-level lowering by way of a greater areal proportion of steep and convex hillslopes and a smaller proportion of non-eroding interfluves. Eventually, as the proportion of interfluves diminishes and hillslope convexity increases, terraces shift from being net loess accumulators to areas of net loess erosion. We investigate the nature of erosion and the geomorphic thresholds associated with this transition. Morphometric analysis of alluvial terraces and terrace remnants of increasing age demonstrated geomorphic evolution through time, with a decrease in extent of original planar terrace tread morphology and an increase in frequency of steeper slopes and convexo-concave land elements. The number of loess sheets and the thickness of loess increased across the three youngest terraces. The next oldest (ca. 150 ka) terrace remnant had the greatest maximum number of loess sheets (3) and loess thickness (8 m) but the loess mantle was highly variable. A detailed loess stratigraphic analysis and the morphometric analysis place this terrace in a transition between dominantly planar, uniformly loess-mantled landforms and loess-free ridge and valley terrain

  17. Different bulk and active bacterial communities in cryoconite from the margin and interior of the Greenland ice sheet

    Stibal, Marek; Schostag, Morten; Cameron, Karen A.


    at the margin site. The rRNA communities at both sites were dominated by a few taxa of Cyanobacteria and Alpha- and/or Betaproteobacteria. The bulk alpha diversity was higher in the margin site community, suggesting that local sources may be contributing towards the gene pool in addition to long distance...

  18. SlamZ: Slide activity on the Hikurangi margin, New Zealand - First results of the RV Sonne expedition SO247

    Huhn, Katrin; Kukowski, Nina; Freudenthal, Tim; Crutchley, Gareth; Goepel, Andreas; Henrys, Stuart; Kasten, Sabine; Kaul, Norbert; Kuhlmann, Jannis; Mountjoy, Joshu; Orpin, Alan; Pape, Thomas; Schwarze, Cornelius; Totsche, Kai-Uwe; Torres, Marta; Villinger, Heiner


    Submarine landslides are important geologic hazards. Although they have been the focus of research for decades, there is still a clear lack in knowledge with respect to the interplay between tectonic movements, slope architecture and sediment physical properties of slope strata, as well as gas hydrate dissociation as controlling factors of slope stability or respectively slope failure processes. The main scientific goal of the Sonne expedition SO247 undertaken in spring 2016 was to gain a better understanding of the factors controlling slope destabilization, especially the interaction of tectonic steepening and gas hydrate transformation, at different tectonic settings along the Hikurangi subduction zone east of New Zealand's North Island. This active continental margin is characterized by various potential triggers for slope failure, e.g. (I) a wide range of tectonic movements which are associated with high seismicity, numerous active faults, sediment uplift and slope over-steepening, and (II) large gas hydrate deposits whose current upper stability limit in some places correlates with the breakoff points of slides. The target areas of SO247 were the frontal accretionary ridge at Rock Garden and the Tuaheni landslide complex (TLC) further north offshore Gisborne. Bathymetric as well as high-resolution seismic reflection and Parasound data were used to select suitable position for 53 gravity cores with a total length of 150 m which were recovered along systematic transects from the undisturbed slope sections to the slid masses in both working areas. In addition, six long sediment cores (three in both working areas) with a total length of approx. 470 m were drilled utilizing the MARUM Bremen drill rig MeBo200. These include a 105 m long continuous sediment core (core recovery > 95%) from an undisturbed slope section in the vicinity of the Tuaheni slide complex. This core represented the first long (i.e. longer than 50 m) sediment record from the Hikurangi margin

  19. The Late Cretaceous-Paleogene active margin of Northeastern Asia: Geodynamic setting of terrigenous sedimentary basins in the Central Koryak terrane

    Chekhovich, V. D.; Palandzhyan, S. A.; Sukhov, A. N.; Egorkin, A. V.; Ben'yamovsky, V. N.


    The northeastern segment of the Late Cretaceous suprasubduction Okhotsk-Chukotka volcanic belt is not an analogue of Andean-type continental margin. During its formation, the belt was separated from the Paleopacific by a complexly built assembly that comprised the Central Koryak continental block and the Essoveem volcanic arc at its margin. Various types of independent terrigenous sedimentary basins were formed in the Late Cretaceous and Early Paleogene at the subsided portion of the microcontinent and its slope. The Uchkhichkhil-type basin was characterized by deposition of polymictic clastic sediments produced during erosion of the volcanic arc and pyroclastic material derived from active volcanic centers of this arc that extended along the microcontinent margin that faced the Okhotsk-Chukotka volcanic belt. The deposition of quartz-feldspathic flyschoid sequences as products of scouring of sialic basement of the continental block was inherent to the Ukelayat type of sedimentation. The closure of the minor oceanic basin that separated the Asian margin from microcontinent in the late Campanian resulted in the cessation of subduction-related activity of the Okhotsk-Chukotka volcanic belt and the Essoveem arc and initiated the formation of the Late Cretaceous accretionary margin of Asia. The deep structure of the central Koryak Highland deduced from the results of seismic surveying with the earthquake converted-wave method has corroborated the geotectonic interpretation.

  20. Active immunization against leptin fails to affect reproduction and exerts only marginal effects on glucose metabolism in young female goats.

    Sauerwein, H; Heintges, U; Bruhns, S C; Hennies, M; Gertler, A


    Approximately 150 days before expected breeding time, 12 female goats (3 months of age) were actively immunized against ovine leptin. Booster injections were given throughout the following year. Control animals (n = 6) were sham-immunized. After the first observed oestrus, a buck was introduced and goats were mated. Blood samples were collected twice weekly and frequent blood sampling series were performed on days -15, 76, 153 and 286 relative to the first immunization. Nine of the immunized goats developed titres within 3 months and had elevated serum concentrations of leptin compared with controls (p 0.05) between the two groups. During the hyperglycaemic clamp there was a trend (p < 0.15) towards increased insulin concentrations in immunized animals whereas glucose infusion rates were not different between the groups. This indicates decreased insulin sensitivity in immunized goats. Our study describes the ontogenesis of serum concentrations of leptin during growth, puberty and first pregnancy and parturition for the caprine species. The effects of the immunization were not detectable or only marginal and the approach aimed at therefore not effective to investigate leptin action in detail.

  1. Temporal evolution of lead isotope ratios in sediments of the Central Portuguese Margin: a fingerprint of human activities.

    Mil-Homens, Mário; Caetano, Miguel; Costa, Ana M; Lebreiro, Susana; Richter, Thomas; de Stigter, Henko; Trancoso, Maria A; Brito, Pedro


    Stable Pb isotope ratios ((206)Pb/(207)Pb, (208)Pb/(206)Pb), (210)Pb, Pb, Al, Ca, Fe, Mn and Si concentrations were measured in 7 sediment cores from the west coast of the Iberian Peninsula to assess the Pb contamination throughout the last 200 years. Independently of their locations, all cores are characterized by increasing Pb/Al rends not related to grain-size changes. Conversely, decreasing trends of (206)Pb/(207)Pb were found towards the present. This tendency suggest a change in Pb sources reflecting an increased proportion derived from anthropogenic activities. The highest anthropogenic Pb inventories for sediments younger than 1950s were found in the two shallowest cores of Cascais and Lisboa submarine canyons, reflecting the proximity of the Tagus estuary. Lead isotope signatures also help demonstrate that sediments contaminated with Pb are not constrained to estuarine-coastal areas and upper parts of submarine canyons, but are also to transferred to a lesser extent to deeper parts of the Portuguese Margin. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Late Holocene uplift history and morphotectonics of the Chabahar and Pozm strand plains along the Makran coast, south-east Iran

    Shah-hosseini, M.; Morhange, C.; Shabanian, E.


    Chabahar and Pozm bays lie on the Iranian coast of Makran, north of the Gulf of Oman. The coast is subjected to tectonic uplift over the Makran Subduction zone due to the northward convergence between Arabian and Eurasian plates. During late Holocene, the shoreline in Chabahar and Pozm bays has been prograded up to about 5 km and formed extensive strand plains adjacent to raised marine terraces. Geomorphic landforms on the strand plains comprise beach ridges, inter-ridge swales, sand dunes and fluvial deposits. The beach ridges, made of marine sand and shell, trend parallel or nearly parallel to the modern shore. We documented relative sea level changes along five coast-normal profiles using ground penetration Radar (GPR) and topographic DGPS profiles. The internal structure of the beach ridges and swales has been imaged using by GPR up to a depth of 10 m, at a resolution of 0.2 m. These profiles are complemented by vibratory coring of sediment sequences. The chronology of the beach deposits relies on the radiocarbon dating of fourteen minimum reworked marine shells collected from the beach ridges. A detailed mapping of tectonic structures took place based on SPOT5 and QuickBird satellite imageries to define the local geomorphic and tectonic structures and to determine their relation with geometry and spatial distribution of the paleo-coastlines. The highest beach ridge is located about 5 km inland and stands approximately 15 m above the present sea level. Dating on the marine shells (family Olividae) from the swash zone deposits yielded calibrated ages between 4800 and 270 years BP at the respective distances of 5 km to 500 m from the modern shore. In the GPR profiles Seaward gently-dipping reflectors represent shoreface deposits. The contact between shoreface and underlying horizontal foreshore reflectors marks the position of paleo-coastline. The beach sediments are sometimes capped by aeolian sediments with steep landward dipping. Spatial position of the paleo

  3. Emergency preparedness in the case of Makran tsunami: a case study on tsunami risk visualization for the western parts of Gujarat, India

    V. M. Patel


    Full Text Available The west coast of India is affected by tsunamigenic earthquake along the Makran subduction zone. On 28 November 1945 at 21:56 coordinated universal time (UTC, a massive Makran earthquake (M8.0 generated a destructive tsunami that propagated across the Northern Arabian Sea and the Indian Ocean. This tsunamigenic earthquake was responsible for the loss of life and great destruction along the coasts of India, Pakistan, Iran and Oman. Modelling of tsunami stages has been made for the coasts of Pakistan, Iran, India and Oman using NAMI-DANCE computer code. The fault parameters of the earthquakes for the generation of tsunami are epicentre (25.15° N, 63.48° E, fault area (200 km length and 100 km width, angle of strike, dip and rake (246°, 7° and 90°, focal depth (15 km, slip magnitude (7 m. The bathymetry data are taken from General Bathymetric Chart of the Oceans (GEBCO and land topography data were collected using Shuttle Radar Topography Mission (SRTM. The present simulation is carried out for a duration of 360 min. It is observed that the maximum calculated tsunami run-ups were about 0.7–1.1 m along the coast of Oman, 0.5 m near Muscat, 0.1 m near Sur, 0.7–1.35 m along the western coast of India, 0.5–2.3 m along the southern coast of Iran and 1.2–5.8 m along the southern coast of Pakistan. After the tsunamigenic earthquake, the tsunami wave reached the Gulf of Kachchh in about 240 min, Okha in about 185 min, Dwarka in about 150 min, Porbandar in about 155 min, Mumbai in about 300 min and Goa in about 210 min. The calculated 2-hr tsunami travel time to the Indian coast is in good agreement with the available reports and published data. If the tsunami strikes during high tide, we should expect more serious hazards which would impact local coastal communities. The results obtained in this study are converted to be compatible with the geographic information system based applications for display and spatial analysis of

  4. Activity-dependent endogenous taurine release facilitates excitatory neurotransmission in the neocortical marginal zone of neonatal rats.

    Qian, Taizhe; Chen, Rongqing; Nakamura, Masato; Furukawa, Tomonori; Kumada, Tatsuro; Akita, Tenpei; Kilb, Werner; Luhmann, Heiko J; Nakahara, Daiichiro; Fukuda, Atsuo


    In the developing cerebral cortex, the marginal zone (MZ), consisting of early-generated neurons such as Cajal-Retzius cells, plays an important role in cell migration and lamination. There is accumulating evidence of widespread excitatory neurotransmission mediated by γ-aminobutyric acid (GABA) in the MZ. Cajal-Retzius cells express not only GABAA receptors but also α2/β subunits of glycine receptors, and exhibit glycine receptor-mediated depolarization due to high [Cl(-)]i. However, the physiological roles of glycine receptors and their endogenous agonists during neurotransmission in the MZ are yet to be elucidated. To address this question, we performed optical imaging from the MZ using the voltage-sensitive dye JPW1114 on tangential neocortical slices of neonatal rats. A single electrical stimulus evoked an action-potential-dependent optical signal that spread radially over the MZ. The amplitude of the signal was not affected by glutamate receptor blockers, but was suppressed by either GABAA or glycine receptor antagonists. Combined application of both antagonists nearly abolished the signal. Inhibition of Na(+), K(+)-2Cl(-) cotransporter by 20 µM bumetanide reduced the signal, indicating that this transporter contributes to excitation. Analysis of the interstitial fluid obtained by microdialysis from tangential neocortical slices with high-performance liquid chromatography revealed that GABA and taurine, but not glycine or glutamate, were released in the MZ in response to the electrical stimulation. The ambient release of taurine was reduced by the addition of a voltage-sensitive Na(+) channel blocker. Immunohistochemistry and immunoelectron microscopy indicated that taurine was stored both in Cajal-Retzius and non-Cajal-Retzius cells in the MZ, but was not localized in presynaptic structures. Our results suggest that activity-dependent non-synaptic release of endogenous taurine facilitates excitatory neurotransmission through activation of glycine

  5. Past and present records of gas hydrate geochemical signatures in a terrigenous materials dominated active margin, southwest of Taiwan

    Lin, S.; Lim, Y.C. [National Taiwan Univ., Taipei (China). Inst. of Oceanography; Wang, C.H. [Academia Sinica, Taipei (China). Inst. of Earth Sciences; Chen, Y.G.; Yang, T.F. [National Taiwan Univ., Taipei (China). Dept. of Geosciences; Wang, Y.; Chung, S.H. [Central Geological Survey., Taipei (China). MOEA


    A 25 meter-long piston core extracted from a continental margin with active tectonic activities in the South China Sea was analyzed. The aim of the study was to investigate temporal variations in the geochemical signatures of gas hydrates. Samples from the core were used to analyze pore water dissolved minerals and gases. The study showed that changes in the deposition environment played a major role in shaping the location. Three distinct geochemical processes were identified in the core sample. High concentrations of dissolved sulfides, high levels of methane and pyrite and low levels of calcium and sulfates were found in pore water samples taken from the first 10 metres of the core. High concentrations of iron oxide in the middle section of the core suggested that the middle sediments were deposited in an oxic environment, while the upper and lower sections of the core were deposited in anoxic conditions caused by rapid methane oxidation. Lower concentrations of pyrite were seen in core sediments from the second 15 to 20 metres of the core. However, levels of pyrite and again increased to concentration levels of 400 {mu}mol per gram in the final 20 to 25 meters of the core. Maximum levels of chloride occurred at 20 meters. Authigenic carbonate nodules were also found in sediments below 20 meters. The stable isotopic carbon composition of the carbonates varied rapidly in in the final 10 meters of the core. It was concluded that varying methane seeps in the past caused the geochemical variations observed in the core sample. 17 refs., 1 fig.

  6. Activity-dependent endogenous taurine release facilitates excitatory neurotransmission in the neocortical marginal zone of neonatal rats

    Taizhe eQian


    Full Text Available In the developing cerebral cortex, the marginal zone (MZ, consisting of early-generated neurons such as Cajal-Retzius cells, plays an important role in cell migration and lamination. There is accumulating evidence of widespread excitatory neurotransmission mediated by γ-aminobutyric acid (GABA in the MZ. Cajal-Retzius cells express not only GABAA receptors but also α2/β subunits of glycine receptors, and exhibit glycine receptor-mediated depolarization due to high [Cl−]i. However, the physiological roles of glycine receptors and their endogenous agonists during neurotransmission in the MZ are yet to be elucidated. To address this question, we performed optical imaging from the MZ using the voltage-sensitive dye JPW1114 on tangential neocortical slices of neonatal rats. A single electrical stimulus evoked an action-potential-dependent optical signal that spread radially over the MZ. The amplitude of the signal was not affected by glutamate receptor blockers, but was suppressed by either GABAA or glycine receptor antagonists. Combined application of both antagonists nearly abolished the signal. Inhibition of Na+, K+-2Cl− cotransporter by 20 µM bumetanide reduced the signal, indicating that this transporter contributes to excitation. Analysis of the interstitial fluid obtained by microdialysis from tangential neocortical slices with high-performance liquid chromatography revealed that GABA and taurine, but not glycine or glutamate, were released in the MZ in response to the electrical stimulation. The ambient release of taurine was reduced by the addition of a voltage-sensitive Na+ channel blocker. Immunohistochemistry and immunoelectron microscopy indicated that taurine was stored both in Cajal-Retzius and non-Cajal-Retzius cells in the MZ, but was not localized in presynaptic structures. Our results suggest that activity-dependent non-synaptic release of endogenous taurine facilitates excitatory neurotransmission through activation of

  7. Workers' marginal costs of commuting

    van Ommeren, Jos; Fosgerau, Mogens


    This paper applies a dynamic search model to estimate workers' marginal costs of commuting, including monetary and time costs. Using data on workers' job search activity as well as moving behaviour, for the Netherlands, we provide evidence that, on average, workers' marginal costs of one hour...

  8. Lesser Himalayan sequences in Eastern Himalaya and their deformation: Implications for Paleoproterozoic tectonic activity along the northern margin of India

    Dilip Saha


    Full Text Available Substantial part of the northern margin of Indian plate is subducted beneath the Eurasian plate during the Caenozoic Himalayan orogeny, obscuring older tectonic events in the Lesser Himalaya known to host Proterozoic sedimentary successions and granitic bodies. Tectonostratigraphic units of the Proterozoic Lesser Himalayan sequence (LHS of Eastern Himalaya, namely the Daling Group in Sikkim and the Bomdila Group in Arunachal Pradesh, provide clues to the nature and extent of Proterozoic passive margin sedimentation, their involvement in pre-Himalayan orogeny and implications for supercontinent reconstruction. The Daling Group, consisting of flaggy quartzite, meta-greywacke and metapelite with minor mafic dyke and sill, and the overlying Buxa Formation with stromatolitic carbonate-quartzite-slate, represent shallow marine, passive margin platformal association. Similar lithostratigraphy and broad depositional framework, and available geochronological data from intrusive granites in Eastern Himalaya indicate strikewise continuity of a shallow marine Paleoproterozoic platformal sequence up to Arunachal Pradesh through Bhutan. Multiple fold sets and tectonic foliations in LHS formed during partial or complete closure of the sea/ocean along the northern margin of Paleoproterozoic India. Such deformation fabrics are absent in the upper Palaeozoic–Mesozoic Gondwana formations in the Lesser Himalaya of Darjeeling-Sikkim indicating influence of older orogeny. Kinematic analysis based on microstructure, and garnet composition suggest Paleoproterozoic deformation and metamorphism of LHS to be distinct from those associated with the foreland propagating thrust systems of the Caenozoic Himalayan collisional belt. Two possibilities are argued here: (1 the low greenschist facies domain in the LHS enveloped the amphibolite to granulite facies domains, which were later tectonically severed; (2 the older deformation and metamorphism relate to a Pacific type

  9. Sequence framework of two different kinds of margins and their response to tectonic activity during the Middle-Late Triassic, Ordos Basin


    Two kinds of margin respectively occur in the Ordos Basin during the Middle-Late Triassic (Yanchang Age), one is foreland margin developed under the background of flexural subsidence by thrusting intensively in the southwest margin, and the other is intracratonic basin margin by stable subsidence in northern and central parts of the basin. The Middle-Late Triassic Yanchang Formation can be divided into four regional third-order sequences, which are separated by gentle angular unconformity or regional erosion surface, made up of lowstand system tract (LST), expanding system tract (EST) and highstand system tract (HST) from lower to upper within a sequence. But there are distinct differences of the sequence framework between the southwest margin and northern and central parts of the basin. The southwest margin develops heavy conglomerate layer and unconformity as a result of orogeny by thrusting, and the intracratonic basin margin by stable subsidence in the northern and central parts grows aggradational sandstone, conglomerate in fluvio-delta system and parallel unconformity. The depositional framework of southwest margin reflects the tectonic evolution from flexural subsidence by thrusting to rebounded uplift. The formation of sequence boundary is related to the resilient uplift and erosion. The sequence stratigraphic framework and depositional system tract configuration in the foreland basin are controlled by structural activity of the fold and thrust belt, and the sequence succession reflects episodic thrusting of the Middle-Late Triassic toward the foreland basin. The sequence evolution in northern and central parts reflects the depositional succession of fluvio-delta system under intracratonic background, composed of coarse-grained sediment in braided channel deposit at the lower, meandering channel deposit in the middle and fine-grained sediment in the flood plain at the upper, dominated by lake level fluctuation. During the deposit of the LST in the

  10. Thermal basin modelling of the Arauco forearc basin, south central Chile — Heat flow and active margin tectonics

    Kuhn, Philipp P.; Echtler, Helmut; Littke, Ralf; Alfaro, Guillermo


    The Arauco basin is part of the coastal forearc domain in South-Central Chile. During its evolution since the Late Cretaceous it was subject to multiple deposition cycles and the erosion of lower bathyal to beach and lagoon sediments. These different environments were established in alternating accretional and erosive subduction tectonic settings along the South Andean active margin. Whereas the general development is well understood, inconsistencies arise regarding the origin of the high thermal maturity of Eocene coals and the estimates of vertical movements of the whole area during the Cenozoic. Thermal modelling of this forearc basin provides new insights regarding its thermal evolution and evaluation of the magnitudes of subsidence and inversion. Results are based on the analysis of coal samples from surface outcrops, mines and drill cores of ten onshore wells from ENAP/Sipetrol. Newly derived vitrinite reflectance (VR r) measurements indicated a temperature in the range of 135-150 °C for the oldest sediment unit of the Arauco basin, which was reached in post Eocene times. Furthermore, 1D basin modelling techniques indicate scenarios that could explain the coalification values in the basin's sediments. The models were calibrated against VR r data from drill core samples supplied by ENAP/Sipetrol. A Miocene and an Oligocene subsidence/inversion scenario were considered, while neither could be securely discarded based on the modelling results. Furthermore, it can be shown that the current thermal maturity was not reached by an increased heat flow (HF) or a deep subsidence only. Consequently, a structural inversion accompanied by the erosion of ~ 3.0 ± 0.4 km depending on the locality in combination with a high HF of ~ 64 ± 4 mW/m 2 is the best explanation of the available data. The HF, which is high for a forearc setting, can be attributed to the increased temperature of the relatively young subducted Nazca Plate and an additional influence of ascending hot

  11. Provenance of a large Lower Cretaceous turbidite submarine fan complex on the active Laurasian margin: Central Pontides, northern Turkey

    Akdoğan, Remziye; Okay, Aral I.; Sunal, Gürsel; Tari, Gabor; Meinhold, Guido; Kylander-Clark, Andrew R. C.


    The Pontides formed the southern active margin of Laurasia during the Mesozoic. They became separated from mainland Laurasia during the Late Cretaceous, with the opening of the Black Sea as an oceanic back-arc basin. During the Early Cretaceous, a large submarine turbidite fan complex developed in the Central Pontides. The turbidites cover an area of 400 km by 90 km with a thickness of more than 2 km. We have investigated the provenance of these turbidites-the Çağlayan Formation-using paleocurrent measurements, U-Pb detrital zircon ages, REE abundances of dated zircons and geochemistry of detrital rutile grains. 1924 paleocurrent measurements from 96 outcrop stations indicate flow direction from northwest to southeast in the eastern part of the Çağlayan Basin and from north-northeast to west-southwest in the western part. 1194 detrital zircon ages from 13 Lower Cretaceous sandstone samples show different patterns in the eastern, central and western parts of the basin. The majority of the U-Pb detrital zircon ages in the eastern part of the basin are Archean and Paleoproterozoic (61% of all zircon ages, 337 grains); rocks of these ages are absent in the Pontides and present in the Ukrainian Shield, which indicates a source north of the Black Sea. In the western part of the basin the majority of the zircons are Carboniferous and Neoproterozoic (68%, 246 grains) implying more local sources within the Pontides. The detrital zircons from the central part show an age spectrum as mixture of zircons from western and eastern parts. Significantly, Jurassic and Early Cretaceous zircons make up less than 2% of the total zircon population, which implies lack of a coeval magmatic arc in the region. This is compatible with the absence of the Lower Cretaceous granites in the Pontides. Thus, although the Çağlayan Basin occupied a fore-arc position above the subduction zone, the arc was missing, probably due to flat subduction, and the basin was largely fed from the Ukrainian

  12. Biogeography, biodiversity and fluid dependence of deep-sea cold-seep communities at active and passive margins

    Sibuet, Myriam; Olu, Karine


    To date, several cold-seep areas which fuel chemosynthesis-based benthic communities have been explored, mainly by deployment of manned submersibles. They are located in the Atlantic and in the Eastern and Western Pacific oceans and in the Mediterranean Sea, in depths ranging between 400 and 6000 m in different geological contexts in passive and active margins. Our study is based on a review of the existent literature on 24 deep cold seeps. The geographic distribution of seeps, the variations of origin and composition of fluids, and rates of fluid flow are presented as they are important factors which explain the spatial heterogeneity and the biomass of biological communities. Methane-rich fluid of thermogenic and/or biogenic origin is the principal source of energy for high-productive communities; however, production of sulphide by sulphate reduction in the sediment also has a major role. The dominant seep species are large bivalves belonging to the families Vesicomyidae or Mytilidae. Other symbiont-containing species occur belonging to Solemyidae, Thyasiridae, Lucinidae bivalves, Pogonophora worms, Cladorhizidae and Hymedesmiidae sponges. Most of the symbiont-containing cold-seep species are new to science. Different symbiont-containing species rely on sulphide or methane oxidation, or both, via chemoautotrophic endosymbiotic bacteria. A total of 211 species, from which 64 are symbiont-containing species, have been inventoried. Patterns in biodiversity and biogeography are proposed. A large majority of the species are endemic to a seep area and the symbiont-containing species are mainly endemic to the cold-seep ecosystem. A comparison of species found in other deep chemosynthesis-based ecosystems, hydrothermal vents, whale carcass and shipwreck reduced habitats, reveals from the existing data, that only 13 species, of which five are symbiont-containing species occur, at both seeps and hydrothermal vents. The species richness of cold-seep communities decreases

  13. Statistical properties of short-selling and margin-trading activities and their impacts on returns in the Chinese stock markets

    Gao, Yan; Gao, Yao


    We investigate the collective behaviors of short-selling and margin-trading between Chinese stocks and their impacts on the co-movements of stock returns by cross-correlation and partial correlation analyses. We find that the collective behaviors of margin-trading are largely attributed to the index cohesive force, while those of short-selling are mainly due to some direct interactions between stocks. Interestingly, the dominant role the finance industry plays in the collective behaviors of short-selling could make it more important in affecting the co-movement structure of stock returns by strengthening its relationship with the market index. By detecting the volume-return and volume-volatility relationships, we find that the investors of the two leverage activities are positively triggered by individual stock volatility first, and next, at the return level, margin-buyers show trend-following properties, while short-sellers are probably informative traders who trade on the information impulse of specific firms. However, the return predictability of the two leverage trading activities and their impacts on stock volatility are not significant. Moreover, both tails of the cumulative distributions of the two leverage trading activities are found following the stretched exponential law better than the power-law.

  14. Active tectonic deformation of the western Indian plate boundary: A case study from the Chaman Fault System

    Crupa, Wanda E.; Khan, Shuhab D.; Huang, Jingqiu; Khan, Abdul S.; Kasi, Aimal


    Collision of the Eurasian and Indian plates has resulted in two spatially offset subduction zones, the Makran subduction zone to the south and the Himalayan convergent margin to the north. These zones are linked by a system of left-lateral strike-slip faults known as the Chaman Fault System, ∼1200 km, which spans along western Pakistan. Although this is one of the greatest strike-slip faults, yet temporal and spatial variation in displacement has not been adequately defined along this fault system. This study conducted geomorphic and geodetic investigations along the Chaman Fault in a search for evidence of spatial variations in motion. Four study areas were selected over the span of the Chaman Fault: (1) Tarnak-Rud area over the Tarnak-Rud valley, (2) Spinatizha area over the Spinatizha Mountain Range, (3) Nushki area over the Nushki basin, and (4) Kharan area over the northern tip of the Central Makran Mountains. Remote sensing data allowed for in depth mapping of different components and faults within the Kohjak group. Wind and water gap pairs along with offset rivers were identified using high-resolution imagery and digital-elevation models to show displacement for the four study areas. The mountain-front-sinuosity ratio, valley height-to-width-ratio, and the stream-length-gradient index were calculated and used to determine the relative tectonic activity of each area. These geomorphic indices suggest that the Kharan area is the most active and the Tarnak-Rud area is the least active. GPS data were processed into a stable Indian plate reference frame and analyzed. Fault parallel velocity versus fault normal distance yielded a ∼8-10 mm/yr displacement rate along the Chaman Fault just north of the Spinatizha area. InSAR data were also integrated to assess displacement rates along the fault system. Geodetic data support that ultra-slow earthquakes similar to those that strike along other major strike-slip faults, such as the San Andreas Fault System, are

  15. Fungal and Prokaryotic Activities in the Marine Subsurface Biosphere at Peru Margin and Canterbury Basin Inferred from RNA-Based Analyses and Microscopy.

    Pachiadaki, Maria G; Rédou, Vanessa; Beaudoin, David J; Burgaud, Gaëtan; Edgcomb, Virginia P


    The deep sedimentary biosphere, extending 100s of meters below the seafloor harbors unexpected diversity of Bacteria, Archaea, and microbial eukaryotes. Far less is known about microbial eukaryotes in subsurface habitats, albeit several studies have indicated that fungi dominate microbial eukaryotic communities and fungal molecular signatures (of both yeasts and filamentous forms) have been detected in samples as deep as 1740 mbsf. Here, we compare and contrast fungal ribosomal RNA gene signatures and whole community metatranscriptomes present in sediment core samples from 6 and 95 mbsf from Peru Margin site 1229A and from samples from 12 and 345 mbsf from Canterbury Basin site U1352. The metatranscriptome analyses reveal higher relative expression of amino acid and peptide transporters in the less nutrient rich Canterbury Basin sediments compared to the nutrient rich Peru Margin, and higher expression of motility genes in the Peru Margin samples. Higher expression of genes associated with metals transporters and antibiotic resistance and production was detected in Canterbury Basin sediments. A poly-A focused metatranscriptome produced for the Canterbury Basin sample from 345 mbsf provides further evidence for active fungal communities in the subsurface in the form of fungal-associated transcripts for metabolic and cellular processes, cell and membrane functions, and catalytic activities. Fungal communities at comparable depths at the two geographically separated locations appear dominated by distinct taxa. Differences in taxonomic composition and expression of genes associated with particular metabolic activities may be a function of sediment organic content as well as oceanic province. Microscopic analysis of Canterbury Basin sediment samples from 4 and 403 mbsf produced visualizations of septate fungal filaments, branching fungi, conidiogenesis, and spores. These images provide another important line of evidence supporting the occurrence and activity of fungi in

  16. Time-Dependent Confounding in the Study of the Effects of Regular Physical Activity in Chronic Obstructive Pulmonary Disease: An Application of the Marginal Structural Model

    Garcia-Aymerich, J.; Lange, P.; Serra, I.;


    PURPOSE: Results from longitudinal studies about the association between physical activity and chronic obstructive pulmonary disease (COPD) may have been biased because they did not properly adjust for time-dependent confounders. Marginal structural models (MSMs) have been proposed to address...... this type of confounding. We sought to assess the presence of time-dependent confounding in the association between physical activity and COPD development and course by comparing risk estimates between standard statistical methods and MSMs. METHODS: By using the population-based cohort Copenhagen City Heart...... Study, 6,568 subjects selected from the general population in 1976 were followed up until 2004 with three repeated examinations. RESULTS: Moderate to high compared with low physical activity was associated with a reduced risk of developing COPD both in the standard analysis (odds ratio [OR] 0.76, p = 0...

  17. Time-Dependent Confounding in the Study of the Effects of Regular Physical Activity in Chronic Obstructive Pulmonary Disease: An Application of the Marginal Structural Model

    Garcia-Aymerich, Judith; Lange, Peter; Serra, Ignasi


    PURPOSE: Results from longitudinal studies about the association between physical activity and chronic obstructive pulmonary disease (COPD) may have been biased because they did not properly adjust for time-dependent confounders. Marginal structural models (MSMs) have been proposed to address...... this type of confounding. We sought to assess the presence of time-dependent confounding in the association between physical activity and COPD development and course by comparing risk estimates between standard statistical methods and MSMs. METHODS: By using the population-based cohort Copenhagen City Heart...... 0.80, p = 0.001; MSM, 0.81, p = 0.008). CONCLUSION: These results support the previously reported associations between physical activity and reduced risk of COPD development, hospitalizations, and mortality, thereby suggesting they were not due to time-dependent confounding....

  18. Glaciomarine sedimentation and bottom current activity on the north-western and northern continental margins of Svalbard during the late Quaternary

    Chauhan, Teena; Noormets, Riko; Rasmussen, Tine L.


    Palaeo-bottom current strength of the West Spitsbergen Current (WSC) and the influence of the Svalbard-Barents Sea Ice Sheet (SBIS) on the depositional environment along the northern Svalbard margins are poorly known. Two gravity cores from the southern Yermak Plateau and the upper slope north of Nordaustlandet, covering marine isotope stage (MIS) 1 to MIS 5, are investigated. Five lithofacies, based on grain size distribution, silt/clay ratio, content and mean of sortable silt (SS), are distinguished to characterise the contourite-dominated sedimentary environments. In addition, depositional environments are described using total organic carbon (TOC), total sulphur (TS) and calcium carbonate (CaCO3) contents of sediments. Facies A, containing coarse SS, suggests strong bottom current activity and good bottom water ventilation conditions as inferred from low TOC content. This facies was deposited during the glacial periods MIS 4, MIS 2 and during the late Holocene. Facies B is dominated by fine SS indicating weak bottom current and poor ventilation (cf. high TOC content of 1.2-1.6%), and correlates with the MIS 4/3 and MIS 2/1 transition periods. With an equal amount of clay and sand, fine SS and high content of TOC, facies C indicates reduced bottom current strength for intervals with sediment supply from proximal sources such as icebergs, sea ice or meltwater discharge. This facies was deposited during the last glacial maximum. Facies D represents mass-flow deposits on the northern Svalbard margin attributed to the SBIS advance at or near the shelf edge. Facies E sediments indicating moderate bottom current strength were deposited during MIS 5 and MIS 3, and during parts of MIS 2. This first late Quaternary proxy record of the WSC flow and sedimentation history from the northern Svalbard margin suggests that the oceanographic conditions and ice sheet processes have exerted first-order control on sediment properties.

  19. Cold seep epifaunal communities on the Hikurangi margin, New Zealand: composition, succession, and vulnerability to human activities.

    Bowden, David A; Rowden, Ashley A; Thurber, Andrew R; Baco, Amy R; Levin, Lisa A; Smith, Craig R


    Cold seep communities with distinctive chemoautotrophic fauna occur where hydrocarbon-rich fluids escape from the seabed. We describe community composition, population densities, spatial extent, and within-region variability of epifaunal communities at methane-rich cold seep sites on the Hikurangi Margin, New Zealand. Using data from towed camera transects, we match observations to information about the probable life-history characteristics of the principal fauna to develop a hypothetical succession sequence for the Hikurangi seep communities, from the onset of fluid flux to senescence. New Zealand seep communities exhibit taxa characteristic of seeps in other regions, including predominance of large siboglinid tubeworms, vesicomyid clams, and bathymodiolin mussels. Some aspects appear to be novel; however, particularly the association of dense populations of ampharetid polychaetes with high-sulphide, high-methane flux, soft-sediment microhabitats. The common occurrence of these ampharetids suggests they play a role in conditioning sulphide-rich sediments at the sediment-water interface, thus facilitating settlement of clam and tubeworm taxa which dominate space during later successional stages. The seep sites are subject to disturbance from bottom trawling at present and potentially from gas hydrate extraction in future. The likely life-history characteristics of the dominant megafauna suggest that while ampharetids, clams, and mussels exploit ephemeral resources through rapid growth and reproduction, lamellibrachid tubeworm populations may persist potentially for centuries. The potential consequences of gas hydrate extraction cannot be fully assessed until extraction methods and target localities are defined but any long-term modification of fluid flow to seep sites would have consequences for all chemoautotrophic fauna.

  20. Cold seep epifaunal communities on the Hikurangi margin, New Zealand: composition, succession, and vulnerability to human activities.

    David A Bowden

    Full Text Available Cold seep communities with distinctive chemoautotrophic fauna occur where hydrocarbon-rich fluids escape from the seabed. We describe community composition, population densities, spatial extent, and within-region variability of epifaunal communities at methane-rich cold seep sites on the Hikurangi Margin, New Zealand. Using data from towed camera transects, we match observations to information about the probable life-history characteristics of the principal fauna to develop a hypothetical succession sequence for the Hikurangi seep communities, from the onset of fluid flux to senescence. New Zealand seep communities exhibit taxa characteristic of seeps in other regions, including predominance of large siboglinid tubeworms, vesicomyid clams, and bathymodiolin mussels. Some aspects appear to be novel; however, particularly the association of dense populations of ampharetid polychaetes with high-sulphide, high-methane flux, soft-sediment microhabitats. The common occurrence of these ampharetids suggests they play a role in conditioning sulphide-rich sediments at the sediment-water interface, thus facilitating settlement of clam and tubeworm taxa which dominate space during later successional stages. The seep sites are subject to disturbance from bottom trawling at present and potentially from gas hydrate extraction in future. The likely life-history characteristics of the dominant megafauna suggest that while ampharetids, clams, and mussels exploit ephemeral resources through rapid growth and reproduction, lamellibrachid tubeworm populations may persist potentially for centuries. The potential consequences of gas hydrate extraction cannot be fully assessed until extraction methods and target localities are defined but any long-term modification of fluid flow to seep sites would have consequences for all chemoautotrophic fauna.

  1. The sequence of moderate-size earthquakes at the junction of the Ligurian basin and the Corsica margin (western Mediterranean): The initiation of an active deformation zone revealed?

    Larroque, Christophe; Delouis, Bertrand; Sage, Françoise; Régnier, Marc; Béthoux, Nicole; Courboulex, Françoise; Deschamps, Anne


    A new seismically active zone is found in the southern part of the Ligurian basin, 80-km west of Corsica (western Mediterranean). The activity began in February 2011 with a foreshock (ML 4) and a mainshock (ML 5.3) 5 days later, followed by numerous aftershocks. We first analyze the fore- and mainshock in detail. We compare the results obtained using classical methods (linear location in a 1D medium and focal mechanisms from P and S polarities) and new approaches (non-linear location in a 3D medium and waveform modeling for determining the seismic moment and the focal mechanism). Both methods provided similar results for location, depth (in the range of 6-13 km) and focal mechanisms, which reveal reverse faulting with nodal planes oriented N-S and NE-SW. We then locate 27 of the aftershocks in the 3D model and find a 10-km-long NE-SW alignment with a depth between 7 and 16 km. In 2012 and 2013, three other moderate-size events (ML 3.8, 4 and 4.5) occurred and confirm that this zone is still active. The epicentral area is located in the oceanic domain of the Ligurian Basin. From analysis of the bathymetry and high-resolution multi-channel seismic profiles, no morphologic anomaly at surface and no inherited fault in the shallow ~ 4 km depth were imaged, which suggest that no significant deformation occurred in the area since 5 Ma. Thus, the structure(s) activated during the 2011-2013 sequence remain unknown. In light of these results, we point out a notable difference on both sides of the Ligurian Basin: the northern margin, close to the alpine chain, suffered strong earthquakes and large cumulated deformation since 5 Ma, while the southern margin, close to the Corsica-Sardinia continental block, is poorly deformed since 5 Ma.

  2. Sequence stratigraphy and U/b shrimp geochronology of the active margin deposits of the Cacheuta sub-basin, Cuyo Basin, Northwestern Argentina

    Avila, Janaina Nunes [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Geociencias]. E-mail:; Chemale Junior, Farid [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Geociencias; Borba, Andre Weissheimer de [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Programa de Pos-graduacao em Geociencias; Cingolani, Carlos [La Plata Univ. Nacional (Argentina)


    This study focuses on the stratigraphic and geochronologic analysis of the deposits related to the faulted active margin of the Cacheuta sub-basin, Cuyo Basin (Triassic), in NW-Argentina. This basin was mainly controlled by extensional tectonics along NW-trending structures inherited from Paleozoic sutures. The whole stratigraphic package of this basin is interpreted as a second order depositional sequence. Low stand deposits comprise coarse-grained alluvial fans (sheet flood and debris-flow deposits). Fluvial and minor lacustrine deposits with expressive volcaniclastic contribution make up the transgressive systems tract. The maximum flooding surface was traced on lacustrine black shales of the Cacheuta Formation (source rock for petroleum accumulations). The high stand system tract comprises fluvial meandering facies and more sparse volcanic contribution. U/Pb SHRIMP dating of a pyroclastic rock inter layered with basal alluvial fans yielded a magmatic age of 243 {+-} 4.7 Ma positioned in the Early to Middle Triassic. (author)

  3. [Sinaloa: the geography of marginalization].

    Aguayo Hernandez, J R


    Sinaloa's State Population Program for 1993-98 contains the objective of promoting integration of demographic criteria into the planning process. The action program calls for establishing indicators of economic and social inequality so that conditions of poverty and margination can be identified. To further these goals, the State Population Council used data from the National Population Council project on regional inequality and municipal margination in Mexico to analyze margination at the state level. Nine indicators of educational status, housing conditions, spatial distribution, and income provide information that allows the definition of municipios and regions that should receive priority in economic and social development programs. The index of municipal margination (IMM) is a statistical summary of the nine indicators, which are based on information in the 1990 census. As of March 1990, 9.9% of Sinaloa's population over age 15 was illiterate and 37.4% had incomplete primary education. 91.0% had electricity, but 18.7% lacked indoor toilet facilities and 19.4% had no piped water. 23.7% of houses had dirt floors. 60% of households were crowded, defined as having more than two persons per bedroom. 43.5% of the state population lived in localities with fewer than 5000 inhabitants, where service delivery is difficult and costly. 55.6% of the economically active population was judged to earn less than the amount needed to satisfy essential needs. All except one municipio bordering the Pacific ocean had low or very low indicators of margination, while all those in the sierra had a medium or high degree of margination. Sinaloa's statewide IMM was eighteenth among Mexico's 32 federal entities, with Chiapas showing the highest degree of margination and the Federal District the lowest.

  4. Role of local to regional-scale collisions in the closure history of the Southern Neotethys, exemplified by tectonic development of the Kyrenia Range active margin/collisional lineament, N Cyprus

    Robertson, Alastair; Kinnaird, Tim; McCay, Gillian; Palamakumbura, Romesh; Chen, Guohui


    Active margin processes including subduction, accretion, arc magmatism and back-arc extension play a key role in the diachronous, and still incomplete closure of the S Neotethys. The S Neotethys rifted along the present-day Africa-Eurasia continental margin during the Late Triassic and, after sea-floor spreading, began to close related to northward subduction during the Late Cretaceous. The northern, active continental margin of the S Neotethys was bordered by several of the originally rifted continental fragments (e.g. Taurides). The present-day convergent lineament ranges from subaqueous (e.g. Mediterranean Ridge), to subaerial (e.g. SE Turkey). The active margin development is partially obscured by microcontinent-continent collision and post-collisional strike-slip deformation (e.g. Tauride-Arabian suture). However, the Kyrenia Range, N Cyprus provides an outstanding record of convergent margin to early stage collisional processes. It owes its existence to strong localised uplift during the Pleistocene, which probably resulted from the collision of a continental promontory of N Africa (Eratosthenes Seamount) with the long-lived S Neotethyan active margin to the north. A multi-stage convergence history is revealed, mainly from a combination of field structural, sedimentological and igneous geochemical studies. Initial Late Cretaceous convergence resulted in greenschist facies burial metamorphism that is likely to have been related to the collision, then rapid exhumation, of a continental fragment (stage 1). During the latest Cretaceous-Palaeogene, the Kyrenia lineament was characterised by subduction-influenced magmatism and syn-tectonic sediment deposition. Early to Mid-Eocene, S-directed thrusting and folding (stage 2) is likely to have been influenced by the suturing of the Izmir-Ankara-Erzincan ocean to the north ('N Neotethys'). Convergence continued during the Neogene, dominated by deep-water terrigenous gravity-flow accumulation in a foredeep setting

  5. Evidence of a Neoproterozoic active continental margin - Geochemistry and isotope geology of high-grade paragneiss from the Ribeira Orogen, SE Brazil

    Capistrano, G. G.; Schmitt, R. S.; Medeiros, S. R.; Fernandes, G. L. F.


    Ediacaran paragneisses from the Palmital Unit are located in a key region, between two major tectonic domains of the Ribeira Orogen (in Rio de Janeiro, SE Brazil): the Cabo Frio Tectonic Domain and the Oriental Terrane. We present here petrographic, geochemical and isotopic data in order to partially unravel the origin and tectonic nature of the protoliths from these metamorphic rocks. Litharenites interpreted as immature sediments, mostly derived from the erosion of felsic rocks (granites/rhyolites and diorites/andesites) are here described. Multi-elements patterns and trace elements ratios reinforce an upper continental crust nature for the composition of the protoliths. These were probably located close to the source area and accommodated in semi-arid climate and high topography conditions. Tectonic discrimination diagrams indicate that the Palmital basin developed in an active continental margin, corroborated by the zircon detrital spectra. The main population of detrital zircon (ca. 750-550 Ma) is partially coeval with the age of the Rio Negro continental magmatic arc, resident in the Oriental Terrane. The Palmital basin could represent a forearc environment with no oceanic crust material, but only a continuous sedimentation of turbidites derived from the arc, with gradational bedding signifying a subaqueous environment, without outside tectonic disturbances. On the other hand, TDM ages of 1.6-1.8 Ga suggest that these sediments are not juvenile, indicating also a contribution from an ancient crust. This recycled continental crust could come either from the basement of the Oriental Terrane (which was not identified yet) or from the basement of the Cabo Frio Tectonic Domain. In the last assumption the Palmital deposition would be concomitant with the initiation of continental collision and the subduction of the passive margin of the Cabo Frio Tectonic Domain towards west. This unit was subsequently metamorphosed/deformed during the ca. 540 Ma collision between

  6. Marginalization of the Youth

    Jensen, Niels Rosendal


    The article is based on a key note speach in Bielefeld on the subject "welfare state and marginalized youth", focusing upon the high ambition of expanding schooling in Denmark from 9 to 12 years. The unintended effect may be a new kind of marginalization.......The article is based on a key note speach in Bielefeld on the subject "welfare state and marginalized youth", focusing upon the high ambition of expanding schooling in Denmark from 9 to 12 years. The unintended effect may be a new kind of marginalization....

  7. Methane efflux from marine sediments in passive and active margins: Estimations from bioenergetic reaction-transport simulations

    Dale, A. W.; Van Cappellen, P.; Aguilera, D. R.; Regnier, P.


    A simplified version of a kinetic-bioenergetic reaction model for anaerobic oxidation of methane (AOM) in marine sediments [Dale, A.W., Regnier, P., Van Cappellen, P., 2006. Bioenergetic controls on anaerobic oxidation of methane (AOM) in coastal marine sediments: a theoretical analysis. Am. J. Sci. 306, 246-294.] is used to assess the impact of transport processes on biomass distributions, AOM rates and methane release fluxes from the sea floor. The model explicitly represents the functional microbial groups and the kinetic and bioenergetic limitations of the microbial metabolic pathways involved in AOM. Model simulations illustrate the dominant control exerted by the transport regime on the activity and abundance of AOM communities. Upward fluid flow at active seep systems restricts AOM to a narrow subsurface reaction zone and sustains high rates of methane oxidation. In contrast, pore-water transport dominated by molecular diffusion leads to deeper and broader zones of AOM, characterized by much lower rates and biomasses. Under steady-state conditions, less than 1% of the upward dissolved methane flux reaches the water column, irrespective of the transport regime. However, a sudden increase in the advective flux of dissolved methane, for example as a result of the destabilization of methane hydrates, causes a transient efflux of methane from the sediment. The benthic efflux of dissolved methane is due to the slow growth kinetics of the AOM community and lasts on the order of 60 years. This time window is likely too short to allow for a significant escape of pore-water methane following a large scale gas hydrate dissolution event such as the one that may have accompanied the Paleocene/Eocene Thermal Maximum (PETM).

  8. TsAg5, a Taenia solium cysticercus protein with a marginal trypsin-like activity in the diagnosis of human neurocysticercosis.

    Rueda, Analiz; Sifuentes, Cecilia; Gilman, Robert H; Gutiérrez, Andrés H; Piña, Ruby; Chile, Nancy; Carrasco, Sebastián; Larson, Sandra; Mayta, Holger; Verástegui, Manuela; Rodriguez, Silvia; Gutiérrez-Correa, Marcel; García, Héctor H; Sheen, Patricia; Zimic, Mirko


    Neurocysticercosis is an endemic parasitic disease caused by Taenia solium larva. Although the mechanism of infection is not completely understood, it is likely driven by proteolytic activity that degrades the intestinal wall to facilitate oncosphere penetration and further infection. We analyzed the publicly available T. solium EST/DNA library and identified two contigs comprising a full-length cDNA fragment very similar to Echinococcus granulosus Ag5 protein. The T. solium cDNA sequence included a proteolytic trypsin-like-domain in the C-terminal region, and a thrombospondin type-1 adherence-domain in the N-terminal region. Both the trypsin-like and adherence domains were expressed independently as recombinant proteins in bacterial systems. TsAg5 showed marginal trypsin-like activity and high sequence similarity to Ag5. The purified antigens were tested in a Western immunoblot assay to diagnose human neurocysticercosis. The sensitivity of the trypsin-like-domain was 96.36% in patients infected with extraparenchymal cysts, 75.44% in patients infected with multiple cysts, and 39.62% in patients with a single cyst. Specificity was 76.70%. The thrombospondin type-1 adherence-domain was not specific for neurocysticercosis.

  9. TsAg5, a Taenia solium cysticercus protein with a marginal trypsin-like activity in the diagnosis of human neurocysticercosis

    Rueda, Analiz; Sifuentes, Cecilia; Gilman, Robert H.; Gutiérrez, Andrés H.; Piña, Ruby; Chile, Nancy; Carrasco, Sebastián; Larson, Sandra; Mayta, Holger; Verástegui, Manuela; Rodriguez, Silvia; Gutiérrez-Correa, Marcel; García, Héctor H.; Sheen, Patricia; Zimic, Mirko


    Neurocysticercosis is an endemic parasitic disease caused by Taenia solium larva. Although the mechanism of infection is not completely understood, it is likely driven by proteolytic activity that degrades the intestinal wall to facilitate oncosphere penetration and further infection. We analyzed the publicly available Taenia solium EST/DNA library and identified two contigs comprising a full-length cDNA fragment very similar to E. granulosus Ag5 protein. The Taenia solium cDNA sequence included a proteolytic trypsin-like-domain in the C-terminal region, and a thrombospondin type-1 adherence-domain in the N-terminal region. Both the trypsin-like and adherence domains were expressed independently as recombinant proteins in bacterial systems. TsAg5 showed marginal trypsin-like activity and high sequence similarity to Ag5. The purified antigens were tested in a Western immunoblot assay to diagnose human neurocysticercosis. The sensitivity of the trypsin-like-domain was 96.36% in patients infected with extraparenchymal cysts, 75.44% in patients infected with multiple cysts, and 39.62% in patients with a single cyst. Specificity was 76.70%. The thrombospondin type-1 adherence-domain was not specific for neurocysticercosis. PMID:21893105

  10. Practical Marginalized Multilevel Models.

    Griswold, Michael E; Swihart, Bruce J; Caffo, Brian S; Zeger, Scott L


    Clustered data analysis is characterized by the need to describe both systematic variation in a mean model and cluster-dependent random variation in an association model. Marginalized multilevel models embrace the robustness and interpretations of a marginal mean model, while retaining the likelihood inference capabilities and flexible dependence structures of a conditional association model. Although there has been increasing recognition of the attractiveness of marginalized multilevel models, there has been a gap in their practical application arising from a lack of readily available estimation procedures. We extend the marginalized multilevel model to allow for nonlinear functions in both the mean and association aspects. We then formulate marginal models through conditional specifications to facilitate estimation with mixed model computational solutions already in place. We illustrate the MMM and approximate MMM approaches on a cerebrovascular deficiency crossover trial using SAS and an epidemiological study on race and visual impairment using R. Datasets, SAS and R code are included as supplemental materials.

  11. Ocean margins workshop



    The Department of Energy (DOE) is announcing the refocusing of its marine research program to emphasize the study of ocean margins and their role in modulating, controlling, and driving Global Change phenomena. This is a proposal to conduct a workshop that will establish priorities and an implementation plan for a new research initiative by the Department of Energy on the ocean margins. The workshop will be attended by about 70 scientists who specialize in ocean margin research. The workshop will be held in the Norfolk, Virginia area in late June 1990.

  12. "We call ourselves marginalized"

    Jørgensen, Nanna Jordt


    In recent decades, indigenous knowledge has been added to the environmental education agenda in an attempt to address the marginalization of non-western perspectives. While these efforts are necessary, the debate is often framed in terms of a discourse of victimization that overlooks the agency o...... argue that researchers not only need to pay attention to how certain voices are marginalized in Environmental Education research and practice, but also to how learners as agents respond to, use and negotiate the marginalization of their perspectives....

  13. Indian Ocean margins

    Naqvi, S.W.A.

    The most important biogeochemical transformations and boundary exchanges in the Indian Ocean seem to occur in the northern region, where the processes originating at the land-ocean boundary extend far beyond the continental margins. Exchanges across...

  14. Learning unbelievable marginal probabilities

    Pitkow, Xaq; Miller, Ken D


    Loopy belief propagation performs approximate inference on graphical models with loops. One might hope to compensate for the approximation by adjusting model parameters. Learning algorithms for this purpose have been explored previously, and the claim has been made that every set of locally consistent marginals can arise from belief propagation run on a graphical model. On the contrary, here we show that many probability distributions have marginals that cannot be reached by belief propagation using any set of model parameters or any learning algorithm. We call such marginals `unbelievable.' This problem occurs whenever the Hessian of the Bethe free energy is not positive-definite at the target marginals. All learning algorithms for belief propagation necessarily fail in these cases, producing beliefs or sets of beliefs that may even be worse than the pre-learning approximation. We then show that averaging inaccurate beliefs, each obtained from belief propagation using model parameters perturbed about some le...

  15. Enhanced solar activity influence on the summer temperature variability of the southeast margin of the Qinghai-Tibetan Plateau in the late Holocene

    Chang, Jie; Zhang, Enlou; Liu, Enfeng; Shulmeister, James


    We present two quantitative chironomid-based Holocene summer temperature records from the southeast margin of the Qinghai-Tibetan Plateau (QTP). The records are from two alpine lakes (Tiancai and Heihai) located at the elevation of close to 4000 m above sea level from Yunnan Province. The mean July temperatures were quantified by applying a transfer function model (r2 = 0.63, RMSEP = 2.3 °C) developed based on a 100-lake modern calibration dataset of south-west China. The results were validated using standard reconstruction diagnostics. Both records show that the total summer temperature variation is within 2.5 °C. The records also show that the overall pattern broadly matches the declining trend of the summer insolation at 30°N and the Asian Summer Monsoon records. The general declining trend is punctuated by a few warm and cool intervals on the centennial scale. We observed a periodicity pattern in the mean July temperature variability and these fluctuations are possibly related to both the solar irradiance and the summer monsoon changes. Solar activity may have played an enhanced role on the highland summer temperature changes in the late Holocene when the monsoon influence to south-western China is generally weakened. More comprehensive investigations are needed to clarify the relationship between solar activity, the East Asian and Indian Ocean summer monsoons and the response of alpine climate in order to disentangle these or the combined effects on the climate change in the broad region of south-western China.

  16. Late Pleistocene to Holocene sedimentation and hydrocarbon seeps on the continental shelf of a steep, tectonically active margin, southern California, USA

    Draut, Amy E.; Hart, Patrick E.; Lorenson, T.D.; Ryan, Holly F.; Wong, Florence L.; Sliter, Ray W.; Conrad, James E.


