Possible Jurassic age for part of Rakaia Terrane: implications for tectonic development of the Torlesse accretionary prism

Greywacke sandstone and argillite beds comprising Rakaia Terrane (Torlesse Complex) in mid Canterbury, South Island, New Zealand, are widely regarded as Late Triassic (Norian) in age based on the occurrence of Torlessia trace fossils, Monotis, and other taxa. This paleontological age assignment is tested using published 40Ar/39Ar mica and U-Pb zircon ages for these rocks and published and new zircon fission track (FT) ages. The youngest U-Pb zircon ages in the Rakaia Terrane rocks in mid Canterbury are Norian, whereas 10-20% of the 40Ar/39Ar muscovite ages are younger than Norian. Numerical modelling of these mica ages shows that they cannot have originated from partial thermal overprinting in the Torlesse prism if the thermal maximum was short-lived and early in the prism history (210-190 Ma), as commonly inferred for these rocks. The young component of mica ages could, however, be explained by extended residence (200-100 Ma) at 265-290deg.C in the prism. Early Jurassic (c. 189 Ma) zircon FT ages for sandstone beds from Arthur's Pass, the Rakaia valley, and the Hermitage (Mt Cook) are interpreted not to have experienced maximum temperatures above 210deg.C, and therefore cannot have been reduced as a result of partial annealing in the Torlesse prism. This is based on identification of a fossil Cretaceous, zircon FT, partial annealing zone in low-grade schists to the west, and the characteristics of the age data. The Early Jurassic zircon FT ages and the young component of 40Ar/39Ar mica ages are regarded therefore as detrital ages reflecting cooling in the source area, and constrain the maximum depositional age of parts of the Rakaia Terrane in mid Canterbury. The zircon FT data also show the initiation (c. 100 Ma) of marked and widespread Late Cretaceous cooling of Rakaia Terrane throughout Canterbury, which is attributed to uplift and erosion of inboard parts of the Torlesse prism due to continuing subduction accretion at its toe. The critical wedge concept is proposed as a new framework for investigating the development of the Torlesse Complex. The Rakaia Terrane may have formed the core of an accretionary wedge imbricated against the New Zealand margin during the Middle or Late Jurassic. Late Jurassic nonmarine sediments (e.g., Clent Hills Formation) accumulated upon the inner parts of the prism as it enlarged, emerged, and continued to be imbricated. Exhumation of Otago Schist from c. 135 Ma may mark the development of a balance (steady state) between sediments entering the prism at the toe and material exiting at the inboard margin. The enlargement of the area of exhumation to all of Canterbury from c. 100 Ma may reflect a dynamic response to widening of the prism through the accretion of Cretaceous sediments. The model of a dynamic critical wedge may help to explain the various expressions of the Rangitata Orogeny

Computation in Classical Mechanics

There is a growing consensus that physics majors need to learn computational skills, but many departments are still devoid of computation in their physics curriculum. Some departments may lack the resources or commitment to create a dedicated course or program in computational physics. One way around this difficulty is to include computation in a standard upper-level physics course. An intermediate classical mechanics course is particularly well suited for including computation. We discuss the ways we have used computation in our classical mechanics courses, focusing on how computational work can improve students' understanding of physics as well as their computational skills. We present examples of computational problems that serve these two purposes. In addition, we provide information about resources for instructors who would like to include computation in their courses.Comment: 6 pages, 3 figures, submitted to American Journal of Physic

