Venous ultrasound imaging was compared with ascending contrast venography for the diagnosis of suspected deep vein thrombosis (DVT) in the femoral, popliteal and calf vein segments of 44 limbs in 44 patients. One femoral and one calf vein segment could not be imaged (1.5% of the segments examined), but during the same period venography failed in six patients because of an inability to cannulate a swollen limb. Ultrasound imaging compared with venography as a means of diagnosing DVT showed an overall sensitivity of 95% and a specificity of 92%. The sensitivity and specificity of ultrasound imaging for the diagnosis of both femoral and popliteal vein thromboses were 100% and 97%, respectively, and for calf vein thrombosis were 85% and 83%, respectively. This study supports the recommendation that ultrasound imaging is now the investigation of choice for the diagnosis of DVT provided that the scan is performed by an experienced vascular technologist. Ultrasound imaging may also define other pathological conditions presenting in the differential diagnosis of DVT, such as superficial thrombophlebitis and Baker's cyst.
Acoustic feedback in hearing aids has received little attention in the literature. Feedback occurs when stability conditions of the open-loop transfer function of an in situ hearing aid are violated. Solving the feedback problem will first require knowledge of the open-loop transfer function. Included in the open-loop transfer function is the acoustical path by which sound emanating from the earmold vent returns to the microphone (i.e., the feedback path). Reported herein are two different mathematical procedures for simulating transfer functions of the feedback path of an eyeglass-type hearing aid. In one procedure the vent exit was modeled as a point source of sound located on a flat plane, while it was treated as a point source on a sphere in the other. Results of laboratory experiments indicate that the mathematical models accurately predict those acoustic phenomena for which they were intended: point sources on plane and spherical baffles. Results of manikin experiments showed both models to be less accurate for simulating the feedback path around the human head. The maximum difference between experiment and theory was 6 dB at one frequency. Surprisingly, the flat-baffle model produced better agreement with experimental results than did the sphere model.
Eight discs, largely concavo-convex in shape and decorated with a symmetrical rosette pattern, were recovered from Tomb I during excavations. A similar undecorated concavo-convex disc was also found. The following paper presents the results of the typological examination of the objects, with the materials and manufacturing techniques published elsewhere in this volume. These discs are widely recogxused in southeastern Arabia, with parallels suggesting a predominantly lron Age date.
The Wadi Suq period and Iron Age ceramics from Sharm are examined in terms of morphological, compositional and decorative features. The assemblage is typical of the second‐ and first‐millennium BC ceramics of southeastern Arabia. The more unusual Iron Age ‘imitation soft stone’ ceramics are amply represented and the Sharm assemblage considerably expands upon this corpus of ceramics which has hitherto been less than abundant in the region. Comparisons with other second‐ and first‐millennium sites suggest the tombs were largely occupied in the late Wadi Suq period, a pattern of occupation which again peaked in the Iron Age II period.
S‐305 is the worked remnant of one half of a spiny oyster which exhibits drill marks consistent with single and double dot‐in‐circle motifs. The object is briefly described with a view to determining its function. The manufacturing marks are analysed elsewhere in this volume by Katia Davis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.