Showing papers by "University of Paris published in 1981"
TL;DR: In this paper, a formalism for carrying out Monte Carlo calculations of field theories with both boson and fermion degrees of freedom is presented, and the structure of the effective action for a wide class of theories is studied.
Abstract: We present a formalism for carrying out Monte Carlo calculations of field theories with both boson and fermion degrees of freedom. The basic approach is to integrate out the fermion degrees of freedom and obtain an effective action for the boson fields to which standard Monte Carlo techniques can be applied. We study the structure of the effective action for a wide class of theories. We develop a procedure for making rapid calculations of the variation in the effective action due to local changes in the boson fields, which is essential for practical numerical calculations.
833 citations
TL;DR: Sodium butyrate, at millimolar concentrations, when added to cell cultures produces many morphological and biochemical modifications in a reversible manner that concern regulatory mechanisms of gene expression and cell growth.
Abstract: Sodium butyrate, at millimolar concentrations, when added to cell cultures produces many morphological and biochemical modifications in a reversible manner. Some of them occur in all cell lines. They concern regulatory mechanisms of gene expression and cell growth: an hyperacetylation of histone resulting from an inhibition of histone deacetylase and an arrest of cell proliferation are almost constantly observed. Some other modifications vary from one cell type to another: induction of proteins, including enzymes, hormones, hemoglobin, inhibition of cell differentiation, reversion of transformed characteristics of cells to normal morphological and biochemical pattern, increase in interferon antiviral efficiency and induction of integrated viruses. Most if not all these effects of butyrate could result from histone hyperacetylation, from changes in chromatin structures as measured by accessibility to DNases and from modifications in cytoskeleton assembly. We do not know at the present time whether butyrate acts on a very specific target site in cell or if it acts on several cell components.
780 citations
TL;DR: The phase diagram of the infinite-range model of spin-glasses exhibits two mixed phases as mentioned in this paper, where ferromagnetism and spin-glass order coexist, due to freezing of the transverse degrees of freedom.
Abstract: The phase diagram of the infinite-range model of spin-glasses exhibits two mixed phases. In these mixed phases, ferromagnetism and spin-glass order coexist, due to freezing of the transverse degrees of freedom or replica symmetry breaking. This may help to interpret a number of recent experimental findings, e.g., in $\mathrm{Au}\mathrm{Fe}$.
731 citations
TL;DR: A survey of various results concerning Hoare's approach to proving partial and total correctness of programs is presented, with emphasis on the soundness and completeness issues.
Abstract: A survey of various results concerning Hoare's approach to proving partial and total correctness of programs is presented. Emphasis is placed on the soundness and completeness issues. Various proof systems for while programs, recursive procedures, local variable declarations, and procedures with parameters, together with the corresponding soundness, completeness, and incompleteness results, are discussed.
576 citations
TL;DR: Voluntary movement of the upper limb is preceded by postural movements occurring in the lower limbs and the pelvis that represent part of a central motor program and tends to reduce the early perturbations of the body's center of gravity.
497 citations
TL;DR: In this article, a new geothermometer for natural waters was proposed for waters of low to moderate salinity (Cl− 0·3 M) log NaLi = 1195T + 0·38.
329 citations
TL;DR: In this paper, the authors derived versions of known results dealing with core, equilibria and Shapley-values of cooperative games in the case of cooperative fuzzy games, i.e., games defined on fuzzy subsets of the set of n players.
Abstract: We derive versions of known results dealing with core, equilibria and Shapley-values of cooperative games in the case of cooperative fuzzy games, i.e., games defined on fuzzy subsets of the set of n players. A fuzzy coalition is an n-vector τ = τi associating with each player i his “rate of participation” τi ∈ [0, 1] in the fuzzy coalition and the real number v· is the coalition worth, assumed to be positively homogeneous. If also v is superadditive, or equivalently concave, the fuzzy game with side payments has a nonempty core. Associated with the coalition-worth function for any ordinary game with side payments is a fuzzy extension thereof, viz., the fuzzy game whose coalition-worth function is the least positively-homogeneous superadditive function majorizing the coalition-worth function of the original game. The fuzzy extension always has a nonempty core. Moreover, if the original game has a nonempty core, it coincides with that of its fuzzy extension. Analogous results are established for games without side payments. An axiomatization of “values” of fuzzy games with side payments is also given. The results are applied to show that the set of Walras equilibria coincides with the fuzzy core of an economy.
