Isolation and Characterization of Bioactive Terpenoids from the Leaves of Ceriops tagal Linn

Plants have been used for medicine from time immemorial because they have fitted the immediate personal need and are easily accessible. These are inexpensive too. In the recent past there has been a tremendous increase in the use of plant based health products in developing as well as developed countries, resulting in an exponential growth of herbal products globally. Herbal medicines have a strong traditional or conceptual base and the potential to be useful as drugs in terms of safety and effectiveness leads for treating different diseases. There are not much chemical investigations on this plant. Ceriops tagal Linn. is a mangrove plant. The leaves of the plant were air dried and dried leaves were used for the detailed chemical and biological investigation. The leaves were extracted with ethanol and the ethanol extract showed promising antidiabetic activity (PTPase inhibitory activity). This prompted us to take up detailed chemical investigation on this plant. We have isolated 12 chemical molecules from the bioassay guided fraction for the location of biological activity. Four molecules [(Stearic acid (94.2%) Betulin (94.4%) (β-hydroxy betulinic acid 90.5%) and (ursolic acid 91.6%)] showed promising PTPase activity at 100 μg/ml

Vascular endothelial growth factor (VEGF ) receptor expression correlates with histologic grade and stage of colorectal cancer

Background: Colorectal carcinoma (CRC) is the seventh-most common malignancy and is the main cause of death in Iraq. The incidence of this cancer has increased sharply after the invasion of Iraq in 2003. Aim: To estimate immunohistochemical expression of vascular endothelial growth factor (VEGF) in CRC in relation to other parameters, such as grade and stage of tumour. Methods: Formalin fixed, paraffin-embedded blocks from 52 patients (27 male and 25 female) with CRC were included in this study. A group of 22 patients with non-cancerous colonic tissues were included as a control group. Avidin-biotin complex method was employed for immunohistochemical detection of VEGF. Results: VEGF immuno-expression was positive in 51.9% of CRC, while it was 18.2% in the normal colonic tissue (p<0.05). VEGF immunostaining was positively correlated with grade of colonic malignancy (p<0.05). Conclusion: These findings provide further evidence for the role of VEGF in the carcinogenesis of CRC. However, VEGF could not be well correlated with stage of tumour and hence may be a poor prognostic parameter of state of malignancy of colonic carcinoma.Keywords: colorectal carcinoma; VEGF; immunohistochemistr

Modeling of uplift resistance of buried pipeline by geogrid and grid-anchor system

This is the author accepted manuscript. The final version is available from the American Society of Civil Engineers via the DOI in this record This paper presents an experimental and numerical analysis of the uplift resistance of pipelines buried in reinforced soil. The behavior of the system is studied using a set of laboratory experiments. The pull-out forces of some reinforcing pipelines are the most important factors affecting the uplift resistance. Buried elements such as pipelines that have high pressure fluids or are under high temperature need to be reinforced in order to increase their pull-out resistance. One of the efficient methods of reinforcement is increasing the involvement between pipe and soil by using geogrids and anchors. The grid-anchor is a recent method for increasing the pull-out resistance of soil, and is the method used in this study. The digital image correlation or particle image velocimetry (DIC/PIV) method is used for measuring the displacement in the field of experimental mechanism. We also examined the influence of parameters affecting the soil. An experimental study was performed to investigate the uplift resistance of the pipelines buried in sand reinforced with this system. The experimental results demonstrate that, for the pipes with a diameter of 50 mm, the grid-anchor system of reinforcement can increase the uplift capacity 2.4 times compared with the conventional geogrid and 4 times compared with nonreinforced sand. In the numerical modeling, likewise, 23 experiments were back-analyzed using the software FLAC-3D. It became known that experimental tests compare well with the numerical results

ANN-derived equation and ITS application in the prediction of dielectric properties of pure and impure CO₂

