The rheumatic forefoot

The prevalence of rheumatic forefoot arthritis is estimated at 85-95%. Early synovitis of the metatarsophalangeal (MTP) joints is frequently neglected or overlooked. The disease leads to depression of the forefoot arch, dislocation of the MTP joints and hallux valgus with severe metatarsalgia. Operative treatment may give good results in 77-91% of cases. Our preferred treatment consists of resection arthroplasties for the smaller toes and use of Swanson spacer for the big toe, extensive capsular and tendon release from the dorsal approach, reduction of the first metatarsal bone, relocation of the extensor hallucis tendon and postoperative corrective dressing for 6-12 weeks. With this technique, we obtained 36 good results out of 46 forefoot reconstructions, the mean observation period being 30 months.     

Tuberculosis in drug users

The rise in tuberculosis (TB) has disproportionately affected specific populations. Historically, many patients with TB became iatrogenic opiate addicts through therapeutic use of these drugs for symptom control. Demographic trends reshaped the relationship between drug use and TB into one in which drug use became a risk factor for tuberculosis as a result of the overlap of epidemiological and social factors associated with both drug use and TB. The spread of human immunodeficiency virus infection has amplified the spread of TB among drug users. We review the epidemiology of TB in drug users as well as the factors relevant to screening and compliance in drug-using populations. Drug users constitute a high-risk group for whom screening, prevention of infection, diagnosis, and treatment pose particular challenges. The development of TB services capable of engaging drug users (those both in and out of drug treatment programs) has potential for disrupting a significant chain of rapid TB transmission.     

Mutation of the RET ligand, neurturin, supports multigenic inheritance in Hirschsprung disease

Hirschsprung disease (HSCR) is a frequent neurocristopathy characterized by the absence of submucosal and myenteric plexuses in a variable length of the gastrointestinal tract. Pedigrees and segregation analyses suggested the involvement of one or several dominant genes with low penetrance in HSCR. Considering that RET and glial cell line-derived neurotrophic factor (GDNF) mutations have been reported in the disease, we regarded the other RET ligand, neurturin (NTN), as an attractive candidate gene, especially as it shares large homologies with GDNF. Here, we report on the finding of a heterozygous missense NTN mutation in a large non-consanguineous family including four children affected with a severe aganglionosis phenotype extending up to the small intestine. Interestingly, it appears that the NTN mutation reported here is not sufficient to cause HSCR, and this multiplex family also segregates a RET mutation. This cascade of independent and additive genetic events fits well with the multigenic pattern of inheritance expected in HSCR, and further support the role of RET ligands in development of the enteric nervous system.     

How Critical Infrastructure Orients International Relief in Cascading Disasters

Critical infrastructure and facilities are central assets in modern societies, but their impact on international disaster relief remains mostly associated with logistics challenges. The emerging literature on cascading disasters suggests the need to integrate the nonlinearity of events in the analyses. This article investigates three case studies: the 2002 floods in the Czech Republic, Hurricane Katrina in 2005 and the 2011 Tohoku earthquake, tsunami and Fukushima meltdown in Japan. We explore how the failure of critical infrastructure can orient international disaster relief by shifting its priorities during the response. We argue that critical infrastructure can influence aid request and delivery, changing needs to address the cascades, and contain cascading technology‐based events. The conclusions propose remaining challenges with applying our findings.     

Dense mirroring surface recovery from 1D homographies and sparse correspondences

In this work, we recover the 3D shape of mirrors, sunglasses, and stainless steel implements. A computer monitor displays several images of parallel stripes, each image at a different angle. Reflections of these stripes in a mirroring surface are captured by the camera. For every image point, the direction of the displayed stripes and their reflections in the image are related by a 1D homography matrix, computed with a robust version of the statistically accurate heteroscedastic approach. By focusing on a sparse set of image points for which monitor-image correspondence is computed, the depth and the local shape may be estimated from these homographies. The depth estimation relies on statistically correct minimization and provides accurate, reliable results. Even for the image points where the depth estimation process is inherently unstable, we are able to characterize this instability and develop an algorithm to detect and correct it. After correcting the instability, dense surface recovery of mirroring objects is performed using constrained interpolation, which does not simply interpolate the surface depth values but also uses the locally computed 1D homographies to solve for the depth, the correspondence, and the local surface shape. The method was implemented and the shape of several objects was densely recovered at submillimeter accuracy.     

Mobile robot characterized by dynamic and kinematic equations and actuator dynamics: Trajectory tracking and related application

This paper establishes control strategies for wheeled mobile robots which are subjected to nonholonomic constraints. The mobile robot model includes the kinematic and dynamic equations of motion and the actuator dynamics. Using the notion of virtual vehicle and the concept of flatness, and applying the backstepping methodology the paper proposes control schemes for trajectory tracking for the considered augmented model of the mobile robot. The resulting controller ensures exponential convergence to a desired trajectory. Applications of the tracking controller for convoy-like vehicles governed by the augmented models are considered as well. Simulation results and lab experiments are demonstrated.     

A decentralized energy-based diffusion algorithm to increase the lifetime of MANETs

In this paper, we introduce a novel approach to improve overall lifetime in mobile ad hoc networks. Given the energy constraint on each node, this problem is formulated as an energy-controlled load balancing problem. Thus, our approach is quite different from usual energy-efficient routing or topology control methods. The proposed algorithm is fully distributed and ensures that each node will cooperate in proportion to its remaining energy, increasing the network lifetime. The relevance of the algorithm is evaluated through both theoretical analysis and simulations.     

On turbo encodedBicm

The superior performance of the binary turbo codes has stimulated vigorous efforts in generating bandwidth efficient modulation schemes adhering to these codes. Several approaches for the integration of turbo-coding and modulation have emerged in recent years but none seem to dominate. In the bit interleaved coded modulation (Bicm) scheme is used to achieve high bandwidth and power efficiency, while separating coding and modulation. As is now well known, theBicm scheme achieves capacity remarkably close to the constellation channel capacity. The turbo-Bicm scheme enjoys high coding diversity (well suited for fading channels), high flexibility as well as design and implementation simplicity, while maintaining good power efficiency. The system comprises one standard turbo code, an interleaver, a mapper and a modulator at the transmitter, corresponding to a demodulator, a de-interleaver and a turbo decoder at the receiver. A modified system, which improves on performance by incorporating the demodulation in the iterative decoding procedure, is investigated, and some performance gain is demonstrated, especially for low rate codes. Information theoretic arguments for the somewhat minor potential improvement in performance are detailed. The preferred mapper and interleaver for this system are considered. Extending previous works, for higher level modulations, we analyze a system including a convolutional code, an interleaver, a differential encoder (De), a mapper and a modulator at the transmitter. As for theBpsk modulation, the serial concatenation of a convolutional code withDe outperforms the single convolutional code. The serial concatenation withDe approach is analyzed also for a turbo code, where it is found to fail in achieving performance improvement. Several structures for the serial concatenation withDe are examined. These results are substantiated through the ‘spectral thinning’ phenomena of the weight distribution of the convolutional and turbocodes.