Evaluating Environmental Cues that Affect Schwann Cell Gene Expression to Enhance Peripheral Nerve Regeneration

The goal of this thesis was to evaluate the effects of different environmental cues on Schwann cell: SC) differentiation and phenotype maintenance to design better SC transplantation therapies for peripheral nerve repair. First, a set of markers, specific for motor or sensory-derived SCs were identified from the literature and gene chips. After 30 days, gene expression patterns of SCs, after expansion in culture, were dysregulated. Cues that have been hypothesized to re-differentiate the SCs in vitro are extracellular matrix: ECM) molecules, growth factors: GFs), and acetylcholine: Ach). To test the effects of ECM, SCs were transplanted into acellular nerve grafts: ANGs), which have an intact ECM, and were used to repair a 14 mm rat sciatic nerve injury. After 2 weeks, the RNA was analyzed for expression levels of GFs: nerve growth factor: NGF), brain derived neurotrophic factor: BDNF), and glial cell derived neurotrophic factor: GDNF)) and also phenotypic markers. The phenotype-specific SCs expressed higher levels of NGF, BDNF, and GDNF compared to levels in the injuries repaired with an isograft. The expression patterns of the phenotypic markers were still disrupted at 2 weeks post transplant suggesting that other cues: GFs or Ach) are necessary to promote native marker expression. The addition of GFs NGF and GDNF to SCs in culture promoted increased mature marker expression: S100) over a period of 7 days. Evaluation of expression patterns showed sensory-derived SCs treated with NGF had increased expression of sensory markers and motor-derived SCs had no detectable expression of sensory markers. GDNF promoted the correct phenotypic marker expression in both sets of SCs treated. Finally, Ach was added to motor-derived SC cultures to determine if it had an effect on the phenotypic maintenance of motor-derived SCs. In addition, Ach receptors were blocked with gallamine to test the specificity of the Ach effect. Gene expression analysis showed that Ach promoted increased expression of motor markers in motor-derived SCs, and that gallamine blocked the effects of Ach. Overall, this work has shown that environmental cues, such as ECM, GFs, and Ach affect SC phenotype and differentiation

Sea ranching of pearl oyster

Sea ranching of pearl oyste

Diasporic Language Issues in the Odum Nathi Novel

A community refers to a group of people living together. Society is formed when individuals live together as a family, group depending on each other. In such a society there are some problems due to economy. When occupational and economic problems occur, people are forced to migrate from one place to another for survival. As they move from one place to another and live there, the changes that occur there will give them a new experience. Language, food, dress, customs, everything will be new for them. Unable to mix with the people there because of language problems, geographical problems, ethnic problems, different foods and customs. Food to eat, clothes to wear and a place to stay are the essentials for a human being. Such migrants are unable to meet such basic needs. Language is a tool that helps you to express your thoughts and so language is a major problem for the migrant people. Language is the first obstacle faced by Tamils who migrate to foreign speaking states in search of survival. Tamils who go to other states are alienated from other people due to their lack of knowledge of the language spoken in that part of the state. Not knowing the language leads to various hardships. There is more mixing in spoken language than in written language. In the novel 'Odum Nathi', Selvan is a character who migrates to Nagaland, does not know the language of the tribal people and goes through various hardships. When we read the novel, we come to come to know about his sufferings in buying tickets to travel and buying food for hunger because of language problem. This article explores this kind of linguistic issues

Current status of biodiversity and health of the coral reef ecosystem of Palk Bay

The coral reefs in Palk Bay run parallel to the shore between longitudes 79°17’ E and 79°8’ E, at the latitude 9°17’ N. It lies in an east-west direction and is about 200 to 600 m away from the shore at different places at a depth of 1 to 5 m

Survey of Valinokkam Bay and adjoining area to assess its suitability for integrated sea farming — A report

The Valinokkam Bay and the adjoining area, east of the Bay surveyed, lie between Lat. 9°9' N and 9° 12' N and Long. 78°30'E and 78°42'E . The available information indicates that the bay and the adjoining grounds in the sea are highly productive and suitable for sea farming activities

Gene expression and growth factor analysis in early nerve regeneration following segmental nerve defect reconstruction with a mesenchymal stromal cell-enhanced decellularized nerve allograft

Abstract Background: The purpose of this study was to evaluate the molecular mechanisms underlying nerve repair by a decellularized nerve allograft seeded with adipose-derived mesenchymal stromal cells (MSCs) and compare it to the unseeded allograft and autograft nerve. Methods: Undifferentiated MSCs were seeded onto decellularized nerve allografts and used to reconstruct a 10 mm gap in a rat sciatic nerve model. Gene expression profiles of genes essential for nerve regeneration and immunohistochemical staining (IHC) for PGP9.5, NGF, RECA-1, and S100 were obtained 2 weeks postoperatively. Results: Semi-quantitative RT-PCR analysis showed that the angiogenic molecule VEGFA was significantly increased in seeded allografts, and transcription factor SOX2 was downregulated in seeded allografts. Seeded grafts showed a significant increase in immunohistochemical markers NGF and RECA-1, when compared with unseeded allografts. Conclusions: MSCs contributed to the secretion of trophic factors. A beneficial effect of the MSCs on angiogenesis was found when compared with the unseeded nerve allograft, but implanted MSCs did not show evidence of differentiation into Schwann cell-like cells

Speaking rate attention-based duration prediction for speed control TTS

With the advent of high-quality speech synthesis, there is a lot of interest in controlling various prosodic attributes of speech. Speaking rate is an essential attribute towards modelling the expressivity of speech. In this work, we propose a novel approach to control the speaking rate for non-autoregressive TTS. We achieve this by conditioning the speaking rate inside the duration predictor, allowing implicit speaking rate control. We show the benefits of this approach by synthesising audio at various speaking rate factors and measuring the quality of speaking rate-controlled synthesised speech. Further, we study the effect of the speaking rate distribution of the training data towards effective rate control. Finally, we fine-tune a baseline pretrained TTS model to obtain speaking rate control TTS. We provide various analyses to showcase the benefits of using this proposed approach, along with objective as well as subjective metrics. We find that the proposed methods have higher subjective scores and lower speaker rate errors across many speaking rate factors over the baseline.Comment: \c{opyright} 20XX IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work