CADMIUM MOBILISATION UNDER CONDITIONS SIMULATING ANAEROBIC TO AEROBIC TRANSITION IN A LANDFILL LEACHATE-POLLUTED AQUIFER

The anaerobic conditions in landfill leachate-polluted aquifers can lead to trapping of many heavy metals as sulfide precipitates. In laboratory experiments with aqueous systems containing sulfidic solid phases (aquifer solids from a landfill leachate plume or amorphous FeS), cadmium previously trapped as a sulfide precipitate was released to the aqueous phase when conditions were changed from initially slightly anaerobic to aerobic. Cadmium was subsequently removed from solution either by adsorption on Fe oxyhydroxide phases or by precipitation as a carbonate mineral, groundwater pH being the major controlling variable.     

DYNAMIC CONTRAST‐ENHANCED MAGNETIC RESONANCE IMAGING OF CANINE BRAIN TUMORS

We evaluated dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) in canine brain tumors. Magnetic resonance data sets were collected on seven canine intracranial tumors with a 3 T magnet using a T1‐weighted fast spin echo fluid attenuated inversion recovery sequence after an IV bolus injection (0.2 mmol/kg) of Gd‐DTPA. The tumors were confirmed histopathologically as adenocarcinoma (n=1), ependymoma (n=1), meningioma (n=3), oligodendroglioma (n=1), and pituitary macroadenoma (n=1) The data were analyzed using a two‐compartment pharmacokinetic model for estimation of three enhancement parameters, E_R (rate of enhancement), K_el (rate of elimination), and K_ep (rate constant), and a model‐free phenomenologic parameter initial area under the Gd concentration curve (IAUGC) defined over the first 90 s postenhancement. Pearson's correlations were calculated between parameters of the two methods. The IAUGC has a relatively strong association with the rate of enhancement E_R, with r ranges from 0.4 to 0.9, but it was weakly associated with K_ep and K_el. To determine whether any two tumors differed significantly, the Kolmogorov–Smirnov test was used. The results showed that there were statistical differences (P<0.05) between distributions of the enhancement pattern of each tumor. These kinetic parameters may characterize the perfusion and vascular permeability of the tumors and the IAUGC may reflect blood flow, vascular permeability, and the fraction of interstitial space. The kinetic parameters and the IAUGC derived from DCE‐MRI present complementary information and they may be appropriate to noninvasively differentiate canine brain tumors although a larger prospective study is necessary.     

CD3+ and BLA.36+ cells do not occur in the epidermis and adnexal epithelia of normal equine skin

A small population of resident T lymphocytes is present in the healthy human and murine epidermis. However, resident epidermal lymphocytes have not been reported in normal skin of the horse. Skin biopsy specimens from the normal skin of 27 horses were examined histologically and immunohistochemically for the presence of lymphocytes, CD3+ cells and BLA.36+ cells in epidermis and adnexal epithelia. All examinations were negative. It appears that lymphocytes occur rarely, if at all, in the epidermis and adnexal epithelia of normal horse skin. Hence, the presence of lymphocytes in these structures should be considered abnormal.     

Chemical Control of the Pine Shoot Moth, Rhyacionia buoliana (Denis and SchiffermUller) (Lepidoptera: Tortricidae) in Seed Orchards in Britain

In 1970 and 1971 a high population of Rhyacionia buoliana (Denisand SchiffermÜller), the Pine shoot moth, appeared in aseed orchard of Pinus contorta Douglas ex Loud, in Wiltshire.The opportunity was taken to compare several alternative insecticideswith DDT. Field trials in March and August showed that fenitrothioncan be used as an alternative to DDT to control the Pine shootmoth.     

