49 research outputs found

    Tissue Microenvironments Define and Get Reinforced by Macrophage Phenotypes in Homeostasis or during Inflammation, Repair and Fibrosis

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    Current macrophage phenotype classifications are based on distinct in vitro culture conditions that do not adequately mirror complex tissue environments. In vivo monocyte progenitors populate all tissues for immune surveillance which supports the maintenance of homeostasis as well as regaining homeostasis after injury. Here we propose to classify macrophage phenotypes according to prototypical tissue environments, e.g. as they occur during homeostasis as well as during the different phases of (dermal) wound healing. In tissue necrosis and/or infection, damage- and/or pathogen-associated molecular patterns induce proinflammatory macrophages by Toll-like receptors or inflammasomes. Such classically activated macrophages contribute to further tissue inflammation and damage. Apoptotic cells and antiinflammatory cytokines dominate in postinflammatory tissues which induce macrophages to produce more antiinflammatory mediators. Similarly, tumor-associated macrophages also confer immunosuppression in tumor stroma. Insufficient parenchymal healing despite abundant growth factors pushes macrophages to gain a profibrotic phenotype and promote fibrocyte recruitment which both enforce tissue scarring. Ischemic scars are largely devoid of cytokines and growth factors so that fibrolytic macrophages that predominantly secrete proteases digest the excess extracellular matrix. Together, macrophages stabilize their surrounding tissue microenvironments by adapting different phenotypes as feed-forward mechanisms to maintain tissue homeostasis or regain it following injury. Furthermore, macrophage heterogeneity in healthy or injured tissues mirrors spatial and temporal differences in microenvironments during the various stages of tissue injury and repair. Copyright (C) 2012 S. Karger AG, Base

    An automata based approach for verifying information flow properties

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    We present an automated verification technique to verify trace based information flow properties for finite state systems. We show that the Basic Security Predicates (BSPs) defined by Mantel in [5], which are shown to be the building blocks of known trace based information flow properties, can be characterised in terms of regularity preserving language theoretic operations. This leads to a decision procedure for checking whether a finite state system satisfies a given BSP. Verification techniques in the literature (e.g. unwinding) are based on the structure of the transition system and are incomplete in some cases. In contrast, our technique is language based and complete for all information flow properties that can be expressed in terms of BSPs

    On the Decidability of Model-Checking Information Flow Properties

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    Current standard security practices do not provide substantial assurance about information flow security: the end-to-end behavior of a computing system. Noninterference is the basic semantical condition used to account for information flow security. In the literature, there are many definitions of noninterference: Non-inference, Separability and so on. Mantel presented a framework of Basic Security Predicates (BSPs) for characterizing the definitions of noninterference in the literature. Model-checking these BSPs for finite state systems was shown to be decidable in [8]. In this paper, we show that verifying these BSPs for the more expressive system model of pushdown systems is undecidable. We also give an example of a simple security property which is undecidable even for finite-state systems: the property is a weak form of non-inference called WNI, which is not expressible in Mantel’s BSP framework

    A comparative study of set up variations and bowel volumes in supine versus prone positions of patients treated with external beam radiation for carcinoma rectum

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    Purpose: A prospective study was undertaken to evaluate the influence of patient positioning on the set up variations to determine the planning target volume (PTV) margins and to evaluate the clinical relevance volume assessment of the small bowel (SB) within the irradiated volume. Materials and Methods: During the period of months from December 2011 to April 2012, a computed tomography (CT) scan was done either in supine position or in prone position using a belly board (BB) for 20 consecutive patients. All the patients had histologically proven rectal cancer and received either post- or pre-operative pelvic irradiation. Using a three-dimensional planning system, the dose-volume histogram for SB was defined in each axial CT slice. Total dose was 46-50 Gy (2 Gy/fraction), delivered using the 4-field box technique. The set up variation of the study group was assessed from the data received from the electronic portal imaging device in the linear accelerator. The shift along X, Y, and Z directions were noted. Both systematic and random errors were calculated and using both these values the PTV margin was calculated. Results: The systematic errors of patients treated in the supine position were 0.87 (X-mm), 0.66 (Y-mm), 1.6 (Z-mm) and in the prone position were 1.3 (X-mm), 0.59 (Y-mm), 1.17 (Z-mm). The random errors of patients treated in the supine positions were 1.81 (X-mm), 1.73 (Y-mm), 1.83 (Z-mm) and in prone position were 2.02 (X-mm), 1.21 (Y-mm), 3.05 (Z-mm). The calculated PTV margins in the supine position were 3.45 (X-mm), 2.87 (Y-mm), 5.31 (Z-mm) and in the prone position were 4.91 (X-mm), 2.32 (Y-mm), 5.08 (Z-mm). The mean volume of the peritoneal cavity was 648.65 cm 3 in the prone position and 1197.37 cm 3 in the supine position. Conclusion: The prone position using BB device was more effective in reducing irradiated SB volume in rectal cancer patients. There were no significant variations in the daily set up for patients treated in both supine and prone positions

    Clinical Profile of Malaria in and around Hubballi-Dharwad: A Region of North Karnataka

