Anticaries Activity of Usnea pictoides G. Awasthi -A macrolichen from Western Ghats of Karnataka, India

The present study was conducted to determine anticaries activity of solvent extracts of a macrolichen Usnea pictoides G. Awasthi (Parmeliaceae)  collected at Mullayanagiri, Western Ghats of Chikmagalur district,  Karnataka, India. The lichen material was sequentially extracted using solvents viz., petroleum ether, ethyl acetate, chloroform and methanol in a soxhlet assembly. Anticaries activity of solvent extracts was determined against four clinical isolates of Streptococcus mutans (recovered from dental caries subjects) by Agar well diffusion assay. All solvent extracts were effective against the clinical isolates. High inhibitory potential was observed in case of chloroform extract. Thin layer chromatogram showed the presence of Usnic acid. Inhibitory effect could be ascribed to the bioactive secondary   metabolites, mainly Usnic acid present in the lichen. Purification of bioactive principles and determination of their anticaries activity are to be conducted

Inhibitory Effect of Cow Urine Extracts of Selected Plants against Pathogens Causing Rhizome Rot of Ginger

No Abstract

Elemental Analysis and Biological Activities of Chrysophyllum roxburghii G. Don (Sapotaceae) Leaves

The present study was performed to estimate elementals and to determine bioactivities namely anticariogenic, antioxidant, pancreatic lipase inhibitory and cytotoxic activity of Chrysophyllum roxburghii leaves. Elemental analysis revealed that calcium and manganese were present in high concentration among principal and trace elements respectively. Preliminary phytochemical analysis revealed the presence of tannins, alkaloids and terpenoids in the extract. Total phenolic content was found to be 179.05mg Gallic acid equivalents/g of extract. The methanol extract caused a dose dependent inhibition of Streptomyces mutans isolates. All the isolates tested were found to be sensitive to extract. In DPPH assay, the extract exhibited marked dose dependent scavenging activity against DPPH free radical with an IC50 value of 3.54ìg/ml. In Ferric reducing assay, the absorbance of the reaction mixture was found to increase with the concentration of extract which is suggestive of reducing power. The activity of chicken pancreatic lipase was affected by the extract and the effect was concentration dependent. Higher inhibition of enzyme (>50%) was observed at extract concentration 50mg/ml. In cytotoxic study, the lethality was found to be directly proportional to extract concentration. Highest mortality (>80%) of shrimps was observed at extract concentration 1000µg/ml. LC50 of extract was 83.04µg/ml. The bioactivities of the extract could be attributed to the presence of secondary metabolites in the plant material. The plant material could be used as a source of important elements required for the body. In suitable form, the plant could be used in the prevention and treatment of dental caries, oxidative damage, obesity and cancer

Analyses for Service Interaction Networks with applications to Service Delivery

One of the distinguishing features of the services industry is the high emphasis on people interacting with other people and serving customers rather than transforming physical goods like in the traditional manufacturing processes. It is evident that analysis of such interactions is an essential aspect of designing effective and efficient services delivery. In this work we focus on learning individual and team behavior of different people or agents of a service organization by studying the patterns and outcomes of historical interactions. For each past interaction, we assume that only the list of participants and an outcome indicating the overall effectiveness of the interaction are known. Note that this offers limited information on the mutual (pairwise) compatibility of different participants. We develop the notion of service interaction networks which is an abstraction of the historical data and allows one to cast practical problems in a formal setting. We identify the unique characteristics of analyzing service interaction networks when compared to traditional analyses considered in social network analysis and establish a need for new modeling and algorithmic techniques for such networks. On the algorithmic front, we develop new algorithms to infer attributes of agents individually and in team settings. Our first algorithm is based on a novel modification to the eigen-vector based centrality for ranking the agents and the second algorithm is an iterative update technique that can be applied for subsets of agents as well. One of the challenges of conducting research in this setting is the sensitive and proprietary nature of the data. Therefore, there is a need for a realistic simulator for studying service interaction networks. We present the initial version of our simulator that is geared to capture several characteristics of service interaction networks that arise in real-life

