self-stabilising

We revisit the approach to Byzantine fault-tolerant clock synchronization based on approximate agreement introduced by Lynch and Welch. Our contribution is threefold: (1) We provide a slightly refined variant of the algorithm yielding improved bounds on the skew that can be achieved and the sustainable frequency offsets. (2) We show how to extend the technique to also synchronize clock rates. This permits less frequent communication without significant loss of precision, provided that clock rates change sufficiently slowly. (3) We present a coupling scheme that allows to make these algorithms self-stabilizing while preserving their high precision. The scheme utilizes a low-precision, but self-stabilizing algorithm for the purpose of recovery

Systems analysis of avascular necrosis of femoral head using integrative data analysis and literature mining delineates pathways associated with disease

Avascular necrosis of femoral head (AVNFH) is a debilitating disease, which affects the middle aged population. Though the disease is managed using bisphosphonate, it eventually leads to total hip replacement due to collapse of femoral head. Studies regarding the association of single nucleotide polymorphisms with AVNFH, transcriptomics, proteomics, metabolomics, biophysical, ultrastructural and histopathology have been carried out. Functional validation of SNPs was carried out using literature. An integrated systems analysis using the available datasets might help to gain further insights into the disease process. We have carried out an analysis of transcriptomic data from GEO-database, SNPs associated with AVNFH, proteomic and metabolomic data collected from literature. Based on deficiency of vitamins in AVNFH, an enzyme-cofactor network was generated. The datasets are analyzed using ClueGO and the genes are binned into pathways. Metabolomic datasets are analyzed using MetaboAnalyst. Centrality analysis using CytoNCA on the data sets showed cystathionine beta synthase and methylmalonyl-CoA-mutase to be common to 3 out of 4 datasets. Further, the genes common to at least two data sets were analyzed using DisGeNET, which showed their involvement with various diseases, most of which were risk factors associated with AVNFH. Our analysis shows elevated homocysteine, hypoxia, coagulation, Osteoclast differentiation and endochondral ossification as the major pathways associated with disease which correlated with histopathology, IHC, MRI, Micro-Raman spectroscopy etc. The analysis shows AVNFH to be a multi-systemic disease and provides molecular signatures that are characteristic to the disease process

Platelet and blood transfusion in a child with dyskeratosis congenita for dental extraction – a case report

Introduction and Objective: Dyskeratosis congenita (DC) also known as Zinsser-Engman- Cole Syndrome is a rare inherited disorder with a prevalence of less than one per million. Zinsser et al. described an inherited variant of ectodermal dysplasia that affected skin, nails and mucous membranes in early 1900s.The syndrome eventually came to be known as DC and is classified as one of the inherited bone marrow failure syndromes (IBMFS). DC is the association of three clinical features: dystrophic nails, oral leukoplakia (white spots on the tongue and oral mucosa) and abnormal skin pigmentation. Case report and Conclusion: This case report describes a dental management of a case of DC. Fluctuating vital and blood parameters and deteriorating overall health status were major challenges delivering dental treatment. Dental extractions of this patient were done while maintaining blood parameters by blood and platelet transfusion.Introduction and Objective: Dyskeratosis congenita (DC) also known as Zinsser-Engman- Cole Syndrome is a rare inherited disorder with a prevalence of less than one per million. Zinsser et al. described an inherited variant of ectodermal dysplasia that affected skin, nails and mucous membranes in early 1900s.The syndrome eventually came to be known as DC and is classified as one of the inherited bone marrow failure syndromes (IBMFS). DC is the association of three clinical features: dystrophic nails, oral leukoplakia (white spots on the tongue and oral mucosa) and abnormal skin pigmentation. Case report and Conclusion: This case report describes a dental management of a case of DC. Fluctuating vital and blood parameters and deteriorating overall health status were major challenges delivering dental treatment. Dental extractions of this patient were done while maintaining blood parameters by blood and platelet transfusion

Self-Stabilizing {B}yzantine Clock Synchronization with Optimal Precision

In the Byzantine-tolerant clock synchronization problem, the goal is to synchronize the clocks of n fully connected nodes. The clocks run at rates between 1 and � > 1, and messages have a delay (including computation) between d − U and d. Moreover, up to f < n/3 of the nodes can fail by deviating arbitrarily from the protocol, i.e., are Byzantine. Despite this interference, correct nodes need to generate distinguished events (or pulses) almost simultaneously and periodically. The quality of the solution is measured by the skew, which is the maximum real time difference between corresponding pulses. In the self-stabilizing setting, in addition we allow for transient failures, possibly of all nodes. Once transient faults have ceased and at most f nodes remain faulty, the system should start generating synchronized pulses again. We design a self-stabilizing solution to this problem with asymptotically optimal skew. We achieve our goal by refining and extending the protocol of Lynch and Welch and make the following contributions in the process. • We give a simple analysis of the Lynch and Welch protocol with improved bounds on skew and tolerable difference in clock rates by rebuilding upon the main ingredient of their protocol, called approximate agreement. • We give a modified version of the protocol so that the frequency and amount of communication between the nodes is reduced. The modification adds a step to adjust the clock rates by another application of approximate agreement. The skew bound achieved is asymptotically optimal for suitable choices of parameters. • We present a method to add self-stabilization to the above protocols while preserving their skew bounds. The heart of the method is a coupling scheme that leverages a self-stabilizing protocol with a larger skew.ISSN:1432-4350ISSN:1433-049

Information Needs and Information Seeking Behavior of Foreign Students in University of Delhi: A Survey

The purpose of this paper is to investigate the information needs and information seeking behavior of foreign students. A survey method was used for the undertaken study. The data were collected using a structured questionnaire, self-administered to 120 foreign students (60 males & 60 females) with 88 (47 males & 41 females) returns. The research is limited to post-graduate, M.Phil. and Ph.D. foreign students in University of Delhi. It was found that post-graduate students need information regarding their program of study while research scholars need information for writing research articles and for doing their research work. Most of them seek information through the internet. Research scholars used electronic resources such as databases, e-journals and e-theses and dissertations. 88.6% of the respondents also use books for seeking information. Their use of the library is limited with complaints about library staff and too few computer terminals. The present study will be helpful in designing new systems and services for the foreign students so that their information needs can be fulfilled easily. Further, findings of the study indicate that how the library professionals should assist foreign students to accomplish their information needs

A PRMT5-ZNF326 axis mediates innate immune activation upon replication stress

DNA replication stress (RS) is a widespread phenomenon in carcinogenesis, causing genomic instability and extensive chromatin alterations. DNA damage leads to activation of innate immune signaling, but little is known about transcriptional regulators mediating such signaling upon RS. Using a chemical screen, we identified protein arginine methyltransferase 5 (PRMT5) as a key mediator of RS-dependent induction of interferon-stimulated genes (ISGs). This response is also associated with reactivation of endogenous retroviruses (ERVs). Using quantitative mass spectrometry, we identify proteins with PRMT5-dependent symmetric dimethylarginine (SDMA) modification induced upon RS. Among these, we show that PRMT5 targets and modulates the activity of ZNF326, a zinc finger protein essential for ISG response. Our data demonstrate a role for PRMT5-mediated SDMA in the context of RS-induced transcriptional induction, affecting physiological homeostasis and cancer therapy