309 research outputs found
Image Encryption Based on Diffusion and Multiple Chaotic Maps
In the recent world, security is a prime important issue, and encryption is
one of the best alternative way to ensure security. More over, there are many
image encryption schemes have been proposed, each one of them has its own
strength and weakness. This paper presents a new algorithm for the image
encryption/decryption scheme. This paper is devoted to provide a secured image
encryption technique using multiple chaotic based circular mapping. In this
paper, first, a pair of sub keys is given by using chaotic logistic maps.
Second, the image is encrypted using logistic map sub key and in its
transformation leads to diffusion process. Third, sub keys are generated by
four different chaotic maps. Based on the initial conditions, each map may
produce various random numbers from various orbits of the maps. Among those
random numbers, a particular number and from a particular orbit are selected as
a key for the encryption algorithm. Based on the key, a binary sequence is
generated to control the encryption algorithm. The input image of 2-D is
transformed into a 1- D array by using two different scanning pattern (raster
and Zigzag) and then divided into various sub blocks. Then the position
permutation and value permutation is applied to each binary matrix based on
multiple chaos maps. Finally the receiver uses the same sub keys to decrypt the
encrypted images. The salient features of the proposed image encryption method
are loss-less, good peak signal-to-noise ratio (PSNR), Symmetric key
encryption, less cross correlation, very large number of secret keys, and
key-dependent pixel value replacement.Comment: 14 pages,9 figures and 5 tables;
http://airccse.org/journal/jnsa11_current.html, 201
ASPERGILLUS FLAVUS MEDIATED SILVER NANOPARTICLES SYNTHESIS AND EVALUATION OF ITS ANTIMICROBIAL ACTIVITY AGAINST DIFFERENT HUMAN PATHOGENS
Objective: Here, we report the extracellular synthesis of silver nanoparticles (AgNPs) using the cell-free extract of fungal isolate Aspergillus flavus and evaluation its inhibitory activity against bacterial pathogens.
Methods: Synthesized AgNPs was characterized via high throughput instrumentation such as UV–Visible spectrophotometer (UV-Vis) and Fourier transform infrared spectroscopy, High-resolution transmission electron microscopy (HRTEM), X-ray Diffraction (XRD) and Energy dispersive X-ray spectroscopy (EDAX).
Results: Formation of yellowish brown colour clearly indicates the synthesis of AgNPs which produces a SPR peak at 420 nm. Active protein metabolites present in the cell-free extract plays a crucial role in reduction and stabilization of AgNPs. It was clearly observed that synthesized AgNPs were faced-centered cubic crystalline in nature with the mean size of 22±11 nm. Further, synthesized AgNPs capped with protein moieties exhibits excellent inhibitory activity against tested bacterial pathogens.
Conclusion: In this study, we have isolated the fungal strain A. flavus from the infected larvae of D. eucharis from the soil. The active metabolites of isolated A. flavus have been successfully used as an eco-friendly reducing agent to generate AgNPs and synthesized particles can be potentially developed as a drug candidature for antimicrobial therapy
1-Methoxy-4-({[(4-methoxyphenyl)sulfanyl](phenyl)methyl}sulfanyl)benzene
The title compound, C21H20O2S2, forms a propeller-shaped structure with the tetrahedral C atom as the central hub and methoxybenzene and phenyl residues as radiating blades. Short C—H⋯π contacts are observed
Diversity of Ascidians from the Great Nicobar Biosphere Reserve (GNBR), India
The Great Nicobar Biosphere Reserve nurtures a diverse amount of life and is very importantto the biological diversity of India. Ascidians diversity has been recorded for the first timefrom the Great Nicobar Biosphere Reserve. In the present study, 15 species of ascidians werenoticed in both intertidal and sub-tidal regions of GNBR, belonging to two orders, threesuborders, six families and ten genera (Didemnum fulgens, Didemnum vexillum, Didemnumgranulatum, Didemnum albidum, Didemnum candidum, Trididemnum cyanophorum,Diplosoma simile, Diplosoma spongiforme, Clavelina oblonga, Aplidium fuscum, Synoicumcastellatum, Pycnoclavella diminuta, Ascidia virginea, Ascidiella aspersa and Styela sp.)during the year 2013-2014 of which, the Didemnidae family was recorded with the highdiversity of 15 species. Species richness were highly recorded in Bquary Beach and lowlyrecorded from Campbell Bay. The present data suggests that GNBR coast offers a uniqueopportunity for future research on the ascidians diversity and ecology assessment.Keywords: Ascidians, Biodiversity, GNB
Characterization of Salivary Glutathione reductase in Normal Individuals and its Implications on Smokers
Abstract: The assay of saliva is an increasing area of research with implications for basic and clinical purposes. Although this biological fluid is easy to manipulate and collect, careful attention must be directed to limit variation in specimen integrity. In this study, glutathione reductase (GR) activity of saliva obtained from smokers and non smokers of both the sex of various age groups were assessed. The investigation of salivary GR from non smokers revealed a pH optimum of 6.8, temperature optimum as 37ºC and a low K m of 0.058 mM for the substrate (Oxidized glutathione, GSSG). A significant reduction in the salivary GR activity has been observed from smokers of both acute and chronic than the non smokers. A drastic decrease in the GR activity was noticed in chronic smokers than the acute smokers, proving the possibility of utilizing the enzyme as a diagnostic biomarker for detecting the oral, throat and neck cancers. This optimized developed protocol was also found to be simple and cost effective
Utilization of Marine Fishery Wastes for Protease Production by Halophilic Bacterium Halolactibacillus Miurensis RSK CAS7- A Microbial Approach
