Disappearing subdural hematomas in children

Serum glucose and plasma C-peptide response to i.v. glucagon administration was evaluated in 24 healthy dogs, 12 dogs with untreated diabetes mellitus, 30 dogs with insulin-treated diabetes mellitus, and 8 dogs with naturally acquired hyperadrenocorticism. Serum insulin response also was evaluated in all dogs, except 20 insulin-treated diabetic dogs. Blood samples for serum glucose, serum insulin, and plasma C-peptide determinations were collected immediately before and 5, 10, 20, 30, and (for healthy dogs) 60 minutes after i.v. administration of 1 mg glucagon per dog. In healthy dogs, the patterns of glucagon-stimulated changes in plasma C-peptide and serum insulin concentrations were identical, with single peaks in plasma C-peptide and serum insulin concentrations observed approximately 15 minutes after i.v. glucagon administration. Mean plasma C-peptide and serum insulin concentrations in untreated diabetic dogs, and mean plasma C-peptide concentration in insulin-treated diabetic dogs did not increase significantly after i.v. glucagon administration. The validity of serum insulin concentration results was questionable in 10 insulin-treated diabetic dogs, possibly because of anti-insulin antibody interference with the insulin radioimmunoassay. Plasma C-peptide and serum insulin concentrations were significantly increased (P < .001) at all blood sampling times after glucagon administration in dogs with hyperadrenocorticism, compared with healthy dogs, and untreated and insulin-treated diabetic dogs. Five-minute C-peptide increment, C-peptide peak response, total C-peptide secretion, and, for untreated diabetic dogs, insulin peak response and total insulin secretion were significantly lower (P < .00l) in diabetic dogs, compared with healthy dogs, whereas these same parameters were significantly increased (P < .01) in dogs with hyperadrenocorticism, compared with healthy dogs, and untreated and insulin-treated diabetic dogs. Although not statistically significant, there was a trend for higher plasma C-peptide concentrations in untreated diabetic dogs compared with insulin-treated diabetic dogs during the glucagon stimulation test. Baseline C-peptide concentrations also were significantly higher (P < .05) in diabetic dogs treated with insulin for less than 6 months, compared with diabetic dogs treated for longer than 1 year. Finally, 7 of 42 diabetic dogs had baseline plasma C-peptide concentrations greater than 2 SD (ie, > 0.29 pmol/mL) above the normal mean plasma C-peptide concentration; values that were significantly higher, compared with the results in healthy dogs (P < .001) and with the other 35 diabetic dogs (P < .001). In summary, measurement of plasma C-peptide concentration during glucagon stimulation testing allowed differentiation among healthy dogs, dogs with impaired beta-cell function (ie, diabetes mellitus), and dogs with increased beta-cell responsiveness to glucagon (ie, insulin resistance). Plasma C-peptide concentrations during glucagon stimulation testing were variable in diabetic dogs and may represent dogs with type-1 and type-2 diabetes or, more likely, differences in severity of beta-cell loss in dogs with type-1 diabetes.     

The sub-rating channel assignment strategy for PCS hand-offs

A new personal communications services (PCS) hand-off scheme is proposed. This scheme provides for hand-off to radio ports on which there is no free channel by “sub-rating” an existing connection. With sub-rating, an occupied full-rate channel is temporarily divided into two half-rate channels: one to serve the existing call and the other to serve the hand-off request. The blocking probabilities (combined forced terminations of existing calls and blocking of new call attempts) of this new scheme compare favorably with the standard scheme (nonprioritizing) and the previously proposed prioritizing schemes. The costs for this scheme are presented and discussed, as well as the additional procedural complexity of implementing on-the-fly sub-rating and the impact of continuing the conversation on a lower rate channel (which may lower speech quality of increase battery drain). Analytical models and simulations investigating the traffic impacts are presented, as are the results that show that even in the highest offered load considered a 3-min conversation in the busy hour experiences less than half a second of sub-rated conversation on average and only about 3% of the calls experience more than 5.12 s of sub-rated conversation. This scheme can increase capacity by 8-35% for systems with 1% call incompletion probability     

Calculation of optimum spacing for a three coil axially symmetric metal detector

When designing an in-line metal detector, a three coil axially symmetric design is often employed. For maximum sensitivity to small particles, the spacing of the coils is an important factor. A formula is derived which predicts the signal produced by a metal sphere when moved along the axis of such a detector and from this a graph is produced to determine the optimum coil spacing.<>     