    Small, steep, uplifting coastal watersheds are prolific sediment producers that contribute significantly to the global marine sediment budget. This study illustrates how sedimentation evolves in one such system where the continental shelf is largely sediment-starved, with most terrestrial sediment bypassing the shelf in favor of deposition in deeper basins. The Santa Barbara-Ventura coast of southern California, USA, is considered a classic area for the study of active tectonics and of Tertiary and Quaternary climatic evolution, interpretations of which depend upon an understanding of sedimentation patterns. High-resolution seismic-reflection data over >570 km2 of this shelf show that sediment production is concentrated in a few drainage basins, with the Ventura and Santa Clara River deltas containing most of the upper Pleistocene to Holocene sediment on the shelf. Away from those deltas, the major factor controlling shelf sedimentation is the interaction of wave energy with coastline geometry. Depocenters containing sediment 5-20 m thick exist opposite broad coastal embayments, whereas relict material (bedrock below a regional unconformity) is exposed at the sea floor in areas of the shelf opposite coastal headlands. Locally, natural hydrocarbon seeps interact with sediment deposition either to produce elevated tar-and-sediment mounds or as gas plumes that hinder sediment settling. As much as 80% of fluvial sediment delivered by the Ventura and Santa Clara Rivers is transported off the shelf (some into the Santa Barbara Basin and some into the Santa Monica Basin via Hueneme Canyon), leaving a shelf with relatively little recent sediment accumulation. Understanding factors that control large-scale sediment dispersal along a rapidly uplifting coast that produces substantial quantities of sediment has implications for interpreting the ancient stratigraphic record of active and transform continental margins, and for inferring the distribution of hydrocarbon resources

  17. Who are the active players of the Iberian Margin deep biosphere? Microbial diversity of borehole U1385 through analysis of 16S rDNA and rRNA

    Russell, J. A.; Orsi, W.; Edgcomb, V. P.; Biddle, J.


    Microbial community structure and activity in marine deep subsurface environments across the globe have been assayed using various molecular biology tools including 16S rDNA sequencing, microarrays, FISH/CARD-FISH, and metagenomics. Many studies involving these techniques are DNA-based. This limits study of microbial function in these environments as DNA does not degrade as quickly as RNA and may lead to misinterpreting relic microbial genes as important for present-day activity. In this study, the diversity of bacteria and archaea from sediments of the Iberian Margin IODP borehole U1385 was analyzed from bulk extracted DNA and RNA at seven different depths ranging from 10 to 123 meters below seafloor (mbsf). Presented data suggests that the picture of microbial diversity obtained from DNA is markedly different from that seen through analysis of RNA. IODP borehole U1385 offers a great comparison to ODP Site 1229, a well characterized borehole on the Peru Margin. Similar sediment depositional history and geochemistry will allow exploration of what represents a 'typical' continental margin sediment microbial community or if microbial endemism is established despite similar conditions. This study represents the first molecular exploration of sediment microbial communities from the Iberian Margin IODP Site U1385.

  18. A Review on Permian to Triassic Active or Convergent Margin in Southeasternmost Gondwanaland: Possibility of Exploration Target for Tin and Hydrocarbon Deposits in the Eastern Indonesia

    Amiruddin Amiruddin


    Full Text Available active convergence of continental margin is probably generated in Gondwanaland during Permian to Triassic period which is characterized by the presence of magmatic and volcanic belts and back-arc ba- sins occupied respectively by Permian to Triassic rocks. The magmatic belt is occupied by peraluminous granitic plutons showing characteristics of S- type granite and is considered as tin-bearing granites. The back-arc basins are occupied by the Southern Papua and Galille-Bowen-Gunnedah-Sydney Basins. Those large basins are respectivelly filled by fluvial, fluvio- deltaic to marine Permian-Triassic sediments, which are unconformably overlain by the Jurrassic-Cretaceous marine succession. The paleomagnetic data, confirmed by flora content found in Australia and Papua, indicate that those areas initially belong to the Gondwanaland before part of them were drifted and rotated into the present day position. Tectonically, the presence of those Permian-Triassic magmatic-volcanic belts and back-arc basins in behind, indicates that at the time there were huge compressive activities: convergence of paleo-oceanic Pasific Plate moving westward, collided and subducted into the Southeastern Gondwana Continental Plate, moved relatively eastwards. This phenomenon resembles to the formation of Sumatera Tertiary tectonic zones producing back-arc basins, i.e. South Sumatera, Central, and North Sumatera Basins including the Tertiary Magmatic Arc. Concerning the similarity of Permian-Triassic geological condition of the magmatic arc and back-arc basins in Eastern Indonesia and Eastern Australia including paleoposition, paleotectonic setting, strati- graphic succession, and lithologic composition, it is suggested to carry out an increase in a more intens- ive tin exploration in the Eastern Indonesia, e.g. Bird Head area and Banggai Sula Island, and also for hydrocarbon target (coal, coalbed methane, oil and gas, and oil

  19. Long-lasting Cadomian magmatic activity along an active northern Gondwana margin: U-Pb zircon and Sr-Nd isotopic evidence from the Brunovistulian Domain, eastern Bohemian Massif

    Soejono, Igor; Janoušek, Vojtěch; Žáčková, Eliška; Sláma, Jiří; Konopásek, Jiří; Machek, Matěj; Hanžl, Pavel


    Cadomian magmatic complexes of the Brunovistulian Domain crop out at the eastern termination of the Bohemian Massif. However, the age, nature and geotectonic affinity of some of pre-Variscan (meta-)igneous rock complexes from this domain are still unknown. Geochronological and geochemical study of the granitic rocks across the Brunovistulian Domain reveals new information about the timing and nature of this magmatic activity originally situated along the northern margin of Gondwana. Zircon U-Pb data (601 ± 3 Ma, Brno Massif; 634 ± 6 Ma, paraautochtonous core of the Svratka Dome; 568 ± 3 Ma, Bíteš orthogneiss) from the allochtonous Moravicum indicate the prolonged magmatic activity within the Brunovistulian Domain during the Ediacaran. The major- and trace-element and Sr-Nd isotopic signatures show heterogeneous geochemical characteristics of the granitic rocks and suggest a magmatic-arc geotectonic setting. The two-stage Depleted Mantle Nd model ages (c. 1.3-2.0 Ga) indicate derivation of the granitic rocks from a relatively primitive crustal source, as well as from an ancient and evolved continental crust of the Brunovistulian Domain. These results constrain the magmatic-arc activity to c. 635-570 Ma and provide a further evidence for a long-lived (at least c. 65 Myr) and likely episodic subduction-related magmatism at the northern margin of Gondwana. The presence of granitic intrusions derived from variously mature crustal sources at different times suggests heterogeneous crustal segments to having been involved in the magmatic-arc system during its multistage evolution.

  20. Zircon U-Pb geochronology, geochemistry and Sr-Nd-Pb isotopes from the metamorphic basement in the Wuhe Complex: Implications for Neoarchean active continental margin along the southeastern North China Craton and constraints on the petrogenesis of Mesozoic granitoids

    Andong Wang


    Full Text Available We report zircon U-Pb geochronology, geochemistry and Sr-Nd-Pb isotope data from mafic granulites and garnet amphibolites of the Wuhe Complex in the southeastern margin of the North China Craton (NCC. In combination with previous data, our results demonstrate that these rocks represent fragments of the ancient lower crust, and have features similar to those of the granulite basement in the northern margin of the NCC. A detailed evaluation of the Pb isotope data shows that Pb isotopes cannot effectively distinguish the role of the Yangtze Craton basement from that of the NCC basement with regard to the source and generation of magmas, at least for southeastern NCC. The age data suggest that the protoliths of the granulites or amphibolites in the Wuhe Complex were most likely generated in Neoarchean and that these rocks were subjected to Paleoproterozoic (1.8–1.9 Ga high-pressure granulite facies metamorphism. This study also shows that the Precambrian metamorphic basement in the southeastern margin of the NCC might have formed in a tectonic setting characterized by a late Neoarchean active continental margin.

  1. Masculinity at the margins

    Jensen, Sune Qvotrup


    This article analyses how young marginalized ethnic minority men in Denmark react to the othering they are subject to in the media as well as in the social arenas of every day life. The article is based on theoretically informed ethnographic fieldwork among such young men as well as interviews an...

  2. From Borders to Margins

    Parker, Noel


    upon Deleuze's philosophy to set out an ontology in which the continual reformulation of entities in play in ‘post-international' society can be grasped.  This entails a strategic shift from speaking about the ‘borders' between sovereign states to referring instead to the ‘margins' between a plethora...

  3. Marginally Deformed Starobinsky Gravity

    Codello, A.; Joergensen, J.; Sannino, Francesco


    We show that quantum-induced marginal deformations of the Starobinsky gravitational action of the form $R^{2(1 -\\alpha)}$, with $R$ the Ricci scalar and $\\alpha$ a positive parameter, smaller than one half, can account for the recent experimental observations by BICEP2 of primordial tensor modes....

  4. "We call ourselves marginalized"

    Jørgensen, Nanna Jordt


    In recent decades, indigenous knowledge has been added to the environmental education agenda in an attempt to address the marginalization of non-western perspectives. While these efforts are necessary, the debate is often framed in terms of a discourse of victimization that overlooks the agency o...

  5. Unraveling the tectonic evolution of a Neoproterozoic-Cambrian active margin in the Ribeira Orogen (Se Brazil): U-Pb and Lu-Hf provenance data

    Fernandes, Gabriel Lamounier de F. [Servico Geologico do Estado do Rio de Janeiro (DRM-RJ), Niteroi, RJ (Brazil); Schmitt, Renata; Bongiolo, Everton M.; Mendes, Julio [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Basei, Miguel S. [Universidade de Sao Paulo (USP), SP (Brazil)


    Full text: The Neoproterozoic-Ordovician Central Ribeira Orogen, in SE Brazil, presents two contrasting tectonic domains in its southern portion: (a) The Arc Domain constituted of Neoproterozoic to Paleozoic magmatic rocks and low P-high T metamorphic para (Sao Fidelis Group) - and ortho- derived units (in Oriental Terrane); and (b) The Basement Domain, constituted of a Paleoproterozoic and Neoproterozoic medium P-high T metamorphic para (Palmital-Buzios Succession)- and ortho-derived units (in Cabo Frio Tectonic Domain). Our work focuses on paraderived rocks sequences from both domains. The provenance analysis using U-Pb and Lu-Hf in zircon grains is presented here as an effective tool to unravel the paleogeography and nature of the pre-collisional sedimentary basins. We performed 505 analyses (U-Pb) on detrital zircon grains and some metamorphic overgrowths from six paragneiss samples. Besides, 141 analyses (Lu-Hf) in six samples only on the detrital zircon grains domains. All samples present a main peak from Neoproterozoic sources (750-570 Ma) and the other minor peak in the Stenian/Tonian periods (1200-850Ma), this indicate an orogenic contribution for this basin. Scarce register from the Mesoproterozoic and two peaks in the Archean/Paleoproterozoic (2.6 and 1.9 Ga) are recognized as a contribution from an ancient continent. The Lu-Hf data reveals a juvenile source for the detrital zircon grains from Buzios Succession while Palmital and Sao Fidelis Group units show a main crustal signature for their detrital zircon population. Based on the U-Pb and Lu-Hf data presented here, plus petrological data, geological correlations, and compilation of data from literature, we propose a tectonic model for the origin of para-derived rocks from the eastern part of the Ribeira Orogen. Starting with an extensional environment of ca. 600 Ma in a back-arc basin (Buzios succession deposition) and continuing as an active margin between 570 and 550 Ma in the fore-arc and prism

  6. Middle Triassic magma mixing in an active continental margin: Evidence from mafic enclaves and host granites from the Dewulu pluton in West Qinling, central China

    Huang, X.; Mo, X.; Yu, X.


    The Qinling-Dabie-Sulu orogen was formed through the collision of the North and South China blocks, but the precise timing of the closure of the Paleo-Tethys ocean between the two blocks remains debated. Large volumes of Triassic granites associated with mafic microgranular enclaves (MMEs) were emplaced in the Qinling terrane. This paper presents field observations, petrography, geochronology and geochemistry of the MMEs and their host granites from the Dewulu pluton in West Qinling. The host rocks comprise granodiorite and granodioritic porphyry, and the The MMEs range in composition from gabbroic diorite to diorite. Zircon LA-ICP-MS U-Pb ages suggest that the granites and MMEs were coeval at ca. 245 Ma. The granites are relatively enriched in LILE and depleted in HFSE, and have evolved Sr-Nd-Pb and zircon Hf isotopic compositions [initial 87Sr/86Sr = 0.7070-0.7076, ɛNd(t) = -7.5 to -6.8, ɛHf(t) = -8.2 to -4.2], indicative of an origin from the amphibolitic lower crust. The near-primitive gabbro-dioritic MMEs bear a remarkable geochemical resemblance to the high-magnesium andesite (HMA), such as moderate SiO2 (~55 wt.%), low FeOT/MgO (~0.75), high Cr (268-308 ppm) and MgO (8.58-8.77 wt.%) with Mg# of ~70. Additionally, they exhibit lower initial 87Sr/86Sr, higher ɛNd(t) and ɛHf(t), and more radiogenic Pb isotopes than the dioritic MMEs which share similar isotopic compositions with the granites. These features, together with the presence of the specific minerals in the MMEs (e.g., felsic xenocrysts and acicular apatite), point to mixing process between the lower crust-derived magmas and the melts produced by the reaction of the subducting sediment-derived components and the overlying mantle. Taking into account the regional occurrence of synchronous plutonic-volcanic complexes (250-234 Ma) ranging from basaltic to granitic variants, we suggest that the Dewulu pluton formed in an active continental margin in response to the local extension triggered by the

  7. Late Mesozoic-Cenozoic sedimentary basins of active continental margin of Southeast Russia: palaeography, tectonics, and coal-oil-gas presence

    Kirillova, G.L. [Russian Academy of Sciences, Khabarovsk (Russian Federation). Institute of Tectonics and Geophysics


    Various settings took place during the Late Mesozoic: divergent, convergent, collisional, and transform. After mid-Jurassic collision of the Siberian and Chinese cratons, a latitudinal system of post-collision troughs developed along the Mongol-Okhotsk suture (the Uda, Torom basins and others), filled with terrigenous coal-bearing molasse. The dispersion of Pangea, creation of oceans during the Late Jurassic is correlated to the emergence of the East Asian submeridional rift system with volcano-terrigenous coal-bearing deposits (the Amur-Zeya basin). At that time, to the east there existed an Andean-type continental margin. Foreland (Upper Bureya, Partizansk, and Razdolny) and flexural (Sangjiang-Middle Amur) basins were formed along the margin of the rigid massifs during the Late Jurassic to Berriasian. During the Valanginian-mid-Albian an oblique subduction of the lzanagi plate beneath the Asian continent occurred, producing a transform margin type, considerable sinistral strike slip displacements, and formation of pull-apart basins filled with turbidites (the Sangjiang- Middle Amur basin). The Aptian is characterized by plate reorganization and formation of epioceanic island arcs, fore-arc and back-are basins in Sakhalin and the Sikhote-Alin (the Alchan and Sangjiang-Middle Amur basins), filled with volcanoclastics. During the mid-Albian a series of terranes accreted to the Asian continental margin. By the end of the Albian, the East Asian marginal volcanic belt began to form due to the subduction of the Kula plate beneath the Asian continent. During the Cenomanian-Coniacian shallow marine coarse clastics accumulated in the fore-arc basins, which were followed by continental deposits in the Santonian-Campanian. From the Coniacian to the Maastrichtian, a thermal subsidence started in rift basins, and continental oil-bearing clastics accumulated (the Amur-Zeya basin). Widespread elevation and denudation were dominant during the Maastrichtian. This is evidenced by

  8. Late Mesozoic-Cenozoic sedimentary basins of active continental margin of Southeast Russia: Paleogeography, tectonics, and coal-oil-gas presence

    Kirillova, G.L. [Russian Academy of Science, Khabarovsk (Russian Federation). Far Eastern Branch


    After mid-Jurassic collision of the Siberian and Chinese cratons. a latitudinal system of post-collision troughs developed along the Mongol-Okhotsk suture, filled with terrigenous coal-bearing molasse. The dispersion of Pangea and creation of oceans during the Late Jurassic are correlated to the emergence of the East Asian submeridional rift system with volcano-terrigenous coal-bearing deposits. Foreland and flexural basins were formed along the margin of the rigid massifs during the Late Jurassic to Berriasian. During the Valanginian-mid-Albian an oblique subduction of the Izanagi plate beneath the Asian continent occurred, producing a transform margin type, considerable sinistral strike slip displacements, and formation of pull-apart basins filled with turbidites. The Aptian is characterized by plate reorganization and formation of epioceanic island arcs, fore-arc and back-arc basins in Sakhalin and the Sikhote-Alin, filled with volcanoclastics. By the end of the Albian, the East Asian marginal volcanic belt began to form due to the subduction of the Kula plate beneath the Asian continent. During the Cenomanian-Coniacian shallow marine coarse clastics accumulated in the fore-arc basins, which were followed by continental deposits in the Santonian-Campanian. From the Coniacian to the Maastrichtian, a thermal subsidence started in rift basins, and continental oil-bearing clastics accumulated. Widespread elevation and denudation were dominant during the Maastrichtian. This is evidenced by thick sediments accumulated in the Western Sakhalin fore-arc basin. During the Cenozoic, an extensive rift belt made up of a system of grabens, which were filled with lacustrine-alluvial coal-and oil-bearing deposits, developed along the East Asian margin.

  9. Geochemical characterization of two distinctive systems with evidence of chemosynthetic activity, explored at the SE Pacific margin off Chile (46°S and 33°S)

    Muñoz, Práxedes; Cárdenas, Lissette J.; Garbe-Schönberg, Dieter; Sellanes, Javier; Dezileau, Laurent; Melville, Ives; Mendes, Stephanie D.


    This study presents the geochemical composition of superficial sediment under oxic and suboxic bottom water conditions along the Chilean continental margin (SE Pacific), where evidence for benthic chemosynthetic activity associated with diffuse seeping of chemically reduced fluids has been reported. The exploration was carried out at: (1) the Chilean Triple Junction (CTJ), at a water depth of ∼2900 m, with the additional indication of hydrothermal activity near a methane-rich cold-seep area (46°S) (German et al., 2010); and (2) the El Quisco methane seep site (EQSS), at ∼340 m water depth (33°S) (Melo et al., 2007; Krylova et al., 2014). While the deeper CTJ is located within an oxic environment (dissolved oxygen in the bottom waters: 164 μM), the shallower EQSS lies within a suboxic environment (dissolved oxygen in bottom water: 23 μM), located within the lower limit of the SE Pacific oxygen minimum zone (OMZ). Pore water from short cores was analyzed for dissolved major, minor, and trace elements (Cl, Na, Mg, K, Ca, Sr, Si, B, P, Ba, Pb, Mn, Fe, Cd, U, and Mo), δ13DIC, sulfide, sulfate, and methane. The solid sediment fraction was likewise analyzed for total organic carbon (TOC), metals, and redox potential. Elevated sediment temperatures were found in superficial sediments (5-13 °C) at the CTJ site, which could be due to warm fluids associated with the proximity of the ridge, where hydrothermal vents may occur. Reduced fluids were also present here, indicated by higher Mn fluxes toward the water column even in oxidized sediments (RPD > 8 cm), which contrasted with the lower fluxes in reduced sediments of the EQSS site (RPD ∼ 2 cm). 13C-depleted DIC, anomalously low pore water Cl (∼15 ppb), and low concentrations of other major elements may be the result of dilution by fluid seeping and precipitation of major elements, producing authigenic enrichment (Ca, Mg, Sr). The fluid could also: (a) be diluted by pure water produced during methane hydrate

  10. Masculinity at the margins

    Jensen, Sune Qvotrup


    of critique although in a masculinist way. These reactions to othering represent a challenge to researchers interested in intersectionality and gender, because gender is reproduced as a hierarchical form of social differentiation at the same time as racism is both reproduced and resisted.......This article analyses how young marginalized ethnic minority men in Denmark react to the othering they are subject to in the media as well as in the social arenas of every day life. The article is based on theoretically informed ethnographic fieldwork among such young men as well as interviews...... and other types of material. Taking the concepts of othering, intersectionality and marginality as point of departure the article analyses how these young men experience othering and how they react to it. One type of reaction, described as stylization, relies on accentuating the latently positive symbolic...

  11. The 2006 Bahía Asunción Earthquake Swarm: Seismic Evidence of Active Deformation Along the Western Margin of Baja California Sur, Mexico

    Munguía, Luis; Mayer, Sergio; Aguirre, Alfredo; Méndez, Ignacio; González-Escobar, Mario; Luna, Manuel


    The study of the Bahía Asunción earthquake swarm is important for two reasons. First, the earthquakes are clear evidence of present activity along the zone of deformation on the Pacific margin of Baja California. The swarm, with earthquakes of magnitude M w of up to 5.0, occurred on the coastline of the peninsula, showing that the Tosco-Abreojos zone of deformation is wider than previously thought. Second, the larger earthquakes in the swarm caused some damage and much concern in Bahía Asunción, a small town located in the zone of epicenters. We relocated the larger earthquakes with regional and/or local seismic data. Our results put the earthquake sources below the urban area of Bahía Asunción, at 40-50 km to the north of the teleseismically determined epicenters. In addition, these new locations are in the area of epicenters of many smaller events that were located with data from local temporary stations. This area trends in an E-W direction and has dimensions of approximately 15 km by 10 km. Most earthquakes had sources at depths that are between 4 and 9 km. A composite focal mechanism for the smaller earthquakes indicated right-lateral strike-slip motion and pure-normal faulting occurred during this swarm. Interestingly, the ANSS earthquake catalog of the United States Geological Survey (USGS) reported each one of these faulting styles for two large events of the swarm, with one of these earthquakes occurring 2 days before the other one. We associate the earthquake with strike-slip mechanism with the San Roque Fault, and the earthquake with the normal faulting style with the Asunción Fault. However, there is need of further study to verify this possible relation between the faults and the earthquakes. In addition, we recorded peak accelerations of up to 0.63 g with an accelerometer installed in Bahía Asunción. At this site, an earthquake of M w 4.9 produced those high values at a distance of 4.1 km. We also used the acceleration dataset from this site

  12. New geochemical and geochronological data of early Cambrian of (SW Iberia): Calc-alkaline magmatism in the transition from active to passive continental margin in North Gondwana

    Sanchez-Garcia, Teresa; Pereira, M. Francisco; Bellido, Felix; Chichorro, Martim; Silva, J. Brandao; Valverde-Vaquero, Pablo; Pin, Christian; Solá, Rita


    The Ossa-Morena Zone (SW Iberia) displays a well-preserved record of the history of the northern Gondwana margin in Late Ediacaran-Early Cambrian times. This period of time is marked by the late-stage evolution of the Cadomian magmatic arc and related back-arc basins (c. 590-545 Ma), and the onset of rifting and widespread magmatism (c. 530-500 Ma) that led to the opening of the Rheic Ocean. Here we present new geochemical and geochronological data on some Cambrian granitoids of Ossa-Morena ...

  13. Preface: Biogeochemistry–ecosystem interaction on changing continental margins in the Anthropocene

    Liu, K-K.; Emeis, K.-C.; Levin, L.A.; Naqvi, S.W.A.; Roman, M.

    of the margin to marginal seas, continental shelves and slopes on the seaward side of the margin. Most importantly many case studies illustrate how human activities on land can impact far reaches of the margin. On the other hand, climate change and oscillations...

  14. Plate Margin Deformation and Active Tectonics Along the Northern Edge of the Yakutat Terrane in the Saint Elias Orogen, Alaska and Yukon, Canada

    Bruhn, Ronald L.; Sauber, Jeanne; Cotton, Michele M.; Pavlis, Terry L.; Burgess, Evan; Ruppert, Natalia; Forster, Richard R.


    The northwest directed motion of the Pacific plate is accompanied by migration and collision of the Yakutat terrane into the cusp of southern Alaska. The nature and magnitude of accretion and translation on upper crustal faults and folds is poorly constrained, however, due to pervasive glaciation. In this study we used high-resolution topography, geodetic imaging, seismic, and geologic data to advance understanding of the transition from strike-slip motion on the Fairweather fault to plate margin deformation on the Bagley fault, which cuts through the upper plate of the collisional suture above the subduction megathrust. The Fairweather fault terminates by oblique-extensional splay faulting within a structural syntaxis, allowing rapid tectonic upwelling of rocks driven by thrust faulting and crustal contraction. Plate motion is partly transferred from the Fairweather to the Bagley fault, which extends 125 km farther west as a dextral shear zone that is partly reactivated by reverse faulting. The Bagley fault dips steeply through the upper plate to intersect the subduction megathrust at depth, forming a narrow fault-bounded crustal sliver in the obliquely convergent plate margin. Since . 20 Ma the Bagley fault has accommodated more than 50 km of dextral shearing and several kilometers of reverse motion along its southern flank during terrane accretion. The fault is considered capable of generating earthquakes because it is linked to faults that generated large historic earthquakes, suitably oriented for reactivation in the contemporary stress field, and locally marked by seismicity. The fault may generate earthquakes of Mw <= 7.5.

  15. Iberian Atlantic Margins Group investigates deep structure of ocean margins

    The Iberian Atlantic Margins Group; Banda, Enric; Torne, Montserrat

    With recent seismic reflection data in hand, investigators for the Iberian Atlantic Margins project are preparing images of the deep continental and oceanic margins of Iberia. In 1993, the IAM group collected near vertical incidence seismic reflection data over a total distance of 3500 km along the North and Western Iberian Margins, Gorringe Bank Region and Gulf of Cadiz (Figure 1). When combined with data on the conjugate margin off Canada, details of the Iberian margin's deep structure should aid in distinguishing rift models and improve understanding of the processes governing the formation of margins.The North Iberian passive continental margin was formed during a Permian to Triassic phase of extension and matured during the early Cretaceous by rotation of the Iberian Peninsula with respect to Eurasia. From the late Cretaceous to the early Oligocene period, Iberia rotated in a counterclockwise direction around an axis located west of Lisbon. The plate boundary between Iberia and Eurasia, which lies along the Pyrenees, follows the north Spanish marginal trough, trends obliquely in the direction of the fossil Bay of Biscay triple junction, and continues along the Azores-Biscay Rise [Sibuet et al., 1994]. Following the NE-SW convergence of Iberia and Eurasia, the reactivation of the North Iberian continental margin resulted in the formation of a marginal trough and accretionary prism [Boillot et al., 1971].

  16. Marginally Stable Nuclear Burning

    Strohmayer, Tod E.; Altamirano, D.


    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high-inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi-periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  17. The marginal costs of climate changing emissions

    Tol, R.S.J.; Downing, T.E.


    This paper presents the marginal costs of the emissions of a selected number of radiatively-active gases, three uniformly-mixed gases – carbon dioxide, methane, nitrous oxide – and two region-specific gases – nitrogen (from aircraft) and sulphur, which influence ozone and sulphate aerosol concentrat

  18. Gaussian quantum marginal problem

    Eisert, J; Sanders, B C; Tyc, T


    The quantum marginal problem asks what local spectra are consistent with a given state of a composite quantum system. This setting, also referred to as the question of the compatibility of local spectra, has several applications in quantum information theory. Here, we introduce the analogue of this statement for Gaussian states for any number of modes, and solve it in generality, for pure and mixed states, both concerning necessary and sufficient conditions. Formally, our result can be viewed as an analogue of the Sing-Thompson Theorem (respectively Horn's Lemma), characterizing the relationship between main diagonal elements and singular values of a complex matrix: We find necessary and sufficient conditions for vectors (d1, ..., dn) and (c1, ..., cn) to be the symplectic eigenvalues and symplectic main diagonal elements of a strictly positive real matrix, respectively. More physically speaking, this result determines what local temperatures or entropies are consistent with a pure or mixed Gaussian state of ...

  19. Pathogenesis of splenic marginal zone lymphoma

    Ming-Qing Du


    Full Text Available Splenic marginal zone lymphoma (SMZL is a distinct low grade B-cell lymphoma with an immunophenotype similar to that of splenic marginal zone B-cells. Like the normal splenic marginal zone B-cells, SMZLs also show variable features in somatic mutations of their rearranged immunoglobulin genes, with ∼90% of cases harbouring somatic mutations but at remarkably variable degrees, suggesting that SMZL may have multiple cell of origins, deriving from the heterogeneous B-cells of the splenic marginal zone. Notably, ∼30% of SMZLs show biased usage of IGHV1-2*04, with the expressed BCR being potentially polyreactive to autoantigens. Recent exome and targeted sequencing studies have identified a wide spectrum of somatic mutations in SMZL with the recurrent mutations targeting multiple signalling pathways that govern the development of splenic marginal zone B-cells. These recurrent mutations occur in KLF2 (20–42%, NOTCH2 (6.5–25%, NF-κB (CARD11 ∼7%, IKBKB ∼7%, TNFAIP3 7–13%, TRAF3 5%, BIRC3 6.3% and TLR (MYD88 5–13% signalling pathways. Interestingly, the majority of SMZL with KLF2 mutation have both 7q32 deletion and IGHV1-2 rearrangement, and these cases also have additional mutations in NOTCH2, or TNFAIP3, or TRAF3. There is a potential oncogenic cooperation among concurrent genetic changes, for example between the IGHV1-2 expressing BCR and KLF2 mutation in activation of the canonical NF-κB pathway, and between KLF2 and TRAF3 mutations in activation of the non-canonical NF-κB pathway. These novel genetic findings have provided considerable insights into the pathogenesis of SMZL and will stimulate the research in both normal and malignant marginal zone B-cells.

  20. 基于平均期望间隔的多标签分类主动学习方法%Active Learning Method for Multi-label Classification Based on Average Expectation Margin

    刘端阳; 邱卫杰


    Aiming at the problems that active learning in multi-label classification is slowly, this paper proposes an improved method for multi-label classification which based on average expectation margin. The method by calculating Support Vector Machine(SVM) expectation margin as the selection criteria. Experimental results show that method proposed in this paper outperforms than other active learning strategy based on decision value and posterior probability strategy in terms of classification accuracy or Hamming Loss or Coverage. It can evaluate the unlabeled sample more appropriate, increase the classification accuracy and classification rate more efficient.%针对多标签主动学习速度较慢的问题,提出一种基于平均期望间隔的多标签分类的主动学习方法.计算支持向量机分类器中的期望rid隔,并将其作为样本选择标准.实验结果表明,该方法在分类精度、Hamming Loss、Coverage等评价标准上优于基于决策值和后验概率等主动学习策略,能更好地评价未标记样本,有效提高分类精度和速度.

  1. Changes in soil particulate organic matter, microbial biomass, and activity following afforestation of marginal agricultural lands in a semi-arid area of northeast China.

    Mao, Rong; Zeng, De-Hui


    Afforestation of agricultural lands has been one of the major land use changes in China in recent decades. To better understand the effect of such land use change on soil quality, we investigated selected soil physical, chemical and microbial properties (0-15 cm depth) in marginal agricultural land and a chronosequence of poplar (Populus euramericana cv. 'N3016') plantations (5-, 10-, 15- and 20-years old) in a semi-arid area of Northeast China. Soil bulk density significantly declined after conversion of agricultural lands to poplar plantations. Soil total organic carbon (TOC) and nitrogen (TN) concentrations, microbial biomass C (MBC) and potential N mineralization rate (PNM) decreased initially following afforestation of agricultural lands, and then increased with stand development. However, soil metabolic quotient (qCO(2)) exhibited a reverse trend. In addition, soil particulate organic matter C (POM-C) and N (POM-N) concentrations showed no significant changes in the first 10 years following afforestation, and then increased with stand age. These findings demonstrated that soil quality declined initially following afforestation of agricultural lands in semi-arid regions, and then recovered with stand development. Following 15 years of afforestation, many soil quality parameters recovered to the values found in agricultural land. We propose that change in soil quality with stand age should be considered in determining optimum rotation length of plantations and best management practices for afforestation programs.

  2. Becoming Marginalized in a Middle School Physical Education Class.

    Smith, Barbara Tyree; Goc-Karp, Grace

    This study examined the effects of social competence, group formation, and group behavior on the marginalization of students in a 7th-grade physical education setting. Marginalized students are defined as those in the class, but not "of" the class. In addition, factors such as individual and team activity and teacher expectations help to…

  3. Classification of remote sensing image based on active learning using committee and soft margin%基于软间隔委员会投票主动学习的遥感影像分类

    程玉虎; 汪婵; 王雪松; 孙伟芳


    Aiming at the characteristics of remote sensing images having large scale of unlabeled samples,an active learning algorithm was adopted to select the most valuable samples that are beneficial for the improvement of classification performance from unlabeled samples.These selected samples were added into labeled samples and participate in the learning of classifier.In this way,overmuch manual intervention can be avoided and the amount of labeled samples can be decreased.Because the traditional active learning algorithm using committee was difficult to deal with noise or linear inseparable data,an active learning algorithm using committee and soft margin was proposed by adding a slack item based on sample distribution to a hard margin which can weaken the influence of hard margin on classification of noise data.The simulation results on remote sensing image show that the proposed active learning algorithm can obtain higher classification accuracy with little training samples.%针对遥感影像数据具有大量未标记样本的特性,采用主动学习方法从未标记样本中,挑选出最有利于改善遥感影像分类性能的样本添加到已标记样本中进行学习,以有效避免过多的人工干预,减少标记样本数量.进一步,针对传统基于委员会投票主动学习难以处理噪声及线性不可分数据的问题,提出基于软间隔的委员会投票主动学习方法,对样本间隔添加考虑样本分布的松弛项,以弱化硬间隔对噪声数据分类的影响.遥感影像数据集上的仿真结果表明,所提算法能够使用较少的训练样本来获得较高的分类精度.

  4. Comparative biogeochemistry-ecosystem-human interactions on dynamic continental margins

    Levin, Lisa A.; Liu, Kon-Kee; Emeis, Kay-Christian; Breitburg, Denise L.; Cloern, James; Deutsch, Curtis; Giani, Michele; Goffart, Anne; Hofmann, Eileen E.; Lachkar, Zouhair; Limburg, Karin; Liu, Su-Mei; Montes, Enrique; Naqvi, Wajih; Ragueneau, Olivier; Rabouille, Christophe; Sarkar, Santosh Kumar; Swaney, Dennis P.; Wassman, Paul; Wishner, Karen F.


    The ocean’s continental margins face strong and rapid change, forced by a combination of direct human activity, anthropogenic CO2-induced climate change, and natural variability. Stimulated by discussions in Goa, India at the IMBER IMBIZO III, we (1) provide an overview of the drivers of biogeochemical variation and change on margins, (2) compare temporal trends in hydrographic and biogeochemical data across different margins (3) review ecosystem responses to these changes, (4) highlight the importance of margin time series for detecting and attributing change and (5) examine societal responses to changing margin biogeochemistry and ecosystems. We synthesize information over a wide range of margin settings in order to identify the commonalities and distinctions among continental margin ecosystems. Key drivers of biogeochemical variation include long-term climate cycles, CO2-induced warming, acidification, and deoxygenation, as well as sea level rise, eutrophication, hydrologic and water cycle alteration, changing land use, fishing, and species invasion. Ecosystem responses are complex and impact major margin services including primary production, fisheries production, nutrient cycling, shoreline protection, chemical buffering, and biodiversity. Despite regional differences, the societal consequences of these changes are unarguably large and mandate coherent actions to reduce, mitigate and adapt to multiple stressors on continental margins.

  5. An information criterion for marginal structural models.

    Platt, Robert W; Brookhart, M Alan; Cole, Stephen R; Westreich, Daniel; Schisterman, Enrique F


    Marginal structural models were developed as a semiparametric alternative to the G-computation formula to estimate causal effects of exposures. In practice, these models are often specified using parametric regression models. As such, the usual conventions regarding regression model specification apply. This paper outlines strategies for marginal structural model specification and considerations for the functional form of the exposure metric in the final structural model. We propose a quasi-likelihood information criterion adapted from use in generalized estimating equations. We evaluate the properties of our proposed information criterion using a limited simulation study. We illustrate our approach using two empirical examples. In the first example, we use data from a randomized breastfeeding promotion trial to estimate the effect of breastfeeding duration on infant weight at 1 year. In the second example, we use data from two prospective cohorts studies to estimate the effect of highly active antiretroviral therapy on CD4 count in an observational cohort of HIV-infected men and women. The marginal structural model specified should reflect the scientific question being addressed but can also assist in exploration of other plausible and closely related questions. In marginal structural models, as in any regression setting, correct inference depends on correct model specification. Our proposed information criterion provides a formal method for comparing model fit for different specifications.

  6. Estimating Marginal Returns to Education

    Carneiro, Pedro; Heckman, James J.; Vytlacil, Edward


    This paper estimates marginal returns to college for individuals induced to enroll in college by different marginal policy changes. The recent instrumental variables literature seeks to estimate this parameter, but in general it does so only under strong assumptions that are tested and found wanting. We show how to utilize economic theory and local instrumental variables estimators to estimate the effect of marginal policy changes. Our empirical analysis shows that returns are higher for individuals with values of unobservables that make them more likely to attend college. We contrast our estimates with IV estimates of the return to schooling. PMID:25110355

  7. Marginal Solutions for the Superstring

    Erler, Theodore


    We construct a class of analytic solutions of WZW-type open superstring field theory describing marginal deformations of a reference D-brane background. The deformations we consider are generated by on-shell vertex operators with vanishing operator products. The superstring solution exhibits an intriguing duality with the corresponding marginal solution of the {\\it bosonic} string. In particular, the superstring problem is ``dual'' to the problem of re-expressing the bosonic marginal solution in pure gauge form. This represents the first nonsingular analytic solution of open superstring field theory.

  8. Comparative biogeochemistry–ecosystem–human interactions on dynamic continental margins..

    Levin, L.A.; Liu, K-K.; Emeis, K.-C.; Breitburg, D.L.; Cloern, J.; Deutsch, C.; Giani, M.; Goffart, A.; Hofmann, E.E.; Lachkar, Z.; Limburg, K.; Liu, Su-Mei; Montes, E.; Naqvi, S.W.A.; Ragueneau, O.; Rabouille, C.; Sarkar, S.K.; Swaney, D.P.; Wassman, P.; Wishner, K.F.

    The oceans' continental margins face strong and rapid change, forced by a combination of direct human activity, anthropogenic CO2-induced climate change, and natural variability. Stimulated by discussions in Goa, India at the IMBER IMBIZO III, we (1...

  9. Mining their own Business in the Margins

    Jensen, Lars

    Mining has long been established in Australian public discourse as an activity that has driven the Australian economy, and guaranteed Australia against the economic ills of the rest of the West. Or put slightly differently, the positive spin on mining in public discourse and the financial market,...... of speaking about margins/marginalisation in relation to the mining industry, that is, as something conducted beyond the horizon, something which defines the horizon - and as a process through which remoteness defines the (national) self....

  10. Constraints of gas venting activity for the interstitial water geochemistry at the shallow gas hydrate site, eastern margin of the Japan Sea; results from high resolution time-series fluid sampling by OsmoSampler

    Owari, S.; Tomaru, H.; Matsumoto, R.


    We have conducted ROV researches in the eastern margin of the Japan Sea where active gas venting and outcropping of gas hydrates were observed near the seafloor and have found the strength and location of venting had changed within a few days. These observations indicate the seafloor environments with the shallow gas hydrate system could have changed for short period compared to a geological time scale. We have applied a long-term osmotic fluid sampling system "OsmoSampler" on the active gas hydrate system for one year in order to document how the gas venting and gas hydrate activity have changed the geochemical environments near the seafloor. All the major ion concentrations in the interstitial water show synchronous increase and decrease repeatedly in three to five days, reflecting the incorporation and release of fresh water in gas hydrates in response to the gas concentration change near the sampling site. Dissolved methane concentration increases rapidly and excessively (over several mM) in the first 40 days corresponding to the active gas venting. The increases of methane concentration are often associated with high ion concentration during high water pressure period, indicating excess gas release from shallow gas pockets. Contrarily, enhanced gas hydrate growth may plug the fluid-gas paths in shallow sediment, reducing gas hydrate formation due to the decrease of methane flux. This study was conducted under the commission from AIST as a part of the methane hydrate research project funded by METI (the Ministry of Economy, Trade and Industry, Japan).

  11. Continental margin sedimentation: from sediment transport to sequence stratigraphy

    Nittrouer, Charles A.; Austin, James A.; Field, Michael E.; Kravitz, Joseph H.; Syvitski, James P.M.; Wiberg, Patricia L.; Nittrouer, Charles A.; Austin, James A.; Field, Michael E.; Kravitz, Joseph H.; Syvitski, James P. M.; Wiberg, Patricia L.


    This volume on continental margin sedimentation brings together an expert editorial and contributor team to create a state-of-the-art resource. Taking a global perspective, the book spans a range of timescales and content, ranging from how oceans transport particles, to how thick rock sequences are formed on continental margins. - Summarizes and integrates our understanding of sedimentary processes and strata associated with fluvial dispersal systems on continental shelves and slopes - Explores timescales ranging from particle transport at one extreme, to deep burial at the other - Insights are presented for margins in general, and with focus on a tectonically active margin (northern California) and a passive margin (New Jersey), enabling detailed examination of the intricate relationships between a wide suite of sedimentary processes and their preserved stratigraphy - Includes observational studies which document the processes and strata found on particular margins, in addition to numerical models and laboratory experimentation, which provide a quantitative basis for extrapolation in time and space of insights about continental-margin sedimentation - Provides a research resource for scientists studying modern and ancient margins, and an educational text for advanced students in sedimentology and stratigraphy

  12. Studies on correlation of positive surgical margin with clinicopathological factors and prognoses in breast conserving surgery

    Nishimura, Reiki; Nagao, Kazuharu; Miyayama, Haruhiko [Kumamoto City Hospital (Japan)


    Out of 484 cases with breast conserving surgery between April 1989 and March 1999, surgical procedures of 34 cases were changed to total mastectomy due to positive surgical margins. In this study we evaluated a clinical significance of surgical margin in relation to clinicopathological factors and prognoses. Ninety-nine cases (20.5%) had positive margins that were judged when cancer cells existed within 5 mm from margin. In multivariate analysis of factors for surgical margin, EIC-comedo status, ly, located site, proliferative activity, and age were significant and independent factors. Regarding local recurrence, positive margin, age, ER and proliferative activity were significant factors in multivariate analysis, especially in cases not receiving postoperative radiation therapy. Radiation therapy may be beneficial for patients with positive surgical margin. And patients with breast recurrence alone had significantly higher survival rates. Therefore, it is suggested that surgical margin may not reflect survival, although it is a significant factor for local recurrence. (author)

  13. Marginal selenium status in northern Tasmania.

    Beckett, Jeffrey M; Ball, Madeleine J


    Se plays many important roles in humans. Marginal Se status has been associated with adverse health effects including an increased risk of chronic disease such as cancer. There are few Australian data, but the population of Tasmania, Australia, is potentially at risk of marginal Se status. A cross-sectional study of 498 men and women aged 25-84 years was undertaken to assess the Se status of the northern Tasmanian population. Se status was assessed using dietary estimates and measures of serum Se and glutathione peroxidase (GPx). Mean Se intakes were 77·4 (sd 31·3) and 65·1 (sd 23·7) μg/d for men and women, respectively; 27 % of the subjects consumed less than the Australian/New Zealand estimated average requirement. Mean serum Se concentration was 89·1 (sd 15·1) μg/l; 83 % of the study subjects had serum Se concentrations below 100 μg/l and 60 % had serum Se concentration below 90 μg/l, suggesting that Se status in many subjects was inadequate for maximal GPx activity. This was supported by the positive association between serum Se and serum GPx (P < 0·001), indicating that enzyme activity was limited by Se concentrations. The lowest mean serum Se concentrations were observed in the oldest age ranges; however, the prevalence of marginal Se status was similar across age ranges and did not appear to be influenced by sex or socio-economic status. The prevalence of marginal Se status was high in all sex and age subgroups, suggesting that the northern Tasmanian population could benefit from increasing Se intakes.

  14. 活动大陆边缘花岗岩类演化——以福州复式岩体为例%Evolution of Granitoids in the Active Continental Margin : a Case Study of the Fuzhou Compound Complex

    林清茶; 程雄卫; 张玉泉; 汪方跃


    中国东南部处于扬子地块、印度板块和太平洋板块的中间地区,位于亚洲东部大陆边缘的最南段,是中生代以来欧亚板块与太平洋板块相互作用非常活跃的区域.本文通过对产在活动大陆边缘的福州复式岩体的花岗岩类中的锆石进行LA-ICP-MS U-Pb定年,得到早期的涧田花岗闪长岩、中期的丹阳二长花岗岩一福州钾长花岗岩和晚期的魁歧晶洞碱性花岗岩年龄分别为110Ma、100~107 Ma、95 Ma,属于燕山晚期,相当于早白垩世中晚期.说明产在活动大陆边缘的福州复式岩体,从早期的钙碱性Ⅰ型花岗岩,到晚期的碱性A型花岗岩,其侵位时间相应从早白垩世中-晚期到晚白垩世早期.表明福州复式岩体岩浆作用的时间持续了15Ma.%Southeast China, located at the interior part of Yangtze block, Indian plate and Pacific plate and the southmost of the continental margin of Eastern Asian, has been most active region due to interaction between Eurasian plate and Pacific plate since the Mesozoic. LA-ICP-MS U-Pb dating of zircons from the granitoids of the Fuzhou compound complex in the active continental margin yields an age of HOMa for the early Jiantian granodiorite, an age of 100~107 Ma for the mid-stage Dangyang monozonitic granite, and an age of 95 Ma for the late-stage Kuiji alkaline granite. All these data suggest they formed in a Yanshanian epoch, equivalent to mid- ot late Late Cretaceous. These data indicate that the Fuzhou compound complex evolved from early calci-alkaline I-type granite to late alkaline A-type granite, and correspondingly, emplacement lasted from mid- and late Early Cretaceous to early Late Cretaceous. Our research shows that magmatism of the Fuzhou compound complex had been active for at least 15 Ma.

  15. Maximum margin Bayesian network classifiers.

    Pernkopf, Franz; Wohlmayr, Michael; Tschiatschek, Sebastian


    We present a maximum margin parameter learning algorithm for Bayesian network classifiers using a conjugate gradient (CG) method for optimization. In contrast to previous approaches, we maintain the normalization constraints on the parameters of the Bayesian network during optimization, i.e., the probabilistic interpretation of the model is not lost. This enables us to handle missing features in discriminatively optimized Bayesian networks. In experiments, we compare the classification performance of maximum margin parameter learning to conditional likelihood and maximum likelihood learning approaches. Discriminative parameter learning significantly outperforms generative maximum likelihood estimation for naive Bayes and tree augmented naive Bayes structures on all considered data sets. Furthermore, maximizing the margin dominates the conditional likelihood approach in terms of classification performance in most cases. We provide results for a recently proposed maximum margin optimization approach based on convex relaxation. While the classification results are highly similar, our CG-based optimization is computationally up to orders of magnitude faster. Margin-optimized Bayesian network classifiers achieve classification performance comparable to support vector machines (SVMs) using fewer parameters. Moreover, we show that unanticipated missing feature values during classification can be easily processed by discriminatively optimized Bayesian network classifiers, a case where discriminative classifiers usually require mechanisms to complete unknown feature values in the data first.

  16. Formation and evolution of magma-poor margins, an example of the West Iberia margin

    Perez-Gussinye, Marta; Andres-Martinez, Miguel; Morgan, Jason P.; Ranero, Cesar R.; Reston, Tim


    The West Iberia-Newfoundland (WIM-NF) conjugate margins have been geophysically and geologically surveyed for the last 30 years and have arguably become a paradigm for magma-poor extensional margins. Here we present a coherent picture of the WIM-NF rift to drift evolution that emerges from these observations and numerical modeling, and point out important differences that may exist with other magma-poor margins world-wide. The WIM-NF is characterized by a continental crust that thins asymmetrically and a wide and symmetric continent-ocean transition (COT) interpreted to consist of exhumed and serpentinised mantle with magmatic products increasing oceanward. The architectural evolution of these margins is mainly dominated by cooling under very slow extension velocities (crust that most probably was not extremely weak at the start of rifting. These conditions lead to a system where initially deformation is distributed over a broad area and the upper, lower crust and lithosphere are decoupled. As extension progresses upper, lower, crust and mantle become tightly coupled and deformation localizes due to strengthening and cooling during rifting. Coupling leads to asymmetric asthenospheric uplift and weakening of the hanginwall of the active fault, where a new fault forms. This continued process leads to the formation of an array of sequential faults that dip and become younger oceanward. Here we show that these processes acting in concert: 1) reproduce the margin asymmetry observed at the WIM-NF, 2) explain the fault geometry evolution from planar, to listric to detachment like by having one common Andersonian framework, 3) lead to the symmetric exhumation of mantle with little magmatism, and 4) explain the younging of the syn-rift towards the basin centre and imply that unconformities separating syn- and post-rift may be diachronous and younger towards the ocean. Finally, we show that different lower crustal rheologies lead to different patterns of extension and to an

  17. Energy system analysis of marginal electricity supply in consequential LCA

    Lund, Henrik; Mathiesen, Brian Vad; Christensen, Per


    Background, aim and scope This paper discusses the identification of the environmental consequences of marginal electricity supplies in consequential life cycle assessments (LCA). According to the methodology, environmental characteristics can be examined by identifying affected activities, i...... evaluation of the environmental consequences. Recommendations and perspectives This paper recommends a combination of LCA and ESA as a methodology for identifying a complex set of marginal technologies. The paper also establishes values for Danish marginal electricity production as a yearly average (YAM......) that can be used in future LCA studies involving Danish electricity....

  18. Tectonic Evolution of the Northern Continental Margin of North China Platform in Middle Proterozoic

    Xu Zhongyuan; Liu Zhenghong


    An orogenic belt developed in late middle Proterozoic in the northern margin of North China Plate extends from Inner Mongolia to Western Liaoning Province and Eastern Jilin Province. It is over 2000km long. The orogenic belt was formed by collision between North China Platform and Siberia Platform during the Rodinian Super- Continent period. From sedimentary formation, magmatic activity and crustal tectonic deformation, it is suggested that along the tectonic belt the paleocontinental margin experienced four stages of tectonic evolution in middle Proterozoic, they are: continental margin rift,passive continental margin, active continental margin and collisional orogenic stages.

  19. Onshore-offshore seismic reflection profiling across the southern margin of the Sea of Japan: back-arc opening, shortening and active strike-slip deformation

    Sato, Hiroshi; Ishiyama, Tatsuya; Kato, Naoko; Toda, Shigeru; Kawasaki, Shinji; Fujiwara, Akira; Tanaka, Yasuhisa; Abe, Susumu


    M7-class crustal earthquakes of overlying plate in subduction system have tendency to increase before megathrust earthquake events. Due to stress buildup by the upcoming Nankai Trough megathrust earthquake, SW Japan has being seismically active for last 20 years. In terms of the mitigation of earthquake and tsunami hazards, to construct seismogenic source fault models is first step for evaluating the strong ground motions and height of tsunamis. Since 2013, we performed intense seismic profiling in and around the southern part of the Sea of Japan. In 2016, a 180-km-long onshore -offshore seismic survey was carried out across the volcanic arc and back-arc basins (from Kurayoshi to the Yamato basin). Onshore section, CMP seismic reflection data were collected using four vibroseis trucks and fixed 1150 channel recorders. Offshore part we acquired the seismic reflection data using 1950 cu inch air-guns towing a 4-km-long streamer cable. We performed CMP reflection and refraction tomography analysis. Obtained seismic section portrays compressively deformed rifted continental crust and undeformed oceanic back-arc basin, reflecting the rheological features. These basic structures were formed during the opening of the Sea of Japan in early Miocene. The sub-horizontal Pliocene sediments unconformably cover the folded Miocene sediments. The opening and clock-wise rotation of SW Japan has been terminated at 15 Ma and contacted to the young Shikoku basin along the Nankai trough. Northward motion of Philippine Sea plate (PHS) and the high thermal regime in the Shikoku basin produced the strong resistance along the Nankai trough. The main shortening deformation observed in the seismic section has been formed this tectonic event. After the initiation of the subduction along the Nankai trough, the rate of shortening deformation was decreased and the folded strata were covered by sub-horizontal Pliocene sediments. The thrusting trending parallel to the arc has been continued from

  20. Profit margins in Japanese retailing

    J.C.A. Potjes; A.R. Thurik (Roy)


    textabstractUsing a rich data source, we explain differences and developments in profit margins of medium-sized stores in Japan. We conclude that the protected environment enables the retailer to pass on all operating costs to the customers and to obtain a relatively high basic income. High service

  1. Profit margins in Japanese retailing

    J.C.A. Potjes; A.R. Thurik (Roy)


    textabstractUsing a rich data source, we explain differences and developments in profit margins of medium-sized stores in Japan. We conclude that the protected environment enables the retailer to pass on all operating costs to the customers and to obtain a relatively high basic income. High service

  2. Respiration in ocean margin sediments

    Andersson, J.H.


    The aim of this thesis was the study of respiration in ocean margin sediments and the assessments of tools needed for this purpose. The first study was on the biological pump and global respiration patterns in the deep ocean using an empirical model based on sediment oxygen consumption data. In this

  3. Respiration in ocean margin sediments

    Andersson, J.H.


    The aim of this thesis was the study of respiration in ocean margin sediments and the assessments of tools needed for this purpose. The first study was on the biological pump and global respiration patterns in the deep ocean using an empirical model based on sediment oxygen consumption data.

  4. The role of Variscan to pre-Jurassic active extension in controlling the architecture of the rifted passive margin of Adria: the example of the Canavese Zone (Western Southern Alps, Italy)

    Succo, Andrea; De Caroli, Sara; Centelli, Arianna; Barbero, Edoardo; Balestro, Gianni; Festa, Andrea


    The Canavese Zone, in the Italian Western Southern Alps, represents the remnant of the Jurassic syn-rift stretching, thinning and dismemberment of the distal passive margin of Adria during the opening of the Penninic Ocean (i.e., Northern Alpine Tethys). Our findings, based on detailed geological mapping, structural analysis and stratigraphic and petrographic observations, document however that the inferred hyper-extensional dismemberment of this distal part of the passive margin of Adria, up to seafloor spreading, was favored by the inherited Variscan geometry and crustal architecture of the rifted margin, and by the subsequent Alpine-related strike-slip deformation. The new field data document, in fact, that the limited vertical displacement of syn-extensional (syn-rift) Jurassic faults was ineffective in producing and justifying the crustal thinning observed in the Canavese Zone. The deformation and thinning of the continental basement of Adria are constrained to the late Variscan time by the unconformable overlying of Late Permian deposits. Late Cretaceous-Early Paleocene and Late Cenozoic strike-slip faulting (i.e., Alpine and Insubric tectonic stages) reactivated previously formed faults, leading to the formation of a complex tectonic jigsaw which only partially coincides with the direct product of the Jurassic syn-rift dismemberment of the distal part of the passive margin of Adria. Our new findings document that this dismemberment of the rifted continental margin of Adria did not simply result from the syn-rift Jurassic extension, but was strongly favored by the inheritance of older (Variscan and post-Variscan) tectonic stages, which controlled earlier lithospheric weakness. The formation of rifted continental margins by extension of continental lithosphere leading to seafloor spreading is a complex and still poorly understood component of the plate tectonic cycle. Geological mapping of rifted continental margins may thus provide significant information to

  5. The Margins of Medieval Manuscripts

    Nataša Kavčič


    Full Text Available Shortly after the mid-thirteenth century, various images began to fill the margins in both religious and secular texts. Many factors influenced the emergence of this type of manuscript decoration, but it has generally been attributed to the revived interest in nature and the Gothic inclination for humorous and anecdotic detail. After highlighting other possible reasons for the occurrence of marginal illumination, this paper introduces two manuscripts from the Archiepiscopal Archives in Ljubljana. The manuscripts show numerous facial drawings affixed to some of the letters. This article addresses how to interpret such drawings and stresses that they do not necessarily function as symbolic images or images with any specific didactic value. Quite the opposite, these drawings seem not to have any meaning and are oft en merely indications of an illuminator’s sense of humor. Because of their exaggerated facial expressions, these drawings could be perceived as the true predecessors of modern caricature.