Mapping Quality of Life in Nebraska: Migration Rates

KEY POINTS AND IMPLICATIONS Nebraska is a state that is not often viewed as affected significantly by mobility and migration. As a state, the net migration rate of 1.1 from 2015 to 2016 is fairly low compared to others like Florida (16.0) or Nevada (14.4). However, data from this report suggests that there is, in fact, substantial movement of people moving in and moving out; as well as pockets within the state where there is higher than average influx of both domestic and international migrants. In general, migration trends in the state mirror national trends of “rural flight” where people are moving out of the rural counties and moving into suburban or metropolitan areas. In fact, 69 of the 93 counties had a negative net migration. This is most likely due to greater economic opportunities associated with urban areas (Harris & Todaro, 1970). However, the population leaving is being offset by international migrants who do come to suburban and rural counties (e.g., Colfax, Dakota, Dawson). Thus, overall the state net migration rate has been minimal with a slight increase. Below are other key points of this fact sheet. • The foreign-born population is highest in the metropolitan counties, particularly in Douglas (48,909) and in Lancaster (21,888). However, the highest concentration of foreign-born is found in micropolitan areas with lower overall population (i.e., at least 10,000 but less than 50,000), such as Dakota, Dawson, and Hall. Most likely, specific industries (e.g., meatpacking plants, industrial plants) in these areas are attracting migrant workers. This is consistent with recent scholars’ recognition of the importance of micropolitan areas in economic and social revitalization of states (e.g., Cantrell, 2007). • The maps of overall net migration rates and domestic migration rates are almost identical. This suggests that domestic migration accounts for much of the population change compared to international migration. Nonetheless, caution must be used in interpreting this pattern. In fact, it may seem that Nebraska has few international migrants. However, international migrants are counted as domestic migrants when they moved within the state in the last 12 months. Thus, it is important to note that the numbers of international migrants are not similar to the numbers of the foreign-born population. • Counties with high numbers of international migrants, particularly the metropolitan areas in the southeast part of the state, also have high numbers of ethnic minorities (e.g., Douglas, Lancaster, Sarpy). Although there are migrants from all over the world who come to Nebraska, the numbers suggest that most of the migrants identify as ‘ethnic minorities’ or non-White (see Population Distribution by Race, Ethnicity, and Age by Taylor et al., 2017). • International migrants are a diverse group and come to Nebraska for different reasons, such as to work and/or to study. The numbers presented above also include refugees, individuals who have been forced to leave their country to escape war, persecution, or natural disaster. Approximately 5,415 refugees from FY 2000 to FY 2010, and 818 refugees in FY 2010 settled in Nebraska. Additionally, as the census does not ask for immigration status, the migration rates and foreign-born population may also include undocumented immigrants, foreign-born individuals who do not have a legal right to live or remain in the country. Overall, this report presents the migration rates and foreign-born population in Nebraska. Data and information in this report intend to inform policymakers and practitioners as they design guidelines and services that are sensitive to current migration trends and responsive to the characteristics of the population

Application of a correlation correction factor in a microarray cross-platform reproducibility study

Background Recent research examining cross-platform correlation of gene expression intensities has yielded mixed results. In this study, we demonstrate use of a correction factor for estimating cross-platform correlations. Results In this paper, three technical replicate microarrays were hybridized to each of three platforms. The three platforms were then analyzed to assess both intra- and cross-platform reproducibility. We present various methods for examining intra-platform reproducibility. We also examine cross-platform reproducibility using Pearson\u27s correlation. Additionally, we previously developed a correction factor for Pearson\u27s correlation which is applicable when X and Y are measured with error. Herein we demonstrate that correcting for measurement error by estimating the disattenuated correlation substantially improves cross-platform correlations. Conclusion When estimating cross-platform correlation, it is essential to thoroughly evaluate intra-platform reproducibility as a first step. In addition, since measurement error is present in microarray gene expression data, methods to correct for attenuation are useful in decreasing the bias in cross-platform correlation estimates

Mapping Quality of Life in Nebraska: Population Distribution by Race, Ethnicity, and Age

