Identification of Molecular Determinants in iRhoms1 and 2 That Contribute to the Substrate Selectivity of Stimulated ADAM17

The metalloprotease ADAM17 is a key regulator of the TNFα, IL-6R and EGFR signaling pathways. The maturation and function of ADAM17 is controlled by the seven-membrane-spanning proteins iRhoms1 and 2. The functional properties of the ADAM17/iRhom1 and ADAM17/iRhom2 complexes differ, in that stimulated shedding of most ADAM17 substrates tested to date can be supported by iRhom2, whereas iRhom1 can only support stimulated shedding of very few ADAM17 substrates, such as TGFα. The first transmembrane domain (TMD1) of iRhom2 and the sole TMD of ADAM17 are important for the stimulated shedding of ADAM17 substrates by iRhom2. However, little is currently known about how the iRhoms interact with different substrates to control their stimulated shedding by ADAM17. To provide new insights into this topic, we tested how various chimeras between iRhom1 and iRhom2 affect the stimulated processing of the EGFR-ligands TGFα (iRhom1- or 2-dependent) and EREG (iRhom2-selective) by ADAM17. This uncovered an important role for the TMD7 of the iRhoms in determining their substrate selectivity. Computational methods utilized to characterize the iRhom1/2/substrate interactions suggest that the substrate selectivity is determined, at least in part, by a distinct accessibility of the substrate cleavage site to stimulated ADAM17. These studies not only provide new insights into why the substrate selectivity of stimulated iRhom2/ADAM17 differs from that of iRhom1/ADAM17, but also suggest new approaches for targeting the release of specific ADAM17 substrates.     

Implicit Continuous User Authentication for Mobile Devices based on Deep Reinforcement Learning

The predominant method for smart phone accessing is confined to methods directing the authentication by means of Point-of-Entry that heavily depend on physiological biometrics like, fingerprint or face. Implicit continuous authentication initiating to be loftier to conventional authentication mechanisms by continuously confirming users’ identities on continuing basis and mark the instant at which an illegitimate hacker grasps dominance of the session. However, divergent issues remain unaddressed. This research aims to investigate the power of Deep Reinforcement Learning technique to implicit continuous authentication for mobile devices using a method called, Gaussian Weighted Cauchy Kriging-based Continuous Czekanowski’s (GWCK-CC). First, a Gaussian Weighted Non-local Mean Filter Preprocessing model is applied for reducing the noise present in the raw input face images. Cauchy Kriging Regression function is employed to reduce the dimensionality. Finally, Continuous Czekanowski’s Classification is utilized for proficient classification between the genuine user and attacker. By this way, the proposed GWCK-CC method achieves accurate authentication with minimum error rate and time. Experimental assessment of the proposed GWCK-CC method and existing methods are carried out with different factors by using UMDAA-02 Face Dataset. The results confirm that the proposed GWCK-CC method enhances authentication accuracy, by 9%, reduces the authentication time, and error rate by 44%, and 43% as compared to the existing methods.     

Use of Spreadsheets as an Introductory Tool for Solving Fluid-Structure Interaction Problem

A simple and intuitive manner for solving fluid-structure interaction problem has been developed using Microsoft Excel spreadsheets. By eliminating the need of previous knowledge of any programming language, the method appears as an interesting introduction to numerical solutions of partial differential equations, due to the direct and didactic way that it is developed. Proposed procedure enables the analysis of tridimensional geometries using the finite difference method and can be extended to other differential equations or boundary conditions. The author＇s objective in this paper is to develop a simple and reliable preliminary method for solving acoustic fluid-structure interaction problems with application to dam-reservoir interaction phenomena and also contribute in the educational growth for undergraduate students that are beginning research in such matter.     

Passive samplers provide a better prediction of PAH bioaccumulation in earthworms and plant roots than exhaustive, mild solvent, and cyclodextrin extractions

A number of extraction methods have been developed to assess polycyclic aromatic hydrocarbon (PAH) bioavailability in soils. As these methods are rarely tested in a comparative manner, against different test organisms, and using field-contaminated soils, it is unclear which method gives the most accurate measure of the actual soil ecosystem exposure. In this study, PAH bioavailability was assessed in ten field-contaminated soils by using exhaustive acetone/hexane extractions, mild solvent (butanol) extractions, cyclodextrin extractions, and two passive sampling methods; solid phase micro extraction (SPME) and polyoxymethylene solid phase extraction (POM-SPE). Results were compared to actual PAH bioaccumulation in earthworms (Eisenia fetida) and rye grass (Lolium multiflorum) roots. Exhaustive, mild solvent and cyclodextrin extractions consistently overpredicted biotic concentrations by a factor of 10-10?000 and therefore seem inappropriate for predicting PAH bioaccumulation in field contaminated soils. In contrast, passive samplers generally predicted PAH concentrations in earthworms within a factor of 10, although correlations between predicted and measured concentrations were considerably scattered. The same applied to the plant data, where passive samplers also tended to underpredict root concentrations. These results indicate the potential of passive samplers to predict PAH bioaccumulation, yet call for comparative studies between passive samplers and further research on plant bioavailability.     

