Stability of proximal femoral grafts in canine hip arthroplasty

In a canine model, the fixation stability of a prosthesis and proximal bone graft composite were measured relative to the distal femur. One group had the prosthesis graft composite cemented into the distal femur. The second group had the prosthesis graft composite press fit into the distal femur for biologic ingrowth. Displacements of the proximal femoral grafts relative to the host bone in each group were measured after ex vivo (acute with graft) implantation and 4 months after implantation. A third group with no osteotomy (acute intact) simulated perfect graft to host bone union. Relative displacements representing 6 degrees freedom (translation and rotation) were calculated from the displacement values measured by 9 eddy current transducers. Measurements of displacement were used to test the hypothesis that distal press fit fixation equals distal cement fixation at 4 months after implantation. In all cases the measured translations and rotations of the graft to implant construct were small and of a magnitude that should encourage bone ingrowth (< 0.05 mm and < 0.1 degree, respectively). The stability of the press fit group at 4 months was not significantly different from the cemented group in axial and transverse displacement during axial and transverse loading, respectively. There was no difference in stabilities at 4 months between distal press fit and cemented fixation in hip replacements requiring a proximal femoral graft.     

Influence of hypertonic saline solution infusion on defibrillation efficacy

BACKGROUND: Transplantation of lung allografts from the same donor into 2 recipients ("twinning") provides an opportunity to study recipient and donor factors that influence early allograft function. METHODS: Twenty-seven pairs of recipients were identified and evaluated using multivariate logistic regression analysis (p < 0.05). Four measures of early graft function were analyzed: alveolar-arterial gradient in the operating room, first alveolar-arterial gradient in the intensive care unit, alveolar-arterial gradient at 24 hours, and days of mechanical ventilation. RESULTS: Analysis of the pooled data without regard to pairing showed that alveolar-arterial gradient in the operating room was influenced by donor age, length of donor hospitalization, recipient mean pulmonary artery (PA) pressure at unclamping, and transplantation of a left lung. The alveolar-arterial gradient in the intensive care unit was correlated with donor age, donor cause of death, and mean PA pressure on arrival in that unit. Only mean PA pressure remained significant at 24 hours. Days of mechanical ventilation was determined by mean PA pressure on arrival in the intensive care unit, drop in mean PA pressure during operation, and diagnosis of the recipient. In the paired analysis, receiving a left lung, recipient diagnosis (pulmonary hypertension worse than others), and need of cardiopulmonary bypass were significantly associated with immediate graft dysfunction, although these influences did not persist beyond the immediate postoperative period. Donor arterial oxygen tension and time of ischemia were not significant predictors in any analysis. CONCLUSIONS: Immediate allograft function was associated with donor-related characteristics initially, but these lost importance over the ensuing 24 hours. Recipient PA pressure was an immediate and persisting influence. In the analysis of differences in function between the members of each pair, transplantation of the left lung, recipient diagnosis, and cardiopulmonary bypass were identified, but their influence did not persist beyond the first 6 hours.     

Propagation of diffuse light in a turbid medium with multiple spherical inhomogeneities

We develop a fast and accurate solver for the forward problem of diffusion tomography in the case of several spherical inhomogeneities. The approach allows one to take into account multiple scattering of diffuse waves between different inhomogeneities. Theoretical results are illustrated with numerical examples; excellent numerical convergence and efficiency are demonstrated. The method is generalized for the case of additional planar diffuse-nondiffuse interfaces and is therefore applicable to the half-space and slab imaging geometries.     

Inverse problem in optical diffusion tomography. IV. Nonlinear inversion formulas

We continue our study of the inverse scattering problem for diffuse light. In contrast to our earlier work, in which we considered the linear inverse problem, we now consider the nonlinear problem. We obtain a solution to this problem in the form of a functional series expansion. The first term in this expansion is the pseudoinverse of the linearized forward-scattering operator and leads to the linear inversion formulas that we have reported previously. The higher-order terms represent nonlinear corrections to this result. We illustrate our results with computer simulations in model systems.     

Geometrical renormalization approach to calculating optical properties of fractal carbonaceous soot

We develop a theoretical approach to calculating optical properties of carbonaceous soot in the long-wavelength limit. Our method is based on geometrical renormalization of clusters; it avoids both the inaccuracy of the dipole approximation in its pure form and the numerical complexity of rigorous direct methods of solving the EM boundary problem. The results are verified by comparison with the experimental measurements for specific extinction of diesel soot in the spectral region from 0.488 microm to 0.857 cm that were performed by Bruce et al. [Appl. Opt. 30, 1537 (1991)]. The theory leads to analytical expressions that are applicable to different soots, with various geometrical properties and optical constants. We show that the functional form of the long-wavelength asymptote of the specific extinction can depend critically on a parameter characterizing the sample geometry, and we identify the critical value of this parameter.     

Web accessibility for people with disabilities: an introduction forWeb developers

The article presents an overview of the topic of Web access for people with disabilities. First, we describe the four basic disabilities and explain the benefits of making sites accessible, as well as the reasons that more sites are not accessible. We review the relevant laws regarding Web access, and then discuss efforts being made by vendors and professional organizations, especially Microsoft and the World Wide Web Consortium, to encourage accessibility. Finally, we describe major resources that Web developers might consult to assist them in making their sites accessible to people with disabilities     

Deep linking: an ethical and legal analysis

Deep linking, the practice of linking to a subsidiary page rather than the home page of another organization's Web site, is the subject of considerable controversy. In several recent lawsuits, plaintiffs have alleged violations of copyright, trademark, and commercial laws. I review the legal and ethical issues regarding deep linking and comment on how the ethical conflict between rights and utility motivates the controversy. I conclude that protecting site owners' rights to control deep linking to their sites is a stronger value than enhancing the utility of the Web for users by allowing completely unrestricted deep linking. Finally, I recommend a collection of resources for Web developers interested in staying current with the evolving controversy     

Judging personality from voice quality.

The hypothesis that specific impressions are determined by voice qualities was tested. Specific impressions were defined as ratings on the Potency and Activity factors of the semantic differential. 10 schizophrenics and 11 nonschizophrenics were recorded reading the same passage. Es heard the voices in random order and made (a) semantic-differential ratings and (b) judgments of the readers they perceived as being schizophrenic. 3 of 4 predictions concerning the effect of voice qualities were confirmed. The results indicate the validity of the hypothesis that specific impressions of a speaker's physical characteristics and demeanor are determined by that speaker's voice qualities, and that adjective pairs representing the Potency and Activity factors are sensitive to these differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)