ANATOMIC AND COMPUTED TOMOGRAPHIC ATLAS OF THE HEAD OF THE NEWBORN BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS)

The head of a newborn dolphin (Tursiops truncatus), that died shortly after birth was imaged using computed tomography (CT). Gross cross-sectional slices of the head were compared with the CT images to identify normal structures of the cranium, brain, and respiratory and digestive pathways. Labelled transverse CT images of the dolphin head are presented sequentially as a reference for normal anatomy.     

The demography of Datura ferox (L.) in soybean crops

The emergence, survival, seed production and seed dispersal of Datura ferox was studied in soybean fields in 1982–1983 and 1984–1985. Most seedling emergence occurred within one month of crop sowing. Later germination, associated with inter-row cultivation, represented 4–26% of the total seedlings, and none survived to seed production. Only 5% of the first cohort in 1982–1983, and 7% in 1984–1985, survived to seed production; it was independent of initial density. Although weed density was greatly reduced by control measures, negative relationships were observed between peak seedling density and plant height, stem diameter, number of ramifications, number of reproductive structures and seed production per plant. Only a small proportion of seeds (about 1%) were shed prior to soybean harvest. Combine harvesters collected more than 90% of capsules, but between 7% and 40% of the seeds were returned to the field. Seed viability was unaffected by passing through the machine. The patterns of seed dispersal varied depending on the design of the combine harvester. Two models shed seeds between 0 m and 21 m from their source, but another shed seeds between 0 m and 98 m. Calculations, based in life history parameters, showed that weed seed production would increase more rapidly if the seeds were dispersed during crop harvesting than if they arc not, even when the return of seeds to the soil by the combine is not large.     

RADIOGRAPHIC SENSITIVITY AND NEGATIVE PREDICTIVE VALUE FOR ACUTE CANINE SPINAL TRAUMA

The objectives of this study were to establish the sensitivity and negative predictive value of radiography for acute spinal osseous lesions in the canine trauma patient, and to evaluate the interobserver variability in radiographic assessment of the spine in traumatized dogs. This was a retrospective multiple observer blinded study. The study population included 30 canine patients that presented following acute trauma, with clinical signs attributable to the spinal column. Radiography and computed tomography (CT) were performed in all cases. Radiographic interpretation was performed independently by four observers with different experience levels who were blinded to clinical information (other than trauma) and the CT results. CT studies were interpreted by a further three radiologists who formed a consensus opinion on the presence of specific osseous lesions. Using the CT results as a gold standard, the sensitivities and negative predictive values of radiography for specific osseous lesions were calculated. Interobserver agreement was also evaluated. Radiography was found to have only a moderate sensitivity for fractures (72%) and subluxations (77.5%). Low negative predictive values were found for the presence of vertebral canal narrowing (58%) and fracture fragments within the vertebral canal (51%). Interobserver agreement was only moderate to fair for most lesion types. In conclusion, radiography cannot be used to reliably rule out potentially unstable acute vertebral lesions in the canine trauma patient, and further imaging is therefore often indicated in the patient with a high risk of such injuries.