Cot-nursing using a heated, water-filled mattress and incubator care: a randomized clinical trial

Aims: To evaluate the thermal responses and weight gain in preterm infants nursed in a cot on a heated, water-filled mattress (HWM) compared with infants receiving care in an air-heated incubator and to compare mothers' stress, anxiety levels and perceptions of their infants in the two groups. Methods: Stable preterm infants weighing 1300 to 1500 g were enrolled, being randomly allocated to either the study group (n = 41) receiving care in a cot on an HWM, or the control group ( n = 33) receiving incubator care. The mean daily body temperature and episodes of cold stress and hyperthermia were recorded. Weight gain (g kg(-1) body weight d(-1)) was also calculated. The mothers completed questionnaires on their perceptions of their infants, and their anxiety and stress levels before randomization, and 2 - 3 wk later during the trial. Results: The mean body temperature was similar for the first week of the trial ( study group 36.9degreesC vs controls 36.9degreesC). There were no significant differences in the incidence of cold stress, while more hyperthermic episodes were seen in the study group ( p = 0.03). There were no significant differences in weight gain during the first ( study group 21.4 g vs controls 19.6 g) or second weeks of the trial ( study group 20.5 g vs controls 19.2 g). Neonatal morbidity did not differ between the groups. There were no differences in mothers' perceptions of their babies, or feelings of stress or anxiety. Conclusion: There were no differences between infants cot-nursed on an HWM and those receiving incubator care, with the exception of episodes of high temperature. The results suggest that the HWM may be used safely for low-weight preterm infants.

A new analytical solution for water table fluctuations in coastal aquifers with sloping beaches

The Boussinesq equation appears as the zeroth-order term in the shallow water flow expansion of the non-linear equation describing the flow of fluid in an unconfined aquifer. One-dimensional models based on the Boussinesq equation have been used to analyse tide-induced water table fluctuations in coastal aquifers. Previous analytical solutions for a sloping beach are based on the perturbation parameter, epsilon(N) = alphaepsilon cot beta (in which beta is the beach slope, alpha is the amplitude parameter and epsilon is the shallow water parameter) and are limited to tan(-1) (alphaepsilon) much less than beta less than or equal to pi/2. In this paper, a new higher-order solution to the non-linear boundary value problem is derived. The results demonstrate the significant influence of the higher-order components and beach slope on the water table fluctuations. The relative difference between the linear solution and the present solution increases as 6 and a increase, and reaches 7% of the linear solution. (C) 2003 Elsevier Ltd. All rights reserved.