1,439 research outputs found
Scientific Endeavors of A.M. Mathai: An Appraisal on the Occasion of his Eightieth Birthday, 28 April 2015
No full textA.M. Mathai is Emeritus Professor of Mathematics and Statistics at McGill University, Canada. He is currently the Director of the Centre for Mathematical and Statistical Sciences India. His research contributions cover a wide spectrum of topics in mathematics, statistics, physics, astronomy, and biology. He is a Fellow of the Institute of Mathematical Statistics, National Academy of Sciences of India, and a member of the International Statistical Institute. He is a founder of the Canadian Journal of Statistics and the Statistical Society of Canada. He was instrumental in the implementation of the United Nations Basic Space Science Initiative (1991–2012). This paper highlights research results of A.M. Mathai in the period of time from 1962 to 2015. He published over 300 research papers and over 25 books
Phlegra prasanna Caleb, Mungkung & Mathai, 2015, sp. nov.
No full textPhlegra prasanna sp. nov. Caleb & Mathai (Figs. 47-56) Type material. Holotype: male, scrub jungle regions, Madras Christian College, Tamil Nadu, India (12°91′97.51″ N, 80°12′24.72″ E, 32m, 20 MAR 2014, coll. John Caleb T. D., NCBS-QA481). Paratypes: 1 male from same location (06 OCT 2014, coll. John Caleb T.D., NCBS-QA482) and 1 male, Kadapa, Andhra Pradesh, India (14°45′10.50″ N, 78°79′38.68″ E, 138 m, 14 JAN 2015, coll. Samson, NCBS-AL062). Etymology. Specific epithet is a noun in apposition, a patronym after the first author's mother, Udaya Prasanna. Diagnosis. Species can be differentiated from other Phlegra species by the dark coloration of the body covered by metallic dark green iridescent hairs (Figs. 47, 50). Palp with long embolus (Figs. 53, 55), RTA with two peaks separated by a V-shaped depression (Figs. 54, 56). Description of male. Total length 4.11; carapace 2.32 long, 1.57 wide; abdomen 1.79 long, 1.03 wide. Cephalothorax dark, eye region covered with forward projecting hairs, inconspicuous pair of white stripes on the dorsal surface, eye field darker (Figs. 48, 51). Three white transverse stripes traverse across the clypeus extending into the cheek region. Anterior eyes surrounded by white scales anteriorly (Fig. 49). Chelicerae blackish, thick transverse stripe of white hairs at the proximal region. Sternum oval, covered with pale hairs (Fig. 52). Legs dark, proximal half of tarsus brownish yellow on all legs (Figs. 48, 49). Abdomen narrow, dark with greenish, iridescent hairs (Fig. 50). Palp with dark cymbium, long, slender embolus (Figs. 53, 55), RTA with two peaks separated by a V-shaped depression (Figs. 54, 56). Distribution. Chennai, India. 1 mm.Published as part of Caleb, John T. D., Mungkung, Soriephy & Mathai, Manu Thomas, 2015, Four new species of jumping spider (Araneae: Salticidae: Aelurillinae) with the description of a new genus from South India, pp. 1-18 in Peckhamia 124 (1) on pages 11-12, DOI: 10.5281/zenodo.509297
An expansion of Meijer's G-function and its application to statistical distributions
No full textMathai Arakaparampil M., Rathie Pushpa Narayan. An expansion of Meijer's G-function and its application to statistical distributions. In: Bulletin de la Classe des sciences, tome 56, 1970. pp. 1073-1084
Stenaelurillus metallicus Caleb & Mathai, 2016, sp. nov.
