Assessing the variability of hydrographic processes influencing the life cycle of the Sicilian Channel anchovy, Engraulis encrasicolus, by satellite imagery

Three oceanographic surveys carried out in the Sicilian Channel during the spawning season (June to July) of anchovy (Engraulis encrasicolus) showed a close relationship between anchovy reproductive strategy and important hydrographic structures. A time series of satellite‐derived sea surface temperature images of the Sicilian Channel were analysed by means of empirical orthogonal functions and the dominant empirical modes were studied in detail. The first empirical mode captured much of the original variance and reproduced the trajectory of the Atlantic Ionian Stream (AIS), the principal hydrodynamic feature of the area. The time coefficients of modes 1 and 2 had seasonal signals which, when combined, accounted for the enhancement of the thermal front, clearly visible off Cape Passero (southernmost coast of Sicily) during summer. As the area constituted the principal nursery ground of the Sicilian Channel anchovy, the combination of the time coefficients of these modes was considered a potential indicator of the food particle concentration usually associated with oceanic fronts, which provided the energy requirements for larval growth. Mode 3 described the north/south displacements of the mean AIS trajectory, which modified the surface temperature regime of the anchovy spawning habitat. Therefore, the time coefficients of this mode were used as a potential indicator of anchovy spawning habitat variability. The capability of time coefficients of modes 2 and 3 to modify the main pattern depicted by mode 1 were tested successfully against in situ oceanographic observations.     

IMAGING DIAGNOSIS—TRANSCRANIAL COLOR‐CODED DUPLEX SONOGRAPHY IN A DOG WITH HEPATIC ENCEPHALOPATHY

We report the use of transcranial Doppler ultrasonography in a dog with hepatic encephalopathy secondary to a congenital portosystemic shunt. A severe increase in the pulsatility index was measured in the right middle cerebral artery, left middle cerebral artery, and basilar artery. These values returned to normal following medical stabilization of the patient and resolution of the neurologic signs. Transcranial Doppler ultrasonography appears to have value for monitoring the status of intracranial hypertension in patients with hepatic encephalopathy.     

A Bayesian model for anchovy (Engraulis encrasicolus): the combined forcing of man and environment

Fishery collapses frequently result from combined pressures of the environment and man, which are difficult to discern because of the complexities involved and our limited knowledge. Models to resolve this complexity often become too sophisticated, with too many assumptions and, consequently, with little capacity to predict beyond calibration data. In this paper we implement a different procedure where the model is kept simple and uncertainty accounts for the equation imperfectness to reproduce ecological complexity. Human and environmental forcing on an anchovy ( Engraulis encrasicolus ) stock are simulated with only six parameters plus their error terms, and the uncertainty is computed with Bayesian methods. The simple structure is able to reproduce the major dynamical features of this species in the Gulf of Cádiz, including data on life stages and age structure that had no contact with the model. This is a distinct performance for a frugal approach working on a mid-trophic species and a positive instance where parsimony can simulate the interaction of man, fish and the environment, provided uncertainty is accounted for in the process.     

ULTRASOUND IMAGE COMPOUNDING: EFFECT ON PERCEIVED IMAGE QUALITY

In order to determine the effect of different image compounding functions on perceived image quality, 84 pairs of ultrasound images were collected, mixed, and reviewed by four independent observers who were asked to identify the highest quality image of each pair. Each image in a pair was made using the same orientation, transducer, frequency, and gain settings but different compounding settings. Outcomes were analyzed using logistic regression. Observers judged compound images to be better quality than noncompound images in 69% cases, the same quality in 24%, and poorer quality in 7%. Overall, compound images were considered significantly better quality than noncompound images (P < 0.001). Compound images were more likely to be considered better quality than the corresponding noncompound images when combined transmit/receive spatial compounding was used rather than receive-only spatial compounding or transmit compounding, and when the vector transducer or the curvilinear transducer were used rather than the linear transducer. Observers considered improved border definition and increased signal to noise ratio to be the properties that accounted most often for higher quality of compound images compared with noncompound images.     

Epidural Injection of Ketamine for Perineal Analgesia in the Horse

Objective—To determine the analgesic, sedative, and cardiopulmonary effects of epidural ketamine in the horse. Animal Population—Six healthy horses (three males and three females) weighing between 350 and 450 kg. Methods—Three doses of ketamine were selected (0.5, 1, and 2 mg/kg). Two months before the beginning of experiments, the carotid artery was exteriorized, and 1 week before experiments began, an epidural catheter was placed percutaneously in all animals with the tip located 12 cm cranially in the midsacrum. One week later, either saline (control) or one of three doses of ketamine was injected epidurally. Each animal received each ketamine dose and saline in random order at 1-week intervals. Ketamine was diluted in saline 0.9% before the experiment, and the volume used was adjusted to horse size and correlated to clinically used volumes. All the animals received a standard noxious stimulus consisting of needle insertion into the skin and deep muscle using a 3-point scale for scoring the response. A second scale was used to score the degree of sedation. The response to a noxious stimulus, the degree of sedation, and arterial blood pressure were assessed at previously determined intervals: before drug and 2, 5, 10, and 15 minutes and every 15 minutes to 210 minutes after ketamine or saline administration. Arterial blood samples were drawn for blood gas analysis before drug and at 15, 30, 60, and 90 minutes. Results—All the tested doses of ketamine were effective in producing analgesia of the tail, perineum, and upper hindlimb. Total tail and perineal analgesia times were similar depending on dosage (30 minutes for 0.5 and 1.0 mg/kg and 75 minutes for 2.0 mg/kg). A sedative effect of ketamine was also observed in a dose-response manner with a peak effect between 15 and 30 minutes postadministration. No cardiopulmonary effects were observed with any dose of ketamine. Conclusions—Results indicate that epidurally administered ketamine in the horse produces local spinal and central nervous system effects with analgesia and sedation but minimal cardiopulmonary effects. Clinical Relevance—Further studies are required to determine whether the analgesia is sufficient for surgery.     

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.