Thrombosis in Cerebral Aneurysms and the Computational Modeling Thereof: A Review

Thrombosis is a condition closely related to cerebral aneurysms and controlled thrombosis is the main purpose of endovascular embolization treatment. The mechanisms governing thrombus initiation and evolution in cerebral aneurysms have not been fully elucidated and this presents challenges for interventional planning. Significant effort has been directed towards developing computational methods aimed at streamlining the interventional planning process for unruptured cerebral aneurysm treatment. Included in these methods are computational models of thrombus development following endovascular device placement. The main challenge with developing computational models for thrombosis in disease cases is that there exists a wide body of literature that addresses various aspects of the clotting process, but it may not be obvious what information is of direct consequence for what modeling purpose (e.g., for understanding the effect of endovascular therapies). The aim of this review is to present the information so it will be of benefit to the community attempting to model cerebral aneurysm thrombosis for interventional planning purposes, in a simplified yet appropriate manner. The paper begins by explaining current understanding of physiological coagulation and highlights the documented distinctions between the physiological process and cerebral aneurysm thrombosis. Clinical observations of thrombosis following endovascular device placement are then presented. This is followed by a section detailing the demands placed on computational models developed for interventional planning. Finally, existing computational models of thrombosis are presented. This last section begins with description and discussion of physiological computational clotting models, as they are of immense value in understanding how to construct a general computational model of clotting. This is then followed by a review of computational models of clotting in cerebral aneurysms, specifically. Even though some progress has been made towards computational predictions of thrombosis following device placement in cerebral aneurysms, many gaps still remain. Answering the key questions will require the combined efforts of the clinical, experimental and computational communities

Timing information in data networks

Thesis (Ph. D.)--University of Washington, 2000The role of timing information is considered as the key to an information theoretic understanding of communication networks. In this dissertation, we focus on the analysis of problems related to timing information in data networks from an information theoretic perspective.One problem is that of identifying the timing capacity of network components, i.e. the maximum information rate achievable by encoding information in the timing of packets. We first consider the timing capacity of discrete-time queues in which at most one packet may arrive or finish service in a slot, and demonstrate the extremal nature of the geometric service time distribution among such queues. We then analyze a discrete-time queueing model with batch arrivals and a batch service mechanism that is related to the leaky bucket flow control system. Within this model, we obtain a closed form expression for the timing capacity of the queue that can serve a geometrically distributed number of packets in a slot. We also establish a connection between the extremal nature of the geometric server and a queueing theoretic property of such queues. Finally, we obtain an upper bound to the timing capacity of a queueing system with multiple servers having i.i.d. geometrically distributed packet service times.Another problem is that of quantifying the amount of information about the times at which messages arrive at the source that must be transmitted to the destination to enable it to decode the messages within a finite amount of time. Suppose that messages are transmitted one at a time, and are decoded in the same order they arrived at the source. By viewing the message arrival and decoding processes as the arrival and departure processes from a hypothetical single-server queue, we can associate a service time with each message. The rate-distortion function of the message arrival process with message service time as the distortion measure is a lower bound for the amount of information about message arrival times that the receiver must receive. We explicitly obtain this rate-distortion function for the Poisson message arrival process

On the Information-Theoretic Capacity of Discrete-Time Queues

this paper, we consider the timing capacity of two models of discrete-time single-server queues. The first model is the discrete-time analogue of the continuous-time model analyzed in [1]. In this model, packets arrive and depart in discrete time slots. We allow at most one packet arrival and at most one packet departure in each slot. Service times of packets are independent, identically distributed (i.i.d.), integer-valued random variables with mean 1=¯ slots. We obtain upper and lower bounds to the -timin

Finding corresponding points based on Bayesian triangulation

In this paper, we consider the problems of finding corresponding points from multiple perspective projection images (the correspondence problem), and estimating the 3-D point from which these points have arisen (the triangulation problem). We pose the triangulation problem as that of finding the Bayesian max-imum a posteriori estimate of the 3-D point, given its projections in N images, assuming a Gaussian error model for the image point coordinates and the camera parameters. We solve this by an iterative steepest descent method. We then consider the correspondence problem as a statistical hypothesis verification prob-lem. Given a set of 2-D points, UndeT the hypothesis that the points are in correspondence, the MAP esti-mate of the 3-D point is computed. Based on the MAP estimate, we derive a statistical test for verifying this hypothesis. To find sets of corresponding points when multiple points in each of N images are given, we pro-pose a method that does the Bayesian triangulation and hypothesis verification on each N-tuple of points, selecting those that pass the hypothesis test. We char-acterize the performance of the Bayesian triangulation in terms of the average distance of the triangulated 3-D point from the true 3-D point, and of the point cor-respondence method in terms of its misdetection and false alarm rates

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Not AvailableThe outer membrane protein, encoded by glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, of Edwardsiella tarda is a highly conserved immunogenic protein. The GAPDH was cloned and expressed in Escherichia coli. The purified protein was used to produce mouse monoclonal antibodies (MAbs). Four stable hybridomas producing MAbs (3G12, 4E9, 5A11 and 9G1) against rGAPDH were obtained. The heavy chains of antibodies produced by the hybridomas were of the isotypes IgG1 and IgM. Cross reactivity of MAbs (3G12 and 9G1) was observed with GAPDH of Aeromonas hydrophila and Micrococcus luteus. MAbs 3G12 and 4E9 reacted with Vibrio cholerae, Salmonella enterica and Penaeus monodon tissues but not with vertebrate GAPDH. None of the MAbs reacted with Staphylococcus aureus. The results indicate that the level of conservation of GAPDH is high among evolutionarily close species. The MAbs developed will be a useful tool to study the evolutionarily conserved and functionally diverse GAPDH.Not Availabl

