COSTS, YIELDS, AND NET RETURNS, COMMERCIAL NO-TILL COTTON PRODUCTION, MISSISSIPPI, 1999

An analysis of a 1999 sample of ten no-till producers indicates that over a reasonable range of cotton lint prices, no-till cotton production may result in larger net returns per acre than conventional tillage. However, the authors caution that additional analysis based on a larger sample of commercial no-till growers on better cotton soils is needed.no-till, spindle harvest, cost of production, yield, Production Economics,

COSTS, YIELDS, AND NET RETURNS, COMMERCIAL ULTRA-NARROW ROW COTTON PRODUCTION, MISSISSIPPI, 1999

An analysis of a 1999 sample of 13 no-till producers indicates that over a reasonable range of cotton lint prices, ultra narrow cotton production may result in larger net returns per acre than conventional production practices. The largest percentage cost reduction is in fixed expenses. In general, total direct expenses per acre are also reduced, although UNRC usually results in higher seed and chemical expenses. UNRC has a lower total cost per pound compared to conventional cotton.UNRC, No-Till, cost of production, yield, stripper, harvest, Production Economics,

THE IMPACT OF CURRENT COTTON PRICE AND PRODUCTION COSTS ON SKIP-ROW COTTON

According to conventional wisdom, low prices favor skip-row planting patterns while high prices favor solid planted cotton. Production costs have been trending upward for many years. Current high production costs have redefined the point at which a low price becomes a high price relative to skip-row versus solid planting pattern decisions. Growers considering a shift from solid to skip-row cotton must be able to produce high yields, more than 90% of the solid yield on a land acre basis.cotton, no-till yields, returns, Production Economics,

ALTERNATIVE COTTON PRODUCTION SYSTEMS

Mississippi cotton farmers are adjusting to the current problem of low cotton price and high cotton production cost by modifying the way(s) they have traditionally grown cotton. This paper compares seven alternative production systems to the costs and returns associated with the conventional or traditional system labeled "solid cotton, 8-row equipment." Systems that combine wider equipment (less labor and machinery time per acre) with reduced tillage technology appear to offer opportunities to increase returns. Specific adjustments on individual farms will probably be dominated by the distribution of soil types.conservation tillage, ultra-narrow, no-till, skip-row, costs, returns, Production Economics,

Characterization of metal ion-induced [3H]inositol hexakisphosphate binding to rat cerebellar membranes

The binding of [3H]inositol hexakisphosphate ([3H] InsP6) to rat cerebellar membranes has been characterized with the objective of establishing the role, if any, of a membrane protein receptor. In the presence of EDTA, we have previously identified an InsP6-binding site with a capacity of approximately 20 pmol/mg protein (Hawkins, P. T., Reynolds, D. J. M., Poyner, D. R., and Hanley, M. R. (1990) Biochem. Biophys. Res. Commun. 167, 819-827). However, in the presence of 1 mM Mg2+, the capacity of [3H]InsP6 binding to membranes was increased approximately 9-fold. This enhancing effect of Mg2+ was reversed by addition of 10 microM of several cation chelators, suggesting that the increased binding required trace quantities of other metal cations. This is supported by experiments where it was possible to saturate binding by addition of excess membranes, despite not significantly depleting radioligand, pointing to removal of some other factor. Removal of endogenous cations from the binding assay by pretreatment with chelex resin also prevents the Mg(2+)-induced potentiation. Consideration of the specificity of the chelators able to abolish this potentiation suggested involvement of Fe3+ or Al3+. Both these ions (but not several others) were able to increase [3H]InsP6 binding to chelex-pretreated membranes at concentrations of 1 microM. It is possible to demonstrate synergy between Fe3+ and Mg2+ under these conditions. We propose that [3H]InsP6 may interact with membranes through non-protein recognition possibly via phospholipids, in a manner dependent upon trace metals. The implications of this for InsP6 biology are considered

