Shape matching and modeling using skeletal context

Shape is a significant visual clue for human perception and shape models show considerable promise as a basis for extracting objects from images. This paper proposes a novel approach for shape matching and modeling using the symmetry characterization of shape interior and the spatial relationships of shape structures. Based on the representative skeletal features, we develop a mechanism to generate a coarse segment matching between different instances of an object. Additionally, the natural correspondence of skeletal branches to sequential segments along the shape curves is employed in the matching process to avoid false correspondences across different segments. Point matches within the corresponding segments are then obtained by solving a constrained assignment problem. The validation of the proposed approach is illustrated on various data sets in the presence of considerable deformation and occlusion and the results are compared with those of popular approaches. We also demonstrate the performance of our method on biological objects for shape modeling, showing better models than those obtained by the state-of-the-art shape modeling approaches.     

ALTAR: achieving learning through action research

This paper describes a collaborative action research (AR) study that took place between a U.K. university and a large U.K. manufacturing organisation, Britvic Soft Drinks Ltd. The ALTAR (Achieving Learning Through Action Research) project involved a number of AR cycles involving participants at different levels of the collaborating organisation. Britvic was already in the process of adopting knowledge management (KM) software but it was recognised that they could better exploit KM technologies by undertaking the AR project described in the paper. The project involved developing academic theory into practical concepts that influenced actions in the organisation and fed back into the academic research. The ALTAR approach and findings are described in this paper and conclusions are drawn about the AR study and its implications for AR, KM and for the future study of organisational learning through AR. The conclusions of the work are of practical use to managers in a variety of organisations and will inform academic research into cognate disciplines using the AR process.     

Interpretation of motion trajectories using focus of expansion

The focus of expansion (FOE) of a group of motion trajectories is defined to be a point in the image plane at which the trajectories intersect when they are extended. The FOE observed over a time sequence defines the locus of the FOE. The authors present an analytical approach for the study of dynamic events as they project on the image plane by analyzing the locus of the FOE. They find that the locus of the FOE can be used to make qualitative assertions regarding the type of motion. Interesting behavior of the locus of the FOE for various types of motion is observed. The cases include a single point and a horizontal, a vertical, and a sloped straight line. It was also possible to determine whether the object has approaching or receding motion or when the object changes its direction of motion. This inference can be used in qualitative computer vision     

Counteracting the inhibitory effect of tea on the in-vitro availability of iron from cereal meals

Studies were carried out on the in-vitro availability of iron to determine the effect of addition of tea, milk and ascorbic acid to a standard cereal meal in all possible combinations. The availability of iron from the cereal meal was low (3.92%). Tea, when added to the meal, had a significant depressing effect on available iron (2.56%). Addition of 100 mg ascorbic acid or 200 g milk completely counteracted the inhibitory effect of tea, and addition of both ascorbic acid and milk brought about an even greater enhancement in the in-vitro availability of iron than when either was added alone. This investigation reveals that milk is as effective a factor as ascorbic acid in counteracting the depressing effect of tea on in-vitro iron availability.     

Meniscus-Assisted High-Efficiency Magnetic Collection and Separation for EWOD Droplet Microfluidics

This paper describes a technique to increase the efficiency of magnetic concentration on an electrowetting-on-dielectric (EWOD)-based droplet (digital) microfluidic platform operated in air, i.e., on dry surface. Key differences in the force scenario for droplet microfluidics vis-a-vis the conventional continuous microfluidic systems are identified to explain the rationale behind the proposed idea. In particular, the weakness of the magnetic force relative to the bead-substrate adhesion and the liquid-air interfacial tension is highlighted, and a new technique to achieve high-efficiency magnetic collection with the assistance of the interfacial force is proposed. An improvement in collection efficiency (e.g., from ~ 73% to ~ 99%) is observed with the new technique of ldquomeniscus-assisted magnetic bead collectionrdquo. In addition, isolation of the magnetic species from a mixed sample of magnetic and nonmagnetic beads is demonstrated. Comparison with other related reports is also presented.     

