920 research outputs found
Effects of single mutations on the stability of horseradish peroxidase to hydrogen peroxide
Horseradish peroxidase (HRP) is a commonly used enzyme in many biotechnological fields. Improvement of HRP stability would further increase its potential application range. In the present study, 13 single- and three double-mutants of solvent exposed, proximal lysine and glutamic acid residues were analysed for enhanced H2O2 stability. Additionally, five single- and one pentuple-consensus mutants were investigated. Most mutants displayed little or no alteration in H2O2 stability; however, three (K232N, K241F and T110V) exhibited significantly increased H2O2 tolerances of 25- (T110V), 18- (K232N), and 12-fold (K241F). This improved stability may be due to an altered enzyme-H2O2 catalysis pathway or to removal of potentially oxidisable residues
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Community Supported Agriculture (CSA) in and around California’s Central Valley: Farm and Farmer Characteristics, Farm-Member Relationships, Economic Viability, Information Sources, and Emerging Issues
Stronger Constraints on the Evolution of the Relation up to
We revisit the possibility of redshift evolution in the
relation with a sample of 22 Seyfert 1 galaxies with
black holes (BHs) in the mass range and redshift
range with spectra obtained from spatially resolved
Keck/Low-Resolution Imaging Spectrometer observations. Stellar velocity
dispersions were measured directly from the Mg Ib region, taking into
consideration the effect of Fe II contamination, active galactic nucleus (AGN)
dilution, and host-galaxy morphology on our measurements. BH masses are
estimated using the H line width, and the luminosity at 5100
\overset{\lower.5em\circ}{\mathrm{A}} is estimated from surface brightness
decomposition of the AGN from the host galaxy using high-resolution imaging
from the Hubble Space Telescope. Additionally, we investigate the use of the [O
III] emission line width as a surrogate for stellar velocity
dispersion, finding better correlation once corrected for Fe II contamination
and any possible blueshifted wing components. Our selection criteria allowed us
to probe lower-luminosity AGNs and lower-mass BHs in the non-local universe
than those measured in previous single-epoch studies. We find that any offset
in the relation up to is consistent with the
scatter of local BH masses, and address the sources of biases and uncertainties
that contribute to this scatter.Comment: Accepted 14 May 2019 for publication in ApJ. 42 pages, 12 figures, 4
tables. Corrected for typographical error
DETERMINANTS OF COW-CALF PAIR PRICES
Cow-calf prices are determined by interaction of many factors. At a particular auction, cow-calf pair prices often had a range of 75% of the mean price. This variability suggests that producers need to be informed regarding cow-calf price determinants. This study uses auction data during 1993 to estimate price differentials associated with cow-calf pair characteristics using a hedonic model. Cow breed, age, health, conditions, horns, frame, and whether the cow had been bred back were significant price determinants. Calf weight, health, and frame had significant price impacts. Highest prices were paid for pens containing 9-12 pairs of young Angus, dehorned, bred back, healthy cows with heavy healthy calves.Demand and Price Analysis,
ImageJ2: ImageJ for the next generation of scientific image data
ImageJ is an image analysis program extensively used in the biological
sciences and beyond. Due to its ease of use, recordable macro language, and
extensible plug-in architecture, ImageJ enjoys contributions from
non-programmers, amateur programmers, and professional developers alike.
Enabling such a diversity of contributors has resulted in a large community
that spans the biological and physical sciences. However, a rapidly growing
user base, diverging plugin suites, and technical limitations have revealed a
clear need for a concerted software engineering effort to support emerging
imaging paradigms, to ensure the software's ability to handle the requirements
of modern science. Due to these new and emerging challenges in scientific
imaging, ImageJ is at a critical development crossroads.
We present ImageJ2, a total redesign of ImageJ offering a host of new
functionality. It separates concerns, fully decoupling the data model from the
user interface. It emphasizes integration with external applications to
maximize interoperability. Its robust new plugin framework allows everything
from image formats, to scripting languages, to visualization to be extended by
the community. The redesigned data model supports arbitrarily large,
N-dimensional datasets, which are increasingly common in modern image
acquisition. Despite the scope of these changes, backwards compatibility is
maintained such that this new functionality can be seamlessly integrated with
the classic ImageJ interface, allowing users and developers to migrate to these
new methods at their own pace. ImageJ2 provides a framework engineered for
flexibility, intended to support these requirements as well as accommodate
future needs
An Infrared Comparison of Type-1 and Type-2 Quasars
We model the optical to far-infrared SEDs of a sample of six type-1 and six
type-2 quasars selected in the mid-infrared. The objects in our sample are
matched in mid-IR luminosity and selected based on their Spitzer IRAC colors.
We obtained new targeted Spitzer IRS and MIPS observations and used archival
photometry to examine the optical to far-IR SEDs. We investigate whether the
observed differences between samples are consistent with orientation-based
unification schemes. The type-1 objects show significant emission at 3 micron.
They do not show strong PAH emission and have less far-IR emission on average
when compared to the type-2 objects. The SEDs of the type-2 objects show a wide
assortment of silicate features, ranging from weak emission to deep silicate
absorption. Some also show strong PAH features. In comparison, silicate is only
seen in emission in the type-1 objects. This is consistent with some of the
type-2s being reddened by a foreground screen of cooler dust, perhaps in the
host galaxy itself. We investigate the AGN contribution to the far-IR emission
and find it to be significant. We also estimate the star formation rate for
each of the objects by integrating the modeled far-IR flux and compare this
with the SFR found from PAH emission. We find the type-2 quasars have a higher
average SFR than the type-1 quasars based on both methods, though this could be
due to differences in bolometric luminosities of the objects. While we find
pronounced differences between the two types of objects, none of them are
inconsistent with orientation-based unification schemes.Comment: Accepted for publication in Ap
A Distance-Limited Imaging Survey of Sub-Stellar Companions to Solar Neighborhood Stars
We report techniques and results of a Palomar 200-inch (5 m) adaptive optics
imaging survey of sub-stellar companions to solar-type stars. The survey
consists of Ks coronagraphic observations of 21 FGK dwarfs out to 20 pc (median
distance about 17 pc). At 1-arcsec separation (17 projected AU) from a typical
target system, the survey achieves median sensitivities 7 mag fainter than the
parent star. In terms of companion mass, that corresponds to sensitivities of
50MJ (1 Gyr), 70MJ (solar age), and 75MJ (10 Gyr), using the evolutionary
models of Baraffe and colleagues. Using common proper motion to distinguish
companions from field stars, we find that no system shows positive evidence of
a previously unknown substellar companion (searchable separation about 20-250
projected AU at the median target distance).Comment: 29 pages, 5 figures. Carson et al. 2008, AJ, in pres
Improving self-management in a complex population through patient-centered education and interdisciplinary communication
The residual cognitive and physical deficits of traumatic brain injury and stroke create unique challenges during rehabilitation. A microsystem assessment of an inpatient rehabilitation unit serving traumatic brain injury and stroke patients identified areas for improvement in patient satisfaction and timely discharge preparation. Both of these issues were linked to poor communication and late initiation of education of patients and care partners. A literature review revealed that formal education and discharge programs for these populations have little effect on patient and care partner outcomes. As a result, an evidence-based project was undertaken using patient-centered education practices shown to be effective in improving patient and care partner satisfaction and self-management in patients returning to the community with residual deficits. A process improvement plan using the Plan-Do-Study-Act model was designed. A process change in patient and care partner education incorporating patient-centered themes and improved interdisciplinary communication was initiated and the results analyzed
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