Necessity of step-stress accelerated life testing experiment at higher steps

Chandra, N.,Khan, Mashroor Ahmad,Pandey, M. The Korean Reliability Society 2014 International Journal of Reliability and Applicati Vol.15 No.2

Accelerated life testing (ALT) is a well famous technique in life testing and reliability studies, this is particularly used to induce so high stress leading to failure of the highly reliable units quickly under stipulated duration of time. The step-stress ALT is one of the systematic experimental strategy of ALT applied to fail the units in steps. In this article we focus on two important issues (i) necessity of life tests at higher steps with relevant causes (ii) to develop a new optimum test plan for 3-step SSALT under the modified cumulative exposure model proposed by Khamis and Higgins (1998). It is assumed that the lifetime of test units follows Rayleigh distribution and its scale parameter at constant stress level is assumed to be a log-linear function of the stress. The maximum likelihood estimates of the parameters involved in the step-stress ALT model are obtained. A simulation study is performed for numerical investigation of the proposed new optimum plan 3-step, step-stress ALT. The necessity of the life test units at 3-step step-stress is also numerically examined in comparison to simple step-stress setup.

Bayesian reliability estimation of bivariate Marshal-Olkin exponential stress-strength model

Chandra, N.,Pandey, M. The Korean Reliability Society 2012 International Journal of Reliability and Applicati Vol.13 No.1

In this article we attempted reliability analysis of a component under the stress-strength pattern with both classical as well as Bayesian techniques. The main focus is made to develop the theory for dealing the reliability problems in various circumstances for bivariate environmental set up in context of Bayesian paradigm. A stress-strength based model describes the life of a component which has strength (Y) and is subjected to stress(X). We develop the Bayes and moment estimators of reliability of a component for each of the three possible conditions, under the assumption that the two stresses (i.e. $X_1$ and $X_2$) on a component are dependent and follow a Bivariate exponential (BVE) of Marshall-Olkin distribution, the strength of a component (Y) following exponential distribution is independent of the stresses. The simulation study is performed with Markov Chain Monte Carlo technique via Gibbs sampler to obtain the estimates of Bayes estimators of reliability, are compared with moment estimators of reliabilities on the basis of absolute biases.

Effect of Remote and Local Acupuncture Points on Periarthritis of Shoulder: A Comparative Study

Kumaresan Poorna Chandran,Prabu Poorna Chandran,Naveena Arumugam,Sendhilkumar Muthappan 사단법인약침학회 2021 Journal of Acupuncture & Meridian Studies Vol.14 No.1

Background: Periarthritis of shoulder is a painful condition of the shoulder, affecting 2-3% of the general population and 20% of diabetic patients. Acupuncture is a widely practiced traditional Chinese medicine. Recent evidence shows that it alleviates shoulder pain with different needling techniques. Objectives: The present study is to compare the efficacy of remote and local points on PAS. Methods: 60 subjects were randomly assigned into two groups, remote acupuncture group (n = 30) and local acupuncture group (n = 30). Both groups were assessed at baseline and at the end of 12 sessions. Shoulder pain and its disability index (SPADI) and (ROM) were measured using goniometer. The intervention was given weekly thrice on alternate days for four weeks with 20 min for each session. Results: The result shows that both remote and local acupuncture points were beneficial in the pain management and rage of motion when compared within the group. The effects of acupuncture at remote acupoints were better than those at local acupoints in SPADI and ROM when compared between two groups. Conclusion: In treatment of periarthritis of shoulder remote acupuncture points may have higher therapeutic value when compared to local points.