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Not AvailableInterferon gamma (IFN-γ) or type II interferon is a cytokine that is critical for innate and adaptive immunity against viral and some bacterial and protozoal infections. The importance of IFN-γ in the immune system lies in its ability to inhibit viral replication directly and most importantly from its immunomodulatory effects. Previously, we successfully co-administered IFN-γ along with GAPDH gene of Edwardsiella tarda as bicistronic DNA vaccine in Labeo rohita. In order to ascertain the individual role of IFN-γ, the present study involves cloning and expression of 552-bp IFN-γ open-reading frame (ORF) of L. rohita in striped snakehead (SSN-1) cell line using eukaryotic expression vector system (pQE-TriSystem) followed by transfection in peripheral blood lymphocytes (PBMCs) to evaluate its immunomodulatory ability in comparison to polyinosinicpolycytidylic acid (Poly I:C)-treated PBMCs. The 18.7-kDa protein, expressed in the pQE-IFNγ-transfected SSN-1 cells, reacted with anti-His antibody in Western blot confirming it to be recombinant IFN-γ, whereas the relative expression of IFN-γ, iNOS, Mx, and IL-1β genes in PBMCs was quantified at 24 h and 48 h post treatment by qPCR. The comparative kinetics of all four genes showed significantly (p < 0.05) high upregulation pattern in both pQE-IFNγ-transfected cell group and Poly I:C-treated cell group demonstrating recombinant IFN-γ as an equally efficient inducer like Poly I:C. Thus, our in vitro experiment results highlight the immunomodulatory potential of recombinant IFN-γ as an analogue to synthetic Poly I:C which warranted future studies to further explore the potential of recombinant IFN-γ as an effective vaccine adjuvant against different microbial invasionNot Availabl

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Not AvailableDNA-based immunization has proven to be an effective prophylactic measure to control aquatic animal diseases. In order to improve the efficiency of vaccine against fish pathogen, novel delivery mechanism needs to be adopted. In the present study we nanoconjugated the previously constructed DNA vaccine (pGPD + IFN) with chitosan nanoparticles (CNPs) by complex coacervation process. After construction of the vaccine, an in vivo vaccination trial was conducted in which 2 groups of rohu (L. rohita) fingerlings were vaccinated with CNPs-pGPD + IFN, one group by oral route (incorporated in feed for 14 days) and the other by immersion route (primary and booster immunised), whereas, a third group was intramuscularly (I/M) injected (initial and booster immunised) with naked pGPD + IFN and subsequently challenged with E. tarda (8.7 104 CFU/fish) at 35-day post initial vaccination. The protective immune responses were determined in terms of relative percentage survival (RPS), specific antibody production, non-specific immune response, expression kinetics of immune-related genes and pathological manifestation. Evaluation of RPS analysis revealed that CNPs-pGPD + IFN groups recorded highest RPS (81.82% and 72.73% in oral and immersion vaccinated fish group respectively) while the naked pGPD + IFN injected group showed 63.62% RPS when compared with 55% cumulative mortality of control group. In addition, NBT, myeloperoxidase activity, serum lysozyme activity and specific antibody titre in case of CNPs-pGPD + IFN groups showed higher activities during all the time points. Furthermore, CNPs-pGPD + IFN groups showed significant (p < 0.05) upregulation of different immune gene transcripts (IgHC, iNOS, TLR22, NOD1 and IL-1b) in three immunologically important tissues post immunization (both primary and booster dose) as well as after challenge. Thus, from this study, we can conclude that oral or immersion vaccination with CNPs-pGPD + IFN can orchestrate an effective immunisation strategy in organizing a coordinative immune response against E. tarda in L. rohita exhibiting minimum stress to the host with maximum efficacyNot Availabl

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Not AvailableDNA-based immunization has proven to be an effective prophylactic measure to control aquatic animal diseases. In order to improve the efficiency of vaccine against fish pathogen, novel delivery mechanism needs to be adopted. In the present study we nanoconjugated the previously constructed DNA vaccine (pGPD + IFN) with chitosan nanoparticles (CNPs) by complex coacervation process. After construction of the vaccine, an in vivo vaccination trial was conducted in which 2 groups of rohu (L. rohita) fingerlings were vaccinated with CNPs-pGPD + IFN, one group by oral route (incorporated in feed for 14 days) and the other by immersion route (primary and booster immunised), whereas, a third group was intramuscularly (I/M) injected (initial and booster immunised) with naked pGPD + IFN and subsequently challenged with E. tarda (8.7* 104 CFU/fish) at 35-day post initial vaccination. The protective immune responses were determined in terms of relative percentage survival (RPS), specific antibody production, non-specific immune response, expression kinetics of immune-related genes and pathological manifestation. Evaluation of RPS analysis revealed that CNPs-pGPD + IFN groups recorded highest RPS (81.82% and 72.73% in oral and immersion vaccinated fish group respectively) while the naked pGPD + IFN injected group showed 63.62% RPS when compared with 55% cumulative mortality of control group. In addition, NBT, myeloperoxidase activity, serum lysozyme activity and specific antibody titre in case of CNPs-pGPD + IFN groups showed higher activities during all the time points. Furthermore, CNPs-pGPD + IFN groups showed significant (p < 0.05) upregulation of different immune gene transcripts (IgHC, iNOS, TLR22, NOD1 and IL-1b) in three immunologically important tissues post immunization (both primary and booster dose) as well as after challenge. Thus, from this study, we can conclude that oral or immersion vaccination with CNPs-pGPD + IFN can orchestrate an effective immunisation strategy in organizing a coordinative immune response against E. tarda in L. rohita exhibiting minimum stress to the host with maximum efficacy.Not Availabl