FREQUENCY EVALUATION FOR MECHANICAL INTEGRATION OF SHROUDED HP ROTOR BLADES IN AN AIRCRAFT ENGINE COMPRESSOR

Frequency evaluation in rotary engine blade design is an important research area because of its critical applications in aircraft engines and land-based gas engines. A compressor blade plays an important role in increasing pressure and velocity of the fluid, which influences the efficiency of gas turbines. Due to peak centrifugal stresses, gas bending loads and vibratory stresses, flow-induced blade vibrations occur leading to blade catastrophe. The airfoil is expected to prove not only the mechanical efficiency but also mechanical integrity for a desired life. The present research focuses on the study of the vibrational behaviour of an Axial HP Shrouded Compressor blade for in-service conditions. A Computational Fluid Dynamics based model is generated with reference to NACA 65-series, to analyse the flow behaviour through a linear cascade of axial compressor blades, followed by mechanical integrity stress checks to take it further with root attachment design. The present work demonstrates the need for shrouds in compressor rotor blades for stiffening the blade to avoid resonance. The positioning of the shroud is a challenge across the blade height by achieving Frequency Separation Margins using Campbell Diagram, an industry best practice

ANTIBACTERIAL AND ANTIFUNGAL ACTIVITY OF THREE RAMALINA SPECIES

Lichens are an association of a photobiont (an alga or a cyanobacterium) and a mycobiont (a fungus). The lichen genus Ramalina is one of the cosmopolitan lichen genera and is characterized by fruticose thallus. In the present study, an antibacterial and antifungal activity of an extract of three Ramalina species (Ramalinaceae) viz. R. hossei Vain, R. conduplicans Vain and R. pacifica Asahina obtained by maceration process were investigated. The lichens were collected from different places of Shivamogga district, Karnataka, India and identified on the basis of morphological, anatomical and chemical tests. The antibacterial and antifungal activity of lichen extracts was carried out by Agar well diffusion and Poisoned food technique respectively. Overall, B. cereus and E. coli were inhibited to higher extent and least extent respectively by extracts of Ramalina species. R. pacifica and R. hossei inhibited bacteria to highest and least extent respectively. In the case of antifungal activity, marked and least inhibitory activity was shown by an extract of R. hossei and R. pacifica respectively. Among fungi, Alternaria sp. and Fusarium sp. were inhibited to highest and least extent respectively. The observed antimicrobial potential could be ascribed to the presence of secondary metabolites such as usnic acid, salazinic acid and sekikaic acid present in the Ramalina species.Key words: Lichens, Ramalina, Antimicrobial, Agar well diffusion, Poisoned food techniqueÂ

Utilization of a deoxynucleoside diphosphate substrate by HIV reverse transcriptase

Background: Deoxynucleoside triphosphates (dNTPs) are the normal substrates for DNA sysnthesis is catalyzed by polymerases such as HIV-1 reverse transcriptase (RT). However, substantial amounts of deoxynucleoside diphosphates (dNDPs) are also present in the cell. Use of dNDPs in HIV-1 DNA sysnthesis could have significant implications for the efficacy of nucleoside RT inhibitors such as AZT which are first line therapeutics fro treatment of HIV infection. Our earlier work on HIV-1 reverse transcriptase (RT) suggested that the interaction between the γ phosphate of the incoming dNTP and RT residue K65 in the active site is not essential for dNTP insertion, implying that this polymerase may be able to insert dNPs in addition to dNTPs. Methodology/Principal Findings: We examined the ability of recombinant wild type (wt) and mutant RTs with substitutions at residue K65 to utilize a dNDP substrate in primer extension reactions. We found that wild type HIV-1 RT indeed catalyzes incorporation of dNDP substrates whereas RT with mutations of residue K645 were unable to catalyze this reaction. Wild type HIV-1 RT also catalyzed the reverse reaction, inorganic phosphate-dependent phosphorolysis. Nucleotide-mediated phosphorolytic removal of chain-terminating 3′-terminal nucleoside inhibitors such as AZT forms the basis of HIV-1 resistance to such drugs, and this removal is enhanced by thymidine analog mutations (TAMs). We found that both wt and TAM-containing RTs were able to catalyze Pi-mediated phosphorolysis of 3′-terminal AZT at physiological levels of Pi with an efficacy similar to that for ATP-dependent AZT-excision. Conclusion: We have identified two new catalytic function of HIV-1 RT, the use of dNDPs as substrates for DNA synthesis, and the use of Pi as substrate for phosphorolytic removal of primer 3′-terminal nucleotides. The ability to insert dNDPs has been documented for only one other DNA polymerase The RB69 DNA polymerase and the reverse reaction employing inorganic phosphate has not been documented for any DNA polymerase. Importantly, our results show that Pi-mediated phosphorolysis can contribute to AZT resistance and indicates that factors that influence HIV resistance to AZT are more complex than previously appreciated. © 2008 Garforth et al