No full text<i>Stenaelurillus metallicus</i> sp. nov. <p>Figs 1–22</p> <p> <b>Type material: Holotype:</b> Male (NCBS-AR103) from Madras Christian College (12.917659°N, 80.122859°E, alt. 32 m), Chennai, Tamil Nadu, India, 21 June 2013, leg. John Caleb T.D. <b>Paratypes</b> (from same location): 1 male (NCBS- AR110), 21 June 2013; 1 male (NCBS-AR109), 18 July 2013; 1 male & 1 female (NCBS-AR104 & AR113), 5 September 2013; 1 female (NCBS-AR112), 11 November 2013; 1 male (NCBS-AR111), 21 April 2015, all leg. John Caleb T.D.; 4 males & 4 females (NCBS-AR105 to AR108 & AR114 to AR117), 30 January 2014, leg. Karthy.</p> <p> <b>Etymology.</b> The specific name, an adjective, refers to the shining spots with metallic sheen on the male abdomen.</p> <p> <b>Diagnosis.</b> The male differs from all known <i>Stenaelurillus</i> species by orangish abdomen, with a pair of dark spots (Fig. 1; usually darker abdomen with white spots in other species). The species seems to be closely related to <i>S. sarojinae</i> Caleb & Mathai, 2014 by the presence of a well-developed ventral femoral distal process in the male palp (Fig. 11), but differs in having a slightly bent, short and thick embolus, not accompanied by a terminal apophysis (compare Fig. 19 herein with fig. 80 in Caleb <i>et al.</i> 2015). The female resembles <i>S. sarojinae</i> in having a pair of white spots on the abdomen, but differs in having globular spermatheca (bean-shaped in <i>S. sarojinae</i>; compare Figs 18, 22 herein with fig. 30 in Caleb & Mathai 2014).</p> <p> <b>Description. Male</b> (holotype). Total length: 4.63; carapace: 2.37 long, 1.64 wide; abdomen: 2.26 long, 1.43 wide. Carapace dark, covered with reddish-brown hairs; a pair of thin longitudinal white stripes extending from behind the ALEs and ending at posterior slope. Posterior end of carapace blackish (Figs 1–2). AMEs surrounded by white orbital setae. Short white hairs clothe the facial region from above the anterior eyes to the clypeal region (Fig. 3). Broad patch of white hairs extend backwards on the lateral margins of the carapace. Outer edge of carapace lined by thin stripe of white hairs. Eye measurements: AME 0.36, ALE 0.21, PME 0.07, PLE 0.26, AME–AME 0.09; AME–ALE 0.12; PME–PME 1.22; PME–PLE 0.19. Sternum oval, darkly pigmented medially, yellowish along the margins (Fig. 8). Chelicerae unident (Fig. 9); labium and maxillae yellowish. Femur I with a black patch prolaterally (Fig. 3). Coxae of all legs with patch of dark pigmentation ventrally (Fig. 8). Leg measurements: I 3.99 (1.35, 0.82, 0.74, 0.58, 0.49); II 3.95 (1.37, 0.79, 0.72, 0.56, 0.51); III 5.87 (1.78, 0.84, 1.14, 1.32, 0.79); IV 5.71 (1.70, 0.80, 1.11, 1.32, 0.78). Leg spination: leg I: Fm d 0-1-1-5; Pt pr 0-1-0; Tb pr 1-1, v 1-1 -2ap; Mt pr 1-1, v 2-2 ap; leg II: Fm d 0-1-1-5, pr 0-1-0; Pt pr and rt 0-1-0; Tb pr 1- 1-1, rt 0-1-0, v 1-1 -2ap; Mt pr 1-1, rt 1-1, v 2 -0-2ap; leg III: Fm d 0-1-1-5, pr 0-1-0; Pt pr and rt 0-1-0; Tb d 1-2-2, pr 1- 1, rt 1-0-1, v 0-1-2ap; Mt d 1-2-1-2, pr 1-1, rt 1-1-1, v 0-0-2ap; leg IV: Fm d 0-1-1-4, pr 0-1-0; Pt pr and rt 0-1-0; Tb d 1- 2-2, pr 1-1, rt 1-1, v 1-2 ap; Mt d 2-2-2, pr 1-1, rt 1-0-1, v 0-1-2ap. Abdomen with dark orange hairs on the sides, paler mid-dorsally with whitish hairs making indistinct chevron shaped markings; a pair of large spots with metallic luster present on the dorsum; a pair of indistinct black spots present laterally further behind. Abdomen outlined laterally by a fringe of long white hairs; spinnerets moderately long, black (Figs 1, 7, 10). Palp covered with short pale yellowish hairs; embolus short, thick and slightly bent, not accompanied by anterior terminal apophysis; RTA single with a broad base tapering toward the tip, slightly curved (Figs 19–20).</p> <p> <b>Female</b> (paratype NCBS-AR112). Total length 4.85; carapace: 2.15 long, 1.68 wide; abdomen: 2.70 long, 2.01 wide. Eye measurements: AME 0.39, ALE 0.20, PME 0.07, PLE 0.22, AME–AME 0.06; AME–ALE 0.10; PME–PME 1.25; PME–PLE 0.19. Leg measurements: I 3.58 (1.30, 0.60, 0.61, 0.48, 0.59); II 3.65 (1.29, 0.65, 0.60, 0.54, 0.58); III 6.19 (1.97, 0.94, 1.29, 1.18, 0.81); IV 5.65 (1.67, 0.80, 1.17, 1.24, 0.77). Leg spination: leg I: Fm d 0-1-1-5; Pt pr 0-1-0; Tb pr 1-1, v 1-1 -2ap; Mt pr 0-2, v 2-1 ap; leg II: Fm d 0-1-1-5, pr 0-1-0; Pt pr 0-1-0; Tb, pr 1-1, v 1-1 -2; Mt d 1-2, pr 0-1, v 2- 1 ap; leg III: Fm d 0-1-1-5, pr 0-1-0; Pt pr and rt 0-1-0; Tb d 1-2-2, pr 1-1, rt 1-1, v 0-1-2ap; Mt d 1-1-2, pr 1-2, rt 1-1-2ap, v 0-1-2ap; leg IV: Fm d 0-1-1-4; Pt pr and rt 0-1-0; Tb d 1-2-2, pr 1-1, rt 1-1, v 1-2 ap; Mt d 2-1-2, pr 1-1, rt 1-1, v 0-1- 2ap. Coloration pattern as in male, but differs in the following: general body color dull reddish-brown (Figs 4, 12).