High-performing equation has been step-wisely extracted from artificial neural network (ANN) simulation and subsequently applied for the prediction of the dielectric properties of pure and impure CO2. Data of relative permittivity (εr) for pure and impure CO2 were used in the ANN to train different ANN structures so that the network can recognise and predict CO2 property under different conditions. Analyses of the results from the training showed that single-layer ANN model [3-6-1] outperformed others. From this best-performing ANN structure, a single mathematical equation was extracted that can be employed in predicting εr for pure CO2 and CO2-ethanol mixture, even without access to ANN software. Using this ANN-based mathematical model, predictions of the relative permittivity (εr) for pure CO2 and CO2-ethanol mixture were performed, under different temperatures and pressures and at different ethanol concentrations. Under similar conditions, the output of the model provides good match with the original experimental εr. With increment in ethanol concentration, the model correctly predicted the rise in εr for the mixture. Also, it was shown that the εr rises with an increase in pressure but decreases with a rise in temperature. The work showed the reliability and applicability of the ANN in characterizing and predicting the dielectric property of pure CO2 as well as its mixture or impurities. The model developed and the techniques demonstrated in this work offers immense benefits and guides for researchers, who may want to explore the behaviours of a pure compound and its mixtures/impurities using ANN, as well as those interested in derived mathematical model from statistical computation tool like ANN

Co-directional replication-transcription conflicts lead to replication restart

August 24, 2011Head-on encounters between the replication and transcription machineries on the lagging DNA strand can lead to replication fork arrest and genomic instability1, 2. To avoid head-on encounters, most genes, especially essential and highly transcribed genes, are encoded on the leading strand such that transcription and replication are co-directional. Virtually all bacteria have the highly expressed ribosomal RNA genes co-directional with replication3. In bacteria, co-directional encounters seem inevitable because the rate of replication is about 10–20-fold greater than the rate of transcription. However, these encounters are generally thought to be benign2, 4, 5, 6, 7, 8, 9. Biochemical analyses indicate that head-on encounters10 are more deleterious than co-directional encounters8 and that in both situations, replication resumes without the need for any auxiliary restart proteins, at least in vitro. Here we show that in vivo, co-directional transcription can disrupt replication, leading to the involvement of replication restart proteins. We found that highly transcribed rRNA genes are hotspots for co-directional conflicts between replication and transcription in rapidly growing Bacillus subtilis cells. We observed a transcription-dependent increase in association of the replicative helicase and replication restart proteins where head-on and co-directional conflicts occur. Our results indicate that there are co-directional conflicts between replication and transcription in vivo. Furthermore, in contrast to the findings in vitro, the replication restart machinery is involved in vivo in resolving potentially deleterious encounters due to head-on and co-directional conflicts. These conflicts probably occur in many organisms and at many chromosomal locations and help to explain the presence of important auxiliary proteins involved in replication restart and in helping to clear a path along the DNA for the replisome.Biotechnology and Biological Sciences Research Council (Great Britain) (Grant BB/E006450/1)Wellcome Trust (London, England) (Grant 091968/Z/10/Z)National Institutes of Health (U.S.) (Grant GM41934)National Institutes of Health (U.S.) (Postdoctoral Fellowship GM093408)Biotechnology and Biological Sciences Research Council (Great Britain) (Sabbatical Visit

Distinct Properties of Hexameric but Functionally Conserved Mycobacterium tuberculosis Transcription-Repair Coupling Factor

Transcription coupled nucleotide excision repair (TC-NER) is involved in correcting UV-induced damage and other road-blocks encountered in the transcribed strand. Mutation frequency decline (Mfd) is a transcription repair coupling factor, involved in repair of template strand during transcription. Mfd from M. tuberculosis (MtbMfd) is 1234 amino-acids long harboring characteristic modules for different activities. Mtbmfd complemented Escherichia coli mfd (Ecomfd) deficient strain, enhanced survival of UV irradiated cells and increased the road-block repression in vivo. The protein exhibited ATPase activity, which was stimulated ∼1.5-fold in the presence of DNA. While the C-terminal domain (CTD) comprising amino acids 630 to 1234 showed ∼2-fold elevated ATPase activity than MtbMfd, the N-terminal domain (NTD) containing the first 433 amino acid residues was able to bind ATP but deficient in hydrolysis. Overexpression of NTD of MtbMfd led to growth defect and hypersensitivity to UV light. Deletion of 184 amino acids from the C-terminal end of MtbMfd (MfdΔC) increased the ATPase activity by ∼10-fold and correspondingly exhibited efficient translocation along DNA as compared to the MtbMfd and CTD. Surprisingly, MtbMfd was found to be distributed in monomer and hexamer forms both in vivo and in vitro and the monomer showed increased susceptibility to proteases compared to the hexamer. MfdΔC, on the other hand, was predominantly monomeric in solution implicating the extreme C-terminal region in oligomerization of the protein. Thus, although the MtbMfd resembles EcoMfd in many of its reaction characteristics, some of its hitherto unknown distinct properties hint at its species specific role in mycobacteria during transcription-coupled repair

