3,634 research outputs found

    Dynamothermal metamorphism of the Chiwaukum Schist in the Steven\u27s Pass Area, Cascade Mountains, Washington

    Get PDF
    The Chiwaukum Schist in the Steven\u27s Pass region of the North Cascade Mountains, Washington is a metamorphic rock suite of pelitic protolith bordering the Mount Steward Batholith. This clay-right parent material experienced contact metamorphism during the intrusion of the Mount Steward batholith, followed by Buchan style, dynamothermal metamorphism. The minerals produced by these early metamorphic events were later overprinted by minerals of Barrovian style, dynamothermal metamorphism. The index minerals of the contact and Buchan facies metamorphism extend into the andalusite zone, while the Barrovian facies is characterized by aluminosilicate polymorph minerals reaching the sillimanite zone. Calculation of mineral abundances and assemblages in thin section allow for the construction of a detailed petrographic analysis of the are

    A Young African-American Woman’s Story: Risk and Protective Factors in Developing Identity

    Get PDF
    The purpose of this research study is to explore the life experiences of an African American young woman specifically focusing on risk and protective factors and their impact on identity formation. The research asks the questions, “What are the risk and protective life experiences of an African American young woman? How do these possible life experiences impact the way the young woman participant views herself and her world?” The methodology chosen for this research is a qualitative case study allowing for an in-depth and holistic look at an individual’s life. Two semi-structured interviews were conducted with a young African American woman and her uncle, who the young woman identified as a “special adult” within her life. Interview questions called upon participants to reflect upon the life of the young woman. The young woman was instructed to take photographs of the places and things that are most important to her allowing an active role within data collection. A visual analysis of photographs taken provides a meaningful interpretation of the young woman’s life including her dreams, values, ambition, and sense of safety. Furthermore, findings suggest risks within the forming identity of a young African American woman are relationships and social perception. Protective factors consist of a vision for her future, a sense of purpose, and resilience. These findings propose a need for future research, funding, and social work practice that is informed of risk and protective factor’s impact on identity development within the lives of young African American women. An informed practice has the potential to create a more inclusive world

    A Young African-American Woman\u27s Story: Risk and Protective Factors in Developing Identity

    Get PDF
    The purpose of this research study is to explore the life experiences of an African American young woman specifically focusing on risk and protective factors and their impact on identity formation. The research asks the questions, What are the risk and protective life experiences of an African American young woman? How do these possible life experiences impact the way the young woman participant views herself and her world? The methodology chosen for this research is a qualitative case study allowing for an in-depth and holistic look at an individual\u27s life. Two semi-structured interviews were conducted with a young African American woman and her uncle, who the young woman identified as a special adult within her life. Interview questions called upon participants to reflect upon the life of the young woman. The young woman was instructed to take photographs of the places and things that are most important to her allowing an active role within data collection. A visual analysis of photographs taken provides a meaningful interpretation of the young woman\u27s life including her dreams, values, ambition, and sense of safety. Furthermore, findings suggest risks within the forming identity of a young African American woman are relationships and social perception. Protective factors consist of a vision for her future, a sense of purpose, and resilience. These findings propose a need for future research, funding, and social work practice that is informed of risk and protective factor\u27s impact on identity development within the lives of young African American women. An informed practice has the potential to create a more inclusive world

    Development of a Translator from LLVM to ACL2

    Full text link
    In our current work a library of formally verified software components is to be created, and assembled, using the Low-Level Virtual Machine (LLVM) intermediate form, into subsystems whose top-level assurance relies on the assurance of the individual components. We have thus undertaken a project to build a translator from LLVM to the applicative subset of Common Lisp accepted by the ACL2 theorem prover. Our translator produces executable ACL2 formal models, allowing us to both prove theorems about the translated models as well as validate those models by testing. The resulting models can be translated and certified without user intervention, even for code with loops, thanks to the use of the def::ung macro which allows us to defer the question of termination. Initial measurements of concrete execution for translated LLVM functions indicate that performance is nearly 2.4 million LLVM instructions per second on a typical laptop computer. In this paper we overview the translation process and illustrate the translator's capabilities by way of a concrete example, including both a functional correctness theorem as well as a validation test for that example.Comment: In Proceedings ACL2 2014, arXiv:1406.123

    EPA Oversight in Determining Best Available Control Technology: The Supreme Court Determines the Proper Scope of Enforcement

    Get PDF
    In Alaska Department of Environmental Conservation v. EPA, the Supreme Court addressed the issue of whether the EPA was authorized to bar construction of a new major emitting facility where it found the state permitting authority’s best available control technology (BACT) determination unreasonable. The Court held that, given the legislative history and plain language of the enforcement provisions contained in the Clean Air Act, the EPA reasonably believes that the state permitting authority has acted arbitrarily in determining BACT. This Note explores the analysis employed by the Court and argues that, in light of the underlying purpose of the PSD program, the Court in Alaska Department of Environmental Conservation reached the correct conclusion

    Drivers and projections of global surface temperature anomalies at the local scale

    Get PDF

    The impact of freeze-drying infant fecal samples on measures of their bacterial community profiles and milk-derived oligosaccharide content.

