Double-Diffusive Convection

Much progress has recently been made in understanding and quantifying vertical mixing induced by double-diffusive instabilities such as fingering convection (usually called thermohaline convection) and oscillatory double-diffusive convection (a process closely related to semiconvection). This was prompted in parts by advances in supercomputing, which allow us to run Direct Numerical Simulations of these processes at parameter values approaching those relevant in stellar interiors, and in parts by recent theoretical developments in oceanography where such instabilities also occur. In this paper I summarize these recent findings, and propose new mixing parametrizations for both processes that can easily be implemented in stellar evolution codes.Comment: To be published in the proceedings of the conference "New Advances in Stellar Physics: from microscopic to macroscopic processes", Roscoff, 27-31st May 201

\u3ci\u3eManepa\u3c/i\u3e in Ladakh: The Revival of a Religious Tradition

Among Buddhist religious specialists in Ladakh, there were until recently people called manepa, the Ladakhi pronunciation of the Tibetan word manipa, literally ‘the one [who recites] mani’. In the western Himalayas the repertoire of these non-monastic practitioners not only contains the famous mantra dedicated to the Great Compassion Bodhisattva Chenrezi (Skt. Avalokiteśvara), but also dozens of biographies which imply liberation in the Buddhist sense of the word and which praise the victory of Dharma over heretics. The Masters of the mani mantra are tantrists who regard the fourteenth-century Tibetan saint Thangtong Gyalpo as their founding preceptor. Among other skills, they perpetuate a fascinating ritual known as pho ba rdo gcog (or rdo gshag), ‘breaking a stone [placed] on the stomach’, which is believed to have been performed for the first time by this great yogi to ward off evil and to avert misfortune. Though the manepa tradition is still alive in the Pin valley in Spiti, where these religious specialists are called buchen (literally ‘great son’), it died out a few decades ago in Ladakh when the last representatives of the two existing manepa lineages passed away without an heir to carry on the family tradition. Recently, however, Tsewang Dorje, the grandson of one of them, decided to revive the tradition. In this article, I trace his life story and, more broadly, the barely known history of the manepa of Ladakh

A Pattern Matching method for finding Noun and Proper Noun Translations from Noisy Parallel Corpora

We present a pattern matching method for compiling a bilingual lexicon of nouns and proper nouns from unaligned, noisy parallel texts of Asian/Indo-European language pairs. Tagging information of one language is used. Word frequency and position information for high and low frequency words are represented in two different vector forms for pattern matching. New anchor point finding and noise elimination techniques are introduced. We obtained a 73.1\% precision. We also show how the results can be used in the compilation of domain-specific noun phrases.Comment: 8 pages, uuencoded compressed postscript file. To appear in the Proceedings of the 33rd AC

Regularity of some invariant distributions on nice symmetric pairs

J.~Sekiguchi determined the semisimple symmetric pairs (g,h), called nice symmetric pairs, on which there is no non-zero invariant eigendistribution with singular support. On such pairs, we study regularity of invariant distributions annihilated by a polynomial of the Casimir operator. We deduce that invariant eigendistributions on (gl(4,R),gl(2,R)*gl(2,R)) are locally integrable functions.Comment: E. Galina and Y. Laurent obtained stronger results on invariant distributions on nice symmetric pairs by different methods based on algebraic properties of D-modules (see references

Evaluation of the genotoxic and teratogenic potential of a municipal sludge and sludge-amended soil using the amphibian Xenopus laevis and the tobacco: Nicotiana tabacum L. var. xanthi Dulieu

The toxic, genotoxic and teratogenicpotential of amunicipal sewage sludge was assessed using the micronucleus assay on the larvae of the amphibianXenopuslaevis and with the tobacco somatic mutation test using the yellow–green xanthiDulieu mutant a1+/a1 a2+/a2. The teratogenicpotential was assessed by means of the Frog Embryo Teratogenesis Assay-Xenopus (FETAX). Various doses of the pasty sludge added to a crop soil were tested using the three bioassays. The test systems were performed either directly with sludge or sludge-amendedsoil samples (plant model) or with aqueous extracts (aquatic animal model). Using the tobacco model, we found no mutagenic impact of the soilamended with the sludge, perhaps because the clay-like nature of the soil, with its high adsorption capacity, may have prevented the contaminants from reaching the target. All leachates of amendedsoils produced a significant size reduction in Xenopus embryos. Depending on the soil/sludge ratio, some leachates were found to be genotoxic but were never teratogenic. This battery of in vivo test systems enabled us to estimate the global long-term effects under agricultural conditions with various genetic endpoints on ecologically relevant organisms characteristic of the aquatic and terrestrial compartments

Optimal Transport with Coulomb cost. Approximation and duality

We revisit the duality theorem for multimarginal optimal transportation problems. In particular, we focus on the Coulomb cost. We use a discrete approximation to prove equality of the extremal values and some careful estimates of the approximating sequence to prove existence of maximizers for the dual problem (Kantorovich's potentials). Finally we observe that the same strategy can be applied to a more general class of costs and that a classical results on the topic cannot be applied here