Non-parametric Models of Distortion in Imaging Systems.

Traditional radial lens distortion models are based on the physical construction of lenses. However, manufacturing defects and physical shock often cause the actual observed distortion to be different from what can be modeled by the physically motivated models. In this work, we initially propose a Gaussian process radial distortion model as an alternative to the physically motivated models. The non-parametric nature of this model helps implicitly select the right model complexity, whereas for traditional distortion models one must perform explicit model selection to decide the right parametric complexity. Next, we forego the radial distortion assumption and present a completely non-parametric, mathematically motivated distortion model based on locally-weighted homographies. The separation from an underlying physical model allows this model to capture arbitrary sources of distortion. We then apply this fully non-parametric distortion model to a zoom lens, where the distortion complexity can vary across zoom levels and the lens exhibits noticeable non-radial distortion. Through our experiments and evaluation, we show that the proposed models are as accurate as the traditional parametric models at characterizing radial distortion while flexibly capturing non-radial distortion if present in the imaging system.PhDComputer Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/120690/1/rpradeep_1.pd

One-step transformation of 2-oxa-3-azabicyclo[2.2.1]hept-5-ene and methyl 2,3-diazabicyclo[2.2.1]heptane-2-carboxylate to ion uptake systems

Linker generated duplexes of the title compounds- prepared from cyclopentadiene- with possibility for positioning of four oxygen in the cavity, are shown to be excellent ion uptake systems. Mass spectrometric doping studies with lithium, sodium, potassium and silver ions, show a clear preference for lithium complexation. The lithium salts of the best examples have been prepared and characterized

Multicomponent and High Entropy Alloys

YesThis paper describes some underlying principles of multicomponent and high entropy alloys, and gives some examples of these materials. Different types of multicomponent alloy and different methods of accessing multicomponent phase space are discussed. The alloys were manufactured by conventional and high speed solidification techniques, and their macroscopic, microscopic and nanoscale structures were studied by optical, X-ray and electron microscope methods. They exhibit a variety of amorphous, quasicrystalline, dendritic and eutectic structures

Molecular Interpretation of ACTH-β-Endorphin Coaggregation: Relevance to Secretory Granule Biogenesis

Peptide/protein hormones could be stored as non-toxic amyloid-like structures in pituitary secretory granules. ACTH and β-endorphin are two of the important peptide hormones that get co-stored in the pituitary secretory granules. Here, we study molecular interactions between ACTH and β-endorphin and their colocalization in the form of amyloid aggregates. Although ACTH is known to be a part of ACTH-β-endorphin aggregate, ACTH alone cannot aggregate into amyloid under various plausible conditions. Using all atom molecular dynamics simulation we investigate the early molecular interaction events in the ACTH-β-endorphin system, β-endorphin-only system and ACTH-only system. We find that β-endorphin and ACTH formed an interacting unit, whereas negligible interactions were observed between ACTH molecules in ACTH-only system. Our data suggest that ACTH is not only involved in interaction with β-endorphin but also enhances the stability of mixed oligomers of the entire system

Issue in Honor of Prof

Abstract Linker generated duplexes of the title compounds-prepared from cyclopentadiene-with possibility for positioning of four oxygen in the cavity, are shown to be excellent ion uptake systems. Mass spectrometric doping studies with lithium, sodium, potassium and silver ions, show a clear preference for lithium complexation. The lithium salts of the best examples have been prepared and characterized

Viral ventilator-associated pneumonia: Uncovering tip of the iceberg

Context: Hospital-acquired infections are frequently encountered by the physicians for ailments demanding prolonged hospitalization, especially in intensive care units, where patients are often mechanically ventilated. The organisms most often implicated are bacteria; viral etiology is infrequent. Aims: The study aims at reviewing lung pathology at autopsy in mechanically ventilated children admitted in pediatric intensive care unit (PICU) to assess the incidence of viral ventilator-associated pneumonias (VAP). Setting and Design: Retrospective analysis. Materials and Methods: Among the 275 children who had been autopsied, 13 who had been admitted in the PICU satisfied the criteria for VAP. These cases were analyzed on the basis of clinical data and pulmonary pathology. Depending on the overall histology, the cases were classified as being viral or bacterial in etiology. Immunohistochemistry (IHC) for detection of viral antigens was also performed. Results: Of the 13 children, nine (five males and four females) had shown the histomorphologic features, suggesting viral inflammation. The mean age was 33 months. Falling oxygen saturation and increasing respiratory distress had necessitated ventilator support. Acute lymphocytic bronchiolitis, interstitial pneumonitis, diffuse alveolar damage, and necrotizing pneumonia were the histological features. The viruses identified in five patients were adenovirus, respiratory syncytial virus and cytomegalovirus. Conclusion: This communication, though not representing the true incidence, emphasizes that a proportion of nosocomial infections is due to viral infections. This should alert the treating intensivists to actively pursue investigations to confirm viral etiology

Bar soaps in dental clinic might be a bacterial reservoir

Aims and Objectives: As the number of patients undergoing dental treatment is on the rise, it becomes essential to know the standard of sterilization protocol followed there and thereby to prevent the cross infection that can result. Thus the present study was undertaken to know whether the bar soaps, used in dental clinic environment can harbor bacteria or not and if so to culture and identify thebacteria.Methods:The study was carried out in 25 different private dental clinics in Chennai. The samples were collected from in use bar soaps, using cotton swabs and immediately introduced into the sterile test tube containing 2 ml normal saline. They were then was inoculated into each of blood agar and MacConkey agar plates and incubated at 37˚C overnight. Colony counts were done and reported as Colony Forming Units (CFU) / ml. The colonies of various morphological features were stained with gram stain and identification was done by standard procedures.Results: Of 25 samples, positive culture was seen in 23 samples. The organisms seen were Pseudomonas, Acinetobacter, Enterobacter, Straph aureus and Straph epidermidis with CFU ranging from 102-106 CFU/ml.Conclusion: It can be understood from our study that dental clinic must be treated like a hospital environment and hence adequate infection control protocols must be followed to prevent cross infection