WorldWideScience

Sample records for geomorphic process domains

  1. Geomorphic process fingerprints in submarine canyons

    Science.gov (United States)

    Brothers, Daniel S.; ten Brink, Uri S.; Andrews, Brian D.; Chaytor, Jason D.; Twichell, David C.

    2013-01-01

    Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment from the continents to the deep sea. Though it is known that submarine canyons form primarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scale morphology of 171 slope-sourced canyons. Log–log regression analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics.

  2. Mapping geomorphic process domains to predict hillslope sediment size distribution using remotely-sensed data and field sampling, Inyo Creek, California

    Science.gov (United States)

    Leclere, S.; Sklar, L. S.; Genetti, J. R.

    2014-12-01

    The size distribution of sediments produced on hillslopes and supplied to channels depends on the geomorphic processes that weather, detach and transport rock fragments down slopes. Little in the way of theory or data is available to predict patterns in hillslope size distributions at the catchment scale from topographic and geologic maps. Here we use aerial imagery and a variety of remote sensing techniques to map and categorize geomorphic landscape units (GLUs) by inferred sediment production process regime, across the steep mountain catchment of Inyo Creek, eastern Sierra Nevada, California. We also use field measurements of particle size and local geomorphic attributes to test and refine GLU determinations. Across the 2 km of relief in this catchment, landcover varies from bare bedrock cliffs at higher elevations to vegetated, regolith-covered convex slopes at lower elevations. Hillslope gradient could provide a simple index of sediment production process, from rock spallation and landsliding at highest slopes, to tree-throw and other disturbance-driven soil production processes at lowest slopes. However, many other attributes are needed for a more robust predictive model, including elevation, curvature, aspect, drainage area, and color. We combine tools from ArcGIS, ERDAS Imagine and Envi with groundtruthing field work to find an optimal combination of attributes for defining sediment production GLUs. Key challenges include distinguishing: weathered from freshly eroded bedrock, boulders from intact bedrock, and landslide deposits from talus slopes. We take advantage of emerging technologies that provide new ways of conducting fieldwork and comparing field data to mapping solutions. In particular, cellphone GPS is approaching the accuracy of dedicated GPS systems and the ability to geo-reference photos simplifies field notes and increases accuracy of later map creation. However, the predictive power of the GLU mapping approach is limited by inherent uncertainty

  3. Geomorphic domains and linear features on Landsat images, Circle Quadrangle, Alaska

    Science.gov (United States)

    Simpson, S.L.

    1984-01-01

    A remote sensing study using Landsat images was undertaken as part of the Alaska Mineral Resource Assessment Program (AMRAP). Geomorphic domains A and B, identified on enhanced Landsat images, divide Circle quadrangle south of Tintina fault zone into two regional areas having major differences in surface characteristics. Domain A is a roughly rectangular, northeast-trending area of relatively low relief and simple, widely spaced drainages, except where igneous rocks are exposed. In contrast, domain B, which bounds two sides of domain A, is more intricately dissected showing abrupt changes in slope and relatively high relief. The northwestern part of geomorphic domain A includes a previously mapped tectonostratigraphic terrane. The southeastern boundary of domain A occurs entirely within the adjoining tectonostratigraphic terrane. The sharp geomorphic contrast along the southeastern boundary of domain A and the existence of known faults along this boundary suggest that the southeastern part of domain A may be a subdivision of the adjoining terrane. Detailed field studies would be necessary to determine the characteristics of the subdivision. Domain B appears to be divisible into large areas of different geomorphic terrains by east-northeast-trending curvilinear lines drawn on Landsat images. Segments of two of these lines correlate with parts of boundaries of mapped tectonostratigraphic terranes. On Landsat images prominent north-trending lineaments together with the curvilinear lines form a large-scale regional pattern that is transected by mapped north-northeast-trending high-angle faults. The lineaments indicate possible lithlogic variations and/or structural boundaries. A statistical strike-frequency analysis of the linear features data for Circle quadrangle shows that northeast-trending linear features predominate throughout, and that most northwest-trending linear features are found south of Tintina fault zone. A major trend interval of N.64-72E. in the linear

  4. Geomorphic and Vegetative Recovery Processes Along Modified Stream Channels of West Tennessee

    National Research Council Canada - National Science Library

    Simon, Andrew; Hupp, Cliff R

    1992-01-01

    .... After all or parts of a stream are straightened, dredged, or cleared, systematic hydrologic, geomorphic, and ecologic processes collectively begin to reduce energy conditions towards the premodified state...

  5. Detecting geomorphic processes and change with high resolution topographic data

    Science.gov (United States)

    Mudd, Simon; Hurst, Martin; Grieve, Stuart; Clubb, Fiona; Milodowski, David; Attal, Mikael

    2016-04-01

    The first global topographic dataset was released in 1996, with 1 km grid spacing. It is astonishing that in only 20 years we now have access to tens of thousands of square kilometres of LiDAR data at point densities greater than 5 points per square meter. This data represents a treasure trove of information that our geomorphic predecessors could only dream of. But what are we to do with this data? Here we explore the potential of high resolution topographic data to dig deeper into geomorphic processes across a wider range of landscapes and using much larger spatial coverage than previously possible. We show how this data can be used to constrain sediment flux relationships using relief and hillslope length, and how this data can be used to detect landscape transience. We show how the nonlinear sediment flux law, proposed for upland, soil mantled landscapes by Roering et al. (1999) is consistent with a number of topographic tests. This flux law allows us to predict how landscapes will respond to tectonic forcing, and we show how these predictions can be used to detect erosion rate perturbations across a range of tectonic settings.

  6. Quantitative analysis of geomorphic processes using satellite image data at different scales

    Science.gov (United States)

    Williams, R. S., Jr.

    1985-01-01

    When aerial and satellite photographs and images are used in the quantitative analysis of geomorphic processes, either through direct observation of active processes or by analysis of landforms resulting from inferred active or dormant processes, a number of limitations in the use of such data must be considered. Active geomorphic processes work at different scales and rates. Therefore, the capability of imaging an active or dormant process depends primarily on the scale of the process and the spatial-resolution characteristic of the imaging system. Scale is an important factor in recording continuous and discontinuous active geomorphic processes, because what is not recorded will not be considered or even suspected in the analysis of orbital images. If the geomorphic process of landform change caused by the process is less than 200 m in x to y dimension, then it will not be recorded. Although the scale factor is critical, in the recording of discontinuous active geomorphic processes, the repeat interval of orbital-image acquisition of a planetary surface also is a consideration in order to capture a recurring short-lived geomorphic process or to record changes caused by either a continuous or a discontinuous geomorphic process.

  7. Exogenic geomorphic processes dynamics at the Black Sea coast, Russia

    Science.gov (United States)

    Kuznetsova, Yulia; Tsvetkova, Daria

    2017-04-01

    Nowadays there is an obvious grow of anthropogenic load going on in many areas worldwide. Under such conditions, intensive activation of a number of exogenic geomorphic processes may be observed. Moreover, if natural environment is aggressive itself their dynamics and rates may reach enormous values. Our work is conducted at the Black Sea coast, known for its mountainous topography, wet subtropical climate and intensive anthropogenic development (especially during the last decade due to the recent Olympic games). We chose two key basins near Sochi, Russia to study a number of presented exogenic processes, including rill, gully and channel erosion, weathering, suffusion and piping, soil creep. A set of field study methods is used to monitor the processes dynamics since 2005 (and late 1970s for soil creep). In addition, soil erosion rates and landslide susceptibility were modelled to get information of the watersheds dynamics. This is ongoing work, but the results of the passed period of observations will be resented. Special attention is paid to the processes connectivity and their input into sediment redistribution over the river basins.

  8. A geomorphic process law for detachment-limited hillslopes

    Science.gov (United States)

    Turowski, Jens

    2015-04-01

    Geomorphic process laws are used to assess the shape evolution of structures at the Earth's surface over geological time scales, and are routinely used in landscape evolution models. There are two currently available concepts on which process laws for hillslope evolution rely. In the transport-limited concept, the evolution of a hillslope is described by a linear or a non-linear diffusion equation. In contrast, in the threshold slope concept, the hillslope is assumed to collapse to a slope equal to the internal friction angle of the material when the load due to the relief exists the material strength. Many mountains feature bedrock slopes, especially in the high mountains, and material transport along the slope is limited by the erosion of the material from the bedrock. Here, I suggest a process law for detachment-limited or threshold-dominated hillslopes, in which the erosion rate is a function of the applied stress minus the surface stress due to structural loading. The process law leads to the prediction of an equilibrium form that compares well to the shape of many mountain domes.

  9. Eruptive and Geomorphic Processes at the Lathrop Wells Scoria Cone

    International Nuclear Information System (INIS)

    G. Valentine; D.J. Krier; F.V. Perry; G. Heiken

    2006-01-01

    The ∼80 ka Lathrop Wells volcano (southern Nevada, U.S.A.) preserves evidence for a range of explosive processes and emplacement mechanisms of pyroclastic deposits and lava fields in a small-volume basaltic center. Early cone building by Strombolian bursts was accompanied by development of a fan-like lava field reaching ∼800 m distance from the cone, built upon a gently sloping surface. Lava flows carried rafts of cone deposits, which provide indirect evidence for cone facies in lieu of direct exposures in the active quarry. Subsequent activity was of a violent Strombolian nature, with many episodes of sustained eruption columns up to a few km in height. These deposited layers of scoria lapilli and ash in different directions depending upon wind direction at the time of a given episode, reaching up to ∼20 km from the vent, and also produced the bulk of the scoria cone. Lava effusion migrated from south to north around the eastern base of the cone as accumulation of lavas successively reversed the topography at the base of the cone. Late lavas were emplaced during violent Strombolian activity and continued for some time after explosive eruptions had waned. Volumes of the eruptive products are: fallout--0.07 km 3 , scoria cone--0.02 km 3 , and lavas--0.03 km 3 . Shallow-derived xenolith concentrations suggest an upper bound on average conduit diameter of ∼21 m in the uppermost 335 m beneath the volcano. The volcano was constructed over a period of at least seven months with cone building occurring only during part of that time, based upon analogy with historical eruptions. Post-eruptive geomorphic evolution varied for the three main surface types that were produced by volcanic activity: (1) scoria cone, (2) low relief surfaces (including lavas) with abundant pyroclastic material, and (3) lavas with little pyroclastic material. The role of these different initial textures must be accounted for in estimating relative ages of volcanic surfaces, and failure to

  10. Eruptive and Geomorphic Processes at the Lathrop Wells Scoria Cone

    Energy Technology Data Exchange (ETDEWEB)

    G. Valentine; D.J. Krier; F.V. Perry; G. Heiken

    2006-08-03

    The {approx}80 ka Lathrop Wells volcano (southern Nevada, U.S.A.) preserves evidence for a range of explosive processes and emplacement mechanisms of pyroclastic deposits and lava fields in a small-volume basaltic center. Early cone building by Strombolian bursts was accompanied by development of a fan-like lava field reaching {approx}800 m distance from the cone, built upon a gently sloping surface. Lava flows carried rafts of cone deposits, which provide indirect evidence for cone facies in lieu of direct exposures in the active quarry. Subsequent activity was of a violent Strombolian nature, with many episodes of sustained eruption columns up to a few km in height. These deposited layers of scoria lapilli and ash in different directions depending upon wind direction at the time of a given episode, reaching up to {approx}20 km from the vent, and also produced the bulk of the scoria cone. Lava effusion migrated from south to north around the eastern base of the cone as accumulation of lavas successively reversed the topography at the base of the cone. Late lavas were emplaced during violent Strombolian activity and continued for some time after explosive eruptions had waned. Volumes of the eruptive products are: fallout--0.07 km{sup 3}, scoria cone--0.02 km{sup 3}, and lavas--0.03 km{sup 3}. Shallow-derived xenolith concentrations suggest an upper bound on average conduit diameter of {approx}21 m in the uppermost 335 m beneath the volcano. The volcano was constructed over a period of at least seven months with cone building occurring only during part of that time, based upon analogy with historical eruptions. Post-eruptive geomorphic evolution varied for the three main surface types that were produced by volcanic activity: (1) scoria cone, (2) low relief surfaces (including lavas) with abundant pyroclastic material, and (3) lavas with little pyroclastic material. The role of these different initial textures must be accounted for in estimating relative ages of

  11. Autogenic geomorphic processes determine the resolution and fidelity of terrestrial paleoclimate records

    OpenAIRE

    Foreman, Brady Z.; Straub, Kyle M.

    2017-01-01

    Terrestrial paleoclimate records rely on proxies hosted in alluvial strata whose beds are deposited by unsteady and nonlinear geomorphic processes. It is broadly assumed that this renders the resultant time series of terrestrial paleoclimatic variability noisy and incomplete. We evaluate this assumption using a model of oscillating climate and the precise topographic evolution of an experimental alluvial system. We find that geomorphic stochasticity can create aliasing in the time series and ...

  12. Autogenic geomorphic processes determine the resolution and fidelity of terrestrial paleoclimate records.

    Science.gov (United States)

    Foreman, Brady Z; Straub, Kyle M

    2017-09-01

    Terrestrial paleoclimate records rely on proxies hosted in alluvial strata whose beds are deposited by unsteady and nonlinear geomorphic processes. It is broadly assumed that this renders the resultant time series of terrestrial paleoclimatic variability noisy and incomplete. We evaluate this assumption using a model of oscillating climate and the precise topographic evolution of an experimental alluvial system. We find that geomorphic stochasticity can create aliasing in the time series and spurious climate signals, but these issues are eliminated when the period of climate oscillation is longer than a key time scale of internal dynamics in the geomorphic system. This emergent autogenic geomorphic behavior imparts regularity to deposition and represents a natural discretization interval of the continuous climate signal. We propose that this time scale in nature could be in excess of 10 4 years but would still allow assessments of the rates of climate change at resolutions finer than the existing age model techniques in isolation.

  13. Seismic constraints on dynamic links between geomorphic processes and routing of sediment in a steep mountain catchment

    Science.gov (United States)

    Burtin, A.; Hovius, N.; McArdell, B. W.; Turowski, J. M.; Vergne, J.

    2014-01-01

    Landscape dynamics are determined by interactions amongst geomorphic processes. These interactions allow the effects of tectonic, climatic and seismic perturbations to propagate across topographic domains, and permit the impacts of geomorphic process events to radiate from their point of origin. Visual remote sensing and in situ observations do not fully resolve the spatiotemporal patterns of surface processes in a landscape. As a result, the mechanisms and scales of geomorphic connectivity are poorly understood. Because many surface processes emit seismic signals, seismology can determine their type, location and timing with a resolution that reveals the operation of integral landscapes. Using seismic records, we show how hillslopes and channels in an Alpine catchment are interconnected to produce evolving, sediment-laden flows. This is done for a convective storm, which triggered a sequence of hillslope processes and debris flows. We observe the evolution of these process events and explore the operation of two-way links between mass wasting and channel processes, which are fundamental to the dynamics of most erosional landscapes. We also track the characteristics and propagation of flows along the debris flow channel, relating changes of observed energy to the deposition/mobilization of sediments, and using the spectral content of debris flow seismic signals to qualitatively infer sediment characteristics and channel abrasion potential. This seismological approach can help to test theoretical concepts of landscape dynamics and yield understanding of the nature and efficiency of links between individual geomorphic processes, which is required to accurately model landscape dynamics under changing tectonic or climatic conditions and to anticipate the natural hazard risk associated with specific meteorological events.

  14. Geologic factors in the isolation of nuclear waste: evaluation of long-term geomorphic processes and events

    International Nuclear Information System (INIS)

    Mara, S.J.

    1979-01-01

    In this report the rate, duration, and magnitude of changes from geomorphic processes and events in the Southwest and the Gulf Coast over the next million years are projected. The projections were made by reviewing the pertinent literature; evaluating the geomorphic history of each region, especially that during the Quaternary Period; identifying the geomorphic processes and events likely to be significant in the two regions of interest; and estimating the average and worst-case conditions expected over the next million years

  15. Measurements and experiments on Geomorphic processes in Antarctic ice-free mountains: A review

    Directory of Open Access Journals (Sweden)

    Norikazu Matsuoka

    1996-07-01

    Full Text Available This paper aims to review dynamic approaches to geomorphic processes in the Antarctic ice-free areas, most of which lie in the cold desert zone, and to propose for future research. A variety of methodologies have been used to measure rock weathering, wind erosion, frost heave, slope processes and patterned ground formation. Whereas a number of attempts have been made to quantify rates of erosion or mass movements, difficulties in long-term, continuous monitoring have long militated against understanding of the physical processes that control the rates. Recent progress in automated data logging techniques enables us to acquire data on the timing and cause of geomorphic changes. These data, combined with cosmogenic exposure ages, can be applied to the reconstruction of Late Cenozoic landscape evolution. Experimental techniques should be standardized to promote intersite comparisons of morphogenetic environments.

  16. Modeling In-Stream Hydro-Geomorphic Processes After 2012 Waldo Canyon Fire, Colorado

    Science.gov (United States)

    Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.

    2016-12-01

    Wildfires can have significant impacts on hydrologic and geomorphic processes. Post-fire sediment transport and runoff generation vary by burn severity, precipitation, and vegetation. A need exists to understand these variable relationships and improve parameterization of post-fire hydro-geomorphic models. This research aims to model pre-fire geomorphic and hydrologic processes in Williams Canyon, a watershed burned by the 2012 Waldo Canyon Fire in Colorado. We develop the KINematic Runoff and EROSion (KINEROS) model with Geographical Information System (GIS)-based information, including a Digital Elevation Model, land cover, soil classification, precipitation, and soil burn severity for a local reference watershed that is unburned. We transfer these parameters to a channel reach in Williams Canyon (Williams Downstream) and adjust them toward post-fire conditions. We model runoff and sediment yield for several storms following the fire. Three post-fire terrestrial Light Detection and Ranging (LiDAR) images (21 April 2013, 14 September 2013, and 16 September 2014) are used to estimate total erosion and deposition at the reach scale. We use the LiDAR-based information to calibrate the post-fire model. Preliminary modeling results indicate 3870-125 kg/ha of sediment in the Williams Downstream reach. The uncalibrated model overestimated (410% in the first year) and underestimated (87.2% in the second year) the erosion. Model calibration reduced the Root Mean Square Error (RMSE) of sediment to 0.016% for the first year and 0.09% for the second year. The parameters calibrated for the Williams Downstream channel reach will be used to develop models for seven other channel reaches within the area burned by the Waldo Canyon Fire, where the performance can be evaluated with LiDAR estimates. Results of this research will enhance our understanding of wildfire disturbance on coupled hydrologic and geomorphic processes. Findings will also improve model parameterization that can

  17. Response of geomorphic and geological processes to insufficient ...

    Indian Academy of Sciences (India)

    Depositional models have been constructed for each segment: a constant shelf break model with insufficient sediment supply in the east, and a migration shelf break model with plenty sediment supply in the west. This case study contributes to the understanding of the upper slope sedimentary process and stratigraphic style ...

  18. Scaling considerations related to interactions of hydrologic, pedologic and geomorphic processes (Invited)

    Science.gov (United States)

    Sidle, R. C.

    2013-12-01

    Hydrologic, pedologic, and geomorphic processes are strongly interrelated and affected by scale. These interactions exert important controls on runoff generation, preferential flow, contaminant transport, surface erosion, and mass wasting. Measurement of hydraulic conductivity (K) and infiltration capacity at small scales generally underestimates these values for application at larger field, hillslope, or catchment scales. Both vertical and slope-parallel saturated flow and related contaminant transport are often influenced by interconnected networks of preferential flow paths, which are not captured in K measurements derived from soil cores. Using such K values in models may underestimate water and contaminant fluxes and runoff peaks. As shown in small-scale runoff plot studies, infiltration rates are typically lower than integrated infiltration across a hillslope or in headwater catchments. The resultant greater infiltration-excess overland flow in small plots compared to larger landscapes is attributed to the lack of preferential flow continuity; plot border effects; greater homogeneity of rainfall inputs, topography and soil physical properties; and magnified effects of hydrophobicity in small plots. At the hillslope scale, isolated areas with high infiltration capacity can greatly reduce surface runoff and surface erosion at the hillslope scale. These hydropedologic and hydrogeomorphic processes are also relevant to both occurrence and timing of landslides. The focus of many landslide studies has typically been either on small-scale vadose zone process and how these affect soil mechanical properties or on larger scale, more descriptive geomorphic studies. One of the issues in translating laboratory-based investigations on geotechnical behavior of soils to field scales where landslides occur is the characterization of large-scale hydrological processes and flow paths that occur in heterogeneous and anisotropic porous media. These processes are not only affected

  19. Landscape evolution space and the relative importance of geomorphic processes and controls

    Science.gov (United States)

    Phillips, Jonathan D.

    2009-08-01

    The concept of landscape evolution space (LES) is introduced as a tool for assessing landscapes and geomorphic systems, intended to be a systematic means for assessing the various factors that contribute to the potential for change in geomorphic systems. The LES conceptual model is based on the energy and mass available to drive and accommodate landscape evolution. An n-dimensional landscape evolution space is defined not only by spatial coordinates, but also by the availability of mass and energy. The LES is thus a space or hypervolume representing the resources available for geomorphic evolution and landscape change. An expression for LES is derived based on elevation, material density, surface area, and inputs of solar, meteoric, and biological energy and mass. Though primarily an heuristic device, the LES model can be used to address concrete problems. Two examples are given. In one, increased surface area due to topographic roughening and dissection of an incised plateau is found to only slightly offset erosional removals of mass in terms of the magnitude of the LES. In the other, sensitivity of coastal plain rivers to several impacts of sea level and climate change is explored. The LES model also leads to the concept of a geomorphological niche, representing the resources available to drive or support a specific process or suite of processes. Considerations of landscape evolution have traditionally focused on the interplay of endogenic vs. exogenic processes, uplift vs. denudation, or soil formation vs. erosion. The LES model explicitly broadens the conceptual framework of landscape evolution beyond the traditional dialectics.

  20. Continuous catchment-scale monitoring of geomorphic processes with a 2-D seismological array

    Science.gov (United States)

    Burtin, A.; Hovius, N.; Milodowski, D.; Chen, Y.-G.; Wu, Y.-M.; Lin, C.-W.; Chen, H.

    2012-04-01

    The monitoring of geomorphic processes during extreme climatic events is of a primary interest to estimate their impact on the landscape dynamics. However, available techniques to survey the surface activity do not provide a relevant time and/or space resolution. Furthermore, these methods hardly investigate the dynamics of the events since their detection are made a posteriori. To increase our knowledge of the landscape evolution and the influence of extreme climatic events on a catchment dynamics, we need to develop new tools and procedures. In many past works, it has been shown that seismic signals are relevant to detect and locate surface processes (landslides, debris flows). During the 2010 typhoon season, we deployed a network of 12 seismometers dedicated to monitor the surface processes of the Chenyoulan catchment in Taiwan. We test the ability of a two dimensional array and small inter-stations distances (~ 11 km) to map in continuous and at a catchment-scale the geomorphic activity. The spectral analysis of continuous records shows a high-frequency (> 1 Hz) seismic energy that is coherent with the occurrence of hillslope and river processes. Using a basic detection algorithm and a location approach running on the analysis of seismic amplitudes, we manage to locate the catchment activity. We mainly observe short-time events (> 300 occurrences) associated with debris falls and bank collapses during daily convective storms, where 69% of occurrences are coherent with the time distribution of precipitations. We also identify a couple of debris flows during a large tropical storm. In contrast, the FORMOSAT imagery does not detect any activity, which somehow reflects the lack of extreme climatic conditions during the experiment. However, high resolution pictures confirm the existence of links between most of geomorphic events and existing structures (landslide scars, gullies...). We thus conclude to an activity that is dominated by reactivation processes. It

  1. Human-induced shifts in geomorphic process rates: An example of landslide activity following forest cover change.

    Science.gov (United States)

    Guns, Marie; Balthazar, Vincent; Vanacker, Veerle

    2013-04-01

    Mountain regions present unique challenges and opportunities to land use change research. Very few, if any, mountain ecosystems remain unaffected by human impact. Based on the exemplary evidence from local case studies, it is not yet possible to have an overall assessment of the extent and impact of human activities on mountain erosion as mountain regions are typically characterized by rapid changes in geomorphic, cryospheric, climatic, hydrologic, ecological and socio-economic conditions over relatively short distances. Here, we present a conceptual model that allows evaluating human-induced shifts in geomorphic process rates. The basic idea behind this model is that the magnitude-frequency distribution of geomorphic processes is dependent on the intensity of human disturbance. The conceptual model is here applied for characterising landslide activity following forest cover change. We selected a tropical Andean catchment with a deforestation rate of 1.4% over the last 45 years. Landslide inventories were established based on historical aerial photographs (1963, 1977, and 1989) and very high-resolution satellite images (2010). Statistical analyses show that the total number of landslides is rising, and that they are increasingly associated with human disturbances (deforestation, road construction). This is particularly the case for shallow landslides that become more frequent after clearcutting. As the human-induced shifts in landslide activity are significant for the low-magnitude events only, the total impact on geomorphic process rates is rather limited in this particular area. This work shows that including information on the magnitude-frequency of geomorphic events before, during and after human disturbances offers new possibilities to quantify the complex response of geomorphic processes to human disturbances.

  2. Anthropogenic control on geomorphic process rates: can we slow down the erosion rates? (Geomorphology Outstanding Young Scientist Award & Penck Lecture)

    Science.gov (United States)

    Vanacker, V.

    2012-04-01

    The surface of the Earth is changing rapidly, largely in response to anthropogenic perturbation. Direct anthropogenic disturbance of natural environments may be much larger in many places than the (projected) indirect effects of climate change. There is now large evidence that humans have significantly altered geomorphic process rates, mainly through changes in vegetation composition, density and cover. While much attention has been given to the impact of vegetation degradation on geomorphic process rates, I suggest that the pathway of restoration is equally important to investigate. First, vegetation recovery after crop abandonment has a rapid and drastic impact on geomorphic process rates. Our data from degraded catchments in the tropical Andes show that erosion rates can be reduced by up to 100 times when increasing the protective vegetation cover. During vegetation restoration, the combined effects of the reduction in surface runoff, sediment production and hydrological connectivity are stronger than the individual effects together. Therefore, changes in erosion and sedimentation during restoration are not simply the reverse of those observed during degradation. Second, anthropogenic perturbation causes a profound but often temporary change in geomorphic process rates. Reconstruction of soil erosion rates in Spain shows us that modern erosion rates in well-vegetated areas are similar to long-term rates, despite evidence of strong pulses in historical erosion rates after vegetation clearance and agriculture. The soil vegetation system might be resilient to short pulses of accelerated erosion (and deposition), as there might exist a dynamic coupling between soil erosion and production also in degraded environments.

  3. Learning processes across knowledge domains

    DEFF Research Database (Denmark)

    Hall-Andersen, Lene Bjerg; Broberg, Ole

    2014-01-01

    Purpose - The purpose of this paper is to shed light on the problematics of learning across knowledge boundaries in organizational settings. The paper specifically explores learning processes that emerge, when a new knowledge domain is introduced into an existing organizational practice with the ...

  4. Geomorphic and vegetation processes of the Willamette River floodplain, Oregon: current understanding and unanswered science questions

    Science.gov (United States)

    Wallick, J. Rose; Jones, Krista L.; O'Connor, Jim E.; Keith, Mackenzie K.; Hulse, David; Gregory, Stanley V.

    2013-01-01

    This report summarizes the current understanding of floodplain processes and landforms for the Willamette River and its major tributaries. The area of focus encompasses the main stem Willamette River above Newberg and the portions of the Coast Fork Willamette, Middle Fork Willamette, McKenzie, and North, South and main stem Santiam Rivers downstream of U.S. Army Corps of Engineers dams. These reaches constitute a large portion of the alluvial, salmon-bearing rivers in the Willamette Basin. The geomorphic, or historical, floodplain of these rivers has two zones - the active channel where coarse sediment is mobilized and transported during annual flooding and overbank areas where fine sediment is deposited during higher magnitude floods. Historically, characteristics of the rivers and geomorphic floodplain (including longitudinal patterns in channel complexity and the abundance of side channels, islands and gravel bars) were controlled by the interactions between floods and the transport of coarse sediment and large wood. Local channel responses to these interactions were then shaped by geologic features like bedrock outcrops and variations in channel slope. Over the last 150 years, floods and the transport of coarse sediment and large wood have been substantially reduced in the basin. With dam regulation, nearly all peak flows are now confined to the main channels. Large floods (greater than 10-year recurrence interval prior to basinwide flow regulation) have been largely eliminated. Also, the magnitude and frequency of small floods (events that formerly recurred every 2–10 years) have decreased substantially. The large dams trap an estimated 50–60 percent of bed-material sediment—the building block of active channel habitats—that historically entered the Willamette River. They also trap more than 80 percent of the estimated bed material in the lower South Santiam River and Middle and Coast Forks of the Willamette River. Downstream, revetments further

  5. Integrating channel form and processes in the Gangetic plains rivers: Implications for geomorphic diversity

    Science.gov (United States)

    Roy, N. G.; Sinha, R.

    2018-02-01

    Geomorphic diversity at a variety of spatial and temporal scales has been studied in the western Ganga plains (WGP), India, to isolate the dominating factors at each scale that have the potential to cause major geomorphic change. The Ganga River and its major tributaries draining the WGP have been investigated in terms of longitudinal, cross-sectional, and planform morphology to assess the influence of potential controls such as climate, geology, topography, land use, hydrology, and sediment transport. These data were then compared with those from the rivers draining the eastern Ganga plains (EGP) to understand the geomorphic diversity across the Ganga plains and the causal factors. Our investigations suggest that in-channel geomorphic diversity over decadal scale in rivers with low width-to-depth (W/D) ratio is caused by periodic incision/aggradation, but it is driven by channel avulsion in rivers characterized by high W/D ratio. Similarly, planform (reach-scale) parameters such as sinuosity and braid-channel-ratio are influenced by intrinsic factors such as changes in hydrological conditions and morphodynamics (cutoffs, small-scale avulsion) that are in turn impacted by natural and human-induced factors. Finally, we have isolated the climatic and hydrologic effects on the longitudinal profile concavity of alluvial trunk channels in tectonically stable and unstable landscapes. We demonstrate that the rivers flowing through a tectonically stable landscape are graded in nature where higher discharge tends to create more concave longitudinal profiles compared to those in tectonically unstable landscape at 103-year scale.

  6. Linking Soil Moisture Variation and Abundance of Plants to Geomorphic Processes: A Generalized Model for Erosion-Uplifting Landscapes

    Science.gov (United States)

    Ding, Junyan; Johnson, Edward A.; Martin, Yvonne E.

    2018-03-01

    The diffusive and advective erosion-created landscapes have similar structure (hillslopes and channels) across different scales regardless of variations in drivers and controls. The relative magnitude of diffusive erosion to advective erosion (D/K ratio) in a landscape development model controls hillslope length, shape, and drainage density, which regulate soil moisture variation, one of the critical resources of plants, through the contributing area (A) and local slope (S) represented by a topographic index (TI). Here we explore the theoretical relation between geomorphic processes, TI, and the abundance and distribution of plants. We derived an analytical model that expresses the TI with D, K, and A. This gives us the relation between soil moisture variation and geomorphic processes. Plant tolerance curves are used to link plant performance to soil moisture. Using the hypothetical tolerance curves of three plants, we show that the abundance and distribution of xeric, mesic, and hydric plants on the landscape are regulated by the D/K ratio. Where diffusive erosion is the major erosion process (large D/K ratio), mesic plants have higher abundance relative to xeric and hydric plants and the landscape has longer and convex-upward hillslope and low channel density. Increasing the dominance of advective erosion increases relative abundance of xeric and hydric plants dominance, and the landscape has short and concave hillslope and high channel density.

  7. A multi-resolution analysis of lidar-DTMs to identify geomorphic processes from characteristic topographic length scales

    Science.gov (United States)

    Sangireddy, H.; Passalacqua, P.; Stark, C. P.

    2013-12-01

    Characteristic length scales are often present in topography, and they reflect the driving geomorphic processes. The wide availability of high resolution lidar Digital Terrain Models (DTMs) allows us to measure such characteristic scales, but new methods of topographic analysis are needed in order to do so. Here, we explore how transitions in probability distributions (pdfs) of topographic variables such as (log(area/slope)), defined as topoindex by Beven and Kirkby[1979], can be measured by Multi-Resolution Analysis (MRA) of lidar DTMs [Stark and Stark, 2001; Sangireddy et al.,2012] and used to infer dominant geomorphic processes such as non-linear diffusion and critical shear. We show this correlation between dominant geomorphic processes to characteristic length scales by comparing results from a landscape evolution model to natural landscapes. The landscape evolution model MARSSIM Howard[1994] includes components for modeling rock weathering, mass wasting by non-linear creep, detachment-limited channel erosion, and bedload sediment transport. We use MARSSIM to simulate steady state landscapes for a range of hillslope diffusivity and critical shear stresses. Using the MRA approach, we estimate modal values and inter-quartile ranges of slope, curvature, and topoindex as a function of resolution. We also construct pdfs at each resolution and identify and extract characteristic scale breaks. Following the approach of Tucker et al.,[2001], we measure the average length to channel from ridges, within the GeoNet framework developed by Passalacqua et al.,[2010] and compute pdfs for hillslope lengths at each scale defined in the MRA. We compare the hillslope diffusivity used in MARSSIM against inter-quartile ranges of topoindex and hillslope length scales, and observe power law relationships between the compared variables for simulated landscapes at steady state. We plot similar measures for natural landscapes and are able to qualitatively infer the dominant geomorphic

  8. Riverbank Collapse on the lower Murray River: recent phenomenon or long-term geomorphic process?

    Science.gov (United States)

    De Carli, E.; Hubble, T.; Jaksa, M.; Clarke, S. L.; Airey, D.; O'Toole, J.; Carpenter, G.

    2013-12-01

    The lower Murray River connects the Murray-Darling River Basin to the Southern Ocean and drains 14% of Australia's landmass. During the Millennium Drought (1997-2011) record low inflows for the Basin were recorded and the lower Murray River received only 19% of its long-term average inflow for 2008-2009, causing the pool-level in the lowermost reaches near Goolwa to fall 1 m below sea level. This event triggered widespread mass failure in the alluvial river banks and ground subsidence in some river-adjacent floodplain deposits between Blanchetown and Lake Alexandrina. Multi-beam bathymetry, sediment core and geotechnical data are presented for a number of sites investigated between Mannum and White Sands. Interpretation of this data indicates three different bank-failure slide morphologies present in the banks and adjacent channel. Type 1, ';recent' (2009-2011) deep-seated rotational slumps characterised by distinct, sharply-defined failure scars and associated debris fields of angular blocks shed from the failure site. Type 2, ';relatively-recent' shallow planar-failures, with less well-defined smoother failure scars and associated debris fields of smoothed or rounded blocks and pinnacles. Type 3, ';relatively-old' shallow planar-failures characterised by subdued relief slump scars that do not present an associated debris field. It is suspected that successive floods or high-flow events progressively erode and redistribute material, smoothing the landslide scars and redistributing the slide-debris deposits. Bank-failure and the delivery of material from the slides into the channel is interpreted as an ongoing and long-term geomorphic characteristic of the lower Murray River, rather than a new phenomenon that occurred as a response to unusually low river levels during the Millennium Drought. The larger size and rotational style of the recent Type 1 failures is most likely to be a consequence of the drought and anthropogenic modifications of the river channel and

  9. Assessment Approach for Identifying Compatibility of Restoration Projects with Geomorphic and Flooding Processes in Gravel Bed Rivers.

    Science.gov (United States)

    DeVries, Paul; Aldrich, Robert

    2015-08-01

    A critical requirement for a successful river restoration project in a dynamic gravel bed river is that it be compatible with natural hydraulic and sediment transport processes operating at the reach scale. The potential for failure is greater at locations where the influence of natural processes is inconsistent with intended project function and performance. We present an approach using practical GIS, hydrologic, hydraulic, and sediment transport analyses to identify locations where specific restoration project types have the greatest likelihood of working as intended because their function and design are matched with flooding and morphologic processes. The key premise is to identify whether a specific river analysis segment (length ~1-10 bankfull widths) within a longer reach is geomorphically active or inactive in the context of vertical and lateral stabilities, and hydrologically active for floodplain connectivity. Analyses involve empirical channel geometry relations, aerial photographic time series, LiDAR data, HEC-RAS hydraulic modeling, and a time-integrated sediment transport budget to evaluate trapping efficiency within each segment. The analysis segments are defined by HEC-RAS model cross sections. The results have been used effectively to identify feasible projects in a variety of alluvial gravel bed river reaches with lengths between 11 and 80 km and 2-year flood magnitudes between ~350 and 1330 m(3)/s. Projects constructed based on the results have all performed as planned. In addition, the results provide key criteria for formulating erosion and flood management plans.

  10. Assessment Approach for Identifying Compatibility of Restoration Projects with Geomorphic and Flooding Processes in Gravel Bed Rivers

    Science.gov (United States)

    DeVries, Paul; Aldrich, Robert

    2015-08-01

    A critical requirement for a successful river restoration project in a dynamic gravel bed river is that it be compatible with natural hydraulic and sediment transport processes operating at the reach scale. The potential for failure is greater at locations where the influence of natural processes is inconsistent with intended project function and performance. We present an approach using practical GIS, hydrologic, hydraulic, and sediment transport analyses to identify locations where specific restoration project types have the greatest likelihood of working as intended because their function and design are matched with flooding and morphologic processes. The key premise is to identify whether a specific river analysis segment (length ~1-10 bankfull widths) within a longer reach is geomorphically active or inactive in the context of vertical and lateral stabilities, and hydrologically active for floodplain connectivity. Analyses involve empirical channel geometry relations, aerial photographic time series, LiDAR data, HEC-RAS hydraulic modeling, and a time-integrated sediment transport budget to evaluate trapping efficiency within each segment. The analysis segments are defined by HEC-RAS model cross sections. The results have been used effectively to identify feasible projects in a variety of alluvial gravel bed river reaches with lengths between 11 and 80 km and 2-year flood magnitudes between ~350 and 1330 m3/s. Projects constructed based on the results have all performed as planned. In addition, the results provide key criteria for formulating erosion and flood management plans.

  11. Land use and surface process domains on alpine hillslopes

    Science.gov (United States)

    Kuhn, Nikolaus J.; Caviezel, Chatrina; Hunziker, Matthias

    2015-04-01

    Shrubs and trees are generally considered to protect hillslopes from erosion. As a consequence, shrub encroachment on mountain pastures after abandoning grazing is not considered a threat to soils. However, the abandonment of mown or grazed grasslands causes a shift in vegetation composition and thus a change in landscape ecology and geomorphology. On many alpine slopes, current changes in land use and vegetation cover are accompanied by climate change, potentially generating a new geomorphic regime. Most of the debate focuses on the effect of land abandonment on water erosion rates. Generally, an established perennial vegetation cover improves the mechanical anchoring of the soil and the regulation of the soil water budget, including runoff generation and erosion. However, changing vegetation composition affects many other above- and below-ground properties like root density, -diversity and -geometry, soil structure, pore volume and acidity. Each combination of these properties can lead to a distinct scenario of dominating surface processes, often not reflected by common erosion risk assessment procedures. The study of soil properties along a chronosequence of green alder (alnusviridis) encroachment on the Unteralptal in central Switzerland reveals that shrub encroachment changes soil and vegetation properties towards an increase of resistance to run-off related erosion processes, but a decrease of slope stability against shallow landslides. The latter are a particular threat because of the currently increasing frequency of slide-triggering high magnitude rainfalls. The potential change of process domain on alpine pastures highlights the need for a careful use of erosion models when assessing future land use and climate scenarios. In mountains, but also other intensively managed agricultural landscapes, risk assessment without the appropriate reflection on the shifting relevance of surface processes carries the risk of missing future threats to environmental

  12. Geomorphic controls on Great Basin riparian vegetation at the watershed and process zone scales

    Science.gov (United States)

    Blake Meneken Engelhardt

    2009-01-01

    Riparian ecosystems supply valuable resources in all landscapes, but especially in semiarid regions such as the Great Basin of the western United States. Over half of Great Basin streams are thought to be in poor ecological condition and further deterioration is of significant concern to stakeholders. A thorough understanding of how physical processes acting at...

  13. Differentiating the relative importance of land cover change and geomorphic processes on fine sediment sequestration in a logged watershed

    Science.gov (United States)

    Kasprak, Alan; Magilligan, Francis J.; Nislow, Keith H.; Renshaw, Carl E.; Snyder, Noah P.; Dade, W. Brian

    2013-03-01

    Timber harvest often results in accelerated soil erosion and subsequent elevated fine (winnowing these fines from the channel bed. These results further suggest that under contemporary land use conditions, the geomorphic and geologic setting represents a first-order control on channel substrate and habitat suitability for salmonid fishes, including federally endangered Atlantic salmon (Salmo salar), in coastal drainages of northeastern Maine.

  14. Rehabilitation of an Incised Stream Using Plant Materials: the Dominance of Geomorphic Processes

    Directory of Open Access Journals (Sweden)

    F. Douglas. Shields, Jr.

    2008-12-01

    Full Text Available The restoration of potentially species-rich stream ecosystems in physically unstable environments is challenging, and few attempts have been evaluated scientifically. Restoration approaches that involve living and dead native vegetation are attractive economically and from an ecological standpoint. A 2-km reach of an incised, sand-bed stream in northern Mississippi was treated with large wood structures and willow plantings to trigger responses that would result in increasing similarity with a lightly degraded reference stream. Experimental approaches for stream bank and gully stabilization were also examined. Although the project was initially successful in producing improved aquatic habitat, after 4 yr it had failed to effectively address issues related to flashy watershed hydrology and physical instability manifest by erosion and sedimentation. The success of ecosystem rehabilitation was thus governed by landscape-scale hydrological and geomorphological processes.

  15. Seasonal geomorphic processes and rates of sand movement at Mount Baldy dune in Indiana, USA

    Science.gov (United States)

    Kilibarda, Zoran; Kilibarda, Vesna

    2016-12-01

    Winds are very strong, frequent, and have high energy (annual DP ∼800 VU) along the southern shores of Lake Michigan, allowing the coexistence of fixed and active dunes. Six years (2007-13) of monitoring Mount Baldy in the Indiana Dunes National Lakeshore reveals that this is the most active coastal dune in the Great Lakes region. This paper documents aeolian processes and changes in the dune's morphology that occur temporarily, following storms, or seasonally, due to weather (climate) variations. Most of the sand transport in this area takes place during strong storms with gale force (>17.5 m/s) winds, which occur in the autumn and winter months. A single storm, such as the October 28-31, 2013 event, can contribute 25% of the annual sand transport and dune movement inland. In its most active year (June 1, 2011 through May 31, 2012), Mount Baldy moved inland on average 4.34 m, with a maximum of 6.52 m along the blowout's axis (155° azimuth). During this particularly active season, there were six storms with sustained gale force winds, winter air temperatures were warmer than average, and shelf ice on Lake Michigan lasted only one day. The dune is least active during the summer season, when the winds are weakest. The late fall and winter winds are the strongest. But in a typical year, most of the dune's advance inland takes place during the spring thaw when sand is released from over-steepened and lumpy slip face, allowing it to avalanche to the toe of the slip face. However, with a warming air temperatures, a reduction in the duration of winter shelf ice, and rising Lake Michigan levels, the annual rates of sand transport and dune movement may increase. The recent Mount Baldy management strategy, which includes planting vegetation and installing wind barriers on the dune's stoss side in an effort to fix the dune and stop its further movement inland, may potentially cause the destruction of the mobile sand, open dune habitat, resulting in the extinction of rare

  16. Magnetization process and domains in MTJ

    Energy Technology Data Exchange (ETDEWEB)

    Czapkiewicz, M.; Zoladz, M.; Wrona, J.; Wisniowski, P.; Rak, R.; Stobiecki, T. [Department of Electronics, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Kim, C.G.; Kim, C.O. [Department of Materials Engineering, Chungnam National University, 305-764 Daejon (Korea); Takahashi, M.; Tsunoda, M. [Department of Electronic Engineering, Tohoku University, 980-8579 Sendai (Japan)

    2004-06-01

    The magnetization process and domain structure of free layers in as deposited and annealed magnetic tunnel junctions (MTJ) of Si/Ta/Cu/Ta/NiFe/Cu/IrMn(10)/CoFe(2.5)/Al-O(1.5)/CoFe(2.5)/NiFe(t)/Ta, where t=10, 30 and 100 nm, were investigated by Kerr microscopy, R-VSM and MOKE magnetometers. Different types of domain patterns observed in free layers (CoFe(2.5)/NiFe(t)) depending on the mutual relation between interlayer coupling energy and free layer magnetostatic energy. For as deposited samples fuzzy domains with fine irregular ''patches'' pattern, typical for weak interlayer coupling, are observed. Annealed MTJs, however, are characterized by large domains superimposed by crossed stripes, which led to the blocking of coherent rotation of magnetization. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Assessment of effectiveness of geologic isolation systems. Geologic factors in the isolation of nuclear waste: evaluation of long-term geomorphic processes and catastrophic events

    International Nuclear Information System (INIS)

    Mara, S.J.

    1980-03-01

    SRI International has projected the rate, duration, and magnitude of geomorphic processes and events in the Southwest and Gulf Coast over the next million years. This information will be used by the Department of Energy's Pacific Northwest Laboratory (PNL) as input to a computer model, which will be used to simulate possible release scenarios and the consequences of the release of nuclear waste from geologic containment. The estimates in this report, although based on best scientific judgment, are subject to considerable uncertainty. An evaluation of the Quaternary history of the two study areas revealed that each had undergone geomorphic change in the last one million years. Catastrophic events were evaluated in order to determine their significance to the simulation model. Given available data, catastrophic floods are not expected to occur in the two study areas. Catastrophic landslides may occur in the Southwest, but because the duration of the event is brief and the amount of material moved is small in comparison to regional denudation, such events need not be included in the simulation model. Ashfalls, however, could result in removal of vegetation from the landscape, thereby causing significant increases in erosion rates. Because the estimates developed during this study may not be applicable to specific sites, general equations were presented as a first step in refining the analysis. These equations identify the general relationships among the important variables and suggest those areas of concern for which further data are required. If the current model indicates that geomorphic processes (taken together with other geologic changes) may ultimately affect the geologic containment of nuclear waste, further research may be necessary to refine this analysis for application to specific sites

  18. Modelling Geomorphic Systems: Landscape Evolution

    OpenAIRE

    Valters, Declan

    2016-01-01

    Landscape evolution models (LEMs) present the geomorphologist with a means of investigating how landscapes evolve in response to external forcings, such as climate and tectonics, as well as internal process laws. LEMs typically incorporate a range of different geomorphic transport laws integrated in a way that simulates the evolution of a 3D terrain surface forward through time. The strengths of LEMs as research tools lie in their ability to rapidly test many different hypotheses of landscape...

  19. Text Processing of Domain-Related Information for Individuals with High and Low Domain Knowledge.

    Science.gov (United States)

    Spilich, George J.; And Others

    1979-01-01

    The way in which previously acquired knowledge affects the processing on new domain-related information was investigated. Text processing was studied in two groups differing in knowledge of the domain of baseball. A knowledge structure for the domain was constructed, and text propositions were classified. (SW)

  20. Domain-General Factors Influencing Numerical and Arithmetic Processing

    Directory of Open Access Journals (Sweden)

    André Knops

    2017-12-01

    Full Text Available This special issue contains 18 articles that address the question how numerical processes interact with domain-general factors. We start the editorial with a discussion of how to define domain-general versus domain-specific factors and then discuss the contributions to this special issue grouped into two core numerical domains that are subject to domain-general influences (see Figure 1. The first group of contributions addresses the question how numbers interact with spatial factors. The second group of contributions is concerned with factors that determine and predict arithmetic understanding, performance and development. This special issue shows that domain-general (Table 1a as well as domain-specific (Table 1b abilities influence numerical and arithmetic performance virtually at all levels and make it clear that for the field of numerical cognition a sole focus on one or several domain-specific factors like the approximate number system or spatial-numerical associations is not sufficient. Vice versa, in most studies that included domain-general and domain-specific variables, domain-specific numerical variables predicted arithmetic performance above and beyond domain-general variables. Therefore, a sole focus on domain-general aspects such as, for example, working memory, to explain, predict and foster arithmetic learning is also not sufficient. Based on the articles in this special issue we conclude that both domain-general and domain-specific factors contribute to numerical cognition. But the how, why and when of their contribution still needs to be better understood. We hope that this special issue may be helpful to readers in constraining future theory and model building about the interplay of domain-specific and domain-general factors.

  1. Time-Frequency Domain Memory and Processing

    National Research Council Canada - National Science Library

    Huestis, David

    2002-01-01

    This report summarizes the results of a 3-year program of research on the physics and technology needed to develop high-performance optical memory and optical processing systems based on the concept...

  2. Evaluating process domains in small arid granitic watersheds: Case study of Pima Wash, South Mountains, Sonoran Desert, USA

    Science.gov (United States)

    Seong, Yeong Bae; Larson, Phillip H.; Dorn, Ronald I.; Yu, Byung Yong

    2016-02-01

    This paper provides support for the concept of geomorphic process domains developed by Montgomery (1999) by linking geomorphic processes to ecological variations seen in the Pima arid granitic watershed of the Sonoran Desert, Phoenix, Arizona. Closer joint spacing shows a statistically significant correlation with lower percentages of mineral grain attachment as measured by digital image processing of backscattered electron microscope imagery. Lower mineral grain attachment leads to more frequent spalling of rock surfaces, as measured by varnish microlamination (VML) ages of the last spalling event. In contrast, more distant joint spacing leads to in situ 10Be erosion rates of 3.4-8.5 mm/ka and the emergence of low domes and kopje granitic landforms; these low domes also serve as knickpoints along ephemeral washes. Distant jointing thus plays a key role in generating the bare bedrock surfaces that funnel limited precipitation to bedrock margins - enhancing the canopy cover of perennial plants next to the bare bedrock. Joint-influenced geomorphic processes at Pima Wash generate four distinct process domains: (PD1) armored drainage divides; (PD2) slopes with different granite landforms; (PD3) mid- and upper basin channels that mix knickzones, strath floodplains, and sandy alluvial sections; and (PD4) the main ephemeral channel transitioning to the piedmont. Distant jointing promotes bedrock exposure and rock armoring along drainage divides in PD1 that then concentrates runoff and promotes perennial plant growth. More distant joint spacing on slopes in PD2 promotes exposure of granitic bedrock forms that shed overland flow to their margin and promotes flora and fauna growths along the margins of low granitic domes and kopjes. Similarly, wider joint spacing along ephemeral washes in PD3 leads to knickpoints, which in turn act to concentrate moisture immediately downstream. The stream terraces in PD4 influence the ecology through xeric desert pavements on terrace treads

  3. Near-census Delineation of Laterally Organized Geomorphic Zones and Associated Sub-width Fluvial Landforms

    Science.gov (United States)

    Pasternack, G. B.; Hopkins, C.

    2017-12-01

    A river channel and its associated riparian corridor exhibit a pattern of nested, geomorphically imprinted, lateral inundation zones (IZs). Each zone plays a key role in fluvial geomorphic processes and ecological functions. Within each zone, distinct landforms (aka geomorphic or morphological units, MUs) reside at the 0.1-10 channel width scale. These features are basic units linking river corridor morphology with local ecosystem services. Objective, automated delineation of nested inundation zones and morphological units remains a significant scientific challenge. This study describes and demonstrates new, objective methods for solving this problem, using the 35-km alluvial lower Yuba River as a testbed. A detrended, high-resolution digital elevation model constructed from near-census topographic and bathymetric data was produced and used in a hypsograph analysis, a commonly used method in oceanographic studies capable of identifying slope breaks at IZ transitions. Geomorphic interpretation mindful of the river's setting was required to properly describe each IZ identified by the hypsograph analysis. Then, a 2D hydrodynamic model was used to determine what flow yields the wetted area that most closely matches each IZ domain. The model also provided meter-scale rasters of depth and velocity useful for MU mapping. Even though MUs are discharge-independent landforms, they can be revealed by analyzing their overlying hydraulics at low flows. Baseflow depth and velocity rasters are used along with a hydraulic landform classification system to quantitatively delineate in-channel bed MU types. In-channel bar and off-channel flood and valley MUs are delineated using a combination of hydraulic and geomorphic indicators, such as depth and velocity rasters for different discharges, topographic contours, NAIP imagery, and a raster of vegetation. The ability to objectively delineate inundation zones and morphological units in tandem allows for better informed river management

  4. Increased vulnerability to wildfires and post fire hydro-geomorphic processes in Portuguese mountain regions: what has changed?

    Directory of Open Access Journals (Sweden)

    Nunes A. N.

    2017-02-01

    Full Text Available The main objectives of this study were to understand the frequency of forest fires, post-fire off-site hydrological response and erosional processes from a social and ecological perspective in two basins located in the central cordillera, Portugal. It also discusses the driving forces that contribute towards increasing the social-ecological vulnerability of systems in the face of hazards and emphasizes the importance of learning from disasters. Based on the historical incidence of wildfires, it is possible to identify several areas affected by two, three or four fires, since 1975. Following the two major fires, in 1987 and 2005, flash floods, intense soil erosion and sedimentation processes were generated, causing severe damage. Significant socioeconomic, political and ecological changes have been affecting mountain regions in the last decades. Approximately 80% of the population and more than 90% of the livestock have disappeared, common lands have been afforested with Pinus pinaster, and several agricultural plots have been abandoned. These factors have all contributed towards creating non- or submanaged landscapes that have led to a dramatic increase in the magnitude and frequency of wildfires and to post-fire hydrological and erosional processes when heavy rainfall occurs. Moreover, the low population density, high level of population ageing and very fire-prone vegetation that now covers large areas of both basins, contribute to a situation of extreme socio-ecological vulnerability, meaning that disasters will continue to occur unless resilience can be restored to improve the capacity to cope with this high susceptibility to hazards.

  5. What do you mean, 'resilient geomorphic systems'?

    Science.gov (United States)

    Thoms, M. C.; Piégay, H.; Parsons, M.

    2018-03-01

    Resilience thinking has many parallels in the study of geomorphology. Similarities and intersections exist between the scientific discipline of geomorphology and the scientific concept of resilience. Many of the core themes fundamental to geomorphology are closely related to the key themes of resilience. Applications of resilience thinking in the study of natural and human systems have expanded, based on the fundamental premise that ecosystems, economies, and societies must be managed as linked social-ecological systems. Despite geomorphology and resilience sharing core themes, appreciation is limited of the history and development of geomorphology as a field of scientific endeavor by many in the field of resilience, as well as a limited awareness of the foundations of the former in the more recent emergence of resilience. This potentially limits applications of resilience concepts to the study of geomorphology. In this manuscript we provide a collective examination of geomorphology and resilience as a means to conceptually advance both areas of study, as well as to further cement the relevance and importance of not only understanding the complexities of geomorphic systems in an emerging world of interdisciplinary challenges but also the importance of viewing humans as an intrinsic component of geomorphic systems rather than just an external driver. The application of the concepts of hierarchy and scale, fundamental tenets of the study of geomorphic systems, provide a means to overcome contemporary scale-limited approaches within resilience studies. Resilience offers a framework for geomorphology to expand its application into the broader social-ecological domain.

  6. From scenarios to domain models: processes and representations

    Science.gov (United States)

    Haddock, Gail; Harbison, Karan

    1994-03-01

    The domain specific software architectures (DSSA) community has defined a philosophy for the development of complex systems. This philosophy improves productivity and efficiency by increasing the user's role in the definition of requirements, increasing the systems engineer's role in the reuse of components, and decreasing the software engineer's role to the development of new components and component modifications only. The scenario-based engineering process (SEP), the first instantiation of the DSSA philosophy, has been adopted by the next generation controller project. It is also the chosen methodology of the trauma care information management system project, and the surrogate semi-autonomous vehicle project. SEP uses scenarios from the user to create domain models and define the system's requirements. Domain knowledge is obtained from a variety of sources including experts, documents, and videos. This knowledge is analyzed using three techniques: scenario analysis, task analysis, and object-oriented analysis. Scenario analysis results in formal representations of selected scenarios. Task analysis of the scenario representations results in descriptions of tasks necessary for object-oriented analysis and also subtasks necessary for functional system analysis. Object-oriented analysis of task descriptions produces domain models and system requirements. This paper examines the representations that support the DSSA philosophy, including reference requirements, reference architectures, and domain models. The processes used to create and use the representations are explained through use of the scenario-based engineering process. Selected examples are taken from the next generation controller project.

  7. Geomorphic control on the δ15N of mountain forests.

    OpenAIRE

    Hilton, R. G.; Galy, A.; West, A. J.; Hovius, N.; Roberts, G.G.

    2013-01-01

    Mountain forests are subject to high rates of physical erosion which can export particulate nitrogen from ecosystems. However, the impact of geomorphic processes on nitrogen budgets remains poorly constrained. We have used the elemental and isotopic composition of soil and plant organic matter to investigate nitrogen cycling in the mountain forest of Taiwan, from 24 sites with distinct geomorphic (topographic slope) and climatic (precipitation, temperature) characteristics. The organic carbon...

  8. Tree ring-based chronology of hydro-geomorphic processes as a fundament for identification of hydro-meteorological triggers in the Hrubý Jeseník Mountains (Central Europe).

    Science.gov (United States)

    Tichavský, Radek; Šilhán, Karel; Tolasz, Radim

    2017-02-01

    Hydro-geomorphic processes have significantly influenced the recent development of valley floors, river banks and depositional forms in mountain environments, have caused considerable damage to manmade developments and have disrupted forest management. Trees growing along streams are affected by the transported debris mass and provide valuable records of debris flow/flood histories in their tree-ring series. Dendrogeomorphic approaches are currently the most accurate methods for creating a chronology of the debris flow/flood events in forested catchments without any field-monitoring or a stream-gauging station. Comprehensive studies focusing on the detailed chronology of hydro-geomorphic events and analysis of meteorological triggers and weather circulation patterns are still lacking for the studied area. We provide a spatio-temporal reconstruction of hydro-geomorphic events in four catchments of the Hrubý Jeseník Mountains, Czech Republic, with an analysis of their triggering factors using meteorological data from four nearby rain gauges. Increment cores from 794 coniferous trees (Picea abies [L.] Karst.) allowed the identification of 40 hydro-geomorphic events during the period of 1889-2013. Most of the events can be explained by extreme daily rainfalls (≥50mm) occurring in at least one rain gauge. However, in several cases, there was no record of extreme precipitation at rain gauges during the debris flow/flood event year, suggesting extremely localised rainstorms at the mountain summits. We concluded that the localisation, intensity and duration of rainstorms; antecedent moisture conditions; and amount of available sediments all influenced the initiation, spatial distribution and characteristics of hydro-geomorphic events. The most frequent synoptic situations responsible for the extreme rainfalls (1946-2015) were related to the meridional atmospheric circulation pattern. Our results enhance current knowledge of the occurrences and triggers of debris flows

  9. Description of chronostratigraphic units preserved as channel deposits and geomorphic processes following a basin-scale disturbance by a wildfire in Colorado

    Science.gov (United States)

    Moody, John A.; Martin, Deborah A.

    2017-10-11

    The consequence of a 1996 wildfire disturbance and a subsequent high-intensity summer convective rain storm (about 110 millimeters per hour) was the deposition of a sediment superslug in the Spring Creek basin (26.8 square kilometers) of the Front Range Mountains in Colorado. Spring Creek is a tributary to the South Platte River upstream from Strontia Springs Reservoir, which supplies domestic water for the cities of Denver and Aurora. Changes in a superslug were monitored over the course of 18 years (1996–2014) by repeat surveys at 18 channel cross sections spaced at nearly equal intervals along a 1,500-meter study reach and by a time series of photographs of each cross section. Surveys were not repeated at regular time intervals but after major changes caused by different geomorphic processes. The focus of this long-term study was to understand the evolution and internal alluvial architecture of chronostratigraphic units (defined as the volume of sediment deposited between two successive surveys), and the preservation or storage of these units in the superslug. The data are presented as a series of 18 narratives (one for each cross section) that summarize the changes, illustrate these changes with photographs, and provide a preservation plot showing the amount of each chronostratigraphic unit still remaining in June 2014.The most significant hydrologic change after the wildfire was an exponential decrease in peak discharge of flash floods caused by summer convective rain storms. In response to these hydrologic changes, all 18 locations went through an aggradation phase, an incision phase, and finally a stabilization phase. However, the architecture of the chronostratigraphic units differs from cross section to cross section, and units are characterized by either a laminar, fragmented, or hybrid alluvial architecture. In response to the decrease in peak-flood discharge and the increase in hillslope and riparian vegetation, Spring Creek abandoned many of the

  10. Soils Developed on Geomorphic Surfaces in the Mountain Region of the State of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Ademir Fontana

    2018-01-01

    Full Text Available ABSTRACT: The evaluation of soils in representative landscapes constitutes an opportunity to evaluate spatial distribution, discuss formation processes, and apply this knowledge to land use and management. In this sense, from the perspective of an environmentally diversified region, the aim of the present study is to evaluate the occurrence and understand the formation of soils in different geomorphic surfaces of a landscape from a mountain region in the state of Rio de Janeiro. The study was developed in the Pito Aceso microbasin in the municipality of Bom Jardim, composed of narrow valleys and a rugged mountain domain, with elevation between 640 and 1,270 m. In a representative landscape, the geomorphic surfaces were obtained from the slope segments and flow lines. On the geomorphic surfaces, soil profiles were described by their morphological properties, collected, and analyzed to describe the chemical and physical properties of each horizon. Geomorphological aspects and possible variations of the parent material directly affected pedogenesis and led to distinct soil classes in the landscape. Variation in the geomorphic surfaces directs the processes for soil formation under current conditions, as well as the preservation of polygenetic soils. Soils of lower development and with greater participation of the exchangeable cations were identified at the summit (talus deposit (Neossolo Litólico and Cambissolo Húmico and toeslope (colluvial-alluvial (Neossolo Flúvico, whereas more developed soils with lower nutrient content occur in the concave (Argissolos Vermelho and Amarelo and convex (Latossolo Amarelo backslope, except for the Argissolo Vermelho-Amarelo in the shoulder, which had high exchangeable cations contents.

  11. The Logic Process Formalism of the Informational Domain

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The performance of present-day informational technologies has two main properties: the universality of the structures used and the flexibility of the final user's interfaces. The first determines the potential cover area of the informational domain. The second determines the diversity and efficiency of processing methods of the proceedings being automated. The mentioned aspects are of great importance in agriculture and ecology because there are complex processes and considerable volumes of used information. For example, the meteoro-logical processes are a part of the ecological one like habitats' existential conditions and are known as a complex prognostic problem. The latter needs considerable computational resources to solve the appropriate equations. Likewise, agriculture as a controlled activity under strong impact from natural conditions has the same high requirements for diverse structures and flexibility of information processing.

  12. How does processing affect storage in working memory tasks? Evidence for both domain-general and domain-specific effects.

    Science.gov (United States)

    Jarrold, Christopher; Tam, Helen; Baddeley, Alan D; Harvey, Caroline E

    2011-05-01

    Two studies that examine whether the forgetting caused by the processing demands of working memory tasks is domain-general or domain-specific are presented. In each, separate groups of adult participants were asked to carry out either verbal or nonverbal operations on exactly the same processing materials while maintaining verbal storage items. The imposition of verbal processing tended to produce greater forgetting even though verbal processing operations took no longer to complete than did nonverbal processing operations. However, nonverbal processing did cause forgetting relative to baseline control conditions, and evidence from the timing of individuals' processing responses suggests that individuals in both processing groups slowed their responses in order to "refresh" the memoranda. Taken together the data suggest that processing has a domain-general effect on working memory performance by impeding refreshment of memoranda but can also cause effects that appear domain-specific and that result from either blocking of rehearsal or interference.

  13. How Does Processing Affect Storage in Working Memory Tasks? Evidence for Both Domain-General and Domain-Specific Effects

    Science.gov (United States)

    Jarrold, Christopher; Tam, Helen; Baddeley, Alan D.; Harvey, Caroline E.

    2011-01-01

    Two studies that examine whether the forgetting caused by the processing demands of working memory tasks is domain-general or domain-specific are presented. In each, separate groups of adult participants were asked to carry out either verbal or nonverbal operations on exactly the same processing materials while maintaining verbal storage items.…

  14. Efficient processing of MPEG-21 metadata in the binary domain

    Science.gov (United States)

    Timmerer, Christian; Frank, Thomas; Hellwagner, Hermann; Heuer, Jörg; Hutter, Andreas

    2005-10-01

    XML-based metadata is widely adopted across the different communities and plenty of commercial and open source tools for processing and transforming are available on the market. However, all of these tools have one thing in common: they operate on plain text encoded metadata which may become a burden in constrained and streaming environments, i.e., when metadata needs to be processed together with multimedia content on the fly. In this paper we present an efficient approach for transforming such kind of metadata which are encoded using MPEG's Binary Format for Metadata (BiM) without additional en-/decoding overheads, i.e., within the binary domain. Therefore, we have developed an event-based push parser for BiM encoded metadata which transforms the metadata by a limited set of processing instructions - based on traditional XML transformation techniques - operating on bit patterns instead of cost-intensive string comparisons.

  15. Simplifying Scalable Graph Processing with a Domain-Specific Language

    KAUST Repository

    Hong, Sungpack; Salihoglu, Semih; Widom, Jennifer; Olukotun, Kunle

    2014-01-01

    Large-scale graph processing, with its massive data sets, requires distributed processing. However, conventional frameworks for distributed graph processing, such as Pregel, use non-traditional programming models that are well-suited for parallelism and scalability but inconvenient for implementing non-trivial graph algorithms. In this paper, we use Green-Marl, a Domain-Specific Language for graph analysis, to intuitively describe graph algorithms and extend its compiler to generate equivalent Pregel implementations. Using the semantic information captured by Green-Marl, the compiler applies a set of transformation rules that convert imperative graph algorithms into Pregel's programming model. Our experiments show that the Pregel programs generated by the Green-Marl compiler perform similarly to manually coded Pregel implementations of the same algorithms. The compiler is even able to generate a Pregel implementation of a complicated graph algorithm for which a manual Pregel implementation is very challenging.

  16. Simplifying Scalable Graph Processing with a Domain-Specific Language

    KAUST Repository

    Hong, Sungpack

    2014-01-01

    Large-scale graph processing, with its massive data sets, requires distributed processing. However, conventional frameworks for distributed graph processing, such as Pregel, use non-traditional programming models that are well-suited for parallelism and scalability but inconvenient for implementing non-trivial graph algorithms. In this paper, we use Green-Marl, a Domain-Specific Language for graph analysis, to intuitively describe graph algorithms and extend its compiler to generate equivalent Pregel implementations. Using the semantic information captured by Green-Marl, the compiler applies a set of transformation rules that convert imperative graph algorithms into Pregel\\'s programming model. Our experiments show that the Pregel programs generated by the Green-Marl compiler perform similarly to manually coded Pregel implementations of the same algorithms. The compiler is even able to generate a Pregel implementation of a complicated graph algorithm for which a manual Pregel implementation is very challenging.

  17. Domain Endurants: An Analysis and Description Process Model

    DEFF Research Database (Denmark)

    Bjørner, Dines

    2014-01-01

    We present a summary, Sect. 2, of a structure of domain analysis and description concepts: techniques and tools. And we link, in Sect. 3, these concepts, embodied in domain analysis prompts and domain description prompts, in a model of how a diligent domain analyser cum describer would use them. We...

  18. Social-ecological resilience and geomorphic systems

    Science.gov (United States)

    Chaffin, Brian C.; Scown, Murray

    2018-03-01

    Governance of coupled social-ecological systems (SESs) and the underlying geomorphic processes that structure and alter Earth's surface is a key challenge for global sustainability amid the increasing uncertainty and change that defines the Anthropocene. Social-ecological resilience as a concept of scientific inquiry has contributed to new understandings of the dynamics of change in SESs, increasing our ability to contextualize and implement governance in these systems. Often, however, the importance of geomorphic change and geomorphological knowledge is somewhat missing from processes employed to inform SES governance. In this contribution, we argue that geomorphology and social-ecological resilience research should be integrated to improve governance toward sustainability. We first provide definitions of engineering, ecological, community, and social-ecological resilience and then explore the use of these concepts within and alongside geomorphology in the literature. While ecological studies often consider geomorphology as an important factor influencing the resilience of ecosystems and geomorphological studies often consider the engineering resilience of geomorphic systems of interest, very few studies define and employ a social-ecological resilience framing and explicitly link the concept to geomorphic systems. We present five key concepts-scale, feedbacks, state or regime, thresholds and regime shifts, and humans as part of the system-which we believe can help explicitly link important aspects of social-ecological resilience inquiry and geomorphological inquiry in order to strengthen the impact of both lines of research. Finally, we discuss how these five concepts might be used to integrate social-ecological resilience and geomorphology to better understand change in, and inform governance of, SESs. To compound these dynamics of resilience, complex systems are nested and cross-scale interactions from smaller and larger scales relative to the system of interest

  19. Eco-geomorphic controls on slope stability

    Science.gov (United States)

    Hales, T.; Ford, C.; Hwang, T.; Vose, J.; Band, L.

    2009-04-01

    Vegetation controls soil-mantled landscape evolution primarily through growth of roots into soil and rock. Root-soil interactions affect the spatial distribution and rate of shallow landsliding and other hillslope processes. Yet the distribution and tensile strength of roots depends on a number of geomorphically-influenced parameters, including soil moisture. Our field-based study investigated the effects of topography on root distributions, tensile strengths, and cohesion. Systematic differences in plant species distribution and soil properties are found in the hollow-nose topography of soil-mantled landscapes; with hollows containing thick colluvial soils and mesic tree species and noses containing thinner, more differentiated soils and more xeric species. We investigated whether these topographic variations in geomorphic and ecologic properties affected the spatial distribution of root cohesion by measuring the distribution and tensile strength of roots from soil pits dug downslope of fifteen individual trees in the Coweeta Hydrologic Laboratory, North Carolina. Our soil pits were located to capture variance in plant species (10 species total), topographic positions (nose, hollow), and sizes (a range of DBH between 5 cm and 60 cm). Root tensile strengths showed little variance with different species, but showed strong differences as a function of topography, with nose roots stronger than hollow roots. Similarly, within species, root cellulose content was systematically greater in trees on nose positions compared to those in hollows. For all species, roots were concentrated close to the soil surface (at least 70% of biomass occurred within 50 cm of the surface) and variations in this pattern were primarily a function of topographic position. Hollow roots were more evenly distributed in the soil column than those on noses, yet trees located on noses had higher mean root cohesion than those in hollows because of a higher root tensile force. These data provide an

  20. A domain-independent descriptive design model and its application to structured reflection on design processes

    NARCIS (Netherlands)

    Reymen, Isabelle; Hammer, D.K.; Kroes, P.A.; van Aken, Joan Ernst; van Aken, J.E.; Dorst, C.H.; Bax, M.F.T.; Basten, T

    2006-01-01

    Domain-independent models of the design process are an important means for facilitating interdisciplinary communication and for supporting multidisciplinary design. Many so-called domain-independent models are, however, not really domain independent. We state that to be domain independent, the

  1. Human geomorphic footprint and global geomorphic change: implications for hydrogeomorphic hazards

    Science.gov (United States)

    Remondo, Juan

    2010-05-01

    The human geomorphic footprint (HGF), expressed as the area affected by the construction of new 'anthropogeoforms' or the volume of geologic materials directly or indirectly displaced by human action has grown considerably in the last decades. Available data suggest that the present HGF is roughly 50,000 km2 a-1 of new anthropogeoforms and 300 x109 t a-1 of solid materials transferred from one part of the earth's surface to another. The latter represents a 'technological denudation' that could be 1-2 orders of magnitude greater than denudation by natural agents or sediment transport by the world's rivers. This implies a profound modification of geomorphic processes that produces a series of often disregarded environmental consequences. Some of those can by directly linked to excavation/accumulation activities and are essentially local, but in other cases the possible relationship appears to be more indirect and could have a widespread character. The transformation of land surface by human action is shown not only by landform construction and transfer of geologic materials, but also by land-use change in general and modification of the characteristics of the surface layer. This seems to affect both the hydrologic response and the sensitivity of that surface layer to different geomorphic agents. The magnitude of the above mentioned modification is logically related to the intensity of human activities, themselves related to the number of people on the planet and their economic and technological capabilities, which grow practically in all regions of the planet. It is thus reasonable to expect that the HGF and its effects should grow with time. If this were so, we should expect to find evidences of a general acceleration of geomorphic processes in the world that could represent a 'global geomorphic change'. The final expression of geomorphic processes, which could be used to test that hypothesis, is sediment generation and deposition. Data are presented on

  2. Microbial Biomass and Activity in Geomorphic Features in Forested and Urban Restored and Degraded Streams

    Science.gov (United States)

    Geomorphic spatial heterogeneity affects sediment denitrification, an anaerobic microbial process that results in the loss of nitrogen (N), and other anaerobic microbial processes such as methanogenesis in urban streams. We measured sediment denitrification potential (DEA), metha...

