3,165 research outputs found
AN ECONOMIC EVALUATION OF THE COLORADO RIVER BASIN SALINITY CONTROL PROGRAM
Dissolved salts (salinity) adversely affect numerous urban and agricultural users of Colorado River water in California and Arizona. Congress in 1974 authorized a major salinity control program. Studies of general economic benefits from salinity abatement and the cost per unit of salinity reduction expected from specific proposed projects have been developed by the responsible federal agencies, but no project-by-project evaluation has been published. We find a conceptual basis for a substantial downward revision of prospective economic benefits of salinity abatement. Revised benefits are compared with estimated costs, and only for five of the nineteen projects do economic benefits appear to exceed costs.Resource /Energy Economics and Policy,
Cultivar-Dependent Expression of a Maize Lipoxygenase Responsive to Seed Infesting Fungi
Maize kernels are highly susceptible to Aspergillus spp. infection and aflatoxin (AF) contamination. Fatty acid signaling molecules appear to mediate the plant–fungal interaction by affecting the growth, development, and AF production of the fungus. In particular, fatty acid derivatives of the plant lipoxygenase (LOX) pathway are implicated in the Aspergillus spp.-seed interaction. The 9(S)-hydroperoxide derivative of linoleic acid promotes transcription of AF genes, whereas the 13(S)-hydroperoxide derivative decreases AF gene expression and production; both are sporulation factors. Our goal was to identify LOX genes responsive to Aspergillus spp. colonization and determine their specificities, 9(S)- or 13(S)-. Screening maize LOX expressed sequence tags (ESTs) identified one clone, cssap 92, which is highly expressed in Aspergillus spp.-infected seed susceptible to AF contamination and repressed in lines with resistance to AF contamination. The accumulation of cssap 92 transcript was similar during Fusarium spp. infection. The cDNA clone has 94% identity to the previously described L2 LOX gene from maize. Product-specificity analysis of the CSSAP 92 protein shows that it preferentially adds oxygen to carbon 9 of linoleic acid. Because 9(S)-hydroperoxy linoleic acid has been implicated as an aflatoxin-signaling molecule, it is possible that cssap 92 could be used as a biomarker that is indicative of AF resistance in maize lines
Cultivar-Dependent Expression of a Maize Lipoxygenase Responsive to Seed Infesting Fungi
Maize kernels are highly susceptible to Aspergillus spp. infection and aflatoxin (AF) contamination. Fatty acid signaling molecules appear to mediate the plant–fungal interaction by affecting the growth, development, and AF production of the fungus. In particular, fatty acid derivatives of the plant lipoxygenase (LOX) pathway are implicated in the Aspergillus spp.-seed interaction. The 9(S)-hydroperoxide derivative of linoleic acid promotes transcription of AF genes, whereas the 13(S)-hydroperoxide derivative decreases AF gene expression and production; both are sporulation factors. Our goal was to identify LOX genes responsive to Aspergillus spp. colonization and determine their specificities, 9(S)- or 13(S)-. Screening maize LOX expressed sequence tags (ESTs) identified one clone, cssap 92, which is highly expressed in Aspergillus spp.-infected seed susceptible to AF contamination and repressed in lines with resistance to AF contamination. The accumulation of cssap 92 transcript was similar during Fusarium spp. infection. The cDNA clone has 94% identity to the previously described L2 LOX gene from maize. Product-specificity analysis of the CSSAP 92 protein shows that it preferentially adds oxygen to carbon 9 of linoleic acid. Because 9(S)-hydroperoxy linoleic acid has been implicated as an aflatoxin-signaling molecule, it is possible that cssap 92 could be used as a biomarker that is indicative of AF resistance in maize lines
Effects of alternative electricity rates and rate structures on electricity and water use on the Colorado High Plains
October 1984.Contract report for Colorado Commission on Higher Education.Bibliography: pages 60-62
A Comprehensive Survey of Hydrogen Chloride in the Galaxy
We report new observations of the fundamental transition of HCl (at
625.918GHz) toward a sample of 25 galactic star-forming regions, molecular
clouds, and evolved stars, carried out using the Caltech Submillimeter
Observatory. Fourteen sources in the sample are also observed in the
corresponding H\tscl\ transition (at 624.978GHz). We have obtained
clear detections in all but four of the targets, often in emission. Absorptions
against bright background continuum sources are also seen in nine cases,
usually involving a delicate balance between emission and absorption features.
From RADEX modeling, we derive gas densities and HCl column densities for
sources with HCl emission. HCl is found in a wide range of environments, with
gas densities ranging from to ~cm. The HCl abundance
relative to H is in the range of . Comparing with the
chlorine abundance in the solar neighborhood, this corresponds to a chlorine
depletion factor of up to 400, assuming that HCl accounts for one third
of the total chlorine in the gas phase. The [\tfcl]/[\tscl] isotopic ratio is
rather varied, from unity to 5, mostly lower than the terrestrial value
of 3.1. Such variation is highly localized, and could be generated by the
nucleosynthesis in supernovae, which predicts a \tscl\ deficiency in most
models. The lower ratios seen in W3IRS4 and W3IRS5 likely confine the
progenitors of the supernovae to stars with relatively large mass
(\ga25M_\sun) and high metallicity (Z0.02).Comment: 11 pages, 5 figures, accepted by Ap
The changing reality of urothelial bladder cancer: should non-squamous variant histology be managed as a distinct clinical entity?
Objectives
To assess the effect of non-squamous differentiation (non-SQD) variant histology on survival in muscle-invasive bladder urothelial cancer (UC).
