11 research outputs found
Robust Aggregation Mechanism in WSN for Mitigating Attacks
Wireless Sensor Network (WSN) is a collection of sensor nodes connected to base station which is characterized by many to one communication. Many sensor nodes will send data to base station making it many to on communication. The sensor nodes can act as sender and receiver of data as the data is sent to base station through intermediary nodes. The nodes are resource constrained as they are deployed in hostile environment or environment where resources are limited. The nodes are expected to participate in sensing or surveillance. WSNs are widely used in civilian and military applications for sending data and surveillance. As WSN is becoming increasingly popular, security needs to be provided in the network as the nodes are vulnerable to various attacks. Since the nodes are energy constrained, it is very useful to use some aggregation technique in order to reduce communication overhead and also energy consumption. Recently Roy et al. focused on aggregation in WSN for filtering out the impact of attackers on the network. Their focus was to use aggregation in WSN in order to reduce communication overhead and reduce the impact of attacks on WSN. In this paper we implement a variant of protocol that takes care of secure communications over WSN besides reducing energy consumption and mitigating attack impact. The simulation results are encouraging
DOI: 10.17762/ijritcc2321-8169.15065
Group Based Secure Sharing of Cloud Data with Provable Data Freshness
With cloud computing technology it is realized that data can be outsource and such data can also be shared among users of cloud. However, the data outsourced to cloud might be subjected to integrity problems due to the problems in the underlying hardware or software errors. Human errors also may contribute to the integrity problems. Many techniques came into existence in order to ensure data integrity. Most of the techniques have some sort of auditing. Public auditing schemes meant for data integrity of shared data might disclose confidential information. To overcome this problem, recently, Wang et al. proposed a novel approach that supports public auditing and also do not disclose confidential information. They exploited ring signatures that are used to compute verification metadata on the fly in order to audit the correctness of shared data. The public verifiers do not know the identity of the signer. It does mean that the verifier can verify data without knowing the identity of the signer. However, this scheme does not consider the freshness of data which is very important in cloud services. Obtaining latest copy of data is very important to avoid stale data access in cloud. Towards this end, in this paper, we proposed an algorithm for ensuring freshness of the data while retrieving the outsourced data in multi-user environment. Our empirical results revealed that the proposed algorithm is efficient.
DOI: 10.17762/ijritcc2321-8169.15065
A Framework for Protecting Cloud Users from Third Party Auditors
Cloud computing has merged to be a now computing paradigm that lets public to access shared pool of resources without capital investment. The users of cloud need to access resources through Internet in pay per use fashion. Thus there is increased use of storage services of cloud in the real world. This service is known as Infrastructure as a Service (IaaS). However, there are security concerns as this service runs in entrusted environment. To ensure data integrity many public verification or auditing schemes came into existence. Nevertheless, there is a concern when the so called Third Party Auditor (TPA) has malicious intentions. In such cases, protection is required against malicious TPAs. Towards this end, recently, Huang et al. proposed a scheme in which users can directly check the integrity of stored data using a feedback based audit scheme. TPA takes process proof from cloud server and gives feedback to cloud user. The feedback is unforgivable and the TPA cannot make any malicious attacks. Based on this scheme, in this paper, we implemented a prototype application that demonstrates the proof of concept. The empirical results are encouraging.
DOI: 10.17762/ijritcc2321-8169.15065
HER2 and Helicobacter pylori Status in Resected Gastric Cancers: A Pathological Study of a Gastroenterological Issue
Introduction: Human epidermal growth factor receptor 2 (HER2)/neu is a critical target for gastric carcinoma treatment utilizing trastuzumab. Helicobacter pylori is a well known causative agent of gastric carcinoma.
Aim: To study association of HER2/neu expression with the presence of H. pylori infection in resected carcinoma stomach patients.
