Lethal and Semilethal Mutation Frequency of the First and Second Chromosomes in Two Natural Populations of "Drosophila melanogaster"

iii, 40 leaves. Advisor: Michael E. MyszewskiThe problem. The present study was undertaken to examine potential genetic diversity as measured by the lethal gene frequencies between two natural populations of "Drosophila melanogaster". High levels of trichloroethylene (TCE) and other suspected mutagens and carcinogens, i.e., vinyl chloride, chloroform, etc., have reportedly been found in subsurface soil and waters near downtown Des Moines, Iowa. Lethal gene frequency of the first (X) and second chromosomes of the toxic population sample (captured within the toxic plume locale), was determined by genetic analysis and compared to that of a "control" population sample captured in an area believed to be free of chemical contamination. Procedure. The Basc technique for determining X-linked lethal mutation frequency and the Cy/Pm method for determining second chromosome lethal mutation frequency were employed. Mutation frequencies were calculated and data was analyzed by the Chi-square method. Findings. The X-linked lethal mutation frequency of the control population sample was found to be 0%. Compared with the toxic population X-linked lethal mutation frequency of 1.47%, the difference is not significant. Drastic (lethal + semilethal) mutation frequency of the control population second chromosomes was found to be 48%. When compared to the toxic population second chromosome drastic mutation frequency of 56%, the difference is not significant. Conclusion. The data obtained from this study showed that the chemical contamination of the toxic population sample habitat had no significant effect on the frequency of X-linked or second chromosome lethal mutation

Subresultants in multiple roots: an extremal case

We provide explicit formulae for the coefficients of the order-d polynomial subresultant of (x-\alpha)^m and (x-\beta)^n with respect to the set of Bernstein polynomials \{(x-\alpha)^j(x-\beta)^{d-j}, \, 0\le j\le d\}. They are given by hypergeometric expressions arising from determinants of binomial Hankel matrices.Comment: 18 pages, uses elsart. Revised version accepted for publication at Linear Algebra and its Application

The IRAC Dark Field; Far- Infrared to X-ray Data

We present 20 band photometry from the far-IR to X-ray in the Spitzer IRAC dark field. The bias for the near-IR camera on Spitzer is calibrated by observing a ~20 arcminute diameter "dark" field near the north ecliptic pole roughly every two-to-three weeks throughout the mission duration of Spitzer. The field is unique for its extreme depth, low background, high quality imaging, time-series information, and accompanying photometry including data taken with Akari, Palomar, MMT, KPNO, Hubble, and Chandra. This serendipitous survey contains the deepest mid-IR data taken to date. This dataset is well suited for studies of intermediate redshift galaxy clusters, high redshift galaxies, the first generation of stars, and the lowest mass brown dwarfs, among others. This paper provides a summary of the data characteristics and catalog generation from all bands collected to date as well as a discussion of photometric redshifts and initial and expected science results and goals. To illustrate the scientific potential of this unique dataset, we also present here IRAC color color diagrams.Comment: 12 pages, ApJS accepte

The Individual Inclination to an Occupation and its Neuronal Correlate

Many young people decide their professional direction during adolescence. This often coincides with vulnerable phases of puberty-related maturation that is usually accompanied by difficulties in assessing one’s personal inclinations and competences. Several psychological tests have been established among teachers and career advisers serving as a tool for professional coaching the teenagers’ competences and preferences. Many tools are based on the “Theory of Vocational Personalities in Work Environment” developed by John L. Holland since the 1950s, comprising the “RIASEC” model. Today, this theory provides the basis for tests which are used and refined all over the world. Professor Stangl’s online assessable “Situational Interest Test” (SIT) is based on Holland’s theory. By means of 30 short assessments the SIT questionnaire assesses the participant’s personality traits: Realistic (“Doers”), Investigative (“Thinkers”), Artistic (“Creators”), Social (“Helpers”), Enterprising (“Persuaders”), and Conventional (“Organizers”). Modern Magnetic Resonance Imaging (MRI) is able to discriminate between the brain’s compartments as Gray and White Matter using Voxel-Based Morphometry (VBM). This tool allows to reshape and to normalize human brains’ structure to statistically examining individual brains. Up to now findings from 20 years of functional MRI gave detailed insights in correlations between brain structures and mental functions. Hence, knowledge on structural base of cognitive or behavioral patterns is available as a brain’s map for assigning anatomical regions to their functions. The present study demonstrates that there are statistically relevant correlations between all dimensions of Holland’s RIASEC theory by assessing individual professional inclinations and the neuronal structures of the brain. Results show correspondence between the personality traits assigned by the RIASEC test and the functions of significant structural alterations in distinct brain areas well-known from literature

