MAGNETIC RESONANCE IMAGING IN FOALS WITH INFECTIOUS ARTHRITIS

The magnetic resonance (MR) imaging findings of foals with infectious and noninfectious arthritis are described. Six foals with infectious arthritis and three foals with noninfectious arthritis were grouped based on synovial fluid analysis results and examined with radiography and MR imaging. Four out of six foals with infectious arthritis had osseous lesions in MR images indicative of osteomyelitis and only 4/19 lesions were detected on digital radiographs. The three foals with noninfectious arthritis had no osseous lesions in MR images or radiographically. Of the six joints that had osseous lesions detected with MR imaging, three had at least one lytic lesion detected radiographically. Osseous lesions in the epiphysis, metaphysis, and physis appeared in MR images as T2W, short tau inversion recovery, and proton density hyperintense foci with a hypointense halo. The same lesions appeared hyperintense in the 3D RSSG water excitation pulse sequence but lacked a surrounding hypointense halo. Most joints of foals with infectious arthritis had heterogenous signals within the synovial fluid whereas all of the nonseptic joints had homogenous synovial fluid signals. MR imaging appears to be better than radiography in the detection of osseous lesions in foals diagnosed with infectious arthritis and may be a valuable screening test for the presence of osteomyelitis.     

Dispersal dynamics of post-larval blue crabs, Callinectes sapidus, within a wind-driven estuary

We examined how post‐larval blue crab (Callinectes sapidus) dispersal occurs within Pamlico Sound, NC, USA, a predominantly wind‐driven system. We sampled during multiple 24‐h periods over 2 years (2000–01) to relate the spatial distribution of post‐larvae in the water column with circulation patterns. A hydrodynamic model of the region was used to recreate dispersal trajectories and to assess potential transport mechanisms and pathways that link near‐inlet and across‐Sound nursery habitats. Most post‐larval blue crabs were collected in surface waters at night, and were consistently distributed within the north‐western region of Pamlico Sound. Particle‐tracking simulations suggested that dispersal from the inlets to across‐Sound nursery habitats only resulted from the combination of tidal and wind‐driven currents. Our simulation results further indicated that the northernmost inlet (Oregon Inlet) was the primary supplier of post‐larval blue crabs throughout the northern basin of Pamlico Sound, as crabs ingressing through Hatteras Inlet to the south were not retained within our study area. A dispersal pathway connecting Oregon Inlet and across‐Sound settlement habitats was evident from field observations. Collectively, our results indicate how multiple forcing agents, coupled with post‐larval vertical positioning within the water column, drive estuarine dispersal and connect spatially separated nursery habitats.     

UNTERSUCHUNGEN UBER DEN EINFLUSS LANGJAHRIG WIEDERHOLTER ANWENDUNG VON DNOC UND 2,4-D AUF IHREN ABBAU IM BODEN

Zusammenfassung. Es wird über die Abbaugeschwindigkeit von DNOC und 2,4-p in eistmals und in langjahrig wiederholt behandeltem Boden berichtet. Der langjahng wiederhoh behandelte Boden stammte aus einem Feldversuch, in dem diese Herbizide in 12 Jahren 12 mal zur Unkrautbekämpfung in Getreide angewandt wurden. Wenn Boden der DNOC-Parzellen 7 Monate nach seiner letzten Behandlung erneut mit DNOC versetzt wurde, war gegenüber erstmals behandeltem kein Unterschied in der Abbaugeschwindigkeit festzustellen. Wurde Boden der 2,4-D-Parzcllen 8 Monate nach der letzten Applikation wieder mit 2,4-D versetzt, verlicf der Abbau des Herbizids schneller als im Boden der zum erstenmal mit dem Herbizid behandelt worden war. Effet d'un traitement à long terme avec le DNOC et le 2,4-D sur leur dègradation dans le sol Résumé. La degradation du DNOC et du 2,4-D a étéétudiée dans un sol traité pour la premiére fois et dans un sol provenant de parcelles en plein champ qui ont recu des traitements annuels durant une période de dotize ans pour le désherbage des céréales. Quand le sol provenant des parcelles traitées au DNOC fut examiné sept mois aprés la derniére application, il ne fut pas constaté de difference dans le taux de degradation par rapport ausol traits pour la premiére fois. La dégradation du 2 ,4-D dans lesol provenant des parcelles traitées et examine huit mois aprés la derniere application fut plus rapide que dans le sol des parcelles traitées pour la premiére fois. The effect of long-Urm treatment with DNOC and 2 ,4-D on their breakdown in soil Summary. The breakdown of DNOC and 2,4-D was studied in soil treated for the first time and in soil from field plots which had received annual treatments over a period of 12 years for weed control in cereals. When soil from DNOC-treated plots was tested 7 months after the last application, there was no difference in the rate of breakdown from that in soil treated for the first time. The breakdown of 2,4-D was more rapid in soil from the treated plots, tested 8 months after the last application, than in soil from plots treated for the first time.     