Efficacy of Enrofloxacin in the Treatment of Canine Bacterial Pyoderma

Abstract— Bacterial pyoderma was diagnosed in 30 dogs which were subsequently treated with enrofloxacin administered orally at 2.5 mg.kg^-1 of body weight every 12 h, for 2 to 14 weeks. Dogs were re-examined at the conclusion of antibiotic treatment and 28 (93.3 per cent) were found to have an excellent response. Relapses were seen in 25 per cent of these dogs after follow up periods of 1 to 4 months. Minor side effects were seen in only 1 dog. On the basis of this study, enrofloxacin is an excellent antibiotic for the treatment of canine bacterial pyoderma but must be administered well beyond the manufacturer's maximum recommendation for duration of therapy. Résumé— Une pyodermite bactérienne a été diagnostiquée chez 30 chiens qui furent traités avec de l'enrofloxacine administrée par voie orale à la dose de 2.5 mg/Kg toutes les 12 heures, pour une durée allant de 2.5 à 14 semaines. Les chiens furent réexaminés à la fin de l'antibiothérapie et 28 d'entre eux (93.3%) présentaient une excellente réponse au traitement. Des rechutes furent observées chez 25% des chiens lors de suivis portant sur des périodes de 1 à 4 mois. Des effets secondaires mineurs furent observés chez l'un des chiens. Cette étude montre que l'enrofloxacine est un excellent antibiotique pour le traitement des pyodermites canines mais, qu'il doit être administré pendant des délais beaucoup plus longs que ceux qui sont indiqués par le fabricant. Zusammenfassung— 30 Hunde mit bakteríellen Pyodermien wurden zweieinhalb bis vierzehn Wochen lang oral mit Enrofloxacin behandelt (2 täglich 2.5 mg/kg KGW). Nach Abschluß der Behandlung wurden die Tiere erneut untersucht. Bei 28 Patienten (93.3%) wurden hervorragende Ergebnisse erzielt. Bei 25% kam as nach 1 bis 4 Monaten zu Rezidiven. Geringe Nebenwirkungen wurden nur in einem Fall beobachtet. Die vorliegende Untersuchung zeigt, daß Enrofloxacin ein hervorragendes Antibiotikum für die Behandlung von Pyodermien ist, aber wesentlich länger als vom Hersteller angegeben verabreicht werden muß. Resumen Treinta perros, a los cuales se había diagnosticado una epiderma bacteriana, fueron tratado con Enrofloxacina via oral a una dosis de 2,5 mg/kg de peso corporal cada 12 horas durante un período de tiempo que oscíló entre las 2,5 semanas y las 14 semanas. Los perros se examinaron clínicamente de nuevo cuando acabó el tratamiento antibiótico y se observó en 28 (93,3%) una respuesta excelente. En un 25% de estos perros se observaron recidivas en un período comprendido entre uno y cuatro meses. Efectos colaterales de poca importancia se observaron úicamente en un animal. Según estos resultados puede concluirse que la Enrofloxacina es un antibiótico excelente para el tratamiento de las piodermas bacterianas del perro, aunque debe administrarse durante un período de tiempo superior al que recomiendan los productores.     

Impacts of Air Pollution Control Strategies in Kentucky

The purpose of this paper is to estimate the impacts of air pollution control strategies for one state, Kentucky, on its own economy. Effects of the Clean Air Act are estimated, but the emphasis is on scenarios for compliance with pending acid rain legislation. The most restrictive scenario involves a 478,000 ton per year reduction in SO₂. Based on elasticity and engineering estimates, we project shifts from high-sulfur Western Kentucky coal to low-sulfur Eastern Kentucky coal, higher electric utility rates and manufacturing costs, and lower manufacturing employment. Impacts are always less than 6 percent of 1985 levels.     

An analysis of crack pattern in clay soil: its density and orientation

The structure of much clay soil is angular blocky, and the pore space consists of a three-dimensional network of narrow, approximately planar cracks. This paper presents a means of describing such a network in terms of its density and orientation. Undisturbed samples are impregnated with resin containing a fluorescent dye. Plane sections of known azimuth and elevation are cut through them and photographed under ultra-violet light. The photographs are projected onto a screen and the spacings between successive cracks along linear probes are measured in several directions. The sets of distances obtained are then analysed. The method was applied to subsoil of the Windsor series. The distribution of inter-crack distances appeared to be exponential but with a dearth of distances less than about 1 mm. The crack pattern was judged to be the outcome of a Poisson process, but one in which some of the very narrow wedges of soil had collapsed. The crack network was perceptibly anisotropic, and was modelled as two superimposed patterns, one isotropic and the other a set of approximately parallel cracks. The orientation of the parallel component was estimated from the sections. The cracks were found to be aligned parallel to the contour of the land and to dip into the hill slope at angles ranging from about 25° to 75° to the horizontal. The intensities in the soil of the two components were estimated as 0.18 mm^?1 for the isotropic component and 0.2 mm^?1 normal to the parallel component, equivalent to 0.1 mm^?1 for a random direction.     

Effect of Tibial Plateau Leveling Osteotomy on Femorotibial Contact Mechanics and Stifle Kinematics

Objective— To evaluate the effects of tibial plateau leveling osteotomy (TPLO) on femorotibial contact mechanics and 3-dimensional (3D) kinematics in cranial cruciate ligament (CrCL)-deficient stifles of dogs.
Study Design— In vitro biomechanical study.
Animals— Unpaired pelvic limbs from 8 dogs, weighing 28–35 kg.
Methods— Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135°. Three-dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL-deficient, and TPLO-treated conditions. Repeated measures analysis of variance with a Tukey post hoc test ( P <.05) was used for statistical comparison.
Results— Significant disturbances to all measured contact mechanical variables were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and increased internal tibial rotation in the CrCL-deficient stifle. No significant differences in 3D femorotibial alignment were observed between normal and TPLO-treated stifles; however, femorotibial contact area remained significantly smaller and peak contact pressures in both medial and lateral stifle compartments were positioned more caudally on the tibial plateau, when compared with normal.
Conclusion— Whereas TPLO eliminates craniocaudal stifle instability during simulated weight bearing, the procedure fails to concurrently restore femorotibial contact mechanics to normal.
Clinical Relevance— Progression of stifle osteoarthritis in dogs treated with TPLO may be partly the result of abnormal stifle contact mechanics induced by altering the orientation of the proximal tibial articulating surface.