  3. Geomorphic consequences of volcanic eruptions in Alaska: A review

    Science.gov (United States)

    Waythomas, Christopher F.

    2015-01-01

    Eruptions of Alaska volcanoes have significant and sometimes profound geomorphic consequences on surrounding landscapes and ecosystems. The effects of eruptions on the landscape can range from complete burial of surface vegetation and preexisting topography to subtle, short-term perturbations of geomorphic and ecological systems. In some cases, an eruption will allow for new landscapes to form in response to the accumulation and erosion of recently deposited volcaniclastic material. In other cases, the geomorphic response to a major eruptive event may set in motion a series of landscape changes that could take centuries to millennia to be realized. The effects of volcanic eruptions on the landscape and how these effects influence surface processes has not been a specific focus of most studies concerned with the physical volcanology of Alaska volcanoes. Thus, what is needed is a review of eruptive activity in Alaska in the context of how this activity influences the geomorphology of affected areas. To illustrate the relationship between geomorphology and volcanic activity in Alaska, several eruptions and their geomorphic impacts will be reviewed. These eruptions include the 1912 Novarupta–Katmai eruption, the 1989–1990 and 2009 eruptions of Redoubt volcano, the 2008 eruption of Kasatochi volcano, and the recent historical eruptions of Pavlof volcano. The geomorphic consequences of eruptive activity associated with these eruptions are described, and where possible, information about surface processes, rates of landscape change, and the temporal and spatial scale of impacts are discussed.A common feature of volcanoes in Alaska is their extensive cover of glacier ice, seasonal snow, or both. As a result, the generation of meltwater and a variety of sediment–water mass flows, including debris-flow lahars, hyperconcentrated-flow lahars, and sediment-laden water floods, are typical outcomes of most types of eruptive activity. Occasionally, such flows can be quite

  4. Quantifying the Geomorphic Dynamics of the Extensively Impacted Lower Yuba River

    Science.gov (United States)

    Wyrick, J. R.; Pasternack, G. B.; Carley, J. K.; Barker, R.; Massa, D.; Bratovich, P.; Reedy, G.; Johnson, T.

    2010-12-01

    Traditionally it is has been thought that rivers possess the capability of adjusting their attributes to accommodate varying flow and sediment transport regimes so that sediment in- and out-fluxes are balanced and landform conditions are “stable”. In reality, however, geomorphic drivers and boundary conditions are much more independently dynamic than classically envisioned, such that landforms may always be in a state of adjustment that is normal and appropriate. Rather than thinking of landforms as stable, it is more appropriate to think of them, and the ecosystem services with which they are associated, as resilient in response to change. Knowledge of historic, pre-human baseline conditions or regional reference conditions is limited and may not be as applicable in understanding natural geomorphic and ecosystem services as once envisioned. In light of this natural complexity, a geomorphic assessment of conditions after a large dam or other facility is built and operated may not be as simple as documenting geomorphic instability and attributing that to human impacts relative to the presumed stable baseline conditions. Rather than compare anthropogenically-impacted conditions to theoretical baseline or reference conditions, a more effective approach is to deduce the geomorphic processes in a system under different regimes and evaluate the implications for resiliency of ecosystem services. Through a mechanistic understanding of environmental systems, it may be possible to rationally rehabilitate an ecosystem to achieve resiliency in cases where it has been lost or is desirable to instill, even if it was not historically present. This analytic paradigm is being used to assess the history and on-going geomorphic dynamism of the lower Yuba River (LYR) in northern California. Despite a legacy of massive hydraulic mining waste deposition, dredger re-working of the river valley, dam construction, and flow regulation, the river has been described as lacking the

  5. Finding Commonalities: Social Information Processing and Domain Theory in the Study of Aggression

    Science.gov (United States)

    Nucci, Larry

    2004-01-01

    The Arsenio and Lemerise (this issue) proposal integrating social information processing (SIP) and domain theory to study children's aggression is evaluated from a domain theory perspective. Basic tenets of domain theory rendering it compatible with SIP are discussed as well as points of divergence. Focus is directed to the proposition that…

  6. Grays River Watershed Geomorphic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Geist, David R

    2005-04-30

    This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

  7. Geomorphic observations from southwestern terminus of Palghat ...

    Indian Academy of Sciences (India)

    4National Centre for Earth Science Studies, Thiruvananthapuram, Kerala 695 031, India. ∗ .... Geomorphic observations from SW terminus of Palghat Gap, south India. 823. Figure. 2. ... tical point of view to determine an average state.

  8. Improving the process of process modelling by the use of domain process patterns

    NARCIS (Netherlands)

    Koschmider, A.; Reijers, H.A.

    2015-01-01

    The use of business process models has become prevalent in a wide area of enterprise applications. But while their popularity is expanding, concerns are growing with respect to their proper creation and maintenance. An obvious way to boost the efficiency of creating high-quality business process

  9. Neural responses to ambiguity involve domain-general and domain-specific emotion processing systems.

    Science.gov (United States)

    Neta, Maital; Kelley, William M; Whalen, Paul J

    2013-04-01

    Extant research has examined the process of decision making under uncertainty, specifically in situations of ambiguity. However, much of this work has been conducted in the context of semantic and low-level visual processing. An open question is whether ambiguity in social signals (e.g., emotional facial expressions) is processed similarly or whether a unique set of processors come on-line to resolve ambiguity in a social context. Our work has examined ambiguity using surprised facial expressions, as they have predicted both positive and negative outcomes in the past. Specifically, whereas some people tended to interpret surprise as negatively valenced, others tended toward a more positive interpretation. Here, we examined neural responses to social ambiguity using faces (surprise) and nonface emotional scenes (International Affective Picture System). Moreover, we examined whether these effects are specific to ambiguity resolution (i.e., judgments about the ambiguity) or whether similar effects would be demonstrated for incidental judgments (e.g., nonvalence judgments about ambiguously valenced stimuli). We found that a distinct task control (i.e., cingulo-opercular) network was more active when resolving ambiguity. We also found that activity in the ventral amygdala was greater to faces and scenes that were rated explicitly along the dimension of valence, consistent with findings that the ventral amygdala tracks valence. Taken together, there is a complex neural architecture that supports decision making in the presence of ambiguity: (a) a core set of cortical structures engaged for explicit ambiguity processing across stimulus boundaries and (b) other dedicated circuits for biologically relevant learning situations involving faces.

  10. Capturing and Modeling Domain Knowledge Using Natural Language Processing Techniques

    National Research Council Canada - National Science Library

    Auger, Alain

    2005-01-01

    .... Initiated in 2004 at Defense Research and Development Canada (DRDC), the SACOT knowledge engineering research project is currently investigating, developing and validating innovative natural language processing (NLP...

  11. Why Process is Extrinsic to the Digital Domain

    DEFF Research Database (Denmark)

    Wilson, Alexander

    2014-01-01

    In this series of notes from 2014, first published on the Empyre list after being asked, "What is a digital process?" and edited down for this posting, it is argued that the digital is moved by exterior forces, that process is not inherent to it, and that the bits, pixels and voxels of the digital...

  12. Capturing and Modeling Domain Knowledge Using Natural Language Processing Techniques

    Science.gov (United States)

    2005-06-01

    Intelligence Artificielle , France, May 2001, p. 109- 118 [Barrière, 2001] -----. “Investigating the Causal Relation in Informative Texts”. Terminology, 7:2...out of the flood of information, military have to create new ways of processing sensor and intelligence information, and of providing the results to...have to create new ways of processing sensor and intelligence information, and of providing the results to commanders who must take timely operational

  13. Cognitive components of regularity processing in the auditory domain.

    Directory of Open Access Journals (Sweden)

    Stefan Koelsch

    Full Text Available BACKGROUND: Music-syntactic irregularities often co-occur with the processing of physical irregularities. In this study we constructed chord-sequences such that perceived differences in the cognitive processing between regular and irregular chords could not be due to the sensory processing of acoustic factors like pitch repetition or pitch commonality (the major component of 'sensory dissonance'. METHODOLOGY/PRINCIPAL FINDINGS: Two groups of subjects (musicians and nonmusicians were investigated with electroencephalography (EEG. Irregular chords elicited an early right anterior negativity (ERAN in the event-related brain potentials (ERPs. The ERAN had a latency of around 180 ms after the onset of the music-syntactically irregular chords, and had maximum amplitude values over right anterior electrode sites. CONCLUSIONS/SIGNIFICANCE: Because irregular chords were hardly detectable based on acoustical factors (such as pitch repetition and sensory dissonance, this ERAN effect reflects for the most part cognitive (not sensory components of regularity-based, music-syntactic processing. Our study represents a methodological advance compared to previous ERP-studies investigating the neural processing of music-syntactically irregular chords.

  14. Textual and chemical information processing: different domains but similar algorithms

    Directory of Open Access Journals (Sweden)

    Peter Willett

    2000-01-01

    Full Text Available This paper discusses the extent to which algorithms developed for the processing of textual databases are also applicable to the processing of chemical structure databases, and vice versa. Applications discussed include: an algorithm for distribution sorting that has been applied to the design of screening systems for rapid chemical substructure searching; the use of measures of inter-molecular structural similarity for the analysis of hypertext graphs; a genetic algorithm for calculating term weights for relevance feedback searching for determining whether a molecule is likely to exhibit biological activity; and the use of data fusion to combine the results of different chemical similarity searches.

  15. A conceptual connectivity framework for understanding geomorphic change in human-impacted fluvial systems

    Science.gov (United States)

    Pöppl, Ronald; Keesstra, Saskia; Maroulis, Jerry

    2017-04-01

    Human-induced landscape change is difficult to predict due to the complexity inherent in both geomorphic and social systems as well as due to emerging coupling relationships between them. To better understand system complexity and system response to change, connectivity has become an important research paradigm within various disciplines including geomorphology, hydrology and ecology. With the proposed conceptual connectivity framework on geomorphic change in human-impacted fluvial systems a cautionary note is flagged regarding the need (i) to include and to systematically conceptualise the role of different types of human agency in altering connectivity relationships in geomorphic systems and (ii) to integrate notions of human-environment interactions to connectivity concepts in geomorphology to better explain causes and trajectories of landscape change. Underpinned by case study examples, the presented conceptual framework is able to explain how geomorphic response of fluvial systems to human disturbance is determined by system-specific boundary conditions (incl. system history, related legacy effects and lag times), vegetation dynamics and human-induced functional relationships (i.e. feedback mechanisms) between the different spatial dimensions of connectivity. It is further demonstrated how changes in social systems can trigger a process-response feedback loop between social and geomorphic systems that further governs the trajectory of landscape change in coupled human-geomorphic systems.

  16. Geomorphic status of regulated rivers in the Iberian Peninsula.

    Science.gov (United States)

    Lobera, G; Besné, P; Vericat, D; López-Tarazón, J A; Tena, A; Aristi, I; Díez, J R; Ibisate, A; Larrañaga, A; Elosegi, A; Batalla, R J

    2015-03-01

    River regulation by dams modifies flow regimes, interrupts the transfer of sediment through channel networks, and alters downstream bed dynamics, altogether affecting channel form and processes. So far, most studies on the geomorphic impacts of dams are restricted to single rivers, or even single river stretches. In this paper we analyse the geomorphic status of 74 river sites distributed across four large basins in the Iberian Peninsula (i.e. 47 sites located downstream of dams). For this purpose, we combine field data with hydrological data available from water agencies, and analyse historical (1970) and current aerial photographs. In particular, we have developed a Geomorphic Status (GS) index that allows us to assess the physical structure of a given channel reach and its change through time. The GS encompasses a determination of changes in sedimentary units, sediment availability, bar stability and channel flow capacity. Sites are statistically grouped in four clusters based on contrasted physical and climate characteristics. Results emphasise that regulation changes river's flow regime with a generalized reduction of the magnitude and frequency of floods (thus flow competence). This, in addition to the decrease downstream sediment supply, results in the loss of active bars as they are encroached by vegetation, to the point that only reaches with little or no regulation maintain exposed sedimentary deposits. The GS of regulated river reaches is negatively correlated with magnitude of the impoundment (regulation). Heavily impacted reaches present channel stabilization and, in contrast to the hydrological response, the distance and number of tributaries do not reverse the geomorphic impact of the dams. Stabilization limits river dynamics and may contribute to the environmental degradation of the fluvial ecosystem. Overall, results describe the degree of geomorphological alteration experienced by representative Iberian rivers mostly because of regulation

  17. Utilizing Domain Knowledge in End-to-End Audio Processing

    DEFF Research Database (Denmark)

    Tax, Tycho; Antich, Jose Luis Diez; Purwins, Hendrik

    2017-01-01

    to learn the commonly-used log-scaled mel-spectrogram transformation. Secondly, we demonstrate that upon initializing the first layers of an end-to-end CNN classifier with the learned transformation, convergence and performance on the ESC-50 environmental sound classification dataset are similar to a CNN......-based model trained on the highly pre-processed log-scaled mel-spectrogram features....

  18. Process Algebra Approach for Action Recognition in the Maritime Domain

    Science.gov (United States)

    Huntsberger, Terry

    2011-01-01

    The maritime environment poses a number of challenges for autonomous operation of surface boats. Among these challenges are the highly dynamic nature of the environment, the onboard sensing and reasoning requirements for obeying the navigational rules of the road, and the need for robust day/night hazard detection and avoidance. Development of full mission level autonomy entails addressing these challenges, coupled with inference of the tactical and strategic intent of possibly adversarial vehicles in the surrounding environment. This paper introduces PACIFIC (Process Algebra Capture of Intent From Information Content), an onboard system based on formal process algebras that is capable of extracting actions/activities from sensory inputs and reasoning within a mission context to ensure proper responses. PACIFIC is part of the Behavior Engine in CARACaS (Cognitive Architecture for Robotic Agent Command and Sensing), a system that is currently running on a number of U.S. Navy unmanned surface and underwater vehicles. Results from a series of experimental studies that demonstrate the effectiveness of the system are also presented.

  19. The interaction of process and domain in prefrontal cortex during inductive reasoning.

    Science.gov (United States)

    Babcock, Laura; Vallesi, Antonino

    2015-01-01

    Inductive reasoning is an everyday process that allows us to make sense of the world by creating rules from a series of instances. Consistent with accounts of process-based fractionations of the prefrontal cortex (PFC) along the left-right axis, inductive reasoning has been reliably localized to left PFC. However, these results may be confounded by the task domain, which is typically verbal. Indeed, some studies show that right PFC activation is seen with spatial tasks. This study used fMRI to examine the effects of process and domain on the brain regions recruited during a novel pattern discovery task. Twenty healthy young adult participants were asked to discover the rule underlying the presentation of a series of letters in varied spatial locations. The rules were either verbal (pertaining to a single semantic category) or spatial (geometric figures). Bilateral ventrolateral PFC activations were seen for the spatial domain, while the verbal domain showed only left ventrolateral PFC. A conjunction analysis revealed that the two domains recruited a common region of left ventrolateral PFC. The data support a central role of left PFC in inductive reasoning. Importantly, they also suggest that both process and domain shape the localization of reasoning in the brain. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Information Pre-Processing using Domain Meta-Ontology and Rule Learning System

    Science.gov (United States)

    Ranganathan, Girish R.; Biletskiy, Yevgen

    Around the globe, extraordinary amounts of documents are being created by Enterprises and by users outside these Enterprises. The documents created in the Enterprises constitute the main focus of the present chapter. These documents are used to perform numerous amounts of machine processing. While using thesedocuments for machine processing, lack of semantics of the information in these documents may cause misinterpretation of the information, thereby inhibiting the productiveness of computer assisted analytical work. Hence, it would be profitable to the Enterprises if they use well defined domain ontologies which will serve as rich source(s) of semantics for the information in the documents. These domain ontologies can be created manually, semi-automatically or fully automatically. The focus of this chapter is to propose an intermediate solution which will enable relatively easy creation of these domain ontologies. The process of extracting and capturing domain ontologies from these voluminous documents requires extensive involvement of domain experts and application of methods of ontology learning that are substantially labor intensive; therefore, some intermediate solutions which would assist in capturing domain ontologies must be developed. This chapter proposes a solution in this direction which involves building a meta-ontology that will serve as an intermediate information source for the main domain ontology. This chapter proposes a solution in this direction which involves building a meta-ontology as a rapid approach in conceptualizing a domain of interest from huge amount of source documents. This meta-ontology can be populated by ontological concepts, attributes and relations from documents, and then refined in order to form better domain ontology either through automatic ontology learning methods or some other relevant ontology building approach.

  1. Processes of fungal proteome evolution and gain of function: gene duplication and domain rearrangement

    International Nuclear Information System (INIS)

    Cohen-Gihon, Inbar; Nussinov, Ruth; Sharan, Roded

    2011-01-01

    During evolution, organisms have gained functional complexity mainly by modifying and improving existing functioning systems rather than creating new ones ab initio. Here we explore the interplay between two processes which during evolution have had major roles in the acquisition of new functions: gene duplication and protein domain rearrangements. We consider four possible evolutionary scenarios: gene families that have undergone none of these event types; only gene duplication; only domain rearrangement, or both events. We characterize each of the four evolutionary scenarios by functional attributes. Our analysis of ten fungal genomes indicates that at least for the fungi clade, species significantly appear to gain complexity by gene duplication accompanied by the expansion of existing domain architectures via rearrangements. We show that paralogs gaining new domain architectures via duplication tend to adopt new functions compared to paralogs that preserve their domain architectures. We conclude that evolution of protein families through gene duplication and domain rearrangement is correlated with their functional properties. We suggest that in general, new functions are acquired via the integration of gene duplication and domain rearrangements rather than each process acting independently

  2. Geomorphic Controls on Floodplain Soil Organic Carbon in the Yukon Flats, Interior Alaska, From Reach to River Basin Scales

    Science.gov (United States)

    Lininger, K. B.; Wohl, E.; Rose, J. R.

    2018-03-01

    Floodplains accumulate and store organic carbon (OC) and release OC to rivers, but studies of floodplain soil OC come from small rivers or small spatial extents on larger rivers in temperate latitudes. Warming climate is causing substantial change in geomorphic process and OC fluxes in high latitude rivers. We investigate geomorphic controls on floodplain soil OC concentrations in active-layer mineral sediment in the Yukon Flats, interior Alaska. We characterize OC along the Yukon River and four tributaries in relation to geomorphic controls at the river basin, segment, and reach scales. Average OC concentration within floodplain soil is 2.8% (median = 2.2%). Statistical analyses indicate that OC varies among river basins, among planform types along a river depending on the geomorphic unit, and among geomorphic units. OC decreases with sample depth, suggesting that most OC accumulates via autochthonous inputs from floodplain vegetation. Floodplain and river characteristics, such as grain size, soil moisture, planform, migration rate, and riverine DOC concentrations, likely influence differences among rivers. Grain size, soil moisture, and age of surface likely influence differences among geomorphic units. Mean OC concentrations vary more among geomorphic units (wetlands = 5.1% versus bars = 2.0%) than among study rivers (Dall River = 3.8% versus Teedrinjik River = 2.3%), suggesting that reach-scale geomorphic processes more strongly control the spatial distribution of OC than basin-scale processes. Investigating differences at the basin and reach scale is necessary to accurately assess the amount and distribution of floodplain soil OC, as well as the geomorphic controls on OC.

  3. Microstructure within domains of melt-processed YBa2Cu3O7-x superconductors

    International Nuclear Information System (INIS)

    Alexander, K.B.; Goyal, A.; Kroeger, D.M.; Selvamanickam, V.; Salama, K.

    1992-01-01

    The microstructure within single domains of melt-processed YBa 2 Cu 3 O 7-x (1:2:3) material has been examined. Rather than composing a ''brick-wall'' structure, the stacked, parallel platelets within the domains are actually portions of a single crystal. A growth mechanism is proposed that is consistent with the observed microstructural features. The anisotropic nature of the growth of 1:2:3 results in gaps separating the platelets. The gaps, however, terminate within domains, resulting in interconnected single-crystalline material. The absence of weak-link behavior for current flow along the c axis and the high critical-current densities observed within domains of melt-processed 1:2:3 material are readily explained by the fact that current flow is solely through single-crystalline material

  4. Hierarchical processing in the prefrontal cortex in a variety of cognitive domains

    Directory of Open Access Journals (Sweden)

    Hyeon-Ae eJeon

    2014-11-01

    Full Text Available This review scrutinizes several findings on human hierarchical processing within the prefrontal cortex (PFC in diverse cognitive domains. Converging evidence from previous studies has shown that the PFC, specifically Brodmann area (BA 44, may function as the essential region for hierarchical processing across the domains. In language fMRI studies, BA 44 was significantly activated for the hierarchical processing of center-embedded sentences and this pattern of activations was also observed in artificial grammar. The same pattern was observed in the visuo-spatial domain where BA44 was actively involved in the processing of hierarchy for the visual symbol. Musical syntax, which is the rule-based arrangement of musical sets, has also been construed as hierarchical processing as in the language domain such that the activation in BA44 was observed in a chord sequence paradigm. P600 ERP was also engendered during the processing of musical hierarchy. Along with a longstanding idea that a human’s number faculty is developed as a by-product of language faculty, BA44 was closely involved in hierarchical processing in mental arithmetic. This review extended its discussion of hierarchical processing to hierarchical behavior, that is, human action which has been referred to as being hierarchically composed. Several lesion and TMS studies supported the involvement of BA44 for hierarchical processing in the action domain. Lastly, the hierarchical organization of cognitive controls was discussed within the PFC, forming a cascade of top-down hierarchical processes operating along a posterior-to-anterior axis of the lateral PFC including BA44 within the network. It is proposed that PFC is actively involved in different forms of hierarchical processing and specifically BA44 may play an integral role in the process. Taking levels of proficiency and subcortical areas into consideration may provide further insight into the functional role of BA44 for hierarchical

  5. A single cognitive heuristic process meets the complexity of domain-specific moral heuristics.

    Science.gov (United States)

    Dubljević, Veljko; Racine, Eric

    2014-10-01

    The inherence heuristic (a) offers modest insights into the complex nature of both the is-ought tension in moral reasoning and moral reasoning per se, and (b) does not reflect the complexity of domain-specific moral heuristics. Formal and general in nature, we contextualize the process described as "inherence heuristic" in a web of domain-specific heuristics (e.g., agent specific; action specific; consequences specific).

  6. Organization Domain Modeling. Volume 1. Conceptual Foundations, Process and Workproduct Description

    Science.gov (United States)

    1993-07-31

    Analysis Companies must often analyze their software products or services relative to those of competitors in the marketplace to determine issues such as...J.A. Hess, W.E. Novak, and A.S. Peterson. Feature-Oriented Domain Analysis ( FODA ) Feasibility Study. Technical Report CMU/SEI-90-TR-21, Software...domain analysis (DA) and modeling, including a structured set of workproducts, a tailorable process model and a set of modeling techniques and guidelines

  7. Aggression and Moral Development: Integrating Social Information Processing and Moral Domain Models

    Science.gov (United States)

    Arsenio, William F.; Lemerise, Elizabeth A.

    2004-01-01

    Social information processing and moral domain theories have developed in relative isolation from each other despite their common focus on intentional harm and victimization, and mutual emphasis on social cognitive processes in explaining aggressive, morally relevant behaviors. This article presents a selective summary of these literatures with…

  8. Social Information-Processing Patterns of Maltreated Children in Two Social Domains

    Science.gov (United States)

    Keil, Vivien; Price, Joseph M.

    2009-01-01

    This study examined relations among social information-processing (SIP) variables in the domains of peer provocation and peer group entry. Using Crick and Dodge's [Crick, N. R., & Dodge, K. A. (1994). "A review and reformulation of social information-processing mechanisms in children's social adjustment." "Psychological Bulletin," 115, 74-101]…

  9. Bridging domains : a comparison between information processing in Archaea and Eukarya

    NARCIS (Netherlands)

    Koning, de B.

    2015-01-01

    Bridging Domains

    A Comparison between Information Processing in Archaea and Eukarya

    Studying Information Processing

    Living cells evolved complex systems to handle the flow of information both

  10. Crystal Structure of the HEAT Domain from the Pre-mRNA Processing Factor Symplekin

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Sarah A.; Frazier, Monica L.; Steiniger, Mindy; Mast, Ann M.; Marzluff, William F.; Redinbo, Matthew R.; (UNC)

    2010-09-30

    The majority of eukaryotic pre-mRNAs are processed by 3'-end cleavage and polyadenylation, although in metazoa the replication-dependent histone mRNAs are processed by 3'-end cleavage but not polyadenylation. The macromolecular complex responsible for processing both canonical and histone pre-mRNAs contains the {approx} 1160-residue protein Symplekin. Secondary-structural prediction algorithms identified putative HEAT domains in the 300 N-terminal residues of all Symplekins of known sequence. The structure and dynamics of this domain were investigated to begin elucidating the role Symplekin plays in mRNA maturation. The crystal structure of the Drosophila melanogaster Symplekin HEAT domain was determined to 2.4 {angstrom} resolution with single-wavelength anomalous dispersion phasing methods. The structure exhibits five canonical HEAT repeats along with an extended 31-amino-acid loop (loop 8) between the fourth and fifth repeat that is conserved within closely related Symplekin sequences. Molecular dynamics simulations of this domain show that the presence of loop 8 dampens correlated and anticorrelated motion in the HEAT domain, therefore providing a neutral surface for potential protein-protein interactions. HEAT domains are often employed for such macromolecular contacts. The Symplekin HEAT region not only structurally aligns with several established scaffolding proteins, but also has been reported to contact proteins essential for regulating 3'-end processing. Together, these data support the conclusion that the Symplekin HEAT domain serves as a scaffold for protein-protein interactions essential to the mRNA maturation process.

  11. Geomorphic reclmation of a coal refuse pile

    Science.gov (United States)

    Hopkinson, L. C.; Quaranta, J.

    2017-12-01

    Geomorphic reclamation is a technique that may offer opportunities to improve mine reclamation in Central Appalachia. The design approach is based on constructing a steady-state, mature landform condition and takes into account the long-term climatic conditions, soil types, terrain grade, and vegetation. Geomorphic reclamation has been applied successfully in semi-arid regions but has not yet been applied in Central Appalachia. This work describes a demonstration study where geomorphic landforming techniques are being applied to a coarse coal refuse pile in southern West Virginia, USA. The reclamation design includes four geomorphic watersheds that radially drain runoff from the pile. Each watershed has one central draining channel and incorporates compound slope profiles similarly to naturally eroded slopes. Planar slopes were also included to maintain the impacted area. The intent is to alter the hydrology to decrease water quality treatment costs. The excavation cut and fill volumes are comparable to those of more conventional refuse pile reclamation designs. If proven successful then this technique can be part of a cost-effective solution to improve water quality at active and future refuse facilities, abandoned mine lands, bond forfeiture sites, landfills, and major earthmoving activities within the region.

  12. Dynamics of ordering processes in annealed dilute systems: Island formation, vacancies at domain boundaries, and compactification

    DEFF Research Database (Denmark)

    Shah, Peter Jivan; Mouritsen, Ole G.

    1990-01-01

    The dynamics of the ordering processes in two-dimensional lattice models with annealed vacancies and nonconserved order parameter is studied as a function of temperature and vacancy concentration by means of Monte Carlo temperature-quenching simulations. The models are Ising antiferromagnets...... with couplings leading to twofold-degenerate as well as fourfold-degenerate ordering. The models are quenched into a phase-separation region, which makes it possible for both types of ordering to observe the following scenario of ordering processes: (i) early-time nucleation and growth of ordered domains, (ii......) intermediate-time trapping of the mobile vacancies at the domain boundaries, and (iii) late-time diffusion of vacancies along the domain-boundary network towards the surface. In the case of high dilution, the ordering processes correspond to early-time island formation and late-time coarsening...

  13. Parallel finite elements with domain decomposition and its pre-processing

    International Nuclear Information System (INIS)

    Yoshida, A.; Yagawa, G.; Hamada, S.

    1993-01-01

    This paper describes a parallel finite element analysis using a domain decomposition method, and the pre-processing for the parallel calculation. Computer simulations are about to replace experiments in various fields, and the scale of model to be simulated tends to be extremely large. On the other hand, computational environment has drastically changed in these years. Especially, parallel processing on massively parallel computers or computer networks is considered to be promising techniques. In order to achieve high efficiency on such parallel computation environment, large granularity of tasks, a well-balanced workload distribution are key issues. It is also important to reduce the cost of pre-processing in such parallel FEM. From the point of view, the authors developed the domain decomposition FEM with the automatic and dynamic task-allocation mechanism and the automatic mesh generation/domain subdivision system for it. (author)

  14. Post-processing of Deep Web Information Extraction Based on Domain Ontology

    Directory of Open Access Journals (Sweden)

    PENG, T.

    2013-11-01

    Full Text Available Many methods are utilized to extract and process query results in deep Web, which rely on the different structures of Web pages and various designing modes of databases. However, some semantic meanings and relations are ignored. So, in this paper, we present an approach for post-processing deep Web query results based on domain ontology which can utilize the semantic meanings and relations. A block identification model (BIM based on node similarity is defined to extract data blocks that are relevant to specific domain after reducing noisy nodes. Feature vector of domain books is obtained by result set extraction model (RSEM based on vector space model (VSM. RSEM, in combination with BIM, builds the domain ontology on books which can not only remove the limit of Web page structures when extracting data information, but also make use of semantic meanings of domain ontology. After extracting basic information of Web pages, a ranking algorithm is adopted to offer an ordered list of data records to users. Experimental results show that BIM and RSEM extract data blocks and build domain ontology accurately. In addition, relevant data records and basic information are extracted and ranked. The performances precision and recall show that our proposed method is feasible and efficient.

  15. Using the domain identification model to study major and career decision-making processes

    Science.gov (United States)

    Tendhar, Chosang; Singh, Kusum; Jones, Brett D.

    2018-03-01

    The purpose of this study was to examine the extent to which (1) a domain identification model could be used to predict students' engineering major and career intentions and (2) the MUSIC Model of Motivation components could be used to predict domain identification. The data for this study were collected from first-year engineering students. We used a structural equation model to test the hypothesised relationship between variables in the partial domain identification model. The findings suggested that engineering identification significantly predicted engineering major intentions and career intentions and had the highest effect on those two variables compared to other motivational constructs. Furthermore, results suggested that success, interest, and caring are plausible contributors to students' engineering identification. Overall, there is strong evidence that the domain identification model can be used as a lens to study career decision-making processes in engineering, and potentially, in other fields as well.

  16. Geomorphic Surface Maps of Northern Frenchman Flat, Nevada Test Site, Southern Nevada

    International Nuclear Information System (INIS)

    Bechtel Nevada

    2005-01-01

    Large-scale (1:6000) surficial geology maps of northern Frenchman Flat were developed in 1995 as part of comprehensive site characterization required to operate a low-level radioactive waste disposal facility in that area. Seven surficial geology maps provide fundamental data on natural processes and are the platform needed to reconstruct the Quaternary history of northern Frenchman Flat. Reconstruction of the Quaternary history provides an understanding of the natural processes that act to develop the landscape, and the time-frames involved in landscape development. The mapping was conducted using color and color-infrared aerial photographs and field verification of map unit composition and boundaries. Criteria for defining the map unit composition of geomorphic surface units are based on relative geomorphic position, landform morphology, and degree of preservation of surface morphology. Seven geomorphic surfaces (Units 1 through 7) are recognized, spanning from the early Quaternary to present time

  17. Eavesdropping on spin waves inside the domain-wall nanochannel via three-magnon processes

    Science.gov (United States)

    Zhang, Beining; Wang, Zhenyu; Cao, Yunshan; Yan, Peng; Wang, X. R.

    2018-03-01

    One recent breakthrough in the field of magnonics is the experimental realization of reconfigurable spin-wave nanochannels formed by a magnetic domain wall with a width of 10-100 nm [Wagner et al., Nat. Nano. 11, 432 (2016), 10.1038/nnano.2015.339]. This remarkable progress enables an energy-efficient spin-wave propagation with a well-defined wave vector along its propagating path inside the wall. In the mentioned experiment, a microfocus Brillouin light scattering spectroscopy was taken in a line-scans manner to measure the frequency of the bounded spin wave. Due to their localization nature, the confined spin waves can hardly be detected from outside the wall channel, which guarantees the information security to some extent. In this work, we theoretically propose a scheme to detect/eavesdrop on the spin waves inside the domain-wall nanochannel via nonlinear three-magnon processes. We send a spin wave (ωi,ki) in one magnetic domain to interact with the bounded mode (ωb,kb) in the wall, where kb is parallel with the domain-wall channel defined as the z ̂ axis. Two kinds of three-magnon processes, i.e., confluence and splitting, are expected to occur. The confluence process is conventional: conservation of energy and momentum parallel with the wall indicates a transmitted wave in the opposite domain with ω (k ) =ωi+ωb and (ki+kb-k ) .z ̂=0 , while the momentum perpendicular to the domain wall is not necessary to be conserved due to the nonuniform internal field near the wall. We predict a stimulated three-magnon splitting (or "magnon laser") effect: the presence of a bound magnon propagating along the domain wall channel assists the splitting of the incident wave into two modes, one is ω1=ωb,k1=kb identical to the bound mode in the channel, and the other one is ω2=ωi-ωb with (ki-kb-k2) .z ̂=0 propagating in the opposite magnetic domain. Micromagnetic simulations confirm our theoretical analysis. These results demonstrate that one is able to uniquely

  18. Tracking geomorphic signatures of watershed suburbanization with multi-temporal LiDAR

    Science.gov (United States)

    Jones, Daniel K.; Baker, Matthew E.; Miller, Andrew J.; Jarnagin, S. Taylor; Hogan, Dianna M.

    2014-01-01

    Urban development practices redistribute surface materials through filling, grading, and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-time comparisons of disparate urban and rural landscapes. However, no previous studies have documented geomorphic changes from development using multiple dates of high-resolution topographic data at the watershed scale. This study utilized a time series of five sequential light detection and ranging (LiDAR) derived digital elevation models (DEMs) to track watershed geomorphic changes within two watersheds throughout development (2002–2008) and across multiple spatial scales (0.01–1 km2). Development-induced changes were compared against an undeveloped forested watershed during the same time period. Changes in elevations, slopes, hypsometry, and surface flow pathways were tracked throughout the development process to assess watershed geomorphic alterations. Results suggest that development produced an increase in sharp topographic breaks between relatively flat surfaces and steep slopes, replacing smoothly varying hillslopes and leading to greater variation in slopes. Examinations of flowpath distributions highlight systematic modifications that favor rapid convergence in unchanneled upland areas. Evidence of channel additions in the form of engineered surface conduits is apparent in comparisons of pre- and post-development stream maps. These results suggest that topographic modification, in addition to impervious surfaces, contributes to altered hydrologic dynamics observed in urban systems. This work highlights important considerations for the use of repeat LiDAR flights in analyzing watershed change through time. Novel methods introduced here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during development and help guide future

  19. The effect of observational learning on students' performance, processes, and motivation in two creative domains.

    Science.gov (United States)

    Groenendijk, Talita; Janssen, Tanja; Rijlaarsdam, Gert; van den Bergh, Huub

    2013-03-01

    Previous research has shown that observation can be effective for learning in various domains, for example, argumentative writing and mathematics. The question in this paper is whether observational learning can also be beneficial when learning to perform creative tasks in visual and verbal arts. We hypothesized that observation has a positive effect on performance, process, and motivation. We expected similarity in competence between the model and the observer to influence the effectiveness of observation. Sample.  A total of 131 Dutch students (10(th) grade, 15 years old) participated. Two experiments were carried out (one for visual and one for verbal arts). Participants were randomly assigned to one of three conditions; two observational learning conditions and a control condition (learning by practising). The observational learning conditions differed in instructional focus (on the weaker or the more competent model of a pair to be observed). We found positive effects of observation on creative products, creative processes, and motivation in the visual domain. In the verbal domain, observation seemed to affect the creative process, but not the other variables. The model similarity hypothesis was not confirmed. Results suggest that observation may foster learning in creative domains, especially in the visual arts. © 2011 The British Psychological Society.

  20. Geomorphic evidence for ancient seas on Mars

    Science.gov (United States)

    Parker, Timothy J.; Schneeberger, Dale M.; Pieri, David C.; Saunders, R. Stephen

    1987-01-01

    Geomorphic evidence is presented for ancient seas on Mars. Several features, similar to terrestrial lacustrine and coastal features, were identified along the northern plains periphery from Viking images. The nature of these features argues for formation in a predominantly liquid, shallow body of standing water. Such a shallow sea would require either relatively rapid development of shoreline morphologies or a warmer than present climate at the time of outflow channel formation.

  1. Heavy-ion peripheral collisions in the Fermi energy domain: fragmentation processes or dissipative collisions

    International Nuclear Information System (INIS)

    Borderie, B.; Rivet, M.F.; Tassan-Got, L.

    1990-01-01

    For several years a new field in nuclear physics has been opened by the opportunity to accelerate heavy ions through an energy domain including the Fermi energy of nucleons. This new domain has to be seen as a link between dissipative processes observed at low energies, dominated by mean field considerations, and high energy collisions for which nucleon-nucleon collisions play an important role. This paper reviews our present knowledge on peripheral collisions. A reminder of contiguous energy domains is done as well as their extension in the new field. Specific calculations are also presented. Finally a wide comparison between experiments and calculations is performed. A fast dissipative stage proves to be responsible for the dominant mechanisms involved, at least when the incident energy is lower than 50 MeV/nucleon

  2. Mono-domain YBa2Cu3Oy superconductor fabrics prepared by an infiltration process

    International Nuclear Information System (INIS)

    Sudhakar Reddy, E.; Noudem, J.G.; Tarka, M.; Schmitz, G.J.

    2000-01-01

    A novel process for the fabrication of a new form of YBa 2 Cu 3 O y (123) superconducting material, with the dimensions of a thick film and the microstructure of a melt-textured single-domain bulk is described. The process allows the fabrication of 123 as a self-supporting fabric or as a thick film on various substrate materials. The process, which is generic and economical, uses commercially available Y 2 O 3 fabrics as a precursor material. The Y 2 O 3 cloth is infiltrated with barium cuprates and copper oxides from a liquid-phase source, then converted into Y 2 BaCuO 5 (211) phase and eventually to 123. The nucleation and growth of the 123 phase is controlled by seeding the cloth with an oriented heterogeneous MgO or Nd123 seed. Interesting application areas for the new form of the 123 mono-domain fabric are discussed. (author)

  3. Survey of Applications of Complex Event Processing (CEP in Health Domain

    Directory of Open Access Journals (Sweden)

    Nadeem Mahmood

    2017-12-01

    Full Text Available It is always difficult to manipulate the production of huge amount of data which comes from multiple sources and to extract meaningful information to make appropriate decisions. When data comes from various input resources, to get required streams of events form this complex input network, the one of the strong functionality of Business Intelligence (BI the Complex Event Processing (CEP is the appropriate solution for the above mention problems. Real time processing, pattern matching, stream processing, big data management, sensor data processing and many more are the application areas of CEP. Health domain itself is a multi-dimension domain such as hospital supply chain, OPD management, disease diagnostic, In-patient, out-patient management, and emergency care etc. In this paper, the main focus is to discuss the application areas of Complex Event Processing (CEP in health domain by using sensor device, such that how CEP manipulate health data set events coming from sensor devices such as blood pressure, heart rate, fall detection, sugar level, temperature or any other vital signs and how this systems respond to these events as quickly as possible. Different existing models and application using CEP are discussed and summarized according to different characteristics.

  4. Combination Across Domains: An MEG Investigation into the Relationship between Mathematical, Pictorial, and Linguistic Processing

    Science.gov (United States)

    Bemis, Douglas K.; Pylkkänen, Liina

    2013-01-01

    Debates surrounding the evolution of language often hinge upon its relationship to cognition more generally and many investigations have attempted to demark the boundary between the two. Though results from these studies suggest that language may recruit domain-general mechanisms during certain types of complex processing, the domain-generality of basic combinatorial mechanisms that lie at the core of linguistic processing is still unknown. Our previous work (Bemis and Pylkkänen, 2011, 2012) used magnetoencephalography to isolate neural activity associated with the simple composition of an adjective and a noun (“red boat”) and found increased activity during this processing localized to the left anterior temporal lobe (lATL), ventro-medial prefrontal cortex (vmPFC), and left angular gyrus (lAG). The present study explores the domain-generality of these effects and their associated combinatorial mechanisms through two parallel non-linguistic combinatorial tasks designed to be as minimal and natural as the linguistic paradigm. In the first task, we used pictures of colored shapes to elicit combinatorial conceptual processing similar to that evoked by the linguistic expressions and find increased activity again localized to the vmPFC during combinatorial processing. This result suggests that a domain-general semantic combinatorial mechanism operates during basic linguistic composition, and that activity generated by its processing localizes to the vmPFC. In the second task, we recorded neural activity as subjects performed simple addition between two small numerals. Consistent with a wide array of recent results, we find no effects related to basic addition that coincide with our linguistic effects and instead find increased activity localized to the intraparietal sulcus. This result suggests that the scope of the previously identified linguistic effects is restricted to compositional operations and does not extend generally to all tasks that are merely similar

  5. A landscape scale valley confinement algorithm: Delineating unconfined valley bottoms for geomorphic, aquatic, and riparian applications

    Science.gov (United States)

    David E. Nagel; John M. Buffington; Sharon L. Parkes; Seth Wenger; Jaime R. Goode

    2014-01-01

    Valley confinement is an important landscape characteristic linked to aquatic habitat, riparian diversity, and geomorphic processes. This report describes a GIS program called the Valley Confinement Algorithm (VCA), which identifies unconfined valleys in montane landscapes. The algorithm uses nationally available digital elevation models (DEMs) at 10-30 m resolution to...

  6. Geomorphic control on the δ15N of mountain forests

    Directory of Open Access Journals (Sweden)

    R. G. Hilton

    2013-03-01

    Full Text Available Mountain forests are subject to high rates of physical erosion which can export particulate nitrogen from ecosystems. However, the impact of geomorphic processes on nitrogen budgets remains poorly constrained. We have used the elemental and isotopic composition of soil and plant organic matter to investigate nitrogen cycling in the mountain forest of Taiwan, from 24 sites with distinct geomorphic (topographic slope and climatic (precipitation, temperature characteristics. The organic carbon to nitrogen ratio of soil organic matter decreased with soil 14C age, providing constraint on average rates of nitrogen loss using a mass balance model. Model predictions suggest that present day estimates of nitrogen deposition exceed contemporary and historic nitrogen losses. We found ∼6‰ variability in the stable isotopic composition (δ15N of soil and plants which was not related to soil 14C age or climatic conditions. Instead, δ15N was significantly, negatively correlated with topographic slope. Using the mass balance model, we demonstrate that the correlation can be explained by an increase in nitrogen loss by non-fractioning pathways on steeper slopes, where physical erosion most effectively removes particulate nitrogen. Published data from forests on steep slopes are consistent with the correlation. Based on our dataset and these observations, we hypothesise that variable physical erosion rates can significantly influence soil δ15N, and suggest particulate nitrogen export is a major, yet underappreciated, loss term in the nitrogen budget of mountain forests.

  7. Process and domain specificity in regions engaged for face processing: an fMRI study of perceptual differentiation.

    Science.gov (United States)

    Collins, Heather R; Zhu, Xun; Bhatt, Ramesh S; Clark, Jonathan D; Joseph, Jane E

    2012-12-01

    The degree to which face-specific brain regions are specialized for different kinds of perceptual processing is debated. This study parametrically varied demands on featural, first-order configural, or second-order configural processing of faces and houses in a perceptual matching task to determine the extent to which the process of perceptual differentiation was selective for faces regardless of processing type (domain-specific account), specialized for specific types of perceptual processing regardless of category (process-specific account), engaged in category-optimized processing (i.e., configural face processing or featural house processing), or reflected generalized perceptual differentiation (i.e., differentiation that crosses category and processing type boundaries). ROIs were identified in a separate localizer run or with a similarity regressor in the face-matching runs. The predominant principle accounting for fMRI signal modulation in most regions was generalized perceptual differentiation. Nearly all regions showed perceptual differentiation for both faces and houses for more than one processing type, even if the region was identified as face-preferential in the localizer run. Consistent with process specificity, some regions showed perceptual differentiation for first-order processing of faces and houses (right fusiform face area and occipito-temporal cortex and right lateral occipital complex), but not for featural or second-order processing. Somewhat consistent with domain specificity, the right inferior frontal gyrus showed perceptual differentiation only for faces in the featural matching task. The present findings demonstrate that the majority of regions involved in perceptual differentiation of faces are also involved in differentiation of other visually homogenous categories.

  8. Process- and Domain-Specificity in Regions Engaged for Face Processing: An fMRI Study of Perceptual Differentiation

    Science.gov (United States)

    Collins, Heather R.; Zhu, Xun; Bhatt, Ramesh S.; Clark, Jonathan D.; Joseph, Jane E.

    2015-01-01

    The degree to which face-specific brain regions are specialized for different kinds of perceptual processing is debated. The present study parametrically varied demands on featural, first-order configural or second-order configural processing of faces and houses in a perceptual matching task to determine the extent to which the process of perceptual differentiation was selective for faces regardless of processing type (domain-specific account), specialized for specific types of perceptual processing regardless of category (process-specific account), engaged in category-optimized processing (i.e., configural face processing or featural house processing) or reflected generalized perceptual differentiation (i.e. differentiation that crosses category and processing type boundaries). Regions of interest were identified in a separate localizer run or with a similarity regressor in the face-matching runs. The predominant principle accounting for fMRI signal modulation in most regions was generalized perceptual differentiation. Nearly all regions showed perceptual differentiation for both faces and houses for more than one processing type, even if the region was identified as face-preferential in the localizer run. Consistent with process-specificity, some regions showed perceptual differentiation for first-order processing of faces and houses (right fusiform face area and occipito-temporal cortex, and right lateral occipital complex), but not for featural or second-order processing. Somewhat consistent with domain-specificity, the right inferior frontal gyrus showed perceptual differentiation only for faces in the featural matching task. The present findings demonstrate that the majority of regions involved in perceptual differentiation of faces are also involved in differentiation of other visually homogenous categories. PMID:22849402

  9. Structural features of the KPI domain control APP dimerization, trafficking, and processing.

    Science.gov (United States)

    Ben Khalifa, Naouel; Tyteca, Donatienne; Marinangeli, Claudia; Depuydt, Mathieu; Collet, Jean-François; Courtoy, Pierre J; Renauld, Jean-Christophe; Constantinescu, Stefan; Octave, Jean-Noël; Kienlen-Campard, Pascal

    2012-02-01

    The two major isoforms of human APP, APP695 and APP751, differ by the presence of a Kunitz-type protease inhibitor (KPI) domain in the extracellular region. APP processing and function is thought to be regulated by homodimerization. We used bimolecular fluorescence complementation (BiFC) to study dimerization of different APP isoforms and mutants. APP751 was found to form significantly more homodimers than APP695. Mutation of dimerization motifs in the TM domain did not affect fluorescence complementation, but native folding of KPI is critical for APP751 homodimerization. APP751 and APP695 dimers were mostly localized at steady state in the Golgi region, suggesting that most of the APP751 and 695 dimers are in the secretory pathway. Mutation of the KPI led to the retention of the APP homodimers in the endoplasmic reticulum. We finally showed that APP751 is more efficiently processed through the nonamyloidogenic pathway than APP695. These findings provide new insight on the particular role of KPI domain in APP dimerization. The correlation observed between dimerization, subcellular localization, and processing suggests that dimerization acts as an efficient regulator of APP trafficking in the secretory compartments that has major consequences on its processing.

  10. Extended chaotic domain in the long optical fibers based on SBS process

    International Nuclear Information System (INIS)

    Gao, Junbo; Ding, Yingchun; Chen, Zhaoyang; Lin, Chengyou

    2014-01-01

    Chaotic stimulated Brillouin scattering (SBS) in optical fibers with weak external optical feedback has been investigated experimentally and theoretically. However, only the bifurcation route to chaos through period-one and quasi-periodic emission was discovered in the former work because the chaotic domain is very short in the general nonlinear system. In order to control the chaos process and observe finer periodic-orbit structures, a novel experiment was designed to extend the chaotic domain by using long optical fibers in the SBS system. In this experiment, the period-one, period-doubling, period-four and period-eight cycle routes to the chaos laser process as well as the more details of chaos, have been observed.

  11. Integrating Geomorphic and Social Dynamics in the Analysis of Anthropogenic Landforms: Examining Landscape Evolution of Terrain Modified by Agricultural Terracing

    Science.gov (United States)

    Glaubius, J.; Maerker, M.

    2016-12-01

    Anthropogenic landforms, such as mines and agricultural terraces, are impacted by both geomorphic and social processes at varying intensities through time. In the case of agricultural terraces, decisions regarding terrace maintenance are intertwined with land use, such as when terraced fields are abandoned. Furthermore, terrace maintenance and land use decisions, either jointly or separately, may be in response to geomorphic processes, as well as geomorphic feedbacks. Previous studies of these complex geomorphic systems considered agricultural terraces as static features or analyzed only the geomorphic response to landowner decisions. Such research is appropriate for short-term or binary landscape scenarios (e.g. the impact of maintained vs. abandoned terraces), but the complexities inherent in these socio-natural systems requires an approach that includes both social and geomorphic processes. This project analyzes feedbacks and emergent properties in terraced systems by implementing a coupled landscape evolution model (LEM) and agent-based model (ABM) using the Landlab and Mesa modeling libraries. In the ABM portion of the model, agricultural terraces are conceptualized using a life-cycle stages schema and implemented using Markov Decision Processes to simulate the changing geomorphic impact of terracing based on human decisions. This paper examines the applicability of this approach by comparing results from a LEM-only model against the coupled LEM-ABM model for a terraced region. Model results are compared by quantify and spatial patterning of sediment transport. This approach fully captures long-term landscape evolution of terraced terrain that is otherwise lost when the life-cycle of terraces is not considered. The coupled LEM-ABM approach balances both environmental and social processes so that the socio-natural feedbacks in such anthropogenic systems can be disentangled.

  12. Business Process Modeling for Domain Outbound Logistics System: Analytic Perspective with BPMN 2.0

    OpenAIRE

    Khabbazi, Mahmood Reza; Hasan, M.K; Sulaiman, R; Shapi’i, A

    2013-01-01

    This paper proposes a generic"to-be" business processes model for domain highest-level outbound logistics system representing the possible alternative structure and behaviour of the system in respect to x-party logistics services applicable in Small-to-medium sized enterprises. The generic framework of outbound logistics model consists of one main modular system named as the Shipping System including five internal sub-systems of the shipping core, shipping requirement, First Party Logistics (...

  13. All-optical signal processing of OTDM and OFDM signals based on time-domain Optical Fourier Transformation

    DEFF Research Database (Denmark)

    Clausen, Anders; Guan, Pengyu; Mulvad, Hans Christian Hansen

    2014-01-01

    All-optical time-domain Optical Fourier Transformation utilised for signal processing of ultra-high-speed OTDM signals and OFDM signals will be presented.......All-optical time-domain Optical Fourier Transformation utilised for signal processing of ultra-high-speed OTDM signals and OFDM signals will be presented....

  14. Geomorphic Change Induced by 100 years of Flow Alteration on the Diamond Fork River, Central Utah

    Science.gov (United States)

    Jones, J.; Belmont, P.; Wilcock, P. R.

    2017-12-01

    Changes in hydrology and sediment supply affect the form of rivers. The rate of change of fluvial form is controlled by a variety of factors, including valley confinement, sediment size, and antecedent condition. The Diamond Fork River in central Utah has been altered by trans-basin flows delivered from the Colorado River system for over a century. Beginning in 1915, water used for irrigation was delivered through a tributary, Sixth Water Creek, with daily summer flows regularly exceeding the 50 - 100 year flood. Elevated flows caused drastic geomorphic change - resulting in incision and widening of the channel, and the destruction of riparian vegetation. Beginning in 1997, the outlet for the trans-basin diversion was moved downstream on Sixth Water, bypassing a large landslide, and flows were drastically reduced in 2004 through management actions. We delineated eight distinct process domains for the Sixth Water-Diamond Fork system and examined the response of each process domain to the altered flow and sediment regimes through the analysis of aerial photographs and repeat cross-sections. We measured a variety of channel metrics, including channel width, areal extent of bars and islands, and sinuosity in ArcGIS. Results indicate that unconfined reaches that were wide and braided during the period of elevated flows have narrowed to become single threaded and meandering in response to the reduced flows. Confined reaches have experienced minor changes since the reduction in flows, suggesting that confinement is a primary control on the degree of channel response. These findings and complimentary studies will provide managers of Sixth Water and Diamond Fork with a greater understanding of the physical response of the streams, and the resulting effects on ecological communities.

  15. Geomorphic aspects of groundwater flow

    Science.gov (United States)

    LaFleur, Robert G.

    The many roles that groundwater plays in landscape evolution are becoming more widely appreciated. In this overview, three major categories of groundwater processes and resulting landforms are considered: (1) Dissolution creates various karst geometries, mainly in carbonate rocks, in response to conditions of recharge, geologic setting, lithology, and groundwater circulation. Denudation and cave formation rates can be estimated from kinetic and hydraulic parameters. (2) Groundwater weathering generates regoliths of residual alteration products at weathering fronts, and subsequent exhumation exposes corestones, flared slopes, balanced rocks, domed inselbergs, and etchplains of regional importance. Groundwater relocation of dissolved salts creates duricrusts of various compositions, which become landforms. (3) Soil and rock erosion by groundwater processes include piping, seepage erosion, and sapping, important agents in slope retreat and headward gully migration. Thresholds and limits are important in many chemical and mechanical groundwater actions. A quantitative, morphometric approach to groundwater landforms and processes is exemplified by selected studies in carbonate and clastic terrains of ancient and recent origins. Résumé Les rôles variés joués par les eaux souterraines dans l'évolution des paysages deviennent nettement mieux connus. La revue faite ici prend en considération trois grandes catégories de processus liés aux eaux souterraines et les formes associées: (1) La dissolution crée des formes karstiques variées, surtout dans les roches carbonatées, en fonction des conditions d'alimentation, du cadre géologique, de la lithologie et de la circulation des eaux souterraines. Les taux d'érosion et de formation des grottes peuvent être estimés à partir de paramètres cinétiques et hydrauliques. (2) L'érosion par les eaux souterraines donne naissance à des régolites, résidus d'altération sur des fronts d'altération, et l'exhumation r

  16. Direct and indirect drivers of instream wood in the interior Pacific Northwest, USA: decoupling climate, vegetation, disturbance, and geomorphic setting

    Directory of Open Access Journals (Sweden)

    Hough-Snee Nate

    2014-06-01

    Full Text Available Instream wood is a driver of geomorphic change in low-order streams, frequently altering morphodynamic processes. Instream wood is a frequently measured component of streams, yet it is a complex metric, responding to ecological and geomorphic forcings at a variety of scales. Here we seek to disentangle the relative importance of physical and biological processes that drive wood growth and delivery to streams across broad spatial extents. In so doing, we ask two primary questions: (1 is riparian vegetation a composite variable that captures the indirect effects of climate and disturbance on instream wood dynamics? (2 What are the direct and indirect relationships between geomorphic setting, vegetation, climate, disturbance, and instream wood dynamics? We measured riparian vegetation composition and wood frequency and volume at 720 headwater reaches within the American interior Pacific Northwest. We used ordination to identify relationships between vegetation and environmental attributes, and subsequently built a structural equation model to identify how climate and disturbance directly affect vegetation composition and how vegetation and geomorphic setting directly affect instream wood volume and frequency. We found that large wood volume and frequency are directly driven by vegetation composition and positively correlated to wildfire, elevation, stream gradient, and channel bankfull width. Indicator species at reaches with high volumes of wood were generally long-lived, conifer trees that persist for extended durations once delivered to stream habitats. Wood dynamics were also indirectly mediated by factors that shape vegetation: wildfire, precipitation, elevation, and temperature. We conclude that wood volume and frequency are driven by multiple interrelated climatic, geomorphic, and ecological variables. Vegetation composition and geomorphic setting directly mediate indirect relationships between landscape environmental processes and instream

  17. APP processing and the APP-KPI domain involvement in the amyloid cascade.

    Science.gov (United States)

    Menéndez-González, M; Pérez-Pinera, P; Martínez-Rivera, M; Calatayud, M T; Blázquez Menes, B

    2005-01-01

    Alternative APP mRNA splicing can generate isoforms of APP containing a Kunitz protease inhibitor (KPI) domain. KPI is one of the main serine protease inhibitors. Protein and mRNA KPI(+)APP levels are elevated in Alzheimer's disease (AD) brain and are associated with increased amyloid beta deposition. In the last years increasing evidence on multiple points in the amyloid cascade where KPI(+)APP is involved has been accumulated, admitting an outstanding position in the pathogenesis of AD to the KPI domain. This review focuses on the APP processing, the molecular activity of KPI and its physiological and pathological roles and the KPI involvement in the amyloid cascade through the nerve growth factor, the lipoprotein receptor-related protein, the tumor necrosis factor-alpha converting enzyme and the Notch1 protein.

  18. Insertion of the T3 DNA polymerase thioredoxin binding domain enhances the processivity and fidelity of Taq DNA polymerase

    OpenAIRE

    Davidson, John F.; Fox, Richard; Harris, Dawn D.; Lyons-Abbott, Sally; Loeb, Lawrence A.

    2003-01-01

    Insertion of the T3 DNA polymerase thioredoxin binding domain (TBD) into the distantly related thermostable Taq DNA polymerase at an analogous position in the thumb domain, converts the Taq DNA polymerase from a low processive to a highly processive enzyme. Processivity is dependent on the presence of thioredoxin. The enhancement in processivity is 20–50-fold when compared with the wild-type Taq DNA polymerase or to the recombinant polymerase in the absence of thioredoxin. The recombinant Taq...

  19. Computational models of music perception and cognition II: Domain-specific music processing

    Science.gov (United States)

    Purwins, Hendrik; Grachten, Maarten; Herrera, Perfecto; Hazan, Amaury; Marxer, Ricard; Serra, Xavier

    2008-09-01

    In Part I [Purwins H, Herrera P, Grachten M, Hazan A, Marxer R, Serra X. Computational models of music perception and cognition I: The perceptual and cognitive processing chain. Physics of Life Reviews 2008, in press, doi:10.1016/j.plrev.2008.03.004], we addressed the study of cognitive processes that underlie auditory perception of music, and their neural correlates. The aim of the present paper is to summarize empirical findings from music cognition research that are relevant to three prominent music theoretic domains: rhythm, melody, and tonality. Attention is paid to how cognitive processes like category formation, stimulus grouping, and expectation can account for the music theoretic key concepts in these domains, such as beat, meter, voice, consonance. We give an overview of computational models that have been proposed in the literature for a variety of music processing tasks related to rhythm, melody, and tonality. Although the present state-of-the-art in computational modeling of music cognition definitely provides valuable resources for testing specific hypotheses and theories, we observe the need for models that integrate the various aspects of music perception and cognition into a single framework. Such models should be able to account for aspects that until now have only rarely been addressed in computational models of music cognition, like the active nature of perception and the development of cognitive capacities from infancy to adulthood.

  20. The geomorphic structure of the runoff peak

    Directory of Open Access Journals (Sweden)

    R. Rigon

    2011-06-01

    Full Text Available This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  1. Downstream ecological effects of dams: A geomorphic perspective

    International Nuclear Information System (INIS)

    Ligon, F.K.; Dietrich, W.E.; Trush, W.J.

    1995-01-01

    The damming of a river changes the flow of water, sediment, nutrients, energy, and biota, interrupting and altering most of a river's ecological processes. This article discusses the importance of geomorphological analysis in river conservation and management. To illustrate how subtle geomorphological adjustments may profoundly influence the ecological relationships downstream from dames, three case studies are presented. Then a geomorphically based approach for assessing and possibly mitigating some of the environmental effects of dams by tailoring dam designed and operation is outlined. The cases are as follows: channel simplification and salmon decline on the McKenzie River in Oregon; Channel incision and reduced floodplain inundation on the Oconee river in Georgia; Increased stability of a braided river in New Zealand's south island. 41 refs., 10 figs., 1 tab

  2. Lagrangian Particle Tracking Simulation for Warm-Rain Processes in Quasi-One-Dimensional Domain

    Science.gov (United States)

    Kunishima, Y.; Onishi, R.

    2017-12-01

    Conventional cloud simulations are based on the Euler method and compute each microphysics process in a stochastic way assuming infinite numbers of particles within each numerical grid. They therefore cannot provide the Lagrangian statistics of individual particles in cloud microphysics (i.e., aerosol particles, cloud particles, and rain drops) nor discuss the statistical fluctuations due to finite number of particles. We here simulate the entire precipitation process of warm-rain, with tracking individual particles. We use the Lagrangian Cloud Simulator (LCS), which is based on the Euler-Lagrangian framework. In that framework, flow motion and scalar transportation are computed with the Euler method, and particle motion with the Lagrangian one. The LCS tracks particle motions and collision events individually with considering the hydrodynamic interaction between approaching particles with a superposition method, that is, it can directly represent the collisional growth of cloud particles. It is essential for trustworthy collision detection to take account of the hydrodynamic interaction. In this study, we newly developed a stochastic model based on the Twomey cloud condensation nuclei (CCN) activation for the Lagrangian tracking simulation and integrated it into the LCS. Coupling with the Euler computation for water vapour and temperature fields, the initiation and condensational growth of water droplets were computed in the Lagrangian way. We applied the integrated LCS for a kinematic simulation of warm-rain processes in a vertically-elongated domain of, at largest, 0.03×0.03×3000 (m3) with horizontal periodicity. Aerosol particles with a realistic number density, 5×107 (m3), were evenly distributed over the domain at the initial state. Prescribed updraft at the early stage initiated development of a precipitating cloud. We have confirmed that the obtained bulk statistics fairly agree with those from a conventional spectral-bin scheme for a vertical column

  3. Studies in astronomical time series analysis: Modeling random processes in the time domain

    Science.gov (United States)

    Scargle, J. D.

    1979-01-01

    Random process models phased in the time domain are used to analyze astrophysical time series data produced by random processes. A moving average (MA) model represents the data as a sequence of pulses occurring randomly in time, with random amplitudes. An autoregressive (AR) model represents the correlations in the process in terms of a linear function of past values. The best AR model is determined from sampled data and transformed to an MA for interpretation. The randomness of the pulse amplitudes is maximized by a FORTRAN algorithm which is relatively stable numerically. Results of test cases are given to study the effects of adding noise and of different distributions for the pulse amplitudes. A preliminary analysis of the optical light curve of the quasar 3C 273 is given.

  4. General purpose graphics-processing-unit implementation of cosmological domain wall network evolution.

    Science.gov (United States)

    Correia, J R C C C; Martins, C J A P

    2017-10-01

    Topological defects unavoidably form at symmetry breaking phase transitions in the early universe. To probe the parameter space of theoretical models and set tighter experimental constraints (exploiting the recent advances in astrophysical observations), one requires more and more demanding simulations, and therefore more hardware resources and computation time. Improving the speed and efficiency of existing codes is essential. Here we present a general purpose graphics-processing-unit implementation of the canonical Press-Ryden-Spergel algorithm for the evolution of cosmological domain wall networks. This is ported to the Open Computing Language standard, and as a consequence significant speedups are achieved both in two-dimensional (2D) and 3D simulations.

  5. Studies in astronomical time series analysis. I - Modeling random processes in the time domain

    Science.gov (United States)

    Scargle, J. D.

    1981-01-01

    Several random process models in the time domain are defined and discussed. Attention is given to the moving average model, the autoregressive model, and relationships between and combinations of these models. Consideration is then given to methods for investigating pulse structure, procedures of model construction, computational methods, and numerical experiments. A FORTRAN algorithm of time series analysis has been developed which is relatively stable numerically. Results of test cases are given to study the effect of adding noise and of different distributions for the pulse amplitudes. A preliminary analysis of the light curve of the quasar 3C 272 is considered as an example.

  6. General purpose graphics-processing-unit implementation of cosmological domain wall network evolution

    Science.gov (United States)

    Correia, J. R. C. C. C.; Martins, C. J. A. P.

    2017-10-01

    Topological defects unavoidably form at symmetry breaking phase transitions in the early universe. To probe the parameter space of theoretical models and set tighter experimental constraints (exploiting the recent advances in astrophysical observations), one requires more and more demanding simulations, and therefore more hardware resources and computation time. Improving the speed and efficiency of existing codes is essential. Here we present a general purpose graphics-processing-unit implementation of the canonical Press-Ryden-Spergel algorithm for the evolution of cosmological domain wall networks. This is ported to the Open Computing Language standard, and as a consequence significant speedups are achieved both in two-dimensional (2D) and 3D simulations.

  7. Domain-Generality of Timing-Based Serial Order Processes in Short-Term Memory: New Insights from Musical and Verbal Domains.

    Directory of Open Access Journals (Sweden)

    Simon Gorin

    Full Text Available Several models in the verbal domain of short-term memory (STM consider a dissociation between item and order processing. This view is supported by data demonstrating that different types of time-based interference have a greater effect on memory for the order of to-be-remembered items than on memory for the items themselves. The present study investigated the domain-generality of the item versus serial order dissociation by comparing the differential effects of time-based interfering tasks, such as rhythmic interference and articulatory suppression, on item and order processing in verbal and musical STM domains. In Experiment 1, participants had to maintain sequences of verbal or musical information in STM, followed by a probe sequence, this under different conditions of interference (no-interference, rhythmic interference, articulatory suppression. They were required to decide whether all items of the probe list matched those of the memory list (item condition or whether the order of the items in the probe sequence matched the order in the memory list (order condition. In Experiment 2, participants performed a serial order probe recognition task for verbal and musical sequences ensuring sequential maintenance processes, under no-interference or rhythmic interference conditions. For Experiment 1, serial order recognition was not significantly more impacted by interfering tasks than was item recognition, this for both verbal and musical domains. For Experiment 2, we observed selective interference of the rhythmic interference condition on both musical and verbal order STM tasks. Overall, the results suggest a similar and selective sensitivity to time-based interference for serial order STM in verbal and musical domains, but only when the STM tasks ensure sequential maintenance processes.

  8. Domain-Generality of Timing-Based Serial Order Processes in Short-Term Memory: New Insights from Musical and Verbal Domains.

    Science.gov (United States)

    Gorin, Simon; Kowialiewski, Benjamin; Majerus, Steve

    2016-01-01

    Several models in the verbal domain of short-term memory (STM) consider a dissociation between item and order processing. This view is supported by data demonstrating that different types of time-based interference have a greater effect on memory for the order of to-be-remembered items than on memory for the items themselves. The present study investigated the domain-generality of the item versus serial order dissociation by comparing the differential effects of time-based interfering tasks, such as rhythmic interference and articulatory suppression, on item and order processing in verbal and musical STM domains. In Experiment 1, participants had to maintain sequences of verbal or musical information in STM, followed by a probe sequence, this under different conditions of interference (no-interference, rhythmic interference, articulatory suppression). They were required to decide whether all items of the probe list matched those of the memory list (item condition) or whether the order of the items in the probe sequence matched the order in the memory list (order condition). In Experiment 2, participants performed a serial order probe recognition task for verbal and musical sequences ensuring sequential maintenance processes, under no-interference or rhythmic interference conditions. For Experiment 1, serial order recognition was not significantly more impacted by interfering tasks than was item recognition, this for both verbal and musical domains. For Experiment 2, we observed selective interference of the rhythmic interference condition on both musical and verbal order STM tasks. Overall, the results suggest a similar and selective sensitivity to time-based interference for serial order STM in verbal and musical domains, but only when the STM tasks ensure sequential maintenance processes.

  9. Scale-dependent geomorphic responses to active restoration and implications for cutthroat trout

    Science.gov (United States)

    Salant, N.; Miller, S. W.

    2009-12-01

    -scale, process-based approach evaluates whether a commonly used restoration strategy creates geomorphic heterogeneity at scales relevant to fish diversity and microhabitat utilization, an understanding that will improve the efficiency and success of future restoration projects.

  10. The influence of punching process on residual stress and magnetic domain structure of non-oriented silicon steel

    International Nuclear Information System (INIS)

    Cao, Hongzhi; Hao, Linpo; Yi, Jingwen; Zhang, Xianglin; Luo, Zhonghan; Chen, Shenglin; Li, Rongfeng

    2016-01-01

    The main purpose of this paper is to investigate the influence of punching process on residual stress and magnetic domain structure. The residual stress in non-oriented silicon steel after punching process was measured by nanoindentation. The maximum depth was kept constant as 300 nm during nanoindentation. The material around indentation region exhibited no significant pile-up deformation. The calculation of residual stress was based on the Suresh theoretical model. Our experimental results show that residual compressive stress was generated around the sheared edge after punching. The width of residual stress affected zone by punching was around 0.4–0.5 mm. After annealing treatment, the residual stress was significantly decreased. Magnetic domain structure was observed according to the Bitter method. The un-annealed sample exhibited complicated domain patterns, and the widths of the magnetic domains varied between 3 µm and 8 µm. Most of the domain patterns of the annealed sample were 180°-domains and 90°-domains, and the widths of the domains decreased to 1–3 µm. - Highlights: • The residual stress distribution on sheared edge was measured. • The residual compressive stress was generated around the sheared edge. • The width of residual stress affected zone was about 0.4–0.5 mm. • The shape and width of the domain structure would be changed by annealing.

  11. Human-induced geomorphic change across environmental gradients

    Science.gov (United States)

    Vanacker, V.; Molina, A.; Bellin, N.; Christl, M.

