Nonlinear Autoregresssive Leading Indicator Models of Output in G-7 Countries

This paper studies linear and nonlinear autoregressive leading indicator models of business cycles in G7 countries. The models use the spread between short-term and long-term interest rates as leading indicators for GDP, and their success in capturing business cycles is gauged by non-parametric shape tests, and their ability to predict the probability of recession. We find that bivariate nonlinear models of output and the interest rate spread can successfully capture the shape of the business cycle in cases where linear models fail. Also, our nonlinear leading indicator models for USA, Canada and the UK outperform other models of GDP with respect to predicting the probability of recession.Business Cycles, Leading Indicators, Model Evaluation, Nonlinear Models, Yield Spreads.

Bose-Fermi Mixtures in One Dimension

We analyze the phase stability and the response of a mixture of bosons and spin-polarized fermions in one dimension (1D). Unlike in 3D, phase separation happens for low fermion densities. The dynamics of the mixture at low energy is independent of the spin-statistics of the components, and zero-sound-like modes exist that are essentially undamped.Comment: 5 pages; 1 figur

A Complex Chemical Potential: Signature of Decay in a Bose-Einstein Condensate

We explore the zero-temperature statics of an atomic Bose-Einstein condensate in which a Feshbach resonance creates a coupling to a second condensate component of quasi-bound molecules. Using a variational procedure to find the equation of state, the appearance of this binding is manifest in a collapsing ground state, where only the molecular condensate is present up to some critical density. Further, an excited state is seen to reproduce the usual low-density atomic condensate behavior in this system, but the molecular component is found to produce an underlying decay, quantified by the imaginary part of the chemical potential. Most importantly, the unique decay rate dependencies on density ($\sim \rho ^{3/2}$) and on scattering length ($\sim a^{5/2}$) can be measured in experimental tests of this theory.Comment: 4 pages, 1 figur

Impacts of the Administration's 2007 Farm Bill Proposal on Representative Crops, Dairy and Beef Cattle Farms -- Revised

For the first time in two decades, the Secretary of Agriculture provided the House and Senate Agriculture Committees a farm bill proposal from the Administration. The Administration’s Proposal is a comprehensive revision of the 2002 farm bill with suggested changes to all titles. Four major proposed changes to Title 1 Commodity Programs are analyzed and reported in this Briefing Paper. The four key policy changes analyzed are: - an increase in direct payment rates, - a reduction in loan rates for most crops, - the replacement of the counter cyclical payment (CCP) program with a counter cyclical revenue (CCR) program, and - a change in eligibility for farm program payments by using $200,000 adjusted gross income (AGI) for a means test. The economic impact of the Administration’s Proposal on the viability of 99 representative crop, dairy, and beef cattle farms is compared to a base situation of continuing the current farm bill through 2012. This report is a companion to FAPRI-UMC Report #11-07 that contains sector level impacts.Agribusiness, Agricultural and Food Policy, Crop Production/Industries, Livestock Production/Industries,

The Farm Level Economic Impacts of Increased Cash Lease Rates

Higher commodity price expectations have led to increases in cash lease rates nationwide. This study evaluates the farm level impacts of higher cash lease rates. Current levels of cash rents along with land tenure arrangements of specific farms are instrumental in determining the impacts of increases in lease rates.Farm Management, Land Economics/Use,

No increase in radiation-induced chromosome aberration complexity detected by m-FISH after culture in the presence of 5’-bromodeoxyuridine

The thymidine analogue, 5’-bromodeoxyuridine (BrdU), is a known mutagen that is routinely introduced into culture media for subsequent Harlequin stain analysis and determination of cell cycle status. Previously, we examined the induction of chromosome aberrations in human peripheral blood lymphocytes (PBL) known to be in their 1st cell division following exposure to a low dose (0.5 Gy, average one -particle per cell) of high-LET α-particles. We found complex chromosome aberrations to be characteristic of exposure to high-LET radiation and suggested the features of complex exchange to reflect qualitatively the spatial deposition of this densely ionising radiation. To exclude the possibility that BrdU addition post-irradiation influenced the complexity of chromosomal damage observed by m-FISH, the effect of increasing BrdU concentration on aberration complexity was investigated. Comparisons between BrdU concentration (0, 10, and 40 M) and between sham- and α-particle irradiated PBL, were made both independently and in combination to enable discrimination between BrdU and high-LET radiation effects. Aberration type, size, complexity and completeness were assessed by m-FISH, and the relative progression through cell division was evaluated. We found no evidence of any qualitative difference in the complexity of damage as visualized by m-FISH but did observe an increase in the frequency of complex exchanges with increasing BrdU concentration indicative of altered cell cycle kinetics. The parameters measured here are consistent with findings from previous in vitro and in vivo work, indicating that each complex aberration visualised by m-FISH is characteristic of the structure of the high-LET α-particle track and the geometry of cell irradiated

A thrips vector of tomato spotted wilt virus responds to tomato acylsugar chemical diversity with reduced oviposition and virus inoculation.

There is increasing evidence that acylsugars deter insect pests and plant virus vectors, including the western flower thrips (WFT), Frankliniella occidentalis (Pergande), vector of tomato spotted wilt virus (TSWV). Acylsugars are sugar-polyesters composed of saturated, un-saturated, and variously branched short and long chain fatty acids (FAs) esterified to a glucose (acylglucose) or sucrose (acylsucrose) moiety. We sought to understand how acylsucrose amount and composition of associated FA profiles interacted to mediate resistance to WFT oviposition and TSWV inoculation on tomato leaves. Towards this goal, we examined WFT oviposition and TSWV inoculation behavior on tomato lines bred to exude varying amounts of acylsucrose in association with diverse FA profiles. Our data show that as acylsucrose amounts increased, WFT egg-laying (oviposition) decreased and TSWV inoculation was suppressed. Western flower thrips also responded to FA profiles that included iC4, iC11, nC12 and nC10 FA. These findings support improving acylsugar-mediated resistance against WFT by breeding tomatoes exuding greater amounts of acylsucrose associated with specific FA profiles. We show that increasing acylsucrose amount output by type IV trichomes and selecting for particular FA profiles through advanced breeding profoundly affects WFT behavior in ways that benefit management of WFT as direct pests and as TSWV vectors

AN INTERACTIVE ILLUSTRATION OF FARM PROGRAM PROVISIONS

Explaining the details and the impacts of government program provisions to agricultural producers can be a challenge for extension educators. This paper introduces a visual interactive tool that demonstrates the calculations of government payments established in the 2002 farm bill. Additionally, the paper explains how the tool is created in Microsoft® Excel and may be used in other areas.Agricultural and Food Policy,