Effect of Soil Buffer Capacity on Soil Reaction (pH) Modification and Subsequent Effects on Growth and Nutrient Uptake of Plantanus occidentalis L. Seedlings

The buffer capacity of a soil is a significant factor in determining the longevity of soil reaction (pH) adjustments by aluminum sulfate, Al2(SO4)3, or calcium carbonate, CaCO₂. After 12 weeks the modified pH values of the highly buffered Emory silt loam had changed substantially toward the original pH value of 7.6. Modified pH values for the Groseclose silt loam soil remained essentially unchanged under the same conditions. These differences in soil response to modified soil pH are related to the differences in the percentage of vermiculite chlorite and chlorite in the clay fractions of the two soils. The longevity of soil pH modification is related to total sycamore seedling dry weight and nutrient uptake. Though these components were significantly affected for plants grown in a Groseclose soil, the lack of significant response differences, except at the extremely low pH adjustment (5.21), in the Emory soil suggests a rapid change in modified soil pH toward the original soil pH value. The condition of the seedlings coupled with total dry weight accumulation and foliar nutrient content elimiates acid toxicity as a factor affecting growth and nutrient uptake. Plants grown in the Groseclose soil at pH 4.31 could be the exception

Effect of Soil Buffer Capacity on Soil Reaction (pH) Modification and Subsequent Effects on Growth and Nutrient Uptake of Plantanus occidentalis L. Seedlings

The buffer capacity of a soil is a significant factor in determining the longevity of soil reaction (pH) adjustments by aluminum sulfate, Al2(SO4)3, or calcium carbonate, CaCO₂. After 12 weeks the modified pH values of the highly buffered Emory silt loam had changed substantially toward the original pH value of 7.6. Modified pH values for the Groseclose silt loam soil remained essentially unchanged under the same conditions. These differences in soil response to modified soil pH are related to the differences in the percentage of vermiculite chlorite and chlorite in the clay fractions of the two soils. The longevity of soil pH modification is related to total sycamore seedling dry weight and nutrient uptake. Though these components were significantly affected for plants grown in a Groseclose soil, the lack of significant response differences, except at the extremely low pH adjustment (5.21), in the Emory soil suggests a rapid change in modified soil pH toward the original soil pH value. The condition of the seedlings coupled with total dry weight accumulation and foliar nutrient content elimiates acid toxicity as a factor affecting growth and nutrient uptake. Plants grown in the Groseclose soil at pH 4.31 could be the exception

An Untraditional Way

Johnny looked about the dimly lit hogan. It was nothing but a few stout timbers covered with mud. In the center of the ceiling, there was a small square hold through which the smoke from the fire drifted..

The Legal Enterprise (By Robert E. Rodes Jr.)

This essay in jurisprudence is a well-wrought urn created by a judicious choice of Aristotelian, Thomistic, Existential materials and much more. Rodes might characterize his synthesis, borrowing from Tennyson\u27s Ulysses, as a book that is part of all he has met. And Rodes has met many authors and many people in the course of years of study and living, individuals motivated by diverse convictions and ideals. He has tested what is good and held fast to that which answered his own aspirations. The book tries to describe, in the terms of Cicero, what lawyering must be-interest in everything that touches men in daily life as they meet in social intercourse or transact affairs

Novae as a Mechanism for Producing Cavities around the Progenitors of SN 2002ic and Other SNe Ia

We propose that a nova shell ejected from a recurrent nova progenitor system created the evacuated region around the explosion center of SN 2002ic. In this picture, periodic shell ejections due to nova explosions on a white dwarf sweep up the slow wind from the binary companion, creating density variations and instabilities that lead to structure in the circumstellar medium (CSM). Our model naturally explains the observed gap between the supernova explosion center and the CSM in SN 2002ic, accounts for the density variations observed in the CSM, and resolves the coincidence problem of the timing of the explosion of SN 2002ic with respect to the apparent cessation of mass-loss in the progenitor system. We also consider such nova outburst sweeping as a generic feature of Type Ia supernovae with recurrent nova progenitors.Comment: Accepted to ApJL. 11 pages, 1 tabl

Photometry of SN 2002ic and Implications for the Progenitor Mass-Loss History

We present new pre-maximum and late-time optical photometry of the Type Ia/IIn supernova 2002ic. These observations are combined with the published V-band magnitudes of Hamuy et al. (2003) and the VLT spectrophotometry of Wang et al. (2004) to construct the most extensive light curve to date of this unusual supernova. The observed flux at late time is significantly higher relative to the flux at maximum than that of any other observed Type Ia supernova and continues to fade very slowly a year after explosion. Our analysis of the light curve suggests that a non-Type Ia supernova component becomes prominent $\sim20$ days after explosion. Modeling of the non-Type Ia supernova component as heating from the shock interaction of the supernova ejecta with pre-existing circumstellar material suggests the presence of a $\sim1.7 10^{15}$ cm gap or trough between the progenitor system and the surrounding circumstellar material. This gap could be due to significantly lower mass-loss $\sim15 (v_w/10 km/s)^{-1}$ years prior to explosion or evacuation of the circumstellar material by a low-density fast wind. The latter is consistent with observed properties of proto-planetary nebulae and with models of white-dwarf + asymptotic giant branch star progenitor systems with the asymptotic giant branch star in the proto-planetary nebula phase.Comment: accepted for publication in Ap

RELIABILITY OF CLINICAL ISOKINETIC DYNAMOMETRY IN PATHOLOGICAL ATHLETIC SHOULDERS

There have been relatively few studies of the reliability of isokinetic shoulder testing, and only Malerba et al. (1993) have investigated patients with shoulder joint pathology (patients ranged in activity level from sedentary to highly active). Furthermore, all existing studies have involved a level of procedural standardisation which, while desirable, cannot always be achieved in a clinical environment, that is, where most isokinetic testing is performed. Therefore, the aim of this study was to assess the reliability of isokinetic testing of pathological athletic shoulders in a clinical environment, under routine clinical conditions. Twenty-two athletic patients (mean age 26 years) presenting with a range of pathologies including post-subluxation, post-dislocation, and post-surgical reconstruction were tested. Patients were tested on two occasions, separated by a time interval during which their clinical status was not expected to change (most tests were one week apart; mean interval 10 days). Bilateral isokinetic strength of the shoulder internal and external rotators were tested on a Cybex 6000 dynamometer at 2.09 and 4.19 radianslsecond (concentric) and 2.09 radianslsecond (eccentric). Patients were tested in a seated position, in 45 degrees of shoulder abduction, and 90 degrees of elbow flexion. Tests were performed in essentially the same fashion on each occasion by the same tester. However, the constraints of a busy clinical environment meant that precise control and exact replication may not have always been achieved. Intra-class correlation coefficients (ICC) for absolute concentric peak torque, work, and average power were all above 0.9. Eccentric ICCs were generally above 0.8. These values are as high as, or higher than, those reported in the literature for studies of healthy subjects conducted under more stringent conditions than can be achieved in a clinical environment. The reliability of commonly calculated ratios, such as agonistlantagonist and involved/uninvolved, was lower than that of the constituent absolute scores, and in some cases were quite poor. Caution is therefore warranted in the use of such ratios. Malerba JL; Adam ML, Harris BA, Krebs DE (1993) Reliability of dynamic and isometric testing of shoulder external and internal rotators. Journal of Orthopaedic and Sports Physical Therapy 18543-552