The Metagalactic Ionizing Radiation Field at Low Redshift

We compute the ionizing radiation field at low redshift, arising from Seyferts, QSOs, and starburst galaxies. This calculation combines recent Seyfert luminosity functions, extrapolated ultraviolet fluxes from our IUE-AGN database, and a new intergalactic opacity model based on Hubble Space Telescope and Keck Ly-alpha absorber surveys. At z = 0 for AGN only, our best estimate for the specific intensity at 1 Ryd is I_0 = 1.3 (+0.8/-0.5) x 10^-23 ergs/cm^2/s/Hz/sr, independent of H_0, Omega_0, and Lambda. The one-sided ionizing photon flux is Phi_ion = 3400 (+2100/-1300) photons/cm^2/s, and the H I photoionization rate is Gamma_HI = 3.2 (+2.0/-1.2) x 10^-14 s^-1 for alpha_s = 1.8. We also derive Gamma_ HI for z = 0 - 4. These error ranges reflect uncertainties in the spectral indexes for the ionizing EUV (alpha_s = 1.8 +/- 0.3) and the optical/UV (alpha_UV = 0.86 +/- 0.05), the IGM opacity model, the range of Seyfert luminosities (0.001 - 100 L*) and the completeness of the luminosity functions. Our estimate is a factor of three lower than the most stringent upper limits on the ionizing background (Phi_ion < 10^4 photons/cm^2/s) obtained from H-alpha observations in external clouds, and it lies within the range implied by other indirect measures. Starburst galaxies with a sufficiently large Lyman continuum escape fraction, f_ esc > 0.05, may provide a comparable background to AGN, I_0 (z=0) = 1.1 (+1.5/-0.7) x 10^{-23). An additional component of the ionizing background of this magnitude would violate neither upper limits from H-alpha observations nor the acceptable range from other measurements.Comment: 30 pages, 9 figures, accepted for Astronomical J. (Oct. 1999

Miro proteins coordinate microtubule- and actin-dependent mitochondrial transport and distribution

In the current model of mitochondrial trafficking, Miro1 and Miro2 Rho-GTPases regulate mitochondrial transport along microtubules by linking mitochondria to kinesin and dynein motors. By generating Miro1/2 double-knockout mouse embryos and single- and double-knockout embryonic fibroblasts, we demonstrate the essential and non-redundant roles of Miro proteins for embryonic development and subcellular mitochondrial distribution. Unexpectedly, the TRAK1 and TRAK2 motor protein adaptors can still localise to the outer mitochondrial membrane to drive anterograde mitochondrial motility in Miro1/2 double-knockout cells. In contrast, we show that TRAK2-mediated retrograde mitochondrial transport is Miro1-dependent. Interestingly, we find that Miro is critical for recruiting and stabilising the mitochondrial myosin Myo19 on the mitochondria for coupling mitochondria to the actin cytoskeleton. Moreover, Miro depletion during PINK1/Parkin-dependent mitophagy can also drive a loss of mitochondrial Myo19 upon mitochondrial damage. Finally, aberrant positioning of mitochondria in Miro1/2 double-knockout cells leads to disruption of correct mitochondrial segregation during mitosis. Thus, Miro proteins can fine-tune actin- and tubulin-dependent mitochondrial motility and positioning, to regulate key cellular functions such as cell proliferation

Immune Modulation by Schistosoma mansoni Antigens in NOD Mice: Effects on Both Innate and Adaptive Immune Systems

We have shown that Schistosoma mansoni egg soluble antigen (SEA) prevents diabetes in the nonobese diabetic (NOD) mouse inducing functional changes in antigen presenting cells (APCs) and expanding T helper (Th) 2 and regulatory T cell (Treg) responses. A Th2 response to S. mansoni infection or its antigens is key to both the establishment of tolerance and successfully reproduction in the host. More recently we demonstrated that SEA treatment upregulates bioactive TGFβ on T cells with consequent expansion of Foxp3+ Tregs, and these cells might be important in SEA-mediated diabetes prevention together with Th2 cells. In this study we profile further the phenotypic changes that SEA induces on APCs, with particular attention to cytokine expression and markers of macrophage alternative activation. Our studies suggest that TGFβ from T cells is important not just for Treg expansion but also for the successful Th2 response to SEA, and therefore, for diabetes prevention in the NOD mouse