Electron transport phosphorylation in rumen butyrivibrios: unprecedented ATP yield for glucose fermentation to butyrate.

From a genomic analysis of rumen butyrivibrios (Butyrivibrio and Pseudobutyrivibrio sp.), we have re-evaluated the contribution of electron transport phosphorylation (ETP) to ATP formation in this group. This group is unique in that most (76%) genomes were predicted to possess genes for both Ech and Rnf transmembrane ion pumps. These pumps act in concert with the NifJ and Bcd-Etf to form a electrochemical potential (ΔμH(+) and ΔμNa(+)), which drives ATP synthesis by ETP. Of the 62 total butyrivibrio genomes currently available from the Hungate 1000 project, all 62 were predicted to possess NifJ, which reduces oxidized ferredoxin (Fdox) during pyruvate conversion to acetyl-CoA. All 62 possessed all subunits of Bcd-Etf, which reduces Fdox and oxidizes reduced NAD during crotonyl-CoA reduction. Additionally, 61 genomes possessed all subunits of the Rnf, which generates ΔμH(+) or ΔμNa(+) from oxidation of reduced Fd (Fdred) and reduction of oxidized NAD. Further, 47 genomes possessed all six subunits of the Ech, which generates ΔμH(+) from oxidation of Fdred. For glucose fermentation to butyrate and H2, the electrochemical potential established should drive synthesis of ∼1.5 ATP by the F0F1-ATP synthase (possessed by all 62 genomes). The total yield is ∼4.5 ATP/glucose after accounting for three ATP formed by classic substrate-level phosphorylation, and it is one the highest yields for any glucose fermentation. The yield was the same when unsaturated fatty acid bonds, not H(+), served as the electron acceptor (as during biohydrogenation). Possession of both Ech and Rnf had been previously documented in only a few sulfate-reducers, was rare in other rumen prokaryotic genomes in our analysis, and may confer an energetic advantage to rumen butyrivibrios. This unique energy conservation system might enhance the butyrivibrios' ability to overcome growth inhibition by unsaturated fatty acids, as postulated herein

Liming Iowa soils

The use of liming materials on acid soils to supply available calcium and correct soil acidity long has been regarded as a basic principle in the Iowa system of soil management. The beneficial effects are associated primarily with the efficient production of legumes in various cropping systems, thereby contributing to the maintenance of soil fertility and conservation of the soil resources. Many of the important agricultural soils in Iowa were originally well supplied with lime, but through leaching, erosion, decomposition processes, removal by crops and the sale of livestock products there has been a gradual tendency for them to become acid

Finer, Better Lime, Please!

During the past 4 years, Iowa farmers have used over 5 million tons of ground limestone, approximately four times as much as in any similar period prior to the AAA Conservation Materials Program. This limestone is helping materially in producing record crops on several million acres of good crop land. But many million acres still need to be mobilized for maximum production by liming

A Study of Certain Green Manure Crops in Making Rock Phosphate Available in Soils

At the present time the world is in the midst of the greatest conflict ever staged. The byword on the lips of every thoughtful American is, Food will win the war. In order that food may be conserved it must first be produced. Therefore, increased crop production must be stimulated. We must produce larger crops upon a given area, that is, intensive farming should be practiced

The measurement of the degree of saturation of soils with bases

1. To determine the degree of saturation of a soil, data must be secured to show the amount of replaceable bases, replaceable hydrogen and base exchange capacity. 2. Experiments have been conducted to determine the accuracy of various methods for these determinations. 3. A study was first made of the electrodialysis method for replaceable bases, using both the Mattson and the Bradfield cells. 4. When 100 grams of soil were electlodialyzed in the Mattson cell for 45 hours, the results seemed satisfactory when compared with the data secured with other methods. 5. When a smaller amount of soil (10 grams) was electrodialyzed in either the Mattson or the Bradfield cell for a shorter time, the end point was not definite and the results could not be considered accurate. Furthermore, there was a continued extraction of basic materials from the soil after more bases had been removed by electrodialysis than were known to be present in a replaceable form in the soil. Hence, it appears that the error in this method may be greater than that caused by solubility effects in the leaching methods. 6. The Hissink (T - S) method for determining the replaceable hydrogen in the soil was compared with the method developed by Parker. 7. In a number of Iowa soils differing widely in characteristics and in soils which had been treated with various amounts of limestone of different degrees of fineness, the Hissink method gave practically the same amounts of replaceable hydrogen. 8. There seemed to be no correlation between the replaceable hydrogen in the soil, when measured by the Hissink method, and the hydrogen ion concentration. With the Webster silty clay loam which had a pH of 7.48, the Hissink method showed more replaceable hydrogen than was found in the Tama silt loam which had a pH of 4.79. 9. The amount of replaceable hydrogen found by the Hissink method was greater in all the soils tested than the total base exchange capacity of the soils. According to Kelley. when this method is used, not only does the barium hydroxide added to the soil react with the exchangeable hydrogen but other side reactions occur. The results with the method are certainly rather unsatisfactory. 10. According to the accepted theories of base exchange, the Parker method for determining replaceable hydrogen is sound in principle and the data secured in this work show that it will give accurate and reliable results. 11. The Parker method for determining the base exchange capacity of soils was also found to give excellent results. The principle of this method has been well established and the method has been used, with certain modifications in technic, by other investigators. 12. After the replaceable hydrogen and base exchange capacity are determined by the Parker method, the amount of replaceable bases and the degree of saturation with bases may be calculated. 13. This method has been tested on a number of Iowa soils and on soils treated with various amounts of lime of different degrees of fineness. In all cases satisfactory results have been secured. 14. In general it is evident that of all the methods tested. that proposed by Parker seems to give the best picture of the actual condition of the base exchange complex in soils. 15. Certain modifications in the technic of this method have been suggested for future work

Choice, Risk, and Moral Judgment: Using Discourse Analysis to Identify the Moral Component of Midwives’ Discourses

Part 1. Communicating risk in healthcare -- Part 2. Communicating risk in legal processes -- Part 3. Communicating risk in social care -- Part 4. Communicating risk in environmental management and biosecurity -- Part 5. Mediating risk -- Part 6. Regulating risk368 page(s

Cutting Ties with Pro-Ana: A Narrative Inquiry Concerning the Experiences of Pro-Ana Disengagement from Six Former Site Users.

Websites advocating the benefits of eating disorders (“Pro-Ana”) tend to reinforce and maintain restrictive eating and purging behaviors. Yet remarkably, no study has explored individual accounts of disengagement from these sites and the associated meanings. Using narrative inquiry, this study sought to address this gap. From the interviews of six women, two overarching storylines emerged. The first closely tied disengagement to recovery with varying positions of personal agency claimed: this ranged from enforced and unwelcomed breaks that ignited change, to a personal choice that became viable through the development of alternative social and personal identities. A strong counternarrative to “disengagement as recovery” also emerged. Here, disengagement from Pro-Ana was storied alongside a need to retain an ED lifestyle. With “recovery” being just one reason for withdrawal from Pro-Ana sites, clinicians must remain curious about the meanings individuals ascribe to this act, without assuming it represents a step toward recovery.Peer reviewedFinal Accepted Versio