Iron and Zinc Deficiencies in Selected Calcareous Soils of Southern Utah

The response of field corn to iron and zinc fertilization was studied using a split plot experimental design in Millard County, Utah, in cooperation with the Utah State University Extension Agent and a local farmer. mainplot treatment applications consisted, on an acre basis, of (1) 5 t ons of sulfuric acid, (2) 1 ton sulfuric acid, (3) 1.8 tons gypsum, (4) check plot. Subplot treatments were (1) Fe at 5 lbs/Ac, (2) Zn at 10 lbs/Ac, (3) Fe and Zn at 5 and 10 lb / Ac, respectively, (4) check plot. The iron and zinc applications were essentially rendered unavailable by reactions of the applied iron and zinc with the highly calcareous soil matrix. Experimental variability and the relatively low rates of applied micronutrients combined to produce insignificant yield responses to micronutrient fertilization. Another study was conducted to predict the soil iron critical level. Five soils from Millard County, representing some of the soils low in iron and zinc, were selected for a greenhouse study. All five of the soils were equally divided into three groups and assigned one of three pretreatments. One- third of the soils were stressed by successive croppings with corn and oats. One-third of the soils were fertilized with Fe chelate and ZnSO4 at 5 ppm each as a pretreatment. And one-third of the soils did not receive a pretreatment. The pretreatments were designed to obtain a broader range of soil iron concentrations. After the pre treatments were completed on all of the soils, a randomized block experimental design was employed to measure potential yield increases in corn produced by the addition of Fe chelate . Two corn genotypes, an iron-efficient corn inbred (WF9) and an iron efficient corn mutant (Ysl/Ysl), were utilized in the gr eenhouse study. The treatments were (1) 5 ppm Fe chelate plus corn inbred WF9, (2) 5 ppm Fe chelate plus corn mutant Ysl/Ysl, (3) no Fe addition plus corn inbred WF9 , (4) no Fe addition plus corn mutant Ysl/Ysl. Significant yield responses to Fe fertilization were determined by an LSD statistical test . Generally, soils with a DTPA extractable iron level greater than 5 ppm did not respond to applied iron. Similar yield responses were obtained for the iron-efficient and ironinefficient varieties. A tentative critical level of DTPA extractable iron of 5 ppm was proposed for the calcareous soils of Millard County, Utah

Critique of a Pion Exchange Model for Interquark Forces

I describe four serious defects of a widely discussed pion exchange model for interquark forces: it doesn't solve the "spin-orbit problem" as advertised, it fails to describe the internal structure of baryon resonances, it leads to disastrous conclusions when extended to mesons, and it is not reasonably connected to the physics of heavy-light systems.Comment: 20 pages, 6 figures; some clarifications and references adde

Energy Transduction of Isothermal Ratchets: Generic Aspects and Specific Examples Close to and Far from Equilibrium

We study the energetics of isothermal ratchets which are driven by a chemical reaction between two states and operate in contact with a single heat bath of constant temperature. We discuss generic aspects of energy transduction such as Onsager relations in the linear response regime as well as the efficiency and dissipation close to and far from equilibrium. In the linear response regime where the system operates reversibly the efficiency is in general nonzero. Studying the properties for specific examples of energy landscapes and transitions, we observe in the linear response regime that the efficiency can have a maximum as a function of temperature. Far from equilibrium in the fully irreversible regime, we find a maximum of the efficiency with values larger than in the linear regime for an optimal choice of the chemical driving force. We show that corresponding efficiencies can be of the order of 50%. A simple analytic argument allows us to estimate the efficiency in this irreversible regime for small external forces.Comment: 16 pages, 10 figure

An interdisciplinary clinical practice model for the management of low-back pain in primary care: the CLIP project

<p>Abstract</p> <p>Background</p> <p>Low-back pain is responsible for significant disability and costs in industrialized countries. Only a minority of subjects suffering from low-back pain will develop persistent disability. However, this minority is responsible for the majority of costs and has the poorest health outcomes. The objective of the Clinic on Low-back pain in Interdisciplinary Practice (CLIP) project was to develop a primary care interdisciplinary practice model for the clinical management of low-back pain and the prevention of persistent disability.</p> <p>Methods</p> <p>Using previously published guidelines, systematic reviews and meta-analyses, a clinical management model for low-back pain was developed by the project team. A structured process facilitating discussions on this model among researchers, stakeholders and clinicians was created. The model was revised following these exchanges, without deviating from the evidence.</p> <p>Results</p> <p>A model consisting of nine elements on clinical management of low-back pain and prevention of persistent disability was developed. The model's two core elements for the prevention of persistent disability are the following: 1) the evaluation of the prognosis at the fourth week of disability, and of key modifiable barriers to return to usual activities if the prognosis is unfavourable; 2) the evaluation of the patient's perceived disability every four weeks, with the evaluation and management of barriers to return to usual activities if perceived disability has not sufficiently improved.</p> <p>Conclusion</p> <p>A primary care interdisciplinary model aimed at improving quality and continuity of care for patients with low-back pain was developed. The effectiveness, efficiency and applicability of the CLIP model in preventing persistent disability in patients suffering from low-back pain should be assessed.</p