S. Jain

Genome-wide association mapping of salinity tolerance in rice (Oryza sativa)

Salinity tolerance in rice is highly desirable to sustain production in areas rendered saline due to various reasons. It is a complex quantitative trait having different components, which can be dissected effectively by genome-wide association study (GWAS). Here, we implemented GWAS to identify loci controlling salinity tolerance in rice. A custom-designed array based on 6,000 single nucleotide polymorphisms (SNPs) in as many stress-responsive genes, distributed at an average physical interval of <100 kb on 12 rice chromosomes, was used to genotype 220 rice accessions using Infinium high-throughput assay. Genetic association was analysed with 12 different traits recorded on these accessions under field conditions at reproductive stage. We identified 20 SNPs (loci) significantly associated with Na+/K+ ratio, and 44 SNPs with other traits observed under stress condition. The loci identified for various salinity indices through GWAS explained 5–18% of the phenotypic variance. The region harbouring Saltol, a major quantitative trait loci (QTLs) on chromosome 1 in rice, which is known to control salinity tolerance at seedling stage, was detected as a major association with Na+/K+ ratio measured at reproductive stage in our study. In addition to Saltol, we also found GWAS peaks representing new QTLs on chromosomes 4, 6 and 7. The current association mapping panel contained mostly indica accessions that can serve as source of novel salt tolerance genes and alleles. The gene-based SNP array used in this study was found cost-effective and efficient in unveiling genomic regions/candidate genes regulating salinity stress tolerance in rice.

Evidence of a common founder for SCA12 in the Indian population.

Spinocerebellar ataxia type 12 (SCA12) is an autosomal dominant cerebellar ataxia associated with the expansion of an unstable CAG repeat in the 5′ region of the PPP2R2B gene on chromosome 5q31–5q32. We found that it accounts for ∼16% (20/124) of all the autosomal dominant ataxia cases diagnosed in AIIMS, a major tertiary referral centre in North India. The length of the expanded allele in this population ranges from 51–69 CAG triplets. Interestingly, all the affected families belong to an endogamous population, which originated in the state of Haryana, India. We identified four novel SNPs and a dinucleotide marker spanning ∼137 kb downstream of CAG repeat in the PPP2R2B gene. Analysis of 20 Indian SCA12 families and ethnically matched normal unrelated individuals revealed one haplotype to be significantly associated with the affected alleles (P= 0.000), clearly indicating the presence of a common founder for SCA12 in the Indian population. This haplotype was not shared by the American pedigree with SCA12. Therefore, the SCA12 expansion appears to have originated at least twice.

Usefulness of short-term video EEG recording with saline induction in pseudoseizures.

Objectives ‐ To study the usefulness of short‐term recording of video electroencephalography (VEEG) as an outpatient procedure with placebo induction (PLIN) and intravenous saline in cases of pseudoseizures (Psz). Material and methods ‐ Fifty cases of suspected Psz were enrolled. They were divided into 2 groups: Group 1 consisted of patients with frank Psz, Group 2 those where diagnosis was uncertain. VEEG recording was done and 10 ml of saline used for placebo‐induction. Results ‐ Of 50 patients, 24 (48%) were in Group 1 and 26 (52%) in Group 2. Fifteen (30%) had a spontaneous event during VEEG and 33% had an event only on PLIN. The diagnosis was confirmed in 60%. In 24% of patients anti‐epileptic drugs were discontinued. Conclusion ‐ Short‐term monitoring with VEEG using PLIN is a useful initial screening procedure and in patients where it is inconclusive, long term recordings may be done.