UNTERSUCHUNGEN ZUR KONKURRENZWIRKUNG VON KULTURPFLANZEN UND UNKRÄUTERN AUFEINANDER

Summary. A 2-year comparison of the development of Avena fatua L. and Sinapis arvensis L., with spring barley and of Alopecurus myosuroides Huds, with winter wheat gave the following results:

• 1 Avena fatua emerged shortly before barley in both years. Development until tillering was somewhat slower than that of barley, but after tillering the growth of both species was about the same. The first seeds of A. fatua matured shortly before harvest.
• 2 Growth of Sinapis arvensis was slower than that of barley during the- early stages, but after tillering was more rapid. Growth ceased more than 10 days before harvest.
• 3 In 1962–63 Alopecurus myosuroides germinated mainly in spring, but in 1963–64 most germination occurred in autumn, so that early development was different in the two years. After tillering the development WAS much faster than that of wheat and at the flowering stage of A. myosuroides, the shoots were taller than those of wheat. Seed was ripened some time before harvest.
• 4 A comparison of the development of A. myosuroides and Avena fatua alone and in competition with cereals revealed no marked influence of competition on the pattern of development, but competition did cause some reduction in shoot length and a marked reduction in weight of the two weed species.

Compétition entre plantes cultivées et mauvaises herbes. I. Développement absolu el développement retalif des céréales et de quelques espèces de mauvaises herbes     

UNTERSUCHUNGEN ÜBER DIE GEGENSEITIGE BEEINFLUSSUNG VON KULTURPFLANZEN UND UNKRÄUTERN IN WASSERKULTUR

Zusammenfassung. Es wurden Untersuchungen über die gegenseitige Beeinflussung von Kulurpflanzen und Uukräutern in Wasserkultur durchgeführt. Hierbei wurde eine Methodik verwendet, die es gestattete, die Ursachen einer gegenseitigen Beeinflussung auf den Wurzelbereich zu beschränken und gleichzeitig die Wirkung einiger Konkurrenz-faktoren (z.B. Licht, Raum) ausz.uschalten. Von insgesamt 57 untersuchten Pflanzen-kombinationen (Ergebnisse s. Tab. 1-4) zeigten etwa ein Drittel keine gesicherten Symptome einer gegenseitigen Beeinflussung. Bei allen anderen Versuchen war ein mehr oder weniger ausgeprágter Hemm- bzw. Förderungseffekt festzustellen. Die Ursache dieser Erscheinung konnte in einigen Fallen als Náhrstoffkonkurrenz (Nr. 5, 6, 7, 23, 44d. Tabellen) erkannt werden, wáhrend bei anderen Versuchen (Nr. 12, 13, 15, 18, 23, 45, 46) mit der Beteiligung allelopathischer Faktoren (Abgabe organischer Verbin-dungen aus lebenden und abgestorbenen Wurzelzellen) gerechnet werden muss. Die Wachstumshemmung bzw.- förderung war in einigen Fällen dann besonders deutlich (Nr. 46, 47, 51), wenn dem einen Partner durch Vorkultur ein gewisser Entwicklungs-vorsprung gegeben wurde. Obwohl einige der vorliegenden Ergebnisse mit Befunden aus der Praxis gut übereinstimmen (Nr. 12, 13, 18), kann man aus naheliegenden Gründen (Abbau von Wurzelstoffen durch Mikroorganismen, Absorptionsverhältnisse im Boden usw.) die in Wasserkultur erzielten Resultate nicht unmittelbar auf die natürlichen Verhältnisse übertragen, Um jedoch den möglichen Ursachen einer gegenseitigen Beeinflussung von Kulturpflanzen und Unkräutern überhaupt einmal náher zu kommen, ist cine getrennte Untersuchung der in Frage kommenden Faktoren unumgánglich.
Experiments on the interaction between cultivated plants and weeds in water-culture     

