269 research outputs found
ANTIBACTERIAL ACTIVITY OF THE WHOLE PLANT OF CARALLUMA NILAGIRIANA KUMARI ET SUBBA RAO – AN ENDEMIC MEDICINAL PLANT SPECIES.
The methanolic, aqueous and chloroform extracts of the endemic medicinal plant species of Caralluma nilagiriana were studied for antibacterial activities against five microorganisms. The zone of inhibition of various extracts was compared with standard tetracycline(30µg/ml). The antibacterial activity justifies its use in traditional medicine. In Salmonella typhi. Escherichia. coli, and Staphylococcus aureus all the three extracts(30µg/ml) was found to have significant antimicrobial activity, but less than that of standard tetracycline. In Klebsiella pneumonia all the three extracts were highly active when compared to standard. But in Pseudomonas aeroginosa the methanolic extracts strongly inhibited the colonial growth against the standard.The other two extracts found to have antimicrobial potency but less than that of standard
Synthesis and Structural Studies of Nanocrystalline Cd0.3Zn0.7Fe2O4
The synthesis of Cd0.3Zn0.7Fe2O4 nanoparticles has been achieved by a simple thermal decomposition method from the inorganic precursor, Cdd0.3Zn0.7Fe2(cin)3(N2H4)2, which was obtained by a novel precipitation method from the corresponding metal salts, cinnamic acid and hydrazine hydrate. The precursor was characterized by hydrazine and metal analyses, infrared spectral analysis and thermogravimetric analysis. Under appropriate annealing conditions, Cd0.3Zn0.7Fe2(cin)3(N2H4)2 yielded Cd0.3Zn0.7Fe2O4 nanoparticles, which were characterized for their size and structure using X-Ray Diffraction (XRD), High Resolution Transmission ElectronMicroscopic(HRTEM),SelectedArea ElectronDiffraction(SAED)andScanning ElectronMicroscopic(SEM)techniques.KEYWORDS: Cd0.3Zn0.7Fe2O4 nanoparticles, XRD, HRTEM, SAED, SEM
In vitro micropropagation of orchid, Oncidium sp. (Dancing Dolls)
A successful procedure was established for in vitro mass multiplication of orchid (Oncidium sp.). In vitro regeneration multiplication and rooting of plantlets were achieved from the immature seeds on Murashige and Skoog's medium supplemented with BAP (2.0 mg/l). Rooted plantlets were then transferred to perforated plastic pots and grown in the green house
In vitro micropropagation of Musa sapientum L. (Cavendish Dwarf)
A complete protocol for micropropagation of Musa sapientum using shoot meristems was developed. Multiple shoots were induced in vitro from shoot meristems. Murashige and Skoog’s medium supplemented with BAP and NAA (3.0 + 0.2 mg/l, respectively) was found to be most suitablecombination. Further multiplication of shoots required habituation of cultures up to 3 passages of 21 days each on the same medium after establishment of culture and initiation of shoot buds. Thereafter 3-fold multiplication rate was achieved during every subculture. For rooting the shoots were excised and transferred to same medium. Rooted plantlets were then transferred to primary and secondary hardening and grown in the green house. These hardened plants have been successfully established insoil
Antimicrobial and antioxidant activities of salt stress callus of Brinjal (Solanum melongena L.)
Ethanolic and methanolic salt stress callus extracts of Solanum melongena L. were tested for in vitro antimicrobial and free radical scavenging assayssuch as DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS+(2,2\u27Azinobis (3-ethyl benzo-thizoline-6-sulfonic acid) . In both the extracts the zone of inhibition is higher in Escherichia coli, Klebsiella pneumonia, Staphylococcus aureusand Streptococcus pyogenesat 90 µl concentration against the control. The antifungal activity of these extracts also the zone of inhibition is higher at 90 µl concentration against the control. The DPPH activity of different concentration of solvent extracts (1 mg/ml to 5 mg/ml) along with standard ascorbic acid among the five different concentration (50 µg/ml to 250 µg/ml) of extracts tested, the higher percentage of inhibition was observed in 250 µg/ml of methanol extract followed by ethanolic extract against the standard ascorbic acid. In ABTS+ activity the absorbance was increased with the increasing concentrations of both methanolic and ethanolic callus extracts
Experimental cultivation of Gracilaria edulis at Valinokkam Bay
Experimental field cultivation of the agar yielding red alga Gracilaria edulis was carried out
at Valinokkam Bay from May 1992 to April 1994 at 1.5 to 3.0 m depths using 2x2 m size coir rope nets
fabricated with 1" thick coir ropes and 1" thick long line coir ropes. The seedlings cultured on nets and
long line ropes during May to December in 1992 and 1993 degenerated due to sedimentation and low
light intensity. The growth of G. edulis seedlings from January to April during 1993 and 1994 was good
and reached harvestable size of 14.4 cm and 22.9 cm (mean length) after 45 and 90 days respectively.