    2016-12-01

    Human-induced land cover changes are causing important adverse effects on the ecological services rendered by mountain ecosystems, and the number of case-studies of the impact of humans on soil erosion and sediment yield has mounted rapidly. Anthropogenic disturbance of natural vegetation can profoundly alter the physical, chemical and biological processes within soils. Rapid removal of topsoil during intense farming can result in an imbalance between soil production through chemical weathering and physical soil erosion, with direct implications on nutrient cycling, soil fertility and agricultural production. In this study, we present a conceptual model for assessing human-induced erosion for a wide variety of environmental settings and pose that human-induced geomorphic change cannot be assessed solely based on modern erosion rates as natural or baseline erosion rates can be important in e.g. mountainous terrain. As such, we assess the vulnerability of a given ecosystem to human-induced land cover change by quantifying the change in catchment-wide erosion rates resulting from anthropogenic changes in vegetation cover. Human-induced erosion is here approximated by the ratio of the total specific sediment yield to the natural erosional mass flux, and is dimensionless. The conceptual model is applied to three contrasting environmental settings where data on soil production, physical soil erosion and long-term denudation are available: the tropical Andes, subtropical southern Brazil, and semi-arid Spanish Cordillera. The magnitude of human-induced geomorphic change strongly differs between the three regions. The data suggest that the sensitivity to human-induced erosion is ecosystem dependent, and related to soil erosivity and potential vegetation cover disturbances as a result of human impact. It may therefore be expected that the potential for erosion regulation is larger in well-vegetated ecosystem where strong differences may exist in vegetation cover between

  12. Variability in fluvial geomorphic response to anthropogenic disturbance

    Science.gov (United States)

    Verstraeten, Gert; Broothaerts, Nils; Van Loo, Maarten; Notebaert, Bastiaan; D'Haen, Koen; Dusar, Bert; De Brue, Hanne

    2017-10-01

    Humans have greatly impacted the processes and intensities of erosion, sediment transport and storage since the introduction of agriculture. In many regions around the world, accelerated floodplain sedimentation can be related to increases in human pressure on the environment. However, the relation between the intensity of anthropogenic disturbance and the magnitude of change in fluvial sediment dynamics is not straightforward and often non-linear. Here, we review a number of case studies from contrasting environmental settings in the European loess belt, the Eastern Mediterranean mountain ranges and the eastern USA. Detailed field-based sediment archive studies and sediment budgets covering time periods ranging from 200 to over 5000 year, as well as the use of pollen and sediment provenance techniques, show that no overarching concept of changes in floodplain sedimentation following anthropogenic disturbance can be established. Slope-channel (dis)connectivity controls the existence of thresholds or tipping points that need to be crossed before significant changes in downstream sediment dynamics are recorded following human impact. This coupling can be related to characteristics of human pressure such as its duration, intensity and spatial patterns, but also to the geomorphic and tectonic setting. Furthermore, internal feedback mechanisms, such as those between erosion and soil thickness, further complicate the story. All these factors controlling the propagation of sediment from eroding hillslopes to river channels vary between regions. Hence, only unique patterns of fluvial geomorphic response can be identified. As a result, unravelling the human impact from current-day sediment archives and predicting the impact of future human disturbances on fluvial sediment dynamics remain a major challenge. This has important implications for interpreting contemporary sediment yields as well as downstream sediment records in large floodplains, deltas and the marine

  13. Impacts of Geomorphic Disturbances on Plant Colonization in Ebba Valley, Central Spitsbergen, Svalbard

    Directory of Open Access Journals (Sweden)

    Stawska Monika

    2017-03-01

    Full Text Available Global warming observed nowadays causes an increase in geomorphic activity in polar regions. Within the areas influenced by cold climatic conditions, relief dynamics and vegetation development are the main landscape shaping processes. The study is limited to the Ebba Valley (78°43’N; 16°37’E in central Spitsbergen (Svalbard, where geomorphologic observations and vegetation sampling were conducted in 2007. The valley was divided into three zones differentiated by dominating geomorphic activity and stability of deposits. The settlement and the evolution of plant cover have been documented there. The main factors that control well developed vegetation cover within raised marine terraces are frost heave and solifluction. In deeper parts of the valley, aeolian processes dominate and high differentiation of microsite conditions causes high variability in plant coverage. The area close to the Ebba glacier marginal zone is characterized by initial stages of plant colonisation where disturbance to vegetation is mainly caused by hydrological processes.

  14. Synthesis of ferrite nanoparticle by milling process for preparation of single domain magnet

    International Nuclear Information System (INIS)

    Suryadi; Hasbiyallah; Agus S W; Nurul TR; Budhy Kurniawan

    2009-01-01

    Study of ferrite nanoparticle synthesis for preparation of single domain magnet by milling of scrap magnet material have been done. Sample preparation were done using disk mill continued with high energy milling (HEM). Some powder were taken after 5, 10 dan 20 hours milling using HEM-E3D. The powder were then characterized using X-Ray Fluorescence (XRF), X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). XRF characterization result, confirmed by XRD analysis result, showed that the sample are of Strontium ferrite phase. Microstructure analysis result showed the occurrence of grain refining process of ferrite particle with increasing of milling time. Particle having size of nanometers successfully obtained, although in unhomogeneous distribution. Magnetic properties characterization result showed the increasing of hysteresis curve area of sample for longer milling time and sintering process. (author)

  15. Search for QCD Instanton-Induced Processes at HERA in the High-$Q^2$ Domain

    CERN Document Server

    Andreev, Vladimir; Begzsuren, Khurelbaatar; Belousov, Anatoli; Bolz, Arthur; Boudry, Vincent; Brandt, Gerhard; Brisson, Violette; Britzger, Daniel; Buniatyan, Armen; Bylinkin, Alexander; Bystritskaya, Lena; Campbell, Alan; Cantun Avila, Karla~Beatriz; Cerny, Karel; Chekelian, Vladimir; Contreras, Guillermo; Cvach, Jaroslav; Dainton, John; Daum, Karin; Diaconu, Cristinel; Dobre, Monica; Dodonov, Vitaliy; Eckerlin, Guenter; Egli, Stephan; Elsen, Eckhard; Favart, Laurent; Fedotov, Alexandre; Feltesse, Joel; Ferencei, Jozef; Fleischer, Manfred; Fomenko, Alexander; Gabathuler, Erwin; Gayler, Joerg; Ghazaryan, Samvel; Goerlich, Lidia; Gogitidze, Nelly; Gouzevitch, Maxime; Grab, Christoph; Grebenyuk, Anastasia; Greenshaw, Timothy; Grindhammer, Guenter; Haidt, Dieter; Henderson, Rob~CW; Hladky, Jan; Hoffmann, Dirk; Horisberger, Roland; Hreus, Tomas; Huber, Florian; Jacquet, Marie; Janssen, Xavier; Jung, Hannes; Kapichine, Mikhail; Katzy, Judith; Kiesling, Christian; Klein, Max; Kleinwort, Claus; Kogler, Roman; Kostka, Peter; Kretzschmar, Jan; Krücker, Dirk; Krüger, K.; Landon, Murrough; Lange, Wolfgang; Laycock, Paul; Lebedev, Andrei; Levonian, Sergey; Lipka, Katerina; List, Benno; List, Jenny; Lobodzinski, Bogdan; Malinovski, Evgenij; Martyn, Hans-Ulrich; Maxfield, Steve~J; Mehta, Andrew; Meyer, Andreas; Meyer, Hinrich; Meyer, Joachim; Mikocki, Stanislav; Morozov, Anatoly; Müller, Katharina; Naumann, Thomas; Newman, Paul~R; Niebuhr, Carsten; Nowak, Grazyna; Olsson, Jan~Erik; Ozerov, Dmitri; Pascaud, Christian; Patel, Girish; Perez, Emmanuelle; Petrukhin, Alexey; Picuric, Ivana; Pirumov, Hayk; Pitzl, Daniel; Placakyte, Ringaile; Pokorny, Boris; Polifka, Richard; Radescu, Voica; Raicevic, Natasa; Ravdandorj, Togoo; Reimer, Petr; Rizvi, Eram; Robmann, Peter; Roosen, Robert; Rostovtsev, Andrei; Rotaru, Marina; Rusakov, Serguei; Salek, David; Sankey, Dave~PC; Sauter, Michel; Sauvan, Emmanuel; Schmitt, Stefan; Schoeffel, Laurent; Schöning, Andre; Sefkow, Felix; Shushkevich, Stanislav; Soloviev, Yuri; Sopicki, Pawel; South, David; Spaskov, Vladimir; Specka, Arnd; Steder, Michael; Stella, Bruno; Straumann, Ulrich; Sykora, Tomas; Thompson, Paul; Traynor, Daniel; Truöl, Peter; Tsakov, Ivan; Tseepeldorj, Baatar; Turnau, Jacek; Valkarova, Alice; Vallee, Claude; Van Mechelen, Pierre; Vazdik, Iakov; Wegener, Dietrich; Wünsch, Eberhard; Zacek, Jozef; Zhang, Zhiqing; Zlebcik, Radek; Zohrabyan, Hamlet; Zomer, Fabian

    2016-07-07

    Signals of QCD instanton-induced processes are searched for in neutral current deep-inelastic scattering at the electron-proton collider HERA in the kinematic region defined by the Bjorken-scaling variable $x > 10^{-3}$, the inelasticity $0.2< y < 0.7$ and the photon virtuality $150 < Q^2 < 15000$ GeV$^2$. The search is performed using H1 data corresponding to an integrated luminosity of ~$351$ pb$^{-1}$. No evidence for the production of QCD instanton-induced events is observed. Upper limits on the cross section for instanton-induced processes between $1.5$~pb and $6$~pb, at $95\\%$~ confidence level, are obtained depending on the kinematic domain in which instantons could be produced. Compared to earlier publications, the limits are improved by an order of magnitude and for the first time are challenging theory predictions.

  16. Search for QCD instanton-induced processes at HERA in the high-Q2 domain

    International Nuclear Information System (INIS)

    Andreev, V.; Baghdasaryan, A.; Begzsuren, K.

    2016-03-01

    Signals of QCD instanton-induced processes are searched for in neutral current deep-inelastic scattering at the electron-proton collider HERA in the kinematic region defined by the Bjorken-scaling variable x>10 -3 , the inelasticity 0.2processes between 1.5 pb and 6 pb, at 95% confidence level, are obtained depending on the kinematic domain in which instantons could be produced. Compared to earlier publications, the limits are improved by an order of magnitude and for the first time are challenging theory predictions.

  17. Applications of quaternary stratigraphic, soil-geomorphic, and quantitative geomorphic analyses to the evaluation of tectonic activity and landscape evolution in the Upper Coastal Plain, South Carolina

    International Nuclear Information System (INIS)

    Hanson, K.L.; Bullard, T.F.; Wit, M.W. de; Stieve, A.L.

    1993-01-01

    Geomorphic analyses combined with mapping of fluvial terraces and upland geomorphic surfaces provide new approaches and data for evaluating the Quaternary activity of post-Cretaceous faults that are recognized in subsurface data at the Savannah River Site in the Upper Coastal Plain of southwestern South Carolina. Analyses of longitudinal stream and terrace profiles, regional slope maps, and drainage basin morphometry indicate long-term uplift and southeast tilt of the site region. Preliminary results of drainage basin characterization suggests an apparent rejuvenation of drainages along the trace of the Pen Branch fault (a Tertiary reactivated reverse fault that initiated as a basin-margin normal fault along the northern boundary of the Triassic Dunbarton Basin). This apparent rejuvenation of drainages may be the result of nontectonic geomorphic processes or local tectonic uplift and tilting within a framework of regional uplift. Longitudinal profiles of fluvial terrace surfaces that are laterally continuous across the projected surface trace of the Pen Branch fault show no obvious evidence of warping or faulting within a resolution of ∼3 m. This combined with the estimated age of the terrace surfaces (350 ka to 1 Ma) indicates that if the Pen Branch fault is active, the Pleistocene rate of slip is very low (0.002 to 0.009 mm/yr)

  18. Geomorphic Unit Tool (GUT): Applications of Fluvial Mapping

    Science.gov (United States)

    Kramer, N.; Bangen, S. G.; Wheaton, J. M.; Bouwes, N.; Wall, E.; Saunders, C.; Bennett, S.; Fortney, S.

    2017-12-01

    Geomorphic units are the building blocks of rivers and represent distinct habitat patches for many fluvial organisms. We present the Geomorphic Unit Toolkit (GUT), a flexible GIS geomorphic unit mapping tool, to generate maps of fluvial landforms from topography. GUT applies attributes to landforms based on flow stage (Tier 1), topographic signatures (Tier 2), geomorphic characteristics (Tier 3) and patch characteristics (Tier 4) to derive attributed maps at the level of detail required by analysts. We hypothesize that if more rigorous and consistent geomorphic mapping is conducted, better correlations between physical habitat units and ecohydraulic model results will be obtained compared to past work. Using output from GUT for coarse bed tributary streams in the Columbia River Basin, we explore relationships between salmonid habitat and geomorphic spatial metrics. We also highlight case studies of how GUT can be used to showcase geomorphic impact from large wood restoration efforts. Provided high resolution topography exists, this tool can be used to quickly assess changes in fluvial geomorphology in watersheds impacted by human activities.

  19. Source Reconstruction of Brain Potentials Using Bayesian Model Averaging to Analyze Face Intra-Domain vs. Face-Occupation Cross-Domain Processing.

    Science.gov (United States)

    Olivares, Ela I; Lage-Castellanos, Agustín; Bobes, María A; Iglesias, Jaime

    2018-01-01

    We investigated the neural correlates of the access to and retrieval of face structure information in contrast to those concerning the access to and retrieval of person-related verbal information, triggered by faces. We experimentally induced stimulus familiarity via a systematic learning procedure including faces with and without associated verbal information. Then, we recorded event-related potentials (ERPs) in both intra-domain (face-feature) and cross-domain (face-occupation) matching tasks while N400-like responses were elicited by incorrect eyes-eyebrows completions and occupations, respectively. A novel Bayesian source reconstruction approach plus conjunction analysis of group effects revealed that in both cases the generated N170s were of similar amplitude but had different neural origin. Thus, whereas the N170 of faces was associated predominantly to right fusiform and occipital regions (the so-called "Fusiform Face Area", "FFA" and "Occipital Face Area", "OFA", respectively), the N170 of occupations was associated to a bilateral very posterior activity, suggestive of basic perceptual processes. Importantly, the right-sided perceptual P200 and the face-related N250 were evoked exclusively in the intra-domain task, with sources in OFA and extensively in the fusiform region, respectively. Regarding later latencies, the intra-domain N400 seemed to be generated in right posterior brain regions encompassing mainly OFA and, to some extent, the FFA, likely reflecting neural operations triggered by structural incongruities. In turn, the cross-domain N400 was related to more anterior left-sided fusiform and temporal inferior sources, paralleling those described previously for the classic verbal N400. These results support the existence of differentiated neural streams for face structure and person-related verbal processing triggered by faces, which can be activated differentially according to specific task demands.

  20. Source Reconstruction of Brain Potentials Using Bayesian Model Averaging to Analyze Face Intra-Domain vs. Face-Occupation Cross-Domain Processing

    Directory of Open Access Journals (Sweden)

    Ela I. Olivares

    2018-03-01

    Full Text Available We investigated the neural correlates of the access to and retrieval of face structure information in contrast to those concerning the access to and retrieval of person-related verbal information, triggered by faces. We experimentally induced stimulus familiarity via a systematic learning procedure including faces with and without associated verbal information. Then, we recorded event-related potentials (ERPs in both intra-domain (face-feature and cross-domain (face-occupation matching tasks while N400-like responses were elicited by incorrect eyes-eyebrows completions and occupations, respectively. A novel Bayesian source reconstruction approach plus conjunction analysis of group effects revealed that in both cases the generated N170s were of similar amplitude but had different neural origin. Thus, whereas the N170 of faces was associated predominantly to right fusiform and occipital regions (the so-called “Fusiform Face Area”, “FFA” and “Occipital Face Area”, “OFA”, respectively, the N170 of occupations was associated to a bilateral very posterior activity, suggestive of basic perceptual processes. Importantly, the right-sided perceptual P200 and the face-related N250 were evoked exclusively in the intra-domain task, with sources in OFA and extensively in the fusiform region, respectively. Regarding later latencies, the intra-domain N400 seemed to be generated in right posterior brain regions encompassing mainly OFA and, to some extent, the FFA, likely reflecting neural operations triggered by structural incongruities. In turn, the cross-domain N400 was related to more anterior left-sided fusiform and temporal inferior sources, paralleling those described previously for the classic verbal N400. These results support the existence of differentiated neural streams for face structure and person-related verbal processing triggered by faces, which can be activated differentially according to specific task demands.

  1. Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes

    Science.gov (United States)

    Zhai, Zhao-Hui; Zhong, Sen-Cheng; Li, Jun; Zhu, Li-Guo; Meng, Kun; Li, Jiang; Liu, Qiao; Peng, Qi-Xian; Li, Ze-Ren; Zhao, Jian-Heng

    2016-09-01

    Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study of irreversible or single shot ultrafast events requires ability to record transient properties at multiple time delays, i.e., time resolved at single shot level, which is not available currently. Here by angular multiplexing use of femtosecond laser pulses, we developed and demonstrated a time resolved, transient terahertz time domain spectroscopy technique, where burst mode THz pulses were generated and then detected in a single shot measurement manner. The burst mode THz pulses contain 2 sub-THz pulses, and the time gap between them is adjustable up to 1 ns with picosecond accuracy, thus it can be used to probe the single shot event at two different time delays. The system can detect the sub-THz pulses at 0.1 THz-2.5 THz range with signal to noise ratio (SNR) of ˜400 and spectrum resolution of 0.05 THz. System design was described here, and optimizations of single shot measurement of THz pulses were discussed in detail. Methods to improve SNR were also discussed in detail. A system application was demonstrated where pulsed THz signals at different time delays of the ultrafast process were successfully acquired within single shot measurement. This time resolved transient terahertz time domain spectroscopy technique provides a new diagnostic tool for irreversible or single shot ultrafast events where dynamic information can be extracted at terahertz range within one-shot experiment.

  2. Predictive modeling of nanoscale domain morphology in solution-processed organic thin films

    Science.gov (United States)

    Schaaf, Cyrus; Jenkins, Michael; Morehouse, Robell; Stanfield, Dane; McDowall, Stephen; Johnson, Brad L.; Patrick, David L.

    2017-09-01

    The electronic and optoelectronic properties of molecular semiconductor thin films are directly linked to their extrinsic nanoscale structural characteristics such as domain size and spatial distributions. In films prepared by common solution-phase deposition techniques such as spin casting and solvent-based printing, morphology is governed by a complex interrelated set of thermodynamic and kinetic factors that classical models fail to adequately capture, leaving them unable to provide much insight, let alone predictive design guidance for tailoring films with specific nanostructural characteristics. Here we introduce a comprehensive treatment of solution-based film formation enabling quantitative prediction of domain formation rates, coverage, and spacing statistics based on a small number of experimentally measureable parameters. The model combines a mean-field rate equation treatment of monomer aggregation kinetics with classical nucleation theory and a supersaturation-dependent critical nucleus size to solve for the quasi-two-dimensional temporally and spatially varying monomer concentration, nucleation rate, and other properties. Excellent agreement is observed with measured nucleation densities and interdomain radial distribution functions in polycrystalline tetracene films. Numerical solutions lead to a set of general design rules enabling predictive morphological control in solution-processed molecular crystalline films.

  3. Vivaldi: A Domain-Specific Language for Volume Processing and Visualization on Distributed Heterogeneous Systems.

    Science.gov (United States)

    Choi, Hyungsuk; Choi, Woohyuk; Quan, Tran Minh; Hildebrand, David G C; Pfister, Hanspeter; Jeong, Won-Ki

    2014-12-01

    As the size of image data from microscopes and telescopes increases, the need for high-throughput processing and visualization of large volumetric data has become more pressing. At the same time, many-core processors and GPU accelerators are commonplace, making high-performance distributed heterogeneous computing systems affordable. However, effectively utilizing GPU clusters is difficult for novice programmers, and even experienced programmers often fail to fully leverage the computing power of new parallel architectures due to their steep learning curve and programming complexity. In this paper, we propose Vivaldi, a new domain-specific language for volume processing and visualization on distributed heterogeneous computing systems. Vivaldi's Python-like grammar and parallel processing abstractions provide flexible programming tools for non-experts to easily write high-performance parallel computing code. Vivaldi provides commonly used functions and numerical operators for customized visualization and high-throughput image processing applications. We demonstrate the performance and usability of Vivaldi on several examples ranging from volume rendering to image segmentation.

  4. An integrated domain specific language for post-processing and visualizing electrophysiological signals in Java.

    Science.gov (United States)

    Strasser, T; Peters, T; Jagle, H; Zrenner, E; Wilke, R

    2010-01-01

    Electrophysiology of vision - especially the electroretinogram (ERG) - is used as a non-invasive way for functional testing of the visual system. The ERG is a combined electrical response generated by neural and non-neuronal cells in the retina in response to light stimulation. This response can be recorded and used for diagnosis of numerous disorders. For both clinical practice and clinical trials it is important to process those signals in an accurate and fast way and to provide the results as structured, consistent reports. Therefore, we developed a freely available and open-source framework in Java (http://www.eye.uni-tuebingen.de/project/idsI4sigproc). The framework is focused on an easy integration with existing applications. By leveraging well-established software patterns like pipes-and-filters and fluent interfaces as well as by designing the application programming interfaces (API) as an integrated domain specific language (DSL) the overall framework provides a smooth learning curve. Additionally, it already contains several processing methods and visualization features and can be extended easily by implementing the provided interfaces. In this way, not only can new processing methods be added but the framework can also be adopted for other areas of signal processing. This article describes in detail the structure and implementation of the framework and demonstrate its application through the software package used in clinical practice and clinical trials at the University Eye Hospital Tuebingen one of the largest departments in the field of visual electrophysiology in Europe.

  5. Time-and-frequency domains approach to data processing in multiwavelength optical scatterometry of dielectric gratings

    KAUST Repository

    Granet, Gérard

    2013-01-01

    This paper focuses on scatterometry problems arising in lithography production of periodic gratings. Namely, the paper introduces a theoretical and numerical-modeling-oriented approach to scatterometry problems and discusses its capabilities. The approach allows for reliable detection of deviations in gratings\\' critical dimensions (CDs) during the manufacturing process. The core of the approach is the one-to-one correspondence between the electromagnetic (EM) characteristics and the geometric/material properties of gratings. The approach is based on highly accurate solutions of initial boundary-value problems describing EM waves\\' interaction on periodic gratings. The advantage of the approach is the ability to perform simultaneously and interactively both in frequency and time domains under conditions of possible resonant scattering of EM waves by infinite or finite gratings. This allows a detection of CDs for a wide range of gratings, and, thus is beneficial for the applied scatterometry. (C) 2013 Optical Society of America

  6. Time-and-frequency domains approach to data processing in multiwavelength optical scatterometry of dielectric gratings

    KAUST Repository

    Granet, Gé rard; Melezhik, Petr N.; Sirenko, Kostyantyn; Yashina, Nataliya P.

    2013-01-01

    This paper focuses on scatterometry problems arising in lithography production of periodic gratings. Namely, the paper introduces a theoretical and numerical-modeling-oriented approach to scatterometry problems and discusses its capabilities. The approach allows for reliable detection of deviations in gratings' critical dimensions (CDs) during the manufacturing process. The core of the approach is the one-to-one correspondence between the electromagnetic (EM) characteristics and the geometric/material properties of gratings. The approach is based on highly accurate solutions of initial boundary-value problems describing EM waves' interaction on periodic gratings. The advantage of the approach is the ability to perform simultaneously and interactively both in frequency and time domains under conditions of possible resonant scattering of EM waves by infinite or finite gratings. This allows a detection of CDs for a wide range of gratings, and, thus is beneficial for the applied scatterometry. (C) 2013 Optical Society of America

  7. Political parties Foundations and Politicization Processes in Brazil: action domain, amalgams and ambivalences

    Directory of Open Access Journals (Sweden)

    Eliana Tavares dos Reis

    2017-12-01

    Full Text Available The article analyzes the space of party foundations in Brazil. This field of action is perceived as a vehicle and a reflection of processes of politicization.The work is based on two axis: 1 the (structural and sociographic configuration of these party sectors and its relative autonomy or dependence according to the party organizations; 2 the possible intersections between political logic and domain and intellectuals from the exploitation of this specific area. It presents data on the creation and the creation chronology of party foundations, its organizational structure (websites, offices, sectors, tasks/roles divisions; requirements of various experts, products such as books, magazines, courses, incomes; etc. from information available on the internet as well as the social, political and cultural profiles of its presidents and former presidents. It was also examined the case of the Perseu Abramo Foundation of the Workers Party.

  8. Geomorphic, flood, and groundwater-flow characteristics of Bayfield Peninsula streams, Wisconsin, and implications for brook-trout habitat

    Science.gov (United States)

    Fitzpatrick, Faith A.; Peppler, Marie C.; Saad, David A.; Pratt, Dennis M.; Lenz, Bernard N.

    2015-01-01

    In 2002–03, the U.S. Geological Survey conducted a study of the geomorphic, flood, and groundwater-flow characteristics of five Bayfield Peninsula streams, Wisconsin (Cranberry River, Bark River, Raspberry River, Sioux River, and Whittlesey Creek) to determine the physical limitations for brook-trout habitat. The goals of the study were threefold: (1) to describe geomorphic characteristics and processes, (2) to determine how land-cover characteristics affect flood peaks, and (3) to determine how regional groundwater flow patterns affect base flow.

  9. Geomorphic and Hydrological challenges in Africa: implications for soil and water conservation

    Science.gov (United States)

    Vanmaercke, Matthias; Poesen, Jean

    2017-04-01

    Expected scenarios of climate change and population growth confront Africa with various important challenges related to food, water and energy security. Many of these challenges are closely linked to the impacts of soil erosion and other geomorphic processes, such as reduced crop yields, sedimentation of reservoirs and reduced freshwater quality. Despite the urgency and extent of many of these challenges, the causes and dynamics of these processes and their impacts remain severely understudied. This becomes apparent when the availability of e.g. soil erosion and catchment sediment export measurements for Africa is compared to that of other continents. Nonetheless, a substantial amount of geomorphic research has been conducted in Africa. Many of this work dates back from several decades ago, and were often only reported in 'gray literature' (e.g. internal reports). Here we present an overview of our current state of knowledge on soil erosion and its implications in Africa. We discuss which geomorphic process rate measurements are currently available and what can be learned from these with respect to the challenged raised above. We especially focus on our current understanding about the effectiveness of soil and water conservation techniques at various spatial and temporal scales. Based on specific case-studies (e.g. in Ethiopia and Uganda) and a meta-analysis of previous work, we highlight some research gaps, research needs and research opportunities when aiming to use Africa's soil and water resources sustainably and efficiently.

  10. Digital signals processing using non-linear orthogonal transformation in frequency domain

    Directory of Open Access Journals (Sweden)

    Ivanichenko E.V.

    2017-12-01

    Full Text Available The rapid progress of computer technology in recent decades led to a wide introduction of methods of digital information processing practically in all fields of scientific research. In this case, among various applications of computing one of the most important places is occupied by digital processing systems signals (DSP that are used in data processing remote solution tasks of navigation of aerospace and marine objects, communications, radiophysics, digital optics and in a number of other applications. Digital Signal Processing (DSP is a dynamically developing an area that covers both technical and software tools. Related areas for digital signal processing are theory information, in particular, the theory of optimal signal reception and theory pattern recognition. In the first case, the main problem is signal extraction against a background of noise and interference of a different physical nature, and in the second - automatic recognition, i.e. classification and signal identification. In the digital processing of signals under a signal, we mean its mathematical description, i.e. a certain real function, containing information on the state or behavior of a physical system under an event that can be defined on a continuous or discrete space of time variation or spatial coordinates. In the broad sense, DSP systems mean a complex algorithmic, hardware and software. As a rule, systems contain specialized technical means of preliminary (or primary signal processing and special technical means for secondary processing of signals. Means of pretreatment are designed to process the original signals observed in general case against a background of random noise and interference of a different physical nature and represented in the form of discrete digital samples, for the purpose of detecting and selection (selection of the useful signal and evaluation characteristics of the detected signal. A new method of digital signal processing in the frequency

  11. Fire passage on geomorphic fractures in Cerrado: effect on vegetation

    OpenAIRE

    Otacílio Antunes Santana; José Marcelo Imaña Encinas; Flávio Luiz de Souza Silveira

    2017-01-01

    Geomorphic fracture is a natural geologic formation that sometimes forms a deep fissure in the rock with the establishment of soil and vegetation. The objective of this work was to analyze vegetation within geomorphic fractures under the effect of wildfire passage. The biometric variables evaluated before and after fire passage were: diameter, height, leaf area index, timber volume, grass biomass, number of trees and shrubs and of species. Results (in fractures) were compared to adjacent area...

  12. Exact solutions of linear reaction-diffusion processes on a uniformly growing domain: criteria for successful colonization.

    Directory of Open Access Journals (Sweden)

    Matthew J Simpson

    Full Text Available Many processes during embryonic development involve transport and reaction of molecules, or transport and proliferation of cells, within growing tissues. Mathematical models of such processes usually take the form of a reaction-diffusion partial differential equation (PDE on a growing domain. Previous analyses of such models have mainly involved solving the PDEs numerically. Here, we present a framework for calculating the exact solution of a linear reaction-diffusion PDE on a growing domain. We derive an exact solution for a general class of one-dimensional linear reaction-diffusion process on 0domain. Comparing our exact solutions with numerical approximations confirms the veracity of the method. Furthermore, our examples illustrate a delicate interplay between: (i the rate at which the domain elongates, (ii the diffusivity associated with the spreading density profile, (iii the reaction rate, and (iv the initial condition. Altering the balance between these four features leads to different outcomes in terms of whether an initial profile, located near x = 0, eventually overcomes the domain growth and colonizes the entire length of the domain by reaching the boundary where x = L(t.

  13. Modeling and Simulation of Voids in Composite Tape Winding Process Based on Domain Superposition Technique

    Science.gov (United States)

    Deng, Bo; Shi, Yaoyao

    2017-11-01

    The tape winding technology is an effective way to fabricate rotationally composite materials. Nevertheless, some inevitable defects will seriously influence the performance of winding products. One of the crucial ways to identify the quality of fiber-reinforced composite material products is examining its void content. Significant improvement in products' mechanical properties can be achieved by minimizing the void defect. Two methods were applied in this study, finite element analysis and experimental testing, respectively, to investigate the mechanism of how void forming in composite tape winding processing. Based on the theories of interlayer intimate contact and Domain Superposition Technique (DST), a three-dimensional model of prepreg tape void with SolidWorks has been modeled in this paper. Whereafter, ABAQUS simulation software was used to simulate the void content change with pressure and temperature. Finally, a series of experiments were performed to determine the accuracy of the model-based predictions. The results showed that the model is effective for predicting the void content in the composite tape winding process.

  14. Domain Immersion Technique And Free Surface Computations Applied To Extrusion And Mixing Processes

    Science.gov (United States)

    Valette, Rudy; Vergnes, Bruno; Basset, Olivier; Coupez, Thierry

    2007-04-01

    This work focuses on the development of numerical techniques devoted to the simulation of mixing processes of complex fluids such as twin-screw extrusion or batch mixing. In mixing process simulation, the absence of symmetry of the moving boundaries (the screws or the rotors) implies that their rigid body motion has to be taken into account by using a special treatment. We therefore use a mesh immersion technique (MIT), which consists in using a P1+/P1-based (MINI-element) mixed finite element method for solving the velocity-pressure problem and then solving the problem in the whole barrel cavity by imposing a rigid motion (rotation) to nodes found located inside the so called immersed domain, each subdomain (screw, rotor) being represented by a surface CAD mesh (or its mathematical equation in simple cases). The independent meshes are immersed into a unique backgound computational mesh by computing the distance function to their boundaries. Intersections of meshes are accounted for, allowing to compute a fill factor usable as for the VOF methodology. This technique, combined with the use of parallel computing, allows to compute the time-dependent flow of generalized Newtonian fluids including yield stress fluids in a complex system such as a twin screw extruder, including moving free surfaces, which are treated by a "level set" and Hamilton-Jacobi method.

  15. From coastal barriers to mountain belts - commonalities in fundamental geomorphic scaling laws

    Science.gov (United States)

    Lazarus, E.

    2016-12-01

    Overwash is a sediment-transport process essential to the form and resilience of coastal barrier landscapes. Driven by storm events, overwash leaves behind distinctive sedimentary features that, although intensively studied, have lacked unifying quantitative descriptions with which to compare their morphological attributes across documented examples or relate them to other morphodynamic phenomena. Geomorphic scaling laws quantify how measures of shape and size change with respect to another - information that helps to constrain predictions of future change and reconstructions of past environmental conditions. Here, a physical model of erosional and depositional overwash morphology yields intrinsic, allometric scaling laws involving length, width, area, volume, and alongshore spacing. Corroborative comparisons with natural washover morphology indicate scale invariance spanning several orders of magnitude. Several observers of the physical model remarked that the overwashed barrier resembled a dissected linear mountain front with an alluvial apron - an intriguing reimagining of the intended analog. Indeed, that resemblance is reflected quantitatively in these new scaling relationships, which align with canonical scaling laws for terrestrial and marine drainage basins and alluvial fans on Earth and Mars. This finding suggests disparate geomorphic systems that share common allometric properties may be related dynamically, perhaps by an influence more fundamental than characteristic erosion and deposition processes. Such an influence could come from emergent behavior at the intersection of advection and diffusion. Geomorphic behaviors at advection-diffusion transitions (and vice versa), specifically, could be the key to disentangling mechanistic causality from acausality in physical landscape patterns.

  16. Human impact on the geomorphic evolution of the HOAL catchment, Lower Austria

    Science.gov (United States)

    Pöppl, Ronald; Kraushaar, Sabine; Strauss, Peter; Fuchs, Markus

    2016-04-01

    Since the beginning of human settlement extensive land cover and land use changes have induced significant geomorphic landscape changes as water and sediment dynamics have been transformed. The presented project focuses on the reconstruction of Holocene geomorphic landscape evolution and the assessment of recent geomorphic processes in the Northern foothills of the Eastern Alps in Austria - an area intensively agriculturally used since the middle ages and often overlooked in its geomorphic evolution. The study area is a small catchment (ca. 66 ha) which is located in the western part of Lower Austria comprising a land use history as well as environmental settings typical for wide regions across the Northern foothills of the Eastern Alps in Austria. The catchment elevation ranges from 268 to 323 m a.s.l. and has a mean slope angle of 8%. The climate in this region can be characterized as humid. The lithology mainly consists of Tertiary marly to sandy deposits which are superimposed by Quaternary sediments (e.g. loesses). Dominant soil types are Cambisols, Luvisols, and Planosols. Furthermore, the catchment is used as a Hydrological Open Air Laboratory (HOAL) implemented for the long-term research of water-related flow and transport processes in the landscape (http://hoal.hydrology.at). The main objective of this research project is to reconstruct Holocene landscape evolution by analyzing physical parameters of sediment cores taken from colluvial and alluvial sediment archives with additional 14C and OSL dating as well as by the measurement of truncated and covered standardized Luvisol profiles. First results will be presented at the EGU General Assembly 2016.

  17. Dynamic anticipatory processing of hierarchical sequential events: a common role for Broca's area and ventral premotor cortex across domains?

    Science.gov (United States)

    Fiebach, Christian J; Schubotz, Ricarda I

    2006-05-01

    This paper proposes a domain-general model for the functional contribution of ventral premotor cortex (PMv) and adjacent Broca's area to perceptual, cognitive, and motor processing. We propose to understand this frontal region as a highly flexible sequence processor, with the PMv mapping sequential events onto stored structural templates and Broca's Area involved in more complex, hierarchical or hypersequential processing. This proposal is supported by reference to previous functional neuroimaging studies investigating abstract sequence processing and syntactic processing.

  18. Using the Domain Identification Model to Study Major and Career Decision-Making Processes

    Science.gov (United States)

    Tendhar, Chosang; Singh, Kusum; Jones, Brett D.

    2018-01-01

    The purpose of this study was to examine the extent to which (1) a domain identification model could be used to predict students' engineering major and career intentions and (2) the MUSIC Model of Motivation components could be used to predict domain identification. The data for this study were collected from first-year engineering students. We…

  19. Monte Carlo simulation for thermal assisted reversal process of micro-magnetic torus ring with bistable closure domain structure

    Energy Technology Data Exchange (ETDEWEB)

    Terashima, Kenichi; Suzuki, Kenji; Yamaguchi, Katsuhiko, E-mail: yama@sss.fukushima-u.ac.jp

    2016-04-01

    Monte Carlo simulations were performed for temperature dependences of closure domain parameter for a magnetic micro-torus ring cluster under magnetic field on limited temperature regions. Simulation results show that magnetic field on tiny limited temperature region can reverse magnetic closure domain structures when the magnetic field is applied at a threshold temperature corresponding to intensity of applied magnetic field. This is one of thermally assisted switching phenomena through a self-organization process. The results show the way to find non-wasteful pairs between intensity of magnetic field and temperature region for reversing closure domain structure by temperature dependence of the fluctuation of closure domain parameter. Monte Carlo method for this simulation is very valuable to optimize the design of thermally assisted switching devices.

  20. Clay mineralogy in different geomorphic surfaces in sugarcane areas

    Science.gov (United States)

    Camargo, L.; Marques, J., Jr.

    2012-04-01

    The crystallization of the oxides and hydroxides of iron and aluminum and kaolinite of clay fraction is the result of pedogenetic processes controlled by the relief. These minerals have influence on the physical and chemical attributes of soil and exhibit spatial dependence. The pattern of spatial distribution is influenced by forms of relief as the geomorphic surfaces. In this sense, the studies aimed at understanding the relationship between relief and the distribution pattern of the clay fraction attributes contribute to the delineation of specific areas of management in the field. The objective of this study was to evaluate the spatial distribution of oxides and hydroxides of iron and aluminum and kaolinite of clay fraction and its relationship with the physical and chemical attributes in different geomorphic surfaces. Soil samples were collected in a transect each 25 m (100 samples) and in the sides of the same (200 samples) as well as an area of 500 ha (1 sample each six hectare). Geomorphic surfaces (GS) in the transect were mapped in detail to support mapping the entire area. The soil samples were taken to the laboratory for chemical, physical, and mineralogical analysis, and the pattern of spatial distribution of soil attributes was obtained by statistics and geostatistics. The GS I is considered the oldest surface of the study area, with depositional character, and a slope ranging from 0 to 4%. GS II and III are considered to be eroded, and the surface II plan a gentle slope that extends from the edge of the surface until the beginning of I and III. The crystallographic characteristics of the oxides and hydroxides of iron and aluminum and kaolinite showed spatial dependence and the distribution pattern corresponding to the limits present of the GS in the field. Surfaces I and II showed the best environments to the degree of crystallinity of hematite and the surface III to the greatest degree of crystallinity of goethite agreeing to the pedoenvironment

  1. Influence of anthropogenic alterations on geomorphic response to climate variations and change in San Francisco Bay-Delta and watershed

    Science.gov (United States)

    Florsheim, J.L.; Dettinger, M.D.

    2004-01-01

    Global warming and attendant sea-level rise may soon impact geomorphic processes in the Sacramento-San Joaquin River and San Francisco Bay Delta systems. During the past two centuries, dramatic anthropogenic changes in sediment supply and pervasive structural controls on rivers and floodplains have altered geomorphic responses to floods throughout a zone that extends upstream from tidally influenced areas to dams that regulate flow. Current geomorphic responses to floods differ from natural responses due to historical actions that concentrated the pre-disturbance multiple-channel and flood-basin system into single channels isolated by levees from increasingly developed floodplains and flood bypass channels, altered flow and sediment regimes, and caused subsidence of leveed Delta Islands. A review of historic and current geomorphic responses to floods illustrates the dominance of structural controls on geomorphic changes in the lowland part of the Sacramento-San Joaquin system. Current climate-change projections for CA suggest that the total volume of snowmelt runoff that may be shifted from spring and added to winter flows is roughly 5 maf/yr, similar to the volume currently available for flood storage in Sierra Nevadan reservoirs. Changes in timing of reservoir releases to accommodate these changes could add to either the magnitude or duration of winter flood peaks, each causing different geomorphic responses. Increased wintertime flows that accompany already large floods could increase overbank flood extent, erosion, and sedimentation, or alternatively increase the depth and strength of confined flows and increase the risk of levee failures. Runoff released from reservoirs as a relatively constant addition to winter baseflow would increase the duration of bankfull or possibly "levee-full" flows. This scenario could lead to bank and levee failure through increased saturation and seepage erosion. Projected sea level rise of 1-2 m would compound vulnerability of

  2. Geomorphic tipping points: convenient metaphor or fundamental landscape property?

    Science.gov (United States)

    Lane, Stuart

    2016-04-01

    In 2000 Malcolm Gladwell published as book that has done much to publicise Tipping Points in society but also in academia. His arguments, re-expressed in a geomorphic sense, have three core elements: (1) a "Law of the Few", where rapid change results from the effects of a relatively restricted number of critical elements, ones that are able to rapidly connect systems together, that are particularly sensitive to an external force, of that are spatially organised in a particular way; (2) a "Stickiness" where an element of the landscape is able to assimilate characteristics which make it progressively more applicable to the "Law of the Few"; and (3), given (1) and (2) a history and a geography that means that the same force can have dramatically different effects, according to where and when it occurs. Expressed in this way, it is not clear that Tipping Points bring much to our understanding in geomorphology that existing concepts (e.g. landscape sensitivity and recovery; cusp-catastrophe theory; non-linear dynamics systems) do not already provide. It may also be all too easy to describe change in geomorphology as involving a Tipping Point: we know that geomorphic processes often involve a non-linear response above a certain critical threshold; we know that landscapes can, after Denys Brunsden, be though of as involving long periods of boredom ("stability") interspersed with brief moments of terror ("change"); but these are not, after Gladwell, sufficient for the term Tipping Point to apply. Following from these issues, this talk will address three themes. First, it will question, through reference to specific examples, notably in high Alpine systems, the extent to which the Tipping Point analogy is truly a property of the world in which we live. Second, it will explore how 'tipping points' become assigned metaphorically, sometimes evolving to the point that they themselves gain agency, that is, shaping the way we interpret landscape rather than vice versa. Third, I

  3. Predicting Geomorphic and Hydrologic Risks after Wildfire Using Harmonic and Stochastic Analyses

    Science.gov (United States)

    Mikesell, J.; Kinoshita, A. M.; Florsheim, J. L.; Chin, A.; Nourbakhshbeidokhti, S.

    2017-12-01

    Wildfire is a landscape-scale disturbance that often alters hydrological processes and sediment flux during subsequent storms. Vegetation loss from wildfires induce changes to sediment supply such as channel erosion and sedimentation and streamflow magnitude or flooding. These changes enhance downstream hazards, threatening human populations and physical aquatic habitat over various time scales. Using Williams Canyon, a basin burned by the Waldo Canyon Fire (2012) as a case study, we utilize deterministic and statistical modeling methods (Fourier series and first order Markov chain) to assess pre- and post-fire geomorphic and hydrologic characteristics, including of precipitation, enhanced vegetation index (EVI, a satellite-based proxy of vegetation biomass), streamflow, and sediment flux. Local precipitation, terrestrial Light Detection and Ranging (LiDAR) scanning, and satellite-based products are used for these time series analyses. We present a framework to assess variability of periodic and nonperiodic climatic and multivariate trends to inform development of a post-wildfire risk assessment methodology. To establish the extent to which a wildfire affects hydrologic and geomorphic patterns, a Fourier series was used to fit pre- and post-fire geomorphic and hydrologic characteristics to yearly temporal cycles and subcycles of 6, 4, 3, and 2.4 months. These cycles were analyzed using least-squares estimates of the harmonic coefficients or amplitudes of each sub-cycle's contribution to fit the overall behavior of a Fourier series. The stochastic variances of these characteristics were analyzed by composing first-order Markov models and probabilistic analysis through direct likelihood estimates. Preliminary results highlight an increased dependence of monthly post-fire hydrologic characteristics on 12 and 6-month temporal cycles. This statistical and probabilistic analysis provides a basis to determine the impact of wildfires on the temporal dependence of

  4. Effects of simultaneous climate change and geomorphic evolution on thermal characteristics of a shallow Alaskan lake

    Science.gov (United States)

    Griffiths, Jennifer R.; Schindler, Daniel E.; Balistrieri, Laurie S.; Ruggerone, Gregory T.

    2011-01-01

    We used a hydrodynamics model to assess the consequences of climate warming and contemporary geomorphic evolution for thermal conditions in a large, shallow Alaskan lake. We evaluated the effects of both known climate and landscape change, including rapid outlet erosion and migration of the principal inlet stream, over the past 50 yr as well as future scenarios of geomorphic restoration. Compared to effects of air temperature during the past 50 yr, lake thermal properties showed little sensitivity to substantial (~60%) loss of lake volume, as the lake maximum depth declined from 6 m to 4 m driven by outlet erosion. The direction and magnitude of future lake thermal responses will be driven largely by the extent of inlet stream migration when it occurs simultaneously with outlet erosion. Maintaining connectivity with inlet streams had substantial effects on buffering lake thermal responses to warming climate. Failing to account for changing rates and types of geomorphic processes under continuing climate change may misidentify the primary drivers of lake thermal responses and reduce our ability to understand the consequences for aquatic organisms.

  5. Soil Response to Global Change: Soil Process Domains and Pedogenic Thresholds (Invited)

    Science.gov (United States)

    Chadwick, O.; Kramer, M. G.; Chorover, J.

    2013-12-01

    The capacity of soil to withstand perturbations, whether driven by climate, land use change, or spread of invasive species, depends on its chemical composition and physical state. The dynamic interplay between stable, well buffered soil process domains and thresholds in soil state and function is a strong determinant of soil response to forcing from global change. In terrestrial ecosystems, edaphic responses are often mediated by availability of water and its flux into and through soils. Water influences soil processes in several ways: it supports biological production, hence proton-donor, electron-donor and complexing-ligand production; it determines the advective removal of dissolution products, and it can promote anoxia that leads microorganisms to utilize alternative electron acceptors. As a consequence climate patterns strongly influence global distribution of soil, although within region variability is governed by other factors such as landscape age, parent material and human land use. By contrast, soil properties can vary greatly among climate regions, variation which is guided by the functioning of a suite of chemical processes that tend to maintain chemical status quo. This soil 'buffering' involves acid-base reactions as minerals weather and oxidation-reduction reactions that are driven by microbial respiration. At the planetary scale, soil pH provides a reasonable indicator of process domains and varies from about 3.5 to10, globally, although most soils lie between about 4.5 and 8.5. Those that are above 7.5 are strongly buffered by the carbonate system, those that are characterized by neutral pH (7.5-6) are buffered by release of non-hydrolyzing cations from primary minerals and colloid surfaces, and those that are buffered by hydrolytic aluminum on colloidal surfaces. Alkali and alkaline (with the exception of limestone parent material) soils are usually associated with arid and semiarid conditions, neutral pH soils with young soils in both dry and wet

  6. Characterizing the geomorphic setting of precariously balanced rocks using terrestrial laser scanning technology

    Science.gov (United States)

    Haddad, D. E.; Arrowsmith, R.

    2009-12-01

    Terrestrial laser scanning (TLS) technology is rapidly becoming an effective three-dimensional imaging tool. Precariously balanced rocks are a subset of spheroidally weathered boulders. They are balanced on bedrock pedestals and are formed in upland drainage basins and pediments of exhumed plutons. Precarious rocks are used as negative evidence of earthquake-driven extreme ground motions. Field surveys of PBRs are coupled with cosmogenic radionuclide (CRN) surface exposure dating techniques to determine their exhumation rates. These rates are used in statistical simulations to estimate the magnitudes and recurrences of earthquake-generated extreme ground shaking as a means to physically validate seismic hazard analyses. However, the geomorphic setting of PBRs in the landscape is poorly constrained when interpreting their exhumation rates from CRN surface exposure dates. Are PBRs located on steep or gentle hillslopes? Are they located near drainages or hillslope crests? What geomorphic processes control the spatial distribution of PBRs in a landscape, and where do these processes dominate? Because the fundamental hillslope transport laws are largely controlled by local hillslope gradient and contributing area, the location of a PBR is controlled by the geomorphic agents and their rates acting on it. Our latest efforts involve using a combination of TLS and airborne laser swath mapping (ALSM) to characterize the geomorphic situation of PBRs. We used a Riegl LPM 800i (LPM 321) terrestrial laser scanner to scan a ~1.5 m tall by ~1 m wide precariously balanced rock in the Granite Dells, central Arizona. The PBR was scanned from six positions, and the scans were aligned to a point cloud totaling 3.4M points. We also scanned a ~50 m by ~150 m area covering PBR hillslopes from five scan positions. The resulting 5.5M points were used to create a digital terrain model of precarious rocks and their hillslopes. Our TLS- and ALSM-generated surface models and DEMs provide a

  7. Exact solutions of linear reaction-diffusion processes on a uniformly growing domain: criteria for successful colonization.

    Science.gov (United States)

    Simpson, Matthew J

    2015-01-01

    Many processes during embryonic development involve transport and reaction of molecules, or transport and proliferation of cells, within growing tissues. Mathematical models of such processes usually take the form of a reaction-diffusion partial differential equation (PDE) on a growing domain. Previous analyses of such models have mainly involved solving the PDEs numerically. Here, we present a framework for calculating the exact solution of a linear reaction-diffusion PDE on a growing domain. We derive an exact solution for a general class of one-dimensional linear reaction-diffusion process on 0exact solutions with numerical approximations confirms the veracity of the method. Furthermore, our examples illustrate a delicate interplay between: (i) the rate at which the domain elongates, (ii) the diffusivity associated with the spreading density profile, (iii) the reaction rate, and (iv) the initial condition. Altering the balance between these four features leads to different outcomes in terms of whether an initial profile, located near x = 0, eventually overcomes the domain growth and colonizes the entire length of the domain by reaching the boundary where x = L(t).

  8. Climatic and geomorphic controls on low flow hydrograph recession

    Science.gov (United States)

    Chandler, D. G.; Daley, M.; Kasaee Roodsari, B.; Shaw, S. B.; McNamara, J.

    2017-12-01

    Large scale operational hydrologic models should be capable of predicting seasonally low flow and stream intermittency as well as peak flow and inundation. We contrast examples of controls on low flow exerted by geomorphic and climatic setting at small catchment study sites in the Northeast and Northwest of the USA to indicate differences in hydrologic processes. Both regions accumulate winter snowpack and have an extended spring freshet, but the Reynolds Creek CZO and Dry Creek Experimental Watershed (both in Idaho mountains) experience a protracted summer drought, with occasional storms whereas precipitation free periods greater than five days are uncommon in the hilly Sleepers River (Vermont), and Yellow Barn State Forest (New York) and at Ley Creek, on a glacial plain (New York). At both Dry Creek and Reynolds Creek, headwater stream flow direction was transverse to groundwater, and below field capacity discharge was well related to either the ground water surface or corresponded to inversion of the hydraulic gradient over the depth of the soil. At all sites except Ley Creek, the headwaters became intermittent as the main tributary discharge declined, often disconnecting the surface source springs and seeps from the valley bottom stream. At the Idaho sites recession analysis for main stem was further complicated by consumptive use for irrigation and domestic wells. Modeling the recession characteristics of these various settings and across stream orders results in a variety of exponent values for power law scaling approaches that indicate the importance of site context for modeling low flow.

  9. Interpretation of recent alpine landscape system evolution using geomorphic mapping and L-band InSAR analyses

    Science.gov (United States)

    Imaizumi, Fumitoshi; Nishiguchi, Takaki; Matsuoka, Norikazu; Trappmann, Daniel; Stoffel, Markus

    2018-06-01

    Alpine landscapes are typically characterized by inherited features of past glaciations and, for the more recent past, by the interplay of a multitude of types of geomorphic processes, including permafrost creep, rockfalls, debris flows, and landslides. These different processes usually exhibit large spatial and temporal variations in activity and velocity. The understanding of these processes in a wide alpine area is often hindered by difficulties in their surveying. In this study, we attempt to disentangle recent changes in an alpine landscape system using geomorphic mapping and L-band DInSAR analyses (ALOS-PALSAR) in the Zermatt Valley, Swiss Alps. Geomorphic mapping points to a preferential distribution of rock glaciers on north-facing slopes, whereas talus slopes are concentrated on south-facing slopes. Field-based interpretation of ground deformation in rock glaciers and movements in talus slopes correlates well with the ratio of InSAR images showing potential ground deformation. Moraines formed during the Little Ice Age, rock glaciers, and talus slopes on north-facing slopes are more active than landforms on south-facing slopes, implying that the presence of permafrost facilitates the deformation of these geomorphic units. Such deformations of geomorphic units prevail also at the elevation of glacier termini. For rock cliffs, the ratio of images indicating retreat is affected by slope orientation and elevation. Linkages between sediment supply from rock cliffs and sediment transport in torrents are different among tributaries, affected by relative locations between sediment supply areas and the channel network. We conclude that the combined use of field surveys and L-band DInSAR analyses can substantially improve process understanding in steep, high-mountain terrain.

  10. Nonlinear Optical Spectroscopy in the Time Domain: Studies of Ultrafast Molecular Processes in the Condensed Phase.

    Science.gov (United States)

    Joo, Taiha

    Ultrafast molecular processes in the condensed phase at room temperature are studied in the time domain by four wave mixing spectroscopy. The structure/dynamics of various quantum states can be studied by varying the time ordering of the incident fields, their polarization, their colors, etc. In one, time-resolved coherent Stokes Raman spectroscopy of benzene is investigated at room temperature. The reorientational correlation time of benzene as well as the T_2 time of the nu _1 ring-breathing mode have been measured by using two different polarization geometries. Bohr frequency difference beats have also been resolved between the nu_1 modes of ^ {12}C_6H_6 and ^{12}C_5^{13 }CH_6.. The dephasing dynamics of the nu _1 ring-breathing mode of neat benzene is studied by time-resolved coherent anti-Stokes Raman scattering. Ultrafast time resolution reveals deviation from the conventional exponential decay. The correlation time, tau _{rm c}, and the rms magnitude, Delta, of the Bohr frequency modulation are determined for the process responsible for the vibrational dephasing by Kubo dephasing function analysis. The electronic dephasing of two oxazine dyes in ethylene glycol at room temperature is investigated by photon echo experiments. It was found that at least two stochastic processes are responsible for the observed electronic dephasing. Both fast (homogeneous) and slow (inhomogeneous) dynamics are recovered using Kubo line shape analysis. Moreover, the slow dynamics is found to spectrally diffuse over the inhomogeneous distribution on the time scale around a picosecond. Time-resolved degenerate four wave mixing signal of dyes in a population measurement geometry is reported. The vibrational coherences both in the ground and excited electronic states produced strong oscillations in the signal together with the usual population decay from the excited electronic state. Absolute frequencies and their dephasing times of the vibrational modes at ~590 cm^{-1} are obtained

  11. Specialized Information Processing Deficits and Distinct Metabolomic Profiles Following TM-Domain Disruption of Nrg1.

    Science.gov (United States)

    O'Tuathaigh, Colm M P; Mathur, Naina; O'Callaghan, Matthew J; MacIntyre, Lynsey; Harvey, Richard; Lai, Donna; Waddington, John L; Pickard, Benjamin S; Watson, David G; Moran, Paula M

    2017-09-01

    Although there is considerable genetic and pathologic evidence for an association between neuregulin 1 (NRG1) dysregulation and schizophrenia, the underlying molecular and cellular mechanisms remain unclear. Mutant mice containing disruption of the transmembrane (TM) domain of the NRG1 gene constitute a heuristic model for dysregulation of NRG1-ErbB4 signaling in schizophrenia. The present study focused on hitherto uncharacterized information processing phenotypes in this mutant line. Using a mass spectrometry-based metabolomics approach, we also quantified levels of unique metabolites in brain. Across 2 different sites and protocols, Nrg1 mutants demonstrated deficits in prepulse inhibition, a measure of sensorimotor gating, that is, disrupted in schizophrenia; these deficits were partially reversed by acute treatment with second, but not first-, generation antipsychotic drugs. However, Nrg1 mutants did not show a specific deficit in latent inhibition, a measure of selective attention that is also disrupted in schizophrenia. In contrast, in a "what-where-when" object recognition memory task, Nrg1 mutants displayed sex-specific (males only) disruption of "what-when" performance, indicative of impaired temporal aspects of episodic memory. Differential metabolomic profiling revealed that these behavioral phenotypes were accompanied, most prominently, by alterations in lipid metabolism pathways. This study is the first to associate these novel physiological mechanisms, previously independently identified as being abnormal in schizophrenia, with disruption of NRG1 function. These data suggest novel mechanisms by which compromised neuregulin function from birth might lead to schizophrenia-relevant behavioral changes in adulthood. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.

  12. Processing grounded-wire TEM signal in time-frequency-pseudo-seismic domain: A new paradigm

    Science.gov (United States)

    Khan, M. Y.; Xue, G. Q.; Chen, W.; Huasen, Z.

    2017-12-01

    Grounded-wire TEM has received great attention in mineral, hydrocarbon and hydrogeological investigations for the last several years. Conventionally, TEM soundings have been presented as apparent resistivity curves as function of time. With development of sophisticated computational algorithms, it became possible to extract more realistic geoelectric information by applying inversion programs to 1-D & 3-D problems. Here, we analyze grounded-wire TEM data by carrying out analysis in time, frequency and pseudo-seismic domain supported by borehole information. At first, H, K, A & Q type geoelectric models are processed using a proven inversion program (1-D Occam inversion). Second, time-to-frequency transformation is conducted from TEM ρa(t) curves to magneto telluric MT ρa(f) curves for the same models based on all-time apparent resistivity curves. Third, 1-D Bostick's algorithm was applied to the transformed resistivity. Finally, EM diffusion field is transformed into propagating wave field obeying the standard wave equation using wavelet transformation technique and constructed pseudo-seismic section. The transformed seismic-like wave indicates that some reflection and refraction phenomena appear when the EM wave field interacts with geoelectric interface at different depth intervals due to contrast in resistivity. The resolution of the transformed TEM data is significantly improved in comparison to apparent resistivity plots. A case study illustrates the successful hydrogeophysical application of proposed approach in recovering water-filled mined-out area in a coal field located in Ye county, Henan province, China. The results support the introduction of pseudo-seismic imaging technology in short-offset version of TEM which can also be an useful aid if integrated with seismic reflection technique to explore possibilities for high resolution EM imaging in future.

  13. How working memory relates to children's reading comprehension: The importance of domain-specificity in storage and processing

    NARCIS (Netherlands)

    Nouwens, S.; Groen, M.A.; Verhoeven, L.T.W.

    2017-01-01

    Working memory is considered a well-established predictor of individual variation in reading comprehension in children and adults. However, how storage and processing capacities of working memory in both the phonological and semantic domain relate to reading comprehension is still unclear. In the

  14. Interplay of domain walls and magnetization rotation on dynamic magnetization process in iron/polymer–matrix soft magnetic composites

    Energy Technology Data Exchange (ETDEWEB)

    Dobák, Samuel, E-mail: samuel.dobak@student.upjs.sk [Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University, Park Angelinum 9, 041 54 Košice (Slovakia); Füzer, Ján; Kollár, Peter [Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University, Park Angelinum 9, 041 54 Košice (Slovakia); Fáberová, Mária; Bureš, Radovan [Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 043 53 Košice (Slovakia)

    2017-03-15

    This study sheds light on the dynamic magnetization process in iron/resin soft magnetic composites from the viewpoint of quantitative decomposition of their complex permeability spectra into the viscous domain wall motion and magnetization rotation. We present a comprehensive view on this phenomenon over the broad family of samples with different average particles dimension and dielectric matrix content. The results reveal the pure relaxation nature of magnetization processes without observation of spin resonance. The smaller particles and higher amount of insulating resin result in the prevalence of rotations over domain wall movement. The findings are elucidated in terms of demagnetizing effects rising from the heterogeneity of composite materials. - Highlights: • A first decomposition of complex permeability into domain wall and rotation parts in soft magnetic composites. • A pure relaxation nature of dynamic magnetization processes. • A complete loss separation in soft magnetic composites. • The domain walls activity is considerably suppressed in composites with smaller iron particles and higher matrix content. • The demagnetizing field acts as a significant factor at the dynamic magnetization process.

  15. How Working Memory Relates to Children's Reading Comprehension: The Importance of Domain-Specificity in Storage and Processing

    Science.gov (United States)

    Nouwens, Suzan; Groen, Margriet A.; Verhoeven, Ludo

    2017-01-01

    Working memory is considered a well-established predictor of individual variation in reading comprehension in children and adults. However, how storage and processing capacities of working memory in both the phonological and semantic domain relate to reading comprehension is still unclear. In the current study, we investigated the contribution of…

  16. Improving performance of natural language processing part-of-speech tagging on clinical narratives through domain adaptation.

    Science.gov (United States)

    Ferraro, Jeffrey P; Daumé, Hal; Duvall, Scott L; Chapman, Wendy W; Harkema, Henk; Haug, Peter J

    2013-01-01

    Natural language processing (NLP) tasks are commonly decomposed into subtasks, chained together to form processing pipelines. The residual error produced in these subtasks propagates, adversely affecting the end objectives. Limited availability of annotated clinical data remains a barrier to reaching state-of-the-art operating characteristics using statistically based NLP tools in the clinical domain. Here we explore the unique linguistic constructions of clinical texts and demonstrate the loss in operating characteristics when out-of-the-box part-of-speech (POS) tagging tools are applied to the clinical domain. We test a domain adaptation approach integrating a novel lexical-generation probability rule used in a transformation-based learner to boost POS performance on clinical narratives. Two target corpora from independent healthcare institutions were constructed from high frequency clinical narratives. Four leading POS taggers with their out-of-the-box models trained from general English and biomedical abstracts were evaluated against these clinical corpora. A high performing domain adaptation method, Easy Adapt, was compared to our newly proposed method ClinAdapt. The evaluated POS taggers drop in accuracy by 8.5-15% when tested on clinical narratives. The highest performing tagger reports an accuracy of 88.6%. Domain adaptation with Easy Adapt reports accuracies of 88.3-91.0% on clinical texts. ClinAdapt reports 93.2-93.9%. ClinAdapt successfully boosts POS tagging performance through domain adaptation requiring a modest amount of annotated clinical data. Improving the performance of critical NLP subtasks is expected to reduce pipeline error propagation leading to better overall results on complex processing tasks.

  17. Modelling the impact of dam removal on geomorphic channel response and sediment delivery: an Austrian case study

    Science.gov (United States)

    Pöppl, Ronald; Coulthard, Tom; Keesstra, Saskia; Keiler, Margreth

    2015-04-01

    Dams are often considered to have the most significant impact on rivers as dam construction generally reduces downstream sediment fluxes which further involves geomorphic changes in the affected river reaches. Since many dams no longer fulfill their intended purpose (e.g. due to siltation), are dangerous (e.g. catastrophic dam failures) and/or are ecologically damaging (e.g. habitat destruction), within the last two decades several dams have been removed and many more are already proposed for removal. Unfortunately, there is still only little empirical knowledge about the geomorphic consequences of dam removals and the related sediment release which represents a big challenge for river management. Modelling is one way to approach this problem. In the presented study we modelled the impacts of dam removal on geomorphic channel processes, channel morphology and sediment delivery further considering the role of channel engineering measures and reservoir excavation within a river reach impacted by a series of dams using the landscape evolution model CAESAR-Lisflood. The model was run with data from a small catchment located in Lower Austria. Modelled geomorphic channel changes and sediment fluxes were spatio-temporally analyzed, related to real-world data and are discussed in the context of river management issues.

  18. Tracking Geomorphic Signatures of Watershed Suburbanization with Multi-Temporal LiDAR

    Science.gov (United States)

    Urban development practices redistribute surface materials through filling, grading and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-t...

  19. A geophysical analysis of hydro-geomorphic controls within a headwater wetland in a granitic landscape, through ERI and IP

    Directory of Open Access Journals (Sweden)

    E. S. Riddell

    2010-08-01

    Full Text Available Wetlands are undergoing considerable degradation in South Africa. As interventions are often technical and costly, there is a requirement to develop conceptual process models for these wetland systems so that rehabilitation attempts will be successful. This paper presents an approach using the geophysical methods of Electrical Resistivity Imaging (ERI and Induced Polarization (IP to delineate sub-surface hydro-geomorphic controls that maintain equilibrium disconnectivity of wetland-catchment processes, which through gully erosion are increasing the catchments connectivity through loss of water and sediment. The findings presented here give insight into the geomorphic processes that maintain the wetland in an un-degraded state, this allows for the development of a conceptual model outlining the wetland forming processes. The analysis suggests that sub-surface clay-plugs, within an otherwise sandy substrate are created by illuviation of clays from the surrounding hillslopes particularly at zones of valley confinement.

  20. The Relation between Cognitive and Metacognitive Processing: Building Bridges between the SRL, MDL, and SAL Domains

    Science.gov (United States)

    Coertjens, Liesje

    2018-01-01

    Aim: The main aim of this commentary was to connect the insights from the contributions of the special issue on the intersection between depth and the regulation of strategy use. The seven contributions in this special issue stem from three perspectives: self-regulated learning (SRL), model of domain learning (MDL), or the student approaches to…

  1. The Effect of Observational Learning on Students' Performance, Processes, and Motivation in Two Creative Domains

    Science.gov (United States)

    Groenendijk, Talita; Janssen, Tanja; Rijlaarsdam, Gert; van den Bergh, Huub

    2013-01-01

    Background. Previous research has shown that observation can be effective for learning in various domains, for example, argumentative writing and mathematics. The question in this paper is whether observational learning can also be beneficial when learning to perform creative tasks in visual and verbal arts. Aims. We hypothesized that observation…

  2. Domain-Specific Control Mechanisms for Emotional and Nonemotional Conflict Processing

    Science.gov (United States)

    Soutschek, Alexander; Schubert, Torsten

    2013-01-01

    Recent neuroimaging studies suggest that the human brain activates dissociable cognitive control networks in response to conflicts arising within the cognitive and the affective domain. The present study tested the hypothesis that nonemotional and emotional conflict regulation can also be dissociated on a functional level. For that purpose, we…

  3. Dynamic Hippocampal and Prefrontal Contributions to Memory Processes and Representations Blur the Boundaries of Traditional Cognitive Domains.

    Science.gov (United States)

    Rubin, Rachael D; Schwarb, Hillary; Lucas, Heather D; Dulas, Michael R; Cohen, Neal J

    2017-07-12

    The hippocampus has long been known to be a critical component of the memory system involved in the formation and use of long-term declarative memory. However, recent findings have revealed that the reach of hippocampal contributions extends to a variety of domains and tasks that require the flexible use of cognitive and social behavior, including domains traditionally linked to prefrontal cortex (PFC), such as decision-making. In addition, the prefrontal cortex (PFC) has gained traction as a necessary part of the memory system. These findings challenge the conventional characterizations of hippocampus and PFC as being circumscribed to traditional cognitive domains. Here, we emphasize that the ability to parsimoniously account for the breadth of hippocampal and PFC contributions to behavior, in terms of memory function and beyond, requires theoretical advances in our understanding of their characteristic processing features and mental representations. Notably, several literatures exist that touch upon this issue, but have remained disjointed because of methodological differences that necessarily limit the scope of inquiry, as well as the somewhat artificial boundaries that have been historically imposed between domains of cognition. In particular, this article focuses on the contribution of relational memory theory as an example of a framework that describes both the representations and processes supported by the hippocampus, and further elucidates the role of the hippocampal-PFC network to a variety of behaviors.

  4. Dynamic Hippocampal and Prefrontal Contributions to Memory Processes and Representations Blur the Boundaries of Traditional Cognitive Domains

    Directory of Open Access Journals (Sweden)

    Rachael D. Rubin

    2017-07-01

    Full Text Available The hippocampus has long been known to be a critical component of the memory system involved in the formation and use of long-term declarative memory. However, recent findings have revealed that the reach of hippocampal contributions extends to a variety of domains and tasks that require the flexible use of cognitive and social behavior, including domains traditionally linked to prefrontal cortex (PFC, such as decision-making. In addition, the prefrontal cortex (PFC has gained traction as a necessary part of the memory system. These findings challenge the conventional characterizations of hippocampus and PFC as being circumscribed to traditional cognitive domains. Here, we emphasize that the ability to parsimoniously account for the breadth of hippocampal and PFC contributions to behavior, in terms of memory function and beyond, requires theoretical advances in our understanding of their characteristic processing features and mental representations. Notably, several literatures exist that touch upon this issue, but have remained disjointed because of methodological differences that necessarily limit the scope of inquiry, as well as the somewhat artificial boundaries that have been historically imposed between domains of cognition. In particular, this article focuses on the contribution of relational memory theory as an example of a framework that describes both the representations and processes supported by the hippocampus, and further elucidates the role of the hippocampal–PFC network to a variety of behaviors.

  5. The role of trees in the geomorphic system of forested hillslopes — A review

    Science.gov (United States)

    Pawlik, Łukasz

    2013-11-01

    Forested hillslopes form a special geoecosystem, an environment of geomorphic processes that depend strongly on forest ecology, including the growth and decay of trees, changes in structure, disturbances and other fluctuations. Hence, the following various functions of trees are reviewed here: their role in both biomechanical and biochemical weathering, as well as their importance for the hillslope geomorphic subsystem and for transport of soil material via tree uprooting and root growth. Special attention is paid to tree uprooting, a process considered the most efficient and most frequent biogeomorphological indicator of bio-physical activity within forest in complex terrain. Trees have varied implications for soil formation in different environments (boreal to tropical forests) and altitudes. In this paper an attempt has been made to emphasize how trees not only modulate geomorphic processes, but also how they act as a direct or indirect agent of microrelief formation, the most striking example of which being widespread and long-lasting pit-and-mound microtopography. Based on the analyzed literature it seems that some problems attributed to forest ecology can have a fundamental effect on forested hillslope dynamics, a relationship which points to the need for its integration and interpretation within the field of geomorphology. The biology of individual trees has a key influence on the development of e.g. rock faces, weathering front migration and changes in the soil biomantle within upper and lower forest belts. Additionally, forms and sediments depend largely on the horizontal and vertical extent, volume and structure of root systems, as well as on active processes taking place in the root zone and rhizosphere. Furthermore, although trees to a large extent stabilize slope surfaces, their presence can also have a dual effect on slope stability due to tree uprooting, a process which in some circumstances can trigger mass movements (e.g. debris avalanches). So far

  6. Wet meadow ecosystems and the longevity of biologically-mediated geomorphic features

    Science.gov (United States)

    Nash, C.; Grant, G.; O'Connor, J. E.

    2016-12-01

    Upland meadows represent a ubiquitous feature of montane landscapes in the U.S. West and beyond. Characterized by flat valley floors flanked by higher-gradient hillslopes, these meadows are important features, both for the diverse ecosystems they support but also because they represent depositional features in what is primarily an erosional environment. As such, they serve as long-term chronometers of both geological and ecological processes in a portion of the landscape where such records are rare, and provide a useful microcosm for exploring many of the questions motivating critical zone science. Specifically, meadows can offer insights into questions regarding the longevity of theses biologically-mediated landscapes, and the geomorphic thresholds associated with transitions between metastable landscape states. Though categorically depositional, wet meadows have been shown to rapidly shift into erosional landscapes characterized by deep arroyos, declining water tables, and sparse, semi-arid ecosystems. Numerous hypotheses have been proposed explaining this shift: intensive ungulate usage, removal of beaver, climatic shifts, and intrinsic geomorphic evolution. Even less is known about the mechanisms controlling the construction of these meadow features. Evidence seems to suggest these channels oscillate between two metastable conditions: deeply incised, single-threaded channels and sheet-flow dominated valley-spanning wetlands. We present new evidence exploring the subsurface architecture of wet meadows and the bidirectional process cascades potentially responsible for their temporal evolution. Using a combination of near surface geophysical techniques and detailed stratigraphic descriptions of incised and un-incised meadows throughout the Silvies River Basin, OR, we examine mechanisms responsible both for the construction of these features and their apparently rapid transition from depositional to erosional. Our investigation focuses specifically on potential

  7. Geomorphic and habitat response to a large-dam removal in a Mediterranean river

    Science.gov (United States)

    Harrison, L.; East, A. E.; Smith, D. P.; Bond, R.; Logan, J. B.; Nicol, C.; Williams, T.; Boughton, D. A.; Chow, K.