</p> <p>Anterior eyes outlined by reddish-brown setae on the upper half and lower half with white orbital setae (Fig. 6). A pair of white spots present on the abdomen (Figs 4, 12). Epigyne placed on a poorly sclerotized plate; copulatory ducts short, leading to the lower chambers (Figs 15, 16, 21); spermathecae globular (Figs 17, 18, 22).</p> <p> <b>Distribution.</b> Known only from type locality.</p>Published as part of <i>Caleb, John T. D. & Mathai, Manu Thomas, 2016, A new jumping spider of the genus Stenaelurillus Simon, 1886 from India (Araneae: Salticidae: Aelurillina), pp. 185-188 in Zootaxa 4103 (2)</i> on pages 185-188, DOI: <a href="http://zenodo.org/record/256878">10.5281/zenodo.256878</a>
Genital and urinary tract infections in pregnancy in southern India : diagnosis, management and impact om perinatal outcome
No full textBackground: Prevalence of sexually transmitted infections varies in different parts of the world. These infections, occurring during pregnancy, can result in adverse outcome. There is paucity of information on the prevalence, effects and management of such infections in pregnancy in India. Similarly, urinary tract infection (UTI) is a common medical problem in pregnancy. But, very little is known about the patterns and mechanism of antimicrobial resistance among bacteria causing UTI and the prescription practices for this condition. Diagnostic methods, used for early onset sepsis (EOS) in the new-born also need evaluation.Methods: Endocervical samples from consecutive pregnant women at 26 to 36 weeks of gestation were tested to detect infection with Chlamydia trachomatis. Association of this infection with adverse pregnancy outcome was determined In another retrospective cohort study, information related to pregnancy and outcome was collected from pregnant women with reactive Venereal Disease Research Laboratory (VDRL) test, which was done as part of antenatal care. Data on susceptibility patterns of bacteria isolated in significant counts from urine of pregnant women suspected to have urinary infection were collected. To understand the mechanism of resistance, the prevalence of integrons among these E. coli were determined Prescribing patterns for these infections were ascertained using a questionnaire and based on antibiotics dispensed to pregnant women. To evaluate the use of CRP in diagnosing EOS, CRP levels in cord blood and neonatal blood at 24 hrs were estimated in two groups of neonates, one at risk of developing infection and the other at low risk of infection.Results: Prevalence of C trachomatis infection was 3.3% and this infection did not contribute significantly to adverse pregnancy outcome. Prevalence of syphilis was also low. However, fetal loss occurred in 32% of the infected women. The difference in outcome between those receiving antenatal care and those without was significant (P = 0.01; RR 7.53 95% Cl 1.1 - 51.9). In 2002, > 90% of E. coli causing UTI was susceptible to nitrofurantoin, a relatively inexpensive and safe drug. However, less than 25% of doctors used it for treatment of cystitis. The choice and duration of therapy varied greatly.Resistance to ampicillin (pDiscussion: The prevalence of STIs among antenatal women is low. However, syphilis is an unrecognised cause of pregnancy loss in the area. There are several lacunae in the diagnosis and treatment of infections in pregnancy - both UTI and STIs. A major reason probably is the lack of locally relevant uniform guidelines for the diagnosis and management of these conditions. There is also complacency because of low prevalence of STIs in pregnancy. We also observed that auditing the management of syphilis in pregnancy could be an effective and simple tool to assess the quality of antenatal care. High prevalence of resistance among E coli is associated with integrons. Since CRP levels rise in babies without infection, this test may be useful only in excluding infection.List of scientific papersI. Alexander R, Mathai E, Nayyar V, Mathew M, Jasper P (1993). "Low prevalence of chlamydial endocervical infection in antenatal south Indian women." Genitourin Med 69(3): 240-1 https://pubmed.ncbi.nlm.nih.gov/8335319II. Mathai E, Mathai M, Prakash