Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Reading LevelReading Level
-
Content TypeContent Type
-
YearFrom:-To:
-
More FiltersMore FiltersItem TypeIs Full-Text AvailableSubjectPublisherSourceDonorLanguagePlace of PublicationContributorsLocation
Done
Filters
Reset
23
result(s) for
"Padakannaya, Prakash"
Sort by:
Family-based genome-wide copy number scan identifies five new genes of dyslexia involved in dendritic spinal plasticity
by
Padakannaya, Prakash
,
Saldanha, Marita
,
Veerappa, Avinash M
in
Adolescent
,
Axon guidance
,
Cell adhesion
2013
Genome-wide screening for copy number variations (CNVs) in ten Indian dyslexic families revealed the presence of five de novo CNVs in regions harboring GABARAP, NEGR1, ACCN1, DCDC5, and one in already known candidate gene CNTNAP2. These genes are located on regions of chromosomes 17p13.1, 1p31.1, 17q11.21, 11p14.1 and 7q35, respectively, and are implicated in learning, cognition and memory processes through dendritic spinal plasticity, though not formally associated with dyslexia. Molecular network analysis of these and other dyslexia-related module genes suggests them to be associated with synaptic transmission, axon guidance and cell adhesion. Thus, we suggest that dyslexia may also be caused by neuronal disconnection in addition to the earlier view that it is due to neuronal migrational disorder.
Journal Article
Analysis of genetic variants of dyslexia candidate genes KIAA0319 and DCDC2 in Indian population
by
Padakannaya, Prakash
,
Siddaiah, Anand
,
Ramachandra, Nallur B
in
Alleles
,
Case-Control Studies
,
Child, Preschool
2013
Developmental dyslexia (DD) is a heritable, complex genetic disorder associated with impairment in reading and writing skills despite having normal intellectual ability and appropriate educational opportunities. Chromosome 6p23-21.3 at DYX2 locus has showed the most consistent evidence of linkage for DD and two susceptible genes KIAA0319 and DCDC2 for DD at DYX2 locus showed significant association. Specific candidate gene-association studies have identified variants, risk haplotypes and microsatellites of KIAA0319 and DCDC2 correlated with wide range of reading-related traits. In this study, we used a case-control approach for analyzing single-nucleotide polymorphisms (SNPs) in KIAA0319 and DCDC2. Our study demonstrated the association of DD with SNP rs4504469 of KIAA0319 and not with any SNPs of DCDC2.
Journal Article
Development of a home literacy environment questionnaire for Tamil-speaking kindergarten children
2017
Background
The development of emergent literacy skills depends upon the literacy environments and experiences of children at home. Children’s home literacy environment is closely related to the development of various aspects of emergent literacy like letter knowledge, phonological awareness, and vocabulary. Dimensions of home literacy environment, such as physical (literacy) environment, child’s own literacy habits, parental literacy habits, parent-child interaction for language and literacy activities, and parental beliefs about literacy, have been reported in literature.
Methods
The present study describes the construction of a home literacy environment questionnaire for Tamil-speaking kindergarten children in the Indian context. The various dimensions of home literacy environment were described, and items related to each dimension were listed. Seventeen judges rated each item on a five-point Likert scale ranging from 0 (no fit) to 4 (excellent fit). Their comments/remarks/opinion, specific to an item or dimension, were also taken. The rating responses were analyzed for content validity and internal consistency.
Results
Content validity index was calculated at item level as well as scale level. The items in each subscale/dimension which had the item level content validity index scores higher than 0.78 were included in the final questionnaire and the other items were rejected. The scale level content validity index scores were higher than 0.90, indicating good content validity. Cronbach’s alpha was calculated as a measure of internal consistency. Cronbach’s alpha values were lower than 0.7 for three domains: physical environment, parent literacy habits, and parental beliefs.
Conclusions
The questionnaire developed promises to be a useful tool to evaluate the home literacy environment of Tamil children who undergo formal education in English medium schools like in India. The questionnaire developed and presented here can help in collecting reliable data to make informed decisions about children’s (whether typically developing or with developmental disabilities) home literacy environment.
