Detection of Pseudomonas fluorescens from broth, water and infected tissues by loop-mediated isothermal amplification (LAMP) method

Loop mediated isothermal amplification is rapid, highly sensitive and specifically developed method for detection of bacterial infections. AprX gene for alkaline metalloprotease of Pseudomonas fluorescens was used to design four primers and loop mediated isothermal amplification (LAMP) conditions were standardized for amplification of DNA. LAMP primers successfully amplified P. fluorescens from DNA and bacterial cells taken directly from broth, water and infected tissues with high specificity and sensitivity (10 pg) under isothermal condition at 61°C.Key words: Pseudomonas fluorescens, loop mediated isothermal amplification (LAMP), rapid, simple, specificity, sensitivity

Effect of reduced link margins on C plus L band elastic optical networks

Network traffic is growing exponentially, which has increased the onus on network operators to expand their network spectral resources beyond the C band. This work explores the effect of operating at a reduced link margin (LM) over the combined C and L bands. For this purpose, we utilize a lightpath optical signal-to-noise ratio (OSNR) estimation model that considers nonlinear interference due to inter-channel stimulated Raman scattering and amplified spontaneous emission noise generated by in-line amplifiers while predicting the OSNR. This model is utilized to account for the benefits of operating at reduced LM in the BT-UK, Pan Europe, and USA-NSFNET networks. Our results indicate that significant gains in capacity can be achieved by operating at low margins across all the networks. Furthermore, it is concluded that the launch power of network lightpaths should be optimized based upon the network size and operating LM

Effect of Channel Launch Power on Fill Margin in C plus L Band Elastic Optical Networks

Increasing traffic in the optical backbone network has made it incumbent upon operators to extend the use of optical spectrum beyond the C-band. In this work we estimate network performance over the C+L band using a physical layer model for estimating the optical signal to noise ratio (OSNR) for lightpaths operating over the C+L band optical spectrum. The model considers nonlinear interference (NLI) due to inter-channel stimulated Raman scattering (ISRS) and the impact of ISRS gain on amplified spontaneous emission (ASE) noise generated by in-line amplifiers while estimating the OSNR. This model is used to account for the capacity benefits associated with OSNR estimation while considering current state of spectral occupancy to account for NLI as compared to the fully-filled, worst-case NLI assumption. OSNR estimation based on current state of spectral occupancy provide higher capacity benefits for smaller networks like the BT-UK while for larger networks like the USA NSFNET the capacity benefit is significantly reduced. Further network capacity benefits of operating over C+L band as compared to C band have been reported. For BT-UK the capacity benefit is more than 100% while for larger networks like USA NSFNET the maximum capacity benefit is 73% with 37.5 GHz of bandwidth until 10% of demands are blocked

Capacity Benefits of Operation Over C+L Band Elastic Optical Network in the Indian Network Scenario

Introduction of high data rate services has increased the traffic load on the backhaul network. In order to cater more demands, the operators are looking for solutions to minimize spectral wastage and to extend their network operations beyond the C-band, especially for inter-city networks. This paper highlights the advantages of operating over C+L band as compared to operations over C band in a large Indian network. The physical model factors in the non-linear interference (NLI) due to inter-channel stimulated Raman scattering (ISRS) and amplified spontaneous emission (ASE) noise while estimating the optical signal to noise ratio (OSNR) of a network lightpath. The OSNR estimation model can dynamically account for the NLI as compared to the conventional worst case assumption. The capacity benefits for the Indian network over the C+L band for channel power -1.5 dBm are about 108.67% for channel bandwidth 50 GHz and 103.98% for channel bandwidth 37.5 GHz until 10% of the demands are blocked

Differential expression of Toll-like receptor genes (TLR2 and TLR4) across different tissues of riverine buffalo

Toll-like receptors (TLRs) are one of the important pattern recognizing receptors which are responsible for the induction of innate as well as adaptive immune response against a wide range of microbial components. Among different TLRs, TLR2 and TLR4 are expressed on the cell surface identifying Gram-positive and Gram-negative bacterial components. The present study was undertaken to analyze the expression of TLR2 and TLR4 genes in different buffalo tissues by using highly sensitive real-time PCR technique. Although the expression of both the genes was observed in all the 8 different tissues taken for the present study, the maximum expression of TLR2 was seen in blood followed by skin, lungs and spleen and the lowest expression was found in the uterus. TLR4 showed maximum expression in blood followed by skin, lungs, mammary gland of non-lactating, lactating buffalo and heifer and the lowest expression was seen again in the uterus.The findings suggest both the genes having important functions in blood and skin, the first line of protection for pathogenic challenge apart from other organs in buffalo