324 citations
TL;DR: A survey of multicriteria analysis can be found in this paper, where the authors present a survey of the different directions in which multi-attribute utility analysis has developed: multiattribute utility theory, outranking relations, interactive methods, and the methodology recently proposed by B. Roy.
308 citations
TL;DR: In this paper, the authors show that the different granitoids of the zoned Querigut complex (Hercynian Pyrenees) are associated with a series of basic to intermediate rocks ranging from hornblende-bearing peridotites to quartz-diorites.
Abstract: The different granitoids of the zoned Querigut complex (Hercynian Pyrenees) are associated with a series of basic to intermediate rocks ranging from hornblende-bearing peridotites to quartz-diorites. The whole complex appears as a calc-alkaline plutonic suite typical of orogenic zones. The distribution of lanthanides and other trace elements amongst coexisting minerals indicate they are essentially held by accessory phases, particularly in granitoids. This restricts the use of those elements in the calculation of petrogenetic models for acidic plutonic rocks. Magmatic differentiation, mainly by hornblende + plagioclase fractionation, can produce the basic series. This differentiation cannot directly produce the different granitoids, which require a preponderant contribution of crustal melts. The sequence of different granitoids can be explained either by an heterogeneity in the source region, or by magmatic differentiation. The most plausible interpretation of the whole complex calls for the emplacement of a mantle-derived magma into a wet, anatectic continental crust, with interactions between basic rocks and the soproduced acidic melts.
275 citations
TL;DR: In the 1980 joint French-Chinese field expedition in Tibet, the area covered was from the High Himalaya in the south, to the region of Nagqu ∼250 km north of Yangbajain this article.
Abstract: Results are reported from the 1980 joint French–Chinese field expedition in Tibet. The area covered was from the High Himalaya in the south, to the region of Nagqu ∼250 km north of Yangbajain. Ophiolites in the Zangbo valley represent remnants of the crust of an ocean basin which lay adjacent to the Gangdise granodiorite belt in the late Mesozoic. The ophiolites were thrust to the south onto the Cretaceous melange and Triassic flysch but the age of this event is unclear. In the Tertiary, sediments of the Indian margin and the Xigaze basin were folded with steeply dipping cleavage, which indicates some north–south shortening of the crust. However, the Tertiary volcanic sequence on the Lhasa block and further north shows comparatively little folding and thrusting. In the Quaternary, deformation of Tibet was characterized by east–west extension.
273 citations
TL;DR: Property of median procedures are organized according to four directions: stabilities and axiomatic characterizations; Arrow-like properties; combinatorial properties; effective computational possibilities; and interesting mathematical problems, related to the notion of median are surveyed.
TL;DR: In this paper, the distribution functions of a two-dimensional one-component plasma are explicitly computed up to the four-body one, and the correlations have a Gaussian falloff.
Abstract: At some special temperature ${T}_{0}$, the distribution functions of a two-dimensional one-component plasma are explicitly computed up to the four-body one. The correlations have a Gaussian falloff. The distribution functions at ${T}_{0}$ are used for building a temperature expansion around ${T}_{0}$.
TL;DR: In this paper, the authors place the Thomas-Fermi-von Weizsacker model of atoms on a firm mathematical footing and prove the existence and uniqueness of solutions of the TFW equation.
Abstract: We place the Thomas-Fermi-von Weizsacker model of atoms on a firm mathematical footing. We prove existence and uniqueness of solutions of the Thomas-Fermi-von Weizsacker equation as well as the fact that they minimize the Thomas-Fermi-von Weizsacker energy functional. Moreover, we prove the existence of binding for two very dissimilar atoms in the frame of this model.
TL;DR: In this article, it is estimated that ca. 1 × 10 10 moles of strontium are cycled in the hydrothermal systems of mid-oceanic ridges, thereby affecting the 87 Sr/86 Sr budget of seawater.
TL;DR: It is concluded that the fossil jawless Craniata provide little information on the affinities of the CraniATA, but they do provide complementary data on distribution of characters.