Anti-Staphylococcal Activity of Eugenia Jambolana L. Against Methicillin–Resistant Staphylococcus Aureus

The antibacterial activity of ethanol extracts of Eugenia jambolana L. and E. uniflora L. (Myrtaceae) were evaluated by agar-well diffusion method and MICs by microdillution method. E. jambolana showed antibacterial activity against MRSA strains (MIC < 1024 μg/mL). E. uniflora did not show significant antibacterial activity (MIC > 1024 μg/mL). It is therefore suggested that extracts from E. jambolana could be used as an anti– Staphylococcus agent. When compared with Methicillin and Gentamicin, the extract was more effective against, being a promising antibacterial agent. Based on the author's knowledge, this is the first report about the antibacterial activity of leave ethanol extract from Eugenia jambolana.     

Assessment of compositional changes during ripening of transgenic papaya modified for protection against papaya ringspot virus

BACKGROUND: Papaya (Carica papaya L.) production is limited by over 20 viruses, the most damaging of which is papaya ringspot virus (PRSV). Owing to a lack of suitable PRSV‐resistant sources in Carica germplasm, transgenic resistance using the coat protein (cp) gene of a local PRSV strain is being developed to manage the disease in Jamaica. For assurance of food safety, the nutritional and antinutritional composition of transgenic papayas during ripening was compared with that of unmodified control samples. RESULTS: Mature unripe fruits of transgenic and non‐transgenic papayas were repeatedly harvested and stored at room temperature for 1 week periods, during which random samples were assessed. With the exception of one transgenic line, no significant differences (P > 0.05) were observed in selected nutrients and antinutrients between the control and test samples at three stages of maturity, although a few random variations were noted. CONCLUSION: Transformation with viral cp gene and two marker genes did not produce any major unintended alterations in either the nutritional or the antinutritional composition of transgenic papayas. These findings must be compared with other physicochemical and safety assessments to provide a scientific basis for concluding substantial equivalence with conventional papayas available on the market in Jamaica. Copyright © 2008 Society of Chemical Industry     

Exposure to polycyclic aromatic hydrocarbons through consumption of edible marine species in Catalonia, Spain

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs; naphthalene, acenaphtylene, acenaphtene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene) were determined by gas chromatography-mass spectrometry in samples of 14 edible marine species (sardine, tuna, anchovy, mackerel, swordfish, salmon, hake, red mullet, sole, cuttlefish, squid, clam, mussel, and shrimp) collected in March and April 2005. These species are widely consumed by the population of Catalonia, Spain. PAH intake was also estimated for eight age and sex groups of this population. Mussel, clam, and shrimp had the highest PAH concentrations (22.4, 21.5, and 15.9 ng/g of fresh weight, respectively). In contrast, sole (2.5 ng/g of fresh weight) and cuttlefish and squid (both 3.0 ng/g of fresh weight) had the lowest mean concentrations. The highest PAH intake was found in women and girls (5.3 and 5.2 ng/kg/day, respectively), but female adolescents and female seniors had the lowest PAH intakes (3.3 ng/kg/day in both groups). The intake of benzo[a]pyrene and six other PAHs that are probably human carcinogens through consumption of these marine species would be associated with 0.27/10(6) increase in the risk of development of cancer over a 70-year life span.     

Effect of preheating on potato texture

Preheating potatoes at 50 to 80°C has a firming effect on the cooked potato tissue. This effect is particularly pronounced at a preheating temperature of 60 to 70°C followed by cooling. Several theories have been presented in the literature to explain this firming effect: retrogradation of starch, leaching of amylose, stabilization of the middle lamellae and cell walls by the activation of the pectin methylesterase (PME) enzyme, and by the release of calcium from gelatinized starch and the formation of calcium bridges between pectin molecules. Most probably, none of these theories alone can explain the phenomenon and more than one mechanism seems to be involved. Some of these mechanisms seem to be interdependent. As an example, calcium could be considered as a link all the way through release after starch gelatinization to cross‐linking pectin substances in the cell wall and the middle lamellae, which has been demethylated by the PME enzyme. More research and “clear cut” experiments are needed in order to elucidate the role of each mechanism, especially which of them is the main contributor to the process of firming. Most probably, the calcium‐pectin‐PME mechanism plays a secondary role, that is, it only retards the collapse of the tissue structure that would otherwise occur during the final heating without preheating, and it is not the main factor of firmness.