Ancient Ancestry of KFDV and AHFV Revealed by Complete Genome Analyses of Viruses Isolated from Ticks and Mammalian Hosts

Alkhurma hemorrhagic fever (AHF) and Kyasanur Forest disease (KFD) viruses both cause serious and sometimes fatal human disease in their respective ranges, Saudi Arabia and India. AHFV was first identified in the mid-1990s and due to its strong genetic similarity to KFDV it has since been considered the result of a recent introduction of KFDV into Saudi Arabia. To gain a better understanding of the evolutionary history of AHFV and KFDV, we sequenced the full-length genomes of 3 KFDV and 16 AHFV. Sequence analyses show a greater genetic diversity within AHFV than previously thought, particularly within the tick population. The phylogeny constructed with these 19 full-length sequences and two AHFV sequences from GenBank indicates AHFV diverged from KFDV almost 700 years ago. Given the presence of competent tick vectors in the regions between and surrounding Saudi Arabia and India and the recent identification of AHFV in Egypt, these results suggest a broader geographic range of AHFV and KFDV, and raise the possibility of other AHFV/KFDV–like viruses circulating in these regions

A Hybrid Color Space for Skin Detection Using Genetic Algorithm Heuristic Search and Principal Component Analysis Technique

Color is one of the most prominent features of an image and used in many skin and face detection applications. Color space transformation is widely used by researchers to improve face and skin detection performance. Despite the substantial research efforts in this area, choosing a proper color space in terms of skin and face classification performance which can address issues like illumination variations, various camera characteristics and diversity in skin color tones has remained an open issue. This research proposes a new three-dimensional hybrid color space termed SKN by employing the Genetic Algorithm heuristic and Principal Component Analysis to find the optimal representation of human skin color in over seventeen existing color spaces. Genetic Algorithm heuristic is used to find the optimal color component combination setup in terms of skin detection accuracy while the Principal Component Analysis projects the optimal Genetic Algorithm solution to a less complex dimension. Pixel wise skin detection was used to evaluate the performance of the proposed color space. We have employed four classifiers including Random Forest, Naïve Bayes, Support Vector Machine and Multilayer Perceptron in order to generate the human skin color predictive model. The proposed color space was compared to some existing color spaces and shows superior results in terms of pixel-wise skin detection accuracy. Experimental results show that by using Random Forest classifier, the proposed SKN color space obtained an average F-score and True Positive Rate of 0.953 and False Positive Rate of 0.0482 which outperformed the existing color spaces in terms of pixel wise skin detection accuracy. The results also indicate that among the classifiers used in this study, Random Forest is the most suitable classifier for pixel wise skin detection applications

Broad spectrum late blight resistance in potato differential set plants MaR8 and MaR9 is conferred by multiple stacked R genes

Phytophthora infestans is the causal agent of late blight in potato. The Mexican species Solanum demissum is well known as a good resistance source. Among the 11 R gene differentials, which were introgressed from S. demissum, especially R8 and R9 differentials showed broad spectrum resistance both under laboratory and under field conditions. In order to gather more information about the resistance of the R8 and R9 differentials, F1 and BC1 populations were made by crossing Mastenbroek (Ma) R8 and R9 clones to susceptible plants. Parents and offspring plants were examined for their pathogen recognition specificities using agroinfiltration with known Avr genes, detached leaf assays (DLA) with selected isolates, and gene-specific markers. An important observation was the discrepancy between DLA and field trial results for Pi isolate IPO-C in all F1 and BC1 populations, so therefore also field trial results were included in our characterization. It was shown that in MaR8 and MaR9, respectively, at least four (R3a, R3b, R4, and R8) and seven (R1, Rpi-abpt1, R3a, R3b, R4, R8, R9) R genes were present. Analysis of MaR8 and MaR9 offspring plants, that contained different combinations of multiple resistance genes, showed that R gene stacking contributed to the Pi recognition spectrum. Also, using a Pi virulence monitoring system in the field, it was shown that stacking of multiple R genes strongly delayed the onset of late blight symptoms. The contribution of R8 to this delay was remarkable since a plant that contained only the R8 resistance gene still conferred a delay similar to plants with multiple resistance genes, like, e.g., cv Sarpo Mira. Using this “de-stacking” approach, many R gene combinations can be made and tested in order to select broad spectrum R gene stacks that potentially provide enhanced durability for future application in new late blight resistant varieties