266 research outputs found
Integrated Computer Aided Planning and Manufacture of Advanced Technology Jet Engines
This paper highlights an attempt at evolving a computer aided manufacturing system on a personal computer. A case study of an advanced technology jet engine component is included to illustrate various outputs from the system. The proposed system could be an alternate solution to sophisticated and expensive CAD/CAM workstations
Emerging functional similarities and divergences between Drosophila Spargel/dPGC-1 and mammalian PGC-1 protein
Peroxisome Proliferator Activated Receptor Gamma Co-activator-1 (PGC-1) is a well- conserved protein among all chordates. Entire Drosophila species subgroup carries a PGC-1 homolog in their genome called spargel/dPGC-1 showing very little divergence. Recent studies have reported that significant functional similarities are shared between vertebrate and invertebrate PGC-1’s based on their role in mitochondrial functions and biogenesis, gluconeogenesis, and most likely in transcription and RNA processing. With the help of genetic epistasis analysis, we established that Drosophila Spargel/dPGC-1 affects cell growth process as a terminal effector in the Insulin-TOR signaling pathway. The association between Spargel and Insulin signaling could also explain its role in the aging process. Here we provided a further comparison between Spargel/dPGC-1 and PGC-1 focusing on nuclear localization, oxidative stress resistance and a possible role of Spargel/dPGC-1 in oogenesis reminiscing the role of Spargel in reproductive aging like many Insulin signaling partners. This led us to hypothesize that the discovery of newer biological functions in Drosophila Spargel/dPGC-1 will pave the way to uncover novel functional equivalents in mammals
Estimation of salivary cortisol level in post-menopausal women with psychosomatic disorders
Background: Stress is an undesirable or health threatening response of the body, which is brought on by deleterious external influences (stressors). Objective measurement of psychosocial stress helps in assessment of pivotal role of stress in precipitation of multitude of health problems and a solution to the same. Salivary biomarkers are suggested to provide a reliable and non-invasive method for the estimation of these general health problems. Salivary cortisol is such biomarker used as tool in the examination of human physiological stress response. Post-menopausal women show an increase in stress levels and hence suffer with multiple health related problems. Hence the present study aimed to estimate salivary cortisol levels in post-menopausal women with clinically diagnosed psychosomatic disorder/disorders of the head and neck region, so as to establish salivary cortisol as a biochemical indicator of stress.Methods: Thorough intra-oral and extra-oral examination was performed to check for the presence of psychosomatic disorder of head and neck. Unstimulated saliva was collected from 100 post-menopausal women with and 100 without clinically diagnosed psychosomatic disorder/disorders through ‘Spit Technique’. Salivary cortisol was estimated using ELISA method.Results: The results were statistically significant as they showed that the salivary cortisol was in higher levels in post- menopausal women with clinically diagnosed psychosomatic disorder/disorders.Conclusion: The geriatric patients feel that they have very little skills or resources to deal with the high levels of stress that they are experiencing and hence suffer from lack of self-worth. The results of this study recommend that stress evaluation should be done on a regular basis for all post- menopausal women. For individuals who do not reveal their psychological distress, salivary analysis of cortisol may be used as an aid to diagnose their situation in conjunction with clinical diagnosis.Keywords: Post-menopausal women, psychosomatic disorder, head and neck, salivary cortisol, biomarker
Membrane-Based Sorbent for Heavy Metal Sequestration
A process is provided for making membrane-based sorbents with enhanced binding activity that are particularly useful for heavy metal sequestration. The process includes the step of selectively hydrolyzing a polyacetylated membrane in order to deacetylate a surface layer of said membrane and expose free hydroxyl groups. This is followed by the oxidizing of the hydroxyl groups to aldehyde groups. This is then followed by the attaching of a polycarboxylic acid such as a polyamino acid, polyalkenoic acid or polypeptide to the membrane through the aldehyde groups. Preferably, the hydrolyzing step is completed under alkaline conditions and the oxidizing step is completed using an aqueous solution of sodium periodate
Preparing and Regenerating a Composite Polymer and Silica-Based Membrane
A method for preparing and regenerating a chemically activated or polyamino acid functionalized membrane includes the steps of permeating the silica-based membrane with a solution of silane and a solvent so as to react methoxy groups of the silane with silanol groups of the membrane to incorporate epoxide groups and attaching a polyamino acid to the membrane by reacting a terminal amine group of the polyamino acid with one of the epoxide groups on the membrane. The membrane is regenerated after metal entrapment by utilizing helix-coil properties of polyamino acids
