40 research outputs found
Development of Phonological Processes in Typically Developing 3-4 Year Old Indian Bilingual Children
INTRODUCTION: Phonological processes are variations in the way phonemes are combined. Study of bilingualism in children is important for our understanding of language development. There is evidence that number of children who are acquiring a second language sequentially is increasing (Brice, 2002). Duchar & Clark (1992) stated that a Spanish-English bilingual child, who studied languages between the ages of 1.7 year & 2.3 years, developed separate voicing systems for two languages. Yavas (1995) studied the first 50 word period of his Portuguese/Turkish bilingual son. A study by Campbell & Sais (1995) on Italian-English bilingual preschool children shows their competency was nearly equal in both the languages. In India, a study on simultaneous bilinguals was done by Chengappa & Thirumalai (1972) on a Kodava-Kannada bilingual child who shows that the vowel contrasts were similar in Kodava and Kannada. Mala (2001) studied development of phonological processes in 3-4 year old Tulu â Kannada normal bilingual children. In countries like India, children are often exposed to more than one or two languages. There is a scarcity of studies on normative information on development of phonological processes in bilingual children in Indian context. Hence, there is a need of the present study. AIMS To study the development of phonological processes in typically developing 3-4 year Kannada- English bilingual children. To compare the obtained results with the reports of monolingual Kannada speaking children of the same age group. METHOD: Ten typically developing Kannada- English speaking bilingual children in the age range of 3-3.6 & 3.6 to 4 years, served as the subjects. Mother-tongue of the children was Kannada (L1) and the second language, English (L2). All children attended English Medium School for their kindergarten education, but the speaking language at home was Kannada. All children were exposed to English all the time at school by teachers and their peer group. Also children had a regular exposure to English programs on Television. Spontaneous speech samples of ten minutes were collected in both the languages (L1 & L2). The tasks were; General conversation, Story narration and Picture description tasks were given where the clinician used picture books and asked the child to describe what was happening in the presented picture. Clinician showed some flash cards of lexical items and children were asked to identify it and express the target lexical items. Articulation tests, Kannada Articulation Test (Ratna & Bettagiri, 1972) & Goldmann Fristoe Articulation Test (English) [Goldman & Fristoe, 1986] were administered. Spontaneous speech samples obtained both in L1 & L2 was analyzed to study various types of phonological processes and the frequency of their occurrence. RESULTS: Results revealed a total of 14 phonological processes have been identified to be occurring. The most commonly occurring processes were fronting, cluster reduction, Epenthesis, initial consonant deletion, affrication, metathesis and final consonant deletion. The least occurring processes were medial consonant deletion, backing of stops, alveolar assimilation, stopping & backing of fricatives, and vowel unrounding. Medial consonant deletion, stopping and alveolar assimilation were the unique processes found only in one subject each. Further, results of the present study were compared with previous findings on Tulu-Kannada bilinguals (Mala, 2001) & Kannada monolingual speaking children (Sunil, 1995) of the same age group. One sample t-test was carried out and results revealed that there was a significant difference seen in Kannada-English bilinguals and Tulu-Kannada bilinguals for fronting, cluster reduction, affrication, medial consonant deletion and epenthesis. On comparing Kannada-English bilinguals and Kannada monolinguals, there was a significant difference seen in fronting, cluster reduction and final consonant deletion. DISCUSSION: Results of the present study on commonly occurring phonological processes are in agreement with the study done by Stoel-Gammon (1985), Roberts & Foot (1990), Louke (1990) & Mala (2001). As the age advanced from 3 -4 years, Fronting, cluster reduction, initial consonant deletion and final consonant deletion persisted even at the age of 4 years because the clusters are acquired at a later age and also the acquisition of all phonemes is not complete by 4 years of age. As the age advances, the phonological process decreases because the acquisition of affricates and stops occur. Most of the phonological processes were less often in bilingual children than in monolingual children of the same age group. This supports the findings of Flege et.al (1992), Cambell & Sias (1995), Bruck & Genesee (1995), Bailystock (2001) & Mala (2001) on monolingual & bilingual comparative studies, where the bilinguals performed better in the phonological tasks. CONCLUSION: Hence, present study on development of phonological processes described the various phonological processes occurring in 3-4 year old bilingual children and also showed that the occurrence of phonological processes in bilingual children is less often than in monolingual children of the same age group. In order to build a normative data base for the development of phonological processes in bilingual children, further studies need to be carried out among different age groups and different languages. This building up a normative data would help Speech Language Pathologists to look at the deviant patterns of of phonological processes in language disordered population
Low platelet counts in pregnancy: an alarm signal for abruption!
