Episodic dust events of Utahs Wasatch Front and adjoining region

pre-printEpisodic dust events cause hazardous air quality along Utah's Wasatch Front and dust loading of the snowpack in the adjacentWasatch Mountains. This paper presents a climatology of episodic dust events of the Wasatch Front and adjoining region that is based on surface weather observations from the Salt Lake City International Airport (KSLC), Geostationary Operational Environmental Satellite (GOES) imagery, and additional meteorological datasets. Dust events at KSLC-defined as any day [mountain standard time (MST)] with at least one report of a dust storm, blowing dust, and/or dust in suspension with a visibility of 10 km or less-average 4.3 per water year (WY: October-September), with considerable in-terannual variability and a general decline in frequency during the 1930-2010 observational record. The distributions of monthly dust-event frequency and total dust flux are bimodal, with primary and secondary maxima in April and September, respectively. Dust reports are most common in the late afternoon and evening. An analysis of the 33most recent (2001-10WY) events at KSLC indicates that 11 were associated with airmass convection, 16 were associated with a cold front or baroclinic trough entering Utah from the west or northwest, 4 were associated with a stationary or slowly moving front or baroclinic trough west of Utah, and 2 were associated with other synoptic patterns. GOES imagery from these 33 events, as well as 61 additional events from the surrounding region, illustrates that emission sources are located primarily in low-elevation Late Pleistocene-Holocene alluvial environments in southern and western Utah and southern and western Nevada

Differential reproductive plasticity under thermal variability in a freshwater fish (Danio rerio)

publishedVersionPaid Open Acces

Differential reproductive plasticity under thermal variability in a freshwater fish (Danio rerio)

Human-driven increases in global mean temperatures are associated with concomitant increases in thermal variability. Yet, few studies have explored the impacts of thermal variability on fitness-related traits, limiting our ability to predict how organisms will respond to dynamic thermal changes. Among the myriad organismal responses to thermal variability, one of the most proximate to fitness—and, thus, a population's ability to persist—is reproduction. Here, we examine how a model freshwater fish (Danio rerio) responds to diel thermal fluctuations that span the species's viable developmental range of temperatures. We specifically investigate reproductive performance metrics including spawning success, fecundity, egg provisioning and sperm concentration. Notably, we apply thermal variability treatments during two ontogenetic timepoints to disentangle the relative effects of developmental plasticity and reversible acclimation. We found evidence of direct, negative effects of thermal variability during later ontogenetic stages on reproductive performance metrics. We also found complex interactive effects of early and late-life exposure to thermal variability, with evidence of beneficial acclimation of spawning success and modification of the relationship between fecundity and egg provisioning. Our findings illuminate the plastic life-history modifications that fish may undergo as their thermal environments become increasingly variable.publishedVersio

Witten's 2+1 gravity on R x (Klein bottle)

Witten's formulation of 2+1 gravity is investigated on the nonorientable three-manifold R x (Klein bottle). The gauge group is taken to consist of all four components of the 2+1 Poincare group. We analyze in detail several components of the classical solution space, and we show that from four of the components one can recover nondegenerate spacetime metrics. In particular, from one component we recover metrics for which the Klein bottles are spacelike. An action principle is formulated for bundles satisfying a certain orientation compatibility property, and the corresponding components of the classical solution space are promoted into a phase space. Avenues towards quantization are briefly discussed.Comment: 33 pages, REVTeX v3.0, 3 figures in a separate PostScript fil

Huntington’s disease age at motor onset is modified by the tandem hexamer repeat in TCERG1

Huntington’s disease is caused by an expanded CAG tract in HTT. The length of the CAG tract accounts for over half the variance in age at onset of disease, and is influenced by other genetic factors, mostly implicating the DNA maintenance machinery. We examined a single nucleotide variant, rs79727797, on chromosome 5 in the TCERG1 gene, previously reported to be associated with Huntington’s disease and a quasi-tandem repeat (QTR) hexamer in exon 4 of TCERG1 with a central pure repeat. We developed a method for calling perfect and imperfect repeats from exome-sequencing data, and tested association between the QTR in TCERG1 and residual age at motor onset (after correcting for the effects of CAG length in the HTT gene) in 610 individuals with Huntington’s disease via regression analysis. We found a significant association between age at onset and the sum of the repeat lengths from both alleles of the QTR (p = 2.1 × 10−9), with each added repeat hexamer reducing age at onset by one year (95% confidence interval [0.7, 1.4]). This association explained that previously observed with rs79727797. The association with age at onset in the genome-wide association study is due to a QTR hexamer in TCERG1, translated to a glutamine/alanine tract in the protein. We could not distinguish whether this was due to cis-effects of the hexamer repeat on gene expression or of the encoded glutamine/alanine tract in the protein. These results motivate further study of the mechanisms by which TCERG1 modifies onset of HD

Creative learning conversations: producing living dialogic spaces

publication-status: Publishedtypes: ArticleBackground ‘Creative learning conversations’, are methodological devices developed in two co-participative qualitative research projects exploring creativity and educational futures at the University of Exeter in England. Sources of evidence Framed by Critical Theory, the projects, one on dance education partnership, the other on student voice and transformation, sought to open space between creativity and performativity to initiate emancipatory educational change. This was undertaken over the course of five years in English primary and secondary schools, prioritising humanising, wise creativity (Chappell, 2008; Craft, 2008). Purpose This paper re-analyses data and methodological processes to characterise and theorise creative learning conversations in terms of social spatiality and dialogue. The characteristics are: partiality, emancipation, working from the ‘bottom up’, participation, debate and difference, openness to action, and embodied and verbalised idea exchange. Main argument This re-analysis theoretically adapts Bronfenbrenner’s (1979) ecological model to situate layered engagement. Utilising Lefebvre’s (1991) conceptualisation of Lived space and Bakhtin’s (1984) work on open-ended dialogue, the paper theorises creative learning conversations as producing living dialogic spaces. Conclusions Creative learning conversations are a way of contributing to change which moves us towards an education future fit for the twenty-first century. From a living dialogic space perspective a creative learning conversation is the ongoing process without forced closure of those in the roles of University academic, teachers, artists, students co-participatively researching and developing knowledge of their ‘lived space’ together. Given traditional lethargy in the educational system as a whole commitment to changing education for better futures demands active involvement in living dialogic space, where our humanity both emerges from and guides our shared learning

