348 research outputs found

    Precambrian Well Data in Nebraska, Including Rock Type and Surface Configuration

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    This bulletin presents, in tabular form, information relating to the Precambrian surface and includes a configuration map of this surface in Nebraska. The data from all of the 1460 deep tests reaching the Precambrian as of January 1, 1966 are listed. It is anticipated that further studies utilizing this data will be made due to the important influence of the Precambrian surface on later sedimentation and structure and the possibility of minerals of economic importance being present in Precambrian rocks. Specific information for each well and samples, except as noted in the tabulation, are on file and available for study in the offices of the Nebraska Geological Survey. Separate copies of the included configuration map and blue-line copies of this map at a scale of 1:500,000 are available. Blue-line copies of the detailed configuration of the Precambrian surface for an eleven county area in southwestern .Nebraska and a thirteen county area in southeastern Nebraska are available at a scale of 1:250,000. Map of Precambrian surface attached below ( 9 MB jpg

    Lithostratigraphy and Correlation of the Mississippian System in Nebraska

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    The purpose of this study is to describe and correlate rocks of Mississippian age within the state of Nebraska. Shales, generally classified as Chattanooga and commonly referred to as Devonian or Mississippian in the northern Mid-Continent, have been included in this study, although these shales are more generally believed to be Devonian and not Mississippian by most stratigraphers and paleontologists at the present time. Since rocks of Mississippian age are present only in the subsurface of Nebraska, the basic information for this report is derived from the microscopic study of cuttings and cores from test wells drilled within the state

    Geology, Geologic Time and Nebraska

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    Island arcs, accretionary terranes and Midcontinent structure New understandings of the geologic architecture of the U.S. Midcontinent

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    A data base collected over the last 100 years, containing both surface and subsurface information, has allowed us to begin to understand the physical framework of Nebraska. We have learned that even in the stable Midcontinent region of North America, there has been an active geologic history. This framework has been deciphered by our programs of surface geologic mapping and by the study of rock samples from both water wells and those deeper test wells for oil and gas. Determining the major structural features across the state (figure 1) has allowed us to better understand both the occurrences of its natural resources and natural hazards. It has been a more difficult problem to explain the process by which this physical framework was established. The last 500 million years of our geologic history is recorded in sedimentary rock layers of sandstone, limestone and shale. These units record an active history of deposition, uplift and erosion. However, it is the older, crystalline igneous and metamorphic rocks of Precambrian age that control the zones of structural weakness across the state. Only by understanding the history of these much older basement rocks - their composition and their method of formation - can we explain the current architecture of our state and possibly anticipate where future activity might occur

    Praxis: An Editorial Statement

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    Praxis: An Editorial Statemen

    Spatial Distribution, Air-Water Fugacity Ratios and Source Apportionment of Polychlorinated Biphenyls in the Lower Great Lakes Basin

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    Polychlorinated biphenyls (PCBs) continue to be contaminants of concern across the Great Lakes. It is unclear whether current concentrations are driven by ongoing primary emissions from their original uses, or whether ambient PCBs are dominated by their environmental cycling. Freely dissolved PCBs in air and water were measured using polyethylene passive samplers across Lakes Erie and Ontario during summer and fall, 2011, to investigate their spatial distribution, determine and apportion their sources and to asses their air–water exchange gradients. Average gaseous and freely dissolved ∑29 PCB concentrations ranged from 5.0 to 160 pg/m3 and 2.0 to 55 pg/L respectively. Gaseous concentrations were significantly correlated (R2 = 0.80) with the urban area within a 3−20 km radius. Fugacity ratios indicated that the majority of PCBs are volatilizing from the water thus acting as a secondary source for the atmosphere. Dissolved PCBs were probably linked to PCB emissions from contaminated sites and areas of concern. Positive matrix factorization indicated that although volatilized Aroclors (gaseous PCBs) and unaltered Aroclors (dissolved PCBs) dominate in some samples, ongoing non-Aroclor sources such as paints/pigments (PCB 11) and coal/wood combustion showed significant contributions across the lower Great Lakes. Accordingly, control strategies should give further attention to PCBs emitted from current use sources

    A Model of Mindful Parenting: Implications for Parent–Child Relationships and Prevention Research

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    This paper introduces a model of “mindful parenting” as a framework whereby parents intentionally bring moment-to-moment awareness to the parent–child relationship. This is done by developing the qualities of listening with full attention when interacting with their children, cultivating emotional awareness and self-regulation in parenting, and bringing compassion and nonjudgmental acceptance to their parenting interactions. First, we briefly outline the theoretical and empirical literature on mindfulness and mindfulness-based interventions. Next, we present an operational definition of mindful parenting as an extension of mindfulness to the social context of parent–child relationships. We discuss the implications of mindful parenting for the quality of parent–child relationships, particularly across the transition to adolescence, and we review the literature on the application of mindfulness in parenting interventions. We close with a synopsis of our own efforts to integrate mindfulness-based intervention techniques and mindful parenting into a well-established, evidence-based family prevention program and our recommendations for future research on mindful parenting interventions

    Synaptic NMDA receptor activity is coupled to the transcriptional control of the glutathione system

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    How the brain’s antioxidant defenses adapt to changing demand is incompletely understood. Here we show that synaptic activity is coupled, via the NMDA receptor (NMDAR), to control of the glutathione antioxidant system. This tunes antioxidant capacity to reflect the elevated needs of an active neuron, guards against future increased demand and maintains redox balance in the brain. This control is mediated via a programme of gene expression changes that boosts the synthesis, recycling and utilization of glutathione, facilitating ROS detoxification and preventing <i>Puma</i>-dependent neuronal apoptosis. Of particular importance to the developing brain is the direct NMDAR-dependent transcriptional control of glutathione biosynthesis, disruption of which can lead to degeneration. Notably, these activity-dependent cell-autonomous mechanisms were found to cooperate with non-cell-autonomous Nrf2-driven support from astrocytes to maintain neuronal GSH levels in the face of oxidative insults. Thus, developmental NMDAR hypofunction and glutathione system deficits, separately implicated in several neurodevelopmental disorders, are mechanistically linked

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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