Journal Article
Perceptual span in reading Aksharic Kannada
2023
Perceptual span, the effective visual field in reading covered in a single fixation, varies across orthographies. The perceptual span for reading English covers 3–4-character spaces to the left of fixation and around 14–15-character spaces to the right of the fixation while for Chinese it is one character space to the left and 3-character spaces to the right of the fixation. In the present study, we estimated the perceptual span for Kannada, a major South Indian language written in akshara (abugida type) using the gaze-contingent moving window paradigm. We recorded eye movements from skilled Kannada readers when they read sentences in different window sizes and compared the eye movement measures with that of full-length sentence reading. Results showed that the perceptual span for Kannada covers one akshara to the left and 6-akshara to the right of the fixation. Future studies need to establish whether all Akshara orthographies show a similar percentual span.
Journal Article
The effect of written scripts’ dissimilarity over ventral and dorsal reading pathway: combined fMRI & DTI study
by
Padakannaya, Prakash
,
Kumar, Uttam
in
Brain Hemisphere Functions
,
Functional magnetic resonance imaging
,
Hindi language
2019
We employed functional magnetic resonance imaging (fMRI) and diffuse tensor imaging (DTI) to study neural implications of silent reading of words in mutually comprehensible but visually and orthographically distinct languages for example Hindi and Urdu by independent groups of skilled readers. The fMRI results (conjunction analyses) showed the left inferior frontal gyrus (BA 44/45), bilateral inferior occipital (BA 18/19), bilateral superior parietal (BA 7), left pre-central region (BA 6), and bilateral inferior temporal gyrus (BA 20) as common regions for Hindi and Urdu readers. Some additional regions such as left ventral occipitotemporal, left middle frontal (BA 46), left middle occipital (BA18), and bilateral post-central regions (BA 3) were observed for Urdu readers. DTI results showed significantly higher FA value at the left inferior fronto-occipital fasciculus in Urdu speakers. Overall findings suggest strong engagement of ventral visual pathway in reading Urdu which has a visually complex deep orthography.
Journal Article
Development of Rapid Automatized Naming (RAN) in Simultaneous Kannada-English Biliterate Children
by
Padakannaya, Prakash
,
Saldanha, Marita
,
Ramachandra, Nallur B.
in
Adolescent
,
Adolescents
,
Ascription
2016
RAN tests were administered to 600 typically developing children, 60 each from grade level one through grade ten (30 boys and 30 girls), who learn two distinct languages, English and Kannada simultaneously from the very first grade. The overall results were in accordance with similar previous studies in English and other European languages. The developmental trajectories were similar across the languages to a large extent; but the results also showed some differences across languages with respect to synchrony between the measures and the overall naming speed. Though some of the differences could be ascribed to the bilingual/biliterate culture and language use, there are enough scopes for future researches to examine these issues.
Journal Article
Neural correlates of auditory comprehension and integration of sanskrit verse: a functional MRI study
by
Padakannaya, Prakash
,
Kumar, Uttam
,
Pandey, Himanshu Raj
in
Adaptability
,
Adult
,
Ancient languages
2025
In this investigation, we delve into the neural underpinnings of auditory processing of Sanskrit verse comprehension, an area not previously explored by neuroscientific research. Our study examines a diverse group of 44 bilingual individuals, including both proficient and non-proficient Sanskrit speakers, to uncover the intricate neural patterns involved in processing verses of this ancient language. Employing an integrated neuroimaging approach that combines functional connectivity-multivariate pattern analysis (fc-MVPA), voxel-based univariate analysis, seed-based connectivity analysis, and the use of sparse fMRI techniques to minimize the interference of scanner noise, we highlight the brain's adaptability and ability to integrate multiple types of information. Our findings from fc-MVPA reveal distinct connectivity patterns in proficient Sanskrit speakers, particularly involving the bilateral inferior temporal, left middle temporal, bilateral orbitofrontal, and bilateral occipital pole. Voxel-based univariate analysis showed significant activation in the right middle frontal gyrus, bilateral caudate nuclei, bilateral middle occipital gyri, left lingual gyrus, bilateral inferior parietal lobules, and bilateral inferior frontal gyri. Seed-based connectivity analysis further emphasizes the interconnected nature of the neural networks involved in language processing, demonstrating how these regions collaborate to support complex linguistic tasks. This research reveals how the brain processes the complex syntactic and semantic elements of Sanskrit verse. Findings indicate that proficient speakers effectively navigate intricate syntactic structures and semantic associations, engaging multiple brain regions in coordination. By examining the cognitive mechanisms underlying Sanskrit verse comprehension, which shares rhythmic and structural features with music and poetry, this study highlights the neural connections between language, culture, and cognition.
