64 research outputs found

    Paleolimnology and paleoecology of the Coal Valley region, Lincoln County, Nevada

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    During Pleistocene time, Coal Valley, Nevada, was situated between a pluvial climatic zone to the north and a non-pluvial climactic zone to the south. The Coal Lake section represents {dollar}\u3e{dollar}20,000 years of continuous deposition, recording a saline lake phase (Early Coal Lake) present since at least 32,000 BP, evolving to a freshwater lake (Coal Lake Intermediate) {dollar}\sim{dollar}28,000 BP. Maximum lake development (290 km{dollar}\sp2{dollar} in area) was within 2000 years of {dollar}\sim{dollar}20,000 BP, and was probably persistent through deglaciation. Ostracode ecology suggests that water salinity varied little through time, which may be indicative of consistently low ambient temperatures, high precipitation levels, and/or high basin seepage rates throughout the life of the lake. Coal Lake probably experienced more direct control by regional groundwater hydrology than by climate. The revised paleohydrologic index of Coal Valley is (Z{dollar}\sb{\rm cv}{dollar} = 0.11, compared to the previous value of 0.07, suggesting that the water balance of Coal Lake was higher than previously thought

    Principles and Principals: Leveraging K-12 Principal Training and Evaluation Standards to Support Environmental, Ecological, and Sustainability Education

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    Ecoliteracy is the pedagogical grouping of environmental science, ecology and sustainability studies. This paper is a policy analysis of how principal training and evaluation standards may support a principal’s building-level efforts to establish and sustain an ecoliteracy mission and curriculum in US public K-12 schools. A comparative case study of leadership standards in Texas and Michigan was conducted to support the argument that school administrator training and evaluation standards in both states can lend formal, codified support to a sufficiently determined school leader’s efforts to center the school’s mission on ecoliteracy. The limitations of this support are also discussed

    Ranking ligand affinity for the DNA minor groove by experiment and simulation

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    The structural and thermodynamic basis for the strength and selectivity of the interactions of minor-groove binders (MGBs) with DNA is not fully understood. In 2003 we reported the first example of a thiazole containing MGB that bound in a phase shifted pattern that spanned 6 base-pairs rather than the usual 4 (for tricyclic distamycin-like compounds). Since then, using DNA footprinting, nuclear magnetic resonance spectroscopy, isothermal titration calorimetry and molecular dynamics, we have established that the flanking bases around the central 4 being read by the ligand have subtle effects on recognition. We have investigated the effect of these flanking sequences on binding and the reasons for the differences and established a computational method to rank ligand affinity against varying DNA sequences

    Repeat associated mechanisms of genome evolution and function revealed by the Mus caroli and Mus pahari genomes

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    Understanding the mechanisms driving lineage-specific evolution in both primates and rodents has been hindered by the lack of sister clades with a similar phylogenetic structure having high-quality genome assemblies. Here, we have created chromosome-level assemblies of the Mus caroli and Mus pahari genomes. Together with the Mus musculus and Rattus norvegicus genomes, this set of rodent genomes is similar in divergence times to the Hominidae (human-chimpanzee-gorilla-orangutan). By comparing the evolutionary dynamics between the Muridae and Hominidae, we identified punctate events of chromosome reshuffling that shaped the ancestral karyotype of Mus musculus and Mus caroli between 3 and 6 million yr ago, but that are absent in the Hominidae. Hominidae show between four- and sevenfold lower rates of nucleotide change and feature turnover in both neutral and functional sequences, suggesting an underlying coherence to the Muridae acceleration. Our system of matched, high-quality genome assemblies revealed how specific classes of repeats can play lineage-specific roles in related species. Recent LINE activity has remodeled protein-coding loci to a greater extent across the Muridae than the Hominidae, with functional consequences at the species level such as reproductive isolation. Furthermore, we charted a Muridae-specific retrotransposon expansion at unprecedented resolution, revealing how a single nucleotide mutation transformed a specific SINE element into an active CTCF binding site carrier specifically in Mus caroli, which resulted in thousands of novel, species-specific CTCF binding sites. Our results show that the comparison of matched phylogenetic sets of genomes will be an increasingly powerful strategy for understanding mammalian biology

    Enhanced Visual Temporal Resolution in Autism Spectrum Disorders

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    Cognitive functions that rely on accurate sequencing of events, such as action planning and execution, verbal and nonverbal communication, and social interaction rely on well-tuned coding of temporal event-structure. Visual temporal event-structure coding was tested in 17 high-functioning adolescents and adults with autism spectrum disorder (ASD) and mental- and chronological-age matched typically-developing (TD) individuals using a perceptual simultaneity paradigm. Visual simultaneity thresholds were lower in individuals with ASD compared to TD individuals, suggesting that autism may be characterised by increased parsing of temporal event-structure, with a decreased capability for integration over time. Lower perceptual simultaneity thresholds in ASD were also related to increased developmental communication difficulties. These results are linked to detail-focussed and local processing bias

    Repeat associated mechanisms of genome evolution and function revealed by the Mus caroli and Mus pahari genomes.