The Infrared Array Camera Dark Field: Far-Infrared to X-ray Data

We present 20 band photometry from the far-IR to X-ray in the Spitzer Infrared Array Camera (IRAC) dark field. The bias for the near-IR camera on Spitzer is calibrated by observing a ~20' diameter "dark" field near the north ecliptic pole roughly every two-to-three weeks throughout the mission duration of Spitzer. The field is unique for its extreme depth, low background, high quality imaging, time-series information, and accompanying photometry including data taken with Akari, Palomar, MMT, KPNO, Hubble, and Chandra. This serendipitous survey contains the deepest mid-IR data taken to date. This data set is well suited for studies of intermediate-redshift galaxy clusters, high-redshift galaxies, the first generation of stars, and the lowest mass brown dwarfs, among others. This paper provides a summary of the data characteristics and catalog generation from all bands collected to date as well as a discussion of photometric redshifts and initial and expected science results and goals. To illustrate the scientific potential of this unique data set, we also present here IRAC color-color diagrams

Galaxy Clusters in the IRAC Dark Field II: Mid-IR Sources

We present infrared luminosities, star formation rates, colors, morphologies, locations, and AGN properties of 24 micron-detected sources in photometrically detected high-redshift clusters in order to understand the impact of environment on star formation and AGN evolution in cluster galaxies. We use three newly-identified z=1 clusters selected from the IRAC dark field; the deepest ever mid-IR survey with accompanying, 14 band multiwavelength data including deep HST imaging and deep wide-area Spitzer MIPS 24 micron imaging. We find 90 cluster members with MIPS detections within two virial radii of the cluster centers, of which 17 appear to have spectral energy distributions dominated by AGN and the rest dominated by star formation. We find that 43 of the star forming are luminous infrared galaxies (LIRGs). The majority of sources (81%) are spirals or irregulars. A large fraction (at least 25%) show obvious signs of interactions. The MIPS -detected member galaxies have varied spatial distributions as compared to the MIPS-undetected members with one of the three clusters showing SF galaxies being preferentially located on the cluster outskirts, while the other 2 clusters show no such trend. Both the AGN fraction and the summed SFR of cluster galaxies increases from z=0 to 1, at a rate that is a few times faster in clusters than over the same redshift range in the field. Cluster environment does have an effect on the evolution of both AGN fraction and SFR from redshift one to the present, but does not effect the infrared luminosities or morphologies of the MIPS sample. Star formation happens in the same way regardless of environment making MIPS sources look the same in the cluster and field, however the cluster environment does encourage a more rapid evolution with time as compared to the field.Comment: 18 pages, 9 figures, ApJ accepte

Structural and functional characterization of the two phosphoinositide binding sites of PROPPINs.

β-propellers that bind polyphosphoinositides (PROPPINs), a eukaryotic WD-40 motif-containing protein family, bind via their predicted β-propeller fold the polyphosphoinositides PtdIns3P and PtdIns(3,5)P2 using a conserved FRRG motif. PROPPINs play a key role in macroautophagy in addition to other functions. We present the 3.0-Å crystal structure of Kluyveromyces lactis Hsv2, which shares significant sequence homologies with its three Saccharomyces cerevisiae homologs Atg18, Atg21, and Hsv2. It adopts a seven-bladed β-propeller fold with a rare nonvelcro propeller closure. Remarkably, in the crystal structure, the two arginines of the FRRG motif are part of two distinct basic pockets formed by a set of highly conserved residues. In comprehensive in vivo and in vitro studies of ScAtg18 and ScHsv2, we define within the two pockets a set of conserved residues essential for normal membrane association, phosphoinositide binding, and biological activities. Our experiments show that PROPPINs contain two individual phosphoinositide binding sites. Based on docking studies, we propose a model for phosphoinositide binding of PROPPINs

Channel coincidence counter: version 1

A thermal neutron coincidence counter has been designed for the assay of fast critical assembly fuel drawers and plutonium-bearing fuel rods. The principal feature of the detector is a 7-cm by 7-cm by 97-cm detector channel, which provides a uniform neutron detection efficiency of 16% along the central 40 cm of the channel. The electronics system is identical to that used for the High-Level Neutron Coincidence Counter

Calibration and data quality of warm IRAC

We present an overview of the calibration and properties of data from the IRAC instrument aboard the Spitzer Space Telescope taken after the depletion of cryogen. The cryogen depleted on 15 May 2009, and shortly afterward a two-month- long calibration and characterization campaign was conducted. The array temperature and bias setpoints were revised on 19 September 2009 to take advantage of lower than expected power dissipation by the instrument and to improve sensitivity. The final operating temperature of the arrays is 28.7 K, the applied bias across each detector is 500 mV and the equilibrium temperature of the instrument chamber is 27.55 K. The final sensitivities are essentially the same as the cryogenic mission with the 3.6 μm array being slightly less sensitive (10%) and the 4.5 μm array within 5% of the cryogenic sensitivity. The current absolute photometric uncertainties are 4% at 3.6 and 4.5 μm, and better than milli-mag photometry is achievable for long-stare photometric observations. With continued analysis, we expect the absolute calibration to improve to the cryogenic value of 3%. Warm IRAC operations fully support all science that was conducted in the cryogenic mission and all currently planned warm science projects (including Exploration Science programs). We expect that IRAC will continue to make ground-breaking discoveries in star formation, the nature of the early universe, and in our understanding of the properties of exoplanets