2,255 research outputs found
Financial Troubleshooting
This publication describes a simple framework that farmers, lenders, or extension specialists can use to identify the type of financial problem a farm business is experiencing, clarify the underlying causes, and list a number of management responses that could contribute to its resolution.
When the Crp Ends: A Look at Production Alternatives for Highly Erodible Land in Southern Iowa
This report examines the potential use of land currently under CRP contract in a three-county region in southern Iowa. The objectives are twofold: first, to inventory or assess the productivity and ownership characteristics of CRP land in this region and, second, to predict the possible use for these land resources should the CRP cease to exist. In particular, we are concerned with the impact that changing economic conditions, agricultural policy, and technology might have on this transition. The broader consequences of CRP termination in terms of rural economic activity or environmental quality in the region will be examined indirectly, reflected primarily in terms of changes in farm income, land use, and potential rates of soil erosion.
Benchmarking acid and base dopants with respect to enabling the ice V to XIII and ice VI to XV hydrogen-ordering phase transitions
Doping the hydrogen-disordered phases of ice V, VI and XII with hydrochloric
acid (HCl) has led to the discovery of their hydrogen-ordered counterparts ices
XIII, XV and XIV. Yet, the mechanistic details of the hydrogen-ordering phase
transitions are still not fully understood. This includes in particular the
role of the acid dopant and the defect dynamics that it creates within the
ices. Here we investigate the effects of several acid and base dopants on the
hydrogen ordering of ices V and VI with calorimetry and X-ray diffraction. HCl
is found to be most effective for both phases which is attributed to a
favourable combination of high solubility and strong acid properties which
create mobile H3O+ defects that enable the hydrogen-ordering processes.
Hydrofluoric acid (HF) is the second most effective dopant highlighting that
the acid strengths of HCl and HF are much more similar in ice than they are in
liquid water. Surprisingly, hydrobromic acid doping facilitates hydrogen
ordering in ice VI whereas only a very small effect is observed for ice V.
Conversely, lithium hydroxide (LiOH) doping achieves a performance comparable
to HF-doping in ice V but it is ineffective in the case of ice VI. Sodium
hydroxide, potassium hydroxide (as previously shown) and perchloric acid doping
are ineffective for both phases. These findings highlight the need for future
computational studies but also raise the question why LiOH-doping achieves
hydrogen-ordering of ice V whereas potassium hydroxide doping is most effective
for the 'ordinary' ice Ih.Comment: 18 pages, 7 figures, 1 tabl
Excess electron solvation in ammonia clusters
We performed a combination of quantum chemical calculations and molecular dynamics simulations to assess the stability of various size ("N" "H" _"3" )_n^- ammonia cluster anions up to n = 32 monomers. In the n = 3 ā 8 size range, cluster anions are optimized and the vertical detachment energy of the excess electron (VDE) from increasing size clusters are computed using various level methods including density functional theory (DFT), MP2 and CCSD(T) calculations. These clusters bind the electron in non-branched hydrogen bonding chains in dipole bound states. The VDE increases with size from a few meV up to ~200 meV. The electron binding energy is weaker than in water clusters but comparable to small methanol cluster VDEs. We located the first branched hydrogen bonding cluster that binds the excess electron at n = 7. For larger (n = 8 ā 32) clusters we generated cold, neutral clusters by semiempirical and ab initio molecular dynamics (AIMD) simulations, and added an extra electron to selected neutral configurations. VDE calculations on the adiabatic and the relaxed anionic structures suggest that the n = 12 - 32 neutral clusters weakly bind the excess electron. Electron binding energies for these clusters (~ 100 meV) appear to be significantly weaker than extrapolated from experimental data. The observed excess electron states are diffuse and localized outside the molecular frame (surface states) with minor (~1%) penetration to the nitrogen frontier orbitals. Stable minima with excess electron states surrounded by solvent molecules (cavity states) were not found in this size regime
Electron Microscope Observations of the Fine Structure of Microsporum Gypseum**From the Department of Zoology, Louisiana State University, Baton Rouge, Louisiana.
LUX -- A Laser-Plasma Driven Undulator Beamline
The LUX beamline is a novel type of laser-plasma accelerator. Building on the
joint expertise of the University of Hamburg and DESY the beamline was
carefully designed to combine state-of-the-art expertise in laser-plasma
acceleration with the latest advances in accelerator technology and beam
diagnostics. LUX introduces a paradigm change moving from single-shot
demonstration experiments towards available, stable and controllable
accelerator operation. Here, we discuss the general design concepts of LUX and
present first critical milestones that have recently been achieved, including
the generation of electron beams at the repetition rate of up to 5 Hz with
energies above 600 MeV and the generation of spontaneous undulator radiation at
a wavelength well below 9 nm.Comment: submitte
Incorporation of dUTP does not mediate mutation of A:T base pairs in Ig genes in vivo
Activation-induced cytidine deaminase (AID) protein initiates Ig gene mutation by deaminating cytosines, converting them into uracils. Excision of AID-induced uracils by uracil-N-glycosylase is responsible for most transversion mutations at G:C base pairs. On the other hand, processing of AID-induced G:U mismatches by mismatch repair factors is responsible for most mutation at Ig A:T base pairs. Why mismatch processing should be error prone is unknown. One theory proposes that long patch excision in G1-phase leads to dUTP-incorporation opposite adenines as a result of the higher G1-phase ratio of nuclear dUTP to dTTP. Subsequent base excision at the A:U base pairs produced could then create non-instructional templates leading to permanent mutations at A:T base pairs (1). This compelling theory has remained untested. We have developed a method to rapidly modify DNA repair pathways in mutating mouse B cells in vivo by transducing Ig knock-in splenic mouse B cells with GFP-tagged retroviruses, then adoptively transferring GFP+ cells, along with appropriate antigen, into primed congenic hosts. We have used this method to show that dUTP-incorporation is unlikely to be the cause of AID-induced mutation of A:T base pairs, and instead propose that A:T mutations might arise as an indirect consequence of nucleotide paucity during AID-induced DNA repair
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