Abstract: The phylogenetic relationships of the extant Craniata are analyzed, and the position of the best known fossil groups of jawless craniates is discussed. Some of the patterns obtained are inconsistent with previous opinions on the phylogeny of the Craniata, e.g. on the question of monophyly of the Cephalaspidomorphi. It is concluded that the fossil jawless Craniata provide little information on the affinities of the Craniata, but they do provide complementary data on distribution of characters. According to their respective positions in the cladogram, these fossil groups allow determination of polarity of some characteristics, such as paired fins, naso-hypophysial complex, and eye musculature.
TL;DR: In this paper, the authors studied the ergodic properties of absolute continuous invariant measures of positive entropy for a map of an interval and proved a Bernoulli property and a characterization by some variational principle.
Abstract: We are interested in ergodic properties of absolutely continuous invariant measures of positive entropy for a map of an interval. We prove a Bernoulli property and a characterization by some variational principle.
01 Jan 1981
TL;DR: The main characteristics of the only steroid-membrane system of physiological significance which has been studied are reported: progesterone at the surface of maturing Xenopus laevis oocytes and dehydroepiandrosterone sulfate in the rat brain.
Abstract: Brain cells contain steroid hormone receptors. Aspects of the intracellular steroid receptor system, including the mechanism of action and utilization of estrogens and non-steroidal antiestrogens, are discussed with reference to a recent review (in “Central Regulation of the Endocrine System” edited by K. Fuxe, T. Hokfelt and R. Luft in 1979 , Plenum Press, New York). Since steroids may also act on the plasma membrane of neurons, we report the main characteristics of the only steroid-membrane system of physiological significance which has been studied: progesterone at the surface of maturing Xenopus laevis oocytes. We describe the direct inhibitory effect of progesterone on Adenylate cyclase and discuss steroid-peptide hormone interactions . Finally, we have identified dehydroepiandrosterone sulfate in the rat brain . Still of unknown function, its accumulation (∼ 10 pmol/g tissue) seems independent of the peripheral endocrine system.
TL;DR: In this paper, the authors studied the reaction of zerovalent palladium to aromatic iodides in tetrahydrofuran in the presence of the ligand triphenylphosphine.
TL;DR: In this paper, the pitch of the helica texture is measured optically and the importnt parameter of the C* phase in a series of schiff bases is measured using an optically measured pitch measure.
Abstract: We persent tempeature measurements of the importnt parameter defming the properties of the semctic C* Phase in a series of schiff bases. The pitch of the helica texture is measured optically. The m...
TL;DR: The notion of stable Banach spaces was introduced in this article by a simple condition on the norm of a Banach space, and it is shown that every infinite dimensional stable space contains LP, for some p, 1≦p < ∞.
Abstract: We define the notion of “stable Banach space” by a simple condition on the norm. We prove that ifE is a stable Banach space, then every subspace ofLp(E) (1≦p<∞) is stable. Our main result asserts that every infinite dimensional stable Banach space containslp, for somep, 1≦p<∞. This is a generalization of a theorem due to D. Aldous: every infinite dimensional subspace ofL1 containslp, for somep in the interval [1, 2].
TL;DR: Extensional-compressional tectonics are analysed along the convergent boundaries of the Aegean Arc and of the Andean Cordillera of south Peru and north Bolivia as mentioned in this paper.
Abstract: Extensional-compressional tectonics are analysed along the convergent boundaries of the Aegean Arc and of the Andean Cordillera of south Peru and north Bolivia. This paper deals only with deformations of Miocene, Pliocene and Pleistocene ages. The prevailing regime in the Aegean basin is extensional. Yet two compressional tectonic phases of U. Miocene—L. Pliocene and of L. Pleistocene age have been recorded. They are also known in many places all around the Mediterranean. Thus forces that induce compressional tectonics in the Aegean seem to have their origin outside the region. They seem to be linked with changes in the conditions of convergence (change in rate?) between the Arabo-African and Eurasian plates. Beneath the Andean Cordillera of south Peru — north Bolivia, the subduction zone plunges at an angle of 25- 30° as it does under the Aegean Arc. There, as in the Aegean Sea, tectonics are predominantly extensional and several short-lived compressional phases break up this extensional regime. The latter may also be induced by changes of the conditions of convergence, here between the Nazca and South American plates. Beneath central Peru, north of the Nazca Ridge, the subduction zone plunges at a small angle, about 10°. There, neotectonic deformations are different. In the Recent they are essentially compressional or expressed by strike-slip faulting. Geological data from the Aegean and Andes seem to demonstrate that the compressional deformation in the crust above subduction zones is strongly controlled by the stress conditions along convergent boundaries.
