The Hell Creek Formation in North Dakota

This paper is a discussion of the surface stratigraphy and petrology of the Hell Creek Formation in North Dakota and eastern Montana. Principal area of study included the Missouri Valley south of Bismarck, North Dakota; the Little Missouri Valley in Slope and Bowman Counties, southwestern North Dakota; the Yellowstone Valley near Glendive, Dawson County, Montana; and the type area of the Hell Creek Formation on Hell Creek and East Hell Creek, Garfield County, Montana on the south shore of the Fort Peck Reservoir. Two and one-half summers were spent in the field measuring 72 stratigraphic sections, correlating between the measured sections, collecting petrographic samples and fossils from the Hell Creek Formation and associated formations. Laboratory studies included heavy mineral analyses, preparation and study of petrographic thin sections, and the identification of the fossils collected. The Hell Creek Formation was found to be divisible into 8 members, 7 of which are new. In central North Dakota (from oldest to youngest) the Crowgheat Member, the Breien Member (named prior to this paper), the Fort Rice Member, the Guff Member, and the Pretty Butte Member were recognized. In southwestern North Dakota (from oldest to youngest) the Little Beaver Creek Member, the Marmarth Member, the Bacon Creek Member, the Huff Member and the Pretty Butte Member were defined. In eastern Montana a set of sandstones at the base of the formation was recognized as a possible ninth member but was not named. The Pretty Butte and Huff Members appear to be present over all of western and central North Dakota as well as eastern Montana. The other members have only local importance. The top of the Hell Creek Formation is considered a time line as a result of the studies of the fossils (particularly dinosaurs) and bentonites. The base of the Hell Creek Formation was found to become progressively younger in an eastward direction. No conformity was found at the top of the formation. The base of the formation was found to be vertically and horizontally gradational with the Fox Hills Sandstone in the east and to lie unconformably upon the Fox Hills Sandstone in the west. The Hell Creek Formation may be visualized as the subaerial top-set beds of a giant delta stretching eastward from the Rocky Mountain Point into the Fox Hills-Cannonball Sea at the close of the Cretaceous time. Laterally equivalent marine top-set beds of this delta are the Fox Hills Formation. Fore-set and bottom-set beds are represented by the Pierre Shale. The climate during Hell Creek times in North Dakota was warm, temperate, summer-moist with probably no frosts as indicated by such plants as Metasequoia, Cercidiphyllum, Ficus, and Magnolia, and by such animals as dinosaurs, crocodiles, and alligators. The early Paleocene climate appears to have changed little if any from the preceding Hell Creek climate since there is a continuation of such plant genera as Cercidiphyllum and Metasequoia and such animals as crocodiles, into the Cenozoic Era

Chemical probes for methyl lysine reader domains

The primary intent of a chemical probe is to establish the relationship between a molecular target, usually a protein whose function is modulated by the probe, and the biological consequences of that modulation. In order to fulfill this purpose, a chemical probe must be profiled for selectivity, mechanism of action, and cellular activity, as the cell is the minimal system in which ‘biology’ can be explored. This review provides a brief overview of progress toward chemical probes for methyl lysine reader domains with a focus on recent progress targeting chromodomains

Use of Dredged Material for Oyster Habitat Creation in Coastal Virginia

Dredging can have a beneficial effect on oyster habitat when the placement of the dredged material is effectively managed to help provide the bottom structure necessary to develop an oyster reef. Construction and maintenance of the Waterway on the Coast of Virginia (WCV) by the U. S. Army Corps of Engineers (Corps) has provided a number of examples of this process, both serendipitous and deliberate. The historical development of reefs that evolved from the random overboard placement of dredged material and the subsequent leasing of these areas for oyster cultivation is reviewed. A monitoring plan for the development of a reef in Swash Bay using maintenance dredging material is also described including pre- and post-dredging hydrographic surveys, surface sediment distributions, and shellfish surveys. After one year, the benthic communities at the recently used placement site, the historical placement site and an unimpacted area in Swash Bay were compared using the Benthic Assessment Method (BAM) to determine short-term impacts. The historical and unimpacted sites had very similar values while the recently used site was somewhat lower. Consequences of continued success in developing oyster reefs in close proximity to a dredged channel are addressed with a suggested management plan that involves rotating the placement among a number of sites. This would allow for the continued maintenance of both the channel and the adjacent oyster reefs.https://scholarworks.wm.edu/vimsbooks/1090/thumbnail.jp

Developing And Evaluating A Machine‐Scorable, Constrained Constructed‐Response Item

The use of constructed response items in large scale standardized testing has been hampered by the costs and difficulties associated with obtaining reliable scores. The advent of expert systems may signal the eventual removal of this impediment. This study investigated the accuracy with which expert systems could score a new, non‐multiple choice item type. The item type presents a faulty solution to a computer programming problem and asks the student to correct the solution. This item type was administered to a sample of high school seniors enrolled in an Advanced Placement course in Computer Science who also took the Advanced Placement Computer Science (APCS) Test. Results indicated that the expert systems were able to produce scores for between 82% and 97% of the solutions encountered and to display high agreement with a human reader on which solutions were and were not correct. Diagnoses of the specific errors produced by students were less accurate. Correlations with scores on the objective and free‐response sections of the APCS examination were moderate. Implications for additional research and for testing practice are offered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108589/1/ets200144.pd

