Underwater noise from submarine turbidity currents.

Noise from turbidity currents flowing down the face of a fjord delta was measured underwater at frequencies from 1 to 1200 kHz. The noise spectra are consistent with sound generation by collisions among sand-sized particles. The spectra from the leading head extend to higher frequencies than those from the trailing body, indicating that collisions were between finer-grained particles in the head and coarser-grained particles in the body. Noise intensity increased 100-fold for a two-fold increase in head speed, consistent with the expected collision rate for granular materials in the high-flow gas-like phase and highly turbulent particle-laden flows.

In vivo temperature dependence of cyclic and pseudocyclic electron transport in barley.

The effect of temperature on the rate of electron transfer through photosystems I and II (PSI and PSII) was investigated in leaves of barley (Hordeum vulgare L.). Measurements of PSI and PSII photochemistry were made in 21% O2 and in 2% O2, to limit electron transport to O2 in the Mehler reaction. Measurements were made in the presence of saturating CO2 concentrations to suppress photorespiration. It was observed that the O2 dependency of PSII electron transport is highly temperature dependent. At 10 degrees C, the quantum yield of PSII (phi PSII) was insensitive to O2 concentration, indicating that there was no Mehler reaction operating. At high temperatures (> 25 degrees C) a substantial reduction in phi PSII was observed when the O2 concentration was reduced. However, under the same conditions, there was no effect of O2 concentration on the delta pH-dependent process of non-photochemical quenching. The rate of electron transport through PSI was also found to be independent of O2 concentration across the temperature range. We conclude that the Mehler reaction is not important in maintaining a thylakoid proton gradient that is capable of controlling PSII activity, and present evidence that cyclic electron transport around PSI acts to maintain membrane energisation at low temperature.

A large-animal model to evaluate the clinical potential of fetal pig pancreas fragment transplantation.

The long-term goal of this study is to assess the feasibility of using fetal pig pancreas fragment (FPPF) transplantation to treat patients with type I diabetes. Using the highly inbred Westran Pigs, our initial aim was to establish a rejection-free transplant model of FPPF grafted into sibling recipient pigs without immunosuppression. FPPFs were isolated from 80-100-day-old fetuses of either Westran Pigs or outbred pigs and transplanted into the thymus, spleen, liver, or kidney of the recipient Westran pig. Biopsies were taken from each transplant site at set time points and assessed histologically for islet viability, rejection, and endocrine function. Fifty-eight fetal donors were used to transplant 16 recipient pigs. A nonspecific inflammation was seen for both outbred and inbred FPPF donor tissue at day 3 and was considered a response to ischemic necrosis. However, all the transplanted outbred FPPF donor tissue was acutely rejected and lost by day 10-14. In contrast, inbred FPPF tissue showed little evidence of graft necrosis after 3 days, and growth and formation of epithelial islet cell nest-like structures were seen to 28 days after transplantation. With time after transplantation, increasing amounts of insulin immunoperoxidase staining was seen together with chromogranin and somatostatin staining. In summary, this study confirms the potential of the Westran pig to answer the unproven ability of fetal pancreatic tissue to reverse type I diabetes in a large animal model.

Courting disaster? A survey of the autopsy service provided by district surgeons in Kwazulu-Natal.

AIM: To provide information on the overall quality of the autopsy service provided by district surgeons in KwaZulu-Natal (KZN) and in particular to identify factors which may have a negative impact on the judicial process. METHOD: Confidential questionnaires were sent to 73 district surgeons and 216 legal practitioners including prosecution advocates, regional court prosecutors, defence advocates and attorneys. One hundred and twenty (43%) replies (47 doctors and 73 lawyers) were suitable for analysis. RESULTS: District surgeons have no shortage of experience or maturity but their performance is hampered by the following: lack of appropriate training in forensic pathology; high case load; inadequate facilities and support staff; and lack of access to ancillary services. CONCLUSION: This study has shown that the standard of autopsy services by district surgeons varies considerably. Overall, there is evidence that inadequacies on the part of district surgeons have negative repercussions for the criminal justice system. Urgent attention should be given to implement training programmes for the district surgeons and to improve service conditions.

Rural home care of a technology-dependent infant.

A multidisciplinary approach is necessary to prepare for home care of technology-dependent infants. The environment must protect, support, and promote the physical, cognitive, and social growth and development of these infants. Parents and caregivers of technology-dependent infants should be taught cardiopulmonary resuscitation and should be helped to develop a plan for obtaining emergency medical assistance.

Comprehensive pharmaceutical services in a medical intensive-care unit.

The clinical and distributive services that have been provided by clinical pharmacists for the past 14 years in the medical intensive care unit (MICU) of a 1600-bed urban teaching hospital are described. The MICU pharmacy staff consists of 4.3 full-time equivalent pharmacists who provide daily 24-hour services. The pharmacists are actively involved in all pharmacological decisions with hands-on control of drug distribution from preparation through delivery and administration. They maintain up-to-date patient medication records and monitoring flow sheets for each patients. The pharmacists identify adverse reactions, formulate contingency plans, and promptly intervene to prevent crises. They provide comprehensive pharmacokinetic services, select drug administration times and routes, and prepare and deliver all medications. All i.v. medications are custom-made to meet the patients' fluid, sodium, or potassium restrictions. The pharmacists set up infusion pumps and select the proper infusion rates for i.v. and intra-arterial drugs. They also recommend and monitor the patients' nutritional support therapy. The program has been well accepted by nurses and physicians; however, only 20% of the inpatient clinical pharmacists desire to work in the MICU. The skills and educational requirements for managing patients in an MICU are discussed. Pharmacists have become an integral part of this MICU by optimal drug therapy, increasing productivity and efficiency, providing prompt and accurate services, and participating in research.

Postoperative pain prevention by continuous epidural infusion. A study of the clinical effects and the plasma concentrations obtained.

A method for postoperative pain prevention is described using epidural bupivacaine infused by means of a variable rate peristaltic pump. High plasma concentrations of bupivacaine were found but no serious signs of bupivacaine toxicity were observed and the method proved satisfactory in practice. Theoretical and practical considerations and aspects of clinical management are discussed.