  6. Respiration in ocean margin sediments

    Andersson, J.H.


    The aim of this thesis was the study of respiration in ocean margin sediments and the assessments of tools needed for this purpose. The first study was on the biological pump and global respiration patterns in the deep ocean using an empirical model based on sediment oxygen consumption data. In this thesis the depth dependence of respiration patterns was modelled using a compiled data set of sediment oxygen consumption rates. We showed that the depth relationship can best be described by a do...

  7. Volcanic passive margins: another way to break up continents.

    Geoffroy, L; Burov, E B; Werner, P


    Two major types of passive margins are recognized, i.e. volcanic and non-volcanic, without proposing distinctive mechanisms for their formation. Volcanic passive margins are associated with the extrusion and intrusion of large volumes of magma, predominantly mafic, and represent distinctive features of Larges Igneous Provinces, in which regional fissural volcanism predates localized syn-magmatic break-up of the lithosphere. In contrast with non-volcanic margins, continentward-dipping detachment faults accommodate crustal necking at both conjugate volcanic margins. These faults root on a two-layer deformed ductile crust that appears to be partly of igneous nature. This lower crust is exhumed up to the bottom of the syn-extension extrusives at the outer parts of the margin. Our numerical modelling suggests that strengthening of deep continental crust during early magmatic stages provokes a divergent flow of the ductile lithosphere away from a central continental block, which becomes thinner with time due to the flow-induced mechanical erosion acting at its base. Crustal-scale faults dipping continentward are rooted over this flowing material, thus isolating micro-continents within the future oceanic domain. Pure-shear type deformation affects the bulk lithosphere at VPMs until continental breakup, and the geometry of the margin is closely related to the dynamics of an active and melting mantle.

  8. Margin Requirements and Equity Option Returns

    Hitzemann, Steffen; Hofmann, Michael; Uhrig-Homburg, Marliese

    In equity option markets, traders face margin requirements both for the options themselves and for hedging-related positions in the underlying stock market. We show that these requirements carry a significant margin premium in the cross-section of equity option returns. The sign of the margin pre...

  9. Biomass energy and marginal areas

    Chassany, J.P.


    The aim of this study was to analyze the conditions and effects of a possible development of the biomass energy upgrading in uneconomical or not rentable areas. The physical, social and economical characteristics of these regions (in France) are described; then the different types of biomass are presented (agricultural wastes, energetic cultures, forest and land products and residues, food processing effluents, municipal wastes) as well as the various energy process (production of alcohol, methane, thermochemical processes, vegetable oils). The development and the feasability of these processes in marginal areas are finally analyzed taking into account the accessibility of the biomass and the technical and commercial impacts.

  10. Dynamics of the continental margins


    On 18--20 June 1990, over 70 oceanographers conducting research in the ocean margins of North America attended a workshop in Virginia Beach, Virginia. The purpose of the workshop was to provide the Department of Energy with recommendations for future research on the exchange of energy-related materials between the coastal and interior ocean and the relationship between the ocean margins and global change. The workshop was designed to optimize the interaction of scientists from specific research disciplines (biology, chemistry, physics and geology) as they developed hypotheses, research questions and topics and implementation plans. The participants were given few restraints on the research they proposed other than realistic time and monetary limits. The interdisciplinary structure of the meeting promoted lively discussion and creative research plans. The meeting was divided into four working groups based on lateral, vertical, air/sea and sediment/water processes. Working papers were prepared and distributed before the meeting. During the meeting the groups revised the papers and added recommendations that appear in this report, which was reviewed by an Executive Committee.

  11. Passive margins getting squeezed in the mantle convection vice

    Husson, Laurent; Yamato, Philippe; Becker, Thorsten; Pedoja, Kevin


    Quaternary coastal geomorphology reveals that passive margins underwent wholesale uplift at least during the glacial cycle. In addition, these not-so-passive margins often exhibit long term exhumation and tectonic inversion, which suggest that compression and tectonic shortening could be the mechanism that triggers their overall uplift. We speculate that the compression in the lithosphere gradually increased during the Cenozoic. The many mountain belts at active margins that accompany this event readily witness this increase. Less clear is how that compression increase affects passive margins. In order to address this issue, we design minimalist 2D viscous models to quantify the impact of plate collision on the stress regime. In these models, a sluggish plate is disposed on a less viscous mantle. It is driven by a "mantle conveyor belt" alternatively excited by lateral shear stresses that represent a downwelling on one side, an upwelling on the other side, or both simultaneously. The lateral edges of the plate are either free or fixed, respectively representing the cases of free convergence and collision. In practice, it dramatically changes the upper boundary condition for mantle circulation and subsequently, for the stress field. The flow pattern transiently evolves almost between two end-members, starting from a situation close to a Couette flow to a pattern that looks like a Poiseuille flow with an almost null velocity at the surface (though in the models, the horizontal velocity at the surface is not strictly null, as the lithosphere deforms). In the second case, the lithosphere is highly stressed horizontally and deforms. For an equivalent bulk driving force, compression increases drastically at passive margins if upwellings are active because they push plates towards the collision. Conversely, if only downwellings are activated, compression occurs on one half of the plate and extension on the other half, because only the downwelling is pulling the plate

  12. Ranking production units according to marginal efficiency contribution

    Ghiyasi, Mojtaba; Hougaard, Jens Leth

    League tables associated with various forms of service activities from schools to hospitals illustrate the public need for ranking institutions by their productive performance. We present a new method for ranking production units which is based on each units marginal contribution to the technical...

  13. Clinical Outcomes of Endoscopic Hemostasis in Marginal Ulcer Bleeding.

    Yamasaki, Yasushi; Takenaka, Ryuta; Hori, Keisuke; Takemoto, Koji; Kawano, Seiji; Kawahara, Yoshiro; Fujiki, Shigeatsu; Okada, Hiroyuki


    The usefulness of endoscopy in marginal ulcer bleeding has rarely been studied, and the optimal method for preventing rebleeding is unclear. Here we assessed the efficacy of endoscopy in marginal ulcer bleeding and examined the efficacy of proton pump inhibitors (PPIs) in the prevention of rebleeding. A total of 28 patients with marginal ulcer bleeding (21 men, 7 women; median age 58.5 years) were treated by endoscopy. We analyzed the clinical characteristics, results of endoscopic therapy, characteristics of rebleeding patients, and relation between the use of PPIs and the duration of rebleeding. Sixteen patients had active bleeding. Initial hemostasis was achieved in all patients. There were no procedure-related adverse events. Rebleeding occurred in one patient within the first month and in 7 patients thereafter. There was a significant difference in the rebleeding rate between the patients who received a PPI and those who did not. In a multivariate analysis, the non-use of PPIs was a risk factor for rebleeding (hazard ratio, 6.22). Therapeutic endoscopy is effective in achieving hemostasis from marginal ulcer bleeding. PPIs may prevent rebleeding from marginal ulcers.

  14. Tectonostratigraphic evolution of Cenozoic marginal basin and continental margin successions in the Bone Mountains, Southwest Sulawesi, Indonesia

    van Leeuwen, Theo M.; Susanto, Eko S.; Maryanto, Sigit; Hadiwisastra, Sapri; Sudijono; Muhardjo; Prihardjo


    The Bone Mountains, located in Southwest Sulawesi along the SE margin of Sundaland, are composed of Oligocene to possibly lower Miocene marginal basin successions (Bone Group) that are juxtaposed against continental margin assemblages of Eocene-Miocene age (Salokalupang Group). Three distinct units make up the latter: (i) Middle-Upper Eocene volcaniclastic sediments with volcanic and limestone intercalations in the upper part (Matajang Formation), reflecting a period of arc volcanism and carbonate development along the Sundaland margin; (ii) a well-bedded series of Oligocene calc-arenites (Karopa Formation), deposited in a passive margin environment following cessation of volcanic activity, and (iii) a series of Lower-Middle Miocene sedimentary rocks, in part turbiditic, which interfinger in the upper part with volcaniclastic and volcanic rocks of potassic affinity (Baco Formation), formed in an extensional regime without subduction. The Bone Group consists of MORB-like volcanics, showing weak to moderate subduction signatures (Kalamiseng Formation), and a series of interbedded hemipelagic mudstones and volcanics (Deko Formation). The Deko volcanics are in part subduction-related and in part formed from melting of a basaltic precursor in the overriding crust. We postulate that the Bone Group rocks formed in a transtensional marginal basin bordered by a transform passive margin to the west (Sundaland) and by a newly initiated westerly-dipping subduction zone on its eastern side. Around 14-13 Ma an extensional tectonic event began in SW Sulawesi, characterized by widespread block-faulting and the onset of potassic volcanism. It reached its peak about 1 Ma year later with the juxtaposition of the Bone Group against the Salokalupang Group along a major strike-slip fault (Walanae Fault Zone). The latter group was sliced up in variously-sized fragments, tilted and locally folded. Potassic volcanism continued up to the end of the Pliocene, and locally into the Quaternary.

  15. Natural Gas Venting on the Northern Cascadia Margin

    Scherwath, M.; Riedel, M.; Roemer, M.; Paull, C. K.; Spence, G.; Veloso, M.


    Over the past decades, hundreds of natural gas vents have been observed along the Northern Cascadia Margin in the Northeast Pacific, and we present a summary of these observations from offshore Vancouver Island, BC, Canada. We have gathered observed locations and analyzed original data from published literature as well as research cruises and fishing sonar from various archives. By far the highest accumulation of gas vent locations appear both shallow (100-200 m) and concentrated towards the mouth of the Juan de Fuca Strait, however these observations are naturally biased toward the distribution of the observation footprints. Normalized observations confirm the shallow high concentrations of gas vents but also establish some deeper sections of focused venting activity. We will speculate about the reasons behind the distribution, focus on specific examples, extrapolate for rough margin flux rate ranges and comment on short-comings and future directions for margin-wide gas vent studies.

  16. Ice-Marginal Environments: Geomorphic and Structural Genesis of Marginal Moraines at Mýrdalsjökull

    Krüger, Johannes; Schomacker, A.; Benediktsson, Ívar Örn


    dynamics and different sedimentary and topographic conditions of the forefields. It is intriguing that without having observed the active ice-marginal moraine genesis year by year, most of the resulting moraine ridges now found in the glacier forefield would have been misinterpreted. We review processes...

  17. Chapter 34: Geology and petroleum potential of the rifted margins of the Canada Basin

    Houseknecht, D.W.; Bird, K.J.


    Three sides of the Canada Basin are bordered by high-standing, conjugate rift shoulders of the Chukchi Borderland, Alaska and Canada. The Alaska and Canada margins are mantled with thick, growth-faulted sediment prisms, and the Chukchi Borderland contains only a thin veneer of sediment. The rift-margin strata of Alaska and Canada reflect the tectonics and sediment dispersal systems of adjacent continental regions whereas the Chukchi Borderland was tectonically isolated from these sediment dispersal systems. Along the eastern Alaska-southern Canada margin, termed herein the 'Canning-Mackenzie deformed margin', the rifted margin is deformed by ongoing Brooks Range tectonism. Additional contractional structures occur in a gravity fold belt that may be present along the entire Alaska and Canada margins of the Canada Basin. Source-rock data inboard of the rift shoulders and regional palaeogeographic reconstructions suggest three potential source-rock intervals: Lower Cretaceous (Hauterivian-Albian), Upper Cretaceous (mostly Turonian) and Lower Palaeogene. Burial history modelling indicates favourable timing for generation from all three intervals beneath the Alaska and Canada passive margins, and an active petroleum system has been documented in the Canning-Mackenzie deformed margin. Assessment of undiscovered petroleum resources indicates the greatest potential in the Canning-Mackenzie deformed margin and significant potential in the Canada and Alaska passive margins. ?? 2011 The Geological Society of London.

  18. Closing the North American Carbon Budget: Continental Margin Fluxes Matter!

    Najjar, R.; Benway, H. M.; Siedlecki, S. A.; Boyer, E. W.; Cai, W. J.; Coble, P. G.; Cross, J. N.; Friedrichs, M. A.; Goni, M. A.; Griffith, P. C.; Herrmann, M.; Lohrenz, S. E.; Mathis, J. T.; McKinley, G. A.; Pilskaln, C. H.; Smith, R. A.; Alin, S. R.


    Despite their relatively small surface area, continental margins are regions of intense carbon and nutrient processing, export and exchange, and thus have a significant impact on global biogeochemical cycles. In response to recommendations for regional synthesis and carbon budget estimation for North America put forth in the North American Continental Margins workshop report (Hales et al., 2008), the Ocean Carbon and Biogeochemistry (OCB) Program and North American Carbon Program (NACP) began coordinating a series of collaborative, interdisciplinary Coastal CARbon Synthesis (CCARS) research activities in five coastal regions of North America (Atlantic Coast, Pacific Coast, Gulf of Mexico, Arctic, Laurentian Great Lakes) to improve quantitative assessments of the North American carbon budget. CCARS workshops and collaborative research activities have resulted in the development of regional coastal carbon budgets based on recent literature- and model-based estimates of major carbon fluxes with estimated uncertainties. Numerous peer-reviewed papers and presentations by involved researchers have highlighted these findings and provided more in-depth analyses of processes underlying key carbon fluxes in continental margin systems. As a culminating outcome of these synthesis efforts, a comprehensive science plan highlights key knowledge gaps identified during this synthesis and provides explicit guidance on future research and observing priorities in continental margin systems to help inform future agency investments in continental margins research. This presentation will provide an overview of regional and flux-based (terrestrial inputs, biological transformations, sedimentary processes, atmospheric exchanges, lateral carbon transport) synthesis findings and key recommendations in the science plan, as well as a set of overarching priorities and recommendations on observations and modeling approaches for continental margin systems.

  19. Performance Evaluation of Portfolios with Margin Requirements

    Hui Ding; Zhongbao Zhou; Helu Xiao; Chaoqun Ma; Wenbin Liu


    In financial markets, short sellers will be required to post margin to cover possible losses in case the prices of the risky assets go up. Only a few studies focus on the optimization and performance evaluation of portfolios in the presence of margin requirements. In this paper, we investigate the theoretical foundation of DEA (data envelopment analysis) approach to evaluate the performance of portfolios with margin requirements from a different perspective. Under the mean-variance framework,...

  20. Treatment of Passive Component Reliability in Risk-Informed Safety Margin Characterization FY 2010 Report

    Robert W Youngblood


    The Risk-Informed Safety Margin Characterization (RISMC) pathway is a set of activities defined under the U.S. Department of Energy (DOE) Light Water Reactor Sustainability Program. The overarching objective of RISMC is to support plant life-extension decision-making by providing a state-of-knowledge characterization of safety margins in key systems, structures, and components (SSCs). A technical challenge at the core of this effort is to establish the conceptual and technical feasibility of analyzing safety margin in a risk-informed way, which, unlike conventionally defined deterministic margin analysis, is founded on probabilistic characterizations of SSC performance.

  1. Faster Algorithms for Privately Releasing Marginals

    Thaler, Justin R; Ullman, Jonathan Robert; Vadhan, Salil P.


    We study the problem of releasing $k$-way marginals of a database $D \\in (\\{0,1\\}^d)^n$, while preserving differential privacy. The answer to a $k$-way marginal query is the fraction of $D$'s records $x \\in \\{0,1\\}^d$ with a given value in each of a given set of up to $k$ columns. Marginal queries enable a rich class of statistical analyses of a dataset, and designing efficient algorithms for privately releasing marginal queries has been identified as an important open problem in private data...

  2. Assessment of seismic margin calculation methods

    Kennedy, R.P.; Murray, R.C.; Ravindra, M.K.; Reed, J.W.; Stevenson, J.D.


    Seismic margin review of nuclear power plants requires that the High Confidence of Low Probability of Failure (HCLPF) capacity be calculated for certain components. The candidate methods for calculating the HCLPF capacity as recommended by the Expert Panel on Quantification of Seismic Margins are the Conservative Deterministic Failure Margin (CDFM) method and the Fragility Analysis (FA) method. The present study evaluated these two methods using some representative components in order to provide further guidance in conducting seismic margin reviews. It is concluded that either of the two methods could be used for calculating HCLPF capacities. 21 refs., 9 figs., 6 tabs.

  3. [Resection margins in conservative breast cancer surgery].

    Medina Fernández, Francisco Javier; Ayllón Terán, María Dolores; Lombardo Galera, María Sagrario; Rioja Torres, Pilar; Bascuñana Estudillo, Guillermo; Rufián Peña, Sebastián


    Conservative breast cancer surgery is facing a new problem: the potential tumour involvement of resection margins. This eventuality has been closely and negatively associated with disease-free survival. Various factors may influence the likelihood of margins being affected, mostly related to the characteristics of the tumour, patient or surgical technique. In the last decade, many studies have attempted to find predictive factors for margin involvement. However, it is currently the new techniques used in the study of margins and tumour localisation that are significantly reducing reoperations in conservative breast cancer surgery. Copyright © 2012 AEC. Published by Elsevier Espana. All rights reserved.

  4. On the evaluation of marginal expected shortfall

    Caporin, Massimiliano; Santucci de Magistris, Paolo


    In the analysis of systemic risk, Marginal Expected Shortfall may be considered to evaluate the marginal impact of a single stock on the market Expected Shortfall. These quantities are generally computed using log-returns, in particular when there is also a focus on returns conditional distribution....... In this case, the market log-return is only approximately equal to the weighed sum of equities log-returns. We show that the approximation error is large during turbulent market phases, with a subsequent impact on Marginal Expected Shortfall. We then suggest how to improve the evaluation of Marginal Expected...

  5. Optimizing Surgical Margins in Breast Conservation

    Preya Ananthakrishnan


    Full Text Available Adequate surgical margins in breast-conserving surgery for breast cancer have traditionally been viewed as a predictor of local recurrence rates. There is still no consensus on what constitutes an adequate surgical margin, however it is clear that there is a trade-off between widely clear margins and acceptable cosmesis. Preoperative approaches to plan extent of resection with appropriate margins (in the setting of surgery first as well as after neoadjuvant chemotherapy, include mammography, US, and MRI. Improvements have been made in preoperative lesion localization strategies for surgery, as well as intraoperative specimen assessment, in order to ensure complete removal of imaging findings and facilitate margin clearance. Intraoperative strategies to accurately assess tumor and cavity margins include cavity shave techniques, as well as novel technologies for margin probes. Ablative techniques, including radiofrequency ablation as well as intraoperative radiation, may be used to extend tumor-free margins without resecting additional tissue. Oncoplastic techniques allow for wider resections while maintaining cosmesis and have acceptable local recurrence rates, however often involve surgery on the contralateral breast. As systemic therapy for breast cancer continues to improve, it is unclear what the importance of surgical margins on local control rates will be in the future.

  6. On the Marginal Stability of Glassy Systems

    Yan, Le; Baity-Jesi, Marco; Müller, Markus; Wyart, Matthieu


    In various glassy systems that are out of equilibrium, like spin glasses and granular packings, the dynamics appears to be critical: avalanches involving almost the whole system could happen. A recent conceptual breakthrough argues that such glassy systems sample the ensemble of marginal stable states, which inevitably results into critical dynamics. However, it is unclear how the marginal stability is dynamically guaranteed. We investigate this marginal stability assumption by studying specifically the critical athermal dynamics of the Sherrington-Kirkpatrick model. We discuss how a pseudo-gap in the density distribution of local fields characterizing the marginal stability arises dynamically.

  7. Safety Margins in Older Adults Increase with Improved Control of a Dynamic Object

    Christopher James Hasson


    Full Text Available Older adults face decreasing motor capabilities due to pervasive neuromuscular degradations. As a consequence errors in movement control increase. Thus, older individuals should maintain larger safety margins than younger adults. While this has been shown for object manipulation tasks, several reports on whole-body activities, such as posture and locomotion, however demonstrate age-related reductions in safety margins. This is despite increased costs for control errors, such as a fall. We posit that this paradox could be explained by the dynamic challenge presented by the body or an external object, and that age-related reductions in safety margins are in part due to a decreased ability to control dynamics. To test this conjecture we used a virtual ball-in-cup task that had challenging dynamics, yet afforded an explicit rendering of the physics and safety margin. The hypotheses were: 1 When manipulating an object with challenging dynamics, older adults have smaller safety margins than younger adults. 2 Older adults increase their safety margins with practice. Nine young and 10 healthy older adults practiced moving the virtual ball-in-cup to a target location in exactly two seconds. The accuracy and precision of the timing error quantified skill and the ball energy relative to an escape threshold quantified the safety margin. Compared to the young adults, older adults had increased timing errors, greater variability, and decreased safety margins. With practice, both young and older adults improved their ability to control the object with decreased timing errors and variability, and increased their safety margins. These results suggest that safety margins are related to the ability to control dynamics, and may explain why in tasks with simple dynamics older adults use adequate safety margins, but in more complex tasks, safety margins may be inadequate. Further, the results indicate that task-specific training may improve safety margins in older

  8. The genetics of nodal marginal zone lymphoma.

    Spina, Valeria; Khiabanian, Hossein; Messina, Monica; Monti, Sara; Cascione, Luciano; Bruscaggin, Alessio; Spaccarotella, Elisa; Holmes, Antony B; Arcaini, Luca; Lucioni, Marco; Tabbò, Fabrizio; Zairis, Sakellarios; Diop, Fary; Cerri, Michaela; Chiaretti, Sabina; Marasca, Roberto; Ponzoni, Maurilio; Deaglio, Silvia; Ramponi, Antonio; Tiacci, Enrico; Pasqualucci, Laura; Paulli, Marco; Falini, Brunangelo; Inghirami, Giorgio; Bertoni, Francesco; Foà, Robin; Rabadan, Raul; Gaidano, Gianluca; Rossi, Davide


    Nodal marginal zone lymphoma (NMZL) is a rare, indolent B-cell tumor that is distinguished from splenic marginal zone lymphoma (SMZL) by the different pattern of dissemination. NMZL still lacks distinct markers and remains orphan of specific cancer gene lesions. By combining whole-exome sequencing, targeted sequencing of tumor-related genes, whole-transcriptome sequencing, and high-resolution single nucleotide polymorphism array analysis, we aimed at disclosing the pathways that are molecularly deregulated in NMZL and we compare the molecular profile of NMZL with that of SMZL. These analyses identified a distinctive pattern of nonsilent somatic lesions in NMZL. In 35 NMZL patients, 41 genes were found recurrently affected in ≥3 (9%) cases, including highly prevalent molecular lesions of MLL2 (also known as KMT2D; 34%), PTPRD (20%), NOTCH2 (20%), and KLF2 (17%). Mutations of PTPRD, a receptor-type protein tyrosine phosphatase regulating cell growth, were enriched in NMZL across mature B-cell tumors, functionally caused the loss of the phosphatase activity of PTPRD, and were associated with cell-cycle transcriptional program deregulation and increased proliferation index in NMZL. Although NMZL shared with SMZL a common mutation profile, NMZL harbored PTPRD lesions that were otherwise absent in SMZL. Collectively, these findings provide new insights into the genetics of NMZL, identify PTPRD lesions as a novel marker for this lymphoma across mature B-cell tumors, and support the distinction of NMZL as an independent clinicopathologic entity within the current lymphoma classification. © 2016 by The American Society of Hematology.

  9. Unlocking hidden community assets : Marginal specialization and community resilience of Gypsy-Travelers in the Netherlands

    Salemink, Koen


    Enduring social exclusion has forced Gypsy-Travelers to specialize in marginal economic activities. These marginal specializations build on specific skills, attitudes, and strategies which are valuable for the communities’ overall development. Today’s Gypsy-Traveler communities face a context of

  10. Unlocking hidden community assets : Marginal specialization and community resilience of Gypsy-Travelers in the Netherlands

    Salemink, Koen


    Enduring social exclusion has forced Gypsy-Travelers to specialize in marginal economic activities. These marginal specializations build on specific skills, attitudes, and strategies which are valuable for the communities’ overall development. Today’s Gypsy-Traveler communities face a context of rap

  11. Unlocking hidden community assets : Marginal specialization and community resilience of Gypsy-Travelers in the Netherlands

    Salemink, Koen


    Enduring social exclusion has forced Gypsy-Travelers to specialize in marginal economic activities. These marginal specializations build on specific skills, attitudes, and strategies which are valuable for the communities’ overall development. Today’s Gypsy-Traveler communities face a context of rap

  12. South Atlantic continental margins of Africa: a comparison of the tectonic vs climate interplay on the evolution of equatorial west Africa and SW Africa margins

    Seranne, M; Seranne, Michel; Anka, Zahie


    The comparative review of 2 representative segments of Africa continental margin: the equatorial western Africa and the SW Africa margins, helps in analysing the main controlling factors on their development. Early Cretaceous active rifting S of the Walvis Ridge resulted in the formation of the SW Africa volcanic margin. The non-volcanic rifting N of the Walvis ridge, led to the formation of the equatorial western Africa margin, with thick and extensive, synrift basins. Regressive erosion of SW Africa prominent shoulder uplift accounts for high clastic sedimentation rate in Late Cretaceous - Eocene, while dominant carbonate production on equatorial western Africa shelf suggests little erosion of a low hinterland. The early Oligocene climate change had contrasted response in both margins. Emplacement of the Congo deep-sea fan reflects increased erosion in equatorial Africa, under the influence of wet climate, whereas establishment of an arid climate over SW Africa induced a drastic decrease of denudation, and ...

  13. Values and marginal preferences in international business

    Maseland, Robbert; van Hoorn, Andre


    In a recent paper in this journal, Maseland and van Hoorn argued that values surveys tend to conflate values and marginal preferences. This assertion has been challenged by Brewer and Venaik, who claim that the wording of most survey items does not suggest that these elicit marginal preferences. Thi

  14. Marginal Utility and Convex Indifference Curves.

    Jackson, A.A.


    Reviews discussion of the relationship between marginal utility and indifference curves which has been presented in recent issues of "Economics." Concludes that indifference analysis does not embody the assumptions of marginal utility theory and that there is no simple relationship between these concepts that does not entail unacceptable…

  15. The homogeneous marginal utility of income assumption

    Demuynck, T.


    We develop a test to verify if every agent from a population of heterogeneous consumers has the same marginal utility of income function. This homogeneous marginal utility of income assumption is often (implicitly) used in applied demand studies because it has nice aggregation properties and facilit

  16. Tumor margin detection using optical biopsy techniques

    Zhou, Yan; Liu, Cheng-hui; Li, Jiyou; Li, Zhongwu; Zhou, Lixin; Chen, Ke; Pu, Yang; He, Yong; Zhu, Ke; Li, Qingbo; Alfano, Robert R.


    The aim of this study is to use the Resonance Raman (RR) and fluorescence spectroscopic technique for tumor margin detection with high accuracy based on native molecular fingerprints of breast and gastrointestinal (GI) tissues. This tumor margins detection method utilizes advantages of RR spectroscopic technique in situ and in real-time to diagnose tumor changes providing powerful tools for clinical guiding intraoperative margin assessments and postoperative treatments. The tumor margin detection procedures by RR spectroscopy were taken by scanning lesion from center or around tumor region in ex-vivo to find the changes in cancerous tissues with the rim of normal tissues using the native molecular fingerprints. The specimens used to analyze tumor margins include breast and GI carcinoma and normal tissues. The sharp margin of the tumor was found by the changes of RR spectral peaks within 2 mm distance. The result was verified using fluorescence spectra with 300 nm, 320 nm and 340 nm excitation, in a typical specimen of gastric cancerous tissue within a positive margin in comparison with normal gastric tissues. This study demonstrates the potential of RR and fluorescence spectroscopy as new approaches with labeling free to determine the intraoperative margin assessment.

  17. Heat flow in northwest Pacific marginal seas

    JIANG Lili; LI Guanbao; LI Naisheng


    Heat flow studies in Northwest Pacific marginal seas has a more than 40 years history with more than 4000 heat flow values obtained. The regional average value is 80.4 mW/m2, which is lower than the world's 87 mW/m2, but higher than those of the Eurasia continent and the Pacific Ocean. This reflects the regional crust property in the area. The studies on distribution of the heat flow and contour pattern of heat flow in 1°×1°and 2°×2°scales in Northwest Pacific marginal seas revealed that the most high heat flow anomalies in the area were found along back-arc basins and island arc in an obviously northeasterly track. Exceptions are the Komandoskaya Basin (KMB), the Izu-Bonin Trough (IBT) and the Mariana Trough (MT), which extend in northwest. The contours of low heat flow marked the boundaries of the continent and the ocean. The present heat flow values reflect the imprint of the last thermal event and relate closely to tectonic activity. The high heat flow gradient areas have high frequency of earthquake. Therefore, the area of faulting controlled the pattern of the heat flow anomalies. Heat flow gradient in 135°direction indicated a major lithosphere transformation oceanward resulting from movement of the earth's material. In this paper, we described patterns of heat flow distribution in the Northwest Pacific, heat flow value changes in horizontal and vertical directions, combining the studies of Shi (1997) on the landforms of the island arcs in east Asia and plate movement, and the results of Shi and Zhang (1998) on heat simulation of subduction of active ocean mountain and the activity of islands arc. A preliminary model of geodynamics in the Northwest Pacific and its adjacent area was put forward. There is a great lateral heat flow gradient on the surface of the mantle between ocean and continent, which indicates that the materials in asthenosphere move from continent to ocean causing movement of the crust.

  18. Paleogene tectono-sedimentary evolution of the Alicante Trough (External Betic Zone, SE Spain) and its bearing on the timing of the deformation of the South-Iberian Margin

    Guerrera, Francesco; Estévez Rubio, Antonio; López Arcos, Mariano; Martín Martín, Manuel; Martín Pérez, Juan Antonio; Serrano Lozano, Francisco


    The Paleogene Alicante Trough of the South-Iberian Margin (External Betic Zone) consists of a narrow sedimentary basin that has active margins located to the north-northwest (active mainly during the Eocene) and to the south-southeast (active during the Oligocene). Both margins, consisting of shallow unstable platforms, were the source areas for the external-platform slope (in the opposite margins) and deepbasin (in the middle) depositional realms. The southern margin, lost under the Mediterr...

  19. Climate Variability, Child Labour and Schooling: Evidence on the Intensive and Extensive Margin

    Colmer, Jonathan


    How does future income uncertainty affect child labour and human capital accumulation? Using a unique panel dataset, we examine the effect of changes in climate variability on the allocation of time among child labour activities (the intensive margin) as well as participation in education and labour activities (the extensive margin). We find robust evidence that increased climate variability increases the number of hours spent on farming activities while reducing the number of hours spent on ...


    Burba, Domininkas


    Full Text Available This article presents and discusses fourteen drawings that portray a human and were found in manuscripts and printed books (documents that were actively used in Lithuania from 17th to 19th centuries. All the drawings were made in the margins of the documents. For the authors the drawings were not planned work but more like quips, scribbles and doodles. Therefore the terms portrait graffiti and (as a synonym portrait marginalia are used to describe the discussed portraits. According to the formal classification of marginal drawings (suggested by J. Liskeviciene two of the examined marginal portraits (no. 10 and 14 are classed as seperate and finished works with their own composition; ten marginal portraits (no. 2, 4, 5, 6, 7, 8, 9, 11, 12 and 13 represent the readers (document users sketch like drawings. Two other portraits (no. 1 and 3 are just scribbles that have nothing to do with artictic perception and are very close to book graffiti. From the artistic approcah the most sophisticated of the marginal portraits are “the hunt scene” (no. 14 and the late (first half of the 19th century “portrait of the teacher” (no. 13. In the viewpoint of documentary and social communication the discussed marginal drawings did not have a direct addressee. They were made not for public but for personal use. Paleographical, structural and content analysis of the document showed that the author of the “bearded nobleman” portrait (no. 2 could have been the elder of Merkine Antanas Kazimieras Sapiega. The political realia of Grand Duchy of Lithuania (from now GDL are reflected by the heart shaped portrait of a youngster who we can guess is portrayed weeping over the countries misfortunes and internal disagreements duringthe period of foreight military interventions in the years from 1733 to 1736. It was forbiden for scribes to daub on court files and other official GDL documents therefore the discussed graffiti could be linked to psychological stress and

  1. Refining MARGINS Mini-Lessons Using Classroom Observations

    Iverson, E. A.; Manduca, C. A.; McDaris, J. R.; Lee, S.


    One of the challenges that we face in developing teaching materials or activities from research findings is testing the materials to determine that they work as intended. Traditionally faculty develop material for their own class, notice what worked and didn’t, and improve them the next year. However, as we move to a community process of creating and sharing teaching materials, a community-based process for testing materials is appropriate. The MARGINS project has piloted such a process for testing teaching materials and activities developed as part of its mini-lesson project ( Building on prior work developing mechanisms for community review of teaching resources (e.g. Kastens, 2002; Hancock and Manduca, 2005; Mayhew and Hall, 2007), the MARGINS evaluation team developed a structured classroom observation protocol. The goals of field testing are to a) gather structured, consistent feedback for the lesson authors based on classroom use; b) guide reviewers of these lessons to reflect on research-based educational practice as a framework for their comments; c) collect information on the data and observations that the reviewer used to underpin their review; d) determine which mini-lessons are ready to be made widely available on the website. The protocol guides faculty observations on why they used the activity, the effectiveness of the activity in their classroom, the success of the activity in leading to the desired learning, and what other faculty need to successfully use the activity. Available online (, the protocol can be downloaded and completed during instruction with the activity. In order to encourage review of mini-lessons using the protocol, a workshop focused on review and revision of activities was held in May 2009. In preparation for the workshop, 13 of the 28 participants chose to field test a mini-lesson prior to the workshop and reported that they found this

  2. Applied Time Domain Stability Margin Assessment for Nonlinear Time-Varying Systems

    Kiefer, J. M.; Johnson, M. D.; Wall, J. H.; Dominguez, A.


    The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation. This technique was implemented by using the Stability Aerospace Vehicle Analysis Tool (SAVANT) computer simulation to evaluate the stability of the SLS system with the Adaptive Augmenting Control (AAC) active and inactive along its ascent trajectory. The gains for which the vehicle maintains apparent time-domain stability defines the gain margins, and the time delay similarly defines the phase margin. This method of extracting the control stability margins from the time-domain simulation is relatively straightforward and the resultant margins can be compared to the linearized system results. The sections herein describe the techniques employed to extract the time-domain margins, compare the results between these nonlinear and the linear methods, and provide explanations for observed discrepancies. The SLS ascent trajectory was simulated with SAVANT and the classical linear stability margins were evaluated at one second intervals. The linear analysis was performed with the AAC algorithm disabled to attain baseline stability

  3. Performance Evaluation of Portfolios with Margin Requirements

    Hui Ding


    Full Text Available In financial markets, short sellers will be required to post margin to cover possible losses in case the prices of the risky assets go up. Only a few studies focus on the optimization and performance evaluation of portfolios in the presence of margin requirements. In this paper, we investigate the theoretical foundation of DEA (data envelopment analysis approach to evaluate the performance of portfolios with margin requirements from a different perspective. Under the mean-variance framework, we construct the optimization model and portfolio possibility set on considering margin requirements. The convexity of the portfolio possibility set is proved and the concept of efficiency in classical economics is extended to the portfolio case. The DEA models are then developed to evaluate the performance of portfolios with margin requirements. Through the simulations carried out in the end, we show that, with adequate portfolios, DEA can be used as an effective tool in computing the efficiencies of portfolios with margin requirements for the performance evaluation purpose. This study can be viewed as a justification of DEA into performance evaluation of portfolios with margin requirements.

  4. Improving and Evaluating Nested Sampling Algorithm for Marginal Likelihood Estimation

    Ye, M.; Zeng, X.; Wu, J.; Wang, D.; Liu, J.


    With the growing impacts of climate change and human activities on the cycle of water resources, an increasing number of researches focus on the quantification of modeling uncertainty. Bayesian model averaging (BMA) provides a popular framework for quantifying conceptual model and parameter uncertainty. The ensemble prediction is generated by combining each plausible model's prediction, and each model is attached with a model weight which is determined by model's prior weight and marginal likelihood. Thus, the estimation of model's marginal likelihood is crucial for reliable and accurate BMA prediction. Nested sampling estimator (NSE) is a new proposed method for marginal likelihood estimation. The process of NSE is accomplished by searching the parameters' space from low likelihood area to high likelihood area gradually, and this evolution is finished iteratively via local sampling procedure. Thus, the efficiency of NSE is dominated by the strength of local sampling procedure. Currently, Metropolis-Hasting (M-H) algorithm is often used for local sampling. However, M-H is not an efficient sampling algorithm for high-dimensional or complicated parameter space. For improving the efficiency of NSE, it could be ideal to incorporate the robust and efficient sampling algorithm - DREAMzs into the local sampling of NSE. The comparison results demonstrated that the improved NSE could improve the efficiency of marginal likelihood estimation significantly. However, both improved and original NSEs suffer from heavy instability. In addition, the heavy computation cost of huge number of model executions is overcome by using an adaptive sparse grid surrogates.

  5. Pricing hospital care: Global budgets and marginal pricing strategies.

    Sutherland, Jason M


    The Canadian province of British Columbia (BC) is adding financial incentives to increase the volume of surgeries provided by hospitals using a marginal pricing approach. The objective of this study is to calculate marginal costs of surgeries based on assumptions regarding hospitals' availability of labor and equipment. This study is based on observational clinical, administrative and financial data generated by hospitals. Hospital inpatient and outpatient discharge summaries from the province are linked with detailed activity-based costing information, stratified by assigned case mix categorizations. To reflect a range of operating constraints governing hospitals' ability to increase their volume of surgeries, a number of scenarios are proposed. Under these scenarios, estimated marginal costs are calculated and compared to prices being offered as incentives to hospitals. Existing data can be used to support alternative strategies for pricing hospital care. Prices for inpatient surgeries do not generate positive margins under a range of operating scenarios. Hip and knee surgeries generate surpluses for hospitals even under the most costly labor conditions and are expected to generate additional volume. In health systems that wish to fine-tune financial incentives, setting prices that create incentives for additional volume should reflect knowledge of hospitals' underlying cost structures. Possible implications of mis-pricing include no response to the incentives or uneven increases in supply. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  6. Exploration of the continental margins of India

    Siddiquie, H.N.; Hashimi, N.H.; Vora, K.H.; Pathak, M.C.

    In mid 1970's the National Institute of Oceanography, Goa, India prepared a plan for systematic regional, geological and geophysical surveys of the continental margins of India. This involved over 75,000 km of underway (bathymetric, side scan sonar...

  7. Mental Depreciation and Marginal Decision Making

    Heath; Fennema


    We propose that individuals practice "mental depreciation," that is, they implicitly spread the fixed costs of their expenses over time or use. Two studies explore how people spread fixed costs on durable goods. A third study shows that depreciation can lead to two distinct errors in marginal decisions: First, people sometimes invest too much effort to get their money's worth from an expense (e.g., they may use a product a lot to spread the fixed expense across more uses). Second, people sometimes invest too little effort to get their money's worth: When people add a portion of the fixed cost to the current costs, their perceived marginal (i.e., incremental) costs exceed their true marginal costs. In response, they may stop investing because their perceived costs surpass the marginal benefits they are receiving. The latter effect is supported by two field studies that explore real board plan decisions by university students.

  8. Time Safety Margin: Theory and Practice


    safety plan as the test event approaches. Did the planners miss anything? What doesn’t make sense ? Is it too conservative or not conservative enough? The...seconds of TSM for a 10-degree dive at 150 KTAS, producing inefficiency with excessive margin. Somewhere in the middle, the restriction makes sense , but...412TW-TIH-16-01 TIME SAFETY MARGIN: THEORY AND PRACTICE WILLIAM R. GRAY, III Chief Test Pilot USAF Test Pilot School SEPTEMBER 2016

  9. Marketing margins and agricultural technology in Mozambique

    Arndt, Channing; Jensen, Henning Tarp; Robinson, Sherman


    Improvements in agricultural productivity and reductions in marketing costs in Mozambique are analysed using a computable general equilibrium (CGE) model. The model incorporates detailed marketing margins and separates household demand for marketed and home-produced goods. Individual simulations...... of improved agricultural technology and lower marketing margins yield welfare gains across the economy. In addition, a combined scenario reveals significant synergy effects, as gains exceed the sum of gains from the individual scenarios. Relative welfare improvements are higher for poor rural households...

  10. Statistical Analysis of Thermal Analysis Margin

    Garrison, Matthew B.


    NASA Goddard Space Flight Center requires that each project demonstrate a minimum of 5 C margin between temperature predictions and hot and cold flight operational limits. The bounding temperature predictions include worst-case environment and thermal optical properties. The purpose of this work is to: assess how current missions are performing against their pre-launch bounding temperature predictions and suggest any possible changes to the thermal analysis margin rules

  11. Polyphase Rifting and Breakup of the Central Mozambique Margin

    Senkans, Andrew; Leroy, Sylvie; d'Acremont, Elia; Castilla, Raymi


    The breakup of the Gondwana supercontinent resulted in the formation of the Central Mozambique passive margin as Africa and Antarctica were separated during the mid-Jurassic period. The identification of magnetic anomalies in the Mozambique Basin and Riiser Larsen Sea means that post-oceanisation plate kinematics are well-constrained. Unresolved questions remain, however, regarding the initial fit, continental breakup process, and the first relative movements of Africa and Antarctica. This study uses high quality multi-channel seismic reflection profiles in an effort to identify the major crustal domains in the Angoche and Beira regions of the Central Mozambique margin. This work is part of the integrated pluri-disciplinary PAMELA project*. Our results show that the Central Mozambique passive margin is characterised by intense but localised magmatic activity, evidenced by the existence of seaward dipping reflectors (SDR) in the Angoche region, as well as magmatic sills and volcanoclastic material which mark the Beira High. The Angoche region is defined by a faulted upper-continental crust, with the possible exhumation of lower crustal material forming an extended ocean-continent transition (OCT). The profiles studied across the Beira high reveal an offshore continental fragment, which is overlain by a pre-rift sedimentary unit likely to belong to the Karoo Group. Faulting of the crust and overlying sedimentary unit reveals that the Beira High has recorded several phases of deformation. The combination of our seismic interpretation with existing geophysical and geological results have allowed us to propose a breakup model which supports the idea that the Central Mozambique margin was affected by polyphase rifting. The analysis of both along-dip and along-strike profiles shows that the Beira High initially experienced extension in a direction approximately parallel to the Mozambique coastline onshore of the Beira High. Our results suggest that the Beira High results

  12. Investigating Mechanisms of Marginal Settlement Life Improvement

    Hamid M. Mohammadi


    Full Text Available The main purpose of this research was to investigate mechanisms to improve marginal settlement life in Koohdasht County in Lorestan province. This research was a sort of the survey studies and a questionnaire was compiled for collection of data. Statistical population of this study was included 1560 households; also sampling method was a sort of random sampling. Number of sample size was estimated 85 households. Questionnaire's reliability was confirmed through computing Cronbach's alpha coefficient which was 0.85. Face validity of questionnaire was confirmed by some Tehran university agricultural extension and education department scientific board members. Also data analyzed by WINspss 11.5. The results of research revealed that marginal area residents had not good financial situation but they undertook great supporting burden and in point of view access to services and life conditions had not good situation. Therefore improvement of life conditions of marginal settlement life such as fundamental infrastructure include communication systems and sanitation offloading system recognized as the most important mechanisms of marginal settlement improvement according to results of priority setting of marginal settlement situation mechanisms. Also the results of factor analysis showed that 7 main mechanisms were be effective in term of marginal settlement life improvement that in order to importance were included servicing and life condition improvement, credit-economic, civil and legal, control and prevention, population and migration control, infrastructures improvement and hygiene situation.

  13. Defining the non-inferiority margin and analyzing non-inferiority: An overview.

    Althunian, Turki A; de Boer, Anthonius; Groenwold, Rolf H H; Klungel, Olaf H


    Non-inferiority trials are used to assess whether the effect of a new drug is not worse than an active comparator by more than a non-inferiority margin. If the difference between the new drug and the active comparator does not exceed this pre-specified margin, non-inferiority can be concluded. This margin must be specified based on clinical and statistical reasoning; however, it is considered as one the most challenging step in the design of non-inferiority trials. Regulators recommend that the margin should be defined based on the historical evidence of the active comparator (the latter is often the well-established standard treatment of the disease), which can be performed by different approaches. There are several factors and assumptions that need to be accounted for during the process of defining the margin and during the analysis of non-inferiority. Three methods are commonly used to analyze non-inferiority trials: the fixed-margin method, the point-estimate method, and the synthesis method. This article provides an overview of analyzing non-inferiority inferiority and choosing the non-inferiority margin.

  14. Fluid and Solute Fluxes from the Deformation Front to the Upper Slope at the Cascadia Margin

    Berg, R. D.; Solomon, E. A.; Johnson, H. P.; Culling, D. P.; Harris, R. N.


    Fluid expulsion from accretionary convergent margins may be an important factor in global geochemical cycling and biogeochemical processes. However, the rates and distribution of fluid flow at these margins are not well known. To better understand these processes at the Cascadia margin, we collected 35 short (Mosquito fluid flow meter measurements along a transect from the deformation front to the upper slope offshore of the Washington coast as part of a coupled heat and fluid flow survey. We identified two active seep areas, one emergent at 1990 mbsl, and one long-lived at 1050 mbsl. At both sites we observed carbonate deposits several meters thick and hundreds of meters in horizontal dimension. Thermogenic hydrocarbons measured in pore waters at the long-lived seep site indicate deeply-sourced fluids originating at >80oC, likely migrating along faults. In addition, pore water solute profiles from the emergent seep site suggest active shallow circulation in the upper sediment column, with implications for the seep biological community and fluid budget of the margin. Pore fluid advection rates along the transect are used to characterize the geographic distribution and geologic controls on active fluid pathways. Pore water solute profiles from the sediment cores are integrated with the measured fluid advection rates to calculate solute fluxes out of the margin. Our transect of fluid flow and pore water chemistry measurements from the Cascadia margin will help to better understand fluid and geochemical cycling at accretionary convergent margins.

  15. Geomorphology and Neogene tectonic evolution of the Palomares continental margin (Western Mediterranean)

    Gómez de la Peña, Laura; Gràcia, Eulàlia; Muñoz, Araceli; Acosta, Juan; Gómez-Ballesteros, María; R. Ranero, César; Uchupi, Elazar


    The Palomares continental margin is located in the southeastern part of Spain. The margin main structure was formed during Miocene times, and it is currently part of the wide deformation zone characterizing the region between the Iberian and African plates, where no well-defined plate boundary occurs. The convergence between these two plates is here accommodated by several structures, including the left lateral strike-slip Palomares Fault. The region is characterized by sparse, low to moderate magnitude (Mw tectonic history of the margin we analyze new high-resolution multibeam bathymetry data and re-processed three multichannel seismic reflection profiles crossing the main structures. The analysis of seafloor morphology and associated subsurface structure provides new insights of the active tectonic features of the area. In contrast to other segments of the southeastern Iberian margin, the Palomares margin contains numerous large and comparatively closely spaced canyons with heads that reach near the coast. The margin relief is also characterized by the presence of three prominent igneous submarine ridges that include the Aguilas, Abubacer and Maimonides highs. Erosive processes evidenced by a number of scars, slope failures, gullies and canyon incisions shape the present-day relief of the Palomares margin. Seismic images reveal the deep structure distinguishing between Miocene structures related to the formation of the margin and currently active features, some of which may reactivate inherited structures. The structure of the margin started with an extensional phase accompanied by volcanic accretion during the Serravallian, followed by a compressional pulse that started during the Latemost Tortonian. Nowadays, tectonic activity offshore is subdued and limited to few, minor faults, in comparison with the activity recorded onshore. The deep Algero-Balearic Basin is affected by surficial processes, associated to halokinesis of Messinian evaporites.

  16. Evaluation of marginal circumference and marginal thickness changes in precrimped stainless steel crowns, after recrimping

    Afshar H


    Full Text Available Background and Aim: The need for recrimping precrimped stainless steel crowns by the dentist in clinic is controversial. This study aimed to evaluate the rate of marginal circumference and marginal thickness change of precrimped stainless steel crowns after recrimping. Materials and Methods: In this experimental study, 30 primary photos were taken from margins of 30 S.S.Cs (3M, Ni-Cr related to tooth 85 with a digital camera fixed at a determined distance. Margins of crowns were crimped by 114 and 137 pliers with a controlled force (0.2 N and then 30 secondary photos were taken in the same conditions. The circumference of crown margins in primary (group A and secondary (group B photos were assessed by a digitizer system. Comparing the circumferences of crown margins in primary and secondary photos showed a significant decrease after crimping. Thickness of 30 random points on the crown margins of a crown similar to mentioned cases was measured by SEM (×150. Then similar procedures including taking a primary photo, crimping and taking a secondary photo was done for the sample crown. After significant reduction in margin circumference, thickness of 30 other random points on the crown margin were measured by SEM. Data were analyzed by paired sample t-test with p<0.05 as the limit of significance. Results: The mean marginal circumference of precrimped stainless steel crowns was reduced by 7.3% which was significant (P<0.001. On the other hand the mean marginal thickness of sample stainless steel crown showed 18µ increase. Conclusion: According to the results of this study, marginal circumference of precrimped stainless steel crowns (3M, Ni-Cr showed a significant decrease after crimping. It is concluded that crimping the stainless steel crowns even for precrimped ones seems necessary.

  17. LRP2 Acts as SHH Clearance Receptor to Protect the Retinal Margin from Mitogenic Stimuli.

    Christ, Annabel; Christa, Anna; Klippert, Julia; Eule, J Corinna; Bachmann, Sebastian; Wallace, Valerie A; Hammes, Annette; Willnow, Thomas E


    During forebrain development, LRP2 promotes morphogen signaling as an auxiliary SHH receptor. However, in the developing retina, LRP2 assumes the opposing function, mediating endocytic clearance of SHH and antagonizing morphogen action. LRP2-mediated clearance prevents spread of SHH activity from the central retina into the retinal margin to protect quiescent progenitor cells in this niche from mitogenic stimuli. Loss of LRP2 in mice increases the sensitivity of the retinal margin for SHH, causing expansion of the retinal progenitor cell pool and hyperproliferation of this tissue. Our findings document the ability of LRP2 to act, in a context-dependent manner, as activator or inhibitor of the SHH pathway. Our current findings uncovered LRP2 activity as the molecular mechanism imposing quiescence of the retinal margin in the mammalian eye and suggest SHH-induced proliferation of the retinal margin as cause of the large eye phenotype observed in mouse models and patients with LRP2 defects.

  18. A 2-D tomographic model of the Juan de Fuca plate from accretion at axial seamount to subduction at the Cascadia margin from an active source ocean bottom seismometer survey

    Horning, G.; Canales, J. P.; Carbotte, S. M.; Han, S.; Carton, H.; Nedimović, M. R.; Keken, P. E.


    We report results from a wide-angle controlled source seismic experiment across the Juan de Fuca plate designed to investigate the evolution of the plate from accretion at the Juan de Fuca ridge to subduction at the Cascadia margin. A two-dimensional velocity model of the crust and upper mantle is derived from a joint reflection-refraction traveltime inversion. To interpret our tomography results, we first generate a plausible baseline velocity model, assuming a plate cooling model and realistic oceanic lithologies. We then use an effective medium theory to infer from our tomography results the extent of porosity, alteration, and water content that would be required to explain the departure from the baseline model. In crust of ages >1 Ma and away from propagator wakes and regions of faulting due to plate bending, we obtain estimates of upper crustal hydration of 0.5-2.1 wt % and find mostly dry lower crust and upper mantle. In sections of the crust affected by propagator wakes we find upper estimates of upper crustal, lower crustal, and upper mantle hydration of 3.1, 0.8, and 1.8 wt %, respectively. At the Cascadia deformation front, we find that the amount of water stored at uppermost mantle levels in the downgoing JdF plate is very limited (<0.3 wt %), with most of the water carried into the subduction zone being stored in the oceanic crust.

  19. Reconstructing Rodinia by Fitting Neoproterozoic Continental Margins

    Stewart, John H.


    Reconstructions of Phanerozoic tectonic plates can be closely constrained by lithologic correlations across conjugate margins by paleontologic information, by correlation of orogenic belts, by paleomagnetic location of continents, and by ocean floor magmatic stripes. In contrast, Proterozoic reconstructions are hindered by the lack of some of these tools or the lack of their precision. To overcome some of these difficulties, this report focuses on a different method of reconstruction, namely the use of the shape of continents to assemble the supercontinent of Rodinia, much like a jigsaw puzzle. Compared to the vast amount of information available for Phanerozoic systems, such a limited approach for Proterozoic rocks, may seem suspect. However, using the assembly of the southern continents (South America, Africa, India, Arabia, Antarctica, and Australia) as an example, a very tight fit of the continents is apparent and illustrates the power of the jigsaw puzzle method. This report focuses on Neoproterozoic rocks, which are shown on two new detailed geologic maps that constitute the backbone of the study. The report also describes the Neoproterozoic, but younger or older rocks are not discussed or not discussed in detail. The Neoproterozoic continents and continental margins are identified based on the distribution of continental-margin sedimentary and magmatic rocks that define the break-up margins of Rodinia. These Neoproterozoic continental exposures, as well as critical Neo- and Meso-Neoproterozoic tectonic features shown on the two new map compilations, are used to reconstruct the Mesoproterozoic supercontinent of Rodinia. This approach differs from the common approach of using fold belts to define structural features deemed important in the Rodinian reconstruction. Fold belts are difficult to date, and many are significantly younger than the time frame considered here (1,200 to 850 Ma). Identifying Neoproterozoic continental margins, which are primarily

  20. Abrupt plate accelerations shape rifted continental margins

    Brune, Sascha; Williams, Simon E.; Butterworth, Nathaniel P.; Müller, R. Dietmar


    Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution, yet quantified extension histories of Earth’s major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength-velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time.

  1. Theory of margination in confined multicomponent suspensions

    Henriquez Rivera, Rafael; Sinha, Kushal; Graham, Michael


    In blood flow, leukocytes and platelets tend to segregate near the vessel walls; this is known as margination. Margination of leukocytes and platelets is important in physiological processes, medical diagnostics and drug delivery. A mechanistic theory is developed to describe flow-induced segregation in confined multicomponent suspensions of deformable particles such as blood. The theory captures the essential features of margination by describing it in terms of two key competing processes in these systems at low Reynolds number: wall-induced migration and hydrodynamic pair collisions. The theory also includes the effect of physical properties of the deformable particles and molecular diffusion. Several regimes of segregation are identified, depending on the value of a ``margination parameter'' M. Moreover, there is a critical value of M below which a sharp ``drainage transition'' occurs: one component is completely depleted from the bulk flow to the vicinity of the walls. Direct hydrodynamic simulations also display this transition in suspensions where the components differ in size or flexibility. The developed mechanistic theory leads to substantial insight into the origins of margination and will help in guiding development of new technologies involving multicomponent suspensions. This work was supported by NSF grant CBET-1436082.

  2. Collapse of modern carbonate platform margins

    Mullins, H.T.; Hine, A.C.; Gardulski, A.


    Modern carbonate platform margins in the Florida-Bahama region have been viewed as depositional or constructional features. However, recent studies have shown that carbonate escarpments, such as the Blake-Bahama and West Florida Escarpments, are erosional in origin where the platform margins have a scalloped or horse-shoe shape. Seismic reflection data from one of these crescentic features along the west Florida platform margin indicate that it originated by large scale gravity collapse (slump). This collapse structure extends for at least 120 km along the margin and has removed about 350 m of strata as young as early Neogene. Although at least three generations of slope failure are recognized, catastrophic collapse appears to have occurred in the mid-Miocene. Gravitational instability due to high rates of sediment accumulation may have been the triggering mechanism. These data suggest that submarine slumping is an important process in the retreat of limestone escarpments and in the generation of carbonate megabreccia debris flows. Scalloped platform margins occur on satellite images of northern Exuma Sound and Columbus Basin in the Bahamas. The authors suggest that large-scale submarine slumping can cause elongation of structurally controlled intraplatform basins (Exuma South), and produce anomalous horse-shoe shaped basins (Columbus Basin) by mega-collapse processes.

  3. Abrupt plate accelerations shape rifted continental margins.

    Brune, Sascha; Williams, Simon E; Butterworth, Nathaniel P; Müller, R Dietmar


    Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution, yet quantified extension histories of Earth's major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength--velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time.

