We mapped histone H3 lysine 4 di- and trimethylation and lysine 9/14 acetylation across the nonrepetitive portions of human chromosomes 21 and 22 and compared patterns of lysine 4 dimethylation for several orthologous human and mouse loci. Both chromosomes show punctate sites enriched for modified histones. Sites showing trimethylation correlate with transcription starts, while those showing mainly dimethylation occur elsewhere in the vicinity of active genes. Punctate methylation patterns are also evident at the cytokine and IL-4 receptor loci. The Hox clusters present a strikingly different picture, with broad lysine 4-methylated regions that overlay multiple active genes. We suggest these regions represent active chromatin domains required for the maintenance of Hox gene expression. Methylation patterns at orthologous loci are strongly conserved between human and mouse even though many methylated sites do not show sequence conservation notably higher than background. This suggests that the DNA elements that direct the methylation represent only a small fraction of the region or lie at some distance from the site.
The Port of Portland, Oregon recently (2015) completed a comprehensive, port-wide seismic risk assessment as part of a long-term plan to improve the Port's seismic resiliency. The Port targeted 20 of their most important marine and aviation assets for this risk analysis and retained a team to develop and apply a seismic performance evaluation of each asset. A multi-hazard level approach was implemented that addressed the range of return periods (i.e. ground motions) commonly applied for both marine and building structures. The seismic performance of each asset was evaluated using inertial loading based on estimated site-specific ground motions and kinematic loading based on estimated seismically-induced soil displacements. This paper focuses on the geotechnical and structural approaches utilized for the marine facilities, and the integrated approach to evaluating dynamic soil-structure interaction for the waterfront structures. Key discussion points include the synthesis and application of archival data, the need for site-specific ground motions due to limitations in code-based soil factors, appropriate level of analyses for seismic risk assessment, and considerations associated with structural and geotechnical mitigation strategies suggested for the subsequent benefit/cost analyses. These analyses provided requisite input for the subsequent port and regional seismic risk analyses addressed in the companion paper by Graf and others (2016). BACKGROUND
Operators for deepwater and extended-reach wells, where daily rig costs can exceed $500k per day, are continuously exploring methods to reduce nonproductive time (NPT) and increase operational efficiency. For example, a common point of focus is liner string deployments in deepwater and highly deviated applications that predominantly employ hydraulic liner hangers. This paper presents a new liner hanger system that uses simple mud flow signals to remotely communicate with a downhole controller on the work string. The controller receives the specific activation signal from the surface and then relays that signal to the liner hanger or running tool via an acoustic signal. The results of the first test trial of the remote liner hanger system controller will be discussed. The traditional method for setting a hydraulic liner hanger includes the use of single or multiple activation balls being dropped from the surface so that pressure can be applied to the work string to function the hydraulic liner hanger and running tool. However, in deepwater and extended-reach applications, many operational issues experienced with running hydraulic liner hangers are related to not landing the ball on seat, which can lead to days of NPT. Developing a liner hanger system that does not rely on dropping activation balls from the surface nor rely on pipe manipulation can reduce the time required to run the liner hanger and minimize issues that lead to higher NPT. This new system does not require dropping activation balls from the surface, reducing the amount of running tools in the work string and the amount of time required to set the liner hanger. The system also allows the use of a solid liner hanger body, eliminating the potential leak paths inherent to hydraulic liner hangers. The results will demonstrate the first deployment of the remote system controller in a well, confirming that it detects various remote commands from the surface. The results will also demonstrate how the system enables operators to choose the activation method depending on the well and rig conditions, for example, varying the flow rate activation signals. This system and method can improve well construction efficiencies and is a step in the direction of a smarter and safer oilfield through more automated operations.
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