    2017-12-01

    The presence of large dams has fundamentally altered physical and biological processes in riverine ecosystems, and dam removal is becoming more common as a river restoration strategy. We used a before-after-control-impact study design to investigate the geomorphic and habitat response to removal of 32-m-high San Clemente Dam on the Carmel River, CA. The project represents the first major dam removal in a Mediterranean river and is also unique among large dam removals in that most reservoir sediment was sequestered in place. We found that in the first year post-removal, a sediment pulse migrated 3.5 km downstream, filling pools and the interstitial pore spaces of gravels with sand. These sedimentary and topographic changes initially reduced the overall quality of steelhead (O. mykiss) spawning and rearing habitat in impacted reaches. Over the second winter after dam removal, a sequence of high flows flushed large volumes of sand from pools and mobilized the river bed throughout much of the active channel. The floods substantially altered fluvial evolution in the upper part of the reservoir, promoting new avulsion and the subsequent delivery of gravel and large wood to below dam reaches. These geomorphic processes increased the availability of spawning-sized gravel and enhanced channel complexity in reaches within several km of the former dam, which should improve habitat for multiple life stages of steelhead. Results indicate that when most reservoir sediment remains impounded, high flows become more important drivers of geomorphic and habitat change than dam removal alone. In such cases, the rates at which biophysical processes are reestablished will depend largely on post-dam removal flow sequencing and the upstream supply of sediment and large wood.

  8. Geomorphic Assessment of Floods within the Urban Environment of ...

    African Journals Online (AJOL)

    This study examined urban geomorphic conditions that lead to flooding in urban areas of ... the elimination of vegetation cover as well as deficient drainage networks ... Department of Geography & Resource Development, University of Ghana, Legon, .... A number of case studies from different parts of the world dealing.

  9. The geomorphic legacy of small dams — An Austrian study

    NARCIS (Netherlands)

    Poeppl, R.E.; Keesstra, S.D.; Hein, T.

    2015-01-01

    Dams represent one of the most dominant forms of human impact upon fluvial systems during the Anthropocene, as they disrupt the downstream transfer of water and sediments. Removing dams restores river continuity and channel morphology. Both dam construction and dam removal induce geomorphic channel

  10. Fire passage on geomorphic fractures in Cerrado: effect on vegetation

    Directory of Open Access Journals (Sweden)

    Otacílio Antunes Santana

    2017-01-01

    Full Text Available Geomorphic fracture is a natural geologic formation that sometimes forms a deep fissure in the rock with the establishment of soil and vegetation. The objective of this work was to analyze vegetation within geomorphic fractures under the effect of wildfire passage. The biometric variables evaluated before and after fire passage were: diameter, height, leaf area index, timber volume, grass biomass, number of trees and shrubs and of species. Results (in fractures were compared to adjacent areas (control. The effect of wildfire passage on vegetation within geomorphic fractures was not significant because fire followed plant biomass bed and when it met the fracture (wetter, it changed from soil surface to canopy surface (jump fire effect, affecting without significance the number of plants or species; so, fracture could be plants refuge against fire passage. We could infer in our experimental model that quality of plant biomass bed could be more significant than quantity, and microclimate variability recruits plants to the refuge (geomorphic fracture.

  11. Assessing geomorphic sensitivity in relation to river capacity for adjustment

    Science.gov (United States)

    Reid, H. E.; Brierley, G. J.

    2015-12-01

    River sensitivity describes the nature and rate of channel adjustments. An approach to analysis of geomorphic river sensitivity outlined in this paper relates potential sensitivity based on the expected capacity of adjustment for a river type to the recent history of channel adjustment. This approach was trialled to assess low, moderate and high geomorphic sensitivity for four different types of river (10 reaches in total) along the Lower Tongariro River, North Island, New Zealand. Building upon the River Styles framework, river types were differentiated based upon valley setting (width and confinement), channel planform, geomorphic unit assemblages and bed material size. From this, the behavioural regime and potential for adjustment (type and extent) were determined. Historical maps and aerial photographs were geo-rectified and the channel planform digitised to assess channel adjustments for each reach from 1928 to 2007. Floodplain width controlled by terraces, exerted a strong influence upon reach scale sensitivity for the partly-confined, wandering, cobble-bed river. Although forced boundaries occur infrequently, the width of the active channel zone is constrained. An unconfined braided river reach directly downstream of the terrace-confined section was the most geomorphically sensitive reach. The channel in this reach adjusted recurrently to sediment inputs that were flushed through more confined, better connected upstream reaches. A meandering, sand-bed river in downstream reaches has exhibited negligible rates of channel migration. However, channel narrowing in this reach and the associated delta indicate that the system is approaching a threshold condition, beyond which channel avulsion is likely to occur. As this would trigger more rapid migration, this reach is considered to be more geomorphically sensitive than analysis of its low migration rate alone would indicate. This demonstrates how sensitivity is fashioned both by the behavioural regime of a reach

  12. Specialized Information Processing Deficits and Distinct Metabolomic Profiles Following TM-Domain Disruption of Nrg1

    OpenAIRE

    O'Tuathaigh, Colm MP; Mathur, Naina; O'Callaghan, Matthew J; MacIntyre, Lynsey; Harvey, Richard; Lai, Dona; Waddington, John L; Pickard, Bemjamom S; Watson, David D; Moran, Paula M

    2017-01-01

    While there is considerable genetic and pathologic evidence for an association between neuregulin 1 (NRG1) dysregulation and schizophrenia, the underlying molecular and cellular mechanisms remain unclear. Mutant mice containing disruption of the transmembrane (TM) domain of the NRG1 gene constitute a heuristic model for dysregulation of NRG1-ErbB4 signalling in schizophrenia. The present study focused on specialised behavioural and characterisation of hitherto un-characterised information pro...

  13. Conformational switching in the coiled-coil domains of a proteasomal ATPase regulates substrate processing.

    Science.gov (United States)

    Snoberger, Aaron; Brettrager, Evan J; Smith, David M

    2018-06-18

    Protein degradation in all domains of life requires ATPases that unfold and inject proteins into compartmentalized proteolytic chambers. Proteasomal ATPases in eukaryotes and archaea contain poorly understood N-terminally conserved coiled-coil domains. In this study, we engineer disulfide crosslinks in the coiled-coils of the archaeal proteasomal ATPase (PAN) and report that its three identical coiled-coil domains can adopt three different conformations: (1) in-register and zipped, (2) in-register and partially unzipped, and (3) out-of-register. This conformational heterogeneity conflicts with PAN's symmetrical OB-coiled-coil crystal structure but resembles the conformational heterogeneity of the 26S proteasomal ATPases' coiled-coils. Furthermore, we find that one coiled-coil can be conformationally constrained even while unfolding substrates, and conformational changes in two of the coiled-coils regulate PAN switching between resting and active states. This switching functionally mimics similar states proposed for the 26S proteasome from cryo-EM. These findings thus build a mechanistic framework to understand regulation of proteasome activity.

  14. Identification of defect distribution at ferroelectric domain walls from evolution of nonlinear dielectric response during the aging process

    Czech Academy of Sciences Publication Activity Database

    Mokrý, Pavel; Sluka, T.

    2016-01-01

    Roč. 93, č. 6 (2016), č. článku 064114. ISSN 2469-9950 R&D Projects: GA ČR(CZ) GA14-32228S Institutional support: RVO:61389021 Keywords : Nonlinear dielectric response * ferroelectric domain walls * aging process * phase field simulations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.836, year: 2016 http://journals.aps.org/prb/abstract/10.1103/PhysRevB.93.064114

  15. Dual Phase Lag Model of Melting Process in Domain of Metal Film Subjected to an External Heat Flux

    Directory of Open Access Journals (Sweden)

    Mochnacki B.

    2016-12-01

    Full Text Available Heating process in the domain of thin metal film subjected to a strong laser pulse are discussed. The mathematical model of the process considered is based on the dual-phase-lag equation (DPLE which results from the generalized form of the Fourier law. This approach is, first of all, used in the case of micro-scale heat transfer problems (the extremely short duration, extreme temperature gradients and very small geometrical dimensions of the domain considered. The external heating (a laser action is substituted by the introduction of internal heat source to the DPLE. To model the melting process in domain of pure metal (chromium the approach basing on the artificial mushy zone introduction is used and the main goal of investigation is the verification of influence of the artificial mushy zone ‘width’ on the results of melting modeling. At the stage of numerical modeling the author’s version of the Control Volume Method is used. In the final part of the paper the examples of computations and conclusions are presented.

  16. Understanding the Canadian adult CT head rule trial: use of the theoretical domains framework for process evaluation

    Directory of Open Access Journals (Sweden)

    Curran Janet A

    2013-02-01

    Full Text Available Abstract Background The Canadian CT Head Rule was prospectively derived and validated to assist clinicians with diagnostic decision-making regarding the use of computed tomography (CT in adult patients with minor head injury. A recent intervention trial failed to demonstrate a decrease in the rate of head CTs following implementation of the rule in Canadian emergency departments. Yet, the same intervention, which included a one-hour educational session and reminders at the point of requisition, was successful in reducing cervical spine imaging rates in the same emergency departments. The reason for the varied effect of the intervention across these two behaviours is unclear. There is an increasing appreciation for the use of theory to conduct process evaluations to better understand how strategies are linked with outcomes in implementation trials. The Theoretical Domains Framework (TDF has been used to explore health professional behaviour and to design behaviour change interventions but, to date, has not been used to guide a theory-based process evaluation. In this proof of concept study, we explored whether the TDF could be used to guide a retrospective process evaluation to better understand emergency physicians’ responses to the interventions employed in the Canadian CT Head Rule trial. Methods A semi-structured interview guide, based on the 12 domains from the TDF, was used to conduct telephone interviews with project leads and physician participants from the intervention sites in the Canadian CT Head Rule trial. Two reviewers independently coded the anonymised interview transcripts using the TDF as a coding framework. Relevant domains were identified by: the presence of conflicting beliefs within a domain; the frequency of beliefs; and the likely strength of the impact of a belief on the behaviour. Results Eight physicians from four of the intervention sites in the Canadian CT Head Rule trial participated in the interviews. Barriers

  17. Man-portable Vector Time Domain EMI Sensor and Discrimination Processing

    Science.gov (United States)

    2012-04-16

    can also serve as as a discriminant. Q may be parametrized by a Pasion Oldenburg type model and/or combined with other parameters, for example from the...IEEE Trans. Geosci. Remote Sens., 43:1490–1498, July 2005. 4, 43 [23] S.D. Billings, L.R. Pasion , N. Lhomme, and D.W. Oldenburg. Discrimination at...Lhomme, L. R. Pasion , S. D. Billings, and D. W. Oldenburg. Inversion of frequency domain data collected in a magnetic setting for the detection of uxo

  18. Business Process Modeling for Domain Inbound Logistics System : Analytical Perspective with BPMN 2.0

    OpenAIRE

    Khabbazi, Mahmood Reza; Hasan, M. K; Sulaiman, R; Shapi’i, A

    2013-01-01

    Among different Business Process Management strategies and methodologies, one common feature is to captureexisting processes and representing the new processes adequately. Business Process Modelling (BPM) plays acrucial role on such an effort. This paper proposes a “to-be” inbound logistics business processes model usingBPMN 2.0 standard specifying the structure and behaviour of the system within the SME environment. Thegeneric framework of inbound logistics model consists of one main high-le...

  19. Perspectives on Geomorphic Processes. Resource Paper No. 3.

    Science.gov (United States)

    Dury, George H.

    Intended as a supplement to undergraduate college geography courses, this resource paper describes the science of geomorphology, the study of landforms. The general aim of this paper is to review the developments which have made geomorphology what it is today, to indicate its present character and status, to demonstrate its increasingly close…

  20. Quantifying and Validating Rapid Floodplain Geomorphic Evolution, a Monitoring and Modelling Case Study

    Science.gov (United States)

    Scott, R.; Entwistle, N. S.

    2017-12-01

    Gravel bed rivers and their associated wider systems present an ideal subject for development and improvement of rapid monitoring tools, with features dynamic enough to evolve within relatively short-term timescales. For detecting and quantifying topographical evolution, UAV based remote sensing has manifested as a reliable, low cost, and accurate means of topographic data collection. Here we present some validated methodologies for detection of geomorphic change at resolutions down to 0.05 m, building on the work of Wheaton et al. (2009) and Milan et al. (2007), to generate mesh based and pointcloud comparison data to produce a reliable picture of topographic evolution. Results are presented for the River Glen, Northumberland, UK. Recent channel avulsion and floodplain interaction, resulting in damage to flood defence structures make this site a particularly suitable case for application of geomorphic change detection methods, with the UAV platform at its centre. We compare multi-temporal, high-resolution point clouds derived from SfM processing, cross referenced with aerial LiDAR data, over a 1.5 km reach of the watercourse. Changes detected included bank erosion, bar and splay deposition, vegetation stripping and incipient channel avulsion. Utilisation of the topographic data for numerical modelling, carried out using CAESAR-Lisflood predicted the avulsion of the main channel, resulting in erosion of and potentially complete circumvention of original channel and flood levees. A subsequent UAV survey highlighted topographic change and reconfiguration of the local sedimentary conveyor as we predicted with preliminary modelling. The combined monitoring and modelling approach has allowed probable future geomorphic configurations to be predicted permitting more informed implementation of channel and floodplain management strategies.

  1. Reconstructing geomorphic patterns and forcing factors from Alpine Lake Sediment

    Science.gov (United States)

    Arnaud, Fabien; Poulenard, Jérôme; Giguet-Covex, Charline; Wilhelm, Bruno; Révillon, Sidonie; Jenny, Jean-Philippe; Revel, Marie; Enters, Dirk; Bajard, Manon; Fouinat, Laurent; Doyen, Elise; Simonneau, Anaëlle; Pignol, Cécile; Chapron, Emmanuel; Vannière, Boris; Sabatier, Pierre

    2017-04-01

    In this paper we review the scientific efforts that were led over the last decades to reconstruct geomorphic patterns from continuous alpine lake sediment records. Whereas our results point a growing importance of humans as erosion forcing factors, we will focus here on climate-related processes. Our main dataset is made of a regional approach which was led without any a priori regarding erosion forcing factors. We hence integrated a set of sediment sequences from various environment along an altitudinal gradient from 200 up to 2400m asl in Northern French Alps. Altogether our data point climate change as one of the main factor of erosion variability. In particular, the last two cold spells that occurred during the early middle age (Dark Age) and between the 14th and the 20th century AD (Little Ice Age) appear to be outstanding compared to any other periods of enhanced erosion along the Holocene. The climatic forcing of those erosion phases is supported by an increase in the contribution of glacier-eroded material at a regional scale. At local scales, our data also point the growing importance, since at least the mid Bronze Age (ca. 3500 cal. BP) of human activities as a major erosion factor. This influence peaked during the late Iron Age and Antiquity periods (200 BC - 400 AD) when we record a regional generalised period of enhanced erosion in response to the development of pasturing activities. Thanks to provenance and weathering markers, we evidenced a strong relationship between the changes in ecosystems, soil development and erosion patterns. We hence showed the vegetal colonisation of bared soil led to a period of intense weathering while new soils were under formation between 11,000 and 8,000 cal. BP. Soils then knew an optimum until the onset of the Neoglacial at ca. 4,500 cal. BP prior to decline under both climate and human pressures. Altogether our data point the complexity of processes that affected the Earth critical zone along the Holocene. However

  2. A geophysical analysis of hydro-geomorphic controls within a headwater wetland in a granitic landscape, through ERI and IP

    OpenAIRE

    E. S. Riddell; S. A. Lorentz; D. C. Kotze

    2010-01-01

    Wetlands are undergoing considerable degradation in South Africa. As interventions are often technical and costly, there is a requirement to develop conceptual process models for these wetland systems so that rehabilitation attempts will be successful. This paper presents an approach using the geophysical methods of Electrical Resistivity Imaging (ERI) and Induced Polarization (IP) to delineate sub-surface hydro-geomorphic controls that maintain equilibrium disconnectivity of wetland-catchmen...

  3. Inhibition of the Hantavirus Fusion Process by Predicted Domain III and Stem Peptides from Glycoprotein Gc.

    Science.gov (United States)

    Barriga, Gonzalo P; Villalón-Letelier, Fernando; Márquez, Chantal L; Bignon, Eduardo A; Acuña, Rodrigo; Ross, Breyan H; Monasterio, Octavio; Mardones, Gonzalo A; Vidal, Simon E; Tischler, Nicole D

    2016-07-01

    Hantaviruses can cause hantavirus pulmonary syndrome or hemorrhagic fever with renal syndrome in humans. To enter cells, hantaviruses fuse their envelope membrane with host cell membranes. Previously, we have shown that the Gc envelope glycoprotein is the viral fusion protein sharing characteristics with class II fusion proteins. The ectodomain of class II fusion proteins is composed of three domains connected by a stem region to a transmembrane anchor in the viral envelope. These fusion proteins can be inhibited through exogenous fusion protein fragments spanning domain III (DIII) and the stem region. Such fragments are thought to interact with the core of the fusion protein trimer during the transition from its pre-fusion to its post-fusion conformation. Based on our previous homology model structure for Gc from Andes hantavirus (ANDV), here we predicted and generated recombinant DIII and stem peptides to test whether these fragments inhibit hantavirus membrane fusion and cell entry. Recombinant ANDV DIII was soluble, presented disulfide bridges and beta-sheet secondary structure, supporting the in silico model. Using DIII and the C-terminal part of the stem region, the infection of cells by ANDV was blocked up to 60% when fusion of ANDV occurred within the endosomal route, and up to 95% when fusion occurred with the plasma membrane. Furthermore, the fragments impaired ANDV glycoprotein-mediated cell-cell fusion, and cross-inhibited the fusion mediated by the glycoproteins from Puumala virus (PUUV). The Gc fragments interfered in ANDV cell entry by preventing membrane hemifusion and pore formation, retaining Gc in a non-resistant homotrimer stage, as described for DIII and stem peptide inhibitors of class II fusion proteins. Collectively, our results demonstrate that hantavirus Gc shares not only structural, but also mechanistic similarity with class II viral fusion proteins, and will hopefully help in developing novel therapeutic strategies against hantaviruses.

  4. Preliminary Correlation Map of Geomorphic Surfaces in North-Central Frenchman Flat, Nevada Test Site

    International Nuclear Information System (INIS)

    Bechtel Nevada

    2005-01-01

    This correlation map (scale = 1:12,000) presents the results of a mapping initiative that was part of the comprehensive site characterization required to operate the Area 5 Radioactive Waste Management Site, a low-level radioactive waste disposal facility located in northern Frenchman Flat at the Nevada Test Site. Eight primary map units are recognized for Quaternary surfaces: remnants of six alluvial fan or terrace surfaces, one unit that includes colluvial aprons associated with hill slopes, and one unit for anthropogenically disturbed surfaces. This surficial geology map provides fundamental data on natural processes for reconstruction of the Quaternary history of northern Frenchman Flat, which in turn will aid in the understanding of the natural processes that act to develop the landscape, and the time-frames involved in landscape development. The mapping was conducted using color and color-infrared aerial photographs and field verification of map unit composition and boundaries. Criteria for defining the map unit composition of geomorphic surface units are based on relative geomorphic position, landform morphology, and degree of preservation of surface morphology. The bedrock units identified on this map were derived from previous published mapping efforts and are included for completeness

  5. Geomorphic controls on Pleistocene knickpoint migration in Alpine valleys

    Science.gov (United States)

    Leith, Kerry; Fox, Matt; Moore, Jeffrey R.; Brosda, Julian; Krautblatter, Michael; Loew, Simon

    2014-05-01

    Recent insights into sub-glacial bedrock stress conditions suggest that the erosional efficiency of glaciers may reduce markedly following a major erosional cycle [Leith et al., 2013]. This implies that the formation of large glacial valleys within the Alps is likely to have occurred shortly after the onset of 100 ky glacial-interglacial cycles (at the mid-Pleistocene Revolution (MPR)). The majority of landscape change since this time may have therefore been driven by sub-aerial processes. This hypothesis is supported by observations of hillslope and channel morphology within Canton Valais (Switzerland), where major tributary valleys display a common morphology along their length, hinting at a shared geomorphic history. Glaciers currently occupy the headwaters of many catchments, while the upper reaches of rivers flow across extensive alluvial planes before abruptly transitioning to steep channels consisting of mixed bedrock and talus fan deposits. The rivers then converge to flow out over the alluvial plane of the Rhone Valley. Characteristically rough topographies within the region are suggested to mark the progressive transition from a glacial to fluvially-dominated landscape, and correlate well with steepened river channel sections determined from a 2.5 m resolution LiDAR DEM. We envisage a landscape in which ongoing tectonic uplift drives the emergence of Alpine bedrock through massive sedimentary valley infills (currently concentrated in the Rhone Valley), whose elevation is fixed by the consistent fluvial baselevel at Lake Geneva. As fluvial incision ceases at the onset of glaciation, continued uplift causes the formation of knickpoints at the former transition from bedrock to sedimentary infill. These knickpoints will then propagate upstream during subsequent interglacial periods. By investigating channel morphologies using an approach based on the steady-state form of the stream power equation, we can correlate steepened channel reaches (degraded

  6. Natural and human forcing in recent geomorphic change; case studies in the Rio de la Plata basin.

    Science.gov (United States)

    Bonachea, Jaime; Bruschi, Viola M; Hurtado, Martín A; Forte, Luis M; da Silva, Mario; Etcheverry, Ricardo; Cavallotto, José L; Dantas, Marcilene F; Pejon, Osni J; Zuquette, Lázaro V; Bezerra, Maria Angélica de O; Remondo, Juan; Rivas, Victoria; Gómez-Arozamena, José; Fernández, Gema; Cendrero, Antonio

    2010-06-01

    An analysis of geomorphic system's response to change in human and natural drivers in some areas within the Río de la Plata basin is presented. The aim is to determine whether an acceleration of geomorphic processes has taken place in recent years and, if so, to what extent it is due to natural (climate) or human (land-use) drivers. Study areas of different size, socio-economic and geomorphic conditions have been selected: the Río de la Plata estuary and three sub-basins within its watershed. Sediment cores were extracted and dated ((210)Pb) to determine sedimentation rates since the end of the 19th century. Rates were compared with time series on rainfall as well as human drivers such as population, GDP, livestock load, crop area, energy consumption or cement consumption, all of them related to human capacity to disturb land surface. Data on river discharge were also gathered. Results obtained indicate that sedimentation rates during the last century have remained essentially constant in a remote Andean basin, whereas they show important increases in the other two, particularly one located by the São Paulo metropolitan area. Rates in the estuary are somewhere in between. It appears that there is an intensification of denudation/sedimentation processes within the basin. Rainfall remained stable or varied very slightly during the period analysed and does not seem to explain increases of sedimentation rates observed. Human drivers, particularly those more directly related to capacity to disturb land surface (GDP, energy or cement consumption) show variations that suggest human forcing is a more likely explanation for the observed change in geomorphic processes. It appears that a marked increase in denudation, of a "technological" nature, is taking place in this basin and leading to an acceleration of sediment supply. This is coherent with similar increases observed in other regions. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  7. Clay mineralogy and magnetic susceptibility of Oxisols in geomorphic surfaces

    Directory of Open Access Journals (Sweden)

    Livia Arantes Camargo

    2014-06-01

    Full Text Available Studies analyzing the variability of clay minerals and magnetic susceptibility provide data for the delineation of site-specific management areas since many of their attributes are important to agronomy and the environment. This study aimed to evaluate the spatial variability of clay minerals, magnetic susceptibility, adsorbed phosphorus and physical attributes in Oxisols of sandstones in different geomorphic surfaces. For that purpose, soil samples were collected every 25 m along a transect located within the area where the geomorphic surfaces were identified and mapped. The transect occupied the central portion of 500 ha, where it was also sampled for density purposes with one sample per six hectares. Soil samples were collected at a depth of 0.0-0.2 m. The results of the physical, chemical, mineralogical and magnetic susceptibility analyses were subjected to statistical and geostatistical analyses. The nature of the clay minerals and magnetic susceptibility was dependent on the variation of the soil parent material. High values of magnetic susceptibility were associated with the presence of maghemite and magnetite of coarse size. The spatial variability of crystallinity and the content of Fe oxides, as well as magnetic susceptibility, were dependent on the age of the geomorphic surfaces. The youngest surface had greater spatial variability of these attributes. The iron (goethite and hematite and aluminum (gibbsite oxides in the youngest geomorphic surface influenced the low values of soil density and high values of total pore volume, micropores and P adsorption. The characterization of the spatial variability of Fe oxides and susceptibility allowed for the delineation of homogeneous areas.

  8. Geomorphic Regionalization of Coastal Zone Using Geospatial Technology

    Directory of Open Access Journals (Sweden)

    Manoranjan Mishra

    2016-08-01

    Full Text Available The world coastal environment is made of diversified landforms and are also potentially vulnerable to climate variability, delta sinking, extreme events and anthropogenic interferences. Sustainable management of coastal resources and transforming quality ecosystem services to future generation are the goals of Integrated Coastal Zone Management (ICZM. Geographical homogenous unit are the basic implementation locus and back bone of these kinds of integrated management strategy and activities. However, coastal zone management projects in developing world using use arbitrary land-ward and sea-ward boundaries from physical reference as unit of management. The oversimplified fixed distance approaches are not able to map the spatial and temporal changes in coastal systems. The spatio-temporal variations of coastal systems are configured in geomorphic landforms and further that work on interaction between natural forces and anthropogenic inputs. The present research work is an attempt to present a simplified method of regionalization geomorphic landforms using geospatial platforms for delineating Orissa coast into smaller homogenous geographic unit as reference point for future management. Geomorphic landforms are reconstructed using Enhanced Thematic Mapper Plus (ETM+ imagery, Survey of India topomaps, field survey and Digital Elevation Model data at geographic information system (GIS plat form. Seventy geomorphic features covering an area of 5033.64 km2 were identified and further, regionalized into five homogenous geographic units. The need of time is to recognize unsustainable coastal systems in these homogenous geographic units by fine tuning development parameters and also same time allowing coastal systems to adapt naturally to any kind of variability. Although, the methodology applied to Orissa for delineation homogenous geographic area but it can be replicated to any coast in world.

  9. Process-aware information system development for the healthcare domain : consistency, reliability and effectiveness

    NARCIS (Netherlands)

    Mans, R.S.; Aalst, van der W.M.P.; Russell, N.C.; Bakker, P.J.M.; Moleman, A.J.; Rinderle-Ma, S.; Sadiq, S.; Leymann, F.

    2010-01-01

    Optimal support for complex healthcare processes cannot be provided by a single out-of-the-box Process-Aware Information System and necessitates the construction of customized applications based on these systems. In order to allow for the seamless integration of the new technology into the existing

  10. Processing and inversion of commercial helicopter time-domain electromagnetic data for environmental assessments and geologic and hydrologic mapping

    DEFF Research Database (Denmark)

    J.E., Podgorski; Auken, Esben; Schamper, Cyril Noel Clarence

    2013-01-01

    Helicopter time-domain electromagnetic (HTEM) surveying has historically been used for mineral exploration, but over the past decade it has started to be used in environmental assessments and geologic and hydrologic mapping. Such surveying is a cost-effective means of rapidly acquiring densely......%-23%, and the artificial lineations were practically eliminated. Our processing and inversion strategy is entirely general, such that with minor system-specific modifications it could be applied to any HTEM data set, including those recorded many years ago. © 2013 Society of Exploration Geophysicists....

  11. Targeted inhibition of disheveled PDZ domain via NSC668036 depresses fibrotic process

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cong, E-mail: wangcongweihai@126.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Dai, Jinghong, E-mail: daijinghongnew@163.com [Department of Respiratory Medicine, Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University (China); Sun, Zhaorui, E-mail: lanseyunduan@163.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Department of Emergency, Jinling Hospital, Medical School, Nanjing University, Nanjing, Jiangsu 210093 (China); Shi, Chaowen, E-mail: willscw@live.cn [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Cao, Honghui, E-mail: caohonghui92@gmail.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); and others

    2015-02-01

    In this study, we determined the effects of transforming growth factor-beta (TGF-β) and Wnt/β-catenin signaling on myofibroblast differentiation of NIH/3T3 fibroblasts in vitro and evaluated the therapeutic efficacy of NSC668036 in bleomycin-induced pulmonary fibrosis murine model. In vitro study, NSC668036, a small organic inhibitor of the PDZ domain in Dvl, suppressed β-catenin-driven gene transcription and abolished TGF-β1-induced migration, expression of collagen I and α-smooth muscle actin (α-SMA) in fibroblasts. In vivo study, we found that NSC668036 significantly suppressed accumulation of collagen I, α-SMA, and TGF-β1 but increased the expression of CK19, Occludin and E-cadherin that can inhibit pulmonary fibrogenesis. Because fibrotic lung exhibit aberrant activation of Wnt/β-catenin signaling, these data collectively suggest that inhibition of Wnt/β-catenin signaling at the Dvl level may be an effective approach to the treatment of fibrotic lung diseases. - Highlights: • NSC668036 inhibited the proliferation and migration of NIH/3T3 fibroblasts. • NSC668036 suppressed the Wnt/β-catenin signaling pathway. • TGF-β-induced stimulation of profibrotic responses were inhibited by NSC668036. • NSC668036 can inhibit the development of bleomycin-induced pulmonary fibrosis.

  12. New domain for image analysis: VLSI circuits testing, with Romuald, specialized in parallel image processing

    Energy Technology Data Exchange (ETDEWEB)

    Rubat Du Merac, C; Jutier, P; Laurent, J; Courtois, B

    1983-07-01

    This paper describes some aspects of specifying, designing and evaluating a specialized machine, Romuald, for the capture, coding, and processing of video and scanning electron microscope (SEM) pictures. First the authors present the functional organization of the process unit of romuald and its hardware, giving details of its behaviour. Then they study the capture and display unit which, thanks to its flexibility, enables SEM images coding. Finally, they describe an application which is now being developed in their laboratory: testing VLSI circuits with new methods: sem+voltage contrast and image processing. 15 references.

  13. Some considerations for different time-domain signal processing of pulse compression radar

    Directory of Open Access Journals (Sweden)

    Maria Graciela Molina

    2010-06-01

    Full Text Available Radar technology has for a long time used various systems that allow detection under high-resolution conditions, while emitting at the same time low peak power. Among these systems, transmitted pulse encoding by means of biphasic codes has been used for the advanced ionospheric sounder that was developed by the AIS-INGV ionosonde. In the receiving process, suitable decoding of the signal must be accomplished. This can be achieved in both the time and the frequency domains. Focusing on the time domain, different approaches are possible. In this study, two of these approaches have been compared, using data acquired by the AIS-INGV and processed by means of software tools (mainly Mathcad©. The analysis reveals the differences under both noiseless and noisy conditions, although this does not allow the conclusive establishment as to which method is better, as each of them has benefits and drawbacks.

  1. Real-time processing for full-range Fourier-domain optical-coherence tomography with zero-filling interpolation using multiple graphic processing units.

    Science.gov (United States)

    Watanabe, Yuuki; Maeno, Seiya; Aoshima, Kenji; Hasegawa, Haruyuki; Koseki, Hitoshi

    2010-09-01

    The real-time display of full-range, 2048?axial pixelx1024?lateral pixel, Fourier-domain optical-coherence tomography (FD-OCT) images is demonstrated. The required speed was achieved by using dual graphic processing units (GPUs) with many stream processors to realize highly parallel processing. We used a zero-filling technique, including a forward Fourier transform, a zero padding to increase the axial data-array size to 8192, an inverse-Fourier transform back to the spectral domain, a linear interpolation from wavelength to wavenumber, a lateral Hilbert transform to obtain the complex spectrum, a Fourier transform to obtain the axial profiles, and a log scaling. The data-transfer time of the frame grabber was 15.73?ms, and the processing time, which includes the data transfer between the GPU memory and the host computer, was 14.75?ms, for a total time shorter than the 36.70?ms frame-interval time using a line-scan CCD camera operated at 27.9?kHz. That is, our OCT system achieved a processed-image display rate of 27.23 frames/s.

  2. Modeling reactive transport processes in fractured rock using the time domain random walk approach within a dual-porosity framework

    Science.gov (United States)

    Roubinet, D.; Russian, A.; Dentz, M.; Gouze, P.

    2017-12-01

    Characterizing and modeling hydrodynamic reactive transport in fractured rock are critical challenges for various research fields and applications including environmental remediation, geological storage, and energy production. To this end, we consider a recently developed time domain random walk (TDRW) approach, which is adapted to reproduce anomalous transport behaviors and capture heterogeneous structural and physical properties. This method is also very well suited to optimize numerical simulations by memory-shared massive parallelization and provide numerical results at various scales. So far, the TDRW approach has been applied for modeling advective-diffusive transport with mass transfer between mobile and immobile regions and simple (theoretical) reactions in heterogeneous porous media represented as single continuum domains. We extend this approach to dual-continuum representations considering a highly permeable fracture network embedded into a poorly permeable rock matrix with heterogeneous geochemical reactions occurring in both geological structures. The resulting numerical model enables us to extend the range of the modeled heterogeneity scales with an accurate representation of solute transport processes and no assumption on the Fickianity of these processes. The proposed model is compared to existing particle-based methods that are usually used to model reactive transport in fractured rocks assuming a homogeneous surrounding matrix, and is used to evaluate the impact of the matrix heterogeneity on the apparent reaction rates for different 2D and 3D simple-to-complex fracture network configurations.

  3. Identifying determinants of medication adherence following myocardial infarction using the Theoretical Domains Framework and the Health Action Process Approach.

    Science.gov (United States)

    Presseau, Justin; Schwalm, J D; Grimshaw, Jeremy M; Witteman, Holly O; Natarajan, Madhu K; Linklater, Stefanie; Sullivan, Katrina; Ivers, Noah M

    2017-10-01

    Despite evidence-based recommendations, adherence with secondary prevention medications post-myocardial infarction (MI) remains low. Taking medication requires behaviour change, and using behavioural theories to identify what factors determine adherence could help to develop novel adherence interventions. Compare the utility of different behaviour theory-based approaches for identifying modifiable determinants of medication adherence post-MI that could be targeted by interventions. Two studies were conducted with patients 0-2, 3-12, 13-24 or 25-36 weeks post-MI. Study 1: 24 patients were interviewed about barriers and facilitators to medication adherence. Interviews were conducted and coded using the Theoretical Domains Framework. Study 2: 201 patients answered a telephone questionnaire assessing Health Action Process Approach constructs to predict intention and medication adherence (MMAS-8). Study 1: domains identified: Beliefs about Consequences, Memory/Attention/Decision Processes, Behavioural Regulation, Social Influences and Social Identity. Study 2: 64, 59, 42 and 58% reported high adherence at 0-2, 3-12, 13-24 and 25-36 weeks. Social Support and Action Planning predicted adherence at all time points, though the relationship between Action Planning and adherence decreased over time. Using two behaviour theory-based approaches provided complimentary findings and identified modifiable factors that could be targeted to help translate Intention into action to improve medication adherence post-MI.

  4. Initial crystallization and growth in melt processing of large-domain YBa2Cu3Ox for magnetic levitation

    International Nuclear Information System (INIS)

    Shi, D.

    1994-10-01

    Crystallization temperature in YBa 2 Cu 3 O x (123) during peritectic reaction has been studied by differential thermal analysis (DTA) and optical microscopy. It has been found that YBa 2 Cu 3 O x experiences partial melting near 1,010 C during heating while crystallization takes place at a much lower temperature range upon cooling indicating a delayed nucleation process. A series of experiments have been conducted to search for the initial crystallization temperature in the Y 2 BaCuO x + liquid phase field. The authors have found that the slow-cool period (1 C/h) for the 123 grain texturing can start at as low as 960 C. This novel processing has resulted in high-quality, large-domain, strongly pinned 123 magnetic levitators

  5. The Geomorphic System and the Effects of Human Interference at Gold Coast Beach in Tainan, Taiwan

    Science.gov (United States)

    Lin, Tsung-Yi

    2017-04-01

    The Gold Coast beach in Tainan, Taiwan, located between Anping harbor and Ur-Jen river mouth, is the subject of this study, which characterizes the beach's geomorphic system through the analysis of information such as sediment grain size, mineral composition, and periodic measurements of morphological changes of the beach. Based upon such characterizations, further analysis is conducted on the effects that human activities of the last 15 years have upon the geomorphic changes within the Gold Coast beach. The study shows that the median grain size of the Gold Coast beach's sediment is medium sand. The mineral composition includes mainly slate fragments and quartz grains, with small amounts of feldspar, sandstone and shell fragments. Based on a comprehensive study of the longshore distribution of beach sediment size and mineral composition of southwestern coast of Taiwan, as well as, the long-term, monitored data of waves, tides, and currents in this region, we conclude that the main process responsible for the sand accumulation at Gold Coast beach is the prevailing longshore sand transport from south to north. The southern breakwater of Anping harbor plays a role in intercepting the longshore transport sand and helps form the beach. Since the Ur-Jen river flows through a mudstone region, the suspended sediment plume during the flood season does not provide much sediment source to the sandy beach. A monthly beach profile survey project conducted between the years 1999 to 2000 revealed that the beach elevation and width had experienced an obvious seasonal change. The beach widened during the winter, but narrowed in the summer due to typhoon wave erosion. When the subaerial beach was eroded, a submerged longshore bar that was oriented almost parallel to the shoreline had formed at a distance about 400-600 meter away. With this observation, we can conclude that beach morphology is also influenced by various seasonal wave actions that affect onshore and offshore sand

  6. Geomorphic Characterization of the FortyMile Wash Alluvial Fan, Nye County, Nevada, In Support of the Yucca Mountain Project

    International Nuclear Information System (INIS)

    Cline; De Long; Pelletier; Harrington

    2005-01-01

    In the event of an unlikely volcanic eruption through the proposed high-level radioactive waste repository at Yucca Mountain, contaminated ash would be deposited in portions of the Fortymile Wash drainage basin and would subsequently be redistributed to the Fortymile Wash alluvial fan by fluvial processes. As part of an effort to quantify the transport of contaminated ash throughout the fluvial system, characterization of the Fortymile Wash alluvial fan is required, especially the spatial distribution of fluvial activity over time scales of repository operation, and the rates of radionuclide migration into different soils on the fan. The Fortymile Wash alluvial fan consists of extremely low relief terraces as old as 70 ka. By conducting soils-geomorphic mapping and correlating relative surface ages with available geochronology from the Fortymile Wash fan and adjacent piedmonts, we identified 4 distinct surfaces on the fan. Surface ages are used to predict the relative stability of different areas of the fan to fluvial activity. Pleistocene-aged surfaces are assumed to be fluvially inactive over the 10 kyr time scale, for example. Our mapping and correlation provides a map of the depozone for contaminated ash that takes into account long-term channel migration the time scales of repository operation, and it provides a geomorphic framework for predicting radionuclide dispersion rates into different soils across the fan. The standard model for vertical migration of radionuclides in soil is diffusion; therefore we used diffusion profiles derived from 137 Cs fallout to determine infiltration rates on the various geomorphic surfaces. The results show a strong inverse correlation of the geomorphic surface age and diffusivity values inferred from the 137 Cs profiles collected on the different surfaces of the fan

  7. Geomorphic Analysis of Mattituck Inlet and Goldsmith Inlet, Long Island, New York

    National Research Council Canada - National Science Library

    Morgan, Michael J; Kraus, Nicholas C; McDonald, Jodi M

    2005-01-01

    This study of Mattituck Inlet and Goldsmith Inlet, Long Island, NY, covers the historic and geomorphic background, literature, field measurements, numerical modeling of tidal circulation, and analysis...

  8. The geomorphic effectiveness of a large flood on the Rio Grande in the Big Bend region: insights on geomorphic controls and post-flood geomorphic response

    Science.gov (United States)

    Dean, David J.; Schmidt, John C.

    2013-01-01

    Since the 1940s, the Rio Grande in the Big Bend region has undergone long periods of channel narrowing, which have been occasionally interrupted by rare, large floods that widen the channel (termed a channel reset). The most recent channel reset occurred in 2008 following a 17-year period of extremely low stream flow and rapid channel narrowing. Flooding was caused by precipitation associated with the remnants of tropical depression Lowell in the Rio Conchos watershed, the largest tributary to the Rio Grande. Floodwaters approached 1500 m3/s (between a 13 and 15 year recurrence interval) and breached levees, inundated communities, and flooded the alluvial valley of the Rio Grande; the wetted width exceeding 2.5 km in some locations. The 2008 flood had the 7th largest magnitude of record, however, conveyed the largest volume of water than any other flood. Because of the narrow pre-flood channel conditions, record flood stages occurred. We used pre- and post-flood aerial photographs, channel and floodplain surveys, and 1-dimensional hydraulic models to quantify the magnitude of channel change, investigate the controls of flood-induced geomorphic changes, and measure the post-flood response of the widened channel. These analyses show that geomorphic changes included channel widening, meander migration, avulsions, extensive bar formation, and vertical floodplain accretion. Reach-averaged channel widening between 26 and 52% occurred, but in some localities exceeded 500%. The degree and style of channel response was related, but not limited to, three factors: 1) bed-load supply and transport, 2) pre-flood channel plan form, and 3) rapid declines in specific stream power downstream of constrictions and areas of high channel bed slope. The post-flood channel response has consisted of channel contraction through the aggradation of the channel bed and the formation of fine-grained benches inset within the widened channel margins. The most significant post-flood geomorphic

  9. Semi-supervised learning and domain adaptation in natural language processing

    CERN Document Server

    Søgaard, Anders

    2013-01-01

    This book introduces basic supervised learning algorithms applicable to natural language processing (NLP) and shows how the performance of these algorithms can often be improved by exploiting the marginal distribution of large amounts of unlabeled data. One reason for that is data sparsity, i.e., the limited amounts of data we have available in NLP. However, in most real-world NLP applications our labeled data is also heavily biased. This book introduces extensions of supervised learning algorithms to cope with data sparsity and different kinds of sampling bias.This book is intended to be both

  10. Impact of stuttering severity on adolescents' domain-specific and general self-esteem through cognitive and emotional mediating processes.

    Science.gov (United States)

    Adriaensens, Stefanie; Beyers, Wim; Struyf, Elke

    2015-01-01

    The theory that self-esteem is substantially constructed based on social interactions implies that having a stutter could have a negative impact on self-esteem. Specifically, self-esteem during adolescence, a period of life characterized by increased self-consciousness, could be at risk. In addition to studying mean differences between stuttering and non-stuttering adolescents, this article concentrates on the influence of stuttering severity on domain-specific and general self-esteem. Subsequently, we investigate if covert processes on negative communication attitudes, experienced stigma, non-disclosure of stuttering, and (mal)adaptive perfectionism mediate the relationship between stuttering severity and self-esteem. Our sample comprised 55 stuttering and 76 non-stuttering adolescents. They were asked to fill in a battery of questionnaires, consisting of: Subjective Screening of Stuttering, Self-Perception Profile for Adolescents, Erickson S-24, Multidimensional Perfectionism Scale, and the Stigmatization and Disclosure in Adolescents Who Stutter Scale. SEM (structural equation modeling) analyses showed that stuttering severity negatively influences adolescents' evaluations of social acceptance, school competence, the competence to experience a close friendship, and global self-esteem. Maladaptive perfectionism and especially negative communication attitudes fully mediate the negative influence of stuttering severity on self-esteem. Group comparison showed that the mediation model applies to both stuttering and non-stuttering adolescents. We acknowledge the impact of having a stutter on those domains of the self in which social interactions and communication matter most. We then accentuate that negative attitudes about communication situations and excessive worries about saying things in ways they perceive as wrong are important processes to consider with regard to the self-esteem of adolescents who stutter. Moreover, we provide evidence that these covert

  11. Distinct Prion Domain Sequences Ensure Efficient Amyloid Propagation by Promoting Chaperone Binding or Processing In Vivo.

    Directory of Open Access Journals (Sweden)

    Christine R Langlois

    2016-11-01

    Full Text Available Prions are a group of proteins that can adopt a spectrum of metastable conformations in vivo. These alternative states change protein function and are self-replicating and transmissible, creating protein-based elements of inheritance and infectivity. Prion conformational flexibility is encoded in the amino acid composition and sequence of the protein, which dictate its ability not only to form an ordered aggregate known as amyloid but also to maintain and transmit this structure in vivo. But, while we can effectively predict amyloid propensity in vitro, the mechanism by which sequence elements promote prion propagation in vivo remains unclear. In yeast, propagation of the [PSI+] prion, the amyloid form of the Sup35 protein, has been linked to an oligopeptide repeat region of the protein. Here, we demonstrate that this region is composed of separable functional elements, the repeats themselves and a repeat proximal region, which are both required for efficient prion propagation. Changes in the numbers of these elements do not alter the physical properties of Sup35 amyloid, but their presence promotes amyloid fragmentation, and therefore maintenance, by molecular chaperones. Rather than acting redundantly, our observations suggest that these sequence elements make complementary contributions to prion propagation, with the repeat proximal region promoting chaperone binding to and the repeats promoting chaperone processing of Sup35 amyloid.

  12. Geomorphic dam-break flows. Part I: conceptual model

    OpenAIRE

    Leal, JGAB; Ferreira, RML; Cardoso, AH

    2010-01-01

    Proceedings of the Institution of Civil Engineers - Water Management 163 Issue WM6 This paper presents a one-dimensional conceptual model for simulating geomorphic dam-break flows. The model is based on conservation laws drawn from continuum mixture theory that are integrated over the flow depth,assuming that the f10w is composed of two transport layers. Closure equations were derived from the review and reanalysis of previous studies on granular flow,debris f10w and sheet flow. The sedime...

  13. Automated Detection of Geomorphic Features in LiDAR Point Clouds of Various Spatial Density

    Science.gov (United States)

    Dorninger, Peter; Székely, Balázs; Zámolyi, András.; Nothegger, Clemens

    2010-05-01

    extraction and modeling of buildings (Dorninger & Pfeifer, 2008) we expected that similar generalizations for geomorphic features can be achieved. Our aim is to recognize as many features as possible from the point cloud in the same processing loop, if they can be geometrically described with appropriate accuracy (e.g., as a plane). For this, we propose to apply a segmentation process allowing determining connected, planar structures within a surface represented by a point cloud. It is based on a robust determination of local tangential planes for all points acquired (Nothegger & Dorninger, 2009). It assumes that for points, belonging to a distinct planar structure, similar tangential planes can be determined. In passing, points acquired at continuous such as vegetation can be identified and eliminated. The plane parameters are used to define a four-dimensional feature space which is used to determine seed-clusters globally for the whole are of interest. Starting from these seeds, all points defining a connected, planar region are assigned to a segment. Due to the design of the algorithm, millions of input points can be processed with acceptable processing time on standard computer systems. This allows for processing geomorphically representative areas at once. For each segment, numerous parameter are derived which can be used for further exploitation. These are, for example, location, area, aspect, slope, and roughness. To prove the applicability of our method for automated geomorphic terrain analysis, we used terrestrial and airborne laser scanning data, acquired at two locations. The data of the Doren landslide located in Vorarlberg, Austria, was acquired by a terrestrial Riegl LS-321 laser scanner in 2008, by a terrestrial Riegl LMS-Z420i laser scanner in 2009, and additionally by three airborne LiDAR measurement campaigns, organized by the Landesvermessungsamt Vorarlberg, Feldkirch, in 2003, 2006, and 2007. The measurement distance of the terrestrial measurements was

  14. A double-loop evaluation process for MOOC design and its pilot application in the university domain

    Directory of Open Access Journals (Sweden)

    Federica Cirulli

    2017-12-01

    Full Text Available The diffusion of Massive Open Online Courses (MOOCs is significantly changing the way people learn and update their knowledge and competencies. Although the benefits characterizing MOOCs, which leverage on free and open access to know-how and digitized materials, there are some challenges which call for improving and enhancing the existing methods and approaches for MOOCs design. By combining theory and practice, this paper presents a process of MOOCs design based on a double-loop phase of evaluation. Specifically, the paper provides evidences on how to take advantage of the learners’ and teachers’ feedback to redesign or rethink the course’s architecture, and especially the storyboard and blueprint. A pilot application of the proposed approach has been made to design a course dealing with entrepreneurship domain, and in particular with crowdfunding. The results of the application are presented to validate the approach and provide teachers and course’s designers with some recommendations.

  15. Time domain reflectometry-measuring dielectric permittivity to detect soil non-acqeous phase liquids contamination-decontamination processes

    Directory of Open Access Journals (Sweden)

    A. Comegna

    2013-09-01

    Full Text Available Contamination of soils with non-aqueous phase liquids (NAPL constitutes a serious geo-environmental problem, given the toxicity level and high mobility of these organic compounds. To develop effective decontamination methods, characterisation and identification of contaminated soils are needed. The objective of this work is to explore the potential of dielectric permittivity measurements to detect the presence of NAPLs in soils. The dielectric permittivity was measured by Time Domain Reflectometry method (TDR in soil samples with either different volumetric content of water (w and NAPL (NAPL or at different stages during immiscible displacement test carried out with two different flushing solutions. A mixing model proposed by Francisca and Montoro, was calibrated to estimate the volume fraction of contaminant present in soil. Obtained results, showed that soil contamination with NAPL and the monitoring of immiscible fluid displacement, during soil remediation processes, can be clearly identified from dielectric measurements.

  16. Camera system considerations for geomorphic applications of SfM photogrammetry

    Science.gov (United States)

    Mosbrucker, Adam; Major, Jon J.; Spicer, Kurt R.; Pitlick, John

    2017-01-01

    The availability of high-resolution, multi-temporal, remotely sensed topographic data is revolutionizing geomorphic analysis. Three-dimensional topographic point measurements acquired from structure-from-motion (SfM) photogrammetry have been shown to be highly accurate and cost-effective compared to laser-based alternatives in some environments. Use of consumer-grade digital cameras to generate terrain models and derivatives is becoming prevalent within the geomorphic community despite the details of these instruments being largely overlooked in current SfM literature. This article is protected by copyright. All rights reserved.A practical discussion of camera system selection, configuration, and image acquisition is presented. The hypothesis that optimizing source imagery can increase digital terrain model (DTM) accuracy is tested by evaluating accuracies of four SfM datasets conducted over multiple years of a gravel bed river floodplain using independent ground check points with the purpose of comparing morphological sediment budgets computed from SfM- and lidar-derived DTMs. Case study results are compared to existing SfM validation studies in an attempt to deconstruct the principle components of an SfM error budget. This article is protected by copyright. All rights reserved.Greater information capacity of source imagery was found to increase pixel matching quality, which produced 8 times greater point density and 6 times greater accuracy. When propagated through volumetric change analysis, individual DTM accuracy (6–37 cm) was sufficient to detect moderate geomorphic change (order 100,000 m3) on an unvegetated fluvial surface; change detection determined from repeat lidar and SfM surveys differed by about 10%. Simple camera selection criteria increased accuracy by 64%; configuration settings or image post-processing techniques increased point density by 5–25% and decreased processing time by 10–30%. This article is protected by copyright. All rights

  17. Dissecting empathy: high levels of psychopathic and autistic traits are characterised by difficulties in different social information processing domains

    Directory of Open Access Journals (Sweden)

    Patricia L Lockwood

    2013-11-01

    Full Text Available Individuals with psychopathy or autism spectrum disorder (ASD can behave in ways that suggest lack of empathy towards others. However, many different cognitive and affective processes may lead to unempathic behavior and the social processing profiles of individuals with high psychopathic vs. ASD traits are likely different. Whilst psychopathy appears characterized by problems with resonating with others’ emotions, ASD appears characterized by problems with cognitive perspective-taking. In addition, alexithymia has previously been associated with both disorders, but the contribution of alexithymia needs further exploration. In a community sample (N=110 we show for the first time that although affective resonance and cognitive perspective-taking are related, high psychopathic traits relate to problems with resonating with others’ emotions, but not cognitive perspective taking. Conversely, high ASD traits relate to problems with cognitive perspective-taking but not resonating with others’ emotions. Alexithymia was associated with problems with affective resonance independently of psychopathic traits, suggesting that different component processes (reduced tendency to feel what others feel and reduced ability to identify and describe feelings comprise affective resonance. Alexithymia was not associated with the reduced cognitive perspective-taking in high ASD traits. Our data suggest that (1 elevated psychopathic and ASD traits are characterized by difficulties in different social information processing domains and (2 reduced affective resonance in individuals with elevated psychopathic traits and the reduced cognitive perspective taking in individuals with elevated ASD traits are not explained by co-occurring alexithymia. (3 Alexithymia is independently associated with reduced affective resonance. Consequently, our data point to different component processes within the construct of empathy that are suggestive of partially separable cognitive

  18. Coastal wetlands, sea level, and the dimensions of geomorphic resilience

    Science.gov (United States)

    Phillips, Jonathan D.

    2018-03-01

    Geomorphic system resilience is often perceived as an intrinsic property of system structure and interactions but is also related to idiosyncratic place and history factors. The importance of geographical and historical circumstances makes it difficult to generate categorical statements about geomorphic resilience. However, network-based analyses of system structure can be used to determine the dynamical stability (= resilience) based on generally applicable relationships and to determine scenarios of stability or instability. These provide guidelines for assessing place and history factors to assess resilience. A model of coastal wetlands is analyzed, based on interactions among relative sea level, wetland surface elevation, hydroperiod, vegetation, and sedimentation. The system is generally (but not always) dynamically unstable and non-resilient. Because of gradients of environmental factors and patchy distributions of microtopography and vegetation, a coastal wetland landscape may have extensive local variations in stability/resilience and in the key relationships that trigger instabilities. This is illustrated by a case study where dynamically unstable fragmentation is found in two nearby coastal wetlands in North Carolina's Neuse River estuary-Otter Creek Mouth and Anderson Creek. Neither is keeping pace with relative sea level rise, and both show unstable state transitions within the wetland system; but locally stable relationships exist within the wetland systems.

  19. Brahmaputra river basin groundwater: Solute distribution, chemical evolution and arsenic occurrences in different geomorphic settings

    Directory of Open Access Journals (Sweden)

    Swati Verma

    2015-09-01

    New hydrological insights for the region: Most groundwater solutes of RCD and YA terrains were derived from both silicate weathering and carbonate dissolution, while silicate weathering process dominates the solute contribution in OA groundwater. Groundwater samples from all terrains are postoxic with mean pe values between Fe(III and As(V–As(III reductive transition. While, reductive dissolution of (Fe–MnOOH is the dominant mechanism of As mobilization in RCD and YA aquifers, As in OA and PD aquifers could be mobilized by combined effect of pH dependent sorption and competitive ion exchange. The present study focuses on the major ion chemistry as well as the chemistry of the redox sensitive solutes of the groundwater in different geomorphic settings and their links to arsenic mobilization in groundwater.

  20. Varying effects of geomorphic change on floodplain inundation and forest communities

    Science.gov (United States)

    Keim, R.; Johnson, E. L.; Edwards, B. L.; King, S. L.; Hupp, C. R.

    2015-12-01

    Overbank flooding in floodplains is an important control on vegetation, but effects of changing flooding are difficult to predict because sensitivities of plant communities to multidimensional flooding (frequency, depth, duration, and timing) are not well understood. We used HEC-RAS to model the changing flooding regime in the lower White River floodplain, Arkansas, in response to rapid incision of the Mississippi River in the 1930s, and quantified flood frequency, depth, and duration by forest community type. Incision has decreased flooding especially in terms of frequency, which is one of the most important variables for ecological processes. Modeled depth-duration curves varied more among floodplain reaches than among forest communities within the same reach, but forest communities are now arranged in accordance with new flood regimes in place after river incision. Forest responses to subtle geomorphic change are slower than other vegetation communities, so detection of the full ramifications of ecohydrologic change may require decades.

  1. Geomorphic consequences of rapid deglaciation at Pasterze Glacier, Hohe Tauern Range, Austria, between 2010 and 2013 based on repeated terrestrial laser scanning data

    Science.gov (United States)

    Avian, M.; Kellerer-Pirklbauer, A.; Lieb, G. K.

    2018-06-01

    Since the end of the Little Ice Age around 1850 CE glaciers in the Alps have been receding dramatically. This study aimed to quantify and characterize the geomorphic and landform changes of a 0.9 km2 large proglacial area at the largest glacier in Austria (Pasterze Glacier, Austria, N 47°04‧, E 12°44‧). Point clouds from multiple terrestrial laserscanning (TLS) and different image data were used to quantify surface elevation changes and distinguish different types of erosional and depositional landforms during the period 2010-2013. Results indicate that the study area is characterized by a total volume loss of 1,309,000 m3. Excluding the area which was deglaciated, the volume loss equals 275,000 m3 in the period 2010-13. The decrease is related to sediment transfer out of study area and due to sediment-buried glacier ice which is slowly melting. The landform classification reveals that drift mantled slopes are most frequent (20.9% of the study area in 2013) next to ice contact terrace landforms (19.7%). In terms of vertical surface elevation changes, our results suggest distinguishing between 3 distinct domains within the study area: (i) a flat valley bottom area consisting of water/sandur areas and ice-cored landforms dominated by widespread subsurface ice melting and lateral fluvial (and thermal) erosion; (ii) a gently-sloping footslope area consisting of ice-contact sediments, former ice marginal channels and deep incised gullies with corresponding debris cones dominated by linear erosion and corresponding deposition; and (iii) a steep lateral slope area mainly built up of consolidated drift material with incised gullies dominated by linear erosion. Our results not only confirm the previously revealed high geomorphic activity for proglacial areas of alpine glaciers in terms of surface elevation variations, they also highlight that landforms might change substantially from one year to the next not only because of erosional/depositional processes, but also

  2. Pharmacology of the Nav1.1 domain IV voltage sensor reveals coupling between inactivation gating processes.

    Science.gov (United States)

    Osteen, Jeremiah D; Sampson, Kevin; Iyer, Vivek; Julius, David; Bosmans, Frank

    2017-06-27

    The Na v 1.1 voltage-gated sodium channel is a critical contributor to excitability in the brain, where pathological loss of function leads to such disorders as epilepsy, Alzheimer's disease, and autism. This voltage-gated sodium (Na v ) channel subtype also plays an important role in mechanical pain signaling by primary afferent somatosensory neurons. Therefore, pharmacologic modulation of Na v 1.1 represents a potential strategy for treating excitability disorders of the brain and periphery. Inactivation is a complex aspect of Na v channel gating and consists of fast and slow components, each of which may involve a contribution from one or more voltage-sensing domains. Here, we exploit the Hm1a spider toxin, a Na v 1.1-selective modulator, to better understand the relationship between these temporally distinct modes of inactivation and ask whether they can be distinguished pharmacologically. We show that Hm1a inhibits the gating movement of the domain IV voltage sensor (VSDIV), hindering both fast and slow inactivation and leading to an increase in Na v 1.1 availability during high-frequency stimulation. In contrast, ICA-121431, a small-molecule Na v 1.1 inhibitor, accelerates a subsequent VSDIV gating transition to accelerate entry into the slow inactivated state, resulting in use-dependent block. Further evidence for functional coupling between fast and slow inactivation is provided by a Na v 1.1 mutant in which fast inactivation removal has complex effects on slow inactivation. Taken together, our data substantiate the key role of VSDIV in Na v channel fast and slow inactivation and demonstrate that these gating processes are sequential and coupled through VSDIV. These findings provide insight into a pharmacophore on VSDIV through which modulation of inactivation gating can inhibit or facilitate Na v 1.1 function.

  3. Use of geomorphic, hydrologic, and nitrogen mass balance data to model ecosystem nitrate retention in tidal freshwater wetlands

    OpenAIRE

    E. D. Seldomridge; K. L. Prestegaard

    2012-01-01

    Geomorphic characteristics have been used as scaling parameters to predict water and other fluxes in many systems. In this study, we combined geomorphic analysis with in-situ mass balance studies of nitrate retention (NR) to evaluate which geomorphic scaling parameters best predicted NR in a tidal freshwater wetland ecosystem. Geomorphic characteristics were measured for 267 individual marshes that constitute the freshwater tidal wetland ecosystem of the Patuxent River...

  4. The role of catastrophic geomorphic events in central Appalachian landscape evolution

    Science.gov (United States)

    Jacobson, R.B.; Miller, A.J.; Smith, J.A.

    1989-01-01

    Catastrophic geomorphic events are taken as those that are large, sudden, and rare on human timescales. In the nonglaciated, low-seismicity central Appalachians, these are dominantly floods and landslides. Evaluation of the role of catastrophic events in landscape evolution includes assessment of their contributions to denudation and formation of prominent landscape features, and how they vary through space and time. Tropical storm paths and topographic barriers at the Blue Ridge and Allegheny Front create significant climatic variability across the Appalachians. For moderate floods, the influence of basin geology is apparent in modifying severity of flooding, but for the most extreme events, flood discharges relate mainly to rainfall characteristics such as intensity, duration, storm size, and location. Landslide susceptibility relates more directly to geologic controls that determine what intensity and duration of rainfall will trigger slope instability. Large floods and landslides are not necessarily effective in producing prominent geomorphic features. Large historic floods in the Piedmont have been minimally effective in producing prominent and persistent geomorphic features. In contrast, smaller floods in the Valley and Ridge produced erosional and depositional features that probably will require thousands of years to efface. Scars and deposits of debris slide-avalanches triggered on sandstone ridges recover slowly and persist much longer than scars and deposits of smaller landslides triggered on finer-grained regolith, even though the smaller landslides may have eroded greater aggregate volume. The surficial stratigraphic record can be used to extend the spatial and temporal limits of our knowledge of catastrophic events. Many prominent alluvial and colluvial landforms in the central Appalachians are composed of sediments that were deposited by processes similar to those observed in historic catastrophic events. Available stratigraphic evidence shows two

  5. Genesis and Development of Soils along Different Geomorphic Surfaces in Kouh Birk Area, Mehrestan City

    Directory of Open Access Journals (Sweden)

    Mohammad Akbar Bahoorzahi

    2017-02-01

    be increased which could be a probable source of gypsum formation. Results of the study showed that more and less developed soils formed on rock pediment and upper terrace geomorphic surfaces, respectively. Illuviation of clay, gypsum, and CaCO3 together with formation of cambic, calcic, petrocalcic, gypsic, argillic, and natric horizons were among the dominant pedogenic processes in studied soils. Paleosols containing Bt horizons were only observed on rock pediment geomorphic surface. Kaolinite, illite, chlorite, and palygorskite clay minerals were observed in almost all surfaces. Smectite was not discovered in rock pediment, but was only investigated in mantled pediment and alluvial fan which could be attributed to higher available moisture of formation time in these surfaces. Secondary calcite and gypsum caused stability of pedogenic palygorskite in soils under study. Micromorphological observations proved the presence of clay and calcite coatings, calcite and gypsum infillings, and gypsum interlocked plates. Gypsum pedofeatures were not observed in rock pediment, but clay and calcite pedofeatures were only found. On the other hand, clay and calcite pedofeatures were not observed in upper terraces and gypsum pedofeatures were the only features determinded in this position. Conclusion Results of the present research showed that difference in soil characteristics is highly affected by geomorphology.

  6. Spectral Difference in the Image Domain for Large Neighborhoods, a GEOBIA Pre-Processing Step for High Resolution Imagery

    Directory of Open Access Journals (Sweden)

    Roeland de Kok

    2012-08-01

    Full Text Available Contrast plays an important role in the visual interpretation of imagery. To mimic visual interpretation and using contrast in a Geographic Object Based Image Analysis (GEOBIA environment, it is useful to consider an analysis for single pixel objects. This should be done before applying homogeneity criteria in the aggregation of pixels for the construction of meaningful image objects. The habit or “best practice” to start GEOBIA with pixel aggregation into homogeneous objects should come with the awareness that feature attributes for single pixels are at risk of becoming less accessible for further analysis. Single pixel contrast with image convolution on close neighborhoods is a standard technique, also applied in edge detection. This study elaborates on the analysis of close as well as much larger neighborhoods inside the GEOBIA domain. The applied calculations are limited to the first segmentation step for single pixel objects in order to produce additional feature attributes for objects of interest to be generated in further aggregation processes. The equation presented functions at a level that is considered an intermediary product in the sequential processing of imagery. The procedure requires intensive processor and memory capacity. The resulting feature attributes highlight not only contrasting pixels (edges but also contrasting areas of local pixel groups. The suggested approach can be extended and becomes useful in classifying artificial areas at national scales using high resolution satellite mosaics.

  7. Integrating the context-appropriate balanced attention model and reinforcement sensitivity theory: Towards a domain-general personality process model.

    Science.gov (United States)

    Collins, Michael D; Jackson, Chris J; Walker, Benjamin R; O'Connor, Peter J; Gardiner, Elliroma

    2017-01-01

    Over the last 40 years or more the personality literature has been dominated by trait models based on the Big Five (B5). Trait-based models describe personality at the between-person level but cannot explain the within-person mental mechanisms responsible for personality. Nor can they adequately account for variations in emotion and behavior experienced by individuals across different situations and over time. An alternative, yet understated, approach to personality architecture can be found in neurobiological theories of personality, most notably reinforcement sensitivity theory (RST). In contrast to static trait-based personality models like the B5, RST provides a more plausible basis for a personality process model, namely, one that explains how emotions and behavior arise from the dynamic interaction between contextual factors and within-person mental mechanisms. In this article, the authors review the evolution of a neurobiologically based personality process model based on RST, the response modulation model and the context-appropriate balanced attention model. They argue that by integrating this complex literature, and by incorporating evidence from personality neuroscience, one can meaningfully explain personality at both the within- and between-person levels. This approach achieves a domain-general architecture based on RST and self-regulation that can be used to align within-person mental mechanisms, neurobiological systems and between-person measurement models. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  8. Living Shorelines: Assessing Geomorphic Change and Water Quality in an Urban Waterway

    Science.gov (United States)

    Huggins, A.; Schwartz, M. C.; Schmutz, P. P.

    2017-12-01

    In recent years, alternative strategies for shoreline armoring have become increasingly popular with coastal property owners. In Northwest Florida, local agencies implemented plans to attenuate wave action and reduce landward shore recession in an urban bayou by installing living shorelines. Living shorelines are constructed in the inter-tidal zones and incorporate both hard and soft structured stabilization. Generally, the hard component is fossilized oyster shells and the soft component is planted intertidal vegetation, such as Spartina alterniflora (Smooth cordgrass) and Juncus roemererianus (Black needlerush). Living shorelines were intended to comprise both ecological and societal implications by significantly slowing erosion processes for property owners, by utilizing oyster beds to improve water quality, and by fostering new ecological habitats in the marsh grasses. The issue presented with living shoreline management is long-term studies have not been carried out on these engineered systems. For this study, geospatial technology was utilized to create 3D images of terrain by interpolation of data points using a TotalStation to compute geomorphic change. Additionally, water samples were analyzed using traditional wet chemistry laboratory methods to determine total oxidized nitrogen (TON), ammonium, and orthophosphate content in water. Over a short three-month preliminary study, sediment accretion was observed primarily within the vegetation with the bulk of the erosion occurring around the oyster beds. TON was detected at levels between 10 µM and 30 µM, ammonium up to 5 µM, and orthophosphate was only detected in very low levels, consistently quality data will be used to establish baseline data for future research to determine volumetric geomorphic change,and to set a standard for water quality trends, surrounding oyster beds and vegetation in response to climatic events.

  9. Large-scale dam removal on the Elwha River, Washington, USA: river channel and floodplain geomorphic change

    Science.gov (United States)

    East, Amy E.; Pess, George R.; Bountry, Jennifer A.; Magirl, Christopher S.; Ritchie, Andrew C.; Logan, Joshua; Randle, Timothy J.; Mastin, Mark C.; Minear, Justin T.; Duda, Jeffrey J.; Liermann, Martin C.; McHenry, Michael L.; Beechie, Timothy J.; Shafroth, Patrick B.

    2015-01-01

    A substantial increase in fluvial sediment supply relative to transport capacity causes complex, large-magnitude changes in river and floodplain morphology downstream. Although sedimentary and geomorphic responses to sediment pulses are a fundamental part of landscape evolution, few opportunities exist to quantify those processes over field scales. We investigated the downstream effects of sediment released during the largest dam removal in history, on the Elwha River, Washington, USA, by measuring changes in riverbed elevation and topography, bed sediment grain size, and channel planform as two dams were removed in stages over two years.

  10. Geomorphic Transport Laws and the Statistics of Topography and Stratigraphy

    Science.gov (United States)

    Schumer, R.; Taloni, A.; Furbish, D. J.

    2016-12-01

    Geomorphic transport laws take the form of partial differential equations in which sediment motion is a deterministic function of slope. The addition of a noise term, representing unmeasurable, or subgrid scale autogenic forcing, reproduces scaling properties similar to those observed in topography, landforms, and stratigraphy. Here we describe a transport law that generalizes previous equations by permitting transport that is local or non-local in addition to different types of noise. More importantly, we use this transport law to link the character of sediment transport to the statistics of topography and stratigraphy. In particular, we link the origin of the Sadler effect to the evolution of the earth surface via a transport law.

  11. Geomorphic versus land use controls on suspended sediment rating curves

    Science.gov (United States)

    Belmont, P.; Vaughan, A. A.; Fisher, A. C. N.

    2017-12-01

    The relation between river discharge (Q) and suspended sediment (SS) concentration reflects the degree to which sediment sources are accessed or depleted across the range of flow conditions. Increased availability of high resolution topography and land use data greatly enhance our ability to evaluate linkages between characteristics of these sediment rating curves (SRCs) and the geomorphic features that influence them. We evaluated Q-SS relations at 45 gages throughout Minnesota, USA representing a wide variety of landscape settings in terms of topography, land use, and geologic history. We characterized the SRCs according to the overall shape, steepness (exponent), vertical offset (coefficient) and SS concentration under low flow (90% exceedance) conditions. Rivers exhibited three distinct SRC shapes, simple power functions, threshold power functions and peaked power functions. We used random forest models to analyze relations between SRC parameters and attributes of the watershed as well as the near-channel environment. The model correctly classified 78% of SRC shapes and explained 60% of variance in the SRC exponent, 43% of the SRC coefficient for rising limb samples, and 45% of variance under low flow conditions. Notably, the random forest models predict that near-channel morphology predominately controls both the shape and steepness of the sediment rating curves. Land use predominately controls the vertical offset (coefficient) and SS concentration under low flow conditions. These findings suggest that land use and watershed restoration practices may have little capacity to alter the shape and steepness of these curves as these characteristics may be dictated by the geologic and geomorphic setting. Rather, human influences in the watershed may exhibit the greatest influence on suspended sediment concentrations at moderate to low flows. Criteria to evaluate improvements in water quality as a result of changes in land management might be most meaningful if they

  12. Geomorphic Controls on Aquifer Geometry in Northwestern India

    Science.gov (United States)

    van Dijk, W. M.; Densmore, A. L.; Sinha, R.; Gupta, S.; Mason, P. J.; Singh, A.; Joshi, S. K.; Nayak, N.; Kumar, M.; Shekhar, S.

    2014-12-01

    The Indo-Gangetic foreland basin suffers from one of the highest rates of groundwater extraction in the world, especially in the Indian states of Punjab, Haryana and Rajasthan. To understand the effects of this extraction on ground water levels, we must first understand the geometry and sedimentary architecture of the aquifer system, which in turn depend upon its geomorphic setting. We use satellite images and digital elevation models to map the geomorphology of the Sutlej and Yamuna river systems, while aquifer geometry is assessed using ~250 wells that extend to ~300 m depth in Punjab and Haryana. The Sutlej and Yamuna rivers have deposited large sedimentary fans at their outlets. Elongate downslope ridges on the fan surfaces form distributary networks that radiate from the Sutlej and Yamuna fan apices, and we interpret these ridges as paleochannel deposits associated with discrete fan lobes. Paleochannels picked out by soil moisture variations illustrate a complex late Quaternary history of channel avulsion and incision, probably associated with variations in monsoon intensity. Aquifer bodies on the Sutlej and Yamuna fans have a median thickness of 7 and 6 m, respectively, and follow a heavy-tailed distribution, probably because of stacked sand bodies. The percentage of aquifer material in individual lithologs decreases downstream, although the exponent on the thickness distribution remains the same, indicating that aquifer bodies decrease in number down fan but do not thin appreciably. Critically, the interfan area between the Sutlej and Yamuna fans has thinner aquifers and a lower proportion of aquifer material, despite its proximal location. Our data show that the Sutlej and Yamuna fan systems form the major aquifer systems in this area, and that their geomorphic setting therefore provides a first-order control on aquifer distribution and geometry. The large spatial heterogeneity of the system must be considered in any future aquifer management scheme.

