Mobility Adaptive Density Connected Clustering Approach in Vehicular Ad Hoc Networks

Clustering is one of the popular topology management approaches that can positively influence the performance of networks. It plays significant role in VANETs. However, VANETs having highly mobile nodes lead to dynamic topology and hence, it is very difficult to construct stable clusters. More homogeneous environment produces more stable clusters. Homogeneous neighbourhood for a vehicle is strongly driven by density and standard deviation of average relative velocity of vehicles in its communication range. So, we propose Mobility Adaptive Density Connected Clustering Algorithm (MADCCA), a density based clustering algorithm. The Cluster Heads (CHs) are selected based on the standard deviation of average relative velocity and density matrices in their neighbourhood. Vehicle, which is having more homogeneous environments, will become the cluster heads and rest of the vehicles in their communication range will be the Cluster Members (CMs). The simulation results demonstrates the better performance of MADCCA over other clustering algorithms new ALM and MOBIC

Sequential extraction of different pools of phosphorus in alluvial and acid soils of Uttarakhand

The sequencing and availability of inorganic and organic fractions of phosphorus at different days interval in two soils after the fertilizer (SSP) application was the objective of this investigation. The study helped to obtain the sequence of dominating pool of phosphorus at different days intervals and the rate of release in the soil. This sequential fractionation was used for two native soils i) Alluvial soil and ii) Acidic soil, with 0 to 80 ppm SSP/ 100 gm soil added in a pot experiment and the soil samples were analyzed at different days intervals started from 5 days to 60 days. The result revealed that amount of maximum total P fell in the range from 325.14 to 387.30 mg kg-1 and 284.60 to 330.25 mg kg-1 for alluvial soil and acid soil, respectively up to 30 days. In case of inorganic P fractions under alluvial soil the dominating species were like Ca-P > Fe-P > Al-P >Saloid-P, while under acidic soil the following order Fe-P > Al-P > Ca-P > Saloid-P was observed. These two observations also drew the concentration of organic-P fractions in soil. The work concluded that the availability of dominant phosphorus fraction up to 30 days received the maximum Ca-P concentration in alluvial soil and Fe-P up to 60 days in acidic soils, respectively

Cosmological implications of an interacting dark energy model with the matter fields

In this paper, we have studied an interacting dark energy model. We have assumed the gravitational interaction between the matter fields i.e. bewteen barotropic fluid and the dark energy. The dark energy evolution within the framework of spatially homogeneous and isotropic Friedmann-Robertson-Walker space-time. Therefore, we examine the cosmic evolution from the perspective of interacting scenario by selecting a suitable ansatz for the scale factor resulting from a parametrization of Hubble parameter. The evolution of the cosmological parameters are discussed in some details in the considered interacting scenario by calculating parameters and quantities such as deceleration parameter, energy density, pressure, equation of state (EoS) etc. Also, we have performed some cosmological tests and analysis in support of our obtained interacting model. Finally, we reconstruct the potential of the scalar field and refute the refined swampland conjecture using the equation of state of dark energy and the relationship between energy density and pressure with the scalar field and potential, and then thoroughly describe the findings

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

Structural characterization of the large soluble oligomers of the GTPase effector domain of dynamin

Dynamin, a protein playing crucial roles in endocytosis, oligomerizes to form spirals around the necks of incipient vesicles and helps their scission from membranes. This oligomerization is known to be mediated by the GTPase effector domain (GED). Here we have characterized the structural features of recombinant GED using a variety of biophysical methods. Gel filtration and dynamic light scattering experiments indicate that in solution, the GED has an intrinsic tendency to oligomerize. It forms large soluble oligomers (molecular mass > 600 kDa). Interestingly, they exist in equilibrium with the monomer, the equilibrium being largely in favour of the oligomers. This equilibrium, observed for the first time for GED, may have regulatory implications for dynamin function. From the circular dichroism measurements the multimers are seen to have a high helical content. From multidimensional NMR analysis we have determined that about 30 residues in the monomeric units constituting the oligomers are flexible, and these include a 17 residue stretch near the N-terminal. This contains two short segments with helical propensities in an otherwise dynamic structure. Negatively charged SDS micelles cause dissociation of the oligomers into monomers, and interestingly, the helical characteristics of the oligomer are completely retained in the individual monomers. The segments along the chain that are likely to form helices have been predicted from five different algorithms, all of which identify two long stretches. Surface electrostatic potential calculation for these helices reveals that there is a distribution of neutral, positive and negative potentials, suggesting that both electrostatic and hydrophobic interactions could be playing important roles in the oligomer core formation. A single point mutation, I697A, in one of the helices inhibited oligomerization quite substantially, indicating firstly, a special role of this residue, and secondly, a decisive, though localized, contribution of hydrophobic interaction in the association process

Efficacy of some insecticides against Thrips, Megalurothrips sjostedti Trybom cowpea crop ecosystem

