614 research outputs found
Consistent and High Rates of Gene Transfer Can Be Obtained Using Flow-Through Transduction over a Wide Range of Retroviral Titers
Overview summary Flow-through transduction provides a means by which high rates of gene transfer can occur without using high titers of virus vector. Reproducibly high numbers of transduced cells can be obtained with a wide range of virus titers, thus relaxing the requirement of set (high) titers within a transduction protocol. Incorporating flow-through transductions within clinical applications of gene therapy may also obviate the need for large volumes of high-titer virus produced by vector producer cell line cultures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63214/1/hum.1996.7.6-743.pd
The Software Required for the Computer Generation of Virtual Environments
Presence, Vol. 2, No. 2, pp. 130-140..Accepted/Published Paper (Refereed
Eccentric lamellar keratolimbal grafts harvested with a manually guided microkeratome
Background: To perform lamellar keratolimbal allograft transplantation in a one- step procedure with a single graft, we investigated the feasibility of harvesting eccentric lamellar keratolimbal grafts from conventionally processed corneoscleral buttons using a manually guided microkeratome in conjunction with an artificial anterior chamber system. Methods: We used the Moria LSK- One microkeratome and the automated lamellar therapeutic keratoplasty ( ALTK) system ( Antony, France). Ten human donor eyes were used to obtain single- piece lamellar keratolimbal grafts. Specimens were processed for light and electron microscopy. Results: Eccentric keratolimbal grafts could be obtained from all human donor buttons. Grafts include a crescent- shaped limbal and a large corneal portion. No visible damage to the limbal region was discernible. Conclusion: Our data show that the LSK- One microkeratome in conjunction with the ALTK system allows harvesting eccentric keratolimbal grafts from donor corneoscleral buttons. Copyright (c) 2007 S. Karger AG, Basel
PTF11iqb: Cool supergiant mass loss that bridges the gap between Type IIn and normal supernovae
PTF11iqb was initially classified as a TypeIIn event caught very early after
explosion. It showed narrow Wolf-Rayet (WR) spectral features on day 2, but the
narrow emission weakened quickly and the spectrum morphed to resemble those of
Types II-L and II-P. At late times, Halpha emission exhibited a complex,
multipeaked profile reminiscent of SN1998S. In terms of spectroscopic
evolution, we find that PTF11iqb was a near twin of SN~1998S, although with
weaker interaction with circumstellar material (CSM) at early times, and
stronger CSM interaction at late times. We interpret the spectral changes as
caused by early interaction with asymmetric CSM that is quickly (by day 20)
enveloped by the expanding SN ejecta photosphere, but then revealed again after
the end of the plateau when the photosphere recedes. The light curve can be
matched with a simple model for weak CSM interaction added to the light curve
of a normal SN~II-P. This plateau requires that the progenitor had an extended
H envelope like a red supergiant, consistent with the slow progenitor wind
speed indicated by narrow emission. The cool supergiant progenitor is
significant because PTF11iqb showed WR features in its early spectrum ---
meaning that the presence of such WR features in an early SN spectrum does not
necessarily indicate a WR-like progenitor. [abridged] Overall, PTF11iqb bridges
SNe~IIn with weaker pre-SN mass loss seen in SNe II-L and II-P, implying a
continuum between these types.Comment: 21 pages, 12 figures, submitted to MNRA
Sal-Site: Integrating new and existing ambystomatid salamander research and informational resources
Salamanders of the genus Ambystoma are a unique model organism system because they enable natural history and biomedical research in the laboratory or field. We developed Sal-Site to integrate new and existing ambystomatid salamander research resources in support of this model system. Sal-Site hosts six important resources: 1) Salamander Genome Project: an information-based web-site describing progress in genome resource development, 2) Ambystoma EST Database: a database of manually edited and analyzed contigs assembled from ESTs that were collected from A. tigrinum tigrinum and A. mexicanum, 3) Ambystoma Gene Collection: a database containing full-length protein-coding sequences, 4) Ambystoma Map and Marker Collection: an image and database resource that shows the location of mapped markers on linkage groups, provides information about markers, and provides integrating links to Ambystoma EST Database and Ambystoma Gene Collection databases, 5) Ambystoma Genetic Stock Center: a website and collection of databases that describe an NSF funded salamander rearing facility that generates and distributes biological materials to researchers and educators throughout the world, and 6) Ambystoma Research Coordination Network: a web-site detailing current research projects and activities involving an international group of researchers. Sal-Site is accessible at
Bacterial Killing Via A Type Iv Secretion System.