  13. Charge-Domain Signal Processing of Direct RF Sampling Mixer with Discrete-Time Filters in Bluetooth and GSM Receivers

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available RF circuits for multi-GHz frequencies have recently migrated to low-cost digital deep-submicron CMOS processes. Unfortunately, this process environment, which is optimized only for digital logic and SRAM memory, is extremely unfriendly for conventional analog and RF designs. We present fundamental techniques recently developed that transform the RF and analog circuit design complexity to digitally intensive domain for a wireless RF transceiver, so that it enjoys benefits of digital and switched-capacitor approaches. Direct RF sampling techniques allow great flexibility in reconfigurable radio design. Digital signal processing concepts are used to help relieve analog design complexity, allowing one to reduce cost and power consumption in a reconfigurable design environment. The ideas presented have been used in Texas Instruments to develop two generations of commercial digital RF processors: a single-chip Bluetooth radio and a single-chip GSM radio. We further present details of the RF receiver front end for a GSM radio realized in a 90-nm digital CMOS technology. The circuit consisting of low-noise amplifier, transconductance amplifier, and switching mixer offers 32.5 dB dynamic range with digitally configurable voltage gain of 40 dB down to 7.5 dB. A series of decimation and discrete-time filtering follows the mixer and performs a highly linear second-order lowpass filtering to reject close-in interferers. The front-end gains can be configured with an automatic gain control to select an optimal setting to form a trade-off between noise figure and linearity and to compensate the process and temperature variations. Even under the digital switching activity, noise figure at the 40 dB maximum gain is 1.8 dB and +50 dBm IIP2 at the 34 dB gain. The variation of the input matching versus multiple gains is less than 1 dB. The circuit in total occupies 3.1 mm 2 . The LNA, TA, and mixer consume less than 15.3 mA at a supply voltage of 1.4 V.

  14. Charge-Domain Signal Processing of Direct RF Sampling Mixer with Discrete-Time Filters in Bluetooth and GSM Receivers

    Directory of Open Access Journals (Sweden)

    Ho Yo-Chuol

    2006-01-01

    Full Text Available RF circuits for multi-GHz frequencies have recently migrated to low-cost digital deep-submicron CMOS processes. Unfortunately, this process environment, which is optimized only for digital logic and SRAM memory, is extremely unfriendly for conventional analog and RF designs. We present fundamental techniques recently developed that transform the RF and analog circuit design complexity to digitally intensive domain for a wireless RF transceiver, so that it enjoys benefits of digital and switched-capacitor approaches. Direct RF sampling techniques allow great flexibility in reconfigurable radio design. Digital signal processing concepts are used to help relieve analog design complexity, allowing one to reduce cost and power consumption in a reconfigurable design environment. The ideas presented have been used in Texas Instruments to develop two generations of commercial digital RF processors: a single-chip Bluetooth radio and a single-chip GSM radio. We further present details of the RF receiver front end for a GSM radio realized in a 90-nm digital CMOS technology. The circuit consisting of low-noise amplifier, transconductance amplifier, and switching mixer offers dB dynamic range with digitally configurable voltage gain of 40 dB down to dB. A series of decimation and discrete-time filtering follows the mixer and performs a highly linear second-order lowpass filtering to reject close-in interferers. The front-end gains can be configured with an automatic gain control to select an optimal setting to form a trade-off between noise figure and linearity and to compensate the process and temperature variations. Even under the digital switching activity, noise figure at the 40 dB maximum gain is 1.8 dB and dBm IIP2 at the 34 dB gain. The variation of the input matching versus multiple gains is less than 1 dB. The circuit in total occupies 3.1 . The LNA, TA, and mixer consume less than mA at a supply voltage of 1.4 V.

  15. Geomorphic Function and Restoration Potential of Spring Creeks in Southeastern Idaho: Analysis and Communication

    Science.gov (United States)

    Hanrahan, T. P.; Hill, Z.; Levell, A.; Maguire, T.; Risso, D.

    2014-12-01

    A large wetland and floodplain complex adjacent to the Snake River in southeastern Idaho, USA, encompasses numerous spring-fed creeks that originate on the floodplain and discharge at their confluence with the Snake River and American Falls Reservoir. Resource managers are implementing a program to restore these spring creeks for the recovery of Yellowstone cutthroat trout and ecosystem health. Our objectives were to evaluate the physical characteristics of these spring creeks, develop a conceptual model of their geomorphic function, compare the restoration potential of individual reaches, and communicate our findings to a broad audience of resource managers and regional stakeholders in order to foster restoration planning. A geomorphic assessment along 38 km of three spring creeks was completed by collecting data at several transects within distinct geomorphic reaches, and by collecting data continuously throughout all reaches. These data were summarized in a GIS database and used to quantify the overall geomorphic functioning of each reach. The geomorphic functional scores were scaled from 0% (non-functional) to 100% (fully functional). Among all three spring creeks, geomorphic function ranged from 29% to 63%, with bank conditions and riparian vegetation being the primary causes of overall channel degradation. Results from the geomorphic assessment fostered the development of a conceptual model for spring creek function, whereby degraded bank conditions represent the primary controlling factor of decreased geomorphic function and fish habitat quality. The reach-based geomorphic functional scoring provides an indicator of relative restoration potential for each reach, and is one of the factors used in determining site-specific priorities for protecting, enhancing, and restoring spring creeks on the Fort Hall Bottoms. The study results, conceptual model and restoration strategy were communicated to resource managers and regional stakeholders through a graphically

  16. GEOMORPHIC AND HYDROLOGIC INTERACTIONS IN THE DETERMINATION OF EQUILIBRIUM SOIL DEPTH

    Science.gov (United States)

    Nicotina, L.; Rinaldo, A.; Tarboton, D. G.

    2009-12-01

    In this work we propose numerical studies of the interactions between hydrology and geomorphology in the formation of the actual soil depth that drives ecologic and hydrologic processes. Sediment transport and geomorphic landscape evolution processes (i.e. erosion/deposition vs. soil production) strongly influence hydrology, carbon sequestration, soil formation and stream water chemistry. The process of rock conversion into soil originates a strong hydrologic control through the formation of the soil depth that participates to hydrologic processes, influence vegetation type and patterns and actively participate in the co-evolution mechanisms that shape the landscape. The description of spatial patterns in hydrology is usually constrained by the availability of field data, especially when dealing with quantities that are not easily measurable. In these circumstances it is deemed fundamental the capability of deriving hydrologic boundary conditions from physically based approaches. Here we aim, in a general framework, at the formulation of an integrated approach for the prediction of soil depth by mean of i) soil production models and ii) geomorphic transport laws. The processes that take place in the critical zone are driven by the extension of it and have foundamental importance over short time scales as well as on geologic time scales (i.e. as biota affects climate that drives hydrology and thus contributes on shaping the landscape). Our study aims at the investigation of the relationships between soil depth, topography and runoff production, we also address the mechanisms that bring to the development of actual patterns of soil depths which at the same time influence runoff. We use a schematic representation of the hydrologic processes that relies on the description of the topography (throuh a topographic wetness index) and the spatially variable soil depths. Such a model is applied in order to investigate the development of equilibrium soil depth patterns under

  17. The Generalized Support Software (GSS) Domain Engineering Process: An Object-Oriented Implementation and Reuse Success at Goddard Space Flight Center

    Science.gov (United States)

    Condon, Steven; Hendrick, Robert; Stark, Michael E.; Steger, Warren

    1997-01-01

    The Flight Dynamics Division (FDD) of NASA's Goddard Space Flight Center (GSFC) recently embarked on a far-reaching revision of its process for developing and maintaining satellite support software. The new process relies on an object-oriented software development method supported by a domain specific library of generalized components. This Generalized Support Software (GSS) Domain Engineering Process is currently in use at the NASA GSFC Software Engineering Laboratory (SEL). The key facets of the GSS process are (1) an architecture for rapid deployment of FDD applications, (2) a reuse asset library for FDD classes, and (3) a paradigm shift from developing software to configuring software for mission support. This paper describes the GSS architecture and process, results of fielding the first applications, lessons learned, and future directions

  18. Unraveling the controls on biogeomorphic succession: the influence of groundwater, soil and geomorphic setting on bio-geomorphic channel evolution

    Science.gov (United States)

    Bätz, Nico; Verrecchia, Eric P.; Lane, Stuart N.

    2017-04-01

    Braided rivers are characterized by high rates of morphological change. However, despite the potential for frequent disturbance, vegetated patches may develop within this system and influence long-term channel dynamics and channel patterns through the "engineering effects" of biogeomorphic succession. The stabilizing effect of developing vegetation on morphological change has been widely shown by flume experiments and (historic) aerial pictures analysis. Thus, there is a balance between disturbance and stabilization, mediated through biogeomorphic succession, that may determine the long-term geomorphic and biogeomorphic evolution of the river. Research has addressed how changes in disturbance frequency affect river channel pattern, but much less has been done to understand what influences the rate of biogeomorphic succession and how it affects river morphodynamics. This study explores the complex pattern of ambient conditions in braided river systems driving the rate of biogeomorphic succession. In particular, we focus on the interplay between groundwater access, soil formation, disturbance frequency and geomorphic setting, in defining what drives vegetation succession rates and its long-term implications on channel pattern evolution. We studied these feedbacks in a transitional gravel-bed river system (braided, wandering, meandering) close to Geneva (Switzerland) - the Allondon River. Results show that, at the beginning of the succession, humification plays a negative role on local ambient conditions necessary for sprouting. Successful vegetation establishment is then related positively to humification, but also to higher disturbance rates. The third biogeomorphic phase, with the highest feedbacks on river morphology, appears to be mainly driven by groundwater access, which in turn defines the rates of humification in this gravelly environment. This in turn defines the decadal morphological response of the channel after a reduction in disturbance frequency over

  19. Dynamic processes of domain switching in lead zirconate titanate under cyclic mechanical loading by in situ neutron diffraction

    International Nuclear Information System (INIS)

    Pojprapai, Soodkhet; Luo, Zhenhua; Clausen, Bjorn; Vogel, Sven C.; Brown, Donald W.; Russel, Jennifer; Hoffman, Mark

    2010-01-01

    The performance of ferroelectric ceramics is governed by the ability of domains to switch. A decrease in the switching ability can lead to degradation of the materials and failure of ferroelectric devices. In this work the dynamic properties of domain reorientation are studied. In situ time-of-flight neutron diffraction is used to probe the evolution of ferroelastic domain texture under mechanical cyclic loading in bulk lead zirconate titanate ceramics. The high sensitivity of neutron diffraction to lattice strain is exploited to precisely analyze the change of domain texture and strain through a full-pattern Rietveld method. These results are then used to construct a viscoelastic model, which explains the correlation between macroscopic phenomena (i.e. creep and recovered deformation) and microscopic dynamic behavior (i.e. ferroelastic switching, lattice strain).

  20. Dynamic Hippocampal and Prefrontal Contributions to Memory Processes and Representations Blur the Boundaries of Traditional Cognitive Domains

    OpenAIRE

    Rachael D. Rubin; Hillary Schwarb; Heather D. Lucas; Michael R. Dulas; Neal J. Cohen

    2017-01-01

    The hippocampus has long been known to be a critical component of the memory system involved in the formation and use of long-term declarative memory. However, recent findings have revealed that the reach of hippocampal contributions extends to a variety of domains and tasks that require the flexible use of cognitive and social behavior, including domains traditionally linked to prefrontal cortex (PFC), such as decision-making. In addition, the prefrontal cortex (PFC) has gained traction as a...

  1. Domain analysis

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2017-01-01

    The domain-analytic approach to knowledge organization (KO) (and to the broader field of library and information science, LIS) is outlined. The article reviews the discussions and proposals on the definition of domains, and provides an example of a domain-analytic study in the field of art studies....... Varieties of domain analysis as well as criticism and controversies are presented and discussed....

  2. Geomorphic and hydrologic study of peak-flow management on the Cedar River, Washington

    Science.gov (United States)

    Magirl, Christopher S.; Gendaszek, Andrew S.; Czuba, Christiana R.; Konrad, Christopher P.; Marineau, Mathieu D.

    2012-01-01

    Assessing the linkages between high-flow events, geomorphic response, and effects on stream ecology is critical to river management. High flows on the gravel-bedded Cedar River in Washington are important to the geomorphic function of the river; however, high flows can deleteriously affect salmon embryos incubating in streambed gravels. A geomorphic analysis of the Cedar River showed evidence of historical changes in river form over time and quantified the effects of anthropogenic alterations to the river corridor. Field measurements with accelerometer scour monitors buried in the streambed provided insight into the depth and timing of streambed scour during high-flow events. Combined with a two-dimensional hydrodynamic model, the recorded accelerometer disturbances allowed the prediction of streambed disturbance at the burial depth of Chinook and sockeye salmon egg pockets for different peak discharges. Insight gained from these analyses led to the development of suggested monitoring metrics for an ongoing geomorphic monitoring program on the Cedar River.

  3. Redd site selection and spawning habitat use by fall chinook salmon: The importance of geomorphic features in large rivers

    International Nuclear Information System (INIS)

    Geist, D.R.; Oregon State Univ., Corvallis, OR; Dauble, D.D.

    1998-01-01

    Knowledge of the three-dimensional connectivity between rivers and groundwater within the hyporheic zone can be used to improve the definition of fall chinook salmon (Oncorhynchus tshawytscha) spawning habitat. Information exists on the microhabitat characteristics that define suitable salmon spawning habitat. However, traditional spawning habitat models that use these characteristics to predict available spawning habitat are restricted because they can not account for the heterogeneous nature of rivers. The authors present a conceptual spawning habitat model for fall chinook salmon that describes how geomorphic features of river channels create hydraulic processes, including hyporheic flows, that influence where salmon spawn in unconstrained reaches of large mainstem alluvial rivers. Two case studies based on empirical data from fall chinook salmon spawning areas in the Hanford Reach of the Columbia River are presented to illustrate important aspects of the conceptual model. The authors suggest that traditional habitat models and the conceptual model be combined to predict the limits of suitable fall chinook salmon spawning habitat. This approach can incorporate quantitative measures of river channel morphology, including general descriptors of geomorphic features at different spatial scales, in order to understand the processes influencing redd site selection and spawning habitat use. This information is needed in order to protect existing salmon spawning habitat in large rivers, as well as to recover habitat already lost

  4. Geomorphic Response to Spatial and Temporal Tectonic uplift on the Kenya Rift of East African Rift System

    Science.gov (United States)

    Xue, L.; Abdelsalam, M. G.

    2017-12-01

    Tectonic uplifts of the shoulders of the East Africa Rift System (EARS) have significant impact on the geological record by reorganizing drainage systems, increasing sediment supply, and changing climate and biogeography. Recent studies in geochronology, geomorphology and geophysics have provided some understanding of the timing of tectonic uplift and its distribution pattern of the (EARS). We do not know how the vertical motion is localized along the rift axis and the relative roles of upwelling of magma and rift extensional processes play in tectonic uplift history. This work presents detailed morphometric study of the fluvial landscape response to the tectonic uplift and climate shifting of the Kenya Rift shoulders in order to reconstruct their incision history, with special attention to timing, location, and intensity of uplift episodes. This work compiles the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) and Sentinel-2A data, summarized previous 39Ar-40Ar and thermochronology data, and calculates long-term incision rate and geomorphic proxies (normalized steepness and chi-integral) along the Kenya Rift. It also models the age of tectonic/climatic events by using knickpoint celerity model and R/SR integrative approach. It found that the maximum long-term incision rates of 300 mm/kyr to be at the central Kenya Rift, possibly related to the mantle-driven process and rapid tectonic uplift. The geomorphic proxies indicate southward decreasing pattern of the short-term incision rate, possibly related to the migration of the mantle plume.

  5. A GIS-Based Model for the analysis of an urban flash flood and its hydro-geomorphic response. The Valencia event of 1957

    Science.gov (United States)

    Portugués-Mollá, I.; Bonache-Felici, X.; Mateu-Bellés, J. F.; Marco-Segura, J. B.

    2016-10-01

    Flash floods are recurrent events around the Mediterranean region. Extreme episodes activate hydro-geomorphic high-intensity processes with low frequency. In urban environments, the complexity becomes higher due to the existence of very quick-response runoff. However, immediate recovery works remove the urban marks. After a short time both the significance and magnitude of the hydro-geomorphic event become completely unrecognizable. Nevertheless, these episodes generate extensive documentation which is testimony of the processes in almost real time. It is necessary to exploit this source typology in order to draw flood sketches when events far in time may lack a sufficiently rich database. This is particularly the case for the Valencia flash flood (October 1957), located in the lower Turia River basin (Eastern Spain). It left numerous pieces of hydro-geomorphic evidence, but its tracks were covered a short while after the flood. In any case, it remains part of a non-systematic legacy that has not yet been exploited, consisting of immediate aerial and oblique high resolution photography, pictures at street level, water marks and administrative records. Paradoxically, despite being considered a milestone in metropolitan territorial planning (the river was definitely diverted), an accurate reconstruction of the hydraulic behaviour was required from an integrated point of view. To this aim, the development of a GIS-Based Model enabled the utilisation of the above-mentioned materials. This non-conventional information was treated jointly from a new perspective. It provided database support through a vast amount of organised, structured and georeferenced information about the 1957 event. In a second stage, the GBM made it possible to characterise the Turia urban reach and interpret both the hydro-geomorphic (trenches along barrier beaches, erosion, deposition, etc.) and hydraulic (urban streams along the streets, flow directions, flood extent, levees breaks, overflows

  6. Earthquake Recurrence and the Resolution Potential of Tectono‐Geomorphic Records

    KAUST Repository

    Zielke, Olaf

    2018-04-17

    A long‐standing debate in active tectonics addresses how slip is accumulated through space and time along a given fault or fault section. This debate is in part still ongoing because of the lack of sufficiently long instrumental data that may constrain the recurrence characteristics of surface‐rupturing earthquakes along individual faults. Geomorphic and stratigraphic records are used instead to constrain this behavior. Although geomorphic data frequently indicate slip accumulation via quasicharacteristic same‐size offset increments, stratigraphic data indicate that earthquake timing observes a quasirandom distribution. Assuming that both observations are valid within their respective frameworks, I want to address here which recurrence model is able to reproduce this seemingly contradictory behavior. I further want to address how aleatory offset variability and epistemic measurement uncertainty affect our ability to resolve single‐earthquake surface slip and along‐fault slip‐accumulation patterns. I use a statistical model that samples probability density functions (PDFs) for geomorphic marker formation (storm events), marker displacement (surface‐rupturing earthquakes), and offset measurement, generating tectono‐geomorphic catalogs to investigate which PDF combination consistently reproduces the above‐mentioned field observations. Doing so, I find that neither a purely characteristic earthquake (CE) nor a Gutenberg–Richter (GR) earthquake recurrence model is able to consistently reproduce those field observations. A combination of both however, with moderate‐size earthquakes following the GR model and large earthquakes following the CE model, is able to reproduce quasirandom earthquake recurrence times while simultaneously generating quasicharacteristic geomorphic offset increments. Along‐fault slip accumulation is dominated by, but not exclusively linked to, the occurrence of similar‐size large earthquakes. Further, the resolution

  7. Outlining precision boundaries among areas with different variability standards using magnetic susceptibility and geomorphic surfaces

    OpenAIRE

    Matias,Sammy S. R.; Marques Júnior,José; Siqueira,Diego S.; Pereira,Gener T.

    2014-01-01

    There is an increasing demand for detailed maps that represent in a simplified way the knowledge of the variability of a particular area or region maps. The objective was to outline precision boundaries among areas with different accuracy variability standards using magnetic susceptibility and geomorphic surfaces. The study was conducted in an area of 110 ha, which identified three compartment landscapes based on the geomorphic surfaces model. To determinate pH, organic matter, phosphorus, po...

  8. Geospatial data sharing, online spatial analysis and processing of Indian Biodiversity data in Internet GIS domain - A case study for raster based online geo-processing

    Science.gov (United States)

    Karnatak, H.; Pandey, K.; Oberai, K.; Roy, A.; Joshi, D.; Singh, H.; Raju, P. L. N.; Krishna Murthy, Y. V. N.

    2014-11-01

    python, PostGIS and PHP for raster data analysis over the web for Biodiversity conservation and prioritization. The developed system takes inputs from users as WKT, Openlayer based Polygon geometry and Shape file upload as AOI to perform raster based operation using Python and GDAL/OGR. The intermediate products are stored in temporary files and tables which generate XML outputs for web representation. The raster operations like clip-zip-ship, class wise area statistics, single to multi-layer operations, diagrammatic representation and other geo-statistical analysis are performed. This is indigenous geospatial data processing engine developed using Open system architecture for spatial analysis of Biodiversity data sets in Internet GIS environment. The performance of this applications in multi-user environment like Internet domain is another challenging task which is addressed by fine tuning the source code, server hardening, spatial indexing and running the process in load balance mode. The developed system is hosted in Internet domain (http://bis.iirs.gov.in) for user access.

  9. A Modeling Approach for Evaluating the Coupled Riparian Vegetation-Geomorphic Response to Altered Flow Regimes

    Science.gov (United States)

    Manners, R.; Wilcox, A. C.; Merritt, D. M.

    2016-12-01

    The ecogeomorphic response of riparian ecosystems to a change in hydrologic properties is difficult to predict because of the interactions and feedbacks among plants, water, and sediment. Most riparian models of community dynamics assume a static channel, yet geomorphic processes strongly control the establishment and survival of riparian vegetation. Using a combination of approaches that includes empirical relationships and hydrodynamic models, we model the coupled vegetation-topographic response of three cross-sections on the Yampa and Green Rivers in Dinosaur National Monument, to a shift in the flow regime. The locations represent the variable geomorphology and vegetation composition of these canyon-bound rivers. We account for the inundation and hydraulic properties of vegetation plots surveyed over three years within International River Interface Cooperative (iRIC) Fastmech, equipped with a vegetation module that accounts for flexible stems and plant reconfiguration. The presence of functional groupings of plants, or those plants that respond similarly to environmental factors such as water availability and disturbance are determined from flow response curves developed for the Yampa River. Using field measurements of vegetation morphology, distance from the channel centerline, and dominant particle size and modeled inundation properties we develop an empirical relationship between these variables and topographic change. We evaluate vegetation and channel form changes over decadal timescales, allowing for the integration of processes over time. From our analyses, we identify thresholds in the flow regime that alter the distribution of plants and reduce geomorphic complexity, predominately through side-channel and backwater infilling. Simplification of some processes (e.g., empirically-derived sedimentation) and detailed treatment of others (e.g., plant-flow interactions) allows us to model the coupled dynamics of riparian ecosystems and evaluate the impact of

  10. Insights into the folding and unfolding processes of wild-type and mutated SH3 domain by molecular dynamics and replica exchange molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Wen-Ting Chu

    Full Text Available Src-homology regions 3 (SH3 domain is essential for the down-regulation of tyrosine kinase activity. Mutation A39V/N53P/V55L of SH3 is found to be relative to the urgent misfolding diseases. To gain insight, the human and gallus SH3 domains (PDB ID: 1NYG and 2LP5, including 58 amino acids in each protein, were selected for MD simulations (Amber11, ff99SB force field and cluster analysis to investigate the influence of mutations on the spatial structure of the SH3 domain. It is found that the large conformational change of mutations mainly exists in three areas in the vicinity of protein core: RT loop, N-src loop, distal β-hairpin to 310 helix. The C-terminus of the mutated gallus SH3 is disordered after simulation, which represents the intermediate state of aggregation. The disappeared strong Hbond net in the mutated human and gallus systems will make these mutated proteins looser than the wild-type proteins. Additionally, by performing the REMD simulations on the gallus SH3 domain, the mutated domain is found to have an obvious effect on the unfolding process. These studies will be helpful for further aggregation mechanisms investigations on SH3 family.

  11. Geomorphic effectiveness of a long profile shape and the role of inherent geological controls in the Himalayan hinterland area of the Ganga River basin, India

    Science.gov (United States)

    Sonam; Jain, Vikrant

    2018-03-01

    Long profiles of rivers provide a platform to analyse interaction between geological and geomorphic processes operating at different time scales. Identification of an appropriate model for river long profile becomes important in order to establish a quantitative relationship between the profile shape, its geomorphic effectiveness, and inherent geological characteristics. This work highlights the variability in the long profile shape of the Ganga River and its major tributaries, its impact on stream power distribution pattern, and role of the geological controls on it. Long profile shapes are represented by the sum of two exponential functions through the curve fitting method. We have shown that coefficients of river long profile equations are governed by the geological characteristics of subbasins. These equations further define the spatial distribution pattern of stream power and help to understand stream power variability in different geological terrains. Spatial distribution of stream power in different geological terrains successfully explains spatial variability in geomorphic processes within the Himalayan hinterland area. In general, the stream power peaks of larger rivers lie in the Higher Himalaya, and rivers in the eastern hinterland area are characterised by the highest magnitude of stream power.

  12. Geomorphic controls on elevational gradients of species richness.

    Science.gov (United States)

    Bertuzzo, Enrico; Carrara, Francesco; Mari, Lorenzo; Altermatt, Florian; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2016-02-16

    Elevational gradients of biodiversity have been widely investigated, and yet a clear interpretation of the biotic and abiotic factors that determine how species richness varies with elevation is still elusive. In mountainous landscapes, habitats at different elevations are characterized by different areal extent and connectivity properties, key drivers of biodiversity, as predicted by metacommunity theory. However, most previous studies directly correlated species richness to elevational gradients of potential drivers, thus neglecting the interplay between such gradients and the environmental matrix. Here, we investigate the role of geomorphology in shaping patterns of species richness. We develop a spatially explicit zero-sum metacommunity model where species have an elevation-dependent fitness and otherwise neutral traits. Results show that ecological dynamics over complex terrains lead to the null expectation of a hump-shaped elevational gradient of species richness, a pattern widely observed empirically. Local species richness is found to be related to the landscape elevational connectivity, as quantified by a newly proposed metric that applies tools of complex network theory to measure the closeness of a site to others with similar habitat. Our theoretical results suggest clear geomorphic controls on elevational gradients of species richness and support the use of the landscape elevational connectivity as a null model for the analysis of the distribution of biodiversity.

  13. Concrete domains

    OpenAIRE

    Kahn, G.; Plotkin, G.D.

    1993-01-01

    This paper introduces the theory of a particular kind of computation domains called concrete domains. The purpose of this theory is to find a satisfactory framework for the notions of coroutine computation and sequentiality of evaluation.

  14. Mechanism of Diphtheria Toxin Catalytic Domain Delivery to the Eukaryotic Cell Cytosol and the Cellular Factors that Directly Participate in the Process

    Science.gov (United States)

    Murphy, John R.

    2011-01-01

    Research on diphtheria and anthrax toxins over the past three decades has culminated in a detailed understanding of their structure function relationships (e.g., catalytic (C), transmembrane (T), and receptor binding (R) domains), as well as the identification of their eukaryotic cell surface receptor, an understanding of the molecular events leading to the receptor-mediated internalization of the toxin into an endosomal compartment, and the pH triggered conformational changes required for pore formation in the vesicle membrane. Recently, a major research effort has been focused on the development of a detailed understanding of the molecular interactions between each of these toxins and eukaryotic cell factors that play an essential role in the efficient translocation of their respective catalytic domains through the trans-endosomal vesicle membrane pore and delivery into the cell cytosol. In this review, I shall focus on recent findings that have led to a more detailed understanding of the mechanism by which the diphtheria toxin catalytic domain is delivered to the eukaryotic cell cytosol. While much work remains, it is becoming increasingly clear that the entry process is facilitated by specific interactions with a number of cellular factors in an ordered sequential fashion. In addition, since diphtheria, anthrax lethal factor and anthrax edema factor all carry multiple coatomer I complex binding motifs and COPI complex has been shown to play an essential role in entry process, it is likely that the initial steps in catalytic domain entry of these divergent toxins follow a common mechanism. PMID:22069710

  15. Domain Engineering

    Science.gov (United States)

    Bjørner, Dines

    Before software can be designed we must know its requirements. Before requirements can be expressed we must understand the domain. So it follows, from our dogma, that we must first establish precise descriptions of domains; then, from such descriptions, “derive” at least domain and interface requirements; and from those and machine requirements design the software, or, more generally, the computing systems.

  16. The p2 domain of human immunodeficiency virus type 1 Gag regulates sequential proteolytic processing and is required to produce fully infectious virions.

    Science.gov (United States)

    Pettit, S C; Moody, M D; Wehbie, R S; Kaplan, A H; Nantermet, P V; Klein, C A; Swanstrom, R

    1994-12-01

    The proteolytic processing sites of the human immunodeficiency virus type 1 (HIV-1) Gag precursor are cleaved in a sequential manner by the viral protease. We investigated the factors that regulate sequential processing. When full-length Gag protein was digested with recombinant HIV-1 protease in vitro, four of the five major processing sites in Gag were cleaved at rates that differ by as much as 400-fold. Three of these four processing sites were cleaved independently of the others. The CA/p2 site, however, was cleaved approximately 20-fold faster when the adjacent downstream p2/NC site was blocked from cleavage or when the p2 domain of Gag was deleted. These results suggest that the presence of a C-terminal p2 tail on processing intermediates slows cleavage at the upstream CA/p2 site. We also found that lower pH selectively accelerated cleavage of the CA/p2 processing site in the full-length precursor and as a peptide primarily by a sequence-based mechanism rather than by a change in protein conformation. Deletion of the p2 domain of Gag results in released virions that are less infectious despite the presence of the processed final products of Gag. These findings suggest that the p2 domain of HIV-1 Gag regulates the rate of cleavage at the CA/p2 processing site during sequential processing in vitro and in infected cells and that p2 may function in the proper assembly of virions.

  17. Global seafloor geomorphic features map: applications for ocean conservation and management

    Science.gov (United States)

    Harris, P. T.; Macmillan-Lawler, M.; Rupp, J.; Baker, E.

    2013-12-01

    Seafloor geomorphology, mapped and measured by marine scientists, has proven to be a very useful physical attribute for ocean management because different geomorphic features (eg. submarine canyons, seamounts, spreading ridges, escarpments, plateaus, trenches etc.) are commonly associated with particular suites of habitats and biological communities. Although we now have better bathymetric datasets than ever before, there has been little effort to integrate these data to create an updated map of seabed geomorphic features or habitats. Currently the best available global seafloor geomorphic features map is over 30 years old. A new global seafloor geomorphic features map (GSGM) has been created based on the analysis and interpretation of the SRTM (Shuttle Radar Topography Mission) 30 arc-second (~1 km) global bathymetry grid. The new map includes global spatial data layers for 29 categories of geomorphic features, defined by the International Hydrographic Organisation. The new geomorphic features map will allow: 1) Characterization of bioregions in terms of their geomorphic content (eg. GOODS bioregions, Large Marine Ecosystems (LMEs), ecologically or biologically significant areas (EBSA)); 2) Prediction of the potential spatial distribution of vulnerable marine ecosystems (VME) and marine genetic resources (MGR; eg. associated with hydrothermal vent communities, shelf-incising submarine canyons and seamounts rising to a specified depth); and 3) Characterization of national marine jurisdictions in terms of their inventory of geomorphic features and their global representativeness of features. To demonstrate the utility of the GSGM, we have conducted an analysis of the geomorphic feature content of the current global inventory of marine protected areas (MPAs) to assess the extent to which features are currently represented. The analysis shows that many features have very low representation, for example fans and rises have less than 1 per cent of their total area

  18. Geomorphic Map of Worcester County, Maryland, Interpreted from a LIDAR-Based, Digital Elevation Model

    Science.gov (United States)

    Newell, Wayne L.; Clark, Inga

    2008-01-01

    A recently compiled mosaic of a LIDAR-based digital elevation model (DEM) is presented with geomorphic analysis of new macro-topographic details. The geologic framework of the surficial and near surface late Cenozoic deposits of the central uplands, Pocomoke River valley, and the Atlantic Coast includes Cenozoic to recent sediments from fluvial, estuarine, and littoral depositional environments. Extensive Pleistocene (cold climate) sandy dune fields are deposited over much of the terraced landscape. The macro details from the LIDAR image reveal 2 meter-scale resolution of details of the shapes of individual dunes, and fields of translocated sand sheets. Most terrace surfaces are overprinted with circular to elliptical rimmed basins that represent complex histories of ephemeral ponds that were formed, drained, and overprinted by younger basins. The terrains of composite ephemeral ponds and the dune fields are inter-shingled at their margins indicating contemporaneous erosion, deposition, and re-arrangement and possible internal deformation of the surficial deposits. The aggregate of these landform details and their deposits are interpreted as the products of arid, cold climate processes that were common to the mid-Atlantic region during the Last Glacial Maximum. In the Pocomoke valley and its larger tributaries, erosional remnants of sandy flood plains with anastomosing channels indicate the dynamics of former hydrology and sediment load of the watershed that prevailed at the end of the Pleistocene. As the climate warmed and precipitation increased during the transition from late Pleistocene to Holocene, dune fields were stabilized by vegetation, and the stream discharge increased. The increased discharge and greater local relief of streams graded to lower sea levels stimulated down cutting and created the deeply incised valleys out onto the continental shelf. These incised valleys have been filling with fluvial to intertidal deposits that record the rising sea

  19. Reclamation Strategies and Geomorphic Outcomes in Coal Surface Mines of Eastern Ohio

    Science.gov (United States)

    Pollock, M.; Jaeger, K. L.

    2014-12-01

    both post-SMCRA (1.72% mean) and unmined (1.67% mean) reaches (1-way ANOVA p=0.0488 n=19). Our results demonstrate the differential alterations resulting from these reclamation strategies, which may lead to alteration of long-term geomorphic processes. Further investigations of hydrology and sediment transport are needed.

  20. Synchrotron FT-IR analyses of microstructured biomineral domains: Hints to the biomineralization processes in freshwater cultured pearls.

    Science.gov (United States)

    Soldati, A. L.; Vicente-Vilas, V.; Gasharova, B.; Jacob, D. E.

    2009-04-01

    Recent investigations in freshwater cultured pearls (bio-carbonate) by micro-Raman spectroscopy (Wehrmeister et al., 2008; Soldati et al., 2008), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) imaging (Jacob et al., 2008) show that the pearl biomineralisation starts with a self assembling process in which an existing gel matrix of amorphous calcium carbonate (ACC) and organic substances reorganizes and conglomerates in small domains; these conglomerates then form prisms and mature nacreous tablets of aragonite or vaterite. Raman spectroscopy shows that the calcium carbonate polymorphs have decreasing luminescence in the order ACC>Vaterite>Aragonite, coinciding with decreasing quantities of S and P (related to the organic matrix) measured by Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS) and Electron Probe Micro Analyzer (EPMA). Although little is known about the process of transformation of the ACC gel into vaterite and aragonite, it is speculated that this probably involves dehydration and change of the accompanying organic matrix. This is also supported by our laboratory FT-IR analysis. However, due to the small size of the areas of ACC (about 10 ?m) and the biogenic crystals an in-situ high spatially resolved IR-method is needed to record how the water content and organic matrix change in the biomineralisation sequence, to understand which processes take place in the self-organization. The beamline IR-1 at the ANKA synchrotron source (Karlsruhe, Germany) was used for this experiment. Freshwater cultured pearls from China cultured in Hyriopsis cumingii mussels by tissue nucleation methods (so-called beadless pearls) as well as by bead implantation methods (aragonite nucleus) were studied. The pearls were cut in half with a diamond-plated saw and polished with diamond paste on a copper plate. Micro-Raman spectroscopy maps (Department of Geosciences, at the Johannes Gutenberg-University, Mainz) were generated

  1. Context-dependent social evaluation in 4.5-month-old human infants: the role of domain-general versus domain-specific processes in the development of social evaluation.

    Science.gov (United States)

    Hamlin, J K

    2014-01-01

    The ability to distinguish friends from foes allows humans to engage in mutually beneficial cooperative acts while avoiding the costs associated with cooperating with the wrong individuals. One way to do so effectively is to observe how unknown individuals behave toward third parties, and to selectively cooperate with those who help others while avoiding those who harm others. Recent research suggests that a preference for prosocial over antisocial individuals emerges by the time that infants are 3 months of age, and by 8 months, but not before, infants evaluate others' actions in context: they prefer those who harm, rather than help, individuals who have previously harmed others. Currently there are at least two reasons for younger infants' failure to show context-dependent social evaluations. First, this failure may reflect fundamental change in infants' social evaluation system over the first year of life, in which infants first prefer helpers in any situation and only later evaluate prosocial and antisocial actors in context. On the other hand, it is possible that this developmental change actually reflects domain-general limitations of younger infants, such as limited memory and processing capacities. To distinguish between these possibilities, 4.5-month-olds in the current studies were habituated, rather than familiarized as in previous work, to one individual helping and another harming a third party, greatly increasing infants' exposure to the characters' actions. Following habituation, 4.5-month-olds displayed context-dependent social preferences, selectively reaching for helpers of prosocial and hinderers of antisocial others. Such results suggest that younger infants' failure to display global social evaluation in previous work reflected domain-general rather than domain-specific limitations.

  2. Context-dependent social evaluation in 4.5-month-old human infants: The role of domain-general versus domain-specific processes in the development of social evaluation

    Directory of Open Access Journals (Sweden)

    J Kiley eHamlin

    2014-06-01

    Full Text Available The ability to distinguish friends from foes allows humans to engage in mutually beneficial cooperative acts while avoiding the costs associated with cooperating with the wrong individuals. One way to do so effectively is to observe how unknown individuals behave toward third parties, and to selectively cooperate with those who help others while avoiding those who harm others. Recent research suggests that a preference for prosocial over antisocial individuals emerges by the time that infants are 3 months of age, and by 8 months, but not before, infants evaluate others’ actions in context: they prefer those who harm, rather than help, individuals who have previously harmed others. Currently there are at least two reasons for younger infants’ failure to show context-dependent social evaluations. First, this failure may reflect fundamental change in infants’ social evaluation system over the first year of life, in which infants first prefer helpers in any situation and only later evaluate prosocial and antisocial actors in context. On the other hand, it is possible that this developmental change actually reflects domain-general limitations of younger infants, such as limited memory and processing capacities. To distinguish between these possibilities, 4.5-month-olds in the current studies were habituated, rather than familiarized as in previous work, to one individual helping and another harming a third party, greatly increasing infants’ exposure to the characters’ actions. Following habituation, 4.5-month-olds displayed context-dependent social preferences, selectively reaching for helpers of prosocial and hinderers of antisocial others. Such results suggest that younger infants’ failure to display global social evaluation in previous work reflected domain-general rather than domain-specific limitations.

  3. Geomorphic legacy of medieval Himalayan earthquakes in the Pokhara Valley

    Science.gov (United States)

    Schwanghart, Wolfgang; Bernhardt, Anne; Stolle, Amelie; Hoelzmann, Philipp; Adhikari, Basanta R.; Andermann, Christoff; Tofelde, Stefanie; Merchel, Silke; Rugel, Georg; Fort, Monique; Korup, Oliver

    2016-04-01

    The Himalayas and their foreland belong to the world's most earthquake-prone regions. With millions of people at risk from severe ground shaking and associated damages, reliable data on the spatial and temporal occurrence of past major earthquakes is urgently needed to inform seismic risk analysis. Beyond the instrumental record such information has been largely based on historical accounts and trench studies. Written records provide evidence for damages and fatalities, yet are difficult to interpret when derived from the far-field. Trench studies, in turn, offer information on rupture histories, lengths and displacements along faults but involve high chronological uncertainties and fail to record earthquakes that do not rupture the surface. Thus, additional and independent information is required for developing reliable earthquake histories. Here, we present exceptionally well-dated evidence of catastrophic valley infill in the Pokhara Valley, Nepal. Bayesian calibration of radiocarbon dates from peat beds, plant macrofossils, and humic silts in fine-grained tributary sediments yields a robust age distribution that matches the timing of nearby M>8 earthquakes in ~1100, 1255, and 1344 AD. The upstream dip of tributary valley fills and X-ray fluorescence spectrometry of their provenance rule out local sediment sources. Instead, geomorphic and sedimentary evidence is consistent with catastrophic fluvial aggradation and debris flows that had plugged several tributaries with tens of meters of calcareous sediment from the Annapurna Massif >60 km away. The landscape-changing consequences of past large Himalayan earthquakes have so far been elusive. Catastrophic aggradation in the wake of two historically documented medieval earthquakes and one inferred from trench studies underscores that Himalayan valley fills should be considered as potential archives of past earthquakes. Such valley fills are pervasive in the Lesser Himalaya though high erosion rates reduce

  4. Geomorphic and erosion studies at the Western New York Nuclear Service Center, West Valley, New York

    International Nuclear Information System (INIS)

    Boothroyd, J.C.; Timson, B.S.; Dana, R.H. Jr.

    1979-12-01

    This report is one in a series of related reports presenting the results of a study to evaluate the containment capability of a low-level, solid radioactive waste-burial ground at West valley, NY. This project is the first portion of a detailed geomorphic and erosion study of the reach of Buttermilk Creek adjacent to the waste-burial site. Buttermilk Creek valley is being actively modified by fluvial transport, lateral channel scour, and landsliding. High surface runoff rates create highly variable but enhanced stream flows that result in coarse-gravel sediment transport within the active channel. The active channel morphology indicates that braided stream processes are common in Buttermilk, leading to active channel down-cutting and lateral migration. Where lateral migration of the active channel has undercut valley wall slopes, large-scale landsliding enhances valley wall retreat. A major site of historical and recent slide activity lies adjacent to the low-level burial trenches. Initial, post-glacial Buttermilk Creek incision began before 9920 +- 240 B.P., the age of the oldest dated fluvial terrace. Future evolution of the system is expected to proceed by Buttermilk valley lowering, tributary and landslide widening, and stream capture

  5. Analyzing Hydro-Geomorphic Responses in Post-Fire Stream Channels with Terrestrial LiDAR

    Science.gov (United States)

    Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.

    2015-12-01

    Wildfires have potential to significantly alter soil properties and vegetation within watersheds. These alterations often contribute to accelerated erosion, runoff, and sediment transport in stream channels and hillslopes. This research applies repeated Terrestrial Laser Scanning (TLS) Light Detection and Ranging (LiDAR) to stream reaches within the Pike National Forest in Colorado following the 2012 Waldo Canyon Fire. These scans allow investigation of the relationship between sediment delivery and environmental characteristics such as precipitation, soil burn severity, and vegetation. Post-fire LiDAR images provide high resolution information of stream channel changes in eight reaches for three years (2012-2014). All images are processed with RiSCAN PRO to remove vegetation and triangulated and smoothed to create a Digital Elevation Model (DEM) with 0.1 m resolution. Study reaches with two or more successive DEM images are compared using a differencing method to estimate the volume of sediment erosion and deposition. Preliminary analysis of four channel reaches within Williams Canyon and Camp Creek yielded erosion estimates between 0.035 and 0.618 m3 per unit area. Deposition was estimated as 0.365 to 1.67 m3 per unit area. Reaches that experienced higher soil burn severity or larger rainfall events produced the greatest geomorphic changes. Results from LiDAR analyses can be incorporated into post-fire hydrologic models to improve estimates of runoff and sediment yield. These models will, in turn, provide guidance for water resources management and downstream hazards mitigation.

  6. A drainage basin scale model for earthflow-prone landscapes over geomorphic timescales

    Science.gov (United States)

    Booth, A. M.; Roering, J. J.

    2009-12-01

    Landscape evolution models can be informative tools for understanding how sediment transport processes, regulated by tectonic and climatic forcing, interact to control fundamental landscape characteristics such as relief, channel network organization, and hillslope form. Many studies have proposed simple mathematical geomorphic transport laws for modeling hillslope and fluvial processes, and these models are capable of generating synthetic landscapes similar to many of those observed in nature. However, deep-seated mass movements dominate the topographic development of many tectonically active landscapes, yet few compelling transport laws exist for accurately describing these processes at the drainage basin scale. Specifically, several detailed field and theoretical studies describe the mechanics of deep-seated earthflows, such as those found throughout the northern California coast ranges, but these studies are often restricted to a single earthflow site. Here, we generalize earthflow behavior to larger spatial and geomorphically significant temporal scales using a mathematical model to determine how interactions between earthflow, weathering, hillslope, and fluvial processes control sediment flux and topographic form. The model couples the evolution of the land surface with the evolution of a weathered zone driven by fluctuations in the groundwater table. The lower boundary of this weathered zone sets the potential failure plane for earthflows, which occur once the shear stress on this plane exceeds a threshold value. Earthflows deform downslope with a non-Newtonian viscous rheology while gullying, modeled with a stream power equation, and soil creep, modeled with a diffusion equation, continuously act on the land surface. To compare the intensities of these different processes, we define a characteristic timescale for each modeled process, and demonstrate how the ratios of these timescales control the steady-state topographic characteristics of the simulated

  7. Bend-scale geomorphic classification and assessment of the Lower Missouri River from Sioux City, Iowa, to the Mississippi River for application to pallid sturgeon management

    Science.gov (United States)

    Jacobson, Robert B.; Colvin, Michael E.; Bulliner, Edward A.; Pickard, Darcy; Elliott, Caroline M.

    2018-06-07

    Management actions intended to increase growth and survival of pallid sturgeon (Scaphirhynchus albus) age-0 larvae on the Lower Missouri River require a comprehensive understanding of the geomorphic habitat template of the river. The study described here had two objectives relating to where channel-reconfiguration projects should be located to optimize effectiveness. The first objective was to develop a bend-scale (that is, at the scale of individual bends, defined as “cross-over to cross-over”) geomorphic classification of the Lower Missouri River to help in the design of monitoring and evaluation of such projects. The second objective was to explore whether geomorphic variables could provide insight into varying capacities of bends to intercept drifting larvae. The bend-scale classification was based on geomorphic and engineering variables for 257 bends from Sioux City, Iowa, to the confluence with the Mississippi River near St. Louis, Missouri. We used k-means clustering to identify groupings of bends that shared the same characteristics. Separate 3-, 4-, and 6-cluster classifications were developed and mapped. The three classifications are nested in a hierarchical structure. We also explored capacities of bends to intercept larvae through evaluation of linear models that predicted persistent sand area or catch per unit effort (CPUE) of age-0 sturgeon as a function of the same geomorphic variables used in the classification. All highly ranked models that predict persistent sand area contained mean channel width and standard deviation of channel width as significant variables. Some top-ranked models also included contributions of channel sinuosity and density of navigation structures. The sand-area prediction models have r-squared values of 0.648–0.674. In contrast, the highest-ranking CPUE models have r-squared values of 0.011–0.170, indicating much more uncertainty for the biological response variable. Whereas the persistent sand model documents that

  8. Relaxation dynamics of the conductive processes for PbNb2O6 ferroelectric ceramics in the frequency and time domain

    International Nuclear Information System (INIS)

    Gonzalez, R L; Leyet, Y; Guerrero, F; Guerra, J de Los S; Venet, M; Eiras, J A

    2007-01-01

    The relaxation dynamics of the conductive process present in PbNb 2 O 6 piezoelectric ceramics was investigated. A relaxation function in the time domain, Φ(t), was found from the frequency dependence of the dielectric modulus (imaginary component, M'') by using a relaxation function in the frequency domain, F*(ω). The best relaxation function, F*(ω), was found to be a Cole-Cole distribution function, in which relaxation characteristic parameters, such as α and τ CC , are involved. On the other hand, the relaxation function, Φ(t), obtained by the time domain method, was found to be a Kohlrausch-Williams-Watts (KWW) function type. The thermal evolution of the characteristics parameters of the KWW function (β and τ*) was analysed. The values of the activation energy (E a ), obtained in the whole investigated temperature interval, suggest the existence of a relaxation mechanism (a conductive process), which may be interpreted by an ion hopping between neighbouring sites within the crystalline lattice. The results are corroborated with the formalism of the AC conductivity

  9. An improvement of the filter diagonalization-based post-processing method applied to finite difference time domain calculations of three-dimensional phononic band structures

    International Nuclear Information System (INIS)

    Su Xiaoxing; Zhang Chuanzeng; Ma Tianxue; Wang Yuesheng

    2012-01-01

    When three-dimensional (3D) phononic band structures are calculated by using the finite difference time domain (FDTD) method with a relatively small number of iterations, the results can be effectively improved by post-processing the FDTD time series (FDTD-TS) based on the filter diagonalization method (FDM), instead of the classical fast Fourier transform. In this paper, we propose a way to further improve the performance of the FDM-based post-processing method by introducing a relatively large number of observing points to record the FDTD-TS. To this end, the existing scheme of FDTD-TS preprocessing is modified. With the new preprocessing scheme, the processing efficiency of a single FDTD-TS can be improved significantly, and thus the entire post-processing method can have sufficiently high efficiency even when a relatively large number of observing points are used. The feasibility of the proposed method for improvement is verified by the numerical results.

  10. P300 as a measure of processing capacity in auditory and visual domains in specific language impairment.

    Science.gov (United States)

    Evans, Julia L; Selinger, Craig; Pollak, Seth D

    2011-05-10

    This study examined the electrophysiological correlates of auditory and visual working memory in children with Specific Language Impairments (SLI). Children with SLI and age-matched controls (11;9-14;10) completed visual and auditory working memory tasks while event-related potentials (ERPs) were recorded. In the auditory condition, children with SLI performed similarly to controls when the memory load was kept low (1-back memory load). As expected, when demands for auditory working memory were higher, children with SLI showed decreases in accuracy and attenuated P3b responses. However, children with SLI also evinced difficulties in the visual working memory tasks. In both the low (1-back) and high (2-back) memory load conditions, P3b amplitude was significantly lower for the SLI as compared to CA groups. These data suggest a domain-general working memory deficit in SLI that is manifested across auditory and visual modalities. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Using HEC-RAS to Enhance Interpretive Capabilities of Geomorphic Assessments

    Science.gov (United States)

    Keefer, L. L.

    2005-12-01

    The purpose of a geomorphic assessment is to characterize and evaluate a fluvial system for determining the past watershed and channel conditions, current geomorphic character and potential future channel adjustments. The geomorphic assessment approach utilized by the Illinois State Water Survey assesses channel response to disturbance at multiple temporal and spatial scales to help identify the underlying factors and events which led to the existing channel morphology. This is accomplished through two phases of investigation that involve a historical and physical analysis of the watershed, disturbance history, and field work at increasing levels of detail. To infer future channel adjustments, the geomorphic assessment protocol combines two methods of analyses that are dependent on the quantity and detail of the available data. The first method is the compilation of multiple lines of evidence using qualitative information related to the dominant fluvial environment, channel gradient, stream power thresholds, and channel evolution models. The second method is the use of hydraulic models which provide additional interpretative skills to evaluate potential channel adjustments. The structured data collection framework of the geomorphic assessment approach is used for the development of a HEC-RAS model. The model results are then used as another tool to determine the influence of bridges and control structures on channel stability, stream power profiles to identify potential channel bed degradation zones, and provide data for physically-based bank stability models. This poster will demonstrate the advantages of using a hydraulic model, such as HEC-RAS, to expand the interpretive capabilities of geomorphic assessments. The results from applying this approach will be demonstrated for the Big Creek watershed of the Cache River Basin in southern Illinois.

  12. Debris Flows and Water Tracks in Continental Antarctica: Water as a geomorphic agent in a hyperarid polar desert

    Science.gov (United States)

    Hauber, E.; Sassenroth, C.; De Vera, J.-P.; Schmitz, N.; Reiss, D.; Hiesinger, H.; Johnsson, A.

    2017-09-01

    Most studies using Antarctica as a Mars analogue have focused on the McMurdo Dry Valleys, which are among the coldest and driest places on Earth. However, other ice-free areas in continental Antarctica also display landforms that can inform the study of the possible geomorphic impact of water in a polar desert. Here we present a new analogue site in the interior of the Transantarctic Mountains in Northern Victoria Land. Gullies show unambiguous evidence for debris flows, and water tracks act as shallow subsurface pathways of water on top of the permafrost tale. Both processes are driven by meltwater from glacier ice and snow in an environ-ment which never experiences rainfall and in which the air temperatures probably never exceed 0°C.

  13. Mechanism of Dynamic Recrystallization and Evolution of Texture in the Hot Working Domains of the Processing Map for Mg-4Al-2Ba-2Ca Alloy

    Directory of Open Access Journals (Sweden)

    Kalidass Suresh

    2017-12-01

    Full Text Available The occurrence of dynamic recrystallization (DRX and its effect on the evolution of texture during uniaxial compression of a creep-resistant cast Mg-4Al-2Ba-2Ca alloy in the temperature range of 260–500 °C and strain rate range of 0.0003–10 s−1 has been studied using transmission electron microscopy and electron backscatter diffraction techniques with a view to understand its mechanism. For this purpose, a processing map has been developed for this alloy, which revealed two domains of DRX in the temperature and strain rate ranges of: (1 300–390 °C/0.0003–0.001 s−1 and (2 400–500 °C/0.0003–0.5 s−1. In Domain 1, DRX occurs by basal slip and recovery by dislocation climb, as indicated by the presence of planar slip bands and high dislocation density leading to tilt boundary formation and a low-intensity basal texture. On the other hand, DRX in Domain 2 occurs by second order pyramidal slip and recovery by cross-slip since the microstructure revealed tangled dislocation structure with twist boundaries and randomized texture. The high volume content of intermetallic phases Mg21Al3Ba2 and (Al,Mg2Ca eutectic phase is considered to be responsible for the observed hot deformation behavior.

  14. Crystallization behavior and domain structure in textured Pb(Zr0.52Ti0.48)O3 thin films by different annealing processes

    International Nuclear Information System (INIS)

    Huang, W.; Jiang, S.W.; Li, Y.R.; Zhu, J.; Zhang, Y.; Wei, X.H.; Zeng, H.Z.

    2006-01-01

    Amorphous Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) thin films were prepared on the Pt/Ti/SiO 2 /Si substrates by radio-frequency magnetron sputtering at room temperature. After rapid thermal annealing (RTA) and conventional furnace annealing (CFA) at different temperatures, the films were transformed into polycrystalline PZT thin films with (111) and (100) orientation, respectively. The phase formation and ferroelectric domains correlated with different orientation were systematically investigated by X-ray diffraction and piezoresponse force microscopy. The results showed that the perovskite PZT crystal with [111] orientation hetero-nucleated preferentially on top of the PtPb intermetallic phase at the PZT/Pt interface during RTA process. It is of interest to find that the domain self-organized into a structure with rounded shape at the early stage of crystallization. While the nucleation of the films treated by CFA dominantly homo-nucleated, thus the (100) orientation grains with minimum surface energy were easy to grow. The texture effects on ferroelectric properties of PZT films were also discussed in relation to the domain structure

  15. All-optical signal processing of OTDM and OFDM signals based on time-domain optical fourier transformation

    DEFF Research Database (Denmark)

    Galili, Michael; Guan, Pengyu; Lillieholm, Mads

    2017-01-01

    In the talk, we will review recent work on optical signal processing based on time lenses. Various applications of optical Fourier transformation for optical communications will be discussed.......In the talk, we will review recent work on optical signal processing based on time lenses. Various applications of optical Fourier transformation for optical communications will be discussed....

  16. 3D Virtual Reality Applied in Tectonic Geomorphic Study of the Gombori Range of Greater Caucasus Mountains

    Science.gov (United States)

    Sukhishvili, Lasha; Javakhishvili, Zurab

    2016-04-01

    Gombori Range represents the southern part of the young Greater Caucasus Mountains and stretches from NW to SE. The range separates Alazani and Iori basins within the eastern Georgian province of Kakheti. The active phase of Caucasian orogeny started in the Pliocene, but according to alluvial sediments of Gombori range (mapped in the Soviet geologic map), we observe its uplift process to be Quaternary event. The highest peak of the Gombori range has an absolute elevation of 1991 m, while its neighboring Alazani valley gains only 400 m. We assume the range has a very fast uplift rate and it could trigger streams flow direction course reverse in Quaternary. To check this preliminary assumptions we are going to use a tectonic and fluvial geomorphic and stratigraphic approaches including paleocurrent analyses and various affordable absolute dating techniques to detect the evidence of river course reverses and date them. For these purposes we have selected river Turdo outcrop. The river itself flows northwards from the Gombori range and nearby region`s main city of Telavi generates 30-40 m high continuous outcrop along 1 km section. Turdo outcrop has very steep walls and requires special climbing skills to work on it. The goal of this particularly study is to avoid time and resource consuming ground survey process of this steep, high and wide outcrop and test 3D aerial and ground base photogrammetric modelling and analyzing approaches in initial stage of the tectonic geomorphic study. Using this type of remote sensing and virtual lab analyses of 3D outcrop model, we roughly delineated stratigraphic layers, selected exact locations for applying various research techniques and planned safe and suitable climbing routes for getting to the investigation sites.

  17. Application of a new genetic classification and semi-automated geomorphic mapping approach in the Perth submarine canyon, Australia

    Science.gov (United States)

    Picard, K.; Nanson, R.; Huang, Z.; Nichol, S.; McCulloch, M.

    2017-12-01

    The acquisition of high resolution marine geophysical data has intensified in recent years (e.g. multibeam echo-sounding, sub-bottom profiling). This progress provides the opportunity to classify and map the seafloor in greater detail, using new methods that preserve the links between processes and morphology. Geoscience Australia has developed a new genetic classification approach, nested within the Harris et al (2014) global seafloor mapping framework. The approach divides parent units into sub-features based on established classification schemes and feature descriptors defined by Bradwell et al. (2016: http://nora.nerc.ac.uk/), the International Hydrographic Organization (https://www.iho.int) and the Coastal Marine and Ecological Classification Standard (https://www.cmecscatalog.org). Owing to the ecological significance of submarine canyon systems in particular, much recent attention has focused on defining their variation in form and process, whereby they can be classified using a range of topographic metrics, fluvial dis/connection and shelf-incising status. The Perth Canyon is incised into the continental slope and shelf of southwest Australia, covering an area of >1500 km2 and extending from 4700 m water depth to the shelf break in 170 m. The canyon sits within a Marine Protected Area, incorporating a Marine National Park and Habitat Protection Zone in recognition of its benthic and pelagic biodiversity values. However, detailed information of the spatial patterns of the seabed habitats that influence this biodiversity is lacking. Here we use 20 m resolution bathymetry and acoustic backscatter data acquired in 2015 by the Schmidt Ocean Institute plus sub-bottom datasets and sediment samples collected Geoscience Australia in 2005 to apply the new geomorphic classification system to the Perth Canyon. This presentation will show the results of the geomorphic feature mapping of the canyon and its application to better defining potential benthic habitats.

  18. Application of structure from motion to digitized historical airphotos to document geomorphic change over the past century

    Science.gov (United States)

    Roberti, Gioachino; Ward, Brent; van Wyk de Vries, Benjamin; Perotti, Luigi; Giardino, Marco; Friele, Pierre; Clague, John

    2017-04-01

    Topographic modeling is becoming more accessible due to the development of structure from motion (SFM), and multi-view stereo (MVS) image matching algorithms in digital photogrammetry. Many studies are utilizing SFM-MVS with either UAV or hand-held consumer-grade digital cameras. However, little work has been done in using SFM-MVS with digitized historical air photos. Large databases of historical airphotos are available in university, public, and government libraries, commonly as paper copies. In many instances, the photos are in poor condition (i.e. deformed by humidity, scratched, or annotated). In addition, the negatives, as well as metadata on the camera and the flight mission, may be missing. Processing such photos using classic stereo-photogrammetry is difficult and in many instances impossible. Yet these photos can provide a valuable archive of geomorphic changes. In this study, we digitized over 1000 vertical air photos of the Mount Meager massif (British Columbia, Canada), acquired during flights between 1947 and 2006. We processed the scans using the commercial SFM-MVS software package PhotoScan. PhotoScan provided high-quality orthophotos (0.42-1.13 m/pixel) and DTMs (1-5 m/pixel). We used the orthophotos to document glacier retreat and deep-seated gravitational deformation over the 60-year photo period. Notably, we reconstructed geomorphic changes that led to the very large (˜50 x 106 m 3) 2010 failure of the south flank of Meager Peak and also documented other unstable areas that might fail catastrophically in the future. This technique can be applied to other photosets to provide rapid high-quality cartographic products that allow researchers to track landscape changes over large areas over the past century.

  19. Geomorphic characterization of four shelf-sourced submarine canyons along the U.S. Mid-Atlantic continental margin

    Science.gov (United States)

    Obelcz, Jeffrey; Brothers, Daniel S.; Chaytor, Jason D.; ten Brink, Uri S.; Ross, Steve W.; Brooke, Sandra

    2013-01-01

    Shelf-sourced submarine canyons are common features of continental margins and are fundamental to deep-sea sedimentary systems. Despite their geomorphic and geologic significance, relatively few passive margin shelf-breaching canyons worldwide have been mapped using modern geophysical methods. Between 2007 and 2012 a series of geophysical surveys was conducted across four major canyons of the US Mid-Atlantic margin: Wilmington, Baltimore, Washington, and Norfolk canyons. More than 5700 km2 of high-resolution multibeam bathymetry and 890 line-km of sub-bottom CHIRP profiles were collected along the outer shelf and uppermost slope (depths of 80-1200 m). The data allowed us to compare and contrast the fine-scale morphology of each canyon system. The canyons have marked differences in the morphology and orientation of canyon heads, steepness and density of sidewall gullies, and the character of the continental shelf surrounding canyon rims. Down-canyon axial profiles for Washington, Baltimore and Wilmington canyons have linear shapes, and each canyon thalweg exhibits morphological evidence for recent, relatively small-scale sediment transport. For example, Washington Canyon displays extremely steep wall gradients and contains ~100 m wide, 5–10 m deep, v-shaped incisions down the canyon axis, suggesting modern or recent sediment transport. In contrast, the convex axial thalweg profile, the absence of thalweg incision, and evidence for sediment infilling at the canyon head, suggest that depositional processes strongly influence Norfolk Canyon during the current sea-level high-stand. The north walls of Wilmington, Washington and Norfolk canyons are steeper than the south walls due to differential erosion, though the underlying cause for this asymmetry is not clear. Furthermore, we speculate that most of the geomorphic features observed within the canyons (e.g., terraces, tributary canyons, gullies, and hanging valleys) were formed during the Pleistocene, and show only

  20. Evaluation of short-term geomorphic changes along the Tagliamento river using LiDAR and terrestrial laser scanner surveys

    Directory of Open Access Journals (Sweden)

    R. Rainato

    2013-09-01

    Full Text Available In the recent years a change in the predominant morphology of several river environments has taken place, consisting in a reduction of the braided pattern in favor to wandering or straight configurations. This evolution seems to be due, according to the scientific community, to anthropic causes and, in particular, to the alteration of flow regimes as well as the reduction of sediment transport. Braided rivers are characterized by two or more active channels, separated by bars and fluvial islands and normally feature a high morphological dynamism. This dynamism is the result of the interaction among different elements as sediment supply, flow regime and in-channel and perifluvial vegetation. These factors have a fundamental role in the erosion and deposition processes which are the basis of the morphological changes. The aims of this study are the assessment of the short period geomorphic and volumetric changes occurred along a reach of the Tagliamento River and the comparison between the results obtained from LiDAR (Light Detection and Ranging and TLS (Terrestrial Laser Scanner data. The Tagliamento river is a natural gravel-bed river located in the NE of Italy, characterized by a relatively low degree of human disturbances. The analyses were carried out considering two different scales (a reach of about 430 ha and a sub-reach of about 25 ha and were based on two subsequent datasets in order to investigate the shortterm geomorphic changes due to eight significant floods. The surveys were performed using two different datasets derived from LiDAR and TLS technologies and used to analyze the reach and sub-reach respectively. The short-term estimates of geomorphic and volumetric changes were performed using DEMs of Difference (DoD based on a Fuzzy Inference System. The results have confirmed the high dynamism of the Tagliamento river, estimating a prevalent deposition at reach and a predominant erosion at sub-reach levels. Finally, a comparative

  1. Diatom-inferred hydrological changes and Holocene geomorphic transitioning of Africa's largest estuarine system, Lake St Lucia

    Science.gov (United States)

    Gomes, M.; Humphries, M. S.; Kirsten, K. L.; Green, A. N.; Finch, J. M.; de Lecea, A. M.

    2017-06-01

    The diverse lagoons and coastal lakes along the east coast of South Africa occupy incised valleys that were flooded during the rise and subsequent stabilisation of relative sea-level during the Holocene. Sedimentary deposits contained within these waterbodies provide an opportunity to investigate complex hydrological and sedimentological processes, and examine sea-level controls governing system geomorphic evolution. In this paper, we combine diatom and sulfur isotope analyses from two sediment cores extracted from the northern sub-basins of Lake St Lucia, a large shallow estuarine lake that is today largely isolated from direct ocean influence behind a Holocene-Pleistocene barrier complex. Analyses allow the reconstruction of hydrological changes associated with the geomorphic development of the system over the mid-to late Holocene. The sedimentary sequences indicate that St Lucia was a shallow, partially enclosed estuary/embayment dominated by strong tidal flows prior to ∼6200 cal. BP. Infilling was initiated when sea-level rise slowed and stabilised around present day levels, resulting in the accumulation of fine-grained sediment behind an emergent proto-barrier. Diatom assemblages, dominated by marine benthic and epiphytic species, reveal a system structured by marine water influx and characterised by marsh and tidal flat habitats until ∼4550 cal. BP. A shift in the biological community at ∼4550 cal. BP is linked to the development of a back-barrier water body that supported a brackish community. Marine planktonics and enrichments in δ34S suggest recurrent, large-scale barrier inundation events during this time, coincident with a mid-Holocene sea-level highstand. Periodic marine incursions associated with episodes of enhanced storminess and overwash remained prevalent until ∼1200 cal. BP, when further barrier construction ultimately isolated the northern basins from the ocean. This study provides the first reconstruction of the palaeohydrological

  2. Behavioral Health Providers for Persons Who Are Deaf, Deafblind, or Hard-of-Hearing: A National Survey of the Structural and Process Domains of Care.

    Science.gov (United States)

    Nolan, Beth A D; Mathos, Kimberly; Fusco, Laura E; Post, Edward P

    2015-01-01

    Research suggests higher prevalence of mental health problems for those with hearing problems than in the general population. Despite barriers, mental health services for persons who are deaf and hard-of-hearing (HOH) have developed to meet the cultural and communication needs of this population. The authors conducted a national survey of mental health service providers to persons who are deaf, deafblind, or HOH, to learn about their structural and process domains of care. Results indicate that services for persons who are deaf, deafblind, or HOH are inadequate for consumers with serious mental illness. Results also uncovered unique pathways to care and practitioners.

  3. Geomorphic changes induced by the April-May 2015 earthquake sequence in the Pharak-Khumbu area (Nepal): preliminary assessments.

    Science.gov (United States)

    Fort, Monique

    2016-04-01

    Landsliding is a common process shaping mountain slopes. There are various potential landslide triggers (rainfall, bank erosion, earthquakes) and their effectiveness depends on their distribution, frequency and magnitude. In a Himalayan context, the effects of monsoon rainfall can be assessed every year whereas the unpredictability and low frequency of large earthquakes make their role in triggering slope instability more obscure. A 7.8 magnitude earthquake struck central Nepal (Gorkha District) on 25 April 2015 and was followed by many aftershocks exceeding magnitude 5, including another strong 7.3 magnitude earthquake on May 12, 2015 (Dolakha District). This seismic crisis provides an exceptional opportunity to assess the disruptions that earthquakes may cause in "regular" geomorphic systems controlled by rainfall. Here we present field observations carried out in the Pharak-Khumbu area (East Nepal, Dudh Kosi catchment) before and after the April-May 2015 earthquakes. The Pharak, a "middle mountains" (2000-4500 m) area, is affected by monsoon rains (3000 m/yr at 2500 m) and characterised by steep hillslopes, shaped by different geomorphic processes according to slope height and aspect, rock type and strength, inherited landforms, stream connectivity and current land use changes. This study focuses on the south of Lukla (Phakding District), and more specifically on the Khari Khola catchment and its surroundings. The area lies at the transition between the Higher Himalayan crystallines and the Lesser Himalayan meta-sediments. On the basis of our diachronic observations (March and November 2015), we surveyed and mapped new earthquake-induced slope instabilities such as rock falls, rockslides, landslides and debris flows and a combination of several of them. Interviews with local people also helped to assess the exact timing of some events. While the first M 7.8 earthquake produced significant impacts in the northern Khumbu area, the M 7.3 aftershock seems to have

  4. The Logic of Adaptive Behavior - Knowledge Representation and Algorithms for the Markov Decision Process Framework in First-Order Domains

    NARCIS (Netherlands)

    van Otterlo, M.

    2008-01-01

    Learning and reasoning in large, structured, probabilistic worlds is at the heart of artificial intelligence. Markov decision processes have become the de facto standard in modeling and solving sequential decision making problems under uncertainty. Many efficient reinforcement learning and dynamic

  5. Highly Conserved Arg Residue of ERFNIN Motif of Pro-Domain is Important for pH-Induced Zymogen Activation Process in Cysteine Cathepsins K and L.

    Science.gov (United States)

    Aich, Pulakesh; Biswas, Sampa

    2018-06-01

    Pro-domain of a cysteine cathepsin contains a highly conserved Ex 2 Rx 2 Fx 2 Nx 3 Ix 3 N (ERFNIN) motif. The zymogen structure of cathepsins revealed that the Arg(R) residue of the motif is a central residue of a salt-bridge/H-bond network, stabilizing the scaffold of the pro-domain. Importance of the arginine is also demonstrated in studies where a single mutation (Arg → Trp) in human lysosomal cathepsin K (hCTSK) is linked to a bone-related genetic disorder "Pycnodysostosis". In the present study, we have characterized in vitro Arg → Trp mutant of hCTSK and the same mutant of hCTSL. The R → W mutant of hCTSK revealed that this mutation leads to an unstable zymogen that is spontaneously activated and auto-proteolytically degraded rapidly. In contrast, the same mutant of hCTSL is sufficiently stable and has proteolytic activity almost like its wild-type counterpart; however it shows an altered zymogen activation condition in terms of pH, temperature and time. Far and near UV circular dichroism and intrinsic tryptophan fluorescence experiments have revealed that the mutation has minimal effect on structure of the protease hCTSL. Molecular modeling studies shows that the mutated Trp31 in hCTSL forms an aromatic cluster with Tyr23 and Trp30 leading to a local stabilization of pro-domain and supplements the loss of salt-bridge interaction mediated by Arg31 in wild-type. In hCTSK-R31W mutant, due to presence of a non-aromatic Ser30 residue such interaction is not possible and may be responsible for local instability. These differences may cause detrimental effects of R31W mutation on the regulation of hCTSK auto-activation process compared to altered activation process in hCTSL.

  6. Geomorphic evaluation of erosional stability at reclaimed surface mines in northwestern Colorado. Water Resources Investigation

    International Nuclear Information System (INIS)

    Elliott, J.G.

