Target Tracking in Non-Gaussian Environment

Masreliez filter which is a Kalman type of recursive filter is implemented and validated. The main computation in Masreliez filter is to evaluate the score function which directly influences the estimates of the target states. Scalar approximation for score function evaluation is extended to vector observations, implemented and validated. The simulation studies have shown that the performance of the Masreliez filter is relatively better than that of the conventional Kalman filter in the presence of significant glint noise in the observation

Tracking filter and multi-sensor data fusion

In this paper factorization filtering, fusion filtering strategy and related algorithms are presented. Some results of implementation and validation using realistic data are given

Evaluation of derivative free Kalman filter and fusion in non-linear estimation

In recent literature a derivative free Kalman filter (DFKF) a method that propagates mean and covariance using non-linear transformation is frequently used. In this paper i) factorised version of EKF (UD Extended Kalman Filter or UDEKF) and ii)DFKF are studied and evaluated using various sets of simulated data of the non-linear systems. Sensitivity study of DFKF with respect to tuning parameters used in creation of sigma points and the associated weight is carried out. DFKF is more accurate and easier to implement. A data fusion scheme is involved. It is observed that fusion enhances the estimation accuracy of the state of non-linear plant. Application of DFKF to non linear parameter estimation problem is also demonstrated

Adaptive neuro-fussy based control surface fault detection and reconfiguration

The aircraft becomes unstable due to fault in actuator or if there is a loss of control surface13; effectiveness due to damaged or blown surfaces. One of the popular methods to detect and reconfigure13; the surface fault is model based approach e.g. Extended Kalman filter (EKF). Using EKF, the parameters13; of control distribution matrix are estimated as augmented states of the system which are subsequently13; used to compute feedback gain to reconfigure the impaired system In this paper, detection and13; reconfiguration of surface fault in elevator of an aircraft is demonstrated using Adaptive Neuro - Fuzzy13; Inference System ANFIS . Under this approach, i) ANFIS is trained using time history of i/o data i.e.13; inputs as errors between nominal (healthy) states of aircraft and its faulty states (noise free) for different13; fault conditions and output as parameters of control distribution matrix and ii) trained ANFIS is13; subsequently used to estimate the parameters of control distribution matrix for the actual fault condition13; and the reconfiguration is carried out by computing new feedback gain using pseudo-inverse technique

INTERACTING MULTIPLE MODEL SEEKER FILTER FOR TRACKING EVASIVE TARGETS

Seeker filter is an important subsystem in modern homing guidance system of advanced intercepting missiles. Seeker filter design for homing guidance requirements are highly demanding and challenging. Very low filter lag, high noise attenuation are some of the challenges that need to be addressed. This paper presents an interacting multiple model augmented extended Kalman filter (IMM-AEKF) design to operate as seeker filter in close loop homing guidance of an interceptor to track evasive targets. The performance of the seeker filter is verified with six degree of freedom interceptor-target engagement simulation with seeker filter in guidance loop of the interceptor. Different filter performance criteria have been used to verify the performance of the seeker filter. The seeker filter efficiently handles the various seeker noise and provides a smooth estimate of target states to generate guidance command for intercepting missile. The miss distance achieved is within the acceptable limits

Genetic diversity study of indigenous cattle (Gir and Kankrej) population of Rajasthan using microsatellite markers

The genetic diversity study of native Gir and Kankrej (Bos indicus) cattle populations were evaluated using nine microsatellite markers (ETH-225, CSRM-60, HEL-9, INRA-005, ETH-10, HAUT-24, BM1818, ILSTS-002 and ILSTS-006) suggested by FAO (ISAG). A total of 60 cattle were sampled from different places of local Rajasthan region. For each, 30 individuals were sampled. The mean number of observed and effective alleles in Kankrej were high (5.222 and 3.714) comparatively and the average expected heterozygosity values (0.5403) indicated high diversity in the Kankrej population than Gir (0.4520). High polymorphism information content (PIC) values observed for most of the markers with an average of 0.5116 are indicative of high polymorphism of these markers in Kankrej breed than in Gir (0.4202), which showed high informativeness of all the microsatellite markers in Kankrej breed. Three microsatellites markers (HAUT24, BM1818 AND ILSTS006) did not show amplification in both breeds. INRA005 was the only markers amplified in Kankrej. The allele diversity (mean observed number of alleles was 6.11; mean effective number of alleles was 5.187) and gene diversity (0.2771) values implied a substantial amount of genetic variability in both populations. Reasonably high PIC values observed for most of the markers, with an average PIC value of 0.5116 across all the loci implied that this set of microsatellite are very informative for evaluation of genetic diversity in both the breeds. This informativeness of microsatellite markers showed it can be used for various applications like, conservation, disease diagnosis and polymorphism in different populations.Key words: Genetic diversity, polymorphism information content (PIC), heterozygosity, polymorphism, marker

A bovine lymphosarcoma cell line infected with theileria annulata exhibits an irreversible reconfiguration of host cell gene expression

