380 research outputs found
Seasonal march of surface pressure gradients across India and the southwest monsoon
No full textIt is well known that the seasonal weather features of Indian sub-continent are associated with corresponding changes in the pressure gradients across the country
Errantum: Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins
No full textLai JCK, Ananthakrishnan G, Jandhyam S, et al. Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins. Int J Nanomedicine. 2010;5:715–723.The wrong image was used in Figure 5 on page 719
Insects and plant defence dynamics /
No full textIncludes bibliographical references.Machine generated contents note: Preface -- Introduction -- Chapter 1 Phytochemical defence profiles ininsect-plant interactions -- TN. Ananthakrishnan -- Chapter 2 The role of essential nutrients and minerals in insect -- resistance in crop plants -- N.K. Fageria and Mark Scriber -- Chapter 3 Synthesis of chemical defenses in maize silks against -- corn earworm and their inheritance in the flavonoid -- pathway -- N.W. Widstrom, M.E. Snook and B.Z Guo -- Chapter 4 Semiochemistry of Crucifer and their Herbivores -- Alireza Aliabadi and Douglas W. Whitman -- Chapter 5 Tetranortriterpenoids and Quassinoids: Constitutive -- chemical defenses of the Rutales -- T.R. Govindachari, G. Suresh and Geetha Gopalakrishnan -- Chapter 6 Role of plant surface in resistance to insect herbivores -- A. John Peter and Thomas G. Shanower -- Chapter 7 Host plant resistance to insects: Measurement, -- mechanisms and Insect-plant environment interactions -- H.C Sharma, B.U. Singh and Rodomiro-Ortiz -- Chapter 8 Defensive tactics of caterpillars against predators and -- parasitoids -- Brent A. Salazar and Douglas W. Whitman -- Chapter 9 Sluggish movement of conspicuousinsects as a defense -- mechanism against motion-oriented predators -- John D. Hatle and Douglas W. Whitman -- Chapter 10 Molecular approaches to host plant defences against -- insects -- TN. Aanthakrishnan -- Chapter 11 Chemical Ecology: The Future -- TN. Ananthakrishnan -- Index
Concentration in Knowledge Output: A case of Economics Journals
No full textThis paper assesses the degree of author concentration in seven economics journals, which were published in India during 1990-2002. To measure the degree of author concentration, Lotka's Law was used. Moreover, we also make an exploratory analysis of the geographic, economics subfield and institutional concentration in 704 economics journals. An important finding of this paper is that specialized journals in the sample report the highest degree of author concentration. This result is quite similar to the findings by Cox and Chung (1991). Furthermore, there are several instances showing that the journals lean towards certain norms; this may affect the flow of innovative ideas into economics. We conclude that a knowledge activity, involving the high degree of concentration and a biased publication process, may affect the flow of new ideas into the discipline.Concentration, Lotka's Law
Effect of 50% hydro-ethanolic leaf extracts of ruellia tuberosa L. and dipteracanthus patulus (Jacq.) on lipid profile in alloxan induced diabetic rats
No full textBackground: The study was undertaken to investigate the effect of 50% hydro -ethanolic leaf extracts of Ruellia tuberosa L. and Dipteracanthus patulus (Jacq.) on lipid profile in alloxan induced diabetic rats.
Method: In lipid profile the parameters studied were serum total cholesterol, phospholipids, triglycerides, HDL-c, LDL-c and VLDL-c level. Extracts were orally administered daily for 30 days at a dosage of 250 and 500 mg/kg bodyweight to alloxan induced diabetic rats.
Results: The levels of phospholipids, triglycerides, LDL-c and VLDL-c were significantly (P < 0.05) reduced. The HDL-c level was found to be increased in the treatment groups. Total cholesterol level was found to be significantly (P < 0.05) decreased at 500 mg/kg bodyweight of both the plant extracts treated groups.