Meta-expression analysis of unannotated genes in rice and approaches for network construction to suggest the probable roles

Chandran, Anil Kumar Nalini,Bhatnagar, Nikita,Yoo, Yo-Han,Moon, Sunok,Park, Sun-Ah,Hong, Woo-Jong,Kim, Beom-Gi,An, Gynheung,Jung, Ki-Hong Springer-Verlag 2018 Plant Molecular Biology Vol.96 No.1

<P>Although the genome of rice (Oryza sativa) has been sequenced, 14,365 genes are considered unannotated because they lack putative annotation information. According to the Rice Genome Annotation Project Database (http://rice.plantbiology.msu.edu/), the proportion of functionally characterized unannotated genes (0.35%) is quite limited when compared with the approximately 3.9% of annotated genes with assigned putative functions. Researchers require additional information to help them investigate the molecular mechanisms associated with those unannotated genes. To determine which of them might regulate morphological or physiological traits in the rice genome, we conducted a meta-analysis of expression data that covered a wide range of tissue/organ samples. Overall, 2020 genes showed cultivar-, tissue-, or organ-preferential patterns of expression. Representative candidates from featured groups were validated by RT-PCR, and the GUS reporter system was used to validate the expression of genes that were clustered according to their leaf or root preference. Taking a molecular and genetics approach, we examined meta-expression data and found that 127 genes were differentially expressed between japonica and indica rice cultivars. This is potentially significant for future agronomic applications. We also used a T-DNA insertional mutant and performed a co-expression network analysis of Sword shape dwarf1 (SSD1), a gene that regulates cell division. This network was refined via RT-PCR analysis. Our results suggested that SSD1 represses the expression of four genes related to the processes of DNA replication or cell division and provides insight into possible molecular mechanisms. Together, these strategies present a valuable tool for in-depth characterization of currently unannotated genes.</P>

Functional classification of rice flanking sequence tagged genes using MapMan terms and global understanding on metabolic and regulatory pathways affected by <i>dxr</i> mutant having defects in light response

Chandran, Anil Kumar Nalini,Lee, Gang-Seob,Yoo, Yo-Han,Yoon, Ung-Han,Ahn, Byung-Ohg,Yun, Doh-Won,Kim, Jin-Hyun,Choi, Hong-Kyu,An, GynHeung,Kim, Tae-Ho,Jung, Ki-Hong Springer US 2016 Rice Vol.9 No.-

<P><B>Background</B></P><P>Rice is one of the most important food crops for humans. To improve the agronomical traits of rice, the functions of more than 1,000 rice genes have been recently characterized and summarized. The completed, map-based sequence of the rice genome has significantly accelerated the functional characterization of rice genes, but progress remains limited in assigning functions to all predicted non-transposable element (non-TE) genes, estimated to number 37,000–41,000.</P><P><B>Results</B></P><P>The International Rice Functional Genomics Consortium (IRFGC) has generated a huge number of gene-indexed mutants by using mutagens such as T-DNA, Tos17 and Ds/dSpm. These mutants have been identified by 246,566 flanking sequence tags (FSTs) and cover 65 % (25,275 of 38,869) of the non-TE genes in rice, while the mutation ratio of TE genes is 25.7 %. In addition, almost 80 % of highly expressed non-TE genes have insertion mutations, indicating that highly expressed genes in rice chromosomes are more likely to have mutations by mutagens such as T-DNA, <I>Ds</I>, <I>dSpm</I> and <I>Tos17</I>. The functions of around 2.5 % of rice genes have been characterized, and studies have mainly focused on transcriptional and post-transcriptional regulation. Slow progress in characterizing the function of rice genes is mainly due to a lack of clues to guide functional studies or functional redundancy. These limitations can be partially solved by a well-categorized functional classification of FST genes. To create this classification, we used the diverse overviews installed in the MapMan toolkit. Gene Ontology (GO) assignment to FST genes supplemented the limitation of MapMan overviews.</P><P><B>Conclusion</B></P><P>The functions of 863 of 1,022 known genes can be evaluated by current FST lines, indicating that FST genes are useful resources for functional genomic studies. We assigned 16,169 out of 29,624 FST genes to 34 MapMan classes, including major three categories such as DNA, RNA and protein. To demonstrate the MapMan application on FST genes, transcriptome analysis was done from a rice mutant of 1-deoxy-D-xylulose 5-phosphate reductoisomerase (<I>DXR)</I> gene with FST. Mapping of 756 down-regulated genes in <I>dxr</I> mutants and their annotation in terms of various MapMan overviews revealed candidate genes downstream of <I>DXR</I>-mediating light signaling pathway in diverse functional classes such as the methyl-D-erythritol 4-phosphatepathway (MEP) pathway overview, photosynthesis, secondary metabolism and regulatory overview. This report provides a useful guide for systematic phenomics and further applications to enhance the key agronomic traits of rice.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s12284-016-0089-2) contains supplementary material, which is available to authorized users.</P>

