How far is far?

Recent comparisons of computed and measured backscattering cross sections of cylindrical bodies revealed unexpectedly large discrepancies which were apparently due to the finite range used in the measurements. This led to a reexamination of the farfield criterion for a variety of two-dimensional scatterers and one three-dimensional object. It was found that large errors can be incurred in measurements at the standard far-field distance, especially of bodies characterized by strong edge scattering. Errors as great as 6 dB can occur and it may be necessary to exceed the usual farfield distance by a factor of 5 or more in order to reduce the error to 1 dB.     

Perioperative bladder management after primary total hip arthroplasty

A retrospective review of 95 consecutive primary total hip arthroplasty patients was performed to assess the clinical outcome of two postoperative bladder management protocols. The first 49 patients (group 1) were treated with a pro re nata straight catheterization protocol. The next 46 patients (group 2) were treated with an indwelling catheterization protocol. There were no differences between the groups with respect to sex or age. The patients in group 2 had significantly lower incidences of urinary retention (P < .0005) and bladder distention (P < .0005) than those in group 1. Preoperative systemic diseases and urologic symptoms did not correlate with the occurrence of postoperative urinary retention or bladder distention. There were no infections in group 1. In group 2, one patient (2%) had bacteriuria and one patient (2%) had a urinary tract infection (P > .1). This trend of increased contamination in the catheterization group may be related to a mean catheterization duration of 72 hours.     

Hemangiopericytoma-like intranasal tumors. A clinicopathologic study of 23 cases

The clinical, microscopic, and gross pathologic features of 23 cases of intranasal hemangiopericytoma-like tumors are reviewed and studied. When in the nasal cavity, these lesions often originated in a paranasal sinus and extended into the nasal cavity secondarily. They occurred most commonly in adults in the sixth and seventh decades of life; there was no significant sex predilection. Twenty-two of the 23 patients were Caucasian. These patients most commonly had symptoms of nasal obstruction and epistaxis. Clinically the lesions were generally thought to represent allergic polyps. Although appearing microscopically as non-differentiated spindle-cell neoplasms, these lesions showed little nuclear or cytoplasmic pleomorphism, minimal mitotic activity, and no necrosis or hemorrhage or other evidence of anaplasia found in malignant tumors. Follow-up data showed no evidence to suggest a malignant or biologically unpredictable lesion. Nineteen of 22 cases followed showed no recurrence regardless of the treatment; those that recurred did so locally. No metastasis or other form of aggressive behavior attributed to hemangiopericytomas in other anatomic locations was seen in this series. Another case, diagnosed as a malignant hemangiopericytoma of the nasal cavity, showed dissimilar and anaplastic histologic features. This case metastasized and is discussed, though not included in this study.     

An Improved Method for Setting Time Standards for Maintenance Work

Comparative Estimating is a work measurement technique which can be used for setting time standards on low repetitive tasks, such as may be met with in the maintenance area. It has been in wide use since 1955 and has probably been more commonly known as Universal Maintenance Standards (UMS). Since its introduction, the concepts of UMS have hardly changed and several reasons could be put forward for this; however, they would be speculative and would serve no real purpose. What is more important is that after almost 30 years it is perhaps time to re-examine the concept. In this paper the concept of Comparative Estimating is re-examined and an alternative approach, which has several advantages, is suggested. Its basic concept is first described with reference to UMS, identifying the problems of time and cost which are associated with this approach. The alternative approach is then outlined. The advantages which can be obtained from this approach are then identified by comparing some of the performance characteristics of the two approaches.     

Synthesis of 1- and 2-substituted indazoles as anthelmintic agents

Selective synthesis of 1- and 2-acyl-, alkoxycarbonyl-, and carbamoylindazoles are described. Spectroscopic data which were the basis for structural assignments are presented. These compounds, particularly methyl 2H-indazole-2-carboxylate and N-heptyl-N-methyl-2H-indazole-2-carboxamide, lack the spectrum of anthelmintic activity of the benzimidazole and benzotriazole anthelmintics to which they are structurally related.