Advanced secondary power system for transport aircraft

A concept for an advanced aircraft power system was identified that uses 20-kHz, 440-V, sin-wave power distribution. This system was integrated with an electrically powered flight control system and with other aircraft systems requiring secondary power. The resulting all-electric secondary power configuration reduced the empty weight of a modern 200-passenger, twin-engine transport by 10 percent and the mission fuel by 9 percent

Peptide Technologies in the Development of Chemical Tools for Chromatin‐Associated Machinery

Discerning a mechanistic understanding of the cause‐and‐effect relationships between chromatin post‐translational modifications (PTMs) and DNA accessibility for replication, transcription, and repair is an elusive goal being pursued using molecular and cellular biology, biochemistry, and more recently chemical inhibition. Chemical intervention of the chromatin‐associated complexes that regulate PTM maintenance and chromatin structure faces numerous challenges due to the broad surface‐groove interactions between many of these proteins and histones; yet, the increasing interest in understanding chromatin‐modifying complexes suggests tractable lead compounds will be critical for elucidating the mechanisms of chromatin dysregulation in disease states and validating the druggability of these domains. Peptides and peptidomimetics afford several advantages to efficient inhibitor development including a rational starting point, modular assembly, and retention of secondary structure. Numerous peptide technologies have been employed in the chromatin field to characterize substrate interactions, evaluate ligand selectivity, and optimize potent peptidomimetic inhibitors. We describe the progress and advantages of these efforts, and provide a perspective on their implications for future chemical probe and drug discovery efforts. Drug Dev Res 78 : 300–312, 2017. © 2017 Wiley Periodicals, Inc

CLASH-VLT: Testing the Nature of Gravity with Galaxy Cluster Mass Profiles

We use high-precision kinematic and lensing measurements of the total mass profile of the dynamically relaxed galaxy cluster MACS J1206.2-0847 at $z=0.44$ to estimate the value of the ratio $\eta=\Psi/\Phi$ between the two scalar potentials in the linear perturbed Friedmann-Lemaitre-Robertson-Walker metric.[...] Complementary kinematic and lensing mass profiles were derived from exhaustive analyses using the data from the Cluster Lensing And Supernova survey with Hubble (CLASH) and the spectroscopic follow-up with the Very Large Telescope (CLASH-VLT). Whereas the kinematic mass profile tracks only the time-time part of the perturbed metric (i.e. only $\Phi$), the lensing mass profile reflects the contribution of both time-time and space-space components (i.e. the sum $\Phi+\Psi$). We thus express $\eta$ as a function of the mass profiles and perform our analysis over the radial range $0.5\,Mpc\le r\le r_{200}=1.96\,Mpc$. Using a spherical Navarro-Frenk-White mass profile, which well fits the data, we obtain \eta(r_{200})=1.01\,_{-0.28}^{+0.31} at the 68\% C.L. We discuss the effect of assuming different functional forms for mass profiles and of the orbit anisotropy in the kinematic reconstruction. Interpreting this result within the well-studied $f(R)$ modified gravity model, the constraint on $\eta$ translates into an upper bound to the interaction length (inverse of the scalaron mass) smaller than 2 Mpc. This tight constraint on the $f(R)$ interaction range is however substantially relaxed when systematic uncertainties in the analysis are considered. Our analysis highlights the potential of this method to detect deviations from general relativity, while calling for the need of further high-quality data on the total mass distribution of clusters and improved control on systematic effects.Comment: 18 pages, 3 figures, submitted to JCA

Targeting Chromatin Readers

Modulation of gene expression through epigenetic signaling has recently emerged as a novel approach in treating human disease. Specifically, chromatin reader proteins, which mediate protein–protein interactions via binding to modified lysine residues, are gaining traction as potential therapeutic targets. Herein, we review recent efforts to understand and modulate the activity of chromatin reader proteins with small-molecule ligands

Humour as social dreaming:Stand-up comedy as therapeutic performance

Stand-up comedy binds dramatic cultural spectacle to ritualised, intimate exposure. Examining ‘case’ examples from live comic performance, this paper describes stand-up as a kind of social dreaming. The article proposes a theoretical frame drawing on Thomas Ogden’s notion of ‘talking as dreaming’ and psychoanalytic accounts connecting humour and melancholia. Locating the stand-up comedian’s propensity for humour in a specialist capacity to hone, display and process traumata, the paper characterises stand-up as a performative oscillation evoking paranoid-schizoid and depressive anxieties. A psychosocial gloss places stand-up as a cultural resource in the service of the popular-as-therapeutic. The paper articulates complementarities between Henri Bergson’s formulations on the function of laughter and an emergent object relations account in order to help to recognise ‘containing’ and ‘cultural-restorative’ aspects of much stand-up, understood as contemporary psychosocial ritual