279 research outputs found
Studies on antibacterial activity of methanolic plant extracts
The antimicrobial activity of methanolic extracts was screened against 3 gram positive and 3 gram negative bacteria using agar well diffusion method. 80 µl of test extract was suspended in the wells. A control well is loaded with equal amount of the solvent i.e. methanol. The plates were then incubated at 37ºC for 24-48 hours. After proper incubation the plates around the extract impregnated wells and this clear zone of growth inhibition was measured in terms of diameter (mm). The inhibition zone is the mean of the three replicates, excluding the well diameter. The (-) sign indicates no activity. Only the aqueous extracts of A. nilotica (leaf and stem) and L. inermis (leaves) were found inhibitory to some of the organisms tested i.e. Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiela pneumoniae and Salmonella typhimurium. Salmonella typhimurium was only inhibited by aqueous extracts of L. inermis (leaves) whereas the rest of the aqueous extracts were found to be inactive against all the test organisms. The maximum activity was shown by aqueous extracts of L. inermis (leaf) against Staphylococcus aureus that is 1.9 mm diameter of inhibition zone and the minimum was observed in the case of aqueous extracts of Pergularia daemia (stem) i.e. 0.6 mm diameter of inhibition zone against Bacillus subtilis . Salmonella epidermidis was found to most resistance to aqueous extracts of the plant followed by Salmonella typhimurium.Keywords- antimicrobial activity; methanolic extract
Health Deficits and (the Absence of) Popular Mobilization in Brazil
The article explains why Brazil’s popular sectors made claims for health during the 1970s and why they did not do so during the 1990s. I argue that the intervention of “external actors”—better situated individuals and social groups—makes all the difference for popular mobilization. This is because they have the skills and resources to challenge dominant ideas, construct mobilization frames and inspire belief among the popular sectors that their actions can be successful. Health movements emerged in the mid-1970s with the intervention of doctors, medical students and the Catholic Church. During the 1990s, however, these external actors largely retreated from an activist role and took up more routine activities. Based on my research in Sapopemba (São Paulo), I argue that without the engagement of middle-class professionals and progressive Church officials, the popular sectors were caught in a “cognitive trap” so that they did not believe their actions would be successful
Performance Analysis of MIMO-OFDM System using MMSE Receiver
Abstract Orthogonal Frequency Division Multiplexing (OFDM) technique has been proposed a
A Survey of Email Spam Filtering Methods
E-mail is one of the most secure medium for online communication and transferring data or messages through the web. An overgrowing increase in popularity, the number of unsolicited data has also increased rapidly. To filtering data, different approaches exist which automatically detect and remove these untenable messages. There are several numbers of email spam filtering technique such as Knowledge-based technique, Clustering techniques, Learning based technique, Heuristic processes and so on. This paper illustrates a survey of different existing email spam filtering system regarding Machine Learning Technique (MLT) such as Naive Bayes, SVM, K-Nearest Neighbor, Bayes Additive Regression, KNN Tree, and rules. However, here we present the classification, evaluation and comparison of different email spam filtering system Keywords: e-mail spam, spam filtering methods, machine learning technique, classification, SVM, AN
Performance Analysis of MIMO-OFDM System using MMSE Receiver
Abstract Orthogonal Frequency Division Multiplexing (OFDM) technique has been proposed a
AODVSEC: A Novel Approach to Secure Ad Hoc on-Demand Distance Vector (AODV) Routing Protocol from Insider Attacks in MANETs
Mobile Ad hoc Network (MANET) is a collection of mobile nodes that can
communicate with each other using multihop wireless links without requiring any
fixed based-station infrastructure and centralized management. Each node in the
network acts as both a host and a router. In such scenario, designing of an
efficient, reliable and secure routing protocol has been a major challenging
issue over the last many years. Numerous schemes have been proposed for secure
routing protocols and most of the research work has so far focused on providing
security for routing using cryptography. In this paper, we propose a novel
approach to secure Ad hoc On-demand Distance Vector (AODV) routing protocol
from the insider attacks launched through active forging of its Route Reply
(RREP) control message. AODV routing protocol does not have any security
provision that makes it less reliable in publicly open ad hoc network. To deal
with the concerned security attacks, we have proposed AODV Security Extension
(AODVSEC) which enhances the scope of AODV for the security provision. We have
compared AODVSEC with AODV and Secure AODV (SAODV) in normal situation as well
as in presence of the three concerned attacks viz. Resource Consumption (RC)
attack, Route Disturb (RD) attack, Route Invasion (RI) attack and Blackhole
(BH) attack. To evaluate the performances, we have considered Packet Delivery
Fraction (PDF), Average End-to-End Delay (AED), Average Throughput (AT),
Normalized Routing Load (NRL) and Average Jitter and Accumulated Average
Processing Time.Comment: 20 Pages, 24 Figure
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