Semi-supervised and Active-learning Scenarios: Efficient Acoustic Model Refinement for a Low Resource Indian Language

We address the problem of efficient acoustic-model refinement (continuous retraining) using semi-supervised and active learning for a low resource Indian language, wherein the low resource constraints are having i) a small labeled corpus from which to train a baseline `seed' acoustic model and ii) a large training corpus without orthographic labeling or from which to perform a data selection for manual labeling at low costs. The proposed semi-supervised learning decodes the unlabeled large training corpus using the seed model and through various protocols, selects the decoded utterances with high reliability using confidence levels (that correlate to the WER of the decoded utterances) and iterative bootstrapping. The proposed active learning protocol uses confidence level based metric to select the decoded utterances from the large unlabeled corpus for further labeling. The semi-supervised learning protocols can offer a WER reduction, from a poorly trained seed model, by as much as 50% of the best WER-reduction realizable from the seed model's WER, if the large corpus were labeled and used for acoustic-model training. The active learning protocols allow that only 60% of the entire training corpus be manually labeled, to reach the same performance as the entire data

Evaluation of different media for cell proliferation in mantle tissue culture of the green mussel, Perna viridis (Linnaeus, 1758)

The aim of the present study was to establish a suitable culture system for tissue explants from the mantle of the green mussel, Perna viridis. The experiments were conducted using healthy, live green mussels in the size range of 75 to 110 g collected from Pulicat Lake, Tamil Nadu. Three different culture media namely M199, Leibovitz L-15 and sterile seawater were used to assess the most suitable medium for growth, proliferation and viability of mantle epithelial cells. The effect of the addition of two supplements viz., 10% foetal calf serum (FCS) and 0.1% yeast extract to the culture media was also evaluated. After carefully isolating the pallial layer from the mantle tissue, 1-2 mm2 size explants were successfully cultured in 12-well plates at 25°C for up to 14 days. Cultures were monitored under light and phase contrast objectives in an inverted microscope. Cell counts were made and cell size was measured for each treatment. Cells were observed to migrate from the periphery of the explant within 24 h after initiation of cultures. The liberated cells were mostly round and were either granulocytes or hyalinocytes. Fibroblast-like cells were also observed. Our results showed that proliferation of epithelial cells from mantle tissue was maximum in seawater medium (7.4x104 cells ml-1), followed by L-15 medium (2.55x104 cells ml-1). Average cell size in seawater medium was 10.72 μm and that in L-15 and M199 media was 8.56 and 6.39 μm, respectively. Adherent cells were also more prominent and higher in number in seawater medium. Supplementation of culture media with 10% FCS and 0.1% yeast extract improved both cell proliferation and cell size in all the three culture media. Four concentrations of 0.1% yeast extract (@ 50 μl, 75 μl, 100 μl, 150 μl ml-1 medium) were tested in the present study and best results were obtained with 100 μl ml-1, with respect to both cell counts and size

Not Available

Not AvailableThe aim of the present study was to establish a suitable culture system for tissue explants from the mantle of the green mussel, Perna viridis. The experiments were conducted using healthy, live green mussels in the size range of 75 to 110 g collected from Pulicat Lake, Tamil Nadu. Three different culture media namely M199, Leibovitz L-15 and sterile seawater were used to assess the most suitable medium for growth, proliferation and viability of mantle epithelial cells. The effect of the addition of two supplements viz., 10% foetal calf serum (FCS) and 0.1% yeast extract to the culture media was also evaluated. After carefully isolating the pallial layer from the mantle tissue, 1-2 mm2 size explants were successfully cultured in 12-well plates at 25°C for up to 14 days. Cultures were monitored under light and phase contrast objectives in an inverted microscope. Cell counts were made and cell size was measured for each treatment. Cells were observed to migrate from the periphery of the explant within 24 h after initiation of cultures. The liberated cells were mostly round and were either granulocytes or hyalinocytes. Fibroblast-like cells were also observed. Our results showed that proliferation of epithelial cells from mantle tissue was maximum in seawater medium (7.4x104 cells ml-1), followed by L-15 medium (2.55x104 cells ml-1). Average cell size in seawater medium was 10.72 μm and that in L-15 and M199 media was 8.56 and 6.39 μm, respectively. Adherent cells were also more prominent and higher in number in seawater medium. Supplementation of culture media with 10% FCS and 0.1% yeast extract improved both cell proliferation and cell size in all the three culture media. Four concentrations of 0.1% yeast extract (@ 50 μl, 75 μl, 100 μl, 150 μl ml-1 medium) were tested in the present study and best results were obtained with 100 μl ml-1, with respect to both cell counts and size.Not Availabl