Silica-Based Membrane Sorbent for Heavy Metal Sequestration
An apparatus providing for metal ion/nitrate entrapment comprises a chemically activated, microfiltration, composite polymer and silica-based membrane including a polyamino acid attached thereto through reaction of a terminal amine group of the polyamino acid with the membrane. A method for preparing such a chemically activated or polyamino acid functionalized membrane includes the steps of permeating the silica-based membrane with a solution of silane and a solvent so as to react methoxy groups of the silane with silanol groups of the membrane to incorporate epoxide groups and attaching a polyamino acid to the membrane by reacting a terminal amine group of the polyamino acid with one of the epoxide groups on the membrane
Method of Preparing a Composite Polymer and Silica-Based Membrane
A method for preparing a chemically activated or polyamino acid functionalized membrane includes the steps of permeating a silica-based membrane with a solution of silane and a solvent so as to react methoxy groups of the silane with silanol groups of the membrane to incorporate epoxide groups and attaching a polyamino acid to the membrane by reacting a terminal amine group of the polyamino acid with one of the epoxide groups on the membrane
Directed evolution for soluble and active periplasmic expression of bovine enterokinase in Escherichia coli
Bovine enterokinase light chain (EKL) is an industrially useful protease for accurate removal of affinity-purification tags from high-value biopharmaceuticals. However, recombinant expression in Escherichia coli produces insoluble inclusion bodies, requiring solubilisation, refolding, and autocatalytic activation to recover functional enzyme. Error-prone PCR and DNA shuffling of the EKL gene, T7 promoter, lac operon, ribosome binding site, and pelB leader sequence, yielded 321 unique variants after screening ~ 6500 colonies. The best variants had > 11,000-fold increased total activity in lysates, producing soluble enzyme that no longer needed refolding. Further characterisation identified the factors that improved total activity from an inactive and insoluble starting point. Stability was a major factor, whereby melting temperatures > 48.4 °C enabled good expression at 37 °C. Variants generally did not alter catalytic efficiency as measured by kcat/Km, which improved for only one variant. Codon optimisation improved the total activity in lysates produced at 37 °C. However, non-optimised codons and expression at 30 °C gave the highest activity through improved protein quality, with increased kcat and Tm values. The 321 variants were statistically analysed and mapped to protein structure. Mutations detrimental to total activity and stability clustered around the active site. By contrast, variants with increased total activity tended to combine stabilising mutations that did not disrupt the active site
Approximation Algorithm for Line Segment Coverage for Wireless Sensor Network
The coverage problem in wireless sensor networks deals with the problem of
covering a region or parts of it with sensors. In this paper, we address the
problem of covering a set of line segments in sensor networks. A line segment `
is said to be covered if it intersects the sensing regions of at least one
sensor distributed in that region. We show that the problem of finding the
minimum number of sensors needed to cover each member in a given set of line
segments in a rectangular area is NP-hard. Next, we propose a constant factor
approximation algorithm for the problem of covering a set of axis-parallel line
segments. We also show that a PTAS exists for this problem.Comment: 16 pages, 5 figures
Pelagic calcium carbonate production and shallow dissolution in the North Pacific Ocean
Planktonic calcifying organisms play a key role in regulating ocean carbonate
chemistry and atmospheric CO 2 . Surprisingly, references to the absolute and
relative contribution of these organisms to calcium carbonate production are
lacking. Here we report quantification of pelagic calcium carbonate produc-
tion in the North Pacific, providing new insights on the contribution of the
three main planktonic calcifying groups. Our results show that coccolitho-
phores dominate the living calcium carbonate (CaCO 3 ) standing stock, with
coccolithophore calcite comprising ~90% of total CaCO 3 production, and
pteropods and foraminifera playing a secondary role. We show that pelagic
CaCO 3 production is higher than the sinking flux of CaCO 3 at 150 and 200 m at
ocean stations ALOHA and PAPA, implying that a large portion of pelagic
calcium carbonate is remineralised within the photic zone; this extensive
shallow dissolution explains the apparent discrepancy between previous
estimates of CaCO 3 production derived from satellite observations/biogeo-
chemical modeling versus estimates from shallow sediment traps. We suggest
future changes in the CaCO 3 cycle and its impact on atmospheric CO 2 will
largely depend on how the poorly-understood processes that determine
whether CaCO 3 is remineralised in the photic zone or exported to depth
respond to anthropogenic warming and acidification
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