426 research outputs found
Genetic Basis of Flocculation in Azospirillum brasilense.
Azospirillum brasilense is a class of rhizobacteria capable of nitrogen fixation, root colonization and hence promoting host plant growth. The bacteria posses cell interaction behaviors like clumping and flocculation that contribute the survival of the organism in nutrient limited conditions. Change in the cell surface adhesive properties allows the cells to progress from free swimming to clumping and finally flocculation. Less is known about the genetic regulation of these processes with flcA being the only transcriptional regulator known so far to directly control flocculation. Recent evidence suggesting that Che1, a chemotaxis like signal transduction pathway controls the cell behavior clumping and hence indirectly controlling flocculation,
To understand the genetic regulation of clumping and flocculation in A. brasilense Sp7, the research here focuses on a subset of 27 of these transposon mutants. The objective of this research was to map the insertion by rescue cloning, characterize the mutant for growth, motility and clumping using qualitative and quantitative assays and characterize the effect of the mutations identified on flocculation.
By rescue cloning we mapped the transposon insertion for nine out of the twenty-seven mutations. The insertions were mapped on glycosyltransferases, glucosyltransferase, putative TonB-dependent siderophore receptor, Acyl-CoA thioesterase and sugar phosphatase of the HAD superfamily. All these mutants were characterized for the clumping and flocculation phenotype and while some of these mutants showed severe delay in clumping and/or flocculation indicating changes in cell surface adhesive properties of the mutants compared to the wild type. Further investigations like supplementation of media with different sources of iron provided an insight into understanding the indirect effect of the PM3 mutation on the iron transport pathway. Also, the lectin-binding assay provided insightful information about the changes in the exopolysaccharide (EPS) composition during the different stages of cell aggregation. In conclusion the experiments provided good measure of information about the changes in the cell surface properties specifically with relation to proteins and EPS as an initial investigation. Future work will concentrate on screening the effects of these mutations on the expression of downstream genes and further phenotypic characterization of the selected mutants
Design and Comparison of LEACH and Improved Centralized LEACH in Wireless Sensor Network
A WSN consists of a setup of sensor nodes/motes which perceives the environment under monitoring, and transfer this information through wireless links to the Base Station (BS) or sink. The sensor nodes can be heterogeneous or homogeneous and can be mobile or stationary. The data gathered is forwarded through single/multiple hops to the BS/sink. In this paper, propose improvements to LEACH routing protocol to reduce energy consumption and extend network life. LEACH Distance Energy (LEACH-DE) not only selects the cluster head node by considering that the remaining energy of the node is greater than the average remaining energy level of the nodes in the network, but also selects the cluster head node parameters based on the geometric distance between the candidate node and the BS. The simulation results show that the algorithm proposed in this work is superior to LEACH and LEACH-C (Centralized) in terms of energy saving and extending the lifetime of wireless sensor networks
Simulating Contact Instability in Soft Thin Films through Finite Element Techniques
When a thin film of soft elastic material comes in contact with an external surface, contact instability triggered by interaction forces, such as van der Waals, engenders topologically functionalized surfaces. Innumerable technological applications such as adhesives; microelecromechanical systems (MEMS), and nanoelectromechanical systems (NEMS) demand understanding of the physics behind the mechanical contact, relationship between the morphologies, and detachment forces in such films. Indentation tests are important experimental approach toward this; there also exist many simulation procedures to model the mechanical contact. Both atomistic level and analytical continuum simulations are computationally expensive and are restricted by the domain geometries that can be handled by them. Polymeric films also particularly demonstrate a rich variety of nonlinear behavior that cannot be adequately captured by the aforementioned methods. In this chapter we show how finite element techniques can be utilized in crack opening and in contact-instability problems
Machine Learning-Based IOT Air Quality and Pollution Detection
In India, gas leakage from the different factories harmful to human surveying in the last fifty years is very low. However, there is a lack of prior detection of the chemical gases detection system in the situation raised. So, In this regard, there is a gap identification of chemical gases intensity detection needed. In this work, the main objective is to identify chemical gases intensity and maintain the stream data in the database from different locations. To fill this gap, that is identifying the high-intensity chemical gases from the chemical gas disaster areas. The first step needs to identify the different chemical gases and natural gas compositions. In this regard in this work for design internet-based gases in the air system. So, the sensors MQ2(Ethanol i-Butane Methane Alcohol Gas Sensor Sensor), MQ3(Sensitivity Alcohol Detector), MQ4 (Methane and Natural Gas (CNG)), MQ-5 ( LPG GAS SENSOR), MQ-7 (CO Gas Sensor Module Test Carbon Monoxide Detector), MQ-8 (hydrogen Gas Sensor), MQ-9 (carbon monoxide), MQ-135 Sensor(Air Quality Sensor Hazardous Gas Detector) and DHT11 Digital Temperature Humidity Sensors. These sensors are interfacing with the micro-control STM 32 board. It is also called one Pollution identification terminal by using it to pull the sensor stream data from location to centralized data. This stream data transportation is a service to pull the data. For this Data pulling, design an algorithm store into a cloud database. In this research work, design the electronic terminal with a wifi circuit using IoT technologies.Moreover, getting these attributes as data. Data need to apply the preprocessing techniques and extracted feature techniques also. This paper discusses mainly designing the terminal for pollution attributes , cleaning the data, and applying the Machine Learning based Feature extraction techniques