The marine wastes generates 50–60% of the total weight of shell fish as waste consists of protein (35–50%), chitin (15–25% of dry weight) which considered as major environmental pollutants due to uncontrolled dumping. The utilisation of marine waste not only solves environmental problems but also decreases the production costs of microbial products. So far in this study, halophilic bacterium was isolated from marine ascidians and identified as Halolactibacillus miurensis RSK CAS7 through 16S rRNA sequence. The effect of different marine wastes such as shrimp shell powder (SSP), crab shell powder (CSP), squid pen powder (SPP), sardinella powder, tuna powder and anchovy powder were tested on protease production. Among these Sardinella powder (579.46 U/ml) and shrimp shell powder (470.36 U/ml) showed maximum level of protease production and followed by other marine wastes. All the significant nutrients identified from the preliminary screening were further screened by using Plackett - Burman Design and it resulted sardinella powder, K2HPO4,NaCl and pH were the highly influencing factors and their concentration were further optimized by using central composite design. Central composite design revealed that four independent variables such as Sardinella powder (14.21 g/l), K2HPO4 (3.81 g/l), NaCl (154.1 g/l) and pH (9.0) were significantly influenced the protease production. With these optimum concentration levels, the maximum protease production (1,794.41 U/ml) was observed. Thus, protease production by microbial conversion of marine wastes suggested its potential utilisation for the production of high value products.Keywords: Waste Management, Protease, Marine Wastes, Halophilic Bacteri
Comparative Profiling of Volatile Compounds in Popular South Indian Traditional and Modern Rice Varieties by Gas Chromatography–Mass Spectrometry Analysis
Rice (Oryza sativa L.) is one of the major cereal crops cultivated across the world,
particularly in Southeast Asia with 95% of global production. The present study was
aimed to evaluate the total phenolic content (TPC) and to profile all the volatile
organic compounds (VOCs) of eight popular traditional and two modern rice varieties
cultivated in South India. Thirty-one VOCs were estimated by gas chromatography–mass
spectrometry (GC-MS). The identified volatile compounds in the 10 rice varieties belong
to the chemical classes of fatty acids, terpenes, alkanes, alkenes, alcohols, phenols,
esters, amides, and others. Interestingly, most of the identified predominant components
were not identical, which indicate the latent variation among the rice varieties. Significant
variations exist for fatty acids (46.9–76.2%), total terpenes (12.6–30.7%), total phenols
(0.9–10.0%), total aliphatic alcohols (0.8–5.9%), total alkanes (0.5–5.1%), and total
alkenes (1.0–4.9%) among the rice varieties. Of all the fatty acid compounds, palmitic
acid, elaidic acid, linoleic acid, and oleic acid predominantly varied in the range of
11.1–33.7, 6.1–31.1, 6.0–28.0, and 0.7–15.1%, respectively. The modern varieties
recorded the highest palmitic acid contents (28.7–33.7%) than the traditional varieties
(11.1–20.6%). However, all the traditional varieties had higher linoleic acid (10.0–28.0%)
than the modern varieties (6.0–8.5%). Traditional varieties had key phenolic compounds,
stearic acid, butyric acid, and glycidyl oleate, which are absent in the modern varieties.
The traditional varieties Seeraga samba and Kichilli samba had the highest azulene and
oleic acid, respectively. All these indicate the higher variability for nutrients and aroma
in traditional varieties. These varieties can be used as potential parents to improve the
largely cultivated high-yielding varieties for the evolving nutritionalmarket. The hierarchical cluster analysis showed three different clusters implying the distinctness of the traditional
and modern varieties. This study provided a comprehensive volatile profile of traditional
and modern rice as a staple food for energy as well as for aroma with nutrition
Exploring DNA quantity and quality from raw materials to botanical extracts
Objectives: The aim of this study was to explore the variability in DNA quality and quantity along a gradient of industrial processing of botanical ingredients from raw materials to extracts.
Methods: A data matrix was assembled for 1242 botanical ingredient samples along a gradient of industrial
processing commonly used in the Natural Health Product (NHP) industry. Multivariate statistics was used to
explore dependant variables for quality and quantity. The success of attaining a positive DNA test result along a
gradient of industrial processing was compared among four biotechnologies: DNA barcoding, NGS, Sanger
sequencing and qPCR.
Results: There was considerable variance in DNA quality and quantity among the samples, which could be
interpreted along a gradient from raw materials with greater quantities (50–120 ng/μL) of DNA and longer DNA
(400-500bp) sequences to extracts, which were characterized by lower quantities (0.1–10.0 ng/μL) and short fragments (50-150bp).
Conclusions: Targeted molecular diagnostic tests for species identity can be used in the NHP industry for raw and processed samples. Non-targeted tests or the use of NGS for any identity test needs considerable research and
development and must be validated before it can be used in commercial operations as these methods are subject
to considerable risk of false negative and positive results. Proper use of these tools can be used to ensure
ingredient authenticity, and to avert adulteration, and contamination with plants that are a health concern. Lastly these tools can be used to prevent the exploitation of rare herbal species and the harvesting of native biodiversity for commercial purposes
Remoção de microcistina-LR de águas eutrofizadas por clarificação e filtração seguidas de adsorção em carvão ativado granular
- …