Genome-wide transcriptome analysis of expression in rice seedling roots in response to supplemental nitrogen

Chandran, A.K.N.,Priatama, R.A.,Kumar, V.,Xuan, Y.,Je, B.I.,Kim, C.M.,Jung, K.H.,Han, C.d. G. Fischer 2016 Journal of plant physiology Vol.200 No.-

<P>Nitrogen (N) is the most important macronutrient for plant growth and grain yields. For rice crops, nitrate and ammonium are the major N sources. To explore the genomic responses to ammonium supplements in rice roots, we used 17-day-old seedlings grown in the absence of external N that were then exposed to 0.5 mM (NH4)(2)SO4 for 3 h. Transcriptomic profiles were examined by microarray experiments. In all, 634 genes were up-regulated at least two-fold by the N-supplement when compared with expression in roots from untreated control plants. Gene Ontology (GO) enrichment analysis revealed that those upregulated genes are associated with 23 GO terms. Among them, metabolic processes for diverse amino acids (i.e., aspartate, threonine, tryptophan, glutamine, L-phenylalanine, and thiamin) as well as nitrogen compounds are highly over-represented, demonstrating that our selected genes are suitable for studying the N-response in roots. This enrichment analysis also indicated that nitrogen is closely linked to diverse transporter activities by primary metabolites, including proteins (amino acids), lipids, and carbohydrates, and is associated with carbohydrate catabolism and cell wall organization. Integration of results from omics analysis of metabolic pathways and transcriptome data using the MapMan tool suggested that the TCA cycle and pathway for mitochondrial electron transport are co-regulated when rice roots are exposed to ammonium. We also investigated the expression of N-responsive marker genes by performing a comparative analysis with root samples from plants grown under different NH4+ treatments. The diverse responses to such treatment provide useful insight into the global changes related to the shift from an N-deficiency to an enhanced N-supply in rice, a model crop plant. (C) 2016 Elsevier GmbH. All rights reserved.</P>

Light Emitting Electrochemical Cells Based on Ionic Iridium Complexes and Ionic Conductor Blend as the Active Layer

Chandran, Midhun,Kwon, Yiseul,Choe, Youngson Informa UK (TaylorFrancis) 2014 Molecular Crystals and Liquid Crystals Vol.601 No.1

Present Status and Problems of Pecan Nut (Carya Illiolensis) Cultivation in Jammu and Kashmir

Chandran Ravindran 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Civil-Military Relations and National Security in ASEAN

( Chandran Jeshurun ) 인하대학교 국제관계연구소 1989 Pacific Focus Vol.4 No.2

Ni(II) complexes with ligands derived from phenylpyridine, active for selective dimerization and trimerization of ethylene

Chandran, D.,Lee, K.M.,Chang, H.C.,Song, G.Y.,Lee, J.E.,Suh, H.,Kim, I. Elsevier Sequoia 2012 Journal of organometallic chemistry Vol.718 No.-

An electrophilic substitution-carbonylation reaction on phenylpyridine based on the concept of 'umpolung' was used to prepare a series of pyridine based carbonyl compounds and bispyridine derivatives. The key intermediate which enhances this reaction is a base aggregate formed by the association of BuLi with lithium 2-dimethylaminoethanolate (LiDMAE) which is stabilized in nonpolar solvents. The presence of polar chelating amides that are used as acyl donors was found to collapse the superbase aggregates liberating nucleophilic 'free' BuLi. These nucleophiles lead a classical nucleophilic reaction to introduce butyl tails on the pre-ligand molecules. Pyridine carbonyl compounds produced by these electrophilic substitution-carbonylation reactions, on treatment with 2,6-diisopropylaniline and (DME)NiBr<SUB>2</SUB> in glacial acetic acid at reflux temperature, gave Ni(II) complexes in good yields in a one pot protocol. These complexes are active toward ethylene, producing selective dimerization and trimerization products.