  4. Digital Margins : How spatially and socially marginalized communities deal with digital exclusion

    Salemink, Koen


    The increasing importance of the Internet as a means of communication has transformed economies and societies. For spatially and socially marginalized communities, this transformation has resulted in digital exclusion and further marginalization. This book presents a study of two kinds of marginaliz

  5. Marginalization revisited: critical, postmodern, and liberation perspectives.

    Hall, J M


    Marginalization was advocated by Hall, Stevens, and Meleis in 1994 as a guiding concept for valuing diversity in knowledge development. Properties, risks, and resilience associated with the concept were detailed. This conceptualization of marginalization is reexamined here for its sociopolitical usefulness to nursing, from (1) critical theory, (2) postmodern, and (3) liberation philosophy perspectives. Additional properties are proposed to update the original conceptualization. These include: exteriority, Eurocentrism, constraint, economics, seduction, testimony, and hope. Effects of Eurocentric capitalism on all marginalized people are explored. Nursing implications include the need for interdisciplinary dialogue about the ethics of promoting and exporting Eurocentrism in nursing education and practice, and the need for integrated economic analyses of all aspects of life and health.

  6. Working marginal reserves using Auger technology

    Celada Tamames, B.


    Following up an idea put forward at a meeting of the PEN (National Energy Plan) R and D working party held in Ponferrada in the province of Leon, Ocicarbon contracted Geocontrol SA to carry out a study on the possible use of Auger technology for working marginal coal reserves. This article summarises the most important points in the final report on this project: current state of Auger technology, inventory of marginal coal reserves in Spain and the use of Auger technology in Spain. 6 figs., 2 tabs.

  7. Algorithms for computing the multivariable stability margin

    Tekawy, Jonathan A.; Safonov, Michael G.; Chiang, Richard Y.


    Stability margin for multiloop flight control systems has become a critical issue, especially in highly maneuverable aircraft designs where there are inherent strong cross-couplings between the various feedback control loops. To cope with this issue, we have developed computer algorithms based on non-differentiable optimization theory. These algorithms have been developed for computing the Multivariable Stability Margin (MSM). The MSM of a dynamical system is the size of the smallest structured perturbation in component dynamics that will destabilize the system. These algorithms have been coded and appear to be reliable. As illustrated by examples, they provide the basis for evaluating the robustness and performance of flight control systems.

  8. Jatropha potential on marginal land in Ethiopia

    Wendimu, Mengistu Assefa

    narrative. But both the availability and suitability of “marginal” land for commercial level jatropha production is not well understood/examined, especially in Africa. Using a case study of large-scale jatropha plantation in Ethiopia, this paper examines the process of land identification for jatropha...... investments, and the agronomic performance of large-scale jatropha plantation on so-called marginal land. Although it has been argued that jatropha can be grown well on marginal land without irrigation, and thus does not compete for land and water or displace food production from agricultural land, this study...

  9. Use of marginal organs in kidney transplantation for marginal recipients: too close to the margins of safety?

    Heuer M


    Full Text Available Abstract Objective Due to organ shortage, average waiting time for a kidney in Germany is about 4 years after start of dialysis. Number of kidney grafts recovered can only be maintained by accepting older and expanded criteria donors. The aim of this study was to analyse the impact of donor and recipient risk on kidney long-term function. Methods All deceased kidney transplantations were considered. We retrospectively studied 332 patients between 2002 and 2006; divided in 4 groups reflecting donor and recipient risk. Results Non-marginal recipients were less likely to receive a marginal organ (69 of 207, 33% as compared to marginal recipients, of whom two-thirds received a marginal organ (p Conclusions As we were able to show expanded criteria donor has a far bigger effect on long-term graft function than the "extra risk" recipient. Although there have been attempts to define groups of recipients who should be offered ECD kidneys primarily the discussion is still ongoing.

  10. 17 CFR 242.405 - Withdrawal of margin.


    ...) REGULATIONS M, SHO, ATS, AC, AND NMS AND CUSTOMER MARGIN REQUIREMENTS FOR SECURITY FUTURES Customer Margin Requirements for Security Futures § 242.405 Withdrawal of margin. (a) By the customer. Except as otherwise... account after such withdrawal is sufficient to satisfy the required margin for the security futures...

  11. Marginal notes for a centenary

    Balázs, Lajos G.


    The Astronomical Research Institute of the Hungarian Academy of Sciences celebrated its centenary on the 20th of May 1999. Due to several political and economical crises it was not so easy in Central Europe in the past century to produce scientific results up to the prevailing international standards. Regular professional astronomical activity started in Hungary with the foundation of the university in Nagyszombat near to the present Bratislava. In 1777 the university was transferred to Buda and an observatory was installed in the tower of the royal palace. At the beginning of the 19th century, in 1815, a new university observatory was opened on the top of the Gellert Hill. The observatory was completely destroyed during the siege of the Buda castle in 1849. The other professional astronomical observatory of Karoly Nagy at the town Bicske, completed just at the beginning of the war in 1848-49, was never allowed to make a contribution. A new start for Hungarian astronomy came from Miklós Konkoly Thege when he established his private observatory in Ógyalla. A significant step in the life of the observatory was when it became the property of the state on the 20th of May, 1899. Astronomical photometry was chosen as the main research field of the new national observatory. The first world war led to the collapse of the Austro-Hungarian empire and resulted in the splitting of Ógyalla from Hungary. The instrumentation was transferred to Hungary and the government decided in 1921 to build a new institute on the Schwabian Hills close to Buda. Research on variable stars became the main field of the new institute, in particular the study of period changes of short-period cepheids. After the second world war solar physics was restarted in the institute and as a result a new independent observatory was formed in 1958. A significant development was the introduction of photoelectric observations. In the fifties a decision was made on building a new mountain station on

  12. On the Evolution of Glaciated Continental Margins

    Sverre Laberg, Jan; Rydningen, Tom Arne; Safronova, Polina A.; Forwick, Matthias


    Glaciated continental margins, continental margins where a grounded ice sheet repeatedly has been at or near the shelf break, are found at both northern and southern high-latitudes. Their evolution are in several aspects different from their low-latitude counterparts where eustatic sea-level variations possess a fundamental control on their evolution and where fluvial systems provide the main sediment input. From studies of the Norwegian - Barents Sea - Svalbard and NE Greenland continental margins we propose the following factors as the main control on the evolution of glaciated continental margins: 1) Pre-glacial relief controlling the accommodation space, 2) Ice sheet glaciology including the location of fast-flowing ice streams where source area morphology exerts a fundamental control, 3) Composition of the glacigenic sediments where the clay content in previous studies have been found to be important, and 4) Sea-level controlled both by eustacy and isostacy. From three case studies, 1) the western Barents Sea, 2) part of the North Norwegian (Troms), and 3) the Mid-Norwegian margin, the influence on these factors for the sea-floor morphology, sedimentary processes of the continental slope - deep sea and continental margin architecture are discussed. The pre-glacial relief of the mid-Norwegian and Troms margins relates to the onset of rifting and plate break-up from the early Cenozoic while for the SW Barents Sea, plate shear was followed by rifting. A wide zone of extended continental crust occurs offshore mid-Norway while this zone is much narrower offshore Troms leading to a more pronounced pre-glacial relief. Regarding sediment delivery and ice sheet glaciology the western Barents Sea exemplifies very high sediment input corresponding to an estimated average erosion of the source area of ~0.4 mm/yr (SW Barents Sea), much of which is related to subglacial erosion of Mesozoic - Cenozoic sedimentary rocks from large paleo-ice streams. The mid-Norwegian margin

  13. Pemberdayaan Peternak Marginal: Studi Kasus di Wilayah Banguntapan Bantul

    Irkham Widiyono


    Full Text Available Over the recent years, villagers in the countryside havefaced the problem of limited resources for livestock and crop productions. Decreased land quality and agricultural land areawith respect to the increased need for housing landhas resulted in economic and environmental problems for livestock farmers in this area. Most livestock farmers have poor standard of education, limited ownership of land and livestock, and  are not capable of managing the natural resources in sustainable ways. The present services for small livestock farmersare aimed to transform the unintegrated livestock and agricultural farming into  a sustainable integrated system in the marginal community. Some efforts were conducted to improve knowledge and skills in zero waste system in livestock and agricultural farming by livestock farmers in marginal areas. The present community development programs were conducted using farmer-centered learning methods (participative learning and mentoring by professionals on the implementation of sustainable integrated farming system (learning by practice. Furthermore, institutional development and cooperative networking with related parties were carried out. Results showed that the livestock farmerswere able to adopt integrated farming practices and the community was capable of independently producing organic fertilizer from livestock wastes and converting agricultural byproducts into animal feed. Both farmers and villagers have come together to cultivate fruit and vegetable plantations in vacant lands and back yards which were previously unused. The farmers’ group has successfully networked with the related partners to ensure sustainability of environmental conservation efforts and improvement of livelihood. In conclusion, active participation of farmersin the marginal area throughout the development process and mentored-practice are key factors for successful agricultural transformation in the marginal community. Implementation of the

  14. Great earthquakes along the Western United States continental margin: implications for hazards, stratigraphy and turbidite lithology

    C. H. Nelson


    Full Text Available We summarize the importance of great earthquakes (Mw ≳ 8 for hazards, stratigraphy of basin floors, and turbidite lithology along the active tectonic continental margins of the Cascadia subduction zone and the northern San Andreas Transform Fault by utilizing studies of swath bathymetry visual core descriptions, grain size analysis, X-ray radiographs and physical properties. Recurrence times of Holocene turbidites as proxies for earthquakes on the Cascadia and northern California margins are analyzed using two methods: (1 radiometric dating (14C method, and (2 relative dating, using hemipelagic sediment thickness and sedimentation rates (H method. The H method provides (1 the best estimate of minimum recurrence times, which are the most important for seismic hazards risk analysis, and (2 the most complete dataset of recurrence times, which shows a normal distribution pattern for paleoseismic turbidite frequencies. We observe that, on these tectonically active continental margins, during the sea-level highstand of Holocene time, triggering of turbidity currents is controlled dominantly by earthquakes, and paleoseismic turbidites have an average recurrence time of ~550 yr in northern Cascadia Basin and ~200 yr along northern California margin. The minimum recurrence times for great earthquakes are approximately 300 yr for the Cascadia subduction zone and 130 yr for the northern San Andreas Fault, which indicates both fault systems are in (Cascadia or very close (San Andreas to the early window for another great earthquake.

    On active tectonic margins with great earthquakes, the volumes of mass transport deposits (MTDs are limited on basin floors along the margins. The maximum run-out distances of MTD sheets across abyssal-basin floors along active margins are an order of magnitude less (~100 km than on passive margins (~1000 km. The great earthquakes along the Cascadia and northern California margins

  15. Anthropogenic impacts on continental margins: New frontiers and engagement arena for global sustainability research and action

    Liu, K. K.; Glavovic, B.; Limburg, K.; Emeis, K. C.; Thomas, H.; Kremer, H.; Avril, B.; Zhang, J.; Mulholland, M. R.; Glaser, M.; Swaney, D. P.


    There is an urgent need to design and implement transformative governance strategies that safeguard Earth's life-support systems essential for long-term human well-being. From a series of meetings of the Continental Margins Working Group co-sponsored by IMBER and LOICZ of IGBP, we conclude that the greatest urgency exists at the ocean-land interface - the continental margins or the Margin - which extends from coastlands over continental shelves and slopes bordering the deep ocean. The Margin is enduring quadruple squeeze from (i) Population growth and rising demands for resources; (ii) Ecosystem degradation and loss; (iii) Rising CO2, climate change and alteration of marine biogeochemistry and ecosystems; and (iv) Rapid and irreversible changes in social-ecological systems. Some areas of the Margin that are subject to the greatest pressures (e.g. the Arctic) are also those for which knowledge of fundamental processes remains most limited. Aside from improving our basic understanding of the nature and variability of the Margin, priority issues include: (i) investment reform to prevent lethal but profitable activities; (ii) risk reduction; and (iii) jurisdiction, equity and fiscal responsibility. However, governance deficits or mismatches are particularly pronounced at the ocean-edge of the Margin and the prevailing Law of the Sea is incapable of resolving these challenges. The "gold rush" of accelerating demands for space and resources, and variability in how this domain is regulated, move the Margin to the forefront of global sustainability research and action. We outline a research strategy in 3 engagement arenas: (a) knowledge and understanding of dynamic Margin processes; (b) development, innovation and risk at the Margin; and (c) governance for sustainability on the Margin. The goals are (1) to better understand Margin social-ecological systems, including their physical and biogeochemical components; (2) to develop practical guidance for sustainable development

  16. Geological features and geophysical signatures of continental margins of India

    Krishna, K.S.

    and classification of continental margins are in general dependent on style of continental splitting, rifting, subsidence and their proximity to the tectonic plate boundaries, at times the margins undergo for modifications by sediment deposition and volcanic... by Deccan-Reunion hotspot volcanism and Bengal Fan sedimentation respectively. Volcanism has dominated on the western continental margin of India, thereby the margin had been turned into a volcanic passive continental margin, while eastern continental...




    BI-OMP supports DOE's mission in Climate Change Research. The program provides the fundamental understanding of the linkages between carbon and nitrogen cycles in ocean margins. Researchers are providing a mechanistic understanding of these cycles, using the tools of modern molecular biology. The models that will allow policy makers to determine safe levels of greenhouse gases for the Earth System.

  18. Recidiva tardia de linfoma da zona marginal

    Rocha,Talita M. B.S.; Bortolheiro,Tereza C.; Costa, Eduardo; Haardt,Daniela; Roberto P. Paes; Chiattone, Carlos S.


    O linfoma de zona marginal é um linfoma de baixo grau com curso clínico indolente e potencial de recidiva.1,2 Apresentamos um caso de recidiva tardia após 25 anos de aparente remissão completa, levantando a possibilidade de recidiva de doença preexistente ou desenvolvimento de novo clone neoplásico.

  19. Large margin image set representation and classification

    Wang, Jim Jing-Yan


    In this paper, we propose a novel image set representation and classification method by maximizing the margin of image sets. The margin of an image set is defined as the difference of the distance to its nearest image set from different classes and the distance to its nearest image set of the same class. By modeling the image sets by using both their image samples and their affine hull models, and maximizing the margins of the images sets, the image set representation parameter learning problem is formulated as an minimization problem, which is further optimized by an expectation - maximization (EM) strategy with accelerated proximal gradient (APG) optimization in an iterative algorithm. To classify a given test image set, we assign it to the class which could provide the largest margin. Experiments on two applications of video-sequence-based face recognition demonstrate that the proposed method significantly outperforms state-of-the-art image set classification methods in terms of both effectiveness and efficiency.

  20. New perceptions of continrntal margin biodiversity

    Menot, L.; Sibuet, M.; Carney, R.S.; Levin, L.A.; Rowe, G.T.; Billett, D.S.M.; Poore, G.; Kitazato, H.; Vanreusel, A.; Galeron, J.; Lavrado, H.P.; Sellanes, J.; Ingole, B.S.; Krylova, E.

    margins to major marine laboratories in developed countries. Such studies shaped our original, sometimes naïve, conceptions of what lives on these steep depth gradients even though we perceived the deep environment from afar and at a poor resolution...

  1. Sustainable biomass production on Marginal Lands (SEEMLA)

    Barbera, Federica; Baumgarten, Wibke; Pelikan, Vincent


    Sustainable biomass production on Marginal Lands (SEEMLA) The main objective of the H2020 funded EU project SEEMLA (acronym for Sustainable Exploitation of Biomass for Bioenergy from Marginal Lands in Europe) is the establishment of suitable innovative land-use strategies for a sustainable production of plant-based energy on marginal lands while improving general ecosystem services. The use of marginal lands (MagL) could contribute to the mitigation of the fast growing competition between traditional food production and production of renewable bio-resources on arable lands. SEEMLA focuses on the promotion of re-conversion of MagLs for the production of bioenergy through the direct involvement of farmers and forester, the strengthening of local small-scale supply chains, and the promotion of plantations of bioenergy plants on MagLs. Life cycle assessment is performed in order to analyse possible impacts on the environment. A soil quality rating tool is applied to define and classify MagL. Suitable perennial and woody bioenergy crops are selected to be grown in pilot areas in the partner countries Ukraine, Greece and Germany. SEEMLA is expected to contribute to an increasing demand of biomass for bioenergy production in order to meet the 2020 targets and beyond.

  2. Female Special Education Directors: Doubly Marginalized.

    Keefe, Charlotte Hendrick; Parmley, Pamela


    A qualitative study of five Texas female special education directors found that although participants achieved an administrative position, they were marginalized due to their leadership style, gender discrimination, and socialization. Participants also indicated a negative connection between being in special education administration and top-level…

  3. The marginal cost of public funds

    Kleven, Henrik Jacobsen; Kreiner, Claus Thustrup


    This paper extends the theory and measurement of the marginal cost of public funds (MCF) to account for labor force participation responses. Our work is motivated by the emerging consensus in the empirical literature that extensive (participation) responses are more important than intensive (hours...


    Nam Dinh; Ronaldo Szilard


    The concept of safety margins has served as a fundamental principle in the design and operation of commercial nuclear power plants (NPPs). Defined as the minimum distance between a system’s “loading” and its “capacity”, plant design and operation is predicated on ensuring an adequate safety margin for safety-significant parameters (e.g., fuel cladding temperature, containment pressure, etc.) is provided over the spectrum of anticipated plant operating, transient and accident conditions. To meet the anticipated challenges associated with extending the operational lifetimes of the current fleet of operating NPPs, the United States Department of Energy (USDOE), the Idaho National Laboratory (INL) and the Electric Power Research Institute (EPRI) have developed a collaboration to conduct coordinated research to identify and address the technological challenges and opportunities that likely would affect the safe and economic operation of the existing NPP fleet over the postulated long-term time horizons. In this paper we describe a framework for developing and implementing a Risk-Informed Safety Margin Characterization (RISMC) approach to evaluate and manage changes in plant safety margins over long time horizons.

  5. Marginal Strength of Collarless Metal Ceramic Crown

    Sikka Swati


    fracture strength at margins of metal ceramic crowns cemented to metal tooth analogs. Crowns evaluated with different marginal configurations, shoulder and shoulder bevel with 0 mm, 0.5 mm, 1 mm, and 1.5 mm, were selected. Methods. Maxillary right canine typhodont tooth was prepared to receive a metal ceramic crown with shoulder margin. This was duplicated to get 20 metal teeth analogs. Then the same tooth was reprepared to get shoulder bevel configuration. These crowns were then cemented onmetal teeth analogs and tested for fracture strength atmargin on an Instron testing machine. A progressive compressive load was applied using 6.3 mm diameter rod with crosshead speed of 2.5 mm per minute. Statisticaly analysis was performed with ANOVA, Student's “t” test and “f” test. Results. The fracture strength of collarless metal ceramic crowns under study exceeded the normal biting force. Therefore it can be suggested that collarless metal ceramic crowns with shoulder or shoulder bevel margins up to 1.5 mm framework reduction may be indicated for anteriormetal ceramic restorations. Significance. k Collarless metal ceramic crowns have proved to be successful for anterior fixed restorations. Hence, it may be subjected to more clinical trials.

  6. Negative Stress Margins - Are They Real?

    Raju, Ivatury S.; Lee, Darlene S.; Mohaghegh, Michael


    Advances in modeling and simulation, new finite element software, modeling engines and powerful computers are providing opportunities to interrogate designs in a very different manner and in a more detailed approach than ever before. Margins of safety are also often evaluated using local stresses for various design concepts and design parameters quickly once analysis models are defined and developed. This paper suggests that not all the negative margins of safety evaluated are real. The structural areas where negative margins are frequently encountered are often near stress concentrations, point loads and load discontinuities, near locations of stress singularities, in areas having large gradients but with insufficient mesh density, in areas with modeling issues and modeling errors, and in areas with connections and interfaces, in two-dimensional (2D) and three-dimensional (3D) transitions, bolts and bolt modeling, and boundary conditions. Now, more than ever, structural analysts need to examine and interrogate their analysis results and perform basic sanity checks to determine if these negative margins are real.

  7. Mundhulens mikroflora hos patienter med marginal parodontitis

    Larsen, Tove; Fiehn, Nils-Erik


    Viden om marginal parodontitis’ mikrobiologi tog for alvor fart for ca. 40 år siden. Den tidlige viden var baseret på mikroskopiske og dyrkningsmæssige undersøgelser af den subgingivale plak. Anvendelsen af de nyere molekylærbiologiske metoder har betydet, at vor viden om de ætiologiske faktorer...

  8. Processes of marginalization in relation to participation

    Lagermann, Laila Colding


    This paper discusses processes of marginalization in relation to the participation of two students, Amir and Saad, in the school in Copenhagen, Denmark, which they attend but also across the school and different communities outside the school. In the paper I discuss the effect of some teachers...

  9. Marginal adaptation of ceramic inserts after cementation

    Ozcan, M; Pfeiffer, P; Nergiz, [No Value


    The advantage of using ceramic inserts is to prevent major drawbacks of composite resins such as polymerization shrinkage, wear and microleakage. This in vitro study evaluated the marginal adaptation of two approximal ceramic insert systems after cementation to the cavities opened with ultrasonic ti

  10. On the concept and process of marginalization

    J.B.W. Kuitenbrouwer (Joost)


    textabstractThe concept of marginalization has its genesis in the processes of transformation which have characterized the societies of Latin America (CEPAL). It is increasingly being used to denote similar processes in other parts of the world through which groups of the population are relegated to

  11. Early math intervention for marginalized students

    Overgaard, Steffen; Tonnesen, Pia Beck


    This study is one of more substudies in the project Early Math Intervention for Marginalized Students (TMTM2014). The paper presents the initial process of this substudy that will be carried out fall 2015. In the TMTM2014 project, 80 teachers, who completed a one week course in the idea of TMTM...

  12. Structural Marginality and the Urban Social Order.

    Kapferer, Bruce


    This article argues for a redefinition of "Marginality" in terms of the principles that influence the developing order of the urban formation as a whole. The emerging social order and the political participation of residents of two shanty areas in Kabwe, Zambia are traced over a period of 40 years. (Author/EB)

  13. u571af.m77t: MGD77T data file for Geophysical data from field activity 71005 (U-5-71-AF) in Continental Margin Liberia from 10/30/1971 to 11/20/1971

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry, gravity, and magnetic data along with transit satellite navigation data was collected as part of field activity 71005 (U-5-71-AF) in...

  14. u571af.m77t: MGD77T data file for Geophysical data from field activity 71005 (U-5-71-AF) in Continental Margin Liberia from 10/30/1971 to 11/20/1971

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry, gravity, and magnetic data along with transit satellite navigation data was collected as part of field activity 71005 (U-5-71-AF) in...

  15. The pre-Caledonian margin of Baltica

    Andersen, Torgeir B.; Jørgen Kjøll, Hans; Jakob, Johannes; Corfu, Fernando; Tegner, Christian


    It is well-documented that the pre-Caledonian margin of Baltica constituted a several hundred-km wide and more than 2000 km long passive margin. Its vestiges occur at low- to intermediate structural levels in the mountain belt, and are variably overprinted by the early- to end-Caledonian orogenic deformation and extension. Attempts to reconstruct the Caledonian margin of Baltica must be based on detailed maps integrated with studies of the rock-complexes that originally constituted the passive margin. The proximal parts of pre-Caledonian margin of Baltica are dominated by continental rift basins with coarse to fine-grained sediments deposited in the late Proterozoic through the Ediacaran and into the Lower Palaeozoic. The youngest dated clastic zircons probably record magmatism associated with initial contraction near or in the distal margin. The 'margin nappes' also comprise Baltican basement slivers and coarse to fine-grained sedimentary units as well as deep-marine basin deposits. A major change in the architecture of the passive margin units takes place across a transvers zone, which is sub-parallel to the present-day Gudbrandsdalen of South Norway. The transition is roughly parallel to the major basement lineament of the Sveconorwegian orogenic front in south Norway. The most important change across this transverse lineament is that the NE segment is magma-rich, characterized by abundant basaltic magmatism. The SW segment is magma-poor, and characterised by numerous (>100) solitary meta-peridotites, mostly meta-dunites and meta-harzburgites as well as a number of detrital serpentinites and soapstones. These are interpreted as fragments of exhumed mantle and their erosion products, respectively. The meta-peridotites emplaced structurally, and covered by dominantly deep-basin sediments, but also by coarser sedimentary breccias and conglomerates, as part of the rifted margin development. This mixed unit (mélange) was locally intruded by Late Cambrian to Early

  16. The Seismicity of Two Hyperextended Margins

    Redfield, Tim; Terje Osmundsen, Per


    A seismic belt marks the outermost edge of Scandinavia's proximal margin, inboard of and roughly parallel to the Taper Break. A similar near- to onshore seismic belt runs along its inner edge, roughly parallel to and outboard of the asymmetric, seaward-facing escarpment. The belts converge at both the northern and southern ends of Scandinavia, where crustal taper is sharp and the proximal margin is narrow. Very few seismic events have been recorded on the intervening, gently-tapering Trøndelag Platform. Norway's distribution of seismicity is systematically ordered with respect to 1) the structural templates of high-beta extension that shaped the thinning gradient during Late Jurassic or Early Cretaceous time, and 2) the topographically resurgent Cretaceous-Cenozoic "accommodation phase" family of escarpments that approximate the innermost limit of crustal thinning [See Redfield and Osmundsen (2012) for diagrams, definitions, discussion, and supporting citations.] Landwards from the belt of earthquake epicenters that mark the Taper Break the crust consistently thickens, and large fault arrays tend to sole out at mid crustal levels. Towards the sea the crystalline continental crust is hyperextended, pervasively faulted, and generally very thin. Also, faulting and serpentinization may have affected the uppermost parts of the distal margin's lithospheric mantle. Such contrasting structural conditions may generate a contrasting stiffness: for a given stress, more strain can be accommodated in the distal margin than in the less faulted proximal margin. By way of comparison, inboard of the Taper Break on the gently-tapered Trøndelag Platform, faulting was not penetrative. There, similar structural conditions prevail and proximal margin seismicity is negligible. Because stress concentration can occur where material properties undergo significant contrast, the necking zone may constitute a natural localization point for post-thinning phase earthquakes. In Scandinavia

  17. Leukocyte margination in a model microvessel

    Freund, Jonathan B.


    The physiological inflammation response depends upon the multibody interactions of blood cells in the microcirculation that bring leukocytes (white blood cells) to the vessel walls. We investigate the fluid mechanics of this using numerical simulations of 29 red blood cells and one leukocyte flowing in a two-dimensional microvessel, with the cells modeled as linearly elastic shell membranes. Despite its obvious simplifications, this model successfully reproduces the increasingly blunted velocity profiles and increased leukocyte margination observed at lower shear rates in actual microvessels. Red cell aggregation is shown to be unnecessary for margination. The relative stiffness of the red cells in our simulations is varied by over a factor of 10, but the margination is found to be much less correlated with this than it is to changes associated with the blunting of the mean velocity profile at lower shear rates. While velocity around the leukocyte when it is near the wall depends upon the red cell properties, it changes little for strongly versus weakly marginating cases. In the more strongly marginating cases, however, a red cell is frequently observed to be leaning on the upstream side of the leukocyte and appears to stabilize it, preventing other red cells from coming between it and the wall. A well-known feature of the microcirculation is a near-wall cell-free layer. In our simulations, it is observed that the leukocyte's most probable position is at the edge of this layer. This wall stand-off distance increases with velocity following a scaling that would be expected for a lubrication mechanism, assuming that there were a nearly constant force pushing the cells toward the wall. The leukocyte's near-wall position is observed to be less stable with increasing mean stand-off distance, but this distance would have potentially greater effect on adhesion since the range of the molecular binding is so short.

  18. Financial Intermediation, Monetary Uncertainty, and Bank Interest Margins Financial Intermediation, Monetary Uncertainty, and Bank Interest Margins

    Leonardo Hernández


    Full Text Available Financial Intermediation, Monetary Uncertainty, and Bank Interest Margins This paper studies a simple model of financial intermediation in order to understand how the lending-borrowing spread or interest margin charged by financial intermediaries is determined in equilibrium in a monetary economy. The main conclusion of the paper concerns the effect on the spread of changes in the distribution of monetary innovations. Thus, changes in the monetary-policy-rule followed by the Central Bank which alter the volatility of inflation will have important effects on the interest margin and also on the amount of credit available to investors. A crosssection empirical analysis strongly supports our hypothesis:

  19. Ensuring Cassini's End-of-Mission Propellant Margins

    Sturm, Erick J., II; Barber, Todd J.; Roth, Duane


    The Cassini spacecraft is in its final years. On September 15, 2017, Cassini will plunge deep into Saturn's atmosphere never to reemerge; thus concluding its second extended mission and 13 years in orbit around the ringed planet. As of October 2014, the spacecraft is four years in to its seven-year, second extended mission, the Cassini Solstice Mission (CSM). With three years left and only 2.5% of its loaded bipropellant and 37% of its loaded monopropellant remaining, the Cassini project actively manages the predicted end-of-mission propellant margins to maintain a high confidence in the spacecraft's ability to complete the CSM as designed.

  20. Segmentation of the eastern North Greenland oblique-shear margin – regional plate tectonic implications

    Andreasen, Arne Døssing; Stemmerik, Lars; Dahl-Jensen, T.


    a highly complex, Paleozoic–early Cenozoic pre-opening setting. However, due to extreme ice conditions, very little is known about the offshore areas seawards of – and between – the peninsulas. Consequently, prevailing structural-tectonic models of the margin tend to be significantly oversimplified...... and inadequate. We present the first, combined onshore–offshore, model of the margin integrating onshore outcrops with potential field data, new offshore seismic reflection data and receiver-function analysis of seismic broad band data. The results reveal a margin which is far more complex than previously...... anticipated. In particular, we interpret strong margin segmentation along N/NE-striking fault structures. The structures are likely to have formed by Late Mesozoic–early Cenozoic strike-slip tectonics and have continued to be active during the late Cenozoic. A more than 8 km deep sedimentary basin...

  1. Rifaximin has a Marginal Impact on Microbial Translocation, T-cell Activation and Inflammation in HIV-Positive Immune Non-responders to Antiretroviral Therapy – ACTG A5286

    Tenorio, Allan R.; Chan, Ellen S.; Bosch, Ronald J.; Macatangay, Bernard J. C.; Read, Sarah W.; Yesmin, Suria; Taiwo, Babafemi; Margolis, David M.; Jacobson, Jeffrey M.; Landay, Alan L.; Wilson, Cara C.; Mellors, John W.; Keshavarzian, Ali; Rodriguez, Benigno; Aziz, Mariam; Presti, Rachel; Deeks, Steven; Ebiasah, Ruth; Myers, Laurie; Borowski, LuAnn; Plants, Jill; Palm, David A.; Weibel, Derek; Putnam, Beverly; Lindsey, Elizabeth; Player, Amy; Albrecht, Mary; Kershaw, Andrea; Sax, Paul; Keenan, Cheryl; Walton, Patricia; Baum, Jane; Stroberg, Todd; Hughes, Valery; Coster, Laura; Kumar, Princy N.; Yin, Michael T.; Noel-Connor, Jolene; Tebas, Pablo; Thomas, Aleshia; Davis, Charles E.; Redfield, Robert R.; Sbrolla, Amy; Flynn, Teri; Davis, Traci; Whitely, Kim; Singh, Baljinder; Swaminathan, Shobha; McGregor, Donna; Palella, Frank; Aberg, Judith; Cavanagh, Karen; Santana Bagur, Jorge L.; Flores, Olga Méndez; Fritsche, Janice; Sha, Beverly; Slamowitz, Debbie; Valle, Sandra; Tashima, Karen; Patterson, Helen; Harber, Heather; Para, Michael; Eaton, Molly; Maddox, Dale; Currier, Judith; Cajahuaringa, Vanessa; Luetkemeyer, Annie; Dwyer, Jay; Fichtenbaum, Carl J.; Saemann, Michelle; Ray, Graham; Campbell, Thomas; Fischl, Margaret A.; Bolivar, Hector; Oakes, Jonathan; Chicurel-Bayard, Miriam; Tripoli, Christine; Weinman, D. Renee; Adams, Mary; Hurley, Christine; Dunaway, Shelia; Storey, Sheryl; Klebert, Michael; Royal, Michael


    Background. Rifaximin, a nonabsorbable antibiotic that decreases lipopolysaccharide (LPS) in cirrhotics, may decrease the elevated levels of microbial translocation, T-cell activation and inflammation in human immunodeficiency virus (HIV)-positive immune nonresponders to antiretroviral therapy (ART). Methods. HIV-positive adults receiving ART for ≥96 weeks with undetectable viremia for ≥48 weeks and CD4+ T-cell counts <350 cells/mm3 were randomized 2:1 to rifaximin versus no study treatment for 4 weeks. T-cell activation, LPS, and soluble CD14 were measured at baseline and at weeks 2, 4, and 8. Wilcoxon rank sum tests compared changes between arms. Results. Compared with no study treatment (n = 22), rifaximin (n = 43) use was associated with a significant difference between study arms in the change from baseline to week 4 for CD8+T-cell activation (median change, 0.0% with rifaximin vs +0.6% with no treatment; P = .03). This difference was driven by an increase in the no-study-treatment arm because there was no significant change within the rifaximin arm. Similarly, although there were significant differences between study arms in change from baseline to week 2 for LPS and soluble CD14, there were no significant changes within the rifaximin arm. Conclusions. In immune nonresponders to ART, rifaximin minimally affected microbial translocation and CD8+T-cell activation. Trial registration number. NCT01466595. PMID:25214516

  2. Evolution of the Mariana Convergent Plate Margin System

    Fryer, Patricia


    The Mariana convergent plate margin system of the western Pacific provides opportunities for studying the tectonic and geochemical processes of intraoceanic plate subduction without the added complexities of continental geology. The system's relative geologic simplicity and the well-exposed sections of lithosphere in each of its tectonic provinces permit in situ examination of processes critical to understanding subduction tectonics. Its general history provides analogs to ancient convergent margin terranes exposed on land and helps to explain the chemical mass balance in convergent plate margins. The Mariana convergent margin's long history of sequential formation of volcanic arcs and extensional back arc basins has created a series of volcanic arcs at the eastern edge of the Philippine Sea plate. The trenchward edge of the overriding plate has a relatively sparse sediment cover. Rocks outcropping on the trench's inner slope are typical of the early formed suprasubduction zone's lithosphere and have been subjected to various processes related to its tectonic history. Pervasive forearc faulting has exposed crust and upper mantle lithosphere. Many large serpentinized peridotite seamounts are within 100 km of the trench axis. From these we can learn the history of regional metamorphism and observe and sample active venting of slab fluids. Ocean drilling recovered suprasubduction zone lava sequences erupted since the Eocene that suggest that the forearc region remains volcanologically dynamic. Seismic studies and seafloor mapping show evidence of deformation throughout forearc evolution. Large portions of uplifted southern forearc are exposed at the larger islands. Active volcanoes at the base of the eastern boundary fault of the Mariana Trough vary in size and composition along strike and record regional differences in source composition. Their locations along strike of the arc are controlled in part by cross-arc structures that also facilitate formation of submarine

  3. Adaptive Marginal Median Filter for Colour Images

    Almanzor Sapena


    Full Text Available This paper describes a new filter for impulse noise reduction in colour images which is aimed at improving the noise reduction capability of the classical vector median filter. The filter is inspired by the application of a vector marginal median filtering process over a selected group of pixels in each filtering window. This selection, which is based on the vector median, along with the application of the marginal median operation constitutes an adaptive process that leads to a more robust filter design. Also, the proposed method is able to process colour images without introducing colour artifacts. Experimental results show that the images filtered with the proposed method contain less noisy pixels than those obtained through the vector median filter.

  4. Distributions with given marginals and statistical modelling

    Fortiana, Josep; Rodriguez-Lallena, José


    This book contains a selection of the papers presented at the meeting `Distributions with given marginals and statistical modelling', held in Barcelona (Spain), July 17-20, 2000. In 24 chapters, this book covers topics such as the theory of copulas and quasi-copulas, the theory and compatibility of distributions, models for survival distributions and other well-known distributions, time series, categorical models, definition and estimation of measures of dependence, monotonicity and stochastic ordering, shape and separability of distributions, hidden truncation models, diagonal families, orthogonal expansions, tests of independence, and goodness of fit assessment. These topics share the use and properties of distributions with given marginals, this being the fourth specialised text on this theme. The innovative aspect of the book is the inclusion of statistical aspects such as modelling, Bayesian statistics, estimation, and tests.

  5. Time Domain Stability Margin Assessment Method

    Clements, Keith


    The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

  6. Rigidity of marginally outer trapped 2-spheres

    Galloway, Gregory J


    In a matter-filled spacetime, perhaps with positive cosmological constant, a stable marginally outer trapped 2-sphere must satisfy a certain area inequality. Namely, as discussed in the paper, its area must be bounded above by $4\\pi/c$, where $c > 0$ is a lower bound on a natural energy-momentum term. We then consider the rigidity that results for stable, or weakly outermost, marginally outer trapped 2-spheres that achieve this upper bound on the area. In particular, we prove a splitting result for 3-dimensional initial data sets analogous to a result of Bray, Brendle and Neves [10] concerning area minimizing 2-spheres in Riemannian 3-manifolds with positive scalar curvature. We further show that these initial data sets locally embed as spacelike hypersurfaces into the Nariai spacetime. Connections to the Vaidya spacetime and dynamical horizons are also discussed.

  7. Passive target tracking using marginalized particle filter


    A marginalized particle filtering(MPF)approach is proposed for target tracking under the background of passive measurement.Essentially,the MPF is a combination of particle filtering technique and Kalman filter.By making full use of marginalization,the distributions of the tractable linear part of the total state variables are updated analytically using Kalman filter,and only the lower-dimensional nonlinear state variable needs to be dealt with using particle filter.Simulation studies are performed on an illustrative example,and the results show that the MPF method leads to a significant reduction of the tracking errors when compared with the direct particle implementation.Real data test results also validate the effectiveness of the presented method.

  8. Marginal Loss Calculations for the DCOPF

    Eldridge, Brent [Federal Energy Regulatory Commission, Washington, DC (United States); Johns Hopkins Univ., Baltimore, MD (United States); O' Neill, Richard P. [Federal Energy Regulatory Commission, Washington, DC (United States); Castillo, Andrea R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    The purpose of this paper is to explain some aspects of including a marginal line loss approximation in the DCOPF. The DCOPF optimizes electric generator dispatch using simplified power flow physics. Since the standard assumptions in the DCOPF include a lossless network, a number of modifications have to be added to the model. Calculating marginal losses allows the DCOPF to optimize the location of power generation, so that generators that are closer to demand centers are relatively cheaper than remote generation. The problem formulations discussed in this paper will simplify many aspects of practical electric dispatch implementations in use today, but will include sufficient detail to demonstrate a few points with regard to the handling of losses.

  9. European refiners re-adjust margins strategy

    Gonzalez, R.G. [ed.


    Refiners in Europe are adjusting operating strategies to reflect the volatilities of tight operating margins. From the unexpected availability of quality crudes (e.g., Brent, 0.3% sulfur), to the role of government in refinery planning, the European refining industry is positioning itself to reverse the past few years of steadily declining profitability. Unlike expected increases in US gasoline demand, European gasoline consumption is not expected to increase, and heavy fuel oil consumption is also declining. However, diesel fuel consumption is expected to increase, even though diesel processing capacity has recently decreased (i.e., more imports). Some of the possible strategies that Europeans may adapt to improve margins and reduce volatility include: Increase conversion capacity to supply growing demand for middle distillates and LPG; alleviate refinery cash flow problems with alliances; and direct discretionary investment toward retail merchandising (unless there is a clear trend toward a widening of the sweet-sour crude price differential).

  10. Marginal longitudinal semiparametric regression via penalized splines

    Al Kadiri, M.


    We study the marginal longitudinal nonparametric regression problem and some of its semiparametric extensions. We point out that, while several elaborate proposals for efficient estimation have been proposed, a relative simple and straightforward one, based on penalized splines, has not. After describing our approach, we then explain how Gibbs sampling and the BUGS software can be used to achieve quick and effective implementation. Illustrations are provided for nonparametric regression and additive models.

  11. Neotectonics in the northern equatorial Brazilian margin

    Rossetti, Dilce F.; Souza, Lena S. B.; Prado, Renato; Elis, Vagner R.


    An increasing volume of publications has addressed the role of tectonics in inland areas of northern Brazil during the Neogene and Quaternary, despite its location in a passive margin. Hence, northern South America plate in this time interval might have not been as passive as usually regarded. This proposal needs further support, particularly including field data. In this work, we applied an integrated approach to reveal tectonic structures in Miocene and late Quaternary strata in a coastal area of the Amazonas lowland. The investigation, undertaken in Marajó Island, mouth of the Amazonas River, consisted of shallow sub-surface geophysical data including vertical electric sounding and ground penetrating radar. These methods were combined with morphostructural analysis and sedimentological/stratigraphic data from shallow cores and a few outcrops. The results revealed two stratigraphic units, a lower one with Miocene age, and an upper one of Late Pleistocene-Holocene age. An abundance of faults and folds were recorded in the Miocene deposits and, to a minor extent, in overlying Late Pleistocene-Holocene strata. In addition to characterize these structures, we discuss their origin, considering three potential mechanisms: Andean tectonics, gravity tectonics related to sediment loading in the Amazon Fan, and rifting at the continental margin. Amongst these hypotheses, the most likely is that the faults and folds recorded in Marajó Island reflect tectonics associated with the history of continental rifting that gave rise to the South Atlantic Ocean. This study supports sediment deposition influenced by transpression and transtension associated with strike-slip divergence along the northern Equatorial Brazilian margin in the Miocene and Late Pleistocene-Holocene. This work records tectonic evidence only for the uppermost few ten of meters of this sedimentary succession. However, available geological data indicate a thickness of up to 6 km, which is remarkably thick for

  12. Negative marginal tax rates and heterogeneity

    Choné, Philippe; Laroque, Guy


    Heterogeneity is likely to be an important determinant of the shape of optimal tax schemes. This article addresses the issue in a model à la Mirrlees with a continuum of agents. The agents differ in their productivities and opportunity costs of work, but their labor supplies depend only on a unidimensional combination of their two characteristics. Conditions are given under which the standard result that marginal tax rates are everywhere non-negative holds. This is in particular the case when...

  13. Authigenic minerals from the continental margins

    Rao, V.P.

    phosphorites have been presumed to be sedimented plankton organic matter, fish debris, and iron-redox phosphate pump. Several workers investigated the genesis of sedimentary phosphorites occurring from Precambrian to Recent and proposed different...-phosphate sediments of the western continental margin of India showed that phosphate occurred as apatite microparticles that resembled fossilized phosphate bacteria and/or microbial filaments (Fig. 3). This established the prominence of micro- environments...


    Ratnawati Tahir


    Full Text Available Abstract: Alternative Education for Marginalized Women in Rural Areas. The study aims to find alter­native forms of education for marginalized women, the process of forming study groups and gender based learning process that serves the center of the development of education, leadership and a source of economic empowerment. The study uses qualitative methods, involving a group of women who have attended an al­ternative education. Researchers and informants from community leaders. The results showed that the form of alternative education is a method of adult education or andragogy. Study groups consisted of basic literacy and functional literacy. The learning process begins with the sharing of learning, reflection on life experience and role play method. The result is 65% of participants have increased the ability of reading, writing and numeracy, and understanding of the issues of women who have confidence in the decision making of households and communities. Abstrak: Pendidikan Alternatif untuk Perempuan Marginal di Pedesaan. Penelitian ini bertujuan mengetahui bentuk pendidikan alternatif untuk perempuan marginal, proses pembentukan kelompok belajar, dan proses pembelajaran berperspektif gender yang berfungsi menjadi pusat pengembangan pendidikan, kepemimpinan, dan sumber penguatan ekonomi. Penelitian menggunakan metode kualitatif, mengambil satu kelompok perempuan yang telah mengikuti pendidikan alternatif. Informan terdiri atas tokoh masyarakat, seperti Kepala Desa, Ketua RT/RW, dan ibu rumah tangga. Hasil penelitian menunjukkan bahwa bentuk pembelajaran pendidikan alternatif adalah metode pendidikan orang dewasa atau andragogy. Pembentukan kelompok belajar terdiri atas; kelompok baca tulis dan keaksaraan fungsional. Proses pembe­lajaran dimulai dengan sharing pembelajaran, refleksi pengalaman hidup, dan metode role play. Hasilnya 65% peserta pembelajaran mengalami peningkatan kemampuan membaca, menulis, dan berhitung, serta pema

  15. Statistical Mechanics of Soft Margin Classifiers

    Risau-Gusman, Sebastian; Gordon, Mirta B.


    We study the typical learning properties of the recently introduced Soft Margin Classifiers (SMCs), learning realizable and unrealizable tasks, with the tools of Statistical Mechanics. We derive analytically the behaviour of the learning curves in the regime of very large training sets. We obtain exponential and power laws for the decay of the generalization error towards the asymptotic value, depending on the task and on general characteristics of the distribution of stabilities of the patte...

  16. Marginal Ice Zone: Biogeochemical Sampling with Gliders


    ocean and base of marine food webs, are responding to changing conditions in the Arctic Ocean . The high-level project goals are to use underwater...observing array (Fig. 1). The glider sensor suite included temperature , temperature microstructure, salinity , oxygen, chlorophyll fluorescence, optical...presented at the Arctic Science Summit Week in Toyama, Japan, in April 2015 (Direct Observations of Ocean Variability Across the Arctic Marginal Ice Zone

  17. Marginal microfiltration in amalgam restorations. Review

    Lahoud Salem, Víctor; Departamento Académico de Estomatología Rehabilitadora. Facultad de Odontología, Universidad Nacional Mayor de San Marcos, Lima. Perú.


    The present articule is review references from phenomenon of microfiltration in restorations with amalgam and yours consecuents in changes of color in the interface tooth-restorations, margin deterioted , sensitivity dentinarea postoperate, caries secondary and pulp inflamation. Besides naming the mechanicals for to reduce microfiltration, and yours effects for use of sealers dentinaries representation for the varnish cavitys and adhesive systens Conclusive indicate wath the amalgam is the ma...

  18. Marginal longitudinal semiparametric regression via penalized splines.

    Kadiri, M Al; Carroll, R J; Wand, M P


    We study the marginal longitudinal nonparametric regression problem and some of its semiparametric extensions. We point out that, while several elaborate proposals for efficient estimation have been proposed, a relative simple and straightforward one, based on penalized splines, has not. After describing our approach, we then explain how Gibbs sampling and the BUGS software can be used to achieve quick and effective implementation. Illustrations are provided for nonparametric regression and additive models.

  19. Application of geoinformation techniques in sustainable development of marginal rural

    Leszczynska, G.


    The basic objective of the studies is to create a geographic information system that would assure integration of activities aimed at protecting biological diversity with sustainable development of marginal rural areas through defining the conditions for development of tourism and recreation in the identified areas. The choice of that solution is a consequence of the fact that numerous phenomena and processes presented in maps are linked to functional relations or they can be viewed as functions of space, time and attributes. The paper presents the system development stage aimed at elaborating the template for the system serving solution of the above-presented problem. In case of this issue the geographic information system will be developed to support development of marginal rural areas through selection of appropriate forms of tourism for the endangered areas including indication of locations for development of appropriate tourist infrastructure. Selection of the appropriate form of tourism will depend on natural, tourist and infrastructure values present in a given area and conditioned by the need to present the biodiversity component present in those areas together with elements of traditional agricultural landscape. The most important problem is to reconcile two seemingly contradictory aims: 1. Preventing social and economic marginalization of the restructured rural areas. 2. Preserving biological diversity in the restructured areas.Agriculture influences many aspects of the natural environment such as water resources, biodiversity and status of natural habitats, status of soils, landscape and, in a wider context, the climate. Project implementation will involve application of technologies allowing analysis of the systems for managing marginal rural areas as spatial models based on geographic information systems. Modelling of marginal rural areas management using the GIS technologies will involve creating spatial models of actual objects. On the basis of data

  20. Target margins in radiotherapy of prostate cancer.

    Yartsev, Slav; Bauman, Glenn


    We reviewed the literature on the use of margins in radiotherapy of patients with prostate cancer, focusing on different options for image guidance (IG) and technical issues. The search in PubMed database was limited to include studies that involved external beam radiotherapy of the intact prostate. Post-prostatectomy studies, brachytherapy and particle therapy were excluded. Each article was characterized according to the IG strategy used: positioning on external marks using room lasers, bone anatomy and soft tissue match, usage of fiducial markers, electromagnetic tracking and adapted delivery. A lack of uniformity in margin selection among institutions was evident from the review. In general, introduction of pre- and in-treatment IG was associated with smaller planning target volume (PTV) margins, but there was a lack of definitive experimental/clinical studies providing robust information on selection of exact PTV values. In addition, there is a lack of comparative research regarding the cost-benefit ratio of the different strategies: insertion of fiducial markers or electromagnetic transponders facilitates prostate gland localization but at a price of invasive procedure; frequent pre-treatment imaging increases patient in-room time, dose and labour; online plan adaptation should improve radiation delivery accuracy but requires fast and precise computation. Finally, optimal protocols for quality assurance procedures need to be established.

  1. Ocean Margins Programs, Phase I research summaries

    Verity, P. [ed.


    During FY 1992, the DOE restructured its regional coastal-ocean programs into a new Ocean Margins Program (OMP), to: Quantify the ecological and biogeochemical processes and mechanisms that affect the cycling, flux, and storage of carbon and other biogenic elements at the land/ocean interface; Define ocean-margin sources and sinks in global biogeochemical cycles, and; Determine whether continental shelves are quantitatively significant in removing carbon dioxide from the atmosphere and isolating it via burial in sediments or export to the interior ocean. Currently, the DOE Ocean Margins Program supports more than 70 principal and co-principal investigators, spanning more than 30 academic institutions. Research funded by the OMP amounted to about $6.9M in FY 1994. This document is a collection of abstracts summarizing the component projects of Phase I of the OMP. This phase included both research and technology development, and comprised projects of both two and three years duration. The attached abstracts describe the goals, methods, measurement scales, strengths and limitations, and status of each project, and level of support. Keywords are provided to index the various projects. The names, addresses, affiliations, and major areas of expertise of the investigators are provided in appendices.

  2. Origin and dynamics of depositionary subduction margins

    Vannucchi, Paola; Morgan, Jason P.; Silver, Eli; Kluesner, Jared


    Here we propose a new framework for forearc evolution that focuses on the potential feedbacks between subduction tectonics, sedimentation, and geomorphology that take place during an extreme event of subduction erosion. These feedbacks can lead to the creation of a “depositionary forearc,” a forearc structure that extends the traditional division of forearcs into accretionary or erosive subduction margins by demonstrating a mode of rapid basin accretion during an erosive event at a subduction margin. A depositionary mode of forearc evolution occurs when terrigenous sediments are deposited directly on the forearc while it is being removed from below by subduction erosion. In the most extreme case, an entire forearc can be removed by a single subduction erosion event followed by depositionary replacement without involving transfer of sediments from the incoming plate. We need to further recognize that subduction forearcs are often shaped by interactions between slow, long-term processes, and sudden extreme events reflecting the sudden influences of large-scale morphological variations in the incoming plate. Both types of processes contribute to the large-scale architecture of the forearc, with extreme events associated with a replacive depositionary mode that rapidly creates sections of a typical forearc margin. The persistent upward diversion of the megathrust is likely to affect its geometry, frictional nature, and hydrogeology. Therefore, the stresses along the fault and individual earthquake rupture characteristics are also expected to be more variable in these erosive systems than in systems with long-lived megathrust surfaces.

  3. Origin and dynamics of depositionary subduction margins

    Vannucchi, Paola; Morgan, Jason P.; Silver, Eli A.; Kluesner, Jared W.


    Here we propose a new framework for forearc evolution that focuses on the potential feedbacks between subduction tectonics, sedimentation, and geomorphology that take place during an extreme event of subduction erosion. These feedbacks can lead to the creation of a "depositionary forearc," a forearc structure that extends the traditional division of forearcs into accretionary or erosive subduction margins by demonstrating a mode of rapid basin accretion during an erosive event at a subduction margin. A depositionary mode of forearc evolution occurs when terrigenous sediments are deposited directly on the forearc while it is being removed from below by subduction erosion. In the most extreme case, an entire forearc can be removed by a single subduction erosion event followed by depositionary replacement without involving transfer of sediments from the incoming plate. We need to further recognize that subduction forearcs are often shaped by interactions between slow, long-term processes, and sudden extreme events reflecting the sudden influences of large-scale morphological variations in the incoming plate. Both types of processes contribute to the large-scale architecture of the forearc, with extreme events associated with a replacive depositionary mode that rapidly creates sections of a typical forearc margin. The persistent upward diversion of the megathrust is likely to affect its geometry, frictional nature, and hydrogeology. Therefore, the stresses along the fault and individual earthquake rupture characteristics are also expected to be more variable in these erosive systems than in systems with long-lived megathrust surfaces.

  4. Marginal historiography: on Stekel's account of things.

    Bos, Jaap


    Psychoanalytic historiography has been, and to a certain extent still is, written mainly from the victor's (Freud's) perspective. One of the first attempts to deliver an alternative account was published in 1926 by Wilhelm Stekel in a little-known paper entitled "On the History of the Analytical Movement," which he wrote in response to Freud's (1925) "An Autobiographical Study" as an attempt to supplement or even counter Freud's version. This paper offers a dialogical reading of Stekel's paper, focusing not on the question of whether or not Stekel was right, but on the problem of marginalization itself. What discursive processes contributed to the marginalization of Stekel's position, and in what sense could Stekel's paper be called an instance of self-marginalization? Analysing various intertextual links between Freud's and Stekel's accounts, the author finds that the two accounts were caught up in an antagonistic dialectic from which it was impossible to escape. Following this paper, an English translation of Stekel's 1926 account is presented here for the first time.

  5. Testing for conditional multiple marginal independence.

    Bilder, Christopher R; Loughin, Thomas M


    Survey respondents are often prompted to pick any number of responses from a set of possible responses. Categorical variables that summarize this kind of data are called pick any/c variables. Counts from surveys that contain a pick any/c variable along with a group variable (r levels) and stratification variable (q levels) can be marginally summarized into an r x c x q contingency table. A question that may naturally arise from this setup is to determine if the group and pick any/c variable are marginally independent given the stratification variable. A test for conditional multiple marginal independence (CMMI) can be used to answer this question. Since subjects may pick any number out of c possible responses, the Cochran (1954, Biometrics 10, 417-451) and Mantel and Haenszel (1959, Journal of the National Cancer Institute 22, 719-748) tests cannot be used directly because they assume that units in the contingency table are independent of each other. Therefore, new testing methods are developed. Cochran's test statistic is extended to r x 2 x q tables, and a modified version of this statistic is proposed to test CMMI. Its sampling distribution can be approximated through bootstrapping. Other CMMI testing methods discussed are bootstrap p-value combination methods and Bonferroni adjustments. Simulation findings suggest that the proposed bootstrap procedures and the Bonferroni adjustments consistently hold the correct size and provide power against various alternatives.

  6. Social  reading - the reader on digital margins

    Ivona Despot


    Full Text Available Electronic books enrich the reading experience through a range of possibilities digital technology offers, such as commenting or adding content at the margin space, marking interesting chapters and sharing the content with other readers. The phenomenon of social reading emerges with the influence of technology in the sphere of reading books and creates interactions for readers with the content and other readers. The great potential of enriching the reading experience is visible in the digital platforms for social reading, where the interaction and the creation of new content encourages the development of new way of reading and creativity. These activities may contribute to better understanding of the text. This enhances the communication about the text thus revitalizing the content and moves the reading itself from private to public sphere. This paper will show how are the activities in the digital margins transformed into a good indicator of the reading behavior, as well as the importance and usefulness of such for publishers to create new publishing products and services.