Computing Deblurred Time-Frequency Distributions Using Artificial Neural Networks

This paper presents an effective correlation vectored taxonomy algorithm to compute highly concentrated time-frequency distributions (TFDs) using localized neural networks (LNNs). Spectrograms and pre-processed Wigner–Ville distributions of known signals are vectorized and clustered as per the elbow criterion to constitute the training data for multiple artificial neural networks. The best trained networks become part of the LNNs. Test TFDs of unknown signals are then processed through the algorithm and presented to the LNNs. Experimental results demonstrate that appropriately vectored and clustered data once processed through the LNNs produce high resolution TFDs. Examples are presented to show the effectiveness of the proposed algorithm via analysis based on entropy and visual interpretation. This work was supported by the Higher Education Commission (HEC) of Pakistan under the 200 Merit Scholarship Scheme.     

The Influence of Conceptual Flow Simulation Model Parameters on Model Solution

This article investigates the influence of conceptual flow simulation model parameters (i.e coefficients and constants that need to be estimated in calibration) on model solution (surface runoff) to understand the characteristics of the model. A new conceptual watershed yield model (WYM) was employed. There are four physical parameters, two fitting coefficients and two initial estimates of the surface water and groundwater storagesthat control the functioning of the model. The conceptual model was applied on Ling River near Kahuta and detailed sensitivity analysis was performed to explore the most sensitive model parameters. The most sensitive model parameters worked out were C _g (a fitting coefficient, which reflects the rate at whichgroundwater runoff occurs), w _r (watershed retention is the initial rainfall losses before runoff begins), p _gr (inputparameter that reflects the discharge capacity of the groundwateraquifer). The model parameters like i _c (infiltration coefficient), g _wsm (input parameter that depends on the subsurface storage available in the watershed) and e _p (input parameter) have negligible effect on model solution. It was observed that w _r (watershed retention) is the only surface runoff controlling parameter and p _gr and C _g are the groundwater runoff controlling parameters.     

Impact of RNase L overexpression on viral and cellular growth and death

The biologic actions of interferons (IFNs) are complex and involve multiple biochemical mechanisms, including the 2-5A system, a regulated RNA decay pathway. The 2-5A system is implicated in the antipicornavirus activity of IFN and in the control of apoptosis. To further investigate involvement of the 2-5A system in the control of viral and cellular growth and death, human RNase L cDNA was stably expressed in murine 3T3 cells from a constitutive cytomegalovirus (CMV) promoter. A clonal cell line, 3T3/pLZ, was isolated that overexpressed RNase L by >100-fold compared with levels of the endogenous murine RNase L. Interestingly, human RNase L levels in 3T3/pLZ cells decreased 3-fold as cells entered a confluent, growth arrest state, suggesting autoregulation. Overexpression of human RNase L greatly enhanced both the cell growth inhibitory activity of IFN and the proapoptotic activity of staurosporine. Furthermore, high levels of RNase L suppressed the replication of diverse viruses: encephalomyocarditis virus, vesicular stomatitis virus, human parainfluenza virus-3, and vaccinia virus. Additional reductions in viral growth were obtained by treating 3T3/pLZ cells with IFN (a + beta) before infections. These results directly demonstrate the anticellular and antiviral potential of the 2-5A system.     

Small cell neuroendocrine carcinoma of the nasal cavity and paranasal sinuses

Small cell neuroendocrine carcinomas (SNECs) of the sinonasal tract are extremely uncommon tumors. We reviewed the clinicopathologic features of six cases of this neoplasm. There was no sex preponderance with three females and three males and a mean age at presentation of 51 years (range, 38 to 68). Two patients had disease limited to the nasal cavity, and in four the tumor involved the nasal cavity and maxillary or ethmoid sinuses. Involvement of the orbit was present in two patients. Surgery was the primary treatment. After a mean follow-up of 37 months, one patient died of local disease and liver metastases, four were alive with recurrent or metastatic disease, and one died of unrelated causes. The tumors were composed of sheets, nests, and trabeculae with extensive areas of necrosis and hemorrhage. The individual cells were small to intermediate in size and had scanty cytoplasm. The nuclei were oval or round and hyperchromatic with absent or inconspicuous nucleoli. Nuclear molding and crush artefact were present in five cases. All tumors had a high mitotic rate with frequent abnormal mitotic figures. All cases stained for Cam 5.2, neuron-specific enolase, and chromogranin. Five cases were positive for AE1:AE3, and four for synaptophysin. No case stained for S-100 protein, or neurofilaments. O-13 stained one case. No case contained EBV-RNA. SNECs of the nasal cavity and paranasal sinuses are aggressive tumors with pathological features similar to those of anaplastic small cell carcinomas of the lung. They exhibit morphological and immunophenotypic features different from olfactory neuroblastoma and should be distinguished from this tumor.