The acute abdomen: a surgeon's approach to diagnosis and treatment

Clinical approach to a patient with acute abdominal distress involves decision making: whether to take a patient to surgery, or manage the patient medically. A thorough and systematic approach requires the use of diagnostic imaging modalities, including radiology and ultrasonography, performing diagnostic peritoneal lavage or abdominal paracentesis techniques, and bloodwork evaluation, including complete blood count and serum biochemistry profiles. In some cases, the results of diagnostic tests may lead to surgical versus medical management, particularly when a patient fails to respond to medical management alone. In other cases, such as GDV syndrome, penetrating abdominal wounds, pyometra, or uncontrolled abdominal hemorrhage, rapid surgical management is necessary for patient survival. This article describes a systematic approach to a small animal patient with acute abdomen.     

Synchronized Terrestrial-Atmospheric Deglacial Records Around the North Atlantic

On the basis of synchronization of three carbon-14 (14C)-dated lacustrine sequences from Sweden with tree ring and ice core records, the absolute age of the Younger Dryas-Preboreal climatic shift was determined to be 11,450 to 11,390 +/- 80 years before the present. A 150-year-long cooling in the early Preboreal, associated with rising Delta14C values, is evident in all records and indicates an ocean ventilation change. This cooling is similar to earlier deglacial coolings, and box-model calculations suggest that they all may have been the result of increased freshwater forcing that inhibited the strength of the North Atlantic heat conveyor, although the Younger Dryas may have begun as an anomalous meltwater event.     

Induced ovulation of female chinook salmon (Oncorhynchus tshawytscha) at a production hatchery

A simple, low-cost method for inducing ovulation in hatchery-held adult chinook salmon was developed. Use of this method resulted in an increase in the number of eggs collected, by circumventing losses due to prespawning mortality.One hundred and twenty 4-year-old chinook salmon which had returned to the Capilano hatchery prior to 1 October were used as a stock population. Three weeks before the peak spawning period, 36 fish were divided into two groups. The control group received two injections of 0.65% saline spaced 3 days apart. The test group received a 0.1-mg/kg SG-G100 (salmon gonadotropin) injection, followed on the third day by a 2.5-mg/kg SG-G100 injection. By Day 8, 73% of the treated group and 0% of the control group had ovulated. Prespawning mortality accounted for 22% of the treated fish and 83.4% of the control fish. Treatment resulted in a net gain of 16,000 eggs over the control. The second experiment began 3 days before the peak spawning period. The 32 fish which remained in the stock population were divided into three groups and received two injections 3 days apart. The two treatment groups received either 0.1 mg SG-G100/kg followed by 2.0 mg SG-100/kg, or 0.1 mg SG-G100/kg followed by 50.0 mg salmon pituitary extract (SPE)/kg. The control group was injected with 0.65% saline. By Day 8, 73% of the SPE group, 82% of the SG-G100 group, and 40% of the control group had ovulated. Treatment resulted in a net gain of 16,000 eggs for the SG-G100 group and 19,000 eggs for the SPE group over the control. No significant differences in egg size or percent survival to the eyed stage were found between test and control groups. The misjudgment of maturity led to the stripping of several fish before their eggs were completely ovulated. The factors leading to these partial ovulations are discussed.     

Aspects of the ecology of meiofauna in Mngazana estuary,Transkei

The intertidal distribution and abundance of sand and mud-flat meiofauna at the mouth and the middle reaches of Mngazana estuary were monitored over a period of 15 months from April 1977 to July 1978 and the data compared with those from other South African estuaries. The meiofauna exhibited an early winter maximum with numbers ranging ranging from 2,74 x 10⁶ to 7,27 x 10⁶m^-2 in sand and from 2,59 x 10⁵ to 4,15 x 10⁵m^-2 in mud, both to a depth of 20 cm. The fluctuations correlated with variations in Eh and temperature. Annual production in the upper 20 cm is estimated at 8,0 gCm^-2h^-1 and 0,6 gCm^-2y^-1 in sand and mud respectively.     

Quantitative Extraction of Meiofauna: A Comparison of Two Methods

Two methods for the quantitative extraction of meiofauna from natural sandy sediments were investigated and compared: Cobb's decanting and sieving technique and the Oostenbrink elutriator. Both techniques were more efficient with pre-fixed samples than with fresh samples. The results indicated that elutriation is the more reliable method due to its low variability, 7,5% for nematodes and 8,4% for harpacticoids and mystacocarids compared to 11,2% and 29,0% respectively in the case of decantation. However, with samples containing 3 000 to 5 000 animals per 200 cc, decantation yielded 25% more animals than elutriation.     

The ecology of sandy beaches in Transkei

Data from an ecological survey of three sandy beaches in Transkei and from Gulu beach on the eastern Cape coast, South Africa, are presented. Physical parameters such as beach profile, sand particle size, Eh and carbonate content, as well as abundance, composition, biomass and distribution of the macrofauna and meiofauna were investigated. Beaches in Transkei are relatively small and are usually associated with estuarine systems. Substrate at Thompson's beach in northern Transkei was relatively coarse with relatively few macrofaunal species. Further south, beaches have fine to medium substrates and are characterized by a diverse macrofaunal community. Major changes in faunal composition occurred in Transkei and this was most evident for Mpande and Cebe beaches where a subtropical east-coast fauna was replaced by species characteristic of the southern Cape coast. Molluscs also became increasingly important southwards and replaced crustaceans as the most important group. Meiofauna was dominated by nematodes and harpac- ticoids on all beaches and there was an increase both in numbers and biomass southwards.     

Measurement of biological oxygen demand in sandy beaches

Measurements of biological oxygen demand in a sandy beach using conventional in situ techniques are compared with laboratory measurements of interstitial oxygen changes in intact cores. Oxygen uptake as measured in the laboratory was approximately three times that measured in the field despite the fact that the cores were undisturbed. In addition, the effect of disturbance on sediment cores was investigated and it was found that oxygen demand in disturbed cores increased by up to 60%, due mainly to an increase in bacterial activity. This effect was still evident after 24 hours of incubation. The applicability of conventional respirometer techniques to well-drained systems such as open sandy beaches is questioned and an alternative approach suggested.