KEY POINTS This section details key points from the data on racial, ethnic, and age groups across Nebraska. RACIAL AND ETHNIC MINORITIES IN NEBRASKA • The proportions of Nebraska’s racial and ethnic minority populations tend to be smaller by 4% (i.e., Asian) to 8% (i.e., Black or African American, Hispanic/Latino) than those of the US, except for the Hawaiian and Pacific Islander and American Indian and Alaska Native populations (i.e., smaller only by 0.1% to 0.2%). • Nebraska’s urban areas, which comprise 73.1% of the Nebraska population, have higher numbers of racial and ethnic minorities than suburban or rural areas. However, when the relative concentration of racial and ethnic minorities is taken into account, many of the lowest populated counties often have the highest relative concentrations of racial and ethnic minority groups, particularly Hawaiian and Pacific Islanders, American Indian and Alaska Natives, and Hispanic/Latinos, compared to the other counties. • Counties across the central part of the state, as well as the northeast corner, tend to have the highest relative concentrations of racial and ethnic minorities. NEBRASKA YOUNG CHILD AND YOUTH POPULATIONS • Counties in northeast Nebraska have the highest relative concentrations of young children and youth compared to the relative number of young children and youth in the entire state. • Other counties with high relative concentrations of young children and youth tend to be the state’s higher populated counties. NEBRASKA ELDERLY POPULATION • Counties with higher relative elderly concentrations tend to be in rural areas, specifically in western Nebraska and along the Nebraska-Kansas border. • Counties with high relative elderly concentrations tend to be counties with lower relative concentrations of young child and youth populations. INTERSECTIONS OF NEBRASKA RACIAL, ETHNIC, AND AGE GROUPS • Counties with high relative concentrations of young children and youth tend to be the ones that also have high relative concentrations of racial and ethnic minority populations, specifically Hispanic/Latinos and American Indian and Alaska Natives (e.g., Thurston, Platte, Colfax, Dakota, and Dawson counties). • Most counties in Nebraska with high racial/ ethnic minority concentrations have lower relative elderly concentrations, suggesting a low relative concentration of minority elders in these counties

President Lincoln and General Grant on Peace and War

The broadside is cream in color and features black ink. It contains an interview of Lincoln conducted by Mills. It also features a letter from Grant, and a poem by Taylor. The broadside has some damage to its corners and right side, but is in otherwise good condition.https://scholarsjunction.msstate.edu/fvw-ephemera/1018/thumbnail.jp

President Lincoln and General Grant on Peace and War

The broadside is cream in color and features black ink. It contains an interview of Lincoln conducted by Mills. It also features a letter from Grant, and a poem by Taylor. The broadside has some damage to its corners and right side, but is in otherwise good condition.https://scholarsjunction.msstate.edu/fvw-artifacts/1091/thumbnail.jp

Structural basis for Fullerene geometry in a human endogenous retrovirus capsid

The HML2 (HERV-K) group constitutes the most recently acquired family of human endogenous retroviruses, with many proviruses less than one million years old. Many maintain intact open reading frames and provirus expression together with HML2 particle formation are observed in early stage human embryo development and are associated with pluripotency as well as inflammatory disease, cancers and HIV-1 infection. Here, we reconstruct the core structural protein (CA) of an HML2 retrovirus, assemble particles in vitro and employ single particle cryogenic electron microscopy (cryo-EM) to determine structures of four classes of CA Fullerene shell assemblies. These icosahedral and capsular assemblies reveal at high-resolution the molecular interactions that allow CA to form both pentamers and hexamers and show how invariant pentamers and structurally plastic hexamers associate to form the unique polyhedral structures found in retroviral cores

Radio Polarimetry of the ELAIS N1 Field: Polarized Compact Sources

We present deep polarimetric observations at 1420 MHz of the European Large Area ISO Survey North 1 region (ELAIS N1) as part of the Dominion Radio Astrophysical Observatory Planck Deep Fields project. By combining closely spaced aperture synthesis fields, we image a region of 7.43 square degrees to a maximum sensitivity in Stokes Q and U of 78 microJy/beam, and detect 786 compact sources in Stokes I. Of these, 83 exhibit polarized emission. We find that the differential source counts (log N - log p) for polarized sources are nearly constant down to p > 500 microJy, and that these faint polarized radio sources are more highly polarized than the strong source population. The median fractional polarization is (4.8 +/- 0.7)% for polarized sources with Stokes I flux density between 1 and 30 mJy; approximately three times larger than sources with I > 100 mJy. The majority of the polarized sources have been identified with galaxies in the Spitzer Wide Area Infrared Extragalactic Survey (SWIRE) image of ELAIS N1. Most of the galaxies occupy regions in the IRAC 5.8/3.6 micron vs. 8.0/4.5 micron color-color diagram associated with dusty AGNs, or with ellipticals with an aging stellar population. A few host galaxies have colors that suggests significant PAH emission in the near-infrared. A small fraction, 12%, of the polarized sources are not detected in the SWIRE data. None of the polarized sources in our sample appears to be associated with an actively star-forming galaxy.Comment: 28 pages, 8 Figures. Figures 2 and 3 as separate gif images. Accepted for publication in the Astrophysical Journa