2,421 research outputs found

    Spatial pattern of nerve differentiation in Hydra is due to a pattern of nerve commitment

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    The pattern of nerve differentiation along the body column of Hydra was investigated. Nerve precursors in late S phase were labeled with [3H]thymidine and their distribution compared with that of newly differentiated nerves. The two distributions were found to be the same. Based on independent evidence that nerve commitment occurs in mid-to late S phase (G. Venugopal and C. David, 1981, Develop. Biol.83, 361–365) it was concluded that the pattern of nerve differentiation along the body column of Hydra is due to differences in nerve commitment in different body regions. Furthermore, the level of nerve commitment in head and foot tissue is sufficiently high to deplete stem cells in these regions as is observed

    Entrepreneurial marketing in subsistence marketplaces

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    There are more than a billion poverty-stricken entrepreneurs in the world who run micro-enterprises to meet basic consumption needs. This pervasive phenomenon presents an interesting theoretical conundrum - that of consumer-entrepreneur duality. This duality blurs the boundaries between consumption and entrepreneurship, which have traditionally been distinct domains of scholarly inquiry. The research reported in this dissertation aims to a) provide a theoretical foundation for the notion of consumer-entrepreneur duality and b) test the implications of the aforementioned duality empirically. A key insight flowing from the investigations is that factors in the consumption domain impact important outcomes in the entrepreneurial domain and vice versa.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-05-01The student, Srinivas Venugopal, accepted the attached license on 2016-04-18 at 08:47.The student, Srinivas Venugopal, submitted this Dissertation for approval on 2016-04-18 at 09:04.This Dissertation was approved for publication on 2016-04-19 at 08:14.DSpace SAF Submission Ingestion Package generated from Vireo submission #9286 on 2016-07-07 at 14:17:05Made available in DSpace on 2016-07-07T21:17:37Z (GMT). No. of bitstreams: 4 VENUGOPAL-DISSERTATION-2016.pdf: 1854109 bytes, checksum: f8e3d9c290a0109c220b8b0fc51c60c1 (MD5) SrinivasVenugopal-DissertationApr17-Final.docx: 5793780 bytes, checksum: b6083d1e61eed44327c6ca98d0843dc4 (MD5) LICENSE.txt: 4215 bytes, checksum: 3a0d71a95b961c52e415358c38df4270 (MD5) PROQUEST_LICENSE.txt: 4561 bytes, checksum: 191925090206f5324017b16a1d5401bd (MD5) Previous issue date: 2016-04-19Embargo set by: Seth Robbins for item 93274 Lift date: 2018-07-07T21:18:16Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 93274 on 2018-07-08T09:15:20Z

    Nerve commitment in Hydra. II. Localization of commitment in S phase

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    The kinetics of nerve differentiation were investigated during head regeneration in Hydra. In particular the cell cycle parameters of stem cells undergoing nerve commitment were determined. Head regeneration induces extensive nerve commitment localized at the regenerating tip (G. Venugopal and C. David, 1981, Develop. Biol.83, 353–360). The appearance of committed nerve precursors is followed 12 hr later by the appearance of newly differentiated nerves. Under these conditions the time from the end of S phase to nerve differentiation is about 9 hr and the time from the beginning of S phase to nerve differentiation is about 18 hr. Thus nerve commitment occurs in mid- to late S phase of the stem cell precursor

    Lewis Base Induced Reductions in Organolanthanide Chemistry

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    Bojer D, Venugopal A, Neumann B, Stammler H-G, Mitzel NW. Lewis Base Induced Reductions in Organolanthanide Chemistry. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION. 2010;49(14):2611-2614

    Drag and inertia coefficients for horizontally submerged rectangular cylinders in waves and currents