Theileria annulata, an intracellular parasite of bovine lymphoid cells, induces substantial phenotypic alterations to its host cell including continuous proliferation, cytoskeletal changes and resistance to apoptosis. While parasite induced modulation of host cell signal transduction pathways and NFκB activation are established, there remains considerable speculation on the complexities of the parasite directed control mechanisms that govern these radical changes to the host cell. Our objectives in this study were to provide a comprehensive analysis of the global changes to host cell gene expression with emphasis on those that result from direct intervention by the parasite. By using comparative microarray analysis of an uninfected bovine cell line and its Theileria infected counterpart, in conjunction with use of the specific parasitacidal agent, buparvaquone, we have identified a large number of host cell gene expression changes that result from parasite infection. Our results indicate that the viable parasite can irreversibly modify the transformed phenotype of a bovine cell line. Fifty percent of genes with altered expression failed to show a reversible response to parasite death, a possible contributing factor to initiation of host cell apoptosis. The genes that did show an early predicted response to loss of parasite viability highlighted a sub-group of genes that are likely to be under direct control by parasite infection. Network and pathway analysis demonstrated that this sub-group is significantly enriched for genes involved in regulation of chromatin modification and gene expression. The results provide evidence that the Theileria parasite has the regulatory capacity to generate widespread change to host cell gene expression in a complex and largely irreversible manner

X-Ray Spectroscopy of Stars

(abridged) Non-degenerate stars of essentially all spectral classes are soft X-ray sources. Low-mass stars on the cooler part of the main sequence and their pre-main sequence predecessors define the dominant stellar population in the galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense, of X-ray spectra from the solar corona. X-ray emission from cool stars is indeed ascribed to magnetically trapped hot gas analogous to the solar coronal plasma. Coronal structure, its thermal stratification and geometric extent can be interpreted based on various spectral diagnostics. New features have been identified in pre-main sequence stars; some of these may be related to accretion shocks on the stellar surface, fluorescence on circumstellar disks due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot stars clearly dominate the interaction with the galactic interstellar medium: they are the main sources of ionizing radiation, mechanical energy and chemical enrichment in galaxies. High-energy emission permits to probe some of the most important processes at work in these stars, and put constraints on their most peculiar feature: the stellar wind. Here, we review recent advances in our understanding of cool and hot stars through the study of X-ray spectra, in particular high-resolution spectra now available from XMM-Newton and Chandra. We address issues related to coronal structure, flares, the composition of coronal plasma, X-ray production in accretion streams and outflows, X-rays from single OB-type stars, massive binaries, magnetic hot objects and evolved WR stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures (partly multiple); some corrections made after proof stag

Portrait of a Pathogen: The Mycobacterium tuberculosis Proteome In Vivo

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is a facultative intracellular pathogen that can persist within the host. The bacteria are thought to be in a state of reduced replication and metabolism as part of the chronic lung infection. Many in vitro studies have dissected the hypothesized environment within the infected lung, defining the bacterial response to pH, starvation and hypoxia. While these experiments have afforded great insight, the picture remains incomplete. The only way to study the combined effects of these environmental factors and the mycobacterial response is to study the bacterial response in vivo.We used the guinea pig model of tuberculosis to examine the bacterial proteome during the early and chronic stages of disease. Lungs were harvested thirty and ninety days after aerosol challenge with Mtb, and analyzed by liquid chromatography-mass spectrometry. To date, in vivo proteomics of the tubercle bacillus has not been described and this work has generated the first large-scale shotgun proteomic data set, comprising over 500 unique protein identifications. Cell wall and cell wall processes, and intermediary metabolism and respiration were the two major functional classes of proteins represented in the infected lung. These classes of proteins displayed the greatest heterogeneity indicating important biological processes for establishment of a productive bacterial infection and its persistence. Proteins necessary for adaptation throughout infection, such as nitrate/nitrite reduction were found at both time points. The PE-PPE protein class, while not well characterized, represented the third most abundant category and showed the most consistent expression during the infection.Cumulatively, the results of this work may provide the basis for rational drug design - identifying numerous Mtb proteins, from essential kinases to products involved in metal regulation and cell wall remodeling, all present throughout the course of infection

PESCADOR, a web-based tool to assist text-mining of biointeractions extracted from PubMed queries

BACKGROUND: Biological function is greatly dependent on the interactions of proteins with other proteins and genes. Abstracts from the biomedical literature stored in the NCBI's PubMed database can be used for the derivation of interactions between genes and proteins by identifying the co-occurrences of their terms. Often, the amount of interactions obtained through such an approach is large and may mix processes occurring in different contexts. Current tools do not allow studying these data with a focus on concepts of relevance to a user, for example, interactions related to a disease or to a biological mechanism such as protein aggregation. RESULTS: To help the concept-oriented exploration of such data we developed PESCADOR, a web tool that extracts a network of interactions from a set of PubMed abstracts given by a user, and allows filtering the interaction network according to user-defined concepts. We illustrate its use in exploring protein aggregation in neurodegenerative disease and in the expansion of pathways associated to colon cancer. CONCLUSIONS: PESCADOR is a platform independent web resource available at: http://cbdm.mdc-berlin.de/tools/pescador