97,441 research outputs found
Joshua Davis: Author of Spare Parts
No full textCitation: K-State First (2016). Joshua Davis: Author of Spare Parts [Flier]. Manhattan, Kansas: K-State First.Flyer advertising Joshua Davis's author talk at Kansas State University
Steven Johnson Author Talk Poster
No full textK-State Book NetworkA poster advertising an author talk by Steven Johnson at Kansas State University on September 3, 2014. Steven Johnson's book "The Ghost Map" was the 2014-2015 common book
Evolutionary synthesis models for the formation of S0 galaxies in clusters
No full textRich galaxy clusters in the local Universe show a large population of S0 galaxies
(~40% of all luminous galaxies). With increasing redshift the fraction of this S0
galaxy population is observed to strongly decrease (e.g. by a factor ~ to
) in favor of the spiral galaxy fraction while the number of bright ellipticals
does not seem to change. The infalling field galaxy population that successively builds
up the cluster also is spiral rich and S0 poor. It has hence been suspected that galaxy
transformation processes, either due to galaxy – galaxy or to galaxy – ICM
interactions, are responsible for this change. Complementing dynamical and morphological
studies, we use evolutionary synthesis models describing various possible effects of
those interactions on the star formation rates of the infalling spirals. We study the
effects of starbursts of various strengths as well as of the truncation of star formation
on the color and luminosity evolution of model galaxies of various spectral types.
Comparison with observed properties of the local S0 galaxy population is used to
constrain possible S0 formation mechanisms. We find that star formation truncation
in spiral galaxies earlier than Sd-type, if occurring not too long ago, as well as
starbursts more than 3 Gyr ago and followed by complete star formation extinction in
spirals – again earlier than Sd– may well account for the observed average S0
luminosities and colors. Late-type galaxies (Sd), even after a strong burst, remain
either too blue or too faint. Our results are in agreement with studies of spectral
features of cluster S0s but allow for stronger constraints
Determination of enantiomerization barriers of hypericin and pseudohypericin by dynamic high-performance liquid chromatography on immobilized polysaccharide-type chiral stationary phases and off-column racemization experiments
No full textDirect enantiomer separation of hypericin, pseudohypericin, and protohypericin
was accomplished by high-performance liquid chromatography (HPLC) using
immobilized polysaccharide-type chiral stationary phases (CSPs). Enantioselectivities
up to 1.30 were obtained in the polar-organic elution mode whereby for hypericin and
pseudohypericin Chiralpak IC [chiral selector being cellulose tris(3,5-dichlorophenylcarbamate)]
and for protohypericin Chiralpak IA (chiral selector being the 3,5-dimethylphenylcarbamate
of amylose) gave favorable results. Enantiomers were distinguished by
on-line electronic circular dichroism detection. Optimized enantioselective chromatographic
conditions were the basis for determining stereodynamic parameters of the
enantiomer interconversion process of hypericin and pseudohypericin. Rate constants
delivered by computational simulation of dynamic HPLC elution profiles (stochastic
model, consideration of peak tailing) were used to calculate averaged enantiomerization
barriers (DG]
enant) of 97.6–99.6 kJ/mol for both compounds (investigated temperature
range 25–458C). Complementary variable temperature off-column (i.e., in solution) racemization
experiments delivered DG]
enant 5 97.1–98.0 kJ/mol (27–458C) for hypericin and
DG]
enant 5 98.9–101.4 kJ/mol (25–558C) for pseudohypericin. An activation enthalpy of
DH# 5 86.0 kJ/mol and an activation entropy of DS# 5 237.7 J/(K mol) were calculated
from hypericin racemization kinetics in solution, whereas for pseudohypericin these
figures amounted to 74.1 kJ/mol and 282.6 J/(K mol), respectively. Although the natural
phenanthroperylene quinone pigments hypericin and pseudohypericin as well as
their biological precursor protohypericin are chiral and can be separated by enantioselective
HPLC low enantiomerization barriers seem to prevent the occurrence of an
excess of one enantiomer under typical physiological conditions—at least as long as
stereoselective intermolecular interactions with other chiral entities are absen
Chemically consistent evolution of galaxies II. Spectrophotometric evolution from zero to high redshift
No full textThe composite stellar populations of galaxies comprise stars of a
wide range of metallicities. Subsolar metallicities become increasingly
important, both in the local universe when going from early towards later galaxy
types as well as for dwarf galaxies and for all types of galaxies towards higher
redshifts.
We present a new generation of chemically consistent evolutionary synthesis models
for galaxies of various spectral types from E through Sd. The models follow the
chemical enrichment of the ISM and take into account the increasing initial
metallicity of successive stellar generations using recently published metallicity
dependent stellar evolutionary isochrones, spectra and yields.
Our first set of closed-box 1-zone models does not include any spatial resolution or
dynamics. For a Salpeter initial mass function (IMF) the star formation rate
(SFR) and its time evolution are shown to successfully parameterise spectral
galaxy types E, ..., Sd. We show how the stellar metallicity distribution in various
galaxy types build up with time to yield after ~12 Gyr agreement with stellar
metallicity distributions observed in our and other local galaxies.