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    The results of an experimental investigation carried out to measure combined wave and current loads on horizontally submerged square and rectangular cylinders are reported in this paper. The wave and current induced forces on a section of the cylinders with breadth-depth (aspect) ratios equal to 1, 0.5, and 0.75 are measured in a wave tank. The maximum value of Keulegan-Carpenter (KC) number obtained in waves alone is about 5 and Reynolds (Re) number ranged from 6.3976103 to 1.186105. The drag (CD) and inertia (CM) coefficients for each cylinder are evaluated using measured sectional wave forces and particle kinematics calculated from linear wave theory. The values of CD and CM obtained for waves alone have already been reported (Venugopal, V., Varyani, K. S., and Barltrop, N. D. P. Wave force coefficients for horizontally submerged rectangular cylinders. Ocean Engineering, 2006, 33, 11-12, 1669-1704) and the coefficients derived in combined waves and currents are presented here. The results indicate that both drag and inertia coefficients are strongly affected by the presenceof the current and show different trends for different cylinders. The values of the vertical component inertia coefficients (CMY) in waves and currents are generally smaller than the inertia coefficients obtained in waves alone, irrespective of the current's magnitude and direction. The results also illustrate the effect of a cylinder's aspect ratio on force coefficients. This study will be useful in the design of offshore structures whose columns and caissons are rectangular sections

    Aggregate breakdown of nanoparticulate titania

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    Six nanosized titanium dioxide powders synthesized from a sulfate process were investigated. The targeted end-use of this powder was for a de-NOx catalyst honeycomb monolith. Alteration of synthesis parameters had resulted principally in differences in soluble ion level and specific surface area of the powders. The goal of this investigation was to understand the role of synthesis parameters in the aggregation behavior of these powders. Investigation via scanning electron microscopy of the powders revealed three different aggregation iterations at specific length scales. Secondary and higher order aggregate strength was investigated via oscillatory stress rheometry as a means of simulating shear conditions encountered during extrusion. G' and G'' were measured as a function of the applied oscillatory stress. Oscillatory rheometry indicated a strong variation as a function of the sulfate level of the particles in the viscoelastic yield strengths. Powder yield stresses ranged from 3.0 Pa to 24.0 Pa of oscillatory stress. Compaction curves to 750 MPa found strong similarities in extrapolated yield point of stage I and II compaction for each of the powders (at approximately 500 MPa) suggesting that the variation in sulfate was greatest above the primary aggregate level. Scanning electron microscopy of samples at different states of shear in oscillatory rheometry confirmed the variation in the linear elastic region and the viscous flow regime. A technique of this investigation was to approach aggregation via a novel perspective: aggregates are distinguished as being loose open structures that are highly disordered and stochastic in nature. The methodology used was to investigate the shear stresses required to rupture the various aggregation stages encountered and investigate the attempt to realign the now free-flowing constituents comprising the aggregate into a denser configuration. Mercury porosimetry was utilized to measure the pore size of the compact resulting from compaction via dry pressing and tape casting secondary scale aggregates. Mercury porosimetry of tapes cast at 0.85 and 9.09 cm/sec exhibited pore sizes ranging from 200-500 nm suggesting packing of intact micron-sized primary aggregates. Porosimetry further showed that this peak was absent in pressed pellets corroborating arguments of ruptured primary aggregates during compaction to 750 MPa.Ph.D.Includes bibliographical references (p. 166-170)

    Use of vacuum-formed retainer for extrusion of a grossly decayed tooth using auxiliaries

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    Introduction: Vacuum-formed retainers are one of the most used retainers because of their esthetic advantage, ease of fabrication as well as the low fabrication cost. While aligners are usually associated with improved esthetics the extended period required to obtain these is one of the reasons the present modification was introduced to achieve the desired tooth movement with patient cooperation. Patient Diagnosis: The patient aged 35 years old came with a missing clinical crown and pain in relation to tooth 11 and was advised to receive re-endodontic treatment. The main finding on intra-oral examination was that the patient’s incisor root was submerged below the gingiva. Clinical innovation: The present innovation describes the use of a vacuum-formed retainer for carrying out movement of a grossly decayed tooth with no clinical crown. While clear retainers are meant for retention their durability can be used as an added advantage for carrying out specific movements with the aid of auxiliary attachments. The main benefits of this innovation were in terms of the time to initiate treatment and cost reduction. Discussion: This appliance is extremely easy to fabricate and does not require extensive scans and treatment planning especially in case of a patient that does not desire a lengthy treatment. Aligners are cost-effective but only when produced in-house which is why clear retainers with auxiliary attachments can be used as a low-cost option when only minor tooth movements are required