Journal Article
Damaging stop gain/loss and frameshift mutations in autism subjects outline impairment in neuronal migration and adhesion pathways
by
Padakannaya, Prakash
,
Ramachandra, Nallur B.
,
Shyamala, K.C.
in
Adhesion
,
Autism
,
Gene expression
2017
Genetic heterogeneity makes it challenging to identify causal-genes responsible for autism pathogenesis. Till date, research studies report only a handful of high confidence genes for autism. There is a need to identify damaging genomic-variants, predisposing an individual towards autism manifestation. Of special interest is stop gain/loss mutations found in the exome. Such variants are prevalent, having an estimated number of 100-200 occurrences per human-genome. Stop-gains and frameshifts may lead to functional consequences. Based on stringent inclusion-exclusion criteria, the study recruited 150 autism subjects of Indian origin, of which 13 were used for WES. To understand the nature and possible consequences of these variants, we first analyzed their characteristics at the genome-level. Genome-wide analysis of more than 30000 variants provided statistical-significance to identify sequence-specific features for severity and to build a pathogenicity score. This sequence-based pathogenicity score was then applied to the analysis of variants in autism susceptibility. Several damaging stop gain/loss mutations encompassing autism genes CDH5, DDX23, CLDN5, and DPP3 were identified with protein truncations ranging from 20-70%. Loss of function mutations disrupted protein domains involved in various autism related pathways such as neuronal migration, synaptogenesis,and neuronal adhesion. Mutations were identified with previous evidences for neuronal migration and adhesion pathways in Drosophila sp, C. elegans and mice models. Homozygosity mapping analysis to identify risk-homozygous-haplotypes showed evidence of recessive polymorphisms in GIGYF1, SERPINE1, and EPHB6. Recessive alleles were identified across all the samples while polymorphisms in FOLH1, BCKDK, CDH11, and CTCF were specific. Mutations in language-specific genes, GCFC1 and MRPL19 were associated with autism phenome. A novel autism candidate gene CLDN5 that physically interacts with genes involved in various autism pathways was identified.CLDN5 belongs to the leukocyte-transendothelial-migration pathway and elevated in autism cortex, impairing the blood brain barrier leading to compensatory gene expression and protein accumulation. This on-going study identified several damaging mutations specific for autism in Indian population, adding to the growing body of mutational spectrum. Validations through Sanger sequencing and allele specific PCR is being done for the mutations identified.
Journal Article
Copy Number Variation of UGT 2B Genes in Indian Families Using Whole Genome Scans
by
Veerappa, Avinash M.
,
Padakannaya, Prakash
,
Ramachandra, Nallur B.
in
Copy number variations
,
Genetic aspects
,
Health aspects
2016
Background and Objectives. Uridine diphospho-glucuronosyltransferase 2B (UGT2B) is a family of genes involved in metabolizing steroid hormones and several other xenobiotics. These UGT2B genes are highly polymorphic in nature and have distinct polymorphisms associated with specific regions around the globe. Copy number variations (CNVs) status of UGT2B17 in Indian population is not known and their disease associations have been inconclusive. It was therefore of interest to investigate the CNV profile of UGT2B genes. Methods. We investigated the presence of CNVs in UGT2B genes in 31 members from eight Indian families using Affymetrix Genome-Wide Human SNP Array 6.0 chip. Results. Our data revealed >50% of the study members carried CNVs in UGT2B genes, of which 76% showed deletion polymorphism. CNVs were observed more in UGT2B17 (76.4%) than in UGT2B15 (17.6%). Molecular network and pathway analysis found enrichment related to steroid metabolic process, carboxylesterase activity, and sequence specific DNA binding. Interpretation and Conclusion. We report the presence of UGT2B gene deletion and duplication polymorphisms in Indian families. Network analysis indicates the substitutive role of other possible genes in the UGT activity. The CNVs of UGT2B genes are very common in individuals indicating that the effect is neutral in causing any suspected diseases.
Journal Article