We report on progress in algorithms for iterative phase retrieval. The theory of convex optimisation is used to develop and to gain insight into counterparts for the nonconvex problem of phase retrieval. We propose a relaxation of averaged alternating reflectors and determine the fixed point set of the related operator in the convex case. A numerical study supports our theoretical observations and demonstrates the effectiveness of the algorithm compared to the current state of the art. This talk is divided into 2 parts as follows. In the 1st part of this talk, we introduce one of the central ideas of the MV-PURE (MinimumVariance Pseudo-Unbiased Reduced-Rank Estimator), by Yamada and Elbadraoui (2006) and Piotrowski and Yamada (2008), which is a novel estimator for ill-conditioned inverse problems. The MV-PURE is a reduced-rank extension of the Gauss-Markov estimator (BLUE: Best Linear Unbiased Estimator) and defined as a closed form solution of a hierarchical nonconvex constrained optimization problem. The MV-PURE achieves the minimum variance among all solutions of the first stage optimization problem for minimizing, under a rank constraint, simultaneously all unitarily invariant norms of an operator applied to the unknown parameter vector in view of suppressing bias of the estimator. The MV-PURE offers a unified view for many estimators including the well-known estimators: the Gauss-Markov (BLUE) estimator, the generalized Marquardt's reduced-rank estimator and the minimum-variance conditionally unbiased affine estimator subject to linear restrictions. In the 2nd part of this talk, we introduce an idea of the deep lipschitzian gradient projector which is defined by Yamagishi and Yamada (2008) as the metric projection onto the level set of the best lower bound of a convex function which is assumed to be (i) bounded below, and (ii) differentiable and its derivative is lipschitzian. The deep lipschitzian gradient projector is computationally efficient and can approximate the level set of the convex function better than the subgradient projector, hence it can improve many computational methodologies employing the subgradient projector as one of their key players. Directly inverting x-ray data requires determining the unmeasured phases (the "phase problem"). We propose a general solution to the phase problem for surface x-ray diffraction (SXRD) termed the phase and amplitude recovery and diffraction image generation method (PARADIGM); atomic structures from a single surface domain or from multiple, symmetry-related domains on a known bulk structure may be recovered. Diffraction rods in reciprocal space may be oversampled relative to the Nyquist frequency of the height of the selvedge. An iterative algorithm alternately satisfies known constraints of the oversampled data in real and reciprocal space, and progressively determines the amplitudes and phases of the surface structure factors. A Fourier transform then constructs an "image" of the selvedge. Using this method, the atomic positions on a Au (110) X-ray dam...

Remodeling of myocyte interconnections may be an important determinant of ventricular tachycardia in regions bordering healed infarcts. We used quantitative electron microscopy to characterize the distribution of gap junctions in 10 canine left ventricles 3-10 wk after coronary occlusion. In three normal canine left ventricles analyzed ultrastructurally, myocardial gap junctions were distributed anisotropically; gap junction profile length was significantly greater in the transverse than in longitudinal planes of section. In infarct border zone tissues, the normal anisotropic distribution was completely abolished and fewer gap junctions per unit intercalated disk length were observed. Analysis of individual gap junction profile length distributions revealed selective disruption of the largest gap junctions that collectively comprised only 9.6% of total junction profiles, but encompassed nearly 40% of aggregate gap junction length in the transverse plane of section. Three-dimensional reconstructions of myocyte interconnections by high resolution quantitative light microscopy of serial sections demonstrated a reduction in the number of cells connected by intercalated disks to a single myocyte from 11.2±1.0 in normal myocardium to 6.5±1.3 in border zone tissues (P < 0.001). Connections of cells in primarily side-to-side apposition were reduced by 75%, whereas primarily end-to-end connections were reduced by only 22% (P < 0.05). These alterations would disproportionately enhance axial resistivity in the transverse direction, potentially contributing to development of reentrant arrhythmias. (J. Clin.

Results demonstrate that when complete elimination of dual AV node physiology is difficult, modification of slow pathway conduction to the extent that repetitive AV node reentry cannot be induced is a definitive end point that portends a good prognosis.

We reviewed 25 patients with neurosarcoidosis followed for at least 5 years or until death. Seventeen patients (68%) had a monophasic illness. Eight (32%) had a relapsing course, with recurrences similar to the original manifestations months later. Patients with cerebral manifestations or hydrocephalus were most likely to relapse. Seven of eight patients with relapsing disease had exacerbations while taking 10 mg prednisone or less.

Background: Asynchronous e-learning is an appealing option for interprofessional education (IPE) as it addresses the geographic and timetabling barriers often encountered when organizing activities across educational programs. Aim: This study examined the extent to which pre-licensure students were able to learn with, from, and about each other through completion of innovative online IPE learning modules. Methods: Seventy-seven students completed e-learning modules developed through a consortium of educational institutions. Evaluation was primarily qualitative through focus groups, interviews, analyses on off-line discussions and an online feedback form. Results: Qualitative analyses of the discussion fora revealed that students were able to solve problems collaboratively, clarify their professional roles, and provide information from their professional perspective. Focus groups and interviews reinforced that students recognized the importance of working together and implicate clinical education as an important venue to reinforce learning about collaborative practice. Analyses of the online feedback form suggest the need for clear processes related to group assignments and deadlines. Conclusion: Students learned about each other's role, solved problems together and had positive perceptions of the online modules as a venue for interprofessional learning. Results are encouraging to those interested in using e-learning in IPE as part of an overall curriculum.