A Profilometric Approach to 3D Face Reconstruction and Its Application to Face Recognition

3D Face Recognition is an active area of research for past several years. For a 3D face recognition system one would like to have an accurate as well as low cost setup for constructing 3D face model. In this paper, we use Profilometry approach to obtain a 3D face model.This method gives a low cost solution to the problem of acquiring 3D data and the 3D face models generated by this method are sufficiently accurate. We also develop an algorithm that can use the 3D face model generated by the above method for the recognition purpose.

Evaluation of 2D image reconstruction using fan-beam FBP algorithm with no backprojection weight from WLP completed truncated projection data

This paper presents the image reconstruction using the fan-beam filtered backprojection (FBP) algorithm with no backprojection weight from windowed linear prediction (WLP) completed truncated projection data. The image reconstruction from truncated projections aims to reconstruct the object accurately from the available limited projection data. Due to the incomplete projection data, the reconstructed image contains truncation artifacts which extends into the region of interest (ROI) making the reconstructed image unsuitable for further use. Data completion techniques have been shown to be effective in such situations. We use windowed linear prediction technique for projection completion and then use the fan-beam FBP algorithm with no backprojection weight for the 2-D image reconstruction. We evaluate the quality of the reconstructed image using fan-beam FBP algorithm with no backprojection weight after WLP completion.

Relaxation: Application to the matrix reconstruction problem

This report describes some preliminary experiments on the use of the relaxation technique for the reconstruction of the elements of a matrix given their various directional sums (or projections).

Automatic Recognition of Facial Features and Landmarking of Digital Human Head

Ergonomic design of products demands accurate human dimensions-anthropometric data. Manual measurement over live subjects, has several limitations like long time, required presence of subjects for every new measurement, physical contact etc. Hence the data currently available is limited and anthropometric data related to facial features is difficult to obtain. In this paper, we discuss a methodology to automatically detect facial features and landmarks from scanned human head models. Segmentation of face into meaningful patches corresponding to facial features is achieved by Watershed algorithms and Mathematical Morphology tools. Many Important physiognomical landmarks are identified heuristically.

ESAT-6 induced COX-2 expression involves coordinated interplay between PI3K and MAPK signaling

Macrophages, as sentinels of robust host immunity, are key regulators of innate immune responses against invading mycobacteria; however, pathogenic mycobacteria survive in the infected host by subverting host innate immunity. Infection dependent expression of early secreted antigenic target protein 6 (ESAT-6) by Mycobacterium tuberculosis is strongly correlated with subversion of innate immune responses against invading mycobacteria. As a part of multifaceted immunity to mycobacterial infection, induced expression of cyclooxygenase-2 (COX-2) may act as an important influencing factor towards effective host immunity. In the current investigation, we demonstrate that ESAT-6 triggers COX-2 expression both in vitro and in vivo in a TLR2 dependent manner. Signaling perturbation data suggest that signaling dynamics of PI3K and p38 and JNK1/2 MAPK assume critical importance in ESAT-6 triggered expression of COX-2 in macrophages. Interestingly, ESAT-6 triggered PI3K-MAPK signaling axis holds the capacity to regulate coordinated activation of NF-kappa B and AP-1. Overall, current investigation provides mechanistic insights into ESAT-6 induced COX-2 expression and unravels TLR2 mediated interplay of PI3K and MAPK signaling axis as a rate-determining step during intricate host immune responses. These findings would serve as a paradigm to understand pathogenesis of mycobacterial infection and clearly pave a way towards development of novel therapeutics. (C) 2011 Elsevier Ltd. All rights reserved.

Network Reconstruction from dynamic data

Over the past decade, many powerful data mining techniques have been developed to analyze temporal and sequential data. The time is now fertile for addressing problems of larger scope under the purview of temporal data mining. The fourth SIGKDD workshop on temporal data mining focused on the question: What can we infer about the structure of a complex dynamical system from observed temporal data? The goals of the workshop were to critically evaluate the need in this area by bringing together leading researchers from industry and academia, and to identify promising technologies and methodologies for doing the same. We provide a brief summary of the workshop proceedings and ideas arising out of the discussions.

