Further analysis of field effects on liquids and solidification

Numerical calculations of the magnitude of external field effects on liquids are presented to describe how external fields can influence the substructure of the field. Quantitative estimates of magnetic and gravitational effects are reported on melts of metals and semiconductors. The results are condensed in tables which contain the input data for calculation of the field effects on diffusion coefficient, solidification rate and for calculation of field forces on individual molecules in the melt

Assessment of Real Estate Brokerage Service Quality with a Practicing Professional's Instrument

This study explores factors that affect service quality for a large residential real estate brokerage in a diverse midwestern city. It examines the extent to which overall service quality influences homebuyers to recommend the brokerage firm and to use the firm for future transactions. A Linear Structural Relations model is fit to data using the firm's service quality instrument. Results indicate statistically significant relationships between both agent characteristics and the tangible aspects of the firm, and three measures of overall service quality. Implications for the real estate industry are discussed and suggestions for improvement and future research are provided.

Online forest biology and tree identification graduate class for public school educators

As a result of certification and accreditation standards, public school teachers are often required to take graduate education courses. However, it is often difficult for these teachers/students to take courses in residence at campuses. Further, there is often a shortage of specialized courses in their area of teaching. There is also a demand for natural-resource-based classes since, in Virginia, many of the standards of learning can be effectively taught using examples from forests. In response to the above issues, we developed an entirely online graduate course that covered forest biology, management, and tree identification. In the summer of 2001, 24 students successfully completed the course. Students were required to learn to identify 80 trees and shrubs in nine separate groups. They were also taught tree growth and structure, reproduction, carbon uptake, water relations, growth regulators, cold hardiness and dormancy, soils and site productivity, and silviculture. The course content was delivered on three CD-ROMS and administration occurred through a Web site. Nine cumulative tree ID quizzes were given online as well as two comprehensive exams covering the tree biology topics. We will present the basic structure of the course, class administration, share insights and student feedback

Formation and clearance of tubulointerstitial immune complexes in kidneys of rats immunized with heterologous antisera to Tamm-Horsfall protein

Formation and clearance of tubulointerstitial immune complexes in kidneys of rats immunized with heterologous antisera to Tamm-Horsfall protein. Tubulointerstitial immune complex nephritis was produced by passive immunization of rats with antisera to rat Tamm-Horsfall protein (TH), a surface membrane glycoprotein of the cells of the thick ascending limb of Henle's loop. Circulating anti-TH antibodies were deposited in the kidney after an intravenous injection of rabbit antisera to TH. These anti-TH antibodies combined with TH at the base of tubular cells in the thick ascending limb of Henle's loop and formed granular immune complexes in situ in the space between basal cell surface membranes and tubular basement membranes. Immune complexes were also selectively formed in this site during perfusion of isolated kidneys with antisera to TH. Tubular immune complexes containing immunoglobulin, complement, and TH were maximal during the first week after an intravenous injection while high circulating anti-TH antibody titers were present. As the antibody titers subsequently fell to undetectable levels, tubular immune complexes were rapidly cleared and were virtually absent 4 weeks after the injection. During this clearance phase, rabbit IgG and rat TH were detected in the renal interstitium and in renal hilar lymph nodes. The rapid clearance of subepithelial TH immune complexes contrasts with the prolonged persistance of both glomerular subepithelial immune complexes and basement membrane deposits formed after injection of heterologous antisera to other renal components. The process of rapid clearance of tubulointerstitial immune complexes may allow rapid reversibility of immune injury in tubulointerstitial nephritis.Formation et disparition d'immuns-complexes tubulo-interstitiels dans les reins de rats immunises avec des anti-serums heterologues contre la proteine de Tamm-Horsfall. Une néphrite tubulo-interstitielle à immuns complexes était produit chez des rats par immunisation passive avec un anti-sérum anti-protéine de Tamm-Horsfall de rat (TH), une glycoprotéine de la surface membranaire des cellules de la partie ascendante large de l'anse de Henle. Des anticorps anti-TH circulants se déposaient dans le rein après injection intraveineuse d'antisérum anti-TH de lapin. Ces anticorps anti-TH se combinaient avec la protéine de TH à la base des cellules tubulaires de la partie large ascendante de l'anse de Henlé et formaient in situ des immuns-complexes granuleux dans l'espace entre les membranes basales cellulaires et la basale tubulaire. De même, des immuns complexes se formaient sélectivement dans cette zone lors de la perfusion de reins isolés avec un antisérum anti-TH. La quantité d'immuns complexes tubulaires contenant des immunoglobulines, du complément et de la protéine de TH était maximale pendant la première semaine après l'injection i.v. au moment ou on trouvait des titres élevés d'anticorps anti-TH. Lorsque les anticorps retombaient à un taux indétectable, les immuns complexes tubulaires disparaissaient rapidement, et on n'en trouvait pratiquement plus 4 semaines après l'injection. Pendant cette période d'élimination on détectait des IgG de lapin et de la protéine de TH de rat dans l'interstitium et les ganglions hilaires rénaux. La disparition rapide des immuns complexes à TH sous épithéliaux contrastait avec la persistance prolongée des immuns complexes sous épithéliaux et des dépôts dans la membrane basale glomérulaire formés après injection d'anti-sérums hétérologues contre d'autres constituants du rein. La disparition rapide des immuns complexes tubulo-interstitiels pourrait permettre une régression rapide des lésions immunes au cours des néphrites tubulo-interstitielles