Effect of non-Newtonian behaviour of lubricant and bearing flexibility on the performance of slot-entry journal bearing

Abstract This work describes the theoretical study concerning the effect of non-linear behaviour of the lubricant on the performance of a slot-entry journal bearing. The analysis considers the generalized Reynolds equation governing the flow of lubricant having variable viscosity in the clearance space and the three dimensional elasticity equations governing the displacement field in the bearing shell, and equation of flow of lubricant through slot restrictor. The non-Newtonian lubricant is assumed to follow the cubic shear stress law ( τ + K τ 3 =γ⨪ ). Bearing performance characteristics have been presented for a typically selected values of non-linearity factor ( K ) and deformation coefficient ( C d ). It has been observed that the combined effect of non-linearity factor ( K ) and bearing flexibility ( C d ) affects the performance characteristics of slot-entry journal bearing quite significantly.

A study of slot-entry hydrostatic/hybrid journal bearing using the finite element method

Abstract A theoretical study concerning the static and dynamic performance of hydrostatic/hybrid journal bearing compensated by slot restrictor has been presented using the finite element method (FEM). Results have been presented for a double row symmetric as well as asymmetric configurations for different values of slot width ratios (SWR) and external load ( W 0 ). In order to have a better understanding of their performance vis-a-vis other non-recessed bearing configurations, the performance characteristics of slot-entry journal bearings have been compared with that of similar hole-entry compensated journal bearings using capillary, orifice and constant flow valve restrictors for the same bearing geometric and operating parameters. The comparative study indicates that asymmetric slot-entry journal bearings provide an improved stability threshold speed margin compared with asymmetric hole entry journal bearings compensated by capillary, orifice and constant flow valve restrictors.

Occurrence of only myoclonic jerks in juvenile myoclonic epilepsy

Objectives ‐ The clinical data on individuals who were diagnosed to have juvenile myoclonic epilepsy (JME) on the basis of myoclonic jerks alone has been analysed. The points in favour and against individuals with only myoclonic jerks being classified as “affected” for research on JME are discussed.

Family Studies and Human Leukocyte Antigen Class II Typing in Indian Probands with Seizures in Association with Single Small Enhancing Computed Tomography Lesions

Summary: Purpose: To define the clinical features of the syndrome of seizures associated with single, small, enhancing computed tomography (CT) lesions (SSELs) in 235 Indian probands and seizure types among their family members. Human leukocyte antigen (HLA) class II genomic typing in randomly selected 41 probands was done to identify the role of hereditary factors in this syndrome.

Occurrence of Epilepsies in Family Members of Indian Probands with Different Epileptic Syndromes

Summary: Purpose: Large numbers of families with many members having seizures have been used to understand the role of hereditary factors in the pathogenesis of human epileptic syndromes. We aimed to establish a genetic database to form a hypothesis on the possible genetic contributions in different epileptic syndromes.

Genetics in Epilepsy: Transcultural Perspectives

Summary: In the last two decades there have been many significant advances with regard to the genetics of human epilepsies. Knowledge of the mutations responsible for inherited human epilepsies not only will help in a better diagnosis and understanding of the mechanisms involved in epileptogenesis and their inheritance, but also will result in the development of better and safer antiepileptic drugs, discovery of novel therapeutic modalities, improved genetic counseling, and perhaps even prevention of epilepsies. The overall impact of these genetic discoveries across different populations and cultures will perhaps be beneficial to improving the lives of the millions affected by these diverse but common brain disorders.

Stability Margin of Hybrid Journal Bearing: Influence of Thermal and Elastic Effects

This paper deals with the stability margin of a constant flow valve compensated hole-entry hybrid journal bearing system considering bearing flexibility and variation of viscosity due to temperature rise of the lubricant. The journal temperature is computed on the basis of average fluid-film temperature and axisymmetric isothermal element is assumed. The coupled solution of Reynolds, energy, conduction, and elasticity equations is obtained using finite element method. The performance of a symmetric and asymmetric hole-entry hybrid journal bearing configurations is studied. The results presented in the study indicate that the bearing flexibility and temperature rise of the lubricant fluid-film affects the performance of the hole-entry hybrid journal bearing system quite significantly and proper selection of restrictor design parameter is quite useful in maintaining the fluid film thickness and threshold speed of the journal.