    1990-01-01

    The report identifies geomorphic, pedologic, vegetation, and hydrologic conditions that are associated with erosion of reclaimed surface-mined lands in northwestern Colorado. The report also presents methods for determining the appropriate values of geomorphic variables that can be manipulated during reclamation to increase erosional stability. A section on geomorphic principles associated with erosion of reclaimed land surfaces is designed for use as a primer by mine personnel and reclamation planners. The areas of interest in the study were those that were reclaimed under jurisdiction of current (1988) SMCRA reclamation regulations, yet were still affected by relatively rapid erosion rates several years after reclamation activities were completed. Geomorphic, pedologic, vegetation, and hydrologic data were collected onsite and from topographic maps. Data from reclaimed areas undergoing accelerated erosion were compared with data from reclaimed areas undergoing minimal erosion to identify conditions that controlled erosion on reclaimed surface-mined lands and to identify some postmining equilibrium landform characteristics. These data also were used to develop threshold relations

  7. Interdependence of geomorphic and ecologic resilience properties in a geographic context

    Science.gov (United States)

    Anthony Stallins, J.; Corenblit, Dov

    2018-03-01

    Ecology and geomorphology recognize the dynamic aspects of resistance and resilience. However, formal resilience theory in ecology has tended to deemphasize the geomorphic habitat template. Conversely, landscape sensitivity and state-and-transition models in geomorphology downweight mechanisms of biotic adaptation operative in fluctuating, spatially explicit environments. Adding to the interdisciplinary challenge of understanding complex biogeomorphic systems is that environmental heterogeneity and overlapping gradients of disturbance complicate inference of the geographic patterns of resistance and resilience. We develop a conceptual model for comparing the resilience properties among barrier dunes. The model illustrates how adaptive cycles and panarchies, the formal building blocks of resilience recognized in ecology, can be expressed as a set of hierarchically nested geomorphic and ecological metrics. The variance structure of these data is proposed as a means to delineate different kinds and levels of resilience. Specifically, it is the dimensionality of these data and how geomorphic and ecological variables load on the first and succeeding axes that facilitates the delineation of resistance and resilience. The construction of dune topographic state space from observations among different barrier islands is proposed as a way to measure the interdependence of geomorphic and ecological resilience properties.

  8. Multivariate geomorphic analysis of forest streams: Implications for assessment of land use impacts on channel condition

    Science.gov (United States)

    Richard. D. Wood-Smith; John M. Buffington

    1996-01-01

    Multivariate statistical analyses of geomorphic variables from 23 forest stream reaches in southeast Alaska result in successful discrimination between pristine streams and those disturbed by land management, specifically timber harvesting and associated road building. Results of discriminant function analysis indicate that a three-variable model discriminates 10...

  9. Constraints on the topographic evolution of Corsica and Sardinia from geological and geomorphic analyses

    Science.gov (United States)

    Quye-Sawyer, Jennifer; Whittaker, Alexander; Roberts, Gareth; Rood, Dylan

    2017-04-01

    The western Mediterranean Sea and its surroundings form part of a well-studied region whose geodynamic history is broadly known. However, how the topography of this area has responded to its tectonic and geodynamic influences is not fully understood. In particular, the relative importance of convergent, extensional and dynamic process is not known. Here we focus on the islands of Corsica, France, and Sardinia, Italy, which have played an important role in Alpine-Apennine system. They experienced a similar kinematic history during the Cenozoic, however their different positions on the Tethyan margin allow the relative effects of Alpine collision and rates of back-arc stretching to be compared. In particular, the two stages of back-arc extension (Liguro-Provençal basin to the west and Tyrrhenian Sea on the east) can provide information about how rollback-induced extension developed with time from the late Oligocene to the present. The two islands are historically tectonically quiescent, however they still preserve evidence of collision and subsequent extension from slab roll-back. In this study we have used a combination of geological and geomorphic techniques to provide new constraints into the vertical motions of Corsica and Sardinia. To quantify the spatial and temporal landscape evolution we have integrated stratigraphic, structural and thermochronological data and re-evaluated these alongside present-day geomorphic and geophysical observations. In addition, we have used digital elevation models to acquire 2030 fluvial longitudinal profiles for both islands. Knickpoints identified on these longitudinal profiles have been compared to geological maps to test the influence of rock strength on erosion. Our analysis reveals the presence of non-lithologically controlled knickpoints which we interpret to have been created by Miocene to Recent changes in uplift rate of the landscape. The longitudinal profiles were subsequently used in drainage inversion modelling, whose

  10. On the Relationship between Holocene Geomorphic Evolution of Rivers and Prehistoric Settlements Distribution in the Songshan Mountain Region of China

    Directory of Open Access Journals (Sweden)

    Peng Lu

    2017-01-01

    Full Text Available This paper deals with the study of Holocene geomorphic evolution of rivers around Songshan Mountain in relation to human frequentation in Prehistoric periods. The investigations were performed by means of an integration of GIS data processing; field surveys and particle size analysis. In 8000–3000 aBP; in the Songshan Mountain Region, large-scale river sedimentation occurred. This increased the elevation of river beds that were higher than today. After 3000 aBP; the upper reaches of the rivers experienced a down cut; while the lower reaches experienced continuing sedimentation. The data on the elevation of prehistoric settlements above the river levels were obtained from Digital Elevation Models (DEMs. These data were corrected according to the evolutionary features of fluvial landforms in order to obtain synchronous elevations above river levels of prehistoric settlements. The relationship between sediment distribution and the Holocene geomorphic evolution was investigated through the statistical analysis of the elevation above the river levels. Outputs from our analyses enabled us to differentiate three evolutionary stages. During the first one, related to Peiligang culture (9000–7500 aBP, populations mainly settled on both hilly relief and high plateaus depending on their agriculture production modes. During the second stage, from Yangshao (7500–5000 aBP to the Longshan period (5000–4000 aBP, settlements were mainly distributed on mountainous areas and hilly lands to avoid flooding and to develop agriculture. Finally, during the Xiashang culture (4000–3000 aBP, a large number of settlements migrated to the plain area to facilitate trade of goods and cultural exchanges.

  11. Building Models in the Classroom: Taking Advantage of Sophisticated Geomorphic Numerical Tools Using a Simple Graphical User Interface

    Science.gov (United States)

    Roy, S. G.; Koons, P. O.; Gerbi, C. C.; Capps, D. K.; Tucker, G. E.; Rogers, Z. A.

    2014-12-01

    Sophisticated numerical tools exist for modeling geomorphic processes and linking them to tectonic and climatic systems, but they are often seen as inaccessible for users with an exploratory level of interest. We have improved the accessibility of landscape evolution models by producing a simple graphics user interface (GUI) that takes advantage of the Channel-Hillslope Integrated Landscape Development (CHILD) model. Model access is flexible: the user can edit values for basic geomorphic, tectonic, and climate parameters, or obtain greater control by defining the spatiotemporal distributions of those parameters. Users can make educated predictions by choosing their own parametric values for the governing equations and interpreting the results immediately through model graphics. This method of modeling allows users to iteratively build their understanding through experimentation. Use of this GUI is intended for inquiry and discovery-based learning activities. We discuss a number of examples of how the GUI can be used at the upper high school, introductory university, and advanced university level. Effective teaching modules initially focus on an inquiry-based example guided by the instructor. As students become familiar with the GUI and the CHILD model, the class can shift to more student-centered exploration and experimentation. To make model interpretations more robust, digital elevation models can be imported and direct comparisons can be made between CHILD model results and natural topography. The GUI is available online through the University of Maine's Earth and Climate Sciences website, through the Community Surface Dynamics Modeling System (CSDMS) model repository, or by contacting the corresponding author.

  12. Biogeomorphic feedbacks in the Southwestern USA: exploring the mechanisms of geomorphic change and the effectiveness of mitigation measures

    Science.gov (United States)

    Dean, D. J.; Diehl, R. M.; Topping, D. J.

    2017-12-01

    Water development and the proliferation of riparian plants have resulted in extensive geomorphic change to rivers worldwide. In many dryland rivers of the Southwestern U.S., these phenomena have contributed to conditions of sediment accumulation leading to channel narrowing, floodplain aggradation, and loss of fluvial habitat. Using a series of field and laboratory measurements, we demonstrate how biogeomorphic feedbacks have promoted channel contraction. Experimental evidence shows that vegetation can have a substantial effect on local hydraulics and sediment-transport fields, depending on plant morphology, but that the impact of plants on physical processes is mediated by flow and sediment supply. In the Little Colorado River in Arizona, water management practices, variations in climate/hydrology, and the resultant expansion of riparian vegetation have resulted in channel narrowing, increases in sinuosity and drag, and decreases in channel slope. These changes have created a biogeomorphic feedback by disrupting downstream flood conveyance; flood travel time has increased resulting in flow attenuation, declines in peak discharge, and continued sediment accumulation at large scales. In the Rio Grande in Big Bend National Park, channel narrowing and floodplain aggradation has led to the loss of channel capacity and an increase in overbank flooding even though discharges have declined. Vegetation expansion into channel environments has exacerbated this condition by reducing channel-margin flow velocities, increasing sediment deposition, and reducing bank erosion thereby creating a biogeomorphic feedback leading to additional narrowing. An understanding of the mechanisms that have driven geomorphic changes in river channels may help to formulate effective mitigation measures. Vegetation removal can have local and reach-scale effects on channel morphology; however, the effectiveness of these actions is dependent upon many variables including the flow regime and

  13. The role of water chemistry and geomorphic control in the presence of Didymosphenia geminata in Quebec

    Science.gov (United States)

    Gillis, C.; Gabor, R. S.; Cullis, J. D.; Ran, L.; Hassan, M. A.

    2010-12-01

    Didymosphenia geminata (didymo), an invasive diatom, was first officially observed and identified in the Matapedia River in Eastern Quebec in July 2006. This Atlantic salmon fishing river has several characteristics shown to favor didymo's ability to form thick, extensive benthic mats, including stable flow and oligotrophic nutrient conditions. Since the incursion, rapid colonization and inter-catchment transfer processes were observed, notably in surrounding watersheds on the Gaspé Peninsula as well as in northern New-Brunswick. All affected watersheds share favorable characteristics for didymo growth, including high light, low nutrient waters, and stable substrate. The nearby North Shore of the St. Lawrence, which also contains rivers with conditions that would favor didymo growth, has not yet shown didymo presence. This system provides a comparison to identify necessary parameters for didymo growth, with differences primarily due to geology-driven water chemistry. Pre-incursion water chemistry was compared between the two regions. Rivers in the region where didymo is present displayed a high alkalinity and corresponding higher pH, due to increases concentrations of magnesium and calcium, than rivers in regions where didymo has not appeared. Also, rivers with didymo show a lower amount of color-causing compounds, such as organic carbon, and clearer water, which supports the theory that high light levels encourage didymo growth. In addition to water chemistry, channel morphology, bed stability and flow patterns are also believed to be key elements in determining the presence of this benthic diatom. In 2007, channel morphology, bed texture, bankfull depth and width, local bed slope and didymo presence were surveyed on a 65 km stretch of the Matapedia River. Relative frequency of didymo presence showed that didymo blooms are most likely to appear in cobble-riffles than in any other morphologies. In fact, cobble riffles promote didymo establishment due to shallow

  14. Single-molecule Imaging Analysis of Binding, Processive Movement, and Dissociation of Cellobiohydrolase Trichoderma reesei Cel6A and Its Domains on Crystalline Cellulose*

    Science.gov (United States)

    Nakamura, Akihiko; Tasaki, Tomoyuki; Ishiwata, Daiki; Yamamoto, Mayuko; Okuni, Yasuko; Visootsat, Akasit; Maximilien, Morice; Noji, Hiroyuki; Uchiyama, Taku; Samejima, Masahiro; Igarashi, Kiyohiko; Iino, Ryota

    2016-01-01

    Trichoderma reesei Cel6A (TrCel6A) is a cellobiohydrolase that hydrolyzes crystalline cellulose into cellobiose. Here we directly observed the reaction cycle (binding, surface movement, and dissociation) of single-molecule intact TrCel6A, isolated catalytic domain (CD), cellulose-binding module (CBM), and CBM and linker (CBM-linker) on crystalline cellulose Iα. The CBM-linker showed a binding rate constant almost half that of intact TrCel6A, whereas those of the CD and CBM were only one-tenth of intact TrCel6A. These results indicate that the glycosylated linker region largely contributes to initial binding on crystalline cellulose. After binding, all samples showed slow and fast dissociations, likely caused by the two different bound states due to the heterogeneity of cellulose surface. The CBM showed much higher specificity to the high affinity site than to the low affinity site, whereas the CD did not, suggesting that the CBM leads the CD to the hydrophobic surface of crystalline cellulose. On the cellulose surface, intact molecules showed slow processive movements (8.8 ± 5.5 nm/s) and fast diffusional movements (30–40 nm/s), whereas the CBM-Linker, CD, and a catalytically inactive full-length mutant showed only fast diffusional movements. These results suggest that both direct binding and surface diffusion contribute to searching of the hydrolysable point of cellulose chains. The duration time constant for the processive movement was 7.7 s, and processivity was estimated as 68 ± 42. Our results reveal the role of each domain in the elementary steps of the reaction cycle and provide the first direct evidence of the processive movement of TrCel6A on crystalline cellulose. PMID:27609516

  15. Photoelectric effect in the relativistic domain revealed by the time-reversed process for highly charged uranium ions

    International Nuclear Information System (INIS)

    Stoehlker, T.; Mokler, P.H.; Kozhuharov, C.; Warczak, A.

    1996-10-01

    The photoelectric effect in the near relativistic energy regime of 80 to 350 keV is studied by the time-reversed process in ion-atom collisions, i.e. by the radiative capture of a quasi-free target electron. We review shell and subshell differential photon-angular distribution studies of radiative capture into highly-charged uranium ions. The experimental data are compared with exact relativistic calculations and give detailed insight into both the atomic structure of high-Z few-electron ions and into the fundamental electron-photon interaction process involved. In particular it is shown that the angular-differential measurements provide a unique method to study the magnetic interaction in relativistic electron-photon encoun- (orig.)

  16. A simple process to obtain anisotropic self-biased magnets constituted of stacked barium ferrite single domain particles

    Science.gov (United States)

    Mattei, Jean-Luc; Le, Cong Nha; Chevalier, Alexis; Maalouf, Azar; Noutehou, Nathan; Queffelec, Patrick; Laur, Vincent

    2018-04-01

    An efficient and inexpensive process is presented that produces highly oriented bulk compacts made of BaM particles. Barium hexaferrite particles (BaM, nominal composition BaFe11O19) were prepared by a chemical coprecipitation method, using different rates and types of precipitating agents (NaOH and Na2CO3). It was demonstrated that when a large excess of Na2CO3 is used, a noteworthy packing of hexagonal BaM platelets is obtained, after mechanical compaction and firing at moderate temperature (1140 °C), without including any more steps than those required for a conventional sintering process. The hysteresis loop displays a very competitive squareness of 0.88 (normalized remanent magnetization) and a coercivity of 215 kA/m, which make this BaM bulk ferrite suitable for self-biased applications.

  17. lop-DWI: A Novel Scheme for Pre-Processing of Diffusion-Weighted Images in the Gradient Direction Domain.

    Science.gov (United States)

    Sepehrband, Farshid; Choupan, Jeiran; Caruyer, Emmanuel; Kurniawan, Nyoman D; Gal, Yaniv; Tieng, Quang M; McMahon, Katie L; Vegh, Viktor; Reutens, David C; Yang, Zhengyi

    2014-01-01

    We describe and evaluate a pre-processing method based on a periodic spiral sampling of diffusion-gradient directions for high angular resolution diffusion magnetic resonance imaging. Our pre-processing method incorporates prior knowledge about the acquired diffusion-weighted signal, facilitating noise reduction. Periodic spiral sampling of gradient direction encodings results in an acquired signal in each voxel that is pseudo-periodic with characteristics that allow separation of low-frequency signal from high frequency noise. Consequently, it enhances local reconstruction of the orientation distribution function used to define fiber tracks in the brain. Denoising with periodic spiral sampling was tested using synthetic data and in vivo human brain images. The level of improvement in signal-to-noise ratio and in the accuracy of local reconstruction of fiber tracks was significantly improved using our method.

  18. Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

    Science.gov (United States)

    Shafroth, Patrick B.; Perry, Laura G; Rose, Chanoane A; Braatne, Jeffrey H

    2016-01-01

    Understanding how dams affect the shifting habitat mosaic of river bottomlands is key for protecting the many ecological functions and related goods and services that riparian forests provide and for informing approaches to riparian ecosystem restoration. We examined the downstream effects of two large dams on patterns of forest composition, structure, and dynamics within different geomorphic contexts and compared them to upstream reference conditions along the Elwha River, Washington, USA. Patterns of riparian vegetation in river segments downstream of the dams were driven largely by channel and bottomland geomorphic responses to a dramatically reduced sediment supply. The river segment upstream of both dams was the most geomorphically dynamic, whereas the segment between the dams was the least dynamic due to substantial channel armoring, and the segment downstream of both dams was intermediate due to some local sediment supply. These geomorphic differences were linked to altered characteristics of the shifting habitat mosaic, including older forest age structure and fewer young Populus balsamifera subsp. trichocarpa stands in the relatively static segment between the dams compared to more extensive early-successional forests (dominated by Alnus rubra and Salix spp.) and pioneer seedling recruitment upstream of the dams. Species composition of later-successional forest communities varied among river segments as well, with greater Pseudotsuga menziesii and Tsuga heterophylla abundance upstream of both dams, Acer spp. abundance between the dams, and P. balsamifera subsp. trichocarpa and Thuja plicata abundance below both dams. Riparian forest responses to the recent removal of the two dams on the Elwha River will depend largely on channel and geomorphic adjustments to the release, transport, and deposition of the large volume of sediment formerly stored in the reservoirs, together with changes in large wood dynamics.

  19. Cosmic ray exposure dating of geo-morphic surface features using in situ-produced 10Be: tectonic and climatic implications

    International Nuclear Information System (INIS)

    Siame, L.; Bellier, O.; Sebrier, M.; Braucher, R.; Bourles, D.L.

    2001-01-01

    The evolution of continental landforms is mainly modulated by the impact of climatic and tectonic processes. Because of their distinctive morphology and the periodicity of their deposition, climatically induced landforms such as alluvial fans or terraces are well suited to infer rates of tectonic and continental climatic processes. Within tectonically active regions, an important step consists in dating displaced geomorphic features to calculate slip rates on active faults. Dating is probably the most critical tool because it is generally much more simpler to measure deformation resulting from tectonic activity than it is to accurately date when that deformation occurred. Recent advances in analytical chemistry and nuclear physics (accelerator mass spectrometry) now allow quantitative abundance measurements of the extremely rare isotopes produced by the interaction of cosmic rays with surface rocks and soils, the so-called in situ-produced cosmogenic nuclides ( 3 He, 10 Be, 21 Ne, 26 Al, 36 Cl), and allow to directly date the duration that a landform has been exposed to cosmic rays at the Earth's surface (Lal, 1991; Nishiizumi et al., 1993; Cerling and Craig, 1994; Clark et al., 1995]. In fact, the abundance of these cosmo-nuclides is proportional to landscape stability and, under favorable circumstances, their abundance within surface rocks can be used as a proxy for erosion rate or exposure age. These cosmo-nuclides thus provide geomorphologists with the opportunity to constrain rates of landscape evolution. This paper presents a new approach that combines cosmic ray exposure (CRE) dating using in situ-produced 10 Be and geomorphic as well as structural analyse. This approach has been applied on two active strike-slip and reverse faults located in the Andean fore-land of western Argentina. These two case studies illustrate how CRE dating using in situ-produced 10 Be is particularly well suited for geomorphic studies that aim to estimate the respective control of

  20. Geomorphic threshold conditions for gully erosion in Southwestern Iran (Boushehr-Samal watershed)

    Science.gov (United States)

    Nazari Samani, Aliakbar; Ahmadi, Hassan; Jafari, Mohammad; Boggs, Guy; Ghoddousi, Jamal; Malekian, Arash

    2009-06-01

    Globally, a large amount of research has been dedicated to furthering our understanding of the factors and mechanisms affecting gully erosion. However, despite the importance of gully erosion in arid and semi arid regions of Iran there has been no comprehensive study of the geomorphic threshold conditions and factors influencing gully initiation. The aim of this article is to investigate the gullying processes and threshold conditions of permanent gullies in an arid region of Iran based upon examination of the slope-area ( S = αA-β) relationship. The data were collected through field and laboratory studies as well as Digital Elevation Model (DEM) analyses. In total, 97 active headcuts were identified across the three study sites and classified based on dominant initiation process including piping, landsliding and overland flow. Soil properties, including EC, SAR and soil texture, as well as landuse practices were found to be the major factors initiating piping and bank gullies. All gullies initiated by landsliding and seepage processes were found to be located in steep areas (28-40% slope) with their distribution further influenced by the lithology and presence of a cohesionless sand layer within the soil profile. An inverse relationship between upslope area ( A) and local slope ( S), in which the α and β coefficients varied, was further investigated based on the dominant gullying process and land use. Gullies occurring in the rangelands that were dominated by overland flow had the strongest relationship while landsliding dominated gullies did not have a statistically significant S- A relationship. In comparison to theoretical and literature based relationships for gully initiation, relatively low values for β were obtained (-0.182 to -0.266), possibly influenced by the presence of seepage and subsurface processes in many gullies. However, this is consistent with other studies in arid regions and may reflect greater potential for gullying in arid zones due to

  1. Evaluating the accuracy of low cost UAV generated topography and its effectiveness for geomorphic change detection

    Science.gov (United States)

    Cook, Kristen

    2015-04-01

    With the recent explosion in the use and availability of unmanned aerial vehicle platforms and development of easy to use structure from motion (SfM) software, UAV based photogrammetry is increasingly being adopted to produce high resolution topography for the study of surface processes. UAV systems can vary substantially in price and complexity, but the tradeoffs between these and the quality of the resulting data are not well constrained. We look at one end of this spectrum and evaluate the effectiveness of a simple low cost UAV setup for obtaining high resolution topography in a challenging field setting. Our study site is the Daan River gorge in western Taiwan, a rapidly eroding bedrock gorge that we have monitored with terrestrial Lidar since 2009. The site presents challenges for the generation and analysis of high resolution topography, including vertical gorge walls, vegetation, wide variation in surface roughness, and a complicated 3D morphology. In order to evaluate the accuracy of the UAV-derived topography, we compare it with terrestrial Lidar data collected during the same survey period. Our UAV setup combines a DJI Phantom 2 quadcopter with a 16 megapixel Canon Powershot camera for a total platform cost of less than 850. The quadcopter is flown manually, and the camera is programmed to take a photograph every 4 seconds, yielding 200-250 pictures per flight. We measured ground control points and targets for both the Lidar scans and the aerial surveys using a Leica RTK GPS with 1-2 cm accuracy. UAV derived point clouds were obtained using Agisoft Photoscan software. We conducted both Lidar and UAV surveys before and after the 2014 typhoon season, allowing us to evaluate the reliability of the UAV survey to detect geomorphic changes in the range of one to several meters. The accuracy of the SfM point clouds depends strongly on the characteristics of the surface being considered, with vegetation and small scale texture causing inaccuracies. However, we

  2. Use of geomorphic, hydrologic, and nitrogen mass balance data to model ecosystem nitrate retention in tidal freshwater wetlands

    Directory of Open Access Journals (Sweden)

    E. D. Seldomridge

    2012-07-01

    Full Text Available Geomorphic characteristics have been used as scaling parameters to predict water and other fluxes in many systems. In this study, we combined geomorphic analysis with in-situ mass balance studies of nitrate retention (NR to evaluate which geomorphic scaling parameters best predicted NR in a tidal freshwater wetland ecosystem. Geomorphic characteristics were measured for 267 individual marshes that constitute the freshwater tidal wetland ecosystem of the Patuxent River, Maryland. Nitrate retention was determined from mass balance measurements conducted at the inlets of marshes of varying size (671, 5705, and 536 873 m2 over a period of several years. Mass balance measurements indicate that NR is proportional to total water flux over the tidal cycle. Relationships between estimated tidal prism (calculated water volume for spring tides and various geomorphic parameters (marsh area, total channel length, and inlet width were defined using measurements from air photos and compared to field data. From these data, NR equations were determined for each geomorphic parameter, and used to estimate NR for all marshes in the ecosystem for a reference spring (high tide. The resulting ecosystem NR estimates were evaluated for (a accuracy and completeness of geomorphic data, (b relationship between the geomorphic parameters and hydrologic flux, and (c the ability to adapt the geomorphic parameter to varying tidal conditions. This analysis indicated that inlet width data were the most complete and provided the best estimate of ecosystem nitrate retention. Predictions based on marsh area were significantly lower than the inlet width-based predictions. Cumulative probability distributions of nitrate retention indicate that the largest 3–4% of the marshes retained half of the total nitrate for the ecosystem.

  3. Euglena in time: Evolution, control of central metabolic processes and multi-domain proteins in carbohydrate and natural product biochemistry

    Directory of Open Access Journals (Sweden)

    Ellis C. O’Neill

    2015-12-01

    Full Text Available Euglena gracilis is a eukaryotic microalgae that has been the subject of scientific study for hundreds of years. It has a complex evolutionary history, with traces of at least four endosymbiotic genomes and extensive horizontal gene transfer. Given the importance of Euglena in terms of evolutionary cell biology and its unique taxonomic position, we initiated a de novo transcriptome sequencing project in order to understand this intriguing organism. By analysing the proteins encoded in this transcriptome, we can identify an extremely complex metabolic capacity, rivalling that of multicellular organisms. Many genes have been acquired from what are now very distantly related species. Herein we consider the biology of Euglena in different time frames, from evolution through control of cell biology to metabolic processes associated with carbohydrate and natural products biochemistry.

  4. Reconstruction for Time-Domain In Vivo EPR 3D Multigradient Oximetric Imaging—A Parallel Processing Perspective

    Directory of Open Access Journals (Sweden)

    Christopher D. Dharmaraj

    2009-01-01

    Full Text Available Three-dimensional Oximetric Electron Paramagnetic Resonance Imaging using the Single Point Imaging modality generates unpaired spin density and oxygen images that can readily distinguish between normal and tumor tissues in small animals. It is also possible with fast imaging to track the changes in tissue oxygenation in response to the oxygen content in the breathing air. However, this involves dealing with gigabytes of data for each 3D oximetric imaging experiment involving digital band pass filtering and background noise subtraction, followed by 3D Fourier reconstruction. This process is rather slow in a conventional uniprocessor system. This paper presents a parallelization framework using OpenMP runtime support and parallel MATLAB to execute such computationally intensive programs. The Intel compiler is used to develop a parallel C++ code based on OpenMP. The code is executed on four Dual-Core AMD Opteron shared memory processors, to reduce the computational burden of the filtration task significantly. The results show that the parallel code for filtration has achieved a speed up factor of 46.66 as against the equivalent serial MATLAB code. In addition, a parallel MATLAB code has been developed to perform 3D Fourier reconstruction. Speedup factors of 4.57 and 4.25 have been achieved during the reconstruction process and oximetry computation, for a data set with 23×23×23 gradient steps. The execution time has been computed for both the serial and parallel implementations using different dimensions of the data and presented for comparison. The reported system has been designed to be easily accessible even from low-cost personal computers through local internet (NIHnet. The experimental results demonstrate that the parallel computing provides a source of high computational power to obtain biophysical parameters from 3D EPR oximetric imaging, almost in real-time.

  5. Reconstruction for time-domain in vivo EPR 3D multigradient oximetric imaging--a parallel processing perspective.

    Science.gov (United States)

    Dharmaraj, Christopher D; Thadikonda, Kishan; Fletcher, Anthony R; Doan, Phuc N; Devasahayam, Nallathamby; Matsumoto, Shingo; Johnson, Calvin A; Cook, John A; Mitchell, James B; Subramanian, Sankaran; Krishna, Murali C

    2009-01-01

    Three-dimensional Oximetric Electron Paramagnetic Resonance Imaging using the Single Point Imaging modality generates unpaired spin density and oxygen images that can readily distinguish between normal and tumor tissues in small animals. It is also possible with fast imaging to track the changes in tissue oxygenation in response to the oxygen content in the breathing air. However, this involves dealing with gigabytes of data for each 3D oximetric imaging experiment involving digital band pass filtering and background noise subtraction, followed by 3D Fourier reconstruction. This process is rather slow in a conventional uniprocessor system. This paper presents a parallelization framework using OpenMP runtime support and parallel MATLAB to execute such computationally intensive programs. The Intel compiler is used to develop a parallel C++ code based on OpenMP. The code is executed on four Dual-Core AMD Opteron shared memory processors, to reduce the computational burden of the filtration task significantly. The results show that the parallel code for filtration has achieved a speed up factor of 46.66 as against the equivalent serial MATLAB code. In addition, a parallel MATLAB code has been developed to perform 3D Fourier reconstruction. Speedup factors of 4.57 and 4.25 have been achieved during the reconstruction process and oximetry computation, for a data set with 23 x 23 x 23 gradient steps. The execution time has been computed for both the serial and parallel implementations using different dimensions of the data and presented for comparison. The reported system has been designed to be easily accessible even from low-cost personal computers through local internet (NIHnet). The experimental results demonstrate that the parallel computing provides a source of high computational power to obtain biophysical parameters from 3D EPR oximetric imaging, almost in real-time.

  6. Domain crossing

    DEFF Research Database (Denmark)

    Schraefel, M. C.; Rouncefield, Mark; Kellogg, Wendy

    2012-01-01

    In CSCW, how much do we need to know about another domain/culture before we observe, intersect and intervene with designs. What optimally would that other culture need to know about us? Is this a “how long is a piece of string” question, or an inquiry where we can consider a variety of contexts a...

  7. Low phase noise microwave extraction from femtosecond laser by frequency conversion pair and IF-domain processing.

    Science.gov (United States)

    Dai, Yitang; Cen, Qizhuang; Wang, Lei; Zhou, Yue; Yin, Feifei; Dai, Jian; Li, Jianqiang; Xu, Kun

    2015-12-14

    Extraction of a microwave component from a low-time-jitter femtosecond pulse train has been attractive for current generation of spectrally pure microwave. In order to avoid the transfer from the optical amplitude noise to microwave phase noise (AM-PM), we propose to down-convert the target component to intermediate frequency (IF) before the opto-electronic conversion. Due to the much lower carrier frequency, the AM-PM is greatly suppressed. The target is then recovered by up-conversion with the same microwave local oscillation (LO). As long as the time delay of the second LO matches that of the IF carrier, the phase noise of the LO shows no impact on the extraction process. The residual noise of the proposed extraction is analyzed in theory, which is also experimentally demonstrated as averagely around -155 dBc/Hz under offset frequency larger than 1 kHz when 10-GHz tone is extracted from a home-made femtosecond fiber laser. Large tunable extraction from 1 GHz to 10 GHz is also reported.

  8. Specialization of the auditory system for the processing of bio-sonar information in the frequency domain: Mustached bats.

    Science.gov (United States)

    Suga, Nobuo

    2018-04-01

    For echolocation, mustached bats emit velocity-sensitive orientation sounds (pulses) containing a constant-frequency component consisting of four harmonics (CF 1-4 ). They show unique behavior called Doppler-shift compensation for Doppler-shifted echoes and hunting behavior for frequency and amplitude modulated echoes from fluttering insects. Their peripheral auditory system is highly specialized for fine frequency analysis of CF 2 (∼61.0 kHz) and detecting echo CF 2 from fluttering insects. In their central auditory system, lateral inhibition occurring at multiple levels sharpens V-shaped frequency-tuning curves at the periphery and creates sharp spindle-shaped tuning curves and amplitude tuning. The large CF 2 -tuned area of the auditory cortex systematically represents the frequency and amplitude of CF 2 in a frequency-versus-amplitude map. "CF/CF" neurons are tuned to a specific combination of pulse CF 1 and Doppler-shifted echo CF 2 or 3 . They are tuned to specific velocities. CF/CF neurons cluster in the CC ("C" stands for CF) and DIF (dorsal intrafossa) areas of the auditory cortex. The CC area has the velocity map for Doppler imaging. The DIF area is particularly for Dopper imaging of other bats approaching in cruising flight. To optimize the processing of behaviorally relevant sounds, cortico-cortical interactions and corticofugal feedback modulate the frequency tuning of cortical and sub-cortical auditory neurons and cochlear hair cells through a neural net consisting of positive feedback associated with lateral inhibition. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. SHI/STY Genes Affect Pre- and Post-meiotic Anther Processes in Auxin Sensing Domains in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Leandro H. Estornell

    2018-02-01

    Full Text Available In flowering plants, mature sperm cells are enclosed in pollen grains formed in structures called anthers. Several cell layers surrounding the central sporogenous cells of the anther are essential for directing the developmental processes that lead to meiosis, pollen formation, and the subsequent pollen release. The specification and function of these tissues are regulated by a large number of genetic factors. Additionally, the plant hormone auxin has previously been shown to play important roles in the later phases of anther development. Using the R2D2 auxin sensor system we here show that auxin is sensed also in the early phases of anther cell layer development, suggesting that spatiotemporal regulation of auxin levels is important for early anther morphogenesis. Members of the SHI/STY transcription factor family acting as direct regulators of YUC auxin biosynthesis genes have previously been demonstrated to affect early anther patterning. Using reporter constructs we show that SHI/STY genes are dynamically active throughout anther development and their expression overlaps with those of three additional downstream targets, PAO5, EOD3 and PGL1. Characterization of anthers carrying mutations in five SHI/STY genes clearly suggests that SHI/STY transcription factors affect anther organ identity. In addition, their activity is important to repress periclinal cell divisions as well as premature entrance into programmed cell death and cell wall lignification, which directly influences the timing of anther dehiscence and the pollen viability. The SHI/STY proteins also prevent premature pollen germination suggesting that they may play a role in the induction or maintenance of pollen dormancy.

  10. Graphics-processing-unit-accelerated finite-difference time-domain simulation of the interaction between ultrashort laser pulses and metal nanoparticles

    Science.gov (United States)

    Nikolskiy, V. P.; Stegailov, V. V.

    2018-01-01

    Metal nanoparticles (NPs) serve as important tools for many modern technologies. However, the proper microscopic models of the interaction between ultrashort laser pulses and metal NPs are currently not very well developed in many cases. One part of the problem is the description of the warm dense matter that is formed in NPs after intense irradiation. Another part of the problem is the description of the electromagnetic waves around NPs. Description of wave propagation requires the solution of Maxwell’s equations and the finite-difference time-domain (FDTD) method is the classic approach for solving them. There are many commercial and free implementations of FDTD, including the open source software that supports graphics processing unit (GPU) acceleration. In this report we present the results on the FDTD calculations for different cases of the interaction between ultrashort laser pulses and metal nanoparticles. Following our previous results, we analyze the efficiency of the GPU acceleration of the FDTD algorithm.

  11. A computational approach identifies two regions of Hepatitis C Virus E1 protein as interacting domains involved in viral fusion process

    Directory of Open Access Journals (Sweden)

    El Sawaf Gamal

    2009-07-01

    Full Text Available Abstract Background The E1 protein of Hepatitis C Virus (HCV can be dissected into two distinct hydrophobic regions: a central domain containing an hypothetical fusion peptide (FP, and a C-terminal domain (CT comprising two segments, a pre-anchor and a trans-membrane (TM region. In the currently accepted model of the viral fusion process, the FP and the TM regions are considered to be closely juxtaposed in the post-fusion structure and their physical interaction cannot be excluded. In the present study, we took advantage of the natural sequence variability present among HCV strains to test, by purely sequence-based computational tools, the hypothesis that in this virus the fusion process involves the physical interaction of the FP and CT regions of E1. Results Two computational approaches were applied. The first one is based on the co-evolution paradigm of interacting peptides and consequently on the correlation between the distance matrices generated by the sequence alignment method applied to FP and CT primary structures, respectively. In spite of the relatively low random genetic drift between genotypes, co-evolution analysis of sequences from five HCV genotypes revealed a greater correlation between the FP and CT domains than respect to a control HCV sequence from Core protein, so giving a clear, albeit still inconclusive, support to the physical interaction hypothesis. The second approach relies upon a non-linear signal analysis method widely used in protein science called Recurrence Quantification Analysis (RQA. This method allows for a direct comparison of domains for the presence of common hydrophobicity patterns, on which the physical interaction is based upon. RQA greatly strengthened the reliability of the hypothesis by the scoring of a lot of cross-recurrences between FP and CT peptides hydrophobicity patterning largely outnumbering chance expectations and pointing to putative interaction sites. Intriguingly, mutations in the CT

  12. A dam in the drylands: Effects of soil geomorphic actions on a mediterranean alluvial scrubland and the endangered Santa Ana woolly star (Eriastrum densifolium spp. sanctorum)

    Science.gov (United States)

    Hernandez, R. R.; Sandquist, D. R.

    2017-12-01

    When dams preclude natural flow, maintenance of river ecosystems adapted to infrequent, catastrophic floods poses unique challenges. Further, riparian mediterranean ecosystems with high inter-annual and seasonal precipitation variability, coupled with complicated patterns of biotic and abiotic heterogeneity, intensify challenges for management under disrupted flow regimes. In this study, we evaluated the impact of six unique soil geomorphic actions on the rare Riversidian alluvial fan sage scrub plant community, which includes the endangered Santa Ana River woolly star (Eriastrum densifolium spp. sanctorum [Eds]) after 5, 7.5, and 13 years of response. We implemented a complete randomized block design, with each block incorporating six geomorphic treatments: cleared, diked, cut, filled (10 cm soil), filled (20 cm soil), and filled (30 cm soil), mimicking one of more physical disturbance process occurring after a natural flood event. We performed native and exotic plant community surveys on full plots in summer 2006, representing 7.5 years of response from the original 1999 disturbance, and on (re-disturbed half) plots in fall 2012, representing (5 years) 13 years of response. We found that recruitment of Eds into late-successional (i.e., control) plots is highly limited (0.0, 4.1, and 2.5% cover) after 5, 7.5, and 13 years, respectively, with implications for the persistence of this species, whereas the cut treatment showed significantly higher cover of Eds (25.3, 53.4, 14.3%, respectively). Our results also suggest that exotic annual grasses may inhibit Eds and other Riversidian alluvial fan sage scrub plant community members under a disrupted flow regime but that soil geomorphic treatment of late-successional habitat can be effective in facilitating Eds and Riversidian alluvial fan sage scrub establishment.

  13. Log Distribution, Persistence, and Geomorphic Function in Streams and Rivers, in the Northeastern U.S.

    Science.gov (United States)

    St Pierre, L.; Burchsted, D.; Warren, D.

    2015-12-01

    Large wood provides critical ecosystem services such as fish habitat, temperature regulation and bank stabilization. In the northeastern U.S., the distribution of large wood is documented; however, there is little understanding of the movement, longevity and geomorphic function. This research examines the hypothesis that tree species control the persistence and geomorphic function of instream wood in the Appalachian region of the northeastern U.S. To do this, we assessed size, location, and species of logs in New Hampshire rivers, including locations in the White Mountain National Forest (WMNF) where these data were collected ten years ago. We expanded the previous dataset to include assessment of geomorphic function, including creation of diversion channels, pool formation, and sediment storage, among others. We also added new sites in the WMNF and sites on a large rural river in southwestern NH to increase the range of geomorphic variables to now include: confined and unconfined channels; 1st to 4th order streams; low to high gradient; meandering, multithreaded, and straight channels; and land use such as historic logging, modern agriculture, and post-agricultural abandonment. At each study site, we located all large logs (>10cm diameter, > 1m length) and log jams (>3 accumulated logs that provide a geomorphic function) along 100m-700m reaches. We marked each identified log with a numbered tag and recorded species, diameter, length, orientation, GPS location, tag number, and photographs. We assessed function and accumulation, decay, stability, and source classes for each log. Along each reach we measured riparian forest composition and structure and channel width. Preliminary analysis suggests that tree species significantly affects the function of logs: yellow birch and American sycamore are highly represented. Additionally, geomorphic setting also plays a primary role, where unconfined reaches have large logs that provide important functions; those functions

  14. Instream wood in a steep headwater channel: geomorphic significance of large and small wood

    Science.gov (United States)

    Galia, Tomáš; Šilhán, Karel; Ruiz-Villanueva, Virginia; Tichavský, Radek

    2016-04-01

    pieces from the 1960s and 1970s. Practically all instream wood was dated from the 1990s and 2000s in the uppermost 150 m of evaluated stream. This observation is in agreement with the hypothesis of a higher intensity of transport processes in the upper parts. Obtained results pointed up on the importance of SW on geomorphic processes in steep narrow channels, when these relatively smaller pieces spanned more frequently the active channel width when compared to LWs.

  15. Trusted Domain

    DEFF Research Database (Denmark)

    Hjorth, Theis Solberg; Torbensen, Rune

    2012-01-01

    remote access via IP-based devices such as smartphones. The Trusted Domain platform fits existing legacy technologies by managing their interoperability and access controls, and it seeks to avoid the security issues of relying on third-party servers outside the home. It is a distributed system...... of wireless standards, limited resources of embedded systems, etc. Taking these challenges into account, we present a Trusted Domain home automation platform, which dynamically and securely connects heterogeneous networks of Short-Range Wireless devices via simple non-expert user. interactions, and allows......In the digital age of home automation and with the proliferation of mobile Internet access, the intelligent home and its devices should be accessible at any time from anywhere. There are many challenges such as security, privacy, ease of configuration, incompatible legacy devices, a wealth...

  16. Fault slip and earthquake recurrence along strike-slip faults — Contributions of high-resolution geomorphic data

    KAUST Repository

    Zielke, Olaf; Klinger, Yann; Arrowsmith, J. Ramon

    2015-01-01

    to contribute to better-informed models of EQ recurrence and slip-accumulation patterns. After reviewing motivation and background, we outline requirements to successfully reconstruct a fault's offset accumulation pattern from geomorphic evidence. We address

  17. Environmental Controls and Eco-geomorphic Interactions of the Barchan-to-parabolic Dune Stabilisation and the Parabolic-to-barchan Dune Reactivation

    Science.gov (United States)

    Yan, Na; Baas, Andreas

    2015-04-01

    Parabolic dunes are one of a few common aeolian landforms which are highly controlled by eco-geomorphic interactions. Parabolic dunes, on the one hand, can be developed from highly mobile dune landforms, barchans for instance, in an ameliorated vegetation condition; or on the other hand, they can be reactivated and transformed back into mobile dunes due to vegetation deterioration. The fundamental mechanisms and eco-geomorphic interactions controlling both dune transformations remain poorly understood. To bridge the gap between complex processes involved in dune transformations on a relatively long temporal scale and real world monitoring records on a very limited temporal scale, this research has extended the DECAL model to incorporate 'dynamic' growth functions and the different 'growth' of perennial shrubs between growing and non-growing seasons, informed by field measurements and remote sensing analysis, to explore environmental controls and eco-geomorphic interactions of both types of dune transformation. A non-dimensional 'dune stabilising index' is proposed to capture the interactions between environmental controls (i.e. the capabilities of vegetation to withstand wind erosion and sand burial, the sandy substratum thickness, the height of the initial dune, and the sand transport potential), and establish the linkage between these controls and the geometry of a stabilising dune. An example demonstrates how to use the power-law relationship between the dune stabilising index and the normalised migration distance to assist in extrapolating the historical trajectories of transforming dunes. The modelling results also show that a slight increase in vegetation cover of an initial parabolic dune can significantly increase the reactivation threshold of climatic impact (both drought stress and wind strength) required to reactivate a stabilising parabolic dune into a barchan. Four eco-geomorphic interaction zones that govern a barchan-to-parabolic dune transformation

  18. Geomorphic and geologic evidence for slip along the San Bernardino strand of the San Andreas Fault System through the San Gorgonio Pass structural knot, southern California

    Science.gov (United States)

    Kendrick, K. J.; Matti, J. C.

    2017-12-01

    The San Gorgonio Pass (SGP) region of southern California represents an extraordinarily complex section of the San Andreas Fault (SAF) zone, often referred to as a structural knot. Complexity is expressed both structurally and geomorphically, and arises because multiple strands of the SAF have evolved here in Quaternary time. Our integration of geologic and geomorphic analyses led to recognition of multiple fault-bounded blocks characterized by crystalline rocks that have similar physical properties. Hence, any morphometric differences in hypsometric analysis, slope, slope distribution, texture, and stream-power measurements and discontinuities reflect landscape response to tectonic processes rather than differences in lithology. We propose that the differing morphometry of the two blocks on either side of the San Bernardino strand (SBS) of the SAF, the high-standing Kitching Peak block to the east and the lower, more subdued Pisgah Peak block to the west, strongly suggests that the blocks experienced different uplift histories. This difference in uplift histories, in turn suggests that dextral slip occurred over a long time interval on the SBS—despite long-lived controversy raised by the fact that, at the surface, a throughgoing trace of the SBS is not present at this location. A different tectonic history between the two blocks is consistent with the gravity data which indicate that low-density rocks underthrusting the Kitching Peak block are absent below the Pisgah Peak block (Langenheim et al., 2015). Throughgoing slip on the SBS implied by geomorphic differences between the two blocks is also consistent with displaced geologic and geomorphic features. We find compelling evidence for discrete offsets of between 0.6 and 6 km of dextral slip on the SBS, including offset of fluvial and landslide deposits, and beheaded drainages. Although we lack numerical age control for the offset features, the degree of soil development associated with displaced landforms

  19. Geomorphic Flood Area (GFA): a QGIS tool for a cost-effective delineation of the floodplains

    Science.gov (United States)

    Samela, Caterina; Albano, Raffaele; Sole, Aurelia; Manfreda, Salvatore

    2017-04-01

    The importance of delineating flood hazard and risk areas at a global scale has been highlighted for many years. However, its complete achievement regularly encounters practical difficulties, above all the lack of data and implementation costs. In conditions of scarce data availability (e.g. ungauged basins, large-scale analyses), a fast and cost-effective floodplain delineation can be carried out using geomorphic methods (e.g., Manfreda et al., 2011; 2014). In particular, an automatic DEM-based procedure has been implemented in an open-source QGIS plugin named Geomorphic Flood Area - tool (GFA - tool). This tool performs a linear binary classification based on the recently proposed Geomorphic Flood Index (GFI), which exhibited high classification accuracy and reliability in several test sites located in Europe, United States and Africa (Manfreda et al., 2015; Samela et al., 2016, 2017; Samela, 2016). The GFA - tool is designed to make available to all users the proposed procedure, that includes a number of operations requiring good geomorphic and GIS competences. It allows computing the GFI through terrain analysis, turning it into a binary classifier, and training it on the base of a standard inundation map derived for a portion of the river basin (a minimum of 2% of the river basin's area is suggested) using detailed methods of analysis (e.g. flood hazard maps produced by emergency management agencies or river basin authorities). Finally, GFA - tool allows to extend the classification outside the calibration area to delineate the flood-prone areas across the entire river basin. The full analysis has been implemented in this plugin with a user-friendly interface that should make it easy to all user to apply the approach and produce the desired results. Keywords: flood susceptibility; data scarce environments; geomorphic flood index; linear binary classification; Digital elevation models (DEMs). References Manfreda, S., Di Leo, M., Sole, A., (2011). Detection of

  20. Geomorphic Proxies to Test Strain Accommodation in Southwestern Puerto Rico from Digital Elevation Models

    Science.gov (United States)

    Barrios Galindez, I. M.; Xue, L.; Laó-Dávila, D. A.

    2017-12-01

    The Puerto Rico and the Virgin Island microplate is located in at the northeastern corner of the Caribbean plate boundary with North America is placed within an oblique subduction zone in which strain patterns remain unresolved. Seismic hazard is a major concern in the region as seen from the seismic history of the Caribbean-North America plate boundary zone. Most of the tectonic models of the microplate show the accommodation of strain occurring offshore, despite evidence from seismic activity, trench studies, and geodetic studies suggesting the existence of strain accomodation in southwest Puerto Rico. These studies also suggest active faulting specially in the western part of the island, but limited work has been done regarding their mechanism. Therefore, this work aims to define and map these active faults in western Puerto Rico by integrating data from analysis of fluvial terrains, and detailed mapping using digital elevation model (DEM) extracted from Shuttle Radar Topography Mission (SRTM) and LIDAR data. The goal is to (1) identify structural features such as surface lineaments and fault scarps for the Cerro Goden fault, South Lajas fault, and other active faults in the western of Puerto Rico, (2) correlate these information with the distribution pattern and values of the geomorphic proxies, including Chi integral (χ), normalized steepness (ksn) and Asymmetric factor (AF). Our preliminary results from geomorphic proxies and Lidar data provide some insight of the displacement and stage of activities of these faults (e.g. Boqueron-Punta Malva Fault and Cerro Goden fault). Also, the anomaly of the geomorphic proxies generally correlate with the locations of the landslides in the southwestern Puerto Rico. The geomorphic model of this work include new information of active faulting fundamental to produce better seismic hazards maps. Additionally, active tectonics studies are vital to issue and adjust construction buildings codes and zonification codes.

  1. Modeling hydrologic and geomorphic hazards across post-fire landscapes using a self-organizing map approach

    Science.gov (United States)

    Friedel, Michael J.

    2011-01-01

    Few studies attempt to model the range of possible post-fire hydrologic and geomorphic hazards because of the sparseness of data and the coupled, nonlinear, spatial, and temporal relationships among landscape variables. In this study, a type of unsupervised artificial neural network, called a self-organized map (SOM), is trained using data from 540 burned basins in the western United States. The sparsely populated data set includes variables from independent numerical landscape categories (climate, land surface form, geologic texture, and post-fire condition), independent landscape classes (bedrock geology and state), and dependent initiation processes (runoff, landslide, and runoff and landslide combination) and responses (debris flows, floods, and no events). Pattern analysis of the SOM-based component planes is used to identify and interpret relations among the variables. Application of the Davies-Bouldin criteria following k-means clustering of the SOM neurons identified eight conceptual regional models for focusing future research and empirical model development. A split-sample validation on 60 independent basins (not included in the training) indicates that simultaneous predictions of initiation process and response types are at least 78% accurate. As climate shifts from wet to dry conditions, forecasts across the burned landscape reveal a decreasing trend in the total number of debris flow, flood, and runoff events with considerable variability among individual basins. These findings suggest the SOM may be useful in forecasting real-time post-fire hazards, and long-term post-recovery processes and effects of climate change scenarios.

  2. Fluvio geomorphic set-up of Noctis Fossae in Noctis Labyrinthus of Syria-Planum Provenance, Mars

    Science.gov (United States)

    Chavan, A. A.; Bhandari, S.

    2017-12-01

    The modern era of planetary exploration has revealed fluvial or fluvial like landforms on the extraterrestrial surfaces of planets and moons of our solar system. This has posed as interesting challenges for advancing our fundamental understanding of fluvial processes and their associated landforms on the planetary surfaces especially on Mars. It has been recognized through earlier studies that the channels and valleys are extensively dissected on Mars. The Valleys are low lying, elongate troughs surrounded by elevated topography. Moreover, valley networks on Mars are the most noticeable features attesting that different geological processes and possibly climatic conditions prevailed in the past and played a vital role in formulating the Martian topography. Channel incisions which are a domino effect both tectonic and surface runoff and groundwater sapping. The components of surface runoff have been deciphered with the help of morphometric exercises. Further, the geomorphological studies of these landforms are critical in understanding the regional tectonics. The present work is an assessment of Fluvio geomorphic set-up of Noctis Fossae in Noctis Labyrinthus of Syria-Planum Provenance, Mars. This study focuses on the fluvio geomorphology of the southern highlands (00 to 400S to 850-1200W) to determine how these features were formed, which process formed these valleys and includes the probable causes resulting into the development of the topography. Keywords: Noctis Fossae; Noctis Labyrinthus; Syria Planum; Mars

  3. Geomorphic stability field reconnaissance site visit, Canonsburg, Pennsylvania, December 1992. Final report

    International Nuclear Information System (INIS)

    1993-05-01

    To license the Canonsburg site, the US Nuclear Regulatory Commission (NRC) has required that geomorphic stability be demonstrated for the stream banks and slopes around the perimeter of the site for 200 years. Based on a study of the stream channel and slopes, it has been determined that due to recent human intervention, the required geomorphic stability cannot now be achieved without installation of erosion protection works and continued monitoring of the site. The Pittsburgh District Corps of Engineers has plans to channelize Chartiers Creek and install erosion protection rock within the next 5 or 6 years, if local government agencies raise the necessary matching funds. Much of the stream bank and slope adjacent to the ''fenced in'' western area of the site is anticipated to remain geomorphically stable for more than 20 years, but less than 200 years without human intervention. Therefore in much of this area, the Corps of Engineers will have adequate time to perform its work without jeopardizing the integrity of the controlled area. In contrast, two approximately 200-foot (ft) (60-meter [m]) long portions of the stream channel located north-northwest of the encapsulation area are subject to active stream erosion that threatens the integrity of the controlled area. These areas should be fixed by installation of erosion protection rock within the next 2 years

  4. Extreme Changes in Stream Geomorphic Conditions induced by Fluvial Scour in Bridges

    Science.gov (United States)

    Özcan, O.; Ozcan, O.

    2016-12-01

    The numerous complexities associated with bridge scour have caused scour to be one of the most active topics of stream geomorphic research. The assessment of local scouring mechanism around bridge piers provides information for decision-making regarding the pile footing design, predicting the safety of bridges under critical scoured conditions, and as a result, may help prevent unnecessary loses. In the study, bridge design plans and HEC-RAS modeling were used for the assessment of changes in stream geomorphic conditions. The derived fluvial scour depths were compared with the field measurements and the empirical formula which is based on stream flow discharge rate, streambed condition and shape of river. Preliminary results revealed that bridge damage resulting from the flood event in 2003 induced substantial scour around bridge piles. Afterwards, significant stream bed change was observed under the influence of fluvial scour in another flood occurred in 2009. Consequently, geomorphic conditions of the stream bed should be considered in the structural design of the bridges.

  5. Cracking up (and down): Linking multi-domain hydraulic properties with multi-scale hydrological processes in shrink-swell soils

    Science.gov (United States)

    Stewart, R. D.; Rupp, D. E.; Abou Najm, M. R.; Selker, J. S.

    2017-12-01

    Shrink-swell soils, often classified as Vertisols or vertic intergrades, are found on every continent except Antarctica and within many agricultural and urban regions. These soils are characterized by cyclical shrinking and swelling, in which bulk density and porosity distributions vary as functions of time and soil moisture. Crack networks that form in these soils act as dominant environmental controls on the movement of water, contaminants, and gases, making it important to develop fundamental understanding and tractable models of their hydrologic characteristics and behaviors. In this study, which took place primarily in the Secano Interior region of South-Central Chile, we quantified soil-water interactions across scales using a diverse and innovative dataset. These measurements were then utilized to develop a set of parsimonious multi-domain models for describing hydraulic properties and hydrological processes in shrink-swell soils. In a series of examples, we show how this model can predict porosity distributions, crack widths, saturated hydraulic conductivities, and surface runoff (i.e., overland flow) thresholds, by capturing the dominant mechanisms by which water moves through and interacts with clayey soils. Altogether, these models successfully link small-scale shrinkage/swelling behaviors with large-scale thresholds, and can be applied to describe important processes such as infiltration, overland flow development, and the preferential flow and transport of fluids and gases.

  6. Functional anthology of intrinsic disorder. 2. Cellular components, domains, technical terms, developmental processes, and coding sequence diversities correlated with long disordered regions.

    Science.gov (United States)

    Vucetic, Slobodan; Xie, Hongbo; Iakoucheva, Lilia M; Oldfield, Christopher J; Dunker, A Keith; Obradovic, Zoran; Uversky, Vladimir N

    2007-05-01

    Biologically active proteins without stable ordered structure (i.e., intrinsically disordered proteins) are attracting increased attention. Functional repertoires of ordered and disordered proteins are very different, and the ability to differentiate whether a given function is associated with intrinsic disorder or with a well-folded protein is crucial for modern protein science. However, there is a large gap between the number of proteins experimentally confirmed to be disordered and their actual number in nature. As a result, studies of functional properties of confirmed disordered proteins, while helpful in revealing the functional diversity of protein disorder, provide only a limited view. To overcome this problem, a bioinformatics approach for comprehensive study of functional roles of protein disorder was proposed in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V. N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Applying this novel approach to Swiss-Prot sequences and functional keywords, we found over 238 and 302 keywords to be strongly positively or negatively correlated, respectively, with long intrinsically disordered regions. This paper describes approximately 90 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes, and coding sequence diversities possessing strong positive and negative correlation with long disordered regions.

  7. Functional Anthology of Intrinsic Disorder. II. Cellular Components, Domains, Technical Terms, Developmental Processes and Coding Sequence Diversities Correlated with Long Disordered Regions

    Science.gov (United States)

    Vucetic, Slobodan; Xie, Hongbo; Iakoucheva, Lilia M.; Oldfield, Christopher J.; Dunker, A. Keith; Obradovic, Zoran; Uversky, Vladimir N.

    2008-01-01

    Biologically active proteins without stable ordered structure (i.e., intrinsically disordered proteins) are attracting increased attention. Functional repertoires of ordered and disordered proteins are very different, and the ability to differentiate whether a given function is associated with intrinsic disorder or with a well-folded protein is crucial for modern protein science. However, there is a large gap between the number of proteins experimentally confirmed to be disordered and their actual number in nature. As a result, studies of functional properties of confirmed disordered proteins, while helpful in revealing the functional diversity of protein disorder, provide only a limited view. To overcome this problem, a bioinformatics approach for comprehensive study of functional roles of protein disorder was proposed in the first paper of this series (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. I. Biological processes and functions of proteins with long disordered regions. J. Proteome Res.). Applying this novel approach to Swiss-Prot sequences and functional keywords, we found over 238 and 302 keywords to be strongly positively or negatively correlated, respectively, with long intrinsically disordered regions. This paper describes ~90 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes and coding sequence diversities possessing strong positive and negative correlation with long disordered regions. PMID:17391015

  8. Climatic and geomorphic drivers of plant organic matter transport in the Arun River, E Nepal

    Science.gov (United States)

    Hoffmann, Bernd; Feakins, Sarah J.; Bookhagen, Bodo; Olen, Stephanie M.; Adhikari, Danda P.; Mainali, Janardan; Sachse, Dirk

    2016-10-01

    Fixation of atmospheric CO2 in terrestrial vegetation, and subsequent export and deposition of terrestrial plant organic matter in marine sediments is an important component of the global carbon cycle, yet it is difficult to quantify. This is partly due to the lack of understanding of relevant processes and mechanisms responsible for organic-matter transport throughout a landscape. Here we present a new approach to identify terrestrial plant organic matter source areas, quantify contributions and ascertain the role of ecologic, climatic, and geomorphic controls on plant wax export in the Arun River catchment spanning the world's largest elevation gradient from 205 to 8848 m asl, in eastern Nepal. Our approach takes advantage of the distinct stable hydrogen isotopic composition (expressed as δD values) of plant wax n-alkanes produced along this gradient, transported in river waters and deposited in flood deposits alongside the Arun River and its tributaries. In mainstem-flood deposits, we found that plant wax n-alkanes were mostly derived from the lower elevations constituting only a small fraction (15%) of the catchment. Informed by remote sensing data, we tested four differently weighted isotopic mixing models that quantify sourcing of tributary plant-derived organic matter along the Arun and compare it to our field observations. The weighting parameters included catchment area, net primary productivity (NPP) and annual rainfall amount as well as catchment relief as erosion proxy. When weighted by catchment area the isotopic mixing model could not explain field observations on plant wax δD values along the Arun, which is not surprising because the large arid Tibetan Plateau is not expected to be a major source. Weighting areal contributions by annual rainfall and NPP captured field observations within model prediction errors suggesting that plant productivity may influence source strength. However weighting by a combination of rainfall and catchment relief also

  9. Evaluating the effectiveness of low cost UAV generated topography for geomorphic change detection

    Science.gov (United States)

    Cook, K. L.

    2014-12-01

    With the recent explosion in the use and availability of unmanned aerial vehicle platforms and development of easy to use structure from motion software, UAV based photogrammetry is increasingly being adopted to produce high resolution topography for the study of surface processes. UAV systems can vary substantially in price and complexity, but the tradeoffs between these and the quality of the resulting data are not well constrained. We look at one end of this spectrum and evaluate the effectiveness of a simple low cost UAV setup for obtaining high resolution topography in a challenging field setting. Our study site is the Daan River gorge in western Taiwan, a rapidly eroding bedrock gorge that we have monitored with terrestrial Lidar since 2009. The site presents challenges for the generation and analysis of high resolution topography, including vertical gorge walls, vegetation, wide variation in surface roughness, and a complicated 3D morphology. In order to evaluate the accuracy of the UAV-derived topography, we compare it with terrestrial Lidar data collected during the same survey period. Our UAV setup combines a DJI Phantom 2 quadcopter with a 16 megapixel Canon Powershot camera for a total platform cost of less than $850. The quadcopter is flown manually, and the camera is programmed to take a photograph every 5 seconds, yielding 200-250 pictures per flight. We measured ground control points and targets for both the Lidar scans and the aerial surveys using a Leica RTK GPS with 1-2 cm accuracy. UAV derived point clouds were obtained using Agisoft Photoscan software. We conducted both Lidar and UAV surveys before and after a summer typhoon season, allowing us to evaluate the reliability of the UAV survey to detect geomorphic changes in the range of one to several meters. We find that this simple UAV setup can yield point clouds with an average accuracy on the order of 10 cm compared to the Lidar point clouds. Well-distributed and accurately located ground

  10. Geomorphic Drainage Capture Recorded by Oxygen Isotopes of Green River Formation Lacustrine Mudstone, Eocene, Wyoming

    Science.gov (United States)

    Doebbert, A. C.; Booth, A. L.; Carroll, A.; Chamberlain, C.; Rhodes, M.

    2005-12-01

    geomorphic processes rather than uplift. These results indicate the need for considerable caution when examining uplift records from other ancient lake deposits.

  11. A coupled geomorphic and ecological model of tidal marsh evolution.

    Science.gov (United States)

    Kirwan, Matthew L; Murray, A Brad

    2007-04-10

    The evolution of tidal marsh platforms and interwoven channel networks cannot be addressed without treating the two-way interactions that link biological and physical processes. We have developed a 3D model of tidal marsh accretion and channel network development that couples physical sediment transport processes with vegetation biomass productivity. Tidal flow tends to cause erosion, whereas vegetation biomass, a function of bed surface depth below high tide, influences the rate of sediment deposition and slope-driven transport processes such as creek bank slumping. With a steady, moderate rise in sea level, the model builds a marsh platform and channel network with accretion rates everywhere equal to the rate of sea-level rise, meaning water depths and biological productivity remain temporally constant. An increase in the rate of sea-level rise, or a reduction in sediment supply, causes marsh-surface depths, biomass productivity, and deposition rates to increase while simultaneously causing the channel network to expand. Vegetation on the marsh platform can promote a metastable equilibrium where the platform maintains elevation relative to a rapidly rising sea level, although disturbance to vegetation could cause irreversible loss of marsh habitat.

  12. Two Step Acceleration Process of Electrons in the Outer Van Allen Radiation Belt by Time Domain Electric Field Bursts and Large Amplitude Chorus Waves

    Science.gov (United States)

    Agapitov, O. V.; Mozer, F.; Artemyev, A.; Krasnoselskikh, V.; Lejosne, S.

    2014-12-01

    A huge number of different non-linear structures (double layers, electron holes, non-linear whistlers, etc) have been observed by the electric field experiment on the Van Allen Probes in conjunction with relativistic electron acceleration in the Earth's outer radiation belt. These structures, found as short duration (~0.1 msec) quasi-periodic bursts of electric field in the high time resolution electric field waveform, have been called Time Domain Structures (TDS). They can quite effectively interact with radiation belt electrons. Due to the trapping of electrons into these non-linear structures, they are accelerated up to ~10 keV and their pitch angles are changed, especially for low energies (˜1 keV). Large amplitude electric field perturbations cause non-linear resonant trapping of electrons into the effective potential of the TDS and these electrons are then accelerated in the non-homogeneous magnetic field. These locally accelerated electrons create the "seed population" of several keV electrons that can be accelerated by coherent, large amplitude, upper band whistler waves to MeV energies in this two step acceleration process. All the elements of this chain acceleration mechanism have been observed by the Van Allen Probes.

  13. Assessment of geomorphic risks and attractiveness to recreational systems: a case of Nalychevo Nature Park (Kamchatka, Russia).

    Science.gov (United States)

    Blinova, I.; Bredikhin, A.

    2012-04-01

    Attractiveness of relief, diversity and rareness were always the basic features of overall recreational attractiveness of a territory. Mountainous regions with high geomorphic diversity served as model for first recreation and tourism researches. The above features often favoured sustainability of touristic system. Unique relief forms are commonly referred to natural sites. They differ from the others in structure or have some morphological and morphometric characteristics not found in other forms of the earth's surface. Such monuments form the main natural functional kernel for a recreation system which is created and exists around them. In general, functions of geomorphological sites in recreation can be divided into socio-cultural and economic. Socio-cultural function is the principal function of recreation. It responds to the cultural or spiritual needs of people such as the knowledge in the broader sense, knowledge of the world and their place in it. The economic function is to create consumer demand for goods and services, and sometimes an entire economy sector. Natural sites are particularly vulnerable to dangerous occurrence of endogenous and exogenous processes as guarantee of environmental stability is an essential condition for a proper system functioning. This requires a comprehensive study of relief dynamics, monitoring and forecasting its evolution in recreation areas. Nowadays educational and environmental tourism in Russia develop rapidly. The unique tectonic position of Kamchatka Peninsula (the active geodynamic area dedicated to the subduction zone) formed a variety of landscapes, attracting visitors from all over the world. Recreational development of this region is slow due to remoteness and poor transport accessibility. However, there are 3 state federal reserves and one federal wildlife sanctuary, 4 natural parks of regional significance, 23 nature preserves of regional significance, and 105 natural monuments officially marked in this region

  14. Geomorphic analysis of the river response to sedimentation downstream of Mount Rainier, Washington

    Science.gov (United States)

    Czuba, Jonathan A.; Magirl, Christopher S.; Czuba, Christiana R.; Curran, Christopher A.; Johnson, Kenneth H.; Olsen, Theresa D.; Kimball, Halley K.; Gish, Casey C.

    2012-01-01

    A study of the geomorphology of rivers draining Mount Rainier, Washington, was completed to identify sources of sediment to the river network; to identify important processes in the sediment delivery system; to assess current sediment loads in rivers draining Mount Rainier; to evaluate if there were trends in streamflow or sediment load since the early 20th century; and to assess how rates of sedimentation might continue into the future using published climate-change scenarios. Rivers draining Mount Rainier carry heavy sediment loads sourced primarily from the volcano that cause acute aggradation in deposition reaches as far away as the Puget Lowland. Calculated yields ranged from 2,000 tonnes per square kilometer per year [(tonnes/km2)/yr] on the upper Nisqually River to 350 (tonnes/km2)/yr on the lower Puyallup River, notably larger than sediment yields of 50–200 (tonnes/km2)/yr typical for other Cascade Range rivers. These rivers can be assumed to be in a general state of sediment surplus. As a result, future aggradation rates will be largely influenced by the underlying hydrology carrying sediment downstream. The active-channel width of rivers directly draining Mount Rainier in 2009, used as a proxy for sediment released from Mount Rainier, changed little between 1965 and 1994 reflecting a climatic period that was relatively quiet hydrogeomorphically. From 1994 to 2009, a marked increase in geomorphic disturbance caused the active channels in many river reaches to widen. Comparing active-channel widths of glacier-draining rivers in 2009 to the distance of glacier retreat between 1913 and 1994 showed no correlation, suggesting that geomorphic disturbance in river reaches directly downstream of glaciers is not strongly governed by the degree of glacial retreat. In contrast, there was a correlation between active-channel width and the percentage of superglacier debris mantling the glacier, as measured in 1971. A conceptual model of sediment delivery processes

  15. Potential Applications of the National Institute of Mental Health's Research Domain Criteria (RDoC) to Clinical Psychiatric Practice: How RDoC Might Be Used in Assessment, Diagnostic Processes, Case Formulation, Treatment Planning, and Clinical Notes.

    Science.gov (United States)

    Yager, Joel; Feinstein, Robert E

    2017-04-01

    Offering a new framework for understanding and studying basic dimensions of normal and abnormal human functioning and mental disorders, the National Institute of Mental Health (NIMH) has initiated the Research Domain Criteria (RDoC) project in which a series of higher order domains, representing major systems of emotion, cognition, motivation, and social behavior, and their constituent operationally defined constructs serve as organizing templates for further research and inquiry, eg, to discover validated biomarkers and endophenotypes. Cutting across traditional DSM diagnoses, the domains are defined as Negative Valence Systems, Positive Valence Systems, Cognitive Systems, Systems for Social Processes, and Arousal/Regulatory Systems. To inform educators, trainees, and practitioners about RDoC, alert them to potential practical applications, and encourage their broad exploration in clinical settings, this article reviews the RDoC domains and their subsystem constructs with regard to potential current clinical considerations and applications. We describe ways in which the RDoC domains and constructs offer transdiagnostic frameworks for complementing traditional practice; suggest clinical questions to help elucidate salient information; and, translating RDoC domains and constructs headings into clinically friendly language, offer a template for the psychiatric review of systems that can serve in clinical notes. © Copyright 2017 Physicians Postgraduate Press, Inc.

  16. .Gov Domains API

    Data.gov (United States)

    General Services Administration — This dataset offers the list of all .gov domains, including state, local, and tribal .gov domains. It does not include .mil domains, or other federal domains outside...

  17. Formalization of knowledge and tools in the risks domain (DRA-35) {omega}-14. Safety of processes implementing powdery fuels; Formalisation du savoir et des outils dans le domaine des risques majeurs (DRA-35) {omega}-14. Securite des procedes mettant en oeuvre des pulverulents combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Chaineaux, J.

    2004-12-15

    This document aims to present a state of the art of the today exhaustive INERIS knowledge concerning the processes implementing powdery fuels. It is a reference document in the framework of the prevention and protection domain against fire, explosion and auto-heating risks. The risks are presented in the first part. The second part discusses the regulatory framework and the last part details the concerned processes. (A.L.B.)

  18. Geomorphic controls on fluvial carbon exports and emissions from upland swamps in eastern Australia.

    Science.gov (United States)

    Cowley, Kirsten; Looman, Arun; Maher, Damien T; Fryirs, Kirstie

    2018-03-15

    Temperate Highland Peat Swamps on Sandstone (THPSS) are upland wetlands, similar to fens in the Northern Hemisphere and are found at the headwaters of low-order streams on the plateaus of Eastern Australia. They are classified as endangered ecological communities under State and National legislation. Previous works have identified particular geomorphic characteristics that are important to carbon storage in these low energy sediment accumulation zones. Changes in the geomorphic structure of THPSS, such as channelisation, may have profound implications for carbon storage. To assess the effect of channelisation on carbon budgets in these ecosystems it is essential to identify and quantify differences in carbon export, emissions and stocks of carbon of intact swamps and those that have become channelised. We undertook seasonal sampling of the perched swamp aquifers and surface waters of two intact swamps and two channelised fills in the Blue Mountains of New South Wales, Australia, to investigate differences in carbon exports and emissions between the two swamp types. We found that channelised fills' mean CO 2 emissions were almost four times higher than intact swamps with mean CH 4 emissions up to five times higher. Annual fluvial carbon exports for channelised fills were up to 18 times that of intact swamps. Channelised fill exports and emissions can represent up to 2% of the total swamp carbon stocks per annum which is 40 times higher than the intact swamps. This work clearly demonstrates that changes in geomorphic structure brought about by incision and channelisation results in profound changes to the carbon storage function of THPSS. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The geomorphic legacy of water and erosion control structures in a semiarid rangeland watershed

    Science.gov (United States)

    Nichols, Mary H.; Magirl, Christopher S.; Sayre, N.F.; Shaw, Jeremy R.