  7. Intraoperative radiological margin assessment in breast-conserving surgery.

    Ihrai, T; Quaranta, D; Fouche, Y; Machiavello, J-C; Raoust, I; Chapellier, C; Maestro, C; Marcy, M; Ferrero, J-M; Flipo, B


    A prospective study was lead in order to analyze the accuracy of an X-ray device settled in the operating room for margin assessment, when performing breast-conserving surgery. One hundred and seventy patients were included. All lesions were visible on the preoperative mammograms. An intraoperative X-ray of the lumpectomy specimen was systematically performed for margins assessment. Final histological data were collected and the accuracy of intraoperative specimen radiography (IOSR) for margin assessment was analyzed. IOSR allowed an evaluation of margins status in 155 cases (91.2%). After final histological examination, the positive margins rate would have been 6.5% if margin assessment had relied only on IOSR. Margin assessment with a two-dimensional X-ray device would have allowed the achievement of negative margins in 93.5% of the cases. Moreover, this procedure allows important time-saving and could have a substantial economical impact. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Intraoperative ultrasound control of surgical margins during partial nephrectomy

    Feras M Alharbi


    Conclusions: The intraoperative US control of resection margins in PN is a simple, efficient, and effective method for ensuring negative surgical margins with a small increase in warm ischemia time and can be conducted by the operating urologist.

  9. Sequential faulting explains the asymmetry and extension discrepancy of conjugate margins.

    Ranero, César R; Pérez-Gussinyé, Marta


    During early extension, cold continental lithosphere thins and subsides, creating rift basins. If extension continues to final break-up, the split and greatly thinned plates subside deep below sea level to form a conjugate pair of rifted margins. Although basins and margins are ubiquitous structures, the deformation processes leading from moderately extended basins to highly stretched margins are unclear, as studies consistently report that crustal thinning is greater than extension caused by brittle faulting. This extension discrepancy might arise from differential stretching of brittle and ductile crustal layers, but that does not readily explain the typical asymmetric structure of conjugate margins-in cross-section, one margin displays gradual thinning accompanied by large faults, and the conjugate margin displays abrupt thinning but smaller-scale faulting. Whole-crust detachments, active from early in the rifting, could in theory create both thinning and asymmetry, but are mechanically problematical. Furthermore, the extension discrepancy occurs at both conjugate margins, leading to the apparent contradiction that both seem to be upper plates to a detachment fault. Alternative models propose that much brittle extension is undetected because of seismic imaging limitations caused either by subseismic-resolution faulting, invisible deformation along top-basement 100-km-scale detachments or the structural complexity of cross-cutting arrays of faults. Here we use depth-migrated seismic images to accurately measure fault extension and compare it with crustal thinning. The observations are used to create a balanced kinematic model of rifting that resolves the extension discrepancy by producing both fault-controlled crustal thinning which progresses from a rift basin to the asymmetric structure, and extreme thinning of conjugate rifted margins. Contrary to current wisdom, the observations support the idea that thinning is to a first degree explained by simple

  10. La Integración de la Sociabilidad y Asociatividad en el Trabajo con Familias Marginales The Integration of Sociability and Active Membership in Social Work With Marginal Families

    Margarita Morandé


    Full Text Available El artículo describe el estudio efectuado en Santiago con familias de microcampamentos a partir del trabajo que realiza la Fundación Trabajo en la Calle. Se analizó la presencia de sociabilidad y asociatividad, desde la percepción que otorgan a este trabajo sus beneficiarios. Se utilizó una etnografía interpretativa, cuyas técnicas fueron la entrevista semi-estructurada y la observación participante. Los participantes fueron seis personas que se encontraban viviendo, al momento del estudio, en alguno de los campamentos en los cuales trabaja la Fundación. Y dos personas que pertenecieron a alguno de los campamentos donde trabajó la Fundación y que obtuvieron sus viviendas. Para el análisis de los datos, se elaboró un documento etnográfico, cuya interpretación se hizo a partir de los antecedentes teóricos. Los resultados muestran una integración de las características de sociabilidad y asociatividad en el trabajo realizado por la Fundación, y que ella se percibiría como significativamente positiva para los beneficiarios.The article describes a research that took place in Santiago de Chile with the families who live in small camps of shacks with whom Fundación Trabajo en la Calle has carried out their social work. Two forms of social interaction, sociability and active membership, were analized from the perceptions that their beneficiares have of this way of social work. The methodology applied was ethnographic hermeneutics, and the procedures for data collection were semi-structured interviews, field work and experiential data. The participants were six people who were living in some of the camps were the Foundation was working at the time of the research and two persons who had belonged to one of the camps and at the moment were living in their own housing. An ethnographic document was worked out for the data analysis and it`s interpretation was based on the theoretical framework of this research. Data show that there is an

  11. Marginal Space Deep Learning: Efficient Architecture for Volumetric Image Parsing.

    Ghesu, Florin C; Krubasik, Edward; Georgescu, Bogdan; Singh, Vivek; Yefeng Zheng; Hornegger, Joachim; Comaniciu, Dorin


    Robust and fast solutions for anatomical object detection and segmentation support the entire clinical workflow from diagnosis, patient stratification, therapy planning, intervention and follow-up. Current state-of-the-art techniques for parsing volumetric medical image data are typically based on machine learning methods that exploit large annotated image databases. Two main challenges need to be addressed, these are the efficiency in scanning high-dimensional parametric spaces and the need for representative image features which require significant efforts of manual engineering. We propose a pipeline for object detection and segmentation in the context of volumetric image parsing, solving a two-step learning problem: anatomical pose estimation and boundary delineation. For this task we introduce Marginal Space Deep Learning (MSDL), a novel framework exploiting both the strengths of efficient object parametrization in hierarchical marginal spaces and the automated feature design of Deep Learning (DL) network architectures. In the 3D context, the application of deep learning systems is limited by the very high complexity of the parametrization. More specifically 9 parameters are necessary to describe a restricted affine transformation in 3D, resulting in a prohibitive amount of billions of scanning hypotheses. The mechanism of marginal space learning provides excellent run-time performance by learning classifiers in clustered, high-probability regions in spaces of gradually increasing dimensionality. To further increase computational efficiency and robustness, in our system we learn sparse adaptive data sampling patterns that automatically capture the structure of the input. Given the object localization, we propose a DL-based active shape model to estimate the non-rigid object boundary. Experimental results are presented on the aortic valve in ultrasound using an extensive dataset of 2891 volumes from 869 patients, showing significant improvements of up to 45

  12. The influence of tectonic and volcanic processes on the morphology of the Iberian continental margins; Influencia de los procesos tectonicos y volcanicos en la morfologia de los margenes continentales ibericos

    Maestro, A.; Bohoyo, F.; Lopez-Martinez, J.; Acosta, J.; Gomez-Ballesteros, M.; Llaave, E.; Munoz, A.; Terrinha, P. G.; Dominguez, M.; Fernandez-Saez, F.


    The Iberian continental margins are mainly passive margins. Nevertheless, the northern sector of the margin was active during some stages of its geological evolution. The southern sector is considered as a transformed margin, which defines the boundary between the Iberian and African plates. This margin was also an active margin in the past. The different types, origins and intensities of the endogenic processes that have affected he Iberian continental margins have led to the development of various tectonic and volcanic morphologies. The North Atlantic rifting allowed the development of large marginal platforms in the Cantabrian and Galician margins the North-Atlantic Ocean spreading. The reactivation of Variscan faults during the Mesozoic and Cenozoic controlled the strike of some of the largest canyons in the Iberian margins. The Gulf of Cadiz margin is characterized by the development of morphologies related to salt tectonic, fluid seepage, thrust fronts and strike-slip fault lineaments hundreds of kilometres long. The Alboran basin and the Betic margin show morphologies connected with the Miocene rift phase, which generated volcanic edifices and various structural reliefs, and with the subsequent compressive phase, when folds and strike-slip, reverse faults, diapirs and mud volcanoes were developed. Finally, the Catalan-Valencian margin and the Balearic promontory are characterized by the presence of horst and graben structures related to the development of the Valencia trough during the Paleogene. The morphological features of endogenic origin have largely controlled the location and extent of the sedimentary processes and morphological products along the Iberian margins. (Author)

  13. Chronobiology of deep-water decapod crustaceans on continental margins.

    Aguzzi, Jacopo; Company, Joan B


    Species have evolved biological rhythms in behaviour and physiology with a 24-h periodicity in order to increase their fitness, anticipating the onset of unfavourable habitat conditions. In marine organisms inhabiting deep-water continental margins (i.e. the submerged outer edges of continents), day-night activity rhythms are often referred to in three ways: vertical water column migrations (i.e. pelagic), horizontal displacements within benthic boundary layer of the continental margin, along bathymetric gradients (i.e. nektobenthic), and endobenthic movements (i.e. rhythmic emergence from the substrate). Many studies have been conducted on crustacean decapods that migrate vertically in the water column, but much less information is available for other endobenthic and nektobenthic species. Also, the types of displacement and major life habits of most marine species are still largely unknown, especially in deep-water continental margins, where steep clines in habitat factors (i.e. light intensity and its spectral quality, sediment characteristics, and hydrography) take place. This is the result of technical difficulties in performing temporally scheduled sampling and laboratory testing on living specimens. According to this scenario, there are several major issues that still need extensive research in deep-water crustacean decapods. First, the regulation of their behaviour and physiology by a biological clock is almost unknown compared to data for coastal species that are easily accessible to direct observation and sampling. Second, biological rhythms may change at different life stages (i.e. size-related variations) or at different moments of the reproductive cycle (e.g. at egg-bearing) based on different intra- and interspecific interactions. Third, there is still a major lack of knowledge on the links that exist among the observed bathymetric distributions of species and selected autoecological traits that are controlled by their biological clock, such as the

  14. Marginal phase correction of truncated Bessel beams



    Approximate analytic expressions are obtained for evaluating the axial intensity and the central-lobe diameter of J0 Bessel beams transmitted through a finite-aperture phase filter. A reasonable quality factor governing the axial-intensity behavior of a phase-undistorted truncated Bessel beam is found to be the inverse square root of the Fresnel number defined, for a given aperture, from the axial point of geometrical shadow. Additional drastic reduction of axial-intensity oscillations is accomplished by using marginal phase correction of the beam instead of the well-known amplitude apodization. A procedure for analytically calculating an optimal monotonic slowly varying correction phase function is described.

  15. Potentials of marginal lands - sponateous ecosystem development

    Gerwin, Werner; Schaaf, Wolfgang


    Marginal lands are often considered as unfertile and not productive. They are widely excluded from modern land use by conventional agriculture. Assessment of soil fertility usually shows very low productivity potentials at least for growing traditional crops. However, it can be frequently observed that natural succession at different types of marginal lands leads to very diverse and nonetheless productive ecosystems. Examples can be found at abandoned former industrial or transportation sites which were set aside and not further maintained - and also in post-mining landscapes. In one of the lignite open cast mines of the State of Brandenburg in Eastern Germany a landscape observatory was established in 2005 for observing this natural ecosystem development under marginal site conditions. The site of 6 ha is part of the post-mining landscapes of Lusatia which are often characterized by poor soil conditions and clearly reduced soil fertility. It is named "Hühnerwasser-Quellgebiet" (Chicken Creek Catchment) after a small stream that is restored again after destruction by the mining operations. It is planned to serve as the headwater of this stream and was left to an unrestricted primary succession. A comprehensive scientific monitoring program is carried out since the start of ecosystem development in 2005. The results offer exemplary insights into the establishment of interaction networks between the developing ecosystem compartments. After 10 years a large biodiversity, expressed by a high number of species, can be found at this site as the result of natural recovery processes. A large number of both tree species and individuals have settled here. Even if no economic use of the site and of the woody biomass produced by these trees is planned, an overall assessment of the biomass production was carried out. The results showed that the biomass production from natural succession without any application of fertilizers etc. is directly comparable with yields from

  16. Area inequalities for stable marginally trapped surfaces

    Jaramillo, José Luis


    We discuss a family of inequalities involving the area, angular momentum and charges of stably outermost marginally trapped surfaces in generic non-vacuum dynamical spacetimes, with non-negative cosmological constant and matter sources satisfying the dominant energy condition. These inequalities provide lower bounds for the area of spatial sections of dynamical trapping horizons, namely hypersurfaces offering quasi-local models of black hole horizons. In particular, these inequalities represent particular examples of the extension to a Lorentzian setting of tools employed in the discussion of minimal surfaces in Riemannian contexts.

  17. Geomorphologic Structures on the South Cretan Margin, Greece

    Nomikou, Paraskevi; Lykousis, Vasilis; Alexandri, Matina; Rousakis, Grigoris; Sakellariou, Dimitris; Lampridou, Danai; Alves, Tiago; Ballas, Dionysios


    the central southern margin, south of Messara basin. It has a main central axis orientated ENE-WSW, a maximum depth of 2600m and is bounded by E-W fault zones. On the other hand, Gavdos Rise occupies a major part of the South Cretan Margin. It is bordered by longitudinal troughs with steep slopes. Two intraslope basins are also distinguishable at the southwestern part of the Rise, with depths 1100 and 2000 m respectively. The gentler slopes of the Rise are relatively channel-free with low morphological values. The very detailed illustration of the bathymetry and morphology of the South Cretan Margin in addition with the study of the canyon system reflects the offshore active tectonics and faulting of the seafloor and the overall deformation since Middle Miocene, in association with the general extension of the South Aegean region.

  18. Recidiva tardia de linfoma da zona marginal Late relapse of marginal zone lymphoma

    Rocha,Talita M. B.S.; Bortolheiro,Tereza C.; Eduardo Costa; Daniela Haardt; Roberto P. Paes; Chiattone, Carlos S.


    O linfoma de zona marginal é um linfoma de baixo grau com curso clínico indolente e potencial de recidiva.1,2 Apresentamos um caso de recidiva tardia após 25 anos de aparente remissão completa, levantando a possibilidade de recidiva de doença preexistente ou desenvolvimento de novo clone neoplásico.Marginal zone lymphoma is a low grade lymphoma with an indolent course and chance to relapse. We present a case of a patient who suffered relapse after 25 years of apparently complete remission of ...

  19. Unraveling the New England orocline, east Gondwana accretionary margin

    Cawood, P. A.; Pisarevsky, S. A.; Leitch, E. C.


    The New England orocline lies within the Eastern Australian segment of the Terra Australis accretionary orogen and developed during the late Paleozoic to early Mesozoic Gondwanide Orogeny (310-230 Ma) that extended along the Pacific margin of the Gondwana supercontinent. The orocline deformed a pre-Permian arc assemblage consisting of a western magmatic arc, an adjoining forearc basin and an eastern subduction complex. The orocline is doubly vergent with the southern and northern segments displaying counter-clockwise and clockwise rotation, respectively, and this has led to contrasting models of formation. We resolve these conflicting models with one that involves buckling of the arc system about a vertical axis during progressive northward translation of the southern segment of the arc system against the northern segment, which is pinned relative to cratonic Gondwana. Paleomagnetic data are consistent with this model and show that an alternative model involving southward motion of the northern segment relative to the southern segment and cratonic Gondwana is not permissible. The timing of the final stage of orocline formation (˜270-265 Ma) overlaps with a major gap in magmatic activity along this segment of the Gondwana margin, suggesting that northward motion and orocline formation were driven by a change from orthogonal to oblique convergence and coupling between the Gondwana and Pacific plates.

  20. Characterizing entanglement with global and marginal entropic measures

    Adesso, G; De Siena, S; Adesso, Gerardo; Illuminati, Fabrizio; Siena, Silvio De


    We qualify the entanglement of arbitrary mixed states of bipartite quantum systems by comparing global and marginal mixednesses quantified by different entropic measures. For systems of two qubits we discriminate the class of maximally entangled states with fixed marginal mixednesses, and determine an analytical upper bound relating the entanglement of formation to the marginal linear entropies. This result partially generalizes to mixed states the quantification of entaglement with marginal mixednesses holding for pure states. We identify a class of entangled states that, for fixed marginals, are globally more mixed than product states when measured by the linear entropy. Such states cannot be discriminated by the majorization criterion.

  1. Numerical modeling of the development of southeastern Red Sea continental margin

    Sunil Kumar Dwivedi; Daigoro Hayashi


    The Red Sea continental margin (RSCM) corresponds to a wide hinge zone between Red Sea and Arabian plate. This margin has been studied through geological and geophysical observations primarily in regard to the evolution of Red Sea rift. This margin is characterized by occurrence of thin sediments, significant onshore uplift, tectonic subsidence of the offshore sedimentary basin, active faulting and seismicity. Studies indicate that sedimentary sequences of the margin are deformed by faults and folds resulting from at least two phases of extension and a phase of uplift. During the two phases of extension due to regional plate stress the sequence was cut by set of extensional faults. While during the phase of uplift the sequence was deformed by folding and faulting. The present paper aims to clear the structural development of RSCM during these tectonic episodes, taken as particular tectonic event, by two-dimensional finite element modeling on plane strain condition. Elastic rheology is assumed for the oceanic, continental and transitional crust along with syntectonic deposits. Stress field, shear stress and fault distribution suggests that mantle plume weakened the crust following rifting due to regional stress and developed the margin. These results are well consistent with those from present seismicity, active faulting and neotec-tonic studies.

  2. Research priorities for zoonoses and marginalized infections.


    This report provides a review and analysis of the research landscape for zoonoses and marginalized infections which affect poor populations, and a list of research priorities to support disease control. The work is the output of the Disease Reference Group on Zoonoses and Marginalized Infectious Diseases of Poverty (DRG6), which is part of an independent think tank of international experts, established and funded by the Special Programme for Research and Training in Tropical Diseases (TDR), to identify key research priorities through review of research evidence and input from stakeholder consultations. The report covers a diverse range of diseases, including zoonotic helminth, protozoan, viral and bacterial infections considered to be neglected and associated with poverty. Disease-specific research issues are elaborated under individual disease sections and many common priorities are identified among the diseases such as the need for new and/or improved drugs and regimens, diagnostics and, where appropriate, vaccines. The disease-specific priorities are described as micro priorities compared with the macro level priorities which will drive policy-making for: improved surveillance; interaction between the health, livestock, agriculture, natural resources and wildlife sectors in tackling zoonotic diseases; and true assessment of the burden of zoonoses. This is one often disease and thematic reference group reports that have come out of the TDR Think Tank, all of which have contributed to the development of the Global Report search on Infectious Diseases of Poverty, available at:

  3. Instability and Tsunamigenic Potential at Convergent Margins

    von Huene, R.; Ranero, C. R.; Watts, P.


    Along many convergent margins multibeam echosounding navigated with GPS has revealed large slope failures that were probably tsunamigenic. Bathymetric data combined with seismic reflection imaging indicate multiple causes. The 55-km wide Nicoya Slump resulted from the steepening slope above an underthrusting seamount on the subducting oceanic plate. This slump may have generated a 27-m high wave. Several 5-7 km wide mid-slope slides off central Nicaragua probably resulted from steepening of the continental slope by tectonic erosion. They may have generated waves 6-7 m high. A 30 km wide mid-slope slump off northern Peru may have generated a 5 m high wave. Its cause will not be understood without better seismic reflection imaging but considerable fluid venting was observed across its headwall. In the Gulf of Alaska a large slide appears to have resulted from rapid sedimentation. Tsunamigenic slope failure along convergent margins is only beginning to be resolved and the causes vary. Subducted ocean floor relief, tectonically steepened slopes, and sites of rapid sedimentation can help target potential failure and possible future tsunami hazards.

  4. Large margin classifier-based ensemble tracking

    Wang, Yuru; Liu, Qiaoyuan; Yin, Minghao; Wang, ShengSheng


    In recent years, many studies consider visual tracking as a two-class classification problem. The key problem is to construct a classifier with sufficient accuracy in distinguishing the target from its background and sufficient generalize ability in handling new frames. However, the variable tracking conditions challenges the existing methods. The difficulty mainly comes from the confused boundary between the foreground and background. This paper handles this difficulty by generalizing the classifier's learning step. By introducing the distribution data of samples, the classifier learns more essential characteristics in discriminating the two classes. Specifically, the samples are represented in a multiscale visual model. For features with different scales, several large margin distribution machine (LDMs) with adaptive kernels are combined in a Baysian way as a strong classifier. Where, in order to improve the accuracy and generalization ability, not only the margin distance but also the sample distribution is optimized in the learning step. Comprehensive experiments are performed on several challenging video sequences, through parameter analysis and field comparison, the proposed LDM combined ensemble tracker is demonstrated to perform with sufficient accuracy and generalize ability in handling various typical tracking difficulties.

  5. Limit theorems for functions of marginal quantiles

    Babu, G Jogesh; Choi, Kwok Pui; Mangalam, Vasudevan; 10.3150/10-BEJ287


    Multivariate distributions are explored using the joint distributions of marginal sample quantiles. Limit theory for the mean of a function of order statistics is presented. The results include a multivariate central limit theorem and a strong law of large numbers. A result similar to Bahadur's representation of quantiles is established for the mean of a function of the marginal quantiles. In particular, it is shown that \\[\\sqrt{n}\\Biggl(\\frac{1}{n}\\sum_{i=1}^n\\phi\\bigl(X_{n:i}^{(1)},...,X_{n:i}^{(d)}\\bigr)-\\bar{\\gamma}\\Biggr)=\\frac{1}{\\sqrt{n}}\\sum_{i=1}^nZ_{n,i}+\\mathrm{o}_P(1)\\] as $n\\rightarrow\\infty$, where $\\bar{\\gamma}$ is a constant and $Z_{n,i}$ are i.i.d. random variables for each $n$. This leads to the central limit theorem. Weak convergence to a Gaussian process using equicontinuity of functions is indicated. The results are established under very general conditions. These conditions are shown to be satisfied in many commonly occurring situations.


    A. Georgescu


    Full Text Available Premises: Sexual hormones may affect the general health condition of women, as early as puberty, continuing during pregnancy and also after menopause. Variations of the hormonal levels may cause different – either local or general – pathological modifications. Sexual hormones may also affect periodontal status, favourizing gingival inflammations and reducing periodontal resistance to the action of the bacterial plaque. Scope: Establishment of the correlations between the debut or the manifestation of menopause and the modifications produced in the superficial periodontium. Materials and method: Clinical and paraclinical investigations were performed on female patients with ages between 45 and 66 years, involving macroscopic, microscopic and radiological recording of the aspect of the superificial periodontium (gingiva. Results: Analysis of the histological sections evidenced atrophic and involutive modifications in the marginal superficial periodontium of female patients at menopause. Conclusions: Sexual hormones intervene in the histological equilibrium of the marginal superficial periodontium, influencing the periodontal health status, which explains the correlation between the subjective symptomatology specific to menopause and the histopatological aspect at epithelial level.

  7. Naturally light dilatons from nearly marginal deformations

    Megias, Eugenio


    We discuss the presence of a light dilaton in CFTs deformed by a nearly-marginal operator O, in the holographic realizations consisting of confining RG flows that end on a soft wall. Generically, the deformations induce a condensate , and the dilaton mode can be identified as the fluctuation of . We obtain a mass formula for the dilaton as a certain average along the RG flow. The dilaton is naturally light whenever i) confinement is reached fast enough (such as via the condensation of O) and ii) the beta function is small (walking) at the condensation scale. These conditions are satisfied for a class of models with a bulk pseudo-Goldstone boson whose potential is nearly flat at small field and exponential at large field values. Thus, the recent observation by Contino, Pomarol and Ratazzi holds in CFTs with a single nearly-marginal operator. We also discuss the holographic method to compute the condensate , based on solving the first-order nonlinear differential equation that the beta function satisfies.

  8. Photogrammetric monitoring of glacier margin lakes

    Christian Mulsow


    Full Text Available The growing number of glacier margin lakes that have developed due to glacier retreat have caused an increase of dangerous glacier lake outburst floods (GLOFs in several regions over the last decade. This normally causes a flood wave downstream the glacier. Typically, such an event takes few to several hours. GLOF scenarios may be a significant hazard to life, property, nature and infrastructure in the affected areas. A GLOF is usually characterized by a progressive water level drop. By observing the water level of the lake, an imminent GLOF-event can be identified. Common gauging systems are often not suitable for the measurement task, as they may be affected by ice fall or landslides in the lake basin. Therefore, in our pilot study, the water level is observed by processing images of a terrestrial camera system observing a glacier margin lake. The paper presents the basic principle of an automatic single-camera-based GLOF early warning system. Challenges and approaches to solve them are discussed. First, results from processed image sequences are presented to show the feasibility of the concept. Water level changes can be determined at decimetre precision.

  9. The Role of Weight Shrinking in Large Margin Perceptron Learning

    Panagiotakopoulos, Constantinos


    We introduce into the classical perceptron algorithm with margin a mechanism that shrinks the current weight vector as a first step of the update. If the shrinking factor is constant the resulting algorithm may be regarded as a margin-error-driven version of NORMA with constant learning rate. In this case we show that the allowed strength of shrinking depends on the value of the maximum margin. We also consider variable shrinking factors for which there is no such dependence. In both cases we obtain new generalizations of the perceptron with margin able to provably attain in a finite number of steps any desirable approximation of the maximal margin hyperplane. The new approximate maximum margin classifiers appear experimentally to be very competitive in 2-norm soft margin tasks involving linear kernels.

  10. Continental margin radiography from a potential field and sediment thickness standpoint: the Iberian Atlantic Margin

    Catalan, M.; Martos, Y. M.; Martin-Davila, J.; Munoz-Martin, A.; Carbo, A.; Druet, M.


    This study reviews the state of knowledge in the Iberian Atlantic margin. In order to do this, the margin has been divided into three provinces: the Galicia margin, the southern Iberian abyssal plain, and the Tagus abyssal plain. We have used potential field and sediment thickness data. This has allowed us to study the crust, setting limits for the continental crust domain, and the amplitude of the so-called ocean-continent transition, whose end marks the beginning of the oceanic crust. The study shows the continental crust in the Galician margin to be the widest, about 210 km in length, whilst the ocean-continent transition varies slightly in this province: between 65 km wide in the south and 56 km wide in the north. This result shows up some differences with the hypothesis of other authors. The situation in the southern Iberian abyssal plain is nearly the opposite. Its continental crust extends approximately 60 km, whilst the ocean-continent transition zone is 185 km long. The Tagus abyssal plain study shows a faster morphological evolution than the others, according with the amount of crustal thinning β, the ocean-continent transition domain spanning 100 km. These results support a transitional intermediate character for almost the whole Tagus plain, in contrary to what other authors have stated. (Author)

  11. The tragedy of the margins: land rights and marginal lands in Vietnam (c. 1800-1945)

    J. Kleinen


    This article deals with aspects of official land registers in pre-colonial and colonial Vietnam and their relationship with marginal lands since the eleventh century and especially since the beginning of the nineteenth century. The changing pattern of land ownership and control is studied in detail

  12. Talking (and Not Talking) about Race, Social Class and Dis/Ability: Working Margin to Margin

    Ferri, Beth A.; Connor, David J.


    In this article we examine some of the omnipresent yet unacknowledged discourses of social and economic disadvantage and dis/ability within schools in the US. First, we document ways that social class, race, and dis/ability function within schools to further disadvantage and exclude already marginalized students. Next, we show how particular ways…

  13. Dehydroepiandrosterone Derivatives as Potent Antiandrogens with Marginal Agonist Activity


    EM, Yao JL, Miyamoto H (corresponding author): Intraoperative frozen section analysis in fibrous pseudotumor of the testicle: a five- case experience...protein (TAP) expression in prostate cancer and its correlation with clinico -pathologic features. The 63rd Annual Meeting of the Northeastern Section...during radical prostatectomy: a 1,993- case experience. United States & Canadian Academy of Pathology 101st Annual Meeting at Vancouver, Canada (March

  14. Real-Time GNSS Positioning Along Canada's Active Coastal Margin

    Henton, J. A.; Dragert, H.; Lu, Y.


    High-rate, low-latency Global Navigation Satellite System (GNSS) data are being refined for real-time applications to monitor and report motions related to large earthquakes in coastal British Columbia. Given the tectonic setting of Canada's west coast, specific goals for real-time regional geodetic monitoring are: (1) the collection of GNSS data with adequate station density to identify the deformation field for regional earthquakes with M>7.3; (2) the robust, continuous real-time analyses of GNSS data with a precision of 1-2 cm and a latency of less than 10s; and (3) the display of results with attending automated alarms and estimations of earthquake parameters. Megathrust earthquakes (M>8) are the primary targets for immediate identification, since the tsunamis they generate will strike the coast within 15 to 20 min. However, large (6.0displacements expected from various offshore events which allows an evaluation of the effectiveness of the current regional coverage. The present distribution and density of real-time sites is largely sufficient for aiding the timely estimation of size, location, and nature of a great (M>8) megathrust earthquake. However, current coverage is inadequate for the unambiguous identification of the same parameters for 7

  15. Dehydroepiandrosterone Derivatives as Potent Antiandrogens with Marginal Agonist Activity


    for the management of androgen-independent prostate cancer. Urology 1996; 47: 61-9. [52] Barrie SE, Potter GA, Goddard PM, Haynes BP, Dowsett M...doi:10.1593/neo.08274) Neal DE, Sharples L, Smith K, Fennelly J, Hall RR & Harris AL 1990 The epidermal growth factor receptor and the prognosis of...Sharples L, Smith K, Fennelly J, Hall RR and Harris AL: The epidermal growth factor receptor and the prognosis of bladder cancer. Cancer 65: 1619-1625

  16. Russia's Unwanted Children: A Cultural Anthropological Study of Marginalized Children in Moscow and St. Petersburg.

    Creuziger, Clementine G. K.


    Studied the plight of marginalized children in urban Russia, including orphans, children with some family ties living in group homes, and street children. Found that changing public views toward these groups since WWII have led to a deterioration in lifestyle for these children, further contributing to criminal activity and poverty in urban areas.…

  17. Targeted drug delivery by ultrasound-triggered margination of microbubbles

    Guckenberger, Achim


    The ideal agent for targeted drug delivery should stay away from the biochemically active walls of the blood vessels during circulation. However, upon reaching its target it should attain a near-wall position. Though seemingly contradictory, we show that coated microbubbles (ultrasound contrast agents) possess precisely these two properties. Using numerical simulations we find that application of a localized ultrasound pulse at the target organ triggers their rapid migration from the vessel center toward the endothelial wall. This ultrasound-triggered margination is due to hydrodynamic interactions between the red blood cells and the oscillating bubbles. Importantly, we find that the effect is very robust, existing even if the duration in the stiff state is five times lower than the opposing time in the soft state. Our results might also explain why recent in-vivo studies found strongly enhanced drug uptake by co-administration of microbubbles with classical drug delivery agents.

  18. Nitrogen cycling in a deep ocean margin sediment (Sagami Bay, Japan)

    Glud, Ronnie Nøhr; Thamdrup, C.; Stahl, H


    On the basis of in situ NO3- microprofiles and chamber incubations complemented by laboratory-based assessments of anammox and denitrification we evaluate the nitrogen turnover of an ocean margin sediment at 1450-m water depth. In situ NO3- profiles horizontally separated by 12 mm reflected highly...... metabolism for 12-52 d, contributed only to a minor extent to the overall N-2 production. The microbial activity in the surface sediment is a net nutrient sink of similar to 1.1 mmol N m(-2) d(-1), which aligns with many studies performed in coastal and shelf environments. Continental margin areas can act...

  19. Evidence for Marginal Stability in Emulsions

    Lin, Jie; Jorjadze, Ivane; Pontani, Lea-Laetitia; Wyart, Matthieu; Brujic, Jasna


    We report the first measurements of the effect of pressure on vibrational modes in emulsions, which serve as a model for soft frictionless spheres at zero temperature. As a function of the applied pressure, we find that the density of states D (ω ) exhibits a low-frequency cutoff ω*, which scales linearly with the number of extra contacts per particle δ z . Moreover, for ω Soft Matter 10, 5628 (2014); S. Franz, G. Parisi, P. Urbani, and F. Zamponi, Proc. Natl. Acad. Sci. U.S.A. 112, 14539 (2015)]. Finally, the degree of localization of the softest low frequency modes increases with compression, as shown by the participation ratio as well as their spatial configurations. Overall, our observations show that emulsions are marginally stable and display non-plane-wave modes up to vanishing frequencies.

  20. Regnar -- Development of a marginal field

    Thalund, K.M.; Brodersen, F.P.; Roigaard-Petersen, B. [Maersk Olie og Gas AS, Copenhagen (Denmark)


    Regnar is a small marginal field located some 13 km from the main Dan F complex and is the first subsea completion in Danish waters, operated by Maersk Olie og Gas AS. A short lifetime has been predicted for the field which therefore has been developed as a low cost project, using a combination of subsea technology and minimum topside facilities. Regnar consists of a subsea x-mas tree producing through a 6 inch pipeline with a 2 1/2 inch chemical piggyback line to Dan F. The x-mas tree and the subsea choke valve are controlled from a buoy moored nearby the well. The buoy is radio linked to Dan F. The Regnar field was brought on stream on September 26, 1993.

  1. Max-margin based Bayesian classifier

    Tao-cheng HU‡; Jin-hui YU


    There is a tradeoff between generalization capability and computational overhead in multi-class learning. We propose a generative probabilistic multi-class classifi er, considering both the generalization capability and the learning/prediction rate. We show that the classifi er has a max-margin property. Thus, prediction on future unseen data can nearly achieve the same performance as in the training stage. In addition, local variables are eliminated, which greatly simplifi es the optimization problem. By convex and probabilistic analysis, an efficient online learning algorithm is developed. The algorithm aggregates rather than averages dualities, which is different from the classical situations. Empirical results indicate that our method has a good generalization capability and coverage rate.


    Mason M. Medizade; John R. Ridgely; Donald G. Nelson


    A marginal expense oil well wireless surveillance system to monitor system performance and production from rod-pumped wells in real time from wells operated by Vaquero Energy in the Edison Field, Main Area of Kern County in California has been successfully designed and field tested. The surveillance system includes a proprietary flow sensor, a programmable transmitting unit, a base receiver and receiving antenna, and a base station computer equipped with software to interpret the data. First, the system design is presented. Second, field data obtained from three wells is shown. Results of the study show that an effective, cost competitive, real-time wireless surveillance system can be introduced to oil fields across the United States and the world.

  3. Sedimentation and potential venting on the rifted continental margin of Dronning Maud Land

    Huang, Xiaoxia; Jokat, Wilfried


    The relief of Dronning Maud Land (DML), formed by Middle and Late Mesozoic tectonic activity, had a strong spatial control on the early fluvial and subsequent glacial erosion and deposition. The sources, processes, and products of sedimentation along the DML margin and in the Lazarev Sea in front of the DML mountains have been barely studied. The onshore mountain belt parallel to the coast of the DML margin acts as a barrier to the transport of terrigenous sediments from the east Antarctic interior to the margin and into the Lazarev Sea. Only the Jutul-Penck Graben system allows a localized ice stream controlled transport of material from the interior of DML across its old mountain belt. Offshore, we attribute repeated large-scale debris flow deposits to instability of sediments deposited locally on the steep gradient of the DML margin by high sediment flux. Two types of canyons are defined based on their axial dimensions and originated from turbidity currents and slope failures during glacial/fluvial transport. For the first time, we report pipe-like seismic structures in this region and suggest that they occurred as consequences of volcanic processes. Sedimentary processes on the DML margin were studied using seismic reflection data and we restricted the seismic interpretation to the identification of major seismic sequences and their basal unconformities.

  4. Sedimentation and potential venting on the rifted continental margin of Dronning Maud Land

    Huang, Xiaoxia; Jokat, Wilfried


    The relief of Dronning Maud Land (DML), formed by Middle and Late Mesozoic tectonic activity, had a strong spatial control on the early fluvial and subsequent glacial erosion and deposition. The sources, processes, and products of sedimentation along the DML margin and in the Lazarev Sea in front of the DML mountains have been barely studied. The onshore mountain belt parallel to the coast of the DML margin acts as a barrier to the transport of terrigenous sediments from the east Antarctic interior to the margin and into the Lazarev Sea. Only the Jutul-Penck Graben system allows a localized ice stream controlled transport of material from the interior of DML across its old mountain belt. Offshore, we attribute repeated large-scale debris flow deposits to instability of sediments deposited locally on the steep gradient of the DML margin by high sediment flux. Two types of canyons are defined based on their axial dimensions and originated from turbidity currents and slope failures during glacial/fluvial transport. For the first time, we report pipe-like seismic structures in this region and suggest that they occurred as consequences of volcanic processes. Sedimentary processes on the DML margin were studied using seismic reflection data and we restricted the seismic interpretation to the identification of major seismic sequences and their basal unconformities.

  5. A tectonic reconstruction of accreted terranes along the paleo-Pacific margin of Gondwana

    Bammel, Brandon

    The southern oceanic margin of Gondwana was nearly 40,000 km long or 24,854.8 miles. The southern margin was the result of the Terra Australis orogen. Spanning 18,000 km or 11,184.7 miles and is proposed as one of the largest and longest lived orogens in Earth history. The paleo-Pacific margin of Gondwana consisted of segments of the Australian-Antarctic craton, southern South America (modern Argentina and Chile), southern South Africa, Marie Byrdland, New Zealand and its adjacent continental shelf, the Ellsworth Mountains, and the Transantarctic Mountains. The process of terrane accretion has played a substantial part in the assembly of the continents as they look today. The paleo-Pacific margin of Gondwana was an active region of terrane accretion from the Neoproterozoic to the Late Mesozoic. This research study examines the accretion of terranes across the paleo-Pacific Gondwana margin to provide a comprehensive reconstruction. A paleogeographic basemap was created using PALEOMAP Project maps and the geology data was provided by the School of Geoscience from the University of Witwatersrand of South Africa. Location and data analyzed for terranes were collected building a PDF library of journal articles across numerous geological publications.

  6. Lithospheric Thermal Isostasy of North Continental Margin of the South China Sea

    Chen Shi; Zhang Jian; Sun Yujun; Shi Yaolin


    Accompanied with rifting and detaching of the north continental margin of the South China Sea,the ernst and the lithosphere become thinner away from the continental margin resulting from the tectonic activities,such as tensile deformation,thermal uplift,and cooling subsidence,etc..Integrated with thermal,gravimetric,and isostatic analysis techniques,based on the seismic interpretation of the deep penetration seismic soundings across the northern margin of the South China Sea,we reconstructed the lithospheric thermal structure and derived the variation of the crust boundary in the east and west parts of the seismic profde by using gravity anomaly data.We mainly studied the thermal isostasy problems using the bathymetry of the profiles and calculated the crust thinning effect due to the thermal variety in the rifting process.The results Indicate that the thermal isostasy may reach 2.5 kin,and the compositional variations in the ilthospheric density and thickness may produce a variation of 4.0 kin.Therefore,the compositional isostatic correction is very important to recover the relationship between surface heat flow and topography.Moreover,because of the high heat flow characteristic of the continental margin,building the model of lithospheric geotherm in this region is of great importan for studying the Cenozoic tectonic thermal evolution of the north passive continental margin of the South China Sea.

  7. Wintertime pytoplankton bloom in the Subarctic Pacific supportedby continental margin iron

    Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus,Matthew A.; Waychunas, Glenn A.; Fung, Inez


    Heightened biological activity was observed in February 1996in the high-nutrient low-chlorophyll (HNLC) subarctic North PacificOcean, a region that is thought to beiron-limited. Here we provideevidence supporting the hypothesis that Ocean Station Papa (OSP) in thesubarctic Pacific received a lateral supply of particulate iron from thecontinental margin off the Aleutian Islands in the winter, coincidentwith the observed biological bloom. Synchrotron X-ray analysis was usedto describe the physical form, chemistry, and depth distributions of ironin size fractionated particulate matter samples. The analysis revealsthat discrete micron-sized iron-rich hotspots are ubiquitous in the upper200m at OSP, more than 900km from the closest coast. The specifics of thechemistry and depth profiles of the Fe hot spots trace them to thecontinental margins. We thus hypothesize that iron hotspots are a markerfor the delivery of iron from the continental margin. We confirm thedelivery of continental margin iron to the open ocean using an oceangeneral circulation model with an iron-like tracer source at thecontinental margin. We suggest that iron from the continental marginstimulated a wintertime phytoplankton bloom, partially relieving the HNLCcondition.

  8. System Guidelines for EMC Safety-Critical Circuits: Design, Selection, and Margin Demonstration

    Lawton, R. M.


    Demonstration of required safety margins on critical electrical/electronic circuits in large complex systems has become an implementation and cost problem. These margins are the difference between the activation level of the circuit and the electrical noise on the circuit in the actual operating environment. This document discusses the origin of the requirement and gives a detailed process flow for the identification of the system electromagnetic compatibility (EMC) critical circuit list. The process flow discusses the roles of engineering disciplines such as systems engineering, safety, and EMC. Design and analysis guidelines are provided to assist the designer in assuring the system design has a high probability of meeting the margin requirements. Examples of approaches used on actual programs (Skylab and Space Shuttle Solid Rocket Booster) are provided to show how variations of the approach can be used successfully.

  9. Assessment of tsunami hazard to the U.S. Atlantic margin

    Ten Brink, Uri; Chaytor, Jason; Geist, Eric L.; Brothers, Daniel S.; Andrews, Brian D.


    Tsunami hazard is a very low-probability, but potentially high-risk natural hazard, posing unique challenges to scientists and policy makers trying to mitigate its impacts. These challenges are illustrated in this assessment of tsunami hazard to the U.S. Atlantic margin. Seismic activity along the U.S. Atlantic margin in general is low, and confirmed paleo-tsunami deposits have not yet been found, suggesting a very low rate of hazard. However, the devastating 1929 Grand Banks tsunami along the Atlantic margin of Canada shows that these events continue to occur. Densely populated areas, extensive industrial and port facilities, and the presence of ten nuclear power plants along the coast, make this region highly vulnerable to flooding by tsunamis and therefore even low-probability events need to be evaluated.

  10. Evolution of high Arctic ocean basins and continental margins

    Engen, Oeyvind


    . At the Laptev Sea continental slope, the change from ultra-slow seafloor spreading to active continental rifting takes place over a less than 60-km-wide continent-ocean transition featuring a 150-200-km-long sheared margin segment. The western Gakkel Ridge province is magmatically segmented. The central, sparsely magmatic segment is characterised by discrete magmatic centres that have been stationary with respect to the spreading axis since at least Chron 6 times (apprx. 19.6 Ma) and possibly since before Chron 18 times (apprx. 39.9 Ma). The westernmost, volcanic segment may have been amagmatic during Chron 13-5 times (apprx. 33.3-9.8 Ma). Sedimentary rocks in the Nansen Basin comprise four turbidite units with typical seismic velocities of 2.3, 2.2, 1.9 and 1.8 km s-1. The upper unit is associated with glaciomarine deposition in the Franz-Victoria Fan system and dates accordingly to approx. 2.3 Ma. The deeper, regional velocity contrast from 2.2 to 1.9 km s-1 probably represents a late Miocene (apprx. 10 Ma) response to major paleoceanographic changes during the opening of the Fram Strait gateway. A location of the continent-ocean transition (COT) on conjugate margins of the western Eurasia Basin and the northern Norwegian-Greenland Sea is proposed from the relation between seismically observed crustal thinning and seaward increasing mantle Bouguer anomalies. A refined location of the COT around the Hovgaard and Greenland ridges is also provided. The new COT location indicates that the distinct segmentation of the western Barents Sea margin is mirrored on the conjugate northeast Greenland margin. The Hinlopen margin north of Svalbard is characterised by a steep boundary fault on the COT and may be a sheared margin segment. The present geological and geophysical data base favours a continental origin of the Yermak Plateau and the Morris Jesup Rise, but a firm conclusion on their crustal structure cannot yet be drawn. A continuous oceanic corridor formed through shear

  11. Analysis of System Margins on Missions Utilizing Solar Electric Propulsion

    Oh, David Y.; Landau, Damon; Randolph, Thomas; Timmerman, Paul; Chase, James; Sims, Jon; Kowalkowski, Theresa


    NASA's Jet Propulsion Laboratory has conducted a study focused on the analysis of appropriate margins for deep space missions using solar electric propulsion (SEP). The purpose of this study is to understand the links between disparate system margins (power, mass, thermal, etc.) and their impact on overall mission performance and robustness. It is determined that the various sources of uncertainty and risk associated with electric propulsion mission design can be summarized into three relatively independent parameters 1) EP Power Margin, 2) Propellant Margin and 3) Duty Cycle Margin. The overall relationship between these parameters and other major sources of uncertainty is presented. A detailed trajectory analysis is conducted to examine the impact that various assumptions related to power, duty cycle, destination, and thruster performance including missed thrust periods have on overall performance. Recommendations are presented for system margins for deep space missions utilizing solar electric propulsion.

  12. Estimation of marginal abatement costs for undesirable outputs in India's power generation sector: An output distance function approach.

    Manish Gupta


    Many production activities generate undesirable byproducts in conjunction with the desirable outputs they produce. The present study uses an output distance function approach and its duality with the revenue function to estimate the marginal abatement cost of CO2 emissions from a sample of thermal plants in India. Two sets of exercises have been undertaken. The marginal abatement cost is first estimated without considering the distinction between the clean and the dirty plants (model-1) and t...

  13. Observations at convergent margins concerning sediment subduction, subduction erosion, and the growth of continental crust

    Von Huene, R.; Scholl, D. W.


    At ocean margins where two plates converge, the oceanic plate sinks or is subducted beneath an upper one topped by a layer of terrestrial crust. This crust is constructed of continental or island arc material. The subduction process either builds juvenile masses of terrestrial crust through arc volcanism or new areas of crust through the piling up of accretionary masses (prisms) of sedimentary deposits and fragments of thicker crustal bodies scraped off the subducting lower plate. At convergent margins, terrestrial material can also bypass the accretionary prism as a result of sediment subduction, and terrestrial matter can be removed from the upper plate by processes of subduction erosion. Sediment subduction occurs where sediment remains attached to the subducting oceanic plate and underthrusts the seaward position of the upper plate's resistive buttress (backstop) of consolidated sediment and rock. Sediment subduction occurs at two types of convergent margins: type 1 margins where accretionary prisms form and type 2 margins where little net accretion takes place. At type 2 margins (???19,000 km in global length), effectively all incoming sediment is subducted beneath the massif of basement or framework rocks forming the landward trench slope. At accreting or type 1 margins, sediment subduction begins at the seaward position of an active buttress of consolidated accretionary material that accumulated in front of a starting or core buttress of framework rocks. Where small-to-mediumsized prisms have formed (???16,300 km), approximately 20% of the incoming sediment is skimmed off a detachment surface or decollement and frontally accreted to the active buttress. The remaining 80% subducts beneath the buttress and may either underplate older parts of the frontal body or bypass the prism entirely and underthrust the leading edge of the margin's rock framework. At margins bordered by large prisms (???8,200 km), roughly 70% of the incoming trench floor section is

  14. Margin Requirements and Portfolio Optimization: A Geometric Approach

    Sheng Guo


    Using geometric illustrations, we investigate what implications of portfolio optimization in equilibrium can be generated by the simple mean-variance framework, under margin borrowing restrictions. First, we investigate the case of uniform marginability on all risky assets. It is shown that changing from unlimited borrowing to margin borrowing shifts the market portfolio to a riskier combination, accompanied by a higher risk premium and a lower price of risk. With the linear risk-return prefe...

  15. Marginal pricing of transmission services. An analysis of cost recovery

    Perez-Arriaga, I.J.., Rubio, F.J. [Instituto de Investigacion Technologica, Universidad Pontificia Comillas, Madrid (Spain); Puerta, J.F.; Arceluz, J.; Marin, J. [Unidad de Planificacion Estrategica, Iberdrola, Madrid (Spain)


    The authors present an in-depth analysis of network revenues that are computed with marginal pricing, and investigate the reasons why marginal prices in actual power systems fail to recover total incurred network costs. The major causes of the failure are identified and illustrated with numerical examples. The paper analyzes the regulatory implications of marginal network pricing in the context of competitive electricity markets and provides suggestions for the meaningful allocation of network costs among users. 5 figs., 9 tabs., 8 refs.

  16. Convex games, clan games, and their marginal games

    Branzei , Rodica; Dimitrov, Dinko; Tijs, Stef


    We provide characterizations of convex games and total clan games by using properties of their corresponding marginal games. As it turns out, a cooperative game is convex if and only if all its marginal games are superadditive, and a monotonic game satisfying the veto player property with respect to the members of a coalition C is a total clan game (with clan C) if and only if all its C-based marginal games are subadditive.

  17. Ex vivo ultrasound control of resection margins during partial nephrectomy.

    Doerfler, Arnaud; Cerantola, Yannick; Meuwly, Jean-Yves; Lhermitte, Benoît; Bensadoun, Henri; Jichlinski, Patrice


    Surgery remains the treatment of choice for localized renal neoplasms. While radical nephrectomy was long considered the gold standard, partial nephrectomy has equivalent oncological results for small tumors. The role of negative surgical margins continues to be debated. Intraoperative frozen section analysis is expensive and time-consuming. We assessed the feasibility of intraoperative ex vivo ultrasound of resection margins in patients undergoing partial nephrectomy and its correlation with margin status on definitive pathological evaluation. A study was done at 2 institutions from February 2008 to March 2011. Patients undergoing partial nephrectomy for T1-T2 renal tumors were included in analysis. Partial nephrectomy was done by a standardized minimal healthy tissue margin technique. After resection the specimen was kept in saline and tumor margin status was immediately determined by ex vivo ultrasound. Sequential images were obtained to evaluate the whole tumor pseudocapsule. Results were compared with margin status on definitive pathological evaluation. A total of 19 men and 14 women with a mean ± SD age of 62 ± 11 years were included in analysis. Intraoperative ex vivo ultrasound revealed negative surgical margins in 30 cases and positive margins in 2 while it could not be done in 1. Final pathological results revealed negative margins in all except 1 case. Ultrasound sensitivity and specificity were 100% and 97%, respectively. Median ultrasound duration was 1 minute. Mean tumor and margin size was 3.6 ± 2.2 cm and 1.5 ± 0.7 mm, respectively. Intraoperative ex vivo ultrasound of resection margins in patients undergoing partial nephrectomy is feasible and efficient. Large sample studies are needed to confirm its promising accuracy to determine margin status. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  18. Boost invariant marginally trapped surfaces in Minkowski 4-space

    Haesen, S [Department of Mathematics, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Heverlee (Belgium); Ortega, M [Departamento de GeometrIa y TopologIa, Universidad de Granada, 18071 Granada (Spain)


    The extremal and partly marginally trapped surfaces in the Minkowski 4-space, which are invariant under the group of boost isometries, are classified. Moreover, it is shown that there do not exist extremal surfaces of this kind with constant Gaussian curvature. A procedure is given in order to construct a partly marginally trapped surface by gluing two marginally trapped surfaces which are invariant under the group of boost isometries. As an application, a proper star-surface is constructed.

  19. Estimation of Margins and Efficiency in the Ghanaian Yam Marketing Chain

    Robert Aidoo


    Full Text Available The main objective of the paper was to examine the costs, returns and efficiency levels obtained by key players in the Ghanaian yam marketing chain.A total of 320 players/actors (farmers, wholesalers, retailers and cross-border traders in the Ghanaian yam industry were selected from four districts (Techiman, Atebubu, Ejura-Sekyedumasi and Nkwanta through a multi-stage sampling approach for the study. In addition to descriptive statistics, gross margin, net margin and marketing efficiency analyses were performed using the field data. There was a long chain of greater than three channels through which yams moved from the producer to the final consumer. Yam marketing was found to be a profitable venture for all the key players in the yam marketing chain.Net marketing margin of about GH¢15.52 (US$9.13 was obtained when the farmer himself sold 100tubers of yams in the market rather than at the farm gate.The net marketing margin obtained by wholesalers was estimated at GH¢27.39 per 100tubers of yam sold, which was equivalent to about 61% of the gross margin obtained.Net marketing margin for retailers was estimated at GH¢15.37, representing 61% of the gross margin obtained.A net marketing margin of GH¢33.91 was obtained for every 100tubers of yam transported across Ghana’s borders by cross-border traders. Generally, the study found out that net marketing margin was highest for cross-border yam traders, followed by wholesalers. Yam marketing activities among retailers, wholesalers and cross-border traders were found to be highly efficient with efficiency ratios in excess of 100%. However, yam marketing among producer-sellers was found to be inefficient with efficiency ratio of about 86%.The study recommended policies and strategies to be adopted by central and local government authorities to address key constraints such as poor road network, limited financial resources, poor storage facilities and high cost of transportation that serve as

  20. Marginal pricing of transmission services: An analysis of cost recovery

    Perez-Arriaga, I.J.; Rubio, F.J. [Univ. Pontificia Comillas, Madrid (Spain); Puerta, J.F.; Arceluz, J.; Marin, J. [IBERDROLA, Bilbao (Spain). Unidad de Planificacion Estrategica


    This paper presents an in-depth analysis of network revenues computed with marginal pricing, and in particular it investigates the reasons why marginal prices fail to recover the total incurred network costs in actual power systems. The basic theoretical results are presented and the major causes of the mismatch between network costs and marginal revenues are identified and illustrated with numerical examples, some tutorial and others of realistic size. The regulatory implications of marginal network pricing in the context of competitive electricity markets are analyzed, and suggestions are provided for the meaningful allocation of the costs of the network among its users.

  1. The many ways to be marginal in a group.

    Ellemers, Naomi; Jetten, Jolanda


    Previous theory and research primarily address marginal group members on the path to achieve core membership status. The authors argue that these only represent one form of marginality and that there are many other ways to be marginal within the group. The authors develop a dynamic model in which marginality is conceptualized as resulting from group and individual negotiation about inclusion (the Marginality as Resulting From Group and Individual Negotiation About Inclusion [MARGINI] model), and where individual and group inclusion goals can converge (resulting in relatively stable forms of marginality) or diverge (resulting in less stable forms of marginality). When the marginal position is unstable, individuals can either be motivated to move toward or move further away from the group, and such changing inclusion goals are associated with different emotions and behaviors. The authors argue that one needs to understand the interplay between individual and group inclusion goals to predict and explain the full complexity and diversity of the behavior of marginal group members.

  2. Maximum-entropy distributions of correlated variables with prespecified marginals.

    Larralde, Hernán


    The problem of determining the joint probability distributions for correlated random variables with prespecified marginals is considered. When the joint distribution satisfying all the required conditions is not unique, the "most unbiased" choice corresponds to the distribution of maximum entropy. The calculation of the maximum-entropy distribution requires the solution of rather complicated nonlinear coupled integral equations, exact solutions to which are obtained for the case of Gaussian marginals; otherwise, the solution can be expressed as a perturbation around the product of the marginals if the marginal moments exist.

  3. Marginal distortion of thermally incompatible metal ceramic crowns with overextended margins.

    Nakamura, Y; Anusavice, K J


    The present study tested the hypothesis that metal ceramic crowns with a varying axial height are more susceptible to marginal distortion during mechanical and thermal processing treatments than crowns with a uniform axial height. Copings of Pd-Cu-Ga alloy with buccal margin extensions of 0, 1.5, and 3.0 mm were prepared. Oxidized copings were veneered with experimental opaque porcelain with a mean thermal contraction coefficient (25 degrees C to 500 degrees C) that was either 2.1 ppm/degree C below (delta alpha = +2.1 ppm/degree C) or 0.1 ppm/degree C above (delta alpha = -0.1 ppm/degree C) that of the alloy. Nine groups of six specimens each were prepared for analysis. Eighteen copings from these 54 specimens were used as porcelain-free controls. All specimens were subjected to a 10-step procedure including grinding, oxidation, firing of four opaque porcelain layers (O1: 0.15 mm; O2: 0.15 mm; O3: 0.5 mm; O4: 0.5 mm), glazing, abrasive blasting for 15 seconds, removal of ceramic by dissolution in hydrogen fluoride, and a postannealing treatment. The control specimens were also subjected to this procedure with the exception of the firing of four layers of porcelain, which were not applied. Marginal gap width was determined using a measuring microscope at a magnification of 30x. Analysis of variance revealed a significant difference in mean gap width as a function of axial length. The largest gap change was associated with a 3.0-mm buccal extension and the negative mismatch condition (delta alpha < 0). Marginal distortion of crowns decreases as the axial length becomes more uniform. Analysis of crown distortion based on differences in the mean contraction coefficients of metal and porcelain alone is not recommended because it ignores the effects of metal grinding, metal sandblasting, and transient stress.