Materials and Methods: A cross-sectional study of 85 gastrectomies received in the department from January 2010 to September 2014 was done. HER2/neu was studied using Immunohistochemistry (IHC) and Giemsa stain was used to detect presence of H. pylori. Chi-square test and Fisherâs exact test were used, to test the correlation between the various parameters. A p-value <0.05 was considered significant.
Results: Our study population included 67 (78.8%) males, and 18 (21.2%) females, ranging from 22 to 84 years, mean 57.68±12.12 years. HER-2 expression, graded from 0 to 3± was correlated with location, histologic type, grade, local invasion, metastasis to lymph nodes, TNM tumour staging and H. pylori infection, graded from 0 to 3+ using Giemsa stain. HER2/neu 3+ was observed in intestinal type of gastric cancer (5/55, 9%) only. Scores 2+ and 3+ were more common in H. pylori-negative patients (5/26, 19.2%) than H. pylori-positive patients (4/59, 6.8%) (p=0.02). TNM stage, extent of local invasion and lymph node metastasis in intestinal gastric carcinomas correlated significantly with HER2/neu expression. H. pylori was present in 59 (69.4%) and absent in 26 (30.6%).
Conclusion: H. pylori-negative gastric cancer showed significant immunophenotypic HER2/neu overexpression i.e., H. pylori might protect against HER2 overexpression that correlated significantly with higher TNM stages of intestinal-type gastric cancer. In contrast, H. pylori infection correlated significantly with Lymph-Vascular Invasion (LVI) but was pN1/2+, thereby diminishing prognostic importance. H. pylori induced intestinal metaplasia was not significantly associated with intestinal-type gastric cancer
Increases in plasma holotranscobalamin can be used to assess vitamin B-12 absorption in individuals with low plasma vitamin B-12
Low plasma concentrations of vitamin B-12 are common in Indians, possibly due to low dietary intakes of animal-source foods. Whether malabsorption of the vitamin contributes to this has not been investigated. A rise in the plasma holotranscobalamin (holo-TC) concentration after a standard dose of oral vitamin B-12 has been proposed as a measure of gastrointestinal absorption in people with normal plasma vitamin B-12 concentrations. We studied 313 individuals (children and parents, 109 families) in the Pune Maternal Nutrition Study. They received 3 doses of 10 ”g (n = 191) or 2 ”g (n = 122) of cyanocobalamin at 6-h intervals. A rise in plasma holo-TC of 15% and >15 pmol/L above baseline was considered normal vitamin B-12 absorption. The baseline plasma vitamin B-12 concentration was <150 pmol/L in 48% of participants; holo-TC was <35 pmol/L in 98% and total homocysteine was high in 50% of participants (>10 ”mol/L in children and >15 ”mol/L in adults). In the 10 ”g group, the plasma holo-TC concentration increased by 4.8-fold from (mean ± SD) 9.3 ± 7.0 pmol/L to 53.8 ± 25.9 pmol/L and in the 2 ”g group by 2.2-fold from 11.1 ± 8.5 pmol/L to 35.7 ± 19.3 pmol/L. Only 10% of the participants, mostly fathers, had an increase less than the suggested cut-points. Our results suggest that an increase in plasma holo-TC may be used to assess vitamin B-12 absorption in individuals with low vitamin B-12 status. Because malabsorption is unlikely to be a major reason for the low plasma vitamin B-12 concentrations in this population, increasing dietary vitamin B-12 should improve their status
Effect of physiological doses of oral vitamin B12 on plasma homocysteine: a randomized, placebo-controlled, double-blind trial in India
