Author
S. Rajashekara
Bio: S. Rajashekara is an academic researcher from Bangalore University. The author has contributed to research in topics: Species richness & Species evenness. The author has an hindex of 7, co-authored 11 publications receiving 81 citations.
Papers
More filters
•
TL;DR: There was a variation in number of waterbird species recorded during summer, monsoon and winter seasons, and Bubulcus ibis showed cent percent frequency, whereas less frequently (4.44%) observed species was Anas platyrhynchos.
Abstract: Observations were made on the occurrence, abundance, richness, and diversity of waterbirds in 15 major lakes in Bangalore city during 2008 - 2009. During the study period 35 species of aquatic birds were recorded. The number of aquatic bird species recorded at various lakes ranged from 23 to 35. The percent abundance of waterbirds recorded in the study lakes ranged from 2.46 to 21.49 and it was significantly different (p 0.05). There was a variation in number of waterbird species recorded during summer, monsoon and winter seasons. Of the 35 waterbird species, Bubulcus ibis showed cent percent frequency, whereas less frequently (4.44%) observed species was Anas platyrhynchos . Among various waterbird species, Bubulcus ibis, Fulica atra, Tringa hypoleucos, Motacilla maderaspatensis, Phalacrocorax niger, Egretta garzetta, Charadrius dubius, Ardeola grayji, Halcyon smyrnensis and Motacilla alba were frequently encountered in most of the study lakes.
20 citations
••
TL;DR: A cytotoxic study against the breast cancer cell lines of MDAMB-231 revealed that the ZnONPs as a good anticancer agent could be sliced by all existing and metabolically active cells.
Abstract: Green synthesis has made us an exciting approach in the field of nanotechnology. Biogenic zinc oxide nanoparticles (ZnONPs) were synthesized using leaf extracts of Calotropis gigantea (L.) Dryand. in the presence of zinc nitrate hexahydrate as a precursor molecule. ZnONPs were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD) patterns, and Fourier transform infrared spectroscopy (FT-IR) analysis and further in understanding the biomedical applications of antimicrobial (minimum inhibitory concentration method) and anticancer (apoptosis assay) activities, cytology (flow cytometry) and cytotoxicity (% cell viability), deoxyribonucleic acid (DNA) fragmentation (reverse transcriptase polymerase chain reaction (RT-PCR)), and caspase assay (polymerase chain reactions (PCR)) studies. The morphology of nanoparticles was determined by SEM analysis. XRD pattern showed the value of highest peak of 36.15° with 101 plane region among the ten recorded peaks. FTIR spectrum indicated stretching vibration of O-H at 3441.77 cm−1. The antibacterial activity of biogenic ZnO nanoparticles was studied against human pathogenic bacteria—Campylobacter jejuni ATCC 29428 and Neisseria gonorrhoeae ATCC 49226—and showed 50% zone of inhibition. A cytotoxic study against the breast cancer cell lines of MDAMB-231 revealed that the ZnONPs as a good anticancer agent could be sliced by all existing and metabolically active cells. Biosynthesized ZnONPs potentially alter the apoptotic protein expression and trigger apoptosis in the MDAMB-231 cells. Therefore, the biogenic ZnO nanoparticles would be useful and have the great potential in the field of biomedical applications.
19 citations
•
TL;DR: The variation in abundance of different species of insectivorous birds was found to be dependent on the availability of variety of crops, number of nesting sites and density of perching trees in the vicinity of agro-ecosystems.
Abstract: A majority of bird species are insectivorous that check the buildup of insect pest species in agro-ecosystems. A study on insectivorous bird communities was conducted at selected ten major agro-ecosystems in the Bengaluru region. Thirty eight species of insectivorous birds belonging to 17 families under 26 genera were recorded. The number of insectivorous bird species was highest in Chandapura, Hesaraghatta and Thippagondanahalli and lowest at Sarjapura regions. The percentage of population density of insectivorous birds was highest in Hesaraghatta (14.23) and lowest at Somanahalli (6.99). The relative percent abundance of Apus affinis was highest (8.36) and it was recorded lowest (0.01) for Parus nuchalis. Muscicapidae was the most abundant family. Maximum insectivorous bird species belonged to Motacillidae and Muscicapidae (six each). The variation in abundance of different species of insectivorous birds was found to be dependent on the availability of variety of crops, number of nesting sites and density of perching trees in the vicinity of agro-ecosystems. The current study will be helpful for preparing and implementing the explicit conservation plans for insectivorous avifauna in different agro-ecosystems.
15 citations
01 Jul 2014
TL;DR: In this paper, the authors have studied the spatial and temporal variation in the occurrence, abundance, density, diversity and community composition of aquatic birds in relation to the characteristics of lakes.
