Effects of Grazing Management on Selected Stream Bank Characteristics and Stream Bank Erosion

Six 30-acre cool-season grass pastures, containing predominantly smooth bromegrass and bisected by a 642- foot stream segment, were grouped into 2 blocks and assigned one of three treatments: continuous stocking - unrestricted stream access (CSU), continuous stocking - restricted stream access (CSR), and rotational stocking (RS). Stream bank condition and surface roughness and stream morphology were evaluated pre-, mid-, and post-grazing from 2005 to 2007. Stream bank erosion was monitored monthly from May through November over the same three years. Stream banks in CSU pastures had greater vegetative cover, stability, and condition scores than did the CSR or RS pastures implying that the stream banks in pastures in which cattle had unrestricted access were more susceptible to erosion than stream banks in pastures in which cattle access to stream banks was restricted or controlled. However, no effect of grazing management on the rate of change of stream cross sectional area, net stream bank erosion, or erosion deposition activity was observed in any of the three years

Effects of Grazing Management on Selected Stream Bank Characteristics and Stream Bank Erosion

Six 30-acre cool-season grass pastures, containing predominantly smooth bromegrass and bisected by a 642- foot stream segment were grouped into two blocks and assigned one of three treatments: continuous stocking - unrestricted stream access (CSU), continuous stocking - restricted stream access (CSR), and rotational stocking (RS). Stream bank condition and surface roughness and stream morphology were evaluated pre-, mid-, and postgrazing over a two-year period. Stream bank erosion was monitored monthly from May through November over the same two-year period. Stream banks in CSU pastures had greater vegetative cover, stability, and condition scores than did the CSR or RS pastures, implying that the stream banks in pastures in which cattle had unlimited access were more susceptible to erosion than stream banks in pastures in which cattle access to stream banks was restricted or controlled. However, no effect of grazing management on net stream bank erosion was observed for either grazing season

Impacts of Beef Cattle–Grazing Systems on Cattle Distribution and Streambank Erosion

Many of Iowa’s surface waters contain high sediment and phosphorus(P) concentrations. It is recognized that overgrazing along pasture streams may result in soil erosion and manure deposition that contribute to P loading of pasture streams. Little research has evaluated the effects of grazing management on sediment and P loading of pasture streams in the Midwest, but grazing management is still generally considered to limit sediment and P loading of pasture streams. The objective of this study was to measure the effects of beef cattle– grazing systems on the spatial and temporal distribution patterns of cattle, the resulting impacts on selected pasture characteristics, and streambank erosion from pasture streams

Ena/VASP Enabled is a highly processive actin polymerase tailored to self-assemble parallel-bundled F-actin networks with Fascin

Enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) proteins are required for the formation and maintenance of filopodia, finger-like projections at the leading edge of migrating cells that are composed of parallel actin filaments bundled by Fascin. We imaged individual fluorescently labeled Drosophila Ena molecules on both single and Fascin-bundled actin filaments in vitro. Ena stimulates actin assembly by remaining continuously associated with the barbed end and increasing the elongation rate by approximately two- to threefold. Remarkably, the frequency and length of Ena’s processive runs are enhanced on filaments within a Fascin bundle, which drives a positive feedback cycle that allows the assembly of uniformly thick filopodia-like F-actin bundles composed of multiple filaments with aligned ends

Tests of a large air‐core superconducting solenoid as a nuclear‐reaction‐product spectrometer

An air‐core superconducting solenoid, with a diameter of 0.2 m and a length of 0.4 m, has been configured for use as a heavy‐ion reaction‐product spectrometer (E/A≤5 MeV/u) near θ=0° (10 to 35 msr). The performance of the spectrometer was established using α‐particle sources and nuclear‐reaction products from (18O, 18Ne), (18O, 20Ne) and (18O, 14O) and masses determined for 30Mg, 108Ru and 109Rh. A system suitable for production of radioactive beams has been constructed, and in‐beam tests are in progress at the University of Notre Dame. Large air‐core solenoids with dΩ≤20 msr and capable of focusing ions with E/A≥30 MeV/u appear feasible.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87304/2/845_1.pd

Oscillations above the barrier in the fusion of 28Si + 28Si

Fusion cross sections of 28Si + 28Si have been measured in a range above the barrier with a very small energy step (DeltaElab = 0.5 MeV). Regular oscillations have been observed, best evidenced in the first derivative of the energy-weighted excitation function. For the first time, quite different behaviors (the appearance of oscillations and the trend of sub-barrier cross sections) have been reproduced within the same theoretical frame, i.e., the coupled-channel model using the shallow M3Y+repulsion potential. The calculations suggest that channel couplings play an important role in the appearance of the oscillations, and that the simple relation between a peak in the derivative of the energy-weighted cross section and the height of a centrifugal barrier is lost, and so is the interpretation of the second derivative of the excitation function as a barrier distribution for this system, at energies above the Coulomb barrier.Comment: submitted to Physics Letters

Modulation of cognitive performance and mood by aromas of peppermint and ylang-ylang

This study provides further evidence for the impact of the aromas of plant essential oils on aspects of cognition and mood in healthy participants. One hundred and forty-four volunteers were randomly assigned to conditions of ylang-ylang aroma, peppermint aroma, or no aroma control. Cognitive performance was assessed using the Cognitive Drug Research computerized assessment battery, with mood scales completed before and after cognitive testing. The analysis of the data revealed significant differences between conditions on a number of the factors underpinning the tests that constitute the battery. Peppermint was found to enhance memory whereas ylang-ylang impaired it, and lengthened processing speed. In terms of subjective mood peppermint increased alertness and ylang-ylang decreased it, but significantly increased calmness. These results provide support for the contention that the aromas of essential oils can produce significant and idiosyncratic effects on both subjective and objective assessments of aspects of human behavior. They are discussed with reference to possible pharmacological and psychological modes of influence

Kinetics of concurrent desorption and diffusion into the solid: D/Zr(0001)

Rapid adsorbate diffusion into the solid is known to suppress the desorption yield measured in a thermal desorption experiment. We show that this suppression can be controlled (at least partly) by pulsed-laser heating at rates in excess of 10(10) K/s. As an example, we analyze the D/Zr system. In this case, deuterium adsorbed on a surface rapidly diffuses into the bulk of Zr with increasing temperature, and the deuterium desorption probability measured with conventional heating rates (beta less than or equal to 100 K/s) is as low as approximate to 10(-4) for polycrystalline Zr foils (deuterium desorption is not observed at all from single-crystal Zr from which dissolved H/D has been removed). Heating the Zr(0001) surface by pulsed-laser thermal excitation with beta similar or equal to 10(11) K/s is demonstrated to result in the increase of the deuterium desorption probability up to approximately 0.01. To interpret this observation, general equations for describing associative desorption accompanied by adsorbate diffusion into the solid are simplified by employing the specifics of the temperature-programmed kinetic regimes with a linear increase of temperature. The desorption yield calculated without any adjustable parameters is in good agreement with the experimental results