History of Grass Breeding for Grazing Lands in the Northern Great Plains of the USA and Canada

• In the early 1930s there were millions of acres of extensively degraded grazing lands and abandoned and eroded cropland in the Northern Plains of the United States and Canada. • Grass breeding and plant materials programs were established by both the US and Canadian governments and cooperating universities to develop revegetation materials. • Efforts of a small number of research locations and people resulted in grass cultivars or varieties that were used to revegetate and preserve the soil on millions of acres of land. • This is a brief history of the people, agencies, and universities that developed these cultivars that restored and increased the productivity of grasslands in the Northern Plains

Feature-Based Change Detection Reveals Inconsistent Individual Differences in Visual Working Memory Capacity

Visual working memory (VWM) is a key cognitive system that enables people to hold visual information in mind after a stimulus has been removed and compare past and present to detect changes that have occurred. VWM is severely capacity limited to around 3–4 items, although there are robust individual differences in this limit. Importantly, these individual differences are evident in neural measures of VWM capacity. Here, we capitalized on recent work showing that capacity is lower for more complex stimulus dimension. In particular, we asked whether individual differences in capacity remain consistent if capacity is shifted by a more demanding task, and, further, whether the correspondence between behavioral and neural measures holds across a shift in VWM capacity. Participants completed a change detection (CD) task with simple colors and complex shapes in an fMRI experiment. As expected, capacity was significantly lower for the shape dimension. Moreover, there were robust individual differences in behavioral estimates of VWM capacity across dimensions. Similarly, participants with a stronger BOLD response for color also showed a strong neural response for shape within the lateral occipital cortex, intraparietal sulcus (IPS), and superior IPS. Although there were robust individual differences in the behavioral and neural measures, we found little evidence of systematic brain-behavior correlations across feature dimensions. This suggests that behavioral and neural measures of capacity provide different views onto the processes that underlie VWM and CD. Recent theoretical approaches that attempt to bridge between behavioral and neural measures are well positioned to address these findings in future work

Exploring the elephant: histopathology in high-throughput phenotyping of mutant mice

Recent advances in gene knockout techniques and the in vivo analysis of mutant mice, together with the advent of large-scale projects for systematic mouse mutagenesis and genome-wide phenotyping, have allowed the creation of platforms for the most complete and systematic analysis of gene function ever undertaken in a vertebrate. The development of high-throughput phenotyping pipelines for these and other large-scale projects allows investigators to search and integrate large amounts of directly comparable phenotype data from many mutants, on a genomic scale, to help develop and test new hypotheses about the origins of disease and the normal functions of genes in the organism. Histopathology has a venerable history in the understanding of the pathobiology of human and animal disease, and presents complementary advantages and challenges to in vivo phenotyping. In this review, we present evidence for the unique contribution that histopathology can make to a large-scale phenotyping effort, using examples from past and current programmes at Lexicon Pharmaceuticals and The Jackson Laboratory, and critically assess the role of histopathology analysis in high-throughput phenotyping pipelines

Switchgrass Biomass Production in the Midwest USA: Harvest and Nitrogen Management

Information on optimal harvest periods and N fertilization rates for switchgrass (Panicum virgatum L.) grown as a biomass or bioenergy crop in the Midwest USA is limited. Our objectives were to determine optimum harvest periods and N rates for biomass production in the region. Established stands of \u27Cave-in-Rock\u27 switchgrass at Ames, IA, and Mead, NE, were fertilized 0, 60, 120, 180, 240, or 300 kg N ha-1. Harvest treatments were two- or one-cut treatments per year, with initial harvest starting in late June or early July (Harvest 1) and continuing at approximately 7-d intervals until the latter part of August (Harvest 7). A final eighth harvest was completed after a killing frost. Regrowth was harvested on previously harvested plots at that time. Soil samples were taken before fertilizer was applied in the spring of 1994 and again in the spring of 1996. Averaged over years, optimum biomass yields were obtained when switchgrass was harvested at the maturity stages R3 to R5 (panicle fully emerged from boot to postanthesis) and fertilized with 120 kg N ha-1. Biomass yields with these treatments averaged 10.5 to 11.2 Mg ha-1 at Mead and 11.6 to 12.6 Mg ha-1 at Ames. At this fertility level, the amount of N removed was approximately the same as the amount applied. At rates above this level, soil NO3-N concentrations increased

Notes: Evaluation Of A Filter Bag System For NDF, ADF, And IVDMD Forage Analysis

A new method of determining in vitro dry matter digestibility (IVDMD) as recently developed in which the digestion is conducted with the forage samples in filter bags. Our objective was to compare the filter bag and conventional IVDMD analysis methods using smooth bromegrass (Bromus inermis Leyss.), switchgrass (Panicum virgatum L.), and forage sorghum [Sorghum bicolor (L.) Moench] samples. In addition, the filter bag analysis systems for determining non-sequential neutral and acid detergent fiber (NDF and ADF), respectively, were compared with the non-sequential conventional analysis systems. In the filter bag systems, the forage samples are sealed in filter bags and the analyses are conducted on a batch basis rather than on an individual basis as in the conventional IVDMD and fiber analysis procedures. The filter bag analysis methods produced results similar to the conventional methods and ranked the forage samples in the same relative order

Notes: Evaluation Of A Filter Bag System For NDF, ADF, And IVDMD Forage Analysis

A new method of determining in vitro dry matter digestibility (IVDMD) as recently developed in which the digestion is conducted with the forage samples in filter bags. Our objective was to compare the filter bag and conventional IVDMD analysis methods using smooth bromegrass (Bromus inermis Leyss.), switchgrass (Panicum virgatum L.), and forage sorghum [Sorghum bicolor (L.) Moench] samples. In addition, the filter bag analysis systems for determining non-sequential neutral and acid detergent fiber (NDF and ADF), respectively, were compared with the non-sequential conventional analysis systems. In the filter bag systems, the forage samples are sealed in filter bags and the analyses are conducted on a batch basis rather than on an individual basis as in the conventional IVDMD and fiber analysis procedures. The filter bag analysis methods produced results similar to the conventional methods and ranked the forage samples in the same relative order

Illumination in symbiotic binary stars: Non-LTE photoionization models. II. Wind case

We describe a non-LTE photoionization code to calculate the wind structure and emergent spectrum of a red giant wind illuminated by the hot component of a symbiotic binary system. We consider spherically symmetric winds with several different velocity and temperature laws and derive predicted line fluxes as a function of the red giant mass loss rate, \mdot. Our models generally match observations of the symbiotic stars EG And and AG Peg for \mdot about 10^{-8} \msunyr to 10^{-7} \msunyr. The optically thick cross- section of the red giant wind as viewed from the hot component is a crucial parameter in these models. Winds with cross-sections of 2--3 red giant radii reproduce the observed fluxes, because the wind density is then high, about 10^9 cm^{-3}. Our models favor winds with acceleration regions that either lie far from the red giant photosphere or extend for 2--3 red giant radii.Comment: 51 pages, LaTeX including three tables, requires 15 Encapsulated Postscript figures, to appear in Ap