Conclusion: The results further suggests that the effect of plant extract treated groups was found to be lower in reducing the lipid levels in serum when compared to the drug (Glibenclamide 600 ΅g/kg body weight) treated group
Laparoscopic surgical management of a gastric dumbbell teratoma
No full textBackground: Teratomas are totipotent tumors commonly seen in gonadal and extragonadal region. Gastric teratomas are very rare and account for <1% of the cases. Conventionally, the treatment of gastric teratoma is open excision of the tumor. We present a rare variant of a gastric teratoma managed laparoscopically. Clinical Description: An 8 months' old male was noted to have pallor and history of blood-tinged spit-ups. The child was worked up for the cause of anemia with an upper gastrointestinal disorder as the first differential. The child had significant anemia with a hemoglobin level of 6 g/dl and was transfused packed red blood cells sequential imaging with an abdominal ultrasound, contrast-enhanced computerized tomographic scan, and magnetic resonance imaging identified the presence of a gastric teratoma with both an intragastric and extragastric component (dumbbell variant). He was referred to the pediatric surgery services for further management. Management: The infant underwent a gastroscopy to further define the intragastric component of the mass. This revealed a sessile submucosal polypoidal lesion with multiple areas of erosions in the region of the fundus. A biopsy from this suggested a teratoma. The child underwent a total laparoscopic excision of the lesion and recovered well. The histopathology of the tumor was consistent with a mature cystic teratoma (Grade 0). The postoperative period was uneventful. Conclusion: Laparoscopic complete surgical excision of the dumbbell variant of gastric teratoma in this child was curative, reduced morbidity, and hospital stay compared to usual open surgery
Music And Speech Analysis Using The 'Bach' Scale Filter-Bank
No full textThe aim of this thesis is to define a perceptual scale for the ‘Time-Frequency’ analysis of music signals. The equal tempered ‘Bach ’ scale is a suitable scale, since it covers most of the genres of music and the error is equally distributed for each semi-tone. However, it may be necessary to allow a tolerance of around 50 cents or half the interval of the Bach scale, so that the interval can accommodate other common intonation schemes. The thesis covers the formulation of the Bach scale filter-bank as a time-varying model. It makes a comparative study with other commonly used perceptual scales. Two applications for the Bach scale filter-bank are also proposed, namely automated segmentation of speech signals and transcription of singing voice for query-by-humming applications.
Even though this filter-bank is suggested with a motivation from music, it could also be applied to speech. A method for automatically segmenting continuous speech into phonetic units is proposed. The results, obtained from the proposed method, show around 82% accuracy for the English and 85% accuracy for the Hindi databases. This is an improvement of around 2 -3% when the performance is compared with other popular methods in the literature. Interestingly, the Bach scale filters perform better than the filters designed for other common perceptual scales, such as Mel and Bark scales.
‘Musical transcription’ refers to the process of converting a musical rendering or performance into a set of symbols or notations. A query in a ‘query-by-humming system’ can be made in several ways, some of which are singing with words, or with arbitrary syllables, or whistling. Two algorithms are suggested to annotate a query. The algorithms are designed to be fairly robust for these various forms of queries. The first algorithm is a frequency selection based method. It works on the basis of selecting the most likely frequency components at any given time instant. The second algorithm works on the basis of finding time-connected contours of high energy in the ‘Time-Frequency’ plane of the input signal. The time domain algorithm works better in terms of instantaneous pitch estimates. It results in an error of around 10 -15%, while the frequency domain method results in an error of around 12 -20%.
A song rendered by two different people will have quite a few different properties. Their absolute pitches, rates of rendering, timbres based on voice quality and inaccuracies, may be different. The thesis discusses a method to quantify the distance between two different renderings of musical pieces. The distance function has been evaluated by attempting a search for a particular song from a database of a size of 315, made up of songs sung by both male and female singers and whistled queries. Around 90 % of the time, the correct song is found among the top five best choices picked.
Thus, the Bach scale has been proposed as a suitable scale for representing the perception of music. It has been explored in two applications, namely automated segmentation of speech and transcription of singing voices. Using the transcription obtained, a measure of the distance between renderings of musical pieces has also been suggested
Optimization of Solar Sailcraft Trajectory for a Comet Sample Return Mission
No full textComets, the sporadic visitors from the outer edges of the Solar System, are considered to hold the key for understanding the formation of planets and the origin of life on Earth. Having spent the majority of time away from the radiative environment of the inner Solar System, the chemistry of the comets has remained unaltered, making them the pristine samples of the matter from the ancient Solar nebula. A mission to bring cometary particles back to Earth enables the examination of the materials in well equipped laboratories and saves the mass of the instruments to be carried on board. As conventional propulsion methods require a large quantity of propellant for this type of mission, the feasibility of using the novel propulsion technique of solar sailing is explored in this thesis. In order to return the comet samples to Earth within a reasonable time period, the orbit transfer is considered as an optimal control problem with constraints placed on the sailcraft’s position and velocity. The Differential Evolution (DE) algorithm was used to search for time-optimal trajectories that minimize the approach distance and the relative velocity with respect to the comet during sample collection. The optimal trajectory obtained predicts the solar sailcraft to reach the comet, collect the samples and return back to Earth in 6.8 years. The time of arrival at the comet was found to match with the comet's perihelion passage, enabling effective sample collection. The outcome of the trajectory analysis, thus successfully demonstrates the applicability of solar sailing to comet sample return missions in the near future.Aerospace Engineering | Astrodynamics & Space Mission
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