Type IV secretion systems (T4SSs) are multiprotein complexes that transport effector proteins and protein-DNA complexes through bacterial membranes to the extracellular milieu or directly into the cytoplasm of other cells. Many bacteria of the family Xanthomonadaceae, which occupy diverse environmental niches, carry a T4SS with unknown function but with several characteristics that distinguishes it from other T4SSs. Here we show that the Xanthomonas citri T4SS provides these cells the capacity to kill other Gram-negative bacterial species in a contact-dependent manner. The secretion of one type IV bacterial effector protein is shown to require a conserved C-terminal domain and its bacteriolytic activity is neutralized by a cognate immunity protein whose 3D structure is similar to peptidoglycan hydrolase inhibitors. This is the first demonstration of the involvement of a T4SS in bacterial killing and points to this special class of T4SS as a mediator of both antagonistic and cooperative interbacterial interactions.6645
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PYROPROCESSING PROGRESS AT IDAHO NATIONAL LABORATORY
At the end of May 2007, 830 and 2600 kilograms of EBR-II driver and blanket metal fuel have been treated by a pyroprocess since spent fuel operations began in June 1996. A new metal waste furnace has completed out-of-cell testing and is being installed in the Hot Fuel Examination Facility. Also, ceramic waste process development and qualification is progressing so integrated nuclear fuel separations and high level waste processes will exist at Idaho National Laboratory. These operations have provided important scale-up and performance data on engineering scale operations. Idaho National Laboratory is also increasing their laboratory scale capabilities so new process improvements and new concepts can be tested before implementation at engineering scale. This paper provides an overview of recent achievements and provides the interested reader references for more details
Reverberation Mapping of the Kepler-Field AGN KA1858+4850
KA1858+4850 is a narrow-line Seyfert 1 galaxy at redshift 0.078 and is among
the brightest active galaxies monitored by the Kepler mission. We have carried
out a reverberation mapping campaign designed to measure the broad-line region
size and estimate the mass of the black hole in this galaxy. We obtained 74
epochs of spectroscopic data using the Kast Spectrograph at the Lick 3-m
telescope from February to November of 2012, and obtained complementary V-band
images from five other ground-based telescopes. We measured the H-beta light
curve lag with respect to the V-band continuum light curve using both
cross-correlation techniques (CCF) and continuum light curve variability
modeling with the JAVELIN method, and found rest-frame lags of lag_CCF = 13.53
(+2.03, -2.32) days and lag_JAVELIN = 13.15 (+1.08, -1.00) days. The H-beta
root-mean-square line profile has a width of sigma_line = 770 +/- 49 km/s.
Combining these two results and assuming a virial scale factor of f = 5.13, we
obtained a virial estimate of M_BH = 8.06 (+1.59, -1.72) x 10^6 M_sun for the
mass of the central black hole and an Eddington ratio of L/L_Edd ~ 0.2. We also
obtained consistent but slightly shorter emission-line lags with respect to the
Kepler light curve. Thanks to the Kepler mission, the light curve of
KA1858+4850 has among the highest cadences and signal-to-noise ratios ever
measured for an active galactic nucleus; thus, our black hole mass measurement
will serve as a reference point for relations between black hole mass and
continuum variability characteristics in active galactic nuclei
Distinct Genetic Architectures for Male and Female Inflorescence Traits of Maize
We compared the genetic architecture of thirteen maize morphological traits in a large population of recombinant inbred lines. Four traits from the male inflorescence (tassel) and three traits from the female inflorescence (ear) were measured and studied using linkage and genome-wide association analyses and compared to three flowering and three leaf traits previously studied in the same population. Inflorescence loci have larger effects than flowering and leaf loci, and ear effects are larger than tassel effects. Ear trait models also have lower predictive ability than tassel, flowering, or leaf trait models. Pleiotropic loci were identified that control elongation of ear and tassel, consistent with their common developmental origin. For these pleiotropic loci, the ear effects are larger than tassel effects even though the same causal polymorphisms are likely involved. This implies that the observed differences in genetic architecture are not due to distinct features of the underlying polymorphisms. Our results support the hypothesis that genetic architecture is a function of trait stability over evolutionary time, since the traits that changed most during the relatively recent domestication of maize have the largest effects
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