Informatics Publishing Limited

A. Rajini ¹, K. Revathy ², G. Selvam ³

Affiliations
1 Sathyabama University, Chennai - 600119, Tamil Nadu, IN
2 Department of Advanced Zoology, Ethiraj College, University of Madras, Chennai - 600119, Tamil Nadu, IN
3 International Institute of Biotechnology and Toxicology, Padappai, Kancheepuram - 601301, Tamil Nadu, IN

Abstract

The objective of this study is to investigate in detail the histopathological changes in gill, liver, brain, spinal cord, ovary and kidney of zebra fish exposed to combination pesticide. Twenty one days semi static exposure to sublethal concentration of 8.4 and 4.2 μg/L of Chloropyrifos 50% + Cypermethrin 5% EC was conducted and it was followed with a reversal period of 7 days without pesticide in the exposure water. Three fish were collected from control and treatment group periodically. Whole body fixation of zebra fish as per OECD guidance document 123 was adopted for obtaining the histopathology sections. Structural damages of gill observed were of inflammatory cell infiltration, minimal congestion in primary lamellae, fusion of secondary lamellae, diffused epithelial hyperplasia and multifoci mucus cell hyperplasia. In liver, moderate, diffused to severe cytoplasmic vacuolation, diffused minimal to mild sinusoidal congestion, steatosis, pyknotic, karyorrhectic nuclei with complete dissolution of necrotic hepatocytes was observed. Minimal focal tubular degeneration was observed in kidney. Minimal to mild multifocal follicular atresia was observed in the ovary. In spinal cord neuronal cell degeneration, cytoplasmic vacuolation and enlargement of neuronal body was observed. In brain, mild to moderate demyelination in the neurophil and mild necrotic changes observed in the cerebrum. Some of the lesions were less pronounced after recuperation period. Pesticide in exposure water was analyzed using Agilent QQQ GC-MS/MS equipped with Election Impact Ionization mode. Limit of detection and quantification was 1 μg/L with a Correlation Co-efficient (CC) of 0.999. The recovery of active content of Chlorpyrifos for 4.2 and 8.4 μg/L at 0 hour was 88.1%, 90.3% and at 48 hour was 83.48%, 85.70%, respectively. Similarly, Cypermethrin active content recovered at 0 hour for 4.2 and 8.4 μg/L was 78.74%, 86.24% and at 48 hour was 57.85%, 62.09%, respectively. Further, this is the first study to report pathological findings in Zebrafish exposed to a combination pesticide formulation. The histopathological finding of this investigation reveals the potential toxic hazard from exposure to sub lethal level of the combination pesticide. Few literatures have reported on the mixture toxicity of pesticides and this research work throws light on histopathological lesions of Zebrafish. Further, this is the first study to report spinal lesions in fish due to pesticide exposure. Pesticides usage in pest management or in agriculture practice should be applied safely to prevent pollution and contamination.

Keywords

Combination Pesticide, Danio rerio, Histopathological Changes

Full Text

   

A. Rajini ¹, K. Revathy ², T. Chitrikha ³

Affiliations
1 Sathyabama University, Chennai - 600119, Tamil Nadu, IN
2 Department of Advanced Zoology, Ethiraj College, University of Madras, Chennai - 600008, Tamil Nadu, IN
3 International Institute of Biotechnology and Toxicology, Padappai - 601301, Tamil Nadu, IN