Surface reconstruction from disparate shading: an integration of shape-from-shading and stereopsis

A cooperative integration of stereopsis and shape-from-shading is presented. The integration makes the process of D surface reconstruction better constrained and more reliable. It also obviates the need for surface boundary conditions, and explicit information about the surface albedo and the light source direction, which can now be estimated in an iterative manner

A pseudo-time EnKF incorporating shape based reconstruction for diffuse optical tomography

Purpose: The authors aim at developing a pseudo-time, sub-optimal stochastic filtering approach based on a derivative free variant of the ensemble Kalman filter (EnKF) for solving the inverse problem of diffuse optical tomography (DOT) while making use of a shape based reconstruction strategy that enables representing a cross section of an inhomogeneous tumor boundary by a general closed curve. Methods: The optical parameter fields to be recovered are approximated via an expansion based on the circular harmonics (CH) (Fourier basis functions) and the EnKF is used to recover the coefficients in the expansion with both simulated and experimentally obtained photon fluence data on phantoms with inhomogeneous inclusions. The process and measurement equations in the pseudo-dynamic EnKF (PD-EnKF) presently yield a parsimonious representation of the filter variables, which consist of only the Fourier coefficients and the constant scalar parameter value within the inclusion. Using fictitious, low-intensity Wiener noise processes in suitably constructed ``measurement'' equations, the filter variables are treated as pseudo-stochastic processes so that their recovery within a stochastic filtering framework is made possible. Results: In our numerical simulations, we have considered both elliptical inclusions (two inhomogeneities) and those with more complex shapes (such as an annular ring and a dumbbell) in 2-D objects which are cross-sections of a cylinder with background absorption and (reduced) scattering coefficient chosen as mu(b)(a)=0.01mm(-1) and mu('b)(s)=1.0mm(-1), respectively. We also assume mu(a) = 0.02 mm(-1) within the inhomogeneity (for the single inhomogeneity case) and mu(a) = 0.02 and 0.03 mm(-1) (for the two inhomogeneities case). The reconstruction results by the PD-EnKF are shown to be consistently superior to those through a deterministic and explicitly regularized Gauss-Newton algorithm. We have also estimated the unknown mu(a) from experimentally gathered fluence data and verified the reconstruction by matching the experimental data with the computed one. Conclusions: The PD-EnKF, which exhibits little sensitivity against variations in the fictitiously introduced noise processes, is also proven to be accurate and robust in recovering a spatial map of the absorption coefficient from DOT data. With the help of shape based representation of the inhomogeneities and an appropriate scaling of the CH expansion coefficients representing the boundary, we have been able to recover inhomogeneities representative of the shape of malignancies in medical diagnostic imaging. (C) 2012 American Association of Physicists in Medicine. [DOI: 10.1118/1.3679855]

Expression of Sonic Hedgehog During Cell Proliferation in the Human Cerebellum

The regulation of cell proliferation in the external granular layer (EGL) of the developing cerebellum is important for its normal patterning. An important signal that regulates EGL cell proliferation is Sonic hedgehog (Shh). Shh is secreted by the Purkinje cells (PC) and has a mitogenic effect on the granule cell precursors of the EGL. Deregulation of Shh signaling has been associated with abnormal development, and been implicated in medulloblastomas, which are tumors that arise from the cerebellum. Given the importance of the Shh pathway in cerebellum development and disease, there has been no systematic study of its expression pattern during human cerebellum development. In this study, we describe the expression pattern of Shh, its receptor patched, smoothened, and its effectors that belong to the Gli family of transcription factors, during normal human cerebellum development from 10 weeks of gestational age, and in medulloblastomas that represents a case of abnormal cell proliferation in the cerebellum. This expression pattern is compared to equivalent stages in the normal development of cerebellum in mouse, as well as in tumors. Important differences between human and mouse that reflect differences in the normal developmental program between the 2 species are observed. First, in humans there appears to be a stage of Shh signaling within the EGL, when the PC are not yet the source of Shh. Second, unlike in the postnatal mouse cerebellum, expression of Shh in the PC in the postnatal human cerebellum is downregulated. Finally, medulloblastomas in the human but not in patched heterozygote mouse express Shh. These results highlight cross-species differences in the regulation of the Shh signaling pathway.