The models give integrated galaxy spectra over a wide wavelength
range (90.9 Å–160 μm), which for ages of ~12 Gyr are in good
agreement not only with observed broad band colours but also with template
spectra for the respective galaxy types.
Using filter functions for Johnson-Cousins , IC, as well as
for HST broad band filters in the optical and Bessel & Brett's NIR J, H, K filter
system, we calculate the luminosity and colour evolution of model galaxies over a
Hubble time.
Including a standard cosmological model () and the
attenuation by intergalactic hydrogen we present evolutionary and cosmological
corrections as well as apparent luminosities in various filters over the redshift
range from to the present for our galaxy types and compare to earlier
models using single (=solar) metallicity input physics only. We also resent a first
comparison of our cc models to HDF data. A more detailed comparison with Hubble
Deep Field (HDF) and other deep field data and an analysis and interpretation of high
redshift galaxies in terms of ages, metallicities, star formation histories and,
galaxy types will be the subject of a forthcoming paper
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Expanding “Communities and Collections” in the K-State Research Exchange (K-REx) to benefit the K-State Community and Beyond
No full textKansas State University has used its institutional repository, the K-State Research Exchange (K-REx), to store and share its first year experience program, K-State First, and notably its common reading program, K-State First Book. We have done so with the aim that the accessibility and preservation of these documents ensures program stability, promotes engagement with first year programming, and provides the ability to foster growth,educational opportunities, and community building outside of K-State. Moving away from research concentrated repositories and taking a more holistic approach to scholarship, especially when realizing the pedagogical significance of collaborative campus programming, institutions can showcase, discover, preserve, and grow programs that shape campus communities and engagement.
This session will provide an overview of K-REx and spotlight the digital archive of the university’s first year experience program and common reading program, K-State First Book. We will discuss the benefits and challenges to expanding the purview of your repositories. We talkthrough the types of materials we decide to host in our repository and why we share what we do. We will also provide recommendations on new ways to evaluate what belongs in institutional repositories and how this diversity can benefit your program, your institution, the community, and others
Ready Player One Program Event Poster
No full textK-State Book NetworkA poster advertising an author talk by Ernest Cline at Kansas State University on October 10, 2013. Ernest Cline's book "Ready Player One" was selected as the 2013-2014 common book
Depolarization and decreased surface expression of K+ channels contribute to NSAID-inhibition of intestinal restitution
No full textNon-steroidal anti-inflammatory drugs (NSAIDs) contribute to gastrointestinal ulcer formation by inhibiting epithelial cell migration and mucosal restitution; however, the drug-affected signaling pathways are poorly defined. We investigated whether NSAID inhibition of intestinal epithelial migration is associated with depletion of intracellular polyamines, depolarization of membrane potential (Em) and altered surface expression of K+ channels. Epithelial cell migration in response to the wounding of confluent IEC-6 and IEC-Cdx2 monolayers was reduced by indomethacin (100μM), phenylbutazone (100μM) and NS-398 (100μM) but not by SC-560 (1μM). NSAID-inhibition of intestinal cell migration was not associated with depletion of intracellular polyamines. Treatment of IEC-6 and IEC-Cdx2 cells with indomethacin, phenylbutazone and NS-398 induced significant depolarization of Em, whereas treatment with SC-560 had no effect on Em. The Em of IEC-Cdx2 cells was: −38.5±1.8mV under control conditions; −35.9±1.6mV after treatment with SC-560; −18.8±1.2mV after treatment with indomethacin; and −23.7±1.4mV after treatment with NS-398. Whereas SC-560 had no significant effects on the total cellular expression of Kv1.4 channel protein, indomethacin and NS-398 decreased not only the total cellular expression of Kv1.4, but also the cell surface expression of both Kv1.4 and Kv1.6 channel subunits in IEC-Cdx2. Both Kv1.4 and Kv1.6 channel proteins were immunoprecipitated by Kv1.4 antibody from IEC-Cdx2 lysates, indicating that these subunits co-assemble to form heteromeric Kv channels. These results suggest that NSAID inhibition of epithelial cell migration is independent of polyamine-depletion, and is associated with depolarization of Em and decreased surface expression of heteromeric Kv1 channels.ID: S0006295207001931; M3: Article; Accession Number: S0006295207001931; Author: L.C. Freeman (b); Author: D.F. Narvaez (a); Author: A. McCoy (a); Author: F.B. von Stein (c); Author: S. Young (b); Author: K. Silver (a); Author: S. Ganta (b); Author: D. Koch (b); Author: R. Hunter (b); Author: R.F. Gilmour (c); Author: J.D. Lillich (a, ⁎); Affiliation: Department of Clinical Sciences, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, United States; Keyword: Non-steroidal anti-inflammatory drugs; Keyword: Intestinal epithelial cells; Keyword: Membrane potential; Keyword: Potassium channels; Number of Pages: 12; Language: English;Source type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=edselp&AN=S0006295207001931&site=eds-live&scope=sit
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