  4. Marginal Life-Cycle Greenhouse Gas Emissions of Electricity Generation in Portugal and Implications for Electric Vehicles

    Rita Garcia


    Full Text Available This article assesses marginal greenhouse gas (GHG emissions of electricity generation in Portugal to understand the impact of activities that affect electricity demand in the near term. In particular, it investigates the introduction of electric vehicles (EVs in the Portuguese light-duty fleet considering different displacement and charging scenarios (vehicle technologies displaced, EV charging time. Coal and natural gas were identified as the marginal sources, but their contribution to the margin depended on the hour of the day, time of year, and system load, causing marginal emissions from electricity to vary significantly. Results show that for an electricity system with a high share of non-dispatchable renewable power, such as the Portuguese system, marginal emissions are considerably higher than average emissions. Because of the temporal variability in the marginal electricity supply, the time of charging may have a major influence on the GHG emissions of EVs. Off-peak charging leads to higher GHG emissions than peak charging, due to a higher contribution of coal to the margin. Furthermore, compared to an all-conventional fleet, EV introduction causes an increase in overall GHG emissions in most cases. However, EV effects are very dependent on the time of charging and the assumptions about the displaced technology.

  5. Seaward dipping reflectors along the SW continental margin of India: Evidence for volcanic passive margin

    K K Ajay; A K Chaubey; K S Krishna; D Gopala Rao; D Sar


    Multi-channel seismic reflection profiles across the southwest continental margin of India (SWCMI) show presence of westerly dipping seismic reflectors beneath sedimentary strata along the western flank of the Laccadive Ridge –northernmost part of the Chagos –Laccadive Ridge system. Velocity structure, seismic character, 2D gravity model and geographic locations of the dipping reflectors suggest that these reflectors are volcanic in origin, which are interpreted as Seaward Dipping Reflectors (SDRs). The SDRs; 15 to 27 km wide overlain by ∼1 km thick sediment; are observed at three locations and characterized by stack of laterally continuous, divergent and off-lapping reflectors. Occurrence of SDRs along western flank of the Laccadive Ridge adjacent to oceanic crust of the Arabian Basin and 2D crustal model deduced from free-air gravity anomaly suggest that they are genetically related to incipient volcanism during separation of Madagascar from India. We suggest that (i)SWCMI is a volcanic passive margin developed during India –Madagascar breakup in the Late Cretaceous, and (ii)continent –ocean transition lies at western margin of the Laccadive Ridge, west of feather edge of the SDRs. Occurrence of SDRs on western flank of the Laccadive Ridge and inferred zone of transition from continent to ocean further suggest continental nature of crust of the Laccadive Ridge.

  6. Treatment of the positive surgical margin following radical prostatectomy


    Objective With increased incidence of prostate cancer and an increased number of patients undergoing radical prostatectomy in China,it will be necessary to elaborate the diagnosis,clinical significance and treatment of patients whose tumors have positive surgical margins following radical prostatectomy.Data sources Positive surgical margin,prostate cancer and radical prostatectomy were used as subject words and the medical literature in recent decades was searched using the PubMed database and the results are summarized.Study selection Using positive surgical margin,prostate cancer and radical prostatectomy as subject words the PubMed medical database produced 275 papers of pertinent literature.By further screening 28 papers were selected and they represent relatively large-scale clinical randomized and controlled clinical trials.Results A pertinent literature of 275 papers was identified and 28 papers on large clinical studies were obtained.Analysis of results indicated that the positive rate of surgical margin after radical prostatectomy is 20%-40%,and although most patients with positive surgical margins are stable for a considerable period,the data available now suggested that the presence of a positive surgical margin will have an impact on the patient's prognosis.The risk factors of positive surgical margin include preoperative prostate specific antigen level,Gleason's score and pelvic lymph node metastasis.The most common site with positive surgical margin is in apical areas of the prostate;therefore surgical technique is also a factor resulting in positive surgical margins.From data available now it appears that as long as the surgical technique is skilled,different surgical modes do not affect the rate of surgical margin.Adjuvant radiotherapy is mainly used to treat patients with positive surgical margin after radical prostatectomy,but combination with androgen deprivation therapy may increase the curative effect.Conclusion The current data indicated that

  7. Seismic margins and calibration of piping systems

    Shieh, L.C.; Tsai, N.C.; Yang, M.S.; Wong, W.L.


    The Seismic Safety Margins Research Program (SSMRP) is a US Nuclear Regulatory Commission-funded, multiyear program conducted by Lawrence Livermore National Laboratory (LLNL). Its objective is to develop a complete, fully coupled analysis procedure for estimating the risk of earthquake-induced radioactive release from a commercial nuclear power plant and to determine major contributors to the state-of-the-art seismic and systems analysis process and explicitly includes the uncertainties in such a process. The results will be used to improve seismic licensing requirements for nuclear power plants. In Phase I of SSMRP, the overall seismic risk assessment methodology was developed and assembled. The application of this methodology to the seismic PRA (Probabilistic Risk Assessment) at the Zion Nuclear Power Plant has been documented. This report documents the method deriving response factors. The response factors, which relate design calculated responses to best estimate values, were used in the seismic response determination of piping systems for a simplified seismic probablistic risk assessment. 13 references, 31 figures, 25 tables.

  8. Salam: Of Dislocation, Marginality and Flexibility

    Efenita M. Taqueban


    Full Text Available This paper reconstructs the life stories of residents of SalamCompound. The compound serves as entry point for many Muslim migrants who leave the southern Philippines. Salam is both a refuge and a halfway point. A sense of dislocation permeates the stories. Dislocation begins with the movement away from a homeland that is familiar and defining of identity. The dislocation is, in a sense, an escape, a desperate project to avoid armed conflict in the southern Philippines or a desperate enterprise in search of work.Salam is a halfway point for transients prospecting for overseas work, the staging area for a global labor exodus. The sense of dislocation is not unlike locating oneself in the margins, portrayed in the residents’ negotiated identitiesand spaces, constantly challenged, implicitly regulated. Dislocation is also depicted as flexibility, portrayed by the residents making do and their everyday creative resistance and struggle in new locations in the city. Gathered throughethnographic method, the stories offer a glimpse into the lives of the residents of the compound, how they negotiate around social constructions of identities — resisting and accommodating internal and external forces that impinge ontheir lives, revealing a rich and poignant tapestry of family relations, community ironies and an ever-impinging world beyond its walls.

  9. A multi-class large margin classifier

    Liang TANG; Qi XUAN; Rong XIONG; Tie-jun WU; Jian CHU


    Currently there are two approaches for a multi-class support vector classifier (SVC). One is to construct and combine several binary classifiers while the other is to directly consider all classes of data in one optimization formulation. For a K-class problem (K>2), the first approach has to construct at least K classifiers, and the second approach has to solve a much larger op-timization problem proportional to K by the algorithms developed so far. In this paper, following the second approach, we present a novel multi-class large margin classifier (MLMC). This new machine can solve K-class problems in one optimization formula-tion without increasing the size of the quadratic programming (QP) problem proportional to K. This property allows us to construct just one classifier with as few variables in the QP problem as possible to classify multi-class data, and we can gain the advantage of speed from it especially when K is large. Our experiments indicate that MLMC almost works as well as (sometimes better than) many other multi-class SVCs for some benchmark data classification problems, and obtains a reasonable performance in face recognition application on the AR face database.

  10. Some Comments on Tectonic Erosion and Sediment Subduction in Convergent Margins

    Clift, P. D.; Vannucchi, P.


    Subduction plate boundaries at which tectonic erosion removes material from the overriding plate account for 57% of the total length of the global subduction system are favored where convergence rates exceed about 6 cm/yr and where the sedimentary cover is less than 1 km. Accretion conversely preferentially occurs in regions of slow orthogonal convergence (1 km. The slope gradients and taper angle of accretionary plate margins correlates with plate convergence rates, while erosive margin slopes appear to be independent of this. Rates of trench retreat do not appear to correlate with any simple characteristic of the plate interaction, but are largely a function of the history of seamount or ridge collisions. 55% of the total continental crustal material subducted globally below forearc regions in the modern ocean comprises material removed by tectonic erosion from the over-riding plate, 45% trench sediment. Even in accretionary margins a median of only 17% of the incoming sedimentary mass is accreted over time scales of 10 my or greater, resulting in long-term net loss of continental crust along convergent margins. Average magmatic productivity in the active margins must exceed 90 km3/my to preserve the current volume of the continental crust. Geological arguments indicate that magmatic accretion rates must be faster in oceanic arcs (91-149 km3/my) and less in the continental arcs (27-135 km3/my). Mass balance arguments in oceanic arcs require that their crustal thicknesses must be Continental growth is principally achieved through the collision of oceanic island arcs to continental margins. Although oceanic arcs are chemically distinct from continental crust, the collision process involves the loss of mafic and ultramafic lower crust and the emplacement of voluminous, high silica, light rare earth element enriched melts, transforming the net composition into something more continental in character.

  11. Analysis of Bubble Plume Distributions to Evaluate Methane Hydrate Decomposition on the Cascadia Margin

    Miller, U. K.; Johnson, H. P.; Salmi, M.; Solomon, E. A.


    Methane gas is formed within the sediments of accretionary prisms by the biological and thermal degradation of organic matter. Some of this methane is trapped as solid-phase methane hydrate, the stability of which is temperature and pressure-dependent. Past fluctuations in global temperatures have resulted in the decomposition of continental margin gas hydrate reservoirs and subsequent emissions of methane, creating a positive feedback to global warming with additional impacts on the marine environment. Temperature data collected over the past four decades show that bottom water on the upper slope of the Washington State continental margin has undergone systematic warming. Thermal models of this heat propagation into the sediments indicate a 40 meter deepening of the methane hydrate stability depth (MHDS) that if correct, would suggest a preferential release of methane into the water column from these depths on the Cascadia margin. Location data for over 100 active methane seeps on the Cascadia margin were compiled from a variety of sources including research cruises, published literature, and local fishermen. Emission site locations show anomalous plume densities at depths associated with the MHDS, which lies at approximately 500 meters water depth in the NE Pacific. This supports the hypothesis that warming of seawater at intermediate depths due to contemporary climate change has begun to destabilize the Cascadia margin gas hydrate reservoir. While relatively small sample size and incomplete coverage due to the ad-hoc nature of data acquisition limit confidence in any conclusions drawn from this dataset, this study provides a framework for future analysis of methane plume distributions and supports the need for a comprehensive and systematic geophysical and geochemical examination of the Cascadia margin.

  12. Passive margin asymmetry and its polarity in the presence of a craton

    Andres-Martinez, Miguel; Perez-Gussinye, Marta; Neto-Araujo, Mario; Morgan, Jason


    When continental lithosphere is extended to break-up it forms two conjugate passive margins. In many instances these margins are asymmetric: while one is wide and extensively faulted, the conjugate thins more abruptly and exhibits little faulting. Recent observational studies have suggested that this asymmetry results from the formation of an oceanward-younging sequential normal fault array on the future wide margin. Numerical models have shown that fault sequentiality arises as a result of asymmetric uplift of the hot mantle towards the hanging wall of the active fault, which weakens this area and promotes the formation of a new oceanward fault. In numerical models the polarity of the asymmetry is random. It results from spontaneous preferential localization of strain in a given fault, a process reinforced by strain weakening effects. Slight changes in the experiments initial grid result in an opposite polarity of the asymmetry. However, along a long stretch of the South Atlantic margins, from the Camamu-Gabon to the North Santos-South Kwanza conjugates, the polarity is not random and is very well correlated with the distance of the rift to nearby cratons. Here, we use numerical experiments to show that the presence of a thick cratonic root inhibits asthenospheric flow from underneath the craton towards the adjacent fold belt, while flow from underneath the fold belt towards the craton is favoured. This enhances and promotes sequential faulting towards the craton and results in a wide faulted margin located in the fold belt and a narrow conjugate margin in the craton side, thereby determining the polarity of the asymmetry, as observed in nature.

  13. Geophysical Signatures of cold vents on the northern Cascadia margin

    Riedel, M.; Paull, C. K.; Spence, G.; Hyndman, R. D.; Caress, D. W.; Thomas, H.; Lundsten, E.; Ussler, W.; Schwalenberg, K.


    The accretionary prism of the northern Cascadia margin is a classic gas hydrate research area. Ocean Drilling Program Leg 146 and Integrated Ocean Drilling Program (IODP) Expedition 311 documented that gas hydrate is widely distributed across the margin. In recent years an increased research focus has been on cold vents, where methane gas is actively released. Two recent expeditions funded by the Monterey Bay Aquarium Research Institute (MBARI) were conducted in the area of IODP Sites U1327 and U1328. An autonomous underwater vehicle (AUV) was used to map the seafloor bathymetry followed by dives with the ROV Doc Ricketts for ground truth information of various seafloor morphological features identified. The two cruises revealed many new seafloor features indicative of methane venting that were previously unknown. Bullseye Vent (BV) has been extensively studied using seismic imaging, piston coring, heat-flow, controlled-source EM, and deep drilling. BV is seismically defined by a circular wipe-out zone but the new AUV data show that BV is rather an elongated depression. BV is associated with a shoaling in the BSR, but lacks evidence for the existence of an underlying fault in the previous data. Although a massive gas-hydrate plug was encountered within the top 40 mbsf in the IODP holes, the ROV observations only revealed some platy methane derived carbonate outcrops at the outer-most rim of the depressions, a few beds of Vesicomya clams, and no observed gas vents, which together do not indicate that BV is especially active now. Further northeast of BV, but along the same trend, active gas venting was found associated with seafloor blistering and bacterial mats suggesting that there is an underlying fault system providing a fluid flow conduit. The newly discovered vent area has few seismic line crossings; however the available seismic data surprisingly are not associated with wipe-out zones. Another prominent fault-related gas vent also was investigated during the

  14. Exploration Breakthrough in Southern Margin of Junggar Basin

    Kang Zhulin; Zheng Jiandong


    @@ The Hutubi structure, located in the southern margin of Junggar Basin, is 60 km norrthwest of Urumqi and 20 km northwest of Changji (Fig. l). The Hu-2 well drilled in the Hutubi structure has gained high-yield gas flow,significant exploration breakthrough in the southern margin of Junggar Basin since the 1950s.

  15. Analytic solutions for marginal deformations in open superstring field theory

    Okawa, Y.


    We extend the calculable analytic approach to marginal deformations recently developed in open bosonic string field theory to open superstring field theory formulated by Berkovits. We construct analytic solutions to all orders in the deformation parameter when operator products made of the marginal operator and the associated superconformal primary field are regular. (orig.)

  16. Estimating Marginal Returns to Education. NBER Working Paper No. 16474

    Carneiro, Pedro; Heckman, James J.; Vytlacil, Edward J.


    This paper estimates the marginal returns to college for individuals induced to enroll in college by different marginal policy changes. The recent instrumental variables literature seeks to estimate this parameter, but in general it does so only under strong assumptions that are tested and found wanting. We show how to utilize economic theory and…

  17. Assessment of Biomass Resources from Marginal Lands in APEC Economies

    Milbrandt, A.; Overend, R. P.


    The goal of this study is to examine the marginal lands in Asia-Pacific Economic Cooperation (APEC) economies and evaluate their biomass productivity potential. Twelve categories of marginal lands are identified using the Global Agro-Ecological Zones system of the United Nations Food and Agriculture Organization.

  18. Carbonate mound development in contrasting settings on the Irish margin

    van der Land, C.; Eisele, M.; Mienis, F; de Haas, H.; Hebbeln, D.; Reijmer, J.J.G.; van Weering, T.C.E.


    Cold-water coral carbonate mounds, formed by framework building cold-water corals, are found in several mound provinces on the Irish margin. Differences in cold-water coral mound development rates and sediment composition between mounds at the southwest Rockall Trough margin and the Galway Mound in

  19. Lorna Dee Cervantes: A Writer in the Margins.

    Connelly, Colette

    Chicana literary authors are sometimes thought to occupy the edges of two "texts," their own culture and the Anglo-American hegemony, where they are oppressed and marginalized by sexism and racism. In these margins, however, Chicana authors can dismantle stereotypes and construct new and empowering images of self. As an example of this…

  20. Challenging conservation agriculture on marginal slopes in Sehoul, Morocco

    Schwilch, G.; Laouina, A.; Chaker, M.; Machouri, N.; Sfa, M.; Stroosnijder, L.


    In Sehoul, Morocco, the use of marginal land for agriculture became a necessity for the local population due to increased poverty and the occupation of the best land by new owners. Desertification poses an additional threat to agricultural production on marginal slopes, which are often stony and deg

  1. Molecular markers in the surgical margin of oral carcinomas

    Bilde, Anders; von Buchwald, Christian; Dabelsteen, Erik


    epithelium in the surgical resection margin may explain the local recurrence rate. The purpose of this study is to investigate the presence of senescence markers, which may represent early malignant changes in the margin that in routine pathological evaluations are classified as histologically normal...

  2. Supervised linear dimensionality reduction with robust margins for object recognition

    Dornaika, F.; Assoum, A.


    Linear Dimensionality Reduction (LDR) techniques have been increasingly important in computer vision and pattern recognition since they permit a relatively simple mapping of data onto a lower dimensional subspace, leading to simple and computationally efficient classification strategies. Recently, many linear discriminant methods have been developed in order to reduce the dimensionality of visual data and to enhance the discrimination between different groups or classes. Many existing linear embedding techniques relied on the use of local margins in order to get a good discrimination performance. However, dealing with outliers and within-class diversity has not been addressed by margin-based embedding method. In this paper, we explored the use of different margin-based linear embedding methods. More precisely, we propose to use the concepts of Median miss and Median hit for building robust margin-based criteria. Based on such margins, we seek the projection directions (linear embedding) such that the sum of local margins is maximized. Our proposed approach has been applied to the problem of appearance-based face recognition. Experiments performed on four public face databases show that the proposed approach can give better generalization performance than the classic Average Neighborhood Margin Maximization (ANMM). Moreover, thanks to the use of robust margins, the proposed method down-grades gracefully when label outliers contaminate the training data set. In particular, we show that the concept of Median hit was crucial in order to get robust performance in the presence of outliers.

  3. Marginal Assessment of Crowns by the Aid of Parallel Radiography

    Farnaz Fattahi


    Full Text Available Introduction: Marginal adaptation is the most critical item in long-term prognosis of single crowns. This study aimed to assess the marginal quality as well asthe discrepancies in marginal integrity of some PFM single crowns of posterior teeth by employing parallel radiography in Shiraz Dental School, Shiraz, Iran. Methods: In this descriptive study, parallel radiographies were taken from 200 fabricated PFM single crowns of posterior teeth after cementation and before discharging the patient. To calculate the magnification of the images, a metallic sphere with the thickness of 4 mm was placed in the direction of the crown margin on the occlusal surface. Thereafter, the horizontal and vertical space between the crown margins, the margin of preparations and also the vertical space between the crown margin and the bone crest were measured by using digital radiological software. Results: Analysis of data by descriptive statistics revealed that 75.5% and 60% of the cases had more than the acceptable space (50µm in the vertical (130±20µm and horizontal (90±15µm dimensions, respectively. Moreover, 85% of patients were found to have either horizontal or vertical gap. In 77% of cases, the margins of crowns invaded the biologic width in the mesial and 70% in distal surfaces. Conclusion: Parallel radiography can be expedient in the stage of framework try-in to yield some important information that cannot be obtained by routine clinical evaluations and may improve the treatment prognosis

  4. Carbonate mound development in contrasting settings on the Irish margin

    van der Land, C.; Eisele, M.; Mienis, F; de Haas, H.; Hebbeln, D.; Reijmer, J.J.G.; van Weering, T.C.E.


    Cold-water coral carbonate mounds, formed by framework building cold-water corals, are found in several mound provinces on the Irish margin. Differences in cold-water coral mound development rates and sediment composition between mounds at the southwest Rockall Trough margin and the Galway Mound in

  5. Rotation Effects on the Target-Volume Margin Determination

    Zhang, Qinghui; Chan, M; Song, Y; Burman, C


    Rotational setup errors are usually neglected in most clinical centers. An analytical formula is developed to determine the extra margin between clinical target volume (CTV) and planning target volume (PTV) to account for setup errors. The proposed formula corrects for both translational and rotational setup errors and then incorporated into margin determination for PTV.

  6. Power margin improvement for OFDMA-PON using hierarchical modulation.

    Cao, Pan; Hu, Xiaofeng; Zhuang, Zhiming; Zhang, Liang; Chang, Qingjiang; Yang, Qi; Hu, Rong; Su, Yikai


    We propose and experimentally demonstrate a hierarchical modulation scheme to improve power margin for orthogonal frequency division multiple access-passive optical networks (OFDMA-PONs). In a PON system, under the same launched optical power, optical network units (ONUs) have different power margins due to unequal distribution fiber lengths. The power margin of the PON system is determined by the ONU with the lowest power margin. In our proposed scheme, ONUs with long and short distribution fibers are grouped together, and downstream signals for the paired ONUs are mapped onto the same OFDM subcarriers using hierarchical modulation. In a pair of ONUs, part of the power margin of the ONU with short distribution fiber is re-allocated to the ONU with long distribution fiber. Therefore, the power margin of the ONU with the longest distribution fiber can be increased, leading to the power margin improvement of the PON system. Experimental results show that the hierarchical modulation scheme improves the power margin by 2.7 dB for an OFDMA-PON system, which can be used to support more users or extend transmission distance.

  7. Cutting Edge: Marginal Zone Macrophages Regulate Antigen Transport by B Cells to the Follicle in the Spleen via CD21.

    Prokopec, Kajsa E; Georgoudaki, Anna-Maria; Sohn, Silke; Wermeling, Fredrik; Grönlund, Hans; Lindh, Emma; Carroll, Michael C; Karlsson, Mikael C I


    Marginal zone macrophages (MZM) are strategically located in the spleen, lining the marginal sinus where they sense inflammation and capture Ag from the circulation. One of the receptors expressed by MZM is scavenger receptor macrophage receptor with collagenous structure (MARCO), which has affinity for modified self-antigens. In this article, we show that engagement of MARCO on murine macrophages induces extracellular ATP and loss of CD21 and CD62L on marginal zone B cells. Engagement of MARCO also leads to reduction of Ag transport by marginal zone B cells and affects the subsequent immune response. This study highlights a novel function for MZM in regulating Ag transport and activation, and we suggest that MARCO-dependent ATP release regulates this through shedding of CD21 and CD62L. Because systemic lupus erythematosus patients were shown to acquire autoantibodies against MARCO, this highlights a mechanism that could affect a patient's ability to combat infections.

  8. Realistic respiratory motion margins for external beam partial breast irradiation

    Conroy, Leigh; Quirk, Sarah [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Smith, Wendy L., E-mail: [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Department of Oncology, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)


    Purpose: Respiratory margins for partial breast irradiation (PBI) have been largely based on geometric observations, which may overestimate the margin required for dosimetric coverage. In this study, dosimetric population-based respiratory margins and margin formulas for external beam partial breast irradiation are determined. Methods: Volunteer respiratory data and anterior–posterior (AP) dose profiles from clinical treatment plans of 28 3D conformal radiotherapy (3DCRT) PBI patient plans were used to determine population-based respiratory margins. The peak-to-peak amplitudes (A) of realistic respiratory motion data from healthy volunteers were scaled from A = 1 to 10 mm to create respiratory motion probability density functions. Dose profiles were convolved with the respiratory probability density functions to produce blurred dose profiles accounting for respiratory motion. The required margins were found by measuring the distance between the simulated treatment and original dose profiles at the 95% isodose level. Results: The symmetric dosimetric respiratory margins to cover 90%, 95%, and 100% of the simulated treatment population were 1.5, 2, and 4 mm, respectively. With patient set up at end exhale, the required margins were larger in the anterior direction than the posterior. For respiratory amplitudes less than 5 mm, the population-based margins can be expressed as a fraction of the extent of respiratory motion. The derived formulas in the anterior/posterior directions for 90%, 95%, and 100% simulated population coverage were 0.45A/0.25A, 0.50A/0.30A, and 0.70A/0.40A. The differences in formulas for different population coverage criteria demonstrate that respiratory trace shape and baseline drift characteristics affect individual respiratory margins even for the same average peak-to-peak amplitude. Conclusions: A methodology for determining population-based respiratory margins using real respiratory motion patterns and dose profiles in the AP direction was

  9. Geophysical constraints on geodynamical processes at convergent margins

    Artemieva, Irina; Thybo, Hans; Shulgin, Alexey


    Convergent margins, being the boundaries between colliding lithospheric plates, form the most disastrous areas in the world due to intensive, strong seismicity and volcanism. We review global geophysical data in order to illustrate the effects of the plate tectonic processes at convergent margins...... on the crustal and upper mantle structure, seismicity, and geometry of subducting slab. We present global maps of free-air and Bouguer gravity anomalies, heat flow, seismicity, seismic Vs anomalies in the upper mantle, and plate convergence rate, as well as 20 profiles across different convergent margins....... A global analysis of these data for three types of convergent margins, formed by ocean-ocean, ocean-continent, and continent-continent collisions, allows us to recognize the following patterns. (1) Plate convergence rate depends on the type of convergent margins and it is significantly larger when...

  10. Studying media at The Margins: learning from the field

    Clemencia Rodríguez


    Full Text Available This article, informed by ethnographic research on media at the margins, proposes a shift in perspective at several different levels: 1 instead of focusing on individual technologies, our research should examine how grassroots communicators operating at the margins exist in a media ecology that offers different potentialities in each historical situation; 2 instead of trying to determine if the media technologies used at the margin are old or new, digital or not digital, we need to explore how embedded community communicators detect local information or communication needs and use available technologies to address these needs; 3 our research on media at the margins should shed light on how grassroots communicators re-invent, hybridize, converge, and bridge technologies from one platform to another. In sum, understanding media at the margins is about embracing complexity, maintaining the notion of media ecologies, and understanding how grassroots communicators, deeply embedded in local contexts, wedge media technologies into everyday life.

  11. Molecular markers in the surgical margin of oral carcinomas

    Bilde, A.; Buchwald, C. von; Dabelsteen, E.;


    BACKGROUND: Local or regional lymph node recurrence is the most common pattern of treatment failure in oral squamous cell carcinoma (SCC). The local recurrence rate is 30% even when the surgical resection margin is diagnosed as tumour free. Accumulation of genetic changes in histologically normal...... epithelium in the surgical resection margin may explain the local recurrence rate. The purpose of this study is to investigate the presence of senescence markers, which may represent early malignant changes in the margin that in routine pathological evaluations are classified as histologically normal....... METHODS: Formalin-fixed, paraffin-embedded surgical specimens from 16 consecutive patients with oral SCC and a clear surgical margin were obtained. The margin was analysed by immunohistochemistry for p53, p16, Chk2, Laminin-5 and glycosylated oncofetal fibronectin. RESULTS: Two patterns of p53 expression...

  12. A simplified approach to the complete porcelain margin.

    Vryonis, P


    The technique described produces a metal-ceramic crown exhibiting excellent esthetic qualities and marginal accuracy superior to that achieved on the cast metal margin. A platinum foil apron or refractory dies are not necessary. A precise shoulder preparation, preferably with two master dies, is required. A chamfer with a bevel, a shoulder with a bevel, or chamfer preparations are not suited to this technique. Quantitative evaluation using a measuring microscope showed that a marginal gap on a crown fabricated on an International Bureau of Standards crown die measured 6 microns at the porcelain shoulder and from 17 to 34 microns on a gold margin of the same crown. On a prepared-tooth, rubber-base compression densite die, the marginal gap on the porcelain shoulder was 10 microns.

  13. Marginality and Social Rejection in Amiri Baraka's Slave Ship

    Hamid Hammad Abed


    Full Text Available Marginality and social rejection are the most influential matters exploited by Baraka to intentionally criticize the American society.  More often than not, these two matters have become the scenes of major or minor acts of humiliation and dehumanization that threaten to violate the ethical rules of living. This paper aims at investigating the impact of marginality and social rejection on a number of black characters in Baraka's Slave Ship who are brought to America to be sold as commodities. It is divided into two sections and conclusion. Section one deals with Amiri Baraka’s dramatic thought and experience of marginality within the American society. The textual analysis of Slave Ship is investigated in section two. The significance of the study lies in its textual exploration of the impact of marginality and social rejection in subverting the American dream of democracy, freedom, and equality in Baraka’s Slave Ship. Keywords: marginality, Baraka, rejection, slave ship, black

  14. Margins of oral leukoplakia: autofluorescence and histopathology.

    Elvers, D; Braunschweig, T; Hilgers, R-D; Ghassemi, A; Möhlhenrich, S C; Hölzle, F; Gerressen, M; Modabber, A


    Autofluorescence devices are widely used to examine oral lesions. The aim of this study was to see whether there were any signs of dysplasia, parakeratosis, or mucosal inflammation in the borders of homogeneous oral leukoplakia using autofluorescence, and we also compared clinically visible extensions with those detected by autofluorescence. Twenty patients with 26 homogeneous areas of oral leukoplakia were included in the study. After the clinically visible extensions of the lesion had been marked, we took a photograph through the autofluorescence device, which showed both borders in one picture. We then used photo-editing software to measure the size of the area of leukoplakia together with the area with loss of autofluorescence. We took 3 punch biopsy specimens: one from the leukoplakia, one 2.5mm from its marked borders, and one from healthy mucosa. Seventy-eight biopsy specimens were examined by an experienced pathologist, and 95% CI calculated to assess the amount of parakeratosis. Spearman's rank correlation was used to assess the association with mucosal inflammation. Ten areas of leukoplakia were surrounded by normal green autofluorescence, and 16 were consistent with loss of autofluorescence with a mean size of 66%, which exceeded the clinically visible size of the area of leukoplakia. We calculated that there was a strong association between these entities and their surrounding areas, with loss of autofluorescence for parakeratosis. Some leukoplakias showed clinically invisible extensions during histopathological examination and autofluorescence. The technique described enables clinicians to measure the extent of these lesions beyond their visible margins. We found no dysplasia, which emphasises that autofluorescence detects non-dysplastic lesions caused by mucosal inflammation and parakeratosis.

  15. Coral reef evolution on rapidly subsiding margins

    Webster, J.M.; Braga, J.C.; Clague, D.A.; Gallup, C.; Hein, J.R.; Potts, D.C.; Renema, W.; Riding, R.; Riker-Coleman, K.; Silver, E.; Wallace, L.M.


    A series of well-developed submerged coral reefs are preserved in the Huon Gulf (Papua New Guinea) and around Hawaii. Despite different tectonics settings, both regions have experienced rapid subsidence (2-6??m/ka) over the last 500??ka. Rapid subsidence, combined with eustatic sea-level changes, is responsible for repeated drowning and backstepping of coral reefs over this period. Because we can place quantitative constraints on these systems (i.e., reef drowning age, eustatic sea-level changes, subsidence rates, accretion rates, basement substrates, and paleobathymetry), these areas represent unique natural laboratories for exploring the roles of tectonics, reef accretion, and eustatic sea-level changes in controlling the evolution of individual reefs, as well as backstepping of the entire system. A review of new and existing bathymetric, radiometric, sedimentary facies and numerical modeling data indicate that these reefs have had long, complex growth histories and that they are highly sensitive, recording drowning not only during major deglaciations, but also during high-frequency, small-amplitude interstadial and deglacial meltwater pulse events. Analysis of five generalized sedimentary facies shows that reef drowning is characterized by a distinct biological and sedimentary sequence. Observational and numerical modeling data indicate that on precessional (20??ka) and sub-orbital timescales, the rate and amplitude of eustatic sea-level changes are critical in controlling initiation, growth, drowning or sub-aerial exposure, subsequent re-initiation, and final drowning. However, over longer timescales (> 100-500??ka) continued tectonic subsidence and basement substrate morphology influence broad scale reef morphology and backstepping geometries. Drilling of these reefs will yield greatly expanded stratigraphic sections compared with similar reefs on slowly subsiding, stable and uplifting margins, and thus they represent a unique archive of sea-level and climate

  16. Vibrational anomalies and marginal stability of glasses

    Marruzzo, Alessia


    The experimentally measured vibrational spectrum of glasses strongly deviates from that expected in Debye\\'s elasticity theory: The density of states deviates from Debye\\'s ω2 law ("boson peak"), the sound velocity shows a negative dispersion in the boson-peak frequency regime, and there is a strong increase in the sound attenuation near the boson-peak frequency. A generalized elasticity theory is presented, based on the model assumption that the shear modulus of the disordered medium fluctuates randomly in space. The fluctuations are assumed to be uncorrelated and have a certain distribution (Gaussian or otherwise). Using field-theoretical techniques one is able to derive mean-field theories for the vibrational spectrum of a disordered system. The theory based on a Gaussian distribution uses a self-consistent Born approximation (SCBA),while the theory for non-Gaussian distributions is based on a coherent-potential approximation (CPA). Both approximate theories appear to be saddle-point approximations of effective replica field theories. The theory gives a satisfactory explanation of the vibrational anomalies in glasses. Excellent agreement of the SCBA theory with simulation data on a soft-sphere glass is reached. Since the SCBA is based on a Gaussian distribution of local shear moduli, including negative values, this theory describes a shear instability as a function of the variance of shear fluctuations. In the vicinity of this instability, a fractal frequency dependence of the density of states and the sound attenuation ∝ ω1+a is predicted with a ≲ 1/2. Such a frequency dependence is indeed observed both in simulations and in experimental data. We argue that the observed frequency dependence stems from marginally stable regions in a glass and discuss these findings in terms of rigidity percolation. © 2013 EDP Sciences and Springer.

  17. City and sea margins. Porto’s Marginal as scale and measure of new spaces

    Giuseppe Parità


    Full Text Available The city has always been confronting with its own end and the beginning of the water system. Among the different kind of margin areas, the ones that border the cities on their watersides are particularly interesting. These new liminal territories are rich in variety and differences and are set up of several elements made of different morphologies that should be carefully read and interpreted: the need of re-thinking the morphological elements that mark an urban edge leads to the identification of several shapes and forms of the water borderlands. Borders, limits, boundaries, edges, margin areas - usually considered as an obstacle to the construction of the city - turn themselves as new possible “design materials” for building that ambiguous distance between city and the sea. The article aims to focus on the case-study of Porto’s Marginal that well explain how many ways a city can live its water edges. On a large scale, it is configured as a strip of 15 kilometers of public space. Within this continuity, the different extent of the distance between city and water leads to reflect on the different types of relationships (and therefore projects between the end of one side and the beginning of another. For Porto, those are not only urban parts, but also different geographical parts (sea, rivers, topography that distance puts in relation through the design sometimes of the line, at time of the border or of a surface. So, the analysis of these heterogeneous but continuous projects aim to focus on the several techniques of urban composition to build contemporary public spaces. On one hand they give form to a continuous “public figure”, on the other hand each one of the project can be considered as part of a “atlas” of liminal places, giving form to public spaces. 

  18. Tiago Marques Aipobureu: um bororo marginal Tiago Marques Aipobureu: a Bororo on the margins

    Florestan Fernandes


    Full Text Available O texto analisa a biografia de um membro da tribo dos Bororo, Tiago Marques Aipobureu, que, nascido no planalto oriental de Mato Grosso, foi levado pelos missionários para estudar em Cuiabá e depois viajou pela Europa. Quando de seu retorno ao Brasil, foi empregado como professor, mas não conseguiu adaptar-se à nova vida. Casado com uma mulher de sua tribo, buscou então reintegrar-se aos Bororo, igualmente sem sucesso. Permanecia, desse modo, no meio do caminho, incapaz de integrar-se plenamente tanto à sociedade e cultura "civilizadas" como à sociedade e cultura indígenas. O desajustamento de Tiago evidencia a situação do homem marginal, daquele que se situa na divisa de duas raças, na margem de duas culturas sem conseguir pertencer integralmente a nenhuma delas.The text analyzes the biography of a member of the Bororo tribe, Tiago Marques Aipobureu. Born on the eastern plateau of Mato Grosso, he was taken by missionaries to study in Cuiabá and later travelled through Europe. On returning to Brazil, he was employed as a teacher, but was unable to adapt to his new life. Married to a woman from his tribe, he tried to rejoin the Bororo, likewise without success. Thus he found himself midway between worlds, unable to join fully either 'civilized' society and culture, or indigenous society and culture. Tiago's maladjustment exemplifies the situation of the marginal person, someone situated on the dividing line between two races, on the margin of two cultures, unable to belong wholly to either.

  19. CD27 expression in the human splenic marginal zone : the infant marginal zone is populated by naive B cells

    Zandvoort, A; Lodewijk, ME; de Boer, NK; Dammers, PM; Kroese, FGM; Timens, W


    The splenic marginal zone of adult humans contains B cells, of which most express CD27, an antigen only recently identified as a marker for somatically, mutated memory B cells. We investigated whether and to which extent the developing marginal zone in infants arid children is populated by either

  20. An Early Cretaceous volcanic arc/marginal basin transition zone, Peninsula hardy, southernmost Chile

    Miller, Christopher A.; Barton, Michael; Hanson, Richard E.; Fleming, Thomas H.


    The Hardy Formation represents a latest Jurassic-Early Cretaceous volcanic arc that was located along the Pacific margin of southern South America. It was separated from the continent by a marginal basin floored by portions of an ophiolite sequence (the Rocas Verdes ophiolites). The transition between the arc and marginal basin occurs on Peninsula Hardy, southernmost Chile, where there is a lateral facies transition from arc deposits of the Hardy Formation into proximal marginal basin fill of the Yahgan Formation. Interfingering of arc and marginal basin sequences demonstrates that subduction-related arc magmatism was concurrent with marginal basin formation. The lateral facies transition is reflected in the geochemistry of volcanic rocks from the Hardy and Yahgan formations. Basalts, andesites and dacites of the arc sequence follow a calc-alkaline differentiation trend whereas basalts from the marginal basin follow a tholeiitic differentiation trend. Estimates of temperature and oxygen fugacity for crystallization of the arc andesites are similar to values reported for other calc-alkaline andesites. It is suggested that water activity influenced the early or late crystallization of Ti-magnetite and this controlled the style of differentiation of the magmas erupted on Peninsula Hardy. Magmas with high water contents evolved along the calc-alkaline differentiation trend whereas those with low water contents evolved along the tholeiitic differentiation trend. Some rhyolites are differentiated from the calc-alkaline andesites and dacites, but most appear to be the products of crustal anatexis on the basis of trace-element evidence. The arc basalts and some marginal basin basalts show relative enrichment in LILE, relative depletion in HFSE, and enrichment in LREE. Other marginal basin basalts are LREE depleted and show small relative depletions in HFSE. Basalts with both calc-alkaline and tholeiitic affinities can also be recognized in the Rocas Verdes ophiolites

  1. Crustal structure and extension mode in the northwestern margin of the South China Sea

    Gao, Jinwei; Wu, Shiguo; McIntosh, Kirk; Mi, Lijun; Liu, Zheng; Spence, George


    Combining multi-channel seismic reflection and gravity modeling, this study has investigated the crustal structure of the northwestern South China Sea margin. These data constrain a hyper-extended crustal area bounded by basin-bounding faults corresponding to an aborted rift below the Xisha Trough with a subparallel fossil ridge in the adjacent Northwest Sub-basin. The thinnest crust is located in the Xisha Trough, where it is remnant lower crust with a thickness of less than 3 km. Gravity modeling also revealed a hyper-extended crust across the Xisha Trough. The postrift magmatism is well developed and more active in the Xisha Trough and farther southeast than on the northwestern continental margin of the South China Sea; and the magmatic intrusion/extrusion was relatively active during the rifting of Xisha Trough and the Northwest Sub-basin. A narrow continent-ocean transition zone with a width of ˜65 km bounded seaward by a volcanic buried seamount is characterized by crustal thinning, rift depression, low gravity anomaly and the termination of the break-up unconformity seismic reflection. The aborted rift near the continental margin means that there may be no obvious detachment fault like that in the Iberia-Newfoundland type margin. The symmetric rift, extreme hyper-extended continental crust and hotter mantle materials indicate that continental crust underwent stretching phase (pure-shear deformation), thinning phase and breakup followed by onset of seafloor spreading and the mantle-lithosphere may break up before crustal-necking in the northwestern South China Sea margin.

  2. Research on the Relationships between Livelihood Capitals and Livelihood Activities of Farmers at Forest Margins of Xiaolong Mountains%小陇山林缘区农户生计资本与生计活动的关系研究

    张文侠; 常跟应; 王鹭


    可持续生计分析框架是研究农村贫困问题的重要方法。基于251户农民家庭的问卷调查和访谈,调查了小陇山林缘区农户的生计资本和生计活动现状,并分析了生计资本对生计活动的影响。结果表明:自然资本缺乏,很大程度上限制了农户生产、子女上学等生计活动;农户拥有的生产性物质资本少,金融资本缺乏,社会资本以亲戚、邻居关系为主,这三种生计资本对自然资本限制下的农户生计活动的补偿作用很小。收入水平较低,以打工为主的非农工作是绝大部分家庭的主要收入来源,而劳动力数量是影响林缘区农户生计的最重要的资本。劳动力受教育程度普遍较低,打工多从事建筑类等简单体力劳动。最后,提出了促进当地农户可持续生计的政策建议。%Sustainable livelihood analysis framework is a key method for understanding poverty in rural ar-eas.Based on questionnaire surveys and interviews of 251 rural households at forest margins of Xiaolong Mountains,this paper investigated their livelihood capitals and livelihood activities and analyzed the im-pact of livelihood capitals on livelihood activities.It is found that poor natural capitals restricted farmer’ s livelihood activities such as productive activity and school accommodation.Farmer’ s productive material capital and financial capital were very limited and their social capitals are mainly relationships with rela-tives and neighbors.These three kinds of capitals have little compensation for farmer’ s livelihoods which are restricted by natural capital.For most of households, salaries as nonagricultural floating worker are the main source of income and the amount of labor is the most important capital affecting the livelihoods of households.Due to their low levels of education, most of floating labors are engaged in physical works such as construction activities.Finally,measures for

  3. Alterations of the marginal soft tissue (gingival margin following periodontal therapy: A clinical study

    Gupta Ira


    Full Text Available Background and Objectives: The evaluation of gingival margin position (GMP plays a vital role in periodontal therapy and is critical in esthetic/plastic surgical procedures revolving around restorative dentistry. Comparative evaluations of GMP measurements in various periodontal therapies are scarce. Thus, the objectives of this study are to measure the alteration in the gingival margin position following various therapies, and to compare GMP alterations among different treatment modalities from the baseline to six months after therapy. Materials and Methods: The changes in GMP were studied for MB, B, DB, ML, and L sites for SRP, curettage, and flap surgery, and for MB, B, and DB sites for crown lengthening cases at the end of one, three, and six months after therapy. The results were interpreted from baseline to one, three, and six months posttreatment. Statistical Analysis : The results were subjected to statistical analysis. Paired ′t′-test was used for intra-group comparisons and intergroup comparisons were done by one-way ANOVA. Results: The GMP changed from baseline in all the sites at different time periods following various therapies. The net results after six months were an apical shift of GMP in SRP, curettage, and flap surgery, and a coronal shift of GMP in crown lengthening. Conclusion: GMP shows various patterns of alteration after various periodontal therapies. One should wait for the GMP to become stable before attempting any restorative procedure.

  4. Quantifying Safety Margin Using the Risk-Informed Safety Margin Characterization (RISMC)

    Grabaskas, David; Bucknor, Matthew; Brunett, Acacia; Nakayama, Marvin


    The Risk-Informed Safety Margin Characterization (RISMC), developed by Idaho National Laboratory as part of the Light-Water Reactor Sustainability Project, utilizes a probabilistic safety margin comparison between a load and capacity distribution, rather than a deterministic comparison between two values, as is usually done in best-estimate plus uncertainty analyses. The goal is to determine the failure probability, or in other words, the probability of the system load equaling or exceeding the system capacity. While this method has been used in pilot studies, there has been little work conducted investigating the statistical significance of the resulting failure probability. In particular, it is difficult to determine how many simulations are necessary to properly characterize the failure probability. This work uses classical (frequentist) statistics and confidence intervals to examine the impact in statistical accuracy when the number of simulations is varied. Two methods are proposed to establish confidence intervals related to the failure probability established using a RISMC analysis. The confidence interval provides information about the statistical accuracy of the method utilized to explore the uncertainty space, and offers a quantitative method to gauge the increase in statistical accuracy due to performing additional simulations.

  5. Influence of Crack Morphology on Leak Before Break Margins

    Weilin Zang (Inspecta Technology AB, Stockholm (SE))


    The purpose of the project is to evaluate the deterministic LBB-margins for different pipe systems in a Swedish PWR-plant and using different crack morphology parameters. Results: - The influence of crack morphology on Leak Before Break (LBB) margins is studied. The subject of the report is a number of LBB-submittals to SKI where deterministic LBB-margins are reported. These submittals typically uses a surface roughness of 0.0762 mm (300 microinch) and number of turns equal to zero and an in-house code for the leak rate evaluations. The present report has shown that these conditions give the largest LBB-margins both in terms of the quotient between the critical crack length and the leakage crack size and for the leak rate margin. - Crack morphology parameters have a strong influence on the leak rate evaluations. Using the SQUIRT code and more recent recommendations for crack morphology parameters, it is shown that in many cases the evaluated margins, using 1 gpm as the reference leak rate detection limit, are below the safety factor of 2 on crack size and 10 on leak rate, which is generally required for LBB approval. - The effect of including weld residual stresses on the LBB margins is also investigated. It is shown that for the two examples studied, weld residual stresses were important for the small diameter thin wall pipe whereas it was negligible for the large diameter thick wall pipe which had a self-balanced weld residual stress distribution

  6. Wave speed structure of the eastern North American margin

    Savage, B.; Covellone, B. M.; Shen, Y.


    The eastern North American margin (ENAM) is the result of nearly a billion years of continental collision and rifting. To the west of this margin lies thick continental lithosphere of the North American craton, and to the east is oceanic lithosphere in the Atlantic. The substantial changes in lithosphere thickness at this boundary are thought to drive asthenosphere upwelling along the edge of the continent. Through iterative, full-waveform, ambient noise tomography, we observe a heterogeneous low wave speed margin along the continent in the upper mantle. Multiple low wave speed features imaged within the margin are consistent with asthenospeheric upwelling due to edge-driven convection. Also within the margin are high wave speed anomalies that maybe the remnants of eclogitic delamination of the Appalachian crustal root, which contribute to convection at the margin. Edge driven, small-scale convection keeps the margin weak and thus controls the large scale plate tectonic patterns and the crustal deformation. The imaged mantle wave speed anomalies, interpreted as edge-driven convection, correlate with and may increase the likelihood of damaging earthquakes in the eastern portion of North America.

  7. Assessment of Margins in Transoral Laser and Robotic Surgery

    Yaniv Hamzany


    Full Text Available The growing practice of endoscopic surgery has changed the therapeutic management of selected head and neck cancers. Although a negative surgical margin in resection of neoplasm is the most important surgical principle in oncologic surgery, controversies exist regarding assessment and interpretation of the status of margin resection. The aim of this review was to summarize the literature considering the assessment and feasibility of negative margins in transoral laser microsurgery (TLM and transoral robotic surgery (TORS. Free margin status is being approached differently in vocal cord cancer (1–2 mm compared with other sites in the upper aerodigestive tract (2–5 mm. Exposure, orientation of the pathological specimen, and co-operation with the pathologist are crucial principles needed to be followed in transoral surgery. Piecemeal resection to better expose deep tumor involvement and biopsies taken from surgical margins surrounding site of resection can improve margin assessment. High rates of negative surgical margins can be achieved with TLM and TORS. Adjuvant treatment decision should take into consideration also the surgeon’s judgment with regard to the completeness of tumor resection.

  8. Stroke: a Hidden Danger of Margin Trading in Stock Markets.

    Lin, Shu-Hui; Wang, Chien-Ho; Liu, Tsai-Ching; Chen, Chin-Shyan


    Using 10-year population data from 2000 through 2009 in Taiwan, this is the first paper to analyze the relationship between margin trading in stock markets and stroke hospitalizations. The results show that 3 and 6 days after an increase of margin trading in the Taiwan stock markets are associated with greater stoke hospitalizations. In general, a 1 % increase in total margin trading positions is associated with an increment of 2.5 in the total number of stroke hospitalizations, where the mean number of hospital admissions is 233 cases a day. We further examine the effects of margin trading by gender and age groups and find that the effects of margin trading are significant for males and those who are 45-74 years old only. In summary, buying stocks with money you do not have is quite risky, especially if the prices of those stocks fall past a certain level or if there is a sudden and severe drop in the stock market. There is also a hidden danger to one's health from margin trading. A person should be cautious before conducting margin trading, because while it can be quite profitable, danger always lurks just around the corner.

  9. Anomalous subsidence at South China Sea rifted margin: Sediments digging their own hole

    Brune, Sascha; Clift, Peter; Quinteros, Javier


    Rifted continental margins subside as a consequence of combined crustal thinning and mantle lithosphere cooling. While standard models predict a slowing of subsidence after the end of rifting, the deep basins on the northern margin of the South China Sea, notably the Baiyun Sag exhibit subsidence that accelerated several million years after the end of active extension. Additionally, backstripping analysis at the South China margin has shown that the amount of subsidence is much greater than that predicted from the degree of brittle upper crustal extension seen in seismic profiles. Here we explain these observations by linking climate change onshore and deformation of the crystalline crust offshore: Early Miocene monsoon intensification increased erosion and thus the sediment flux to offshore basins after the cessation of active extension. When the sediment load encountered the weak crust of the South China Sea margin, it induced lower crustal flow away from the basin axis so that the deep Baiyun basin was formed nearly without brittle extension. We corroborate this concept using seismic observations and backstripping techniques, as well as thermo-mechanical forward modeling. The numerical forward model is a 2D version of the finite element code SLIM3D. The code includes nonlinear temperature- and stress-dependent elasto-visco-plastic rheology and is able to reproduces a wide range of rift-related deformation processes such as flexure, lower crustal flow, and faulting. We find that two factors allow to satisfy the observational constraints: (1) Post-rift increase of sediment load: The East Asian Summer Monsoon strengthened around the start of the Miocene (~23 Ma), several million years after continental rupture. Changes in the flora of continental China date from around this time and sedimentation rates across continental margins and deltas in South and Southeast Asia increased, as might be expected under the influence of heavier precipitation driving faster erosion

  10. Dealing with the Margins of Law: Adult Sex Workers' Resistance in Everyday Life

    Marisa Natalia Fassi


    Full Text Available This article looks at the way sex workers in Córdoba, Argentina, have dealt with legal marginalization, focusing on their understandings and associated practices of resistance. Sex workers position in law shows the group is on the margins of law, which means that their activity is not considered to be legal but is not illegal either. Since 2000 a group of sex workers started to organize to stop the constant detentions and humiliations by police officers. The organization called AMMAR (Asociación de Mujeres Meretrices Argentinas implied a major shift from an oppression of consciousness to a consciousness of oppression, modifying in this process the terms of their resistance from mere tactics of survival to a struggle for redefinition of their position in law and society. This article firstly explores the idea of margins of law, consciousness, power and resistance, and also describes the regulation of sex work in the city of Córdoba; secondly, it refers to sex workers experiences, perceptions and practices of resistance before the organization in relation to the police, the Judiciary, as well as with other institutions, and relates this experiences with their practices of resistance in that period; thirdly, it explains the process of organization and the way it has influenced their reflective awareness and practices of resistance, it describes as well the heterogeneity of understandings regarding law. Lastly, the Conclusion revisits the outcomes and literature to propose final reflections about dealing with the margins of law in everyday life.

  11. Effect of postponed polishing on marginal adaptation of resin used with dentin-bonding agent.

    Hansen, E K; Asmussen, E


    Dentin cavities, prepared in extracted human teeth, were treated with two different dentin-bonding agents and filled with a light-activated microfilled resin. The maximum width of the contraction gap (MG) and the extent of the gap (GP) were then measured, using a light microscope, approximately 0.1 mm below the original free surface of the filling. The contraction gap was measured 30 s, 10 min or 60 min, and remeasured 65 min, after stop of irradiation. A positive correlation was found between the two variables, MG and GP. The product of MG and GP was chosen as basis for the statistical analyses. This "marginal index" was significantly reduced when polishing of the marginal area was postponed for 10 min with one of the dentin-bonding agents and for 60 min with the other. Even though the improvement in marginal adaptation was statistically significant, this improvement was considered clinically irrelevant. It is concluded that polishing of the marginal area should not be done before the hygroscopic expansion of the resin restoration has closed the contraction gap.




    Full Text Available The Guadalquivir foreland basin, located between the Iberian basement northward and the Betic orogen to the South, represents the western sector of the earlier foredeep basin of the Betic Cordillera. Along the northern foreland margin, the sedimentary fill of this basin includes a Tortonian Basal Transgressive Complex (BTC, composed of five internal sequences bounded by transgressive surfaces. Two main parts are distinguished within each sequence: the lower transgressive lag deposits, and the upper stillstand/prograding sediments. Three facies associations were distinguished within this stratigraphic succession along the central sector of this basin margin: unfossiliferous conglomerates and coarse-grained sands (A, fossiliferous conglomerates and coarse-grained sands (B, and yellow medium-coarse-grained fossiliferous sands (C. A fourth facies association (D: blue silty marlstones and shales overlies the BTC. Deposits of alluvial sediments (facies association A and shallow-marine/foreshore sediments (facies association C, were recurrently interrupted by transgressive pulses (facies associations B and C. Every pulse is recorded by an erosional, cemented sandy-conglomerate bar with bivalves (Ostreidae, Isognomon, balanids, gastropods and other marine bioclasts; or their transgressive equivalents. The lateral facies changes in each individual sequence of the BTC are related to: (1 the influence on the northern foreland margin of the tectonic activity of the southern orogenic margin; (2 the palaeorelief formed by irregularities of the substrate which controls the sediment dispersal; and (3 the evolution stages of the sedimentary systems. 

  13. Contrasts between the cryoconite and ice-marginal bacterial communities of Svalbard glaciers

    Arwyn Edwards


    Full Text Available Cryoconite holes are foci of unusually high microbial diversity and activity on glacier surfaces worldwide, comprising melt-holes formed by the darkening of ice by biogenic granular debris. Despite recent studies linking cryoconite microbial community structure to the functionality of cryoconite habitats, little is known of the processes shaping the cryoconite bacterial community. In particular, the assertions that the community is strongly influenced by aeolian transfer of biota from ice-marginal habitats and the potential for cryoconite microbes to inoculate proglacial habitats are poorly quantified despite their longevity in the literature. Therefore, the bacterial community structures of cryoconite holes on three High-Arctic glaciers were compared to bacterial communities in adjacent moraines and tundra using terminal-restriction fragment length polymorphism. Distinct community structures for cryoconite and ice-marginal communities were observed. Only a minority of phylotypes are present in both habitat types, implying that cryoconite habitats comprise distinctive niches for bacterial taxa when compared to ice-marginal habitats. Curiously, phylotype abundance distributions for both cryoconite and ice-marginal sites best fit models relating to succession. Our analyses demonstrate clearly that cryoconites have their own, distinct functional microbial communities despite significant inputs of cells from other habitats.

  14. Origin of the Blue Ridge escarpment along the passive margin of Eastern North America

    Spotila, J.A.; Bank, G.C.; Reiners, P.W.; Naeser, C.W.; Naeser, N.D.; Henika, B.S.


    The Blue Ridge escarpment is a rugged landform situated within the ancient Appalachian orogen. While similar in some respects to the great escarpments along other passive margins, which have evolved by erosion following rifting, its youthful topographic expression has inspired proposals of Cenozoic tectonic rejuvenation in eastern North America. To better understand the post-orogenic and post-rift geomorphic evolution of passive margins, we have examined the origin of this landform using low-temperature thermochronometry and manipulation of topographic indices. Apatite (U-Th)/He and fission-track analyses along transects across the escarpment reveal a younging trend towards the coast. This pattern is consistent with other great escarpments and fits with an interpretation of having evolved by prolonged erosion, without the requirement of tectonic rejuvenation. Measured ages are also comparable specifically to those measured along other great escarpments that are as much as 100 Myr younger. This suggests that erosional mechanisms that maintain rugged escarpments in the early post-rift stages may remain active on ancient passive margins for prolonged periods. The precise erosional evolution of the escarpment is less clear, however, and several end-member models can explain the data. Our preferred model, which fits with all data, involves a significant degree of erosional escarpment retreat in the Cenozoic. Although this suggests that early onset of topographic stability is not required of passive margin evolution, more data are required to better constrain the details of the escarpment's development. ?? 2003 Blackwell Publishing Ltd.