    RS_GV at SemEval-2021 Task 1: Sense Relative Lexical Complexity Prediction

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    Stodden R, Venugopal G. RS_GV at SemEval-2021 Task 1: Sense Relative Lexical Complexity Prediction. In: Proceedings of the 15th International Workshop on Semantic Evaluation (SemEval-2021). Stroudsburg, PA, USA: Association for Computational Linguistics; 2021: 640-649.We present the technical report of the system called RS_GV at SemEval-2021 Task 1 on lexical complexity prediction of English words. RS_GV is a neural network using hand-crafted linguistic features in combination with character and word embeddings to predict target words’ complexity. For the generation of the hand-crafted features, we set the target words in relation to their senses. RS_GV predicts the complexity well of biomedical terms but it has problems with the complexity prediction of very complex and very simple target words

    Overview of Manufacturing PMC's Using Traditional and 3D printing Technology (FDM)

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    Abstract: Composite materials are those materials which are made by combining two or more materials with unique properties. Polymer matrix composites are one of the most important composites which are used in various industries due to their light weight, high stiffness and high strength. Because of its advantages it is important to know the manufacturing techniques of PMCs. PMCs are used by automotive, pharmaceutical, sports and aerospace industries. This paper gives detailed review of different traditional and 3d printing methods of manufacturing Polymer Matrix Composites. These methods are more effective in making special shapes west bullet proofs, boat bodies and heavy cylinders. In recent research on effecting manufacturing of composite materials, it is found that the 3d printing technology makes some difference in making PMC with much better properties. In this review we also discuss about one of the 3d printing methods, that is Fusion Deposition Modeling for making PMCs with improved strength and properties. Keywords: Stiffness, Strength, Polymer Matrix Composite, Manufacturing, FDM, 3d printing. Title: Overview of Manufacturing PMC’s Using Traditional and 3D printing Technology (FDM) Author: Eashwaroju Venugopal Chary, G Akshay Kumar International Journal of Recent Research in Civil and Mechanical Engineering (IJRRCME) ISSN 2393-8471 Vol. 9, Issue 1, April 2022 - September 2022 Page No: 6-10 Paper Publications Website: www.paperpublications.org Published date: 02-July-2022 DOI: https://doi.org/10.5281/zenodo.6790490 Paper Download Link (Source) https://www.paperpublications.org/upload/book/Overview%20of%20Manufacturing%20PMC’s-02072022-8.pdfInternational Journal of Recent Research in Civil and Mechanical Engineering (IJRRCME), ISSN 2393-8471, Paper Publications, Website: www.paperpublications.or

    Impacts of physical calibration of a spectral wave model and effects of using different temporal wind inputs

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    Spectral wave modelling can reduce uncertainties in the estimation of wave energy resource assessment, converter design, extreme value analysis, etc. In spectral models, wave growth is represented with different approaches, resulting in wave resource assessments having large differences especially at high wave values. In this paper a modified version of the North Sea Wave Database is used to quantify the impact of wind temporal fidelity on the wind growth components. The Simulating WAves Nearshore (SWAN) model has been modified, with two different wind inputs used from the European Centre for Medium-Range Weather Forecasts (ECMWF). Results are compared with in-situ measurements an inter-comparison for 20 years (1980-1999). Differences are found on mean and maxima values of wave parameters, with little changes in directionality. However, higher temporal resolution of the wind does not mean always a better hindcast, in fact attention to the calibration of wind-wave growth interactions and whitecaps leads to similar results. Finally, the high fidelity hindcasts are compared, identifying limitations and opportunities for improvements in wave energy assessments.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Offshore Engineerin
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