    2018-01-01

    Control over water supply and distribution is critical for agriculture in drylands where manipulating surface runoff often serves the dual purpose of erosion control. However, little is known of the geomorphic impacts and legacy effects of rangeland water manipulation infrastructure, especially if not maintained. This study investigated the geomorphic impacts of structures such as earthen berms, water control gates, and stock tanks, in a semiarid rangeland in the southwestern USA that is responding to both regional channel incision that was initiated over a century ago, and a more recent land use change that involved cattle removal and abandonment of structures. The functional condition of remnant structures was inventoried, mapped, and assessed using aerial imagery and lidar data. Headcut initiation, scour, and channel incision associated with compromised lateral channel berms, concrete water control structures, floodplain water spreader berms, and stock tanks were identified as threats to floodplains and associated habitat. Almost half of 27 identified lateral channel berms (48%) have been breached and 15% have experienced lateral scour; 18% of 218 shorter water spreader berms have been breached and 17% have experienced lateral scour. A relatively small number of 117 stock tanks (6%) are identified as structurally compromised based on analysis of aerial imagery, although many currently do not provide consistent water supplies. In some cases, the onset of localized disturbance is recent enough that opportunities for mitigation can be identified to alter the potentially damaging erosion trajectories that are ultimately driven by regional geomorphic instability. Understanding the effects of prior land use and remnant structures on channel and floodplain morphologic condition is critical because both current land management and future land use options are constrained by inherited land use legacy effects.

  20. Bio-geomorphic feedback causes alternative stable landscape states: insights from coastal marshes and tidal flats

    Science.gov (United States)

    Temmerman, Stijn; Wang, Chen

    2014-05-01

    Many bio-geomorphic systems, such as hill slopes, river floodplains, tidal floodplains and dune areas, seem to be vulnerable to shifts between alternative bare and vegetated landscape states, and these shifts seem to be driven by bio-geomorphic feedbacks. Here we search for empirical evidence for alternative stable state behavior in intertidal flats and marshes, where bio-geomorphic interactions are known to be intense. Large-scale transitions have been reported worldwide between high-elevation vegetated marshes and low-elevation bare flats in intertidal zones of deltas, estuaries, and coastal embayments. It is of significant importance to understand and predict such transitions, because vegetated marshes provide significant services to coastal societies. Previous modeling studies suggest that the ecological theory of catastrophic shifts between alternative stable ecosystem states potentially explains the transition between bare flats and vegetated marshes. However, up to now only few empirical evidence exists. In our study, the hypothesis is empirically tested that vegetated marshes and bare tidal flats can be considered as alternative stable landscape states with rapid shifts between them. We studied historical records (1930s - 2000s) of intertidal elevation surveys and aerial pictures from the Westerschelde estuary (SW Netherlands). Our results demonstrated the existence of: (1) bimodality in the intertidal elevation distribution, i.e., the presence of two peaks in the elevation frequency distribution corresponding to a completely bare state and a densely vegetated state; (2) the relatively rapid transition in elevation when intertidal flats evolve from bare to vegetated states, with sedimentation rates that are 2 to 8 times faster than during the stable states; (3) a threshold elevation above which the shift from bare to vegetated state has a high chance to occur. Our observations demonstrate the abrupt non-linear shift between low-elevation bare flats and high

  1. Active Structures as Deduced from Geomorphic Features: A case in Hsinchu Area, northwestern Taiwan

    Science.gov (United States)

    Chen, Y.; Shyu, J.; Ota, Y.; Chen, W.; Hu, J.; Tsai, B.; Wang, Y.

    2002-12-01

    Hsinchu area is located in the northwestern Taiwan, the fold-and thrust belt created by arc-continent collision between Eurasian and Philippine. Since the collision event is still ongoing, the island is tectonically active and full of active faults. According to the historical records, some of the faults are seismically acting. In Hsinchuarea two active faults, the Hsinchu and Hsincheng, have been previously mapped. To evaluate the recent activities, we studied the related geomorphic features by using newly developed Digital Elevation Model (DEM), the aerial photos and field investigation. Geologically, both of the faults are coupled with a hanging wall anticline. The anticlines are recently active due to the deformation of the geomorphic surfaces. The Hsinchu fault system shows complicate corresponding scarps, distributed sub-parallel to the fault trace previously suggested by projection of subsurface geology. This is probably caused by its strike-slip component tearing the surrounding area along the main trace. The scarps associated with the Hsincheng fault system are rather simple and unique. It offsets a flight of terraces all the way down to recent flood plain, indicating its long lasting activity. One to two kilometers to east of main trace a back-thrust is found, showing coupled vertical surface offsets with the main fault. The striking discovery in this study is that the surface deformation is only distributed in the southern bank of Touchien river, also suddenly decreasing when crossing another tear fault system, which is originated from Hsincheng fault in the west and extending southeastward parallel to the Touchien river. The strike-slip fault system mentioned above not only bisects the Hsinchu fault, but also divides the Hsincheng fault into segments. The supporting evidence found in this study includes pressure ridges and depressions. As a whole, the study area is tectonically dominated by three active fault systems and two actively growing anticlines

  2. Quantifying geomorphic change at ephemeral stream restoration sites using a coupled-model approach

    Science.gov (United States)

    Norman, Laura M.; Sankey, Joel B.; Dean, David; Caster, Joshua J.; DeLong, Stephen B.; Henderson-DeLong, Whitney; Pelletier, Jon D.

    2017-01-01

    Rock-detention structures are used as restoration treatments to engineer ephemeral stream channels of southeast Arizona, USA, to reduce streamflow velocity, limit erosion, retain sediment, and promote surface-water infiltration. Structures are intended to aggrade incised stream channels, yet little quantified evidence of efficacy is available. The goal of this 3-year study was to characterize the geomorphic impacts of rock-detention structures used as a restoration strategy and develop a methodology to predict the associated changes. We studied reaches of two ephemeral streams with different watershed management histories: one where thousands of loose-rock check dams were installed 30 years prior to our study, and one with structures constructed at the beginning of our study. The methods used included runoff, sediment transport, and geomorphic modelling and repeat terrestrial laser scanner (TLS) surveys to map landscape change. Where discharge data were not available, event-based runoff was estimated using KINEROS2, a one-dimensional kinematic-wave runoff and erosion model. Discharge measurements and estimates were used as input to a two-dimensional unsteady flow-and-sedimentation model (Nays2DH) that combined a gridded flow, transport, and bed and bank simulation with geomorphic change. Through comparison of consecutive DEMs, the potential to substitute uncalibrated models to analyze stream restoration is introduced. We demonstrate a new approach to assess hydraulics and associated patterns of aggradation and degradation resulting from the construction of check-dams and other transverse structures. Notably, we find that stream restoration using rock-detention structures is effective across vastly different timescales.

  3. Erosion and Deposition Monitoring Using High-Density Aerial Lidar and Geomorphic Change Detection Software Analysis at Los Alamos National Laboratory, Los Alamos New Mexico, LA-UR-17-26743

    Science.gov (United States)

    Walker, T.; Kostrubala, T. L.; Muggleton, S. R.; Veenis, S.; Reid, K. D.; White, A. B.

    2017-12-01

    The Los Alamos National Laboratory storm water program installed sediment transport mitigation structures to reduce the migration of contaminants within the Los Alamos and Pueblo (LA/P) watershed in Los Alamos, NM. The goals of these structures are to minimize storm water runoff and erosion, enhance deposition, and reduce mobility of contaminated sediments. Previous geomorphological monitoring used GPS surveyed cross-sections on a reach scale to interpolate annual geomorphic change in sediment volumes. While monitoring has confirmed the LA/P watershed structures are performing as designed, the cross-section method proved difficult to estimate uncertainty and the coverage area was limited. A new method, using the Geomorphic Change Detection (GCD) plugin for ESRI ArcGIS developed by Wheaton et al. (2010), with high-density aerial lidar data, has been used to provide high confidence uncertainty estimates and greater areal coverage. Following the 2014 monsoon season, airborne lidar data has been collected annually and the resulting DEMs processed using the GCD method. Additionally, a more accurate characterization of low-amplitude geomorphic changes, typical of low-flow/low-rainfall monsoon years, has been documented by applying a spatially variable error to volume change calculations using the GCD based fuzzy inference system (FIS). The FIS method allows for the calculation of uncertainty based on data set quality and density e.g. point cloud density, ground slope, and degree of surface roughness. At the 95% confidence level, propagated uncertainty estimates of the 2015 and 2016 lidar DEM comparisons yielded detectable changes greater than 0.3 m - 0.46 m. Geomorphic processes identified and verified in the field are typified by low-amplitude, within-channel aggradation and incision and out of channel bank collapse that over the course of a monsoon season result in localized and dectetable change. While the resulting reach scale volume change from 2015 - 2016 was often

  4. Ecologically relevant geomorphic attributes of streams are impaired by even low levels of watershed effective imperviousness

    Science.gov (United States)

    Vietz, Geoff J.; Sammonds, Michael J.; Walsh, Christopher J.; Fletcher, Tim D.; Rutherfurd, Ian D.; Stewardson, Michael J.

    2014-02-01

    Urbanization almost inevitably results in changes to stream morphology. Understanding the mechanisms for such impacts is a prerequisite to minimizing stream degradation and achieving restoration goals. However, investigations of urban-induced changes to stream morphology typically use indicators of watershed urbanization that may not adequately represent degrading mechanisms and commonly focus on geomorphic attributes such as channel dimensions that may be of little significance to the ecological goals for restoration. We address these shortcomings by testing if a measure characterizing urban stormwater drainage system connections to streams (effective imperviousness, EI) is a better predictor of change to ecologically relevant geomorphic attributes than a more general measure of urban density (total imperviousness, TI). We test this for 17 sites in independent watersheds across a gradient of urbanization. We found that EI was a better predictor of all geomorphic variables tested than was TI. Bank instability was positively correlated with EI, while width/depth (a measure of channel incision), bedload sediment depth, and frequency of bars, benches, and large wood were negatively correlated. Large changes in all geomorphic variables were detected at very low levels of EI (Urbanization influences stream morphology more than any other land use (Douglas, 2011): it alters hydrology and sediment inputs leading to deepening and widening of streams (Chin, 2006). Concomitantly, urbanization often directly impairs stream morphology through channel and riparian zone interventions, e.g., culverts (Hawley et al., 2012), rock protection (Vietz et al., 2012b), and constricted floodplains (Gurnell et al., 2007). These changes to channel geomorphology in turn contribute to poor in-stream ecological condition (Morley and Karr, 2002; Walsh et al., 2005b; Gurnell et al., 2007; Elosegi et al., 2010).The common conception is that channels undergo gross morphologic alterations if > 10

  5. Geomorphic floodplain with organic matter (biomass) estimates for Fanno Creek, Oregon

    Science.gov (United States)

    Sobieszczyk, Steven

    2011-01-01

    Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the geomorphic floodplain as derived from light detection and ranging (LiDAR) data and aerial photographic imagery. The floodplain represents current conditions including both anthropogenic alterations and natural historic floodplain features. The floodplain dataset is divided into 13 reach segments and attributed with corresponding organic material load estimates for each reach.

  6. Using Geomorphic Change Detection to Understand Restoration Project Success Relative to Stream Size

    Science.gov (United States)

    Yeager, A.; Segura, C.

    2017-12-01

    Large wood (LW) jams have long been utilized as a stream restoration strategy to create fish habitat, with a strong focus on Coho salmon in the Pacific Northwest. These projects continue to be implemented despite limited understanding of their success in streams of different size. In this study, we assessed the changes triggered by LW introductions in 10 alluvial plane bed reaches with varying drainage areas (3.9-22 km²) and bankfull widths (6.4-14.7 m) in one Oregon Coast Range basin. In this basin, LW was added in an effort to improve winter rearing habitat for Coho salmon. We used detailed topographic mapping (0.5 m² resolution) to describe the local stream and floodplain geometry. Pebble counts were used to monitor changes in average substrate size after the LW addition. Field surveys were conducted immediately after the LW were installed, in the summer of 2016, and one year after installation, in the summer of 2017. We used geomorphic change detection analysis to quantify the amount of scour and deposition at each site along with changes in average bankfull width. Then we determined the relative amount of change among all sites to identify which size stream changed the most. We also modeled fluctuations in water surface elevation at each site, correlating frequency and inundation of the LW with geomorphic changes detected from the topographic surveys. Preliminary results show an increase in channel width and floodplain connectivity at all sites, indicating an increase in off-channel habitat for juvenile Coho salmon. Bankfull widths increased up to 75% in small sites and up to 25% in large sites. Median grain size became coarser in large streams (increased up to 20%), while we saw a similar amount of fining at smaller sites. The overall increase in channel width is compensated by an overall decrease in bed elevation at both large and small sites, suggesting the maintenance of overall geomorphic equilibrium. Further work will include quantifying these

  7. The long-term legacy of geomorphic and riparian vegetation feedbacks on the dammed Bill Williams River, Arizona, USA

    Science.gov (United States)

    Kui, Li; Stella, John C.; Shafroth, Patrick B.; House, P. Kyle; Wilcox, Andrew C.

    2017-01-01

    On alluvial rivers, fluvial landforms and riparian vegetation communities codevelop as a result of feedbacks between plants and abiotic processes. The influence of vegetation on river channel and floodplain geomorphology can be particularly strong on dammed rivers with altered hydrology and reduced flood disturbance. We used a 56-year series of aerial photos on the dammed Bill Williams River (Arizona, USA) to investigate how (a) different woody riparian vegetation types influence river channel planform and (b) how different fluvial landforms drive the composition of riparian plant communities over time. We mapped vegetation types and geomorphic surfaces and quantified how relations between fluvial and biotic processes covaried over time using linear mixed models. In the decades after the dam was built, woody plant cover within the river's bottomland nearly doubled, narrowing the active channel by 60% and transforming its planform from wide and braided to a single thread and more sinuous channel. Compared with native cottonwood–willow vegetation, nonnative tamarisk locally induced a twofold greater reduction in channel braiding. Vegetation expanded at different rates depending on the type of landform, with tamarisk cover on former high-flow channels increasing 17% faster than cottonwood–willow. Former low-flow channels with frequent inundation supported a greater increase in cottonwood–willow relative to tamarisk. These findings give insight into how feedbacks between abiotic and biotic processes in river channels accelerate and fortify changes triggered by dam construction, creating river systems increasingly distinct from predam ecological communities and landforms, and progressively more resistant to restoration of predam forms and processes.

  8. Caesium-137 as an indicator of geomorphic processes in a drainage basin system

    International Nuclear Information System (INIS)

    Campbell, B.L.; Elliott, G.L.

    1982-01-01

    Caesium-137 from fallout from nuclear weapons tests is adsorbed on fine sediments and becomes an effective tracer. It is hypothesised that within a drainage basin, sites undergoing little or no erosion accumulate Cs-137 in their upper layers; cultivated soils will have Cs-137 uniformly distributed within the cultivated layer; eroded soils, cultivated or not, will have relatively less Cs-137, depending on the severity of erosion. Accumulated sediments will have characteristic Cs-137 profiles reflecting temporal fallout variations and sedimentation history. This hypothetical model is largely confirmed by results from Maluna Creek basin, where erosion and accumulation of sediments has taken place. Soils under viticulture have about one third the Cs-137 content of soils with grass cover, indicating more severe erosion under cultivation. Caesium-137 profiles in alluvial fan and flood plain deposits correlate with sediment layers and known cultivation history

  9. A micromagnetic study of domain structure modeling

    International Nuclear Information System (INIS)

    Matsuo, Tetsuji; Mimuro, Naoki; Shimasaki, Masaaki

    2008-01-01

    To develop a mesoscopic model for magnetic-domain behavior, a domain structure model (DSM) was examined and compared with a micromagnetic simulation. The domain structure of this model is given by several domains with uniform magnetization vectors and domain walls. The directions of magnetization vectors and the locations of domain walls are determined so as to minimize the magnetic total energy of the magnetic material. The DSM was modified to improve its representation capability for domain behavior. The domain wall energy is multiplied by a vanishing factor to represent the disappearance of magnetic domain. The sequential quadratic programming procedure is divided into two steps to improve an energy minimization process. A comparison with micromagnetic simulation shows that the modified DSM improves the representation accuracy of the magnetization process

  10. The Herpes Simplex Virus Protein pUL31 Escorts Nucleocapsids to Sites of Nuclear Egress, a Process Coordinated by Its N-Terminal Domain.

    Directory of Open Access Journals (Sweden)

    Christina Funk

    2015-06-01

    Full Text Available Progeny capsids of herpesviruses leave the nucleus by budding through the nuclear envelope. Two viral proteins, the membrane protein pUL34 and the nucleo-phosphoprotein pUL31 form the nuclear egress complex that is required for capsid egress out of the nucleus. All pUL31 orthologs are composed of a diverse N-terminal domain with 1 to 3 basic patches and a conserved C-terminal domain. To decipher the functions of the N-terminal domain, we have generated several Herpes simplex virus mutants and show here that the N-terminal domain of pUL31 is essential with basic patches being critical for viral propagation. pUL31 and pUL34 entered the nucleus independently of each other via separate routes and the N-terminal domain of pUL31 was required to prevent their premature interaction in the cytoplasm. Unexpectedly, a classical bipartite nuclear localization signal embedded in this domain was not required for nuclear import of pUL31. In the nucleus, pUL31 associated with the nuclear envelope and newly formed capsids. Viral mutants lacking the N-terminal domain or with its basic patches neutralized still associated with nucleocapsids but were unable to translocate them to the nuclear envelope. Replacing the authentic basic patches with a novel artificial one resulted in HSV1(17+Lox-UL31-hbpmp1mp2, that was viable but delayed in nuclear egress and compromised in viral production. Thus, while the C-terminal domain of pUL31 is sufficient for the interaction with nucleocapsids, the N-terminal domain was essential for capsid translocation to sites of nuclear egress and a coordinated interaction with pUL34. Our data indicate an orchestrated sequence of events with pUL31 binding to nucleocapsids and escorting them to the inner nuclear envelope. We propose a common mechanism for herpesviral nuclear egress: pUL31 is required for intranuclear translocation of nucleocapsids and subsequent interaction with pUL34 thereby coupling capsid maturation with primary

  11. Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution

    Science.gov (United States)

    Ganju, N.K.; Schoellhamer, D.H.

    2009-01-01

    Modeling geomorphic evolution in estuaries is necessary to model the fate of legacy contaminants in the bed sediment and the effect of climate change, watershed alterations, sea level rise, construction projects, and restoration efforts. Coupled hydrodynamic and sediment transport models used for this purpose typically are calibrated to water level, currents, and/or suspended-sediment concentrations. However, small errors in these tidal-timescale models can accumulate to cause major errors in geomorphic evolution, which may not be obvious. Here we present an intermediate step towards simulating decadal-timescale geomorphic change: calibration to estimated sediment fluxes (mass/time) at two cross-sections within an estuary. Accurate representation of sediment fluxes gives confidence in representation of sediment supply to and from the estuary during those periods. Several years of sediment flux data are available for the landward and seaward boundaries of Suisun Bay, California, the landward-most embayment of San Francisco Bay. Sediment flux observations suggest that episodic freshwater flows export sediment from Suisun Bay, while gravitational circulation during the dry season imports sediment from seaward sources. The Regional Oceanic Modeling System (ROMS), a three-dimensional coupled hydrodynamic/sediment transport model, was adapted for Suisun Bay, for the purposes of hindcasting 19th and 20th century bathymetric change, and simulating geomorphic response to sea level rise and climatic variability in the 21st century. The sediment transport parameters were calibrated using the sediment flux data from 1997 (a relatively wet year) and 2004 (a relatively dry year). The remaining years of data (1998, 2002, 2003) were used for validation. The model represents the inter-annual and annual sediment flux variability, while net sediment import/export is accurately modeled for three of the five years. The use of sediment flux data for calibrating an estuarine geomorphic

  12. Associations of stream geomorphic conditions and prevalence of alternative reproductive tactics among sockeye salmon populations.

    Science.gov (United States)

    DeFilippo, L B; Schindler, D E; Carter, J L; Walsworth, T E; Cline, T J; Larson, W A; Buehrens, T

    2018-02-01

    In many species, males may exhibit alternative life histories to circumvent the costs of intrasexual competition and female courtship. While the evolution and underlying genetic and physiological mechanisms behind alternative reproductive tactics are well studied, there has been less consideration of the ecological factors that regulate their prevalence. Here, we examine six decades of age composition records from thirty-six populations of sockeye salmon (Oncorhynchus nerka) to quantify associations between spawning habitat characteristics and the prevalence of precocious sneakers known as 'jacks'. Jack prevalence was independent of neutral genetic structure among stream populations, but varied among habitat types and as a function of continuous geomorphic characteristics. Jacks were more common in streams relative to beaches and rivers, and their prevalence was negatively associated with stream width, depth, elevation, slope and area, but positively related to bank cover. Behavioural observations showed that jacks made greater use of banks, wood and shallows than guard males, indicating that their reproductive success depends on the availability of such refuges. Our results emphasize the role of the physical habitat in shaping reproductive tactic frequencies among populations, likely through local adaptation in response to variable fitness expectations under different geomorphic conditions. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  13. Geomorphic determinants of species composition of alpine tundra, Glacier National Park, U.S.A.

    Science.gov (United States)

    George P. Malanson,; Bengtson, Lindsey E.; Fagre, Daniel B.

    2012-01-01

    Because the distribution of alpine tundra is associated with spatially limited cold climates, global warming may threaten its local extent or existence. This notion has been challenged, however, based on observations of the diversity of alpine tundra in small areas primarily due to topographic variation. The importance of diversity in temperature or moisture conditions caused by topographic variation is an open question, and we extend this to geomorphology more generally. The extent to which geomorphic variation per se, based on relatively easily assessed indicators, can account for the variation in alpine tundra community composition is analyzed versus the inclusion of broad indicators of regional climate variation. Visual assessments of topography are quantified and reduced using principal components analysis (PCA). Observations of species cover are reduced using detrended correspondence analysis (DCA). A “best subsets” regression approach using the Akaike Information Criterion for selection of variables is compared to a simple stepwise regression with DCA scores as the dependent variable and scores on significant PCA axes plus more direct measures of topography as independent variables. Models with geographic coordinates (representing regional climate gradients) excluded explain almost as much variation in community composition as models with them included, although they are important contributors to the latter. The geomorphic variables in the model are those associated with local moisture differences such as snowbeds. The potential local variability of alpine tundra can be a buffer against climate change, but change in precipitation may be as important as change in temperature.

  14. Associations of stream geomorphic conditions and prevalence of alternative reproductive tactics among sockeye salmon populations

    Science.gov (United States)

    DeFilippo, L. B.; Schindler, D.E.; Carter, J.L.; Walsworth, Timothy E.; Cline, T. J.; Larson, Wesley; Buehrens, T.

    2018-01-01

    In many species, males may exhibit alternative life histories to circumvent the costs of intrasexual competition and female courtship. While the evolution and underlying genetic and physiological mechanisms behind alternative reproductive tactics are well studied, there has been less consideration of the ecological factors that regulate their prevalence. Here, we examine six decades of age composition records from thirty‐six populations of sockeye salmon (Oncorhynchus nerka) to quantify associations between spawning habitat characteristics and the prevalence of precocious sneakers known as ‘jacks’. Jack prevalence was independent of neutral genetic structure among stream populations, but varied among habitat types and as a function of continuous geomorphic characteristics. Jacks were more common in streams relative to beaches and rivers, and their prevalence was negatively associated with stream width, depth, elevation, slope and area, but positively related to bank cover. Behavioural observations showed that jacks made greater use of banks, wood and shallows than guard males, indicating that their reproductive success depends on the availability of such refuges. Our results emphasize the role of the physical habitat in shaping reproductive tactic frequencies among populations, likely through local adaptation in response to variable fitness expectations under different geomorphic conditions.

  15. Tectono-geomorphic indices of the Erin basin, NE Kashmir valley, India

    Science.gov (United States)

    Ahmad, Shabir; Alam, Akhtar; Ahmad, Bashir; Afzal, Ahsan; Bhat, M. I.; Sultan Bhat, M.; Farooq Ahmad, Hakim; Tectonics; Natural Hazards Research Group

    2018-01-01

    The present study aims to assess the tectonic activity in the Erin basin (NE Kashmir) on the basis of several relevant geomorphic indices and field observations. We use Digital Elevation Model (SRTM) and Survey of India (SoI) topographic maps in GIS environment to compute the geomorphic indices. The indices i.e., convex hypsometric curve, high hypsometric integral value (Hi > 0.5), low basin elongation ratio (Eb = 0.17), low mountain front sinuosity values (Smf = 1.08 average), low valley floor width ratios (Vf 4) suggest that the area is tectonically active. Moreover, prominent irregularities (knickpoints/knickzones) along longitudinal profile of the Erin River even in homogenous resistant lithology (Panjal trap) and anomalous stream gradient index (SL) values reflect that the Erin basin is dissected by two faults (EF-1 and EF-2) with NNW-SSE and SSW-NNE trends respectively. The results of this preliminary study further substantiate the recent GPS studies, which argue that the maximum strain is accumulating in the NE part of the Kashmir Himalaya.

  16. Ca isotopes, chemical weathering, and geomorphic controls on long-term climate

    Science.gov (United States)

    Moore, J.; Jacobson, A. D.; Holmden, C. E.; Craw, D.

    2009-12-01

    Calcium isotope geochemistry (δ44Ca) offers a unique opportunity to directly quantify proportions of riverine Ca originating from silicate versus carbonate weathering, which is essential for understanding how geomorphic processes affecting landscape evolution, such as tectonic uplift and glaciation, influence the long-term cycling of atmospheric CO2. We measured the elemental and δ44Ca chemistry of river and rock samples from the New Zealand Southern Alps. In combination with our geochemical data, we used runoff and suspended sediment fluxes to elucidate relationships between chemical weathering, mechanical erosion, and long-term climate. The S. Alps have uniform bedrock chemistry but significant tectonic and climatic gradients. West of the main topographic divide, watersheds drain schist and experience high runoff, uplift, and erosion rates. East of the main divide, watersheds drain greywacke or schist and experience lower runoff, uplift, and erosion rates. Glaciated watersheds with high erosion rates are present throughout the mountain range. Both schist and greywacke contain up to 3% metamorphic and hydrothermal calcite. Waters exhibit two-component mixing between calcite and silicate end-members when plotted as δ44Ca versus Ca/Sr. Scatter about the mixing curve is generally smaller than the analytical uncertainty of the measurements and likely reflects variability of the end-member compositions rather than fractionation. We used the mixing relationships to calculate percentages of Ca from silicate weathering. Rivers draining greywacke average 27.6% of Ca from silicate weathering with glaciated and non-glaciated watersheds yielding 41.8 and 19.5%, respectively. Rivers draining schist average 9.8% with glaciated and non-glaciated watersheds yielding 17.7 and 3.9%, respectively. Although Ca fluxes are larger west of the main divide where erosion and runoff are higher, the percentage of Ca from silicate weathering is smaller. Hence, long-term atmospheric CO2

  17. Applications of UAS-SfM for coastal vulnerability assessment: Geomorphic feature extraction and land cover classification from fine-scale elevation and imagery data

    Science.gov (United States)

    Sturdivant, E. J.; Lentz, E. E.; Thieler, E. R.; Remsen, D.; Miner, S.

    2016-12-01

    Characterizing the vulnerability of coastal systems to storm events, chronic change and sea-level rise can be improved with high-resolution data that capture timely snapshots of biogeomorphology. Imagery acquired with unmanned aerial systems (UAS) coupled with structure from motion (SfM) photogrammetry can produce high-resolution topographic and visual reflectance datasets that rival or exceed lidar and orthoimagery. Here we compare SfM-derived data to lidar and visual imagery for their utility in a) geomorphic feature extraction and b) land cover classification for coastal habitat assessment. At a beach and wetland site on Cape Cod, Massachusetts, we used UAS to capture photographs over a 15-hectare coastal area with a resulting pixel resolution of 2.5 cm. We used standard SfM processing in Agisoft PhotoScan to produce an elevation point cloud, an orthomosaic, and a digital elevation model (DEM). The SfM-derived products have a horizontal uncertainty of +/- 2.8 cm. Using the point cloud in an extraction routine developed for lidar data, we determined the position of shorelines, dune crests, and dune toes. We used the output imagery and DEM to map land cover with a pixel-based supervised classification. The dense and highly precise SfM point cloud enabled extraction of geomorphic features with greater detail than with lidar. The feature positions are reported with near-continuous coverage and sub-meter accuracy. The orthomosaic image produced with SfM provides visual reflectance with higher resolution than those available from aerial flight surveys, which enables visual identification of small features and thus aids the training and validation of the automated classification. We find that the high-resolution and correspondingly high density of UAS data requires some simple modifications to existing measurement techniques and processing workflows, and that the types of data and the quality provided is equivalent to, and in some cases surpasses, that of data

  18. Control of the geomorphic evolution of an active crater: Popocatpetl (Mexico) 1994-2003.

    Science.gov (United States)

    Andrés, N.; Zamorano, J. J.; Palacios, D.; Macias, J. L.; Sanjosé, J. J.

    2009-04-01

    Volcanic activity often causes intense and successive geomorphic changes to occur inside a crater. In terms of hazard mitigation, it is important to understand the cause of these changes whether they be exterior lava spills, sequences of explosions or massive glacier melt. Access to an active crater, however, is very difficult and dangerous, so analytical approaches involving remote study must substitute actual fieldwork. Several studies done at Popocatepetl volcano during its most recent eruptive phase that began in December 1994, use remote techniques and are described in Cruz-Reyna et al. (1998), Wright et al. (2002), Martín-Del Pozo et al. (2003), Tanarro et al. (2005), Matiella et al. (2008), and Zamorano et al. (1996,1998), among others. The compendium of results reveals that recent volcanic activity on Popocatépetl is characterized by successive dome growth and destruction inside the crater. Macias and Siebe (2005) even suggest that the walls of the crater may no longer withstand future dome growth. The purpose of this study is to understand the morphologic evolution of the interior of the crater during the most active period of the present eruptive phase on Popocatepetl from 1994 to 2003. The methodology is based on photogrammetry techniques that have been used successfully at volcanic sites by Donnadieu et al. (2003), and on a GIS to organize information, draft maps and 3-D images, and to calculate spatial variations in landforms (Procter et al., 2006; Schilling et al., 2006). Traditional aerial photo interpretation was used for 22 triplets selected from a collection of photos taken by the Mexican Highway and Transport Secretariat, from 1982 to 2003, and enabled us to draft geomorphic maps of the interior of the crater. The photos and maps were rectified and georeferenced with ArcGis software, and then the maps were digitized. The areas containing morphologic units associated with a date (exterior crater walls, colluvial ramps and recent volcanic complex

  19. Processing of single- and multi-domain YBa2Cu3Ox bulk materials for levitation applications by Nd1+xBa2-xCu3Oy seeding

    International Nuclear Information System (INIS)

    Todt, V.R.

    1995-01-01

    Melt processing of YBa 2 Cu 3 O x (Y123) is a well established technique to produce materials for levitation applications. We report our new results on the melt-processing of Y123. To achieve materials with high levitation forces we utilize a seeding technique using Nd 1+x Ba 2-x Cu 3 O y- seeds (Nd123). Two different kinds of Nd13-seeds, one plate-shaped and the other cube-shaped, were developed and used for this study. The microstructures of the levitators depended strongly on the type of the seeding material used and on the seeding geometry. We were able to produce large single domains as well as materials containing five domains with three different c-axis orientations. Levitation forces up to 8.2 N for samples with a diameter of about 18 mm were found for the multi-domain samples, which is well within the area of the levitation forces measured for the single domain materials

  20. Probing the Gaps: A Synthesis of Well-known and Lesser-known Hydrological Feedbacks Influencing Vegetation Patterning and Long-term Geomorphic Change in Low-gradient Fluvial Landscapes

    Science.gov (United States)

    Larsen, L.; Christensen, A.; Harvey, J. W.; Ma, H.; Newman, S.; Saunders, C.; Twilley, R.

    2017-12-01

    Emergence of vegetation patterning in fluvial landscapes is a classic example of how autogenic processes can drive long term fluvial and geomorphic adjustments in aquatic ecosystems. Studies elucidating the physics of flow through vegetation patches have produced understanding of how patterning in topography and vegetation commonly emerges and what effect it has on long term geomorphic change. However, with regard to mechanisms underlying pattern existence and resilience, several knowledge gaps remain, including the role of landscape-scale flow-vegetation feedbacks, feedbacks that invoke additional biogeochemical or biological agents, and determination of the relative importance of autogenic processes relative to external drivers. Here we provide a synthesis of the processes over a range of scales known to drive vegetation patterning and sedimentation in low gradient fluvial landscapes, emphasizing recent field and modeling studies in the Everglades, FL and Wax Lake Delta, LA that address these gaps. In the Everglades, while flow routing and sediment redistribution at the patch scale is known to be a primary driver of vegetation pattern emergence, landscape-scale routing of flow, as driven by the landscape's connectivity, can set up positive feedbacks that influence the rate of pattern degradation. Recent flow release experiments reveal that an additional feedback, involving phosphorus concentrations, flow, and floating vegetation communities that are abundant under low phosphorus, low flow conditions further stabilizes the alternative landscape states established through local scale sediment redistribution. Biogeochemistry-vegetation-sediment feedbacks may also be important for geomorphic development of newly emerging landscapes such as the Wax Lake Delta. There, fine sediment deposition shapes hydrogeomorphic zones with vegetation patterns that stimulate the growth of biofilm, while biofilm characteristics override the physical characteristics of vegetation

  1. Geomorphic Effects, Chronologies, and Archaeological Significance of El Nino Floods in Southern Peru

    Science.gov (United States)

    Magilligan, F. J.; Manners, R.; Goldstein, P.

    2003-12-01

    The catastrophic effects of large floods have been well documented, on both contemporary and paleo-timecales, especially for the conterminous U.S. Less is known, however, about extreme events in hyper-arid sub-tropical climates where synoptic scale meteorological causes, such as El Nino-Southern Oscillation events, are the driving atmospheric mechanism. This research documents the geomorphic effects of extreme floods in the Moquegua River valley of southern Peru, in the core of the Atacama Desert. Using a combination of geomorphic mapping, hydrolologic modeling, aerial photography, ASTER satellite imagery, and GIS, we document the geomorphic signature of large contemporary floods within the mid-valley section (1500 masl) of the Rio Moquegua. Stratigraphic evidence and paleostage indicators of paleofloods, such as slackwater deposits and preserved high level flood gravels, are used to evidence late Holocene paleoflood magnitude-frequency relationships. On contemporary timescales, channel belt expansion by lateral erosion during large floods, such as the recent '97 and '98 floods, correspond to as much as 30-40 hectares of floodplain loss along the 20 km study reach. Sixty years of repeat aerial photography indicates that channel belt expansion and floodplain erosion commonly occurs along the Rio Moquegua. The frequent resetting of floodplain alluvium conditioned by these large floods is supported by radiocarbon dating of floodplain exposures. These dates indicate that most of the contemporary floodplain alluvium is younger that 560 14C yrs BP. The highest terrace remnants date to 3250 14C yrs BP and record a series of overbank flood gravels. Evidence for the regionally extensive Miraflores ENSO flood, ca. 1300 AD, exists in tributary and along mainstem sections. This flood has been documented along the coasts of Northern Chile to northern Peru, and has been evoked to explain significant social collapse. Our field evidence indicates that it catastrophically affected

  2. Effect of Sediment Availability in Bedload-Dominated Rivers on Fluvial Geomorphic Equilibrium

    Science.gov (United States)

    Marti, M.

    2016-12-01

    Channels are known to compensate for changes in sediment supply via covariate changes in channel properties, yet the timescale for adjustment remains poorly constrained. We propose that reductions in sediment flux inhibit equilibrium re-establishment and thus impact the timescale of system adjustment. Using run-of-river dams as natural experiments, this study quantifies the geomorphic response of channels to sediment supply reduction. Channel traits that facilitate increased sediment trapping behind the dam, such as large reservoir storage capacity relative to annual inflow and low slope, were expected to inhibit a channel's ability to re-establish equilibrium following impoundment, lengthening the equilibrium establishment timescale to tens or hundreds of years. Reaches associated with increased trapping were therefore anticipated to exhibit non-equilibrium forms. Channel equilibrium was evaluated downstream of 8 ROR dams in New England with varying degrees of sediment trapping. Sites cover a range of watershed sizes (3-155 km2), channel slopes (.05-5%), 2-year discharges (1.5-60 m3/s) and storage capacity volumes. Because equilibrium channel form is just sufficient to mobilize grains under bankfull conditions in bedload-dominated rivers, the Shields parameter was used to assess equilibrium form. Unregulated, upstream Shields values and regulated, downstream values were calculated at 14 total cross-sections extending 300-450 m upstream and downstream of each dam. Sediment trapping was estimated using Brune's curve (1953). On the Charles Brown Brook (VT), a marginally significant (p=0.08) increase in Shields values from a mean of 0.14 upstream to 0.41 downstream of a 100+ year old dam was observed. In contrast, reaches downstream of the 100+ year old Pelham dam (MA) exhibit significantly lower Shields values. This suggests that trapping behind the dam inhibits the downstream channel from reaching an equilibrium state, but not always in the same way. Better

  3. Geomorphic and vegetation changes in a meandering dryland river regulated by a large dam, Sauce Grande River, Argentina

    Science.gov (United States)

    Casado, Ana; Peiry, Jean-Luc; Campo, Alicia M.

    2016-09-01

    This paper investigates post-dam geomorphic and vegetation changes in the Sauce Grande River, a meandering dryland river impounded by a large water-conservation dam. As the dam impounds a river section with scarce influence of tributaries, sources for fresh water and sediment downstream are limited. Changes were inspected based on (i) analysis of historical photographs/imagery spanning pre- (1961) and post-dam (1981, 2004) channel conditions for two river segments located above and below the dam, and (ii) field survey of present channel conditions for a set of eight reference reaches along the river segments. Whilst the unregulated river exhibited active lateral migration with consequent adjustments of the channel shape and size, the river section below the dam was characterized by (i) marked planform stability (93 to 97%), and by (ii) vegetation encroachment leading to alternating yet localized contraction of the channel width (up to 30%). The present river displays a moribund, stable channel where (i) redistribution of sediment along the river course no longer occurs and (ii) channel forms constitute a remnant of a fluvial environment created before closing the dam, under conditions of higher energy. In addition to providing new information on the complex geomorphic response of dryland rivers to impoundment, this paper represents the very first geomorphic assessment of the regulated Sauce Grande and therefore provides an important platform to underpin further research assessing the geomorphic state of this highly regulated dryland river.

  4. Hydraulic, geomorphic, and trout habitat conditions of the Lake Fork of the Gunnison River in Hinsdale County, Lake City, Colorado, Water Years 2010-2011

    Science.gov (United States)

    Williams, Cory A.; Richards, Rodney J.; Schaffrath, Keelin R.

    2015-01-01

    Channel rehabilitation, or reconfiguration, to mitigate a variety of riverine problems has become a common practice in the western United States. However, additional work to monitor and assess the channel response to, and the effectiveness of, these modifications over longer periods of time (decadal or longer) is still needed. The Lake Fork of the Gunnison River has been an area of active channel modification to accommodate the needs of the Lake City community since the 1950s. The Lake Fork Valley Conservancy District began a planning process to assess restoration options for a reach of the Lake Fork in Lake City to enhance hydraulic and ecologic characteristics of the reach. Geomorphic channel form is affected by land-use changes within the basin and geologic controls within the reach. The historic channel was defined as a dynamic, braided channel with an active flood plain. This can result in a natural tendency for the channel to braid. A braided channel can affect channel stability of reconfigured reaches when a single-thread meandering channel is imposed on the stream. The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board and Colorado River Water Conservation District, began a study in 2010 to quantify existing hydraulic and habitat conditions for a reach of the Lake Fork of the Gunnison River in Lake City, Colorado. The purpose of this report is to quantify existing Lake Fork hydraulic and habitat conditions and establish a baseline against which post-reconfiguration conditions can be compared. This report (1) quantifies the existing hydraulic and geomorphic conditions in a 1.1-kilometer section of the Lake Fork at Lake City that has been proposed as a location for future channel-rehabilitation efforts, (2) characterizes the habitat suitability of the reach for two trout species based on physical conditions within the stream, and (3) characterizes the current riparian canopy density.

  5. Controls on large landslide distribution and implications for the geomorphic evolution of the southern interior Columbia River basin

    Science.gov (United States)

    Safran, E.B.; Anderson, S.W.; Mills-Novoa, M.; House, P.K.; Ely, L.

    2011-01-01

    Large landslides (>0.1 km2) are important agents of geomorphic change. While most common in rugged mountain ranges, large landslides can also be widespread in relatively low-relief (several 100 m) terrain, where their distribution has been relatively little studied. A fuller understanding of the role of large landslides in landscape evolution requires addressing this gap, since the distribution of large landslides may affect broad regions through interactions with channel processes, and since the dominant controls on landslide distribution might be expected to vary with tectonic setting. We documented >400 landslides between 0.1 and ~40 km2 across ~140,000 km2 of eastern Oregon, in the semiarid, southern interior Columbia River basin. The mapped landslides cluster in a NW-SE-trending band that is 50-100 km wide. Landslides predominantly occur where even modest local relief (~100 m) exists near key contacts between weak sedimentary or volcaniclastic rock and coherent cap rock. Fault density exerts no control on landslide distribution, while ~10% of mapped landslides cluster within 3-10 km of mapped fold axes. Landslide occurrence is curtailed to the NE by thick packages of coherent basalt and to the SW by limited local relief. Our results suggest that future mass movements will localize in areas stratigraphically preconditioned for landsliding by a geologic history of fluviolacustrine and volcaniclastic sedimentation and episodic capping by coherent lava flows. In such areas, episodic landsliding may persist for hundreds of thousands of years or more, producing valley wall slopes of ~7??-13?? and impacting local channels with an evolving array of mass movement styles. ?? 2011 Geological Society of America.

  6. Genesis and geomorphic evolution of the Velké pinky stopes in the Zlatohorská Highlands, Eastern Sudetes

    Science.gov (United States)

    Lenart, Jan; Tichavský, Radek; Večeřa, Josef; Kapustová, Veronika; Šilhán, Karel

    2017-11-01

    Montanogenic landforms are commonly viewed as hazards by society, but they are also holders of specific and uncommon morphology with unique dynamics that act as remarks on landscape history. The Velké pinky stopes in the Zlatohorská Highlands, Eastern Sudetes, are naturally revitalized post-mining landforms with long-term geoecological succession. Their genetic origin is diverse but recent processes, such as deep-seated slope deformations, rockfalls and ground subsidence, have resulted in a distinct morphology dominated by rock walls and the accumulation of blocks and debris wedges. This morphology predisposes the stopes to become the core area of the most recent dynamic geomorphic activity within the wider, relatively homogenous area. By dendrogeomorphic techniques, we identified more than 20 rockfall events within three of the stopes with increased activity since the 1980s. Only the 1991 and 2006 events were identical for all three stopes. We obtained the years of exposures from 10 roots, revealing the ground subsidence and opening of tension cracks or even the lateral retreat of the flanks of minor depressions. The Schmidt hammer test revealed the most recent and fresh gravitational activity in one of the stopes. A relationship between the superficial morphology and underground structure was proven by electrical resistivity profiling. Compared to the previous studies engaged with the abandoned mines, we presented how complex their evolution can be. Our study brings new information about the historical development of anthropogenic relief forms. Moreover, our results suggest that standard research approaches can be successfully applied for development analysis of these specific forms.

  7. SH2 Domain Histochemistry.

    Science.gov (United States)

    Buhs, Sophia; Nollau, Peter

    2017-01-01

    Among posttranslational modifications, the phosphorylation of tyrosine residues is a key modification in cell signaling. Because of its biological importance, characterization of the cellular state of tyrosine phosphorylation is of great interest. Based on the unique properties of endogenously expressed SH2 domains recognizing tyrosine phosphorylated signaling proteins with high specificity we have developed an alternative approach, coined SH2 profiling, enabling us to decipher complex patterns of tyrosine phosphorylation in various normal and cancerous tissues. So far, SH2 profiling has largely been applied for the analysis of protein extracts with the limitation that information on spatial distribution and intensity of tyrosine phosphorylation within a tissue is lost. Here, we describe a novel SH2 domain based strategy for differential characterization of the state of tyrosine phosphorylation in formaldehyde-fixed and paraffin-embedded tissues. This approach demonstrates that SH2 domains may serve as very valuable tools for the analysis of the differential state of tyrosine phosphorylation in primary tissues fixed and processed under conditions frequently applied by routine pathology laboratories.

  8. An algorithm for generation of DEMs from contour lines considering geomorphic features

    Directory of Open Access Journals (Sweden)

    Xiao-Ping Rui

    2016-04-01

    Full Text Available Geomorphic information is omitted from many existing methods of generating gridded digital elevation models (DEMs from contour lines, resulting in significant errors during interpolation. Here, we present an advanced schema for improvement of the comprehensive regionalized method of linear interpolation. This approach uses a moving fitting method for an interpolated point and selects elevation points that are representative of geomorphic features as a whole to improve interpolation quality. A total of 16 points are selected, according to certain criteria, in eight directions surrounding the interpolated point; thus, there are two points in each direction, which is sufficient to provide an accurate representation of the geomorphic features of the DEM. Our method introduces virtual control points to prevent sudden changes in the interpolation results, which helps to overcome problems related to the distortion of the local geospatial distribution in areas where feature geomorphic information is inadequate. We construct the spline interpolation function using intersection points and virtual control points, all of which are applied to compute the point elevation. Moreover, we index all elevation values and spatial points of linear features using the R-tree method to ensure that points related to an interpolated position can be retrieved as quickly as possible. Finally, we test our method using a coal mine elevation dataset. The results confirm that our proposed method can generate DEMs smoothly and, in particular, avoid problems related to local distortion.    Resumen La información geomórfica se omite en muchos de los métodos de generación de Modelos Digitales de Elevación (DEM, en inglés que se elaboran a partir de líneas de contorno, lo que resulta en errores significativos durante la interpolación. En este trabajo se presenta un esquema avanzado para el mejoramiento del método comprensivo regionalizado de interpolación lineal. Esta

  9. Geomorphic and Geologic Controls of Geohazards induced by Nepal's 2015 Gorkha Earthquake

    Science.gov (United States)

    Kargel, J. S.; Leonard, G. J.; Shugar, D. H.; Haritashya, U.K.; Bevington, A.; Fielding, E. J.; Fujita, K.; Geertsema, M.; Miles, E. S.; Steiner, J.; hide

    2015-01-01

    The Gorkha earthquake (Magnitude 7.8) on 25 April 2015 and later aftershocks struck South Asia, killing approx.9,000 and damaging a large region. Supported by a large campaign of responsive satellite data acquisitions over the earthquake disaster zone, our team undertook a satellite image survey of the earthquakes induced geohazards in Nepal and China and an assessment of the geomorphic, tectonic, and lithologic controls on quake-induced landslides. Timely analysis and communication aided response and recovery and informed decision makers. We mapped 4,312 co-seismic and post-seismic landslides. We also surveyed 491 glacier lakes for earthquake damage, but found only 9 landslide-impacted lakes and no visible satellite evidence of outbursts. Landslide densities correlate with slope, peak ground acceleration, surface downdrop, and specific metamorphic lithologies and large plutonic intrusions.

  10. Geomorphic evidence for ancient seas in west Deuteronilus Mensae, Mars-1: Regional geomorphology

    Science.gov (United States)

    Parker, Timothy J.; Schneeberger, Dale M.; Pieri, David C.; Saunders, R. Stephen

    1987-01-01

    The fretted terrain in west Deuteronilus Mensae consists of extensive cratered upland penninsulas or isolated plateaus cut by long, finger-like canyons typically 10 to 20 km wide and upwards of 300 km long. The longest of these canyons trend roughly north-south to north-northeast, which may reflect some local structural and/or topographic control. At least three geomorphic zones roughly parallel to the lowland/upland boundary, suggestive of increasing modification northward, can be recognized on the fretted region of the region. The southern-most zone (zone A) consists of sharply defined fretted terrain. The middle zone (zone B) consists of well defined fretted terrain in which the plateau surfaces appear smoother, with a somewhat darker and much less varied albedo surface than those of zone A. The northern-most zone (zone C) consists of rounded or softened fretted terrain. The zones were interpreted as surface exposures of successively lower stratigraphic units.

  11. Crater Lakes on Mars: Development of Quantitative Thermal and Geomorphic Models

    Science.gov (United States)

    Barnhart, C. J.; Tulaczyk, S.; Asphaug, E.; Kraal, E. R.; Moore, J.

    2005-01-01

    Impact craters on Mars have served as catchments for channel-eroding surface fluids, and hundreds of examples of candidate paleolakes are documented [1,2] (see Figure 1). Because these features show similarity to terrestrial shorelines, wave action has been hypothesized as the geomorphic agent responsible for the generation of these features [3]. Recent efforts have examined the potential for shoreline formation by wind-driven waves, in order to turn an important but controversial idea into a quantitative, falsifiable hypothesis. These studies have concluded that significant wave-action shorelines are unlikely to have formed commonly within craters on Mars, barring Earth-like weather for approx.1000 years [4,5,6].

  12. How does landscape structure influence catchment transit time across different geomorphic provinces?

    Science.gov (United States)

    Tetzlaff, D.; Seibert, J.; McGuire, K.J.; Laudon, H.; Burns, Douglas A.; Dunn, S.M.; Soulsby, C.

    2009-01-01

    Despite an increasing number of empirical investigations of catchment transit times (TTs), virtually all are based on individual catchments and there are few attempts to synthesize understanding across different geographical regions. Uniquely, this paper examines data from 55 catchments in five geomorphic provinces in northern temperate regions (Scotland, United States of America and Sweden). The objective is to understand how the role of catchment topography as a control on the TTs differs in contrasting geographical settings. Catchment inverse transit time proxies (ITTPs) were inferred by a simple metric of isotopic tracer damping, using the ratio of standard deviation of ??18O in streamwater to the standard deviation of ??18O in precipitation. Quantitative landscape analysis was undertaken to characterize the catchments according to hydrologically relevant topographic indices that could be readily determined from a digital terrain model (DTM). The nature of topographic controls on transit times varied markedly in different geomorphic regions. In steeper montane regions, there are stronger gravitational influences on hydraulic gradients and TTs tend to be lower in the steepest catchments. In provinces where terrain is more subdued, direct topographic control weakened; in particular, where flatter areas with less permeable soils give rise to overland flow and lower TTs. The steeper slopes within this flatter terrain appear to have a greater coverage of freely draining soils, which increase sub-surface flow, therefore increasing TTs. Quantitative landscape analysis proved a useful tool for intercatchment comparison. However, the critical influence of sub-surface permeability and connectivity may limit the transferability of predictive tools of hydrological function based on topographic parameters alone. Copyright ?? 2009 John Wiley & Sons, Ltd.

  13. Statistical and Conceptual Model Testing Geomorphic Principles through Quantification in the Middle Rio Grande River, NM.

    Science.gov (United States)

    Posner, A. J.

    2017-12-01

    The Middle Rio Grande River (MRG) traverses New Mexico from Cochiti to Elephant Butte reservoirs. Since the 1100s, cultivating and inhabiting the valley of this alluvial river has required various river training works. The mid-20th century saw a concerted effort to tame the river through channelization, Jetty Jacks, and dam construction. A challenge for river managers is to better understand the interactions between a river training works, dam construction, and the geomorphic adjustments of a desert river driven by spring snowmelt and summer thunderstorms carrying water and large sediment inputs from upstream and ephemeral tributaries. Due to its importance to the region, a vast wealth of data exists for conditions along the MRG. The investigation presented herein builds upon previous efforts by combining hydraulic model results, digitized planforms, and stream gage records in various statistical and conceptual models in order to test our understanding of this complex system. Spatially continuous variables were clipped by a set of river cross section data that is collected at decadal intervals since the early 1960s, creating a spatially homogenous database upon which various statistical testing was implemented. Conceptual models relate forcing variables and response variables to estimate river planform changes. The developed database, represents a unique opportunity to quantify and test geomorphic conceptual models in the unique characteristics of the MRG. The results of this investigation provides a spatially distributed characterization of planform variable changes, permitting managers to predict planform at a much higher resolution than previously available, and a better understanding of the relationship between flow regime and planform changes such as changes to longitudinal slope, sinuosity, and width. Lastly, data analysis and model interpretation led to the development of a new conceptual model for the impact of ephemeral tributaries in alluvial rivers.

  14. Predicting geomorphically-induced flood risk for the Nepalese Terai communities

    Science.gov (United States)

    Dingle, Elizabeth; Creed, Maggie; Attal, Mikael; Sinclair, Hugh; Mudd, Simon; Borthwick, Alistair; Dugar, Sumit; Brown, Sarah

    2017-04-01

    Rivers sourced from the Himalaya irrigate the Indo-Gangetic Plain via major river networks that support 10% of the global population. However, many of these rivers are also the source of devastating floods. During the 2014 Karnali River floods in west Nepal, the Karnali rose to around 16 m at Chisapani (where it enters the Indo-Gangetic Plain), 1 m higher than the previous record in 1983; the return interval for this event was estimated to be 1000 years. Flood risk may currently be underestimated in this region, primarily because changes to the channel bed are not included when identifying areas at risk of flooding from events of varying recurrence intervals. Our observations in the field, corroborated by satellite imagery, show that river beds are highly mobile and constantly evolve through each monsoon. Increased bed levels due to sediment aggradation decreases the capacity of the river, increasing significantly the risk of devastating flood events; we refer to these as 'geomorphically-induced floods'. Major, short-lived episodes of sediment accumulation in channels are caused by stochastic variability in sediment flux generated by storms, earthquakes and glacial outburst floods from upstream parts of the catchment. Here, we generate a field-calibrated, geomorphic flood risk model for varying upstream scenarios, and predict changing flood risk for the Karnali River. A numerical model is used to carry out a sensitivity analysis of changes in channel geometry (particularly aggradation or degradation) based on realistic flood scenarios. In these scenarios, water and sediment discharge are varied within a range of plausible values, up to extreme sediment and water fluxes caused by widespread landsliding and/or intense monsoon precipitation based on existing records. The results of this sensitivity analysis will be used to inform flood hazard maps of the Karnali River floodplain and assess the vulnerability of the populations in the region.

  15. A geomorphic approach to 100-year floodplain mapping for the Conterminous United States

    Science.gov (United States)

    Jafarzadegan, Keighobad; Merwade, Venkatesh; Saksena, Siddharth

    2018-06-01

    Floodplain mapping using hydrodynamic models is difficult in data scarce regions. Additionally, using hydrodynamic models to map floodplain over large stream network can be computationally challenging. Some of these limitations of floodplain mapping using hydrodynamic modeling can be overcome by developing computationally efficient statistical methods to identify floodplains in large and ungauged watersheds using publicly available data. This paper proposes a geomorphic model to generate probabilistic 100-year floodplain maps for the Conterminous United States (CONUS). The proposed model first categorizes the watersheds in the CONUS into three classes based on the height of the water surface corresponding to the 100-year flood from the streambed. Next, the probability that any watershed in the CONUS belongs to one of these three classes is computed through supervised classification using watershed characteristics related to topography, hydrography, land use and climate. The result of this classification is then fed into a probabilistic threshold binary classifier (PTBC) to generate the probabilistic 100-year floodplain maps. The supervised classification algorithm is trained by using the 100-year Flood Insurance Rated Maps (FIRM) from the U.S. Federal Emergency Management Agency (FEMA). FEMA FIRMs are also used to validate the performance of the proposed model in areas not included in the training. Additionally, HEC-RAS model generated flood inundation extents are used to validate the model performance at fifteen sites that lack FEMA maps. Validation results show that the probabilistic 100-year floodplain maps, generated by proposed model, match well with both FEMA and HEC-RAS generated maps. On average, the error of predicted flood extents is around 14% across the CONUS. The high accuracy of the validation results shows the reliability of the geomorphic model as an alternative approach for fast and cost effective delineation of 100-year floodplains for the CONUS.

  16. Evolution of strike-slip fault systems and associated geomorphic structures. Model test

    International Nuclear Information System (INIS)

    Ueta, Keichi

    2003-01-01

    Sandbox experiments were performed to investigate evolution of fault systems and its associated geomorphic structures caused by strike-slip motion on basement faults. A 200 cm long, 40 cm wide, 25 cm high sandbox was used in a strike-slip fault model test. Computerized X-ray tomography applied to the sandbox experiments made it possible to analyze the kinematic evaluation, as well as the three-dimensional geometry, of the faults. The deformation of the sand pack surface was analyzed by use of a laser method 3D scanner, which is a three-dimensional noncontact surface profiling instrument. A comparison of the experimental results with natural cases of active faults reveals the following: In the left-lateral strike-slip fault experiments, the deformation of the sand pack with increasing basement displacement is observed as follows. 1) In three dimensions, the right-stepping shears that have a cirque'/'shell'/'shipbody' shape develop on both sides of the basement fault. The shears on one side of the basement fault join those on the other side, resulting in helicoidal shaped shear surfaces. Shears reach the surface of the sand near or above the basement fault and en echelon Riedel shears are observed at the surface of the sand. The region between two Riedels is always an up-squeezed block. 2) lower-angle shears generally branch off from the first Riedel shears. 3) Pressure ridges develop within the zone defined by the right-stepping helicoidal shaped lower-angle shears. 4) Grabens develop between the pressure ridges. 5) Y-shears offset the pressure ridges. 6) With displacement concentrated on the central throughgoing fault zone, a liner trough developed directly above the basement fault. R1 shear and P foliation are observed in the liner trough. Such evolution of the shears and its associated structures in the fault model tests agrees well with that of strike-slip fault systems and its associated geomorphic structures. (author)

  17. The Golgi-Localized γ-Ear-Containing ARF-Binding (GGA Proteins Alter Amyloid-β Precursor Protein (APP Processing through Interaction of Their GAE Domain with the Beta-Site APP Cleaving Enzyme 1 (BACE1.

    Directory of Open Access Journals (Sweden)

    Bjoern von Einem

    Full Text Available Proteolytic processing of amyloid-β precursor protein (APP by beta-site APP cleaving enzyme 1 (BACE1 is the initial step in the production of amyloid beta (Aβ, which accumulates in senile plaques in Alzheimer's disease (AD. Essential for this cleavage is the transport and sorting of both proteins through endosomal/Golgi compartments. Golgi-localized γ-ear-containing ARF-binding (GGA proteins have striking cargo-sorting functions in these pathways. Recently, GGA1 and GGA3 were shown to interact with BACE1, to be expressed in neurons, and to be decreased in AD brain, whereas little is known about GGA2. Since GGA1 impacts Aβ generation by confining APP to the Golgi and perinuclear compartments, we tested whether all GGAs modulate BACE1 and APP transport and processing. We observed decreased levels of secreted APP alpha (sAPPα, sAPPβ, and Aβ upon GGA overexpression, which could be reverted by knockdown. GGA-BACE1 co-immunoprecipitation was impaired upon GGA-GAE but not VHS domain deletion. Autoinhibition of the GGA1-VHS domain was irrelevant for BACE1 interaction. Our data suggest that all three GGAs affect APP processing via the GGA-GAE domain.

  18. Evaluation of Terrestrial LIDAR for Monitoring Geomorphic Change at Archeological Sites in Grand Canyon National Park, Arizona

    Science.gov (United States)

    Collins, Brian D.; Brown, Kristin M.; Fairley, Helen C.

    2008-01-01

    element of study were to 1. test the methodology and survey protocols of terrestrial LIDAR surveying under actual archeological site field conditions, 2. examine the ability to collect topographic data of entire archeological sites given such constraints as vegetation and rough topography, and 3. evaluate the ability of terrestrial LIDAR to accurately map the locations of key geomorphic features already being collected by total station methods such as gully thalweg and knickpoint locations. This report focuses on the ability of terrestrial LIDAR to duplicate total station methods, including typical erosion-related change features such as the plan view gully thalweg location and the gully thalweg long profile. The report also presents information concerning the use of terrestrial LIDAR for archeological site monitoring in a general sense. In addition, a detailed comparison of the site impacts caused by both total station and terrestrial LIDAR survey methods is presented using a suite of indicators, including total field survey time, field footstep count, and data-processing time. A thorough discussion of the relative benefits and limitations of using terrestrial LIDAR for monitoring erosion-induced changes at archeological sites in Grand Canyon National Park concludes this report.

  19. Three-Dimensional Growth of Flexural Slip Fault-Bend and Fault-Propagation Folds and Their Geomorphic Expression

    Directory of Open Access Journals (Sweden)

    Asdrúbal Bernal

    2018-03-01

    Full Text Available The three-dimensional growth of fault-related folds is known to be an important process during the development of compressive mountain belts. However, comparatively little is known concerning the manner in which fold growth is expressed in topographic relief and local drainage networks. Here we report results from a coupled kinematic and surface process model of fault-related folding. We consider flexural slip fault-bend and fault-propagation folds that grow in both the transport and strike directions, linked to a surface process model that includes bedrock channel development and hillslope diffusion. We investigate various modes of fold growth under identical surface process conditions and critically analyse their geomorphic expression. Fold growth results in the development of steep forelimbs and gentler, wider backlimbs resulting in asymmetric drainage basin development (smaller basins on forelimbs, larger basins on backlimbs. However, topographies developed above fault-propagation folds are more symmetric than those developed above fault-bend folds as a result of their different forelimb kinematics. In addition, the surface expression of fault-bend and fault-propagation folds depends both on the slip distribution along the fault and on the style of fold growth. When along-strike plunge is a result of slip events with gently decreasing slip towards the fault tips (with or without lateral propagation, large plunge-panel drainage networks are developed at the expense of backpanel (transport-opposing and forepanel (transport-facing drainage basins. In contrast, if the fold grows as a result of slip events with similar displacements along strike, plunge-panel drainage networks are poorly developed (or are transient features of early fold growth and restricted to lateral fold terminations, particularly when the number of propagation events is small. The absence of large-scale plunge-panel drainage networks in natural examples suggests that the

  20. Locality and nonlocality in geomorphic transport laws: Implications of a particle-based model of hillslope evolution

    Science.gov (United States)

    Tucker, G. E.; Bradley, D. N.

    2008-12-01

    Many geomorphic transport laws assume that the transport process is local, meaning that the space and time scales of particle displacement are short relative to those of the system as a whole. This assumption allows one to express sediment flux in terms of at-a-point properties such as the local surface gradient. However, while this assumption is quite reasonable for some processes (for example, grain displacement by raindrop impact), it is questionable for others (such as landsliding). Moreover, particle displacement distance may also depend on slope angle, becoming longer as gradient increases. For example, the average motion distance during sediment ravel events on very steep slopes may approach the length of the entire hillslope. In such cases, the mass flux through a given point may depend not only on the local topography but also on topography some distance upslope, thus violating the locality assumption. Here we use a stochastic, particle- based model of hillslope evolution to gain insight into the potential for, and consequences of, nonlocality in sediment transport. The model is designed as a simple analogy for a host of different processes that displace sediment grains on hillslopes. The hillslope is represented as a two-dimensional pile of particles. These particles undergo quasi-random motion according to the following rules: (1) during each iteration, a particle and a direction are selected at random; (2) the particle hops in the direction of motion with a probability that depends on the its height relative to that of its immediate neighbor; (3) the particle continues making hops in the same direction and with the same probability dependence, until coming to rest or exiting the base of the slope. The topography and motion statistics that emerge from these rules show a range of behavior that depends on a dimensionless relief parameter. At low relief, hillslope shape is parabolic, mean displacement length is on the order of two particle widths, and the

  1. Domain wall motion and magnetization reversal processes in a FeSi picture frame single crystal studied by the time-dependent neutron depolarization technique

    International Nuclear Information System (INIS)

    Schaik, F.J. van.

    1979-01-01

    The three dimensional neutron depolarization technique, which gives detailed information about the static properties of ferromagnetic materials, has been extended to a method by means of which the time dependence of magnetic phenomena can be studied. The measurement of the neutron depolarization against time is made possible by applying a periodical magnetic field on the investigated specimen and by continuous sampling of the transmitted neutron intensity in time channels, which are started synchronously with the applied field. The technique has been used in the study of the magnetic domain structure at room temperature of a (010) [001] picture frame FeSi single crystal (3.5 wt.% Si) with outer dimensions of (15 x 10 x 0.26) mm and a frame width of 2.78 mm. (Auth.)

  2. The p2 domain of human immunodeficiency virus type 1 Gag regulates sequential proteolytic processing and is required to produce fully infectious virions.

    OpenAIRE

    Pettit, S C; Moody, M D; Wehbie, R S; Kaplan, A H; Nantermet, P V; Klein, C A; Swanstrom, R

    1994-01-01

    The proteolytic processing sites of the human immunodeficiency virus type 1 (HIV-1) Gag precursor are cleaved in a sequential manner by the viral protease. We investigated the factors that regulate sequential processing. When full-length Gag protein was digested with recombinant HIV-1 protease in vitro, four of the five major processing sites in Gag were cleaved at rates that differ by as much as 400-fold. Three of these four processing sites were cleaved independently of the others. The CA/p...

  3. Spatial Analysis of Large Woody Debris Arrangement in a Midwestern U.S. River System: Geomorphic Implications and Influences

    Science.gov (United States)

    Martin, D. J.

    2013-12-01

    patterns and geomorphic and riparian variables. Understanding these spatial patterns and relationships will provide valuable insight into the application of LWD-related stream and watershed management practices, and fill a necessary regional knowledge gap in our understanding of LWD's role in fluvial processes.

  4. Automated identification of stream-channel geomorphic features from high‑resolution digital elevation models in West Tennessee watersheds

    Science.gov (United States)

    Cartwright, Jennifer M.; Diehl, Timothy H.

    2017-01-17

    High-resolution digital elevation models (DEMs) derived from light detection and ranging (lidar) enable investigations of stream-channel geomorphology with much greater precision than previously possible. The U.S. Geological Survey has developed the DEM Geomorphology Toolbox, containing seven tools to automate the identification of sites of geomorphic instability that may represent sediment sources and sinks in stream-channel networks. These tools can be used to modify input DEMs on the basis of known locations of stormwater infrastructure, derive flow networks at user-specified resolutions, and identify possible sites of geomorphic instability including steep banks, abrupt changes in channel slope, or areas of rough terrain. Field verification of tool outputs identified several tool limitations but also demonstrated their overall usefulness in highlighting likely sediment sources and sinks within channel networks. In particular, spatial clusters of outputs from multiple tools can be used to prioritize field efforts to assess and restore eroding stream reaches.

  5. Charge-Domain Signal Processing of Direct RF SamplingMixer with Discrete-Time Filters in Bluetooth and GSM Receivers

    NARCIS (Netherlands)

    Ho, Y.C.; Staszewski, R.B.; Muhammad, K.; Hung, C.M.; Leipold, D.; Maggio, K.

    2006-01-01

    RF circuits for multi-GHz frequencies have recently migrated to low-cost digital deep-submicron CMOS processes. Unfortunately, this process environment, which is optimized only for digital logic and SRAM memory, is extremely unfriendly for conventional analog and RF designs. We present fundamental

  6. Geomorphic assessment of uranium mill tailings disposal sites. Summary report of the workshop by the panel of geomorphologists

    International Nuclear Information System (INIS)

    Schumm, S.A.; Costa, J.E.; Toy, T.; Knox, J.; Warner, R.; Scott, J.

    1982-01-01

    The following report of the panel of geomorphologists is a summary of the principal findings of the geomorphological Workshop with respect to its three objectives: 1) examination of geomorphic controls on site stability, 2) demonstration of the application of the principles of geomorphology to the siting (and design) of stable tailings disposal containment systems, 3) development (in outline) of a procedure for the evaluation of long-term stability of tailing disposal sites

  7. Geomorphic factors in the rehabilitation of earthen mine structures (with reference to uranium mining in the Northern Territory)

    International Nuclear Information System (INIS)

    Cull, R.F.; East, T.J.

    1987-01-01

    Geomorphic research forms part of the Institute's brief of researching the effects of uranium mining on the environment of the Alligator Rivers Region of which Kakadu National Park is a part. A major research focus is the containment of uranium mill tailings and non uraniferous solid wastes within the confines of mine areas. Government guidelines specify that the objective in the engineering of a tailings management structure should be to attain a design life of at least 200 years and a structural life of a substantially longer period - perhaps a 1000 years. It is this need to incorporate a 1000-year time frame which necessitates the inclusion of geomorphic factors into the design of rehabilitated structures. The study being undertaken treats steep natural hillslopes in the region as analogues of rehabilitated slopes. The aim of the study is to investigate the properties of steep (stable) natural hillslopes in order to determine what characteristics impart their inherent stability against both mass movement and erosion. It is proposed then to incorporate these characteristics in the design of rehabilitated structures. Whilst this research is directed primarily at the rehabilitation of earthen structures at mines in the Alligator Rivers Region, geomorphic principles should also be applicable in rehabilitation of waste rock and overburden stockpiles, tailings dams and other earthen mine structures in a variety of environments

  8. Phylogeny of the TRAF/MATH domain.

    Science.gov (United States)

    Zapata, Juan M; Martínez-García, Vanesa; Lefebvre, Sophie

    2007-01-01

    The TNF-receptor associated factor (TRAF) domain (TD), also known as the meprin and TRAF-C homology (MATH) domain is a fold of seven anti-parallel p-helices that participates in protein-protein interactions. This fold is broadly represented among eukaryotes, where it is found associated with a discrete set of protein-domains. Virtually all protein families encompassing a TRAF/MATH domain seem to be involved in the regulation of protein processing and ubiquitination, strongly suggesting a parallel evolution of the TRAF/MATH domain and certain proteolysis pathways in eukaryotes. The restricted number of living organisms for which we have information of their genetic and protein make-up limits the scope and analysis of the MATH domain in evolution. However, the available information allows us to get a glimpse on the origins, distribution and evolution of the TRAF/MATH domain, which will be overviewed in this chapter.

  9. Ferroelectric domain continuity over grain boundaries

    DEFF Research Database (Denmark)

    Mantri, Sukriti; Oddershede, Jette; Damjanovic, Dragan

    2017-01-01

    Formation and mobility of domain walls in ferroelectric materials is responsible for many of their electrical and mechanical properties. Domain wall continuity across grain boundaries has been observed since the 1950's and is speculated to affect the grain boundary-domain interactions, thereby...... impacting macroscopic ferroelectric properties in polycrystalline systems. However detailed studies of such correlated domain structures across grain boundaries are limited. In this work, we have developed the mathematical requirements for domain wall plane matching at grain boundaries of any given...... orientation. We have also incorporated the effect of grain boundary ferroelectric polarization charge created when any two domains meet at the grain boundary plane. The probability of domain wall continuity for three specific grain misorientations is studied. Use of this knowledge to optimize processing...