Background: Thrombocytopenia, defined as a platelet count less than 150 million/mm3, affects 6% to 10% of all pregnant women and other than anemia is the most common hematologic disorder in pregnancy.Methods: We studied all patients with thrombocytopenia in pregnancy from June 2012 to May 2013. There were 86 patients recruited into the study. Pregnant women with preeclampsia and suspected connective tissue disorder were also screened for thrombocytopenia. All women with platelet count of <1.50,000/”l during the study period were included.Results: Patients were grouped in to mild thrombocytopenia (platelet 100,000-149,999/”l), moderate thrombocytopenia (platelet 50,000-99,999/”l) and severe thrombocytopenia (platelet <49,999/”l. Pregnancy specific cause of thrombocytopenia was in 63 (73.2%) women and non-pregnancy specific were in 23(26.7%) patients.Conclusions: Preeclampsia and HELLP syndrome is more common cause of thrombocytopenia in pregnancy. Abruption can occur in patients with severe thrombocytopenia. Though platelet count is not routinely done in pregnancy it is advisable to do so as it may help in detecting gestational thrombocytopenia or other immune related condition
Association Between Exposure to E-Cigarette Content Across 10 Social Media Sites and Youth E-Cigarette Use
Paratope plasticity in diverse modes facilitates molecular mimicry in antibody response
The immune response against methyl-α -D-mannopyranoside mimicking 12-mer peptide (DVFYPYPYASGS) was analyzed at the molecular level towards understanding the equivalence of these otherwise disparate Ags. The Ab 7C4 recognized the immunizing peptide and its mimicking carbohydrate Ag with comparable affinities. Thermodynamic analyses of the binding interactions of both molecules suggested that the mAb 7C4 paratope lacks substantial conformational flexibility, an obvious possibility for facilitating binding to chemically dissimilar Ags. Favorable changes in entropy during binding indicated the importance of hydrophobic interactions in recognition of the mimicking carbohydrate Ag. Indeed, the topology of the Ag-combining site was dominated by a cluster of aromatic residues, contributed primarily by the specificity defining CDR H3. Epitope-mapping analysis demonstrated the critical role of three aromatic residues of the 12-mer in binding to the Ab. Our studies delineate a mechanism by which mimicry is manifested in the absence of either structural similarity of the epitopes or conformational flexibility in the paratope. An alternate mode of recognition of dissimilar yet mimicking Ags by the anti-peptide Ab involves plasticity associated with aromatic/hydrophobic and van der Waals interactions. Thus, antigenic mimicry may be a consequence of paratope-specific modulations rather than being dependent only on the properties of the epitope. Such modulations may have evolved toward minimizing the consequences of antigenic variation by invading pathogens
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Integrase residues that determine nucleotide preferences at sites of HIV-1 integration: implications for the mechanism of target DNA binding
Retroviruses favor target-DNA (tDNA) distortion and particular bases at sites of integration, but the mechanism underlying HIV-1 selectivity is unknown. Crystal structures revealed a network of prototype foamy virus (PFV) integrase residues that distort tDNA: Ala188 and Arg329 interact with tDNA bases, while Arg362 contacts the phosphodiester backbone. HIV-1 integrase residues Ser119, Arg231, and Lys258 were identified here as analogs of PFV integrase residues Ala188, Arg329 and Arg362, respectively. Thirteen integrase mutations were analyzed for effects on integrase activity in vitro and during virus infection, yielding a total of 1610 unique HIV-1 integration sites. Purine (R)/pyrimidine (Y) dinucleotide sequence analysis revealed HIV-1 prefers the tDNA signature (0)RYXRY(4), which accordingly favors overlapping flexible dinucleotides at the center of the integration site. Consistent with roles for Arg231 and Lys258 in sequence specific and non-specific binding, respectively, the R231E mutation altered integration site nucleotide preferences while K258E had no effect. S119A and S119T integrase mutations significantly altered base preferences at positions â3 and 7 from the site of viral DNA joining. The S119A preference moreover mimicked wild-type PFV selectivity at these positions. We conclude that HIV-1 IN residue Ser119 and PFV IN residue Ala188 contact analogous tDNA bases to effect virus integration
Biochemical and virological analysis of the 18-residue C-terminal tail of HIV-1 integrase
