2,472 research outputs found
Nitrogen fertilization management for no-till cereal production in the Canadian great plains
Non-Peer Reviewe
Stability of the non-extremal enhancon solution I: perturbation equations
We consider the stability of the two branches of non-extremal enhancon
solutions. We argue that one would expect a transition between the two branches
at some value of the non-extremality, which should manifest itself in some
instability. We study small perturbations of these solutions, constructing a
sufficiently general ansatz for linearised perturbations of the non-extremal
solutions, and show that the linearised equations are consistent. We show that
the simplest kind of perturbation does not lead to any instability. We reduce
the problem of studying the more general spherically symmetric perturbation to
solving a set of three coupled second-order differential equations.Comment: 20 pages, 1 figure, references added, typos fixed, version to appear
in PR
PSY75 PREVALENCE RATIOS AGAINST ODDS RATIOS AS EFFECT MEASURES IN A CROSS-SECTIONAL STUDY OF OBESITY AND ITS CHRONIC COMORBID CONDITIONS
Studies on Hypoxia: XII. Detrimental Effects of Synthetic Polyribonucleotides on Epiphyseal Plates of Rats Exposed to Hypoxia
The effect of different doses of polyadenylic and polyuridylic acids (poly A:U) was studied in control rats and in rats exposed to hypoxia. In the control rats, administration of different doses of poly A:U did not change the thickness of the epiphyseal plate or increase the incorporation of 3H-phenylalanine as judged using radioautography. Rats exposed to hypoxia showed a significant dose-related reduction in the thickness of the epiphyseal plate and 3H-phenylalanine incorporation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67926/2/10.1177_00220345760550041701.pd
Floodplain restoration enhances denitrification and reach-scale nitrogen removal in an agricultural stream
Streams of the agricultural Midwest, USA, export large quantities of nitrogen, which impairs downstream water quality, most notably in the Gulf of Mexico. The two-stage ditch is a novel restoration practice, in which floodplains are constructed alongside channelized ditches. During high flows, water flows across the floodplains, increasing benthic surface area and stream water residence time, as well as the potential for nitrogen removal via denitrification. To determine two-stage ditch nitrogen removal efficacy, we measured denitrification rates in the channel and on the floodplains of a two-stage ditch in north-central Indiana for one year before and two years after restoration. We found that instream rates were similar before and after the restoration, and they were influenced by surface water concentration and sediment organic matter content. Denitrification rates were lower on the constructed floodplains and were predicted by soil exchangeable concentration. Using storm flow simulations, we found that two-stage ditch restoration contributed significantly to removal during storm events, but because of the high loads at our study site, <10% of the load was removed under all storm flow scenarios. The highest percentage of removal occurred at the lowest loads; therefore, the two-stage ditch's effectiveness at reducing downstream N loading will be maximized when the practice is coupled with efforts to reduce N inputs from adjacent fields
Dibaryon Spectroscopy
The AdS/CFT correspondence relates dibaryons in superconformal gauge theories
to holomorphic curves in Kaehler-Einstein surfaces. The degree of the
holomorphic curves is proportional to the gauge theory conformal dimension of
the dibaryons. Moreover, the number of holomorphic curves should match, in an
appropriately defined sense, the number of dibaryons. Using AdS/CFT backgrounds
built from the generalized conifolds of Gubser, Shatashvili, and Nekrasov
(1999), we show that the gauge theory prediction for the dimension of
dibaryonic operators does indeed match the degree of the corresponding
holomorphic curves. For AdS/CFT backgrounds built from cones over del Pezzo
surfaces, we are able to match the degree of the curves to the conformal
dimension of dibaryons for the n'th del Pezzo surface, n=1,2,...,6. Also, for
the del Pezzos and the A_k type generalized conifolds, for the dibaryons of
smallest conformal dimension, we are able to match the number of holomorphic
curves with the number of possible dibaryon operators from gauge theory.Comment: 30 pages, 6 figures, corrected refs; v3 typos correcte
Superconductivity from D3/D7: Holographic Pion Superfluid
We show that a D3/D7 system (at zero quark mass limit) at finite isospin
chemical potential goes through a superconductor (superfluid) like phase
transition. This is similar to a flavored superfluid phase studied in QCD
literature, where mesonic operators condensate. We have studied the frequency
dependent conductivity of the condensate and found a delta function pole in the
zero frequency limit. This is an example of superconductivity in a string
theory context. Consequently we have found a superfluid/supercurrent type
solution and studied the associated phase diagram. The superconducting
transition changes from second order to first order at a critical superfluid
velocity. We have studied various properties of the superconducting system like
superfluid density, energy gap, second sound etc. We investigate the
possibility of the isospin chemical potential modifying the embedding of the
flavor branes by checking whether the transverse scalars also condense at low
temperature. This however does not seem to be the case.Comment: 18 pages, 8 figures, revtex
Optimizing N fertilizer rates for seed yield in Camelina sativa and Brassica carinata
Non-Peer Reviewe
Oceanographic patterns associated with Nassau Grouper aggregation spawn timing: shifts in surface currents on the nights of peak spawning
Magnetic fan structures in Ba0.5Sr1.5Zn2Fe12O22 hexaferrite revealed by resonant soft x-ray diffraction
The hexaferrites are known to exhibit a wide range of magnetic structures, some of which are connected to important technological applications and display magnetoelectric properties. We present data on the low magnetic field structures stabilized in a Y-type hexaferrite as observed by resonant soft x-ray diffraction. The helical spin block arrangement that is present in zero applied magnetic field becomes fanlike as a field is applied in plane. The propagation vectors associated with each fan structure are studied as a function of magnetic field, and a new magnetic phase is reported. Mean field calculations indicate this phase should stabilize close to the boundary of the previously reported phases
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