IMAGING DIAGNOSIS—CONGENITAL LOBAR EMPHYSEMA IN A DOG

A 14‐week‐old female West Highland White Terrier developed acute dyspnea. Radiographically there was an enlarged, hyperlucent caudal portion of the left cranial lung lobe and a diffuse, severe interstitial‐to‐alveolar pattern in the remaining lung lobes that was accentuated caudodorsally. Computed tomography confirmed the presence of the emphysematous lobe and further showed it to have focal lobar bronchial collapse. Lung lobe resection was performed, and the diagnosis was congenital lobar emphysema secondary to bronchial cartilage hypoplasia.     

STUDIEN ZUR VERTEILUNG VON 14C-MARKIERTEM 2,4-D IN VERSCHIEDEN EMPFINDLICHEN UNKRÄUTERN

Studies of the absorption and translocation of ¹⁴C-2,4-D in Chenopodium album L., Galinsoga parviflora Cav., Datura stramonium L. and Galium aparine L. in relation to their susceptibility gave the following results: In G aparine (resistant) there was little transport of 2,4-D applied to the leaves, and a probable relationship between resistance and the immediate binding of the 2,4-D in the treated leaf. D. stramonium (relatively resistant) transported 2,4-D in considerable amounts alter uptake through the leaf, while C. album (very susceptible) and G. parviflora (susceptible) were intermediate in respect of 2,4-D translocation. No relationship between susceptibility of these four species and 2,4-D uptake and translocation from the leaves could be established. After application to the root systems of the four species, 2,4-D was taken up and translocated in the shoot to varying extents. In G. aparine much 2,4-D was taken up and translocated. In contrast to leaf application, the herbicide was not immediately converted into a strongly-held immobile form. In C. album, G. parviflora and D. stramonium, however, no 2,4-D was translocated in the shoot. There was thus no correlation between susceptibility and shoot transport of 2,4-D in the four species studied. Distribution du 2,4-D marqué au ¹⁴C dans des espèces de mauvaises herbes présentant des sensibilités diverses     

FLUOROSCOPIC STUDY OF THE NORMAL GASTROINTESTINAL MOTILITY AND MEASUREMENTS IN THE HISPANIOLAN AMAZON PARROT (AMAZONA VENTRALIS)

Contrast fluoroscopy is a valuable tool to examine avian gastrointestinal motility. However, the lack of a standardized examination protocol and reference ranges prevents the objective interpretation of motility disorders and other gastrointestinal abnormalities. Our goals were to evaluate gastrointestinal motility in 20 Hispaniolan Amazon parrots (Amazona ventralis) by contrast fluoroscopy. Each parrot was crop‐fed an equal part mixture of barium sulfate and hand‐feeding formula and placed in a cardboard box for fluoroscopy. Over a 3‐h period, 1.5 minute segments of lateral and ventrodorsal fluoroscopy were recorded every 30 min. The gastric cycle and patterns of intestinal motility were described. The frequency of crop contractions, esophageal boluses, and gastric cycles were determined in lateral and ventrodorsal views. A range of 3.4–6.6 gastric cycles/min was noted on the lateral view and 3.0–6.6 gastric cycles/min on the ventrodorsal view. Circular measurements of the proventriculus diameter, ventriculus width, and length were obtained using the midshaft femoral diameter as a standard reference unit. The upper limits of the reference ranges were 3.6 and 4.7 femoral units for the proventriculus diameter in the lateral and ventrodorsal view, respectively. Two consecutive measurements were obtained and the measurement technique was found to have high reproducibility. In this study, we established a standardized protocol for contrast fluoroscopic examination of the gastrointestinal tract and a reliable measurement method of the proventriculus and ventriculus using femoral units in the Hispaniolan Amazon parrot.