Background The 18 residue tail abutting the SH3 fold that comprises the heart of the C-terminal domain is the only part of HIV-1 integrase yet to be visualized by structural biology. To ascertain the role of the tail region in integrase function and HIV-1 replication, a set of deletion mutants that successively lacked three amino acids was constructed and analyzed in a variety of biochemical and virus infection assays. HIV-1/2 chimers, which harbored the analogous 23-mer HIV-2 tail in place of the HIV-1 sequence, were also studied. Because integrase mutations can affect steps in the replication cycle other than integration, defective mutant viruses were tested for integrase protein content and reverse transcription in addition to integration. The F185K core domain mutation, which increases integrase protein solubility, was furthermore analyzed in a subset of mutants. Results Purified proteins were assessed for in vitro levels of 3' processing and DNA strand transfer activities whereas HIV-1 infectivity was measured using luciferase reporter viruses. Deletions lacking up to 9 amino acids (1-285, 1-282, and 1-279) displayed near wild-type activities in vitro and during infection. Further deletion yielded two viruses, HIV-11-276 and HIV-11-273, that displayed approximately two and 5-fold infectivity defects, respectively, due to reduced integrase function. Deletion mutant HIV-11-270 and the HIV-1/2 chimera were non-infectious and displayed approximately 3 to 4-fold reverse transcription in addition to severe integration defects. Removal of four additional residues, which encompassed the C-terminal β strand of the SH3 fold, further compromised integrase incorporation into virions and reverse transcription. Conclusion HIV-11-270, HIV-11-266, and the HIV-1/2 chimera were typed as class II mutant viruses due to their pleiotropic replication defects. We speculate that residues 271-273 might play a role in mediating the known integrase-reverse transcriptase interaction, as their removal unveiled a reverse transcription defect. The F185K mutation reduced the in vitro activities of 1-279 and 1-276 integrases by about 25%. Mutant proteins 1-279/F185K and 1-276/F185K are therefore highlighted as potential structural biology candidates, whereas further deleted tail variants (1-273/F185K or 1-270/F185K) are less desirable due to marginal or undetectable levels of integrase function
A study on tuberculosis disease disclosure patterns and its associated factors: Findings from a prospective observational study in Chennai
BACKGROUND: Disclosure of tuberculosis (TB) status by patients is a critical step in their treatment cascade of care. There is a lack of systematic assessment of TB disclosure patterns and its positive outcomes which happens dynamically over the disease period of individual patients with their family and wider social network relations. METHODS: This prospective observational study was conducted in Chennai Corporation treatment units during 2019â2021. TB patients were recruited and followed-up from treatment initiation to completion. Information on disease disclosures made to different social members at different time points, and outcomes were collected and compared. Bivariate and multi variate analysis were used to identify the patients and contact characteristics predictive of TB disclosure status. RESULTS: A total of 466 TB patients were followed-up, who listed a total of 4039 family, extra familial and social network contacts of them. Maximum disclosures were made with family members (93%) and half of the relatives, occupational contacts and friendship contacts (44â58%) were disclosed within 15 days of treatment initiation. Incremental disclosures made during the 150â180 days of treatment were highest among neighbourhood contacts (12%), and was significantly different between treatment initiation and completion period. Middle aged TB patients (31 years and 46â55 years) were found less likely to disclose (AOR 0.56 and 0.46 respectively; p71%). CONCLUSION: Findings explain that family level disclosures were predominant and disclosures made to extra familial network contacts significantly increased during the latter part of treatment. Emotional support was predominantly received by TB patients from all their contacts post disclosure. Findings could inform in developing interventions to facilitate disclosure of disease status in a beneficial way for TB patients
An influence of dew point temperature on the occurrence of Mycobacterium tuberculosis disease in Chennai, India.
Climate factors such as dew point temperature, relative humidity and atmospheric temperature may be crucial for the spread of tuberculosis. This study was conducted for the first time to investigate the relationship of climatic factors with TB occurrence in an Indian setting. Daily tuberculosis notification data during 2008-2015 were generated from the National Treatment Elimination Program, and analogous daily climatic data were obtained from the Regional Meteorological Centre at Chennai city, Tamil Nadu, India. The decomposition method was adopted to split the series into deterministic and non-deterministic components, such as seasonal, non-seasonal, trend and cyclical, and non-deterministic climate factors. A generalized linear model was used to assess the relation independently. TB disease progression from latent stage infection to active was supported by higher dew point temperature and moderate temperature. It had a significant association with TB progression in the summer and monsoon seasons. The relative humidity may be favored in the winter and post-monsoon. The water tiny dew droplets may support the TB bacterium to recuperate in the environment