17 research outputs found
Prairie Crop Diversification
The Canadian prairies traditionally have been dominated by spring wheat production. Crop diversification is now being advocated to enhance farm-level risk management, ecological benefits, nutrient cycling, and pest and disease control, and to reduce the farm economy’s reliance on income from a single crop. There has always been interest in diversifying away from wheat, but until recently, economically feasible alternatives have been limited, and government policies may have constrained the shift to other crops. Knowing the impact of prices and policies on crop diversification is essential to understanding producer response and to determining strategies to enhance cropping diversity.Marketing,
Tag Type and Location-Dependent Retention Impart Varied Levels of Bias on Mark–Recapture Parameter Estimates
Population parameter estimates from mark–recapture studies are dependent on individuals retaining marks or tags. Therefore, tag retention estimates are needed for different tag types and anatomical tagging locations. Few studies have empirically quantified the bias from tag retention on fish population parameters that are derived from mark–recapture studies. We examined differences in retention between T-bar anchor tags and PIT tags as well as among four anatomical locations for PIT tags in Brown Trout Salmo trutta in a tailwater fishery in Arkansas, USA. We also estimated the relative bias of tag type and PIT tag location on apparent survival estimates from Cormack–Jolly–-Seber models. Tag retention for the anchor tags was 15.1% lower than that for the PIT tags after 1 year and 46.1% lower after 4 years. Greater PIT tag retention resulted in less biased estimates of apparent survival for PIT tags (average −7.1%) than for anchor tags (average −37.8%). However, PIT tags that were placed in different anatomical locations had varying retention rates, so the degree of relative bias that was associated with their apparent survival estimates also varied. Inserting the PIT tags in the cheek or dorsal musculature provided the greatest retention for Brown Trout and may provide the least biased apparent survival estimates from future mark–recapture studies
Glycogen Synthase Kinase (GSK) 3β phosphorylates and protects nuclear myosin 1c from proteasome-mediated degradation to activate rDNA transcription in early G1 cells
Nuclear myosin 1c (NM1) mediates RNA polymerase I (pol I) transcription activation and cell cycle progression by facilitating PCAF-mediated H3K9 acetylation, but the molecular mechanism by which NM1 is regulated remains unclear. Here, we report that at early G1 the glycogen synthase kinase (GSK) 3β phosphorylates and stabilizes NM1, allowing for NM1 association with the chromatin. Genomic analysis by ChIP-Seq showed that this mechanism occurs on the rDNA as active GSK3β selectively occupies the gene. ChIP assays and transmission electron microscopy in GSK3β-/- mouse embryonic fibroblasts indicated that at G1 rRNA synthesis is suppressed due to decreased H3K9 acetylation leading to a chromatin state incompatible with transcription. We found that GSK3β directly phosphorylates the endogenous NM1 on a single serine residue (Ser-1020) located within the NM1 C-terminus. In G1 this phosphorylation event stabilizes NM1 and prevents NM1 polyubiquitination by the E3 ligase UBR5 and proteasome-mediated degradation. We conclude that GSK3β-mediated phosphorylation of NM1 is required for pol I transcription activation
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
Data from: Effects of environmental factors on sucker catch rate, size structure, species composition, and precision from boat electrofishing
This data is associated with the article "Effects of environmental factors on sucker catch rate, size structure, species composition, and precision from boat electrofishing." The data consists of two XLSX files and one README file associated with the methodology and documentation to allow for replication and verification of findings.Catostomidae (catostomids) are suckers of the order Cyprinifores and the majority of species are native to North America; however, species in this group are understudied and rarely managed. The popularity in bowfishing and gigging for suckers in the United States has increased concerns related to overfishing. Little information exists about the relative gear effectiveness for sampling catostomids. Our study objective was to evaluate the relative effectiveness of boat electrofishing for sampling Black Redhorse Moxostoma duquesnei, Golden Redhorse M. erythrurum, Northern Hogsucker Hypentelium nigricans, White Sucker, and Spotted Sucker populations in Lake Eucha, OK. We used an information theoretic approach to determine the abiotic variables related to sucker catch per effort (C/f). Our analysis indicated that sucker C/f was highest during night and decreased with increasing water temperature. Sucker size structure was significantly different between daytime and nighttime samples; however, effect size estimates for size structure comparisons indicated size distributions exhibited moderate overlap. Distributional comparisons indicated daytime and nighttime samples were similar for fish >180 mm total length (TL). Effect size estimates also suggested little association between the proportion of each species captured and time of day or water temperature. Night electrofishing at water temperatures from 16-25 ⁰C yielded the most precise C/f estimates. If managers are interested in precision, then we recommend night electrofishing suckers in reservoirs at water temperatures from 16-25 ⁰C; though, if total number of suckers is more important than precision, samples taken at night from 6-15 ⁰C are recommended. Further study of the relationship between abiotic variables and catostomid catchability using various gears would be beneficial to agencies interested in these populations.Natural Resource Ecology and Managemen
Prairie Crop Diversification
The Canadian prairies traditionally have been dominated by spring wheat production. Crop diversification is now being advocated to enhance farm-level risk management, ecological benefits, nutrient cycling, and pest and disease control, and to reduce the farm economy’s reliance on income from a single crop. There has always been interest in diversifying away from wheat, but until recently, economically feasible alternatives have been limited, and government policies may have constrained the shift to other crops. Knowing the impact of prices and policies on crop diversification is essential to understanding producer response and to determining strategies to enhance cropping diversity