Further analysis of field effects on liquids and solidification. Study of the liquid-solid transition for materials processing in space

Expressions for diffusion coefficient, D, and solidification rate, Uc, from the free volume model of liquids developed by Turnbull and Cohen have been used to estimate the effects which microgravity and magnetic fields will have on these quantities. The mathematical formalism describing changes in D and Uc is the same for both the microgravity and magnetic field cases, but the difference between the magnitudes of the two effects is quite large. The change in D and Uc is found to be less than 0.0001% for the microgravity case and on the order of 0.1 to 1.1% for the magnetic field case for four representative materials. D and Uc are found to increase under the influence of an applied magnetic field, and this is in agreement with experimental observations

Involution and Constrained Dynamics I: The Dirac Approach

We study the theory of systems with constraints from the point of view of the formal theory of partial differential equations. For finite-dimensional systems we show that the Dirac algorithm completes the equations of motion to an involutive system. We discuss the implications of this identification for field theories and argue that the involution analysis is more general and flexible than the Dirac approach. We also derive intrinsic expressions for the number of degrees of freedom.Comment: 28 pages, latex, no figure

Stratospheric and tropospheric NO₂ variability on the diurnal and annual scale: a combined retrieval from ENVISAT/SCIAMACHY and solar FTIR at the Permanent Ground-Truthing Facility Zugspitze/Garmisch

International audienceColumnar NO2 retrievals from solar FTIR measurements at the Zugspitze (47.42° N, 10.98° E, 2964 m a.s.l.), Germany were investigated synergistically with columnar NO2 retrieved from SCIAMACHY data by the University of Bremen scientific algorithm UB1.5 for the time span July 2002-October 2004. A new concept to match FTIR data to the time of satellite overpass makes use of the NO2 daytime increasing rate retrieved from the FTIR data set itself [+1.02(6)E+14 cm-2/h]. This measured increasing rate shows no significant seasonal variation. SCIAMACHY data within a 200-km radius around Zugspitze were considered, and a pollution-clearing scheme was developed to select only pixels corresponding to clean background (free) tropospheric conditions, and exclude local pollution hot spots. The resulting difference between SCIAMACHY and FTIR columns (without correcting for the different sensitivities of the instruments) varies between 0.60-1.24E+15 cm-2 with an average of 0.83E+15 cm-2. A day-to-day scatter of daily means of ?7-10% could be retrieved in mutual agreement from FTIR and SCIAMACHY. Both data sets are showing sufficient precisions to make this assessment. Analysis of the averaging kernels gives proof that at high-mountain-site FTIR is a highly accurate measure for the pure stratospheric column, while SCIAMACHY shows significant tropospheric sensitivity. Based on this finding, we set up a combined a posteriori FTIR-SCIAMACHY retrieval for tropospheric NO2, based upon the averaging kernels. It yields an annual cycle of the clean background (free) tropospheric column (-2, an average of 1.09E+15 cm-2, and an intermediate phase between that of the well known boundary layer and stratospheric annual cycles. The outcome is a concept for an integrated global observing system for tropospheric NO2 that comprises DOAS nadir satellite measurements and a set of latitudinally distributed mountain-site or clean-air FTIR stations