A REVIEW OF ANALYTICAL TECHNIQUES FOR DETERMINATION OF ANTI-HIV DRUGS
Pharmaceutical analysis plays a very prominent role in quality assurance as well as quality control of bulk drugs and pharmaceutical formulations. Rapid increase in pharmaceutical industries and production of drug in various parts of the world has brought a rise in demand for new analytical techniques in the pharmaceutical industries. As a consequence, analytical method development has become the basic activity of analysis. From the times of yore, people were trying to find safe and sound ways to treat viral infections. In the current scenario, due to the emerging of new viruses, the development of drugs for their treatment is also gaining equal importance. Before launching to the market, these drugs should undergo a validation process. High-performance liquid chromatography (HPLC) coupled with ultraviolet (UV), Photodiode array detectors (PDA), Mass spectrophotometer (MS) detectors etc. is one of the fastest, safe and precise technologies used for determination and separation of pharmaceutical drugs, impurities and biological samples. HPLC is versatile and it takes less time for quantification of drugs as compared to old liquid chromatography techniques. Tenofovir disoproxil fumarate (TDF), Emtricitabine (FTC) and Efavirenz (EFV) is antiretroviral medicine used treat AIDS as well as chronic Hepatitis-B. It is used alone or with other HIV medications to help control HIV infection. The present review article assesses the published analytical methods and a variety of approach for investigation of TDF, FTC and EFV in bulk drug as well as pharmaceutical formulations including combinations. The present studies revealed that HPLC technique along with the spectroscopic have been most widely explored for the analysis. The investigatory review may provide the comprehensive details to the researchers who are working in the area of analytical research of TDF, FTC and EFV
A Study of Crop Yield Prediction Using Machine Learning Approaches
Agriculture plays a pivotal role in our society by providing food, fiber, and raw materials for various industries. The world's population is steadily growing, and there is increasing pressure on agriculture to meet the rising global food demand. In this context, the use of machine learning approaches to predict crop yields has gained significant importance. This paper aim is to study the significance of crop yield prediction through machine learning, its methods, applications, and its potential to revolutionize the agricultural sector
Transdermal Delivery of Antihypertensive Agents: A tabular update
Transdermal Drug Delivery System is viable drug delivery platform technology and has a strong market world wide. Transdermal Drug Delivery System is particularly desirable for drugs that need prolonged administration at controlled plasma level that basis make appropriateness to antihypertensive agents for their transdermal development. Controlled zero order absorption, easily termination of drug delivery, easy to administration also support for popularity of transdermal delivery. This paper reviews the work on transdermal studies of antihypertensive agents in the tabular form.Keywords: Transdermal, Antihypertensive agents
Pyrrolidinyl Group as Charge Donor for the Excited State Intramolecular Chargetransferin 3-(4-methoxyphenyl)-1-(4-(pyrrolidin-1-yl) phenyl) Prop-2-en-1-one
The absorption and steady state emission properties of a chemically synthesized chalcone, 3-(4-methoxyphenyl)-1-(4-(pyrrolidin-1-yl) phenyl) prop-2-en-1-one (MPPP) containing asymmetrical donor and acceptor groups has been investigated both experimentally and theoretically. The ground state, MPPP has a significant intramolecular charge transfer (ICT) character and a great sensitivity to the hydrogen bond donating ability of the medium as reflected from the absorption spectra in pure non polar, polar and neutral solvents. On the other hand, its excited singlet state exhibits high ICT characters as manifested by the drastic solvatochromic effects. These results are consistent with the data. The absorption spectra of the compound MPPP undergoes minor changes with increasing polarity of the solvents and the fluorescence spectra experiences a distinct bathochromic shifts in the both position and fluorescence quantum yields, increases reaching a maximum before decrease with increasing the solvent effects. The quantum yields decrease with increase in the solvent polarity. The magnitude of change in the dipole moment was also calculated using Austin Model 1 (AM1). These results suggest that the evidence about the intramolecular charge transfer in the emitting singlet state of this compound. The solvent dependence of quantum yields of MPPP was interpreted on the basis of positive and negative solvatokinetic as well as hydrogen bonding effects. Intramolecular charge (ICT) transfer took place from pyrrolidine nitrogen to α, β unsaturated carbonyl in the ground state
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