Introduction: reconsidering the region in India: mobilities, actors and development politics

In this introduction to a special issue on ‘Reconsidering the Region in India’, we aim to develop a synthetic and theoretically nuanced account of the multifarious ways in which the idea of region has been imbricated in diverse spatial, political, cultural and socio-economic configurations. We draw from various bodies of anthropological, geographic and historical literature to elaborate on three themes that we believe are central to understanding contemporary processes of region-making in India: trans-regional mobilities and connections; the actors who produce and perform regional imaginaries; and changing regional politics of development.IS

CAG repeat not polyglutamine length determines timing of Huntington’s disease onset

Variable, glutamine-encoding, CAA interruptions indicate that a property of the uninterrupted HTT CAG repeat sequence, distinct from the length of huntingtin’s polyglutamine segment, dictates the rate at which Huntington’s disease (HD) develops. The timing of onset shows no significant association with HTT cis-eQTLs but is influenced, sometimes in a sex-specific manner, by polymorphic variation at multiple DNA maintenance genes, suggesting that the special onset-determining property of the uninterrupted CAG repeat is a propensity for length instability that leads to its somatic expansion. Additional naturally occurring genetic modifier loci, defined by GWAS, may influence HD pathogenesis through other mechanisms. These findings have profound implications for the pathogenesis of HD and other repeat diseases and question the fundamental premise that polyglutamine length determines the rate of pathogenesis in the “polyglutamine disorders.

The Magellan-TESS Survey I: Survey Description and Mid-Survey Results

One of the most significant revelations from Kepler is that roughly one-third of Sun-like stars host planets which orbit their stars within 100 days and are between the size of Earth and Neptune. How do these super-Earth and sub-Neptune planets form, what are they made of, and do they represent a continuous population or naturally divide into separate groups? Measuring their masses and thus bulk densities can help address these questions of their origin and composition. To that end, we began the Magellan-TESS Survey (MTS), which uses Magellan II/PFS to obtain radial velocity (RV) masses of 30 transiting exoplanets discovered by TESS and develops an analysis framework that connects observed planet distributions to underlying populations. In the past, RV measurements of small planets have been challenging to obtain due to the faintness and low RV semi-amplitudes of most Kepler systems, and challenging to interpret due to the potential biases in the existing ensemble of small planet masses from non-algorithmic decisions for target selection and observation plans. The MTS attempts to minimize these biases by focusing on bright TESS targets and employing a quantitative selection function and multi-year observing strategy. In this paper, we (1) describe the motivation and survey strategy behind the MTS, (2) present our first catalog of planet mass and density constraints for 25 TESS Objects of Interest (TOIs; 20 in our population analysis sample, five that are members of the same systems), and (3) employ a hierarchical Bayesian model to produce preliminary constraints on the mass-radius (M-R) relation. We find qualitative agreement with prior mass-radius relations but some quantitative differences (abridged). The the results of this work can inform more detailed studies of individual systems and offer a framework that can be applied to future RV surveys with the goal of population inferences.Comment: 101 pages (39 of main text and references, the rest an appendix of figures and tables). Submitted to AAS Journal

Integrative analysis of large scale expression profiles reveals core transcriptional response and coordination between multiple cellular processes in a cyanobacterium

<p>Abstract</p> <p>Background</p> <p>Cyanobacteria are the only known prokaryotes capable of oxygenic photosynthesis. They play significant roles in global biogeochemical cycles and carbon sequestration, and have recently been recognized as potential vehicles for production of renewable biofuels. <it>Synechocystis </it>sp. PCC 6803 has been extensively used as a model organism for cyanobacterial studies. DNA microarray studies in <it>Synechocystis </it>have shown varying degrees of transcriptome reprogramming under altered environmental conditions. However, it is not clear from published work how transcriptome reprogramming affects pre-existing networks of fine-tuned cellular processes.</p> <p>Results</p> <p>We have integrated 163 transcriptome data sets generated in response to numerous environmental and genetic perturbations in <it>Synechocystis</it>. Our analyses show that a large number of genes, defined as the core transcriptional response (CTR), are commonly regulated under most perturbations. The CTR contains nearly 12% of <it>Synechocystis </it>genes found on its chromosome. The majority of genes in the CTR are involved in photosynthesis, translation, energy metabolism and stress protection. Our results indicate that a large number of differentially regulated genes identified in most reported studies in <it>Synechocystis </it>under different perturbations are associated with the general stress response. We also find that a majority of genes in the CTR are coregulated with 25 regulatory genes. Some of these regulatory genes have been implicated in cellular responses to oxidative stress, suggesting that reactive oxygen species are involved in the regulation of the CTR. A Bayesian network, based on the regulation of various KEGG pathways determined from the expression patterns of their associated genes, has revealed new insights into the coordination between different cellular processes.</p> <p>Conclusion</p> <p>We provide here the first integrative analysis of transcriptome data sets generated in a cyanobacterium. This compilation of data sets is a valuable resource to researchers for all cyanobacterial gene expression related queries. Importantly, our analysis provides a global description of transcriptional reprogramming under different perturbations and a basic framework to understand the strategies of cellular adaptations in <it>Synechocystis</it>.</p