Patients and Methods
A cohort of 411 radical cystectomy (RC) cases performed with curative intent for muscle-invasive primary UC was identified between 2008 and June 2013. Survival analysis was evaluated using Kaplan–Meier methodology comparing non-variant (NV) + SQD histology to non-SQD variant histology (non-SQD variants). Multivariable cox proportional hazards regression assessed all-cause and disease-specific mortality.
Results
Of the 411 RC cases, 77 (19%) had non-SQD variant histology. The median overall survival (OS) for non-SQD variant histology was 28 months, whereas the NV+SQD group had not reached the median OS at 74 months (log-rank test P < 0.001). After adjusting for sex, age, pathological stage, and any systemic chemotherapy, patients with non-SQD variant histology at RC had a 1.57-times increased adjusted risk of all-cause mortality (P = 0.027) and 1.69-times increased risk of disease-specific mortality (P = 0.030) compared with NV+SQD patients.
Conclusions
While SQD behaves similarly to NV, non-SQD variant histology portends worse OS and disease-specific survival regardless of neoadjuvant or adjuvant chemotherapy and pathological stage. Non-SQD variants of UC could perhaps be considered a distinct clinical entity in UC with goals for developing new treatment algorithms through novel clinical trials
An Optical/Near-Infrared Study of Radio-Loud Quasar Environments II. Imaging Results
We use optical and near-IR imaging to examine the properties of the
significant excess population of K>=19 galaxies found in the fields of 31 z=1-2
radio-loud quasars by Hall, Green & Cohen (1998). The excess occurs on two
spatial scales: a component at <40'' from the quasars significant compared to
the galaxy surface density at >40'' in the same fields, and a component roughly
uniform to ~100'' significant compared to the galaxy surface density seen in
random-field surveys in the literature. The r-K color distributions of the
excess galaxy populations are indistinguishable and are significantly redder
than the color distribution of the field population.
The excess galaxies are consistent with being predominantly early-type
galaxies at the quasar redshifts, and there is no evidence that they are
associated with intervening MgII absorption systems. The average excess within
0.5 Mpc (~65'') of the quasars corresponds to Abell richness class ~0 compared
to the galaxy surface density at >0.5 Mpc from the quasars, and to Abell
richness class ~1.5 compared to that from the literature.
We discuss the spectral energy distributions (SEDs) of galaxies in fields
with data in several passbands. Most candidate quasar-associated galaxies are
consistent with being 2-3 Gyr old early-types at the quasar redshifts of z~1.5.
However, some objects have SEDs consistent with being 4-5 Gyr old at z~1.5, and
a number of others are consistent with ~2 Gyr old but dust-reddened galaxies at
the quasar redshifts. These potentially different galaxy types suggest there
may be considerable dispersion in the properties of early-type cluster galaxies
at z~1.5. There is also a population of galaxies whose SEDs are best modelled
by background galaxies at z>2.5.Comment: Accepted to ApJ; 54 pages including 30 figures; 2 color GIF files
available separately; also available from
http://www.astro.utoronto.ca/~hall/thesis.htm
Evaluation of the marginal fit of three margin designs of resin composite crowns using CAD/CAM
OBJECTIVES:
To examine the marginal fit of resin composite crowns manufactured with the CEREC 3 system employing three different margin designs; bevel, chamfer and shoulder, by means of a replica technique and a luting agent.
METHODS:
Three master casts were fabricated from an impression of a typodont molar tooth and a full-coverage crown prepared with a marginal finish of a bevel, a chamfer and a shoulder. Each cast was replicated 10 times (n = 10). Scanning of the replicas and crown designing was performed using the CEREC ScanTM system. The crowns were milled from Paradigm MZ100TM composite resin blocks. The marginal fit of the crowns was evaluated with a replica technique (AquasilTM LV, Dentsply), and with a resin composite cement (RelyXTM Unicem, AplicapTM) and measured with a travelling microscope. Statistical analysis was performed using two-way ANOVA.
RESULTS:
For the replica technique the average marginal gaps recorded were: Bevel Group 105±34 mm, Chamfer Group 94±27 mm and Shoulder Group 91±22 mm. For the resin composite cement the average marginal gaps were: Bevel Group 102±28 mm, Chamfer Group 91±11 mm and Shoulder Group 77±8 mm. Two-way ANOVA analysis showed that there was no statistically significant difference between the three groups of finishing lines regardless of the cementation technique used.
CONCLUSIONS:
The marginal gap of resin composite crowns manufactured with the CEREC 3 system is within the range of clinical acceptance, regardless of the finishing line prepared or the cementation technique used
Galaxies in Southern Bright Star Fields I. Near-infrared imaging
As a prerequisite for cosmological studies using adaptive optics techniques,
we have begun to identify and characterize faint sources in the vicinity of
bright stars at high Galactic latitudes. The initial phase of this work has
been a program of K_s imaging conducted with SOFI at the ESO NTT. From
observations of 42 southern fields evenly divided between the spring and autumn
skies, we have identified 391 additional stars and 1589 galaxies lying at
separations 60" from candidate guide stars in the magnitude range 9.0 R 12.4.
When analyzed as a "discrete deep field" with 131 arcmin^2 area, our dataset
gives galaxy number counts that agree with those derived previously over the
range 16 K_s 20.5. This consistency indicates that in the aggregate, our fields
should be suitable for future statistical studies. We provide our source
catalogue as a resource for users of large telescopes in the southern
hemisphere.Comment: 10 pages, 7 figures, accepted by A&A; Table 3 is available at
http://www.rzg.mpg.de/~ajb/data.html pending upload to CD
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