  10. Geomorphic investigation of the Late-Quaternary landforms in the southern Zanskar Valley, NW Himalaya

    Science.gov (United States)

    Sharma, Shubhra; Hussain, Aadil; Mishra, Amit K.; Lone, Aasif; Solanki, Tarun; Khan, Mohammad Khatib

    2018-02-01

    The Suru, Doda and Zanskar river valleys in the semi-arid region of Southern Zanskar Ranges (SZR) preserve a rich repository of the glacial and fluvial landforms, alluvial fans, and lacustrine deposits. Based on detailed field observations, geomorphic mapping and limited optical ages, we suggest four glaciations of decreasing magnitude in the SZR. The oldest Southern Zanskar Glaciation Stage (SZS-4) is inferred from glacially polished bedrock and tillite pinnacles. The SZS-4 is ascribed to the Marine Isotopic Stage (MIS)-4/3. The subsequent SZS-3 is represented by obliterated and dissected moraines, and is assigned to MIS-2/Last Glacial Maximum. The multiple recessional moraines of SZS-2 glaciation are assigned the early to mid Holocene age whereas, the youngest SZS-1 moraines were deposited during the Little Ice Age. We suggest that during the SZS-2 glaciation, the Drang-Drung glacier shifted its course from Suru Valley (west) to the Doda Valley (east). The study area has preserved three generations of outwash gravel terraces, which broadly correlate with the phases of deglaciation associated with SZS-3, 2, and 1. The alluvial fan aggradation, lacustrine sedimentation, and loess deposition occurred during the mid-to-late Holocene. We suggest that glaciation was driven by a combination of the mid-latitude westerlies and the Indian Summer Monsoon during periods of cooler temperature, while phases of deglaciation occurred during enhanced temperature.

  11. Appraisal of active tectonics in Hindu Kush: Insights from DEM derived geomorphic indices and drainage analysis

    Directory of Open Access Journals (Sweden)

    Syed Amer Mahmood

    2012-07-01

    The results obtained from these indices were combined to yield an index of relative active tectonics (IRAT using GIS. The average of the seven measured geomorphic indices was used to evaluate the distribution of relative tectonic activity in the study area. We defined four classes to define the degree of relative tectonic activity: class 1__very high (1.0 ≤ IRAT < 1.3; class 2__high (1.3 ≥ IRAT < 1.5; class 3—moderate (1.5 ≥ IRAT < 1.8; and class 4—low (1.8 ≥ IRAT. In view of the results, we conclude that this combined approach allows the identification of the highly deformed areas related to active tectonics. Landsat imagery and field observations also evidence the presence of active tectonics based on the deflected streams, deformed landforms, active mountain fronts and triangular facets. The indicative values of IRAT are consistent with the areas of known relative uplift rates, landforms and geology.

  12. Modeling post-fire hydro-geomorphic recovery in the Waldo Canyon Fire

    Science.gov (United States)

    Kinoshita, Alicia; Nourbakhshbeidokhti, Samira; Chin, Anne

    2016-04-01

    Wildfire can have significant impacts on watershed hydrology and geomorphology by changing soil properties and removing vegetation, often increasing runoff and soil erosion and deposition, debris flows, and flooding. Watershed systems may take several years or longer to recover. During this time, post-fire channel changes have the potential to alter hydraulics that influence characteristics such as time of concentration and increase time to peak flow, flow capacity, and velocity. Using the case of the 2012 Waldo Canyon Fire in Colorado (USA), this research will leverage field-based surveys and terrestrial Light Detection and Ranging (LiDAR) data to parameterize KINEROS2 (KINematic runoff and EROSion), an event oriented, physically-based watershed runoff and erosion model. We will use the Automated Geospatial Watershed Assessment (AGWA) tool, which is a GIS-based hydrologic modeling tool that uses commonly available GIS data layers to parameterize, execute, and spatially visualize runoff and sediment yield for watersheds impacted by the Waldo Canyon Fire. Specifically, two models are developed, an unburned (Bear Creek) and burned (Williams) watershed. The models will simulate burn severity and treatment conditions. Field data will be used to validate the burned watersheds for pre- and post-fire changes in infiltration, runoff, peak flow, sediment yield, and sediment discharge. Spatial modeling will provide insight into post-fire patterns for varying treatment, burn severity, and climate scenarios. Results will also provide post-fire managers with improved hydro-geomorphic modeling and prediction tools for water resources management and mitigation efforts.

  13. Conceptual frameworks, geomorphic interpretation and storytelling: Tales from Lockyer Creek , Australia.

    Science.gov (United States)

    Croke, Jacky; Phillips, Jonathan; Van Dyke, Chris

    2017-04-01

    Earth science knowledge and insight begins with case studies, and theories should be derived from and ultimately evaluated against empirical, case study evidence. However, isolated case studies not linked conceptually to other locations or embedded within a broader framework are often of limited use beyond the study site. Geomorphic evidence and phenomena may be interpreted using a variety of conceptual frameworks (theories, models, laws, methodologies, etc.). The evidence may be, or at least appear to be, consistent with multiple frameworks, even when those constructs are derived from entirely different assumptions or frames of reference. Thus different interpretations and stories can be derived from the same evidence. Our purpose here is to illustrate this phenomenon via a case study from Lockyer Creek, southeast Queensland, Australia. Lockyer Creek is fast becoming one of Australia's most studied catchments with a wealth of data emerging following two extreme flood events in 2011 and 2013. Whilst the initial objective of the Big Flood project was to provide information on the frequency and magnitude of these extreme events, in essence the project revealed a rich 'story' of river evolution and adjustment which at first glance did not appear to 'fit' many established conceptual frameworks and theories. This presentation tells the tale of Lockyer Creek as it relates to selected key conceptual frameworks and importantly how this information can then be used for more effective catchment and flood management.

  14. Geomorphic effects and sedimentological record of flash floods in the Copiapó River salt marsh (Atacama coast, Northern Chile)

    Science.gov (United States)

    Abad, Manuel; Fernández, Rolando; Izquierdo, Tatiana

    2017-04-01

    The Copiapó River is located South of the Atacama Desert (northern Chile) that is considered one of the most arid areas of the planet. On March 25 2015 this fluvial valley experienced one the largest hydrometeorological events recorded in historical times. The rain, unusually high, favored the run off in fluvial channels and alluvial fans that were dry for decades and triggered the rise and overflow of the Copiapó River at different points along the valley causing severe damages. In this work, we realize a characterization of the geomorphic configuration of the Copiapó River before and after this event with the aim of analyzing the main changes produced in the river mouth, where and extent coastal wetland of high ecological value is developed. The geomorphological mapping show a drastic change in the river mouth with the development of forms related with the river overflow and the flooding of the coastal plain such as levees, activation of abandoned channels, flooding lagoons, widening and deepening of the main channel, foredune rupture and, more importantly, a large mud sheet that covers almost the 80% of the study area, including the wetland and the main coastal dune systems. Just a small area of the wetland, far from the main channel, was not affected by this process as it was protected by the levees formed during the first stages of the overflow. The mud flow facies are homogeneous and consist of a layer of massive silty sands with a maximum thickness of 10-75 cm overlied by 5-20 cm of clay with wavy top and carbonaceous rest. It also presents a wide development of mud cracks and salt crusts. At the same time, 4 stages have been differentiated along the event: 1) arrival to the wetland of the first surge that flows in the channel and flooding of the southern sector of the wetland; 2) flooding of the complete mouth area because of the peak discharge arrival and generalize overflow with and associate muddy facies deposition; 3) erosional stage of the channel

  15. Geomorphic and geochemical controls on leaf wax biomarker transport and preservation in alluvial river systems: Rio Bermejo, Argentina

    Science.gov (United States)

    Repasch, M. N.; Sachse, D.; Hovius, N.; Scheingross, J. S.; Szupiany, R. N.

    2017-12-01

    Rivers are the primary conduits for organic carbon (OC) transfer from vegetation-rich uplands to long-term sinks, and thus are responsible for significant fluxes among different reservoirs of the carbon cycle. Fluxes of terrestrial OC out of river systems are generally less than fluxes into the systems, indicating loss of OC either during active fluvial transport, during residence in the active channel belt, or in older deposits outside of the active channel belt. Sedimentary biomarkers can be used to elucidate the mechanisms of transport, preservation, and/or transformation of OC during its passage from source to sink. In this study we evaluate the influence of fluvial sediment transport on preservation of terrestrial leaf wax n-alkanes. Our natural laboratory is the Rio Bermejo in northern Argentina, which transports sediment and organic matter from the central Andes over 700 km across the foreland basin without input of foreign material from tributaries. Rapid channel migration rates in a region of flexural foreland basin uplift (the forebulge) are responsible for remobilization of floodplain sediment and terrestrial OC. By sampling suspended sediment, river bank sediment, and soil from several locations along the length of the Rio Bermejo, and analyzing the dissolved chemistry, biomarker composition, and compound-specific stable isotopes, we can evaluate the geomorphic and geochemical processes that act to influence the preservation of terrestrial biomarkers through the river system. Data suggest that concentrations of long-chain terrestrial (C25-C33) alkanes decrease downstream, while concentrations of short-chain (C15-C19) alkanes increase. This trend is corroborated by a downstream increase in suspended sediment δ13C values, suggesting a replacement of terrestrial OC by microbial OC. It is likely that microbial degradation is responsible for loss of terrestrial biomarkers as their residence time in the river system increases. Controlled laboratory

  16. Post-wildfire natural restoration of riparian vegetation under stable hydro-geomorphic conditions: Nahal Grar, Northern Negev Desert, Israel

    Science.gov (United States)

    Egozi, Roey

    2015-04-01

    Wildfires are common to the Mediterranean region due to its defined dry season and long historical anthropogenic activities. Most of post-wildfire studies focus on mountains areas and thus refer to the hill-slope and its physical characteristics, e.g. morphology, length, angles, and aspect; its soil characteristics, e.g. type, infiltration rate, repellency; and its vegetative covers, e.g. planted trees vs. natural forest or native vs. exotic vegetation. In contrary there is very limited literature focusing on ecological and hydro-geomorphic aspects of post-wildfire of riparian vegetation / zone probably because of its negligible burned area relative to the spread of the fire, sometimes, over the whole watershed area. The limited literature on the topic is surprising given the fact that riparian vegetation zone has been acknowledged as a unique and important habitat supporting rich biodiversity. Herein we report on a wildfire event occurred on October 14th 2009 in a river section of Nahal Grar, Northern Negev Desert, Israel. The wildfire although was limited in its area (only 3 hectare) extended over the channel alone from bank to bank and thus provide a unique case study of completely burn down of riparian vegetation, mainly dense stands of Common Red (Australis Phragmites. Therefore a detailed study of this event provides an opportunity to tackle one of the basics questions which is determining the rate of natural restoration process that act at the immediate time after the wildfire event occurred. This type of information is most valuable to professional and stakeholders for better management of post-fire riparian zones. The results of the study suggest that under stable conditions, i.e. no major flood events occurred; disturbance time was short and ranged over 200 days due to, almost, immediate recovery of the riparian vegetation. However the re-growth of the riparian vegetation was not even but rather deferential and more complex then reported in the literature

  17. The Reaches Project : Ecological and Geomorphic Dtudies Supporting Normative Flows in the Yakima River Basin, Washington, Final Report 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Stanford, Jack A.; Lorang, Mark N.; Matson, Phillip L. (University of Montana, Flathead Lake Biological Station, Poison, MT)

    2002-10-01

    stem and ocean bottlenecks are not overriding, restoration of floodplain connectivity by elevating base flows throughout the corridor, removing revetments and refilling gravel pits by natural riverine transport of gravel where possible could be successful in substantially enhancing Yakima salmon and steelhead runs. Hence, the overarching purpose of this research was to determine the ecology of major floodplain reaches of the Yakima River: Cle Elum, Kittitas, Naches, Union Gap and Wapato. Specifically, the study documented groundwater-channel connectivity and flow relations; use and quality of side channel and other floodplain habitats by salmonid fishes; and classification and analysis of floodplain habitat using remote sensing and documentation of geomorphic processes, required for a robust understanding of the feasibility of revetment removal and establishment of a normative flow regime for the mainstem river.

  18. A geomorphic and tectonic model for the formation of the flight of Holocene marine terraces at Mahia Peninsula, New Zealand

    Science.gov (United States)

    Berryman, Kelvin; Clark, Kate; Cochran, Ursula; Beu, Alan; Irwin, Sarah

    2018-04-01

    At Table Cape, Mahia Peninsula, North Island, New Zealand, four marine terraces have been uplifted coseismically during the past 3500 years. Detailed facies assessment of the terrace coverbed sequence coupled with identification of modern analogues on the active shore platform were used to infer the process of marine terrace formation and to estimate the timing and amount of past uplift events (earthquakes). The modern platform can be subdivided into seven depositional zones: subtidal, outer platform, intertidal sand pockets, inner platform, high-tide, mid-storm, and storm beach. Terrace coverbeds were characterised from two trenches excavated across the full width of the uplifted terrace sequence. Off-lapping packages of high tidal, mid-storm, and storm beach sediments were most common. Outer platform sediments occurred only rarely near the base of some uplifted shore platforms. Overlying the marine sediments were near-horizontal terrestrial deposits of airfall tephra (on the two highest terraces), subsoil, topsoil, rare wedges of colluvial sediment (slopewash) shed from terrace risers, and an anomalous deposit possibly emplaced by a tsunami. Fifty-one radiocarbon ages, obtained from molluscs in the marine coverbeds, showed a general pattern of seaward-younging across the coastal plain and across each terrace and a less pronounced pattern of decreasing age upward in each coverbed sequence. The distinctive stepped geomorphology of the terraces, the facies and age structure of the terrace deposits and historical earthquake causation of similar terraces elsewhere in New Zealand provided the data to invoke an earthquake-driven model for terrace formation. Marine terrace development following an uplift event involved rapid cutting of a new intertidal shore platform and generally regressive deposition of high-tide to storm beach deposits. Following further uplift, the platform became a geomorphic terrace (above marine influence) and was then mantled by terrestrial

  19. Fault slip and earthquake recurrence along strike-slip faults — Contributions of high-resolution geomorphic data

    KAUST Repository

    Zielke, Olaf

    2015-01-01

    Understanding earthquake (EQ) recurrence relies on information about the timing and size of past EQ ruptures along a given fault. Knowledge of a fault\\'s rupture history provides valuable information on its potential future behavior, enabling seismic hazard estimates and loss mitigation. Stratigraphic and geomorphic evidence of faulting is used to constrain the recurrence of surface rupturing EQs. Analysis of the latter data sets culminated during the mid-1980s in the formulation of now classical EQ recurrence models, now routinely used to assess seismic hazard. Within the last decade, Light Detection and Ranging (lidar) surveying technology and other high-resolution data sets became increasingly available to tectono-geomorphic studies, promising to contribute to better-informed models of EQ recurrence and slip-accumulation patterns. After reviewing motivation and background, we outline requirements to successfully reconstruct a fault\\'s offset accumulation pattern from geomorphic evidence. We address sources of uncertainty affecting offset measurement and advocate approaches to minimize them. A number of recent studies focus on single-EQ slip distributions and along-fault slip accumulation patterns. We put them in context with paleoseismic studies along the respective faults by comparing coefficients of variation CV for EQ inter-event time and slip-per-event and find that a) single-event offsets vary over a wide range of length-scales and the sources for offset variability differ with length-scale, b) at fault-segment length-scales, single-event offsets are essentially constant, c) along-fault offset accumulation as resolved in the geomorphic record is dominated by essentially same-size, large offset increments, and d) there is generally no one-to-one correlation between the offset accumulation pattern constrained in the geomorphic record and EQ occurrence as identified in the stratigraphic record, revealing the higher resolution and preservation potential of

  20. Individual differences in the perception of melodic contours and pitch-accent timing in speech: Support for domain-generality of pitch processing.

    Science.gov (United States)

    Morrill, Tuuli H; McAuley, J Devin; Dilley, Laura C; Hambrick, David Z

    2015-08-01

    Do the same mechanisms underlie processing of music and language? Recent investigations of this question have yielded inconsistent results. Likely factors contributing to discrepant findings are use of small samples and failure to control for individual differences in cognitive ability. We investigated the relationship between music and speech prosody processing, while controlling for cognitive ability. Participants (n = 179) completed a battery of cognitive ability tests, the Montreal Battery of Evaluation of Amusia (MBEA) to assess music perception, and a prosody test of pitch peak timing discrimination (early, as in insight vs. late, incite). Structural equation modeling revealed that only music perception was a significant predictor of prosody test performance. Music perception accounted for 34.5% of variance on prosody test performance; cognitive abilities and music training added only about 8%. These results indicate musical pitch and temporal processing are highly predictive of pitch discrimination in speech processing, even after controlling for other possible predictors of this aspect of language processing. (c) 2015 APA, all rights reserved).

  1. Processing, fusogenicity, virion incorporation and CXCR4-binding activity of a feline immunodeficiency virus envelope glycoprotein lacking the two conserved N-glycosylation sites at the C-terminus of the V3 domain.

    Science.gov (United States)

    González, Silvia A; Affranchino, José L

    2016-07-01

    The process of feline immunodeficiency virus (FIV) entry into its target cells is initiated by the association of the surface (SU) subunit of the viral envelope glycoprotein (Env) with the cellular receptors CD134 and CXCR4. This event is followed by the fusion of the viral and cellular membranes, which is mediated by the transmembrane (TM) subunit of Env. We and others have previously demonstrated that the V3 domain of the SU subunit of Env is essential for CXCR4 binding. Of note, there are two contiguous and highly conserved potential N-glycosylation sites ((418)NST(420) and (422)NLT(424)) located at the C-terminal side of the V3 domain. We therefore decided to study the relevance for Env functions of these N-glycosylation motifs and found that disruption of both of them by introducing the N418Q/N422Q double amino acid substitution drastically impairs Env processing into the SU and TM subunits. Moreover, the simultaneous mutation of these N-glycosylation sites prevents Env incorporation into virions and Env-mediated cell-to-cell fusion. Notably, a recombinant soluble version of the SU glycoprotein carrying the double amino acid replacement N418Q/N422Q at the V3 C-terminal side binds to CXCR4 with an efficiency similar to that of wild-type SU.

  2. Domain-Specific Control of Selective Attention

    Science.gov (United States)

    Lin, Szu-Hung; Yeh, Yei-Yu

    2014-01-01

    Previous research has shown that loading information on working memory affects selective attention. However, whether the load effect on selective attention is domain-general or domain-specific remains unresolved. The domain-general effect refers to the findings that load in one content (e.g. phonological) domain in working memory influences processing in another content (e.g., visuospatial) domain. Attentional control supervises selection regardless of information domain. The domain-specific effect refers to the constraint of influence only when maintenance and processing operate in the same domain. Selective attention operates in a specific content domain. This study is designed to resolve this controversy. Across three experiments, we manipulated the type of representation maintained in working memory and the type of representation upon which the participants must exert control to resolve conflict and select a target into the focus of attention. In Experiments 1a and 1b, participants maintained digits and nonverbalized objects, respectively, in working memory while selecting a target in a letter array. In Experiment 2, we presented auditory digits with a letter flanker task to exclude the involvement of resource competition within the same input modality. In Experiments 3a and 3b, we replaced the letter flanker task with an object flanker task while manipulating the memory load on object and digit representation, respectively. The results consistently showed that memory load modulated distractibility only when the stimuli of the two tasks were represented in the same domain. The magnitude of distractor interference was larger under high load than under low load, reflecting a lower efficacy of information prioritization. When the stimuli of the two tasks were represented in different domains, memory load did not modulate distractibility. Control of processing priority in selective attention demands domain-specific resources. PMID:24866977

  3. Frequency Domain Image Filtering Using CUDA

    Directory of Open Access Journals (Sweden)

    Muhammad Awais Rajput

    2014-10-01

    Full Text Available In this paper, we investigate the implementation of image filtering in frequency domain using NVIDIA?s CUDA (Compute Unified Device Architecture. In contrast to signal and image filtering in spatial domain which uses convolution operations and hence is more compute-intensive for filters having larger spatial extent, the frequency domain filtering uses FFT (Fast Fourier Transform which is much faster and significantly reduces the computational complexity of the filtering. We implement the frequency domain filtering on CPU and GPU respectively and analyze the speed-up obtained from the CUDA?s parallel processing paradigm. In order to demonstrate the efficiency of frequency domain filtering on CUDA, we implement three frequency domain filters, i.e., Butterworth, low-pass and Gaussian for processing different sizes of images on CPU and GPU respectively and perform the GPU vs. CPU benchmarks. The results presented in this paper show that the frequency domain filtering with CUDA achieves significant speed-up over the CPU processing in frequency domain with the same level of (output image quality on both the processing architectures

  4. Frequency domain image filtering using cuda

    International Nuclear Information System (INIS)

    Rajput, M.A.; Khan, U.A.

    2014-01-01

    In this paper, we investigate the implementation of image filtering in frequency domain using NVIDIA's CUDA (Compute Unified Device Architecture). In contrast to signal and image filtering in spatial domain which uses convolution operations and hence is more compute-intensive for filters having larger spatial extent, the frequency domain filtering uses FFT (Fast Fourier Transform) which is much faster and significantly reduces the computational complexity of the filtering. We implement the frequency domain filtering on CPU and GPU respectively and analyze the speed-up obtained from the CUDA's parallel processing paradigm. In order to demonstrate the efficiency of frequency domain filtering on CUDA, we implement three frequency domain filters, i.e., Butter worth, low-pass and Gaussian for processing different sizes of images on CPU and GPU respectively and perform the GPU vs. CPU benchmarks. The results presented in this paper show that the frequency domain filtering with CUDA achieves significant speed-up over the CPU processing in frequency domain with the same level of (output) image quality on both the processing architectures. (author)

  5. Numerical modeling of the late Cenozoic geomorphic evolution of Grand Canyon, Arizona

    Science.gov (United States)

    Pelletier, J. D.

    2008-12-01

    The late Cenozoic geomorphic evolution of Grand Canyon has been influenced by three primary tectonic and drainage adjustment events. First, incision into the Paleozoic strata of the southwestern margin of the Colorado Plateau began at 16 Ma in response to relief production along the Grand Wash Fault. Second, the ancestral Upper Colorado River reversed drainage and became integrated with the Lower Colorado River basin through Grand Canyon between 5.5 and 6 Ma. Third, the Colorado River was influenced by Plio- Quaternary normal faulting along the Hurricane and Toroweap Faults. Despite the relatively firm constraints available on the timing of these events, the geomorphic evolution of Grand Canyon is still not well constrained and many questions remain. For example, was there a deeply-incised gorge in western Grand Canyon before Colorado River integration? How and where was the Colorado River integrated? How have incision rates varied in space and time? In this paper, I describe the results of a numerical modeling study designed to address these questions. The model integrates the stream power model for bedrock channel erosion with cliff retreat and the flexural-isostatic response to erosion. The model honors the structural geology of the Grand Canyon region, including the variable erodibility of rocks in the Colorado Plateau and the occurrence of Plio-Quaternary normal faulting along the Hurricane-Toroweap Fault system. We present the results of two models designed to bracket the possible drainage architectures of the southwestern margin of the Colorado Plateau in Miocene time. In the first model, we assume a 13,000 km2 drainage basin primarily sourced from the Hualapai and Coconino Plateaux. The results of this model indicate that relief production along the Grand Wash fault initiated the formation of a large (700 m) knickpoint that migrated headward at a rate of 15 km/Myr prior to drainage integration at 6 Ma to form a deep gorge in western Grand Canyon. This model

  6. Geomorphic changes resulting from floods in reconfigured gravel-bed river channels in Colorado, USA

    Science.gov (United States)

    Elliott, J.G.; Capesius, J.P.

    2009-01-01

    Geomorphic changes in reconfi gured reaches of three Colorado rivers in response to floods in 2005 provide a benchmark for "restoration" assessment. Sedimententrainment potential is expressed as the ratio of the shear stress from the 2 yr, 5 yr, 10 yr, and 2005 floods to the critical shear stress for sediment. Some observed response was explained by the excess of flood shear stress relative to the resisting force of the sediment. Bed-load entrainment in the Uncompahgre River and the North Fork Gunnison River, during 4 and 6 yr floods respectively, resulted in streambed scour, streambed deposition, lateral-bar accretion, and channel migration at various locations. Some constructed boulder and log structures failed because of high rates of bank erosion or bed-material deposition. The Lake Fork showed little or no net change after the 2005 flood; however, this channel had not conveyed floods greater than the 2.5 yr flood since reconfi guration. Channel slope and the 2 yr flood, a surrogate for bankfull discharge, from all three reconfi gured reaches plotted above the Leopold and Wolman channel-pattern threshold in the "braided channel" region, indicating that braiding, rather than a single-thread meandering channel, and midchannel bar formation may be the natural tendency of these gravel-bed reaches. When plotted against a total stream-power and median-sediment-size threshold for the 2 yr flood, however, the Lake Fork plotted in the "single-thread channel" region, the North Fork Gunnison plotted in the " multiplethread" region, and the Uncompahgre River plotted on the threshold. All three rivers plotted in the multiple-thread region for floods of 5 yr recurrence or greater. ?? 2009 Geological Society of America.

  7. Channel dynamics and geomorphic resilience in an ephemeral Mediterranean river affected by gravel mining

    Science.gov (United States)

    Calle, Mikel; Alho, Petteri; Benito, Gerardo

    2017-05-01

    Gravel mining has been a widespread activity in ephemeral rivers worldwide whose long-lasting hydrogeomorphological impacts preclude effective implementation of water and environmental policies. This paper presents a GIS-based method for temporal assessment of morphosedimentary changes in relation to in-channel gravel mining in a typical ephemeral Mediterranean stream, namely the Rambla de la Viuda (eastern Spain). The aims of this work were to identify morphosedimentary changes and responses to human activities and floods, quantify river degradations and analyze factors favoring fluvial recovery for further applications in other rivers. Aerial photographs and LiDAR topography data were studied to analyze geomorphic evolution over the past 70 years along a 7.5-km reach of an ephemeral gravel stream that has been mined intensively since the 1970s. To evaluate changes in the riverbed, we mapped comparable units applying morphological, hydraulic, and stability (based on vegetation density and elevation) criteria to 13 sets of aerial photographs taken from 1946 to 2012. A detailed spatiotemporal analysis of comparable units revealed a 50% reduction in the active section and a 20% increase in stable areas, compared to the conditions observed prior to gravel mining. Instream mining was first observed in 1976 aerial photograph covering already up to 50% of the 1956 riverbed area. River degradation since then was quantified by means of a LiDAR DTM and RTK-GPS measurements, which revealed a 3.5-m incision that had started simultaneously with gravel mining. Climate and land use changes were present but the effects were completely masked by changes produced by instream gravel mining. Therefore, river incision/degradation was triggered by scarcity of sediment and lack of longitudinal sedimentary connection, creating an unbalanced river system that is still adjusting to the present hydrosedimentary conditions.

  8. High Resolution Monitoring of River Bluff Erosion Reveals Failure Mechanisms and Geomorphically Effective Flows

    Directory of Open Access Journals (Sweden)

    Sara Ann Kelly

    2018-03-01

    Full Text Available Using a combination of Structure from Motion and time lapse photogrammetry, we document rapid river bluff erosion occurring in the Greater Blue Earth River (GBER basin, a muddy tributary to the sediment-impaired Minnesota River in south central Minnesota. Our datasets elucidated dominant bluff failure mechanisms and rates of bluff retreat in a transient system responding to ongoing streamflow increases and glacial legacy impacts. Specifically, we document the importance of fluvial scour, freeze–thaw, as well as other drivers of bluff erosion. We find that even small flows, a mere 30% of the two-year recurrence interval flow, are capable of causing bluff erosion. During our study period (2014–2017, the most erosion was associated with two large flood events with 13- and 25-year return periods. However, based on the frequency of floods and magnitude of bluff face erosion associated with floods over the last 78 years, the 1.2-year return interval flood has likely accomplished the most cumulative erosion, and is thus more geomorphically effective than larger magnitude floods. Flows in the GBER basin are nonstationary, increasing across the full range of return intervals. We find that management implications differ considerably depending on whether the bluff erosion-runoff power law exponent, γ, is greater than, equal to, or less than 1. Previous research has recommended installation of water retention sites in tributaries to the Minnesota River in order to reduce flows and sediment loading from river bluffs. Our findings support the notion that water retention would be an effective practice to reduce sediment loading and highlight the importance of managing for both runoff frequency and magnitude.

  9. Geomorphic hazards and intense rainfall: the case study of the Recco Stream catchment (Eastern Liguria, Italy

    Directory of Open Access Journals (Sweden)

    F. Faccini

    2012-04-01

    Full Text Available A critical pluviometric event occurred in the central-eastern Ligurian Riviera, 15 km from Genoa, on 1 June 2007. This event caused landslides and hydraulic problems between Sori and Camogli and in the inland area of the Recco Valley.

    An analysis of the heavy rainfall was conducted. Hourly precipitation data revealed a critical event between 04:00 a.m. and 07:00 a.m. local time, with more than 220 mm of precipitation over three hours.

    Slope movements were mainly debris flows that detached from the lateral valleys of the Recco Stream catchment and from well-maintained, wooded slopes that were also characterised by cultivated terraces.

    Numerous slide planes corresponded to the interface between the surface cover and the underlying bedrock, which presents an unfavourable geologic structure in terms of stability assessment.

    In most cases, the displaced material had a limited thickness. Debris cover was rapidly channelled along small valleys, which controlled the critical hydraulic conditions in the secondary drainage network.

    Man-made drainage systems were partially or totally blocked in a very short time and, like the natural watercourses, accumulated thick and extensive alluvial fans.

    Most of the instability phenomena occurred in areas that had been designated medium or low-risk areas during land planning, and in sectors that were defined as stable, because they lacked geomorphic indicators connected to landslide risks.

    The above considerations highlight some gaps of the Recco Stream Master Plan. Therefore, to update this land planning tool, it is necessary to extensively investigate local geomorphological characteristics and to adopt a different method for assigning weights to the geohazard maps.

  10. Geomorphic and sedimentologic evidence for the separation of Lake Superior from Lake Michigan and Huron

    Science.gov (United States)

    Johnston, J.W.; Thompson, T.A.; Wilcox, D.A.; Baedke, S.J.

    2007-01-01

    A common break was recognized in four Lake Superior strandplain sequences using geomorphic and sedimentologic characteristics. Strandplains were divided into lakeward and landward sets of beach ridges using aerial photographs and topographic surveys to identify similar surficial features and core data to identify similar subsurface features. Cross-strandplain, elevation-trend changes from a lowering towards the lake in the landward set of beach ridges to a rise or reduction of slope towards the lake in the lakeward set of beach ridges indicates that the break is associated with an outlet change for Lake Superior. Correlation of this break between study sites and age model results for the strandplain sequences suggest that the outlet change occurred sometime after about 2,400 calendar years ago (after the Algoma phase). Age model results from one site (Grand Traverse Bay) suggest an alternate age closer to about 1,200 calendar years ago but age models need to be investigated further. The landward part of the strandplain was deposited when water levels were common in all three upper Great Lakes basins (Superior, Huron, and Michigan) and drained through the Port Huron/Sarnia outlet. The lakeward part was deposited after the Sault outlet started to help regulate water levels in the Lake Superior basin. The landward beach ridges are commonly better defined and continuous across the embayments, more numerous, larger in relief, wider, have greater vegetation density, and intervening swales contain more standing water and peat than the lakeward set. Changes in drainage patterns, foreshore sediment thickness and grain size help in identifying the break between sets in the strandplain sequences. Investigation of these breaks may help identify possible gaps in the record or missing ridges in strandplain sequences that may not be apparent when viewing age distributions and may justify the need for multiple age and glacial isostatic adjustment models. ?? 2006 Springer Science

  11. Active tectonics of the Rif Mountains (Morocco) from geomorphic and geochronological data

    Science.gov (United States)

    Ritz, Jean-François; Poujol, Antoine; Tahayt, Abdelilah; Vernant, Philippe; Condomines, Michel; Blard, Pierre-Henri; Braucher, Régis; Benedetti, Lucilla; Bourles, Didier; Leroux-Mallouf, Romain; Ferry, Matthieu; Maate, Soufian

    2014-05-01

    We present results of a geomorphological and morphotectonic analysis of the Rif Mountains (Morocco). We show that the present day kinematics of the Rif is characterized by active deformation along normal and left-lateral strike-slip faults in the North-East (Trougout, Rouadi, Boujibar and Nekor faults), reverse fault in the South (the South Rif Front) and inherited fold structures in the West. Digital Elevation Models of offset drainage features (streams, fluvial terraces) allow determining horizontal cumulative displacements of ~25-35m along the Trougout fault and ~40m along the Nekor fault. 14C dating of tectonic markers yields vertical and horizontal slip rates of ~2.8 mm/yr and ~2.3 mm/yr respectively, along the Trougout fault. For the first time, cosmogenic 3He method is used on volcanic rocks to date the successive exposure of the fault plane. Along the Trougout fault, this yields recurrence time between 3,1 and 4,1 ka. The present-day localized transtension seen in the northeastern Rif morphology (Ras Tarf) is coeval with uplifted marine terraces near the Al Hoceima Bay. U/Th dating of shells yields an average uplift rate of ~0.2 mm/yr during the past 500 Ka. These data show that active transtension in the northeastern Rif is also associated with uplift. Comparison with cosmogenic 10Be/3He dating of perched fluvial surface located above these marine terraces is in progress and may allow us to confirm or not this uplift rate. In the western Rif, geomorphic markers allow us to suggest that active deformation is accommodated along blind thrust and NNW-SSE inherited folds. These new morphotectonic constraints are consistent with the GPS measurements showing southwestward overall motion of most of the Rif belt with respect to stable Africa and suggest a continuum of the deformation from the Pliocene.

  12. Hydrologic and Geomorphic Impacts of Glacial Lake Outburst Floods From Low-Order Tributaries

    Science.gov (United States)

    McCoy, S. W.; Jacquet, J.; McGrath, D.; George, D. L.; Koschitzki, R.; Nimick, D.; Fahey, M. J.; Okuinghttons, J.

    2017-12-01

    Lakes dammed by glacial ice or moraines are common features in the headwaters of both glaciated and recently deglaciated catchments. These dams can fail releasing water in a glacial lake outburst flood (GLOF), which raises the question: do GLOFs from low-order tributaries significantly alter the hydrology and sediment transport regimes of the large mainstem rivers to which they drain? Here we use repeat satellite imagery, in situ measurements, and 2D hydrodynamic modeling to quantify the hydrologic and geomorphic changes that resulted from 22 GLOFs that occurred between 2008 and 2016 from Lago Cachet Dos, Patagonia, Chile. We find that the complicated flood path that includes two lakes and a broad floodplain can dampen peak discharges from over 15,000 m³/s at the source lake to generally less than 2,000 m³/s where the floods enter the mainstem Rio Baker, 40 km downstream. Despite this dampening of GLOF peak discharge, peak discharges still exceeded the peak annual discharge of the Rio Baker, the largest river in Chile by volume, by 1 to 2 times, which in turn increased the frequency and magnitude of flood events. We also document the sediment dynamics in the source lake, where we find that over 25,000,000 m³ of stored sediment was removed during the GLOF cycle that began in 2008. Further downstream, repeat satellite imagery reveals that the large discharges associated with GLOFs produced a nonsteady channel configuration in which old stable channels were abandoned, many new channels were formed, and conveyance capacity changed, best illustrated by the 200 m of delta progradation from the GLOF-affected tributary into the Rio Baker that locally narrowed the Rio Baker channel width from 300 m to 60 m. In total, this analysis demonstrates that GLOFs from distant source lakes can have an outsized impact, both in terms of changing flood characteristics as well as sediment transport, even on the largest river systems.

  13. Evaluation of Geomorphic Changes, Using Landsat Data and its Impact on Coastal Community

    Science.gov (United States)

    Mahar, G. A.

    2017-12-01

    temporal study with the help of landsat satellite image has been carried out to assess the degree of the geomorphic degradation of different deltaic features and its consequent impact on the demography and socioeconomics of the people. Interactive correlation of the present analyses of the Indus water-flow in relation to the manmade water divergent structures reveals that the massive water divergence to upstream areas by depleting water availability into the downstream areas have caused severe imbalance in the equilibrium between the fluvial and marine hydrodynamics. The dominance of the marine hydrodynamic conditions have caused irreversible damage to the physical environment due to the rapid landward sea invasion. Based on the results of the present study it has been identified that i) the coastline is rapidly retreating; ii) individual creeks and the creeks' network are enlarging by the erosional phenomenon laterally as well as longitudinally; iii) tidally influenced areas are rapidly expanding; iv) overall area of the deltaic lakes is reducing but the frequency of the lakes occurrences is increasing; v) the course and the thalweg of the Indus river is widening seaward and narrowing landward; vi) populated areas along the coastline have been evacuated due to the massive seawater intrusions; vii) agricultural and fishing activities are tremendously declining and viii) food productivity per acre is decreasing. Moreover, it is also revealed that i) the shelf slope is steeping and retreating faster and ii) geometry of the Indus canyon is also rapidly changing. This phenomenon has affected the socio-economic of the coastal community and from many place force them to move from their native places.

  14. Cross-industry standard process for data mining is applicable to the lung cancer surgery domain, improving decision making as well as knowledge and quality management.

    Science.gov (United States)

    Rivo, Eduardo; de la Fuente, Javier; Rivo, Ángel; García-Fontán, Eva; Cañizares, Miguel-Ángel; Gil, Pedro

    2012-01-01

    The aim of this study was to assess the applicability of knowledge discovery in database methodology, based upon data mining techniques, to the investigation of lung cancer surgery. According to CRISP 1.0 methodology, a data mining (DM) project was developed on a data warehouse containing records for 501 patients operated on for lung cancer with curative intention. The modelling technique was logistic regression. The finally selected model presented the following values: sensitivity 9.68%, specificity 100%, global precision 94.02%, positive predictive value 100% and negative predictive value 93.98% for a cut-off point set at 0.5. A receiver operating characteristic (ROC) curve was constructed. The area under the curve (CI 95%) was 0.817 (0.740- 0.893) (p CRISP-DM process model is very suitable for lung cancer surgery analysis, improving decision making as well as knowledge and quality management.

  15. Relation of urbanization to stream habitat and geomorphic characteristics in nine metropolitan areas of the United States

    Science.gov (United States)

    Fitzpatrick, Faith A.; Peppler, Marie C.

    2010-01-01

    The relation of urbanization to stream habitat and geomorphic characteristics was examined collectively and individually for nine metropolitan areas of the United States?Portland, Oregon; Salt Lake City, Utah; Denver, Colorado; Dallas?Forth Worth, Texas; Milwaukee?Green Bay, Wisconsin; Birmingham, Alabama; Atlanta, Georgia; Raleigh, North Carolina; and Boston, Massachusetts. The study was part of a larger study conducted by the U.S. Geological Survey from 1999 to 2004 to examine the effects of urbanization on the physical, chemical, and biological components of stream ecosystems. The objectives of the current study were to determine how stream habitat and geomorphic characteristics relate to different aspects of urbanization across a variety of diverse environmental settings and spatial scales. A space-for-time rural-to-urban land-cover gradient approach was used. Reach-scale habitat data and geomorphic characteristic data were collected once during low flow and included indicators of potential habitat degradation such as measures of channel geometry and hydraulics, streambed substrate, low-flow reach volume (an estimate of base-flow conditions), habitat complexity, and riparian/bank conditions. Hydrologic metrics included in the analyses were those expected to be altered by increases in impervious surfaces, such as high-flow frequency and duration, flashiness, and low-flow duration. Other natural and human features, such as reach-scale channel engineering, geologic setting, and slope, were quantified to identify their possible confounding influences on habitat relations with watershed-scale urbanization indicators. Habitat and geomorphic characteristics were compared to several watershed-scale indicators of urbanization, natural landscape characteristics, and hydrologic metrics by use of correlation analyses and stepwise linear regression. Habitat and geomorphic characteristics were related to percentages of impervious surfaces only in some metropolitan areas and

  16. The Use of Aerial RGB Imagery and LIDAR in Comparing Ecological Habitats and Geomorphic Features on a Natural versus Man-Made Barrier Island

    Directory of Open Access Journals (Sweden)

    Carlton P. Anderson

    2016-07-01

    Full Text Available The Mississippi (MS barrier island chain along the northern Gulf of Mexico coastline is subject to rapid changes in habitat, geomorphology and elevation by natural and anthropogenic disturbances. The purpose of this study was to compare habitat type coverage with respective elevation, geomorphic features and short-term change between the naturally-formed East Ship Island and the man-made Sand Island. Ground surveys, multi-year remotely-sensed data, habitat classifications and digital elevation models were used to quantify short-term habitat and geomorphic change, as well as to examine the relationships between habitat types and micro-elevation. Habitat types and species composition were the same on both islands with the exception of the algal flat existing on the lower elevated spits of East Ship. Both islands displayed common patterns of vegetation succession and ranges of existence in elevation. Additionally, both islands showed similar geomorphic features, such as fore and back dunes and ponds. Storm impacts had the most profound effects on vegetation and geomorphic features throughout the study period. Although vastly different in age, these two islands show remarkable commonalities among the traits investigated. In comparison to East Ship, Sand Island exhibits key characteristics of a natural barrier island in terms of its vegetated habitats, geomorphic features and response to storm impacts, although it was established anthropogenically only decades ago.

  17. Geomorphic and hydrologic assessment of erosion hazards at the Norman municipal landfill, Canadian River floodplain, Central Oklahoma

    Science.gov (United States)

    Curtis, J.A.; Whitney, J.W.

    2003-01-01

    The Norman, Oklahoma, municipal landfill closed in 1985 after 63 years of operation, because it was identified as a point source of hazardous leachate composed of organic and inorganic compounds. The landfill is located on the floodplain of the Canadian River, a sand-bed river characterized by erodible channel boundaries and by large variation in mean monthly discharges. In 1986, floodwaters eroded riprap protection at the southern end of the landfill and penetrated the landfill's clay cap, thereby exposing the landfill contents. The impact of this moderate-magnitude flood event (Q12) was the catalyst to investigate erosion hazards at the Norman landfill. This geomorphic investigation analyzed floodplain geomorphology and historical channel changes, flood-frequency distributions, an erosion threshold, the geomorphic effectiveness of discharge events, and other factors that influence erosion hazards at the landfill site. The erosion hazard at the Norman landfill is a function of the location of the landfill with respect to the channel thalweg, erosional resistance of the channel margins, magnitude and duration of discrete discharge events, channel form and hydraulic geometry, and cumulative effects related to a series of discharge events. Based on current climatic conditions and historical channel changes, a minimum erosion threshold is set at bankfull discharge (Q = 572 m3/s). The annual probability of exceeding this threshold is 0.53. In addition, this analysis indicates that peak stream power is less informative than total energy expenditures when estimating the erosion potential or geomorphic effectiveness of discrete discharge events. On the Canadian River, long-duration, moderate-magnitude floods can have larger total energy expenditures than shorter-duration, high-magnitude floods and therefore represent the most serious erosion hazard to floodplain structures.

  18. Geomorphic change in Dingzi Bay, East China since the 1950s: impacts of human activity and fluvial input

    Science.gov (United States)

    Tian, Qing; Wang, Qing; Liu, Yalong

    2017-06-01

    This study examines the geomorphic evolution of Dingzi Bay, East China in response to human activity and variations in fluvial input since the 1950s. The analysis is based on data from multiple mathematical methods, along with information obtained from Remote Sensing, Geographic Information System and Global Position System technology. The results show that the annual runoff and sediment load discharged into Dingzi Bay display significant decreasing trends overall, and marked downward steps were observed in 1966 and 1980. Around 60%-80% of the decline is attributed to decreasing precipitation in the Wulong River Basin. The landform types in Dingzi Bay have changed significantly since the 1950s, especially over the period between 1981 and 1995. Large areas of tidal flats, swamp, salt fields, and paddy fields have been reclaimed, and aquaculture ponds have been constructed. Consequently, the patterns of erosion and deposition in the bay have changed substantially. Despite a reduction in sediment input of 65.68% after 1966, low rates of sediment deposition continued in the bay. However, deposition rates changed significantly after 1981 owing to large-scale development in the bay, with a net depositional area approximately 10 times larger than that during 1961-1981. This geomorphic evolution stabilized following the termination of large-scale human activity in the bay after 1995. Overall, Dingzi Bay has shown a tendency towards silting-up during 1952-2010, with the bay head migrating seaward, the number of channels in the tidal creek system decreasing, and the tidal inlet becoming narrower and shorter. In conclusion, largescale development and human activity in Dingzi Bay have controlled the geomorphic evolution of the bay since the 1950s.

  19. GIS Framework for Large River Geomorphic Classification to Aid in the Evaluation of Flow-Ecology Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Vernon, Christopher R.; Arntzen, Evan V.; Richmond, Marshall C.; McManamay, R. A.; Hanrahan, Timothy P.; Rakowski, Cynthia L.

    2013-02-01

    Assessing the environmental benefits of proposed flow modification to large rivers provides invaluable insight into future hydropower project operations and relicensing activities. Providing a means to quantitatively define flow-ecology relationships is integral in establishing flow regimes that are mutually beneficial to power production and ecological needs. To compliment this effort an opportunity to create versatile tools that can be applied to broad geographic areas has been presented. In particular, integration with efforts standardized within the ecological limits of hydrologic alteration (ELOHA) is highly advantageous (Poff et al. 2010). This paper presents a geographic information system (GIS) framework for large river classification that houses a base geomorphic classification that is both flexible and accurate, allowing for full integration with other hydrologic models focused on addressing ELOHA efforts. A case study is also provided that integrates publically available National Hydrography Dataset Plus Version 2 (NHDPlusV2) data, Modular Aquatic Simulation System two-dimensional (MASS2) hydraulic data, and field collected data into the framework to produce a suite of flow-ecology related outputs. The case study objective was to establish areas of optimal juvenile salmonid rearing habitat under varying flow regimes throughout an impounded portion of the lower Snake River, USA (Figure 1) as an indicator to determine sites where the potential exists to create additional shallow water habitat. Additionally, an alternative hydrologic classification useable throughout the contiguous United States which can be coupled with the geomorphic aspect of this framework is also presented. This framework provides the user with the ability to integrate hydrologic and ecologic data into the base geomorphic aspect of this framework within a geographic information system (GIS) to output spatiotemporally variable flow-ecology relationship scenarios.

  20. The hydrological function of upland swamps in eastern Australia: The role of geomorphic condition in regulating water storage and discharge

    Science.gov (United States)

    Cowley, Kirsten L.; Fryirs, Kirstie A.; Hose, Grant C.

    2018-06-01

    Temperate Highland Peat Swamps on Sandstone (THPSS) are a type of wetland found in low-order streams on the plateaus of eastern Australia. They are sediment and organic matter accumulation zones, which combined with a climate of high rainfall and low evaporation function as water storage systems. Changes to the geomorphic structure of these systems via incision and channelisation can have profound impacts on their hydrological function. The aim of this study was to develop an understanding of how changes to the geomorphic structure of these systems alter their hydrological function, measured as changes and variability in swamp water table levels and discharge. We monitored the water table levels and discharges of three intact and three channelised THPSS in the Blue Mountains between March 2015 and June 2016. We found that water levels in intact swamps were largely stable over the monitoring period. Water levels rose only in high rainfall events, returned quickly to antecedent levels after rain, and drawdown during dry periods was not significant. In contrast, the water table levels in channelised THPSS were highly variable. Water levels rose quickly after almost all rainfall events and declined significantly during dry periods. Discharge also showed marked differences with the channelised THPSS discharging 13 times more water than intact swamps, even during dry periods. Channelised THPSS also had flashier storm hydrographs than intact swamps. These results have profound implications for the capacity of these swamps to act as water storage reservoirs in the headwaters of catchments and for their ability to maintain base flow to downstream catchments during dry times. Changes to geomorphic structure and hydrological function also have important implications for a range of other swamp functions such as carbon storage, emission and exports, contaminant sorption, downstream water quality and biodiversity, as well as the overall fate of these swamps under a changing

  1. Supersymmetric domain walls

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Kleinschmidt, Axel; Riccioni, Fabio

    2012-01-01

    We classify the half-supersymmetric "domain walls," i.e., branes of codimension one, in toroidally compactified IIA/IIB string theory and show to which gauged supergravity theory each of these domain walls belong. We use as input the requirement of supersymmetric Wess-Zumino terms, the properties of

  2. Hydrologic, ecologic, and geomorphic responses of Brewery Creek to construction of a residential subdivision, Dane County, Wisconsin, 1999-2002

    Science.gov (United States)

    Selbig, William R.; Jopke, Peter L.; Marhshall, David W.; Sorge, Michael J.

    2004-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Dane County Land Conservation Department (LCD) and the Wisconsin Department of Natural Resources (DNR), investigated the instream effects from construction of a residential subdivision on Brewery Creek in Dane County, Wisconsin. The purpose of the investigation was to determine whether a variety of storm-runoff and erosion-control best-management practices (BMPs) would effectively control the overall sediment load, as well as minimize any hydrologic, ecologic, and geomorphic stresses to Brewery Creek.

  3. Alignment of Outcome Instruments Used in Hand Therapy With the Occupational Therapy Practice Framework: Domain and Process and the International Classification of Functioning, Disability and Health: A Scoping Review.

    Science.gov (United States)

    Lesher, Danielle Ann-Marie; Mulcahey, M J; Hershey, Peter; Stanton, Donna Breger; Tiedgen, Andrea C

    We sought to identify outcome instruments used in rehabilitation of the hand and upper extremity; to determine their alignment with the constructs of the International Classification of Functioning, Disability and Health (ICF) and the Occupational Therapy Practice Framework: Domain and Process; and to report gaps in the constructs measured by outcome instruments as a basis for future research. We searched CINAHL, MEDLINE, OTseeker, and the Cochrane Central Register of Controlled Trials using scoping review methodology and evaluated outcome instruments for concordance with the ICF and the Framework. We identified 18 outcome instruments for analysis. The findings pertain to occupational therapists' focus on body functions, body structures, client factors, and activities of daily living; a gap in practice patterns in use of instruments; and overestimation of the degree to which instruments used are occupationally based. Occupational therapy practitioners should use outcome instruments that embody conceptual frameworks for classifying function and activity. Copyright © 2017 by the American Occupational Therapy Association, Inc.

  4. Environmental vulnerability and agriculture in the karstic domain: landscape indicators and cases in the Atlas Highlands, Morocco.

    Directory of Open Access Journals (Sweden)

    Akdim Brahim

    1999-01-01

    Full Text Available After the brief presentation of the major karstic areas in Morocco, the article focused essentially on the Atlas mountains to investigate the impact of the agriculture on the natural systems equilibrium. Socio-economic changes (demographic pressure, escalation of the landscape use, utilisation of new techniques in water harvesting, etc... have sometimes fathered mechanisms of degradation. Many indicators seem to reflect these mechanisms. The pedologic indicators, soil erosion, the hydrologic and geomorphic indicators, are apprehended to demonstrate existent correlation between different variables and the often negative impacts of land over-use in the karstic domain of the Middle Atlas.

  5. History of pedogenesis and geomorphic processes in the Valley of Teotihuacán, Mexico: Micromorphological evidences from a soil catena Historia de la edafogénesis y de los procesos geomorfológicos en el Valle de Teotihuacán, México: evidencias micromorfológicas de una catena de suelos História da pedogénese e dos processos geomorfológicos no Vale de Teotihuacán, México: evidencias micromorfológicas de uma catena de solos

    Directory of Open Access Journals (Sweden)

    M. Lourdes González-Arqueros

    2013-11-01

    Full Text Available The paper provides new evidence on the pedogeomorphic history of the Valley of Teotihuacán, Mexico. The soil landscape here consists of Luvisol and "black soil", the micromorphology of which allowed us to (a distinguish between in situ and inherited processes and (b establish spatial relationships of erosion and sedimentation along a toposequence of three soil profiles. Soil profiles sites were selected by photointerpretation followed by verification on a toposequence from middle mountain slope to colluvial piedmont. Samples of these profiles were characterized by physical and chemical analyses, including micromorphological observation under a petrographic microscope. The results are summarized as geomorphic observations, description and analysis of soil profiles along a catena, and micromorphological features. The final data set permits recognition and interpretation of both present-day pedofeatures and inherited pedofeatures due to past hillslope processes. In the "black soil", the key processes include development of vertic features, humification and CaCO3 accumulation; while micromorphology revealed fragments of illuvial clay along with disorthic ferruginous nodules. In the Luvisol, clay illuviation dominates and is associated with redoximorphic features. Strongly weathered pumice fragments and less weathered mineral and rock fragments were observed in the vertic horizons. Because the pedofeatures of the "black soil" strongly differ from those of the Luvisol, we can readily identify the cases where Luvisol materials were inherited by the "black soil". Thus, the micromorphological observations allow us to propose that the "black soil" was likely to incorporate Luvisol materials that were earlier colluviated. The presumed erosional phase may correspond with climatic aridization.Este trabajo proporciona nuevas evidencias sobre la historia edafológica y geomorfológica en el Valle de Teotihuacán, México. El paisaje del suelo en este lugar

  6. Sixty Years of Geomorphic Change and Restoration Challenges on Two Unchannelized Reaches of the Missouri River

    Science.gov (United States)

    Elliott, C. M.; Jacobson, R. B.; Bulliner, E. A., IV

    2016-12-01

    The Missouri National Recreational River is a National Park Service unit that includes two Missouri River segments that despite considerable alterations to hydrology, retain some aspects of channel complexity similar to conditions present in the pre-dam Missouri River. Complexity has been lost through the construction of five large reservoirs in the Missouri River system and the channelization of the lower 1,200 kilometers of river downstream from the reservoirs. These two river segments on the Nebraska and South Dakota border consist of a 63-km long inter-reservoir segment below Fort Randall Dam and a 95-km segment below Gavins Point Dam, the downstream-most dam in the Missouri River system. We present an analysis from U.S. Army Corps of Engineers cross-section data spanning 60 years. Our analysis quantifies geomorphic adjustment and resultant changes in habitat diversity since 1955, two years prior to the closure of Gavins Point Dam. In the inter-reservoir segment, sedimentation at the confluence of the Niobrara River has created a transition zone from free-flowing river, to delta, to reservoir; this transition is moving upstream as sedimentation progresses. The delta ecosystem provides wetland habitat and recreational areas for fishing and hunting, yet sedimentation threatens infrastructure and reservoir storage. In both reaches, relatively high-elevation bare sandbars are used for nesting by the endangered least tern (Sternula antillarum) and the threatened piping plover (Charadrius melodus). Two large flood events, in 1997 and 2011, created the bulk of new sandbar nesting habitat on these river segments. Sandbars erode and vegetate between flood events, and in recent decades vegetation removal and costly mechanical sandbar construction have been used to maintain bare nesting sandbar habitat. Management decisions in the segment downstream from Gavins Point Dam include evaluating tradeoffs between maintaining sandbar habitat for nesting and allowing some

  7. Distinctive channel geometry and riparian vegetation: A geomorphic classification for arid ephemeral streams

    Science.gov (United States)

    Sutfin, N.; Shaw, J. R.; Wohl, E. E.; Cooper, D.

    2012-12-01

    Interactions between hydrology, channel form, and riparian vegetation along arid ephemeral streams are not thoroughly understood and current stream classifications do not adequately represent variability in channel geometry and associated riparian communities. Relatively infrequent hydrologic disturbances in dryland environments are responsible for creation and maintenance of channel form that supports riparian communities. To investigate the influence of channel characteristics on riparian vegetation in the arid southwestern United States, we develop a geomorphic classification for arid ephemeral streams based on the degree of confinement and the composition of confining material that provide constraints on available moisture. Our conceptual model includes five stream types: 1) bedrock channels entirely confined by exposed bedrock and devoid of persistent alluvium; 2) bedrock with alluvium channels at least partially confined by bedrock but containing enough alluvium to create bedforms that persist through time; 3) incised alluvium channels bound only by unconsolidated alluvial material into which they are incised; 4) braided washes that exhibit multi-thread, braided characteristics regardless of the composition of confining material; and 5) piedmont headwater 0-2nd order streams (Strahler) confined only by unconsolidated alluvium and which initiate as secondary channels on piedmont surfaces. Eighty-six study reaches representing the five stream types were surveyed on the U.S. Army Yuma Proving Ground in the Sonoran Desert of southwestern Arizona. Non-parametric multivariate analysis of variance (PERMANOVA) indicates significant differences between the five stream types with regards to channel geometry (i.e., stream gradient, width-to-depth ratio, the ratio between valley width and channel width (Wv/Wc), shear stress, and unit stream power) and riparian vegetation (i.e., presence and canopy coverage by species, canopy stratum, and life form). Discriminant analysis

  8. Identifying data gaps and prioritizing restoration strategies for Fremont cottonwood using linked geomorphic and population models

    Science.gov (United States)

    Harper, E. B.; Stella, J. C.; Fremier, A. K.

    2009-12-01

    Fremont cottonwood (Populus fremontii) is an important component of semi-arid riparian ecosystems throughout western North America, but its populations are in decline due to flow regulation. Achieving a balance between human resource needs and riparian ecosystem function requires a mechanistic understanding of the multiple geomorphic and biological factors affecting tree recruitment and survival, including the timing and magnitude of river flows, and the concomitant influence on suitable habitat creation and mortality from scour and sedimentation burial. Despite a great deal of empirical research on some components of the system, such as factors affecting cottonwood recruitment, other key components are less studied. Yet understanding the relative influence of the full suite of physical and life-history drivers is critical to modeling whole-population dynamics under changing environmental conditions. We addressed these issues for the Fremont cottonwood population along the Sacramento River, CA using a sensitivity analysis approach to quantify uncertainty in parameters on the outcomes of a patch-based, dynamic population model. Using a broad range of plausible values for 15 model parameters that represent key physical, biological and climatic components of the ecosystem, we ran 1,000 population simulations that consisted of a subset of 14.3 million possible combinations of parameter estimates to predict the frequency of patch colonization and total forest habitat predicted to occur under current hydrologic conditions after 175 years. Results indicate that Fremont cottonwood populations are highly sensitive to the interactions among flow regime, sedimentation rate and the depth of the capillary fringe (Fig. 1). Estimates of long-term floodplain sedimentation rate would substantially improve model accuracy. Spatial variation in sediment texture was also important to the extent that it determines the depth of the capillary fringe, which regulates the availability of

  9. Combining geomorphic and documentary flood evidence to reconstruct extreme events in Mediterranean basins

    Science.gov (United States)

    Thorndycraft, V. R.; Benito, G.; Barriendos, M.; Rico, M.; Sánchez-Moya, Y.; Sopeña, A.; Casas, A.

    2009-09-01

    there was no geomorphic evidence of any flooding of greater magnitude than 2000 m3/s, or the 1982 event.

  10. Large-scale dam removal on the Elwha River, Washington, USA: coastal geomorphic change

    Science.gov (United States)

    Gelfenbaum, Guy R.; Stevens, Andrew W.; Miller, Ian M.; Warrick, Jonathan A.; Ogston, Andrea S.; Eidam, Emily

    2015-01-01

    Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of mud, sand, and gravel since 1927, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams, initiated in September 2011, induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the geomorphic response of a coastal delta to these increases. Detailed measurements of beach topography and nearshore bathymetry show that ~ 2.5 million m3 of sediment was deposited during the first two years of dam removal, which is ~ 100 times greater than deposition rates measured prior to dam removal. The majority of the deposit was located in the intertidal and shallow subtidal region immediately offshore of the river mouth and was composed of sand and gravel. Additional areas of deposition include a secondary sandy deposit to the east of the river mouth and a muddy deposit west of the mouth. A comparison with fluvial sediment fluxes suggests that ~ 70% of the sand and gravel and ~ 6% of the mud supplied by the river was found in the survey area (within about 2 km of the mouth). A hydrodynamic and sediment transport model, validated with in-situ measurements, shows that tidal currents interacting with the larger relict submarine delta help disperse fine sediment large distances east and west of the river mouth. The model also suggests that waves and currents erode the primary deposit located near the river mouth and transport sandy sediment eastward to form the secondary deposit. Though most of the substrate of the larger relict submarine delta was unchanged during the first two years of dam removal, portions of the seafloor close to the river mouth became finer, modifying habitats for biological communities. These results show that river restoration, like natural changes in river sediment supply, can result in rapid and substantial coastal geomorphological

  11. Geomorphic evidence for enhanced Pliocene-Quaternary faulting in the northwestern Basin and Range

    Science.gov (United States)

    Ellis, Magdalena A; Barnes Jason B,; Colgan, Joseph P.

    2014-01-01

    Mountains in the U.S. Basin and Range Province are similar in form, yet they have different histories of deformation and uplift. Unfortunately, chronicling fault slip with techniques like thermochronology and geodetics can still leave sizable, yet potentially important gaps at Pliocene–Quaternary (∼105–106 yr) time scales. Here, we combine existing geochronology with new geomorphic observations and approaches to investigate the Miocene to Quaternary slip history of active normal faults that are exhuming three footwall ranges in northwestern Nevada: the Pine Forest Range, the Jackson Mountains, and the Santa Rosa Range. We use the National Elevation Dataset (10 m) digital elevation model (DEM) to measure bedrock river profiles and hillslope gradients from these ranges. We observe a prominent suite of channel convexities (knickpoints) that segment the channels into upper reaches with low steepness (mean ksn = ∼182; θref = 0.51) and lower, fault-proximal reaches with high steepness (mean ksn = ∼361), with a concomitant increase in hillslope angles of ∼6°–9°. Geologic maps and field-based proxies for rock strength allow us to rule out static causes for the knickpoints and interpret them as transient features triggered by a drop in base level that created ∼20% of the existing relief (∼220 m of ∼1050 m total). We then constrain the timing of base-level change using paleochannel profile reconstructions, catchment-scale volumetric erosion fluxes, and a stream-power–based knickpoint celerity (migration) model. Low-temperature thermochronology data show that faulting began at ca. 11–12 Ma, yet our results estimate knickpoint initiation began in the last 5 Ma and possibly as recently as 0.1 Ma with reasonable migration rates of 0.5–2 mm/yr. We interpret the collective results to be evidence for enhanced Pliocene–Quaternary fault slip that may be related to tectonic reorganization in the American West, although we cannot rule out climate as a

  12. Cooperative interactions between paired domain and homeodomain.

    Science.gov (United States)

    Jun, S; Desplan, C

    1996-09-01

    The Pax proteins are a family of transcriptional regulators involved in many developmental processes in all higher eukaryotes. They are characterized by the presence of a paired domain (PD), a bipartite DNA binding domain composed of two helix-turn-helix (HTH) motifs,the PAI and RED domains. The PD is also often associated with a homeodomain (HD) which is itself able to form homo- and hetero-dimers on DNA. Many of these proteins therefore contain three HTH motifs each able to recognize DNA. However, all PDs recognize highly related DNA sequences, and most HDs also recognize almost identical sites. We show here that different Pax proteins use multiple combinations of their HTHs to recognize several types of target sites. For instance, the Drosophila Paired protein can bind, in vitro, exclusively through its PAI domain, or through a dimer of its HD, or through cooperative interaction between PAI domain and HD. However, prd function in vivo requires the synergistic action of both the PAI domain and the HD. Pax proteins with only a PD appear to require both PAI and RED domains, while a Pax-6 isoform and a new Pax protein, Lune, may rely on the RED domain and HD. We propose a model by which Pax proteins recognize different target genes in vivo through various combinations of their DNA binding domains, thus expanding their recognition repertoire.

  13. SOT1, a pentatricopeptide repeat protein with a small MutS-related domain, is required for correct processing of plastid 23S-4.5S rRNA precursors in Arabidopsis thaliana.

    Science.gov (United States)

    Wu, Wenjuan; Liu, Sheng; Ruwe, Hannes; Zhang, Delin; Melonek, Joanna; Zhu, Yajuan; Hu, Xupeng; Gusewski, Sandra; Yin, Ping; Small, Ian D; Howell, Katharine A; Huang, Jirong

    2016-03-01

    Ribosomal RNA processing is essential for plastid ribosome biogenesis, but is still poorly understood in higher plants. Here, we show that SUPPRESSOR OF THYLAKOID FORMATION1 (SOT1), a plastid-localized pentatricopeptide repeat (PPR) protein with a small MutS-related domain, is required for maturation of the 23S-4.5S rRNA dicistron. Loss of SOT1 function leads to slower chloroplast development, suppression of leaf variegation, and abnormal 23S and 4.5S processing. Predictions based on the PPR motif sequences identified the 5' end of the 23S-4.5S rRNA dicistronic precursor as a putative SOT1 binding site. This was confirmed by electrophoretic mobility shift assay, and by loss of the abundant small RNA 'footprint' associated with this site in sot1 mutants. We found that more than half of the 23S-4.5S rRNA dicistrons in sot1 mutants contain eroded and/or unprocessed 5' and 3' ends, and that the endonucleolytic cleavage product normally released from the 5' end of the precursor is absent in a sot1 null mutant. We postulate that SOT1 binding protects the 5' extremity of the 23S-4.5S rRNA dicistron from exonucleolytic attack, and favours formation of the RNA structure that allows endonucleolytic processing of its 5' and 3' ends. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  14. Anthropogenic features and hillslope processes interaction

    Science.gov (United States)

    Tarolli, Paolo; Sofia, Giulia

    2016-04-01

    Topography emerges as a result of natural driving forces, but some human activities (such as mining, agricultural practices and the construction of road networks) directly or indirectly move large quantities of soil, which leave clear topographic signatures embedded on the Earth's morphology. These signatures can cause drastic changes to the geomorphological organization of the landscape, with direct consequences on Earth surface processes (Tarolli and Sofia, 2016). To this point, the present research investigates few case studies highlighting the influences of anthropogenic topographic signatures on hillslope processes, and it shows the effectiveness of High-Resolution Topography (HRT) derived from the recent remote sensing technologies (e.g. lidar, satellite, structure from motion photogrammetry), to better understand this interaction. The first example is related to agricultural terraces. In recent times, terraced areas acquired a new relevance to modern concerns about erosion and land instability, being the agricultural land mostly threatened by abandonment or intensification and specialization of agriculture, resulting in more landslide-prone bench terraces, or heavy land levelling with increased erosion. The second case study discusses about the role of agricultural and forest roads on surface erosion and landslides. The third case study investigates geomorphic processes in an open pit mine. In all case studies, HRT served as the basis for the development of new methodologies able to recognize and analyze changes on Earth surface processes along hillslopes. The results show how anthropogenic elements have crucial effects on sediment production and sediment delivery, also influencing the landscape connectivity. The availability of HRT can improve our ability to actually model anthropogenic morphologies, quantify them, and analyse the links between anthropogenic elements and geomorphic processes. The results presented here, and the creation and dissemination of

  15. Using context to improve protein domain identification

    Directory of Open Access Journals (Sweden)

    Llinás Manuel

    2011-03-01

    Full Text Available Abstract Background Identifying domains in protein sequences is an important step in protein structural and functional annotation. Existing domain recognition methods typically evaluate each domain prediction independently of the rest. However, the majority of proteins are multidomain, and pairwise domain co-occurrences are highly specific and non-transitive. Results Here, we demonstrate how to exploit domain co-occurrence to boost weak domain predictions that appear in previously observed combinations, while penalizing higher confidence domains if such combinations have never been observed. Our framework, Domain Prediction Using Context (dPUC, incorporates pairwise "context" scores between domains, along with traditional domain scores and thresholds, and improves domain prediction across a variety of organisms from bacteria to protozoa and metazoa. Among the genomes we tested, dPUC is most successful at improving predictions for the poorly-annotated malaria parasite Plasmodium falciparum, for which over 38% of the genome is currently unannotated. Our approach enables high-confidence annotations in this organism and the identification of orthologs to many core machinery proteins conserved in all eukaryotes, including those involved in ribosomal assembly and other RNA processing events, which surprisingly had not been previously known. Conclusions Overall, our results demonstrate that this new context-based approach will provide significant improvements in domain and function prediction, especially for poorly understood genomes for which the need for additional annotations is greatest. Source code for the algorithm is available under a GPL open source license at http://compbio.cs.princeton.edu/dpuc/. Pre-computed results for our test organisms and a web server are also available at that location.

  16. Explaining linkages (and lack of) between riparian vegetation biodiversity and geomorphic complexity in restored streams of northern Sweden

    Science.gov (United States)

    Polvi, Lina; Maher Hasselquist, Eliza; Nilsson, Christer

    2014-05-01

    Ecological theory suggests that species richness and habitat heterogeneity are positively correlated; therefore stream restoration often relies on increasing geomorphic complexity to promote biodiversity. However, past studies have failed to demonstrate a link between post-restoration biodiversity and geomorphic complexity. These studies have usually relied on only one metric for quantifying complexity, rather than a holistic metric for complexity that represents several aspects of the channel morphology, and have based their observations in catchments with widespread land-use impacts. We use a geomorphic complexity gradient based on five geomorphic aspects (longitudinal, cross-sectional, planform, sediment texture, and instream wood) to determine whether streams with higher levels of complexity also have greater riparian vegetation biodiversity. We also compare biodiversity values with the potential complexity of reaches based on the large-scale controls of valley and channel gradient and the presence of large glacial legacy sediment (boulders). We focus on tributary channels in boreal forests of northern Sweden, where stream modification associated with log-floating from the 1850s to the 1960s created highly simplified channels. Driven by concerns for fish, restoration began in the 1970s by returning large cobbles and boulders into the main channel from the channel edge, and evolved into 'demonstration restoration,' placing very large boulders and trees into the channel, reopening side channels, and constructing fish spawning areas. We evaluate 22 reaches along tributaries of the Vindel River in northern Sweden with four restoration statuses: channelized, restored, demonstration restored, and unimpacted. Detailed morphologic, sediment, and instream wood data allow calculation of 29 metrics of geomorphic complexity, from which a complexity gradient was identified using multivariate statistics. The percent cover of riparian vegetation was identified in 0.5 x 0.5 m

  17. Conserved Domain Database (CDD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — CDD is a protein annotation resource that consists of a collection of well-annotated multiple sequence alignment models for ancient domains and full-length proteins.

  18. Geomorphic Response of a Low-Gradient Channel to Modern, Progressive Base-Level Lowering: Nahal HaArava, the Dead Sea

    Science.gov (United States)

    Dente, Elad; Lensky, Nadav G.; Morin, Efrat; Grodek, Tamir; Sheffer, Nathan A.; Enzel, Yehouda

    2017-12-01

    The geomorphic response of channels to base-level fall is an important factor in landscape evolution. To better understand the complex interactions between the factors controlling channel evolution in an emerging continental shelf setting, we use an extensive data set (high-resolution digital elevation models, aerial photographs, and Landsat imagery) of a newly incising, perennial segment of Nahal (Wadi) HaArava, Israel. This channel responds to the rapid and progressive lowering of its base-level, the Dead Sea (>30 m in 35 years; 0.5-1.3 m yr-1). Progressively evolving longitudinal profiles, channel width, sinuosity, and knickpoint retreat during the last few decades were documented or reconstructed. The results indicate that even under fast base-level fall, rapid delta progradation on top of the shelf and shelf edge can moderate channel mouth slopes and, therefore, largely inhibit channel incision and knickpoint propagation. This channel elongation stage ends when the delta reaches an extended accommodation within the receiving basin and fails to keep the channel mouth slopes as low as the channel bed slopes. Then, processes of incision, narrowing, and meandering begin to shape the channel and expand upstream. When the down-cutting channel encounters a more resistant stratum within the channel substrate, these processes are restricted to a downstream reach by formation of a retreating vertical knickpoint. When the knickpoint and the channel incise to a level below this stratum, a spatially continuous, diffusion-like evolution characterizes the channel's response and source-to-sink transport can be implemented. These results emphasize the mouth slope and channel substrate resistance as the governing factors over long-term channel evolution, whereas flash floods have only local and short-lived impacts in a confined, continuously incising channel. The documented channel response applies to eustatic base-level fall under steepening basin bathymetry, rapid delta

  19. Deposition and growth of domains in one dimension

    Science.gov (United States)

    Rodgers, G. J.; Tavassoli, Z.

    1998-09-01

    A model of deposition and growth in one dimension is studied in which finite sized domains are deposited by the random sequential adsorption process. The domains then grow with a time dependent growth rate. When the initial deposited domains are monomers and dimers the coverage is found exactly for a number of different growth rates. A continuum version of this model is also considered.

  20. Holocene tectono-geomorphic evolution of parts of the Upper and Middle Gangetic plains, India

    Science.gov (United States)

    Pati, Pitambar; Parkash, B.