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    Understanding the mechanisms driving lineage-specific evolution in both primates and rodents has been hindered by the lack of sister clades with a similar phylogenetic structure having high-quality genome assemblies. Here, we have created chromosome-level assemblies of the Mus caroli and Mus pahari genomes. Together with the Mus musculus and Rattus norvegicus genomes, this set of rodent genomes is similar in divergence times to the Hominidae (human-chimpanzee-gorilla-orangutan). By comparing the evolutionary dynamics between the Muridae and Hominidae, we identified punctate events of chromosome reshuffling that shaped the ancestral karyotype of Mus musculus and Mus caroli between 3 and 6 million yr ago, but that are absent in the Hominidae. Hominidae show between four- and sevenfold lower rates of nucleotide change and feature turnover in both neutral and functional sequences, suggesting an underlying coherence to the Muridae acceleration. Our system of matched, high-quality genome assemblies revealed how specific classes of repeats can play lineage-specific roles in related species. Recent LINE activity has remodeled protein-coding loci to a greater extent across the Muridae than the Hominidae, with functional consequences at the species level such as reproductive isolation. Furthermore, we charted a Muridae-specific retrotransposon expansion at unprecedented resolution, revealing how a single nucleotide mutation transformed a specific SINE element into an active CTCF binding site carrier specifically in Mus caroli, which resulted in thousands of novel, species-specific CTCF binding sites. Our results show that the comparison of matched phylogenetic sets of genomes will be an increasingly powerful strategy for understanding mammalian biology

    Depletion of stromal cells expressing fibroblast activation protein-α from skeletal muscle and bone marrow results in cachexia and anemia.

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    Fibroblast activation protein-α (FAP) identifies stromal cells of mesenchymal origin in human cancers and chronic inflammatory lesions. In mouse models of cancer, they have been shown to be immune suppressive, but studies of their occurrence and function in normal tissues have been limited. With a transgenic mouse line permitting the bioluminescent imaging of FAP(+) cells, we find that they reside in most tissues of the adult mouse. FAP(+) cells from three sites, skeletal muscle, adipose tissue, and pancreas, have highly similar transcriptomes, suggesting a shared lineage. FAP(+) cells of skeletal muscle are the major local source of follistatin, and in bone marrow they express Cxcl12 and KitL. Experimental ablation of these cells causes loss of muscle mass and a reduction of B-lymphopoiesis and erythropoiesis, revealing their essential functions in maintaining normal muscle mass and hematopoiesis, respectively. Remarkably, these cells are altered at these sites in transplantable and spontaneous mouse models of cancer-induced cachexia and anemia. Thus, the FAP(+) stromal cell may have roles in two adverse consequences of cancer: their acquisition by tumors may cause failure of immunosurveillance, and their alteration in normal tissues contributes to the paraneoplastic syndromes of cachexia and anemia

    Identifying ecoliteracy in the El Paso Borderplex

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    Ecoliteracy is a pedagogy that values earth ecology and sustainable, nondestructive human relationships to natural systems. This is in contrast to the pedagogy of economics-based education, which views natural systems as raw materials for unlimited economic growth, usually at the expense of the environment and citizens with less economic and political power. Ecoliterate thought is scarcely developed among sampled residents of the Borderplex, and by extrapolation, people at-large. However, individual themes did manifest. The values behind these expressed themes were cultivated primarily through lived experiences, to a lesser extent media exposure, and to a minimal extent, education. No significant results were yielded by the pilot statistical study I conducted to determine if conservation attitudes and behavior were related to ethnicity, sex, country of origin and age. However, conservation and ecoliteracy resist attempts to be defined and characterized by the observation of behaviors because of their holistic, iteratively complex natures. The implementation of an ecoliterate educational model is recommended for El Paso. Content and curricula must based on the four thematic texts of ecoliteracy including stewardship, environmental justice, deep time and systems/processes thinking. This would serve to connect learners and teachers to their environment, to empower groups equally regardless of socioeconomic status and to cultivate the natural scientific abilities of children and adults

    Un-packaging Manuscript Preparation and Review Guidelines for Curriculum and Instruction and Research Papers

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    In November 2015 the Journal of Geoscience Education Editorial Board met to review and discussed the criteria for curriculum and instruction (C&I) and Researchmanuscripts. The criteria are important for two primary reasons: these guide authors in manuscriptpreparation, and also serve as standards to which reviewers and editors evaluate manuscript content and organization. The criteria that the board examined were put in place in 2009 and consisted of a single document (i.e., webpage link). The categories of criteria were broadly applied to both Curriculum and Instruction and ResearchManuscripts, unless otherwise specially noted. These criteria helped make clear that all scholarly work in geoscience education that were to be considered for publication in JGE needed to be grounded in the literature, needed a well-defined purpose, and needed to include a description of the study setting and population. In addition, all papers needed to explain and justify the methods used, and describe the results. Importantly, it also required that conclusions must be evidence-based, and that the validity and reliability of the results be considered. Lastly, it required that the broader implications of the findings be discussed.The Editors and Associate Editors are in agreement that these fundamental manuscript expectations hold true today. However, based on their experience working with submitting authors and reviewers over the last several years, felt that authors and reviewers would benefit by un-packaging of the guidelines into separate documents for Curriculum and InstructionManuscripts and for ResearchManuscripts. Such a step has allowed us to make some important distinctions between these two types of papers, especially in terms of their purpose, study design, and methods, and allows us to provide clarifications and examples that are relevant to the each type of paper. In addition, we have added the expectation of a Limitations section to both types of papers. The outcomes of the criteria revision effort are provided below, and are also accessible online at nagt-jge.org under Author Information.The criteria should be used to guide both the content and organization of manuscripts. In addition, see the recently updated Manuscript Submission, Format, and Revision Instructions (nagt-jge.org under Author Information) which address submission and revision requirements, format guidelines, and offers technical advice
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