Mass transport processes and deposits in offshore Trinidad and Venezuela, and their role in continental margin development

textMass transport complexes (MTC) form a significant component of the stratigraphic record in ancient and modern deep water basins. One such basin, the deep marine margin of eastern offshore Trinidad, situated along the obliquely converging boundary of the Caribbean and South American plates and proximal to the mouth of the Orinoco River, is characterized by catastrophic shelf margin processes, intrusive and extrusive mobile shales, active tectonics and possible migration and sequestration of hydrocarbons. Major structural elements found in the deep water slope regions include: large transpressional fault zones along which mobile shales extrude to form seafloor ridges; fault-cored anticlinal structures overlain by extrusive seafloor mud volcanos; shallow-rooted sediment bypass grabens near the shelf break; and normal and counterregional faults. A data volume consisting of 10,708 km2 of several merged 3D seismic data volumes enable subseafloor interpretation of several mass transport event deposits and the erosional surfaces that form their boundaries. The data shows numerous mass transport complexes which are characterized by chaotic, mounded seismic facies and fanlike geometries. Their extent (up to 2017 sq. km) and thickness (up to 250 m) is strongly influenced by seafloor topography. Depositional and erosional architectures identified with these units includes: large magnitude lateral erosional edges, thrust faulting, linear basal scours, side-wall failures, flow geometries, possible displaced blocks and chaotic matrix material. Active tectonism in the region, high sedimentation rates associated with the Orinoco Delta System, and abundant unstable gas hydrates suggest the presence of higher frequency mechanisms at work for MTCs generation than sea-level fluctuations alone. Three types of mass transport complexes are identified in offshore Trinidad; shelfattached systems that were fed by shelf edge deltas whose sediment input is controlled by sea level fluctuations, slope- attached systems which occur when upper slope sediments catastrophically fail due to gas hydrate disruptions, earthquakes and/or storm activity, and locally detached systems formed when local instabilities in the sea floor trigger small collapses. Such classification of the relationship between slope mass failures and the sourcing regions enables an understanding of the nature of initiation, length of development history, petrography and petrophysics of MTC’s. In addition, a collection of morphometric parameters of MTCs from different continental margins are analyzed in order to better understand their causal mechanisms, and to establish whether systematic morphometric parameters characterize these deposits across different tectonic settings. Observations suggest that there is a clear relationship between morphometric parameters of MTC and their causal mechanisms.Geological Science

Uniform Mixed Equilibria in Network Congestion Games with Link Failures

Motivated by possible applications in fault-tolerant routing, we introduce the notion of uniform mixed equilibria in network congestion games with adversarial link failures, where players need to route traffic from a source to a destination node. Given an integer rho >= 1, a rho-uniform mixed strategy is a mixed strategy in which a player plays exactly rho edge disjoint paths with uniform probabilities, so that a rho-uniform mixed equilibrium is a tuple of rho-uniform mixed strategies, one for each player, in which no player can lower her cost by deviating to another rho-uniform mixed strategy. For games with weighted players and affine latency functions, we show existence of rho-uniform mixed equilibria and provide a tight characterization of their price of anarchy. For games with unweighted players, instead, we extend the existential guarantee to any class of latency functions and, restricted to games with affine latencies, we derive a tight characterization of both the prices of anarchy and stability

Care of the Healthcare Provider

Evidence has shown a strong correlation between a healthy provider and the positive care that the provider can promote to others. Many evidence-based health promotion programs have been implemented throughout many health systems. These programs have shown improvement of the providers’ overall health. And in return, these providers are able to better care for their patients. Detailed reports have shown many health consequences that healthcare providers have acquired due to long hours, intense training, lack of time, lack of sleep, and the concept of always putting their patients first. A health system in Springfield, Illinois was examined to determine if a health promotion program would benefit their providers. This health system had not yet implemented a health promotion program for providers, due to time and uncertainty if people would participate. Surveying was taken into great detail to evaluate what areas of health providers would like to focus on improving, and how they would want this information presented to them. Providers also rated their overall health. This information was interpreted and presented to stakeholders at this specific health system. An explanation of the data collected was provided, as well as a sample health promotion program they would be able to implement. This sample program was developed using an evidence-based planning method. This specific program was developed based on survey results. An evaluation was then completed after the presentation to determine the likelihood they would implement the health promotion program, along with any potential issues. A follow-up project would be recommended to implement the actual program discussed in this project and to evaluate its effectiveness

Teens Surfing The Net: How Do They Learn To Protect Their Privacy?

This study invokes the consumer socialization process to investigate how teens develop knowledge of ‘privacy concern’ as it relates to protecting their privacy when using the Internet.  The data in this study show a correlation between teens that are raised in homes where parents practice concept-oriented family communication and the development of privacy concern.  The data also show a correlation between parental co-viewing of the Internet and the development of privacy concern.  Finally, the date link peer communication with the development of privacy concern.  Overall the date appear to show that discussion with parents and friends about Internet use is key to the development of adopting concern for protecting teens privacy when they use the Internet.&nbsp

Nash Social Welfare in Selfish and Online Load Balancing (Short Paper)

