Bindhu, C V; Harilal, S S; Issac, Riju C; Geetha K, Varier; Nampoori, V P N; Vallabhan, C P G(Pramana, March , 1995)
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Abstract:
Thermal lens signals in solutions of rhodamine B laser dye in methanol are
measured using the dual beam pump-probe technique. The nature of variations of signal
strength with concentration is found to be different for 514 and 488 nm Ar + laser excitations.
However, both the pump wavelengths produce an oscillatory type variation of thermal lens
signal amplitude with the concentration of the dye solution. Probable reasons for this peculiar
behaviour (which is absent in the case of fluorescent intensity) are mentioned.
Poulose Jacob,K; Surekha, Mariam Varghese(2007 ACADEMY PUBLISHER, December 1, 2007)
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Abstract:
This paper discusses our research in developing
a generalized and systematic method for anomaly detection.
The key ideas are to represent normal program behaviour
using system call frequencies and to incorporate
probabilistic techniques for classification to detect
anomalies and intrusions. Using experiments on the
sendmail system call data, we demonstrate that concise and
accurate classifiers can be constructed to detect anomalies.
An overview of the approach that we have implemented is
provided.
Hatha, A A M; Vivekanandhan, G; Savithamani, K; Lakshmanaperumalsamy, P(Elsevier, November 27, 2001)
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Abstract:
A total of 319 strains of Aeromonas hydrophila were isolated from 536 fish and 278 prawns for a 2-year period. All the
strains were tested for resistance to 15 antibiotics and 100% of the strains was resistant to methicillin and rifampicin followed by
bacitracin and novobiocin (99%). Only 3% of the strains exhibited resistance against chloramphenicol. The multiple antibiotic
resistance (MAR) indexing of A. hydrophila strains showed that all of them originated from high-risk sources
Description:
International Journal of Food Microbiology 76 (2002) 165– 168
Hatha, A A M; Divya, P Sukumaran; Srinivasan, Durairaj(Hindawi Publishing Corporation, July 31, 2012)
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Abstract:
This study aimed at detecting the prevalence of antibiotic-resistant serotypes of Escherichia coli in Cochin estuary, India. E. coli
strains were isolated during the period January 2010–December 2011 from five different stations set at Cochin estuary. Water
samples from five different stations in Cochin estuary were collected on a monthly basis for a period of two years. Isolates were
serotyped, antibiogram-phenotyped for twelve antimicrobial agents, and genotyped by polymerase chain reaction for uid gene
that codes for β-D-glucuronidase. These E. coli strains from Cochin estuary were tested against twelve antibiotics to determine
the prevalence of multiple antibiotic resistance among them. The results revealed that more than 53.33% of the isolates were
multiple antibiotic resistant. Thirteen isolates showed resistance to sulphonamides and two of them contained the sul 1 gene.
Class 1 integrons were detected in two E. coli strains which were resistant to more than seven antibiotics. In the present study,
O serotyping, antibiotic sensitivity, and polymerase chain reaction were employed with the purpose of establishing the present
distribution of multiple antibiotic-resistant serotypes, associated with E. coli isolated from different parts of Cochin estuary.
Description:
Interdisciplinary Perspectives on Infectious Diseases
Volume 2012, Article ID 124879, 7 pages
Hatha, A A M; Vivekanandhan, A A; Julie Joice, G; Christol(Elsevier, May 28, 2004)
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Abstract:
Motile aeromonads isolated from the intestines of farm-raised freshwater fish such as Catla catla, Labeo rohita and
Ctenopharyngodon idella have been characterized to species level. Morphological and physiological grouping revealed 61%
Aeromonas hydrophila, 30% Aeromonas caviae, 7% Aeromonas sobria and 2% which remained unidentified. Hemolytic
activity was detected mostly in A. hydrophila, while only half of the A. sobria and A. caviae showed this activity. Antibiotic
resistance patterns of the strains revealed that they had acquired a relatively higher resistance to oxytetracycline, amoxycillin,
ampicillin, novobiocin and polymixin-B, implicating possible use of these antibiotics in the aquaculture systems.
Description:
International Journal of Food Microbiology 98 (2005) 131– 134
Jayaprakash, N S; Bright Singh, I S(School of Environmental Studies, 2005)
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Abstract:
The main objective of the work undertaken here was to develop an appropriate microbial technology to protect the larvae of M.rosenbergii in hatchery from vibriosis. This technology precisely is consisted of a rapid detection system of vibrios and effective antagonistic probiotics for the management of vibrios. The present work was undertaken with the realizations that to stabilize the production process of commercial hatcheries an appropriate, comprehensive and fool proof technology is required primarily for the rapid detection of Vibrio and subsequently for its management. Nine species of Vibrio have been found to be associated with larvae of M. rosenbergii in hatchery. Haemolytic assay of the Vibrio and Aeromonas on prawn blood agar showed that all isolates of V. alginolyticus and Aeromonas sp., from moribund, necrotized larve were haemolytic and the isolates of V.cholerae, V.splendidus II, V.proteolyticus and V.fluvialis from the larvae obtained from apparently healthy larval rearing systems were non-haemolytic.
Hydrolytic enzymes such as lipase, chitinase and gelatinase were widespread amongst the Vibrio and Aeromonas isolates. Dominance of V.alginolyticus among the isolates from necrotic larvae and the failure in isolating them from rearing water strongly suggest that they infect larvae and multiply in the larval body and cause mortality in the hatchery. The observation suggested that the isolate V. alginolyticus was a pathogen to the larvae of M.rosenbergii. To sum up, through this work, nine species of Vibrio and genus Aeromonas associated with M.rosenbergii larval rearing systems could be isolated and segregated based on the haemolytic activity and the antibodies (PA bs) for use in diagnosis or epidemiological studies could be produced, based on a virulent culture of V.alginolyticus. This could possibly replace the conventional biochemical tests for identification. As prophylaxis to vibriosis, four isolates of Micrococcus spp. and an isolate of Pseudomonas sp. could be obtained which could possibly be used as antagonistic probiotics in the larval rearing system of M.rosenbergii.
