Search Strategies of Visually Impaired Persons using a Camera Phone Wayfinding System.

We report new experiments conducted using a camera phone wayfinding system, which is designed to guide a visually impaired user to machine-readable signs (such as barcodes) labeled with special color markers. These experiments specifically investigate search strategies of such users detecting, localizing and touching color markers that have been mounted in various ways in different environments: in a corridor (either flush with the wall or mounted perpendicular to it) or in a large room with obstacles between the user and the markers. The results show that visually impaired users are able to reliably find color markers in all the conditions that we tested, using search strategies that vary depending on the environment in which they are placed.

Spectral characteristics and motion-compensated restoration of composite frames.

The practice of superimposing the fields of a frame is applied in various fields, for example, thermographic and biomedical imaging. The pictures obtained in this way, which are termed composite frames, are severely degraded if the scene's objects are not perfectly still. The restoration of composite frames affected by motion-induced blurring requires the ability to estimate the field displacement from composite frames. The frequency domain analysis of composite frames proposed in the paper suggests a displacement estimation technique of a phase-correlation type that can be applied to composite frames.

Synovial fluid in arthropathy.

The authors examined 487 synovial fluid specimens in patients affected with spontaneous effusion in the knee. In 202 of the cases the features indicating the nature of the effusion were observed (rheumatoid arthritis: 27; active S.L.E.: 2; microcrystals: 77; infections: 38; doubts as to rheumatoid arthritis or other connectivitis: 58). In 84 cases no features were determined despite the presence of specific clinical signs (psoriasis, arthrosis, previous trauma). In 201 cases where there were no clinical signs in the synovial fluid, the authors were able to differentiate moderate phlogosis in 27 specimens, and intense phlogosis in 104. Based on the results obtained, an attempt was made to define which tests are best to measure the amount of inflammation and which may be correlated with the etiology of the joint effusion.

An evaluation of some leukocytary phenotypes in subjects with evolutive primary coxarthrosis and in subjects with hip prostheses.

The authors examined 52 patients (36 females and 16 males) of whom 15 affected with evolutive primary coxarthrosis, 27 with hip prostheses for 4 to 13 years, and 10 with a prosthetic implant which was not tolerated. A method of indirect immunofluorescence with monoclonal antibodies against specific antigens of the cellular surface was used to typify the T-lymphocytic subpopulations (T-helper/inducer and T-suppressor/cytotoxic), the activated mononucleate cells (DR+), and the B-lymphocytes and monocytes. A good correlation between the imbalances in the T-lymphocytic subpopulations, an increase in the activated mononucleate cells (principally due to T-lymphocytes) and the tolerance of the implant were observed. Based on the results obtained, the authors hypothesize the possibility of using the typing of T-lymphocytes and activated mononucleate cells, together with other biohumoral parameters, as indicators of periprosthetic tissue phologosis.

Prognostic value of serum alkaline phosphatase in osteosarcoma.

In 163 patients with osteosarcoma of the extremities treated with adjuvant chemotherapy, serum alkaline phosphatase (SAP) levels were evaluated before treatment and successively closely monitored in an attempt to determine whether serum levels of this enzyme had clinical value in predicting the course of the disease. Of 121 patients with elevated preoperative SAP levels, 78 (64%) recurred. Of 42 patients with normal preoperative SAP levels, only 8 (19%) recurred (P less than 0.00001). Of the 140 patients locally treated with amputation, SAP returned to normal values in 77 patients; 46 of these (59%) relapsed. Of the 21 patients whose SAP remained elevated after amputation, all but 2 relapsed (90%). Among 119 patients with normal postoperative values of SAP, at the time of relapse SAP resulted elevated in 22 of 41 patients (53%). These data confirm that in osteosarcoma, preoperative SAP levels have a definite value in establishing the prognosis and that posttreatment follow-up examination should include SAP determination, since persistent elevated or increasing values herald the appearance of a recurrence.