  15. Marginal Generation Technology in the Chinese Power Market towards 2030 Based on Consequential Life Cycle Assessment

    Guangling Zhao


    Full Text Available Electricity consumption is often the hotspot of life cycle assessment (LCA of products, industrial activities, or services. The objective of this paper is to provide a consistent, scientific, region-specific electricity-supply-based inventory of electricity generation technology for national and regional power grids. Marginal electricity generation technology is pivotal in assessing impacts related to additional consumption of electricity. China covers a large geographical area with regional supply grids; these are arguably equally or less integrated. Meanwhile, it is also a country with internal imbalances in regional energy supply and demand. Therefore, we suggest an approach to achieve a geographical subdivision of the Chinese electricity grid, corresponding to the interprovincial regional power grids, namely the North, the Northeast, the East, the Central, the Northwest, and the Southwest China Grids, and the China Southern Power Grid. The approach combines information from the Chinese national plans on for capacity changes in both production and distribution grids, and knowledge of resource availability. The results show that nationally, marginal technology is coal-fired electricity generation, which is the same scenario in the North and Northwest China Grid. In the Northeast, East, and Central China Grid, nuclear power gradually replaces coal-fired electricity and becomes the marginal technology. In the Southwest China Grid and the China Southern Power Grid, the marginal electricity is hydropower towards 2030.

  16. Marginal grafts increase early mortality in liver transplantation

    Telesforo Bacchella

    Full Text Available CONTEXT AND OBJECTIVE: Expanded donor criteria (marginal grafts are an important solution for organ shortage. Nevertheless, they raise an ethical dilemma because they may increase the risk of transplant failure. This study compares the outcomes from marginal and non-marginal graft transplantation in 103 cases of liver transplantation due to chronic hepatic failure. DESIGN AND SETTING: One hundred and three consecutive liver transplantations to treat chronic liver disease performed in the Liver Transplantation Service of Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo between January 2001 and March 2006 were retrospectively analyzed. METHODS: We estimated graft quality according to a validated scoring system. We assessed the pre-transplantation liver disease category using the Model for End-Stage Liver Disease (MELD, as low MELD ( 20. The parameters for marginal and non-marginal graft comparison were the one-week, one-month and one-year recipient survival rates, serum liver enzyme peak, post-transplantation hospital stay and incidence of surgical complications and retransplantation. The significance level was 0.05. RESULTS: There were no differences between the groups regarding post-transplantation hospital stay, serum liver enzyme levels and surgical complications. In contrast, marginal grafts decreased overall recipient survival one month after transplantation. Furthermore, low-MELD recipients of non-marginal grafts showed better one-week and one-month survival than did high-MELD recipients of marginal livers. After the first month, patient survival was comparable in all groups up to one year. CONCLUSION: The use of marginal graft increases early mortality in liver transplantation, particularly among high-MELD recipients.

  17. Intraoperative ultrasound control of surgical margins during partial nephrectomy.

    Alharbi, Feras M; Chahwan, Charles K; Le Gal, Sophie G; Guleryuz, Kerem M; Tillou, Xavier P; Doerfler, Arnaud P


    To evaluate a simple and fast technique to ensure negative surgical margins on partial nephrectomies, while correlating margin statuses with the final pathology report. This study was conducted for patients undergoing partial nephrectomy (PN) with T1-T2 renal tumors from January 2010 to the end of December 2015. Before tumor removal, intraoperative ultrasound (US) localization was performed. After tumor removal and before performing hemostasis of the kidney, the specimens were placed in a saline solution and a US was performed to evaluate if the tumor's capsule were intact, and then compared to the final pathology results. In 177 PN(s) (147 open procedures and 30 laparoscopic procedures) were performed on 147 patients. Arterial clamping was done for 32 patients and the mean warm ischemia time was 19 ± 6 min. The mean US examination time was 41 ± 7 s. The US analysis of surgical margins was negative in 172 cases, positive in four, and in only one case it was not possible to conclude. The final pathology results revealed one false positive surgical margin and one false negative surgical margin, while all other margins were in concert with US results. The mean tumor size was 3.53 ± 1.43 cm, and the mean surgical margin was 2.8 ± 1.5 mm. The intraoperative US control of resection margins in PN is a simple, efficient, and effective method for ensuring negative surgical margins with a small increase in warm ischemia time and can be conducted by the operating urologist.

  18. Evolution of Devonian carbonate-shelf margin, Nevada

    Morrow, J.R.; Sandberg, C.A.


    The north-trending, 550-km-long Nevada segment of the Devonian carbonate-shelf margin, which fringed western North America, evidences the complex interaction of paleotectonics, eustasy, biotic changes, and bolide impact-related influences. Margin reconstruction is complicated by mid-Paleozoic to Paleogene compressional tectonics and younger extensional and strike-slip faulting. Reports published during the past three decades identify 12 important events that influenced development of shelf-margin settings; in chronological order, these are: (1) Early Devonian inheritance of Silurian stable shelf inargin, (2) formation of Early to early Middle 'Devonian shelf-margin basins, (3) propradation of later Middle Devonian shelf margin, (4) late Middle Devonian Taghanic ondap and continuing long-term Frasnian transgression, (5) initiation of latest Middle Devonian to early Frasnian proto-Antler orogenic forebulge, (6) mid-Frasnian Alamo Impact, (7) accelerated development of proto-Antler forebulge and backbulge Pilot basin, (8) global late Frasnian sentichatovae sea-level rise, (9) end-Frasnian sea-level fluctuations and ensuing mass extinction, (10) long-term Famennian regression and continept-wide erosion, (11) late Famennian emergence: of Ahtler orogenic highlands, and (12) end-Devonian eustatic sea-level fall. Although of considerable value for understanding facies relationships and geometries, existing standard carbonate platform-margin models developed for passive settings else-where do not adequately describe the diverse depositional and, structural settings along the Nevada Devonian platform margin. Recent structural and geochemical studies suggest that the Early to Middle Devonian-shelf-margin basins may have been fault-bound and controlled by inherited Precambrian structure. Subsequently, the migrating latest Middle to Late Devonian Antler orogenic forebulge exerted a dominant control on shelf-margin position, morphology, and sedimentation. ??Geological Society of

  19. Balance of microtubule stiffness and cortical tension determines the size of blood cells with marginal band across species.

    Dmitrieff, Serge; Alsina, Adolfo; Mathur, Aastha; Nédélec, François J


    The fast bloodstream of animals is associated with large shear stresses. To withstand these conditions, blood cells have evolved a special morphology and a specific internal architecture to maintain their integrity over several weeks. For instance, nonmammalian red blood cells, mammalian erythroblasts, and platelets have a peripheral ring of microtubules, called the marginal band, that flattens the overall cell morphology by pushing on the cell cortex. In this work, we model how the shape of these cells stems from the balance between marginal band rigidity and cortical tension. We predict that the diameter of the cell scales with the total microtubule polymer and verify the predicted law across a wide range of species. Our analysis also shows that the combination of the marginal band rigidity and cortical tension increases the ability of the cell to withstand forces without deformation. Finally, we model the marginal band coiling that occurs during the disk-to-sphere transition observed, for instance, at the onset of blood platelet activation. We show that when cortical tension increases faster than cross-linkers can unbind, the marginal band will coil, whereas if the tension increases more slowly, the marginal band may shorten as microtubules slide relative to each other.

  20. At the Margins of the Economy? Chinese Migrants in Lesotho’s Wholesale and Retail Sector

    Sarah Hanisch


    Full Text Available This article examines the relationship between the economic activities of Chinese migrants in the wholesale and retail sector in Lesotho, and the larger structural framework. More specifically, it investigates this relationship with reference to the general debate on Chinese migrants in Africa. These themes locate Chinese migrants at the margins of the economy, assume some Chinese exceptionalism, and imply a kind of neocolonialism. The article demonstrates that Chinese migrants are, in fact, not operating at the margins of the economy, but have become a vital element of Lesotho’s wholesale and retail sector. The analysis of the structural framework indicates that the economic activities of Chinese migrants are a reflection of existing structural constraints and opportunities rather than Chinese exceptionalism or neocolonialism. This in turn implies that future research would benefit from placing the interplay of Chinese migrants and the larger structural framework in respective African countries at the centre of analysis.

  1. Biodiversity and agro-ecology in field margins.

    De Cauwer, B; Reheul, D; Nijs, I; Milbau, A


    This multidisciplinary study investigates agro-ecological functions (nature conservation, agriculture, environment) and implications of newly created, mown sown and unsown field margin strips installed on ex-arable land to increase biodiversity. From conservational concern, the development of species rich field margin strips was not strongly affected by the installed type of margin strip since species diversity converged over time, whether strips were sown or not. Convergence between unsown and sown margin strips occurred also in terms of species composition: unsown and sown strips became similar over time. Mowing without removal of cuttings significantly reduced species richness, yielded more grassy margin strips and delayed similarity in species composition between sown and unsown margin strips. Species richness on the longer term was not significantly affected by light regime nor by disturbance despite significant temporary effects shortly after the disturbance event. On the contrary vegetation composition in terms of importance of functional groups changed after disturbance: the share of spontaneous species within functional groups increased resulting in higher similarity between the sown and unsown vegetation. Furthermore risk of invasion was highest in the disturbed unsown community on the unshaded side of a tree lane. A positive effect of botanical diversity on insect number and diversity was found. However the effects of botanical diversity on insect number was mediated by light regime. At high light availability differences between plant communities were more pronounced compared to low light availablilty. The abundance of some insect families was dependent on the vegetation composition. Furthermore light availability significantly influenced insect diversity as well as the spatial distribution of families. From agricultural concern, installing margin strips by sowing a species mixture and a mowing regime with removal of cuttings are good practices to

  2. Rifting of the northern margin of the Australian continent and the origin of some microcontinents in Eastern Indonesia

    Pigram, C. J.; Panggabean, H.


    Continental Australia is bounded on the east, south and west sides by passive margins, and the geological histories of these are well documented (Falvey and Mutter, 1981). The northern margin of the Australian continent is now an active collision margin. Its previous history as a passive margin has rarely been examined. This paper shows how the Late Palaeozoic to Mesozoic sequence which forms the northern margin of the Australian continent, in the island of New Guinea, is readily related to the tectonic stages of a rift-drift sequence. Rifting (start of breakup) began at about 230 m.y. ago at the Permian-Triassic boundary. The onset of seafloor spreading is marked by a post-breakup unconformity and ranges in age along the northern margin of the continent, from 185 m.y. in Papua New Guinea to 170 m.y. in Irian Jaya. From there the age of the post-breakup unconformity continues to young in a southwesterly direction along the western margin of the Australian continent reflecting the opening of the Indian Ocean off Western Australia. The timing of the onset of spreading in central Papua New Guinea is consistent with the timing of the initiation of spreading in the proto-Pacific ocean proposed by Nur and Ben Avraham (1977). By the end of the Jurassic the northern margin of the Australian continent faced a seaway which linked the proto-Indian and proto-Pacific oceans. This newly formed ocean was separated from the pre-existing oceans of the Neo-Tethys and Panthalassa by a screen of continents or microcontinents. The identity of this screen is discussed and it is suggested that part of it is preserved in the microcontinents of Eastern Indonesia.

  3. Simple shear detachment fault system and marginal grabens in the southernmost Red Sea rift

    Tesfaye, Samson; Ghebreab, Woldai


    The NNW-SSE oriented Red Sea rift, which separates the African and Arabian plates, bifurcates southwards into two parallel branches, southeastern and southern, collectively referred to as the southernmost Red Sea rift. The southern branch forms the magmatically and seismo-tectonically active Afar rift, while the less active southeastern branch connects the Red Sea to the Gulf of Aden through the strait of Bab el Mandeb. The Afar rift is characterized by lateral heterogeneities in crustal thickness, and along-strike variation in extension. The Danakil horst, a counterclockwise rotating, narrow sliver of coherent continental relic, stands between the two rift branches. The western margin of the Afar rift is marked by a series of N-S aligned right-lateral-stepping and seismo-tectonically active marginal grabens. The tectonic configuration of the parallel rift branches, the alignment of the marginal grabens, and the Danakil horst are linked to the initial mode of stretching of the continental crust and its progressive deformation that led to the breakup of the once contiguous African-Arabian plates. We attribute the initial stretching of the continental crust to a simple shear ramp-flat detachment fault geometry where the marginal grabens mark the breakaway zone. The rift basins represent the ramps and the Danakil horst corresponds to the flat in the detachment fault system. As extension progressed, pure shear deformation dominated and overprinted the initial low-angle detachment fault system. Magmatic activity continues to play an integral part in extensional deformation in the southernmost Red Sea rift.


    Luksic, Magela


    The purpose of this research has been to initiate and conduct an active participatory research process by promoting dialogue and self- reflective analysis of the reality with community participants through the creation of plans and proposals built from their own perspective and daily life experience, in order to produce social change about marginality and social exclusion conditions, using " Photovoice " an instrument that seeks to make them aware of their own concerns and personal, family an...

  5. The Agulhas-Karoo Geoscience Transect: Structures and processes along the southern African continental margin

    N. Parsiegla; Gohl, K.; Uenzelmann-Neben, G.; Jacek Stankiewicz


    The southern African continental transform margin is of great interest for the understanding of processes related to continental breakup, transform fault formation and vertical plate motion. Open questions include the cause and consequences for the high topography of southern Africa, neotectonic activity along the Agulhas-Falkland Fracture Zone and the formation of the Outeniqua Basin. As a component of the project “Inkaby yeAfrica”, the 900 km long Agulhas-Karoo Geoscience Transect was carri...

  6. Collision processes at the northern margin of the Black Sea

    Gobarenko, V. S.; Murovskaya, A. V.; Yegorova, T. P.; Sheremet, E. E.


    Extended along the Crimea-Caucasus coast of the Black Sea, the Crimean Seismic Zone (CSZ) is an evidence of active tectonic processes at the junction of the Scythian Plate and Black Sea Microplate. A relocation procedure applied to weak earthquakes (mb ≤ 3) recorded by ten local stations during 1970-2013 helped to determine more accurately the parameters of hypocenters in the CSZ. The Kerch-Taman, Sudak, Yuzhnoberezhnaya (South Coast), and Sevastopol subzones have also been recognized. Generalization of the focal mechanisms of 31 strong earthquakes during 1927-2013 has demonstrated the predominance of reverse and reverse-normal-faulting deformation regimes. This ongoing tectonic process occurs under the settings of compression and transpression. The earthquake foci with strike-slip component mechanisms concentrate in the west of the CSZ. Comparison of deformation modes in the western and eastern Crimean Mountains according to tectonophysical data has demonstrated that the western part is dominated by strike-slip and normal- faulting, while in the eastern part, reverse-fault and strike-slip deformation regimes prevail. Comparison of the seismicity and gravity field and modes of deformation suggests underthusting of the East Black Sea Microplate with thin suboceanic crust under the Scythian Plate. In the Yuzhnoberezhnaya Subzone, this process is complicated by the East Black Sea Microplate frontal part wedging into the marginal part of the Scythian Plate crust. The indentation mechanism explains the strong gravity anomaly in the Crimean Mountains and their uplift.

  7. Using Safety Margins for a German Seismic PRA

    Ralf Obenland


    Full Text Available The German regulatory guide demands the performance of a probabilistic risk assessment (PRA including external events. In 2005, a new methodology guideline (Methodenband based on the current state of science and technology was released to provide the analyst with a set of suitable tools and methodologies for the analysis of all PRA events. In the case of earthquake, a multilevel verification procedure is suggested. The verification procedure which has to be used depends on the seismic risk at the site of the plant. For sites in areas with low seismic activity no analysis or only a reduced analysis is proposed. This paper describes the evaluation of safety margins of buildings, structures, components and systems for plants at sites with high seismic risk, corresponding to the German methodology guideline. The seismic PRA results in an estimation of core damage frequencies caused by earthquakes. Additionally, the described approach can also be adapted for the usage in a reduced analysis for sites with lower earthquake risks. Westinghouse has wide experience in performing seismic PRA for both BWR as well as PWR plants. Westinghouse uses the documented set of seismic design analyses dating from construction phase and from later updates, if done, as a basis for a seismic PRA, which means that usually no costly new structural mechanics calculations have to be performed.

  8. Ophiolite and Tectonic Development of the East Pacific Margin

    Moores, E. M.


    Well-preserved ophiolites represent oceanic crust and mantle formed at a spreading center and emplaced by collision of a mantle-rooted thrust fault (subduction zone) with a continental margin or island arc. Ophiolite nappes thus represent remnants of lithospheric plates; their basal thrusts (fossil subduction zones) intrinscally cannot be balanced; their displacements are unknown but very large. Many environments of formation are possible for ophiolites: mid-ocean ridge, back-arc, forearc, or intra-arc spreading vrnyrtd, but geochemistry alone is inadequate to differentiate between the possibilities; geologic field evidence is needed, as well. Mesozoic ophiolites in western North America are associated either with the Stikine-Intermontane superterrane (e.g. Sierra Nevada, Klamath Mountains, California. Guerrero terrane, Mexico?), or lie west of it (e.g. Great Valley/Coast Range ophiolite and correlatives to north and south.). The "Great Arc" of the Caribbean (Burke, 1988), including ophiolitic rocks in Cuba, Hispaniola, Puerto Rico, Venezuela, and Colombia, may also correlate with the Great Valley/Coast Range ophiolite and/or with ophiolites in the Sierra Nevada. The Wrangellia/Insular superterrane may have extended to the south and at times may have included parts of the Chortis-Choco blocks of Central America, as well as the Cordillera Occidental of Colombia and Ecuador). These relations suggest the hypothesis that in mid-late Mesozoic time, a separate intra-oceanic plate similar to the present Philippine plate, herein informally called "Americordilleria" was separated by active island arc complexes from the American andFarallon/Kula plates to the east and west, respectively. Basement rocks of the Colombian, Venezuelan, and Yucatan basins, as well as the Great Valley/Coast Range ophiolite, may represent remnants of "Americordilleria". Convergence and collision of "Americordilleria" and its island arc margins with the American continents were major factors in

  9. The lithosphere of the Appalachian orogen and Atlantic passive margin

    Fischer, K. M.; MacDougall, J. G.; Hawman, R. B.; Parker, E. H.; Wagner, L. S.


    The lithosphere of the Appalachian orogen and Atlantic passive margin has recorded repeated episodes of continental collision and break-up. Improved resolution of crust and mantle structure in this region holds promise for better understanding of orogenesis, rifting and passive margin development. At a broad scale, tomographic models manifest a decrease in lithospheric thickness from the central U.S. craton into the Appalachian orogen. Migration of Sp scattered waves indicates that a significant drop in shear-wave velocity typically occurs at depths of 80-120 km in the eastern U.S., and where these phases fall within the transition from high velocity lid to lower velocity mantle obtained from tomography, they are interpretable as the seismological lithosphere-asthenosphere boundary. Beneath the Appalachians and coastal plain, Sp-derived lithospheric thicknesses are larger than those found in the tectonically active western U.S. where values range from 40-90 km. The vertical shear velocity gradients required to produce the observed Sp phases are sharp (drops of 4-10% over governed solely by temperature, but they may be explained by small amounts of partial melt or enhanced volatile content in the asthenosphere. While an asthenospheric low velocity zone appears to be ubiquitous beneath the continent, minimum velocities (and likely viscosities) within the eastern U.S. asthenosphere are not as low as those in the western U.S. At smaller scales, Sp imaging hints at lithospheric thickness variations that are correlated with tectonic features (e.g. orogenic boundaries, failed rifts) but resolution will be vastly improved with analysis of data from USArray Transportable and Flexible Arrays. The goal of the Southeastern Suture of the Appalachian Margin Experiment (SESAME) is to better understand lithospheric structures produced by accretion and rifting processes, with a particular focus on the Laurentia-Gondwana suture proposed in southern Georgia, adjacent regions of

  10. Rare Posterior Pharyngeal Mass: Atypical Marginal Zone Hyperplasia.

    Eliçora, Sultan Şevik; Güven, Mehmet; Varli, Ali F; Yilmaz, Mahmut S; Alponat, Selin


    Cases of posterior pharyngeal masses are quite rare, and are typically derived from schwannoma or encephalocele, or are of vascular or infectious origin. They are clinically significant due to their tendency to cause airway obstruction. The aim of this study was to present a rare atypical marginal hyperplasia case of a posterior pharyngeal wall mass. A 10-year-old male was admitted to our clinic with dyspnea. A plane-surfaced 4 × 3 × 3 cm mass was observed on the posterior pharyngeal wall upon physical examination. The patient underwent magnetic resonance imaging and surgical treatment. Following excision of material from the patient's mass, a pathologic diagnosis of atypical marginal zone hyperplasia was made. Atypical marginal zone hyperplasia of the posterior pharyngeal wall has not yet been reported in the literature. Marginal zone hyperplasia associated with a lymphoproliferative disease should be considered when making differential diagnoses of posterior pharyngeal wall masses.

  11. Stochastic margin-based structure learning of Bayesian network classifiers.

    Pernkopf, Franz; Wohlmayr, Michael


    The margin criterion for parameter learning in graphical models gained significant impact over the last years. We use the maximum margin score for discriminatively optimizing the structure of Bayesian network classifiers. Furthermore, greedy hill-climbing and simulated annealing search heuristics are applied to determine the classifier structures. In the experiments, we demonstrate the advantages of maximum margin optimized Bayesian network structures in terms of classification performance compared to traditionally used discriminative structure learning methods. Stochastic simulated annealing requires less score evaluations than greedy heuristics. Additionally, we compare generative and discriminative parameter learning on both generatively and discriminatively structured Bayesian network classifiers. Margin-optimized Bayesian network classifiers achieve similar classification performance as support vector machines. Moreover, missing feature values during classification can be handled by discriminatively optimized Bayesian network classifiers, a case where purely discriminative classifiers usually require mechanisms to complete unknown feature values in the data first.

  12. Marginal revenue and length of stay in inpatient psychiatry.

    Pletscher, Mark


    This study examines the changes in marginal revenue during psychiatric inpatient stays in a large Swiss psychiatric hospital after the introduction of a mixed reimbursement system with tariff rates that vary over length of stay. A discrete time duration model with a difference-in-difference specification and time-varying coefficients is estimated to assess variations in policy effects over length of stay. Among patients whose costs are fully reimbursed by the mixed scheme, the model demonstrates a significant effect of marginal revenue on length of stay. No significant policy effects are found among patients for whom only health insurance rates are delivered as mixed tariffs and government contributions are made retrospectively. The results indicate that marginal revenue can affect length of stay in inpatient psychiatry facilities, but that the reduction in marginal revenue must be sufficiently large.

  13. Slumping on the western continental margin of India

    Guptha, M.V.S.; Mohan, R.; Muralinath, A.S.

    A short gravity core from the Western Continental Margin of India has been examined to understand the nature and characteristics of slumping in the area. The present study and also the earlier studies revealed that the slumping on the western...

  14. Extranodal marginal zone (MALT) lymphoma in common variable immunodeficiency.

    Desar, I.M.; Keuter, M.; Raemaekers, J.M.M.; Jansen, J.B.M.J.; Krieken, J.H.J.M. van; Meer, J.W.M. van der


    We describe two patients with common variable immunodeficiency (CVID) who developed extranodal marginal zone lymphoma (formerly described as mucosa-associated lymphoid tissue lymphoma or MALT lymphoma). One patient, with documented pernicious anaemia and chronic atrophic gastritis with metaplasia, d

  15. The Paleoecology of Vegetation on Pennsylvanian Basin Margins

    Bashforth, Arden Roy

    on a fluvial megafan under strongly seasonal conditions, gigantic cordaitalean forests dominated the landscape, particularly alongside ephemeral channels.  Floodplains were largely dry and degraded, although pteridosperms, ferns, and lycopsids persisted around poorly drained depressions.  On the Nýrany Member...... braided-river plain (Middle Pennsylvanian, Central and Western Bohemian Basin, Czech Republic), raised channel margins supported long-lived site-occupiers, such as cordaitaleans and pteridosperms.  Pioneering vegetation comprising fast-growing, opportunistic taxa, particularly ferns and sphenopsids......, was common on wetter, shifting substrates of frequently flooded abandoned channels, low-lying floodplains, and lake margins.  In La Magdalena Coalfield (Late Pennsylvanian, Spain), pteridosperms dominated marginal wetlands adjacent to steep basin margins.  Opportunistic ferns were abundant in or adjacent...

  16. U.S. East Coast Continental Margin (CONMAR) Sediment Data

    National Oceanic and Atmospheric Administration, Department of Commerce — The USGS/WHOI Continental Margin (CONMAR) Data set was compiled by the U.S. Geological Survey and the Woods Hole Oceanographic Institution as a joint program of...

  17. Total Sediment Thickness of the World's Oceans & Marginal Seas

    National Oceanic and Atmospheric Administration, Department of Commerce — A digital total-sediment-thickness database for the world's oceans and marginal seas has been compiled by the NOAA National Geophysical Data Center (NGDC). The data...

  18. Lead poisoning and marginalization in newborns of Morelos, Mexico

    Martha María Téllez-Rojo; Luis F Bautista-Arredondo; Vesta Richardson; Daniel Estrada-Sánchez; Laura Ávila-Jiménez; Camilo Ríos; Alejandra Cantoral-Preciado; Martín Romero-Martínez; Delia Flores-Pimentel; Maria del Carmen Melo-Zurita; Anita Romero-Ramírez; Marco Antonio León-Mazón; Sergio Montes; Richard Fuller; Mauricio Hernández-Avila


    Objective. To determine the prevalence of lead (Pb) poi- soning at birth in Morelos, analyze its distribution by social marginalization level, and estimate the association with the use of lead glazed ceramics (LGC...

  19. Russula herrerae, a new species with marginal veil from Mexico.

    Kong, Alejandro; Montoya, Adriana; Estrada-Torres, Arturo


    Russula herrerae, a new species belonging to section Plorantes, subsection Lactarioideae, characterized by the presence of a marginal veil and collected in a temperate Quercus forest in Tlaxcala, Mexico, is described and illustrated.

  20. The marginal social cost of headway for a scheduled service

    Fosgerau, Mogens


    waiting time costs as well as schedule delay costs measured relative to their desired time of arrival at the destination. They may either arrive at the station to choose just the next departure or they may plan for a specific departure in which case they incur also a planning cost. Then planning......This brief paper derives the marginal social cost of headway for a scheduled service, i.e. the cost for users of marginal increases to the time interval between departures. In brief we may call it the value of headway in analogy with the value of travel time and the value of reliability. Users have...... for a specific departure is costly but becomes more attractive at longer headways. Simple expressions for the user cost result. In particular, the marginal cost of headway is large at short headways and smaller at long headways. The difference in marginal costs is the value of time multiplied by half the headway....

  1. Multilevel random effect and marginal models for longitudinal data ...

    Multilevel random effect and marginal models for longitudinal data. ... Ethiopian Journal of Science and Technology ... the occurrence of specific adverse events than children injected with licensed vaccine, and if so, to quantify the difference.

  2. Locational marginal prices with SVC in Indian electricity market


    real and reactive power has become central issue for better and economic operation of system. .... bilateral contract model used in this paper is basically a subset of the full ...... Wheeling rates of reactive flow under marginal cost theory.

  3. The effect of exchange rate on marketing margin

    Leila Torki


    Full Text Available This study presents a new structural model that incorprates price linkage and marketing marketing margin identity into a common framework. The inclusiom of exchange rate expands the framework to include goods traded in different currencies. This allows emprical estimates to be made of how changes in domestic prices exchange rates and middlemen costs are transmitted to foreign prices and the international marketing margin. The framework is emprically applied to international marketing channel using farmed apple data to investigate how Iranian export prices exchange rates and middlemen costs affect turkey wholesale prices and the marketing margin. Results suggest that the markets are via complete price and exchange rate pass through purely competitive and that the marketing margin only increase when costs of marketing service increase.

  4. Quaternary alluvial stratigraphy and palaeoclimatic reconstruction at the Thar margin

    Jain, M.; Tandon, S.K.


    Quaternary alluvial record at the Thar desert margin has been examined using the exposed succession along Mahudi, Sabarmati river, Western India. Different alluvial facies, their associations and granulometry have been studied for palaeoenvironmental reconstruction. Clay mineral indices smectite/...

  5. Crustal thinning and tectonic geomorphology: redefining the passive margin

    Redfield, T.; Osmundsen, P. T.


    We describe Scandinavia's passive margin in terms of a hyper-extended distal margin, a variably tapered proximal margin that includes the outer onshore areas, and an upwarped, unstretched, continent-sloping hinterland that terminates against the "undeformed" cratonic interior. Two benchmark locations, defined as the taper break (TB) and the Hinterland Break in Slope (HBSL), occur at the inner boundary of the distal margin and at the transition from the continent-sloping hinterland and craton, respectively. The elevation of the seaward-facing escarpment is directly scaled to the distance between the taper break and the Hinterland Break in Slope. Scaling relationships between the taper of the crystalline crust in the direction of the distal margin and the length/dip of the hinterland backslope follow directly. The shape factors of major catchments are directly scaled to the taper of the proximal margin and drainage azimuths are parallel to the mean transport lineation recorded from a distinct population of range-bounding normal faults. Topographic expressions of the footwalls and offsets in apatite fission-track age-patterns indicate that fault movement controlled topography, locally and regionally inboard of sharp crustal tapers long after the main phase of crustal thinning. We extend our definition of the passive margin to other post-breakup margins. One particularly fine example is SE Brasil. New data (Zalan et al., 2011) suggest the direct correlation of SE Brasil's Taper Break with its escarpment elevation in a manner consistent with our Scandinavian and global observations. The Taper Hypothesis appears to hold across old and young, glaciated, and unglaciated margins. Following the stretching, thinning, and exhumation phase, an "accommodation phase" is warranted. During accommodation, the initially elevated escarpments can be eroded to very low base levels and subsequently undergo inboard rejuvenation by footwall uplift, in response to tensile stresses

  6. Australia's southern margin: a product of oblique extension

    Willcox, J. B.; Stagg, H. M. J.


    Recently developed detachment models of continental margin formation interpret the southern margin of Australia to have formed when the lower-plate Australian margin was pulled out from beneath the upper-plate Antarctic margin. Data now available and summarised in this paper, point very strongly to a generally NW-SE direction of initial continental extension for the southern margin, in contrast to the widely held picture of simple N-S rifting. The evidence for this extension direction comes from the analysis of deep Seismic data acquired by the Bureau of Mineral Resources in 1986 in the central Great Australian Bight (GAB), the gravity field of the GAB, Seismic and magnetic basement structures in the Eyre Sub-basin, Polda Trough, Ceduna Depocentre and Duntroon Basin and from the analysis of the magnetic seafloor spreading anomalies produced during the slow first phase of drifting between Australia and Antarctica. Further, it is now believed that the formation of the southern margin of Australia can be described in terms of three phases of continental extension (El to E3) and two phases of drifting (D1 and D2). In summary, these phases were as follows. E1: approximately 300 km of Late Jurassic (?or older) to Early Cretaceous NW-SE-oriented extension in the GAB, with strike-slip motion in the nascent Otway Basin and along the Tasmanian margin. E2: 120 km of Early Cretaceous NNE-SSW-oriented extension which formed the basins of southeastern Australia (Otway, Bass, Gippsland) and which probably produced a structural overprinting in the GAB Basin. E3/D1: minor continental extension and the first 500 km of slow drift between Australia and Antarctica on an azimuth of 165°; wrenching on the Tasmanian margin. D2: 2600 km of fast drifting between Australia and Antarctica on a N-S azimuth.

  7. The origin of marginal zone B cells in the rat

    Dammers, PM; de Boer, NK; Deenen, GJ; Nieuwenhuis, P; Kroese, FGM


    The marginal zone is a unique compartment that is only found in the spleen. Rat marginal zone B cells (MZ-B) can be distinguished from other B cells, e.g. recirculating follicular B cells (RF-B), by several phenotypic characteristics. Typically MZ-B cells are surface (s)IgM(hi), sIgD(lo) and CD45R(B

  8. Analysis of Marketing Margins in Eco-Labeled Products

    Carambas, Maria Cristina D.M.


    This article aims to explain the marketing margins in the eco-labeled products market in Thailand and the Philippines. It focuses on labeled organic agricultural commodities that are commonly exported especially in Europe, which has demand for this type of products. Understanding the interplay of economic variables influencing marketing margins in the eco-labeled market as compared to its conventional counterpart is relevant in understanding how this growing niche market works. The analytical...

  9. The marginal benefit of diversification in commercial real estate portfolios

    Lee, Stephen L.


    The number of properties to hold to achieve a well-diversified real estate property portfolio presents a puzzle, as the estimated number is considerably higher than that seen in actual portfolios. However, Statman (1987) argues that investors should only increase the number of holdings as long as the marginal benefits of diversification exceed their costs. Using this idea we find that the marginal benefits of diversification in real estate portfolios are so small that investors are probably r...

  10. Mud-dominated basin margin progradation: processes and implications

    Poyatos-Moré, M; Jones, GD; Brunt, RL; Hodgson, DM; Wild, RJ; Flint, SS


    The accretion of coarse-grained material at the shelf-edge rollover has been emphasized in studies of basin margin progradation, despite fine grained sediment (clay and silt) representing a volumetrically more significant component of subaqueous clinothems. The timing and processes of fine-grained sediment transport across the shelf and onto the slope remains an understudied facet of sedimentary basin stratigraphy. Three exhumed basin margin-scale clinothems of the Permian Waterford Formation...

  11. The effect of exchange rate on marketing margin

    Leila Torki; AhmadAli Rezaei; Shekofeh Nagheli


    This study presents a new structural model that incorprates price linkage and marketing marketing margin identity into a common framework. The inclusiom of exchange rate expands the framework to include goods traded in different currencies. This allows emprical estimates to be made of how changes in domestic prices exchange rates and middlemen costs are transmitted to foreign prices and the international marketing margin. The framework is emprically applied to international marketing channel ...

  12. Glacial evolution of Central-East Greenland Margin: a GLANAM project contribution

    Pérez, Lara F.; Nielsen, Tove


    The dynamic evolution of the Greenland Ice Sheet is directly related to the Northern Hemisphere glaciation. The ice sheet has influenced the Greenland margins construction conditioning their morphology and their reply to other control factors in the evolution, as tectonic and oceanographic events. Thus, the sedimentary record preserved around Greenland has registered the glacial oscillations of the Northern Hemisphere, as well as the influence of other conditioning factors in the development of a permanent ice sheet on Greenland. The aim of this work is to summarize the new insights of Central-East Greenland glacial evolution reached within the framework of the Marie Curie Initial Training Network (ITN-FP7-PEOPLE-2012-ITN): Glaciated North Atlantic Margins (GLANAM) project. Several multichannel seismic profiles have been acquired along Central-East Greenland Margin, with both research and exploration proposes. They enable the large-scale reconstruction of the major stratigraphic events from late Miocene to Present, in agreement with an age correlation with ODP sites along the margin. High-resolution seismic, sub-bottom profiles, swath bathymetry and sediment cores are also locally available supporting detailed interpretation of the Quaternary sedimentary record. While ice-rafter debris (IRD) in the northern seas have been interpreted as indicators of tidewater glaciers on Greenland, the acoustic and seismic evidences summarized in this work allow reconstruction of different episodes of cross-shelf advances of the Greenland Ice Sheet along the central-east margin. The results of this work reveal an early cross-shelf glaciation occurred off Blosseville Kyst during late Miocene and early Pliocene followed by major ice-stream activity off Scoresby Sund during early Quaternary and glacial advance off Liverpool Land in late Quaternary. Higher resolution of the Quaternary data off Liverpool Land suggests that the intense ice-stream of the Scoresby Sund fjord was gradually

  13. Physical Performance of Migrant Schoolchildren with Marginal and Severe Iron Deficiency in the Suburbs of Beijing



    Objectivess To investigate relationship between iron deficiency of different degrees and physical performance and habitual activity of migrant schoolchildren at the age of 11-14 years. Methods Ninety one randomly selected schoolchildren were divided into three groups according to their iron status. Iron status including hemoglobin (Hb), serum ferritin (SF), serum iron (SI) and sTfR was determined. Physical performance tests included maximum oxygen consumption (VO2max) and maximum work time. Energy expenditure (EE) and daily physical activity were estimated by recording 24-h heart rate (HR). Dietary intake was assessed with frequency questionnaires, and physical activity level was estimated with frequency and physical activity questionnaires. Results Severe iron deficiency (IDA) impaired the aerobic capacity and habitual physical activity. When fat-free mass (FFM) was considered, VO2max (VO2max/FFM) was significantly lower in the iron-marginal group than in the iron-adequate groups among girls (P=0.02), but such a deference was not found among boys (p=0.28). Aerobic activity and EE at leisure were significantly lower in the severe iron deficient group than in the marginal iron deficient and iron adequate groups. Net HR at leisure time was correlated with Hb, log SF, body weight, and FFM (P<0.05). Conclusion The functional effect of iron deficiency on physical performance and habitual physical activity rely on the degree of current iron deficiency. Severe iron deficiency significantly impairs both aerobic capacity and habitual physical activity. Iron-marginal deficiency impairs VO2max/FFM in girls, rather than in boys.

  14. Certifiable higher order sliding mode control: Practical stability margins approach

    Panathula, Chandrasekhara Bharath

    The Higher Order Sliding Mode (HOSM) controllers are well known for their robustness/insensitivity to bounded perturbations and for handling any given arbitrary relative degree system. The HOSM controller is to be certified for robustness to unmodeled dynamics, before deploying the controller for practical applications. Phase Margin (PM) and Gain Margin ( GM) are the classical characteristics used in linear systems to quantify the linear controller robustness to unmodeled dynamics, and certain values of these margins are required to certify the controller. These conventional margins (PM and GM) are extended to Practical Stability Phase Margin (PSPM) and Practical Stability Gain Margin (PSGM) in this dissertation, and are used to quantify the HOSM control robustness to unmodeled dynamics, presiding the tool to close the gap for HOSM control certification. The proposed robustness metrics ( PSPM and PSGM) are identified by developing tools/algorithms based on Describing Function-Harmonic Balance method. In order for the HOSM controller to achieve the prescribed values on robustness metrics ( PSPM and PSGM), the HOSM controller is cascaded with a linear compensator. A case study of the application of the proposed metrics (PSPM and PSGM) for the certification of F-16 aircraft HOSM attitude control robustness to cascade unmodeled dynamics is presented. In addition, several simulation examples are presented to verify and to validate the proposed methodology.

  15. The evolution and evolutionary consequences of marginal thermostability in proteins.

    Goldstein, Richard A


    When we seek to explain the characteristics of living systems in their evolutionary context, we are often interested in understanding how and why certain properties arose through evolution, and how these properties then affected the continuing evolutionary process. This endeavor has been assisted by the use of simple computational models that have properties characteristic of natural living systems but allow simulations over evolutionary timescales with full transparency. We examine a model of the evolution of a gene under selective pressure to code for a protein that exists in a prespecified folded state at a given growth temperature. We observe the emergence of proteins with modest stabilities far below those possible with the model, with a denaturation temperature tracking the simulation temperature, despite the absence of selective pressure for such marginal stability. This demonstrates that neither observations of marginally stable proteins, nor even instances where increased stability interferes with function, provide evidence that marginal stability is an adaptation. Instead the marginal stability is the result of a balance between predominantly destabilizing mutations and selection that shifts depending on effective population size. Even if marginal stability is not an adaptation, the natural tendency of proteins toward marginal stability, and the range of stabilities that occur during evolution, may have significant effect on the evolutionary process.

  16. Disability and marginal utility of income: evidence from hypothetical choices.

    Tengstam, Sven


    It is often assumed that disability reduces the marginal utility of income. In this article, individuals' marginal utility of income in two states-(i) paralyzed in both legs from birth and (ii) not mobility impaired at all-is measured through hypothetical choices between imagined lotteries behind a so-called veil of ignorance. The outcomes of the lotteries include both income and disability status. It is found that most people have higher marginal utility when paralyzed than when not mobility impaired at all. The two marginal utilities are evaluated at the same levels of income. Having personal experience of mobility impairment and supporting the Left Party, the Social Democratic Party, the Green Party, or the Liberal Party are associated with having a higher marginal utility when paralyzed. The results suggest that more than full insurance of income losses connected to being disabled is optimal. The results further suggest that, given a utilitarian social welfare function, resources should be transferred to rather than from disabled people. Finally, if the transfers are not large enough to smooth out the marginal utilities of the disabled and the nondisabled, distributional weights based on disability status should be used in cost-benefit analysis.

  17. Phase Transitions, Diffraction Studies and Marginal Dimensionality

    Als-Nielsen, Jens Aage


    Continuous phase transitions and the associated critical phenomena have been one of the most active areas of research in condensed matter physics for several decades. This short review is only one cut through this huge subject and the author has chosen to emphasize diffraction studies as a basic...

  18. The Eastern Sardinian Margin (Tyrrhenian Sea, Western Mediterranean) : a key area to study the rifting and post-breakup evolution of a back-arc passive continental margin

    Gaullier, Virginie; Chanier, Frank; Vendeville, Bruno; Maillard, Agnès; Thinon, Isabelle; Graveleau, Fabien; Lofi, Johanna; Sage, Françoise


    post-breakup deformation also occurred during the Pliocene. Some Pliocene vertical movements have been evidenced by discovering localized gravity gliding of the salt and its Late Messinian (UU) and Early Pliocene overburden. To the South, crustal-scale southward tilting triggered along-strike gravity gliding of salt and cover recorded by upslope extension and downslope shortening. To the North, East of the Baronie Ridge, there was some post-salt crustal activity along a narrow N-S basement trough, bounded by crustal faults. The salt geometry would suggest that nothing happened after Messinian times, but some structural features (confirmed by analogue modelling) show that basement fault slip was accommodated by lateral salt flow, which thinned upslope and thickened downslope, while the overlying sediments remained sub-horizontal. Along the inner domain of Eastern Sardinian margin, the post-rift deformation style greatly varies. Compressional structures (reverse faults and folds) are observed both onshore and offshore while post-rift extensional structures are mainly identified offshore. Such late deformation could be attributed to mechanisms acting alone or combined, such as : i. the reactivation of the margin, as already described for the Ligurian, Algerian or South-Balearic margins due to the Eurasian-African convergence ; 2. the Zanclean reflooding and the resulting water overload on the elastic lithosphere ; 3. an episodic mantle upwelling.

  19. Risk-Informed Safety Margin Characterization Methods Development Work

    Smith, Curtis L [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ma, Zhegang [Idaho National Lab. (INL), Idaho Falls, ID (United States); Riley, Tom [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Nielsen, Joseph W [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States)


    This report summarizes the research activity developed during the Fiscal year 2014 within the Risk Informed Safety Margin and Characterization (RISMC) pathway within the Light Water Reactor Sustainability (LWRS) campaign. This research activity is complementary to the one presented in the INL/EXT-??? report which shows advances Probabilistic Risk Assessment Analysis using RAVEN and RELAP-7 in conjunction to novel flooding simulation tools. Here we present several analyses that prove the values of the RISMC approach in order to assess risk associated to nuclear power plants (NPPs). We focus on simulation based PRA which, in contrast to classical PRA, heavily employs system simulator codes. Firstly we compare, these two types of analyses, classical and RISMC, for a Boiling water reactor (BWR) station black out (SBO) initiating event. Secondly we present an extended BWR SBO analysis using RAVEN and RELAP-5 which address the comments and suggestions received about he original analysis presented in INL/EXT-???. This time we focus more on the stochastic analysis such probability of core damage and on the determination of the most risk-relevant factors. We also show some preliminary results regarding the comparison between RELAP5-3D and the new code RELAP-7 for a simplified Pressurized Water Reactors system. Lastly we present some conceptual ideas regarding the possibility to extended the RISMC capabilities from an off-line tool (i.e., as PRA analysis tool) to an online-tool. In this new configuration, RISMC capabilities can be used to assist and inform reactor operator during real accident scenarios.

  20. Geophysical constraints on geodynamic processes at convergent margins: A global perspective

    Artemieva, Irina; Thybo, Hans; Shulgin, Alexey


    convergence rate. (4) Local isostasy is not satisfied at the convergent margins as evidenced by strong free air gravity anomalies of positive and negative signs. However, near-isostatic equilibrium may exist in broad zones of distributed deformation such as Tibet. (5) No systematic patterns are recognized in heat flow data due to strong heterogeneity of measured values which are strongly affected by hydrothermal circulation, magmatic activity, crustal faulting, horizontal heat transfer, and also due to low number of heat flow measurements across many margins. (6) Low upper mantle Vs seismic velocities beneath the convergent margins are restricted to the upper 150 km and may be related to mantle wedge melting which is confined to shallow mantle levels. Artemieva, I.M., Thybo, H., and Shulgin, A., 2015. Geophysical constraints on geodynamic processes at convergent margins: A global perspective. Gondwana Research,

  1. Marginal integrity of class V restorations: SEM versus dye penetration.

    Ernst, Claus-Peter; Galler, Pia; Willershausen, Brita; Haller, Bernd


    To perform an in vitro investigation on the marginal integrity of different adhesives (Optibond FL, Scotchbond 1XT, Clearfil SE Bond, Adper Prompt L-Pop, S(3) Bond, iBond exp., Adper Prompt L-Pop) in combination with Tetric Ceram as well as an experimental silorane-restorative (Hermes, Hermes Bond; 3M ESPE) using SEM and dye penetration (2% methylene blue) in a comparative manner. Standardized class V-cavities (3 mm x 1.5 mm) were prepared in 70 extracted human teeth (n=10). The adhesives were applied according to manufacturers' instructions. The cavities were restored with three increments. After finishing and polishing (Sof-Lex discs) and thermocycling (5000x, 5/55 degrees C), replicas were taken and the teeth immersed in the dye for 10s (D10) and evaluated. After another penetration of 30 min (D30) a final evaluation of the percentage of dye-penetrated margins was conducted. The median percentages in marginal gaps (%) at the enamel margins for the three methods investigated (D10/D30/SEM) were--Optibond FL: 0/0/4, Scotchbond 1 XT: 5/16/11, Clearfil SE Bond: 0/0/0, S(3) Bond: 0/0/1, iBond exp.: 20/42/12, Adper Prompt L-Pop: 5/23/8, Hermes/Hermes Bond: 5/45/24. Cementum margins--Optibond FL: 0/1/0, Scotchbond 1 XT: 0/21/23, Clearfil SE Bond: 0/0/4, S(3) Bond: 0/0/0, iBond exp.: 0/0/0, Adper Prompt L-Pop: 10/32/23, Hermes/Hermes Bond: 0/0/13. After pooling the data of all groups, a Spearmann's rho test showed a good correlation between the methods D10 and D30 at the enamel margins and at the entire cavity margins (correlation coefficient 0.8 and 0.7). SEM did not correlate with the results obtained from D10 (correlation coefficient <0.5). A fair correlation was found between SEM and D30 for the entire cavity margin but a good correlation for the enamel margins. No correlation between investigation methods was determined at the cementum margins. D30 showed a better correlation to SEM than D10 did. Therefore, 30 min of dye penetration time seems to be more suitable

  2. Changes in ice-margin processes and sediment routing during ice-sheet advance across a marginal moraine

    Knight, P.G.; Jennings, C.E.; Waller, R.I.; Robinson, Z.P.


    Advance of part of the margin of the Greenland ice sheet across a proglacial moraine ridge between 1968 and 2002 caused progressive changes in moraine morphology, basal ice formation, debris release, ice-marginal sediment storage, and sediment transfer to the distal proglacial zone. When the ice margin is behind the moraine, most of the sediment released from the glacier is stored close to the ice margin. As the margin advances across the moraine the potential for ice-proximal sediment storage decreases and distal sediment flux is augmented by reactivation of moraine sediment. For six stages of advance associated with distinctive glacial and sedimentary processes we describe the ice margin, the debris-rich basal ice, debris release from the glacier, sediment routing into the proglacial zone, and geomorphic processes on the moraine. The overtopping of a moraine ridge is a significant glaciological, geomorphological and sedimentological threshold in glacier advance, likely to cause a distinctive pulse in distal sediment accumulation rates that should be taken into account when glacial sediments are interpreted to reconstruct glacier fluctuations. ?? 2007 Swedish Society for Anthropology and Geography.

  3. The ESCIN-3-1 deep seismic profile in the northwestern Galicia margin revisited

    Carbonell, R.; Alvarez-Marron, J.; Ayarza, P.; Torne, M.


    The ESCIN-3.1 profile was acquired in 1993 offshore northwest Galicia (Spain), and recorded 20 s of near vertical reflection seismic data. This 140 km long profile was intended to provide an image of the crustal structure of this sector of the continental margin from near the coastline to the deep-sea area. The tectonic evolution of the northwest Galicia margin initiated by rifting during Late Jurassic-Early Cretaceous times and progressed to sea floor spreading during Albian- Late Cretaceous times when the Bay of Biscay opened. Subsequently, the margin was active during the convergence of Eurasia and Iberia in the Late Oligocene to Early Miocene. Here we present a new interpretation of the mentioned profile based on a newly reprocessed depth migrated image and corresponding gravity model. In the deep-sea areas, a free-air gravity low reach up to - 120 mGal and the sea bottom is at more than 5000 m deep. The 7 km thick flat lying undisturbed sedimentary cover appears above a 10 km thick, ~120 Ma old oceanic basement. This flat sediments onlap toward the ocean-continent transition on a folded and disturbed 20 km long wedge shaped sedimentary body. A major landward dipping structure reaches from the foot of the slope to beneath the sub horizontal Moho of the continental slope. The slope has a gentle dip of about 2° in this section, and include large mass flow deposits. Fault bound sediments are imaged in the upper continental margin that could correspond to preserved syn-rift Mesozoic structures. The structure of what correspond to the continental basement in the thicker part of the margin is not well resolved. Only in the landward side of the profile a layered lower crust is seen where the Moho reaches depths of 29 km. The ocean-continent transition in this profile may be interpreted as that of an active compressional boundary with some accretion of deep-sea sediments that are underthrust by a thinned continental margin with large submarine landslides and mass flow

  4. Teaching marginalized children at primary schools: teachers professional development through collaborative action research

    T. Subahan Mohd Meerah


    Full Text Available This paper discusses an attempt on teachers’ professional development through collaborative action research to enhance marginalized children’s learning. Despite all efforts to overcome the difficulties of learning encountered by marginalized children, their performance both in the external as well as in the school-based assessments show poor performance especially in subjects like Science and Mathematics. This situation prevails and has resulted in dropout of the students at the primary level before they pursue for secondary education. Based on a series of observations, focus group discussions (FGD with teachers and consecutive school visits, it was identified that the teachers face some difficulties in teaching Science, Mathematics and language. Teachers tend to use similar teaching approaches as those were being used in the urban schools, which are more teacher-directed in nature. Further, many teachers do not possess sound pedagogical skills to teach Science and Mathematics and to employ alternative approaches suitable for marginalized children in their context. To overcome this situation, teaching modules are developed by the teachers and researchers to provide alternative ways of teaching science. Additionally, teachers become known to the concept of action research. Two professional development workshops have been conducted to introduce some alternative approaches to teach primary science. Preliminary findings show that teachers perceive the modules very useful and beneficial to them. Moreover, the students demonstrate better motivation to learn as well as active involvement in the learning activities.

  5. Climate modulated erosion and sediment flux control offshore crustal structure at South China Sea continental margin

    Clift, P. D.; Brune, S.; Quinteros, J.


    Rifted continental lithosphere subsides as a consequence of combined crustal thinning and mantle lithosphere cooling yet basins on some continental margins experience anomalous subsidence events that postdate active extension. Deep basins on the northern margin of the South China Sea, notably the Baiyun Sag, show basement subsidence accelerating after ~21 Ma, postdating extension by several million years. Similar subsidence events are seen after 5 Ma in the Song Hong Basin and after 11 Ma in the Qiongdongnan Basin. We combine geophysical observations and numerical forward modeling to show that loading of the offshore basins by increased sediment flux caused by faster onshore erosion following Early Miocene monsoon intensification is a viable trigger for ductile flow after the cessation of active extension. Loading works in conjunction with onshore uplift to drive flow of the lower crust away from the rift axis. As well as sediment supply rates distribution patterns and drainage capture can be significant in controlling crustal flow and thinning. This illustrates that offshore basin dynamics at continental margins with weak crust can be controlled by onshore surface processes in a newly recognized form of climate-tectonic coupling.

  6. Symposium on North Atlantic Margin Petroleum Resources: Technical Program: Papers Presented



    This program lists the papers presented at a symposium, held as part of the Geological Association--Mineralogical Association of Canada 2001 Joint Annual Meeting. Thirty-nine papers and seven poster exhibits were presented on a wide diversity of subjects dealing with (1) development activities and exploration potential of the North Atlantic margins of Nova Scotia, across the ocean to Ireland and offshore Morocco; (2) recently activated hydrocarbon fields off Canada's eastern shores; (3) integration of local and regional geological data with production data and new and proven technologies; (4) a short course on ichnofossils and fossil footprints and the sedimentology of shallow-and marginal marine systems using core from the Jeanne d'Arc Basin; and (5) modern products and processes that are fundamental to successful production from marginal marine reservoirs. This program lists only the titles of the papers presented in each of the six sessions and the titles of the poster exhibits. The abstracts themselves are available on the Internet at the address cited above.


    Ni Made Suciani


    Full Text Available Some schools experienced termerjinalkan circumstances amid the bustle of the city of Denpasar . The problems studied are factors causing some schools experiencing marginalization , how to provide education to marginalized schools , and bagaimanaimplementasinya associated with the five pillars of national education policy and its implications for students , institutions, schools , and masyarakat.Penelitian inimenggunakan qualitative approach . The theory used is the deconstruction theory , structuration theory , and critical education theory . Data was collected using the method of observation , interviews , and documentary techniques , and analyzed qualitatively . The results showed that the appearance of marginalization at some schools due to cultural dualism between public schools and private schools , which includes the views and policies of the government , private sector and the impact of marginality teacher certification . Another factor is the culture , character and public perceptions of the school negeriserta labeling of the marginal private schools , and the lack of financial management and imaging schools to survive for the sake of prestige . In addition there are also technical factors such as the lack of human resource management , lack of competence danusaha - business competence improvement also poor communication and school partnerships with stakeholders , as well as the lack of supervision and evaluation of the achievement of national standards on school education pendidikan.Penyelenggaraan marginalized can be seen from intangible side as diseconomies kumunitas , dehumanization of education and culture in school imaging termarjinalkan.Sedangkan of the tangible results of self-evaluation is through education at school sekolah.Implementasi marginalized related to the five pillars of the national education policy is the availability , affordability , quality , equality and assuredness service besides it also analyzed the

  8. Clinical experience in the use of marginal donor hearts

    XIE Ai-ni; DONG Nian-guo; ZHANG Kai-lun; XIA Jia-hong; XIAO Shi-liang; SUN Zong-quan


    Background Although heart transplantation has become a standard therapy for end-stage heart disease, there are few published studies regarding the use of transplant organs from marginal donors. Here we describe the clinical outcome we have obtained using marginal donor hearts.Methods We analyzed 21 cases of orthotropic heart transplantation for end-stage heart disease performed in our department between September 2008 and July 2010. Of these patients, six received hearts from marginal donors and the remainder received standard-donor hearts. The two groups were compared in terms of both mortality and the incidence of perioperative complications such as infection, acute rejection, and right heart insufficiency.Results The 1-year survival rate of both groups was 100%. Only one death was recorded in standard-donor group during follow-up. Patients who received marginal donor hearts (83%) experienced more early complications than did the standard-donor-heart group (13%), but the mortality of the two groups was the same. The duration of post-ICU stay was greater in the marginal donor group than in the standard-donor group, (35.5±17.4) days and (21.7±2.6) days, respectively (P <0.05).Conclusions The use of marginal donor hearts increases the number of patients who can receive and benefit from transplants. However, it may introduce an increased risk of early complications, thus care should be taken both in the choice of patients who will receive marginal donor hearts and in the perioperative treatment of those for whom the procedure is performed.

  9. Inherited crustal deformation along the East Gondwana margin revealed by seismic anisotropy tomography

    Pilia, S.; Arroucau, P.; Rawlinson, N.; Reading, A. M.; Cayley, R. A.