Perspectives on tracking data reuse across biodata resources

c The Author(s) 2024. Published by Oxford University Press.Motivation: Data reuse is a common and vital practice in molecular biology and enables the knowledge gathered over recent decades to drive discovery and innovation in the life sciences. Much of this knowledge has been collated into molecular biology databases, such as UniProtKB, and these resources derive enormous value from sharing data among themselves. However, quantifying and documenting this kind of data reuse remains a challenge. Results: The article reports on a one-day virtual workshop hosted by the UniProt Consortium in March 2023, attended by representatives from biodata resources, experts in data management, and NIH program managers. Workshop discussions focused on strategies for tracking data reuse, best practices for reusing data, and the challenges associated with data reuse and tracking. Surveys and discussions showed that data reuse is widespread, but critical information for reproducibility is sometimes lacking. Challenges include costs of tracking data reuse, tensions between tracking data and open sharing, restrictive licenses, and difficulties in tracking commercial data use. Recommendations that emerged from the discussion include: development of standardized formats for documenting data reuse, education about the obstacles posed by restrictive licenses, and continued recognition by funding agencies that data management is a critical activity that requires dedicated resources

Empirical investigation to explore potential gains from the amalgamation of Phase Changing Materials (PCMs) and wood shavings

The reduction of gained heat, heat peak shifting and the mitigation of air temperature fluctuations are some desirable properties that are sought after in any thermal insulation system. It cannot be overstated that these factors, in addition to others, govern the performance of such systems thus their effect on indoor ambient conditions. The effect of such systems extends also to Heating, Ventilation and Air-conditioning (HVAC) systems that are set up to operate optimally in certain conditions. Where literature shows that PCMs and natural materials such as wood-shavings can provide efficient passive insulation for buildings, it is evident that such approaches utilise methods that are of a degree of intricacy which requires specialist knowledge and complex techniques, such as micro-encapsulation for instance. With technical and economic aspects in mind, an amalgam of PCM and wood-shavings has been created for the purpose of being utilised as a feasible thermal insulation. The amalgamation was performed in the simplest of methods, through submerging the wood shavings in PCM. An experimental procedure was devised to test the thermal performance of the amalgam and compare this to the performance of the same un-amalgamated materials. Comparative analysis revealed that no significant thermal gains would be expected from such amalgamation. However, significant reduction in the total weight of the insulation system would be achieved that, in this case, shown to be up to 20.94%. Thus, further reducing possible strains on structural elements due to the application of insulation on buildings. This can be especially beneficial in vernacular architectural approaches where considerably large amounts and thicknesses of insulations are used. In addition, cost reduction could be attained as wood shavings are significantly cheaper compared to the cost of PCMs

Multivariable analysis to determine if HIV-1 Tat dicysteine motif is associated with neurodevelopmental delay in HIV-infected children in Malawi

Background HIV-1 Tat protein is implicated in HIV-neuropathogenesis. Tat C31S polymorphism (TatCS) has been associated with milder neuropathology in vitro and in animal models but this has not been addressed in a cohort of HIV-infected adults or children. Methods HIV viral load (VL) in plasma and cerebrospinal fluid (CSF) were determined and plasma HIV tat gene was sequenced. Neurodevelopmental assessment was performed using Bayley Scales of Infant Development III (BSID-III), with scores standardized to Malawian norms. The association between TatCS and BSID-III scores was evaluated using multivariate linear regression. Results Neurodevelopmental assessment and HIV tat genotyping were available for 33 children. Mean age was 19.4 (SD 7.1) months, mean log VL was 5.9 copies/mL (SD 0.1) in plasma and 3.9 copies/mL (SD 0.9) in CSF. The prevalence of TatCC was 27 %. Z-scores for BSID-III subtests ranged from −1.3 to −3.9. TatCC was not associated with higher BSID-III z-scores. Conclusions The hypothesis of milder neuropathology in individuals infected with HIV TatCS was not confirmed in this small cohort of Malawian children. Future studies of tat genotype and neurocognitive disorder should be performed using larger sample sizes and investigate if this finding is due to differences in HIV neuropathogenesis between children and adults