Harvest could not be made, as many of the grown up plants were grazed by fishes. Data collected on
environmental and hydrological parameters from the culture site at fortnightly interval were correlated
with the growth of cultured seaweed. The result obtained in this experiment is compared with the results
on the experimental field cultivation of G.edulis carried out in the near shore areas of Mandapam and
lagoon of Minicoy and Lakshadwee
A Study on Lapsation of Insurance Polices of Select Insurance Companies
Purpose: Lapsation is the discontinuation of payment of premia for reasons other than the death of a policy holder. A majority of insurance companies notice that half of their policyholders do not pay their insurance premia regularly leading to an increase in lapsation of policies. Increase in lapsation not only affects the policyholders’ welfare but also insurance companies’ business growth. So, the present study was carried out to determine where lapsation rate is high and to offer solutions to reduce the rate of lapsation.
Design/Methodology/Approach: The present study is descriptive in nature. A carefully constructed questionnaire was used to gather the study's pertinent data. Data were collected from life insurance company employees in Tamilnadu using the convenience sampling method. The questionnaire includes inquiries about different policy kinds, distribution methods, agent information, and different commission structures.
Findings: Result of cross tabulation discloses that high rate of lapsation rate is noticed with term and endowment insurance policies both at LIC and private insurance companies. High rate of lapsation is noticed under insurance policies distributed by direct sale teams of insurance companies. Further, it is noticed that lapsation rate is high in Private insurance companies, where insurance agents receive low commission. Lapsation rate is low at Public and Private Insurance companies, where insurance agents receive high and moderate level of commission.
Practical Implications: The result of the study will be immensely useful to policyholders in particular and insurance companies in general. Reduction in policy lapsation rate will assist policyholder to reap the benefit of availing insurance policies and aids life insurance companies to expand their business volume to a greater extent.
Social Implications: Life insurance companies not only safeguard interest of policyholders but also invests their excess amount of premium in corporate securities, thereby assists not only growth of industries but also Indian economy as well. Lapsation of insurance policies may affect transfer of excess premium towards industry investment. Thus, the present study assist to understand the reason for lapsation of policies and to offer suitable suggestions to reduce rate of lapsation and assist not only growth of insurance companies but also economy too.
Originality/Value: Questionnaire is employed for collecting first hand data. By contacting the life insurance company employees in person data required for the study has been gathered
Ultrasonic technology applied against mosquito larvae
The effective management of mosquito vectors is a timely challenge for medical and veterinary entomology. In this study, we evaluated the acoustic Larvasonic device to control young instars of the mosquito Aedes aegypti in diverse freshwater environments. Under laboratory conditions, we investigated the effect of exposure time and distance from the transducer on the mortality of larvae and pupae of Ae. aegypti. Furthermore, we evaluated the effectiveness of the ultrasound window of the electromagnetic spectrum under different field conditions. Results showed that first and second instar larvae were more sensitive to the frequency range of 18-30 kHz of the Larvasonic device. Ultrasonic waves applied for 180 s at a frequency from 18 to 30 kHz caused 100% larval mortality at a distance of 60 cm from the transducer. No mortality was observed in the non-target copepod Megacyclops formosanus. The exposure to the soundwaves produced by the acoustic larvicidal device over different distances effectively damaged Ae. aegypti through destruction of the larval dorsal tracheal trunk, thorax and abdomen. Overall, results indicated that the Larvasonic device tested can provide an alternative tool to reduce young instar populations of Ae. aegypti, without any effects on non-target aquatic invertebrates like copepods. It turned out to be a useful device for mosquito biocontrol. This technology has a relevant potential to fight the spread of mosquito-borne diseases
Seaweed resources of the Tuticorin-Tiruchendur coast, Tamil Nadu, India
The southern coast of Tamil Nadu (Mandapam to Kanyakumari) supports luxuriant growth
of economic seaweeds. The entire indigenous phycocoUoid industry of the country gets the raw
material from this region and during the last two decades, due to indiscriminate harvesting, there
has been over-exploitation of the resource. The present paper deals with survey conducted in the
first sector from Tuticorin to Tiruchendur during December 1986—March 1987. In this study 58
species of marine algae were recorded of which 7 belong to Chlorophyta, 12 to Phaeophyta and 39
to Rhodophyta besides 3 species of seagrasses namely Cymodocea seiriilata, Halophila ovalis and //.
ovata within 650 sq. km area surveyed. The total standing crop of the seaweeds was estimated at 9,100
tonnes (wt.). The estimates for the dominant species are Dictyota maxima 530 t, Sargassum tenerrium
640 t, D. bartayresiana 8601, Selieria rebusta 2,0901 and Hypnea valemiae 2,4301. The seaweed potential
for commercial exploitation has been briefly discussed
Seaweeds
Research works oti various aspects of seaweeds have been
caried out since last five decades. They inchide resources survey,
studies on distribution, Uixonomy, ecology, biology, phycocolioids,
biochemicals, culture and utilisation of marine algae growing in
Tamil Nadu, Kercda, Lakshadwe^p and Andaman-Nicobar Islands.
Information was also gathered since 1978 on the quantity of
seaweeds commercially exploited from the natural seaweed beds
occurring in Tamil Nadu coast. The results obtained on these aspects
are reviewed in this paper. The prospects of seaweed research,
industry and utilisation in India are also briefly described
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