TL;DR: In this paper, a Lagrangian representation of the vortex sheet analogous to the Birkhoff equation in two dimensions is presented, and the global existence of a weak solution to the Euler equation with such initial conditions is established.
Abstract: The well-posed property for the finite time vortex sheet problem with analytic initial data was first conjectured by Birkhoff in two dimensions and is shown here to hold both in two and three dimensions. Incompressible, inviscid and irrotational flow with a velocity jump across an interface is assumed. In two dimensions, global existence of a weak solution to the Euler equation with such initial conditions is established. In three dimensions, a Lagrangian representation of the vortex sheet analogous to the Birkhoff equation in two dimensions is presented.
TL;DR: In this article, a large number of north-south normal faults were mapped in southern Tibet, which sharply cut the glacial and post-glacial morphology, and followed several recent earthquake breaks along faults detected on satellite and aerial photographs.
Abstract: Crustal thickening does not now occur in southern Tibet. Field observations made during the Chinese–French expedition of 1980 support an earlier hypothesis based on a combined analysis of satellite images and fault plane solutions of earthquakes. Immediately north of the highest peaks of the Himalayas, the tectonic regime is dominated by east–west extension. We have mapped a large number of north–south normal faults which sharply cut the glacial and post-glacial morphology, and followed several recent earthquake breaks along faults detected on satellite and aerial photographs. Microtectonic measurements in the Quaternary suggest that the maximum principal stress is vertical.
TL;DR: In this article, the authors used thermogravimetrie and electrical measurements to give accurate informations on the nature of the defects produced by reduction of TiO2 between 800 and 1100°C.
TL;DR: In this paper, a necessary and sufficient condition for the existence of monotone trajectories to differential inclusions is given, where the monotonicity property is related to a given preorder on a locally compact subset of Rp.
Abstract: The paper gives a necessary and sufficient condition for the existence of monotone trajectories to differential inclusionsdx/dt ∈S[x(t)] defined on a locally compact subsetX ofRp, the monotonicity being related to a given preorder onX. This result is then extended to functional differential inclusions with memory which are the multivalued case to retarded functional differential equations. We give a similar necessary and sufficient condition for the existence of trajectories which reach a given closed set at timet=0 and stay in it with the monotonicity property fort≧0.
TL;DR: The results suggest that alpha-granules or their content has an influence on not only the platelet aggregation but also the dense bodies involved in the [14C]5HT release reaction.
TL;DR: In this paper, the authors identify a succession of compressional and extensional events in southwestern Anatolia and characterize the direction of corresponding regional stresses, and show that the three most important compressive phases occurred during the Miocene and a much smaller one near the Plio-Quaternary boundary.
TL;DR: In this article, it was shown that the empirical dependence function can be canonically separated into a finite set of independent Gaussian processes, enabling one to test the existence of dependence relationships within each subset of coordinates independently (in an asymptotic way) of what occurs in other subsets.
TL;DR: There is a critical stage (stage 16) which is the same for both male and female differentiation of the gonads in Emys orbicularis, and the thermosensensitive periods are rather long, corresponding to 11–12 days at 25°C and 30°C.
Abstract: In order to determine the temperature sensitive stages for sexual differentiation of the gonads in Emys orbicularis, eggs of this turtle were shifted at different stages of embryonic development from the male-producing temperature of 25°C to the female-producing temperature of 30°C and reciprocally. Based on the series of developmental stages described by Yntema ('68) for Chelydra serpentina, temperature begins to influence sexual differentiation of Emys orbicularis at stage 16, a stage in which the gonads are still histologically undifferentiated. Its action lasts over the first steps of histological differentiation of the gonads. The minimal exposure at 25°C required for male differentiation of all individuals extends from stage 16 to somewhat before stage 21. For 100% female differentiation, incubation at 30°C must be longer, from stage 16 to somewhat before stage 22. Shorter exposures at 25°C or 30°C during these periods result in different percentages of males, females, and intersexes. Our results show that there is a critical stage (stage 16) which is the same for both male and female differentiation of the gonads. The thermosensensitive periods are rather long, corresponding to 11-12 days at 25°C and 30°C.