Abstract

Daphnia magna is ubiquitous link in ecological food chain; they are small planktonic crustacean used in ecotoxicological acute tests and chronic reproduction studies. Daphnia species are very sensitive to xenobiotics and very low concentrations will affect their survival. The objective is to investigate the toxicity and reproductive effect of Daphnia magna exposed to different concentrations of combination pesticide in M4 medium in accordance to OECD 211 guideline and in exposure water. To maintain the water hardness within the range in the exposure water as per the OECD guideline reverse osmosis water and drinking well water was blended 1:1 ratio. Twenty one days semi-static exposure was conducted with 10 daphnia held individually in each treatment and control. Daphnids were exposed to 0.0000134, 0.000134, 0.00134, 0.0134, 0.134, 1.34 and 13.4 µg/L of Chlorpyrifos 50% + Cypermethrin 5% EC. 10 µL of alga and yeast were fed with for daphnia of water and only alga was provided M4 medium during the semi-static 48 hour medium change. Agilent QQQ GC-MS/MS, Election Impact Ionization mode was used for active content analysis. Stock solution of 13.4 µg/L was analyzed for its active content chlorpyrifos and cypermethrin. At 0 hour it was 89.7%, 87.5% and at 48 hour it was 85.3%, 72.4%, respectively. 0.0000134 µg/L was below limit of quantification level. Statistical analysis was performed with ECOSTATS program version 2012.06.03 (SAS Version 9.3, SAS Institute Inc., Cary, NC, USA, 2002-2010). EC50 calculated was 0.012 µg/L for M4 medium and 0.003 µg/L for exposure water at the end of 21 days. Parental mortality of daphnia and reproduction rate decline of off-springs collected in M4 medium and exposure water was found to be dose dependent. Significant change (P < 0.05) in off-spring reproduction was observed in M4 medium and exposure water by ANOVA Student-Newman-Keuls test. Based on the EC50 it is concluded that the pesticide is toxic to daphnids exposed in water than M4 medium exposure. Pesticide mixture effects and its interactions within mixtures is an area of concern to public and regulatory authorities, hence the combined actions of pesticides need to be addressed in the risk assessment process since mixtures of these chemicals may cause higher toxicity effects than those expected from the single compounds. Endocrine disrupting chemicals are compounds that alter the normal functioning of the endocrine system of both wildlife and humans and the tested pesticide active ingredient is considered as endocrine disruptor; no reliable data is available on the reproduction effect of the combination pesticide and this experiment throws light that exposure water can also be used to assess contamination of pesticide like M4 medium which is used regularly in ecotoxicological studies for pesticide toxicity assessment

Keywords

Combination Pesticide, Daphnia Magna, Reproductive Effect, Toxicity

Full Text

   

D. Muhammad Noorul Mubarak ¹, M. Mohamed Sathik ², S. Zulaikha Beevi ³, K. Revathy ¹

Affiliations
1 Department of Computer Science, University of Kerala, Trivandrum, IN
2 Sathakathullah Appa College, Tirunelveli, Tamilnadu, IN
3 Department of IT, National College of Engineering, Tirunelveli, Tamilnadu, IN

Abstract

In this paper, we have made improvements in region growing image segmentation. The First one is seeds select method, we use Harris corner detect theory to auto find growing seeds. Through this method, we can improve the segmentation speed. In this method, we use the Improved Harris corner detect theory for maintaining the distance vector between the seed pixel and maintain minimum distance between the seed pixels. The homogeneity criterion usually depends on image formation properties that are not known to the user. We induced a new uncertainty theory called Cloud Model Computing (CMC) to realize automatic and adaptive segmentation threshold selecting, which considers the uncertainty of image and extracts concepts from characteristics of the region to be segmented like human being. Next to region growing operation, we use canny edge detector to enhance the border of the regions. The method was tested for segmentation on X-rays, CT scan and MR images. We found the method works reliable on homogeneity and region characteristics. Furthermore, the method is simple but robust and it can extract objects and boundary smoothly.

Keywords

Region Growing, Segmentation, Seeds Selection, Homogeneity Criterion, Cloud Model.

Full Text

   

K. Revathy ¹, M. Jayamohan ¹

Affiliations
1 Department of Computer Science, University of Kerala, Thiruvananthapuram, Kerala, IN

Abstract

Fractal image compression is attractive except for its high encoding time requirements. The image is encoded as a set of contractive affine transformations. The image is partitioned into non-overlapping range blocks, and a best matching domain block larger than the range block is identified. There are many attempts on improving the encoding time by reducing the size of search pool for range-domain matching. But these methods are attempting to prepare a static domain pool that remains unchanged throughout the encoding process. This paper proposes dynamic preparation of separate domain pool for each range block. This will result in significant reduction in the encoding time. The domain pool for a particular range block can be decided based upon a parametric value. Here we use classification based on local fractal dimension.

Keywords

Fractal Image Compression, Dynamic Domain Pool, RMS, Fractal Dimension.

Full Text