In load balancing problems there is a set of clients, each wishing to select a resource from a set of permissible ones, in order to execute a certain task. Each resource has a latency function, which depends on its workload, and a client's cost is the completion time of her chosen resource. Two fundamental variants of load balancing problems are selfish load balancing (aka. load balancing games), where clients are non-cooperative selfish players aimed at minimizing their own cost solely, and online load balancing, where clients appear online and have to be irrevocably assigned to a resource without any knowledge about future requests. We revisit both problems under the objective of minimizing the Nash Social Welfare, i.e., the geometric mean of the clients' costs. To the best of our knowledge, despite being a celebrated welfare estimator in many social contexts, the Nash Social Welfare has not been considered so far as a benchmarking quality measure in load balancing problems. We provide tight bounds on the price of anarchy of pure Nash equilibria and on the competitive ratio of the greedy algorithm under very general latency functions, including polynomial ones. For this particular class, we also prove that the greedy strategy is optimal, as it matches the performance of any possible online algorithm

Sharing the cost of multicast transmissions in wireless networks

AbstractA crucial issue in non-cooperative wireless networks is that of sharing the cost of multicast transmissions to different users residing at the stations of the network. Each station acts as a selfish agent that may misreport its utility (i.e., the maximum cost it is willing to incur to receive the service, in terms of power consumption) in order to maximize its individual welfare, defined as the difference between its true utility and its charged cost. A provider can discourage such deceptions by using a strategyproof cost sharing mechanism, that is a particular public algorithm that, by forcing the agents to truthfully reveal their utility, starting from the reported utilities, decides who gets the service (the receivers) and at what price. A mechanism is said budget balanced (BB) if the receivers pay exactly the (possibly minimum) cost of the transmission, and β-approximate budget balanced (β-BB) if the total cost charged to the receivers covers the overall cost and is at most β times the optimal one, while it is efficient if it maximizes the sum of the receivers’ utilities minus the total cost over all receivers’ sets. In this paper, we first investigate cost sharing strategyproof mechanisms for symmetric wireless networks, in which the powers necessary for exchanging messages between stations may be arbitrary and we provide mechanisms that are either efficient or BB when the power assignments are induced by a fixed universal spanning tree, or (3ln(k+1))-BB (k is the number of receivers), otherwise. Then we consider the case in which the stations lay in a d-dimensional Euclidean space and the powers fall as 1/dα, and provide strategyproof mechanisms that are either 1-BB or efficient for α=1 or d=1. Finally, we show the existence of 2(3d-1)-BB strategyproof mechanisms in any d-dimensional space for every α⩾d. For the special case of d=2 such a result can be improved to achieve 12-BB mechanisms

Origin and anatomy of two different types of mass-transport complexes: a 3D seismic case study from the northern South China Sea margin

Integration of 2D and 3D seismic data from the Qiongdongnan Basin along the northwestern South China Sea margin has enabled the seismic stratigraphy, seismic geomorphology and emplacement mechanisms of eight separate, previously undocumented, mass-transport complexes (MTCs) to be characterized. These eight MTCs can be grouped into two types:. (1) Localized detached MTCs, which are confined to submarine canyons and cover hundreds of km, consist of a few tens of km remobilized sediments and show long striations at their base. They resulted from small-scale mass-wasting processes induced by regional tectonic events and gravitational instabilities on canyon margins.(2) Regional attached MTCs, which occur within semi-confined or unconfined settings and are distributed roughly perpendicular to the strike of the regional slope. Attached MTCs occupy hundreds to thousands of km and are composed of tens to hundreds of km of remobilized sediments. They contain headwall escarpments, translated blocks, remnant blocks, pressure ridges, and basal striations and cat-claw grooves. They were created by large-scale mass-wasting processes triggered by high sedimentation rates, slope oversteepening by shelf-edge deltas, and seismicity.Our results show that MTCs may act as both lateral and top seals for underlying hydrocarbon reservoirs and could create MTC-related stratigraphic traps that represent potential drilling targets on continental margins, helping to identify MTC-related hydrocarbon traps

Assessment of Corneal Fluorescein Staining in Different Dry Eye Subtypes Using Digital Image Analysis

To describe a new objective technique of digital image analysis for the quantification and the morphological characterization of corneal staining in the setting of dry eye disease (DED), and to apply it to distinguish Sj\uf6gren syndrome (SS) from ocular graft versus-host disease (oGVHD)

Mass-Transport Complexes as Markers of Deep-Water Fold-and-Thrust Belt Evolution: Insights From the Southern Magdalena Fan, Offshore Colombia

Mass-wasting of tectonically active margins is an important process in the degradation of deep-water fold-and-thrust belts. However, tectono-stratigraphic links between mass-transport complexes (MTCs), the evolution of MTC basal surfaces, and the timing, and spatial progression of deformation have not been extensively studied. This study uses high-quality, 3D seismic reflection data from the southern Magdalena Fan, offshore Colombia to investigate how the growth of a deep-water fold-and-thrust belt (the southern Sinú Fold Belt) is reflected in the source, distribution and size of MTCs. At least 11 distinct, but now-coalesced MTCs, overlie this surface. Their size and source location changed through time: the oldest, ‘detached’ MTCs are relatively small (10-160 km2) and sourced from the flanks of growing anticlines; the younger, ‘shelf-attached’ MTCs are considerably larger (200-400 km2), are sourced from the shelf and post-date the main phase of active thrusting and folding. Changes in the source, distribution and size of MTCs are tied to the sequential nucleation, amplification and along-strike propagation of individual structures showing that MTCs can be used to constrain the timing and style of deformation, and seascape evolution in time and space. The basal surface of the largest MTC was created by multiple syn-tectonic and post-tectonic mass-wasting events, is highly diachronous and represents an extended period of slope instability. Thus, the geometry and extent of MTC basal surfaces can evolve through time, and the deposits that overlie them do not necessarily record the processes that led to their creation. These insights complicate assessments of the anatomy and genesis of MTC basal surfaces and could be applied at deeper burial depths where seismic resolution may be poor