Extending the Absorption Limit of BiVO4 Photoanodes with Hydrogen Sulfide Treatment

Bismuth vanadate is a promising photoanode material for photoelectrochemical water splitting due to its relative stability, low cost, and nontoxic properties. However, its performance is limited by the large bandgap Eg of 2.4 amp; 8201;eV, and the record photocurrent is already within 90 of its theoretical limit. Further photocurrent enhancement could only be obtained by increasing its optical absorption, for example, by reducing Eg. Herein, sulfur incorporated bismuth vanadate S BiVO4 thin films are synthesized via spray pyrolysis combined with post treatment in hydrogen sulfide environment. Under optimal H2S treatment conditions, sulfur can be incorporated successfully into the BiVO4 lattice, without the formation of any secondary phases. The use of reactive H2S, instead of solid sulfur powders, allows us to decrease the required annealing temperature and increase the kinetics for sulfur incorporation into BiVO4. The Eg of the resulting S BiVO4 films is decreased by gt;200 amp; 8201;meV vs. pristine BiVO4 , which theoretically corresponds to a 20 increase in the theoretical photocurrent limit. Finally, the stability limitation of S BiVO4 is overcome by introducing pulsed laser deposited NiOx protection layers. The modified S BiVO4 NiOx film exhibits higher photocurrent density with no reduction of photocurrent during the 9 amp; 8201;h stability test with AM1.5 illuminatio

Atlantic salmon cardiac primary cultures:An in vitro model to study viral host pathogen interactions and pathogenesis

Development of Salmon Cardiac Primary Cultures (SCPCs) from Atlantic salmon pre-hatch embryos and their application as in vitro model for cardiotropic viral infection research are described. Producing SCPCs requires plating of trypsin dissociated embryos with subsequent targeted harvest from 24h up to 3 weeks, of relevant tissues after visual identification. SCPCs are then transferred individually to chambered wells for culture in isolation, with incubation at 15-22°. SCPCs production efficiency was not influenced by embryo's origin (0.75/ farmed or wild embryo), but mildly influenced by embryonic developmental stage (0.3 decline between 380 and 445 accumulated thermal units), and strongly influenced by time of harvest post-plating (0.6 decline if harvested after 72 hours). Beating rate was not significantly influenced by temperature (15-22°) or age (2-4 weeks), but was significantly lower on SCPCs originated from farmed embryos with a disease resistant genotype (F = 5.3, p<0.05). Two distinct morphologies suggestive of an ex vivo embryonic heart and a de novo formation were observed sub-grossly, histologically, ultra-structurally and with confocal microscopy. Both types contained cells consistent with cardiomyocytes, endothelium, and fibroblasts. Ageing of SCPCs in culture was observed with increased auto fluorescence in live imaging, and as myelin figures and cellular degeneration ultra-structurally. The SCPCs model was challenged with cardiotropic viruses and both the viral load and the mx gene expression were measurable along time by qPCR. In summary, SCPCs represent a step forward in salmon cardiac disease research as an in vitro model that partially incorporates the functional complexity of the fish heart

Biogenesis of nanoparticles: A review

Advancement in nanotechnology mainly depends upon advancement in nanomaterial. There are many chemical routes known to use toxic chemicals for synthesis of nanoparticles but the need of the hour is to use environmental benign, greener and safer routes. Researchers are looking to use various living organisms as ‘nanoparticle factories’. Various biological entities like bacteria, fungi, diatoms, higher plants, actinomycetes and viruses have been used for this purpose. Due to their normal biosynthetic pathways, they can reduce salt into corresponding nanoparticles. This review includes some of the biological sources which have been used by researchers for the synthesis of nanoparticles and their applications.Keywords: Biogenesis, nanofactories, nanoparticles, antimicrobial activity, semiconductor nanoparticles.African Journal of Biotechnology Vol 13(28) 2778-278