CAD on geocomposite vertical strip drains

In recent years, an increasing need has arisen for various types of construction on sites underlain by soft cohesive soils. In such cases, some methods of soil improvement are usually required to provide adequate bearing capacity and tolerable postconstruction total and differential settlements. These goals often may be achieved by precompression or preloading the site prior to construction. Precompression and preloading are frequently used in combination with vertical drains, especially in very thick soft deposits, otherwise the time required for consolidation may be unacceptably long or the instability of the foundation may be a serious concern. Therefore, the vertical geocomposite (jute and coir) drain may be used to accelerate the settlement of soil thereby making the site available for use in the shortest time. The computer program and the design chart for determining the spacing between geocomposite drains are presented. This technique is generally useful for embankment construction, tank foundation, underwater construction and landfill areas. Two projects (Haldia in West Bengal and Vashi Station Complex in Bombay) have utilized the application of geocomposite drains reported in this paper.     

Base alumina ceramics with dispersoids: mechanical behaviour and tissue response afterin vivo implantation

Base alumina ceramics with dispersoids (BAC) are a new class of ceramics with improved mechanical properties as compared to pure alumina. They are obtained by dispersion of powder within an alumina matrix. Of the three new ceramics studied here, A20Z possesses the best mechanical properties as well as tribological properties superior to those of pure alumina whether it is used in ceramic-ceramic or ceramic-polyethylene combination.Mechanical behaviour and tissue response afterin vivo implantation were studied. Small four-point flexion bars obtained by pressureless sintering were implanted subcutaneously in the rat. The mechanical properties were unmodified even after one year from implantation.The tissue response was studied up to one year on cylinders implanted in the paravertebral muscles of Wistar rats, and was evaluated by qualitative examination of the encapsulating membrane and measurement of its thickness in relation to pure alumina. The tissue responses were comparable for both alumina and the three tested ceramics.     

Experimental densities for compressed R134a

This paper reports densities of compressed R134a (1,1,1,2-tetrafluoroethane) determined by using a contiuously weighed pycnometer at 20 K intervals between 180 and 380 K at pressures from slightly greater than the vapour pressure to 70 MPa. The results are accurate to within ±0.1%. Saturated liquid densities derived by extrapolation from the experimental values agree with other reported values to within ±0.3%.     

Planar-flow spin-casting of molten metals: process behaviour

An experimental study of the planar-flow melt-spinning process was performed in order to gain a better understanding of the steady-state production of microcrystalline and amorphous ribbons. The dependence of the thickness of the ribbon product,T, on process parameters (wheel speed,U, nozzle/wheel gap,G, overpressure, ΔP, nozzle-slot breadth,R, and nozzle-slot width,W) was determined using an apparatus designed to deliver reproducible results. Thicknesses were reproducible to within 5%–8%. Guided by dimensional analysis, the non-dimensional thickness (T/G) was found to depend, within the experimental error, only on a non-dimensional pressure drop (ΔP/ρU ²) and slot breadth (R/G) for fixed thermal conditions. Data from the literature and our data, which considerably extend the range, correlate consistently on this basis. In contrast to the steady behaviour, the limits within which a uniform ribbon can be formed depend on a larger set of parameters; this dependence is sketched with the available data. Finally, a variety of observed ribbon surface textures (free meniscus side) is catalogued.     

Performance characteristics of a composite multivariate quality control system.

We present the results of an evaluation of the performance characteristics of a composite multivariate quality control (CMQC) system that incorporates quality control rules for univariate, multivariate, and correlation conditions. The CMQC system evaluated is designed to help analysts detect unacceptable trends and systematic error in one or more variables, unacceptable random error in one or more variables, and unacceptable changes in the correlation structure of any pair of variables. It is also designed to be tolerant of missing data, to allow analysts to reject as few as one or as many as all variables in a run, and to provide analysts with control statistics and graphics that logically relate to sources of analytical error. We show that the various components of the CMQC system have adequate statistical power to detect systematic errors, random errors, and correlation changes under the conditions likely to be encountered with multivariate analytical measurement systems: (1) a single variable with increased systematic or random error; (2) all variables or a subgroup of variables affected by a common problem that increases systematic or random error; and (3) missing data for one or more variables in a run. We also show that the power of the multivariate component of the CMQC system to detect systematic and random errors is higher than the power of an alternative multivariate test criterion.