Background/Objectives: vitamin B12 (B12) deficiency is common in Indians and a major contributor to hyperhomocysteinemia, which may influence fetal growth, risk of type II diabetes and cardiovascular disease. The purpose of this paper was to study the effect of physiological doses of B12 and folic acid on plasma total homocysteine (tHcy) concentration.Subjects/Methods: a cluster randomized, placebo-controlled, double-blind, 2 Ă 3 factorial trial, using the family as the randomization unit. B12 was given as 2 or 10??g capsules, with or without 200??g folic acid, forming six groups (B0F0, B2F0, B10F0, B0F200, B2F200 and B10F200). Plasma tHcy concentration was measured before and after 4 and 12 months of supplementation.Results: from 119 families in the Pune Maternal Nutrition Study, 300 individuals were randomized. There was no interaction between B12 and folic acid (P=0.14) in relation to tHcy concentration change and their effects were analyzed separately: B0 vs. B2 vs. B10; and F0 vs. F200. At 12 months, tHcy concentration reduced by a mean 5.9 (95% CI: ?7.8, ?4.1) ?mol/l in B2, and by 7.1 (95% CI: ?8.9, ?5.4) ?mol/l in B10, compared to nonsignificant rise of 1.2 (95% CI: ?0.5, 2.9) ?mol/l in B0. B2 and B10 did not differ significantly. In F200, tHcy concentration decreased by 4.8 (95% CI: ?6.3, ?3.3) ?mol/l compared to 2.8 (95% CI: ?4.3, ?1.2) ?mol/l in F0.Conclusion: daily oral supplementation with physiological doses of B12 is an effective community intervention to reduce tHcy. Folic acid (200??g per day) showed no additional benefit, neither had any unfavorable effects
Effect of general anaesthesia on functional outcome in patients with anterior circulation ischaemic stroke having endovascular thrombectomy versus standard care: a meta-analysis of individual patient data
Background:
General anaesthesia (GA) during endovascular thrombectomy has been associated with worse patient outcomes in observational studies compared with patients treated without GA. We assessed functional outcome in ischaemic stroke patients with large vessel anterior circulation occlusion undergoing endovascular thrombectomy under GA, versus thrombectomy not under GA (with or without sedation) versus standard care (ie, no thrombectomy), stratified by the use of GA versus standard care.
Methods:
For this meta-analysis, patient-level data were pooled from all patients included in randomised trials in PuMed published between Jan 1, 2010, and May 31, 2017, that compared endovascular thrombectomy predominantly done with stent retrievers with standard care in anterior circulation ischaemic stroke patients (HERMES Collaboration). The primary outcome was functional outcome assessed by ordinal analysis of the modified Rankin scale (mRS) at 90 days in the GA and non-GA subgroups of patients treated with endovascular therapy versus those patients treated with standard care, adjusted for baseline prognostic variables. To account for between-trial variance we used mixed-effects modelling with a random effect for trials incorporated in all models. Bias was assessed using the Cochrane method. The meta-analysis was prospectively designed, but not registered.
Findings:
Seven trials were identified by our search; of 1764 patients included in these trials, 871 were allocated to endovascular thrombectomy and 893 were assigned standard care. After exclusion of 74 patients (72 did not undergo the procedure and two had missing data on anaesthetic strategy), 236 (30%) of 797 patients who had endovascular procedures were treated under GA. At baseline, patients receiving GA were younger and had a shorter delay between stroke onset and randomisation but they had similar pre-treatment clinical severity compared with patients who did not have GA. Endovascular thrombectomy improved functional outcome at 3 months both in patients who had GA (adjusted common odds ratio (cOR) 1·52, 95% CI 1·09â2·11, p=0·014) and in those who did not have GA (adjusted cOR 2·33, 95% CI 1·75â3·10, p<0·0001) versus standard care. However, outcomes were significantly better for patients who did not receive GA versus those who received GA (covariate-adjusted cOR 1·53, 95% CI 1·14â2·04, p=0·0044). The risk of bias and variability between studies was assessed to be low.
Interpretation:
Worse outcomes after endovascular thrombectomy were associated with GA, after adjustment for baseline prognostic variables. These data support avoidance of GA whenever possible. The procedure did, however, remain effective versus standard care in patients treated under GA, indicating that treatment should not be withheld in those who require anaesthesia for medical reasons