    The mechanisms of continental growth are a crucial part of plate tectonic theory, yet a clear understanding of the processes involved remains elusive. Here we determine seismic Rayleigh wave phase anisotropy variations in the crust beneath the southern Tasmanides of Australia, a Paleozoic accretionary margin. Our results reveal a complex, thick-skinned pervasive deformation that was driven by the tectonic interaction between the proto-Pacific Ocean and the ancient eastern margin of Gondwana. Stress-induced effects triggered by the collision and entrainment of a microcontinent into the active subduction zone are evident in the anisotropy signature. The paleofracturing trend of failed rifting between Australia and Antarctica is also recorded in the anisotropy pattern as well as a tightly curved feature in central Tasmania. The observed patterns of anisotropy correlate well with recent geodynamic and kinematic models of the Tasmanides and provide a platform from which the spatial extent of deformational domains can be refined.

  10. Marginal contrasts and the Contrastivist Hypothesis

    Daniel Currie Hall


    Full Text Available The Contrastivist Hypothesis (CH; Hall 2007; Dresher 2009 holds that the only features that can be phonologically active in any language are those that serve to distinguish phonemes, which presupposes that phonemic status is categorical. Many researchers, however, demonstrate the existence of gradient relations. For instance, Hall (2009 quantifies these using the information-theoretic measure of entropy (unpredictability of distribution and shows that a pair of sounds may have an entropy between 0 (totally predictable and 1 (totally unpredictable. We argue that the existence of such intermediate degrees of contrastiveness does not make the CH untenable, but rather offers insight into contrastive hierarchies. The existence of a continuum does not preclude categorical distinctions: a categorical line can be drawn between zero entropy (entirely predictable, and thus by the CH phonologically inactive and non-zero entropy (at least partially contrastive, and thus potentially phonologically active. But this does not mean that intermediate degrees of surface contrastiveness are entirely irrelevant to the CH; rather, we argue, they can shed light on how deeply ingrained a phonemic distinction is in the phonological system. As an example, we provide a case study from Pulaar [ATR] harmony, which has previously been claimed to be problematic for the CH.

  11. The giant Ruatoria debris avalanche on the northern Hikurangi margin, New Zealand: Result of oblique seamount subduction

    Collot, Jean-Yves; Lewis, Keith; Lamarche, Geoffroy; Lallemand, Serge


    Despite convergent margins being unstable systems, most reports of huge submarine slope failure have come from oceanic volcanoes and passive margins. Swath bathymetry and seismic profiles of the northern Hikurangi subduction system, New Zealand, show a tapering 65-30 km wide by 65 km deep margin indentation, with a giant, 3150±630 km3, blocky, debris avalanche deposit projecting 40 km out across horizontal trench fill, and a debris flow deposit projecting over 100 km. Slide blocks are well-bedded, up to 18 km across and 1.2 km high, the largest being at the avalanche deposit's leading edge. Samples dredged from them are mainly Miocene shelf calc-mudstones similar to those outcropping around the indentation. Cores from cover beds suggest that failure occurred ˜170±40 ka, possibly synchronously with a major extension collapse in the upper indentation. However, the northern part of the indentation is much older. The steep, straight northern wall is close to the direction of plate convergence and probably formed around 2.0-0.16 Ma as a large seamount subducted, leaving in its wake a deep groove obliquely across the margin and an unstable triangle of fractured rock in the 60° angle between groove and oversteepened margin front. The triangle collapsed as a blocky avalanche, leaving a scalloped southern wall and probably causing a large tsunami. Tentative calculations of compacted volumes suggest that the indentation is over 600 km3 larger than the avalanche, supporting a two-stage origin that includes subduction erosion. Since failure, convergence has carried the deposits ˜9 km back toward the margin, causing internal compression. The eventual subduction/accretion of the Ruatoria avalanche explains the scarcity of such features on active margins and perhaps the nature of olistostromes in fold belts.

  12. MRI Evaluation of Resection Margins in Bone Tumour Surgery

    Simon Vandergugten


    Full Text Available In 12 patients operated on for bone sarcoma resection, a postoperative magnetic resonance imaging of the resection specimens was obtained in order to assess the surgical margins. Margins were classified according to MRI in R0, R1, and R2 by three independent observers: a radiologist and two orthopaedic surgeons. Final margin evaluation (R0, R1, and R2 was assessed by a confirmed pathologist. Agreement for margin evaluation between the pathologist and the radiologist was perfect (κ=1. Agreement between the pathologist and an experienced orthopaedic surgeon was very good while it was fair between the pathologist and a junior orthopaedic surgeon. MRI should be considered as a tool to give quick information about the adequacy of margins and to help the pathologist to focus on doubtful areas and to spare time in specimen analysis. But it may not replace the pathological evaluation that gives additional information about tumor necrosis. This study shows that MRI extemporaneous analysis of a resection specimen may be efficient in bone tumor oncologic surgery, if made by an experienced radiologist with perfect agreement with the pathologist.

  13. Carbonate mound development in contrasting settings on the Irish margin

    van der Land, Cees; Eisele, Markus; Mienis, Furu; de Haas, Henk; Hebbeln, Dierk; Reijmer, John J. G.; van Weering, Tjeerd C. E.


    Cold-water coral carbonate mounds, formed by framework building cold-water corals, are found in several mound provinces on the Irish margin. Differences in cold-water coral mound development rates and sediment composition between mounds at the southwest Rockall Trough margin and the Galway Mound in the Porcupine Seabight are investigated. Variations in sediment composition in the two mound provinces are related to the local environmental conditions and sediment sources. Mound accumulation rates are possibly higher at the Galway Mound probably due to a higher influx of hemipelagic fine grained non-carbonate sediments. In both cold-water coral mound areas, mound growth has been continuous for the last ca 11,000 years, before this period several hiatuses and unconformities exist in the mound record. The most recent unconformity can be correlated across multiple mounds and mound provinces at the Irish margin on the basis of apparent age. On the southwest Rockall Trough margin these hiatuses/unconformities are associated with post-depositional aragonite dissolution in, and lithification of, certain intervals, while at Galway Mound no lithification occurs. This study revealed that the influx and types of material transported to cold-water coral mounds may have a direct impact on the carbonate mound accumulation rate and on post-depositional processes. Significantly, the Logachev Mounds on the SW Rockall Trough margin accumulate slower but, because they contain lithified layers, are less susceptible to erosion. This net effect may account for their larger size compared to the Belgica Mounds.

  14. Marginal land-based biomass energy production in China.

    Tang, Ya; Xie, Jia-Sui; Geng, Shu


    Fast economic development in China has resulted in a significant increase in energy demand. Coal accounts for 70% of China's primary energy consumption and its combustion has caused many environmental and health problems. Energy security and environmental protection requirements are the main drivers for renewable energy development in China. Small farmland and food security make bioenergy derived from corn or sugarcane unacceptable to China: the focus should be on generating bioenergy from ligno-cellulosic feedstock sources. As China cannot afford biomass energy production from its croplands, marginal lands may play an important role in biomass energy production. Although on a small scale, marginal land has already been used for various purposes. It is estimated that some 45 million hm(2) of marginal land could be brought into high potential biomass energy production. For the success of such an initiative, it will likely be necessary to develop multipurpose plants. A case study, carried out on marginal land in Ningnan County, Sichuan Province with per capita cropland of 0.07 ha, indicated that some 380,000 tons of dry biomass could be produced each year from annual pruning of mulberry trees. This study supports the feasibility of producing large quantities of biomass from marginal land sources.

  15. Influence of cavity depth on marginal degradation of amalgam restorations.

    Jokstad, A


    In a 5-year clinical trial it was observed that the marginal degradation of class-II amalgam restorations could be related to the bulk of the restoration. The association between the occlusal cavity depth and the marginal degradation was observed after 6 months and varied for the different types of alloy. Ridit scores of the marginal degradation were correlated to various indices of the cavity sizes, to assess the possible reason for this association. The possibilities of the relationship being an indirect effect caused by longer condensation times or by poorer condensation due to the use of larger condenser sizes were rejected. Furthermore, the possibility that the association was the result of potential buildup of stresses on the restoration margins caused by flexible cusps and axial walls was not apparent. A possible mechanism may be that marginal degradation is the result of short-term or long-term expansion, or even extrusion of amalgam. Expansion may theoretically be caused over short periods by temperature changes or over long periods by corrosion or phase shifts in the amalgam. The theory does not exclude the role of creep or corrosion and may furthermore explain the lack of correlation between in-vitro tests and in-vivo performance of amalgam restorations.

  16. On the Furthest Hyperplane Problem and Maximal Margin Clustering

    Liberty, Edo; Weinstein, Omri


    This paper introduces the Furthest Hyperplane Problem (FHP). Given a set of $n$ points in $\\R^d$, the objective is to produce the hyperplane (through the origin) which maximizes the separation margin, that is, the minimal distance between the hyperplane and an input point. We prove that FHP is NP-hard to approximate to within some small (multiplicative) constant, by presenting a gap preserving reduction from a particular version of the PCP theorem. We also present an algorithm which runs in time $O(n^{\\tilde{O}(1/\\theta^2)})$ where $\\theta$ is the optimal margin. It is based on a dimension reduction technique combined with an $\\eps$-net argument in the reduced dimension. As a consequence, we obtain the first polynomial time algorithm for Maximal Margin Clustering (MMC), which is the unsupervised counterpart of Support Vector Machines (SVM), for the case where the margin is a constant factor of the point cloud diameter. Indeed, this is our main motivation. Our algorithm's running time dependance on the margin ...

  17. Assessment of bioenergy potential on marginal land in China

    Zhuang, Dafang; Jiang, Dong; Liu, Lei; Huang, Yaohuan [Data Center for Resources and Environmental Sciences, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Chaoyang District, Beijing 100101 (China)


    Bioenergy developed from energy plants will play a more and more important role in future energy supply. Much attention has been paid to energy plants in recent years. As China has fairly limited cultivated land resources, the bioenergy development may mainly rely on the exploitation of marginal land. This study focused on the assessment of marginal land resources and bio-fuel potential in China using newly acquired data and Geographic Information System (GIS) techniques. A multi-factor analysis method was adopted to identify marginal lands for bioenergy development in China, with data of several main types of energy plants on the eco-environmental requirements and natural habits employed. A combined planting zonation strategy was proposed, which was targeted for five species of energy plants including Helianthus tuberous L., Pistacia chinensis, Jatropha curcas L., Cassava and Vernicia fordii. The results indicated that total area of marginal land exploitable for development of energy plants on a large scale was about 43.75 million ha. If 10% of this marginal land was fully utilized for growing the energy plants, the production of bio-fuel would be 13.39 million tons. (author)

  18. Mining their own Business in the Margins

    Jensen, Lars

    Mining has long been established in Australian public discourse as an activity that has driven the Australian economy, and guaranteed Australia against the economic ills of the rest of the West. Or put slightly differently, the positive spin on mining in public discourse and the financial market...... construct story-telling of what they are, and what they do. I want to relate this story-telling to broader issues, or let’s say competing narratives about corporate achievement, such as CSR, environmental protection and the effect on local communities where they operate. I am particularly interested...... in the question of mining in ‘remote areas’ (‘’ because what is remote to whom?) in Australia and outside. At the time of writing this, I am thinking about taking my departure in Alexis Wright’s Carpentaria as representing one of these marginalised ways of telling alternative versions of mining and its impact...

  19. The East Greenland rifted volcanic margin

    C. Kent Brooks


    Full Text Available The Palaeogene North Atlantic Igneous Province is among the largest igneous provinces in the world and this review of the East Greenland sector includes large amounts of information amassed since previous reviews around 1990.The main area of igneous rocks extends from Kangerlussuaq (c. 67°N to Scoresby Sund (c. 70°N, where basalts extend over c. 65 000 km2, with a second area from Hold with Hope (c. 73°N to Shannon (c. 75°N. In addition, the Ocean Drilling Project penetrated basalt at five sites off South-East Greenland. Up to 7 km thickness of basaltic lavas have been stratigraphically and chemically described and their ages determined. A wide spectrum of intrusions are clustered around Kangerlussuaq, Kialeeq (c. 66°N and Mesters Vig (c. 72°N. Layered gabbros are numerous (e.g. the Skaergaard and Kap Edvard Holm intrusions, as are under- and oversaturated syenites, besides small amounts of nephelinite-derived products, such as the Gardiner complex (c. 69°N with carbonatites and silicate rocks rich in melilite, perovskite etc. Felsic extrusive rocks are sparse. A single, sanidine-bearing tuff found over an extensive area of the North Atlantic is thought to be sourced from the Gardiner complex.The province is famous for its coast-parallel dyke swarm, analogous to the sheeted dyke swarm of ophiolites, its associated coastal flexure, and many other dyke swarms, commonly related to central intrusive complexes as in Iceland. The dyke swarms provide time markers, tracers of magmatic evolution and evidence of extensional events. A set of dykes with harzburgite nodules gives unique insight into the Archaean subcontinental lithosphere.Radiometric dating indicates extrusion of huge volumes of basalt over a short time interval, but the overall life of the province was prolonged, beginning with basaltic magmas at c. 60 Ma and continuing to the quartz porphyry stock at Malmbjerg (c. 72°N at c. 26 Ma. Indeed, activity was renewed in the Miocene with

  20. Land-ocean tectonics (LOTs) and the associated seismic hazard over the Eastern Continental Margin of India (ECMI)

    Murthy, K.S.R.; Subrahmanyam, V.; Subrahmanyam, A.S.; Murty, G.P.S.; Sarma, K.V.L.N.S.

    of negligible tectonic activity like earthquakes, volcanoes, mountain building, etc. The Eastern Continental Margin of India (ECMI) is considered as a passive margin, though the geodynamic processes and the resultant seismo- tectonics prevalent in the vicinity...-up seems to have occurred at the bight of the present day Krishna-Godavari (K-G) basin (Ramana 2003), in two major stages along two different segments; the northern (K-G) rifted segment and the southern (Cauvery) sheared or transform segment...

  1. Continental Margins and the Law of the Sea - an `Arranged Marriage' with Huge Research Potential

    Parson, L.


    next four years an unprecedented phase of surveying and analysis on margins will take place in order to prepare for the deadline. The international scientific community as a whole must recognise the potential for research in this work and ensure the data is made available as soon as practically possible for the scientific community. In conclusion, by way of a reality check, this presentation highlights the likely areas of most intense UNCLOS-driven research activity up to 2009, the type of data acquisition anticipated and their likely location, and speculates on the areas of understanding of margin evolution which will be most advanced by this process.

  2. Assessment of dust activity and dust-plume pathways over Jazmurian Basin, southeast Iran

    Rashki, A.; Arjmand, M.; Kaskaoutis, D. G.


    Jazmurian (or hamun-e Jaz Murian) is a dried lake located in a topographic-low basin in southeast Iran and a major source for high dust emissions under favorable weather conditions. This work examines for the first time the dust activity over the basin by classifying the dust events (DEs, visibility Iran, while no significant tendency is found during the period 1990-2013. Further, the DEs and DSEs exhibit a clear diurnal pattern with highest frequency between 15:30 and 18:30 LST due to thermal convection and transported dust plumes. The analysis reveals an average frequency of 12.7 dust-storm days per year, while the DSEs last for 5.1 h, on average, during the dust-storm days. The dust storms originating from Jazmurian affect mostly the northern coast of the Arabian Sea (Makran mountains), the Oman Sea, the southeastern Arabian Peninsula and the western Pakistan, while air masses from the arid/desert areas of central-eastern Iran and Arabia seem to further aggravate the dust-aerosol loading over Jazmurian.

  3. Improved statistical confirmation of margins for setpoints and transients

    Nutt, W.T. [Framatome ANP Richland, INC., WA (United States)


    Framatome ANP Richland, Inc. has developed an integrated, automated, statistical methodology for Pressurized Water Reactors (PWRs). Margins for transients and calculated trips are confirmed using several new applications of probability theory. The methods used for combining statistics reduces the conservatisms inherent in conventional methods and avoids the numerical limitations and time constraints imposed by Monte Carlo techniques. The new methodology represents the state of the art in the treatment of uncertainties for reactor protection systems. It all but eliminates concerns with the calculated trips for PWRs and by improving the margin for all transients will allow for far more aggressive peaking limits and fuel management schemes. The automated nature of the bulk of this process saves Framatome ANP time and effort, minimizes the potential for errors and makes the analysis for all cycles and plants consistent. The enhanced margins remove analytical limitations from the customer and allow for more economical operation of the plant. (authors)

  4. An assessment of seismic margins in nuclear plant piping

    Chen, W.P.; Jaquay, K.R. [Energy Technology Engineering Center, Canoga Park, CA (United States); Chokshi, N.C.; Terao, D. [Nuclear Regulatory Commission, Washington DC (United States)


    Interim results of an ongoing program to assist the U.S. Nuclear Regulatory Commission (NRC) in developing regulatory positions on the seismic analyses of piping and overall safety margins of piping systems are reported. Results of: (1) reviews of seismic testing of piping components performed as part of the Electric Power Research Institute (EPRI)/NRC Piping and Fitting Dynamic Reliability (PFDR) Program, and (2) assessments of safety margins inherent in the ASME Code, Section III, piping seismic design criteria as revised by the 1994 Addenda are reported. The reviews indicate that the margins inherent in the revised criteria may be less than acceptable and that modifications to these criteria may be required.

  5. Post Rift Evolution of the Indian Margin of Southern Africa

    Baby, Guillaume; Guillocheau, François; Robin, Cécile; Dall'asta, Massimo


    The objective of this study is to discuss the evolution of the South African Plateau along the Indian margin of Southern Africa. Since the classical works of A. du Toit and L.C. King and the improvement of thermochronological methods and numerical models, the question of the uplift of South African Plateau was highly debated with numerous scenarios: early Cretaceous at time of rifting (Van der Beek et al., J.Geophys.Res., 2002), late Cretaceous (Braun et al., Solid Earth, 2014), late Cenozoic (Burke & Gunnell, Geol.Soc.of America, 2008). Limited attention has been paid on the constraints provided by the offshore stratigraphic record of the surrounding margins. The objective of our study is to integrate onshore and offshore data (seismic profiles and industrial wells) to (1) analyse the infill of the whole margin (21°S to 31°S) from its hinterland to the distal deep water basin, (2) to constrain and quantify the vertical movements. We discuss the impact on accommodation and sediments partitioning, and their significance on South African Plateau uplift history. 1. Sedimentary basins of the Indian margin of Southern Africa are related to the break-up of Gondwana during late Jurassic, resulting in rifts and flexural basins. First marine incursions started during early Cretaceous times (oldest marine outcropping sediments are of Barremian age ~128 Ma). The region developed as a normal continental shelf at the Aptian-Albian transition (~113 Ma). 2. The Cretaceous geological history of the basins is characterized by differential uplift and subsidence of the basement, controlled by structures inherited from break up. As example, major early Cretaceous depocenters of the margin are located on the north of Save-Limpopo uplift (Forster, Paleogography, Paleoclimatology, Paleoecology, 1975) showing an eastward drainage pattern, maybe related to a proto Limpopo drainage. Those observations suggest that the escarpment bordering the Bushveld depression is an old relief inherited

  6. Reconstructing marginality: a new model of cultural diversity in nursing.

    Southwick, Margaret; Polaschek, Nick


    This article presents a new model of cultural diversity in nursing that critically reconstructs the concept of marginality that underpins other models. Rather than viewing the marginal as "other," marginality is redefined as the space in between the dominant cultural reality and the cultural realities of minority groups located within a society. Members of a minority cultural group who become skilled in the difficult process of negotiating this in-between space open the possibility of transformation within nursing education and practice. This model has been applied in a study of the experience of nursing students of Pacific ethnicity in New Zealand. Subsequently, an undergraduate Pacific nursing program was developed, with greatly increased success rates in registration of Pacific nurses. This model of cultural diversity can also be used to understand nursing practice involving people from minority cultures or other socially excluded categories.

  7. Critical behavior of marginal aperiodic sequences: a Monte Carlo study

    Branco, Nilton


    We study layered marginal aperiodic sequences for the Ising and q=8 Potts model on a square lattice. The phase transition is continuous for the former and first-order for the latter. Using the Wolff algorithm we calculate critical exponents and the critical temperature for the Potts model when the interaction constant can assume two values, according to an aperiodic sequence: the period-doubling one for the Ising model and the Fibonacci one for the Potts model. These sequences and models chracterize marginal critical behavior, according to the Luck criterion and, therefore, interaction-dependent exponents are expected for a continuous transition. For first-order phase transitions, no study so far has been done on the influence of marginal sequences.

  8. On the marginally relevant operator in z=2 Lifshitz holography

    Holsheimer, Kristian [Institute of Physics, University of Amsterdam,Science Park 904, Postbus 94485, 1090 GL Amsterdam (Netherlands)


    We study holographic renormalization and RG flow in a strongly-coupled Lifshitz-type theory in 2+1 dimensions with dynamical exponent z=2. The bottom-up gravity dual we use is 3+1 dimensional Einstein gravity coupled to a massive vector field. This model contains a marginally relevant operator around the Lifshitz fixed point. We show how holographic renormalization works in the presence of this marginally relevant operator without the need to introduce explicitly cutoff-dependent counterterms. A simple closed-form expression is found for the renormalized on-shell action. We also discuss how asymptotically Lifshitz geometries flow to AdS in the interior due to the marginally relevant operator. We study the behavior of the renormalized entanglement entropy and confirm that it decreases monotonically along the Lifshitz-to-AdS RG flow.

  9. Potato production in Europe - a gross margin analysis

    Pedersen, Søren Marcus; Bizik, Jan; Costa, Luisa Dalla;

    The purpose of this paper is to examine different cropping practices, cost structures and gross margins for producing conventional table potatoes in 6 different regions within the European Union: Czech Republic, Denmark, Italy, Poland, Portugal and Slovakia. Findings from this study show that pot......The purpose of this paper is to examine different cropping practices, cost structures and gross margins for producing conventional table potatoes in 6 different regions within the European Union: Czech Republic, Denmark, Italy, Poland, Portugal and Slovakia. Findings from this study show...... that potato cropping practices varies signifi-cantly between these countries with major differences in yields and costs. Italy and Denmark are the two regions with highest gross margins due to high yields and reve-nues. Poland is by far the largest potato producing country among the 6 countries ex...

  10. Marginal production in the Gulf of Mexico - II. Model results

    Kaiser, Mark J.; Yu, Yunke [Center for Energy Studies, Louisiana State University, Baton Rouge, LA 70803 (United States)


    In the second part of this two-part article on marginal production in the Gulf of Mexico, we estimate the number of committed assets in water depth less than 1000 ft that are expected to be marginal over a 60-year time horizon. We compute the expected quantity and value of the production and gross revenue streams of the gulf's committed asset inventory circa. January 2007 using a probabilistic model framework. Cumulative hydrocarbon production from the producing inventory is estimated to be 1056 MMbbl oil and 13.3 Tcf gas. Marginal production from the committed asset inventory is expected to contribute 4.1% of total oil production and 5.4% of gas production. A meta-evaluation procedure is adapted to present the results of sensitivity analysis. Model results are discussed along with a description of the model framework and limitations of the analysis. (author)

  11. The Cadiz margin study off Spain: An introduction

    Nelson, C.H.; Maldonado, A.


    The Cadiz continental margin of the northeastern Gulf of Cadiz off Spain was selected for a multidisciplinary project because of the interplay of complex tectonic history between the Iberian and African plates, sediment supply from multiple sources, and unique Mediterranean Gateway inflow and outflow currents. The nature of this complex margin, particularly during the last 5 million years, was investigated with emphasis on tectonic history, stratigraphic sequences, marine circulation, contourite depositional facies, geotechnical properties, geologic hazards, and human influences such as dispersal of river contaminants. This study provides an integrated view of the tectonic, sediment supply and oceanographic factors that control depositional processes and growth patterns of the Cadiz and similar modem and ancient continental margins.

  12. Isotropy and marginally trapped surfaces in a spacetime

    Cabrerizo, J L; Fernandez, M; Gomez, J S, E-mail: jaraiz@us.e, E-mail: mafernan@us.e, E-mail: jsalvador@us.e [Geometria y Topologia, Universidad de Sevilla, Apdo. 1160, 41080 Sevilla (Spain)


    In this paper we shall study the notions of an isotropic and marginally trapped surface in a spacetime by using a differential geometric approach. We first consider spacelike isotropic surfaces in a Lorentzian manifold and, in particular, in a four-dimensional spacetime, where the isotropy function appears to be determined by the mean curvature vector field of the surface. Explicit examples of isotropic marginally outer trapped surfaces are given in the standard four-dimensional space forms: Minkowski, de Sitter and anti-de Sitter spaces. Then we prove rigidity theorems for complete spacelike 0-isotropic surfaces without flat points in these standard space forms. As a consequence, we also obtain characterizations of complete spacelike isotropic marginally trapped surfaces in these backgrounds.

  13. Thermal evolution of a sheared continental margin: Insights from the Ballenas transform in Baja California, Mexico

    Seiler, Christian; Gleadow, Andrew J. W.; Fletcher, John M.; Kohn, Barry P.


    The Ballenas transform margin in central Baja California offers an unparalleled opportunity to study the thermal behaviour of a sheared continental margin during various stages of its evolution. Apatite fission track and (U-Th)/He results from two transects perpendicular to the coast reveal a pronounced latest Pliocene to Pleistocene (~ 1.8 Ma) heating event related to the Neogene opening of the Gulf of California. Proximity to a regional pre-rift unconformity indicates that samples remained at near-surface levels since Paleogene unroofing, despite having experienced reheating to maximum paleotemperatures within or above the fission track partial annealing zone. In general, maximum paleotemperatures during overprinting decrease from > 100-120 °C near the coast to below 60 °C ca. 5-8 km further inland, suggesting lateral heat flow from a source within the Gulf of California. Heat sources related to the structural development of the Ballenas transform fault, located approximately 1.5-4.5 km offshore from the two sample transects, most likely controlled the observed reheating. Overprinting patterns do not support conductive reheating due to reburial, magmatism or frictional shear. Instead, a pronounced thermal spike in between much less overprinted neighbouring samples strongly favours convective heating by hydrothermal fluids as the dominant overprinting process. Hydrothermal activity may be caused by either deep fluid circulation along newly formed shear zones of the transform fault or, more likely, magmatic leaking along the transform fault. Latest Pliocene to Pleistocene (~ 1.8 Ma) activity on the Ballenas transform fault is closely linked to extension in the Lower and Upper Delfín basins and provides a minimum age for the structural reorganisation and the relocation of extension in the northern Gulf of California. This study shows that hydrothermal activity can cause significant thermal events in a transform margin before the passage of the spreading centre

  14. Reconstructing the tectonic history of Fennoscandia from its margins: The past 100 million years

    Muir Wood, R. [EQE International Ltd (United Kingdom)


    In the absence of onland late Mesozoic and Cenozoic geological formations the tectonic history of the Baltic Shield over the past 100 million years can be reconstructed from the thick sedimentary basins that surround Fennoscandia on three sides. Tectonic activity around Fennoscandia through this period has been diverse but can be divided into four main periods: a. pre North Atlantic spreading ridge (100-60 Ma) when transpressional deformation on the southern margins of Fennoscandia and transtensional activity to the west was associated with a NNE-SSW maximum compressive stress direction; b. the creation of the spreading ridge (60-45 Ma) when there was rifting along the western margin; c. the re-arrangement of spreading axes (45-25 Ma) when there was a radial compression around Fennoscandia, and d. the re-emergence of the Iceland hot-spot (25-0 Ma) when the stress-field has come to accord with ridge or plume `push`. Since 60 Ma the Alpine plate boundary has had little influence on Fennoscandia. The highest levels of deformation on the margins of Fennoscandia were achieved around 85 Ma, 60-55 Ma, with strain-rates around 10{sup -9}/year. Within the Baltic Shield long term strain rates have been around 10{sup -1}1/year, with little evidence for significant deformations passing into the shield from the margins. Fennoscandian Border Zone activity, which was prominent from 90-60 Ma, was largely abandoned following the creation of the Norwegian Sea spreading ridge, and with the exception of the Lofoten margin, there is subsequently little evidence for deformation passing into Fennoscandia. Renewal of modest compressional deformation in the Voering Basin suggest that the `Current Tectonic Regime` is of Quaternary age although the orientation of the major stress axis has remained consistent since around 10 Ma. The past pattern of changes suggest that in the geological near-future variations are to be anticipated in the magnitude rather than the orientation of stresses.

  15. Drilling in Current-Controlled Sedimentary Environments on the Southeast African Margin - The SAFARI Pre-Site Survey Challenges on the Madagascar, Mozambique and the South African Margin

    Spiess, V.; Preu, B.; Schwenk, T.; Palamenghi, L.; Schneider, R.; Zahn, R.; Hall, I.


    As part of the global conveyer belt circulation, the Agulhas, Mozambique and Madagascar Currents are guided southward along the Southeast African margin as strong contour currents, affecting local sediment mobilization, redistribution and deposition. To gain a better understanding of their evolution through time, a transect of drill sites ranging from the southern tip of Africa to Madagascar was proposed by Zahn et al. (SAFARI, IODP proposal 702). As contour currents become erosive in their vicinity, deposition may be inhibited and incoming sediment will be redistributed. To find suitable drill sites, they must be positioned strategically to provide continuous depositional records on the one hand by not not being located in the core of the current, and to record variations in current activity and strength, which requires a certain proximity to the mean current position. Furthermore, sources of sediment and their spatial and temporal variability play a role for the interpretation of accumulation rates, provenance of particles, reconstruction of current velocities and terrestrial input, which can be compared as climate indicators with marine geochemical tracers. Six different working areas, West of Capetown, Natal Valley, Limpopo Cone, Zambezi margin, Davie Ridge and N-Madagascar margin, were visited during R/V Meteor Cruises M63/1 (2005) and M75/3 (2008) to gain an understanding of sediment deposition and to select sites for the drilling proposal. Main observations of both cruises were, in contrast to the expectation of margins being predominantly shaped by fan deposition and mass wasting processes, the widespread occurrences of large scales contourite bodies, which were situated between 100 and 1500 m water depth. They appear to be independent of the mechanisms and volume of sediment input, revealing a close relationship to the acting contour currents. Accordingly, the drift bodies appear to be suitable deposits which record the activity of the currents by

  16. Marginal Congestion Cost on a Dynamic Expressway Network

    Fosgerau, Mogens; Small, Kenneth A.


    a dynamic econometric model using unusually complete and accurate data from Danish motorways. We use the results to estimate the marginal external cost of adding a vehicle to a link's entry flow, finding it is highly influenced by the dynamic properties of the system of relationships between travel times......We formulate an empirical model of congestion for a series of sequential expressway links where queues may form and spill back. Its purpose is to disentangle the dynamic effect that a marginal vehicle has on the distribution of travel times experienced there and on connected links. We estimate...

  17. Nadir Margins in TerraSAR-X Timing Commanding

    Wollstadt, Steffen; Mittermayer, Josef


    This paper presents an analysis and discussion of the Nadir return in the context of radar timing. Results obtained during the Commissioning Phase of TerraSAR-X in verification and measurement of Nadir return and timing margins are shown. Pre-launch assumptions about the Nadir margins were verified and optimized, which led to an improvement in the timing commanding, i.e. a relaxing of the timing. By means of three early acquired TerraSAR-X images which contain Nadir re...

  18. Marginal pricing and supplement cost allocation in transmission open access

    Rudnick, H.; Palma, R.; Fernandez, J.E. [Pontificia Univ. Catolica de Chile, Santiago (Chile). Escuela de Ingenieria


    The application of marginal costing to transmission pricing in open access schemes requires the collection of a supplement to finance the transmission systems. The paper describes the application of marginal cost based pricing in the Chilean power system and the difficulties faced in allocating the supplement among parties involved. Alternatives methods for defining the allocation are formulated. Generalized generation and load distribution factors for cost allocation are formulated and implemented. The methods are applied to allocate payments for transmission services provided by the transmission network and by a distribution company.

  19. Soft Drink Influence on Margin Integrity in Composite Resin Restorations

    Lafuente DDS, MS, Jose; Abad DDS, Karol


    The purpose of this study was to evaluate the effect that certain previously selected soda drinks could have on the integrity of the margins of composite restorations made on 25 human teeth, where the margins were placed both on enamel and dentin. Specimens were divided in different groups (n=5) to be exposed to soft drinks 30 minutes a day for 30 days. Selected drinks were: Coca Cola, Coca Cola Zero, Squirt, Gladiator and water. SEM pictures were taken at the beginning and at the 30 day mark...

  20. Tight Sample Complexity of Large-Margin Learning

    Sabato, Sivan; Tishby, Naftali


    We obtain a tight distribution-specific characterization of the sample complexity of large-margin classification with L_2 regularization: We introduce the \\gamma-adapted-dimension, which is a simple function of the spectrum of a distribution's covariance matrix, and show distribution-specific upper and lower bounds on the sample complexity, both governed by the \\gamma-adapted-dimension of the source distribution. We conclude that this new quantity tightly characterizes the true sample complexity of large-margin classification. The bounds hold for a rich family of sub-Gaussian distributions.

  1. Asymptotic Marginal Tax Rate of Individual Income Tax in China



    This paper examines the asymptotic marginal rate of individual income tax which maximizes China’s social welfare through numerical simulation based on the elasticity of China’s labor supply, income distribution and the social objectives of redistribution in accordance with the optimal direct taxation theory. Taking advantage of the optimal direct taxation model with consideration of the income effect, it comes to the conclusion that combined with China’s reality, the asymptotic marginal rate of individual labor income tax in China should be between 35% and 40%.

  2. How a Curvilinear Continental Margin Influences Its Subsidence History

    Sacek, V.; Ussami, N.


    Current one-dimensional (1D) and two-dimensional (2D) thermo-mechanical models successfully explain the first-order vertical motions of sedimentary basins created by lithospheric extension. However, the modeling of second-order effects such as extra-subsidence, non-monotonic-subsidence or protracted-subsidence still remains controversial. One aspect that has not been fully considered in the current models is that the rifting direction leading to the continental break-up does not always follow a straight line, which demands a three-dimensional (3D) approach. The aim of this work is to demonstrate the importance of using a 3D model that takes into account the curvature of rifting along the margin and theoretically predicts some of the second-order subsidence observations. Our results indicate that concave oceanward margins tend to subside faster than convex ones. This differential subsidence of the margin is a result of the combined effect of lateral thermal conduction, small-scale mantle (or edge driven) convection and the curvature of the rifting. We have used the finite element code CITCOM (Moresi & Gurnis, 1996; Zhong et al., 2000) to construct 3D numerical models of the mantle convection and its effect on the surface evolution. We observed that the differential subsidence along a curved margin is dependent on the viscosity structure of the mantle: for an asthenospheric viscosity of 5×1020 Pa.s the differential subsidence can reach more than 700 m assuming a sediment filled basin; however, for low asthenospheric viscosity (geometry. As an application of this 3D conceptual model for curved margin, we analysed the stratigraphic evolution of the Santos Basin, offshore Southeastern Brazil, and we propose that the variations in the subsidence history along the margin can be explained by its 3D geometry and the dynamical evolution of the mantle. We conclude that the incorporation of the third dimension in the study of the subsidence history of divergent margins may

  3. Marginal linearization method in modeling on fuzzy control systems


    Marginal linearization method in modeling on fuzzy control systems is proposed, which is to deal with the nonlinear model with variable coefficients. The method can turn a nonlinear model with variable coefficients into a linear model with variable coefficients in the way that the membership functions of the fuzzy sets in fuzzy partitions of the universes are changed from triangle waves into rectangle waves. However, the linearization models are incomplete in their forms because of their lacking some items. For solving this problem, joint approximation by using linear models is introduced. The simulation results show that marginal linearization models are of higher approximation precision than their original nonlinear models.

  4. Marginal granilocytic pool in the treatment of malignant tumors

    Angelova, I.; Bakalov, M.; Zografov, D. (Meditsinska Akademiya, Sofia (Bulgaria). Nauchen Inst. po Rentgenologiya i Radiobiologiya)


    Using the adrenaline test in 57 patients with malignant tumors, the authors examined the marginal granulocytic pool at different time in the course of treatment. The state of the pool was correlated with that of the neutrophilic cells in the circulating blood and with its state before treatment was started. It is concluded that in the course of treatment the neutrophilic cell counts in the marginal cells pool undergo changes similar to those in the circulation pool. It is therefore unjustifiable to include the adrenaline test in the control examination of patients with leucopenia.

  5. Spatial Variation in Anaerobic Microbial Communities in Wetland Margin Soils

    Rich, H.; Kannenberg, S.; Ludwig, S.; Nelson, L. C.; Spawn, S.; Porterfield, J.; Schade, J. D.


    Climate change is predicted to increase the severity and frequency of precipitation and drought events, which may result in substantial temporal variation in the size of wetlands. Wetlands are the world's largest natural emitter of methane, a greenhouse gas that is 20 times more effective at trapping heat than carbon dioxide. Changes in the dynamics of wetland size may lead to changes in the extent and timing of inundation of soils in ephemeral margins, which is likely to influence microbes that rely on anoxic conditions. The impact on process rates may depend on the structure of the community of microbes present in the soil, however, the link between microbial structure and patterns in process rates in soils is not well understood. Our goal was to use molecular techniques to compare microorganism communities in two wetlands that differ in the extent and duration of inundation of marginal soils to assess how these communities may change with changes in climate, and the potential consequences for methane production. This will allow us to examine how community composition changes with soil conditions such as moisture content, frequency of drought and abundance of available carbon. The main focus of this project was to determine the presence or absence of acetoclastic (AC) and hydrogenotrophic (HT) methanogens. AC methanogens use acetate as their main substrate, while HT methanogens use Hydrogen and Carbon dioxide. The relative proportion of these pathways depends on soil conditions, such as competition with other anaerobic microbes and the amount of labile carbon, and spatial patterns in the presence of each can give insight into the soil conditions of a wetland site. We sampled soil from three different wetland ponds of varying permanence in the St Olaf Natural Lands in Northfield, Minnesota, and extracted DNA from these soil samples with a MoBio PowerSoil DNA Isolation Kit. With PCR and seven different primer sets, we tested the extracted DNA for the presence of

  6. Metagenomic insights into particles and their associated microbiota in a coastal margin ecosystem

    Holly M Simon


    Full Text Available Our previously published research was one of the pioneering studies on the use of metagenomics to directly compare taxonomic and metabolic properties of aquatic microorganisms from different filter size-fractions. We compared size-fractionated water samples representing free-living and particle-attached communities from four diverse habitats in the Columbia River coastal margin, analyzing 12 metagenomes consisting of >5 million sequence reads (>1.6 Gbp. With predicted peptide and rRNA data we evaluated eukaryotic, bacterial and archaeal populations across size fractions and related their properties to attached and free-living lifestyles, and their potential roles in carbon and nutrient cycling. In this focused review, we expand our discussion on the use of high-throughput sequence data to relate microbial community structure and function to the origin, fate and transport of particulate organic matter in coastal margins. We additionally discuss the potential impact of the priming effect on organic matter cycling at the land-ocean interface, and build a case for the importance, in particle-rich estuaries and coastal margin waters, of bacterial activities in low-oxygen microzones within particle interiors.

  7. Effect of delayed light curing of a resin composite on marginal integrity in cylindrical dentine cavities.

    Manabe, A; Debari, K; Itoh, K; Hisamitsu, H; Wakumoto, S


    The effect of delayed light curing of resin composite on marginal adaptation has been examined by measuring the wall-to-wall polymerization contraction gap when using a commercial resin composite together with experimental dentine bonding systems to restore cylindrical preparations in dentine. Morphological changes in dentine during dentine bonding procedures were observed using a scanning electron microscope. In a previous report, the contraction gap width for a resin composite increased when irradiation of the resin system was delayed, despite the use of a dentine bonding system considered to be 'contraction' gap free. Such deterioration in marginal adaptation was minimized by use of an experimental dentine primer, 40% erythritol methacrylate aqueous solution (EM), followed by the use of a commercial dual- or autocured dentine bonding agent. Under scanning electron microscopy, the dentine surface microstructure became unclear after EM priming, and a polymer film was detected after polymerization of the dual-cured dentine bonding agent. The hydrogelled primer and the formation of a polymer network on the dentine surface may prevent the flow of fluid from the pulp through the dentine tubules, and maintain marginal integrity if there is delay in light curing of light-activated resin composite systems.

  8. The role of discourse practices in the emergence of marginal status of Messianic Jewish communities

    Anna Panteleeva


    Full Text Available The author attempts to analyze the most significant stages of the developing of the Messianic conception within Judaism as well as the cultural and historical conditions and mechanisms which contributed to the marginalizing of Messianic Jewish communities within Judaism. The main research instrument used by the author is the discourse analysis method proposed by M. Foucault as well as the method of problematization developed and systematized later by Castel. Given methodology presupposes a reconstruction of historical events as refracted by their modern perception; the aims are, fi rstly, to discover invariant models or continuity that are instrumental in preserving the identity of problematization in its constant transformations and, secondly, to single out the principles of varying, that is the variant models of the phenomenon under study. In our case, the problematization emerges at the moment when abruption or marginalization of Messianic Jewish communities takes place. At the end the author arrives at the following conclusions: with respect to Messianic Judaism it is obvious that in the course of its historical development the term «Messianic» has acquired and appropriated negative connotations which was preconditioned mainly by the fact that Messianic communities and groups which shared and actively propagated the Messianic ideas in the society were perceived and declared by the dominant religious tradition as unacceptable, heretical or marginal phenomena destabilizing the established order.

  9. Constraining the stepwise migration of the eastern Tibetan Plateau margin by apatite fission track thermochronology


    Granites sampled from Garzê-Litang thrust, Longmen Shan thrust, Garzê and Litang strike-slip faults in the eastern Tibetan Plateau have been analyzed with apatite fission track thermochronological method in this study. The measured fission track apparent ages, combined with the simulated annealing mod- eling of the thermal history, have been used to reconstruct the thermal evolutionary histories of the samples and interpret the active history of the thrusts and faults in these areas. Thermal history mod- eling shows that earlier tectonic cooling occurred in the Garzê-Litang thrust in Miocene (~20―16 Ma) whereas the later cooling occurred mainly in the Longmen Shan thrust since ~5 Ma. Our study sug- gests that the margin of eastern Tibetan Plateau was extended by stages: through strike-slip faults deformations and related thrusts, the upper crust formed the Garzê-Litang margin in the Miocene epoch and then moved to the Longmen Shan margin since ~5 Ma. During this process, the deformations of different phases in the eastern Tibetan Plateau were absorbed by the thrusts within them and conse- quently the tectonic events of long-distance slip and extrusion up to hundreds of kilometers have not been found.

  10. Constraining the stepwise migration of the eastern Tibetan Plateau margin by apatite fission track thermochronology

    LAI QingZhou; DING Lin; WANG HongWei; YUE YaHui; CAI FuLong


    Granites sampled from Garzê-Litang thrust, Longmen Shan thrust, Garzê and Litang strike-slip faults in the eastern Tibetan Plateau have been analyzed with apatite fission track thermochronological method in this study. The measured fission track apparent ages, combined with the simulated annealing modeling of the thermal history, have been used to reconstruct the thermal evolutionary histories of the samples and interpret the active history of the thrusts and faults in these areas. Thermal history modeling shows that earlier tectonic cooling occurred in the Garzê-Litang thrust in Miocene (~20―16 Ma) whereas the later cooling occurred mainly in the Longmen Shan thrust since ~5 Ma. Our study suggests that the margin of eastern Tibetan Plateau was extended by stages: through strike-slip faults deformations and related thrusts, the upper crust formed the Garzê-Litang margin in the Miocene epoch and then moved to the Longmen Shan margin since ~5 Ma. During this process, the deformations of different phases in the eastern Tibetan Plateau were absorbed by the thrusts within them and consequently the tectonic events of long-distance slip and extrusion up to hundreds of kilometers have not been found.

  11. Marginal biotin deficiency can be induced experimentally in humans using a cost-effective outpatient design.

    Stratton, Shawna L; Henrich, Cindy L; Matthews, Nell I; Bogusiewicz, Anna; Dawson, Amanda M; Horvath, Thomas D; Owen, Suzanne N; Boysen, Gunnar; Moran, Jeffery H; Mock, Donald M


    To date, marginal, asymptomatic biotin deficiency has been successfully induced experimentally by the use of labor-intensive inpatient designs requiring rigorous dietary control. We sought to determine if marginal biotin deficiency could be induced in humans in a less expensive outpatient design incorporating a self-selected, mixed general diet. We sought to examine the efficacy of three outpatient study designs: two based on oral avidin dosing and one based on a diet high in undenatured egg white for a period of 28 d. In study design 1, participants (n = 4; 3 women) received avidin in capsules with a biotin binding capacity of 7 times the estimated dietary biotin intake of a typical self-selected diet. In study design 2, participants (n = 2; 2 women) received double the amount of avidin capsules (14 times the estimated dietary biotin intake). In study design 3, participants (n = 5; 3 women) consumed egg-white beverages containing avidin with a biotin binding capacity of 7 times the estimated dietary biotin intake. Established indices of biotin status [lymphocyte propionyl-CoA carboxylase activity; urinary excretion of 3-hydroxyisovaleric acid, 3-hydroxyisovaleryl carnitine (3HIA-carnitine), and biotin; and plasma concentration of 3HIA-carnitine] indicated that study designs 1 and 2 were not effective in inducing marginal biotin deficiency, but study design 3 was as effective as previous inpatient study designs that induced deficiency by egg-white beverage. Marginal biotin deficiency can be induced experimentally by using a cost-effective outpatient design by avidin delivery in egg-white beverages. This design should be useful to the broader nutritional research community.

  12. Sedimentary history of the Tethyan margins of eastern Gondwana during the Mesozoic

    Ogg, James G.; Gradstein, Felix; Dumoulin, Julie A.; Sarti, Massimo; Brown, Paul; Duncan, Robert A.; Rea, David K.; Kidd, Robert B.; von Rad, Ulrich; Weissel, Jeffrey K.


    A composite Mesozoic geological history for the Gondwana margins to the Eastern Tethys Ocean can be assembled from stratigraphic successions on the Australian and Himalayan margins and from drill sites of Ocean Drilling Program Legs 122 and 123. During the Triassic, this region drifted northwards, entering tropical paleolatitudes during the Late Triassic-Early Jurassic, then returned to mid-latitudes for the Middle Jurassic through Early Cretaceous. Shallow-water carbonates are restricted to the tropical-latitude interval; at other times, the margins are dominated by clastic deposition. Episodes of deltaic sandstone progradation over the shelves are caused by eustatic sealevel fluctuations, by wet climatic conditions within the source regions and by local tectonic activity. A major hiatus between Callovian shallow-water shelf deposits and Oxfordian deep-water sediments is an ubiquitous feature, which may be related to a widespread plate tectonic reorganization and the cascading effects of associated sealevel rise and elevated carbon dioxide levels. Off Northwest Australia, this Callovian/Oxfordian event also coincides with an episode of block faulting. Marginal sediments deposited during the Late Jurassic are mainly marine claystone containing abundant terrigenous organic matter. Shallow depths of carbonate compensation (CCD) during the Late Jurassic through Early Cretaceous prevented the preservation of carbonate over most of the Argo basin off Northwest Australia, and these deep-sea sediments consist mainly of condensed, oxygenated radiolarian-rich claystone. During the late Kimmeridgian-early Tithonian, a downward excursion in the CCD enabled limited preservation of some larger nannofossils and mollusc fragments within the pelagic deposits, a feature also recorded in coeval deposits in the Atlantic. Explosive volcanism accompanied the final stages of rifting between India and Australia during the late Berriasian and Valanginian, producing volcaniclastic debris

  13. Sedimentary history of the Tethyan margins of Eastern Gondwana during the Mesozoic

    Ogg, James G.; Gradstein, Felix M.; Dumoulin, Julie A.; Sarti, Massimo; Bown, Paul

    A composite Mesozoic geological history for the Gondwana margins to the Eastern Tethys Ocean can be assembled from stratigraphic successions on the Australian and Himalayan margins and from drill sites of Ocean Drilling Program Legs 122 and 123. During the Triassic, this region drifted northwards, entering tropical paleolatitudes during the Late Triassic-Early Jurassic, then returned to mid-latitudes for the Middle Jurassic through Early Cretaceous. Shallow-water carbonates are restricted to the tropical-latitude interval; at other times, the margins are dominated by clastic deposition. Episodes of deltaic sandstone progradation over the shelves are caused by eustatic sealevel fluctuations, by wet climatic conditions within the source regions and by local tectonic activity. A major hiatus between Callovian shallow-water shelf deposits and Oxfordian deep-water sediments is an ubiquitous feature, which may be related to a widespread plate tectonic reorganization and the cascading effects of associated sealevel rise and elevated carbon dioxide levels. Off Northwest Australia, this Callovian/Oxfordian event also coincides with an episode of block faulting. Marginal sediments deposited during the Late Jurassic are mainly marine claystone containing abundant terrigenous organic matter. Shallow depths of carbonate compensation (CCD) during the Late Jurassic through Early Cretaceous prevented the preservation of carbonate over most of the Argo basin off Northwest Australia, and these deep-sea sediments consist mainly of condensed, oxygenated radiolarian-rich claystone. During the late Kimmeridgian-early Tithonian, a downward excursion in the CCD enabled limited preservation of some larger nannofossils and mollusc fragments within the pelagic deposits, a feature also recorded in coeval deposits in the Atlantic. Explosive volcanism accompanied the final stages of rifting between India and Australia during the late Berriasian and Valanginian, producing volcaniclastic debris

  14. Bathymetric and regional changes in benthic macrofaunal assemblages on the deep Eastern Brazilian margin, SW Atlantic

    Bernardino, Angelo Fraga; Berenguer, Vanessa; Ribeiro-Ferreira, Venina P.


    Deep-sea continental slopes have valuable mineral and biological resources in close proximity to diverse, undersampled and fragile marine benthic ecosystems. The eastern Brazilian Continental Margin (19.01°S to 21.06°S, 37.88°W to 40.22°W) is an important economic region for both fishing and oil industries, but is poorly understood with respect to the structure of the soft-sediment benthic fauna, their regional distribution and their bathymetric patterns. To identify spatial and temporal patterns of benthic macrofaunal assemblages on the slope (400 to 3000 m), the Espirito Santo Basin Assessment Project (AMBES, coordinated by Cenpes-Petrobras) sampled 42 stations across the Brazilian Eastern Slope during both Summer 2012 and Winter 2013. We found a significant decrease in macrofaunal abundance at the 400 m isobath along the slope near the northern region of the Espirito Santo Basin, suggesting benthic responses to upwelling events towards the south in Campos Basin and southern Espirito Santo Basin. The taxonomic diversity and assemblage composition also changed significantly across depth zones with mid-slope peaks of diversity at 1000-1300 m. In general, macrofaunal assemblages were strongly related to slope depth, suggesting a strong influence of productivity gradients and water mass distribution on this oligotrophic margin. Sediment grain size was marginally important to macrofaunal composition on the upper slope. In general, macrofaunal assemblages on the slope of Espirito Santo Basin are similar to other areas of the SE Brazilian margin, but regional changes in response to productivity and depth need to be considered for management strategies in the face of increasing economic activities off-shore.

  15. Facies, stratal and stacking patterns of syn-rift sequences along present-day and fossil hyperextended rifted margins

    Ribes, Charlotte; Epin, Marie-Eva; Gillard, Morgane; Chenin, Pauline; Ghienne, Jean-Francois; Manatschal, Gianreto; Karner, Garry D.; Johnson, Christopher A.


    Research on the formation and evolution of deep-water rifted margins has undergone a major paradigm shift in recent years. An increasing number of studies of present-day and fossil rifted margins allows us to identify and characterize the architecture of hyperextended rifted margins. However, at present, little is known about the depositional environments, sedimentary facies and stacking and stratal patterns in syn-rift sequences within these domains. In this context, characterizing and understanding the spatial and temporal evolution of the stratal and stacking patterns is a new challenge. The syn-rift sequence at rifted margins is deposited during the initial stages of stretching to the onset of oceanic accretion and comprises pre-, syn- and post-kinematic deposits along the margin. A difficulty arises from the fact that the observed stratigraphic geometries and facies relationships result from the complex interplay between sediment supply and creation of accommodation, which in turn are controlled by regional synchronous events (i.e. crustal necking and onset of seafloor spreading) and diachronous events (i.e. migration of deformation during rifting, lags in sediment input to the distal margin). These parameters are poorly constrained in hyperextended rift systems. Indeed, the complex structural evolution of hyperextended systems include an evolution from initially distributed to localized extension (i.e. necking) and the development of poly-phase in-sequence and/or out of sequence extensional faulting associated with mantle exhumation and magmatic activity. This multiphase structural evolution can generate complex accommodation patterns over a highly structured top basement but can only be recognized if there is sufficient sediment input to record the events. In our presentation, we show preliminary results for fossil Alpine Tethys margins exposed in the Alps and seismic examples of the present-day deep water rifted margins offshore Australian-Antarctica, East


    Pendell, Dustin L.; Schroeder, Ted C.


    Debates about captive supplies have been ongoing for more than a decade. This study investigates the effects captive supplies have on the beef farm-to-wholesale marketing margin. A relative price spread (RPS) model is used to estimate beef farm-to-wholesale marketing margins. Estimates indicate that forward contracts and marketing agreements have a small positive relationship with margins that is marginally significant. Packer fed cattle may or may not be related to margins to depending upon ...

  17. The CUC1 and CUC2 Genes Promote Carpel Margin Meristem Formation during Arabidopsis Gynoecium Development

    Yuri eKamiuchi


    Full Text Available Carpel margin meristems (CMMs, a pair of meristematic tissues present along the margins of two fused carpel primordia of Arabidopsis thaliana, are essential for the formation of ovules and the septum, two major internal structures of the gynoecium. Although a number of regulatory factors involved in shoot meristem activity are known to be required for the formation of these gynoecial structures, their direct roles in CMM development have yet to be addressed. Here we show that the CUP-SHAPED COTYLEDON genes CUC1 and CUC2, which are essential for shoot meristem initiation, are also required for formation and stable positioning of the CMMs. Early in CMM formation, CUC1 and CUC2 are also required for expression of the SHOOT MERISTEMLESS gene, a central regulator for stem cell maintenance in the shoot meristem. Moreover, plants carrying miR164-resistant forms of CUC1 and CUC2 resulted in extra CMM activity with altered positioning. Our results thus indicate that the regulatory proteins controlling shoot meristem activity also play critical roles in elaboration of the female reproductive organ through the control of meristematic activity.

  18. Early diagenesis of phosphorus in continental margin sediments.

    Slomp, C.P.


    Most of the organic material in the oceans that reaches the sea floor is deposited on continental margins and not in the deep sea. This organic matter is the principal carrier of phosphorus (P) to sediments. A part of the organic material is buried definitely. The other part decomposes, resulting in

  19. Methodological issues in testing the marginal productivity theory

    P.T. Gottschalk (Peter); J. Tinbergen (Jan)


    textabstractPrevious tests of the marginal productivity theory have been criticized on several grounds reviewed by the authors. One important deficiency has been the small number of factor inputs entered in the production functions. In 1978 Gottschalk suggested a method to estimate production functi

  20. Brain death and marginal grafts in liver transplantation.

    Jiménez-Castro, M B; Gracia-Sancho, J; Peralta, C


    It is well known that most organs for transplantation are currently procured from brain-dead donors; however, the presence of brain death is an important risk factor in liver transplantation. In addition, one of the mechanisms to avoid the shortage of liver grafts for transplant is the use of marginal livers, which may show higher risk of primary non-function or initial poor function. To our knowledge, very few reviews have focused in the field of liver transplantation using brain-dead donors; moreover, reviews that focused on both brain death and marginal grafts in liver transplantation, both being key risk factors in clinical practice, have not been published elsewhere. The present review aims to describe the recent findings and the state-of-the-art knowledge regarding the pathophysiological changes occurring during brain death, their effects on marginal liver grafts and summarize the more controversial topics of this pathology. We also review the therapeutic strategies designed to date to reduce the detrimental effects of brain death in both marginal and optimal livers, attempting to explain why such strategies have not solved the clinical problem of liver transplantation.