Luteinizing hormone regulates inhibin-alpha subunit expression through multiple signaling pathways involving steroidogenic factor-1 and beta-catenin in the macaque corpus luteum

We employed different experimental model systems to define the role of GATA4, beta-catenin, and steroidogenic factor (SF-1) transcriptional factors in the regulation of monkey luteal inhibin secretion. Reverse transcription polymerase chain reactions and western blotting analyses show high expression of inhibin-alpha, GATA4, and beta-catenin in corpus luteum (CL) of the mid-luteal phase. Gonadotropin-releasing hormone receptor antagonist-induced luteolysis model suggested the significance of luteinizing hormone (LH) in regulating these transcriptional factors. Inducible cyclic AMP early repressor mRNA expression was detected in the CL and no change was observed in different stages of CL. Following amino acid sequence analysis, interaction between SF-1 and beta-catenin in mid-stage CL was verified by reciprocal co-immunoprecipitation experiments coupled to immunoblot analysis. Electrophoretic mobility shift analysis support the role of SF-1 in regulating luteal inhibin-alpha expression. Our results suggest a possible multiple crosstalk of Wnt, cAMP, and SF-1 in the regulation of luteal inhibin secretion.

Silencing of toxic gene expression by Fis

Bacteria and bacteriophages have evolved DNA modification as a strategy to protect their genomes. Mom protein of bacteriophage Mu modifies the phage DNA, rendering it refractile to numerous restriction enzymes and in turn enabling the phage to successfully invade a variety of hosts. A strong fortification, a combined activity of the phage and host factors, prevents untimely expression of mom and associated toxic effects. Here, we identify the bacterial chromatin architectural protein Fis as an additional player in this crowded regulatory cascade. Both in vivo and in vitro studies described here indicate that Fis acts as a transcriptional repressor of mom promoter. Further, our data shows that Fis mediates its repressive effect by denying access to RNA polymerase at mom promoter. We propose that a combined repressive effect of Fis and previously characterized negative regulatory factors could be responsible to keep the gene silenced most of the time. We thus present a new facet of Fis function in Mu biology. In addition to bringing about overall downregulation of Mu genome, it also ensures silencing of the advantageous but potentially lethal mom gene.

Practical fully three-dimensional reconstruction algorithms for diffuse optical tomography

We have developed an efficient fully three-dimensional (3D) reconstruction algorithm for diffuse optical tomography (DOT). The 3D DOT, a severely ill-posed problem, is tackled through a pseudodynamic (PD) approach wherein an ordinary differential equation representing the evolution of the solution on pseudotime is integrated that bypasses an explicit inversion of the associated, ill-conditioned system matrix. One of the most computationally expensive parts of the iterative DOT algorithm, the reevaluation of the Jacobian in each of the iterations, is avoided by using the adjoint-Broyden update formula to provide low rank updates to the Jacobian. In addition, wherever feasible, we have also made the algorithm efficient by integrating along the quadratic path provided by the perturbation equation containing the Hessian. These algorithms are then proven by reconstruction, using simulated and experimental data and verifying the PD results with those from the popular Gauss-Newton scheme. The major findings of this work are as follows: (i) the PD reconstructions are comparatively artifact free, providing superior absorption coefficient maps in terms of quantitative accuracy and contrast recovery; (ii) the scaling of computation time with the dimension of the measurement set is much less steep with the Jacobian update formula in place than without it; and (iii) an increase in the data dimension, even though it renders the reconstruction problem less ill conditioned and thus provides relatively artifact-free reconstructions, does not necessarily provide better contrast property recovery. For the latter, one should also take care to uniformly distribute the measurement points, avoiding regions close to the source so that the relative strength of the derivatives for measurements away from the source does not become insignificant. (c) 2012 Optical Society of America