JA, Bergstrom S (2001). "Audit of management of pregnant women with positive VDRL tests." Natl Med J India 14(4): 202-4 https://pubmed.ncbi.nlm.nih.gov/11547524III. Mathai E, Thomas RJ, Chandy S, Mathai M, Bergstrom S (2004). "Antimicrobials for the treatment of urinary tract infection in pregnancy: practices in southern India. " Pharmacoepidemiol Drug Saf 13(9): 645-52 https://pubmed.ncbi.nlm.nih.gov/15362088IV. Mathai E, Grape M, Kronvall G (2004). "Integrons and multidrug resistance among Escherichia coli causing community-acquired urinary tract infection in southern India. " APMIS 112(3): 159-64 https://pubmed.ncbi.nlm.nih.gov/15153157V. Mathai E, Christopher U, Mathai M, Jana AK, Rose D, Bergstrom S (2004). "Is C-reactive protein level useful in differentiating infected from uninfected neonates among those at risk of infection? " Indian Pediatr 41(9): 895-900 https://pubmed.ncbi.nlm.nih.gov/15475630</p
D-branes, RR-fields and duality on noncommutative manifolds
No full textWe develop some of the ingredients needed for string theory on noncommutative spacetimes, proposing an axiomatic formulation of T-duality as well as establishing a very general formula for D-brane charges. This formula is closely related to a noncom4 mutative Grothendieck-Riemann-Roch theorem that is proved here. Our approach relies on a very general form of Poincaré duality, which is studied here in detail. Among the technical tools employed are calculations with iterated products in bivariant K-theory and cyclic theory, which are simplified using a novel diagram calculus reminiscent of Feynman diagrams
On a Generalized Entropy Measure Leading to the Pathway Model with a Preliminary Application to Solar Neutrino Data
No full textAn entropy for the scalar variable case, parallel to Havrda-Charvat entropy, was introduced by the first author, and the properties and its connection to Tsallis non-extensive statistical mechanics and the Mathai pathway model were examined by the authors in previous papers. In the current paper, we extend the entropy to cover the scalar case, multivariable case, and matrix variate case. Then, this measure is optimized under different types of restrictions, and a number of models in the multivariable case and matrix variable case are obtained. Connections of these models to problems in statistical and physical sciences are pointed out. An application of the simplest case of the pathway model to the interpretation of solar neutrino data by applying standard deviation analysis and diffusion entropy analysis is provided
Mathai-Quillen forms and Lefschetz theory
No full textMathai-Quillen forms are used to give an integral formula for the Lefschetz number of a smooth map of a closed manifold. Applied to the identity map, this formula reduces to the Chern-Gauss-Bonnet theorem. The formula is computed explicitly for constant curvature metrics. There is in fact a one-parameter family of integral expressions. As the parameter goes to infinity, a topological version of the heat equation proof of the Lefschetz fixed submanifold formula is obtained. As the parameter goes to zero and under a transversality assumption, a lower bound for the number of points mapped into their cut locus is obtained. For diffeomorphisms with Lefschetz number unequal to the Euler characteristic, this number is infinite for most metrics, in particular for metrics of non-positive curvature.First author draf
T-duality of current algebras and their quantization
No full textIn this paper we show that the T-duality transform of Bouwknegt, Evslin and Mathai applies to determine isomorphisms of certain current algebras and their associated vertex algebras on topologically distinct T-dual spacetimes compactified to circle bundles with -flux.Pedram Hekmati, Varghese Matha
Geometric quantization for proper actions
No full textWe first introduce an invariant index for G-equivariant elliptic differential operators on a locally compact manifold M admitting a proper cocompact action of a locally compact group G. It generalizes the Kawasaki index for orbifolds to the case of proper cocompact actions. Our invariant index is used to show that an analog of the Guillemin-Sternberg geometric quantization conjecture holds if M is symplectic with a Hamiltonian action of G that is proper and cocompact. This essentially solves a conjecture of Hochs and Landsman. © 2010 Elsevier Inc.Varghese Mathai and Weiping Zhan
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