The study was conducted to determine efficacy of insecticides against Thrips, Megalurothrips sjostedti Trybom on cowpea grown at field experiments were conducted at Breeder Seed Production Centre, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar 2014.The most effective treatment for the control of thrips Megalurothrips sjostedti Trybom was seed treatment with fipronil @ 3 ml/kg + spray with fipronil @ 5 ml/lt with maximum reduction (70.06%) in the thrips population of cowpea while lowest effective treatment for the control of thrips Megalurothrips sjostedti Trybom was seed treatment with imidacloprid 17.8SL @ 10ml/kg + spray with monocrotophos 36SL @ 2ml/lt with minimum reduction (16.02%) in the thrips, Megalurothrips sjostedti Trybom population of cowpea crop

PHARMACOVIGILANCE IN THE ERA OF COVID-19: A CONCISE REVIEW OF THE CURRENT SCENARIO, IMPLICATIONS, AND CHALLENGES

The pandemic of Coronavirus Disease 2019 (COVID-19) has now affected the entire globe which was first surfaced in China in December 2019. In absence of effective therapy to manage COVID-19, repurposed therapies were being used to manage the condition. In view of an urgent need for definitive therapy, multiple repurposed drugs, and investigational drug candidates are being tried in clinical trials which may lead to the emergence of unknown short term and long term adverse drug reactions (ADRs), and hence it is crucial to assess the safety of the tried therapeutic interventions. The lag in the pharmacovigilance activities in the midst of this pandemic fosters under-reporting of ADRs. Difficulty in causality assessment due to factors like wide variations in clinical presentation, concomitant use of multiple drugs, associated comorbidities, drug-drug and drug-disease interaction which forestalls the appropriate causality assessment. Hydroxychloroquine, a repurposed antimalarial drug has been a part of hue and cry at present because of its in-question safety in patients with cardiac disorders. National and International Drug monitoring centers have stressed upon reporting of ADRs and to boost up the process and come up with various recommendations. We can overcome these issues by working cohesively, motivating HCPs and patients to report ADRs electronically, and by setting up dedicated pharmacovigilance rapid response team to tackle the issues at the earliest

Folding regulates autoprocessing of HIV-1 protease precursor

Autoprocessing of HIV-1 protease (PR) precursors is a crucial step in the generation of the mature protease. Very little is known regarding the molecular mechanism and regulation of this important process in the viral life cycle. In this context we report here the first and complete residue level investigations on the structural and folding characteristics of the 17-kDa precursor TFR-PR-Cnn (161 residues) of HIV-1 protease. The precursor shows autoprocessing activity indicating that the solution has a certain population of the folded active dimer. Removal of the 5-residue extension, Cnn at the C-terminal of PR enhanced the activity to some extent. However, NMR structural characterization of the precursor containing a mutation, D25N in the PR at pH 5.2 and 32 °C under different conditions of partial and complete denaturation by urea, indicate that the precursor has a high tendency to be unfolded. The major population in the ensemble displays some weak folding propensities in both the TFR and the PR regions, and many of these in the PR region are the non-native type. As both D25N mutant and wild-type PR are known to fold efficiently to the same native dimeric form, we infer that TFR cleavage enables removal of the non-native type of preferences in the PR domain to cause constructive folding of the protein. These results indicate that intrinsic structural and folding preferences in the precursor would have important regulatory roles in the autoprocessing reaction and generation of the mature enzyme

Dynamin interacts with members of the sumoylation machinery

Dynamin is a GTP-binding protein whose oligomerization-dependent assembly around the necks of lipid vesicles mediates their scission from parent membranes. Dynamin is thus directly involved in the regulation of endocytosis. Sumoylation is a post-translational protein modification whereby the ubiquitin-like modifier Sumo is covalently attached to lysine residues on target proteins by a process requiring the concerted action of an activating enzyme (ubiquitin-activating enzyme), a conjugating enzyme (ubiquitin carrier protein), and a ligating enzyme (ubiquitin-protein is opeptide ligase). Here, we show that dynamin interacts with Sumo-1, Ubc9, and PIAS-1, all of which are members of the sumoylation machinery. Ubc9 and PIAS-1 are known ubiquitin carrier protein and ubiquitin-protein isopeptide ligase enzymes, respectively, for the process of sumoylation. We have identified the coiled-coil GTPase effector domain (GED) of dynamin as the site on dynamin that interacts with Sumo-1, Ubc9, and PIAS-1. Although we saw no evidence of covalent Sumo-1 attachment to dynamin, Sumo-1 and Ubc9 are shown here to inhibit the lipid-dependent oligomerization of dynamin. Expression of Sumo-1 and Ubc9 in mammalian cells down-regulated the dynamin-mediated endocytosis of transferrin, whereas dynamin-independent fluid-phase uptake was not affected. Furthermore, using high resolution NMR spectroscopy, we have identified amino acid residues on Sumo-1 that directly interact with the GED of dynamin. The results suggest that the GED of dynamin may serve as a scaffold that concentrates the sumoylation machinery in the vicinity of potential acceptor proteins