    Get PDF
    Infant fecal samples are commonly studied to investigate the impacts of breastfeeding on the development of the microbiota and subsequent health effects. Comparisons of infants living in different geographic regions and environmental contexts are needed to aid our understanding of evolutionarily-selected milk adaptations. However, the preservation of fecal samples from individuals in remote locales until they can be processed can be a challenge. Freeze-drying (lyophilization) offers a cost-effective way to preserve some biological samples for transport and analysis at a later date. Currently, it is unknown what, if any, biases are introduced into various analyses by the freeze-drying process. Here, we investigated how freeze-drying affected analysis of two relevant and intertwined aspects of infant fecal samples, marker gene amplicon sequencing of the bacterial community and the fecal oligosaccharide profile (undigested human milk oligosaccharides). No differences were discovered between the fecal oligosaccharide profiles of wet and freeze-dried samples. The marker gene sequencing data showed an increase in proportional representation of Bacteriodes and a decrease in detection of bifidobacteria and members of class Bacilli after freeze-drying. This sample treatment bias may possibly be related to the cell morphology of these different taxa (Gram status). However, these effects did not overwhelm the natural variation among individuals, as the community data still strongly grouped by subject and not by freeze-drying status. We also found that compensating for sample concentration during freeze-drying, while not necessary, was also not detrimental. Freeze-drying may therefore be an acceptable method of sample preservation and mass reduction for some studies of microbial ecology and milk glycan analysis

    On using Cholesky-based factorizations and regularization for solving rank-deficient sparse linear least-squares problems

    Get PDF
    By examining the performance of modern parallel sparse direct solvers and exploiting our knowledge of the algorithms behind them, we perform numerical experiments to study how they can be used to efficiently solve rank-deficient sparse linear least-squares problems arising from practical applications. The Cholesky factorization of the normal equations breaks down when the least-squares problem is rank-deficient, while applying a symmetric indefinite solver to the augmented system can give an unacceptable level of fill in the factors. To try to resolve these difficulties, we consider a regularization procedure that modifies the diagonal of the unregularized matrix. This leads to matrices that are easier to factorize. We consider both the regularized normal equations and the regularized augmented system. We employ the computed factors of the regularized systems as preconditioners with an iterative solver to obtain the solution of the original (unregularized) problem. Furthermore, we look at using limited-memory incomplete Cholesky-based factorizations and how these can offer the potential to solve very large problems

    Brown Anole (Anolis sagrei) Hoxa5: Insights into the Divergence of Hoxa5 Gene Expression and Regulation Across Evolutionarily Divergent Gnathostome Vertebrates

    Get PDF
    Hox genes are evolutionarily conserved developmental regulatory genes that function, in part, to pattern the anterior-posterior (AP) axis of organs and organ systems during animal embryonic development. Hoxa5, specifically, is shown to be expressed in the spinal cord, somites, or transient compartments giving rise to the vertebrae and ribs, developing gut, lungs, and limbs of the mouse (Mus musculus). The cis-regulatory elements (CREs), or short DNA sequences, that direct Hoxa5 expression in these embryonic domains have been mapped and functionally tested in the mouse as well. Similar Hoxa5 expression patterns have been observed in chicken (Gallus gallus), American alligator (Alligator mississipiensis), and dogfish shark (Scyliorhinus canicular), but have shown divergence in the anterior limit of expression within the somites. Specifically, while mouse expression begins in somite 3, chicken, alligator, and shark begin in 8, 9, and 9, respectively. Further, no hoxa5 expression has been observed in the somites for teleost fish. Here, we present the embryonic Hoxa5 expression pattern within brown anole lizard (Anolis sagrei). Our data shows that Hoxa5 within the lizard has an anterior limit of expression in somite 6 and exhibits a more similar expression pattern to that of mouse, chicken, alligator, and shark than to teleost fishes. Furthermore, our comparative genomic DNA sequence analyses display that the functional CREs mapped in the mouse are conserved among the tetrapods, but not with the shark or teleost fishes. Our analyses suggest that divergent Hoxa5 expression patterns result from divergence within their respective CREs
    • …
    corecore