The Economics of Barley Production in the Delta Junction Area of Interior Alaska

The discovery of oil at Prudhoe Bay on the north slope of Alaska and the subsequent initial lease sale for rights to drill for oil on state land marked the beginning of a new era in the economy of the state. Construction of the trans-Alaska pipeline to carry oil 860 miles from the northern coast to the port of Valdez brought jobs to the state and increased personal income for many residents. When oil began to flow, the state began to receive revenues from royalty oil sales. Wealth from oil revenues made it possible for the state to support the development of Alaska's renewable resources. One of the resources considered was land which had been classified as having potential for production of agricultural products . There had been attempts in the past by the Federal and state governments to increase substantially agricultural production in Alaska, but none were completely successful (Stone 1950, Burton 1971, Snodgrass et a!. 1982, Lewis et al. 1987)

Semiregular automorphisms of vertex-transitive graphs of certain valencies

AbstractIt is shown that a vertex-transitive graph of valency p+1, p a prime, admitting a transitive action of a {2,p}-group, has a non-identity semiregular automorphism. As a consequence, it is proved that a quartic vertex-transitive graph has a non-identity semiregular automorphism, thus giving a partial affirmative answer to the conjecture that all vertex-transitive graphs have such an automorphism and, more generally, that all 2-closed transitive permutation groups contain such an element (see [D. Marušič, On vertex symmetric digraphs, Discrete Math. 36 (1981) 69–81; P.J. Cameron (Ed.), Problems from the Fifteenth British Combinatorial Conference, Discrete Math. 167/168 (1997) 605–615])

Potential Regulation of Age-0 Gizzard Shad by Hybrid Striped Bass in Ohio Reservoirs

Piscivores can control prey populations in north temperate lakes, leading to increased zooplankton and reduced phytoplankton. In reservoirs with gizzard shad Dorosoma cepedianum, an omnivorous planktivore, this cascade occurs with lower probability because while this fish is shorter than 60 mm in total length (TL) it readily consumes zooplankton but also switches to phytoplankton and detritus. Prospects for gizzard shad control probably hinge on piscivore consumption of age-0 individuals. Hence, we quantified capture efficiency of hybrids of striped bass Morone saxatilis × white bass M. chrysops (small: 190–250 mm, TL; large: 310–360 mm, TL) when combined with three gizzard shad size-groups (of five possible, ranging 40–120 mm) in a 500-L aquarium. Small hybrid striped bass selected 40-mm gizzard shad but preferred neither 60-mm nor 80-mm prey. Large hybrid striped bass demonstrated no selection for 40–120-mm gizzard shad. We incorporated these data into a bioenergetics model to evaluate whether hybrid striped bass could sufficiently reduce abundance of age-0 gizzard shad in Ohio reservoirs to permit increased zooplankton, thereby improving the potential for resident sport fish recruitment in reservoirs. Hybrid striped bass potentially increased larval sport fish occurrence only when they were stocked at high densities (≥350 fish/ha or ≥22 kg/ha) coupled with age-0 gizzard shad suffering low natural mortality and occurring at an intermediate peak density of 25 fish/m3 or less. We believe gizzard shad are largely immune to control by hybrid striped bass in Ohio reservoirs. Hence, managers must consider combining watershed management with predator stocking to regulate gizzard shad.This work was funded by Federal Aid in Sport Fish Restoration projects F-57-R and F-69-P, which were administered jointly by the U.S. Fish and Wildlife Service and the ODW, and by National Science Foundation grants DEB-9107173 and DEB-9407859 to R.A.S

Role of infochemical mediated zooplankton grazing in a phytoplankton competition model

Infochemicals released by marine phytoplankton play important roles in food web interactions by influencing the feeding behavior and selectivity of zooplanktonic predators. Recent modeling efforts have focused on the role of such chemicals as toxic grazing deterrents in phytoplankton competition. However, infochemicals may also be utilized as grazing cues, leading predators to profitable foraging patches. Here we investigate the role of infochemical mediated zooplankton grazing in a standard 3-species phytoplankton competition model, with the aim of further elucidating the ecological role of phytoplankton derived infochemicals. We then extend this to consider a more realistic 4-species model. The models produce a range of solutions depending on the strength of competition and microzooplankton grazing selectivity. Our key result is that infochemical chemoattractants, which increase the susceptibility of the producer to grazing, can provide a refuge for both competing phytoplankton species by attracting carnivorous copepods to consume microzooplankton grazers in a multi-trophic interaction. Our results indicate that infochemicals potentially have important consequences for the dynamics of marine food webs. © 2012 Elsevier B.V

Production of few-layer phosphorene by liquid exfoliation of black phosphorus

We report the liquid exfoliation of black phosphorus to form few-layer phosphorene nanosheets.</p

Multi Purpose Crew Vehicle Environmental Control and Life Support Development Status

The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in 2014. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the completing the components which are on EFT1. Additional development work has been done to keep the remaining component progressing towards implementation for a flight tests in of EM1 in 2017 and in and EM2 in 2020. This paper covers the Orion ECLS development from April 2012 to April 2013

FORMATION OF SLOW-REACTING SUBSTANCE OF ANAPHYLAXIS IN HUMAN LUNG TISSUE AND CELLS BEFORE RELEASE

The capacity to extract slow-reacting substance of anaphylaxis (SRS-A) from human lung tissue or cells after immunologic activation, together with the measurement of SRS-A in both the extract and the surrounding fluid, permits study of total SRS-A generation. That the material extracted is SRS-A was established by both differential bioassay and purification. SRS-A accumulation was entirely intracellular after limited IgE-dependent direct or reversed anaphylactic activation. Intracellular accumulation also generally preceded release, with generation of SRS-A continuing well beyond a plateau in the cellular SRS-A level and the release of preformed mediators. The quantity of SRS-A generated after immunologic activation was modulated by the introduction of exogenous cyclic nucleotides, revealing a site of cyclic nucleotide action distinct from that on mediator release. The capacity to determine not only the release of preformed mediators but also the generation of a newly formed mediator, the sum of SRS-A in cells and supernate, adds an additional dimension to the analysis of the cellular events of immediate hypersensitivity