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    Introduction: Malaria is an endemic vector borne parasitic infection. Plasmodium vivax has been associated with severe malaria while P. falciparum is traditionally associated with severe course. Of late, P. vivax is increasingly reported to cause severe and life threatening disease. However, majority of P. vivax are sensitive to antimalarials and therefore, it is important to speculate this pathogen. Aim: To study the clinical profile of confirmed malaria cases. Materials and Methods: This prospective study was undertaken at SDM College of Medical Sciences and Hospital, Dharwad, Karnataka, India, between the period of 2010 to 2012 for the duration of two years. A total of 124 clinically suspected malaria cases aged from 8 years to 65 years were included in the study. Laboratory identification was done by Quantitative Buffy Coat (QBC). A comparative analysis of clinical presentations in 62 QBC positive samples and an equal number of age and sex matched QBC negative was done. Results: Out of 62 QBC positive samples, Plasmodium vivax was seen in 40/62 (64.52%) patients while P. falciparum in 10/40 (16.13%) cases. Mixed infection by P. vivax and P. falciparum was seen in 12/40 (19.35%) cases. Fever, chills and headache were common symptoms. Pallor was seen in 23/40 (37.1%) cases and icterus, splenomegaly and vomiting were seen in 14/62 (22.6%) cases followed by hepatosplenomegaly in 11 (17.7%) cases. Among QBC negative controls, fever (100%), chills 51/62 (82.3%), rigors 21/62 (33.9%) and pain abdomen (24.2 %) were the common symptoms. Pallor and hepatomegaly was seen in 19.4 % and 11.3% respectively among the QBC negatives. Ten out of 11 (90.9%) of females and 37/51 (72.5%) of males suffering from malaria had anaemia. Thrombocytopenia was seen in 59/62 (95.2%) cases of which 33 cases had moderate thrombocytopenia (53.2%) while 17 cases had severe thrombocytopenia. In QBC negative controls, severe thrombocytopenia was noted in 4 (6.5%) samples, mild and moderate thrombocytopenia was seen in 14 and 16 (22.5 and 25.8%) patients respectively. About 94% cases recovered completely. One patient suffering from P. vivax succumbed to the infection. Conclusion: Plasmodium vivax, traditionally thought to cause benign malaria can also produce life threatening complications similar to falciparum malaria. Early recognition of signs and symptoms of severe malaria and laboratory confirmation of species is most important in management of this condition

    SDVADC: Secure Deduplication and Virtual Auditing of Data in Cloud

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    Over the last few years, deploying data to cloud service for repository is an appealing passion that avoids efforts on significant information sustenance and administration. In distributed repository utilities, deduplication technique is often exploited to minimize the capacity and bandwidth necesseties of amenities by erasing repetitive data and caching only a solitary duplicate of them. Proof-of-Ownership mechanisms authorize any possessor of the identical information to approve to the distributed repository server that he possess the information in a dynamic way. In repository utilities with enormous information, the repository servers may intend to minimize the capacity of cached information, and the customers may want to examine the integrity of their information with a reasonable cost. We propose Secure Deduplication and Virtual Auditing of Data in Cloud (SDVADC) mechanism that realizes integrity auditing and deduplication of information in cloud. The mechanism supports secure deduplication of information and effective virtual auditing of the documents during the download process. In addition, the proposed mechanism lowers the burden of dataowner to audit documents by himself and there is no need to delegate auditing to the Third Party Auditor (TPA). Experimental results demonstrate that the virtual auditing has low auditing time cost relative to the existing public auditing schemes

    CRUPA: collusion resistant user revocable public auditing of shared data in cloud

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    Cloud repository is one of the most important services afforded by Cloud Computing where information is preserved, maintained, archived in distant servers and made available to the users over the Internet. Provided with the cloud repository facilities, customers can organize themselves as a cluster and distribute information with one another. In order to allow public integrity auditing on the information stored in semi-trusted cloud server, customers compute the signatures for every chunk of the shared information. When a malicious client is repudiated from the group, the chunks that were outsourced to the cloud server by this renounced customer need to be verified and re-signed by the customer present in the cluster (i.e., the straightforward approach) which results in huge transmission and reckoning cost for the customer. In order to minimize the burden of customers present in the cluster, in the existing scheme Panda, the semi-trusted Cloud Service Provider (CSP) is allowed to compute the Re−sign key. Further, the CSP audits and re-signs the revoked customer chunks by utilizing the Re−sign key. So, it is easy for the CSP by colluding with the revoked customer to find the secret keys of the existing customer. We introduce a novel Collusion Resistant User Revocable Public Auditing of Shared Data in Cloud (CRUPA) by making use of the concept of regression technique. In order to secure the secret keys of the existing customers from the CSP, we have allowed the information proprietor to compute the Re−sign key using the regression technique. Whenever the information proprietor revokes the customer from the cluster, the information proprietor computes the Re−sign key using the regression technique and sends to the CSP. Further, the CSP audits and re-signs the revoked customer chunks using the Re−sign key. The Re−sign key computed by the information proprietor using regression method is highly secure and the malicious CSP cannot find the private information of the customers in the cluster. Besides, our mechanism achieves significant improvement in the computation cost of the Re−sign key by information proprietor. Further, the proposed scheme is collusion resistant, supports effective and secure customer repudiation, multi-information proprietor batch auditing and is scalable
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