Abstract: Eco - spatial and temporal variation in the occurrence, abundance, density, diversity and community composition of aquatic birds in relation to the characteristics of lakes was studied from February 2008 to January 2010 in Bengaluru city. The species diversity, evenness, and richness of waterbird species were varied among different lakes. Also, the indices of various waterbird popul ations at different lakes between two years were significantly different (paired Student’s t - test at P0.05). The decrease in an anthropogenic disturbances and an increasing water depth of lakes show positive impact on the aquatic avian density in the urban lakes. The present study clearly brought out the need for preparing and implementing the specif ic conservation plans for urban lake ecosystem.
11 citations
••
01 Dec 2018TL;DR: In this paper, the authors calculated disturbance scores for 15 lakes along a gradient from low (LDL) to high (HDL) disturbance levels based on vegetation structure and composition and found that HDL had the highest threat scores and the lowest number of waterbird species whereas LDL supported the highest number of species.
Abstract: Threats to waterbird communities on urban wetlands in the Bengaluru city, South India are poorly known We calculated disturbance scores for 15 lakes along a gradient from low (LDL) to high (HDL) disturbance levels based on vegetation structure and composition HDL had the highest threat scores and the lowest number of waterbird species whereas LDL supported the highest number of species Human activities included commercial fishing and aquaculture, and shoreline development leading to habitat fragmentation and degradation We discuss strategies for the conservation of urban wetlands and the preservation of waterbird diversity
10 citations
Cited by
More filters
01 Jun 2004
123 citations
••
TL;DR: A review of the recent advances in the synthesis, mechanism routes, characterization techniques, and applications of biosynthesized ZnO NPS in agriculture, medicine, and textile industries is presented in this paper.
Abstract: Zinc oxide nanoparticles (ZnO NPs) are one of the prominent metal oxide nanoparticles with significant applications in many industries and research institutes. Various methods of synthesis have been adopted in the production of ZnO NPs so as to meet its high demand. The environmental implications and economic challenges attached to most of the means of ZnO NPs synthesis have resulted in the quest for other alternatives with environmental and economic benefits. Interestingly, the biological method of synthesis using plant sources have been found appropriate for the production of ZnO NPs dues to its numerous health, environmental, economic, and medicinal benefits. The distinctive features of ZnO NPs synthesized using plant extracts enhanced its application in agriculture for the production of fertilizers, pesticides, and fumigants. In the field of medicine and pharmacy, phytosynthesized ZnO NPs have gained remarkable usage in the production of disinfectant, antifungal, anticancer, antioxidant, anti-inflammatory and antidiabetics agents. Despite the enlisted benefits of biosynthesized ZnO NPs, the difficulties associated with the elucidation of formation mechanism and reactions still remain unraveled. This review described the summary of the recent advances in the synthesis, mechanism routes, characterization techniques, and applications of biosynthesized ZnO NPS in agriculture, medicine, and textile industries.
74 citations
••
TL;DR: In this article , the potential biomedical applications of green synthesized zinc oxide nanoparticles (ZnO-NPs) have been investigated, which shows that they have outstanding potential as a potent biological agent, as well as related hazardous properties.
Abstract: The field of nanotechnology is concerned with the creation and application of materials having a nanoscale spatial dimensioning. Having a considerable surface area to volume ratio, nanoparticles have particularly unique properties. Several chemical and physical strategies have been used to prepare zinc oxide nanoparticles (ZnO-NPs). Still, biological methods using green or natural routes in various underlying substances (e.g., plant extracts, enzymes, and microorganisms) can be more environmentally friendly and cost-effective than chemical and/or physical methods in the long run. ZnO-NPs are now being studied as antibacterial agents in nanoscale and microscale formulations. The purpose of this study is to analyze the prevalent traditional method of generating ZnO-NPs, as well as its harmful side effects, and how it might be addressed utilizing an eco-friendly green approach. The study’s primary focus is on the potential biomedical applications of green synthesized ZnO-NPs. Biocompatibility and biomedical qualities have been improved in green-synthesized ZnO-NPs over their traditionally produced counterparts, making them excellent antibacterial and cancer-fighting drugs. Additionally, these ZnO-NPs are beneficial when combined with the healing processes of wounds and biosensing components to trace small portions of biomarkers linked with various disorders. It has also been discovered that ZnO-NPs can distribute and sense drugs. Green-synthesized ZnO-NPs are compared to traditionally synthesized ones in this review, which shows that they have outstanding potential as a potent biological agent, as well as related hazardous properties.
72 citations
••
TL;DR: It is suggested that regulating hydrological regime was crucial in management works and could offer scientific information for species conservation in the context of habitat changes in East Dongting Lake wetland and provide potential insights into habitat management in this area.
37 citations