Bright Singh, I S; Rosamma, Philip; Swapna, Antony P; Valsamma, Joseph(Elsevier, June 21, 2011)
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Abstract:
White Spot Syndrome Virus (WSSV) is the most devastating disease affecting shrimp culture around the
world. Though, considerable progress has been made in the detection and molecular characterization of WSSV
in recent years, information pertaining to immune gene expression in shrimps with respect to WSSV infection
remains limited. In this context, the present study was undertaken to understand the differential expression
of antimicrobial peptide (AMP) genes in the haemocytes of Penaeus monodon in response to WSSV infection
on a time-course basis employing semi-quantitative RT-PCR. The present work analyzes the expression profile
of six AMP genes (ALF, crustin-1, crustin-2, crustin-3, penaeidin-3 and penaeidin-5), eight WSSV genes (DNA
polymerase, endonuclease, immediate early gene, latency related gene, protein kinase, ribonucleotide
reductase, thymidine kinase and VP28) and three control genes (18S rRNA, β-actin and ELF) in P. monodon in
response to WSSV challenge. Penaeidins were found to be up-regulated during early hours of infection and
crustin-3 during late period of infection. However, ALF was found to be up-regulated early to late period of
WSSV infection. The present study suggests that AMPs viz. ALF and crustin-3 play an important role in
antiviral defense in shrimps. WSSV gene transcripts were detected post-challenge day 1 itself and increased
considerably day 5 onwards. Evaluation of the control genes confirmed ELF as the most reliable control gene
followed by 18S rRNA and β-actin for gene expression studies in shrimps. This study indicated the role of
AMPs in the protection of shrimps against viral infection and their possible control through the up-regulation
of AMPs
Antimedian graphs are introduced as the graphs in which for every triple
of vertices there exists a unique vertex x that maximizes the sum of the
distances from x to the vertices of the triple. The Cartesian product of
graphs is antimedian if and only if its factors are antimedian. It is proved
that multiplying a non-antimedian vertex in an antimedian graph yields
a larger antimedian graph. Thin even belts are introduced and proved to
be antimedian. A characterization of antimedian trees is given that leads
to a linear recognition algorithm.
Bright Singh, I S; Anas, A; Paul, S; Jayaprakash, N S; PhIlip, R(Inter-Research, November 9, 2005)
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Abstract:
Chitosan is a biocompatible and biodegradable natural polymer with established
antimicrobial properties against specific microorganisms. The present study demonstrates its
antibacterial activity against 48 isolates of Vibrio species from prawn larval rearing systems. The
antibacterial activity had a positive correlation with the concentration of chitosan. This work opens
up avenues for using chitosan as a prophylactic biopolymer for protecting prawn larvae from
vibriosis.
Rosamma, Philip; Kumar, S; Achuthankutty, C T(2006)
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Abstract:
Aquaculture farms, particularly in Southeast Asia are
facing severe crisis due to increasing incidences of
White Spot Syndrome Virus (WSSV). Actinomycetes
have provided many important bioactive compounds of high prophylactic and therapeutic value and are
continually being screened for new compounds. In this
communication, the results of a study made to determine
the effectiveness of marine actinomycetes against the white spot disease in penaeid shrimps are presented.
Twenty-five isolates of actinomycetes were tested for
their ability to reduce infection due to WSSV among
cultured shrimps. When these actinomycetes were
made available as feed additives to the post-larvae of
the black tiger shrimp Penaeus monodon for two weeks and challenged with WSSV, the post challenge survival
showed variations from 11 to 83%. However, six
isolates have shown to be the most potential candidates
for further study.
Bright Singh, I S; Rosamma, Philip; Sudheer, N S(Springer, May 29, 2012)
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Abstract:
White spot syndrome virus (WSSV), the most
contagious pathogen of cultured shrimp, causes mass
mortality, leading to huge economic loss to the shrimp
industry. The lack of effective therapeutic or prophylactic
measures has aggravated the situation, necessitating the
development of antiviral agents. With this objective, the
antiviral activity in the aqueous extract of a mangrove plant
Ceriops tagal in Penaeus monodon was evaluated. The
Ceriops tagal aqueous extract (CTAE) was non-toxic to
shrimps at 50 mg/ml when injected intramuscularly at a
dosage of 10 lL/animal (0.5 mg/animal) and showed a
protective effect against WSSV at 30 mg/ml when mixed
with WSSV suspension at a 1:1 ratio. When the extract was
administered along with the diet and the animals were
challenged orally, there was a dose-dependent increase in
survival, culminating in 100 % survival at a concentration
of 500 mg/kg body weight/day. Neither hypertrophied
nuclei nor the viral envelope protein VP28 could be demonstrated
in surviving shrimps using histology and indirect
immunofluorescence histochemistry (IIFH), respectively.
To elucidate the mode of action, the temporal expression of
WSSV genes and shrimp immune genes, including antimicrobial
peptides, was attempted. None of the viral genes
were found to be expressed in shrimps that were fed with
the extract and challenged or in those that were administered
CTAE-exposed WSSV. The overall results suggest
that the aqueous extract from C. tagal can protect
P. monodon from white spot syndrome virus infection.
Description:
Arch Virol (2012) 157:1665–1675
DOI 10.1007/s00705-012-1346-3